build: Refactor normal to unicast

This completes the renaming of the normal IPCP to the unicast IPCP in
the sources, to get everything consistent with the documentation.

Signed-off-by: Dimitri Staessens <dimitri@ouroboros.rocks>
Signed-off-by: Sander Vrijders <sander@ouroboros.rocks>

41 files changed, 10036 insertions, 0 deletions

diff --git a/src/ipcpd/unicast/CMakeLists.txt b/src/ipcpd/unicast/CMakeLists.txt
new file mode 100644
index 00000000..c9344f89
--- /dev/null
+++ b/src/ipcpd/unicast/CMakeLists.txt
@@ -0,0 +1,69 @@
+get_filename_component(CURRENT_SOURCE_PARENT_DIR
+  ${CMAKE_CURRENT_SOURCE_DIR} DIRECTORY)
+get_filename_component(CURRENT_BINARY_PARENT_DIR
+  ${CMAKE_CURRENT_BINARY_DIR} DIRECTORY)
+
+include_directories(${CMAKE_CURRENT_SOURCE_DIR})
+include_directories(${CMAKE_CURRENT_BINARY_DIR})
+
+include_directories(${CURRENT_SOURCE_PARENT_DIR})
+include_directories(${CURRENT_BINARY_PARENT_DIR})
+
+include_directories(${CMAKE_SOURCE_DIR}/include)
+include_directories(${CMAKE_BINARY_DIR}/include)
+
+set(IPCP_UNICAST_TARGET ipcpd-unicast CACHE INTERNAL "")
+
+protobuf_generate_c(KAD_PROTO_SRCS KAD_PROTO_HDRS kademlia.proto)
+
+math(EXPR PFT_EXPR "1 << 12")
+set(PFT_SIZE ${PFT_EXPR} CACHE STRING
+  "Size of the PDU forwarding table")
+if (HAVE_FUSE)
+  set(IPCP_FLOW_STATS TRUE CACHE BOOL
+    "Enable flow statistics tracking in IPCP")
+    if (IPCP_FLOW_STATS)
+       message(STATUS "IPCP flow statistics enabled")
+    else ()
+       message(STATUS "IPCP flow statistics disabled")
+    endif ()
+endif ()
+
+
+set(SOURCE_FILES
+  # Add source files here
+  addr_auth.c
+  connmgr.c
+  dht.c
+  dir.c
+  dt.c
+  enroll.c
+  fa.c
+  main.c
+  pff.c
+  routing.c
+  psched.c
+  # Add policies last
+  pol/alternate_pff.c
+  pol/flat.c
+  pol/link_state.c
+  pol/graph.c
+  pol/simple_pff.c
+  )
+
+add_executable(ipcpd-unicast ${SOURCE_FILES} ${IPCP_SOURCES}
+  ${KAD_PROTO_SRCS} ${LAYER_CONFIG_PROTO_SRCS})
+target_link_libraries(ipcpd-unicast LINK_PUBLIC ouroboros-dev)
+
+include(AddCompileFlags)
+if (CMAKE_BUILD_TYPE MATCHES "Debug*")
+  add_compile_flags(ipcpd-unicast -DCONFIG_OUROBOROS_DEBUG)
+endif ()
+
+install(TARGETS ipcpd-unicast RUNTIME DESTINATION ${CMAKE_INSTALL_SBINDIR})
+
+add_subdirectory(pol/tests)
+
+if (NOT GNU)
+  add_subdirectory(tests)
+endif ()
diff --git a/src/ipcpd/unicast/addr_auth.c b/src/ipcpd/unicast/addr_auth.c
new file mode 100644
index 00000000..50c56055
--- /dev/null
+++ b/src/ipcpd/unicast/addr_auth.c
@@ -0,0 +1,58 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Address authority
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#define OUROBOROS_PREFIX "addr_auth"
+
+#include <ouroboros/logs.h>
+
+#include "addr_auth.h"
+#include "pol-addr-auth-ops.h"
+#include "pol/flat.h"
+
+#include <stdlib.h>
+
+struct pol_addr_auth_ops * ops;
+
+int addr_auth_init(enum pol_addr_auth type,
+                   const void *       info)
+{
+        switch (type) {
+        case ADDR_AUTH_FLAT_RANDOM:
+                ops = &flat_ops;
+                break;
+        default:
+                log_err("Unknown address authority type.");
+                return -1;
+        }
+
+        return ops->init(info);
+}
+
+uint64_t addr_auth_address(void)
+{
+        return ops->address();
+}
+
+int addr_auth_fini(void)
+{
+        return ops->fini();
+}
diff --git a/src/ipcpd/unicast/addr_auth.h b/src/ipcpd/unicast/addr_auth.h
new file mode 100644
index 00000000..cf1509ab
--- /dev/null
+++ b/src/ipcpd/unicast/addr_auth.h
@@ -0,0 +1,37 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Address authority
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#ifndef OUROBOROS_IPCPD_UNICAST_ADDR_AUTH_H
+#define OUROBOROS_IPCPD_UNICAST_ADDR_AUTH_H
+
+#include <ouroboros/ipcp.h>
+
+#include <stdint.h>
+
+int      addr_auth_init(enum pol_addr_auth type,
+                        const void *       info);
+
+int      addr_auth_fini(void);
+
+uint64_t addr_auth_address(void);
+
+#endif /* OUROBOROS_IPCPD_UNICAST_ADDR_AUTH_H */
diff --git a/src/ipcpd/unicast/comp.h b/src/ipcpd/unicast/comp.h
new file mode 100644
index 00000000..b8294c3b
--- /dev/null
+++ b/src/ipcpd/unicast/comp.h
@@ -0,0 +1,48 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Components for the unicast IPC process
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#ifndef OUROBOROS_IPCPD_UNICAST_COMP_H
+#define OUROBOROS_IPCPD_UNICAST_COMP_H
+
+#include <ouroboros/cacep.h>
+
+#include "dt.h"
+
+#define DST_MAX_STRLEN 64
+
+enum comp_id {
+        COMPID_DT = 0,
+        COMPID_ENROLL,
+        COMPID_MGMT,
+        COMPID_MAX
+};
+
+struct conn {
+        struct conn_info conn_info;
+        struct {
+                char      dst[DST_MAX_STRLEN + 1];
+                int       fd;
+                qosspec_t qs;
+        } flow_info;
+};
+
+#endif /* OUROBOROS_IPCPD_UNICAST_COMP_H */
diff --git a/src/ipcpd/unicast/connmgr.c b/src/ipcpd/unicast/connmgr.c
new file mode 100644
index 00000000..7c1280c3
--- /dev/null
+++ b/src/ipcpd/unicast/connmgr.c
@@ -0,0 +1,525 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Handles connections between components
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#if defined(__linux__) || defined(__CYGWIN__)
+#define _DEFAULT_SOURCE
+#else
+#define _POSIX_C_SOURCE 200112L
+#endif
+
+#define OUROBOROS_PREFIX "connection-manager"
+
+#include <ouroboros/dev.h>
+#include <ouroboros/cacep.h>
+#include <ouroboros/errno.h>
+#include <ouroboros/list.h>
+#include <ouroboros/logs.h>
+#include <ouroboros/notifier.h>
+
+#include "comp.h"
+#include "connmgr.h"
+#include "dir.h"
+#include "enroll.h"
+#include "ipcp.h"
+
+#include <pthread.h>
+#include <string.h>
+#include <stdlib.h>
+#include <assert.h>
+
+enum connmgr_state {
+        CONNMGR_NULL = 0,
+        CONNMGR_INIT,
+        CONNMGR_RUNNING
+};
+
+struct conn_el {
+        struct list_head next;
+        struct conn      conn;
+};
+
+struct comp {
+        struct conn_info info;
+
+        struct list_head conns;
+        struct list_head pending;
+
+        pthread_cond_t   cond;
+        pthread_mutex_t  lock;
+};
+
+struct {
+        struct comp        comps[COMPID_MAX];
+        enum connmgr_state state;
+
+        pthread_t          acceptor;
+} connmgr;
+
+static int get_id_by_name(const char * name)
+{
+        enum comp_id i;
+
+        for (i = 0; i < COMPID_MAX; ++i)
+                if (strcmp(name, connmgr.comps[i].info.comp_name) == 0)
+                        return i;
+
+        return -1;
+}
+
+static int get_conn_by_fd(int           fd,
+                          enum comp_id  id,
+                          struct conn * conn)
+{
+        struct list_head * p;
+
+        pthread_mutex_lock(&connmgr.comps[id].lock);
+
+        list_for_each(p, &connmgr.comps[id].conns) {
+                struct conn_el * c =
+                        list_entry(p, struct conn_el, next);
+                if (c->conn.flow_info.fd == fd) {
+                        *conn = c->conn;
+                        pthread_mutex_unlock(&connmgr.comps[id].lock);
+                        return 0;
+                }
+        }
+
+        pthread_mutex_unlock(&connmgr.comps[id].lock);
+
+        return -1;
+}
+
+static int add_comp_conn(enum comp_id       id,
+                         int                fd,
+                         qosspec_t          qs,
+                         struct conn_info * rcv_info)
+{
+        struct conn_el * el;
+
+        el = malloc(sizeof(*el));
+        if (el == NULL) {
+                log_err("Not enough memory.");
+                return -1;
+        }
+
+        el->conn.conn_info    = *rcv_info;
+        el->conn.flow_info.fd = fd;
+        el->conn.flow_info.qs = qs;
+
+        pthread_mutex_lock(&connmgr.comps[id].lock);
+
+        list_add(&el->next, &connmgr.comps[id].pending);
+        pthread_cond_signal(&connmgr.comps[id].cond);
+
+        pthread_mutex_unlock(&connmgr.comps[id].lock);
+
+        return 0;
+}
+
+static void * flow_acceptor(void * o)
+{
+        int               fd;
+        qosspec_t         qs;
+        struct conn_info  rcv_info;
+        struct conn_info  fail_info;
+
+        (void) o;
+
+        memset(&fail_info, 0, sizeof(fail_info));
+
+        while (true) {
+                int id;
+
+                fd = flow_accept(&qs, NULL);
+                if (fd < 0) {
+                        if (fd != -EIRMD)
+                                log_warn("Flow accept failed: %d", fd);
+                        continue;
+                }
+
+                if (cacep_rcv(fd, &rcv_info)) {
+                        log_dbg("Error establishing application connection.");
+                        flow_dealloc(fd);
+                        continue;
+                }
+
+                id = get_id_by_name(rcv_info.comp_name);
+                if (id < 0) {
+                        log_dbg("Connection request for unknown component %s.",
+                                rcv_info.comp_name);
+                        cacep_snd(fd, &fail_info);
+                        flow_dealloc(fd);
+                        continue;
+                }
+
+                assert(id < COMPID_MAX);
+
+                if (cacep_snd(fd, &connmgr.comps[id].info)) {
+                        log_dbg("Failed to respond to request.");
+                        flow_dealloc(fd);
+                        continue;
+                }
+
+                if (add_comp_conn(id, fd, qs, &rcv_info)) {
+                        log_dbg("Failed to add new connection.");
+                        flow_dealloc(fd);
+                        continue;
+                }
+        }
+
+        return (void *) 0;
+}
+
+static void handle_event(void *       self,
+                         int          event,
+                         const void * o)
+{
+        struct conn conn;
+
+        (void) self;
+
+        if (!(event == NOTIFY_DT_FLOW_UP ||
+              event == NOTIFY_DT_FLOW_DOWN ||
+              event == NOTIFY_DT_FLOW_DEALLOC))
+                return;
+
+        if (get_conn_by_fd(*((int *) o), COMPID_DT, &conn))
+                return;
+
+        switch (event) {
+        case NOTIFY_DT_FLOW_UP:
+                notifier_event(NOTIFY_DT_CONN_UP, &conn);
+                break;
+        case NOTIFY_DT_FLOW_DOWN:
+                notifier_event(NOTIFY_DT_CONN_DOWN, &conn);
+                break;
+        case NOTIFY_DT_FLOW_DEALLOC:
+                notifier_event(NOTIFY_DT_CONN_DEL, &conn);
+                break;
+        default:
+                break;
+        }
+}
+
+int connmgr_init(void)
+{
+        connmgr.state = CONNMGR_INIT;
+
+        if (notifier_reg(handle_event, NULL))
+                return -1;
+
+        return 0;
+}
+
+void connmgr_fini(void)
+{
+        int i;
+
+        notifier_unreg(handle_event);
+
+        if (connmgr.state == CONNMGR_RUNNING)
+                pthread_join(connmgr.acceptor, NULL);
+
+        for (i = 0; i < COMPID_MAX; ++i)
+                connmgr_comp_fini(i);
+}
+
+int connmgr_start(void)
+{
+        if (pthread_create(&connmgr.acceptor, NULL, flow_acceptor, NULL))
+                return -1;
+
+        connmgr.state = CONNMGR_RUNNING;
+
+        return 0;
+}
+
+void connmgr_stop(void)
+{
+        if (connmgr.state == CONNMGR_RUNNING)
+                pthread_cancel(connmgr.acceptor);
+}
+
+int connmgr_comp_init(enum comp_id             id,
+                      const struct conn_info * info)
+{
+        struct comp * comp;
+
+        assert(id >= 0 && id < COMPID_MAX);
+
+        comp = connmgr.comps + id;
+
+        if (pthread_mutex_init(&comp->lock, NULL))
+                return -1;
+
+        if (pthread_cond_init(&comp->cond, NULL)) {
+                pthread_mutex_destroy(&comp->lock);
+                return -1;
+        }
+
+        list_head_init(&comp->conns);
+        list_head_init(&comp->pending);
+
+        memcpy(&connmgr.comps[id].info, info, sizeof(connmgr.comps[id].info));
+
+        return 0;
+}
+
+void connmgr_comp_fini(enum comp_id id)
+{
+        struct list_head * p;
+        struct list_head * h;
+        struct comp *      comp;
+
+        assert(id >= 0 && id < COMPID_MAX);
+
+        if (strlen(connmgr.comps[id].info.comp_name) == 0)
+                return;
+
+        comp = connmgr.comps + id;
+
+        pthread_mutex_lock(&comp->lock);
+
+        list_for_each_safe(p, h, &comp->conns) {
+                struct conn_el * e = list_entry(p, struct conn_el, next);
+                list_del(&e->next);
+                free(e);
+        }
+
+        list_for_each_safe(p, h, &comp->pending) {
+                struct conn_el * e = list_entry(p, struct conn_el, next);
+                list_del(&e->next);
+                free(e);
+        }
+
+        pthread_mutex_unlock(&comp->lock);
+
+        pthread_cond_destroy(&comp->cond);
+        pthread_mutex_destroy(&comp->lock);
+
+        memset(&connmgr.comps[id].info, 0, sizeof(connmgr.comps[id].info));
+}
+
+int connmgr_ipcp_connect(const char * dst,
+                         const char * component,
+                         qosspec_t    qs)
+{
+        struct conn_el * ce;
+        int              id;
+
+        assert(dst);
+        assert(component);
+
+        ce = malloc(sizeof(*ce));
+        if (ce == NULL) {
+                log_dbg("Out of memory.");
+                return -1;
+        }
+
+        id = get_id_by_name(component);
+        if (id < 0) {
+                log_dbg("No such component: %s", component);
+                free(ce);
+                return -1;
+        }
+
+        if (connmgr_alloc(id, dst, &qs, &ce->conn)) {
+                free(ce);
+                return -1;
+        }
+
+        if (strlen(dst) > DST_MAX_STRLEN) {
+                log_warn("Truncating dst length for connection.");
+                memcpy(ce->conn.flow_info.dst, dst, DST_MAX_STRLEN);
+                ce->conn.flow_info.dst[DST_MAX_STRLEN] = '\0';
+        } else {
+                strcpy(ce->conn.flow_info.dst, dst);
+        }
+
+        pthread_mutex_lock(&connmgr.comps[id].lock);
+
+        list_add(&ce->next, &connmgr.comps[id].conns);
+
+        pthread_mutex_unlock(&connmgr.comps[id].lock);
+
+        return 0;
+}
+
+int connmgr_ipcp_disconnect(const char * dst,
+                            const char * component)
+{
+        struct list_head * p;
+        struct list_head * h;
+        int                id;
+
+        assert(dst);
+        assert(component);
+
+        id = get_id_by_name(component);
+        if (id < 0)
+                return -1;
+
+        pthread_mutex_lock(&connmgr.comps[id].lock);
+
+        list_for_each_safe(p,h, &connmgr.comps[id].conns) {
+                struct conn_el * el = list_entry(p, struct conn_el, next);
+                if (strcmp(el->conn.flow_info.dst, dst) == 0) {
+                        int ret;
+                        pthread_mutex_unlock(&connmgr.comps[id].lock);
+                        list_del(&el->next);
+                        ret = connmgr_dealloc(id, &el->conn);
+                        free(el);
+                        return ret;
+                }
+        }
+
+        pthread_mutex_unlock(&connmgr.comps[id].lock);
+
+        return 0;
+}
+
+int connmgr_alloc(enum comp_id  id,
+                  const char *  dst,
+                  qosspec_t *   qs,
+                  struct conn * conn)
+{
+        assert(id >= 0 && id < COMPID_MAX);
+        assert(dst);
+
+        conn->flow_info.fd = flow_alloc(dst, qs, NULL);
+        if (conn->flow_info.fd < 0) {
+                log_dbg("Failed to allocate flow to %s.", dst);
+                return -1;
+        }
+
+        if (qs != NULL)
+                conn->flow_info.qs = *qs;
+        else
+                memset(&conn->flow_info.qs, 0, sizeof(conn->flow_info.qs));
+
+        log_dbg("Sending cacep info for protocol %s to fd %d.",
+                connmgr.comps[id].info.protocol, conn->flow_info.fd);
+
+        if (cacep_snd(conn->flow_info.fd, &connmgr.comps[id].info)) {
+                log_dbg("Failed to create application connection.");
+                flow_dealloc(conn->flow_info.fd);
+                return -1;
+        }
+
+        if (cacep_rcv(conn->flow_info.fd, &conn->conn_info)) {
+                log_dbg("Failed to connect to application.");
+                flow_dealloc(conn->flow_info.fd);
+                return -1;
+        }
+
+        if (strcmp(connmgr.comps[id].info.protocol, conn->conn_info.protocol)) {
+                log_dbg("Unknown protocol (requested %s, got %s).",
+                        connmgr.comps[id].info.protocol,
+                        conn->conn_info.protocol);
+                flow_dealloc(conn->flow_info.fd);
+                return -1;
+        }
+
+        if (connmgr.comps[id].info.pref_version !=
+            conn->conn_info.pref_version) {
+                log_dbg("Unknown protocol version.");
+                flow_dealloc(conn->flow_info.fd);
+                return -1;
+        }
+
+        if (connmgr.comps[id].info.pref_syntax != conn->conn_info.pref_syntax) {
+                log_dbg("Unknown protocol syntax.");
+                flow_dealloc(conn->flow_info.fd);
+                return -1;
+        }
+
+        switch (id) {
+        case COMPID_DT:
+                notifier_event(NOTIFY_DT_CONN_ADD, conn);
+#ifdef IPCP_CONN_WAIT_DIR
+                dir_wait_running();
+#endif
+                break;
+        case COMPID_MGMT:
+                notifier_event(NOTIFY_MGMT_CONN_ADD, conn);
+                break;
+        default:
+                break;
+        }
+
+        return 0;
+}
+
+int connmgr_dealloc(enum comp_id  id,
+                    struct conn * conn)
+{
+        switch (id) {
+        case COMPID_DT:
+                notifier_event(NOTIFY_DT_CONN_DEL, conn);
+                break;
+        case COMPID_MGMT:
+                notifier_event(NOTIFY_MGMT_CONN_DEL, conn);
+                break;
+        default:
+                break;
+        }
+
+        return flow_dealloc(conn->flow_info.fd);
+}
+
+
+int connmgr_wait(enum comp_id  id,
+                 struct conn * conn)
+{
+        struct conn_el * el;
+        struct comp *    comp;
+
+        assert(id >= 0 && id < COMPID_MAX);
+        assert(conn);
+
+        comp = connmgr.comps + id;
+
+        pthread_mutex_lock(&comp->lock);
+
+        pthread_cleanup_push((void(*)(void *))pthread_mutex_unlock,
+                             (void *) &comp->lock);
+
+        while (list_is_empty(&comp->pending))
+                pthread_cond_wait(&comp->cond, &comp->lock);
+
+        pthread_cleanup_pop(false);
+
+        el = list_first_entry((&comp->pending), struct conn_el, next);
+        if (el == NULL) {
+                pthread_mutex_unlock(&comp->lock);
+                return -1;
+        }
+
+        *conn = el->conn;
+
+        list_del(&el->next);
+        list_add(&el->next, &connmgr.comps[id].conns);
+
+        pthread_mutex_unlock(&comp->lock);
+
+        return 0;
+}
diff --git a/src/ipcpd/unicast/connmgr.h b/src/ipcpd/unicast/connmgr.h
new file mode 100644
index 00000000..44a3fe39
--- /dev/null
+++ b/src/ipcpd/unicast/connmgr.h
@@ -0,0 +1,74 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Handles the different AP connections
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#ifndef OUROBOROS_IPCPD_UNICAST_CONNMGR_H
+#define OUROBOROS_IPCPD_UNICAST_CONNMGR_H
+
+#include <ouroboros/cacep.h>
+#include <ouroboros/qos.h>
+
+#include "comp.h"
+
+#define NOTIFY_DT_CONN_ADD     0x00D0
+#define NOTIFY_DT_CONN_DEL     0x00D1
+#define NOTIFY_DT_CONN_QOS     0x00D2
+#define NOTIFY_DT_CONN_UP      0x00D3
+#define NOTIFY_DT_CONN_DOWN    0x00D4
+#define NOTIFY_DT_FLOW_UP      0x00D5
+#define NOTIFY_DT_FLOW_DOWN    0x00D6
+#define NOTIFY_DT_FLOW_DEALLOC 0x00D7
+
+#define NOTIFY_MGMT_CONN_ADD   0x00F0
+#define NOTIFY_MGMT_CONN_DEL   0x00F1
+
+int         connmgr_init(void);
+
+void        connmgr_fini(void);
+
+int         connmgr_start(void);
+
+void        connmgr_stop(void);
+
+int         connmgr_comp_init(enum comp_id             id,
+                              const struct conn_info * info);
+
+void        connmgr_comp_fini(enum comp_id id);
+
+int         connmgr_ipcp_connect(const char * dst,
+                                 const char * component,
+                                 qosspec_t    qs);
+
+int         connmgr_ipcp_disconnect(const char * dst,
+                                    const char * component);
+
+int         connmgr_alloc(enum comp_id  id,
+                          const char *  dst,
+                          qosspec_t *   qs,
+                          struct conn * conn);
+
+int         connmgr_dealloc(enum comp_id  id,
+                            struct conn * conn);
+
+int         connmgr_wait(enum comp_id  id,
+                         struct conn * conn);
+
+#endif /* OUROBOROS_IPCPD_UNICAST_CONNMGR_H */
diff --git a/src/ipcpd/unicast/dht.c b/src/ipcpd/unicast/dht.c
new file mode 100644
index 00000000..f24a2c51
--- /dev/null
+++ b/src/ipcpd/unicast/dht.c
@@ -0,0 +1,2840 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Distributed Hash Table based on Kademlia
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * version 2.1 as published by the Free Software Foundation.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#if defined(__linux__) || defined(__CYGWIN__)
+#define _DEFAULT_SOURCE
+#else
+#define _POSIX_C_SOURCE 200112L
+#endif
+
+#include "config.h"
+
+#define DHT              "dht"
+#define OUROBOROS_PREFIX DHT
+
+#include <ouroboros/hash.h>
+#include <ouroboros/ipcp-dev.h>
+#include <ouroboros/bitmap.h>
+#include <ouroboros/errno.h>
+#include <ouroboros/logs.h>
+#include <ouroboros/list.h>
+#include <ouroboros/notifier.h>
+#include <ouroboros/random.h>
+#include <ouroboros/time_utils.h>
+#include <ouroboros/tpm.h>
+#include <ouroboros/utils.h>
+
+#include "connmgr.h"
+#include "dht.h"
+#include "dt.h"
+
+#include <pthread.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <inttypes.h>
+#include <limits.h>
+
+#include "kademlia.pb-c.h"
+typedef KadMsg kad_msg_t;
+typedef KadContactMsg kad_contact_msg_t;
+
+#ifndef CLOCK_REALTIME_COARSE
+#define CLOCK_REALTIME_COARSE CLOCK_REALTIME
+#endif
+
+#define DHT_MAX_REQS  2048 /* KAD recommends rnd(), bmp can be changed.    */
+#define KAD_ALPHA     3    /* Parallel factor, proven optimal value.       */
+#define KAD_K         8    /* Replication factor, MDHT value.              */
+#define KAD_T_REPL    900  /* Replication time, tied to k. MDHT value.     */
+#define KAD_T_REFR    900  /* Refresh time stale bucket, MDHT value.       */
+#define KAD_T_JOIN    8    /* Response time to wait for a join.            */
+#define KAD_T_RESP    5    /* Response time to wait for a response.        */
+#define KAD_R_PING    2    /* Ping retries before declaring peer dead.     */
+#define KAD_QUEER     15   /* Time to declare peer questionable.           */
+#define KAD_BETA      8    /* Bucket split factor, must be 1, 2, 4 or 8.   */
+#define KAD_RESP_RETR 6    /* Number of retries on sending a response.     */
+#define KAD_JOIN_RETR 8    /* Number of retries sending a join.            */
+#define KAD_JOIN_INTV 1    /* Time (seconds) between join retries.         */
+#define HANDLE_TIMEO  1000 /* Timeout for dht_handle_packet tpm check (ms) */
+#define DHT_RETR_ADDR 1    /* Number of addresses to return on retrieve    */
+
+enum dht_state {
+        DHT_INIT = 0,
+        DHT_SHUTDOWN,
+        DHT_JOINING,
+        DHT_RUNNING,
+};
+
+enum kad_code {
+        KAD_JOIN = 0,
+        KAD_FIND_NODE,
+        KAD_FIND_VALUE,
+        /* Messages without a response below. */
+        KAD_STORE,
+        KAD_RESPONSE
+};
+
+enum kad_req_state {
+        REQ_NULL = 0,
+        REQ_INIT,
+        REQ_PENDING,
+        REQ_RESPONSE,
+        REQ_DONE,
+        REQ_DESTROY
+};
+
+enum lookup_state {
+        LU_NULL = 0,
+        LU_INIT,
+        LU_PENDING,
+        LU_UPDATE,
+        LU_COMPLETE,
+        LU_DESTROY
+};
+
+struct kad_req {
+        struct list_head   next;
+
+        uint32_t           cookie;
+        enum kad_code      code;
+        uint8_t *          key;
+        uint64_t           addr;
+
+        enum kad_req_state state;
+        pthread_cond_t     cond;
+        pthread_mutex_t    lock;
+
+        time_t             t_exp;
+};
+
+struct cookie_el {
+        struct list_head next;
+
+        uint32_t         cookie;
+};
+
+struct lookup {
+        struct list_head  next;
+
+        struct list_head  cookies;
+
+        uint8_t *         key;
+
+        struct list_head  contacts;
+        size_t            n_contacts;
+
+        uint64_t *        addrs;
+        size_t            n_addrs;
+
+        enum lookup_state state;
+        pthread_cond_t    cond;
+        pthread_mutex_t   lock;
+};
+
+struct val {
+        struct list_head next;
+
+        uint64_t         addr;
+
+        time_t           t_exp;
+        time_t           t_rep;
+};
+
+struct ref_entry {
+        struct list_head next;
+
+        uint8_t *        key;
+
+        time_t           t_rep;
+};
+
+struct dht_entry {
+        struct list_head next;
+
+        uint8_t *        key;
+        size_t           n_vals;
+        struct list_head vals;
+};
+
+struct contact {
+        struct list_head next;
+
+        uint8_t *        id;
+        uint64_t         addr;
+
+        size_t           fails;
+        time_t           t_seen;
+};
+
+struct bucket {
+        struct list_head contacts;
+        size_t           n_contacts;
+
+        struct list_head alts;
+        size_t           n_alts;
+
+        time_t           t_refr;
+
+        size_t           depth;
+        uint8_t          mask;
+
+        struct bucket *  parent;
+        struct bucket *  children[1L << KAD_BETA];
+};
+
+struct cmd {
+        struct list_head     next;
+
+        struct shm_du_buff * sdb;
+};
+
+struct dht {
+        size_t           alpha;
+        size_t           b;
+        size_t           k;
+
+        time_t           t_expire;
+        time_t           t_refresh;
+        time_t           t_replic;
+        time_t           t_repub;
+
+        uint8_t *        id;
+        uint64_t         addr;
+
+        struct bucket *  buckets;
+
+        struct list_head entries;
+
+        struct list_head refs;
+
+        struct list_head lookups;
+
+        struct list_head requests;
+        struct bmp *     cookies;
+
+        enum dht_state   state;
+        struct list_head cmds;
+        pthread_cond_t   cond;
+        pthread_mutex_t  mtx;
+
+        pthread_rwlock_t lock;
+
+        int              fd;
+
+        struct tpm *     tpm;
+
+        pthread_t        worker;
+};
+
+struct join_info {
+        struct dht * dht;
+        uint64_t     addr;
+};
+
+struct packet_info {
+        struct dht *         dht;
+        struct shm_du_buff * sdb;
+};
+
+static uint8_t * dht_dup_key(const uint8_t * key,
+                             size_t          len)
+{
+        uint8_t * dup;
+
+        dup = malloc(sizeof(*dup) * len);
+        if (dup == NULL)
+                return NULL;
+
+        memcpy(dup, key, len);
+
+        return dup;
+}
+
+static enum dht_state dht_get_state(struct dht * dht)
+{
+        enum dht_state state;
+
+        pthread_mutex_lock(&dht->mtx);
+
+        state = dht->state;
+
+        pthread_mutex_unlock(&dht->mtx);
+
+        return state;
+}
+
+static int dht_set_state(struct dht *   dht,
+                         enum dht_state state)
+{
+        pthread_mutex_lock(&dht->mtx);
+
+        if (state == DHT_JOINING && dht->state != DHT_INIT) {
+                 pthread_mutex_unlock(&dht->mtx);
+                 return -1;
+        }
+
+        dht->state = state;
+
+        pthread_cond_broadcast(&dht->cond);
+
+        pthread_mutex_unlock(&dht->mtx);
+
+        return 0;
+}
+
+int dht_wait_running(struct dht * dht)
+{
+        int ret = 0;
+
+        pthread_mutex_lock(&dht->mtx);
+
+        pthread_cleanup_push((void *)(void *) pthread_mutex_unlock,
+                             &dht->mtx);
+
+        while (dht->state == DHT_JOINING)
+                pthread_cond_wait(&dht->cond, &dht->mtx);
+
+        if (dht->state != DHT_RUNNING)
+                ret = -1;
+
+        pthread_cleanup_pop(true);
+
+        return ret;
+}
+
+static uint8_t * create_id(size_t len)
+{
+        uint8_t * id;
+
+        id = malloc(len);
+        if (id == NULL)
+                return NULL;
+
+        if (random_buffer(id, len) < 0) {
+                free(id);
+                return NULL;
+        }
+
+        return id;
+}
+
+static void kad_req_create(struct dht * dht,
+                           kad_msg_t *  msg,
+                           uint64_t     addr)
+{
+        struct kad_req *   req;
+        pthread_condattr_t cattr;
+        struct timespec    t;
+        size_t             b;
+
+        req = malloc(sizeof(*req));
+        if (req == NULL)
+                return;
+
+        list_head_init(&req->next);
+
+        clock_gettime(CLOCK_REALTIME_COARSE, &t);
+
+        req->t_exp  = t.tv_sec + KAD_T_RESP;
+        req->addr   = addr;
+        req->state  = REQ_INIT;
+        req->cookie = msg->cookie;
+        req->code   = msg->code;
+        req->key    = NULL;
+
+        pthread_rwlock_rdlock(&dht->lock);
+        b = dht->b;
+        pthread_rwlock_unlock(&dht->lock);
+
+        if (msg->has_key) {
+                req->key = dht_dup_key(msg->key.data, b);
+                if (req->key == NULL) {
+                        free(req);
+                        return;
+                }
+        }
+
+        if (pthread_mutex_init(&req->lock, NULL)) {
+                free(req->key);
+                free(req);
+                return;
+        }
+
+        pthread_condattr_init(&cattr);
+#ifndef __APPLE__
+        pthread_condattr_setclock(&cattr, PTHREAD_COND_CLOCK);
+#endif
+
+        if (pthread_cond_init(&req->cond, &cattr)) {
+                pthread_condattr_destroy(&cattr);
+                pthread_mutex_destroy(&req->lock);
+                free(req->key);
+                free(req);
+                return;
+        }
+
+        pthread_condattr_destroy(&cattr);
+
+        pthread_rwlock_wrlock(&dht->lock);
+
+        list_add(&req->next, &dht->requests);
+
+        pthread_rwlock_unlock(&dht->lock);
+}
+
+static void cancel_req_destroy(void * o)
+{
+        struct kad_req * req = (struct kad_req *) o;
+
+        pthread_mutex_unlock(&req->lock);
+
+        pthread_cond_destroy(&req->cond);
+        pthread_mutex_destroy(&req->lock);
+
+        if (req->key != NULL)
+                free(req->key);
+
+        free(req);
+}
+
+static void kad_req_destroy(struct kad_req * req)
+{
+        assert(req);
+
+        pthread_mutex_lock(&req->lock);
+
+        switch (req->state) {
+        case REQ_DESTROY:
+                pthread_mutex_unlock(&req->lock);
+                return;
+        case REQ_PENDING:
+                req->state = REQ_DESTROY;
+                pthread_cond_signal(&req->cond);
+                break;
+        case REQ_INIT:
+        case REQ_DONE:
+                req->state = REQ_NULL;
+                break;
+        case REQ_RESPONSE:
+        case REQ_NULL:
+        default:
+                break;
+        }
+
+        pthread_cleanup_push(cancel_req_destroy, req);
+
+        while (req->state != REQ_NULL && req->state != REQ_DONE)
+                pthread_cond_wait(&req->cond, &req->lock);
+
+        pthread_cleanup_pop(true);
+}
+
+static int kad_req_wait(struct kad_req * req,
+                        time_t           t)
+{
+        struct timespec timeo = {t, 0};
+        struct timespec abs;
+        int ret = 0;
+
+        assert(req);
+
+        clock_gettime(PTHREAD_COND_CLOCK, &abs);
+
+        ts_add(&abs, &timeo, &abs);
+
+        pthread_mutex_lock(&req->lock);
+
+        req->state = REQ_PENDING;
+
+        pthread_cleanup_push((void *)(void *) pthread_mutex_unlock,
+                             &req->lock);
+
+        while (req->state == REQ_PENDING && ret != -ETIMEDOUT)
+                ret = -pthread_cond_timedwait(&req->cond, &req->lock, &abs);
+
+        switch(req->state) {
+        case REQ_DESTROY:
+                ret = -1;
+                req->state = REQ_NULL;
+                pthread_cond_signal(&req->cond);
+                break;
+        case REQ_PENDING: /* ETIMEDOUT */
+        case REQ_RESPONSE:
+                req->state = REQ_DONE;
+                pthread_cond_broadcast(&req->cond);
+                break;
+        default:
+                break;
+        }
+
+        pthread_cleanup_pop(true);
+
+        return ret;
+}
+
+static void kad_req_respond(struct kad_req * req)
+{
+        pthread_mutex_lock(&req->lock);
+
+        req->state = REQ_RESPONSE;
+        pthread_cond_signal(&req->cond);
+
+        pthread_mutex_unlock(&req->lock);
+}
+
+static struct contact * contact_create(const uint8_t * id,
+                                       size_t          len,
+                                       uint64_t        addr)
+{
+        struct contact * c;
+        struct timespec  t;
+
+        c = malloc(sizeof(*c));
+        if (c == NULL)
+                return NULL;
+
+        list_head_init(&c->next);
+
+        clock_gettime(CLOCK_REALTIME_COARSE, &t);
+
+        c->addr   = addr;
+        c->fails  = 0;
+        c->t_seen = t.tv_sec;
+        c->id     = dht_dup_key(id, len);
+        if (c->id == NULL) {
+                free(c);
+                return NULL;
+        }
+
+        return c;
+}
+
+static void contact_destroy(struct contact * c)
+{
+        if (c != NULL)
+                free(c->id);
+
+        free(c);
+}
+
+static struct bucket * iter_bucket(struct bucket * b,
+                                   const uint8_t * id)
+{
+        uint8_t byte;
+        uint8_t mask;
+
+        assert(b);
+
+        if (b->children[0] == NULL)
+                return b;
+
+        byte = id[(b->depth * KAD_BETA) / CHAR_BIT];
+
+        mask = ((1L << KAD_BETA) - 1) & 0xFF;
+
+        byte >>= (CHAR_BIT - KAD_BETA) -
+                (((b->depth) * KAD_BETA) & (CHAR_BIT - 1));
+
+        return iter_bucket(b->children[(byte & mask)], id);
+}
+
+static struct bucket * dht_get_bucket(struct dht *    dht,
+                                      const uint8_t * id)
+{
+        assert(dht->buckets);
+
+        return iter_bucket(dht->buckets, id);
+}
+
+/*
+ * If someone builds a network where the n (n > k) closest nodes all
+ * have IDs starting with the same 64 bits: by all means, change this.
+ */
+static uint64_t dist(const uint8_t * src,
+                     const uint8_t * dst)
+{
+        return betoh64(*((uint64_t *) src) ^ *((uint64_t *) dst));
+}
+
+static size_t list_add_sorted(struct list_head * l,
+                              struct contact *   c,
+                              const uint8_t *    key)
+{
+        struct list_head * p;
+
+        assert(l);
+        assert(c);
+        assert(key);
+        assert(c->id);
+
+        list_for_each(p, l) {
+                struct contact * e = list_entry(p, struct contact, next);
+                if (dist(c->id, key) > dist(e->id, key))
+                        break;
+        }
+
+        list_add_tail(&c->next, p);
+
+        return 1;
+}
+
+static size_t dht_contact_list(struct dht *       dht,
+                               struct list_head * l,
+                               const uint8_t *    key)
+{
+        struct list_head * p;
+        struct bucket *    b;
+        size_t             len = 0;
+        size_t             i;
+        struct timespec    t;
+
+        assert(l);
+        assert(dht);
+        assert(key);
+        assert(list_is_empty(l));
+
+        clock_gettime(CLOCK_REALTIME_COARSE, &t);
+
+        b = dht_get_bucket(dht, key);
+        if (b == NULL)
+                return 0;
+
+        b->t_refr = t.tv_sec + KAD_T_REFR;
+
+        if (b->n_contacts == dht->k || b->parent == NULL) {
+                list_for_each(p, &b->contacts) {
+                        struct contact * c;
+                        c = list_entry(p, struct contact, next);
+                        c = contact_create(c->id, dht->b, c->addr);
+                        if (list_add_sorted(l, c, key) == 1)
+                                if (++len == dht->k)
+                                        break;
+                }
+        } else {
+                struct bucket * d = b->parent;
+                for (i = 0; i < (1L << KAD_BETA) && len < dht->k; ++i) {
+                        list_for_each(p, &d->children[i]->contacts) {
+                                struct contact * c;
+                                c = list_entry(p, struct contact, next);
+                                c = contact_create(c->id, dht->b, c->addr);
+                                if (c == NULL)
+                                        continue;
+                                if (list_add_sorted(l, c, key) == 1)
+                                        if (++len == dht->k)
+                                                break;
+                        }
+                }
+        }
+
+        assert(len == dht->k || b->parent == NULL);
+
+        return len;
+}
+
+static struct lookup * lookup_create(struct dht *    dht,
+                                     const uint8_t * id)
+{
+        struct lookup *    lu;
+        pthread_condattr_t cattr;
+
+        assert(dht);
+        assert(id);
+
+        lu = malloc(sizeof(*lu));
+        if (lu == NULL)
+                goto fail_malloc;
+
+        list_head_init(&lu->contacts);
+        list_head_init(&lu->cookies);
+
+        lu->state   = LU_INIT;
+        lu->addrs   = NULL;
+        lu->n_addrs = 0;
+        lu->key     = dht_dup_key(id, dht->b);
+        if (lu->key == NULL)
+                goto fail_id;
+
+        if (pthread_mutex_init(&lu->lock, NULL))
+                goto fail_mutex;
+
+        pthread_condattr_init(&cattr);
+#ifndef __APPLE__
+        pthread_condattr_setclock(&cattr, PTHREAD_COND_CLOCK);
+#endif
+
+        if (pthread_cond_init(&lu->cond, &cattr))
+                goto fail_cond;
+
+        pthread_condattr_destroy(&cattr);
+
+        pthread_rwlock_wrlock(&dht->lock);
+
+        list_add(&lu->next, &dht->lookups);
+
+        lu->n_contacts = dht_contact_list(dht, &lu->contacts, id);
+
+        pthread_rwlock_unlock(&dht->lock);
+
+        return lu;
+
+ fail_cond:
+        pthread_condattr_destroy(&cattr);
+        pthread_mutex_destroy(&lu->lock);
+ fail_mutex:
+        free(lu->key);
+ fail_id:
+        free(lu);
+ fail_malloc:
+        return NULL;
+}
+
+static void cancel_lookup_destroy(void * o)
+{
+        struct lookup *    lu;
+        struct list_head * p;
+        struct list_head * h;
+
+        lu = (struct lookup *) o;
+
+        if (lu->key != NULL)
+                free(lu->key);
+        if (lu->addrs != NULL)
+                free(lu->addrs);
+
+        list_for_each_safe(p, h, &lu->contacts) {
+                struct contact * c = list_entry(p, struct contact, next);
+                list_del(&c->next);
+                contact_destroy(c);
+        }
+
+        list_for_each_safe(p, h, &lu->cookies) {
+                struct cookie_el * c = list_entry(p, struct cookie_el, next);
+                list_del(&c->next);
+                free(c);
+        }
+
+        pthread_mutex_unlock(&lu->lock);
+
+        pthread_mutex_destroy(&lu->lock);
+
+        free(lu);
+}
+
+static void lookup_destroy(struct lookup * lu)
+{
+        assert(lu);
+
+        pthread_mutex_lock(&lu->lock);
+
+        switch (lu->state) {
+        case LU_DESTROY:
+                pthread_mutex_unlock(&lu->lock);
+                return;
+        case LU_PENDING:
+                lu->state = LU_DESTROY;
+                pthread_cond_broadcast(&lu->cond);
+                break;
+        case LU_INIT:
+        case LU_UPDATE:
+        case LU_COMPLETE:
+                lu->state = LU_NULL;
+                break;
+        case LU_NULL:
+        default:
+                break;
+        }
+
+        pthread_cleanup_push(cancel_lookup_destroy, lu);
+
+        while (lu->state != LU_NULL)
+                pthread_cond_wait(&lu->cond, &lu->lock);
+
+        pthread_cleanup_pop(true);
+}
+
+static void lookup_update(struct dht *    dht,
+                          struct lookup * lu,
+                          kad_msg_t *     msg)
+{
+        struct list_head * p = NULL;
+        struct list_head * h;
+        struct contact *   c = NULL;
+        size_t             n;
+        size_t             pos = 0;
+        bool               mod = false;
+
+        assert(lu);
+        assert(msg);
+
+        if (dht_get_state(dht) != DHT_RUNNING)
+                return;
+
+        pthread_mutex_lock(&lu->lock);
+
+        list_for_each_safe(p, h, &lu->cookies) {
+                struct cookie_el * e = list_entry(p, struct cookie_el, next);
+                if (e->cookie == msg->cookie) {
+                        list_del(&e->next);
+                        free(e);
+                        break;
+                }
+        }
+
+        if (lu->state == LU_COMPLETE) {
+                pthread_mutex_unlock(&lu->lock);
+                return;
+        }
+
+        if (msg->n_addrs > 0) {
+                if (lu->addrs == NULL) {
+                        lu->addrs = malloc(sizeof(*lu->addrs) * msg->n_addrs);
+                        for (n = 0; n < msg->n_addrs; ++n)
+                                lu->addrs[n] = msg->addrs[n];
+                        lu->n_addrs = msg->n_addrs;
+                }
+
+                lu->state = LU_COMPLETE;
+                pthread_cond_broadcast(&lu->cond);
+                pthread_mutex_unlock(&lu->lock);
+                return;
+        }
+
+        pthread_cleanup_push((void *)(void *) pthread_mutex_unlock,
+                             &lu->lock);
+
+        while (lu->state == LU_INIT) {
+                pthread_rwlock_unlock(&dht->lock);
+                pthread_cond_wait(&lu->cond, &lu->lock);
+                pthread_rwlock_rdlock(&dht->lock);
+        }
+
+        pthread_cleanup_pop(false);
+
+        for (n = 0; n < msg->n_contacts; ++n) {
+                c = contact_create(msg->contacts[n]->id.data,
+                                   dht->b, msg->contacts[n]->addr);
+                if (c == NULL)
+                        continue;
+
+                pos = 0;
+
+                list_for_each(p, &lu->contacts) {
+                        struct contact * e;
+                        e = list_entry(p, struct contact, next);
+                        if (!memcmp(e->id, c->id, dht->b)) {
+                                contact_destroy(c);
+                                c = NULL;
+                                break;
+                        }
+
+                        if (dist(c->id, lu->key) > dist(e->id, lu->key))
+                                break;
+
+                        pos++;
+                }
+
+                if (c == NULL)
+                        continue;
+
+                if (lu->n_contacts < dht->k) {
+                        list_add_tail(&c->next, p);
+                        ++lu->n_contacts;
+                        mod = true;
+                } else if (pos == dht->k) {
+                        contact_destroy(c);
+                } else {
+                        struct contact * d;
+                        list_add_tail(&c->next, p);
+                        d = list_last_entry(&lu->contacts,
+                                            struct contact, next);
+                        list_del(&d->next);
+                        assert(lu->contacts.prv != &d->next);
+                        contact_destroy(d);
+                        mod = true;
+                }
+        }
+
+        if (list_is_empty(&lu->cookies) && !mod)
+                lu->state = LU_COMPLETE;
+        else
+                lu->state = LU_UPDATE;
+
+        pthread_cond_broadcast(&lu->cond);
+        pthread_mutex_unlock(&lu->lock);
+        return;
+}
+
+static ssize_t lookup_get_addrs(struct lookup * lu,
+                                uint64_t *      addrs)
+{
+        ssize_t n;
+
+        assert(lu);
+
+        pthread_mutex_lock(&lu->lock);
+
+        for (n = 0; (size_t) n < lu->n_addrs; ++n)
+                addrs[n] = lu->addrs[n];
+
+        assert((size_t) n == lu->n_addrs);
+
+        pthread_mutex_unlock(&lu->lock);
+
+        return n;
+}
+
+static ssize_t lookup_contact_addrs(struct lookup * lu,
+                                    uint64_t *      addrs)
+{
+        struct list_head * p;
+        ssize_t            n = 0;
+
+        assert(lu);
+        assert(addrs);
+
+        pthread_mutex_lock(&lu->lock);
+
+        list_for_each(p, &lu->contacts) {
+                struct contact * c = list_entry(p, struct contact, next);
+                addrs[n] = c->addr;
+                n++;
+        }
+
+        pthread_mutex_unlock(&lu->lock);
+
+        return n;
+}
+
+static void lookup_new_addrs(struct lookup * lu,
+                             uint64_t *      addrs)
+{
+        struct list_head * p;
+        size_t             n = 0;
+
+        assert(lu);
+        assert(addrs);
+
+        pthread_mutex_lock(&lu->lock);
+
+        /* Uses fails to check if the contact has been contacted. */
+        list_for_each(p, &lu->contacts) {
+                struct contact * c = list_entry(p, struct contact, next);
+                if (c->fails == 0) {
+                        c->fails = 1;
+                        addrs[n] = c->addr;
+                        n++;
+                }
+
+                if (n == KAD_ALPHA)
+                        break;
+        }
+
+        assert(n <= KAD_ALPHA);
+
+        addrs[n] = 0;
+
+        pthread_mutex_unlock(&lu->lock);
+}
+
+static void lookup_set_state(struct lookup *   lu,
+                             enum lookup_state state)
+{
+        pthread_mutex_lock(&lu->lock);
+
+        lu->state = state;
+        pthread_cond_broadcast(&lu->cond);
+
+        pthread_mutex_unlock(&lu->lock);
+}
+
+static void cleanup_wait(void * o)
+{
+        struct lookup * lu = (struct lookup *) o;
+        lu->state = LU_NULL;
+        pthread_mutex_unlock(&lu->lock);
+        lookup_destroy(lu);
+}
+
+static enum lookup_state lookup_wait(struct lookup * lu)
+{
+        struct timespec   timeo = {KAD_T_RESP, 0};
+        struct timespec   abs;
+        enum lookup_state state;
+        int               ret = 0;
+
+        clock_gettime(PTHREAD_COND_CLOCK, &abs);
+
+        ts_add(&abs, &timeo, &abs);
+
+        pthread_mutex_lock(&lu->lock);
+
+        if (lu->state == LU_INIT || lu->state == LU_UPDATE)
+                lu->state = LU_PENDING;
+
+        pthread_cleanup_push(cleanup_wait, lu);
+
+        while (lu->state == LU_PENDING && ret != -ETIMEDOUT)
+                ret = -pthread_cond_timedwait(&lu->cond, &lu->lock, &abs);
+
+        pthread_cleanup_pop(false);
+
+        if (ret == -ETIMEDOUT)
+                lu->state = LU_COMPLETE;
+
+        state = lu->state;
+
+        pthread_mutex_unlock(&lu->lock);
+
+        return state;
+}
+
+static struct kad_req * dht_find_request(struct dht * dht,
+                                         kad_msg_t *  msg)
+{
+        struct list_head * p;
+
+        assert(dht);
+        assert(msg);
+
+        list_for_each(p, &dht->requests) {
+                struct kad_req * r = list_entry(p, struct kad_req, next);
+                if (r->cookie == msg->cookie)
+                        return r;
+        }
+
+        return NULL;
+}
+
+static struct lookup * dht_find_lookup(struct dht *    dht,
+                                       uint32_t        cookie)
+{
+        struct list_head * p;
+        struct list_head * p2;
+        struct list_head * h2;
+
+        assert(dht);
+        assert(cookie > 0);
+
+        list_for_each(p, &dht->lookups) {
+                struct lookup * l = list_entry(p, struct lookup, next);
+                pthread_mutex_lock(&l->lock);
+                list_for_each_safe(p2, h2, &l->cookies) {
+                        struct cookie_el * e;
+                        e = list_entry(p2, struct cookie_el, next);
+                        if (e->cookie == cookie) {
+                                list_del(&e->next);
+                                free(e);
+                                pthread_mutex_unlock(&l->lock);
+                                return l;
+                        }
+                }
+                pthread_mutex_unlock(&l->lock);
+        }
+
+        return NULL;
+}
+
+static struct val * val_create(uint64_t addr,
+                               time_t   exp)
+{
+        struct val *    v;
+        struct timespec t;
+
+        v = malloc(sizeof(*v));
+        if (v == NULL)
+                return NULL;
+
+        list_head_init(&v->next);
+        v->addr = addr;
+
+        clock_gettime(CLOCK_REALTIME_COARSE, &t);
+
+        v->t_exp = t.tv_sec + exp;
+        v->t_rep = t.tv_sec + KAD_T_REPL;
+
+        return v;
+}
+
+static void val_destroy(struct val * v)
+{
+        assert(v);
+
+        free(v);
+}
+
+static struct ref_entry * ref_entry_create(struct dht *    dht,
+                                           const uint8_t * key)
+{
+        struct ref_entry * e;
+        struct timespec    t;
+
+        assert(dht);
+        assert(key);
+
+        e = malloc(sizeof(*e));
+        if (e == NULL)
+                return NULL;
+
+        e->key = dht_dup_key(key, dht->b);
+        if (e->key == NULL) {
+                free(e);
+                return NULL;
+        }
+
+        clock_gettime(CLOCK_REALTIME_COARSE, &t);
+
+        e->t_rep = t.tv_sec + dht->t_repub;
+
+        return e;
+}
+
+static void ref_entry_destroy(struct ref_entry * e)
+{
+        free(e->key);
+        free(e);
+}
+
+static struct dht_entry * dht_entry_create(struct dht *    dht,
+                                           const uint8_t * key)
+{
+        struct dht_entry * e;
+
+        assert(dht);
+        assert(key);
+
+        e = malloc(sizeof(*e));
+        if (e == NULL)
+                return NULL;
+
+        list_head_init(&e->next);
+        list_head_init(&e->vals);
+
+        e->n_vals = 0;
+
+        e->key = dht_dup_key(key, dht->b);
+        if (e->key == NULL) {
+                free(e);
+                return NULL;
+        }
+
+        return e;
+}
+
+static void dht_entry_destroy(struct dht_entry * e)
+{
+        struct list_head * p;
+        struct list_head * h;
+
+        assert(e);
+
+        list_for_each_safe(p, h, &e->vals) {
+                struct val * v = list_entry(p, struct val, next);
+                list_del(&v->next);
+                val_destroy(v);
+        }
+
+        free(e->key);
+
+        free(e);
+}
+
+static int dht_entry_add_addr(struct dht_entry * e,
+                              uint64_t           addr,
+                              time_t             exp)
+{
+        struct list_head * p;
+        struct val * val;
+        struct timespec t;
+
+        clock_gettime(CLOCK_REALTIME_COARSE, &t);
+
+        list_for_each(p, &e->vals) {
+                struct val * v = list_entry(p, struct val, next);
+                if (v->addr == addr) {
+                        if (v->t_exp < t.tv_sec + exp) {
+                                v->t_exp = t.tv_sec + exp;
+                                v->t_rep = t.tv_sec + KAD_T_REPL;
+                        }
+
+                        return 0;
+                }
+        }
+
+        val = val_create(addr, exp);
+        if (val == NULL)
+                return -ENOMEM;
+
+        list_add(&val->next, &e->vals);
+        ++e->n_vals;
+
+        return 0;
+}
+
+
+static void dht_entry_del_addr(struct dht_entry * e,
+                               uint64_t           addr)
+{
+        struct list_head * p;
+        struct list_head * h;
+
+        assert(e);
+
+        list_for_each_safe(p, h, &e->vals) {
+                struct val * v = list_entry(p, struct val, next);
+                if (v->addr == addr) {
+                        list_del(&v->next);
+                        val_destroy(v);
+                        --e->n_vals;
+                }
+        }
+
+        if (e->n_vals == 0) {
+                list_del(&e->next);
+                dht_entry_destroy(e);
+        }
+}
+
+static uint64_t dht_entry_get_addr(struct dht *       dht,
+                                   struct dht_entry * e)
+{
+        struct list_head * p;
+
+        assert(e);
+        assert(!list_is_empty(&e->vals));
+
+        list_for_each(p, &e->vals) {
+                struct val * v = list_entry(p, struct val, next);
+                if (v->addr != dht->addr)
+                        return v->addr;
+        }
+
+        return 0;
+}
+
+/* Forward declaration. */
+static struct lookup * kad_lookup(struct dht *    dht,
+                                  const uint8_t * key,
+                                  enum kad_code   code);
+
+
+/* Build a refresh list. */
+static void bucket_refresh(struct dht *       dht,
+                           struct bucket *    b,
+                           time_t             t,
+                           struct list_head * r)
+{
+        size_t i;
+
+        if (*b->children != NULL)
+                for (i = 0; i < (1L << KAD_BETA); ++i)
+                        bucket_refresh(dht, b->children[i], t, r);
+
+        if (b->n_contacts == 0)
+                return;
+
+        if (t > b->t_refr) {
+                struct contact * c;
+                struct contact * d;
+                c = list_first_entry(&b->contacts, struct contact, next);
+                d = contact_create(c->id, dht->b, c->addr);
+                if (c != NULL)
+                        list_add(&d->next, r);
+                return;
+        }
+}
+
+
+static struct bucket * bucket_create(void)
+{
+        struct bucket * b;
+        struct timespec t;
+        size_t          i;
+
+        b = malloc(sizeof(*b));
+        if (b == NULL)
+                return NULL;
+
+        list_head_init(&b->contacts);
+        b->n_contacts = 0;
+
+        list_head_init(&b->alts);
+        b->n_alts = 0;
+
+        clock_gettime(CLOCK_REALTIME_COARSE, &t);
+        b->t_refr = t.tv_sec + KAD_T_REFR;
+
+        for (i = 0; i < (1L << KAD_BETA); ++i)
+                b->children[i]  = NULL;
+
+        b->parent = NULL;
+        b->depth = 0;
+
+        return b;
+}
+
+static void bucket_destroy(struct bucket * b)
+{
+        struct list_head * p;
+        struct list_head * h;
+        size_t             i;
+
+        assert(b);
+
+        for (i = 0; i < (1L << KAD_BETA); ++i)
+                if (b->children[i] != NULL)
+                        bucket_destroy(b->children[i]);
+
+        list_for_each_safe(p, h, &b->contacts) {
+                struct contact * c = list_entry(p, struct contact, next);
+                list_del(&c->next);
+                contact_destroy(c);
+                --b->n_contacts;
+        }
+
+        list_for_each_safe(p, h, &b->alts) {
+                struct contact * c = list_entry(p, struct contact, next);
+                list_del(&c->next);
+                contact_destroy(c);
+                --b->n_contacts;
+        }
+
+        free(b);
+}
+
+static bool bucket_has_id(struct bucket * b,
+                          const uint8_t * id)
+{
+        uint8_t mask;
+        uint8_t byte;
+
+        if (b->depth == 0)
+                return true;
+
+        byte = id[(b->depth * KAD_BETA) / CHAR_BIT];
+
+        mask = ((1L << KAD_BETA) - 1) & 0xFF;
+
+        byte >>= (CHAR_BIT - KAD_BETA) -
+                (((b->depth - 1) * KAD_BETA) & (CHAR_BIT - 1));
+
+        return ((byte & mask) == b->mask);
+}
+
+static int split_bucket(struct bucket * b)
+{
+        struct list_head * p;
+        struct list_head * h;
+        uint8_t mask = 0;
+        size_t i;
+        size_t c;
+
+        assert(b);
+        assert(b->n_alts == 0);
+        assert(b->n_contacts);
+        assert(b->children[0] == NULL);
+
+        c = b->n_contacts;
+
+        for (i = 0; i < (1L << KAD_BETA); ++i) {
+                b->children[i] = bucket_create();
+                if (b->children[i] == NULL) {
+                        size_t j;
+                        for (j = 0; j < i; ++j)
+                                bucket_destroy(b->children[j]);
+                        return -1;
+                }
+
+                b->children[i]->depth  = b->depth + 1;
+                b->children[i]->mask   = mask;
+                b->children[i]->parent = b;
+
+                list_for_each_safe(p, h, &b->contacts) {
+                        struct contact * c;
+                        c = list_entry(p, struct contact, next);
+                        if (bucket_has_id(b->children[i], c->id)) {
+                                list_del(&c->next);
+                                --b->n_contacts;
+                                list_add(&c->next, &b->children[i]->contacts);
+                                ++b->children[i]->n_contacts;
+                        }
+                }
+
+                mask++;
+        }
+
+        for (i = 0; i < (1L << KAD_BETA); ++i)
+                if (b->children[i]->n_contacts == c)
+                        split_bucket(b->children[i]);
+
+        return 0;
+}
+
+/* Locked externally to mandate update as (final) part of join transaction. */
+static int dht_update_bucket(struct dht *    dht,
+                             const uint8_t * id,
+                             uint64_t        addr)
+{
+        struct list_head * p;
+        struct list_head * h;
+        struct bucket *    b;
+        struct contact *   c;
+
+        assert(dht);
+
+        b = dht_get_bucket(dht, id);
+        if (b == NULL)
+                return -1;
+
+        c = contact_create(id, dht->b, addr);
+        if (c == NULL)
+                return -1;
+
+        list_for_each_safe(p, h, &b->contacts) {
+                struct contact * d = list_entry(p, struct contact, next);
+                if (d->addr == addr) {
+                        list_del(&d->next);
+                        contact_destroy(d);
+                        --b->n_contacts;
+                }
+        }
+
+        if (b->n_contacts == dht->k) {
+                if (bucket_has_id(b, dht->id)) {
+                        list_add_tail(&c->next, &b->contacts);
+                        ++b->n_contacts;
+                        if (split_bucket(b)) {
+                                list_del(&c->next);
+                                contact_destroy(c);
+                                --b->n_contacts;
+                        }
+                } else if (b->n_alts == dht->k) {
+                        struct contact * d;
+                        d = list_first_entry(&b->alts, struct contact, next);
+                        list_del(&d->next);
+                        contact_destroy(d);
+                        list_add_tail(&c->next, &b->alts);
+                } else {
+                        list_add_tail(&c->next, &b->alts);
+                        ++b->n_alts;
+                }
+        } else {
+                list_add_tail(&c->next, &b->contacts);
+                ++b->n_contacts;
+        }
+
+        return 0;
+}
+
+static int send_msg(struct dht * dht,
+                    kad_msg_t *  msg,
+                    uint64_t     addr)
+{
+#ifndef __DHT_TEST__
+        struct shm_du_buff * sdb;
+        size_t               len;
+#endif
+        int                  retr = 0;
+
+        if (msg->code == KAD_RESPONSE)
+                retr = KAD_RESP_RETR;
+
+        pthread_rwlock_wrlock(&dht->lock);
+
+        if (dht->id != NULL) {
+                msg->has_s_id = true;
+                msg->s_id.data = dht->id;
+                msg->s_id.len  = dht->b;
+        }
+
+        msg->s_addr = dht->addr;
+
+        if (msg->code < KAD_STORE) {
+                msg->cookie = bmp_allocate(dht->cookies);
+                if (!bmp_is_id_valid(dht->cookies, msg->cookie)) {
+                        pthread_rwlock_unlock(&dht->lock);
+                        goto fail_bmp_alloc;
+                }
+        }
+
+        pthread_rwlock_unlock(&dht->lock);
+
+#ifndef __DHT_TEST__
+        len = kad_msg__get_packed_size(msg);
+        if (len == 0)
+                goto fail_msg;
+
+        while (true) {
+                if (ipcp_sdb_reserve(&sdb, len))
+                        goto fail_msg;
+
+                kad_msg__pack(msg, shm_du_buff_head(sdb));
+
+                if (dt_write_packet(addr, QOS_CUBE_BE, dht->fd, sdb) == 0)
+                        break;
+
+                ipcp_sdb_release(sdb);
+
+                sleep(1);
+
+                if (--retr < 0)
+                        goto fail_msg;
+        }
+
+#else
+        (void) addr;
+        (void) retr;
+#endif /* __DHT_TEST__ */
+
+        if (msg->code < KAD_STORE && dht_get_state(dht) != DHT_SHUTDOWN)
+                kad_req_create(dht, msg, addr);
+
+        return msg->cookie;
+#ifndef __DHT_TEST__
+ fail_msg:
+        pthread_rwlock_wrlock(&dht->lock);
+        bmp_release(dht->cookies, msg->cookie);
+        pthread_rwlock_unlock(&dht->lock);
+#endif /* !__DHT_TEST__ */
+ fail_bmp_alloc:
+        return -1;
+}
+
+static struct dht_entry * dht_find_entry(struct dht *    dht,
+                                         const uint8_t * key)
+{
+        struct list_head * p;
+
+        list_for_each(p, &dht->entries) {
+                struct dht_entry * e = list_entry(p, struct dht_entry, next);
+                if (!memcmp(key, e->key, dht->b))
+                        return e;
+        }
+
+        return NULL;
+}
+
+static int kad_add(struct dht *              dht,
+                   const kad_contact_msg_t * contacts,
+                   ssize_t                   n,
+                   time_t                    exp)
+{
+        struct dht_entry * e;
+
+        pthread_rwlock_wrlock(&dht->lock);
+
+        while (n-- > 0) {
+                if (contacts[n].id.len != dht->b)
+                        log_warn("Bad key length in contact data.");
+
+                e = dht_find_entry(dht, contacts[n].id.data);
+                if (e != NULL) {
+                        if (dht_entry_add_addr(e, contacts[n].addr, exp))
+                                goto fail;
+                } else {
+                        e = dht_entry_create(dht, contacts[n].id.data);
+                        if (e == NULL)
+                                goto fail;
+
+                        if (dht_entry_add_addr(e, contacts[n].addr, exp)) {
+                                dht_entry_destroy(e);
+                                goto fail;
+                        }
+
+                        list_add(&e->next, &dht->entries);
+                }
+        }
+
+        pthread_rwlock_unlock(&dht->lock);
+        return 0;
+
+ fail:
+        pthread_rwlock_unlock(&dht->lock);
+        return -ENOMEM;
+}
+
+static int wait_resp(struct dht * dht,
+                     kad_msg_t *  msg,
+                     time_t       timeo)
+{
+        struct kad_req * req;
+
+        assert(dht);
+        assert(msg);
+
+        pthread_rwlock_rdlock(&dht->lock);
+
+        req = dht_find_request(dht, msg);
+        if (req == NULL) {
+                pthread_rwlock_unlock(&dht->lock);
+                return -EPERM;
+        }
+
+        pthread_rwlock_unlock(&dht->lock);
+
+        return kad_req_wait(req, timeo);
+}
+
+static int kad_store(struct dht *    dht,
+                     const uint8_t * key,
+                     uint64_t        addr,
+                     uint64_t        r_addr,
+                     time_t          ttl)
+{
+        kad_msg_t msg = KAD_MSG__INIT;
+        kad_contact_msg_t cmsg = KAD_CONTACT_MSG__INIT;
+        kad_contact_msg_t * cmsgp[1];
+
+        cmsg.id.data = (uint8_t *) key;
+        cmsg.addr    = addr;
+
+        pthread_rwlock_rdlock(&dht->lock);
+
+        cmsg.id.len  = dht->b;
+
+        pthread_rwlock_unlock(&dht->lock);
+
+        cmsgp[0] = &cmsg;
+
+        msg.code         = KAD_STORE;
+        msg.has_t_expire = true;
+        msg.t_expire     = ttl;
+        msg.n_contacts   = 1;
+        msg.contacts     = cmsgp;
+
+        if (send_msg(dht, &msg, r_addr) < 0)
+                return -1;
+
+        return 0;
+}
+
+static ssize_t kad_find(struct dht *     dht,
+                        struct lookup *  lu,
+                        const uint64_t * addrs,
+                        enum kad_code    code)
+{
+        kad_msg_t msg  = KAD_MSG__INIT;
+        ssize_t   sent = 0;
+
+        assert(dht);
+        assert(lu->key);
+
+        msg.code = code;
+
+        msg.has_key       = true;
+        msg.key.data      = (uint8_t *) lu->key;
+        msg.key.len       = dht->b;
+
+        while (*addrs != 0) {
+                struct cookie_el * c;
+                int ret;
+
+                if (*addrs == dht->addr) {
+                        ++addrs;
+                        continue;
+                }
+
+                ret = send_msg(dht, &msg, *addrs);
+                if (ret < 0)
+                        break;
+
+                c = malloc(sizeof(*c));
+                if (c == NULL)
+                        break;
+
+                c->cookie = (uint32_t) ret;
+
+                pthread_mutex_lock(&lu->lock);
+
+                list_add_tail(&c->next, &lu->cookies);
+
+                pthread_mutex_unlock(&lu->lock);
+
+                ++sent;
+                ++addrs;
+        }
+
+        return sent;
+}
+
+static void lookup_detach(struct dht *    dht,
+                          struct lookup * lu)
+{
+        pthread_rwlock_wrlock(&dht->lock);
+
+        list_del(&lu->next);
+
+        pthread_rwlock_unlock(&dht->lock);
+}
+
+static struct lookup * kad_lookup(struct dht *    dht,
+                                  const uint8_t * id,
+                                  enum kad_code   code)
+{
+        uint64_t          addrs[KAD_ALPHA + 1];
+        enum lookup_state state;
+        struct lookup *   lu;
+
+        lu = lookup_create(dht, id);
+        if (lu == NULL)
+                return NULL;
+
+        lookup_new_addrs(lu, addrs);
+
+        if (addrs[0] == 0) {
+                lookup_detach(dht, lu);
+                lookup_destroy(lu);
+                return NULL;
+        }
+
+        if (kad_find(dht, lu, addrs, code) == 0) {
+                lookup_detach(dht, lu);
+                return lu;
+        }
+
+        while ((state = lookup_wait(lu)) != LU_COMPLETE) {
+                switch (state) {
+                case LU_UPDATE:
+                        lookup_new_addrs(lu, addrs);
+                        if (addrs[0] == 0)
+                                break;
+
+                        kad_find(dht, lu, addrs, code);
+                        break;
+                case LU_DESTROY:
+                        lookup_detach(dht, lu);
+                        lookup_set_state(lu, LU_NULL);
+                        return NULL;
+                default:
+                        break;
+                }
+        }
+
+        assert(state = LU_COMPLETE);
+
+        lookup_detach(dht, lu);
+
+        return lu;
+}
+
+static void kad_publish(struct dht *    dht,
+                        const uint8_t * key,
+                        uint64_t        addr,
+                        time_t          exp)
+{
+        struct lookup * lu;
+        uint64_t      * addrs;
+        ssize_t         n;
+        size_t          k;
+        time_t          t_expire;
+
+
+        assert(dht);
+        assert(key);
+
+        pthread_rwlock_rdlock(&dht->lock);
+
+        k        = dht->k;
+        t_expire = dht->t_expire;
+
+        pthread_rwlock_unlock(&dht->lock);
+
+        addrs = malloc(k * sizeof(*addrs));
+        if (addrs == NULL)
+                return;
+
+        lu = kad_lookup(dht, key, KAD_FIND_NODE);
+        if (lu == NULL) {
+                free(addrs);
+                return;
+        }
+
+        n = lookup_contact_addrs(lu, addrs);
+
+        while (n-- > 0) {
+                if (addrs[n] == dht->addr) {
+                        kad_contact_msg_t msg = KAD_CONTACT_MSG__INIT;
+                        msg.id.data = (uint8_t *) key;
+                        msg.id.len  = dht->b;
+                        msg.addr    = addr;
+                        kad_add(dht, &msg, 1, exp);
+                } else {
+                        if (kad_store(dht, key, addr, addrs[n], t_expire))
+                                log_warn("Failed to send store message.");
+                }
+        }
+
+        lookup_destroy(lu);
+
+        free(addrs);
+}
+
+static int kad_join(struct dht * dht,
+                    uint64_t     addr)
+{
+        kad_msg_t       msg = KAD_MSG__INIT;
+
+        msg.code = KAD_JOIN;
+
+        msg.has_alpha       = true;
+        msg.has_b           = true;
+        msg.has_k           = true;
+        msg.has_t_refresh   = true;
+        msg.has_t_replicate = true;
+        msg.alpha           = KAD_ALPHA;
+        msg.k               = KAD_K;
+        msg.t_refresh       = KAD_T_REFR;
+        msg.t_replicate     = KAD_T_REPL;
+
+        pthread_rwlock_rdlock(&dht->lock);
+
+        msg.b               = dht->b;
+
+        pthread_rwlock_unlock(&dht->lock);
+
+        if (send_msg(dht, &msg, addr) < 0)
+                return -1;
+
+        if (wait_resp(dht, &msg, KAD_T_JOIN) < 0)
+                return -1;
+
+        dht->id = create_id(dht->b);
+        if (dht->id == NULL)
+                return -1;
+
+        pthread_rwlock_wrlock(&dht->lock);
+
+        dht_update_bucket(dht, dht->id, dht->addr);
+
+        pthread_rwlock_unlock(&dht->lock);
+
+        return 0;
+}
+
+static void dht_dead_peer(struct dht * dht,
+                          uint8_t *    key,
+                          uint64_t     addr)
+{
+        struct list_head * p;
+        struct list_head * h;
+        struct bucket *    b;
+
+        b = dht_get_bucket(dht, key);
+
+        list_for_each_safe(p, h, &b->contacts) {
+                struct contact * c = list_entry(p, struct contact, next);
+                if (b->n_contacts + b->n_alts <= dht->k) {
+                        ++c->fails;
+                        return;
+                }
+
+                if (c->addr == addr) {
+                        list_del(&c->next);
+                        contact_destroy(c);
+                        --b->n_contacts;
+                        break;
+                }
+        }
+
+        while (b->n_contacts < dht->k && b->n_alts > 0) {
+                struct contact * c;
+                c = list_first_entry(&b->alts, struct contact, next);
+                list_del(&c->next);
+                --b->n_alts;
+                list_add(&c->next, &b->contacts);
+                ++b->n_contacts;
+        }
+}
+
+static int dht_del(struct dht *    dht,
+                   const uint8_t * key,
+                   uint64_t        addr)
+{
+        struct dht_entry * e;
+
+        pthread_rwlock_wrlock(&dht->lock);
+
+        e = dht_find_entry(dht, key);
+        if (e == NULL) {
+                pthread_rwlock_unlock(&dht->lock);
+                return -EPERM;
+        }
+
+        dht_entry_del_addr(e, addr);
+
+        pthread_rwlock_unlock(&dht->lock);
+
+        return 0;
+}
+
+static buffer_t dht_retrieve(struct dht *    dht,
+                             const uint8_t * key)
+{
+        struct dht_entry * e;
+        struct list_head * p;
+        buffer_t           buf;
+        uint64_t *         pos;
+        size_t             addrs = 0;
+
+        pthread_rwlock_rdlock(&dht->lock);
+
+        e = dht_find_entry(dht, key);
+        if (e == NULL)
+                goto fail;
+
+        buf.len = MIN(DHT_RETR_ADDR, e->n_vals);
+        if (buf.len == 0)
+                goto fail;
+
+        pos = malloc(sizeof(dht->addr) * buf.len);
+        if (pos == NULL)
+                goto fail;
+
+        buf.data = (uint8_t *) pos;
+
+        list_for_each(p, &e->vals) {
+                struct val * v = list_entry(p, struct val, next);
+                *pos++ = v->addr;
+                if (++addrs >= buf.len)
+                        break;
+        }
+
+        pthread_rwlock_unlock(&dht->lock);
+
+        return buf;
+
+ fail:
+        pthread_rwlock_unlock(&dht->lock);
+        buf.len = 0;
+
+        return buf;
+}
+
+static ssize_t dht_get_contacts(struct dht *          dht,
+                                const uint8_t *       key,
+                                kad_contact_msg_t *** msgs)
+{
+        struct list_head   l;
+        struct list_head * p;
+        struct list_head * h;
+        size_t             len;
+        size_t             i = 0;
+
+        list_head_init(&l);
+
+        pthread_rwlock_wrlock(&dht->lock);
+
+        len = dht_contact_list(dht, &l, key);
+        if (len == 0) {
+                pthread_rwlock_unlock(&dht->lock);
+                return 0;
+        }
+
+        *msgs = malloc(len * sizeof(**msgs));
+        if (*msgs == NULL) {
+                pthread_rwlock_unlock(&dht->lock);
+                return 0;
+        }
+
+        list_for_each_safe(p, h, &l) {
+                struct contact * c = list_entry(p, struct contact, next);
+                (*msgs)[i] = malloc(sizeof(***msgs));
+                if ((*msgs)[i] == NULL) {
+                        pthread_rwlock_unlock(&dht->lock);
+                        while (i > 0)
+                                free(*msgs[--i]);
+                        free(*msgs);
+                        return 0;
+                }
+
+                kad_contact_msg__init((*msgs)[i]);
+
+                (*msgs)[i]->id.data = c->id;
+                (*msgs)[i]->id.len  = dht->b;
+                (*msgs)[i++]->addr  = c->addr;
+                list_del(&c->next);
+                free(c);
+        }
+
+        pthread_rwlock_unlock(&dht->lock);
+
+        return i;
+}
+
+static time_t gcd(time_t a,
+                  time_t b)
+{
+        if (a == 0)
+                return b;
+
+        return gcd(b % a, a);
+}
+
+static void * work(void * o)
+{
+        struct dht *       dht;
+        struct timespec    now;
+        struct list_head * p;
+        struct list_head * h;
+        struct list_head   reflist;
+        time_t             intv;
+        struct lookup *    lu;
+
+        dht = (struct dht *) o;
+
+        pthread_rwlock_rdlock(&dht->lock);
+
+        intv = gcd(dht->t_expire, dht->t_repub);
+        intv = gcd(intv, gcd(KAD_T_REPL, KAD_T_REFR)) / 2;
+
+        pthread_rwlock_unlock(&dht->lock);
+
+        list_head_init(&reflist);
+
+        while (true) {
+                clock_gettime(CLOCK_REALTIME_COARSE, &now);
+
+                pthread_rwlock_wrlock(&dht->lock);
+
+                /* Republish registered hashes. */
+                list_for_each(p, &dht->refs) {
+                        struct ref_entry * e;
+                        uint8_t *          key;
+                        uint64_t           addr;
+                        time_t             t_expire;
+                        e = list_entry(p, struct ref_entry, next);
+                        if (now.tv_sec > e->t_rep) {
+                                key = dht_dup_key(e->key, dht->b);
+                                if (key == NULL)
+                                        continue;
+                                addr = dht->addr;
+                                t_expire = dht->t_expire;
+                                e->t_rep = now.tv_sec + dht->t_repub;
+
+                                pthread_rwlock_unlock(&dht->lock);
+                                kad_publish(dht, key, addr, t_expire);
+                                pthread_rwlock_wrlock(&dht->lock);
+                                free(key);
+                        }
+                }
+
+                /* Remove stale entries and republish if necessary. */
+                list_for_each_safe(p, h, &dht->entries) {
+                        struct list_head * p1;
+                        struct list_head * h1;
+                        struct dht_entry * e;
+                        uint8_t *          key;
+                        time_t             t_expire;
+                        e = list_entry (p, struct dht_entry, next);
+                        list_for_each_safe(p1, h1, &e->vals) {
+                                struct val * v;
+                                uint64_t     addr;
+                                v = list_entry(p1, struct val, next);
+                                if (now.tv_sec > v->t_exp) {
+                                        list_del(&v->next);
+                                        val_destroy(v);
+                                        continue;
+                                }
+
+                                if (now.tv_sec > v->t_rep) {
+                                        key  = dht_dup_key(e->key, dht->b);
+                                        addr = v->addr;
+                                        t_expire = dht->t_expire = now.tv_sec;
+                                        v->t_rep = now.tv_sec + dht->t_replic;
+                                        pthread_rwlock_unlock(&dht->lock);
+                                        kad_publish(dht, key, addr, t_expire);
+                                        pthread_rwlock_wrlock(&dht->lock);
+                                        free(key);
+                                }
+                        }
+                }
+
+                /* Check the requests list for unresponsive nodes. */
+                list_for_each_safe(p, h, &dht->requests) {
+                        struct kad_req * r;
+                        r = list_entry(p, struct kad_req, next);
+                        if (now.tv_sec > r->t_exp) {
+                                list_del(&r->next);
+                                bmp_release(dht->cookies, r->cookie);
+                                dht_dead_peer(dht, r->key, r->addr);
+                                kad_req_destroy(r);
+                        }
+                }
+
+                /* Refresh unaccessed buckets. */
+                bucket_refresh(dht, dht->buckets, now.tv_sec, &reflist);
+
+                pthread_rwlock_unlock(&dht->lock);
+
+                list_for_each_safe(p, h, &reflist) {
+                        struct contact * c;
+                        c = list_entry(p, struct contact, next);
+                        lu = kad_lookup(dht, c->id, KAD_FIND_NODE);
+                        if (lu != NULL)
+                                lookup_destroy(lu);
+                        list_del(&c->next);
+                        contact_destroy(c);
+                }
+
+                sleep(intv);
+        }
+
+        return (void *) 0;
+}
+
+static int kad_handle_join_resp(struct dht *     dht,
+                                struct kad_req * req,
+                                kad_msg_t *      msg)
+{
+        assert(dht);
+        assert(req);
+        assert(msg);
+
+        /* We might send version numbers later to warn of updates if needed. */
+        if (!(msg->has_alpha && msg->has_b && msg->has_k && msg->has_t_expire &&
+              msg->has_t_refresh && msg->has_t_replicate)) {
+                log_warn("Join refused by remote.");
+                return -1;
+        }
+
+        if (msg->b < sizeof(uint64_t)) {
+                log_err("Hash sizes less than 8 bytes unsupported.");
+                return -1;
+        }
+
+        pthread_rwlock_wrlock(&dht->lock);
+
+        dht->buckets = bucket_create();
+        if (dht->buckets == NULL) {
+                pthread_rwlock_unlock(&dht->lock);
+                return -1;
+        }
+
+        /* Likely corrupt packet. The member will refuse, we might here too. */
+        if (msg->alpha != KAD_ALPHA || msg->k != KAD_K)
+                log_warn("Different kademlia parameters detected.");
+
+        if (msg->t_replicate != KAD_T_REPL)
+                log_warn("Different kademlia replication time detected.");
+
+        if (msg->t_refresh != KAD_T_REFR)
+                log_warn("Different kademlia refresh time detected.");
+
+        dht->k        = msg->k;
+        dht->b        = msg->b;
+        dht->t_expire = msg->t_expire;
+        dht->t_repub  = MAX(1, dht->t_expire - 10);
+
+        if (pthread_create(&dht->worker, NULL, work, dht)) {
+                bucket_destroy(dht->buckets);
+                pthread_rwlock_unlock(&dht->lock);
+                return -1;
+        }
+
+        kad_req_respond(req);
+
+        dht_update_bucket(dht, msg->s_id.data, msg->s_addr);
+
+        pthread_rwlock_unlock(&dht->lock);
+
+        log_dbg("Enrollment of DHT completed.");
+
+        return 0;
+}
+
+static int kad_handle_find_resp(struct dht *     dht,
+                                struct kad_req * req,
+                                kad_msg_t *      msg)
+{
+        struct lookup * lu;
+
+        assert(dht);
+        assert(req);
+        assert(msg);
+
+        pthread_rwlock_rdlock(&dht->lock);
+
+        lu = dht_find_lookup(dht, req->cookie);
+        if (lu == NULL) {
+                pthread_rwlock_unlock(&dht->lock);
+                return -1;
+        }
+
+        lookup_update(dht, lu, msg);
+
+        pthread_rwlock_unlock(&dht->lock);
+
+        return 0;
+}
+
+static void kad_handle_response(struct dht * dht,
+                                kad_msg_t *  msg)
+{
+        struct kad_req * req;
+
+        assert(dht);
+        assert(msg);
+
+        pthread_rwlock_wrlock(&dht->lock);
+
+        req = dht_find_request(dht, msg);
+        if (req == NULL) {
+                pthread_rwlock_unlock(&dht->lock);
+                return;
+        }
+
+        bmp_release(dht->cookies, req->cookie);
+        list_del(&req->next);
+
+        pthread_rwlock_unlock(&dht->lock);
+
+        switch(req->code) {
+        case KAD_JOIN:
+                if (kad_handle_join_resp(dht, req, msg))
+                        log_err("Enrollment of DHT failed.");
+                break;
+        case KAD_FIND_VALUE:
+        case KAD_FIND_NODE:
+                if (dht_get_state(dht) != DHT_RUNNING)
+                        break;
+                kad_handle_find_resp(dht, req, msg);
+                break;
+        default:
+                break;
+        }
+
+        kad_req_destroy(req);
+}
+
+int dht_bootstrap(struct dht * dht,
+                  size_t       b,
+                  time_t       t_expire)
+{
+        assert(dht);
+
+        pthread_rwlock_wrlock(&dht->lock);
+
+        dht->id = create_id(b);
+        if (dht->id == NULL)
+                goto fail_id;
+
+        dht->buckets = bucket_create();
+        if (dht->buckets == NULL)
+                goto fail_buckets;
+
+        dht->buckets->depth = 0;
+        dht->buckets->mask  = 0;
+
+        dht->b        = b / CHAR_BIT;
+        dht->t_expire = MAX(2, t_expire);
+        dht->t_repub  = MAX(1, t_expire - 10);
+        dht->k        = KAD_K;
+
+        if (pthread_create(&dht->worker, NULL, work, dht))
+                goto fail_pthread_create;
+
+        dht->state = DHT_RUNNING;
+
+        dht_update_bucket(dht, dht->id, dht->addr);
+
+        pthread_rwlock_unlock(&dht->lock);
+
+        return 0;
+
+ fail_pthread_create:
+        bucket_destroy(dht->buckets);
+        dht->buckets = NULL;
+ fail_buckets:
+        free(dht->id);
+        dht->id = NULL;
+ fail_id:
+        pthread_rwlock_unlock(&dht->lock);
+        return -1;
+}
+
+static struct ref_entry * ref_entry_get(struct dht *    dht,
+                                        const uint8_t * key)
+{
+        struct list_head * p;
+
+        list_for_each(p, &dht->refs) {
+                struct ref_entry * r = list_entry(p, struct ref_entry, next);
+                if (!memcmp(key, r->key, dht-> b) )
+                        return r;
+        }
+
+        return NULL;
+}
+
+int dht_reg(struct dht *    dht,
+            const uint8_t * key)
+{
+        struct ref_entry * e;
+        uint64_t           addr;
+        time_t             t_expire;
+
+        assert(dht);
+        assert(key);
+        assert(dht->addr != 0);
+
+        if (dht_wait_running(dht))
+                return -1;
+
+        pthread_rwlock_wrlock(&dht->lock);
+
+        if (ref_entry_get(dht, key) != NULL) {
+                log_dbg("Name already registered.");
+                pthread_rwlock_unlock(&dht->lock);
+                return 0;
+        }
+
+        e = ref_entry_create(dht, key);
+        if (e == NULL) {
+                pthread_rwlock_unlock(&dht->lock);
+                return -ENOMEM;
+        }
+
+        list_add(&e->next, &dht->refs);
+
+        t_expire = dht->t_expire;
+        addr = dht->addr;
+
+        pthread_rwlock_unlock(&dht->lock);
+
+        kad_publish(dht, key, addr, t_expire);
+
+        return 0;
+}
+
+int dht_unreg(struct dht *    dht,
+              const uint8_t * key)
+{
+        struct list_head * p;
+        struct list_head * h;
+
+        assert(dht);
+        assert(key);
+
+        if (dht_get_state(dht) != DHT_RUNNING)
+                return -1;
+
+        pthread_rwlock_wrlock(&dht->lock);
+
+        list_for_each_safe(p, h, &dht->refs) {
+                struct ref_entry * r = list_entry(p, struct ref_entry, next);
+                if (!memcmp(key, r->key, dht-> b) ) {
+                        list_del(&r->next);
+                        ref_entry_destroy(r);
+                }
+        }
+
+        dht_del(dht, key, dht->addr);
+
+        pthread_rwlock_unlock(&dht->lock);
+
+        return 0;
+}
+
+uint64_t dht_query(struct dht *    dht,
+                   const uint8_t * key)
+{
+        struct dht_entry * e;
+        struct lookup *    lu;
+        uint64_t           addrs[KAD_K];
+        size_t             n;
+
+        addrs[0] = 0;
+
+        if (dht_wait_running(dht))
+                return 0;
+
+        pthread_rwlock_rdlock(&dht->lock);
+
+        e = dht_find_entry(dht, key);
+        if (e != NULL)
+                addrs[0] = dht_entry_get_addr(dht, e);
+
+        pthread_rwlock_unlock(&dht->lock);
+
+        if (addrs[0] != 0)
+                return addrs[0];
+
+        lu = kad_lookup(dht, key, KAD_FIND_VALUE);
+        if (lu == NULL)
+                return 0;
+
+        n = lookup_get_addrs(lu, addrs);
+        if (n == 0) {
+                lookup_destroy(lu);
+                return 0;
+        }
+
+        lookup_destroy(lu);
+
+        /* Current behaviour is anycast and return the first peer address. */
+        if (addrs[0] != dht->addr)
+                return addrs[0];
+
+        if (n > 1)
+                return addrs[1];
+
+        return 0;
+}
+
+static void * dht_handle_packet(void * o)
+{
+        struct dht * dht = (struct dht *) o;
+
+        assert(dht);
+
+        while (true) {
+                kad_msg_t *          msg;
+                kad_contact_msg_t ** cmsgs;
+                kad_msg_t            resp_msg = KAD_MSG__INIT;
+                uint64_t             addr;
+                buffer_t             buf;
+                size_t               i;
+                size_t               b;
+                size_t               t_expire;
+                struct cmd *         cmd;
+
+                pthread_mutex_lock(&dht->mtx);
+
+                pthread_cleanup_push((void *)(void *) pthread_mutex_unlock,
+                                     &dht->mtx);
+
+                while (list_is_empty(&dht->cmds))
+                        pthread_cond_wait(&dht->cond, &dht->mtx);
+
+                cmd = list_last_entry(&dht->cmds, struct cmd, next);
+                list_del(&cmd->next);
+
+                pthread_cleanup_pop(true);
+
+                i = shm_du_buff_tail(cmd->sdb) - shm_du_buff_head(cmd->sdb);
+
+                msg = kad_msg__unpack(NULL, i, shm_du_buff_head(cmd->sdb));
+#ifndef __DHT_TEST__
+                ipcp_sdb_release(cmd->sdb);
+#endif
+                free(cmd);
+
+                if (msg == NULL) {
+                        log_err("Failed to unpack message.");
+                        continue;
+                }
+
+                if (msg->code != KAD_RESPONSE && dht_wait_running(dht)) {
+                        kad_msg__free_unpacked(msg, NULL);
+                        log_dbg("Got a request message when not running.");
+                        continue;
+                }
+
+                pthread_rwlock_rdlock(&dht->lock);
+
+                b        = dht->b;
+                t_expire = dht->t_expire;
+
+                pthread_rwlock_unlock(&dht->lock);
+
+                if (msg->has_key && msg->key.len != b) {
+                        kad_msg__free_unpacked(msg, NULL);
+                        log_warn("Bad key in message.");
+                        continue;
+                }
+
+                if (msg->has_s_id && !msg->has_b && msg->s_id.len != b) {
+                        kad_msg__free_unpacked(msg, NULL);
+                        log_warn("Bad source ID in message of type %d.",
+                                 msg->code);
+                        continue;
+                }
+
+                tpm_dec(dht->tpm);
+
+                addr = msg->s_addr;
+
+                resp_msg.code   = KAD_RESPONSE;
+                resp_msg.cookie = msg->cookie;
+
+                switch(msg->code) {
+                case KAD_JOIN:
+                        /* Refuse enrollee on check fails. */
+                        if (msg->alpha != KAD_ALPHA || msg->k != KAD_K) {
+                                log_warn("Parameter mismatch. "
+                                         "DHT enrolment refused.");
+                                break;
+                        }
+
+                        if (msg->t_replicate != KAD_T_REPL) {
+                                log_warn("Replication time mismatch. "
+                                         "DHT enrolment refused.");
+
+                                break;
+                        }
+
+                        if (msg->t_refresh != KAD_T_REFR) {
+                                log_warn("Refresh time mismatch. "
+                                         "DHT enrolment refused.");
+                                break;
+                        }
+
+                        resp_msg.has_alpha       = true;
+                        resp_msg.has_b           = true;
+                        resp_msg.has_k           = true;
+                        resp_msg.has_t_expire    = true;
+                        resp_msg.has_t_refresh   = true;
+                        resp_msg.has_t_replicate = true;
+                        resp_msg.alpha           = KAD_ALPHA;
+                        resp_msg.b               = b;
+                        resp_msg.k               = KAD_K;
+                        resp_msg.t_expire        = t_expire;
+                        resp_msg.t_refresh       = KAD_T_REFR;
+                        resp_msg.t_replicate     = KAD_T_REPL;
+                        break;
+                case KAD_FIND_VALUE:
+                        buf = dht_retrieve(dht, msg->key.data);
+                        if (buf.len != 0) {
+                                resp_msg.n_addrs = buf.len;
+                                resp_msg.addrs   = (uint64_t *) buf.data;
+                                break;
+                        }
+                        /* FALLTHRU */
+                case KAD_FIND_NODE:
+                        /* Return k closest contacts. */
+                        resp_msg.n_contacts =
+                                dht_get_contacts(dht, msg->key.data, &cmsgs);
+                        resp_msg.contacts = cmsgs;
+                        break;
+                case KAD_STORE:
+                        if (msg->n_contacts < 1) {
+                                log_warn("No contacts in store message.");
+                                break;
+                        }
+
+                        if (!msg->has_t_expire) {
+                                log_warn("No expiry time in store message.");
+                                break;
+                        }
+
+                        kad_add(dht, *msg->contacts, msg->n_contacts,
+                                msg->t_expire);
+                        break;
+                case KAD_RESPONSE:
+                        kad_handle_response(dht, msg);
+                        break;
+                default:
+                        assert(false);
+                        break;
+                }
+
+                if (msg->code != KAD_JOIN) {
+                        pthread_rwlock_wrlock(&dht->lock);
+                        if (dht_get_state(dht) == DHT_JOINING &&
+                            dht->buckets == NULL) {
+                                pthread_rwlock_unlock(&dht->lock);
+                                break;
+                        }
+
+                        if (dht_update_bucket(dht, msg->s_id.data, addr))
+                                log_warn("Failed to update bucket.");
+                        pthread_rwlock_unlock(&dht->lock);
+                }
+
+                if (msg->code < KAD_STORE && send_msg(dht, &resp_msg, addr) < 0)
+                                log_warn("Failed to send response.");
+
+                kad_msg__free_unpacked(msg, NULL);
+
+                if (resp_msg.n_addrs > 0)
+                        free(resp_msg.addrs);
+
+                if (resp_msg.n_contacts == 0) {
+                        tpm_inc(dht->tpm);
+                        continue;
+                }
+
+                for (i = 0; i < resp_msg.n_contacts; ++i)
+                        kad_contact_msg__free_unpacked(resp_msg.contacts[i],
+                                                       NULL);
+                free(resp_msg.contacts);
+
+                tpm_inc(dht->tpm);
+        }
+
+        return (void *) 0;
+}
+
+static void dht_post_packet(void *               comp,
+                            struct shm_du_buff * sdb)
+{
+        struct cmd * cmd;
+        struct dht * dht = (struct dht *) comp;
+
+        if (dht_get_state(dht) == DHT_SHUTDOWN) {
+#ifndef __DHT_TEST__
+                ipcp_sdb_release(sdb);
+#endif
+                return;
+        }
+
+        cmd = malloc(sizeof(*cmd));
+        if (cmd == NULL) {
+                log_err("Command failed. Out of memory.");
+                return;
+        }
+
+        cmd->sdb = sdb;
+
+        pthread_mutex_lock(&dht->mtx);
+
+        list_add(&cmd->next, &dht->cmds);
+
+        pthread_cond_signal(&dht->cond);
+
+        pthread_mutex_unlock(&dht->mtx);
+}
+
+void dht_destroy(struct dht * dht)
+{
+        struct list_head * p;
+        struct list_head * h;
+
+        if (dht == NULL)
+                return;
+
+#ifndef __DHT_TEST__
+        tpm_stop(dht->tpm);
+
+        tpm_destroy(dht->tpm);
+#endif
+        if (dht_get_state(dht) == DHT_RUNNING) {
+                dht_set_state(dht, DHT_SHUTDOWN);
+                pthread_cancel(dht->worker);
+                pthread_join(dht->worker, NULL);
+        }
+
+        pthread_rwlock_wrlock(&dht->lock);
+
+        list_for_each_safe(p, h, &dht->cmds) {
+                struct cmd * c = list_entry(p, struct cmd, next);
+                list_del(&c->next);
+#ifndef __DHT_TEST__
+                ipcp_sdb_release(c->sdb);
+#endif
+                free(c);
+        }
+
+        list_for_each_safe(p, h, &dht->entries) {
+                struct dht_entry * e = list_entry(p, struct dht_entry, next);
+                list_del(&e->next);
+                dht_entry_destroy(e);
+        }
+
+        list_for_each_safe(p, h, &dht->requests) {
+                struct kad_req * r = list_entry(p, struct kad_req, next);
+                list_del(&r->next);
+                kad_req_destroy(r);
+        }
+
+        list_for_each_safe(p, h, &dht->refs) {
+                struct ref_entry * e = list_entry(p, struct ref_entry, next);
+                list_del(&e->next);
+                ref_entry_destroy(e);
+        }
+
+        list_for_each_safe(p, h, &dht->lookups) {
+                struct lookup * l = list_entry(p, struct lookup, next);
+                list_del(&l->next);
+                lookup_destroy(l);
+        }
+
+        pthread_rwlock_unlock(&dht->lock);
+
+        if (dht->buckets != NULL)
+                bucket_destroy(dht->buckets);
+
+        bmp_destroy(dht->cookies);
+
+        pthread_mutex_destroy(&dht->mtx);
+
+        pthread_rwlock_destroy(&dht->lock);
+
+        free(dht->id);
+
+        free(dht);
+}
+
+static void * join_thr(void * o)
+{
+        struct join_info * info = (struct join_info *) o;
+        struct lookup *    lu;
+        size_t             retr = 0;
+
+        assert(info);
+
+        while (kad_join(info->dht, info->addr)) {
+                if (dht_get_state(info->dht) == DHT_SHUTDOWN) {
+                        log_dbg("DHT enrollment aborted.");
+                        goto finish;
+                }
+
+                if (retr++ == KAD_JOIN_RETR) {
+                        dht_set_state(info->dht, DHT_INIT);
+                        log_warn("DHT enrollment attempt failed.");
+                        goto finish;
+                }
+
+                sleep(KAD_JOIN_INTV);
+        }
+
+        dht_set_state(info->dht, DHT_RUNNING);
+
+        lu = kad_lookup(info->dht, info->dht->id, KAD_FIND_NODE);
+        if (lu != NULL)
+                lookup_destroy(lu);
+
+ finish:
+        free(info);
+
+        return (void *) 0;
+}
+
+static void handle_event(void *       self,
+                         int          event,
+                         const void * o)
+{
+        struct dht * dht = (struct dht *) self;
+
+        if (event == NOTIFY_DT_CONN_ADD) {
+                pthread_t          thr;
+                struct join_info * inf;
+                struct conn *      c     = (struct conn *) o;
+                struct timespec    slack = {0, DHT_ENROLL_SLACK * MILLION};
+
+                /* Give the pff some time to update for the new link. */
+                nanosleep(&slack, NULL);
+
+                switch(dht_get_state(dht)) {
+                case DHT_INIT:
+                        inf = malloc(sizeof(*inf));
+                        if (inf == NULL)
+                                break;
+
+                        inf->dht  = dht;
+                        inf->addr = c->conn_info.addr;
+
+                        if (dht_set_state(dht, DHT_JOINING) == 0 ||
+                            dht_wait_running(dht)) {
+                                if (pthread_create(&thr, NULL, join_thr, inf)) {
+                                        dht_set_state(dht, DHT_INIT);
+                                        free(inf);
+                                        return;
+                                }
+                                pthread_detach(thr);
+                        } else {
+                                free(inf);
+                        }
+                        break;
+                case DHT_RUNNING:
+                        /*
+                         * FIXME: this lookup for effiency reasons
+                         * causes a SEGV when stressed with rapid
+                         * enrollments.
+                         * lu = kad_lookup(dht, dht->id, KAD_FIND_NODE);
+                         * if (lu != NULL)
+                         *         lookup_destroy(lu);
+                         */
+                        break;
+                default:
+                        break;
+                }
+        }
+}
+
+struct dht * dht_create(uint64_t addr)
+{
+        struct dht * dht;
+
+        dht = malloc(sizeof(*dht));
+        if (dht == NULL)
+                goto fail_malloc;
+
+        dht->buckets = NULL;
+
+        list_head_init(&dht->entries);
+        list_head_init(&dht->requests);
+        list_head_init(&dht->refs);
+        list_head_init(&dht->lookups);
+        list_head_init(&dht->cmds);
+
+        if (pthread_rwlock_init(&dht->lock, NULL))
+                goto fail_rwlock;
+
+        if (pthread_mutex_init(&dht->mtx, NULL))
+                goto fail_mutex;
+
+        if (pthread_cond_init(&dht->cond, NULL))
+                goto fail_cond;
+
+        dht->cookies = bmp_create(DHT_MAX_REQS, 1);
+        if (dht->cookies == NULL)
+                goto fail_bmp;
+
+        dht->b    = 0;
+        dht->addr = addr;
+        dht->id   = NULL;
+#ifndef __DHT_TEST__
+        dht->tpm = tpm_create(2, 1, dht_handle_packet, dht);
+        if (dht->tpm == NULL)
+                goto fail_tpm_create;
+
+        if (tpm_start(dht->tpm))
+                goto fail_tpm_start;
+
+        dht->fd   = dt_reg_comp(dht, &dht_post_packet, DHT);
+        notifier_reg(handle_event, dht);
+#else
+        (void) handle_event;
+        (void) dht_handle_packet;
+        (void) dht_post_packet;
+#endif
+        dht->state = DHT_INIT;
+
+        return dht;
+#ifndef __DHT_TEST__
+ fail_tpm_start:
+        tpm_destroy(dht->tpm);
+ fail_tpm_create:
+        bmp_destroy(dht->cookies);
+#endif
+ fail_bmp:
+        pthread_cond_destroy(&dht->cond);
+ fail_cond:
+        pthread_mutex_destroy(&dht->mtx);
+ fail_mutex:
+        pthread_rwlock_destroy(&dht->lock);
+ fail_rwlock:
+        free(dht);
+ fail_malloc:
+        return NULL;
+}
diff --git a/src/ipcpd/unicast/dht.h b/src/ipcpd/unicast/dht.h
new file mode 100644
index 00000000..7d7601f5
--- /dev/null
+++ b/src/ipcpd/unicast/dht.h
@@ -0,0 +1,52 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Distributed Hash Table based on Kademlia
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * version 2.1 as published by the Free Software Foundation.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#ifndef OUROBOROS_IPCPD_UNICAST_DHT_H
+#define OUROBOROS_IPCPD_UNICAST_DHT_H
+
+#include <ouroboros/ipcp-dev.h>
+
+#include <stdint.h>
+#include <sys/types.h>
+
+struct dht;
+
+struct dht * dht_create(uint64_t addr);
+
+int          dht_bootstrap(struct dht * dht,
+                           size_t       b,
+                           time_t       t_expire);
+
+void         dht_destroy(struct dht * dht);
+
+int          dht_reg(struct dht *    dht,
+                     const uint8_t * key);
+
+int          dht_unreg(struct dht *    dht,
+                       const uint8_t * key);
+
+uint64_t     dht_query(struct dht *    dht,
+                       const uint8_t * key);
+
+int          dht_wait_running(struct dht * dht);
+
+#endif /* OUROBOROS_IPCPD_UNICAST_DHT_H */
diff --git a/src/ipcpd/unicast/dir.c b/src/ipcpd/unicast/dir.c
new file mode 100644
index 00000000..3b0446fa
--- /dev/null
+++ b/src/ipcpd/unicast/dir.c
@@ -0,0 +1,101 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Directory
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#if defined(__linux__) || defined(__CYGWIN__)
+#define _DEFAULT_SOURCE
+#else
+#define _POSIX_C_SOURCE 200112L
+#endif
+
+#define OUROBOROS_PREFIX "directory"
+
+#include <ouroboros/endian.h>
+#include <ouroboros/errno.h>
+#include <ouroboros/logs.h>
+#include <ouroboros/utils.h>
+
+#include "dir.h"
+#include "dht.h"
+#include "ipcp.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <inttypes.h>
+#include <limits.h>
+
+#define KAD_B (hash_len(ipcpi.dir_hash_algo) * CHAR_BIT)
+
+struct dht * dht;
+
+int dir_init(void)
+{
+        dht = dht_create(ipcpi.dt_addr);
+        if (dht == NULL)
+                return -ENOMEM;
+
+        return 0;
+}
+
+void dir_fini(void)
+{
+        dht_destroy(dht);
+}
+
+int dir_bootstrap(void) {
+        log_dbg("Bootstrapping directory.");
+
+        /* TODO: get parameters for bootstrap from IRM tool. */
+        if (dht_bootstrap(dht, KAD_B, 86400)) {
+                dht_destroy(dht);
+                return -ENOMEM;
+        }
+
+        log_info("Directory bootstrapped.");
+
+        return 0;
+}
+
+int dir_reg(const uint8_t * hash)
+{
+        return dht_reg(dht, hash);
+}
+
+int dir_unreg(const uint8_t * hash)
+{
+        return dht_unreg(dht, hash);
+}
+
+uint64_t dir_query(const uint8_t * hash)
+{
+        return dht_query(dht, hash);
+}
+
+int dir_wait_running(void)
+{
+        if (dht_wait_running(dht)) {
+                log_warn("Directory did not bootstrap.");
+                return -1;
+        }
+
+        return 0;
+}
diff --git a/src/ipcpd/unicast/dir.h b/src/ipcpd/unicast/dir.h
new file mode 100644
index 00000000..8aba8b1d
--- /dev/null
+++ b/src/ipcpd/unicast/dir.h
@@ -0,0 +1,40 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Directory
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#ifndef OUROBOROS_IPCPD_UNICAST_DIR_H
+#define OUROBOROS_IPCPD_UNICAST_DIR_H
+
+int      dir_init(void);
+
+void     dir_fini(void);
+
+int      dir_bootstrap(void);
+
+int      dir_reg(const uint8_t * hash);
+
+int      dir_unreg(const uint8_t * hash);
+
+uint64_t dir_query(const uint8_t * hash);
+
+int      dir_wait_running(void);
+
+#endif /* OUROBOROS_IPCPD_UNICAST_DIR_H */
diff --git a/src/ipcpd/unicast/dt.c b/src/ipcpd/unicast/dt.c
new file mode 100644
index 00000000..2fd3c060
--- /dev/null
+++ b/src/ipcpd/unicast/dt.c
@@ -0,0 +1,913 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Data Transfer Component
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#if defined(__linux__) || defined(__CYGWIN__)
+#define _DEFAULT_SOURCE
+#else
+#define _POSIX_C_SOURCE 200112L
+#endif
+
+#include "config.h"
+
+#define DT               "dt"
+#define OUROBOROS_PREFIX DT
+
+#include <ouroboros/bitmap.h>
+#include <ouroboros/errno.h>
+#include <ouroboros/logs.h>
+#include <ouroboros/dev.h>
+#include <ouroboros/notifier.h>
+#include <ouroboros/rib.h>
+#ifdef IPCP_FLOW_STATS
+#include <ouroboros/fccntl.h>
+#endif
+
+#include "connmgr.h"
+#include "ipcp.h"
+#include "dt.h"
+#include "pff.h"
+#include "routing.h"
+#include "psched.h"
+#include "comp.h"
+#include "fa.h"
+
+#include <stdlib.h>
+#include <stdbool.h>
+#include <pthread.h>
+#include <string.h>
+#include <inttypes.h>
+#include <assert.h>
+
+#define QOS_BLOCK_LEN 672
+#define STAT_FILE_LEN (189 + QOS_BLOCK_LEN * QOS_CUBE_MAX)
+
+#ifndef CLOCK_REALTIME_COARSE
+#define CLOCK_REALTIME_COARSE CLOCK_REALTIME
+#endif
+
+struct comp_info {
+        void (* post_packet)(void * comp, struct shm_du_buff * sdb);
+        void * comp;
+        char * name;
+};
+
+/* Fixed field lengths */
+#define TTL_LEN 1
+#define QOS_LEN 1
+#define ECN_LEN 1
+
+struct dt_pci {
+        uint64_t  dst_addr;
+        qoscube_t qc;
+        uint8_t   ttl;
+        uint8_t   ecn;
+        uint32_t  eid;
+};
+
+struct {
+        uint8_t         addr_size;
+        uint8_t         eid_size;
+        size_t          head_size;
+
+        /* Offsets */
+        size_t          qc_o;
+        size_t          ttl_o;
+        size_t          ecn_o;
+        size_t          eid_o;
+
+        /* Initial TTL value */
+        uint8_t         max_ttl;
+} dt_pci_info;
+
+static int dt_pci_ser(struct shm_du_buff * sdb,
+                      struct dt_pci *      dt_pci)
+{
+        uint8_t * head;
+        uint8_t   ttl = dt_pci_info.max_ttl;
+
+        assert(sdb);
+        assert(dt_pci);
+
+        head = shm_du_buff_head_alloc(sdb, dt_pci_info.head_size);
+        if (head == NULL)
+                return -EPERM;
+
+        /* FIXME: Add check and operations for Big Endian machines. */
+        memcpy(head, &dt_pci->dst_addr, dt_pci_info.addr_size);
+        memcpy(head + dt_pci_info.qc_o, &dt_pci->qc, QOS_LEN);
+        memcpy(head + dt_pci_info.ttl_o, &ttl, TTL_LEN);
+        memcpy(head + dt_pci_info.ecn_o,  &dt_pci->ecn, ECN_LEN);
+        memcpy(head + dt_pci_info.eid_o, &dt_pci->eid, dt_pci_info.eid_size);
+
+        return 0;
+}
+
+static void dt_pci_des(struct shm_du_buff * sdb,
+                       struct dt_pci *      dt_pci)
+{
+        uint8_t * head;
+
+        assert(sdb);
+        assert(dt_pci);
+
+        head = shm_du_buff_head(sdb);
+
+        /* Decrease TTL */
+        --*(head + dt_pci_info.ttl_o);
+
+        /* FIXME: Add check and operations for Big Endian machines. */
+        memcpy(&dt_pci->dst_addr, head, dt_pci_info.addr_size);
+        memcpy(&dt_pci->qc, head + dt_pci_info.qc_o, QOS_LEN);
+        memcpy(&dt_pci->ttl, head + dt_pci_info.ttl_o, TTL_LEN);
+        memcpy(&dt_pci->ecn, head + dt_pci_info.ecn_o, ECN_LEN);
+        memcpy(&dt_pci->eid, head + dt_pci_info.eid_o, dt_pci_info.eid_size);
+}
+
+static void dt_pci_shrink(struct shm_du_buff * sdb)
+{
+        assert(sdb);
+
+        shm_du_buff_head_release(sdb, dt_pci_info.head_size);
+}
+
+struct {
+        struct psched *    psched;
+
+        struct pff *       pff[QOS_CUBE_MAX];
+        struct routing_i * routing[QOS_CUBE_MAX];
+#ifdef IPCP_FLOW_STATS
+        struct {
+                time_t          stamp;
+                uint64_t        addr;
+                size_t          snd_pkt[QOS_CUBE_MAX];
+                size_t          rcv_pkt[QOS_CUBE_MAX];
+                size_t          snd_bytes[QOS_CUBE_MAX];
+                size_t          rcv_bytes[QOS_CUBE_MAX];
+                size_t          lcl_r_pkt[QOS_CUBE_MAX];
+                size_t          lcl_r_bytes[QOS_CUBE_MAX];
+                size_t          lcl_w_pkt[QOS_CUBE_MAX];
+                size_t          lcl_w_bytes[QOS_CUBE_MAX];
+                size_t          r_drp_pkt[QOS_CUBE_MAX];
+                size_t          r_drp_bytes[QOS_CUBE_MAX];
+                size_t          w_drp_pkt[QOS_CUBE_MAX];
+                size_t          w_drp_bytes[QOS_CUBE_MAX];
+                size_t          f_nhp_pkt[QOS_CUBE_MAX];
+                size_t          f_nhp_bytes[QOS_CUBE_MAX];
+                pthread_mutex_t lock;
+        } stat[PROG_MAX_FLOWS];
+
+        size_t             n_flows;
+#endif
+        struct bmp *       res_fds;
+        struct comp_info   comps[PROG_RES_FDS];
+        pthread_rwlock_t   lock;
+
+        pthread_t          listener;
+} dt;
+
+static int dt_stat_read(const char * path,
+                        char *       buf,
+                        size_t       len)
+{
+#ifdef IPCP_FLOW_STATS
+        int         fd;
+        int         i;
+        char        str[QOS_BLOCK_LEN + 1];
+        char        addrstr[20];
+        char        tmstr[20];
+        size_t      rxqlen = 0;
+        size_t      txqlen = 0;
+        struct tm * tm;
+
+        /* NOTE: we may need stronger checks. */
+        fd = atoi(path);
+
+        if (len < STAT_FILE_LEN)
+                return 0;
+
+        buf[0] = '\0';
+
+        pthread_mutex_lock(&dt.stat[fd].lock);
+
+        if (dt.stat[fd].stamp == 0) {
+                pthread_mutex_unlock(&dt.stat[fd].lock);
+                return 0;
+        }
+
+        if (dt.stat[fd].addr == ipcpi.dt_addr)
+                sprintf(addrstr, "%s", dt.comps[fd].name);
+        else
+                sprintf(addrstr, "%" PRIu64, dt.stat[fd].addr);
+
+        tm = localtime(&dt.stat[fd].stamp);
+        strftime(tmstr, sizeof(tmstr), "%F %T", tm);
+
+        if (fd >= PROG_RES_FDS) {
+                fccntl(fd, FLOWGRXQLEN, &rxqlen);
+                fccntl(fd, FLOWGTXQLEN, &txqlen);
+        }
+
+        sprintf(buf,
+                "Flow established at:      %20s\n"
+                "Endpoint address:         %20s\n"
+                "Queued packets (rx):      %20zu\n"
+                "Queued packets (tx):      %20zu\n\n",
+                tmstr, addrstr, rxqlen, txqlen);
+
+        for (i = 0; i < QOS_CUBE_MAX; ++i) {
+                sprintf(str,
+                        "Qos cube %3d:\n"
+                        " sent (packets):          %20zu\n"
+                        " sent (bytes):            %20zu\n"
+                        " rcvd (packets):          %20zu\n"
+                        " rcvd (bytes):            %20zu\n"
+                        " local sent (packets):    %20zu\n"
+                        " local sent (bytes):      %20zu\n"
+                        " local rcvd (packets):    %20zu\n"
+                        " local rcvd (bytes):      %20zu\n"
+                        " dropped ttl (packets):   %20zu\n"
+                        " dropped ttl (bytes):     %20zu\n"
+                        " failed writes (packets): %20zu\n"
+                        " failed writes (bytes):   %20zu\n"
+                        " failed nhop (packets):   %20zu\n"
+                        " failed nhop (bytes):     %20zu\n",
+                        i,
+                        dt.stat[fd].snd_pkt[i],
+                        dt.stat[fd].snd_bytes[i],
+                        dt.stat[fd].rcv_pkt[i],
+                        dt.stat[fd].rcv_bytes[i],
+                        dt.stat[fd].lcl_w_pkt[i],
+                        dt.stat[fd].lcl_w_bytes[i],
+                        dt.stat[fd].lcl_r_pkt[i],
+                        dt.stat[fd].lcl_r_bytes[i],
+                        dt.stat[fd].r_drp_pkt[i],
+                        dt.stat[fd].r_drp_bytes[i],
+                        dt.stat[fd].w_drp_pkt[i],
+                        dt.stat[fd].w_drp_bytes[i],
+                        dt.stat[fd].f_nhp_pkt[i],
+                        dt.stat[fd].f_nhp_bytes[i]
+                        );
+                strcat(buf, str);
+        }
+
+        pthread_mutex_unlock(&dt.stat[fd].lock);
+
+        return STAT_FILE_LEN;
+#else
+        (void) path;
+        (void) buf;
+        (void) len;
+        return 0;
+#endif
+}
+
+static int dt_stat_readdir(char *** buf)
+{
+#ifdef IPCP_FLOW_STATS
+        char   entry[RIB_PATH_LEN + 1];
+        size_t i;
+        int    idx = 0;
+
+        pthread_rwlock_rdlock(&dt.lock);
+
+        if (dt.n_flows < 1) {
+                pthread_rwlock_unlock(&dt.lock);
+                return 0;
+        }
+
+        *buf = malloc(sizeof(**buf) * dt.n_flows);
+        if (*buf == NULL) {
+                pthread_rwlock_unlock(&dt.lock);
+                return -ENOMEM;
+        }
+
+        for (i = 0; i < PROG_MAX_FLOWS; ++i) {
+                pthread_mutex_lock(&dt.stat[i].lock);
+
+                if (dt.stat[i].stamp == 0) {
+                        pthread_mutex_unlock(&dt.stat[i].lock);
+                        /* Optimization: skip unused res_fds. */
+                        if (i < PROG_RES_FDS)
+                                i = PROG_RES_FDS;
+                        continue;
+                }
+
+                sprintf(entry, "%zu", i);
+
+                (*buf)[idx] = malloc(strlen(entry) + 1);
+                if ((*buf)[idx] == NULL) {
+                        while (idx-- > 0)
+                                free((*buf)[idx]);
+                        free(buf);
+                        pthread_mutex_unlock(&dt.stat[i].lock);
+                        pthread_rwlock_unlock(&dt.lock);
+                        return -ENOMEM;
+                }
+
+                strcpy((*buf)[idx++], entry);
+
+                pthread_mutex_unlock(&dt.stat[i].lock);
+        }
+
+        pthread_rwlock_unlock(&dt.lock);
+
+        assert((size_t) idx == dt.n_flows);
+
+        return idx;
+#else
+        (void) buf;
+        return 0;
+#endif
+}
+
+static int dt_stat_getattr(const char *  path,
+                           struct stat * st)
+{
+#ifdef IPCP_FLOW_STATS
+        int fd;
+
+        fd = atoi(path);
+
+        st->st_mode  = S_IFREG | 0755;
+        st->st_nlink = 1;
+        st->st_uid   = getuid();
+        st->st_gid   = getgid();
+
+        pthread_mutex_lock(&dt.stat[fd].lock);
+
+        if (dt.stat[fd].stamp != -1) {
+                st->st_size  = STAT_FILE_LEN;
+                st->st_mtime = dt.stat[fd].stamp;
+        } else {
+                st->st_size  = 0;
+                st->st_mtime = 0;
+        }
+
+        pthread_mutex_unlock(&dt.stat[fd].lock);
+#else
+        (void) path;
+        (void) st;
+#endif
+        return 0;
+}
+
+static struct rib_ops r_ops = {
+        .read    = dt_stat_read,
+        .readdir = dt_stat_readdir,
+        .getattr = dt_stat_getattr
+};
+
+#ifdef IPCP_FLOW_STATS
+
+static void stat_used(int      fd,
+                      uint64_t addr)
+{
+        struct timespec now;
+
+        clock_gettime(CLOCK_REALTIME_COARSE, &now);
+
+        pthread_mutex_lock(&dt.stat[fd].lock);
+
+        memset(&dt.stat[fd], 0, sizeof(dt.stat[fd]));
+
+        dt.stat[fd].stamp = (addr != INVALID_ADDR) ? now.tv_sec : 0;
+        dt.stat[fd].addr = addr;
+
+        pthread_mutex_unlock(&dt.stat[fd].lock);
+
+        pthread_rwlock_wrlock(&dt.lock);
+
+        (addr != INVALID_ADDR) ? ++dt.n_flows : --dt.n_flows;
+
+        pthread_rwlock_unlock(&dt.lock);
+}
+#endif
+
+static void handle_event(void *       self,
+                         int          event,
+                         const void * o)
+{
+        struct conn * c;
+
+        (void) self;
+
+        c = (struct conn *) o;
+
+        switch (event) {
+        case NOTIFY_DT_CONN_ADD:
+#ifdef IPCP_FLOW_STATS
+                stat_used(c->flow_info.fd, c->conn_info.addr);
+#endif
+                psched_add(dt.psched, c->flow_info.fd);
+                log_dbg("Added fd %d to packet scheduler.", c->flow_info.fd);
+                break;
+        case NOTIFY_DT_CONN_DEL:
+#ifdef IPCP_FLOW_STATS
+                stat_used(c->flow_info.fd, INVALID_ADDR);
+#endif
+                psched_del(dt.psched, c->flow_info.fd);
+                log_dbg("Removed fd %d from "
+                        "packet scheduler.", c->flow_info.fd);
+                break;
+        default:
+                break;
+        }
+}
+
+static void packet_handler(int                  fd,
+                           qoscube_t            qc,
+                           struct shm_du_buff * sdb)
+{
+        struct dt_pci dt_pci;
+        int           ret;
+        int           ofd;
+#ifdef IPCP_FLOW_STATS
+        size_t        len;
+#else
+        (void)        fd;
+#endif
+
+#ifdef IPCP_FLOW_STATS
+        len = shm_du_buff_tail(sdb) - shm_du_buff_head(sdb);
+#endif
+        memset(&dt_pci, 0, sizeof(dt_pci));
+        dt_pci_des(sdb, &dt_pci);
+        if (dt_pci.dst_addr != ipcpi.dt_addr) {
+                if (dt_pci.ttl == 0) {
+                        log_dbg("TTL was zero.");
+                        ipcp_sdb_release(sdb);
+#ifdef IPCP_FLOW_STATS
+                        pthread_mutex_lock(&dt.stat[fd].lock);
+
+                        ++dt.stat[fd].rcv_pkt[qc];
+                        dt.stat[fd].rcv_bytes[qc] += len;
+                        ++dt.stat[fd].r_drp_pkt[qc];
+                        dt.stat[fd].r_drp_bytes[qc] += len;
+
+                        pthread_mutex_unlock(&dt.stat[fd].lock);
+#endif
+                        return;
+                }
+
+                /* FIXME: Use qoscube from PCI instead of incoming flow. */
+                ofd = pff_nhop(dt.pff[qc], dt_pci.dst_addr);
+                if (ofd < 0) {
+                        log_dbg("No next hop for %" PRIu64, dt_pci.dst_addr);
+                        ipcp_sdb_release(sdb);
+#ifdef IPCP_FLOW_STATS
+                        pthread_mutex_lock(&dt.stat[fd].lock);
+
+                        ++dt.stat[fd].rcv_pkt[qc];
+                        dt.stat[fd].rcv_bytes[qc] += len;
+                        ++dt.stat[fd].f_nhp_pkt[qc];
+                        dt.stat[fd].f_nhp_bytes[qc] += len;
+
+                        pthread_mutex_unlock(&dt.stat[fd].lock);
+#endif
+                        return;
+                }
+
+                ret = ipcp_flow_write(ofd, sdb);
+                if (ret < 0) {
+                        log_dbg("Failed to write packet to fd %d.", ofd);
+                        if (ret == -EFLOWDOWN)
+                                notifier_event(NOTIFY_DT_FLOW_DOWN, &ofd);
+                        ipcp_sdb_release(sdb);
+#ifdef IPCP_FLOW_STATS
+                        pthread_mutex_lock(&dt.stat[fd].lock);
+
+                        ++dt.stat[fd].rcv_pkt[qc];
+                        dt.stat[fd].rcv_bytes[qc] += len;
+
+                        pthread_mutex_unlock(&dt.stat[fd].lock);
+                        pthread_mutex_lock(&dt.stat[ofd].lock);
+
+                        ++dt.stat[ofd].w_drp_pkt[qc];
+                        dt.stat[ofd].w_drp_bytes[qc] += len;
+
+                        pthread_mutex_unlock(&dt.stat[ofd].lock);
+#endif
+                        return;
+                }
+#ifdef IPCP_FLOW_STATS
+                pthread_mutex_lock(&dt.stat[fd].lock);
+
+                ++dt.stat[fd].rcv_pkt[qc];
+                dt.stat[fd].rcv_bytes[qc] += len;
+
+                pthread_mutex_unlock(&dt.stat[fd].lock);
+                pthread_mutex_lock(&dt.stat[ofd].lock);
+
+                ++dt.stat[ofd].snd_pkt[qc];
+                dt.stat[ofd].snd_bytes[qc] += len;
+
+                pthread_mutex_unlock(&dt.stat[ofd].lock);
+#endif
+        } else {
+                dt_pci_shrink(sdb);
+                if (dt_pci.eid >= PROG_RES_FDS) {
+                        if (ipcp_flow_write(dt_pci.eid, sdb)) {
+                                ipcp_sdb_release(sdb);
+#ifdef IPCP_FLOW_STATS
+                                pthread_mutex_lock(&dt.stat[fd].lock);
+                                ++dt.stat[fd].rcv_pkt[qc];
+                                dt.stat[fd].rcv_bytes[qc] += len;
+                                pthread_mutex_unlock(&dt.stat[fd].lock);
+
+                                pthread_mutex_lock(&dt.stat[dt_pci.eid].lock);
+                                ++dt.stat[dt_pci.eid].w_drp_pkt[qc];
+                                dt.stat[dt_pci.eid].w_drp_bytes[qc] += len;
+                                pthread_mutex_unlock(&dt.stat[dt_pci.eid].lock);
+#endif
+
+                        }
+#ifdef IPCP_FLOW_STATS
+                        pthread_mutex_lock(&dt.stat[fd].lock);
+
+                        ++dt.stat[fd].rcv_pkt[qc];
+                        dt.stat[fd].rcv_bytes[qc] += len;
+
+                        pthread_mutex_unlock(&dt.stat[fd].lock);
+                        pthread_mutex_lock(&dt.stat[dt_pci.eid].lock);
+
+                        ++dt.stat[dt_pci.eid].rcv_pkt[qc];
+                        dt.stat[dt_pci.eid].rcv_bytes[qc] += len;
+                        ++dt.stat[dt_pci.eid].lcl_r_pkt[qc];
+                        dt.stat[dt_pci.eid].lcl_r_bytes[qc] += len;
+
+                        pthread_mutex_unlock(&dt.stat[dt_pci.eid].lock);
+#endif
+                        return;
+                }
+
+                if (dt.comps[dt_pci.eid].post_packet == NULL) {
+                        log_err("No registered component on eid %d.",
+                                dt_pci.eid);
+                        ipcp_sdb_release(sdb);
+#ifdef IPCP_FLOW_STATS
+                        pthread_mutex_lock(&dt.stat[fd].lock);
+
+                        ++dt.stat[fd].rcv_pkt[qc];
+                        dt.stat[fd].rcv_bytes[qc] += len;
+
+                        pthread_mutex_unlock(&dt.stat[fd].lock);
+                        pthread_mutex_lock(&dt.stat[dt_pci.eid].lock);
+
+                        ++dt.stat[dt_pci.eid].w_drp_pkt[qc];
+                        dt.stat[dt_pci.eid].w_drp_bytes[qc] += len;
+
+                        pthread_mutex_unlock(&dt.stat[dt_pci.eid].lock);
+#endif
+                        return;
+                }
+#ifdef IPCP_FLOW_STATS
+                pthread_mutex_lock(&dt.stat[fd].lock);
+
+                ++dt.stat[fd].rcv_pkt[qc];
+                dt.stat[fd].rcv_bytes[qc] += len;
+                ++dt.stat[fd].lcl_r_pkt[qc];
+                dt.stat[fd].lcl_r_bytes[qc] += len;
+
+                pthread_mutex_unlock(&dt.stat[fd].lock);
+                pthread_mutex_lock(&dt.stat[dt_pci.eid].lock);
+
+                ++dt.stat[dt_pci.eid].snd_pkt[qc];
+                dt.stat[dt_pci.eid].snd_bytes[qc] += len;
+
+                pthread_mutex_unlock(&dt.stat[dt_pci.eid].lock);
+#endif
+                dt.comps[dt_pci.eid].post_packet(dt.comps[dt_pci.eid].comp,
+                                                 sdb);
+        }
+}
+
+static void * dt_conn_handle(void * o)
+{
+        struct conn conn;
+
+        (void) o;
+
+        while (true) {
+                if (connmgr_wait(COMPID_DT, &conn)) {
+                        log_err("Failed to get next DT connection.");
+                        continue;
+                }
+
+                /* NOTE: connection acceptance policy could be here. */
+
+                notifier_event(NOTIFY_DT_CONN_ADD, &conn);
+        }
+
+        return 0;
+}
+
+int dt_init(enum pol_routing pr,
+            enum pol_pff     pp,
+            uint8_t          addr_size,
+            uint8_t          eid_size,
+            uint8_t          max_ttl)
+{
+        int              i;
+        int              j;
+        char             dtstr[256];
+        struct conn_info info;
+
+        memset(&info, 0, sizeof(info));
+
+        strcpy(info.comp_name, DT_COMP);
+        strcpy(info.protocol, DT_PROTO);
+        info.pref_version = 1;
+        info.pref_syntax  = PROTO_FIXED;
+        info.addr         = ipcpi.dt_addr;
+
+        dt_pci_info.addr_size = addr_size;
+        dt_pci_info.eid_size  = eid_size;
+        dt_pci_info.max_ttl   = max_ttl;
+
+        dt_pci_info.qc_o      = dt_pci_info.addr_size;
+        dt_pci_info.ttl_o     = dt_pci_info.qc_o + QOS_LEN;
+        dt_pci_info.ecn_o     = dt_pci_info.ttl_o + TTL_LEN;
+        dt_pci_info.eid_o     = dt_pci_info.ecn_o + ECN_LEN;
+        dt_pci_info.head_size = dt_pci_info.eid_o + dt_pci_info.eid_size;
+
+        if (notifier_reg(handle_event, NULL)) {
+                log_err("Failed to register with notifier.");
+                goto fail_notifier_reg;
+        }
+
+        if (connmgr_comp_init(COMPID_DT, &info)) {
+                log_err("Failed to register with connmgr.");
+                goto fail_connmgr_comp_init;
+        }
+
+        if (routing_init(pr)) {
+                log_err("Failed to init routing.");
+                goto fail_routing;
+        }
+
+        for (i = 0; i < QOS_CUBE_MAX; ++i) {
+                dt.pff[i] = pff_create(pp);
+                if (dt.pff[i] == NULL) {
+                        log_err("Failed to create a PFF.");
+                        for (j = 0; j < i; ++j)
+                                pff_destroy(dt.pff[j]);
+                        goto fail_pff;
+                }
+        }
+
+        for (i = 0; i < QOS_CUBE_MAX; ++i) {
+                dt.routing[i] = routing_i_create(dt.pff[i]);
+                if (dt.routing[i] == NULL) {
+                        for (j = 0; j < i; ++j)
+                                routing_i_destroy(dt.routing[j]);
+                        goto fail_routing_i;
+                }
+        }
+
+        if (pthread_rwlock_init(&dt.lock, NULL)) {
+                log_err("Failed to init rwlock.");
+                goto fail_rwlock_init;
+        }
+
+        dt.res_fds = bmp_create(PROG_RES_FDS, 0);
+        if (dt.res_fds == NULL)
+                goto fail_res_fds;
+#ifdef IPCP_FLOW_STATS
+        memset(dt.stat, 0, sizeof(dt.stat));
+
+        for (i = 0; i < PROG_MAX_FLOWS; ++i)
+                if (pthread_mutex_init(&dt.stat[i].lock, NULL)) {
+                        for (j = 0; j < i; ++j)
+                                pthread_mutex_destroy(&dt.stat[j].lock);
+                        goto fail_stat_lock;
+                }
+
+        dt.n_flows = 0;
+#endif
+        sprintf(dtstr, "%s.%" PRIu64, DT, ipcpi.dt_addr);
+        if (rib_reg(dtstr, &r_ops))
+                goto fail_rib_reg;
+
+        return 0;
+
+ fail_rib_reg:
+#ifdef IPCP_FLOW_STATS
+        for (i = 0; i < PROG_MAX_FLOWS; ++i)
+                pthread_mutex_destroy(&dt.stat[i].lock);
+ fail_stat_lock:
+#endif
+        bmp_destroy(dt.res_fds);
+ fail_res_fds:
+        pthread_rwlock_destroy(&dt.lock);
+ fail_rwlock_init:
+        for (j = 0; j < QOS_CUBE_MAX; ++j)
+                routing_i_destroy(dt.routing[j]);
+ fail_routing_i:
+        for (i = 0; i < QOS_CUBE_MAX; ++i)
+                pff_destroy(dt.pff[i]);
+ fail_pff:
+        routing_fini();
+ fail_routing:
+        connmgr_comp_fini(COMPID_DT);
+ fail_connmgr_comp_init:
+        notifier_unreg(&handle_event);
+ fail_notifier_reg:
+        return -1;
+}
+
+void dt_fini(void)
+{
+        int i;
+
+        rib_unreg(DT);
+#ifdef IPCP_FLOW_STATS
+        for (i = 0; i < PROG_MAX_FLOWS; ++i)
+                pthread_mutex_destroy(&dt.stat[i].lock);
+#endif
+        bmp_destroy(dt.res_fds);
+
+        pthread_rwlock_destroy(&dt.lock);
+
+        for (i = 0; i < QOS_CUBE_MAX; ++i)
+                routing_i_destroy(dt.routing[i]);
+
+        for (i = 0; i < QOS_CUBE_MAX; ++i)
+                pff_destroy(dt.pff[i]);
+
+        routing_fini();
+
+        connmgr_comp_fini(COMPID_DT);
+
+        notifier_unreg(&handle_event);
+}
+
+int dt_start(void)
+{
+        dt.psched = psched_create(packet_handler);
+        if (dt.psched == NULL) {
+                log_err("Failed to create N-1 packet scheduler.");
+                return -1;
+        }
+
+        if (pthread_create(&dt.listener, NULL, dt_conn_handle, NULL)) {
+                log_err("Failed to create listener thread.");
+                psched_destroy(dt.psched);
+                return -1;
+        }
+
+        return 0;
+}
+
+void dt_stop(void)
+{
+        pthread_cancel(dt.listener);
+        pthread_join(dt.listener, NULL);
+        psched_destroy(dt.psched);
+}
+
+int dt_reg_comp(void * comp,
+                void (* func)(void * func, struct shm_du_buff *),
+                char * name)
+{
+        int res_fd;
+
+        assert(func);
+
+        pthread_rwlock_wrlock(&dt.lock);
+
+        res_fd = bmp_allocate(dt.res_fds);
+        if (!bmp_is_id_valid(dt.res_fds, res_fd)) {
+                log_warn("Reserved fds depleted.");
+                pthread_rwlock_unlock(&dt.lock);
+                return -EBADF;
+        }
+
+        assert(dt.comps[res_fd].post_packet == NULL);
+        assert(dt.comps[res_fd].comp == NULL);
+        assert(dt.comps[res_fd].name == NULL);
+
+        dt.comps[res_fd].post_packet = func;
+        dt.comps[res_fd].comp     = comp;
+        dt.comps[res_fd].name     = name;
+
+        pthread_rwlock_unlock(&dt.lock);
+#ifdef IPCP_FLOW_STATS
+        stat_used(res_fd, ipcpi.dt_addr);
+#endif
+        return res_fd;
+}
+
+int dt_write_packet(uint64_t             dst_addr,
+                    qoscube_t            qc,
+                    int                  np1_fd,
+                    struct shm_du_buff * sdb)
+{
+        int           fd;
+        struct dt_pci dt_pci;
+        int           ret;
+#ifdef IPCP_FLOW_STATS
+        size_t        len;
+#endif
+        assert(sdb);
+        assert(dst_addr != ipcpi.dt_addr);
+
+        fd = pff_nhop(dt.pff[qc], dst_addr);
+        if (fd < 0) {
+                log_dbg("Could not get nhop for addr %" PRIu64 ".", dst_addr);
+#ifdef IPCP_FLOW_STATS
+                len = shm_du_buff_tail(sdb) - shm_du_buff_head(sdb);
+
+                pthread_mutex_lock(&dt.stat[np1_fd].lock);
+
+                ++dt.stat[np1_fd].lcl_r_pkt[qc];
+                dt.stat[np1_fd].lcl_r_bytes[qc] += len;
+                ++dt.stat[np1_fd].f_nhp_pkt[qc];
+                dt.stat[np1_fd].f_nhp_bytes[qc] += len;
+
+                pthread_mutex_unlock(&dt.stat[np1_fd].lock);
+#endif
+                return -1;
+        }
+
+        dt_pci.dst_addr = dst_addr;
+        dt_pci.qc       = qc;
+        dt_pci.eid      = np1_fd;
+        dt_pci.ecn      = 0;
+
+        if (dt_pci_ser(sdb, &dt_pci)) {
+                log_dbg("Failed to serialize PDU.");
+#ifdef IPCP_FLOW_STATS
+                len = shm_du_buff_tail(sdb) - shm_du_buff_head(sdb);
+#endif
+                goto fail_write;
+        }
+#ifdef IPCP_FLOW_STATS
+        len = shm_du_buff_tail(sdb) - shm_du_buff_head(sdb);
+#endif
+        ret = ipcp_flow_write(fd, sdb);
+        if (ret < 0) {
+                log_dbg("Failed to write packet to fd %d.", fd);
+                if (ret == -EFLOWDOWN)
+                        notifier_event(NOTIFY_DT_FLOW_DOWN, &fd);
+                goto fail_write;
+        }
+#ifdef IPCP_FLOW_STATS
+        pthread_mutex_lock(&dt.stat[np1_fd].lock);
+
+        ++dt.stat[np1_fd].lcl_r_pkt[qc];
+        dt.stat[np1_fd].lcl_r_bytes[qc] += len;
+
+        pthread_mutex_unlock(&dt.stat[np1_fd].lock);
+        pthread_mutex_lock(&dt.stat[fd].lock);
+
+        if (dt_pci.eid < PROG_RES_FDS) {
+                ++dt.stat[fd].lcl_w_pkt[qc];
+                dt.stat[fd].lcl_w_bytes[qc] += len;
+        }
+        ++dt.stat[fd].snd_pkt[qc];
+        dt.stat[fd].snd_bytes[qc] += len;
+
+        pthread_mutex_unlock(&dt.stat[fd].lock);
+#endif
+        return 0;
+
+ fail_write:
+#ifdef IPCP_FLOW_STATS
+        pthread_mutex_lock(&dt.stat[np1_fd].lock);
+
+        ++dt.stat[np1_fd].lcl_w_pkt[qc];
+        dt.stat[np1_fd].lcl_w_bytes[qc] += len;
+
+        pthread_mutex_unlock(&dt.stat[np1_fd].lock);
+        pthread_mutex_lock(&dt.stat[fd].lock);
+
+        if (dt_pci.eid < PROG_RES_FDS) {
+                ++dt.stat[fd].lcl_w_pkt[qc];
+                dt.stat[fd].lcl_w_bytes[qc] += len;
+        }
+        ++dt.stat[fd].w_drp_pkt[qc];
+        dt.stat[fd].w_drp_bytes[qc] += len;
+
+        pthread_mutex_unlock(&dt.stat[fd].lock);
+#endif
+        return -1;
+}
diff --git a/src/ipcpd/unicast/dt.h b/src/ipcpd/unicast/dt.h
new file mode 100644
index 00000000..5f2ee1a5
--- /dev/null
+++ b/src/ipcpd/unicast/dt.h
@@ -0,0 +1,56 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Data Transfer component
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#ifndef OUROBOROS_IPCPD_UNICAST_DT_H
+#define OUROBOROS_IPCPD_UNICAST_DT_H
+
+#include <ouroboros/ipcp.h>
+#include <ouroboros/qoscube.h>
+#include <ouroboros/shm_rdrbuff.h>
+
+#define DT_COMP      "Data Transfer"
+#define DT_PROTO     "dtp"
+#define INVALID_ADDR 0
+
+int  dt_init(enum pol_routing pr,
+             enum pol_pff     pp,
+             uint8_t          addr_size,
+             uint8_t          eid_size,
+             uint8_t          max_ttl
+);
+
+void dt_fini(void);
+
+int  dt_start(void);
+
+void dt_stop(void);
+
+int  dt_reg_comp(void * comp,
+                 void (* func)(void * comp, struct shm_du_buff * sdb),
+                 char * name);
+
+int  dt_write_packet(uint64_t             dst_addr,
+                     qoscube_t            qc,
+                     int                  res_fd,
+                     struct shm_du_buff * sdb);
+
+#endif /* OUROBOROS_IPCPD_UNICAST_DT_H */
diff --git a/src/ipcpd/unicast/enroll.c b/src/ipcpd/unicast/enroll.c
new file mode 100644
index 00000000..b572f89d
--- /dev/null
+++ b/src/ipcpd/unicast/enroll.c
@@ -0,0 +1,382 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Enrollment Task
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#if defined(__linux__) || defined(__CYGWIN__)
+#define _DEFAULT_SOURCE
+#else
+#define _POSIX_C_SOURCE 199309L
+#endif
+
+#define OUROBOROS_PREFIX "enrollment"
+
+#include <ouroboros/endian.h>
+#include <ouroboros/errno.h>
+#include <ouroboros/time_utils.h>
+#include <ouroboros/dev.h>
+#include <ouroboros/logs.h>
+#include <ouroboros/errno.h>
+#include <ouroboros/sockets.h>
+
+#include "connmgr.h"
+#include "enroll.h"
+#include "ipcp.h"
+
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+#include <pthread.h>
+
+#include "ipcp_config.pb-c.h"
+typedef EnrollMsg enroll_msg_t;
+
+#define ENROLL_COMP             "Enrollment"
+#define ENROLL_PROTO            "OEP" /* Ouroboros enrollment protocol */
+#define ENROLL_WARN_TIME_OFFSET 20
+#define ENROLL_BUF_LEN          1024
+
+enum enroll_state {
+        ENROLL_NULL = 0,
+        ENROLL_INIT,
+        ENROLL_RUNNING
+};
+
+struct {
+        struct ipcp_config conf;
+        enum enroll_state  state;
+        pthread_t          listener;
+} enroll;
+
+static int send_rcv_enroll_msg(int fd)
+{
+        enroll_msg_t    req = ENROLL_MSG__INIT;
+        enroll_msg_t *  reply;
+        uint8_t         buf[ENROLL_BUF_LEN];
+        ssize_t         len;
+        ssize_t         delta_t;
+        struct timespec t0;
+        struct timespec rtt;
+
+        req.code = ENROLL_CODE__ENROLL_REQ;
+
+        len = enroll_msg__get_packed_size(&req);
+        if (len < 0) {
+                log_dbg("Failed pack request message.");
+                return -1;
+        }
+
+        enroll_msg__pack(&req, buf);
+
+        clock_gettime(CLOCK_REALTIME, &t0);
+
+        if (flow_write(fd, buf, len)) {
+                log_dbg("Failed to send request message.");
+                return -1;
+        }
+
+        len = flow_read(fd, buf, ENROLL_BUF_LEN);
+        if (len < 0) {
+                log_dbg("No enrollment reply received.");
+                return -1;
+        }
+
+        log_dbg("Received enrollment info (%zd bytes).", len);
+
+        reply = enroll_msg__unpack(NULL, len, buf);
+        if (reply == NULL) {
+                log_dbg("No enrollment response.");
+                return -1;
+        }
+
+        if (reply->code != ENROLL_CODE__ENROLL_BOOT) {
+                log_dbg("Failed to unpack enrollment response.");
+                enroll_msg__free_unpacked(reply, NULL);
+                return -1;
+        }
+
+        if (!(reply->has_t_sec && reply->has_t_nsec)) {
+                log_dbg("No time in response message.");
+                enroll_msg__free_unpacked(reply, NULL);
+                return -1;
+        }
+
+        clock_gettime(CLOCK_REALTIME, &rtt);
+
+        delta_t = ts_diff_ms(&t0, &rtt);
+
+        rtt.tv_sec  = reply->t_sec;
+        rtt.tv_nsec = reply->t_nsec;
+
+        if (labs(ts_diff_ms(&t0, &rtt)) - delta_t > ENROLL_WARN_TIME_OFFSET)
+                log_warn("Clock offset above threshold.");
+
+        strcpy(enroll.conf.layer_info.layer_name,
+               reply->conf->layer_info->layer_name);
+        enroll.conf.type           = reply->conf->ipcp_type;
+        enroll.conf.addr_size      = reply->conf->addr_size;
+        enroll.conf.eid_size       = reply->conf->eid_size;
+        enroll.conf.max_ttl        = reply->conf->max_ttl;
+        enroll.conf.addr_auth_type = reply->conf->addr_auth_type;
+        enroll.conf.routing_type   = reply->conf->routing_type;
+        enroll.conf.pff_type       = reply->conf->pff_type;
+        enroll.conf.layer_info.dir_hash_algo
+                = reply->conf->layer_info->dir_hash_algo;
+
+        enroll_msg__free_unpacked(reply, NULL);
+
+        return 0;
+}
+
+static ssize_t enroll_pack(uint8_t ** buf)
+{
+        enroll_msg_t      msg        = ENROLL_MSG__INIT;
+        ipcp_config_msg_t config     = IPCP_CONFIG_MSG__INIT;
+        layer_info_msg_t  layer_info = LAYER_INFO_MSG__INIT;
+        struct timespec   now;
+        ssize_t           len;
+
+        clock_gettime(CLOCK_REALTIME, &now);
+
+        msg.code       = ENROLL_CODE__ENROLL_BOOT;
+        msg.has_t_sec  = true;
+        msg.t_sec      = now.tv_sec;
+        msg.has_t_nsec = true;
+        msg.t_nsec     = now.tv_nsec;
+        msg.conf       = &config;
+
+        config.ipcp_type          = enroll.conf.type;
+        config.has_addr_size      = true;
+        config.addr_size          = enroll.conf.addr_size;
+        config.has_eid_size       = true;
+        config.eid_size           = enroll.conf.eid_size;
+        config.has_max_ttl        = true;
+        config.max_ttl            = enroll.conf.max_ttl;
+        config.has_addr_auth_type = true;
+        config.addr_auth_type     = enroll.conf.addr_auth_type;
+        config.has_routing_type   = true;
+        config.routing_type       = enroll.conf.routing_type;
+        config.has_pff_type       = true;
+        config.pff_type           = enroll.conf.pff_type;
+        config.layer_info         = &layer_info;
+
+        layer_info.layer_name     = (char *) enroll.conf.layer_info.layer_name;
+        layer_info.dir_hash_algo  = enroll.conf.layer_info.dir_hash_algo;
+
+        len = enroll_msg__get_packed_size(&msg);
+
+        *buf = malloc(len);
+        if (*buf == NULL)
+                return -1;
+
+        enroll_msg__pack(&msg, *buf);
+
+        return len;
+}
+
+static void * enroll_handle(void * o)
+{
+        struct conn    conn;
+        uint8_t        buf[ENROLL_BUF_LEN];
+        uint8_t *      reply;
+        ssize_t        len;
+        enroll_msg_t * msg;
+
+        (void) o;
+
+        while (true) {
+                if (connmgr_wait(COMPID_ENROLL, &conn)) {
+                        log_err("Failed to get next connection.");
+                        continue;
+                }
+
+                len = flow_read(conn.flow_info.fd, buf, ENROLL_BUF_LEN);
+                if (len < 0) {
+                        log_err("Failed to read from flow.");
+                        connmgr_dealloc(COMPID_ENROLL, &conn);
+                        continue;
+                }
+
+                msg = enroll_msg__unpack(NULL, len, buf);
+                if (msg == NULL) {
+                        log_err("Failed to unpack message.");
+                        connmgr_dealloc(COMPID_ENROLL, &conn);
+                        continue;
+                }
+
+                if (msg->code != ENROLL_CODE__ENROLL_REQ) {
+                        log_err("Wrong message type.");
+                        connmgr_dealloc(COMPID_ENROLL, &conn);
+                        enroll_msg__free_unpacked(msg, NULL);
+                        continue;
+                }
+
+                log_dbg("Enrolling a new neighbor.");
+
+                enroll_msg__free_unpacked(msg, NULL);
+
+                len = enroll_pack(&reply);
+                if (reply == NULL) {
+                        log_err("Failed to pack enrollment message.");
+                        connmgr_dealloc(COMPID_ENROLL, &conn);
+                        continue;
+                }
+
+                log_dbg("Sending enrollment info (%zd bytes).", len);
+
+                if (flow_write(conn.flow_info.fd, reply, len)) {
+                        log_err("Failed respond to enrollment request.");
+                        connmgr_dealloc(COMPID_ENROLL, &conn);
+                        free(reply);
+                        continue;
+                }
+
+                free(reply);
+
+                len = flow_read(conn.flow_info.fd, buf, ENROLL_BUF_LEN);
+                if (len < 0) {
+                        log_err("Failed to read from flow.");
+                        connmgr_dealloc(COMPID_ENROLL, &conn);
+                        continue;
+                }
+
+                msg = enroll_msg__unpack(NULL, len, buf);
+                if (msg == NULL) {
+                        log_err("Failed to unpack message.");
+                        connmgr_dealloc(COMPID_ENROLL, &conn);
+                        continue;
+                }
+
+                if (msg->code != ENROLL_CODE__ENROLL_DONE || !msg->has_result) {
+                        log_err("Wrong message type.");
+                        enroll_msg__free_unpacked(msg, NULL);
+                        connmgr_dealloc(COMPID_ENROLL, &conn);
+                        continue;
+                }
+
+                if (msg->result == 0)
+                        log_dbg("Neighbor enrollment successful.");
+                else
+                        log_dbg("Neigbor reported failed enrollment.");
+
+                enroll_msg__free_unpacked(msg, NULL);
+
+                connmgr_dealloc(COMPID_ENROLL, &conn);
+        }
+
+        return 0;
+}
+
+int enroll_boot(struct conn * conn)
+{
+        log_dbg("Getting boot information.");
+
+        if (send_rcv_enroll_msg(conn->flow_info.fd)) {
+                log_err("Failed to enroll.");
+                return -1;
+        }
+
+        return 0;
+}
+
+int enroll_done(struct conn * conn,
+                int           result)
+{
+        enroll_msg_t msg = ENROLL_MSG__INIT;
+        uint8_t      buf[ENROLL_BUF_LEN];
+        ssize_t       len;
+
+        msg.code       = ENROLL_CODE__ENROLL_DONE;
+        msg.has_result = true;
+        msg.result     = result;
+
+        len = enroll_msg__get_packed_size(&msg);
+        if (len < 0) {
+                log_dbg("Failed pack request message.");
+                return -1;
+        }
+
+        enroll_msg__pack(&msg, buf);
+
+        if (flow_write(conn->flow_info.fd, buf, len)) {
+                log_dbg("Failed to send acknowledgment.");
+                return -1;
+        }
+
+        return 0;
+}
+
+void enroll_bootstrap(const struct ipcp_config * conf)
+{
+        assert(conf);
+
+        memcpy(&enroll.conf, conf, sizeof(enroll.conf));
+}
+
+struct ipcp_config * enroll_get_conf(void)
+{
+        return &enroll.conf;
+}
+
+int enroll_init(void)
+{
+        struct conn_info info;
+
+        memset(&info, 0, sizeof(info));
+
+        strcpy(info.comp_name, ENROLL_COMP);
+        strcpy(info.protocol, ENROLL_PROTO);
+        info.pref_version = 1;
+        info.pref_syntax  = PROTO_GPB;
+        info.addr         = 0;
+
+        if (connmgr_comp_init(COMPID_ENROLL, &info)) {
+                log_err("Failed to register with connmgr.");
+                return -1;
+        }
+
+        enroll.state = ENROLL_INIT;
+
+        return 0;
+}
+
+void enroll_fini(void)
+{
+        if (enroll.state == ENROLL_RUNNING)
+                pthread_join(enroll.listener, NULL);
+
+        connmgr_comp_fini(COMPID_ENROLL);
+}
+
+int enroll_start(void)
+{
+        if (pthread_create(&enroll.listener, NULL, enroll_handle, NULL))
+                return -1;
+
+        enroll.state = ENROLL_RUNNING;
+
+        return 0;
+}
+
+void enroll_stop(void)
+{
+        if (enroll.state == ENROLL_RUNNING)
+                pthread_cancel(enroll.listener);
+}
diff --git a/src/ipcpd/unicast/enroll.h b/src/ipcpd/unicast/enroll.h
new file mode 100644
index 00000000..0a1ce5fc
--- /dev/null
+++ b/src/ipcpd/unicast/enroll.h
@@ -0,0 +1,47 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Enrollment Task
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#ifndef OUROBOROS_IPCPD_UNICAST_ENROLL_H
+#define OUROBOROS_IPCPD_UNICAST_ENROLL_H
+
+#include <ouroboros/ipcp.h>
+
+#include "comp.h"
+
+int                  enroll_init(void);
+
+void                 enroll_fini(void);
+
+int                  enroll_start(void);
+
+void                 enroll_stop(void);
+
+void                 enroll_bootstrap(const struct ipcp_config * conf);
+
+int                  enroll_boot(struct conn * conn);
+
+int                  enroll_done(struct conn * conn,
+                                 int           result);
+
+struct ipcp_config * enroll_get_conf(void);
+
+#endif /* OUROBOROS_IPCPD_UNICAST_ENROLL_H */
diff --git a/src/ipcpd/unicast/fa.c b/src/ipcpd/unicast/fa.c
new file mode 100644
index 00000000..fbcbc6fa
--- /dev/null
+++ b/src/ipcpd/unicast/fa.c
@@ -0,0 +1,491 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Flow allocator of the IPC Process
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#if defined(__linux__) || defined(__CYGWIN__)
+#define _DEFAULT_SOURCE
+#else
+#define _POSIX_C_SOURCE 200112L
+#endif
+
+#include "config.h"
+
+#define FA               "flow-allocator"
+#define OUROBOROS_PREFIX FA
+
+#include <ouroboros/logs.h>
+#include <ouroboros/fqueue.h>
+#include <ouroboros/errno.h>
+#include <ouroboros/dev.h>
+#include <ouroboros/ipcp-dev.h>
+
+#include "dir.h"
+#include "fa.h"
+#include "psched.h"
+#include "ipcp.h"
+#include "dt.h"
+
+#include <pthread.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define TIMEOUT 10000 /* nanoseconds */
+
+#define FLOW_REQ   0
+#define FLOW_REPLY 1
+
+struct fa_msg {
+        uint64_t s_addr;
+        uint32_t r_eid;
+        uint32_t s_eid;
+        uint8_t  code;
+        int8_t   response;
+        /* QoS parameters from spec, aligned */
+        uint8_t  availability;
+        uint8_t  in_order;
+        uint32_t delay;
+        uint64_t bandwidth;
+        uint32_t loss;
+        uint32_t ber;
+        uint32_t max_gap;
+} __attribute__((packed));
+
+struct cmd {
+        struct list_head     next;
+        struct shm_du_buff * sdb;
+};
+
+struct {
+        pthread_rwlock_t flows_lock;
+        int              r_eid[PROG_MAX_FLOWS];
+        uint64_t         r_addr[PROG_MAX_FLOWS];
+        int              fd;
+
+        struct list_head cmds;
+        pthread_cond_t   cond;
+        pthread_mutex_t  mtx;
+        pthread_t        worker;
+
+        struct psched *  psched;
+} fa;
+
+static void packet_handler(int                  fd,
+                           qoscube_t            qc,
+                           struct shm_du_buff * sdb)
+{
+        pthread_rwlock_rdlock(&fa.flows_lock);
+
+        if (dt_write_packet(fa.r_addr[fd], qc, fa.r_eid[fd], sdb)) {
+                pthread_rwlock_unlock(&fa.flows_lock);
+                ipcp_sdb_release(sdb);
+                log_warn("Failed to forward packet.");
+                return;
+        }
+
+        pthread_rwlock_unlock(&fa.flows_lock);
+}
+
+static void destroy_conn(int fd)
+{
+        fa.r_eid[fd]   = -1;
+        fa.r_addr[fd] = INVALID_ADDR;
+}
+
+static void fa_post_packet(void *               comp,
+                           struct shm_du_buff * sdb)
+{
+        struct cmd * cmd;
+
+        assert(comp == &fa);
+
+        (void) comp;
+
+        cmd = malloc(sizeof(*cmd));
+        if (cmd == NULL) {
+                log_err("Command failed. Out of memory.");
+                ipcp_sdb_release(sdb);
+                return;
+        }
+
+        cmd->sdb = sdb;
+
+        pthread_mutex_lock(&fa.mtx);
+
+        list_add(&cmd->next, &fa.cmds);
+
+        pthread_cond_signal(&fa.cond);
+
+        pthread_mutex_unlock(&fa.mtx);
+}
+
+static void * fa_handle_packet(void * o)
+{
+        struct timespec ts  = {0, TIMEOUT * 1000};
+
+        (void) o;
+
+        while (true) {
+                struct timespec abstime;
+                int             fd;
+                uint8_t *       buf;
+                struct fa_msg * msg;
+                qosspec_t       qs;
+                struct cmd *    cmd;
+
+                pthread_mutex_lock(&fa.mtx);
+
+                pthread_cleanup_push((void (*)(void *)) pthread_mutex_unlock,
+                                     &fa.mtx);
+
+                while (list_is_empty(&fa.cmds))
+                        pthread_cond_wait(&fa.cond, &fa.mtx);
+
+                cmd = list_last_entry(&fa.cmds, struct cmd, next);
+                list_del(&cmd->next);
+
+                pthread_cleanup_pop(true);
+
+                buf = malloc(sizeof(*msg) + ipcp_dir_hash_len());
+                if (buf == NULL) {
+                        log_err("Failed to allocate memory.");
+                        ipcp_sdb_release(cmd->sdb);
+                        free(cmd);
+                        continue;
+                }
+
+                msg = (struct fa_msg *) buf;
+
+                /* Depending on the message call the function in ipcp-dev.h */
+
+                assert(sizeof(*msg) + ipcp_dir_hash_len() >=
+                       (unsigned long int) (shm_du_buff_tail(cmd->sdb) -
+                                            shm_du_buff_head(cmd->sdb)));
+
+                memcpy(msg, shm_du_buff_head(cmd->sdb),
+                       shm_du_buff_tail(cmd->sdb) - shm_du_buff_head(cmd->sdb));
+
+                ipcp_sdb_release(cmd->sdb);
+
+                free(cmd);
+
+                switch (msg->code) {
+                case FLOW_REQ:
+                        clock_gettime(PTHREAD_COND_CLOCK, &abstime);
+
+                        pthread_mutex_lock(&ipcpi.alloc_lock);
+
+                        while (ipcpi.alloc_id != -1 &&
+                               ipcp_get_state() == IPCP_OPERATIONAL) {
+                                ts_add(&abstime, &ts, &abstime);
+                                pthread_cond_timedwait(&ipcpi.alloc_cond,
+                                                       &ipcpi.alloc_lock,
+                                                       &abstime);
+                        }
+
+                        if (ipcp_get_state() != IPCP_OPERATIONAL) {
+                                pthread_mutex_unlock(&ipcpi.alloc_lock);
+                                log_dbg("Won't allocate over non-operational"
+                                        "IPCP.");
+                                free(msg);
+                                continue;
+                        }
+
+                        assert(ipcpi.alloc_id == -1);
+
+                        qs.delay        = ntoh32(msg->delay);
+                        qs.bandwidth    = ntoh64(msg->bandwidth);
+                        qs.availability = msg->availability;
+                        qs.loss         = ntoh32(msg->loss);
+                        qs.ber          = ntoh32(msg->ber);
+                        qs.in_order     = msg->in_order;
+                        qs.max_gap      = ntoh32(msg->max_gap);
+
+                        fd = ipcp_flow_req_arr((uint8_t *) (msg + 1),
+                                               ipcp_dir_hash_len(),
+                                               qs);
+                        if (fd < 0) {
+                                pthread_mutex_unlock(&ipcpi.alloc_lock);
+                                log_err("Failed to get fd for flow.");
+                                free(msg);
+                                continue;
+                        }
+
+                        pthread_rwlock_wrlock(&fa.flows_lock);
+
+                        fa.r_eid[fd]  = ntoh32(msg->s_eid);
+                        fa.r_addr[fd] = ntoh64(msg->s_addr);
+
+                        pthread_rwlock_unlock(&fa.flows_lock);
+
+                        ipcpi.alloc_id = fd;
+                        pthread_cond_broadcast(&ipcpi.alloc_cond);
+
+                        pthread_mutex_unlock(&ipcpi.alloc_lock);
+
+                        break;
+                case FLOW_REPLY:
+                        pthread_rwlock_wrlock(&fa.flows_lock);
+
+                        fa.r_eid[ntoh32(msg->r_eid)] = ntoh32(msg->s_eid);
+
+                        ipcp_flow_alloc_reply(ntoh32(msg->r_eid),
+                                              msg->response);
+
+                        if (msg->response < 0)
+                                destroy_conn(ntoh32(msg->r_eid));
+                        else
+                                psched_add(fa.psched, ntoh32(msg->r_eid));
+
+                        pthread_rwlock_unlock(&fa.flows_lock);
+
+                        break;
+                default:
+                        log_err("Got an unknown flow allocation message.");
+                        break;
+                }
+
+                free(msg);
+        }
+}
+
+int fa_init(void)
+{
+        int i;
+
+        for (i = 0; i < PROG_MAX_FLOWS; ++i)
+                destroy_conn(i);
+
+        if (pthread_rwlock_init(&fa.flows_lock, NULL))
+                goto fail_rwlock;
+
+        if (pthread_mutex_init(&fa.mtx, NULL))
+                goto fail_mtx;
+
+        if (pthread_cond_init(&fa.cond, NULL))
+                goto fail_cond;
+
+        list_head_init(&fa.cmds);
+
+        fa.fd = dt_reg_comp(&fa, &fa_post_packet, FA);
+
+        return 0;
+
+ fail_cond:
+        pthread_mutex_destroy(&fa.mtx);
+ fail_mtx:
+        pthread_rwlock_destroy(&fa.flows_lock);
+ fail_rwlock:
+        log_err("Failed to initialize flow allocator.");
+        return -1;
+}
+
+void fa_fini(void)
+{
+        pthread_cond_destroy(&fa.cond);;
+        pthread_mutex_destroy(&fa.mtx);
+        pthread_rwlock_destroy(&fa.flows_lock);
+}
+
+int fa_start(void)
+{
+        struct sched_param  par;
+        int                 pol;
+        int                 max;
+
+        fa.psched = psched_create(packet_handler);
+        if (fa.psched == NULL) {
+                log_err("Failed to start packet scheduler.");
+                goto fail_psched;
+        }
+
+        if (pthread_create(&fa.worker, NULL, fa_handle_packet, NULL)) {
+                log_err("Failed to create worker thread.");
+                goto fail_thread;
+        }
+
+        if (pthread_getschedparam(fa.worker, &pol, &par)) {
+                log_err("Failed to get worker thread scheduling parameters.");
+                goto fail_sched;
+        }
+
+        max = sched_get_priority_max(pol);
+        if (max < 0) {
+                log_err("Failed to get max priority for scheduler.");
+                goto fail_sched;
+        }
+
+        par.sched_priority = max;
+
+        if (pthread_setschedparam(fa.worker, pol, &par)) {
+                log_err("Failed to set scheduler priority to maximum.");
+                goto fail_sched;
+        }
+
+        return 0;
+
+ fail_sched:
+        pthread_cancel(fa.worker);
+        pthread_join(fa.worker, NULL);
+ fail_thread:
+        psched_destroy(fa.psched);
+ fail_psched:
+        log_err("Failed to start flow allocator.");
+        return -1;
+}
+
+void fa_stop(void)
+{
+        pthread_cancel(fa.worker);
+        pthread_join(fa.worker, NULL);
+
+        psched_destroy(fa.psched);
+}
+
+int fa_alloc(int             fd,
+             const uint8_t * dst,
+             qosspec_t       qs)
+{
+        struct fa_msg *      msg;
+        uint64_t             addr;
+        struct shm_du_buff * sdb;
+        qoscube_t            qc;
+
+        addr = dir_query(dst);
+        if (addr == 0)
+                return -1;
+
+        if (ipcp_sdb_reserve(&sdb, sizeof(*msg) + ipcp_dir_hash_len()))
+                return -1;
+
+        msg               = (struct fa_msg *) shm_du_buff_head(sdb);
+        msg->code         = FLOW_REQ;
+        msg->s_eid        = hton32(fd);
+        msg->s_addr       = hton64(ipcpi.dt_addr);
+        msg->delay        = hton32(qs.delay);
+        msg->bandwidth    = hton64(qs.bandwidth);
+        msg->availability = qs.availability;
+        msg->loss         = hton32(qs.loss);
+        msg->ber          = hton32(qs.ber);
+        msg->in_order     = qs.in_order;
+        msg->max_gap      = hton32(qs.max_gap);
+
+        memcpy(msg + 1, dst, ipcp_dir_hash_len());
+
+        qc = qos_spec_to_cube(qs);
+
+        if (dt_write_packet(addr, qc, fa.fd, sdb)) {
+                ipcp_sdb_release(sdb);
+                return -1;
+        }
+
+        pthread_rwlock_wrlock(&fa.flows_lock);
+
+        assert(fa.r_eid[fd] == -1);
+        fa.r_addr[fd] = addr;
+
+        pthread_rwlock_unlock(&fa.flows_lock);
+
+        return 0;
+}
+
+int fa_alloc_resp(int fd,
+                  int response)
+{
+        struct timespec      ts = {0, TIMEOUT * 1000};
+        struct timespec      abstime;
+        struct fa_msg *      msg;
+        struct shm_du_buff * sdb;
+        qoscube_t            qc;
+
+        clock_gettime(PTHREAD_COND_CLOCK, &abstime);
+
+        pthread_mutex_lock(&ipcpi.alloc_lock);
+
+        while (ipcpi.alloc_id != fd && ipcp_get_state() == IPCP_OPERATIONAL) {
+                ts_add(&abstime, &ts, &abstime);
+                pthread_cond_timedwait(&ipcpi.alloc_cond,
+                                       &ipcpi.alloc_lock,
+                                       &abstime);
+        }
+
+        if (ipcp_get_state() != IPCP_OPERATIONAL) {
+                pthread_mutex_unlock(&ipcpi.alloc_lock);
+                return -1;
+        }
+
+        ipcpi.alloc_id = -1;
+        pthread_cond_broadcast(&ipcpi.alloc_cond);
+
+        pthread_mutex_unlock(&ipcpi.alloc_lock);
+
+        if (ipcp_sdb_reserve(&sdb, sizeof(*msg) + ipcp_dir_hash_len())) {
+                destroy_conn(fd);
+                return -1;
+        }
+
+        pthread_rwlock_wrlock(&fa.flows_lock);
+
+        msg           = (struct fa_msg *) shm_du_buff_head(sdb);
+        msg->code     = FLOW_REPLY;
+        msg->r_eid    = hton32(fa.r_eid[fd]);
+        msg->s_eid    = hton32(fd);
+        msg->response = response;
+
+        if (response < 0) {
+                destroy_conn(fd);
+                ipcp_sdb_release(sdb);
+        } else {
+                psched_add(fa.psched, fd);
+        }
+
+        ipcp_flow_get_qoscube(fd, &qc);
+
+        assert(qc >= 0 && qc < QOS_CUBE_MAX);
+
+        if (dt_write_packet(fa.r_addr[fd], qc, fa.fd, sdb)) {
+                destroy_conn(fd);
+                pthread_rwlock_unlock(&fa.flows_lock);
+                ipcp_sdb_release(sdb);
+                return -1;
+        }
+
+        pthread_rwlock_unlock(&fa.flows_lock);
+
+        return 0;
+}
+
+int fa_dealloc(int fd)
+{
+        if (ipcp_flow_fini(fd) < 0)
+                return 0;
+
+        pthread_rwlock_wrlock(&fa.flows_lock);
+
+        psched_del(fa.psched, fd);
+
+        destroy_conn(fd);
+
+        pthread_rwlock_unlock(&fa.flows_lock);
+
+        flow_dealloc(fd);
+
+        return 0;
+}
diff --git a/src/ipcpd/unicast/fa.h b/src/ipcpd/unicast/fa.h
new file mode 100644
index 00000000..ea055ec2
--- /dev/null
+++ b/src/ipcpd/unicast/fa.h
@@ -0,0 +1,46 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Flow allocator of the IPC Process
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#ifndef OUROBOROS_IPCPD_UNICAST_FA_H
+#define OUROBOROS_IPCPD_UNICAST_FA_H
+
+#include <ouroboros/qos.h>
+#include <ouroboros/utils.h>
+
+int  fa_init(void);
+
+void fa_fini(void);
+
+int  fa_start(void);
+
+void fa_stop(void);
+
+int  fa_alloc(int             fd,
+              const uint8_t * dst,
+              qosspec_t       qs);
+
+int  fa_alloc_resp(int fd,
+                   int response);
+
+int  fa_dealloc(int fd);
+
+#endif /* OUROBOROS_IPCPD_UNICAST_FA_H */
diff --git a/src/ipcpd/unicast/kademlia.proto b/src/ipcpd/unicast/kademlia.proto
new file mode 100644
index 00000000..6bd78b38
--- /dev/null
+++ b/src/ipcpd/unicast/kademlia.proto
@@ -0,0 +1,45 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * KAD protocol
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * version 2.1 as published by the Free Software Foundation.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+syntax = "proto2";
+
+message kad_contact_msg {
+        required bytes  id   = 1;
+        required uint64 addr = 2;
+};
+
+message kad_msg {
+        required uint32 code              =  1;
+        required uint32 cookie            =  2;
+        required uint64 s_addr            =  3;
+        optional bytes  s_id              =  4;
+        optional bytes  key               =  5;
+        repeated uint64 addrs             =  6;
+        repeated kad_contact_msg contacts =  7;
+        // enrolment parameters
+        optional uint32 alpha             =  8;
+        optional uint32 b                 =  9;
+        optional uint32 k                 = 10;
+        optional uint32 t_expire          = 11;
+        optional uint32 t_refresh         = 12;
+        optional uint32 t_replicate       = 13;
+};
\ No newline at end of file
diff --git a/src/ipcpd/unicast/main.c b/src/ipcpd/unicast/main.c
new file mode 100644
index 00000000..c159b26d
--- /dev/null
+++ b/src/ipcpd/unicast/main.c
@@ -0,0 +1,378 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Unicast IPC Process
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#if defined(__linux__) || defined(__CYGWIN__)
+#define _DEFAULT_SOURCE
+#else
+#define _POSIX_C_SOURCE 200809L
+#endif
+
+#include "config.h"
+
+#define OUROBOROS_PREFIX "unicast-ipcp"
+
+#include <ouroboros/errno.h>
+#include <ouroboros/hash.h>
+#include <ouroboros/ipcp-dev.h>
+#include <ouroboros/logs.h>
+#include <ouroboros/notifier.h>
+#include <ouroboros/rib.h>
+#include <ouroboros/time_utils.h>
+
+#include "addr_auth.h"
+#include "connmgr.h"
+#include "dir.h"
+#include "dt.h"
+#include "enroll.h"
+#include "fa.h"
+#include "ipcp.h"
+
+#include <stdbool.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <inttypes.h>
+
+#define THIS_TYPE IPCP_UNICAST
+
+static int initialize_components(const struct ipcp_config * conf)
+{
+        ipcpi.layer_name = strdup(conf->layer_info.layer_name);
+        if (ipcpi.layer_name == NULL) {
+                log_err("Failed to set layer name.");
+                goto fail_layer_name;
+        }
+
+        ipcpi.dir_hash_algo = conf->layer_info.dir_hash_algo;
+
+        assert(ipcp_dir_hash_len() != 0);
+
+        if (addr_auth_init(conf->addr_auth_type,
+                           &conf->addr_size)) {
+                log_err("Failed to init address authority.");
+                goto fail_addr_auth;
+        }
+
+        ipcpi.dt_addr = addr_auth_address();
+        if (ipcpi.dt_addr == 0) {
+                log_err("Failed to get a valid address.");
+                goto fail_addr_auth;
+        }
+
+        log_dbg("IPCP got address %" PRIu64 ".", ipcpi.dt_addr);
+
+        if (dt_init(conf->routing_type,
+                    conf->pff_type,
+                    conf->addr_size,
+                    conf->eid_size,
+                    conf->max_ttl)) {
+                log_err("Failed to initialize data transfer component.");
+                goto fail_dt;
+        }
+
+        if (fa_init()) {
+                log_err("Failed to initialize flow allocator component.");
+                goto fail_fa;
+        }
+
+        if (dir_init()) {
+                log_err("Failed to initialize directory.");
+                goto fail_dir;
+        }
+
+        ipcp_set_state(IPCP_INIT);
+
+        return 0;
+
+ fail_dir:
+        fa_fini();
+ fail_fa:
+        dt_fini();
+ fail_dt:
+        addr_auth_fini();
+ fail_addr_auth:
+        free(ipcpi.layer_name);
+ fail_layer_name:
+        return -1;
+}
+
+static void finalize_components(void)
+{
+        dir_fini();
+
+        fa_fini();
+
+        dt_fini();
+
+        addr_auth_fini();
+
+        free(ipcpi.layer_name);
+}
+
+static int start_components(void)
+{
+        assert(ipcp_get_state() == IPCP_INIT);
+
+        ipcp_set_state(IPCP_OPERATIONAL);
+
+        if (fa_start()) {
+                log_err("Failed to start flow allocator.");
+                goto fail_fa_start;
+        }
+
+        if (enroll_start()) {
+                log_err("Failed to start enrollment.");
+                goto fail_enroll_start;
+        }
+
+        if (connmgr_start()) {
+                log_err("Failed to start AP connection manager.");
+                goto fail_connmgr_start;
+        }
+
+        return 0;
+
+ fail_connmgr_start:
+        enroll_stop();
+ fail_enroll_start:
+        fa_stop();
+ fail_fa_start:
+        ipcp_set_state(IPCP_INIT);
+        return -1;
+}
+
+static void stop_components(void)
+{
+        assert(ipcp_get_state() == IPCP_OPERATIONAL ||
+               ipcp_get_state() == IPCP_SHUTDOWN);
+
+        connmgr_stop();
+
+        enroll_stop();
+
+        fa_stop();
+
+        ipcp_set_state(IPCP_INIT);
+}
+
+static int bootstrap_components(void)
+{
+        if (dir_bootstrap()) {
+                log_err("Failed to bootstrap directory.");
+                dt_stop();
+                return -1;
+        }
+
+        return 0;
+}
+
+static int unicast_ipcp_enroll(const char *        dst,
+                               struct layer_info * info)
+{
+        struct conn conn;
+
+        if (connmgr_alloc(COMPID_ENROLL, dst, NULL, &conn)) {
+                log_err("Failed to get connection.");
+                goto fail_er_flow;
+        }
+
+        /* Get boot state from peer. */
+        if (enroll_boot(&conn)) {
+                log_err("Failed to get boot information.");
+                goto fail_enroll_boot;
+        }
+
+        if (initialize_components(enroll_get_conf())) {
+                log_err("Failed to initialize IPCP components.");
+                goto fail_enroll_boot;
+        }
+
+        if (dt_start()) {
+                log_err("Failed to initialize IPCP components.");
+                goto fail_dt_start;
+        }
+
+        if (start_components()) {
+                log_err("Failed to start components.");
+                goto fail_start_comp;
+        }
+
+        if (enroll_done(&conn, 0))
+                log_warn("Failed to confirm enrollment with peer.");
+
+        if (connmgr_dealloc(COMPID_ENROLL, &conn))
+                log_warn("Failed to deallocate enrollment flow.");
+
+        log_info("Enrolled with %s.", dst);
+
+        info->dir_hash_algo = ipcpi.dir_hash_algo;
+        strcpy(info->layer_name, ipcpi.layer_name);
+
+        return 0;
+
+ fail_start_comp:
+        dt_stop();
+ fail_dt_start:
+        finalize_components();
+ fail_enroll_boot:
+        connmgr_dealloc(COMPID_ENROLL, &conn);
+ fail_er_flow:
+        return -1;
+}
+
+static int unicast_ipcp_bootstrap(const struct ipcp_config * conf)
+{
+        assert(conf);
+        assert(conf->type == THIS_TYPE);
+
+        enroll_bootstrap(conf);
+
+        if (initialize_components(conf)) {
+                log_err("Failed to init IPCP components.");
+                goto fail_init;
+        }
+
+        if (dt_start()) {
+                log_err("Failed to initialize IPCP components.");
+                goto fail_dt_start;
+        };
+
+        if (start_components()) {
+                log_err("Failed to init IPCP components.");
+                goto fail_start;
+        }
+
+        if (bootstrap_components()) {
+                log_err("Failed to bootstrap IPCP components.");
+                goto fail_bootstrap;
+        }
+
+        log_dbg("Bootstrapped in layer %s.", conf->layer_info.layer_name);
+
+        return 0;
+
+ fail_bootstrap:
+        stop_components();
+ fail_start:
+        dt_stop();
+ fail_dt_start:
+        finalize_components();
+ fail_init:
+        return -1;
+}
+
+static int unicast_ipcp_query(const uint8_t * dst)
+{
+        return dir_query(dst) ? 0 : -1;
+}
+
+static struct ipcp_ops unicast_ops = {
+        .ipcp_bootstrap       = unicast_ipcp_bootstrap,
+        .ipcp_enroll          = unicast_ipcp_enroll,
+        .ipcp_connect         = connmgr_ipcp_connect,
+        .ipcp_disconnect      = connmgr_ipcp_disconnect,
+        .ipcp_reg             = dir_reg,
+        .ipcp_unreg           = dir_unreg,
+        .ipcp_query           = unicast_ipcp_query,
+        .ipcp_flow_alloc      = fa_alloc,
+        .ipcp_flow_join       = NULL,
+        .ipcp_flow_alloc_resp = fa_alloc_resp,
+        .ipcp_flow_dealloc    = fa_dealloc
+};
+
+int main(int    argc,
+         char * argv[])
+{
+        if (ipcp_init(argc, argv, &unicast_ops) < 0) {
+                log_err("Failed to init IPCP.");
+                goto fail_init;
+        }
+
+        /* These components must be init at creation. */
+        if (rib_init(ipcpi.name)) {
+                log_err("Failed to initialize RIB.");
+                goto fail_rib_init;
+        }
+
+        if (notifier_init()) {
+                log_err("Failed to initialize notifier component.");
+                goto fail_notifier_init;
+        }
+
+        if (connmgr_init()) {
+                log_err("Failed to initialize connection manager.");
+                goto fail_connmgr_init;
+        }
+
+        if (enroll_init()) {
+                log_err("Failed to initialize enrollment component.");
+                goto fail_enroll_init;
+        }
+
+        if (ipcp_boot() < 0) {
+                log_err("Failed to boot IPCP.");
+                goto fail_boot;
+        }
+
+        if (ipcp_create_r(0)) {
+                log_err("Failed to notify IRMd we are initialized.");
+                ipcp_set_state(IPCP_NULL);
+                goto fail_create_r;
+        }
+
+        ipcp_shutdown();
+
+        if (ipcp_get_state() == IPCP_SHUTDOWN) {
+                dt_stop();
+                stop_components();
+                finalize_components();
+        }
+
+        enroll_fini();
+
+        connmgr_fini();
+
+        notifier_fini();
+
+        rib_fini();
+
+        ipcp_fini();
+
+        exit(EXIT_SUCCESS);
+
+ fail_create_r:
+        ipcp_shutdown();
+ fail_boot:
+        enroll_fini();
+ fail_enroll_init:
+        connmgr_fini();
+ fail_connmgr_init:
+        notifier_fini();
+ fail_notifier_init:
+        rib_fini();
+ fail_rib_init:
+       ipcp_fini();
+ fail_init:
+        ipcp_create_r(-1);
+        exit(EXIT_FAILURE);
+}
diff --git a/src/ipcpd/unicast/pff.c b/src/ipcpd/unicast/pff.c
new file mode 100644
index 00000000..5b1fa429
--- /dev/null
+++ b/src/ipcpd/unicast/pff.c
@@ -0,0 +1,127 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * PDU Forwarding Function
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#define OUROBOROS_PREFIX "pff"
+
+#include <ouroboros/errno.h>
+#include <ouroboros/logs.h>
+
+#include "pff.h"
+#include "pol-pff-ops.h"
+#include "pol/alternate_pff.h"
+#include "pol/simple_pff.h"
+
+struct pff {
+        struct pol_pff_ops * ops;
+        struct pff_i *       pff_i;
+};
+
+struct pff * pff_create(enum pol_pff pol)
+{
+        struct pff * pff;
+
+        pff = malloc(sizeof(*pff));
+        if (pff == NULL)
+                return NULL;
+
+        switch (pol) {
+        case PFF_ALTERNATE:
+                log_dbg("Using alternate PFF policy.");
+                pff->ops = &alternate_pff_ops;
+                break;
+        case PFF_SIMPLE:
+                log_dbg("Using simple PFF policy.");
+                pff->ops = &simple_pff_ops;
+                break;
+        default:
+                goto err;
+        }
+
+        pff->pff_i = pff->ops->create();
+        if (pff->pff_i == NULL)
+                goto err;
+
+        return pff;
+ err:
+        free(pff);
+        return NULL;
+}
+
+void pff_destroy(struct pff * pff)
+{
+        pff->ops->destroy(pff->pff_i);
+
+        free(pff);
+}
+
+void pff_lock(struct pff * pff)
+{
+        return pff->ops->lock(pff->pff_i);
+}
+
+void pff_unlock(struct pff * pff)
+{
+        return pff->ops->unlock(pff->pff_i);
+}
+
+int pff_add(struct pff * pff,
+            uint64_t     addr,
+            int *        fd,
+            size_t       len)
+{
+        return pff->ops->add(pff->pff_i, addr, fd, len);
+}
+
+int pff_update(struct pff * pff,
+               uint64_t     addr,
+               int *        fd,
+               size_t       len)
+{
+        return pff->ops->update(pff->pff_i, addr, fd, len);
+}
+
+int pff_del(struct pff * pff,
+            uint64_t     addr)
+{
+        return pff->ops->del(pff->pff_i, addr);
+}
+
+void pff_flush(struct pff * pff)
+{
+        return pff->ops->flush(pff->pff_i);
+}
+
+int pff_nhop(struct pff * pff,
+             uint64_t     addr)
+{
+        return pff->ops->nhop(pff->pff_i, addr);
+}
+
+int pff_flow_state_change(struct pff * pff,
+                          int          fd,
+                          bool         up)
+{
+        if (pff->ops->flow_state_change != NULL)
+                return pff->ops->flow_state_change(pff->pff_i, fd, up);
+
+        return 0;
+}
diff --git a/src/ipcpd/unicast/pff.h b/src/ipcpd/unicast/pff.h
new file mode 100644
index 00000000..9533395f
--- /dev/null
+++ b/src/ipcpd/unicast/pff.h
@@ -0,0 +1,63 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * PDU Forwarding Function
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#ifndef OUROBOROS_IPCPD_UNICAST_PFF_H
+#define OUROBOROS_IPCPD_UNICAST_PFF_H
+
+#include <ouroboros/ipcp.h>
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdbool.h>
+
+struct pff * pff_create(enum pol_pff pol);
+
+void         pff_destroy(struct pff * pff);
+
+void         pff_lock(struct pff * pff);
+
+void         pff_unlock(struct pff * pff);
+
+int          pff_add(struct pff * pff,
+                     uint64_t     addr,
+                     int *        fd,
+                     size_t       len);
+
+int          pff_update(struct pff * pff,
+                        uint64_t     addr,
+                        int *        fd,
+                        size_t       len);
+
+int          pff_del(struct pff * pff,
+                     uint64_t     addr);
+
+void         pff_flush(struct pff * pff);
+
+/* Returns fd towards next hop */
+int          pff_nhop(struct pff * pff,
+                      uint64_t     addr);
+
+int          pff_flow_state_change(struct pff * pff,
+                                   int          fd,
+                                   bool         up);
+
+#endif /* OUROBOROS_IPCPD_UNICAST_PFF_H */
diff --git a/src/ipcpd/unicast/pol-addr-auth-ops.h b/src/ipcpd/unicast/pol-addr-auth-ops.h
new file mode 100644
index 00000000..7b1a4514
--- /dev/null
+++ b/src/ipcpd/unicast/pol-addr-auth-ops.h
@@ -0,0 +1,34 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Address authority policy ops
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#ifndef OUROBOROS_IPCPD_UNICAST_POL_ADDR_AUTH_OPS_H
+#define OUROBOROS_IPCPD_UNICAST_POL_ADDR_AUTH_OPS_H
+
+struct pol_addr_auth_ops {
+        int      (* init)(const void * info);
+
+        int      (* fini)(void);
+
+        uint64_t (* address)(void);
+};
+
+#endif /* OUROBOROS_IPCPD_UNICAST_POL_ADDR_AUTH_OPS_H */
diff --git a/src/ipcpd/unicast/pol-pff-ops.h b/src/ipcpd/unicast/pol-pff-ops.h
new file mode 100644
index 00000000..766bb5b8
--- /dev/null
+++ b/src/ipcpd/unicast/pol-pff-ops.h
@@ -0,0 +1,63 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Pff policy ops
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#ifndef OUROBOROS_IPCPD_UNICAST_POL_PFF_OPS_H
+#define OUROBOROS_IPCPD_UNICAST_POL_PFF_OPS_H
+
+#include <stdbool.h>
+
+struct pff_i;
+
+struct pol_pff_ops {
+        struct pff_i * (* create)(void);
+
+        void           (* destroy)(struct pff_i * pff_i);
+
+        void           (* lock)(struct pff_i * pff_i);
+
+        void           (* unlock)(struct pff_i * pff_i);
+
+        int            (* add)(struct pff_i * pff_i,
+                               uint64_t       addr,
+                               int *          fd,
+                               size_t         len);
+
+        int            (* update)(struct pff_i * pff_i,
+                                  uint64_t       addr,
+                                  int *          fd,
+                                  size_t         len);
+
+        int            (* del)(struct pff_i * pff_i,
+                               uint64_t       addr);
+
+        void           (* flush)(struct pff_i * pff_i);
+
+        int            (* nhop)(struct pff_i * pff_i,
+                                uint64_t       addr);
+
+        /* Optional operation. */
+        int            (* flow_state_change)(struct pff_i * pff_i,
+                                             int            fd,
+                                             bool           up);
+};
+
+#endif /* OUROBOROS_IPCPD_UNICAST_POL_PFF_OPS_H */
diff --git a/src/ipcpd/unicast/pol-routing-ops.h b/src/ipcpd/unicast/pol-routing-ops.h
new file mode 100644
index 00000000..ae8e632d
--- /dev/null
+++ b/src/ipcpd/unicast/pol-routing-ops.h
@@ -0,0 +1,38 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Routing policy ops
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#ifndef OUROBOROS_IPCPD_UNICAST_POL_ROUTING_OPS_H
+#define OUROBOROS_IPCPD_UNICAST_POL_ROUTING_OPS_H
+
+#include "pff.h"
+
+struct pol_routing_ops {
+        int                (* init)(enum pol_routing pr);
+
+        void               (* fini)(void);
+
+        struct routing_i * (* routing_i_create)(struct pff * pff);
+
+        void               (* routing_i_destroy)(struct routing_i * instance);
+};
+
+#endif /* OUROBOROS_IPCPD_UNICAST_POL_ROUTING_OPS_H */
diff --git a/src/ipcpd/unicast/pol/alternate_pff.c b/src/ipcpd/unicast/pol/alternate_pff.c
new file mode 100644
index 00000000..38937297
--- /dev/null
+++ b/src/ipcpd/unicast/pol/alternate_pff.c
@@ -0,0 +1,403 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Policy for PFF with alternate next hops
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#define _POSIX_C_SOURCE 200112L
+
+#include "config.h"
+
+#include <ouroboros/hashtable.h>
+#include <ouroboros/errno.h>
+#include <ouroboros/list.h>
+
+#include <string.h>
+#include <assert.h>
+#include <pthread.h>
+
+#include "alternate_pff.h"
+
+struct nhop {
+        struct list_head next;
+        int              fd;
+};
+
+struct addr {
+        struct list_head next;
+        uint64_t         addr;
+};
+
+struct pff_i {
+        struct htable *  table;
+
+        struct list_head addrs;
+
+        struct list_head nhops_down;
+
+        pthread_rwlock_t lock;
+};
+
+struct pol_pff_ops alternate_pff_ops = {
+        .create            = alternate_pff_create,
+        .destroy           = alternate_pff_destroy,
+        .lock              = alternate_pff_lock,
+        .unlock            = alternate_pff_unlock,
+        .add               = alternate_pff_add,
+        .update            = alternate_pff_update,
+        .del               = alternate_pff_del,
+        .flush             = alternate_pff_flush,
+        .nhop              = alternate_pff_nhop,
+        .flow_state_change = alternate_flow_state_change
+};
+
+static int add_addr(struct pff_i * pff_i,
+                    uint64_t       addr)
+{
+        struct addr * a;
+
+        a = malloc(sizeof(*a));
+        if (a == NULL)
+                return -1;
+
+        a->addr = addr;
+
+        list_add(&a->next, &(pff_i->addrs));
+
+        return 0;
+}
+
+static void del_addr(struct pff_i * pff_i,
+                     uint64_t       addr)
+{
+        struct list_head * pos = NULL;
+        struct list_head * n   = NULL;
+
+        list_for_each_safe(pos, n, &(pff_i->addrs)) {
+                struct addr * e = list_entry(pos, struct addr, next);
+                if (e->addr == addr) {
+                        list_del(&e->next);
+                        free(e);
+                        return;
+                }
+        }
+}
+
+static void del_addrs(struct pff_i * pff_i)
+{
+        struct list_head * pos = NULL;
+        struct list_head * n   = NULL;
+
+        list_for_each_safe(pos, n, &(pff_i->addrs)) {
+                struct addr * e = list_entry(pos, struct addr, next);
+                list_del(&e->next);
+                free(e);
+        }
+}
+
+static void del_nhops_down(struct pff_i * pff_i)
+{
+        struct list_head * pos = NULL;
+        struct list_head * n   = NULL;
+
+        list_for_each_safe(pos, n, &(pff_i->nhops_down)) {
+                struct nhop * e = list_entry(pos, struct nhop, next);
+                list_del(&e->next);
+                free(e);
+        }
+}
+
+static int del_nhop_down(struct pff_i * pff_i,
+                         int            fd)
+{
+        struct list_head * pos = NULL;
+        struct list_head * n   = NULL;
+
+        list_for_each_safe(pos, n, &(pff_i->nhops_down)) {
+                struct nhop * e = list_entry(pos, struct nhop, next);
+                if (e->fd == fd) {
+                        list_del(&e->next);
+                        free(e);
+                        return 0;
+                }
+        }
+
+        return -1;
+}
+
+static int add_nhop_down(struct pff_i * pff_i,
+                         int            fd)
+{
+        struct nhop *      nhop;
+
+        nhop = malloc(sizeof(*nhop));
+        if (nhop == NULL)
+                return -1;
+
+        nhop->fd = fd;
+
+        list_add(&nhop->next, &(pff_i->nhops_down));
+
+        return 0;
+}
+
+static bool nhops_down_has(struct pff_i * pff_i,
+                           int            fd)
+{
+        struct list_head * pos = NULL;
+
+        list_for_each(pos, &pff_i->nhops_down) {
+                struct nhop * e = list_entry(pos, struct nhop, next);
+                if (e->fd == fd)
+                        return true;
+        }
+
+        return false;
+}
+
+static int add_to_htable(struct pff_i * pff_i,
+                         uint64_t       addr,
+                         int *          fd,
+                         size_t         len)
+{
+        int * val;
+
+        assert(pff_i);
+        assert(len > 0);
+
+        val = malloc(sizeof(*val) * (len + 1));
+        if (val == NULL)
+                goto fail_malloc;
+
+        memcpy(val, fd, len * sizeof(*val));
+        /* Put primary hop again at the end */
+        val[len] = val[0];
+
+        if (htable_insert(pff_i->table, addr, val, len))
+                goto fail_insert;
+
+        return 0;
+
+ fail_insert:
+        free(val);
+ fail_malloc:
+        return -1;
+}
+
+struct pff_i * alternate_pff_create(void)
+{
+        struct pff_i * tmp;
+
+        tmp = malloc(sizeof(*tmp));
+        if (tmp == NULL)
+                goto fail_malloc;
+
+        if (pthread_rwlock_init(&tmp->lock, NULL))
+                goto fail_lock;
+
+        tmp->table = htable_create(PFT_SIZE, false);
+        if (tmp->table == NULL)
+                goto fail_table;
+
+        list_head_init(&tmp->nhops_down);
+        list_head_init(&tmp->addrs);
+
+        return tmp;
+
+ fail_table:
+        pthread_rwlock_destroy(&tmp->lock);
+ fail_lock:
+        free(tmp);
+ fail_malloc:
+        return NULL;
+}
+
+void alternate_pff_destroy(struct pff_i * pff_i)
+{
+        assert(pff_i);
+
+        htable_destroy(pff_i->table);
+        del_nhops_down(pff_i);
+        del_addrs(pff_i);
+        pthread_rwlock_destroy(&pff_i->lock);
+        free(pff_i);
+}
+
+void alternate_pff_lock(struct pff_i * pff_i)
+{
+        pthread_rwlock_wrlock(&pff_i->lock);
+}
+
+void alternate_pff_unlock(struct pff_i * pff_i)
+{
+        pthread_rwlock_unlock(&pff_i->lock);
+}
+
+int alternate_pff_add(struct pff_i * pff_i,
+                      uint64_t       addr,
+                      int *          fd,
+                      size_t         len)
+{
+        assert(pff_i);
+        assert(len > 0);
+
+        if (add_to_htable(pff_i, addr, fd, len))
+                return -1;
+
+        if (add_addr(pff_i, addr)) {
+                htable_delete(pff_i->table, addr);
+                return -1;
+        }
+
+        return 0;
+}
+
+int alternate_pff_update(struct pff_i * pff_i,
+                         uint64_t       addr,
+                         int *          fd,
+                         size_t         len)
+{
+        assert(pff_i);
+        assert(len > 0);
+
+        if (htable_delete(pff_i->table, addr))
+                return -1;
+
+        if (add_to_htable(pff_i, addr, fd, len))
+                return -1;
+
+        return 0;
+}
+
+int alternate_pff_del(struct pff_i * pff_i,
+                      uint64_t       addr)
+{
+        assert(pff_i);
+
+        del_addr(pff_i, addr);
+
+        if (htable_delete(pff_i->table, addr))
+                return -1;
+
+        return 0;
+}
+
+void alternate_pff_flush(struct pff_i * pff_i)
+{
+        assert(pff_i);
+
+        htable_flush(pff_i->table);
+
+        del_nhops_down(pff_i);
+
+        del_addrs(pff_i);
+}
+
+int alternate_pff_nhop(struct pff_i * pff_i,
+                       uint64_t       addr)
+{
+        int    fd = -1;
+        size_t len;
+        void * el;
+
+        assert(pff_i);
+
+        pthread_rwlock_rdlock(&pff_i->lock);
+
+        if (htable_lookup(pff_i->table, addr, &el, &len)) {
+                pthread_rwlock_unlock(&pff_i->lock);
+                return -1;
+        }
+
+        fd = *((int *) el);
+
+        pthread_rwlock_unlock(&pff_i->lock);
+
+        return fd;
+}
+
+int alternate_flow_state_change(struct pff_i * pff_i,
+                                int            fd,
+                                bool           up)
+{
+        struct list_head * pos = NULL;
+        size_t             len;
+        void *             el;
+        int *              fds;
+        size_t             i;
+        int                tmp;
+
+        assert(pff_i);
+
+        pthread_rwlock_wrlock(&pff_i->lock);
+
+        if (up) {
+                if (del_nhop_down(pff_i, fd)) {
+                        pthread_rwlock_unlock(&pff_i->lock);
+                        return -1;
+                }
+        } else {
+                if (add_nhop_down(pff_i, fd)) {
+                        pthread_rwlock_unlock(&pff_i->lock);
+                        return -1;
+                }
+        }
+
+        list_for_each(pos, &pff_i->addrs) {
+                struct addr * e = list_entry(pos, struct addr, next);
+                if (htable_lookup(pff_i->table, e->addr, &el, &len)) {
+                        pthread_rwlock_unlock(&pff_i->lock);
+                        return -1;
+                }
+
+                fds = (int *) el;
+
+                if (up) {
+                        /* It is using an alternate */
+                        if (fds[len] == fd && fds[0] != fd) {
+                                for (i = 0 ; i < len; i++) {
+                                        /* Found the primary */
+                                        if (fds[i] == fd) {
+                                                tmp = fds[0];
+                                                fds[0] = fds[i];
+                                                fds[i] = tmp;
+                                                break;
+                                        }
+                                }
+                        }
+                } else {
+                        /* Need to switch to a (different) alternate */
+                        if (fds[0] == fd) {
+                                for (i = 1; i < len; i++) {
+                                        /* Usable alternate */
+                                        if (!nhops_down_has(pff_i, fds[i])) {
+                                                tmp = fds[0];
+                                                fds[0] = fds[i];
+                                                fds[i] = tmp;
+                                                break;
+                                        }
+                                }
+                        }
+                }
+        }
+
+        pthread_rwlock_unlock(&pff_i->lock);
+
+        return 0;
+}
diff --git a/src/ipcpd/unicast/pol/alternate_pff.h b/src/ipcpd/unicast/pol/alternate_pff.h
new file mode 100644
index 00000000..7bdf26de
--- /dev/null
+++ b/src/ipcpd/unicast/pol/alternate_pff.h
@@ -0,0 +1,61 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Policy for PFF with alternate next hops
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#ifndef OUROBOROS_IPCPD_UNICAST_ALTERNATE_PFF_H
+#define OUROBOROS_IPCPD_UNICAST_ALTERNATE_PFF_H
+
+#include "pol-pff-ops.h"
+
+struct pff_i * alternate_pff_create(void);
+
+void           alternate_pff_destroy(struct pff_i * pff_i);
+
+void           alternate_pff_lock(struct pff_i * pff_i);
+
+void           alternate_pff_unlock(struct pff_i * pff_i);
+
+int            alternate_pff_add(struct pff_i * pff_i,
+                                 uint64_t       addr,
+                                 int *          fd,
+                                 size_t         len);
+
+int            alternate_pff_update(struct pff_i * pff_i,
+                                    uint64_t       addr,
+                                    int *          fd,
+                                    size_t         len);
+
+int            alternate_pff_del(struct pff_i * pff_i,
+                                 uint64_t       addr);
+
+void           alternate_pff_flush(struct pff_i * pff_i);
+
+/* Returns fd towards next hop */
+int            alternate_pff_nhop(struct pff_i * pff_i,
+                                  uint64_t       addr);
+
+int            alternate_flow_state_change(struct pff_i * pff_i,
+                                           int            fd,
+                                           bool           up);
+
+struct pol_pff_ops alternate_pff_ops;
+
+#endif /* OUROBOROS_IPCPD_UNICAST_ALTERNATE_PFF_H */
diff --git a/src/ipcpd/unicast/pol/flat.c b/src/ipcpd/unicast/pol/flat.c
new file mode 100644
index 00000000..157885f9
--- /dev/null
+++ b/src/ipcpd/unicast/pol/flat.c
@@ -0,0 +1,87 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Policy for flat addresses in a distributed way
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#if defined(__linux__) || defined(__CYGWIN__)
+#define _DEFAULT_SOURCE
+#else
+#define _POSIX_C_SOURCE 200112L
+#endif
+
+#define OUROBOROS_PREFIX "flat-addr-auth"
+
+#include <ouroboros/logs.h>
+#include <ouroboros/errno.h>
+#include <ouroboros/time_utils.h>
+#include <ouroboros/utils.h>
+
+#include "ipcp.h"
+#include "flat.h"
+
+#include <time.h>
+#include <stdlib.h>
+#include <math.h>
+#include <string.h>
+#include <assert.h>
+
+#define NAME_LEN 8
+
+struct {
+        uint8_t addr_size;
+} flat;
+
+#define INVALID_ADDRESS 0
+
+struct pol_addr_auth_ops flat_ops = {
+        .init    = flat_init,
+        .fini    = flat_fini,
+        .address = flat_address
+};
+
+int flat_init(const void * info)
+{
+        flat.addr_size = *((uint8_t *) info);
+
+        if (flat.addr_size != 4) {
+                log_err("Flat address policy mandates 4 byte addresses.");
+                return -1;
+        }
+
+        return 0;
+}
+
+int flat_fini(void)
+{
+        return 0;
+}
+
+uint64_t flat_address(void)
+{
+        struct timespec t;
+        uint32_t        addr;
+
+        clock_gettime(CLOCK_REALTIME, &t);
+        srand(t.tv_nsec);
+
+        addr = (rand() % (RAND_MAX - 1) + 1) & 0xFFFFFFFF;
+
+        return addr;
+}
diff --git a/src/ipcpd/unicast/pol/flat.h b/src/ipcpd/unicast/pol/flat.h
new file mode 100644
index 00000000..64aa9ce0
--- /dev/null
+++ b/src/ipcpd/unicast/pol/flat.h
@@ -0,0 +1,36 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Policy for flat addresses in a distributed way
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#ifndef OUROBOROS_IPCPD_UNICAST_FLAT_H
+#define OUROBOROS_IPCPD_UNICAST_FLAT_H
+
+#include "pol-addr-auth-ops.h"
+
+int      flat_init(const void * info);
+
+int      flat_fini(void);
+
+uint64_t flat_address(void);
+
+struct pol_addr_auth_ops flat_ops;
+
+#endif /* OUROBOROS_IPCPD_UNICAST_FLAT_H */
diff --git a/src/ipcpd/unicast/pol/graph.c b/src/ipcpd/unicast/pol/graph.c
new file mode 100644
index 00000000..499dc2de
--- /dev/null
+++ b/src/ipcpd/unicast/pol/graph.c
@@ -0,0 +1,695 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Undirected graph structure
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#if defined(__linux__) || defined(__CYGWIN__)
+#define _DEFAULT_SOURCE
+#else
+#define _POSIX_C_SOURCE 200112L
+#endif
+
+#define OUROBOROS_PREFIX "graph"
+
+#include <ouroboros/logs.h>
+#include <ouroboros/errno.h>
+#include <ouroboros/list.h>
+
+#include "graph.h"
+#include "ipcp.h"
+
+#include <assert.h>
+#include <pthread.h>
+#include <stdlib.h>
+#include <limits.h>
+#include <string.h>
+
+struct edge {
+        struct list_head next;
+        struct vertex *  nb;
+        qosspec_t        qs;
+        int              announced;
+};
+
+struct vertex {
+        struct list_head next;
+        uint64_t         addr;
+        struct list_head edges;
+        int              index;
+};
+
+struct graph {
+        size_t           nr_vertices;
+        struct list_head vertices;
+        pthread_mutex_t  lock;
+};
+
+static struct edge * find_edge_by_addr(struct vertex * vertex,
+                                       uint64_t        dst_addr)
+{
+        struct list_head * p = NULL;
+
+        list_for_each(p, &vertex->edges) {
+                struct edge * e = list_entry(p, struct edge, next);
+                if (e->nb->addr == dst_addr)
+                        return e;
+        }
+
+        return NULL;
+}
+
+static struct vertex * find_vertex_by_addr(struct graph * graph,
+                                           uint64_t       addr)
+{
+        struct list_head * p = NULL;
+
+        list_for_each(p, &graph->vertices) {
+                struct vertex * e = list_entry(p, struct vertex, next);
+                if (e->addr == addr)
+                        return e;
+        }
+
+        return NULL;
+}
+
+static struct edge * add_edge(struct vertex * vertex,
+                              struct vertex * nb)
+{
+        struct edge * edge;
+
+        edge = malloc(sizeof(*edge));
+        if (edge == NULL)
+                return NULL;
+
+        list_head_init(&edge->next);
+        edge->nb = nb;
+        edge->announced = 0;
+
+        list_add(&edge->next, &vertex->edges);
+
+        return edge;
+}
+
+static void del_edge(struct edge * edge)
+{
+       list_del(&edge->next);
+       free(edge);
+}
+
+static struct vertex * add_vertex(struct graph * graph,
+                                  uint64_t       addr)
+{
+        struct vertex *    vertex;
+        struct list_head * p;
+        int                i = 0;
+
+        vertex = malloc(sizeof(*vertex));
+        if (vertex == NULL)
+                return NULL;
+
+        list_head_init(&vertex->next);
+        list_head_init(&vertex->edges);
+        vertex->addr = addr;
+
+        /* Keep them ordered on address. */
+        list_for_each(p, &graph->vertices) {
+                struct vertex * v = list_entry(p, struct vertex, next);
+                if (v->addr > addr)
+                        break;
+                i++;
+        }
+
+        vertex->index = i;
+
+        list_add_tail(&vertex->next, p);
+
+        /* Increase the index of the vertices to the right. */
+        list_for_each(p, &graph->vertices) {
+                struct vertex * v = list_entry(p, struct vertex, next);
+                if (v->addr > addr)
+                        v->index++;
+        }
+
+        graph->nr_vertices++;
+
+        return vertex;
+}
+
+static void del_vertex(struct graph * graph,
+                       struct vertex * vertex)
+{
+        struct list_head * p = NULL;
+        struct list_head * n = NULL;
+
+        list_del(&vertex->next);
+
+        /* Decrease the index of the vertices to the right. */
+        list_for_each(p, &graph->vertices) {
+                struct vertex * v = list_entry(p, struct vertex, next);
+                if (v->addr > vertex->addr)
+                        v->index--;
+        }
+
+        list_for_each_safe(p, n, &vertex->edges) {
+                struct edge * e = list_entry(p, struct edge, next);
+                del_edge(e);
+        }
+
+        free(vertex);
+
+        graph->nr_vertices--;
+}
+
+struct graph * graph_create(void)
+{
+        struct graph * graph;
+
+        graph = malloc(sizeof(*graph));
+        if (graph == NULL)
+                return NULL;
+
+        if (pthread_mutex_init(&graph->lock, NULL)) {
+                free(graph);
+                return NULL;
+        }
+
+        graph->nr_vertices = 0;
+        list_head_init(&graph->vertices);
+
+        return graph;
+}
+
+void graph_destroy(struct graph * graph)
+{
+        struct list_head * p = NULL;
+        struct list_head * n = NULL;
+
+        assert(graph);
+
+        pthread_mutex_lock(&graph->lock);
+
+        list_for_each_safe(p, n, &graph->vertices) {
+                struct vertex * e = list_entry(p, struct vertex, next);
+                del_vertex(graph, e);
+        }
+
+        pthread_mutex_unlock(&graph->lock);
+
+        pthread_mutex_destroy(&graph->lock);
+
+        free(graph);
+}
+
+int graph_update_edge(struct graph * graph,
+                      uint64_t       s_addr,
+                      uint64_t       d_addr,
+                      qosspec_t      qs)
+{
+        struct vertex * v;
+        struct edge *   e;
+        struct vertex * nb;
+        struct edge *   nb_e;
+
+        assert(graph);
+
+        pthread_mutex_lock(&graph->lock);
+
+        v = find_vertex_by_addr(graph, s_addr);
+        if (v == NULL) {
+                v = add_vertex(graph, s_addr);
+                if (v == NULL) {
+                        pthread_mutex_unlock(&graph->lock);
+                        log_err("Failed to add vertex.");
+                        return -ENOMEM;
+                }
+        }
+
+        nb = find_vertex_by_addr(graph, d_addr);
+        if (nb == NULL) {
+                nb = add_vertex(graph, d_addr);
+                if (nb == NULL) {
+                        if (list_is_empty(&v->edges))
+                                del_vertex(graph, v);
+                        pthread_mutex_unlock(&graph->lock);
+                        log_err("Failed to add vertex.");
+                        return -ENOMEM;
+                }
+        }
+
+        e = find_edge_by_addr(v, d_addr);
+        if (e == NULL) {
+                e = add_edge(v, nb);
+                if (e == NULL) {
+                        if (list_is_empty(&v->edges))
+                                del_vertex(graph, v);
+                        if (list_is_empty(&nb->edges))
+                                del_vertex(graph, nb);
+                        pthread_mutex_unlock(&graph->lock);
+                        log_err("Failed to add edge.");
+                        return -ENOMEM;
+                }
+        }
+
+        e->announced++;
+        e->qs = qs;
+
+        nb_e = find_edge_by_addr(nb, s_addr);
+        if (nb_e == NULL) {
+                nb_e = add_edge(nb, v);
+                if (nb_e == NULL) {
+                        if (--e->announced == 0)
+                                del_edge(e);
+                        if (list_is_empty(&v->edges))
+                                del_vertex(graph, v);
+                        if (list_is_empty(&nb->edges))
+                                del_vertex(graph, nb);
+                        pthread_mutex_unlock(&graph->lock);
+                        log_err("Failed to add edge.");
+                        return -ENOMEM;
+                }
+        }
+
+        nb_e->announced++;
+        nb_e->qs = qs;
+
+        pthread_mutex_unlock(&graph->lock);
+
+        return 0;
+}
+
+int graph_del_edge(struct graph * graph,
+                   uint64_t       s_addr,
+                   uint64_t       d_addr)
+{
+        struct vertex * v;
+        struct edge *   e;
+        struct vertex * nb;
+        struct edge *   nb_e;
+
+        assert(graph);
+
+        pthread_mutex_lock(&graph->lock);
+
+        v = find_vertex_by_addr(graph, s_addr);
+        if (v == NULL) {
+                pthread_mutex_unlock(&graph->lock);
+                log_err("No such source vertex.");
+                return -1;
+        }
+
+        nb = find_vertex_by_addr(graph, d_addr);
+        if (nb == NULL) {
+                pthread_mutex_unlock(&graph->lock);
+                log_err("No such destination vertex.");
+                return -1;
+        }
+
+        e = find_edge_by_addr(v, d_addr);
+        if (e == NULL) {
+                pthread_mutex_unlock(&graph->lock);
+                log_err("No such source edge.");
+                return -1;
+        }
+
+        nb_e = find_edge_by_addr(nb, s_addr);
+        if (nb_e == NULL) {
+                pthread_mutex_unlock(&graph->lock);
+                log_err("No such destination edge.");
+                return -1;
+        }
+
+        if (--e->announced == 0)
+                del_edge(e);
+        if (--nb_e->announced == 0)
+                del_edge(nb_e);
+
+        /* Removing vertex if it was the last edge */
+        if (list_is_empty(&v->edges))
+                del_vertex(graph, v);
+        if (list_is_empty(&nb->edges))
+                del_vertex(graph, nb);
+
+        pthread_mutex_unlock(&graph->lock);
+
+        return 0;
+}
+
+static int get_min_vertex(struct graph *   graph,
+                          int *            dist,
+                          bool *           used,
+                          struct vertex ** v)
+{
+        int                min = INT_MAX;
+        int                index = -1;
+        int                i = 0;
+        struct list_head * p = NULL;
+
+        *v = NULL;
+
+        list_for_each(p, &graph->vertices) {
+                if (!used[i] && dist[i] < min) {
+                        min = dist[i];
+                        index = i;
+                        *v = list_entry(p, struct vertex, next);
+                }
+
+                i++;
+        }
+
+        if (index != -1)
+                used[index] = true;
+
+        return index;
+}
+
+static int dijkstra(struct graph *    graph,
+                    uint64_t          src,
+                    struct vertex *** nhops,
+                    int **            dist)
+{
+        bool *             used;
+        struct list_head * p = NULL;
+        int                i = 0;
+        struct vertex *    v = NULL;
+        struct edge *      e = NULL;
+        int                alt;
+
+        *nhops = malloc(sizeof(**nhops) * graph->nr_vertices);
+        if (*nhops == NULL)
+                goto fail_pnhops;
+
+        *dist = malloc(sizeof(**dist) * graph->nr_vertices);
+        if (*dist == NULL)
+                goto fail_pdist;
+
+        used = malloc(sizeof(*used) * graph->nr_vertices);
+        if (used == NULL)
+                goto fail_used;
+
+        /* Init the data structures */
+        memset(used, 0, sizeof(*used) * graph->nr_vertices);
+        memset(*nhops, 0, sizeof(**nhops) * graph->nr_vertices);
+        memset(*dist, 0, sizeof(**dist) * graph->nr_vertices);
+
+        list_for_each(p, &graph->vertices) {
+                v = list_entry(p, struct vertex, next);
+                (*dist)[i++]  = (v->addr == src) ? 0 : INT_MAX;
+        }
+
+        /* Perform actual Dijkstra */
+        i = get_min_vertex(graph, *dist, used, &v);
+        while (v != NULL) {
+                list_for_each(p, &v->edges) {
+                        e = list_entry(p, struct edge, next);
+
+                        /* Only include it if both sides announced it. */
+                        if (e->announced != 2)
+                                continue;
+
+                        /*
+                         * NOTE: Current weight is just hop count.
+                         * Method could be extended to use a different
+                         * weight for a different QoS cube.
+                         */
+                        alt = (*dist)[i] + 1;
+                        if (alt < (*dist)[e->nb->index]) {
+                                (*dist)[e->nb->index] = alt;
+                                if (v->addr == src)
+                                        (*nhops)[e->nb->index] = e->nb;
+                                else
+                                        (*nhops)[e->nb->index] = (*nhops)[i];
+                        }
+                }
+                i = get_min_vertex(graph, *dist, used, &v);
+        }
+
+        free(used);
+
+        return 0;
+
+ fail_used:
+        free(*dist);
+ fail_pdist:
+        free(*nhops);
+ fail_pnhops:
+        return -1;
+
+}
+
+static void free_routing_table(struct list_head * table)
+{
+        struct list_head * h;
+        struct list_head * p;
+        struct list_head * q;
+        struct list_head * i;
+
+        list_for_each_safe(p, h, table) {
+                struct routing_table * t =
+                        list_entry(p, struct routing_table, next);
+                list_for_each_safe(q, i, &t->nhops) {
+                        struct nhop * n =
+                                list_entry(q, struct nhop, next);
+                        list_del(&n->next);
+                        free(n);
+                }
+                list_del(&t->next);
+                free(t);
+        }
+}
+
+void graph_free_routing_table(struct graph *     graph,
+                              struct list_head * table)
+{
+        assert(table);
+
+        pthread_mutex_lock(&graph->lock);
+
+        free_routing_table(table);
+
+        pthread_mutex_unlock(&graph->lock);
+}
+
+static int graph_routing_table_simple(struct graph *     graph,
+                                      uint64_t           s_addr,
+                                      struct list_head * table,
+                                      int **             dist)
+{
+        struct vertex **       nhops;
+        struct list_head *     p;
+        int                    i = 0;
+        struct vertex *        v;
+        struct routing_table * t;
+        struct nhop *          n;
+
+        /* We need at least 2 vertices for a table */
+        if (graph->nr_vertices < 2)
+                goto fail_vertices;
+
+        if (dijkstra(graph, s_addr, &nhops, dist))
+                goto fail_vertices;
+
+        list_head_init(table);
+
+        /* Now construct the routing table from the nhops. */
+        list_for_each(p, &graph->vertices) {
+                v = list_entry(p, struct vertex, next);
+
+                /* This is the src */
+                if (nhops[i] == NULL) {
+                        i++;
+                        continue;
+                }
+
+                t = malloc(sizeof(*t));
+                if (t == NULL)
+                        goto fail_t;
+
+                list_head_init(&t->nhops);
+
+                n = malloc(sizeof(*n));
+                if (n == NULL)
+                        goto fail_n;
+
+                t->dst = v->addr;
+                n->nhop = nhops[i]->addr;
+
+                list_add(&n->next, &t->nhops);
+                list_add(&t->next, table);
+
+                i++;
+        }
+
+        free(nhops);
+
+        return 0;
+
+ fail_n:
+        free(t);
+ fail_t:
+        free_routing_table(table);
+        free(nhops);
+        free(*dist);
+ fail_vertices:
+        *dist = NULL;
+        return -1;
+}
+
+static int add_lfa_to_table(struct list_head * table,
+                            uint64_t           addr,
+                            uint64_t           lfa)
+{
+        struct list_head * p = NULL;
+        struct nhop *      n;
+
+        n = malloc(sizeof(*n));
+        if (n == NULL)
+                return -1;
+
+        n->nhop = lfa;
+
+        list_for_each(p, table) {
+                struct routing_table * t =
+                        list_entry(p, struct routing_table, next);
+                if (t->dst == addr) {
+                        list_add_tail(&n->next, &t->nhops);
+                        return 0;
+                }
+        }
+
+        free(n);
+
+        return -1;
+}
+
+int graph_routing_table(struct graph *     graph,
+                        enum routing_algo  algo,
+                        uint64_t           s_addr,
+                        struct list_head * table)
+{
+        int *              s_dist;
+        int *              n_dist[PROG_MAX_FLOWS];
+        uint64_t           addrs[PROG_MAX_FLOWS];
+        int                n_index[PROG_MAX_FLOWS];
+        struct list_head * p;
+        struct list_head * q;
+        struct vertex *    v;
+        struct edge *      e;
+        struct vertex **   nhops;
+        int                i = 0;
+        int                j = 0;
+        int                k;
+
+        assert(graph);
+        assert(table);
+
+        pthread_mutex_lock(&graph->lock);
+
+        /* Get the simple next hops routing table. */
+        if (graph_routing_table_simple(graph, s_addr, table, &s_dist))
+                goto fail_table_simple;
+
+        /* Possibly augment the routing table. */
+        switch (algo) {
+        case ROUTING_SIMPLE:
+                break;
+        case ROUTING_LFA:
+                for (j = 0; j < PROG_MAX_FLOWS; j++) {
+                        n_dist[j] = NULL;
+                        n_index[j] = -1;
+                        addrs[j] = -1;
+                }
+
+                list_for_each(p, &graph->vertices) {
+                        v = list_entry(p, struct vertex, next);
+
+                        if (v->addr != s_addr)
+                                continue;
+
+                        /*
+                         * Get the distances for every neighbor
+                         * of the source.
+                         */
+                        list_for_each(q, &v->edges) {
+                                e = list_entry(q, struct edge, next);
+
+                                addrs[i] = e->nb->addr;
+                                n_index[i] = e->nb->index;
+                                if (dijkstra(graph, e->nb->addr,
+                                             &nhops, &(n_dist[i++])))
+                                        goto fail_dijkstra;
+
+                                free(nhops);
+                        }
+
+                        break;
+                }
+
+                /* Loop though all nodes to see if we have a LFA for them. */
+                list_for_each(p, &graph->vertices) {
+                        v = list_entry(p, struct vertex, next);
+
+                        if (v->addr == s_addr)
+                                continue;
+
+                        /*
+                         * Check for every neighbor if
+                         * dist(neighbor, destination) <
+                         * dist(neighbor, source) + dist(source, destination).
+                         */
+                        for (j = 0; j < i; j++) {
+                                /* Exclude ourselves. */
+                                if (addrs[j] == v->addr)
+                                        continue;
+
+                                if (n_dist[j][v->index] <
+                                    s_dist[n_index[j]] + s_dist[v->index])
+                                        if (add_lfa_to_table(table, v->addr,
+                                                             addrs[j]))
+                                                goto fail_add_lfa;
+                        }
+                }
+
+                for (j = 0; j < i; j++)
+                        free(n_dist[j]);
+
+                break;
+        default:
+                log_err("Unsupported algorithm.");
+                goto fail_algo;
+        }
+
+        pthread_mutex_unlock(&graph->lock);
+
+        free(s_dist);
+
+        return 0;
+
+ fail_add_lfa:
+        for (k = j; k < i; k++)
+                free(n_dist[k]);
+ fail_dijkstra:
+        free_routing_table(table);
+ fail_algo:
+        free(s_dist);
+ fail_table_simple:
+        pthread_mutex_unlock(&graph->lock);
+
+        return -1;
+}
diff --git a/src/ipcpd/unicast/pol/graph.h b/src/ipcpd/unicast/pol/graph.h
new file mode 100644
index 00000000..06a2bd0d
--- /dev/null
+++ b/src/ipcpd/unicast/pol/graph.h
@@ -0,0 +1,68 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Undirected graph structure
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#ifndef OUROBOROS_IPCPD_UNICAST_GRAPH_H
+#define OUROBOROS_IPCPD_UNICAST_GRAPH_H
+
+#include <ouroboros/list.h>
+#include <ouroboros/qos.h>
+
+#include <inttypes.h>
+
+enum routing_algo {
+         ROUTING_SIMPLE = 0,
+         ROUTING_LFA
+};
+
+struct nhop {
+        struct list_head next;
+        uint64_t         nhop;
+};
+
+struct routing_table {
+        struct list_head next;
+        uint64_t         dst;
+        struct list_head nhops;
+};
+
+struct graph * graph_create(void);
+
+void           graph_destroy(struct graph * graph);
+
+int            graph_update_edge(struct graph * graph,
+                                 uint64_t       s_addr,
+                                 uint64_t       d_addr,
+                                 qosspec_t      qs);
+
+int            graph_del_edge(struct graph * graph,
+                              uint64_t       s_addr,
+                              uint64_t       d_addr);
+
+int            graph_routing_table(struct graph *     graph,
+                                   enum routing_algo  algo,
+                                   uint64_t           s_addr,
+                                   struct list_head * table);
+
+void           graph_free_routing_table(struct graph *     graph,
+                                        struct list_head * table);
+
+#endif /* OUROBOROS_IPCPD_UNICAST_GRAPH_H */
diff --git a/src/ipcpd/unicast/pol/link_state.c b/src/ipcpd/unicast/pol/link_state.c
new file mode 100644
index 00000000..d8f0e263
--- /dev/null
+++ b/src/ipcpd/unicast/pol/link_state.c
@@ -0,0 +1,1022 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Link state routing policy
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#if defined(__linux__) || defined(__CYGWIN__)
+#define _DEFAULT_SOURCE
+#else
+#define _POSIX_C_SOURCE 200112L
+#endif
+
+#include "config.h"
+
+#define OUROBOROS_PREFIX "link-state-routing"
+
+#include <ouroboros/endian.h>
+#include <ouroboros/dev.h>
+#include <ouroboros/errno.h>
+#include <ouroboros/fccntl.h>
+#include <ouroboros/fqueue.h>
+#include <ouroboros/list.h>
+#include <ouroboros/logs.h>
+#include <ouroboros/notifier.h>
+#include <ouroboros/rib.h>
+#include <ouroboros/utils.h>
+
+#include "comp.h"
+#include "connmgr.h"
+#include "graph.h"
+#include "ipcp.h"
+#include "link_state.h"
+#include "pff.h"
+
+#include <assert.h>
+#include <stdlib.h>
+#include <inttypes.h>
+#include <string.h>
+#include <pthread.h>
+
+#define RECALC_TIME    4
+#define LS_UPDATE_TIME 15
+#define LS_TIMEO       60
+#define LS_ENTRY_SIZE  104
+#define LSDB           "lsdb"
+
+#ifndef CLOCK_REALTIME_COARSE
+#define CLOCK_REALTIME_COARSE CLOCK_REALTIME
+#endif
+
+struct lsa {
+        uint64_t d_addr;
+        uint64_t s_addr;
+        uint64_t seqno;
+} __attribute__((packed));
+
+struct routing_i {
+        struct list_head next;
+
+        struct pff *     pff;
+        pthread_t        calculator;
+
+        bool             modified;
+        pthread_mutex_t  lock;
+};
+
+/* TODO: link weight support. */
+struct adjacency {
+        struct list_head next;
+
+        uint64_t         dst;
+        uint64_t         src;
+
+        uint64_t         seqno;
+
+        time_t           stamp;
+};
+
+enum nb_type {
+        NB_DT = 0,
+        NB_MGMT
+};
+
+struct nb {
+        struct list_head next;
+
+        uint64_t         addr;
+        int              fd;
+        enum nb_type     type;
+};
+
+struct {
+        struct list_head  nbs;
+        size_t            nbs_len;
+        fset_t *          mgmt_set;
+
+        struct list_head  db;
+        size_t            db_len;
+
+        pthread_rwlock_t  db_lock;
+
+        struct graph *    graph;
+
+        pthread_t         lsupdate;
+        pthread_t         lsreader;
+        pthread_t         listener;
+
+        struct list_head  routing_instances;
+        pthread_mutex_t   routing_i_lock;
+
+        enum routing_algo routing_algo;
+} ls;
+
+struct pol_routing_ops link_state_ops = {
+        .init              = link_state_init,
+        .fini              = link_state_fini,
+        .routing_i_create  = link_state_routing_i_create,
+        .routing_i_destroy = link_state_routing_i_destroy
+};
+
+static int str_adj(struct adjacency * adj,
+                   char *             buf,
+                   size_t             len)
+{
+        char        tmbuf[64];
+        char        srcbuf[64];
+        char        dstbuf[64];
+        char        seqnobuf[64];
+        struct tm * tm;
+
+        if (len < LS_ENTRY_SIZE)
+                return -1;
+
+        tm = localtime(&adj->stamp);
+        strftime(tmbuf, sizeof(tmbuf), "%F %T", tm); /* 19 chars */
+
+        sprintf(srcbuf, "%" PRIu64, adj->src);
+        sprintf(dstbuf, "%" PRIu64, adj->dst);
+        sprintf(seqnobuf, "%" PRIu64, adj->seqno);
+
+        sprintf(buf, "src: %20s\ndst: %20s\nseqno: %18s\nupd: %20s\n",
+                srcbuf, dstbuf, seqnobuf, tmbuf);
+
+        return LS_ENTRY_SIZE;
+}
+
+static struct adjacency * get_adj(const char * path)
+{
+        struct list_head * p;
+        char               entry[RIB_PATH_LEN + 1];
+
+        assert(path);
+
+        list_for_each(p, &ls.db) {
+                struct adjacency * a = list_entry(p, struct adjacency, next);
+                sprintf(entry, "%" PRIu64 ".%" PRIu64, a->src, a->dst);
+                if (strcmp(entry, path) == 0)
+                        return a;
+        }
+
+        return NULL;
+}
+
+static int lsdb_getattr(const char *  path,
+                        struct stat * st)
+{
+        struct adjacency * adj;
+        struct timespec    now;
+
+        clock_gettime(CLOCK_REALTIME_COARSE, &now);
+
+        pthread_rwlock_rdlock(&ls.db_lock);
+
+        adj = get_adj(path);
+        if (adj != NULL) {
+                st->st_mtime = adj->stamp;
+                st->st_size  = LS_ENTRY_SIZE;
+        } else {
+                st->st_mtime = now.tv_sec;
+                st->st_size  = 0;
+        }
+
+        st->st_mode  = S_IFREG | 0755;
+        st->st_nlink = 1;
+        st->st_uid   = getuid();
+        st->st_gid   = getgid();
+
+        pthread_rwlock_unlock(&ls.db_lock);
+
+        return 0;
+}
+
+static int lsdb_read(const char * path,
+                     char *       buf,
+                     size_t       len)
+{
+        struct adjacency * a;
+        int                size;
+
+        pthread_rwlock_rdlock(&ls.db_lock);
+
+        if (ls.db_len + ls.nbs_len == 0)
+                goto fail;
+
+        a = get_adj(path);
+        if (a == NULL)
+                goto fail;
+
+        size = str_adj(a, buf, len);
+        if (size < 0)
+                goto fail;
+
+        pthread_rwlock_unlock(&ls.db_lock);
+        return size;
+
+ fail:
+        pthread_rwlock_unlock(&ls.db_lock);
+        return -1;
+}
+
+static int lsdb_readdir(char *** buf)
+{
+        struct list_head * p;
+        char               entry[RIB_PATH_LEN + 1];
+        ssize_t            idx = 0;
+
+        pthread_rwlock_rdlock(&ls.db_lock);
+
+        if (ls.db_len + ls.nbs_len == 0) {
+                pthread_rwlock_unlock(&ls.db_lock);
+                return 0;
+        }
+
+        *buf = malloc(sizeof(**buf) * (ls.db_len + ls.nbs_len));
+        if (*buf == NULL) {
+                pthread_rwlock_unlock(&ls.db_lock);
+                return -ENOMEM;
+        }
+
+        list_for_each(p, &ls.nbs) {
+                struct nb * nb = list_entry(p, struct nb, next);
+                char * str = (nb->type == NB_DT ? "dt." : "mgmt.");
+                sprintf(entry, "%s%" PRIu64, str, nb->addr);
+                (*buf)[idx] = malloc(strlen(entry) + 1);
+                if ((*buf)[idx] == NULL) {
+                        while (idx-- > 0)
+                                free((*buf)[idx]);
+                        free(buf);
+                        pthread_rwlock_unlock(&ls.db_lock);
+                        return -ENOMEM;
+                }
+
+                strcpy((*buf)[idx], entry);
+
+                idx++;
+        }
+
+        list_for_each(p, &ls.db) {
+                struct adjacency * a = list_entry(p, struct adjacency, next);
+                sprintf(entry, "%" PRIu64 ".%" PRIu64, a->src, a->dst);
+                (*buf)[idx] = malloc(strlen(entry) + 1);
+                if ((*buf)[idx] == NULL) {
+                        ssize_t j;
+                        for (j = 0; j < idx; ++j)
+                                free(*buf[j]);
+                        free(buf);
+                        pthread_rwlock_unlock(&ls.db_lock);
+                        return -ENOMEM;
+                }
+
+                strcpy((*buf)[idx], entry);
+
+                idx++;
+        }
+
+        pthread_rwlock_unlock(&ls.db_lock);
+
+        return idx;
+}
+
+static struct rib_ops r_ops = {
+        .read    = lsdb_read,
+        .readdir = lsdb_readdir,
+        .getattr = lsdb_getattr
+};
+
+static int lsdb_add_nb(uint64_t     addr,
+                       int          fd,
+                       enum nb_type type)
+{
+        struct list_head * p;
+        struct nb *        nb;
+
+        pthread_rwlock_wrlock(&ls.db_lock);
+
+        list_for_each(p, &ls.nbs) {
+                struct nb * el = list_entry(p, struct nb, next);
+                if (el->addr == addr && el->type == type) {
+                        log_dbg("Already know %s neighbor %" PRIu64 ".",
+                                type == NB_DT ? "dt" : "mgmt", addr);
+                        if (el->fd != fd) {
+                                log_warn("Existing neighbor assigned new fd.");
+                                el->fd = fd;
+                        }
+                        pthread_rwlock_unlock(&ls.db_lock);
+                        return -EPERM;
+                }
+
+                if (addr > el->addr)
+                        break;
+        }
+
+        nb = malloc(sizeof(*nb));
+        if (nb == NULL) {
+                pthread_rwlock_unlock(&ls.db_lock);
+                return -ENOMEM;
+        }
+
+        nb->addr  = addr;
+        nb->fd    = fd;
+        nb->type  = type;
+
+        list_add_tail(&nb->next, p);
+
+        ++ls.nbs_len;
+
+        log_dbg("Type %s neighbor %" PRIu64 " added.",
+                nb->type == NB_DT ? "dt" : "mgmt", addr);
+
+        pthread_rwlock_unlock(&ls.db_lock);
+
+        return 0;
+}
+
+static int lsdb_del_nb(uint64_t     addr,
+                       int          fd)
+{
+        struct list_head * p;
+        struct list_head * h;
+
+        pthread_rwlock_wrlock(&ls.db_lock);
+
+        list_for_each_safe(p, h, &ls.nbs) {
+                struct nb * nb = list_entry(p, struct nb, next);
+                if (nb->addr == addr && nb->fd == fd) {
+                        list_del(&nb->next);
+                        --ls.nbs_len;
+                        pthread_rwlock_unlock(&ls.db_lock);
+                        log_dbg("Type %s neighbor %" PRIu64 " deleted.",
+                                nb->type == NB_DT ? "dt" : "mgmt", addr);
+                        free(nb);
+                        return 0;
+                }
+        }
+
+        pthread_rwlock_unlock(&ls.db_lock);
+
+        return -EPERM;
+}
+
+static int nbr_to_fd(uint64_t addr)
+{
+        struct list_head * p;
+
+        pthread_rwlock_rdlock(&ls.db_lock);
+
+        list_for_each(p, &ls.nbs) {
+                struct nb * nb = list_entry(p, struct nb, next);
+                if (nb->addr == addr && nb->type == NB_DT) {
+                        pthread_rwlock_unlock(&ls.db_lock);
+                        return nb->fd;
+                }
+        }
+
+        pthread_rwlock_unlock(&ls.db_lock);
+
+        return -1;
+}
+
+static void calculate_pff(struct routing_i * instance)
+{
+        int                fd;
+        struct list_head   table;
+        struct list_head * p;
+        struct list_head * q;
+        int                fds[PROG_MAX_FLOWS];
+
+        if (graph_routing_table(ls.graph, ls.routing_algo,
+                                ipcpi.dt_addr, &table))
+                return;
+
+        pff_lock(instance->pff);
+
+        pff_flush(instance->pff);
+
+        /* Calculate forwarding table from routing table. */
+        list_for_each(p, &table) {
+                int                    i = 0;
+                struct routing_table * t =
+                        list_entry(p, struct routing_table, next);
+
+                list_for_each(q, &t->nhops) {
+                        struct nhop * n = list_entry(q, struct nhop, next);
+
+                        fd = nbr_to_fd(n->nhop);
+                        if (fd == -1)
+                                continue;
+
+                        fds[i++] = fd;
+                }
+                if (i > 0)
+                        pff_add(instance->pff, t->dst, fds, i);
+        }
+
+        pff_unlock(instance->pff);
+
+        graph_free_routing_table(ls.graph, &table);
+}
+
+static void set_pff_modified(bool calc)
+{
+        struct list_head * p;
+
+        pthread_mutex_lock(&ls.routing_i_lock);
+        list_for_each(p, &ls.routing_instances) {
+                struct routing_i * inst =
+                        list_entry(p, struct routing_i, next);
+                pthread_mutex_lock(&inst->lock);
+                inst->modified = true;
+                pthread_mutex_unlock(&inst->lock);
+                if (calc)
+                        calculate_pff(inst);
+        }
+        pthread_mutex_unlock(&ls.routing_i_lock);
+}
+
+static int lsdb_add_link(uint64_t    src,
+                         uint64_t    dst,
+                         uint64_t    seqno,
+                         qosspec_t * qs)
+{
+        struct list_head * p;
+        struct adjacency * adj;
+        struct timespec    now;
+        int                ret = -1;
+
+        clock_gettime(CLOCK_REALTIME_COARSE, &now);
+
+        pthread_rwlock_wrlock(&ls.db_lock);
+
+        list_for_each(p, &ls.db) {
+                struct adjacency * a = list_entry(p, struct adjacency, next);
+                if (a->dst == dst && a->src == src) {
+                        if (a->seqno < seqno) {
+                                a->stamp = now.tv_sec;
+                                a->seqno = seqno;
+                                ret = 0;
+                        }
+                        pthread_rwlock_unlock(&ls.db_lock);
+                        return ret;
+                }
+
+                if (a->dst > dst || (a->dst == dst && a->src > src))
+                        break;
+        }
+
+        adj = malloc(sizeof(*adj));
+        if (adj == NULL) {
+                pthread_rwlock_unlock(&ls.db_lock);
+                return -ENOMEM;
+        }
+
+        adj->dst   = dst;
+        adj->src   = src;
+        adj->seqno = seqno;
+        adj->stamp = now.tv_sec;
+
+        list_add_tail(&adj->next, p);
+
+        ls.db_len++;
+
+        if (graph_update_edge(ls.graph, src, dst, *qs))
+                log_warn("Failed to add edge to graph.");
+
+        pthread_rwlock_unlock(&ls.db_lock);
+
+        set_pff_modified(true);
+
+        return 0;
+}
+
+static int lsdb_del_link(uint64_t src,
+                         uint64_t dst)
+{
+        struct list_head * p;
+        struct list_head * h;
+
+        pthread_rwlock_wrlock(&ls.db_lock);
+
+        list_for_each_safe(p, h, &ls.db) {
+                struct adjacency * a = list_entry(p, struct adjacency, next);
+                if (a->dst == dst && a->src == src) {
+                        list_del(&a->next);
+                        if (graph_del_edge(ls.graph, src, dst))
+                                log_warn("Failed to delete edge from graph.");
+
+                        ls.db_len--;
+
+                        pthread_rwlock_unlock(&ls.db_lock);
+                        set_pff_modified(false);
+                        free(a);
+                        return 0;
+                }
+        }
+
+        pthread_rwlock_unlock(&ls.db_lock);
+
+        return -EPERM;
+}
+
+static void * periodic_recalc_pff(void * o)
+{
+        bool               modified;
+        struct routing_i * inst = (struct routing_i *) o;
+
+        while (true) {
+                pthread_mutex_lock(&inst->lock);
+                modified = inst->modified;
+                inst->modified = false;
+                pthread_mutex_unlock(&inst->lock);
+
+                if (modified)
+                        calculate_pff(inst);
+                sleep(RECALC_TIME);
+        }
+
+        return (void *) 0;
+}
+
+static void send_lsm(uint64_t src,
+                     uint64_t dst,
+                     uint64_t seqno)
+{
+        struct lsa         lsm;
+        struct list_head * p;
+
+        lsm.d_addr = hton64(dst);
+        lsm.s_addr = hton64(src);
+        lsm.seqno  = hton64(seqno);
+
+        list_for_each(p, &ls.nbs) {
+                struct nb * nb = list_entry(p, struct nb, next);
+                if (nb->type == NB_MGMT)
+                        flow_write(nb->fd, &lsm, sizeof(lsm));
+        }
+}
+
+/* replicate the lsdb to a mgmt neighbor */
+static void lsdb_replicate(int fd)
+{
+        struct list_head * p;
+        struct list_head * h;
+        struct list_head   copy;
+
+        list_head_init(&copy);
+
+        /* Lock the lsdb, copy the lsms and send outside of lock. */
+        pthread_rwlock_rdlock(&ls.db_lock);
+
+        list_for_each(p, &ls.db) {
+                struct adjacency * adj;
+                struct adjacency * cpy;
+                adj = list_entry(p, struct adjacency, next);
+                cpy = malloc(sizeof(*cpy));
+                if (cpy == NULL) {
+                        log_warn("Failed to replicate full lsdb.");
+                        break;
+                }
+
+                cpy->dst   = adj->dst;
+                cpy->src   = adj->src;
+                cpy->seqno = adj->seqno;
+
+                list_add_tail(&cpy->next, &copy);
+        }
+
+        pthread_rwlock_unlock(&ls.db_lock);
+
+        list_for_each_safe(p, h, &copy) {
+                struct lsa         lsm;
+                struct adjacency * adj;
+                adj = list_entry(p, struct adjacency, next);
+                lsm.d_addr = hton64(adj->dst);
+                lsm.s_addr = hton64(adj->src);
+                lsm.seqno  = hton64(adj->seqno);
+                list_del(&adj->next);
+                free(adj);
+                flow_write(fd, &lsm, sizeof(lsm));
+        }
+}
+
+static void * lsupdate(void * o)
+{
+        struct list_head * p;
+        struct list_head * h;
+        struct timespec    now;
+
+        (void) o;
+
+        while (true) {
+                clock_gettime(CLOCK_REALTIME_COARSE, &now);
+
+                pthread_rwlock_rdlock(&ls.db_lock);
+
+                pthread_cleanup_push((void (*) (void *)) pthread_rwlock_unlock,
+                                     (void *) &ls.db_lock);
+
+                list_for_each_safe(p, h, &ls.db) {
+                        struct adjacency * adj;
+                        adj = list_entry(p, struct adjacency, next);
+                        if (now.tv_sec - adj->stamp > LS_TIMEO) {
+                                list_del(&adj->next);
+                                log_dbg("%" PRIu64 " - %" PRIu64" timed out.",
+                                        adj->src, adj->dst);
+                                if (graph_del_edge(ls.graph, adj->src,
+                                                   adj->dst))
+                                        log_err("Failed to del edge.");
+                                free(adj);
+                                continue;
+                        }
+
+                        if (adj->src == ipcpi.dt_addr) {
+                                adj->seqno++;
+                                send_lsm(adj->src, adj->dst, adj->seqno);
+                                adj->stamp = now.tv_sec;
+                        }
+                }
+
+                pthread_cleanup_pop(true);
+
+                sleep(LS_UPDATE_TIME);
+        }
+
+        return (void *) 0;
+}
+
+static void * ls_conn_handle(void * o)
+{
+        struct conn conn;
+
+        (void) o;
+
+        while (true) {
+                if (connmgr_wait(COMPID_MGMT, &conn)) {
+                        log_err("Failed to get next MGMT connection.");
+                        continue;
+                }
+
+                /* NOTE: connection acceptance policy could be here. */
+
+                notifier_event(NOTIFY_MGMT_CONN_ADD, &conn);
+        }
+
+        return 0;
+}
+
+
+static void forward_lsm(uint8_t * buf,
+                        size_t    len,
+                        int       in_fd)
+{
+        struct list_head * p;
+
+        pthread_rwlock_rdlock(&ls.db_lock);
+
+        pthread_cleanup_push((void (*))(void *) pthread_rwlock_unlock,
+                             &ls.db_lock);
+
+        list_for_each(p, &ls.nbs) {
+                struct nb * nb = list_entry(p, struct nb, next);
+                if (nb->type == NB_MGMT && nb->fd != in_fd)
+                        flow_write(nb->fd, buf, len);
+        }
+
+        pthread_cleanup_pop(true);
+}
+
+static void * lsreader(void * o)
+{
+        fqueue_t *   fq;
+        int          ret;
+        uint8_t      buf[sizeof(struct lsa)];
+        int          fd;
+        qosspec_t    qs;
+        struct lsa * msg;
+        size_t       len;
+
+        (void) o;
+
+        memset(&qs, 0, sizeof(qs));
+
+        fq = fqueue_create();
+        if (fq == NULL)
+                return (void *) -1;
+
+        pthread_cleanup_push((void (*) (void *)) fqueue_destroy,
+                             (void *) fq);
+
+        while (true) {
+                ret = fevent(ls.mgmt_set, fq, NULL);
+                if (ret < 0) {
+                        log_warn("Event error: %d.", ret);
+                        continue;
+                }
+
+                while ((fd = fqueue_next(fq)) >= 0) {
+                        if (fqueue_type(fq) != FLOW_PKT)
+                                continue;
+
+                        len = flow_read(fd, buf, sizeof(*msg));
+                        if (len <= 0 || len != sizeof(*msg))
+                                continue;
+
+                        msg = (struct lsa *) buf;
+
+                        if (lsdb_add_link(ntoh64(msg->s_addr),
+                                          ntoh64(msg->d_addr),
+                                          ntoh64(msg->seqno),
+                                          &qs))
+                                continue;
+
+                        forward_lsm(buf, len, fd);
+                }
+        }
+
+        pthread_cleanup_pop(true);
+
+        return (void *) 0;
+}
+
+static void flow_event(int  fd,
+                       bool up)
+{
+
+        struct list_head * p;
+
+        log_dbg("Notifying routing instances of flow event.");
+
+        pthread_mutex_lock(&ls.routing_i_lock);
+
+        list_for_each(p, &ls.routing_instances) {
+                struct routing_i * ri = list_entry(p, struct routing_i, next);
+                pff_flow_state_change(ri->pff, fd, up);
+        }
+
+        pthread_mutex_unlock(&ls.routing_i_lock);
+}
+
+static void handle_event(void *       self,
+                         int          event,
+                         const void * o)
+{
+        /* FIXME: Apply correct QoS on graph */
+        struct conn *      c;
+        qosspec_t          qs;
+        int                flags;
+
+        (void) self;
+
+        c = (struct conn *) o;
+
+        memset(&qs, 0, sizeof(qs));
+
+        switch (event) {
+        case NOTIFY_DT_CONN_ADD:
+                pthread_rwlock_rdlock(&ls.db_lock);
+                send_lsm(ipcpi.dt_addr, c->conn_info.addr, 0);
+                pthread_rwlock_unlock(&ls.db_lock);
+
+                if (lsdb_add_nb(c->conn_info.addr, c->flow_info.fd, NB_DT))
+                        log_dbg("Failed to add neighbor to LSDB.");
+
+                if (lsdb_add_link(ipcpi.dt_addr, c->conn_info.addr, 0, &qs))
+                        log_dbg("Failed to add new adjacency to LSDB.");
+                break;
+        case NOTIFY_DT_CONN_DEL:
+                flow_event(c->flow_info.fd, false);
+
+                if (lsdb_del_nb(c->conn_info.addr, c->flow_info.fd))
+                        log_dbg("Failed to delete neighbor from LSDB.");
+
+                if (lsdb_del_link(ipcpi.dt_addr, c->conn_info.addr))
+                        log_dbg("Local link was not in LSDB.");
+                break;
+        case NOTIFY_DT_CONN_QOS:
+                log_dbg("QoS changes currently unsupported.");
+                break;
+        case NOTIFY_DT_CONN_UP:
+                flow_event(c->flow_info.fd, true);
+                break;
+        case NOTIFY_DT_CONN_DOWN:
+                flow_event(c->flow_info.fd, false);
+                break;
+        case NOTIFY_MGMT_CONN_ADD:
+                fccntl(c->flow_info.fd, FLOWGFLAGS, &flags);
+                fccntl(c->flow_info.fd, FLOWSFLAGS, flags | FLOWFRNOPART);
+                fset_add(ls.mgmt_set, c->flow_info.fd);
+                if (lsdb_add_nb(c->conn_info.addr, c->flow_info.fd, NB_MGMT))
+                        log_warn("Failed to add mgmt neighbor to LSDB.");
+                /* replicate the entire lsdb */
+                lsdb_replicate(c->flow_info.fd);
+                break;
+        case NOTIFY_MGMT_CONN_DEL:
+                fset_del(ls.mgmt_set, c->flow_info.fd);
+                if (lsdb_del_nb(c->conn_info.addr, c->flow_info.fd))
+                        log_warn("Failed to delete mgmt neighbor from LSDB.");
+                break;
+        default:
+                break;
+        }
+}
+
+struct routing_i * link_state_routing_i_create(struct pff * pff)
+{
+        struct routing_i * tmp;
+
+        assert(pff);
+
+        tmp = malloc(sizeof(*tmp));
+        if (tmp == NULL)
+                goto fail_tmp;
+
+        tmp->pff      = pff;
+        tmp->modified = false;
+
+        if (pthread_mutex_init(&tmp->lock, NULL))
+                goto fail_instance_lock_init;
+
+        if (pthread_create(&tmp->calculator, NULL,
+                           periodic_recalc_pff, tmp))
+                goto fail_pthread_create_lsupdate;
+
+        pthread_mutex_lock(&ls.routing_i_lock);
+
+        list_add(&tmp->next, &ls.routing_instances);
+
+        pthread_mutex_unlock(&ls.routing_i_lock);
+
+        return tmp;
+
+ fail_pthread_create_lsupdate:
+        pthread_mutex_destroy(&tmp->lock);
+ fail_instance_lock_init:
+        free(tmp);
+ fail_tmp:
+        return NULL;
+}
+
+void link_state_routing_i_destroy(struct routing_i * instance)
+{
+        assert(instance);
+
+        pthread_mutex_lock(&ls.routing_i_lock);
+
+        list_del(&instance->next);
+
+        pthread_mutex_unlock(&ls.routing_i_lock);
+
+        pthread_cancel(instance->calculator);
+
+        pthread_join(instance->calculator, NULL);
+
+        pthread_mutex_destroy(&instance->lock);
+
+        free(instance);
+}
+
+int link_state_init(enum pol_routing pr)
+{
+        struct conn_info info;
+
+        memset(&info, 0, sizeof(info));
+
+        strcpy(info.comp_name, LS_COMP);
+        strcpy(info.protocol, LS_PROTO);
+        info.pref_version = 1;
+        info.pref_syntax  = PROTO_GPB;
+        info.addr         = ipcpi.dt_addr;
+
+        switch (pr) {
+        case ROUTING_LINK_STATE:
+                log_dbg("Using link state routing policy.");
+                ls.routing_algo = ROUTING_SIMPLE;
+                break;
+        case ROUTING_LINK_STATE_LFA:
+                log_dbg("Using Loop-Free Alternates policy.");
+                ls.routing_algo = ROUTING_LFA;
+                break;
+        default:
+                goto fail_graph;
+        }
+
+        ls.graph = graph_create();
+        if (ls.graph == NULL)
+                goto fail_graph;
+
+        if (notifier_reg(handle_event, NULL))
+                goto fail_notifier_reg;
+
+        if (pthread_rwlock_init(&ls.db_lock, NULL))
+                goto fail_db_lock_init;
+
+        if (pthread_mutex_init(&ls.routing_i_lock, NULL))
+                goto fail_routing_i_lock_init;
+
+        if (connmgr_comp_init(COMPID_MGMT, &info))
+                goto fail_connmgr_comp_init;
+
+        ls.mgmt_set = fset_create();
+        if (ls.mgmt_set == NULL)
+                goto fail_fset_create;
+
+        list_head_init(&ls.db);
+        list_head_init(&ls.nbs);
+        list_head_init(&ls.routing_instances);
+
+        if (pthread_create(&ls.lsupdate, NULL, lsupdate, NULL))
+                goto fail_pthread_create_lsupdate;
+
+        if (pthread_create(&ls.lsreader, NULL, lsreader, NULL))
+                goto fail_pthread_create_lsreader;
+
+        if (pthread_create(&ls.listener, NULL, ls_conn_handle, NULL))
+                goto fail_pthread_create_listener;
+
+        if (rib_reg(LSDB, &r_ops))
+                goto fail_rib_reg;
+
+        ls.db_len      = 0;
+        ls.nbs_len     = 0;
+
+        return 0;
+
+ fail_rib_reg:
+        pthread_cancel(ls.listener);
+        pthread_join(ls.listener, NULL);
+ fail_pthread_create_listener:
+        pthread_cancel(ls.lsreader);
+        pthread_join(ls.lsreader, NULL);
+ fail_pthread_create_lsreader:
+        pthread_cancel(ls.lsupdate);
+        pthread_join(ls.lsupdate, NULL);
+ fail_pthread_create_lsupdate:
+        fset_destroy(ls.mgmt_set);
+ fail_fset_create:
+        connmgr_comp_fini(COMPID_MGMT);
+ fail_connmgr_comp_init:
+        pthread_mutex_destroy(&ls.routing_i_lock);
+ fail_routing_i_lock_init:
+        pthread_rwlock_destroy(&ls.db_lock);
+ fail_db_lock_init:
+        notifier_unreg(handle_event);
+ fail_notifier_reg:
+        graph_destroy(ls.graph);
+ fail_graph:
+        return -1;
+}
+
+void link_state_fini(void)
+{
+        struct list_head * p;
+        struct list_head * h;
+
+        rib_unreg(LSDB);
+
+        pthread_cancel(ls.listener);
+        pthread_join(ls.listener, NULL);
+
+        pthread_cancel(ls.lsreader);
+        pthread_join(ls.lsreader, NULL);
+
+        pthread_cancel(ls.lsupdate);
+        pthread_join(ls.lsupdate, NULL);
+
+        fset_destroy(ls.mgmt_set);
+
+        connmgr_comp_fini(COMPID_MGMT);
+
+        graph_destroy(ls.graph);
+
+        pthread_rwlock_wrlock(&ls.db_lock);
+
+        list_for_each_safe(p, h, &ls.db) {
+                struct adjacency * a = list_entry(p, struct adjacency, next);
+                list_del(&a->next);
+                free(a);
+        }
+
+        pthread_rwlock_unlock(&ls.db_lock);
+
+        pthread_rwlock_destroy(&ls.db_lock);
+
+        pthread_mutex_destroy(&ls.routing_i_lock);
+
+        notifier_unreg(handle_event);
+}
diff --git a/src/ipcpd/unicast/pol/link_state.h b/src/ipcpd/unicast/pol/link_state.h
new file mode 100644
index 00000000..a7b44b4e
--- /dev/null
+++ b/src/ipcpd/unicast/pol/link_state.h
@@ -0,0 +1,41 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Link state routing policy
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#ifndef OUROBOROS_IPCPD_UNICAST_POL_LINK_STATE_H
+#define OUROBOROS_IPCPD_UNICAST_POL_LINK_STATE_H
+
+#define LS_COMP  "Management"
+#define LS_PROTO "LSP"
+
+#include "pol-routing-ops.h"
+
+int                link_state_init(enum pol_routing pr);
+
+void               link_state_fini(void);
+
+struct routing_i * link_state_routing_i_create(struct pff * pff);
+
+void               link_state_routing_i_destroy(struct routing_i * instance);
+
+struct pol_routing_ops link_state_ops;
+
+#endif /* OUROBOROS_IPCPD_UNICAST_POL_LINK_STATE_H */
diff --git a/src/ipcpd/unicast/pol/simple_pff.c b/src/ipcpd/unicast/pol/simple_pff.c
new file mode 100644
index 00000000..4338c53c
--- /dev/null
+++ b/src/ipcpd/unicast/pol/simple_pff.c
@@ -0,0 +1,187 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Simple PDU Forwarding Function
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#define _POSIX_C_SOURCE 200112L
+
+#include "config.h"
+
+#include <ouroboros/hashtable.h>
+#include <ouroboros/errno.h>
+
+#include <assert.h>
+#include <pthread.h>
+
+#include "simple_pff.h"
+
+struct pff_i {
+        struct htable *  table;
+        pthread_rwlock_t lock;
+};
+
+struct pol_pff_ops simple_pff_ops = {
+        .create            = simple_pff_create,
+        .destroy           = simple_pff_destroy,
+        .lock              = simple_pff_lock,
+        .unlock            = simple_pff_unlock,
+        .add               = simple_pff_add,
+        .update            = simple_pff_update,
+        .del               = simple_pff_del,
+        .flush             = simple_pff_flush,
+        .nhop              = simple_pff_nhop,
+        .flow_state_change = NULL
+};
+
+struct pff_i * simple_pff_create(void)
+{
+        struct pff_i * tmp;
+
+        tmp = malloc(sizeof(*tmp));
+        if (tmp == NULL)
+                return NULL;
+
+        if (pthread_rwlock_init(&tmp->lock, NULL)) {
+                free(tmp);
+                return NULL;
+        }
+
+        tmp->table = htable_create(PFT_SIZE, false);
+        if (tmp->table == NULL) {
+                pthread_rwlock_destroy(&tmp->lock);
+                free(tmp);
+                return NULL;
+        }
+
+        return tmp;
+}
+
+void simple_pff_destroy(struct pff_i * pff_i)
+{
+        assert(pff_i);
+
+        htable_destroy(pff_i->table);
+
+        pthread_rwlock_destroy(&pff_i->lock);
+        free(pff_i);
+}
+
+void simple_pff_lock(struct pff_i * pff_i)
+{
+        pthread_rwlock_wrlock(&pff_i->lock);
+}
+
+void simple_pff_unlock(struct pff_i * pff_i)
+{
+        pthread_rwlock_unlock(&pff_i->lock);
+}
+
+int simple_pff_add(struct pff_i * pff_i,
+                   uint64_t       addr,
+                   int *          fd,
+                   size_t         len)
+{
+        int * val;
+
+        assert(pff_i);
+        assert(len > 0);
+
+        (void) len;
+
+        val = malloc(sizeof(*val));
+        if (val == NULL)
+                return -ENOMEM;
+
+        *val = fd[0];
+
+        if (htable_insert(pff_i->table, addr, val, 1)) {
+                free(val);
+                return -1;
+        }
+
+        return 0;
+}
+
+int simple_pff_update(struct pff_i * pff_i,
+                      uint64_t       addr,
+                      int *          fd,
+                      size_t         len)
+{
+        int * val;
+
+        assert(pff_i);
+        assert(len > 0);
+
+        (void) len;
+
+        val = malloc(sizeof(*val));
+        if (val == NULL)
+                return -ENOMEM;
+        *val = fd[0];
+
+        if (htable_delete(pff_i->table, addr)) {
+                free(val);
+                return -1;
+        }
+
+        if (htable_insert(pff_i->table, addr, val, 1)) {
+                free(val);
+                return -1;
+        }
+
+        return 0;
+}
+
+int simple_pff_del(struct pff_i * pff_i,
+                   uint64_t       addr)
+{
+        assert(pff_i);
+
+        if (htable_delete(pff_i->table, addr))
+                return -1;
+
+        return 0;
+}
+
+void simple_pff_flush(struct pff_i * pff_i)
+{
+        assert(pff_i);
+
+        htable_flush(pff_i->table);
+}
+
+int simple_pff_nhop(struct pff_i * pff_i,
+                    uint64_t       addr)
+{
+        void * j;
+        size_t len;
+        int    fd = -1;
+
+        assert(pff_i);
+
+        pthread_rwlock_rdlock(&pff_i->lock);
+
+        if (!htable_lookup(pff_i->table, addr, &j, &len))
+                fd = *((int *) j);
+
+        pthread_rwlock_unlock(&pff_i->lock);
+
+        return fd;
+}
diff --git a/src/ipcpd/unicast/pol/simple_pff.h b/src/ipcpd/unicast/pol/simple_pff.h
new file mode 100644
index 00000000..02c09a58
--- /dev/null
+++ b/src/ipcpd/unicast/pol/simple_pff.h
@@ -0,0 +1,57 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Simple policy for PFF
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#ifndef OUROBOROS_IPCPD_UNICAST_SIMPLE_PFF_H
+#define OUROBOROS_IPCPD_UNICAST_SIMPLE_PFF_H
+
+#include "pol-pff-ops.h"
+
+struct pff_i * simple_pff_create(void);
+
+void           simple_pff_destroy(struct pff_i * pff_i);
+
+void           simple_pff_lock(struct pff_i * pff_i);
+
+void           simple_pff_unlock(struct pff_i * pff_i);
+
+int            simple_pff_add(struct pff_i * pff_i,
+                              uint64_t       addr,
+                              int *          fd,
+                              size_t         len);
+
+int            simple_pff_update(struct pff_i * pff_i,
+                                 uint64_t       addr,
+                                 int *          fd,
+                                 size_t         len);
+
+int            simple_pff_del(struct pff_i * pff_i,
+                              uint64_t       addr);
+
+void           simple_pff_flush(struct pff_i * pff_i);
+
+/* Returns fd towards next hop */
+int            simple_pff_nhop(struct pff_i * pff_i,
+                               uint64_t       addr);
+
+struct pol_pff_ops simple_pff_ops;
+
+#endif /* OUROBOROS_IPCPD_UNICAST_SIMPLE_PFF_H */
diff --git a/src/ipcpd/unicast/pol/tests/CMakeLists.txt b/src/ipcpd/unicast/pol/tests/CMakeLists.txt
new file mode 100644
index 00000000..d0652533
--- /dev/null
+++ b/src/ipcpd/unicast/pol/tests/CMakeLists.txt
@@ -0,0 +1,34 @@
+get_filename_component(CURRENT_SOURCE_PARENT_DIR
+  ${CMAKE_CURRENT_SOURCE_DIR} DIRECTORY)
+get_filename_component(CURRENT_BINARY_PARENT_DIR
+  ${CMAKE_CURRENT_BINARY_DIR} DIRECTORY)
+
+include_directories(${CMAKE_CURRENT_SOURCE_DIR})
+include_directories(${CMAKE_CURRENT_BINARY_DIR})
+
+include_directories(${CURRENT_SOURCE_PARENT_DIR})
+include_directories(${CURRENT_BINARY_PARENT_DIR})
+
+include_directories(${CMAKE_SOURCE_DIR}/include)
+include_directories(${CMAKE_BINARY_DIR}/include)
+
+get_filename_component(PARENT_PATH ${CMAKE_CURRENT_SOURCE_DIR} DIRECTORY)
+get_filename_component(PARENT_DIR ${PARENT_PATH} NAME)
+
+create_test_sourcelist(${PARENT_DIR}_tests test_suite.c
+  # Add new tests here
+  graph_test.c
+  )
+
+add_executable(${PARENT_DIR}_test EXCLUDE_FROM_ALL ${${PARENT_DIR}_tests})
+target_link_libraries(${PARENT_DIR}_test ouroboros-common)
+
+add_dependencies(check ${PARENT_DIR}_test)
+
+set(tests_to_run ${${PARENT_DIR}_tests})
+remove(tests_to_run test_suite.c)
+
+foreach (test ${tests_to_run})
+  get_filename_component(test_name ${test} NAME_WE)
+  add_test(${test_name} ${C_TEST_PATH}/${PARENT_DIR}_test ${test_name})
+endforeach (test)
diff --git a/src/ipcpd/unicast/pol/tests/graph_test.c b/src/ipcpd/unicast/pol/tests/graph_test.c
new file mode 100644
index 00000000..a312c1a8
--- /dev/null
+++ b/src/ipcpd/unicast/pol/tests/graph_test.c
@@ -0,0 +1,300 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Test of the graph structure
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#define _POSIX_C_SOURCE 200112L
+
+#include <ouroboros/utils.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "graph.c"
+
+struct graph *   graph;
+struct list_head table;
+qosspec_t        qs;
+
+int graph_test_entries(int entries)
+{
+        struct list_head * p;
+        int                i = 0;
+
+        if (graph_routing_table(graph, ROUTING_SIMPLE, 1, &table)) {
+                printf("Failed to get routing table.\n");
+                return -1;
+        }
+
+        list_for_each(p, &table)
+                i++;
+
+        if (i != entries) {
+                printf("Wrong number of entries.\n");
+                graph_free_routing_table(graph, &table);
+                return -1;
+        }
+
+        graph_free_routing_table(graph, &table);
+
+        return 0;
+}
+
+int graph_test_double_link(void)
+{
+        struct list_head * p;
+        int                i = 0;
+
+        if (graph_routing_table(graph, ROUTING_SIMPLE, 1, &table)) {
+                printf("Failed to get routing table.\n");
+                return -1;
+        }
+
+        list_for_each(p, &table)
+                i++;
+
+        if (i != 2) {
+                printf("Wrong number of entries.\n");
+                graph_free_routing_table(graph, &table);
+                return -1;
+        }
+
+        list_for_each(p, &table) {
+                struct routing_table * t =
+                        list_entry(p, struct routing_table, next);
+                struct nhop *          n =
+                        list_first_entry(&t->nhops, struct nhop, next);
+
+                if ((t->dst != 2 && n->nhop != 2) ||
+                    (t->dst != 3 && n->nhop != 2)) {
+                        printf("Wrong routing entry.\n");
+                        graph_free_routing_table(graph, &table);
+                        return -1;
+                }
+        }
+
+        graph_free_routing_table(graph, &table);
+
+        return 0;
+}
+
+int graph_test_single_link(void)
+{
+        struct list_head * p;
+        int                i = 0;
+
+        if (graph_routing_table(graph, ROUTING_SIMPLE, 1, &table)) {
+                printf("Failed to get routing table.\n");
+                return -1;
+        }
+
+        list_for_each(p, &table)
+                i++;
+
+        if (i != 1) {
+                printf("Wrong number of entries.\n");
+                graph_free_routing_table(graph, &table);
+                return -1;
+        }
+
+        list_for_each(p, &table) {
+                struct routing_table * t =
+                        list_entry(p, struct routing_table, next);
+                struct nhop *          n =
+                        list_first_entry(&t->nhops, struct nhop, next);
+
+                if (t->dst != 2 && n->nhop != 2) {
+                        printf("Wrong routing entry.\n");
+                        graph_free_routing_table(graph, &table);
+                        return -1;
+                }
+        }
+
+        graph_free_routing_table(graph, &table);
+
+        return 0;
+}
+
+int graph_test(int     argc,
+               char ** argv)
+{
+        int                nhop;
+        int                dst;
+        struct list_head * p;
+
+        (void) argc;
+        (void) argv;
+
+        memset(&qs, 0, sizeof(qs));
+
+        graph = graph_create();
+        if (graph == NULL) {
+                printf("Failed to create graph.\n");
+                return -1;
+        }
+
+        graph_destroy(graph);
+
+        graph = graph_create();
+        if (graph == NULL) {
+                printf("Failed to create graph.\n");
+                return -1;
+        }
+
+        if (graph_update_edge(graph, 1, 2, qs)) {
+                printf("Failed to add edge.\n");
+                graph_destroy(graph);
+                return -1;
+        }
+
+        if (graph_update_edge(graph, 2, 1, qs)) {
+                printf("Failed to add edge.\n");
+                graph_destroy(graph);
+                return -1;
+        }
+
+        if (graph_test_single_link()) {
+                graph_destroy(graph);
+                return -1;
+        }
+
+        if (graph_update_edge(graph, 2, 3, qs)) {
+                printf("Failed to add edge.\n");
+                graph_destroy(graph);
+                return -1;
+        }
+
+        if (graph_update_edge(graph, 3, 2, qs)) {
+                printf("Failed to add edge.\n");
+                graph_destroy(graph);
+                return -1;
+        }
+
+
+        if (graph_test_double_link()) {
+                graph_destroy(graph);
+                return -1;
+        }
+
+        if (graph_del_edge(graph, 2, 3)) {
+                printf("Failed to delete edge.\n");
+                graph_destroy(graph);
+                return -1;
+        }
+
+        if (graph_del_edge(graph, 3, 2)) {
+                printf("Failed to delete edge.\n");
+                graph_destroy(graph);
+                return -1;
+        }
+
+        if (graph_test_single_link()) {
+                graph_destroy(graph);
+                return -1;
+        }
+
+        graph_update_edge(graph, 2, 3, qs);
+        graph_update_edge(graph, 3, 2, qs);
+        graph_update_edge(graph, 1, 3, qs);
+        graph_update_edge(graph, 3, 1, qs);
+
+        if (graph_test_entries(2)) {
+                graph_destroy(graph);
+                return -1;
+        }
+
+        graph_update_edge(graph, 3, 4, qs);
+        graph_update_edge(graph, 4, 3, qs);
+        graph_update_edge(graph, 4, 5, qs);
+        graph_update_edge(graph, 5, 4, qs);
+
+        if (graph_test_entries(4)) {
+                graph_destroy(graph);
+                return -1;
+        }
+
+        graph_update_edge(graph, 2, 6, qs);
+        graph_update_edge(graph, 6, 2, qs);
+        graph_update_edge(graph, 6, 7, qs);
+        graph_update_edge(graph, 7, 6, qs);
+        graph_update_edge(graph, 3, 7, qs);
+        graph_update_edge(graph, 7, 3, qs);
+
+        if (graph_test_entries(6)) {
+                graph_destroy(graph);
+                return -1;
+        }
+
+        if (graph_routing_table(graph, ROUTING_SIMPLE, 1, &table)) {
+                printf("Failed to get routing table.\n");
+                return -1;
+        }
+
+        list_for_each(p, &table) {
+                struct routing_table * t =
+                        list_entry(p, struct routing_table, next);
+                struct nhop *          n =
+                        list_first_entry(&t->nhops, struct nhop, next);
+
+                dst = t->dst;
+                nhop = n->nhop;
+
+                if (dst == 3 && nhop != 3) {
+                        printf("Wrong entry.");
+                        graph_free_routing_table(graph, &table);
+                        return -1;
+                }
+
+                if (dst == 2 && nhop != 2) {
+                        printf("Wrong entry.");
+                        graph_free_routing_table(graph, &table);
+                        return -1;
+                }
+
+                if (dst == 6 && nhop != 2) {
+                        printf("Wrong entry.");
+                        graph_free_routing_table(graph, &table);
+                        return -1;
+                }
+
+                if (dst == 4 && nhop != 3) {
+                        printf("Wrong entry.");
+                        graph_free_routing_table(graph, &table);
+                        return -1;
+                }
+
+                if (dst == 5 && nhop != 3) {
+                        printf("Wrong entry.");
+                        graph_free_routing_table(graph, &table);
+                        return -1;
+                }
+
+                if (dst == 7 && nhop != 3) {
+                        printf("Wrong entry.");
+                        graph_free_routing_table(graph, &table);
+                        return -1;
+                }
+        }
+
+        graph_free_routing_table(graph, &table);
+
+        return 0;
+}
diff --git a/src/ipcpd/unicast/psched.c b/src/ipcpd/unicast/psched.c
new file mode 100644
index 00000000..6e8c4e0e
--- /dev/null
+++ b/src/ipcpd/unicast/psched.c
@@ -0,0 +1,239 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Packet scheduler component
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#if defined(__linux__) || defined(__CYGWIN__)
+#define _DEFAULT_SOURCE
+#else
+#define _POSIX_C_SOURCE 200112L
+#endif
+
+#include "config.h"
+
+#include <ouroboros/errno.h>
+#include <ouroboros/notifier.h>
+
+#include "ipcp.h"
+#include "psched.h"
+#include "connmgr.h"
+
+#include <assert.h>
+#include <sched.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+
+static int qos_prio [] = {
+        QOS_PRIO_BE,
+        QOS_PRIO_VIDEO,
+        QOS_PRIO_VOICE,
+};
+
+struct psched {
+        fset_t *         set[QOS_CUBE_MAX];
+        next_packet_fn_t callback;
+        pthread_t        readers[QOS_CUBE_MAX * IPCP_SCHED_THR_MUL];
+};
+
+struct sched_info {
+        struct psched * sch;
+        qoscube_t       qc;
+};
+
+static void cleanup_reader(void * o)
+{
+        fqueue_destroy((fqueue_t *) o);
+}
+
+static void * packet_reader(void * o)
+{
+        struct psched *       sched;
+        struct shm_du_buff *  sdb;
+        int                   fd;
+        fqueue_t *            fq;
+        qoscube_t             qc;
+
+        sched = ((struct sched_info *) o)->sch;
+        qc    = ((struct sched_info *) o)->qc;
+
+        ipcp_lock_to_core();
+
+        free(o);
+
+        fq = fqueue_create();
+        if (fq == NULL)
+                return (void *) -1;
+
+        pthread_cleanup_push(cleanup_reader, fq);
+
+        while (true) {
+                int ret = fevent(sched->set[qc], fq, NULL);
+                if (ret < 0)
+                        continue;
+
+                while ((fd = fqueue_next(fq)) >= 0) {
+                        switch (fqueue_type(fq)) {
+                        case FLOW_DEALLOC:
+                                notifier_event(NOTIFY_DT_FLOW_DEALLOC, &fd);
+                                break;
+                        case FLOW_DOWN:
+                                notifier_event(NOTIFY_DT_FLOW_DOWN, &fd);
+                                break;
+                        case FLOW_UP:
+                                notifier_event(NOTIFY_DT_FLOW_UP, &fd);
+                                break;
+                        case FLOW_PKT:
+                                if (ipcp_flow_read(fd, &sdb))
+                                        continue;
+
+                                sched->callback(fd, qc, sdb);
+                                break;
+                        default:
+                                break;
+                        }
+                }
+        }
+
+        pthread_cleanup_pop(true);
+
+        return (void *) 0;
+}
+
+struct psched * psched_create(next_packet_fn_t callback)
+{
+        struct psched *       psched;
+        struct sched_info *   infos[QOS_CUBE_MAX * IPCP_SCHED_THR_MUL];
+        int                   i;
+        int                   j;
+
+        assert(callback);
+
+        psched = malloc(sizeof(*psched));
+        if (psched == NULL)
+                goto fail_malloc;
+
+        psched->callback = callback;
+
+        for (i = 0; i < QOS_CUBE_MAX; ++i) {
+                psched->set[i] = fset_create();
+                if (psched->set[i] == NULL) {
+                        for (j = 0; j < i; ++j)
+                                fset_destroy(psched->set[j]);
+                        goto fail_flow_set;
+                }
+        }
+
+        for (i = 0; i < QOS_CUBE_MAX * IPCP_SCHED_THR_MUL; ++i) {
+                infos[i] = malloc(sizeof(*infos[i]));
+                if (infos[i] == NULL) {
+                        for (j = 0; j < i; ++j)
+                                free(infos[j]);
+                        goto fail_infos;
+                }
+                infos[i]->sch = psched;
+                infos[i]->qc  = i % QOS_CUBE_MAX;
+        }
+
+        for (i = 0; i < QOS_CUBE_MAX * IPCP_SCHED_THR_MUL; ++i) {
+                if (pthread_create(&psched->readers[i], NULL,
+                                   packet_reader, infos[i])) {
+                        for (j = 0; j < i; ++j)
+                                pthread_cancel(psched->readers[j]);
+                        for (j = 0; j < i; ++j)
+                                pthread_join(psched->readers[j], NULL);
+                        for (j = i; j < QOS_CUBE_MAX * IPCP_SCHED_THR_MUL; ++j)
+                                free(infos[i]);
+                        goto fail_infos;
+                }
+        }
+
+        for (i = 0; i < QOS_CUBE_MAX * IPCP_SCHED_THR_MUL; ++i) {
+                struct sched_param  par;
+                int                 pol = SCHED_RR;
+                int                 min;
+                int                 max;
+
+                min = sched_get_priority_min(pol);
+                max = sched_get_priority_max(pol);
+
+                min = (max - min) / 2;
+
+                par.sched_priority = min +
+                        (qos_prio[i % QOS_CUBE_MAX] * (max - min) / 99);
+
+                if (pthread_setschedparam(psched->readers[i], pol, &par))
+                        goto fail_sched;
+        }
+
+        return psched;
+
+ fail_sched:
+        for (j = 0; j < QOS_CUBE_MAX * IPCP_SCHED_THR_MUL; ++j)
+                pthread_cancel(psched->readers[j]);
+        for (j = 0; j < QOS_CUBE_MAX * IPCP_SCHED_THR_MUL; ++j)
+                pthread_join(psched->readers[j], NULL);
+ fail_infos:
+        for (j = 0; j < QOS_CUBE_MAX; ++j)
+                fset_destroy(psched->set[j]);
+ fail_flow_set:
+        free(psched);
+ fail_malloc:
+        return NULL;
+}
+
+void psched_destroy(struct psched * psched)
+{
+        int i;
+
+        assert(psched);
+
+        for (i = 0; i < QOS_CUBE_MAX * IPCP_SCHED_THR_MUL; ++i) {
+                pthread_cancel(psched->readers[i]);
+                pthread_join(psched->readers[i], NULL);
+        }
+
+        for (i = 0; i < QOS_CUBE_MAX; ++i)
+                fset_destroy(psched->set[i]);
+
+        free(psched);
+}
+
+void psched_add(struct psched * psched,
+                int             fd)
+{
+        qoscube_t qc;
+
+        assert(psched);
+
+        ipcp_flow_get_qoscube(fd, &qc);
+        fset_add(psched->set[qc], fd);
+}
+
+void psched_del(struct psched * psched,
+                int             fd)
+{
+        qoscube_t qc;
+
+        assert(psched);
+
+        ipcp_flow_get_qoscube(fd, &qc);
+        fset_del(psched->set[qc], fd);
+}
diff --git a/src/ipcpd/unicast/psched.h b/src/ipcpd/unicast/psched.h
new file mode 100644
index 00000000..bc98670b
--- /dev/null
+++ b/src/ipcpd/unicast/psched.h
@@ -0,0 +1,43 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Packet scheduler component
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#ifndef OUROBOROS_IPCPD_UNICAST_PSCHED_H
+#define OUROBOROS_IPCPD_UNICAST_PSCHED_H
+
+#include <ouroboros/ipcp-dev.h>
+#include <ouroboros/fqueue.h>
+
+typedef void (* next_packet_fn_t)(int                  fd,
+                                  qoscube_t            qc,
+                                  struct shm_du_buff * sdb);
+
+struct psched * psched_create(next_packet_fn_t callback);
+
+void            psched_destroy(struct psched * psched);
+
+void            psched_add(struct psched * psched,
+                           int             fd);
+
+void            psched_del(struct psched * psched,
+                           int             fd);
+
+#endif /* OUROBOROS_IPCPD_UNICAST_PSCHED_H */
diff --git a/src/ipcpd/unicast/routing.c b/src/ipcpd/unicast/routing.c
new file mode 100644
index 00000000..2cd24707
--- /dev/null
+++ b/src/ipcpd/unicast/routing.c
@@ -0,0 +1,59 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Routing component of the IPCP
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#define _POSIX_C_SOURCE 200112L
+
+#include <ouroboros/errno.h>
+
+#include "routing.h"
+#include "pol/link_state.h"
+
+struct pol_routing_ops * r_ops;
+
+int routing_init(enum pol_routing pr)
+{
+        switch (pr) {
+        case ROUTING_LINK_STATE:
+        case ROUTING_LINK_STATE_LFA:
+                r_ops = &link_state_ops;
+                break;
+        default:
+                return -ENOTSUP;
+        }
+
+        return r_ops->init(pr);
+}
+
+struct routing_i * routing_i_create(struct pff * pff)
+{
+        return r_ops->routing_i_create(pff);
+}
+
+void routing_i_destroy(struct routing_i * instance)
+{
+        return r_ops->routing_i_destroy(instance);
+}
+
+void routing_fini(void)
+{
+        r_ops->fini();
+}
diff --git a/src/ipcpd/unicast/routing.h b/src/ipcpd/unicast/routing.h
new file mode 100644
index 00000000..ffded5bf
--- /dev/null
+++ b/src/ipcpd/unicast/routing.h
@@ -0,0 +1,41 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Routing component of the IPCP
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#ifndef OUROBOROS_IPCPD_UNICAST_ROUTING_H
+#define OUROBOROS_IPCPD_UNICAST_ROUTING_H
+
+#include <ouroboros/ipcp.h>
+#include <ouroboros/qos.h>
+
+#include "pff.h"
+
+#include <stdint.h>
+
+int                routing_init(enum pol_routing pr);
+
+void               routing_fini(void);
+
+struct routing_i * routing_i_create(struct pff * pff);
+
+void               routing_i_destroy(struct routing_i * instance);
+
+#endif /* OUROBOROS_IPCPD_UNICAST_ROUTING_H */
diff --git a/src/ipcpd/unicast/tests/CMakeLists.txt b/src/ipcpd/unicast/tests/CMakeLists.txt
new file mode 100644
index 00000000..482711d5
--- /dev/null
+++ b/src/ipcpd/unicast/tests/CMakeLists.txt
@@ -0,0 +1,37 @@
+get_filename_component(CURRENT_SOURCE_PARENT_DIR
+  ${CMAKE_CURRENT_SOURCE_DIR} DIRECTORY)
+get_filename_component(CURRENT_BINARY_PARENT_DIR
+  ${CMAKE_CURRENT_BINARY_DIR} DIRECTORY)
+
+include_directories(${CMAKE_CURRENT_SOURCE_DIR})
+include_directories(${CMAKE_CURRENT_BINARY_DIR})
+
+include_directories(${CURRENT_SOURCE_PARENT_DIR})
+include_directories(${CURRENT_BINARY_PARENT_DIR})
+
+include_directories(${CMAKE_SOURCE_DIR}/include)
+include_directories(${CMAKE_BINARY_DIR}/include)
+
+get_filename_component(PARENT_PATH ${CMAKE_CURRENT_SOURCE_DIR} DIRECTORY)
+get_filename_component(PARENT_DIR ${PARENT_PATH} NAME)
+
+create_test_sourcelist(${PARENT_DIR}_tests test_suite.c
+  # Add new tests here
+  dht_test.c
+  )
+
+protobuf_generate_c(KAD_PROTO_SRCS KAD_PROTO_HDRS ../kademlia.proto)
+
+add_executable(${PARENT_DIR}_test EXCLUDE_FROM_ALL ${${PARENT_DIR}_tests}
+  ${KAD_PROTO_SRCS})
+target_link_libraries(${PARENT_DIR}_test ouroboros-common)
+
+add_dependencies(check ${PARENT_DIR}_test)
+
+set(tests_to_run ${${PARENT_DIR}_tests})
+remove(tests_to_run test_suite.c)
+
+foreach (test ${tests_to_run})
+  get_filename_component(test_name ${test} NAME_WE)
+  add_test(${test_name} ${C_TEST_PATH}/${PARENT_DIR}_test ${test_name})
+endforeach (test)
diff --git a/src/ipcpd/unicast/tests/dht_test.c b/src/ipcpd/unicast/tests/dht_test.c
new file mode 100644
index 00000000..26e9102e
--- /dev/null
+++ b/src/ipcpd/unicast/tests/dht_test.c
@@ -0,0 +1,99 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Unit tests of the DHT
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#define __DHT_TEST__
+
+#include "dht.c"
+
+#include <pthread.h>
+#include <time.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#define KEY_LEN  32
+
+#define EXP      86400
+#define CONTACTS 1000
+
+int dht_test(int     argc,
+             char ** argv)
+{
+        struct dht * dht;
+        uint64_t     addr = 0x0D1F;
+        uint8_t      key[KEY_LEN];
+        size_t       i;
+
+        (void) argc;
+        (void) argv;
+
+        dht = dht_create(addr);
+        if (dht == NULL) {
+                printf("Failed to create dht.\n");
+                return -1;
+        }
+
+        dht_destroy(dht);
+
+        dht = dht_create(addr);
+        if (dht == NULL) {
+                printf("Failed to re-create dht.\n");
+                return -1;
+        }
+
+        if (dht_bootstrap(dht, KEY_LEN, EXP)) {
+                printf("Failed to bootstrap dht.\n");
+                dht_destroy(dht);
+                return -1;
+        }
+
+        dht_destroy(dht);
+
+        dht = dht_create(addr);
+        if (dht == NULL) {
+                printf("Failed to re-create dht.\n");
+                return -1;
+        }
+
+        if (dht_bootstrap(dht, KEY_LEN, EXP)) {
+                printf("Failed to bootstrap dht.\n");
+                dht_destroy(dht);
+                return -1;
+        }
+
+        for (i = 0; i < CONTACTS; ++i) {
+                uint64_t addr;
+                random_buffer(&addr, sizeof(addr));
+                random_buffer(key, KEY_LEN);
+                pthread_rwlock_wrlock(&dht->lock);
+                if (dht_update_bucket(dht, key, addr)) {
+                        pthread_rwlock_unlock(&dht->lock);
+                        printf("Failed to update bucket.\n");
+                        dht_destroy(dht);
+                        return -1;
+                }
+                pthread_rwlock_unlock(&dht->lock);
+        }
+
+        dht_destroy(dht);
+
+        return 0;
+}