Merged in dstaesse/ouroboros/be-unify (pull request #251)

lib, ipcp: Revise fast path and flow interfaces

13 files changed, 1103 insertions, 2234 deletions

diff --git a/src/ipcpd/flow.h b/src/ipcpd/flow.h
deleted file mode 100644
index 01226c1e..00000000
--- a/src/ipcpd/flow.h
+++ /dev/null
@@ -1,39 +0,0 @@
-/*
- * Ouroboros - Copyright (C) 2016
- *
- * Flows
- *
- *    Dimitri Staessens <dimitri.staessens@intec.ugent.be>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
-
-#ifndef OUROBOROS_IPCP_FLOW_H
-#define OUROBOROS_IPCP_FLOW_H
-
-#include <ouroboros/list.h>
-#include <ouroboros/shm_ap_rbuff.h>
-
-#include <stdint.h>
-
-struct flow {
-        int                   port_id;
-        struct shm_ap_rbuff * rb;
-        enum flow_state       state;
-
-        pid_t                 api;
-};
-
-#endif /* OUROBOROS_FLOW_H */
diff --git a/src/ipcpd/ipcp-data.h b/src/ipcpd/ipcp-data.h
index 36245eea..4971dbb5 100644
--- a/src/ipcpd/ipcp-data.h
+++ b/src/ipcpd/ipcp-data.h
@@ -30,7 +30,6 @@
 #include <pthread.h>
 
 #include "ipcp-ops.h"
-#include "flow.h"
 
 struct ipcp_data {
         enum ipcp_type      type;
@@ -46,24 +45,32 @@ struct ipcp_data {
 };
 
 struct ipcp_data * ipcp_data_create();
+
 struct ipcp_data * ipcp_data_init(struct ipcp_data * dst,
                                   enum ipcp_type     ipcp_type);
+
 void               ipcp_data_destroy(struct ipcp_data * data);
 
-int          ipcp_data_add_reg_entry(struct ipcp_data * data,
-                                     char *             name);
-int          ipcp_data_del_reg_entry(struct ipcp_data * data,
-                                     const char *       name);
-int          ipcp_data_add_dir_entry(struct ipcp_data * data,
-                                     char *             ap_name,
-                                     uint64_t           addr);
-int          ipcp_data_del_dir_entry(struct ipcp_data * data,
-                                     const char *       ap_name,
-                                     uint64_t           addr);
-bool         ipcp_data_is_in_registry(struct ipcp_data * data,
-                                      const char *       name);
-bool         ipcp_data_is_in_directory(struct ipcp_data * data,
-                                       const char *       ap_name);
-uint64_t     ipcp_data_get_addr(struct ipcp_data * data,
-                                const char *       ap_name);
+int                ipcp_data_add_reg_entry(struct ipcp_data * data,
+                                           char *             name);
+
+int                ipcp_data_del_reg_entry(struct ipcp_data * data,
+                                           const char *       name);
+
+int                ipcp_data_add_dir_entry(struct ipcp_data * data,
+                                           char *             ap_name,
+                                           uint64_t           addr);
+
+int                ipcp_data_del_dir_entry(struct ipcp_data * data,
+                                           const char *       ap_name,
+                                           uint64_t           addr);
+
+bool               ipcp_data_is_in_registry(struct ipcp_data * data,
+                                            const char *       name);
+
+bool               ipcp_data_is_in_directory(struct ipcp_data * data,
+                                             const char *       ap_name);
+
+uint64_t           ipcp_data_get_addr(struct ipcp_data * data,
+                                      const char *       ap_name);
 #endif /* IPCPD_IPCP_DATA_H */
diff --git a/src/ipcpd/ipcp-ops.h b/src/ipcpd/ipcp-ops.h
index e43c2c38..815cda09 100644
--- a/src/ipcpd/ipcp-ops.h
+++ b/src/ipcpd/ipcp-ops.h
@@ -25,23 +25,26 @@
 #define IPCPD_IPCP_OPS_H
 
 #include <ouroboros/irm_config.h>
-#include <ouroboros/common.h>
-#include <sys/types.h>
+#include <ouroboros/shared.h>
 
 struct ipcp_ops {
         int   (* ipcp_bootstrap)(struct dif_config * conf);
+
         int   (* ipcp_enroll)(char * dif_name);
-        int   (* ipcp_name_reg)(char *   name);
+
+        int   (* ipcp_name_reg)(char * name);
+
         int   (* ipcp_name_unreg)(char * name);
-        int   (* ipcp_flow_alloc)(pid_t         n_api,
-                                  int           port_id,
+
+        int   (* ipcp_flow_alloc)(int           fd,
                                   char *        dst_ap_name,
                                   char *        src_ae_name,
                                   enum qos_cube qos);
-        int   (* ipcp_flow_alloc_resp)(pid_t n_api,
-                                       int   port_id,
-                                       int   response);
-        int   (* ipcp_flow_dealloc)(int port_id);
+
+        int   (* ipcp_flow_alloc_resp)(int fd,
+                                       int response);
+
+        int   (* ipcp_flow_dealloc)(int fd);
 };
 
 #endif /* IPCPD_IPCP_OPS_H */
diff --git a/src/ipcpd/ipcp.c b/src/ipcpd/ipcp.c
index ec5ab927..db72b88d 100644
--- a/src/ipcpd/ipcp.c
+++ b/src/ipcpd/ipcp.c
@@ -21,8 +21,12 @@
  */
 
 #include <ouroboros/config.h>
-#include <ouroboros/ipcp.h>
 #include <ouroboros/time_utils.h>
+#include <ouroboros/utils.h>
+#include <ouroboros/sockets.h>
+#include <ouroboros/errno.h>
+#include <ouroboros/dev.h>
+#include <ouroboros/np1_flow.h>
 
 #define OUROBOROS_PREFIX "ipcpd/ipcp"
 #include <ouroboros/logs.h>
@@ -32,62 +36,68 @@
 #include <stdlib.h>
 #include "ipcp.h"
 
-struct ipcp * ipcp_instance_create()
+int ipcp_init(enum ipcp_type type, struct ipcp_ops * ops)
 {
         pthread_condattr_t cattr;
 
-        struct ipcp * i = malloc(sizeof *i);
-        if (i == NULL)
-                return NULL;
+        ipcpi.irmd_fd = -1;
+        ipcpi.state   = IPCP_INIT;
 
-        i->data    = NULL;
-        i->ops     = NULL;
-        i->irmd_fd = -1;
-        i->state   = IPCP_INIT;
+        ipcpi.ops = ops;
 
-        pthread_rwlock_init(&i->state_lock, NULL);
-        pthread_mutex_init(&i->state_mtx, NULL);
+        ipcpi.data = ipcp_data_create();
+        if (ipcpi.data == NULL)
+                return -ENOMEM;
+
+        ipcp_data_init(ipcpi.data, type);
+
+        pthread_rwlock_init(&ipcpi.state_lock, NULL);
+        pthread_mutex_init(&ipcpi.state_mtx, NULL);
         pthread_condattr_init(&cattr);
 #ifndef __APPLE__
         pthread_condattr_setclock(&cattr, PTHREAD_COND_CLOCK);
 #endif
-        pthread_cond_init(&i->state_cond, &cattr);
+        pthread_cond_init(&ipcpi.state_cond, &cattr);
 
-        return i;
+        pthread_create(&ipcpi.mainloop, NULL, ipcp_main_loop, NULL);
+
+        return 0;
 }
 
-void ipcp_set_state(struct ipcp * ipcp,
-                    enum ipcp_state state)
+void ipcp_fini()
 {
-        if (ipcp == NULL)
-            return;
+        pthread_join(ipcpi.mainloop, NULL);
 
-        pthread_mutex_lock(&ipcp->state_mtx);
+        ipcp_data_destroy(ipcpi.data);
+        pthread_cond_destroy(&ipcpi.state_cond);
+        pthread_mutex_destroy(&ipcpi.state_mtx);
+        pthread_rwlock_destroy(&ipcpi.state_lock);
+}
+
+void ipcp_set_state(enum ipcp_state state)
+{
+        pthread_mutex_lock(&ipcpi.state_mtx);
 
-        ipcp->state = state;
+        ipcpi.state = state;
 
-        pthread_cond_broadcast(&ipcp->state_cond);
-        pthread_mutex_unlock(&ipcp->state_mtx);
+        pthread_cond_broadcast(&ipcpi.state_cond);
+        pthread_mutex_unlock(&ipcpi.state_mtx);
 }
 
-enum ipcp_state ipcp_get_state(struct ipcp * ipcp)
+enum ipcp_state ipcp_get_state()
 {
         enum ipcp_state state;
 
-        if (ipcp == NULL)
-                return IPCP_NULL;
+        pthread_mutex_lock(&ipcpi.state_mtx);
 
-        pthread_mutex_lock(&ipcp->state_mtx);
+        state = ipcpi.state;
 
-        state = ipcp->state;
-
-        pthread_mutex_unlock(&ipcp->state_mtx);
+        pthread_mutex_unlock(&ipcpi.state_mtx);
 
         return state;
 }
 
-int ipcp_wait_state(struct ipcp *           ipcp,
-                    enum ipcp_state         state,
+int ipcp_wait_state(enum ipcp_state         state,
                     const struct timespec * timeout)
 {
         struct timespec abstime;
@@ -95,24 +105,24 @@ int ipcp_wait_state(struct ipcp *           ipcp,
         clock_gettime(PTHREAD_COND_CLOCK, &abstime);
         ts_add(&abstime, timeout, &abstime);
 
-        pthread_mutex_lock(&ipcp->state_mtx);
+        pthread_mutex_lock(&ipcpi.state_mtx);
 
-        while (ipcp->state != state && ipcp->state != IPCP_SHUTDOWN) {
+        while (ipcpi.state != state && ipcpi.state != IPCP_SHUTDOWN) {
                 int ret;
                 if (timeout == NULL)
-                        ret = pthread_cond_wait(&ipcp->state_cond,
-                                                &ipcp->state_mtx);
+                        ret = pthread_cond_wait(&ipcpi.state_cond,
+                                                &ipcpi.state_mtx);
                 else
-                        ret = pthread_cond_timedwait(&ipcp->state_cond,
-                                                     &ipcp->state_mtx,
+                        ret = pthread_cond_timedwait(&ipcpi.state_cond,
+                                                     &ipcpi.state_mtx,
                                                      &abstime);
                 if (ret) {
-                        pthread_mutex_unlock(&ipcp->state_mtx);
+                        pthread_mutex_unlock(&ipcpi.state_mtx);
                         return -ret;
                 }
         }
 
-        pthread_mutex_unlock(&ipcp->state_mtx);
+        pthread_mutex_unlock(&ipcpi.state_mtx);
 
         return 0;
 }
@@ -161,7 +171,6 @@ void * ipcp_main_loop(void * o)
         int     lsockfd;
         int     sockfd;
         uint8_t buf[IPCP_MSG_BUF_SIZE];
-        struct ipcp * _ipcp = (struct ipcp *) o;
 
         ipcp_msg_t * msg;
         ssize_t      count;
@@ -180,12 +189,6 @@ void * ipcp_main_loop(void * o)
         struct timeval ltv = {(SOCKET_TIMEOUT / 1000),
                              (SOCKET_TIMEOUT % 1000) * 1000};
 
-
-        if (_ipcp == NULL) {
-                LOG_ERR("Invalid ipcp struct.");
-                return (void *) 1;
-        }
-
         sock_path = ipcp_sock_path(getpid());
         if (sock_path == NULL)
                 return (void *) 1;
@@ -202,13 +205,15 @@ void * ipcp_main_loop(void * o)
                 LOG_WARN("Failed to set timeout on socket.");
 
         while (true) {
-                pthread_rwlock_rdlock(&_ipcp->state_lock);
-                if (ipcp_get_state(_ipcp) == IPCP_SHUTDOWN) {
-                        pthread_rwlock_unlock(&_ipcp->state_lock);
+                int fd = -1;
+
+                pthread_rwlock_rdlock(&ipcpi.state_lock);
+                if (ipcp_get_state() == IPCP_SHUTDOWN) {
+                        pthread_rwlock_unlock(&ipcpi.state_lock);
                         break;
                 }
 
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
 
                 ret_msg.code = IPCP_MSG_CODE__IPCP_REPLY;
 
@@ -235,7 +240,7 @@ void * ipcp_main_loop(void * o)
 
                 switch (msg->code) {
                 case IPCP_MSG_CODE__IPCP_BOOTSTRAP:
-                        if (_ipcp->ops->ipcp_bootstrap == NULL) {
+                        if (ipcpi.ops->ipcp_bootstrap == NULL) {
                                 LOG_ERR("Bootstrap unsupported.");
                                 break;
                         }
@@ -267,72 +272,102 @@ void * ipcp_main_loop(void * o)
                                 conf.if_name = conf_msg->if_name;
 
                         ret_msg.has_result = true;
-                        ret_msg.result = _ipcp->ops->ipcp_bootstrap(&conf);
+                        ret_msg.result = ipcpi.ops->ipcp_bootstrap(&conf);
                         if (ret_msg.result < 0)
                                 free(conf.dif_name);
                         break;
                 case IPCP_MSG_CODE__IPCP_ENROLL:
-                        if (_ipcp->ops->ipcp_enroll == NULL) {
+                        if (ipcpi.ops->ipcp_enroll == NULL) {
                                 LOG_ERR("Enroll unsupported.");
                                 break;
                         }
                         ret_msg.has_result = true;
-                        ret_msg.result = _ipcp->ops->ipcp_enroll(msg->dif_name);
+                        ret_msg.result = ipcpi.ops->ipcp_enroll(msg->dif_name);
 
                         break;
                 case IPCP_MSG_CODE__IPCP_NAME_REG:
-                        if (_ipcp->ops->ipcp_name_reg == NULL) {
+                        if (ipcpi.ops->ipcp_name_reg == NULL) {
                                 LOG_ERR("Ap_reg unsupported.");
                                 break;
                         }
                         msg_name_dup = strdup(msg->name);
                         ret_msg.has_result = true;
                         ret_msg.result =
-                                _ipcp->ops->ipcp_name_reg(msg_name_dup);
+                                ipcpi.ops->ipcp_name_reg(msg_name_dup);
                         if (ret_msg.result < 0)
                                 free(msg_name_dup);
                         break;
                 case IPCP_MSG_CODE__IPCP_NAME_UNREG:
-                        if (_ipcp->ops->ipcp_name_unreg == NULL) {
+                        if (ipcpi.ops->ipcp_name_unreg == NULL) {
                                 LOG_ERR("Ap_unreg unsupported.");
                                 break;
                         }
                         ret_msg.has_result = true;
                         ret_msg.result =
-                                _ipcp->ops->ipcp_name_unreg(msg->name);
+                                ipcpi.ops->ipcp_name_unreg(msg->name);
                         break;
                 case IPCP_MSG_CODE__IPCP_FLOW_ALLOC:
-                        if (_ipcp->ops->ipcp_flow_alloc == NULL) {
+                        if (ipcpi.ops->ipcp_flow_alloc == NULL) {
                                 LOG_ERR("Flow_alloc unsupported.");
                                 break;
                         }
+                        fd = np1_flow_alloc(msg->api, msg->port_id);
+                        if (fd < 0) {
+                                LOG_ERR("Could not get fd for flow.");
+                                ret_msg.has_result = true;
+                                ret_msg.result = -1;
+                                break;
+                        }
+
                         ret_msg.has_result = true;
                         ret_msg.result =
-                                _ipcp->ops->ipcp_flow_alloc(msg->api,
-                                                            msg->port_id,
+                                ipcpi.ops->ipcp_flow_alloc(fd,
                                                             msg->dst_name,
                                                             msg->src_ae_name,
                                                             msg->qos_cube);
+                        if (ret_msg.result < 0) {
+                                LOG_DBG("Deallocating failed flow on port_id %d.",
+                                        msg->port_id);
+                                flow_dealloc(fd);
+                        }
                         break;
                 case IPCP_MSG_CODE__IPCP_FLOW_ALLOC_RESP:
-                        if (_ipcp->ops->ipcp_flow_alloc_resp == NULL) {
+                        if (ipcpi.ops->ipcp_flow_alloc_resp == NULL) {
                                 LOG_ERR("Flow_alloc_resp unsupported.");
                                 break;
                         }
+
+                        if (!msg->response) {
+                                fd = np1_flow_resp(msg->api, msg->port_id);
+                                if (fd < 0) {
+                                        LOG_ERR("Could not get fd for flow.");
+                                        ret_msg.has_result = true;
+                                        ret_msg.result = -1;
+                                        break;
+                                }
+                        }
                         ret_msg.has_result = true;
                         ret_msg.result =
-                                _ipcp->ops->ipcp_flow_alloc_resp(msg->api,
-                                                                 msg->port_id,
-                                                                 msg->result);
+                                ipcpi.ops->ipcp_flow_alloc_resp(fd,
+                                                                msg->response);
                         break;
                 case IPCP_MSG_CODE__IPCP_FLOW_DEALLOC:
-                        if (_ipcp->ops->ipcp_flow_dealloc == NULL) {
+                        if (ipcpi.ops->ipcp_flow_dealloc == NULL) {
                                 LOG_ERR("Flow_dealloc unsupported.");
                                 break;
                         }
+
+                        fd = np1_flow_dealloc(msg->port_id);
+                        if (fd < 0) {
+                                LOG_ERR("Could not get fd for flow.");
+                                ret_msg.has_result = true;
+                                ret_msg.result = -1;
+                                break;
+                        }
+
                         ret_msg.has_result = true;
                         ret_msg.result =
-                                _ipcp->ops->ipcp_flow_dealloc(msg->port_id);
+                                ipcpi.ops->ipcp_flow_dealloc(fd);
                         break;
                 default:
                         LOG_ERR("Don't know that message code");
diff --git a/src/ipcpd/ipcp.h b/src/ipcpd/ipcp.h
index edaea0fd..87c0c5d1 100644
--- a/src/ipcpd/ipcp.h
+++ b/src/ipcpd/ipcp.h
@@ -24,7 +24,6 @@
 #define IPCPD_IPCP_H
 
 #include <ouroboros/config.h>
-#include <ouroboros/shared.h>
 
 #include <pthread.h>
 #include <time.h>
@@ -50,23 +49,23 @@ struct ipcp {
         pthread_rwlock_t   state_lock;
         pthread_mutex_t    state_mtx;
         pthread_cond_t     state_cond;
-};
 
-struct ipcp *   ipcp_instance_create();
+        pthread_t          mainloop;
+} ipcpi;
+
+int             ipcp_init();
 
-void            ipcp_set_state(struct ipcp *   ipcp,
-                               enum ipcp_state state);
+void            ipcp_fini();
 
-enum ipcp_state ipcp_get_state(struct ipcp * ipcp);
+void            ipcp_set_state(enum ipcp_state state);
 
-int             ipcp_wait_state(struct ipcp *           ipcp,
-                                enum ipcp_state         state,
+enum ipcp_state ipcp_get_state();
+
+int             ipcp_wait_state(enum ipcp_state         state,
                                 const struct timespec * timeout);
 
 void *          ipcp_main_loop(void * o);
 
-void *          ipcp_sdu_loop(void * o);
-
 int             ipcp_parse_arg(int argc,
                                char * argv[]);
 
diff --git a/src/ipcpd/local/main.c b/src/ipcpd/local/main.c
index c0809429..1ccec0c0 100644
--- a/src/ipcpd/local/main.c
+++ b/src/ipcpd/local/main.c
@@ -22,17 +22,10 @@
 
 #include <ouroboros/config.h>
 #include "ipcp.h"
-#include "flow.h"
 #include <ouroboros/errno.h>
-#include <ouroboros/shm_rdrbuff.h>
-#include <ouroboros/shm_ap_rbuff.h>
-#include <ouroboros/list.h>
-#include <ouroboros/utils.h>
-#include <ouroboros/ipcp.h>
-#include <ouroboros/irm_config.h>
-#include <ouroboros/bitmap.h>
-#include <ouroboros/shared.h>
 #include <ouroboros/dev.h>
+#include <ouroboros/ipcp-dev.h>
+#include <ouroboros/local-dev.h>
 #define OUROBOROS_PREFIX "ipcpd/local"
 
 #include <ouroboros/logs.h>
@@ -46,176 +39,51 @@
 
 #define THIS_TYPE IPCP_LOCAL
 
-#define shim_data(type) ((struct ipcp_local_data *) type->data)
-
 /* global for trapping signal */
 int irmd_api;
 
-/* this IPCP's data */
-#ifdef MAKE_CHECK
-extern struct ipcp * _ipcp; /* defined in test */
-#else
-struct ipcp * _ipcp;
-#endif
-
-/*
- * copied from ouroboros/dev. The shim needs access to the internals
- * because it doesn't follow all steps necessary steps to get
- * the info
- */
-
-/* the shim needs access to these internals */
-struct shim_ap_data {
-        pid_t                 api;
-        struct shm_rdrbuff *  rdrb;
-        struct bmp *          fds;
-        struct shm_ap_rbuff * rb;
-
-        int                   in_out[AP_MAX_FLOWS];
+struct {
+        int                   in_out[IRMD_MAX_FLOWS];
 
-        struct flow           flows[AP_MAX_FLOWS];
-        pthread_rwlock_t      flows_lock;
-
-        pthread_t             mainloop;
+        pthread_rwlock_t      lock;
         pthread_t             sduloop;
+} local_data;
 
-} * _ap_instance;
-
-static int shim_ap_init()
+void local_data_init()
 {
         int i;
+        for (i = 0; i < IRMD_MAX_FLOWS; ++i)
+                local_data.in_out[i] = -1;
 
-        _ap_instance = malloc(sizeof(struct shim_ap_data));
-        if (_ap_instance == NULL) {
-                return -1;
-        }
-
-        _ap_instance->api = getpid();
-
-        _ap_instance->fds = bmp_create(AP_MAX_FLOWS, 0);
-        if (_ap_instance->fds == NULL) {
-                free(_ap_instance);
-                return -1;
-        }
-
-        _ap_instance->rdrb = shm_rdrbuff_open();
-        if (_ap_instance->rdrb == NULL) {
-                bmp_destroy(_ap_instance->fds);
-                free(_ap_instance);
-                return -1;
-        }
-
-        _ap_instance->rb = shm_ap_rbuff_create_n();
-        if (_ap_instance->rb == NULL) {
-                shm_rdrbuff_close(_ap_instance->rdrb);
-                bmp_destroy(_ap_instance->fds);
-                free(_ap_instance);
-                return -1;
-        }
-
-        for (i = 0; i < AP_MAX_FLOWS; i ++) {
-                _ap_instance->flows[i].rb = NULL;
-                _ap_instance->flows[i].port_id = -1;
-                _ap_instance->flows[i].state = FLOW_NULL;
-                _ap_instance->in_out[i] = -1;
-        }
-
-        pthread_rwlock_init(&_ap_instance->flows_lock, NULL);
-
-        return 0;
-}
-
-void shim_ap_fini()
-{
-        int i = 0;
-
-        if (_ap_instance == NULL)
-                return;
-
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
-
-        if (_ipcp->state != IPCP_SHUTDOWN)
-                LOG_WARN("Cleaning up AP while not in shutdown.");
-
-        if (_ap_instance->fds != NULL)
-                bmp_destroy(_ap_instance->fds);
-
-        /* remove all remaining sdus */
-        while ((i = shm_ap_rbuff_peek_idx(_ap_instance->rb)) >= 0)
-                shm_rdrbuff_remove(_ap_instance->rdrb, i);
-
-        if (_ap_instance->rdrb != NULL)
-                shm_rdrbuff_close(_ap_instance->rdrb);
-        if (_ap_instance->rb != NULL)
-                shm_ap_rbuff_destroy(_ap_instance->rb);
-
-        pthread_rwlock_wrlock(&_ap_instance->flows_lock);
-
-        for (i = 0; i < AP_MAX_FLOWS; i ++)
-                if (_ap_instance->flows[i].rb != NULL)
-                        shm_ap_rbuff_close(_ap_instance->flows[i].rb);
-
-        pthread_rwlock_unlock(&_ap_instance->flows_lock);
-        pthread_rwlock_unlock(&_ipcp->state_lock);
-
-        free(_ap_instance);
+        pthread_rwlock_init(&local_data.lock, NULL);
 }
 
-/* only call this under flows_lock */
-static int port_id_to_fd(int port_id)
+void local_data_fini()
 {
-        int i;
-
-        for (i = 0; i < AP_MAX_FLOWS; ++i) {
-                if (_ap_instance->flows[i].port_id == port_id
-                    && _ap_instance->flows[i].state != FLOW_NULL)
-                        return i;
-        }
-
-        return -1;
+        pthread_rwlock_destroy(&local_data.lock);
 }
 
-/*
- * end copy from dev.c
- */
-
-/* FIXME: if we move _ap_instance to dev.h, we can reuse it everywhere */
 static void * ipcp_local_sdu_loop(void * o)
 {
         while (true) {
-                struct rb_entry * e;
-                int fd;
-
-                e = shm_ap_rbuff_read(_ap_instance->rb);
-                if (e == NULL) {
-                        continue;
-                }
+                struct rb_entry e;
+                int fd = local_flow_read(&e);
 
-                pthread_rwlock_rdlock(&_ipcp->state_lock);
+                pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-                if (_ipcp->state != IPCP_ENROLLED) {
-                        pthread_rwlock_unlock(&_ipcp->state_lock);
+                if (ipcp_get_state() != IPCP_ENROLLED) {
+                        pthread_rwlock_unlock(&ipcpi.state_lock);
                         return (void *) 1; /* -ENOTENROLLED */
                 }
 
-                pthread_rwlock_rdlock(&_ap_instance->flows_lock);
-                fd = _ap_instance->in_out[port_id_to_fd(e->port_id)];
-                if (fd == -1) {
-                        pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                        pthread_rwlock_unlock(&_ipcp->state_lock);
-                        free(e);
-                        continue;
-                }
-
-                e->port_id = _ap_instance->flows[fd].port_id;
-
-                while (shm_ap_rbuff_write(_ap_instance->flows[fd].rb, e) < 0)
-                        ;
+                pthread_rwlock_rdlock(&local_data.lock);
+                fd = local_data.in_out[fd];
+                pthread_rwlock_unlock(&local_data.lock);
 
-                pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+                if (fd != -1)
+                        local_flow_write(fd, &e);
 
-                free(e);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
         }
 
         return (void *) 1;
@@ -223,10 +91,6 @@ static void * ipcp_local_sdu_loop(void * o)
 
 void ipcp_sig_handler(int sig, siginfo_t * info, void * c)
 {
-        sigset_t  sigset;
-        sigemptyset(&sigset);
-        sigaddset(&sigset, SIGINT);
-
         switch(sig) {
         case SIGINT:
         case SIGTERM:
@@ -236,11 +100,11 @@ void ipcp_sig_handler(int sig, siginfo_t * info, void * c)
                         LOG_DBG("IPCP %d terminating by order of %d. Bye.",
                                 getpid(), info->si_pid);
 
-                        pthread_rwlock_wrlock(&_ipcp->state_lock);
+                        pthread_rwlock_wrlock(&ipcpi.state_lock);
 
-                        ipcp_set_state(_ipcp, IPCP_SHUTDOWN);
+                        ipcp_set_state(IPCP_SHUTDOWN);
 
-                        pthread_rwlock_unlock(&_ipcp->state_lock);
+                        pthread_rwlock_unlock(&ipcpi.state_lock);
                 }
         default:
                 return;
@@ -254,307 +118,154 @@ static int ipcp_local_bootstrap(struct dif_config * conf)
                 return -1;
         }
 
-        pthread_rwlock_wrlock(&_ipcp->state_lock);
+        pthread_rwlock_wrlock(&ipcpi.state_lock);
 
-        if (ipcp_get_state(_ipcp) != IPCP_INIT) {
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+        if (ipcp_get_state() != IPCP_INIT) {
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 LOG_ERR("IPCP in wrong state.");
                 return -1;
         }
 
-        ipcp_set_state(_ipcp, IPCP_ENROLLED);
+        ipcp_set_state(IPCP_ENROLLED);
 
-        pthread_create(&_ap_instance->sduloop,
-                       NULL,
-                       ipcp_local_sdu_loop,
-                       NULL);
+        pthread_create(&local_data.sduloop, NULL, ipcp_local_sdu_loop, NULL);
 
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
-        LOG_DBG("Bootstrapped local IPCP with api %d.",
-                getpid());
+        LOG_INFO("Bootstrapped local IPCP with api %d.", getpid());
 
         return 0;
 }
 
 static int ipcp_local_name_reg(char * name)
 {
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-        if (ipcp_data_add_reg_entry(_ipcp->data, name)) {
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+        if (ipcp_data_add_reg_entry(ipcpi.data, name)) {
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 LOG_DBGF("Failed to add %s to local registry.", name);
                 return -1;
         }
 
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
-        LOG_DBG("Registered %s.", name);
+        LOG_INFO("Registered %s.", name);
 
         return 0;
 }
 
 static int ipcp_local_name_unreg(char * name)
 {
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-        ipcp_data_del_reg_entry(_ipcp->data, name);
+        ipcp_data_del_reg_entry(ipcpi.data, name);
 
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
+
+        LOG_INFO("Unregistered %s.", name);
 
         return 0;
 }
 
-static int ipcp_local_flow_alloc(pid_t         n_api,
-                                 int           port_id,
+static int ipcp_local_flow_alloc(int           fd,
                                  char *        dst_name,
                                  char *        src_ae_name,
                                  enum qos_cube qos)
 {
-        int in_fd = -1;
         int out_fd = -1;
 
-        struct shm_ap_rbuff * rb;
-
-        LOG_INFO("Allocating flow to %s.", dst_name);
+        LOG_DBG("Allocating flow to %s on fd %d.", dst_name, fd);
 
         if (dst_name == NULL || src_ae_name == NULL)
                 return -1;
 
         /* This ipcpd has all QoS */
 
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-        if (ipcp_get_state(_ipcp) != IPCP_ENROLLED) {
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+        if (ipcp_get_state() != IPCP_ENROLLED) {
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 LOG_DBGF("Won't register with non-enrolled IPCP.");
                 return -1; /* -ENOTENROLLED */
         }
 
-        rb = shm_ap_rbuff_open_s(n_api);
-        if (rb == NULL) {
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                return -1; /* -ENORBUFF */
-        }
-
-        pthread_rwlock_wrlock(&_ap_instance->flows_lock);
+        pthread_rwlock_wrlock(&local_data.lock);
 
-        in_fd = bmp_allocate(_ap_instance->fds);
-        if (!bmp_is_id_valid(_ap_instance->fds, in_fd)) {
-                pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                return -EMFILE;
-        }
+        out_fd = ipcp_flow_req_arr(getpid(), dst_name, src_ae_name);
 
-        _ap_instance->flows[in_fd].port_id = port_id;
-        _ap_instance->flows[in_fd].state   = FLOW_PENDING;
-        _ap_instance->flows[in_fd].rb      = rb;
+        local_data.in_out[fd]  = out_fd;
+        local_data.in_out[out_fd] = fd;
 
-        LOG_DBGF("Pending local flow with port_id %d.", port_id);
+        pthread_rwlock_unlock(&local_data.lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
-        /* reply to IRM */
-        port_id = ipcp_flow_req_arr(getpid(),
-                                    dst_name,
-                                    src_ae_name);
-
-        if (port_id < 0) {
-                pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                LOG_ERR("Could not get port id from IRMd");
-                /* shm_ap_rbuff_close(n_api); */
-                return -1;
-        }
-
-        out_fd = bmp_allocate(_ap_instance->fds);
-        if (!bmp_is_id_valid(_ap_instance->fds, out_fd)) {
-                /* shm_ap_rbuff_close(n_api); */
-                pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                return -1; /* -ENOMOREFDS */
-        }
-
-        _ap_instance->flows[out_fd].port_id = port_id;
-        _ap_instance->flows[out_fd].rb      = NULL;
-        _ap_instance->flows[out_fd].state   = FLOW_PENDING;
-
-        _ap_instance->in_out[in_fd]  = out_fd;
-        _ap_instance->in_out[out_fd] = in_fd;
-
-        pthread_rwlock_unlock(&_ap_instance->flows_lock);
-        pthread_rwlock_unlock(&_ipcp->state_lock);
-
-        LOG_DBGF("Pending local allocation request, port_id %d.", port_id);
+        LOG_INFO("Pending local allocation request on fd %d.", fd);
 
         return 0;
 }
 
-static int ipcp_local_flow_alloc_resp(pid_t n_api,
-                                      int   port_id,
-                                      int   response)
+static int ipcp_local_flow_alloc_resp(int fd, int response)
 {
-        struct shm_ap_rbuff * rb;
-        int in_fd = -1;
         int out_fd = -1;
         int ret = -1;
 
+        LOG_DBG("Received response for fd %d: %d.", fd, response);
+
         if (response)
                 return 0;
 
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
-
-        /* awaken pending flow */
-
-        pthread_rwlock_wrlock(&_ap_instance->flows_lock);
-
-        in_fd = port_id_to_fd(port_id);
-        if (in_fd < 0) {
-                pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                LOG_DBGF("Could not find flow with port_id %d.", port_id);
-                return -1;
-        }
-
-        if (_ap_instance->flows[in_fd].state != FLOW_PENDING) {
-                pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                LOG_DBGF("Flow was not pending.");
-                return -1;
-        }
-
-        rb = shm_ap_rbuff_open_s(n_api);
-        if (rb == NULL) {
-                LOG_ERR("Could not open N + 1 ringbuffer.");
-                _ap_instance->flows[in_fd].state   = FLOW_NULL;
-                _ap_instance->flows[in_fd].port_id = -1;
-                _ap_instance->in_out[in_fd] = -1;
-                pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                return -1;
-        }
-
-        _ap_instance->flows[in_fd].state = FLOW_ALLOCATED;
-        _ap_instance->flows[in_fd].rb    = rb;
-
-        LOG_DBGF("Accepted flow, port_id %d on fd %d.", port_id, in_fd);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-        out_fd = _ap_instance->in_out[in_fd];
+        out_fd = local_data.in_out[fd];
         if (out_fd < 0) {
-                pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                LOG_DBGF("No pending local flow with port_id %d.", port_id);
+                pthread_rwlock_unlock(&local_data.lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 return -1;
         }
 
-        if (_ap_instance->flows[out_fd].state != FLOW_PENDING) {
-                 /* FIXME: clean up other end */
-                pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                LOG_DBGF("Flow was not pending.");
-                return -1;
-        }
-
-        _ap_instance->flows[out_fd].state = FLOW_ALLOCATED;
-
-        pthread_rwlock_unlock(&_ap_instance->flows_lock);
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
-        if ((ret = ipcp_flow_alloc_reply(getpid(),
-                                         _ap_instance->flows[out_fd].port_id,
-                                         response)) < 0) {
-                return -1; /* -EPIPE */
-        }
+        if ((ret = ipcp_flow_alloc_reply(out_fd, response)) < 0)
+                return -1;
 
-        LOG_INFO("Flow allocation completed, port_ids (%d, %d).",
-                 _ap_instance->flows[out_fd].port_id,
-                 _ap_instance->flows[in_fd].port_id);
+        LOG_INFO("Flow allocation completed, fds (%d, %d).", out_fd, fd);
 
         return ret;
 }
 
-static int ipcp_local_flow_dealloc(int port_id)
+static int ipcp_local_flow_dealloc(int fd)
 {
-        int fd = -1;
-        struct shm_ap_rbuff * rb;
-
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
-        pthread_rwlock_wrlock(&_ap_instance->flows_lock);
-
-        fd = port_id_to_fd(port_id);
-        if (fd < 0) {
-                pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                LOG_DBGF("Could not find flow with port_id %d.", port_id);
-                return 0;
-        }
-
-        bmp_release(_ap_instance->fds, fd);
-
-        if (_ap_instance->in_out[fd] != -1)
-                _ap_instance->in_out[_ap_instance->in_out[fd]] = -1;
-
-        _ap_instance->in_out[fd] = -1;
-
-        _ap_instance->flows[fd].state   = FLOW_NULL;
-        _ap_instance->flows[fd].port_id = -1;
-        rb = _ap_instance->flows[fd].rb;
-        _ap_instance->flows[fd].rb      = NULL;
-
-        pthread_rwlock_unlock(&_ap_instance->flows_lock);
-
-        if (rb != NULL)
-                shm_ap_rbuff_close(rb);
-
-        pthread_rwlock_unlock(&_ipcp->state_lock);
-
-        LOG_DBGF("Flow with port_id %d deallocated.", port_id);
-
-        return 0;
-}
-
-static struct ipcp * ipcp_local_create()
-{
-        struct ipcp * i;
-        struct ipcp_ops *  ops;
+        int out_fd = -1;
 
-        i = ipcp_instance_create();
-        if (i == NULL)
-                return NULL;
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
+        pthread_rwlock_wrlock(&local_data.lock);
 
-        i->data = ipcp_data_create();
-        if (i->data == NULL) {
-                free(i);
-                return NULL;
-        }
+        out_fd = local_data.in_out[fd];
 
-        if (ipcp_data_init(i->data, THIS_TYPE) == NULL) {
-                free(i->data);
-                free(i);
-                return NULL;
+        if (out_fd != -1) {
+                local_data.in_out[out_fd] = -1;
+                flow_dealloc(out_fd);
         }
 
-        ops = malloc(sizeof(*ops));
-        if (ops == NULL) {
-                free(i->data);
-                free(i);
-                return NULL;
-        }
+        local_data.in_out[fd] = -1;
 
-        ops->ipcp_bootstrap       = ipcp_local_bootstrap;
-        ops->ipcp_enroll          = NULL;                       /* shim */
-        ops->ipcp_name_reg        = ipcp_local_name_reg;
-        ops->ipcp_name_unreg      = ipcp_local_name_unreg;
-        ops->ipcp_flow_alloc      = ipcp_local_flow_alloc;
-        ops->ipcp_flow_alloc_resp = ipcp_local_flow_alloc_resp;
-        ops->ipcp_flow_dealloc    = ipcp_local_flow_dealloc;
+        pthread_rwlock_unlock(&local_data.lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
-        i->ops = ops;
+        LOG_INFO("Flow with fd %d deallocated.", fd);
 
-        i->state = IPCP_INIT;
-
-        return i;
+        return 0;
 }
 
-#ifndef MAKE_CHECK
+static struct ipcp_ops local_ops = {
+        .ipcp_bootstrap       = ipcp_local_bootstrap,
+        .ipcp_enroll          = NULL,                       /* shim */
+        .ipcp_name_reg        = ipcp_local_name_reg,
+        .ipcp_name_unreg      = ipcp_local_name_unreg,
+        .ipcp_flow_alloc      = ipcp_local_flow_alloc,
+        .ipcp_flow_alloc_resp = ipcp_local_flow_alloc_resp,
+        .ipcp_flow_dealloc    = ipcp_local_flow_dealloc
+};
 
 int main(int argc, char * argv[])
 {
@@ -571,7 +282,9 @@ int main(int argc, char * argv[])
                 exit(EXIT_FAILURE);
         }
 
-        if (shim_ap_init() < 0) {
+        local_data_init();
+
+        if (ap_init(NULL) < 0) {
                 close_logfile();
                 exit(EXIT_FAILURE);
         }
@@ -591,17 +304,13 @@ int main(int argc, char * argv[])
         sigaction(SIGHUP,  &sig_act, NULL);
         sigaction(SIGPIPE, &sig_act, NULL);
 
-        _ipcp = ipcp_local_create();
-        if (_ipcp == NULL) {
-                LOG_ERR("Failed to create IPCP.");
+        pthread_sigmask(SIG_BLOCK, &sigset, NULL);
+
+        if (ipcp_init(THIS_TYPE, &local_ops) < 0) {
                 close_logfile();
                 exit(EXIT_FAILURE);
         }
 
-        pthread_sigmask(SIG_BLOCK, &sigset, NULL);
-
-        pthread_create(&_ap_instance->mainloop, NULL, ipcp_main_loop, _ipcp);
-
         pthread_sigmask(SIG_UNBLOCK, &sigset, NULL);
 
         if (ipcp_create_r(getpid())) {
@@ -610,21 +319,16 @@ int main(int argc, char * argv[])
                 exit(EXIT_FAILURE);
         }
 
-        pthread_join(_ap_instance->mainloop, NULL);
-
-        pthread_cancel(_ap_instance->sduloop);
-        pthread_join(_ap_instance->sduloop, NULL);
+        ipcp_fini();
 
-        shim_ap_fini();
+        pthread_cancel(local_data.sduloop);
+        pthread_join(local_data.sduloop, NULL);
 
-        ipcp_data_destroy(_ipcp->data);
+        ap_fini();
 
-        free(_ipcp->ops);
-        free(_ipcp);
+        local_data_fini();
 
         close_logfile();
 
         exit(EXIT_SUCCESS);
 }
-
-#endif /* MAKE_CHECK */
diff --git a/src/ipcpd/normal/fmgr.c b/src/ipcpd/normal/fmgr.c
index 79b1bb4b..b6ec1984 100644
--- a/src/ipcpd/normal/fmgr.c
+++ b/src/ipcpd/normal/fmgr.c
@@ -26,7 +26,7 @@
 #include <ouroboros/logs.h>
 #include <ouroboros/dev.h>
 #include <ouroboros/list.h>
-#include <ouroboros/ipcp.h>
+#include <ouroboros/ipcp-dev.h>
 
 #include <stdlib.h>
 #include <stdbool.h>
@@ -41,10 +41,8 @@
 #include "flow_alloc.pb-c.h"
 typedef FlowAllocMsg flow_alloc_msg_t;
 
-extern struct ipcp * _ipcp;
-
 struct n_flow {
-        struct flow flow;
+        int fd;
         struct frct_i * frct_i;
         enum qos_cube qos;
 
@@ -57,7 +55,7 @@ struct n_1_flow {
         struct list_head next;
 };
 
-struct fmgr {
+struct {
         pthread_t listen_thread;
 
         struct list_head n_1_flows;
@@ -66,10 +64,9 @@ struct fmgr {
         struct list_head n_flows;
         /* FIXME: Make this a read/write lock */
         pthread_mutex_t n_flows_lock;
-} * fmgr = NULL;
+} fmgr;
 
-static int add_n_1_fd(int fd,
-                      char * ae_name)
+static int add_n_1_fd(int fd, char * ae_name)
 {
         struct n_1_flow * tmp;
 
@@ -85,9 +82,9 @@ static int add_n_1_fd(int fd,
 
         INIT_LIST_HEAD(&tmp->next);
 
-        pthread_mutex_lock(&fmgr->n_1_flows_lock);
-        list_add(&tmp->next, &fmgr->n_1_flows);
-        pthread_mutex_unlock(&fmgr->n_1_flows_lock);
+        pthread_mutex_lock(&fmgr.n_1_flows_lock);
+        list_add(&tmp->next, &fmgr.n_1_flows);
+        pthread_mutex_unlock(&fmgr.n_1_flows_lock);
 
         return 0;
 }
@@ -98,16 +95,16 @@ static void * fmgr_listen(void * o)
         char * ae_name;
 
         while (true) {
-                ipcp_wait_state(_ipcp, IPCP_ENROLLED, NULL);
+                ipcp_wait_state(IPCP_ENROLLED, NULL);
 
-                pthread_rwlock_rdlock(&_ipcp->state_lock);
+                pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-                if (ipcp_get_state(_ipcp) == IPCP_SHUTDOWN) {
-                        pthread_rwlock_unlock(&_ipcp->state_lock);
+                if (ipcp_get_state() == IPCP_SHUTDOWN) {
+                        pthread_rwlock_unlock(&ipcpi.state_lock);
                         return 0;
                 }
 
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
 
                 fd = flow_accept(&ae_name);
                 if (fd < 0) {
@@ -161,17 +158,13 @@ static void * fmgr_listen(void * o)
 
 int fmgr_init()
 {
-        fmgr = malloc(sizeof(*fmgr));
-        if (fmgr == NULL)
-                return -1;
+        INIT_LIST_HEAD(&fmgr.n_1_flows);
+        INIT_LIST_HEAD(&fmgr.n_flows);
 
-        INIT_LIST_HEAD(&fmgr->n_1_flows);
-        INIT_LIST_HEAD(&fmgr->n_flows);
+        pthread_mutex_init(&fmgr.n_1_flows_lock, NULL);
+        pthread_mutex_init(&fmgr.n_flows_lock, NULL);
 
-        pthread_mutex_init(&fmgr->n_1_flows_lock, NULL);
-        pthread_mutex_init(&fmgr->n_flows_lock, NULL);
-
-        pthread_create(&fmgr->listen_thread, NULL, fmgr_listen, NULL);
+        pthread_create(&fmgr.listen_thread, NULL, fmgr_listen, NULL);
 
         return 0;
 }
@@ -180,23 +173,20 @@ int fmgr_fini()
 {
         struct list_head * pos = NULL;
 
-        pthread_cancel(fmgr->listen_thread);
+        pthread_cancel(fmgr.listen_thread);
 
-        pthread_join(fmgr->listen_thread, NULL);
+        pthread_join(fmgr.listen_thread, NULL);
 
-        list_for_each(pos, &fmgr->n_1_flows) {
-                struct n_1_flow * e =
-                        list_entry(pos, struct n_1_flow, next);
+        list_for_each(pos, &fmgr.n_1_flows) {
+                struct n_1_flow * e = list_entry(pos, struct n_1_flow, next);
                 if (e->ae_name != NULL)
                         free(e->ae_name);
                 if (ribmgr_remove_flow(e->fd))
                     LOG_ERR("Failed to remove management flow.");
         }
 
-        pthread_mutex_destroy(&fmgr->n_1_flows_lock);
-        pthread_mutex_destroy(&fmgr->n_flows_lock);
-
-        free(fmgr);
+        pthread_mutex_destroy(&fmgr.n_1_flows_lock);
+        pthread_mutex_destroy(&fmgr.n_flows_lock);
 
         return 0;
 }
@@ -243,8 +233,7 @@ int fmgr_mgmt_flow(char * dst_name)
         return 0;
 }
 
-int fmgr_dt_flow(char * dst_name,
-                 enum qos_cube qos)
+int fmgr_dt_flow(char * dst_name, enum qos_cube qos)
 {
         int fd;
         int result;
@@ -288,14 +277,13 @@ int fmgr_dt_flow(char * dst_name,
 }
 
 /* Call under n_flows lock */
-static struct n_flow * get_n_flow_by_port_id(int port_id)
+static struct n_flow * get_n_flow_by_fd(int fd)
 {
         struct list_head * pos = NULL;
 
-        list_for_each(pos, &fmgr->n_flows) {
-                struct n_flow * e =
-                        list_entry(pos, struct n_flow, next);
-                if (e->flow.port_id == port_id)
+        list_for_each(pos, &fmgr.n_flows) {
+                struct n_flow * e = list_entry(pos, struct n_flow, next);
+                if (e->fd == fd)
                         return e;
         }
 
@@ -307,9 +295,8 @@ static struct n_flow * get_n_flow_by_frct_i(struct frct_i * frct_i)
 {
         struct list_head * pos = NULL;
 
-        list_for_each(pos, &fmgr->n_flows) {
-                struct n_flow * e =
-                        list_entry(pos, struct n_flow, next);
+        list_for_each(pos, &fmgr.n_flows) {
+                struct n_flow * e = list_entry(pos, struct n_flow, next);
                 if (e->frct_i == frct_i)
                         return e;
         }
@@ -317,8 +304,7 @@ static struct n_flow * get_n_flow_by_frct_i(struct frct_i * frct_i)
         return NULL;
 }
 
-int fmgr_flow_alloc(pid_t         n_api,
-                    int           port_id,
+int fmgr_flow_alloc(int           fd,
                     char *        dst_ap_name,
                     char *        src_ae_name,
                     enum qos_cube qos)
@@ -355,49 +341,40 @@ int fmgr_flow_alloc(pid_t         n_api,
 
         flow_alloc_msg__pack(&msg, buf.data);
 
-        pthread_mutex_lock(&fmgr->n_flows_lock);
+        pthread_mutex_lock(&fmgr.n_flows_lock);
 
         frct_i = frct_i_create(address, &buf, qos);
         if (frct_i == NULL) {
                 free(buf.data);
                 free(flow);
-                pthread_mutex_unlock(&fmgr->n_flows_lock);
+                pthread_mutex_unlock(&fmgr.n_flows_lock);
                 return -1;
         }
 
         free(buf.data);
 
-        flow->flow.rb = shm_ap_rbuff_open_s(n_api);
-        if (flow->flow.rb == NULL) {
-                pthread_mutex_unlock(&fmgr->n_flows_lock);
-                free(flow);
-                return -1;
-        }
-
-        flow->flow.api = n_api;
-        flow->flow.port_id = port_id;
-        flow->flow.state = FLOW_PENDING;
+        flow->fd     = fd;
         flow->frct_i = frct_i;
-        flow->qos = qos;
+        flow->qos    = qos;
 
         INIT_LIST_HEAD(&flow->next);
 
-        list_add(&flow->next, &fmgr->n_flows);
+        list_add(&flow->next, &fmgr.n_flows);
 
-        pthread_mutex_unlock(&fmgr->n_flows_lock);
+        pthread_mutex_unlock(&fmgr.n_flows_lock);
 
         return 0;
 }
 
 /* Call under n_flows lock */
-static int n_flow_dealloc(int port_id)
+static int n_flow_dealloc(int fd)
 {
         struct n_flow * flow;
         flow_alloc_msg_t msg = FLOW_ALLOC_MSG__INIT;
         buffer_t buf;
         int ret;
 
-        flow = get_n_flow_by_port_id(port_id);
+        flow = get_n_flow_by_fd(fd);
         if (flow == NULL)
                 return -1;
 
@@ -414,8 +391,6 @@ static int n_flow_dealloc(int port_id)
         flow_alloc_msg__pack(&msg, buf.data);
 
         ret = frct_i_destroy(flow->frct_i, &buf);
-        if (flow->flow.rb != NULL)
-                shm_ap_rbuff_close(flow->flow.rb);
         list_del(&flow->next);
 
         free(flow);
@@ -424,25 +399,17 @@ static int n_flow_dealloc(int port_id)
         return ret;
 }
 
-int fmgr_flow_alloc_resp(pid_t n_api,
-                         int   port_id,
-                         int   response)
+int fmgr_flow_alloc_resp(int fd, int response)
 {
         struct n_flow * flow;
         flow_alloc_msg_t msg = FLOW_ALLOC_MSG__INIT;
         buffer_t buf;
 
-        pthread_mutex_lock(&fmgr->n_flows_lock);
+        pthread_mutex_lock(&fmgr.n_flows_lock);
 
-        flow = get_n_flow_by_port_id(port_id);
+        flow = get_n_flow_by_fd(fd);
         if (flow == NULL) {
-                pthread_mutex_unlock(&fmgr->n_flows_lock);
-                return -1;
-        }
-
-        if (flow->flow.state != FLOW_PENDING) {
-                pthread_mutex_unlock(&fmgr->n_flows_lock);
-                LOG_ERR("Flow is not pending.");
+                pthread_mutex_unlock(&fmgr.n_flows_lock);
                 return -1;
         }
 
@@ -452,13 +419,13 @@ int fmgr_flow_alloc_resp(pid_t n_api,
 
         buf.len = flow_alloc_msg__get_packed_size(&msg);
         if (buf.len == 0) {
-                pthread_mutex_unlock(&fmgr->n_flows_lock);
+                pthread_mutex_unlock(&fmgr.n_flows_lock);
                 return -1;
         }
 
         buf.data = malloc(buf.len);
         if (buf.data == NULL) {
-                pthread_mutex_unlock(&fmgr->n_flows_lock);
+                pthread_mutex_unlock(&fmgr.n_flows_lock);
                 return -1;
         }
 
@@ -469,106 +436,85 @@ int fmgr_flow_alloc_resp(pid_t n_api,
                 free(buf.data);
                 list_del(&flow->next);
                 free(flow);
-        } else {
-                if (frct_i_accept(flow->frct_i, &buf)) {
-                        pthread_mutex_unlock(&fmgr->n_flows_lock);
-                        return -1;
-                }
-
-                flow->flow.state = FLOW_ALLOCATED;
-                flow->flow.api = n_api;
-
-                flow->flow.rb = shm_ap_rbuff_open_s(n_api);
-                if (flow->flow.rb == NULL) {
-                        n_flow_dealloc(port_id);
-                        pthread_mutex_unlock(&fmgr->n_flows_lock);
-                        return -1;
-                }
+        } else if (frct_i_accept(flow->frct_i, &buf)) {
+                pthread_mutex_unlock(&fmgr.n_flows_lock);
+                return -1;
         }
 
-        pthread_mutex_unlock(&fmgr->n_flows_lock);
+        pthread_mutex_unlock(&fmgr.n_flows_lock);
 
         return 0;
 }
 
-int fmgr_flow_dealloc(int port_id)
+int fmgr_flow_dealloc(int fd)
 {
         int ret;
 
-        pthread_mutex_lock(&fmgr->n_flows_lock);
-        ret = n_flow_dealloc(port_id);
-        pthread_mutex_unlock(&fmgr->n_flows_lock);
+        pthread_mutex_lock(&fmgr.n_flows_lock);
+        ret = n_flow_dealloc(fd);
+        pthread_mutex_unlock(&fmgr.n_flows_lock);
 
         return ret;
 }
 
-int fmgr_flow_alloc_msg(struct frct_i * frct_i,
-                        buffer_t *      buf)
+int fmgr_flow_alloc_msg(struct frct_i * frct_i, buffer_t * buf)
 {
         struct n_flow * flow;
         int ret = 0;
-        int port_id;
+        int fd;
         flow_alloc_msg_t * msg;
 
-        pthread_mutex_lock(&fmgr->n_flows_lock);
+        pthread_mutex_lock(&fmgr.n_flows_lock);
 
-        /* Depending on what is in the message call the function in ipcp.h */
+        /* Depending on the message call the function in ipcp-dev.h */
 
         msg = flow_alloc_msg__unpack(NULL, buf->len, buf->data);
         if (msg == NULL) {
-                pthread_mutex_unlock(&fmgr->n_flows_lock);
+                pthread_mutex_unlock(&fmgr.n_flows_lock);
                 LOG_ERR("Failed to unpack flow alloc message");
                 return -1;
         }
 
         switch (msg->code) {
         case FLOW_ALLOC_CODE__FLOW_REQ:
-
                 flow = malloc(sizeof(*flow));
                 if (flow == NULL) {
-                        pthread_mutex_unlock(&fmgr->n_flows_lock);
+                        pthread_mutex_unlock(&fmgr.n_flows_lock);
                         flow_alloc_msg__free_unpacked(msg, NULL);
                         return -1;
                 }
 
-                flow->flow.state = FLOW_PENDING;
                 flow->frct_i = frct_i;
                 flow->qos = msg->qos_cube;
-                flow->flow.rb = NULL;
-                flow->flow.api = 0;
-
-                port_id = ipcp_flow_req_arr(getpid(),
-                                            msg->dst_name,
-                                            msg->src_ae_name);
-                if (port_id < 0) {
-                        pthread_mutex_unlock(&fmgr->n_flows_lock);
+
+                fd = ipcp_flow_req_arr(getpid(),
+                                       msg->dst_name,
+                                       msg->src_ae_name);
+                if (fd < 0) {
+                        pthread_mutex_unlock(&fmgr.n_flows_lock);
                         free(flow);
                         flow_alloc_msg__free_unpacked(msg, NULL);
-                        LOG_ERR("Failed to get port-id from IRMd.");
+                        LOG_ERR("Failed to get fd for flow.");
                         return -1;
                 }
 
-                flow->flow.port_id = port_id;
+                flow->fd = fd;
 
                 INIT_LIST_HEAD(&flow->next);
 
-                list_add(&flow->next, &fmgr->n_flows);
+                list_add(&flow->next, &fmgr.n_flows);
                 break;
         case FLOW_ALLOC_CODE__FLOW_REPLY:
                 flow = get_n_flow_by_frct_i(frct_i);
                 if (flow == NULL) {
-                        pthread_mutex_unlock(&fmgr->n_flows_lock);
+                        pthread_mutex_unlock(&fmgr.n_flows_lock);
                         flow_alloc_msg__free_unpacked(msg, NULL);
                         LOG_ERR("No such flow in flow manager.");
                         return -1;
                 }
 
-                ret = ipcp_flow_alloc_reply(getpid(),
-                                            flow->flow.port_id,
-                                            msg->response);
-
+                ret = ipcp_flow_alloc_reply(flow->fd, msg->response);
                 if (msg->response < 0) {
-                        shm_ap_rbuff_close(flow->flow.rb);
                         list_del(&flow->next);
                         free(flow);
                 }
@@ -577,13 +523,13 @@ int fmgr_flow_alloc_msg(struct frct_i * frct_i,
         case FLOW_ALLOC_CODE__FLOW_DEALLOC:
                 flow = get_n_flow_by_frct_i(frct_i);
                 if (flow == NULL) {
-                        pthread_mutex_unlock(&fmgr->n_flows_lock);
+                        pthread_mutex_unlock(&fmgr.n_flows_lock);
                         flow_alloc_msg__free_unpacked(msg, NULL);
                         LOG_ERR("No such flow in flow manager.");
                         return -1;
                 }
 
-                ret = irm_flow_dealloc(flow->flow.port_id);
+                ret = flow_dealloc(flow->fd);
                 break;
         default:
                 LOG_ERR("Got an unknown flow allocation message.");
@@ -591,7 +537,7 @@ int fmgr_flow_alloc_msg(struct frct_i * frct_i,
                 break;
         }
 
-        pthread_mutex_unlock(&fmgr->n_flows_lock);
+        pthread_mutex_unlock(&fmgr.n_flows_lock);
 
         flow_alloc_msg__free_unpacked(msg, NULL);
 
diff --git a/src/ipcpd/normal/fmgr.h b/src/ipcpd/normal/fmgr.h
index 342410ca..7e3ef5f4 100644
--- a/src/ipcpd/normal/fmgr.h
+++ b/src/ipcpd/normal/fmgr.h
@@ -35,25 +35,25 @@
 #define DT_AE "Data transfer"
 
 int fmgr_init();
+
 int fmgr_fini();
 
 /* N-flow ops */
 int fmgr_mgmt_flow(char * dst_name);
+
 int fmgr_dt_flow(char * dst_name,
                  enum qos_cube qos);
 
 /* N+1-flow ops, local */
-int fmgr_flow_alloc(pid_t         n_api,
-                    int           port_id,
+int fmgr_flow_alloc(int           fd,
                     char *        dst_ap_name,
                     char *        src_ae_name,
                     enum qos_cube qos);
 
-int fmgr_flow_alloc_resp(pid_t n_api,
-                         int   port_id,
-                         int   response);
+int fmgr_flow_alloc_resp(int fd,
+                         int response);
 
-int fmgr_flow_dealloc(int port_id);
+int fmgr_flow_dealloc(int fd);
 
 /* N+1-flow ops, remote */
 int fmgr_flow_alloc_msg(struct frct_i * frct_i,
diff --git a/src/ipcpd/normal/frct.h b/src/ipcpd/normal/frct.h
index 09873445..0ee87004 100644
--- a/src/ipcpd/normal/frct.h
+++ b/src/ipcpd/normal/frct.h
@@ -24,7 +24,7 @@
 #define OUROBOROS_IPCP_FRCT_H
 
 #include <ouroboros/shared.h>
-#include <ouroboros/common.h>
+#include <ouroboros/utils.h>
 
 #include "dt_const.h"
 
diff --git a/src/ipcpd/normal/main.c b/src/ipcpd/normal/main.c
index 082973f4..4611408d 100644
--- a/src/ipcpd/normal/main.c
+++ b/src/ipcpd/normal/main.c
@@ -24,10 +24,8 @@
 
 #include <ouroboros/config.h>
 #include <ouroboros/logs.h>
-#include <ouroboros/shm_rdrbuff.h>
-#include <ouroboros/shm_ap_rbuff.h>
 #include <ouroboros/dev.h>
-#include <ouroboros/ipcp.h>
+#include <ouroboros/ipcp-dev.h>
 #include <ouroboros/time_utils.h>
 
 #include <stdbool.h>
@@ -47,26 +45,8 @@
 /* global for trapping signal */
 int irmd_api;
 
-struct ipcp * _ipcp;
-
-#define normal_data(type) ((struct normal_ipcp_data *) type->data)
-
-struct normal_ipcp_data {
-        /* Keep ipcp_data first for polymorphism. */
-        struct ipcp_data      ipcp_data;
-
-        struct shm_rdrbuff *  rdrb;
-        struct shm_ap_rbuff * rb;
-
-        pthread_t             mainloop;
-};
-
 void ipcp_sig_handler(int sig, siginfo_t * info, void * c)
 {
-        sigset_t  sigset;
-        sigemptyset(&sigset);
-        sigaddset(&sigset, SIGINT);
-
         switch(sig) {
         case SIGINT:
         case SIGTERM:
@@ -75,11 +55,11 @@ void ipcp_sig_handler(int sig, siginfo_t * info, void * c)
                         LOG_DBG("IPCP %d terminating by order of %d. Bye.",
                                 getpid(), info->si_pid);
 
-                        pthread_rwlock_wrlock(&_ipcp->state_lock);
+                        pthread_rwlock_wrlock(&ipcpi.state_lock);
 
-                        ipcp_set_state(_ipcp, IPCP_SHUTDOWN);
+                        ipcp_set_state(IPCP_SHUTDOWN);
 
-                        pthread_rwlock_unlock(&_ipcp->state_lock);
+                        pthread_rwlock_unlock(&ipcpi.state_lock);
                 }
         default:
                 return;
@@ -88,15 +68,15 @@ void ipcp_sig_handler(int sig, siginfo_t * info, void * c)
 
 static int normal_ipcp_name_reg(char * name)
 {
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-        if (ipcp_data_add_reg_entry(_ipcp->data, name)) {
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+        if (ipcp_data_add_reg_entry(ipcpi.data, name)) {
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 LOG_ERR("Failed to add %s to local registry.", name);
                 return -1;
         }
 
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
         LOG_DBG("Registered %s.", name);
 
@@ -105,11 +85,11 @@ static int normal_ipcp_name_reg(char * name)
 
 static int normal_ipcp_name_unreg(char * name)
 {
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-        ipcp_data_del_reg_entry(_ipcp->data, name);
+        ipcp_data_del_reg_entry(ipcpi.data, name);
 
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
         return 0;
 }
@@ -119,59 +99,59 @@ static int normal_ipcp_enroll(char * dif_name)
         struct timespec timeout = {(ENROLL_TIMEOUT / 1000),
                                    (ENROLL_TIMEOUT % 1000) * MILLION};
 
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-        if (ipcp_get_state(_ipcp) != IPCP_INIT) {
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+        if (ipcp_get_state() != IPCP_INIT) {
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 LOG_ERR("Won't enroll an IPCP that is not in INIT.");
                 return -1; /* -ENOTINIT */
         }
 
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
         if (fmgr_mgmt_flow(dif_name)) {
                 LOG_ERR("Failed to establish management flow.");
                 return -1;
         }
 
-        if (ipcp_wait_state(_ipcp, IPCP_ENROLLED, &timeout) == -ETIMEDOUT) {
+        if (ipcp_wait_state(IPCP_ENROLLED, &timeout) == -ETIMEDOUT) {
                 LOG_ERR("Enrollment timed out.");
                 return -1;
         }
 
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-        if (ipcp_get_state(_ipcp) != IPCP_ENROLLED) {
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+        if (ipcp_get_state() != IPCP_ENROLLED) {
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 return -1;
         }
 
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
         return 0;
 }
 
 static int normal_ipcp_bootstrap(struct dif_config * conf)
 {
-        pthread_rwlock_wrlock(&_ipcp->state_lock);
+        pthread_rwlock_wrlock(&ipcpi.state_lock);
 
-        if (ipcp_get_state(_ipcp) != IPCP_INIT) {
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+        if (ipcp_get_state() != IPCP_INIT) {
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 LOG_ERR("Won't bootstrap an IPCP that is not in INIT.");
                 return -1; /* -ENOTINIT */
         }
 
         if (ribmgr_bootstrap(conf)) {
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 LOG_ERR("Failed to bootstrap RIB manager.");
                 return -1;
         }
 
-        ipcp_set_state(_ipcp, IPCP_ENROLLED);
+        ipcp_set_state(IPCP_ENROLLED);
 
-        _ipcp->data->dif_name = conf->dif_name;
+        ipcpi.data->dif_name = conf->dif_name;
 
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
         LOG_DBG("Bootstrapped in DIF %s.", conf->dif_name);
 
@@ -188,67 +168,6 @@ static struct ipcp_ops normal_ops = {
         .ipcp_flow_dealloc    = fmgr_flow_dealloc
 };
 
-struct normal_ipcp_data * normal_ipcp_data_create()
-{
-        struct normal_ipcp_data * normal_data;
-        enum ipcp_type            ipcp_type;
-
-        normal_data = malloc(sizeof(*normal_data));
-        if (normal_data == NULL) {
-                LOG_ERR("Failed to allocate.");
-                return NULL;
-        }
-
-        ipcp_type = THIS_TYPE;
-        if (ipcp_data_init((struct ipcp_data *) normal_data,
-                           ipcp_type) == NULL) {
-                free(normal_data);
-                return NULL;
-        }
-
-        normal_data->rdrb = shm_rdrbuff_open();
-        if (normal_data->rdrb == NULL) {
-                free(normal_data);
-                return NULL;
-        }
-
-        normal_data->rb = shm_ap_rbuff_create_n();
-        if (normal_data->rb == NULL) {
-                shm_rdrbuff_close(normal_data->rdrb);
-                free(normal_data);
-                return NULL;
-        }
-
-        return normal_data;
-}
-
-
-void normal_ipcp_data_destroy()
-{
-        int idx = 0;
-
-        if (_ipcp == NULL)
-                return;
-
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
-
-        if (ipcp_get_state(_ipcp) != IPCP_SHUTDOWN)
-                LOG_WARN("Cleaning up while not in shutdown.");
-
-        /* remove all remaining sdus */
-        while ((idx = shm_ap_rbuff_peek_idx(normal_data(_ipcp)->rb)) >= 0)
-                shm_rdrbuff_remove(normal_data(_ipcp)->rdrb, idx);
-
-        if (normal_data(_ipcp)->rdrb != NULL)
-                shm_rdrbuff_close(normal_data(_ipcp)->rdrb);
-        if (normal_data(_ipcp)->rb != NULL)
-                shm_ap_rbuff_close(normal_data(_ipcp)->rb);
-
-        ipcp_data_destroy(_ipcp->data);
-
-        pthread_rwlock_unlock(&_ipcp->state_lock);
-}
-
 int main(int argc, char * argv[])
 {
         struct sigaction sig_act;
@@ -285,56 +204,38 @@ int main(int argc, char * argv[])
         sigaction(SIGHUP,  &sig_act, NULL);
         sigaction(SIGPIPE, &sig_act, NULL);
 
-        _ipcp = ipcp_instance_create();
-        if (_ipcp == NULL) {
-                LOG_ERR("Failed to create instance.");
-                close_logfile();
-                exit(EXIT_FAILURE);
-        }
+        pthread_sigmask(SIG_BLOCK, &sigset, NULL);
 
-        _ipcp->data = (struct ipcp_data *) normal_ipcp_data_create();
-        if (_ipcp->data == NULL) {
-                LOG_ERR("Failed to create instance data.");
-                free(_ipcp);
+        if (ipcp_init(THIS_TYPE, &normal_ops) < 0) {
+                LOG_ERR("Failed to create instance.");
                 close_logfile();
                 exit(EXIT_FAILURE);
         }
 
-        _ipcp->ops = &normal_ops;
-        _ipcp->state = IPCP_INIT;
+        pthread_sigmask(SIG_UNBLOCK, &sigset, NULL);
 
         if (fmgr_init()) {
-                normal_ipcp_data_destroy();
-                free(_ipcp);
+                ipcp_fini();
                 close_logfile();
                 exit(EXIT_FAILURE);
         }
 
         if (ribmgr_init()) {
-                normal_ipcp_data_destroy();
                 fmgr_fini();
-                free(_ipcp);
+                ipcp_fini();
                 close_logfile();
                 exit(EXIT_FAILURE);
         }
 
-        pthread_sigmask(SIG_BLOCK, &sigset, NULL);
-
-        pthread_create(&normal_data(_ipcp)->mainloop, NULL,
-                       ipcp_main_loop, _ipcp);
-
-        pthread_sigmask(SIG_UNBLOCK, &sigset, NULL);
-
         if (ipcp_create_r(getpid())) {
                 LOG_ERR("Failed to notify IRMd we are initialized.");
-                normal_ipcp_data_destroy();
                 fmgr_fini();
-                free(_ipcp);
+                ipcp_fini();
                 close_logfile();
                 exit(EXIT_FAILURE);
         }
 
-        pthread_join(normal_data(_ipcp)->mainloop, NULL);
+        ipcp_fini();
 
         if (fmgr_fini())
                 LOG_ERR("Failed to finalize flow manager.");
@@ -345,10 +246,9 @@ int main(int argc, char * argv[])
         if (frct_fini())
                 LOG_ERR("Failed to finalize FRCT.");
 
-        normal_ipcp_data_destroy();
-        free(_ipcp);
         close_logfile();
 
         ap_fini();
+
         exit(EXIT_SUCCESS);
 }
diff --git a/src/ipcpd/normal/ribmgr.c b/src/ipcpd/normal/ribmgr.c
index 9733abc9..99d156f5 100644
--- a/src/ipcpd/normal/ribmgr.c
+++ b/src/ipcpd/normal/ribmgr.c
@@ -27,6 +27,7 @@
 #include <ouroboros/cdap.h>
 #include <ouroboros/list.h>
 #include <ouroboros/time_utils.h>
+#include <ouroboros/ipcp-dev.h>
 
 #include <stdlib.h>
 #include <pthread.h>
@@ -45,15 +46,13 @@ typedef StaticInfoMsg static_info_msg_t;
 #define ENROLLMENT  "enrollment"
 #define STATIC_INFO "static DIF information"
 
-extern struct ipcp * _ipcp;
-
 struct mgmt_flow {
         struct cdap *    instance;
         int              fd;
         struct list_head next;
 };
 
-struct rib {
+struct {
         struct dt_const  dtc;
 
         uint32_t         address;
@@ -63,7 +62,7 @@ struct rib {
 
         struct list_head cdap_reqs;
         pthread_mutex_t  cdap_reqs_lock;
-} * rib = NULL;
+} rib;
 
 /* Call while holding cdap_reqs_lock */
 /* FIXME: better not to call blocking functions under any lock */
@@ -84,13 +83,13 @@ int cdap_result_wait(struct cdap * instance,
                 return -1;
         }
 
-        list_add(&req->next, &rib->cdap_reqs);
+        list_add(&req->next, &rib.cdap_reqs);
 
-        pthread_mutex_unlock(&rib->cdap_reqs_lock);
+        pthread_mutex_unlock(&rib.cdap_reqs_lock);
 
         ret = cdap_request_wait(req);
 
-        pthread_mutex_lock(&rib->cdap_reqs_lock);
+        pthread_mutex_lock(&rib.cdap_reqs_lock);
 
         if (ret == -1)  /* should only be on ipcp shutdown */
                 LOG_DBG("Waiting CDAP request destroyed.");
@@ -112,22 +111,16 @@ int cdap_result_wait(struct cdap * instance,
 
 int ribmgr_init()
 {
-        rib = malloc(sizeof(*rib));
-        if (rib == NULL)
-                return -1;
+        INIT_LIST_HEAD(&rib.flows);
+        INIT_LIST_HEAD(&rib.cdap_reqs);
 
-        INIT_LIST_HEAD(&rib->flows);
-        INIT_LIST_HEAD(&rib->cdap_reqs);
-
-        if (pthread_rwlock_init(&rib->flows_lock, NULL)) {
+        if (pthread_rwlock_init(&rib.flows_lock, NULL)) {
                 LOG_ERR("Failed to initialize rwlock.");
-                free(rib);
                 return -1;
         }
 
-        if (pthread_mutex_init(&rib->cdap_reqs_lock, NULL)) {
+        if (pthread_mutex_init(&rib.cdap_reqs_lock, NULL)) {
                 LOG_ERR("Failed to initialize mutex.");
-                free(rib);
                 return -1;
         }
 
@@ -139,19 +132,18 @@ int ribmgr_fini()
         struct list_head * pos = NULL;
         struct list_head * n = NULL;
 
-        pthread_mutex_lock(&rib->cdap_reqs_lock);
-        list_for_each_safe(pos, n, &rib->cdap_reqs) {
+        pthread_mutex_lock(&rib.cdap_reqs_lock);
+        list_for_each_safe(pos, n, &rib.cdap_reqs) {
                 struct cdap_request * req =
                         list_entry(pos, struct cdap_request, next);
-
                 free(req->name);
                 list_del(&req->next);
                 free(req);
         }
-        pthread_mutex_unlock(&rib->cdap_reqs_lock);
+        pthread_mutex_unlock(&rib.cdap_reqs_lock);
 
-        pthread_rwlock_wrlock(&rib->flows_lock);
-        list_for_each_safe(pos, n, &rib->flows) {
+        pthread_rwlock_wrlock(&rib.flows_lock);
+        list_for_each_safe(pos, n, &rib.flows) {
                 struct mgmt_flow * flow =
                         list_entry(pos, struct mgmt_flow, next);
                 if (cdap_destroy(flow->instance))
@@ -159,9 +151,10 @@ int ribmgr_fini()
                 list_del(&flow->next);
                 free(flow);
         }
-        pthread_rwlock_unlock(&rib->flows_lock);
+        pthread_rwlock_unlock(&rib.flows_lock);
 
-        free(rib);
+        pthread_mutex_destroy(&rib.cdap_reqs_lock);
+        pthread_rwlock_destroy(&rib.flows_lock);
 
         return 0;
 }
@@ -174,9 +167,9 @@ int ribmgr_cdap_reply(struct cdap * instance,
 {
         struct list_head * pos, * n = NULL;
 
-        pthread_mutex_lock(&rib->cdap_reqs_lock);
+        pthread_mutex_lock(&rib.cdap_reqs_lock);
 
-        list_for_each_safe(pos, n, &rib->cdap_reqs) {
+        list_for_each_safe(pos, n, &rib.cdap_reqs) {
                 struct cdap_request * req =
                         list_entry(pos, struct cdap_request, next);
                 if (req->instance == instance &&
@@ -191,15 +184,15 @@ int ribmgr_cdap_reply(struct cdap * instance,
                                         "executed succesfully",
                                         req->code, req->name);
 
-                        pthread_mutex_unlock(&rib->cdap_reqs_lock);
+                        pthread_mutex_unlock(&rib.cdap_reqs_lock);
 
                         /* FIXME: In case of a read, update values here */
                         cdap_request_respond(req, result);
 
-                        pthread_mutex_lock(&rib->cdap_reqs_lock);
+                        pthread_mutex_lock(&rib.cdap_reqs_lock);
                 }
         }
-        pthread_mutex_unlock(&rib->cdap_reqs_lock);
+        pthread_mutex_unlock(&rib.cdap_reqs_lock);
 
         return 0;
 }
@@ -223,34 +216,34 @@ int ribmgr_cdap_write(struct cdap * instance,
         static_info_msg_t * msg;
         int ret = 0;
 
-        pthread_rwlock_wrlock(&_ipcp->state_lock);
-        if (ipcp_get_state(_ipcp) == IPCP_PENDING_ENROLL &&
+        pthread_rwlock_wrlock(&ipcpi.state_lock);
+        if (ipcp_get_state() == IPCP_PENDING_ENROLL &&
             strcmp(name, STATIC_INFO) == 0) {
                 LOG_DBG("Received static DIF information.");
 
                 msg = static_info_msg__unpack(NULL, len, data);
                 if (msg == NULL) {
-                        ipcp_set_state(_ipcp, IPCP_INIT);
-                        pthread_rwlock_unlock(&_ipcp->state_lock);
+                        ipcp_set_state(IPCP_INIT);
+                        pthread_rwlock_unlock(&ipcpi.state_lock);
                         cdap_send_reply(instance, invoke_id, -1, NULL, 0);
                         LOG_ERR("Failed to unpack static info message.");
                         return -1;
                 }
 
-                rib->dtc.addr_size = msg->addr_size;
-                rib->dtc.cep_id_size = msg->cep_id_size;
-                rib->dtc.pdu_length_size = msg->pdu_length_size;
-                rib->dtc.seqno_size = msg->seqno_size;
-                rib->dtc.has_ttl = msg->has_ttl;
-                rib->dtc.has_chk = msg->has_chk;
-                rib->dtc.min_pdu_size = msg->min_pdu_size;
-                rib->dtc.max_pdu_size = msg->max_pdu_size;
+                rib.dtc.addr_size = msg->addr_size;
+                rib.dtc.cep_id_size = msg->cep_id_size;
+                rib.dtc.pdu_length_size = msg->pdu_length_size;
+                rib.dtc.seqno_size = msg->seqno_size;
+                rib.dtc.has_ttl = msg->has_ttl;
+                rib.dtc.has_chk = msg->has_chk;
+                rib.dtc.min_pdu_size = msg->min_pdu_size;
+                rib.dtc.max_pdu_size = msg->max_pdu_size;
 
-                rib->address = msg->address;
+                rib.address = msg->address;
 
-                if (frct_init(&rib->dtc, rib->address)) {
-                        ipcp_set_state(_ipcp, IPCP_INIT);
-                        pthread_rwlock_unlock(&_ipcp->state_lock);
+                if (frct_init(&rib.dtc, rib.address)) {
+                        ipcp_set_state(IPCP_INIT);
+                        pthread_rwlock_unlock(&ipcpi.state_lock);
                         cdap_send_reply(instance, invoke_id, -1, NULL, 0);
                         static_info_msg__free_unpacked(msg, NULL);
                         LOG_ERR("Failed to init FRCT");
@@ -262,7 +255,7 @@ int ribmgr_cdap_write(struct cdap * instance,
                 ret = -1;
         }
 
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
         if (cdap_send_reply(instance, invoke_id, ret, NULL, 0)) {
                 LOG_ERR("Failed to send reply to write request.");
@@ -303,39 +296,39 @@ int ribmgr_cdap_start(struct cdap * instance,
         size_t len = 0;
         int iid = 0;
 
-        pthread_rwlock_wrlock(&_ipcp->state_lock);
-        if (ipcp_get_state(_ipcp) == IPCP_ENROLLED &&
+        pthread_rwlock_wrlock(&ipcpi.state_lock);
+        if (ipcp_get_state() == IPCP_ENROLLED &&
             strcmp(name, ENROLLMENT) == 0) {
                 LOG_DBG("New enrollment request.");
 
                 if (cdap_send_reply(instance, invoke_id, 0, NULL, 0)) {
-                        pthread_rwlock_unlock(&_ipcp->state_lock);
+                        pthread_rwlock_unlock(&ipcpi.state_lock);
                         LOG_ERR("Failed to send reply to enrollment request.");
                         return -1;
                 }
 
-                stat_info.addr_size = rib->dtc.addr_size;
-                stat_info.cep_id_size = rib->dtc.cep_id_size;
-                stat_info.pdu_length_size = rib->dtc.pdu_length_size;
-                stat_info.seqno_size = rib->dtc.seqno_size;
-                stat_info.has_ttl = rib->dtc.has_ttl;
-                stat_info.has_chk = rib->dtc.has_chk;
-                stat_info.min_pdu_size  = rib->dtc.min_pdu_size;
-                stat_info.max_pdu_size = rib->dtc.max_pdu_size;
+                stat_info.addr_size = rib.dtc.addr_size;
+                stat_info.cep_id_size = rib.dtc.cep_id_size;
+                stat_info.pdu_length_size = rib.dtc.pdu_length_size;
+                stat_info.seqno_size = rib.dtc.seqno_size;
+                stat_info.has_ttl = rib.dtc.has_ttl;
+                stat_info.has_chk = rib.dtc.has_chk;
+                stat_info.min_pdu_size  = rib.dtc.min_pdu_size;
+                stat_info.max_pdu_size = rib.dtc.max_pdu_size;
 
                 /* FIXME: Hand out an address. */
                 stat_info.address = 0;
 
                 len = static_info_msg__get_packed_size(&stat_info);
                 if (len == 0) {
-                        pthread_rwlock_unlock(&_ipcp->state_lock);
+                        pthread_rwlock_unlock(&ipcpi.state_lock);
                         LOG_ERR("Failed to get size of static information.");
                         return -1;
                 }
 
                 data = malloc(len);
                 if (data == NULL) {
-                        pthread_rwlock_unlock(&_ipcp->state_lock);
+                        pthread_rwlock_unlock(&ipcpi.state_lock);
                         LOG_ERR("Failed to allocate memory.");
                         return -1;
                 }
@@ -344,59 +337,59 @@ int ribmgr_cdap_start(struct cdap * instance,
 
                 LOG_DBGF("Sending static info...");
 
-                pthread_mutex_lock(&rib->cdap_reqs_lock);
+                pthread_mutex_lock(&rib.cdap_reqs_lock);
 
                 iid = cdap_send_write(instance, STATIC_INFO, data, len, 0);
                 if (iid < 0) {
-                        pthread_mutex_unlock(&rib->cdap_reqs_lock);
-                        pthread_rwlock_unlock(&_ipcp->state_lock);
+                        pthread_mutex_unlock(&rib.cdap_reqs_lock);
+                        pthread_rwlock_unlock(&ipcpi.state_lock);
                         free(data);
                         LOG_ERR("Failed to send static information.");
                         return -1;
                 }
 
                 if (cdap_result_wait(instance, WRITE, STATIC_INFO, iid)) {
-                        pthread_mutex_unlock(&rib->cdap_reqs_lock);
-                        pthread_rwlock_unlock(&_ipcp->state_lock);
+                        pthread_mutex_unlock(&rib.cdap_reqs_lock);
+                        pthread_rwlock_unlock(&ipcpi.state_lock);
                         free(data);
                         LOG_ERR("Remote did not receive static information.");
                         return -1;
                 }
-                pthread_mutex_unlock(&rib->cdap_reqs_lock);
+                pthread_mutex_unlock(&rib.cdap_reqs_lock);
 
                 /* FIXME: Send neighbors here. */
 
                 LOG_DBGF("Sending stop enrollment...");
 
-                pthread_mutex_lock(&rib->cdap_reqs_lock);
+                pthread_mutex_lock(&rib.cdap_reqs_lock);
 
                 iid = cdap_send_stop(instance, ENROLLMENT);
                 if (iid < 0) {
-                        pthread_mutex_unlock(&rib->cdap_reqs_lock);
-                        pthread_rwlock_unlock(&_ipcp->state_lock);
+                        pthread_mutex_unlock(&rib.cdap_reqs_lock);
+                        pthread_rwlock_unlock(&ipcpi.state_lock);
                         free(data);
                         LOG_ERR("Failed to send stop of enrollment.");
                         return -1;
                 }
 
                 if (cdap_result_wait(instance, STOP, ENROLLMENT, iid)) {
-                        pthread_mutex_unlock(&rib->cdap_reqs_lock);
-                        pthread_rwlock_unlock(&_ipcp->state_lock);
+                        pthread_mutex_unlock(&rib.cdap_reqs_lock);
+                        pthread_rwlock_unlock(&ipcpi.state_lock);
                         free(data);
                         LOG_ERR("Remote failed to complete enrollment.");
                         return -1;
                 }
-                pthread_mutex_unlock(&rib->cdap_reqs_lock);
+                pthread_mutex_unlock(&rib.cdap_reqs_lock);
 
                 free(data);
         } else {
                 if (cdap_send_reply(instance, invoke_id, -1, NULL, 0)) {
-                        pthread_rwlock_unlock(&_ipcp->state_lock);
+                        pthread_rwlock_unlock(&ipcpi.state_lock);
                         LOG_ERR("Failed to send reply to start request.");
                         return -1;
                 }
         }
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
         return 0;
 }
@@ -407,21 +400,21 @@ int ribmgr_cdap_stop(struct cdap * instance,
 {
         int ret = 0;
 
-        pthread_rwlock_wrlock(&_ipcp->state_lock);
-        if (ipcp_get_state(_ipcp) == IPCP_PENDING_ENROLL &&
+        pthread_rwlock_wrlock(&ipcpi.state_lock);
+        if (ipcp_get_state() == IPCP_PENDING_ENROLL &&
             strcmp(name, ENROLLMENT) == 0) {
                 LOG_DBG("Stop enrollment received.");
 
-                ipcp_set_state(_ipcp, IPCP_ENROLLED);
+                ipcp_set_state(IPCP_ENROLLED);
         } else
                 ret = -1;
 
         if (cdap_send_reply(instance, invoke_id, ret, NULL, 0)) {
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 LOG_ERR("Failed to send reply to stop request.");
                 return -1;
         }
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
         return 0;
 }
@@ -457,19 +450,18 @@ int ribmgr_add_flow(int fd)
         flow->instance = instance;
         flow->fd = fd;
 
-        pthread_rwlock_wrlock(&_ipcp->state_lock);
-        pthread_rwlock_wrlock(&rib->flows_lock);
-        if (list_empty(&rib->flows) &&
-            ipcp_get_state(_ipcp) == IPCP_INIT) {
-                ipcp_set_state(_ipcp, IPCP_PENDING_ENROLL);
+        pthread_rwlock_wrlock(&ipcpi.state_lock);
+        pthread_rwlock_wrlock(&rib.flows_lock);
+        if (list_empty(&rib.flows) && ipcp_get_state() == IPCP_INIT) {
+                ipcp_set_state(IPCP_PENDING_ENROLL);
 
-                pthread_mutex_lock(&rib->cdap_reqs_lock);
+                pthread_mutex_lock(&rib.cdap_reqs_lock);
                 iid = cdap_send_start(instance,
                                       ENROLLMENT);
                 if (iid < 0) {
-                        pthread_mutex_unlock(&rib->cdap_reqs_lock);
-                        pthread_rwlock_unlock(&rib->flows_lock);
-                        pthread_rwlock_unlock(&_ipcp->state_lock);
+                        pthread_mutex_unlock(&rib.cdap_reqs_lock);
+                        pthread_rwlock_unlock(&rib.flows_lock);
+                        pthread_rwlock_unlock(&ipcpi.state_lock);
                         LOG_ERR("Failed to start enrollment.");
                         cdap_destroy(instance);
                         free(flow);
@@ -477,20 +469,20 @@ int ribmgr_add_flow(int fd)
                 }
 
                 if (cdap_result_wait(instance, START, ENROLLMENT, iid)) {
-                        pthread_mutex_unlock(&rib->cdap_reqs_lock);
-                        pthread_rwlock_unlock(&rib->flows_lock);
-                        pthread_rwlock_unlock(&_ipcp->state_lock);
+                        pthread_mutex_unlock(&rib.cdap_reqs_lock);
+                        pthread_rwlock_unlock(&rib.flows_lock);
+                        pthread_rwlock_unlock(&ipcpi.state_lock);
                         LOG_ERR("Failed to start enrollment.");
                         cdap_destroy(instance);
                         free(flow);
                         return -1;
                 }
-                pthread_mutex_unlock(&rib->cdap_reqs_lock);
+                pthread_mutex_unlock(&rib.cdap_reqs_lock);
         }
 
-        list_add(&flow->next, &rib->flows);
-        pthread_rwlock_unlock(&rib->flows_lock);
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        list_add(&flow->next, &rib.flows);
+        pthread_rwlock_unlock(&rib.flows_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
         return 0;
 }
@@ -499,20 +491,20 @@ int ribmgr_remove_flow(int fd)
 {
         struct list_head * pos, * n = NULL;
 
-        pthread_rwlock_wrlock(&rib->flows_lock);
-        list_for_each_safe(pos, n, &rib->flows) {
+        pthread_rwlock_wrlock(&rib.flows_lock);
+        list_for_each_safe(pos, n, &rib.flows) {
                 struct mgmt_flow * flow =
                         list_entry(pos, struct mgmt_flow, next);
                 if (flow->fd == fd) {
                         if (cdap_destroy(flow->instance))
                                 LOG_ERR("Failed to destroy CDAP instance.");
                         list_del(&flow->next);
-                        pthread_rwlock_unlock(&rib->flows_lock);
+                        pthread_rwlock_unlock(&rib.flows_lock);
                         free(flow);
                         return 0;
                 }
         }
-        pthread_rwlock_unlock(&rib->flows_lock);
+        pthread_rwlock_unlock(&rib.flows_lock);
 
         return -1;
 }
@@ -525,19 +517,19 @@ int ribmgr_bootstrap(struct dif_config * conf)
                 return -1;
         }
 
-        rib->dtc.addr_size = conf->addr_size;
-        rib->dtc.cep_id_size  = conf->cep_id_size;
-        rib->dtc.pdu_length_size = conf->pdu_length_size;
-        rib->dtc.seqno_size = conf->seqno_size;
-        rib->dtc.has_ttl = conf->has_ttl;
-        rib->dtc.has_chk = conf->has_chk;
-        rib->dtc.min_pdu_size = conf->min_pdu_size;
-        rib->dtc.max_pdu_size = conf->max_pdu_size;
+        rib.dtc.addr_size = conf->addr_size;
+        rib.dtc.cep_id_size  = conf->cep_id_size;
+        rib.dtc.pdu_length_size = conf->pdu_length_size;
+        rib.dtc.seqno_size = conf->seqno_size;
+        rib.dtc.has_ttl = conf->has_ttl;
+        rib.dtc.has_chk = conf->has_chk;
+        rib.dtc.min_pdu_size = conf->min_pdu_size;
+        rib.dtc.max_pdu_size = conf->max_pdu_size;
 
         /* FIXME: Set correct address. */
-        rib->address = 0;
+        rib.address = 0;
 
-        if (frct_init(&rib->dtc, rib->address)) {
+        if (frct_init(&rib.dtc, rib.address)) {
                 LOG_ERR("Failed to initialize FRCT.");
                 return -1;
         }
diff --git a/src/ipcpd/shim-eth-llc/main.c b/src/ipcpd/shim-eth-llc/main.c
index d74984cc..2cf46e51 100644
--- a/src/ipcpd/shim-eth-llc/main.c
+++ b/src/ipcpd/shim-eth-llc/main.c
@@ -24,24 +24,19 @@
 
 #define _DEFAULT_SOURCE
 
-#include "ipcp.h"
-#include "flow.h"
 #include <ouroboros/errno.h>
-#include <ouroboros/shm_rdrbuff.h>
-#include <ouroboros/shm_ap_rbuff.h>
 #include <ouroboros/list.h>
 #include <ouroboros/utils.h>
-#include <ouroboros/ipcp.h>
-#include <ouroboros/irm_config.h>
-#include <ouroboros/sockets.h>
 #include <ouroboros/bitmap.h>
-#include <ouroboros/flow.h>
 #include <ouroboros/dev.h>
+#include <ouroboros/ipcp-dev.h>
 
 #define OUROBOROS_PREFIX "ipcpd/shim-eth-llc"
 
 #include <ouroboros/logs.h>
 
+#include "ipcp.h"
+
 #include <net/if.h>
 #include <signal.h>
 #include <stdlib.h>
@@ -79,18 +74,12 @@ typedef ShimEthLlcMsg shim_eth_llc_msg_t;
 #define LLC_HEADER_SIZE 3
 #define MAX_SAPS 64
 #define ETH_HEADER_SIZE (2 * MAC_SIZE + 2)
-#define ETH_FRAME_SIZE (SHIM_ETH_LLC_MAX_SDU_SIZE + ETH_HEADER_SIZE +       \
-                        LLC_HEADER_SIZE + 2)
+#define ETH_FRAME_SIZE (ETH_HEADER_SIZE + LLC_HEADER_SIZE \
+                        + SHIM_ETH_LLC_MAX_SDU_SIZE)
 
 /* global for trapping signal */
 int irmd_api;
 
-struct ipcp * _ipcp;
-
-#define shim_data(type) ((struct eth_llc_ipcp_data *) type->data)
-
-#define ipcp_flow(index) ((struct flow *) &(shim_data(_ipcp)->flows[index]))
-
 struct eth_llc_frame {
         uint8_t dst_hwaddr[MAC_SIZE];
         uint8_t src_hwaddr[MAC_SIZE];
@@ -98,196 +87,78 @@ struct eth_llc_frame {
         uint8_t dsap;
         uint8_t ssap;
         uint8_t cf;
-        uint8_t size[2];
         uint8_t payload;
 };
 
-struct eth_llc_flow {
-        struct flow flow;
-        uint8_t     sap;
-        uint8_t     r_sap;
-        uint8_t     r_addr[MAC_SIZE];
+struct ef {
+        int8_t  sap;
+        int8_t  r_sap;
+        uint8_t r_addr[MAC_SIZE];
 };
 
-struct eth_llc_ipcp_data {
-        /* Keep ipcp_data first for polymorphism. */
-        struct ipcp_data      ipcp_data;
-
+struct {
 #ifdef __FreeBSD__
-        struct sockaddr_dl    device;
+        struct sockaddr_dl device;
 #else
-        struct sockaddr_ll    device;
+        struct sockaddr_ll device;
 #endif
-        int                   s_fd;
-
-        struct bmp *          indices;
-        struct bmp *          saps;
+        int                s_fd;
 
-        struct shm_rdrbuff *  rdrb;
-        struct shm_ap_rbuff * rb;
-
-        uint8_t *             rx_ring;
-        uint8_t *             tx_ring;
-        int                   tx_offset;
-
-        struct eth_llc_flow   flows[AP_MAX_FLOWS];
-        pthread_rwlock_t      flows_lock;
+        struct bmp *       saps;
+#if defined(PACKET_RX_RING) && defined(PACKET_TX_RING)
+        uint8_t *          rx_ring;
+        uint8_t *          tx_ring;
+        int                tx_offset;
+#endif
+        int *              ef_to_fd;
+        struct ef *        fd_to_ef;
+        pthread_rwlock_t   flows_lock;
 
-        pthread_t             mainloop;
-        pthread_t             sdu_writer;
-        pthread_t             sdu_reader;
-};
+        pthread_t          sdu_writer;
+        pthread_t          sdu_reader;
+} eth_llc_data;
 
-struct eth_llc_ipcp_data * eth_llc_ipcp_data_create()
+static int eth_llc_data_init()
 {
-        struct eth_llc_ipcp_data * eth_llc_data;
-        enum ipcp_type             ipcp_type;
-
-        eth_llc_data = malloc(sizeof(*eth_llc_data));
-        if (eth_llc_data == NULL) {
-                LOG_ERR("Failed to allocate.");
-                return NULL;
-        }
-
-        ipcp_type = THIS_TYPE;
-        if (ipcp_data_init((struct ipcp_data *) eth_llc_data,
-                           ipcp_type) == NULL) {
-                free(eth_llc_data);
-                return NULL;
-        }
-
-        eth_llc_data->rdrb = shm_rdrbuff_open();
-        if (eth_llc_data->rdrb == NULL) {
-                free(eth_llc_data);
-                return NULL;
-        }
-
-        eth_llc_data->rb = shm_ap_rbuff_create_n();
-        if (eth_llc_data->rb == NULL) {
-                shm_rdrbuff_close(eth_llc_data->rdrb);
-                free(eth_llc_data);
-                return NULL;
-        }
+        int i;
 
-        eth_llc_data->indices = bmp_create(AP_MAX_FLOWS, 0);
-        if (eth_llc_data->indices == NULL) {
-                shm_ap_rbuff_destroy(eth_llc_data->rb);
-                shm_rdrbuff_close(eth_llc_data->rdrb);
-                free(eth_llc_data);
-                return NULL;
-        }
+        eth_llc_data.fd_to_ef = malloc(sizeof(struct ef) * IRMD_MAX_FLOWS);
+        if (eth_llc_data.fd_to_ef == NULL)
+                return -ENOMEM;
 
-        eth_llc_data->saps = bmp_create(MAX_SAPS, 2);
-        if (eth_llc_data->indices == NULL) {
-                bmp_destroy(eth_llc_data->indices);
-                shm_ap_rbuff_destroy(eth_llc_data->rb);
-                shm_rdrbuff_close(eth_llc_data->rdrb);
-                free(eth_llc_data);
-                return NULL;
+        eth_llc_data.ef_to_fd = malloc(sizeof(struct ef) * MAX_SAPS);
+        if (eth_llc_data.ef_to_fd == NULL) {
+                free(eth_llc_data.fd_to_ef);
+                return -ENOMEM;
         }
 
-        pthread_rwlock_init(&eth_llc_data->flows_lock, NULL);
-
-        return eth_llc_data;
-}
-
-void eth_llc_ipcp_data_destroy()
-{
-        int i = 0;
-
-        if (_ipcp == NULL)
-                return;
-
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
-
-        if (ipcp_get_state(_ipcp) != IPCP_SHUTDOWN)
-                LOG_WARN("Cleaning up while not in shutdown.");
-
-        /* remove all remaining sdus */
-        while ((i = shm_ap_rbuff_peek_idx(shim_data(_ipcp)->rb)) >= 0)
-                shm_rdrbuff_remove(shim_data(_ipcp)->rdrb, i);
-
-        if (shim_data(_ipcp)->rdrb != NULL)
-                shm_rdrbuff_close(shim_data(_ipcp)->rdrb);
-        if (shim_data(_ipcp)->rb != NULL)
-                shm_ap_rbuff_destroy(shim_data(_ipcp)->rb);
-        if (shim_data(_ipcp)->indices != NULL)
-                bmp_destroy(shim_data(_ipcp)->indices);
-        if (shim_data(_ipcp)->saps != NULL)
-                bmp_destroy(shim_data(_ipcp)->saps);
-
-        pthread_rwlock_wrlock(&shim_data(_ipcp)->flows_lock);
-
-        for (i = 0; i < AP_MAX_FLOWS; i ++)
-                if (ipcp_flow(i)->rb != NULL)
-                        shm_ap_rbuff_close(ipcp_flow(i)->rb);
-
-        pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-        pthread_rwlock_unlock(&_ipcp->state_lock);
-
-        ipcp_data_destroy(_ipcp->data);
-}
-
-/* only call this under flows_lock */
-static int port_id_to_index(int port_id)
-{
-        int i;
-
-        for (i = 0; i < AP_MAX_FLOWS; ++i) {
-                if (ipcp_flow(i)->port_id == port_id
-                    && ipcp_flow(i)->state != FLOW_NULL)
-                        return i;
+        eth_llc_data.saps = bmp_create(MAX_SAPS, 2);
+        if (eth_llc_data.saps == NULL) {
+                free(eth_llc_data.ef_to_fd);
+                free(eth_llc_data.fd_to_ef);
+                return -ENOMEM;
         }
 
-        return -1;
-}
+        for (i = 0; i < MAX_SAPS; ++i)
+                eth_llc_data.ef_to_fd[i] = -1;
 
-/* only call this under flows_lock */
-static int addr_and_saps_to_index(const uint8_t * r_addr,
-                                  uint8_t   r_sap,
-                                  uint8_t   sap)
-{
-        int i = 0;
-
-        for (i = 0; i < AP_MAX_FLOWS; i++) {
-                if (ipcp_flow(i)->state == FLOW_ALLOCATED &&
-                    shim_data(_ipcp)->flows[i].r_sap == r_sap &&
-                    shim_data(_ipcp)->flows[i].sap == sap &&
-                    !memcmp(shim_data(_ipcp)->flows[i].r_addr,
-                            r_addr,
-                            MAC_SIZE)) {
-                        return i;
-                }
+        for (i = 0; i < IRMD_MAX_FLOWS; ++i) {
+                eth_llc_data.fd_to_ef[i].sap   = -1;
+                eth_llc_data.fd_to_ef[i].r_sap = -1;
+                memset(&eth_llc_data.fd_to_ef[i].r_addr, 0, MAC_SIZE);
         }
 
-        return -1;
-}
+        pthread_rwlock_init(&eth_llc_data.flows_lock, NULL);
 
-/* only call this under flows_lock */
-static int sap_to_index(uint8_t sap)
-{
-        int i = 0;
-
-        for (i = 0; i < AP_MAX_FLOWS; i++) {
-                if (shim_data(_ipcp)->flows[i].sap == sap) {
-                        return i;
-                }
-        }
-
-        return -1;
+        return 0;
 }
 
-/* only call this under flows_lock */
-static void destroy_ipcp_flow(int index)
+void eth_llc_data_fini()
 {
-        ipcp_flow(index)->port_id = -1;
-        if (ipcp_flow(index)->rb != NULL)
-                shm_ap_rbuff_close(ipcp_flow(index)->rb);
-        ipcp_flow(index)->rb = NULL;
-        ipcp_flow(index)->state = FLOW_NULL;
-        bmp_release(shim_data(_ipcp)->indices, index);
-        bmp_release(shim_data(_ipcp)->saps,
-                    shim_data(_ipcp)->flows[index].sap);
+        bmp_destroy(eth_llc_data.saps);
+        free(eth_llc_data.fd_to_ef);
+        free(eth_llc_data.ef_to_fd);
+        pthread_rwlock_destroy(&eth_llc_data.flows_lock);
 }
 
 static uint8_t reverse_bits(uint8_t b)
@@ -299,7 +170,7 @@ static uint8_t reverse_bits(uint8_t b)
         return b;
 }
 
-static int eth_llc_ipcp_send_frame(uint8_t   dst_addr[MAC_SIZE],
+static int eth_llc_ipcp_send_frame(uint8_t * dst_addr,
                                    uint8_t   dsap,
                                    uint8_t   ssap,
                                    uint8_t * payload,
@@ -307,24 +178,16 @@ static int eth_llc_ipcp_send_frame(uint8_t   dst_addr[MAC_SIZE],
 {
         int frame_len = 0;
         uint8_t cf = 0x03;
-        int fd;
-
-        uint16_t size;
         uint16_t length;
-
 #if defined(PACKET_RX_RING) && defined(PACKET_TX_RING)
         struct pollfd pfd;
         struct tpacket_hdr * header;
         uint8_t * frame;
 #else
         uint8_t frame[SHIM_ETH_LLC_MAX_SDU_SIZE];
-#ifdef __FreeBSD__
-        struct sockaddr_dl    device;
-#else
-        struct sockaddr_ll    device;
-#endif
 #endif
         struct eth_llc_frame * llc_frame;
+
         if (payload == NULL) {
                 LOG_ERR("Payload was NULL.");
                 return -1;
@@ -333,79 +196,75 @@ static int eth_llc_ipcp_send_frame(uint8_t   dst_addr[MAC_SIZE],
         if (len > SHIM_ETH_LLC_MAX_SDU_SIZE)
                 return -1;
 
-        fd = (shim_data(_ipcp))->s_fd;
-
 #if defined(PACKET_RX_RING) && defined(PACKET_TX_RING)
-        header = (void *) shim_data(_ipcp)->tx_ring +
-                (shim_data(_ipcp)->tx_offset * SHM_RDRB_BLOCK_SIZE);
+        header = (void *) (eth_llc_data.tx_ring +
+                           eth_llc_data.tx_offset * SHM_RDRB_BLOCK_SIZE);
 
         while (header->tp_status != TP_STATUS_AVAILABLE) {
-                pfd.fd = fd;
+                pfd.fd = eth_llc_data.s_fd;
                 pfd.revents = 0;
                 pfd.events = POLLIN | POLLRDNORM | POLLERR;
 
                 if (poll(&pfd, 1, -1) <= 0) {
-                        LOG_ERR("Failed to poll: %s.", strerror(errno));
+                        LOG_ERR("Failed to poll.");
                         continue;
                 }
 
-                header = (void *) shim_data(_ipcp)->tx_ring +
-                        (shim_data(_ipcp)->tx_offset * SHM_RDRB_BLOCK_SIZE);
+                header = (void *) (eth_llc_data.tx_ring
+                                   + eth_llc_data.tx_offset
+                                   * SHM_RDRB_BLOCK_SIZE);
         }
 
-        frame = (void *) header + TPACKET_HDRLEN - sizeof(struct sockaddr_ll);
+        frame = (uint8_t *) header
+                + TPACKET_HDRLEN - sizeof(struct sockaddr_ll);
 #endif
-
         llc_frame = (struct eth_llc_frame *) frame;
 
-        memcpy(&llc_frame->dst_hwaddr, dst_addr, MAC_SIZE);
-        memcpy(&llc_frame->src_hwaddr,
+        memcpy(llc_frame->dst_hwaddr, dst_addr, MAC_SIZE);
+        memcpy(llc_frame->src_hwaddr,
 #ifdef __FreeBSD__
-               LLADDR(&shim_data(_ipcp)->device),
+               LLADDR(&eth_llc_data.device),
 #else
-               shim_data(_ipcp)->device.sll_addr,
+               eth_llc_data.device.sll_addr,
 #endif
                MAC_SIZE);
 
-        length = htons(LLC_HEADER_SIZE + sizeof(size) + len);
+        length = htons(LLC_HEADER_SIZE + len);
         memcpy(&llc_frame->length, &length, sizeof(length));
         llc_frame->dsap = dsap;
         llc_frame->ssap = ssap;
-        llc_frame->cf = cf;
-        /* write the payload length, can't trust the driver */
-        size = htons(len);
-        memcpy(&llc_frame->size, &size, sizeof(size));
+        llc_frame->cf   = cf;
         memcpy(&llc_frame->payload, payload, len);
 
-        frame_len = ETH_HEADER_SIZE + LLC_HEADER_SIZE + sizeof(uint16_t) + len;
+        frame_len = ETH_HEADER_SIZE + LLC_HEADER_SIZE + len;
 
 #if defined(PACKET_RX_RING) && defined(PACKET_TX_RING)
         header->tp_len = frame_len;
         header->tp_status = TP_STATUS_SEND_REQUEST;
 
-        if (send(fd, NULL, 0, MSG_DONTWAIT) < 0) {
+        if (send(eth_llc_data.s_fd, NULL, 0, MSG_DONTWAIT) < 0) {
                 LOG_ERR("Failed to write frame into TX_RING.");
                 return -1;
         }
 
-        shim_data(_ipcp)->tx_offset =
-                (shim_data(_ipcp)->tx_offset + 1)
-                & (SHM_BUFFER_SIZE -1);
+        eth_llc_data.tx_offset =
+                (eth_llc_data.tx_offset + 1) & (SHM_BUFFER_SIZE - 1);
 #else
-        device = (shim_data(_ipcp))->device;
-
-        if (sendto(fd, frame, frame_len, 0,
-                   (struct sockaddr *) &device, sizeof(device)) <= 0) {
+        if (sendto(eth_llc_data.s_fd,
+                   frame,
+                   frame_len,
+                   0,
+                   (struct sockaddr *) &eth_llc_data.device,
+                   sizeof(eth_llc_data.device)) <= 0) {
                 LOG_ERR("Failed to send message.");
                 return -1;
         }
 #endif
-
         return 0;
 }
 
 static int eth_llc_ipcp_send_mgmt_frame(shim_eth_llc_msg_t * msg,
-                                        uint8_t              dst_addr[MAC_SIZE])
+                                        uint8_t *            dst_addr)
 {
         size_t    len;
         uint8_t * buf;
@@ -423,6 +282,7 @@ static int eth_llc_ipcp_send_mgmt_frame(shim_eth_llc_msg_t * msg,
         if (eth_llc_ipcp_send_frame(dst_addr, reverse_bits(MGMT_SAP),
                                     reverse_bits(MGMT_SAP), buf, len)) {
                 LOG_ERR("Failed to send management frame.");
+                free(buf);
                 return -1;
         }
 
@@ -431,10 +291,10 @@ static int eth_llc_ipcp_send_mgmt_frame(shim_eth_llc_msg_t * msg,
         return 0;
 }
 
-static int eth_llc_ipcp_port_alloc(uint8_t dst_addr[MAC_SIZE],
-                                   uint8_t ssap,
-                                   char *  dst_name,
-                                   char *  src_ae_name)
+static int eth_llc_ipcp_sap_alloc(uint8_t * dst_addr,
+                                  uint8_t   ssap,
+                                  char *    dst_name,
+                                  char *    src_ae_name)
 {
         shim_eth_llc_msg_t msg = SHIM_ETH_LLC_MSG__INIT;
 
@@ -446,10 +306,10 @@ static int eth_llc_ipcp_port_alloc(uint8_t dst_addr[MAC_SIZE],
         return eth_llc_ipcp_send_mgmt_frame(&msg, dst_addr);
 }
 
-static int eth_llc_ipcp_port_alloc_resp(uint8_t dst_addr[MAC_SIZE],
-                                        uint8_t ssap,
-                                        uint8_t dsap,
-                                        int     response)
+static int eth_llc_ipcp_sap_alloc_resp(uint8_t * dst_addr,
+                                       uint8_t   ssap,
+                                       uint8_t   dsap,
+                                       int       response)
 {
         shim_eth_llc_msg_t msg = SHIM_ETH_LLC_MSG__INIT;
 
@@ -463,8 +323,7 @@ static int eth_llc_ipcp_port_alloc_resp(uint8_t dst_addr[MAC_SIZE],
         return eth_llc_ipcp_send_mgmt_frame(&msg, dst_addr);
 }
 
-static int eth_llc_ipcp_port_dealloc(uint8_t dst_addr[MAC_SIZE],
-                                     uint8_t ssap)
+static int eth_llc_ipcp_sap_dealloc(uint8_t * dst_addr, uint8_t ssap)
 {
         shim_eth_llc_msg_t msg = SHIM_ETH_LLC_MSG__INIT;
 
@@ -474,142 +333,102 @@ static int eth_llc_ipcp_port_dealloc(uint8_t dst_addr[MAC_SIZE],
         return eth_llc_ipcp_send_mgmt_frame(&msg, dst_addr);
 }
 
-static int eth_llc_ipcp_port_req(uint8_t r_sap,
-                                 uint8_t r_addr[MAC_SIZE],
-                                 char *  dst_name,
-                                 char *  src_ae_name)
+static int eth_llc_ipcp_sap_req(uint8_t   r_sap,
+                                uint8_t * r_addr,
+                                char *    dst_name,
+                                char *    src_ae_name)
 {
-        int port_id;
-        ssize_t index = 0;
-        int i;
+        int fd;
 
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
-        pthread_rwlock_wrlock(&shim_data(_ipcp)->flows_lock);
-
-        index = bmp_allocate(shim_data(_ipcp)->indices);
-        if (index < 0) {
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-                LOG_ERR("Out of free indices.");
-                return -1;
-        }
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
+        pthread_rwlock_wrlock(&eth_llc_data.flows_lock);
 
         /* reply to IRM */
-        port_id = ipcp_flow_req_arr(getpid(),
-                                    dst_name,
-                                    src_ae_name);
-
-        if (port_id < 0) {
-                bmp_release(shim_data(_ipcp)->indices, index);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-                LOG_ERR("Could not get port id from IRMd.");
+        fd = ipcp_flow_req_arr(getpid(), dst_name, src_ae_name);
+        if (fd < 0) {
+                pthread_rwlock_unlock(&eth_llc_data.flows_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
+                LOG_ERR("Could not get new flow from IRMd.");
                 return -1;
         }
 
-        ipcp_flow(index)->port_id = port_id;
-        ipcp_flow(index)->rb      = NULL;
-        ipcp_flow(index)->state   = FLOW_PENDING;
-        shim_data(_ipcp)->flows[index].r_sap = r_sap;
-        for (i = 0; i < MAC_SIZE; i++) {
-                shim_data(_ipcp)->flows[index].r_addr[i] = r_addr[i];
-        }
+        eth_llc_data.fd_to_ef[fd].r_sap = r_sap;
+        memcpy(eth_llc_data.fd_to_ef[fd].r_addr, r_addr, MAC_SIZE);
 
-        pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&eth_llc_data.flows_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
-        LOG_DBG("New flow request, port_id %d, remote SAP %d.", port_id, r_sap);
+        LOG_DBG("New flow request, fd %d, remote SAP %d.", fd, r_sap);
 
         return 0;
 }
 
-static int eth_llc_ipcp_port_alloc_reply(uint8_t ssap,
-                                         uint8_t r_addr[MAC_SIZE],
-                                         int     dsap,
-                                         int     response)
+static int eth_llc_ipcp_sap_alloc_reply(uint8_t   ssap,
+                                        uint8_t * r_addr,
+                                        int       dsap,
+                                        int       response)
 {
-        int index = -1;
         int ret = 0;
-        int port_id = -1;
-        int i;
+        int fd = -1;
 
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
-        pthread_rwlock_rdlock(&shim_data(_ipcp)->flows_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
+        pthread_rwlock_rdlock(& eth_llc_data.flows_lock);
 
-        index = sap_to_index(ssap);
-        if (index < 0) {
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+        fd = eth_llc_data.ef_to_fd[dsap];
+        if (fd < 0) {
+                pthread_rwlock_unlock(& eth_llc_data.flows_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 LOG_ERR("No flow found with that SAP.");
                 return -1; /* -EFLOWNOTFOUND */
         }
 
-        if (ipcp_flow(index)->state != FLOW_PENDING) {
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                return -1; /* -EFLOWNOTPENDING */
-        }
-
-        port_id = ipcp_flow(index)->port_id;
-
         if (response) {
-                destroy_ipcp_flow(index);
+                bmp_release(eth_llc_data.saps, eth_llc_data.fd_to_ef[fd].sap);
         } else {
-                ipcp_flow(index)->state = FLOW_ALLOCATED;
-                shim_data(_ipcp)->flows[index].r_sap = dsap;
-                for (i = 0; i < MAC_SIZE; i++) {
-                        shim_data(_ipcp)->flows[index].r_addr[i] = r_addr[i];
-                }
+                eth_llc_data.fd_to_ef[fd].r_sap = ssap;
+                memcpy(eth_llc_data.fd_to_ef[fd].r_addr, r_addr, MAC_SIZE);
         }
 
-        pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&eth_llc_data.flows_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
-        LOG_DBG("Flow reply, port_id %d, remote SAP %d.", port_id, dsap);
+        LOG_DBG("Flow reply, fd %d, SSAP %d, DSAP %d.", fd, ssap, dsap);
 
-        if ((ret = ipcp_flow_alloc_reply(getpid(),
-                                         port_id,
-                                         response)) < 0) {
-                return -1; /* -EPIPE */
-        }
+        if ((ret = ipcp_flow_alloc_reply(fd, response)) < 0)
+                return -1;
 
         return ret;
 
 }
 
-static int eth_llc_ipcp_flow_dealloc_req(uint8_t ssap,
-                                         uint8_t r_addr[MAC_SIZE])
+static int eth_llc_ipcp_flow_dealloc_req(uint8_t ssap, uint8_t * r_addr)
 {
-        int port_id = -1;
-        int i = 0;
+        int fd = -1;
 
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
-        pthread_rwlock_wrlock(&shim_data(_ipcp)->flows_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
+        pthread_rwlock_wrlock(&eth_llc_data.flows_lock);
 
-        i = sap_to_index(ssap);
-        if (i < 0) {
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+        fd = eth_llc_data.ef_to_fd[ssap];
+        if (fd < 0) {
+                pthread_rwlock_unlock(&eth_llc_data.flows_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 LOG_ERR("No flow found for remote deallocation request.");
                 return 0;
         }
 
-        port_id = ipcp_flow(i)->port_id;
-        destroy_ipcp_flow(i);
+        bmp_release(eth_llc_data.saps, eth_llc_data.fd_to_ef[fd].sap);
 
-        pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&eth_llc_data.flows_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
-        irm_flow_dealloc(port_id);
+        flow_dealloc(fd);
 
-        LOG_DBG("Flow with port_id %d deallocated.", port_id);
+        LOG_DBG("Flow with fd %d deallocated.", fd);
 
         return 0;
 }
 
-static int eth_llc_ipcp_mgmt_frame(uint8_t * buf,
-                                   size_t    len,
-                                   uint8_t   r_addr[MAC_SIZE])
+static int eth_llc_ipcp_mgmt_frame(uint8_t * buf, size_t len, uint8_t * r_addr)
 {
         shim_eth_llc_msg_t * msg = NULL;
 
@@ -621,27 +440,24 @@ static int eth_llc_ipcp_mgmt_frame(uint8_t * buf,
 
         switch (msg->code) {
         case SHIM_ETH_LLC_MSG_CODE__FLOW_REQ:
-                if (ipcp_data_is_in_registry(_ipcp->data,
-                                             msg->dst_name)) {
-                        eth_llc_ipcp_port_req(msg->ssap,
-                                              r_addr,
-                                              msg->dst_name,
-                                              msg->src_ae_name);
+                if (ipcp_data_is_in_registry(ipcpi.data, msg->dst_name)) {
+                        eth_llc_ipcp_sap_req(msg->ssap,
+                                             r_addr,
+                                             msg->dst_name,
+                                             msg->src_ae_name);
                 }
                 break;
         case SHIM_ETH_LLC_MSG_CODE__FLOW_REPLY:
-                eth_llc_ipcp_port_alloc_reply(msg->ssap,
-                                              r_addr,
-                                              msg->dsap,
-                                              msg->response);
+                eth_llc_ipcp_sap_alloc_reply(msg->ssap,
+                                             r_addr,
+                                             msg->dsap,
+                                             msg->response);
                 break;
         case SHIM_ETH_LLC_MSG_CODE__FLOW_DEALLOC:
-                eth_llc_ipcp_flow_dealloc_req(msg->ssap,
-                                              r_addr);
+                eth_llc_ipcp_flow_dealloc_req(msg->ssap, r_addr);
                 break;
         default:
-                LOG_ERR("Unknown message received %d.",
-                        msg->code);
+                LOG_ERR("Unknown message received %d.", msg->code);
                 shim_eth_llc_msg__free_unpacked(msg, NULL);
                 return -1;
         }
@@ -652,15 +468,11 @@ static int eth_llc_ipcp_mgmt_frame(uint8_t * buf,
 
 static void * eth_llc_ipcp_sdu_reader(void * o)
 {
-        ssize_t index;
-        struct rb_entry e;
         uint8_t br_addr[MAC_SIZE];
+        uint16_t length;
         uint8_t dsap;
         uint8_t ssap;
-        int i = 0;
-        struct eth_llc_frame * llc_frame;
-        uint16_t size;
-
+        int fd;
 #if defined(PACKET_RX_RING) && defined(PACKET_TX_RING)
         struct pollfd pfd;
         int offset = 0;
@@ -670,43 +482,43 @@ static void * eth_llc_ipcp_sdu_reader(void * o)
         uint8_t buf[ETH_FRAME_SIZE];
         int frame_len = 0;
 #endif
+        struct eth_llc_frame * llc_frame;
 
         memset(br_addr, 0xff, MAC_SIZE * sizeof(uint8_t));
 
         while (true) {
 #if defined(PACKET_RX_RING) && defined(PACKET_TX_RING)
-                header = (void *) shim_data(_ipcp)->rx_ring +
-                        (offset * SHM_RDRB_BLOCK_SIZE);
+                header = (void *) (eth_llc_data.rx_ring +
+                                   offset * SHM_RDRB_BLOCK_SIZE);
                 while (!(header->tp_status & TP_STATUS_USER)) {
-                        pfd.fd = shim_data(_ipcp)->s_fd;
+                        pfd.fd = eth_llc_data.s_fd;
                         pfd.revents = 0;
                         pfd.events = POLLIN | POLLRDNORM | POLLERR;
 
                         if (poll(&pfd, 1, -1) <= 0) {
-                                LOG_ERR("Failed to poll: %s.", strerror(errno));
+                                LOG_ERR("Failed to poll.");
                                 continue;
                         }
 
-                        header = (void *) shim_data(_ipcp)->rx_ring +
-                                (offset * SHM_RDRB_BLOCK_SIZE);
+                        header = (void *) (eth_llc_data.rx_ring +
+                                           offset * SHM_RDRB_BLOCK_SIZE);
                 }
 
-                buf = (void * ) header + header->tp_mac;
+                buf = (uint8_t * ) header + header->tp_mac;
 #else
-                frame_len = recv(shim_data(_ipcp)->s_fd, buf,
+                frame_len = recv(eth_llc_data.s_fd, buf,
                                  SHIM_ETH_LLC_MAX_SDU_SIZE, 0);
                 if (frame_len < 0) {
-                        LOG_ERR("Failed to recv frame.");
+                        LOG_ERR("Failed to receive frame.");
                         continue;
                 }
 #endif
-
                 llc_frame = (struct eth_llc_frame *) buf;
 
 #ifdef __FreeBSD__
-                if (memcmp(LLADDR(&shim_data(_ipcp)->device),
+                if (memcmp(LLADDR(&eth_llc_data.device),
 #else
-                if (memcmp(shim_data(_ipcp)->device.sll_addr,
+                if (memcmp(eth_llc_data.device.sll_addr,
 #endif
                            &llc_frame->dst_hwaddr,
                            MAC_SIZE) &&
@@ -721,46 +533,29 @@ static void * eth_llc_ipcp_sdu_reader(void * o)
                 dsap = reverse_bits(llc_frame->dsap);
                 ssap = reverse_bits(llc_frame->ssap);
 
-                memcpy(&size, &llc_frame->size, sizeof(size));
+                memcpy(&length, &llc_frame->length, sizeof(length));
+                length = ntohs(length) - LLC_HEADER_SIZE;
 
                 if (ssap == MGMT_SAP && dsap == MGMT_SAP) {
                         eth_llc_ipcp_mgmt_frame(&llc_frame->payload,
-                                                ntohs(size),
+                                                length,
                                                 llc_frame->src_hwaddr);
                 } else {
-                        pthread_rwlock_rdlock(&shim_data(_ipcp)->flows_lock);
-
-                        i = addr_and_saps_to_index(llc_frame->src_hwaddr,
-                                                   ssap,
-                                                   dsap);
-                        if (i < 0) {
-                                pthread_rwlock_unlock(&shim_data(_ipcp)->
-                                                      flows_lock);
+                        pthread_rwlock_rdlock(&eth_llc_data.flows_lock);
+
+                        fd = eth_llc_data.ef_to_fd[dsap];
+                        if (fd < 0) {
+                                pthread_rwlock_unlock(&eth_llc_data.flows_lock);
 #if defined(PACKET_RX_RING) && defined(PACKET_TX_RING)
-                                offset = (offset + 1)
-                                        & (SHM_BUFFER_SIZE - 1);
+                                offset = (offset + 1) & (SHM_BUFFER_SIZE - 1);
                                 header->tp_status = TP_STATUS_KERNEL;
 #endif
                                 continue;
                         }
 
-                        while ((index =
-                                shm_rdrbuff_write(shim_data(_ipcp)->rdrb,
-                                                 ipcp_flow(i)->api,
-                                                 0,
-                                                 0,
-                                                 &llc_frame->payload,
-                                                 ntohs(size)))
-                                < 0)
-                                ;
-
-                        e.index = index;
-                        e.port_id = ipcp_flow(i)->port_id;
-
-                        while (shm_ap_rbuff_write(ipcp_flow(i)->rb, &e) < 0)
-                                ;
+                        pthread_rwlock_unlock(&eth_llc_data.flows_lock);
 
-                        pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
+                        flow_write(fd, &llc_frame->payload, length);
                 }
 #if defined(PACKET_RX_RING) && defined(PACKET_TX_RING)
                 offset = (offset + 1) & (SHM_BUFFER_SIZE -1);
@@ -774,51 +569,34 @@ static void * eth_llc_ipcp_sdu_reader(void * o)
 static void * eth_llc_ipcp_sdu_writer(void * o)
 {
         while (true) {
-                struct rb_entry * e;
-                int i;
-                int len = 0;
-                uint8_t * buf;
+                int fd;
+                struct shm_du_buff * sdb;
                 uint8_t ssap;
                 uint8_t dsap;
+                uint8_t r_addr[MAC_SIZE];
 
-                e = shm_ap_rbuff_read(shim_data(_ipcp)->rb);
-                if (e == NULL)
-                        continue;
-
-                pthread_rwlock_rdlock(&_ipcp->state_lock);
-
-                len = shm_rdrbuff_read((uint8_t **) &buf,
-                                      shim_data(_ipcp)->rdrb,
-                                      e->index);
-                if (len <= 0) {
-                        free(e);
-                        LOG_ERR("Length of du map read was %d.", len);
-                        continue;
-                }
+                pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-                pthread_rwlock_rdlock(&shim_data(_ipcp)->flows_lock);
-
-                i = port_id_to_index(e->port_id);
-                if (i < 0) {
-                        free(e);
-                        pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
+                fd = ipcp_flow_read(&sdb);
+                if (fd < 0) {
+                        pthread_rwlock_unlock(&ipcpi.state_lock);
                         continue;
                 }
 
-                ssap = reverse_bits(shim_data(_ipcp)->flows[i].sap);
-                dsap = reverse_bits(shim_data(_ipcp)->flows[i].r_sap);
-
-                eth_llc_ipcp_send_frame(shim_data(_ipcp)->flows[i].r_addr,
-                                        dsap, ssap, buf, len);
-
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
+                pthread_rwlock_rdlock(&eth_llc_data.flows_lock);
 
-                if (shim_data(_ipcp)->rdrb != NULL)
-                        shm_rdrbuff_remove(shim_data(_ipcp)->rdrb, e->index);
+                ssap = reverse_bits(eth_llc_data.fd_to_ef[fd].sap);
+                dsap = reverse_bits(eth_llc_data.fd_to_ef[fd].r_sap);
+                memcpy(r_addr, eth_llc_data.fd_to_ef[fd].r_addr, MAC_SIZE);
 
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+                pthread_rwlock_unlock(&eth_llc_data.flows_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
 
-                free(e);
+                eth_llc_ipcp_send_frame(r_addr, dsap, ssap,
+                                        shm_du_buff_head(sdb),
+                                        shm_du_buff_tail(sdb)
+                                        - shm_du_buff_head(sdb));
+                ipcp_flow_del(sdb);
         }
 
         return (void *) 1;
@@ -826,10 +604,6 @@ static void * eth_llc_ipcp_sdu_writer(void * o)
 
 void ipcp_sig_handler(int sig, siginfo_t * info, void * c)
 {
-        sigset_t  sigset;
-        sigemptyset(&sigset);
-        sigaddset(&sigset, SIGINT);
-
         switch(sig) {
         case SIGINT:
         case SIGTERM:
@@ -838,12 +612,11 @@ void ipcp_sig_handler(int sig, siginfo_t * info, void * c)
                         LOG_DBG("IPCP %d terminating by order of %d. Bye.",
                                 getpid(), info->si_pid);
 
-                        pthread_rwlock_wrlock(&_ipcp->state_lock);
-
-                        ipcp_set_state(_ipcp, IPCP_SHUTDOWN);
+                        pthread_rwlock_wrlock(&ipcpi.state_lock);
 
-                        pthread_rwlock_unlock(&_ipcp->state_lock);
+                        ipcp_set_state(IPCP_SHUTDOWN);
 
+                        pthread_rwlock_unlock(&ipcpi.state_lock);
                 }
         default:
                 return;
@@ -852,7 +625,7 @@ void ipcp_sig_handler(int sig, siginfo_t * info, void * c)
 
 static int eth_llc_ipcp_bootstrap(struct dif_config * conf)
 {
-        int fd = -1;
+        int skfd = -1;
         struct ifreq ifr;
         int idx;
 #ifdef __FreeBSD__
@@ -882,17 +655,10 @@ static int eth_llc_ipcp_bootstrap(struct dif_config * conf)
 
         memset(&ifr, 0, sizeof(ifr));
 
-        fd = socket(AF_UNIX, SOCK_STREAM, 0);
-        if (fd < 0) {
-                LOG_ERR("Failed to open socket.");
-                return -1;
-        }
-
         memcpy(ifr.ifr_name, conf->if_name, strlen(conf->if_name));
 
 #ifdef __FreeBSD__
         if (getifaddrs(&ifaddr) < 0)  {
-                close(fd);
                 LOG_ERR("Could not get interfaces.");
                 return -1;
         }
@@ -900,8 +666,7 @@ static int eth_llc_ipcp_bootstrap(struct dif_config * conf)
         for (ifa = ifaddr, idx = 0; ifa != NULL; ifa = ifa->ifa_next, ++idx) {
                 if (strcmp(ifa->ifa_name, conf->if_name))
                         continue;
-                LOG_DBGF("Interface %s found.", conf->if_name);
-
+                LOG_DBG("Interface %s found.", conf->if_name);
                 memcpy(&ifr.ifr_addr, ifa->ifa_addr, sizeof(*ifa->ifa_addr));
                 break;
         }
@@ -913,30 +678,33 @@ static int eth_llc_ipcp_bootstrap(struct dif_config * conf)
         }
 
         freeifaddrs(ifaddr);
-
 #else
-        if (ioctl(fd, SIOCGIFHWADDR, &ifr)) {
-                close(fd);
-                LOG_ERR("Failed to ioctl: %s.", strerror(errno));
+        skfd = socket(AF_UNIX, SOCK_STREAM, 0);
+        if (skfd < 0) {
+                LOG_ERR("Failed to open socket.");
+                return -1;
+        }
+
+        if (ioctl(skfd, SIOCGIFHWADDR, &ifr)) {
+                LOG_ERR("Failed to ioctl.");
+                close(skfd);
                 return -1;
         }
 
+        close(skfd);
+
         idx = if_nametoindex(conf->if_name);
         if (idx == 0) {
                 LOG_ERR("Failed to retrieve interface index.");
+                close(skfd);
                 return -1;
         }
 #endif
-
-        close(fd);
-
         memset(&(device), 0, sizeof(device));
 #ifdef __FreeBSD__
         device.sdl_index = idx;
         device.sdl_family = AF_LINK;
-        memcpy(LLADDR(&device),
-               ifr.ifr_addr.sa_data,
-               MAC_SIZE * sizeof (uint8_t));
+        memcpy(LLADDR(&device), ifr.ifr_addr.sa_data, MAC_SIZE);
         device.sdl_alen = MAC_SIZE;
         /* TODO: replace socket calls with bpf for BSD */
         LOG_MISSING;
@@ -944,23 +712,21 @@ static int eth_llc_ipcp_bootstrap(struct dif_config * conf)
 #else
         device.sll_ifindex = idx;
         device.sll_family = AF_PACKET;
-        memcpy(device.sll_addr,
-               ifr.ifr_hwaddr.sa_data,
-               MAC_SIZE * sizeof (uint8_t));
+        memcpy(device.sll_addr, ifr.ifr_hwaddr.sa_data, MAC_SIZE);
         device.sll_halen = MAC_SIZE;
         device.sll_protocol = htons(ETH_P_ALL);
 
-        fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_802_2));
+        skfd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_802_2));
 #endif
-        if (fd < 0) {
-                LOG_ERR("Failed to create socket: %s.", strerror(errno));
+        if (skfd < 0) {
+                LOG_ERR("Failed to create socket.");
                 return -1;
         }
 
 #if defined(PACKET_RX_RING) && defined(PACKET_TX_RING)
         if (SHIM_ETH_LLC_MAX_SDU_SIZE > SHM_RDRB_BLOCK_SIZE) {
                 LOG_ERR("Max SDU size is bigger than DU map block size.");
-                close(fd);
+                close(skfd);
                 return -1;
         }
 
@@ -969,68 +735,68 @@ static int eth_llc_ipcp_bootstrap(struct dif_config * conf)
         req.tp_block_nr = SHM_BUFFER_SIZE;
         req.tp_frame_nr = SHM_BUFFER_SIZE;
 
-        if (setsockopt(fd, SOL_PACKET, PACKET_RX_RING,
+        if (setsockopt(skfd, SOL_PACKET, PACKET_RX_RING,
                        (void *) &req, sizeof(req))) {
                 LOG_ERR("Failed to set sockopt PACKET_RX_RING");
-                close(fd);
+                close(skfd);
                 return -1;
         }
 
-        if (setsockopt(fd, SOL_PACKET, PACKET_TX_RING,
+        if (setsockopt(skfd, SOL_PACKET, PACKET_TX_RING,
                        (void *) &req, sizeof(req))) {
                 LOG_ERR("Failed to set sockopt PACKET_TX_RING");
-                close(fd);
+                close(skfd);
                 return -1;
         }
 #endif
-
-        if (bind(fd,(struct sockaddr *) &device, sizeof(device))) {
+        if (bind(skfd, (struct sockaddr *) &device, sizeof(device))) {
                 LOG_ERR("Failed to bind socket to interface");
-                close(fd);
+                close(skfd);
                 return -1;
         }
 
 #if defined(PACKET_RX_RING) && defined(PACKET_TX_RING)
-        shim_data(_ipcp)->rx_ring = mmap(NULL,
-                                         2 * SHM_RDRB_BLOCK_SIZE
-                                         * SHM_BUFFER_SIZE,
-                                         PROT_READ | PROT_WRITE, MAP_SHARED,
-                                         fd, 0);
-        if (shim_data(_ipcp)->rx_ring == NULL) {
+        eth_llc_data.rx_ring = mmap(NULL, 2 * SHM_RDRB_BLOCK_SIZE
+                                    * SHM_BUFFER_SIZE,
+                                    PROT_READ | PROT_WRITE, MAP_SHARED,
+                                    skfd, 0);
+        if (eth_llc_data.rx_ring == NULL) {
                 LOG_ERR("Failed to mmap");
-                close(fd);
+                close(skfd);
                 return -1;
         }
-        shim_data(_ipcp)->tx_ring = shim_data(_ipcp)->rx_ring
-                + (SHM_RDRB_BLOCK_SIZE * SHM_BUFFER_SIZE);
 
+        eth_llc_data.tx_ring = eth_llc_data.rx_ring
+                + SHM_RDRB_BLOCK_SIZE * SHM_BUFFER_SIZE;
 #endif
-        pthread_rwlock_wrlock(&_ipcp->state_lock);
+        pthread_rwlock_wrlock(&ipcpi.state_lock);
 
-        if (ipcp_get_state(_ipcp) != IPCP_INIT) {
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+        if (ipcp_get_state() != IPCP_INIT) {
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 LOG_ERR("IPCP in wrong state.");
-                close(fd);
+                close(skfd);
                 return -1;
         }
 
-        shim_data(_ipcp)->s_fd = fd;
-        shim_data(_ipcp)->device = device;
-        shim_data(_ipcp)->tx_offset = 0;
+        eth_llc_data.s_fd = skfd;
+        eth_llc_data.device = device;
+#if defined(PACKET_RX_RING) && defined(PACKET_TX_RING)
+        eth_llc_data.tx_offset = 0;
+#endif
 
-        ipcp_set_state(_ipcp, IPCP_ENROLLED);
+        ipcp_set_state(IPCP_ENROLLED);
 
-        pthread_create(&shim_data(_ipcp)->sdu_reader,
+        pthread_create(&eth_llc_data.sdu_reader,
                        NULL,
                        eth_llc_ipcp_sdu_reader,
                        NULL);
 
-        pthread_create(&shim_data(_ipcp)->sdu_writer,
+        pthread_create(&eth_llc_data.sdu_writer,
                        NULL,
                        eth_llc_ipcp_sdu_writer,
                        NULL);
 
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
         LOG_DBG("Bootstrapped shim IPCP over Ethernet with LLC with api %d.",
                 getpid());
@@ -1040,15 +806,15 @@ static int eth_llc_ipcp_bootstrap(struct dif_config * conf)
 
 static int eth_llc_ipcp_name_reg(char * name)
 {
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-        if (ipcp_data_add_reg_entry(_ipcp->data, name)) {
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+        if (ipcp_data_add_reg_entry(ipcpi.data, name)) {
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 LOG_ERR("Failed to add %s to local registry.", name);
                 return -1;
         }
 
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
         LOG_DBG("Registered %s.", name);
 
@@ -1057,25 +823,22 @@ static int eth_llc_ipcp_name_reg(char * name)
 
 static int eth_llc_ipcp_name_unreg(char * name)
 {
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-        ipcp_data_del_reg_entry(_ipcp->data, name);
+        ipcp_data_del_reg_entry(ipcpi.data, name);
 
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
         return 0;
 }
 
-static int eth_llc_ipcp_flow_alloc(pid_t         n_api,
-                                   int           port_id,
+static int eth_llc_ipcp_flow_alloc(int           fd,
                                    char *        dst_name,
                                    char *        src_ae_name,
                                    enum qos_cube qos)
 {
-        struct shm_ap_rbuff * rb;
         uint8_t ssap = 0;
         uint8_t r_addr[MAC_SIZE];
-        int index = 0;
 
         LOG_INFO("Allocating flow to %s.", dst_name);
 
@@ -1083,182 +846,122 @@ static int eth_llc_ipcp_flow_alloc(pid_t         n_api,
                 return -1;
 
         if (qos != QOS_CUBE_BE)
-                LOG_DBGF("QoS requested. Ethernet LLC can't do that. For now.");
-
-        rb = shm_ap_rbuff_open_s(n_api);
-        if (rb == NULL)
-                return -1; /* -ENORBUFF */
+                LOG_DBG("QoS requested. Ethernet LLC can't do that. For now.");
 
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-        if (ipcp_get_state(_ipcp) != IPCP_ENROLLED) {
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                shm_ap_rbuff_close(rb);
-                LOG_DBGF("Won't allocate flow with non-enrolled IPCP.");
+        if (ipcp_get_state() != IPCP_ENROLLED) {
+                pthread_rwlock_unlock(&ipcpi.state_lock);
+                LOG_DBG("Won't allocate flow with non-enrolled IPCP.");
                 return -1; /* -ENOTENROLLED */
         }
 
-        index = bmp_allocate(shim_data(_ipcp)->indices);
-        if (index < 0) {
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                shm_ap_rbuff_close(rb);
-                return -1;
-        }
-
-        pthread_rwlock_wrlock(&shim_data(_ipcp)->flows_lock);
+        pthread_rwlock_wrlock(&eth_llc_data.flows_lock);
 
-        ssap = bmp_allocate(shim_data(_ipcp)->saps);
+        ssap = bmp_allocate(eth_llc_data.saps);
         if (ssap < 0) {
-                shm_ap_rbuff_close(rb);
-                bmp_release(shim_data(_ipcp)->indices, index);
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+                pthread_rwlock_unlock(&eth_llc_data.flows_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 return -1;
         }
 
-        ipcp_flow(index)->port_id = port_id;
-        ipcp_flow(index)->state = FLOW_PENDING;
-        ipcp_flow(index)->rb = rb;
-        shim_data(_ipcp)->flows[index].sap = ssap;
-
-        pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-        pthread_rwlock_unlock(&_ipcp->state_lock);
-
-        memset(r_addr, 0xff, MAC_SIZE * sizeof(uint8_t));
-
-        if (eth_llc_ipcp_port_alloc(r_addr, ssap,
-                                    dst_name,
-                                    src_ae_name) < 0) {
-                LOG_DBGF("Port alloc returned -1.");
-                pthread_rwlock_rdlock(&_ipcp->state_lock);
-                pthread_rwlock_wrlock(&shim_data(_ipcp)->flows_lock);
-                destroy_ipcp_flow(index);
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+        eth_llc_data.fd_to_ef[fd].sap = ssap;
+        eth_llc_data.ef_to_fd[ssap]   = fd;
+
+        pthread_rwlock_unlock(&eth_llc_data.flows_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
+
+        memset(r_addr, 0xff, MAC_SIZE);
+
+        if (eth_llc_ipcp_sap_alloc(r_addr, ssap, dst_name, src_ae_name) < 0) {
+                pthread_rwlock_rdlock(&ipcpi.state_lock);
+                pthread_rwlock_wrlock(&eth_llc_data.flows_lock);
+                bmp_release(eth_llc_data.saps, eth_llc_data.fd_to_ef[fd].sap);
+                eth_llc_data.fd_to_ef[fd].sap = -1;
+                eth_llc_data.ef_to_fd[ssap]   = -1;
+                pthread_rwlock_unlock(&eth_llc_data.flows_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 return -1;
         }
 
-        LOG_DBG("Pending flow with port_id %d on SAP %d.",
-                port_id, ssap);
+        LOG_DBG("Pending flow with fd %d on SAP %d.", fd, ssap);
 
-        return index;
+        return 0;
 }
 
-static int eth_llc_ipcp_flow_alloc_resp(pid_t n_api,
-                                        int   port_id,
-                                        int   response)
+static int eth_llc_ipcp_flow_alloc_resp(int fd, int response)
 {
-        struct shm_ap_rbuff * rb;
-        int index = -1;
         uint8_t ssap = 0;
+        uint8_t r_sap = 0;
+        uint8_t r_addr[MAC_SIZE];
 
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
-        pthread_rwlock_wrlock(&shim_data(_ipcp)->flows_lock);
-
-        index = port_id_to_index(port_id);
-        if (index < 0) {
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                LOG_DBGF("Could not find flow with port_id %d.", port_id);
-                return -1;
-        }
-
-        if (ipcp_flow(index)->state != FLOW_PENDING) {
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                LOG_DBGF("Flow was not pending.");
-                return -1;
-        }
-
-        rb = shm_ap_rbuff_open_s(n_api);
-        if (rb == NULL) {
-                LOG_ERR("Could not open N + 1 ringbuffer.");
-                ipcp_flow(index)->state = FLOW_NULL;
-                ipcp_flow(index)->port_id = -1;
-                bmp_release(shim_data(_ipcp)->indices, index);
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                return -1;
-        }
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
+        pthread_rwlock_wrlock(&eth_llc_data.flows_lock);
 
-        ssap = bmp_allocate(shim_data(_ipcp)->saps);
+        ssap = bmp_allocate(eth_llc_data.saps);
         if (ssap < 0) {
-                ipcp_flow(index)->state = FLOW_NULL;
-                ipcp_flow(index)->port_id = -1;
-                shm_ap_rbuff_close(ipcp_flow(index)->rb);
-                bmp_release(shim_data(_ipcp)->indices, index);
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+                pthread_rwlock_unlock(&eth_llc_data.flows_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 return -1;
         }
 
-        ipcp_flow(index)->state = FLOW_ALLOCATED;
-        ipcp_flow(index)->rb = rb;
-        shim_data(_ipcp)->flows[index].sap = ssap;
-
-        pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        eth_llc_data.fd_to_ef[fd].sap = ssap;
+        memcpy(r_addr, eth_llc_data.fd_to_ef[fd].r_addr, MAC_SIZE);
+        r_sap = eth_llc_data.fd_to_ef[fd].r_sap;
+        eth_llc_data.ef_to_fd[ssap] = fd;
 
-        if (eth_llc_ipcp_port_alloc_resp(shim_data(_ipcp)->flows[index].r_addr,
-                                         shim_data(_ipcp)->flows[index].r_sap,
-                                         ssap,
-                                         response) < 0) {
-                pthread_rwlock_rdlock(&_ipcp->state_lock);
-                pthread_rwlock_wrlock(&shim_data(_ipcp)->flows_lock);
-                destroy_ipcp_flow(index);
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&eth_llc_data.flows_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
-                LOG_DBGF("Could not send response.");
+        if (eth_llc_ipcp_sap_alloc_resp(r_addr, ssap, r_sap, response) < 0) {
+                pthread_rwlock_rdlock(&ipcpi.state_lock);
+                pthread_rwlock_wrlock(&eth_llc_data.flows_lock);
+                bmp_release(eth_llc_data.saps, eth_llc_data.fd_to_ef[fd].sap);
+                pthread_rwlock_unlock(&eth_llc_data.flows_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 return -1;
         }
 
-        LOG_DBG("Accepted flow, port_id %d, SAP %d.", port_id, ssap);
+        LOG_DBG("Accepted flow, fd %d, SAP %d.", fd, ssap);
 
         return 0;
 }
 
-static int eth_llc_ipcp_flow_dealloc(int port_id)
+static int eth_llc_ipcp_flow_dealloc(int fd)
 {
-        int index = -1;
         uint8_t sap;
         uint8_t addr[MAC_SIZE];
-        int i;
         int ret;
 
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
-        pthread_rwlock_wrlock(&shim_data(_ipcp)->flows_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
+        pthread_rwlock_wrlock(&eth_llc_data.flows_lock);
 
-        index = port_id_to_index(port_id);
-        if (index < 0) {
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                return 0;
-        }
+        sap = eth_llc_data.fd_to_ef[fd].r_sap;
+        memcpy(addr, eth_llc_data.fd_to_ef[fd].r_addr, MAC_SIZE);
 
-        sap = shim_data(_ipcp)->flows[index].r_sap;
-        for (i = 0; i < MAC_SIZE; i++) {
-                addr[i] = shim_data(_ipcp)->flows[index].r_addr[i];
-        }
+        bmp_release(eth_llc_data.saps, eth_llc_data.fd_to_ef[fd].sap);
+        eth_llc_data.fd_to_ef[fd].sap = -1;
+        eth_llc_data.fd_to_ef[fd].r_sap = -1;
+        memset(&eth_llc_data.fd_to_ef[fd].r_addr, 0, MAC_SIZE);
 
-        destroy_ipcp_flow(index);
+        eth_llc_data.ef_to_fd[sap] = -1;
 
-        pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
+        pthread_rwlock_unlock(&eth_llc_data.flows_lock);
 
-        ret = eth_llc_ipcp_port_dealloc(addr, sap);
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        ret = eth_llc_ipcp_sap_dealloc(addr, sap);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
         if (ret < 0)
-                LOG_DBGF("Could not notify remote.");
+                LOG_DBG("Could not notify remote.");
 
-        LOG_DBG("Flow with port_id %d deallocated.", port_id);
+        LOG_DBG("Flow with fd %d deallocated.", fd);
 
         return 0;
 }
 
 static struct ipcp_ops eth_llc_ops = {
         .ipcp_bootstrap       = eth_llc_ipcp_bootstrap,
-        .ipcp_enroll          = NULL,                       /* shim */
+        .ipcp_enroll          = NULL,
         .ipcp_name_reg        = eth_llc_ipcp_name_reg,
         .ipcp_name_unreg      = eth_llc_ipcp_name_unreg,
         .ipcp_flow_alloc      = eth_llc_ipcp_flow_alloc,
@@ -1270,7 +973,6 @@ int main(int argc, char * argv[])
 {
         struct sigaction sig_act;
         sigset_t  sigset;
-        int i = 0;
 
         sigemptyset(&sigset);
         sigaddset(&sigset, SIGINT);
@@ -1283,6 +985,14 @@ int main(int argc, char * argv[])
                 exit(EXIT_FAILURE);
         }
 
+        if (eth_llc_data_init() < 0)
+                exit(EXIT_FAILURE);
+
+        if (ap_init(NULL) < 0) {
+                close_logfile();
+                exit(EXIT_FAILURE);
+        }
+
         /* store the process id of the irmd */
         irmd_api = atoi(argv[1]);
 
@@ -1298,35 +1008,13 @@ int main(int argc, char * argv[])
         sigaction(SIGHUP,  &sig_act, NULL);
         sigaction(SIGPIPE, &sig_act, NULL);
 
-        _ipcp = ipcp_instance_create();
-        if (_ipcp == NULL) {
-                LOG_ERR("Failed to create instance.");
-                close_logfile();
-                exit(EXIT_FAILURE);
-        }
+        pthread_sigmask(SIG_BLOCK, &sigset, NULL);
 
-        _ipcp->data = (struct ipcp_data *) eth_llc_ipcp_data_create();
-        if (_ipcp->data == NULL) {
-                LOG_ERR("Failed to create instance data.");
-                free(_ipcp);
+        if (ipcp_init(THIS_TYPE, &eth_llc_ops) < 0) {
                 close_logfile();
                 exit(EXIT_FAILURE);
         }
 
-        for (i = 0; i < AP_MAX_FLOWS; i++) {
-                ipcp_flow(i)->rb = NULL;
-                ipcp_flow(i)->port_id = -1;
-                ipcp_flow(i)->state = FLOW_NULL;
-        }
-
-        _ipcp->ops = &eth_llc_ops;
-        _ipcp->state = IPCP_INIT;
-
-        pthread_sigmask(SIG_BLOCK, &sigset, NULL);
-
-        pthread_create(&shim_data(_ipcp)->mainloop, NULL,
-                       ipcp_main_loop, _ipcp);
-
         pthread_sigmask(SIG_UNBLOCK, &sigset, NULL);
 
         if (ipcp_create_r(getpid())) {
@@ -1335,17 +1023,17 @@ int main(int argc, char * argv[])
                 exit(EXIT_FAILURE);
         }
 
-        pthread_join(shim_data(_ipcp)->mainloop, NULL);
+        ipcp_fini();
 
-        pthread_cancel(shim_data(_ipcp)->sdu_reader);
-        pthread_cancel(shim_data(_ipcp)->sdu_writer);
+        pthread_cancel(eth_llc_data.sdu_reader);
+        pthread_cancel(eth_llc_data.sdu_writer);
 
-        pthread_join(shim_data(_ipcp)->sdu_writer, NULL);
-        pthread_join(shim_data(_ipcp)->sdu_reader, NULL);
+        pthread_join(eth_llc_data.sdu_writer, NULL);
+        pthread_join(eth_llc_data.sdu_reader, NULL);
 
-        eth_llc_ipcp_data_destroy();
+        ap_fini();
 
-        free(_ipcp);
+        eth_llc_data_fini();
 
         close_logfile();
 
diff --git a/src/ipcpd/shim-udp/main.c b/src/ipcpd/shim-udp/main.c
index c35bd244..8c31e11a 100644
--- a/src/ipcpd/shim-udp/main.c
+++ b/src/ipcpd/shim-udp/main.c
@@ -22,18 +22,11 @@
 
 #include <ouroboros/config.h>
 #include "ipcp.h"
-#include "flow.h"
 #include "shim_udp_config.h"
-#include <ouroboros/shm_rdrbuff.h>
-#include <ouroboros/shm_ap_rbuff.h>
 #include <ouroboros/list.h>
 #include <ouroboros/utils.h>
-#include <ouroboros/ipcp.h>
-#include <ouroboros/irm_config.h>
-#include <ouroboros/sockets.h>
-#include <ouroboros/bitmap.h>
-#include <ouroboros/flow.h>
 #include <ouroboros/dev.h>
+#include <ouroboros/ipcp-dev.h>
 
 #define OUROBOROS_PREFIX "ipcpd/shim-udp"
 
@@ -63,268 +56,93 @@ typedef ShimUdpMsg shim_udp_msg_t;
 #define DNS_TTL 86400
 #define FD_UPDATE_TIMEOUT 100 /* microseconds */
 
-#define shim_data(type) ((struct ipcp_udp_data *) type->data)
+#define local_ip (udp_data.s_saddr.sin_addr.s_addr)
 
-#define local_ip (((struct ipcp_udp_data *)                     \
-                   _ipcp->data)->s_saddr.sin_addr.s_addr)
+#define UDP_MAX_PORTS 0xFFFF
 
 /* global for trapping signal */
 int irmd_api;
 
-/* this IPCP's data */
-#ifdef MAKE_CHECK
-extern struct ipcp * _ipcp; /* defined in test */
-#else
-struct ipcp * _ipcp;
-#endif
-
-/*
- * copied from ouroboros/dev. The shim needs access to the internals
- * because it doesn't follow all steps necessary steps to get
- * the info
- */
-
-/* the shim needs access to these internals */
-struct shim_ap_data {
-        pid_t                 api;
-        struct shm_rdrbuff *  rdrb;
-        struct bmp *          fds;
-        struct shm_ap_rbuff * rb;
-
-        struct flow           flows[AP_MAX_FLOWS];
-        pthread_rwlock_t      flows_lock;
-
-        pthread_t             mainloop;
-        pthread_t             sduloop;
-        pthread_t             handler;
-        pthread_t             sdu_reader;
-
-        bool                  fd_set_mod;
-        pthread_cond_t        fd_set_cond;
-        pthread_mutex_t       fd_set_lock;
-} * _ap_instance;
-
-static int shim_ap_init()
-{
-        int i;
-
-        _ap_instance = malloc(sizeof(struct shim_ap_data));
-        if (_ap_instance == NULL) {
-                return -1;
-        }
-
-        _ap_instance->api = getpid();
-
-        _ap_instance->fds = bmp_create(AP_MAX_FLOWS, 0);
-        if (_ap_instance->fds == NULL) {
-                free(_ap_instance);
-                return -1;
-        }
-
-        _ap_instance->rdrb = shm_rdrbuff_open();
-        if (_ap_instance->rdrb == NULL) {
-                bmp_destroy(_ap_instance->fds);
-                free(_ap_instance);
-                return -1;
-        }
-
-        _ap_instance->rb = shm_ap_rbuff_create_n();
-        if (_ap_instance->rb == NULL) {
-                shm_rdrbuff_close(_ap_instance->rdrb);
-                bmp_destroy(_ap_instance->fds);
-                free(_ap_instance);
-                return -1;
-        }
-
-        for (i = 0; i < AP_MAX_FLOWS; i ++) {
-                _ap_instance->flows[i].rb = NULL;
-                _ap_instance->flows[i].port_id = -1;
-                _ap_instance->flows[i].state = FLOW_NULL;
-        }
-
-        pthread_rwlock_init(&_ap_instance->flows_lock, NULL);
-        pthread_cond_init(&_ap_instance->fd_set_cond, NULL);
-        pthread_mutex_init(&_ap_instance->fd_set_lock, NULL);
-
-        return 0;
-}
-
-void shim_ap_fini()
-{
-        int i = 0;
-
-        if (_ap_instance == NULL)
-                return;
-
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
-
-        if (_ipcp->state != IPCP_SHUTDOWN)
-                LOG_WARN("Cleaning up AP while not in shutdown.");
-
-        if (_ap_instance->fds != NULL)
-                bmp_destroy(_ap_instance->fds);
-
-        /* remove all remaining sdus */
-        while ((i = shm_ap_rbuff_peek_idx(_ap_instance->rb)) >= 0)
-                shm_rdrbuff_remove(_ap_instance->rdrb, i);
-
-        if (_ap_instance->rdrb != NULL)
-                shm_rdrbuff_close(_ap_instance->rdrb);
-        if (_ap_instance->rb != NULL)
-                shm_ap_rbuff_destroy(_ap_instance->rb);
+struct uf {
+        int                udp;
+        int                skfd;
+};
 
-        pthread_rwlock_wrlock(&_ap_instance->flows_lock);
+struct {
+        uint32_t           ip_addr;
+        uint32_t           dns_addr;
+        /* listen server */
+        struct sockaddr_in s_saddr;
+        int                s_fd;
 
-        for (i = 0; i < AP_MAX_FLOWS; i ++)
-                if (_ap_instance->flows[i].rb != NULL)
-                        shm_ap_rbuff_close(_ap_instance->flows[i].rb);
+        fd_set             flow_fd_s;
+        /* bidir mappings of (n - 1) file descriptor to (n) flow descriptor */
+        int                uf_to_fd[FD_SETSIZE];
+        struct uf          fd_to_uf[IRMD_MAX_FLOWS];
+        pthread_rwlock_t   flows_lock;
 
-        pthread_rwlock_unlock(&_ap_instance->flows_lock);
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_t          sduloop;
+        pthread_t          handler;
+        pthread_t          sdu_reader;
 
-        free(_ap_instance);
-}
+        bool               fd_set_mod;
+        pthread_cond_t     fd_set_cond;
+        pthread_mutex_t    fd_set_lock;
+} udp_data;
 
-/* only call this under flows_lock */
-static int port_id_to_fd(int port_id)
+static void udp_data_init()
 {
         int i;
 
-        for (i = 0; i < AP_MAX_FLOWS; ++i) {
-                if (_ap_instance->flows[i].port_id == port_id
-                    && _ap_instance->flows[i].state != FLOW_NULL)
-                        return i;
-        }
+        for (i = 0; i < FD_SETSIZE; ++i)
+                udp_data.uf_to_fd[i] = -1;
 
-        return -1;
-}
-
-static ssize_t ipcp_udp_flow_write(int fd, void * buf, size_t count)
-{
-        ssize_t index;
-        struct rb_entry e;
-
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
-        pthread_rwlock_rdlock(&_ap_instance->flows_lock);
-
-        index = shm_rdrbuff_write_b(_ap_instance->rdrb,
-                                   _ap_instance->flows[fd].api,
-                                   0,
-                                   0,
-                                   (uint8_t *) buf,
-                                   count);
-        if (index < 0) {
-                pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                return -1;
+        for (i = 0; i < IRMD_MAX_FLOWS; ++i) {
+                udp_data.fd_to_uf[i].skfd = -1;
+                udp_data.fd_to_uf[i].udp = -1;
         }
 
-        e.index   = index;
-        e.port_id = _ap_instance->flows[fd].port_id;
-
-        shm_ap_rbuff_write(_ap_instance->flows[fd].rb, &e);
+        FD_ZERO(&udp_data.flow_fd_s);
 
-        pthread_rwlock_unlock(&_ap_instance->flows_lock);
-        pthread_rwlock_unlock(&_ipcp->state_lock);
-
-        return 0;
+        pthread_rwlock_init(&udp_data.flows_lock, NULL);
+        pthread_cond_init(&udp_data.fd_set_cond, NULL);
+        pthread_mutex_init(&udp_data.fd_set_lock, NULL);
 }
 
-/*
- * end copy from dev.c
- */
-
-/* only call this under flows_lock */
-static int udp_port_to_fd(int udp_port)
+static void udp_data_fini()
 {
-        int i;
-
-        struct sockaddr_in f_saddr;
-        socklen_t len = sizeof(f_saddr);
-
-        for (i = 0; i < AP_MAX_FLOWS; ++i) {
-                if (_ap_instance->flows[i].state == FLOW_NULL)
-                        continue;
-
-                if (getsockname(i, (struct sockaddr *) &f_saddr, &len) < 0)
-                        continue;
-
-                if (f_saddr.sin_port == udp_port)
-                        return i;
-        }
-
-        return -1;
-}
-
-struct ipcp_udp_data {
-        /* keep ipcp_data first for polymorphism */
-        struct ipcp_data ipcp_data;
-
-        uint32_t ip_addr;
-        uint32_t dns_addr;
-        /* listen server */
-        struct sockaddr_in s_saddr;
-        int                s_fd;
-
-        /* only modify under _ap_instance->flows_lock */
-        fd_set flow_fd_s;
-};
-
-struct ipcp_udp_data * ipcp_udp_data_create()
-{
-        struct ipcp_udp_data * udp_data;
-        struct ipcp_data *     data;
-        enum ipcp_type         ipcp_type;
-
-        udp_data = malloc(sizeof(*udp_data));
-        if (udp_data == NULL) {
-                LOG_ERR("Failed to allocate.");
-                return NULL;
-        }
-
-        ipcp_type = THIS_TYPE;
-        data = (struct ipcp_data *) udp_data;
-        if (ipcp_data_init(data, ipcp_type) == NULL) {
-                free(udp_data);
-                return NULL;
-        }
-
-        FD_ZERO(&udp_data->flow_fd_s);
-
-        return udp_data;
+        pthread_rwlock_destroy(&udp_data.flows_lock);
+        pthread_mutex_destroy(&udp_data.fd_set_lock);
+        pthread_cond_destroy(&udp_data.fd_set_cond);
 }
 
 static void set_fd(int fd)
 {
-        pthread_mutex_lock(&_ap_instance->fd_set_lock);
+        pthread_mutex_lock(&udp_data.fd_set_lock);
 
-        _ap_instance->fd_set_mod = true;
-        FD_SET(fd, &shim_data(_ipcp)->flow_fd_s);
+        udp_data.fd_set_mod = true;
+        FD_SET(fd, &udp_data.flow_fd_s);
 
-        while (_ap_instance->fd_set_mod)
-                pthread_cond_wait(&_ap_instance->fd_set_cond,
-                                  &_ap_instance->fd_set_lock);
+        while (udp_data.fd_set_mod)
+                pthread_cond_wait(&udp_data.fd_set_cond, &udp_data.fd_set_lock);
 
-        pthread_mutex_unlock(&_ap_instance->fd_set_lock);
+        pthread_mutex_unlock(&udp_data.fd_set_lock);
 }
 
 static void clr_fd(int fd)
 {
-        pthread_mutex_lock(&_ap_instance->fd_set_lock);
+        pthread_mutex_lock(&udp_data.fd_set_lock);
 
-        _ap_instance->fd_set_mod = true;
-        FD_CLR(fd, &shim_data(_ipcp)->flow_fd_s);
+        udp_data.fd_set_mod = true;
+        FD_CLR(fd, &udp_data.flow_fd_s);
 
-        while (_ap_instance->fd_set_mod)
-                pthread_cond_wait(&_ap_instance->fd_set_cond,
-                                  &_ap_instance->fd_set_lock);
+        while (udp_data.fd_set_mod)
+                pthread_cond_wait(&udp_data.fd_set_cond, &udp_data.fd_set_lock);
 
-        pthread_mutex_unlock(&_ap_instance->fd_set_lock);
+        pthread_mutex_unlock(&udp_data.fd_set_lock);
 }
 
-
-static int send_shim_udp_msg(shim_udp_msg_t * msg,
-                             uint32_t dst_ip_addr)
+static int send_shim_udp_msg(shim_udp_msg_t * msg, uint32_t dst_ip_addr)
 {
        buffer_t           buf;
        struct sockaddr_in r_saddr;
@@ -340,13 +158,12 @@ static int send_shim_udp_msg(shim_udp_msg_t * msg,
        }
 
        buf.data = malloc(SHIM_UDP_MSG_SIZE);
-       if (buf.data == NULL) {
+       if (buf.data == NULL)
                return -1;
-       }
 
        shim_udp_msg__pack(msg, buf.data);
 
-       if (sendto(shim_data(_ipcp)->s_fd,
+       if (sendto(udp_data.s_fd,
                   buf.data,
                   buf.len,
                   0,
@@ -409,8 +226,8 @@ static int ipcp_udp_port_req(struct sockaddr_in * c_saddr,
                              char * dst_name,
                              char * src_ae_name)
 {
-        int  fd;
-        int  port_id;
+        int skfd;
+        int fd;
 
         struct sockaddr_in f_saddr;
         socklen_t          f_saddr_len = sizeof(f_saddr);
@@ -418,7 +235,7 @@ static int ipcp_udp_port_req(struct sockaddr_in * c_saddr,
         LOG_DBG("Port request arrived from UDP port %d",
                  ntohs(c_saddr->sin_port));
 
-        if ((fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
+        if ((skfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
                 LOG_ERR("Could not create UDP socket.");
                 return -1;
         }
@@ -426,73 +243,72 @@ static int ipcp_udp_port_req(struct sockaddr_in * c_saddr,
         memset((char *) &f_saddr, 0, sizeof(f_saddr));
         f_saddr.sin_family      = AF_INET;
         f_saddr.sin_addr.s_addr = local_ip;
-
-        /*
-         * FIXME: we could have a port dedicated per registered AP
-         * Not that critical for UDP, but will be for LLC
-         */
-
         f_saddr.sin_port        = 0;
 
-        if (bind(fd, (struct sockaddr *) &f_saddr, sizeof(f_saddr)) < 0) {
+        if (bind(skfd, (struct sockaddr *) &f_saddr, sizeof(f_saddr)) < 0) {
                 LOG_ERR("Could not bind to socket.");
-                close(fd);
+                close(skfd);
                 return -1;
         }
 
-        if (getsockname(fd, (struct sockaddr *) &f_saddr, &f_saddr_len) < 0) {
+        if (getsockname(skfd, (struct sockaddr *) &f_saddr, &f_saddr_len) < 0) {
                 LOG_ERR("Could not get address from fd.");
                 return -1;
         }
 
-        /*
-         * store the remote address in the file descriptor
-         * this avoids having to store the sockaddr_in in
-         * the flow structure
-         */
-
-        if (connect(fd, (struct sockaddr *) c_saddr, sizeof(*c_saddr)) < 0) {
+        /* connect stores the remote address in the file descriptor */
+        if (connect(skfd, (struct sockaddr *) c_saddr, sizeof(*c_saddr)) < 0) {
                 LOG_ERR("Could not connect to remote UDP client.");
-                close(fd);
+                close(skfd);
                 return -1;
         }
 
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
-        pthread_rwlock_wrlock(&_ap_instance->flows_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
 
         /* reply to IRM */
-        port_id = ipcp_flow_req_arr(getpid(),
-                                    dst_name,
-                                    src_ae_name);
-
-        if (port_id < 0) {
-                pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                LOG_ERR("Could not get port id from IRMd");
-                close(fd);
+        fd = ipcp_flow_req_arr(getpid(), dst_name, src_ae_name);
+        if (fd < 0) {
+                pthread_rwlock_unlock(&udp_data.flows_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
+                LOG_ERR("Could not get new flow from IRMd.");
+                close(skfd);
                 return -1;
         }
 
-        _ap_instance->flows[fd].port_id = port_id;
-        _ap_instance->flows[fd].rb      = NULL;
-        _ap_instance->flows[fd].state   = FLOW_PENDING;
+        pthread_rwlock_wrlock(&udp_data.flows_lock);
+
+        udp_data.uf_to_fd[skfd]    = fd;
+        udp_data.fd_to_uf[fd].skfd = skfd;
+        udp_data.fd_to_uf[fd].udp  = f_saddr.sin_port;
 
-        pthread_rwlock_unlock(&_ap_instance->flows_lock);
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&udp_data.flows_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
-        LOG_DBG("Pending allocation request, port_id %d, UDP port (%d, %d).",
-                port_id, ntohs(f_saddr.sin_port), ntohs(c_saddr->sin_port));
+        LOG_DBG("Pending allocation request, fd %d, UDP port (%d, %d).",
+                fd, ntohs(f_saddr.sin_port), ntohs(c_saddr->sin_port));
 
         return 0;
 }
 
+/* returns the n flow descriptor */
+static int udp_port_to_fd(int udp_port)
+{
+        int i;
+
+        for (i = 0; i < IRMD_MAX_FLOWS; ++i)
+                if (udp_data.fd_to_uf[i].udp == udp_port)
+                        return i;
+
+        return -1;
+}
+
 static int ipcp_udp_port_alloc_reply(int src_udp_port,
                                      int dst_udp_port,
                                      int response)
 {
-        int  fd        = -1;
-        int  ret       =  0;
-        int  port_id   = -1;
+        int fd   = -1;
+        int ret  =  0;
+        int skfd = -1;
 
         struct sockaddr_in t_saddr;
         socklen_t          t_saddr_len = sizeof(t_saddr);
@@ -500,117 +316,82 @@ static int ipcp_udp_port_alloc_reply(int src_udp_port,
         LOG_DBG("Received reply for flow on udp port %d.",
                 ntohs(dst_udp_port));
 
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
-        pthread_rwlock_rdlock(&_ap_instance->flows_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
+        pthread_rwlock_rdlock(&udp_data.flows_lock);
 
         fd = udp_port_to_fd(dst_udp_port);
-        if (fd == -1) {
-                pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                LOG_DBG("Unknown flow on UDP port %d.", ntohs(dst_udp_port));
-                return -1; /* -EUNKNOWNFLOW */
-        }
+        skfd = udp_data.fd_to_uf[fd].skfd;
 
-        if (_ap_instance->flows[fd].state != FLOW_PENDING) {
-                pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                LOG_DBG("Flow on UDP port %d not pending.",
-                         ntohs(dst_udp_port));
-                return -1; /* -EFLOWNOTPENDING */
-        }
-
-        port_id = _ap_instance->flows[fd].port_id;
-
-        if (response) {
-                _ap_instance->flows[fd].port_id = -1;
-                _ap_instance->flows[fd].rb      = NULL;
-                shm_ap_rbuff_close(_ap_instance->flows[fd].rb);
-                _ap_instance->flows[fd].state   = FLOW_NULL;
-        } else {
-                /* get the original address with the LISTEN PORT */
-                if (getpeername(fd,
-                                (struct sockaddr *) &t_saddr,
-                                &t_saddr_len) < 0) {
-                        pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                        pthread_rwlock_unlock(&_ipcp->state_lock);
-                        LOG_DBG("Flow with port_id %d has no peer.", port_id);
-                        return -1;
-                }
+        pthread_rwlock_unlock(&udp_data.flows_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
-                /* connect to the flow udp port */
-                t_saddr.sin_port = src_udp_port;
+        /* get the original address with the LISTEN PORT */
+        if (getpeername(skfd, (struct sockaddr *) &t_saddr, &t_saddr_len) < 0) {
+                LOG_DBG("Flow with fd %d has no peer.", fd);
+                return -1;
+        }
 
-                if (connect(fd,
-                            (struct sockaddr *) &t_saddr,
-                            sizeof(t_saddr)) < 0) {
-                        pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                        pthread_rwlock_unlock(&_ipcp->state_lock);
-                        close(fd);
-                        return -1;
-                }
+        /* connect to the flow udp port */
+        t_saddr.sin_port = src_udp_port;
 
-                _ap_instance->flows[fd].state   = FLOW_ALLOCATED;
+        if (connect(skfd, (struct sockaddr *) &t_saddr, sizeof(t_saddr)) < 0) {
+                close(skfd);
+                return -1;
         }
 
-        pthread_rwlock_unlock(&_ap_instance->flows_lock);
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
+        pthread_rwlock_rdlock(&udp_data.flows_lock);
 
+        set_fd(skfd);
 
-        if ((ret = ipcp_flow_alloc_reply(getpid(),
-                                         port_id,
-                                         response)) < 0) {
-                return -1; /* -EPIPE */
-        }
+        pthread_rwlock_unlock(&udp_data.flows_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
+
+        if (ipcp_flow_alloc_reply(fd, response) < 0)
+                return -1;
 
-        LOG_INFO("Flow allocation completed, UDP ports: (%d, %d).",
+        LOG_DBG("Flow allocation completed, UDP ports: (%d, %d).",
                  ntohs(dst_udp_port), ntohs(src_udp_port));
 
         return ret;
-
 }
 
 static int ipcp_udp_flow_dealloc_req(int udp_port)
 {
-        int fd      = -1;
-        int port_id = -1;
-
-        struct shm_ap_rbuff * rb;
+        int skfd = -1;
+        int fd   = -1;
 
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
-        pthread_rwlock_rdlock(&_ap_instance->flows_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
+        pthread_rwlock_wrlock(&udp_data.flows_lock);
 
         fd = udp_port_to_fd(udp_port);
         if (fd < 0) {
-                pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+                pthread_rwlock_unlock(&udp_data.flows_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 LOG_DBG("Could not find flow on UDP port %d.",
                          ntohs(udp_port));
                 return 0;
         }
 
-        clr_fd(fd);
-
-        pthread_rwlock_unlock(&_ap_instance->flows_lock);
-        pthread_rwlock_wrlock(&_ap_instance->flows_lock);
+        skfd = udp_data.fd_to_uf[fd].skfd;
 
-        _ap_instance->flows[fd].state   = FLOW_NULL;
-        port_id = _ap_instance->flows[fd].port_id;
-        _ap_instance->flows[fd].port_id = -1;
-        rb = _ap_instance->flows[fd].rb;
-        _ap_instance->flows[fd].rb      = NULL;
+        udp_data.uf_to_fd[skfd]    = -1;
+        udp_data.fd_to_uf[fd].udp  = -1;
+        udp_data.fd_to_uf[fd].skfd = -1;
 
-        pthread_rwlock_unlock(&_ap_instance->flows_lock);
+        pthread_rwlock_unlock(&udp_data.flows_lock);
+        pthread_rwlock_rdlock(&udp_data.flows_lock);
 
-        if (rb != NULL)
-                shm_ap_rbuff_close(rb);
+        clr_fd(skfd);
 
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&udp_data.flows_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
-        irm_flow_dealloc(port_id);
+        flow_dealloc(fd);
 
-        close(fd);
+        close(skfd);
 
-        LOG_DBG("Flow with port_id %d deallocated.", port_id);
+        LOG_DBG("Flow with fd %d deallocated.", fd);
 
         return 0;
 }
@@ -619,39 +400,28 @@ static void * ipcp_udp_listener()
 {
         uint8_t buf[SHIM_UDP_MSG_SIZE];
         int  n = 0;
-
         struct sockaddr_in c_saddr;
+        int sfd = udp_data.s_fd;
 
         while (true) {
-                int sfd = 0;
                 shim_udp_msg_t * msg = NULL;
 
-                pthread_rwlock_rdlock(&_ipcp->state_lock);
-
-                sfd = shim_data(_ipcp)->s_fd;
-
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-
                 memset(&buf, 0, SHIM_UDP_MSG_SIZE);
                 n = sizeof(c_saddr);
                 n = recvfrom(sfd, buf, SHIM_UDP_MSG_SIZE, 0,
                              (struct sockaddr *) &c_saddr, (unsigned *) &n);
-
-                if (n < 0) {
+                if (n < 0)
                         continue;
-                }
 
                 /* flow alloc request from other host */
                 if (gethostbyaddr((const char *) &c_saddr.sin_addr.s_addr,
                                   sizeof(c_saddr.sin_addr.s_addr), AF_INET)
-                    == NULL) {
+                    == NULL)
                         continue;
-                }
 
                 msg = shim_udp_msg__unpack(NULL, n, buf);
-                if (msg == NULL) {
+                if (msg == NULL)
                         continue;
-                }
 
                 switch (msg->code) {
                 case SHIM_UDP_MSG_CODE__FLOW_REQ:
@@ -685,103 +455,80 @@ static void * ipcp_udp_listener()
 static void * ipcp_udp_sdu_reader()
 {
         int n;
+        int skfd;
         int fd;
+        /* FIXME: avoid this copy */
         char buf[SHIM_UDP_MAX_SDU_SIZE];
         struct sockaddr_in r_saddr;
         fd_set read_fds;
         int flags;
+        struct timeval tv = {0, FD_UPDATE_TIMEOUT};
 
         while (true) {
-                struct timeval tv = {0, FD_UPDATE_TIMEOUT};
-
-                pthread_rwlock_rdlock(&_ipcp->state_lock);
-                pthread_rwlock_rdlock(&_ap_instance->flows_lock);
-                pthread_mutex_lock(&_ap_instance->fd_set_lock);
+                pthread_rwlock_rdlock(&ipcpi.state_lock);
+                pthread_rwlock_rdlock(&udp_data.flows_lock);
+                pthread_mutex_lock(&udp_data.fd_set_lock);
 
-                read_fds = shim_data(_ipcp)->flow_fd_s;
-                _ap_instance->fd_set_mod = false;
-                pthread_cond_broadcast(&_ap_instance->fd_set_cond);
+                read_fds = udp_data.flow_fd_s;
+                udp_data.fd_set_mod = false;
+                pthread_cond_broadcast(&udp_data.fd_set_cond);
 
-                pthread_mutex_unlock(&_ap_instance->fd_set_lock);
-                pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+                pthread_mutex_unlock(&udp_data.fd_set_lock);
+                pthread_rwlock_unlock(&udp_data.flows_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
 
-                if (select(FD_SETSIZE, &read_fds, NULL, NULL, &tv) <= 0) {
+                if (select(FD_SETSIZE, &read_fds, NULL, NULL, &tv) <= 0)
                         continue;
-                }
 
-                for (fd = 0; fd < FD_SETSIZE; ++fd) {
-                        if (!FD_ISSET(fd, &read_fds))
+                for (skfd = 0; skfd < FD_SETSIZE; ++skfd) {
+                        if (!FD_ISSET(skfd, &read_fds))
                                 continue;
-                        flags = fcntl(fd, F_GETFL, 0);
-                        fcntl(fd, F_SETFL, flags | O_NONBLOCK);
-
+                        flags = fcntl(skfd, F_GETFL, 0);
+                        fcntl(skfd, F_SETFL, flags | O_NONBLOCK);
+                        fd = udp_data.uf_to_fd[skfd];
                         n = sizeof(r_saddr);
-                        if ((n = recvfrom(fd,
-                                          buf,
+                        if ((n = recvfrom(skfd,
+                                          &buf,
                                           SHIM_UDP_MAX_SDU_SIZE,
                                           0,
                                           (struct sockaddr *) &r_saddr,
                                           (unsigned *) &n)) <= 0)
                                 continue;
 
-                        /* send the sdu to the correct port_id */
-                        ipcp_udp_flow_write(fd, buf, n);
+                        /* send the sdu to the correct fd */
+                        flow_write(fd, buf, n);
                 }
         }
 
         return (void *) 0;
 }
 
-/* FIXME: if we move _ap_instance to dev.h, we can reuse it everywhere */
 static void * ipcp_udp_sdu_loop(void * o)
 {
 
         while (true) {
-                struct rb_entry * e;
                 int fd;
-                int len = 0;
-                char * buf;
+                struct shm_du_buff * sdb;
 
-                e = shm_ap_rbuff_read(_ap_instance->rb);
-                if (e == NULL) {
+                fd = ipcp_flow_read(&sdb);
+                if (fd < 0)
                         continue;
-                }
 
-                pthread_rwlock_rdlock(&_ipcp->state_lock);
+                pthread_rwlock_rdlock(&ipcpi.state_lock);
+                pthread_rwlock_rdlock(&udp_data.flows_lock);
 
-                len = shm_rdrbuff_read((uint8_t **) &buf,
-                                      _ap_instance->rdrb,
-                                      e->index);
-                if (len <= 0) {
-                        pthread_rwlock_unlock(&_ipcp->state_lock);
-                        free(e);
-                        continue;
-                }
-
-                pthread_rwlock_rdlock(&_ap_instance->flows_lock);
+                fd = udp_data.fd_to_uf[fd].skfd;
 
-                fd = port_id_to_fd(e->port_id);
-
-                pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-
-                if (fd == -1) {
-                        free(e);
-                        continue;
-                }
+                pthread_rwlock_unlock(&udp_data.flows_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
 
-                if (send(fd, buf, len, 0) < 0)
+                if (send(fd,
+                         shm_du_buff_head(sdb),
+                         shm_du_buff_tail(sdb) - shm_du_buff_head(sdb),
+                         0) < 0)
                         LOG_ERR("Failed to send SDU.");
 
-                pthread_rwlock_rdlock(&_ipcp->state_lock);
-
-                if (_ap_instance->rdrb != NULL)
-                        shm_rdrbuff_remove(_ap_instance->rdrb, e->index);
-
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-
-                free(e);
+                ipcp_flow_del(sdb);
         }
 
         return (void *) 1;
@@ -789,23 +536,16 @@ static void * ipcp_udp_sdu_loop(void * o)
 
 void ipcp_sig_handler(int sig, siginfo_t * info, void * c)
 {
-        sigset_t  sigset;
-        sigemptyset(&sigset);
-        sigaddset(&sigset, SIGINT);
-
         switch(sig) {
         case SIGINT:
         case SIGTERM:
         case SIGHUP:
                 if (info->si_pid == irmd_api) {
-                        LOG_DBG("IPCP %d terminating by order of %d. Bye.",
-                                getpid(), info->si_pid);
-
-                        pthread_rwlock_wrlock(&_ipcp->state_lock);
+                        pthread_rwlock_wrlock(&ipcpi.state_lock);
 
-                        ipcp_set_state(_ipcp, IPCP_SHUTDOWN);
+                        ipcp_set_state(IPCP_SHUTDOWN);
 
-                        pthread_rwlock_unlock(&_ipcp->state_lock);
+                        pthread_rwlock_unlock(&ipcpi.state_lock);
                 }
         default:
                 return;
@@ -865,54 +605,52 @@ static int ipcp_udp_bootstrap(struct dif_config * conf)
                 LOG_WARN("Failed to set SO_REUSEADDR.");
 
         memset((char *) &s_saddr, 0, sizeof(s_saddr));
-        shim_data(_ipcp)->s_saddr.sin_family      = AF_INET;
-        shim_data(_ipcp)->s_saddr.sin_addr.s_addr = conf->ip_addr;
-        shim_data(_ipcp)->s_saddr.sin_port        = LISTEN_PORT;
+        udp_data.s_saddr.sin_family      = AF_INET;
+        udp_data.s_saddr.sin_addr.s_addr = conf->ip_addr;
+        udp_data.s_saddr.sin_port        = LISTEN_PORT;
 
         if (bind(fd,
-                 (struct sockaddr *) &shim_data(_ipcp)->s_saddr,
-                 sizeof(shim_data(_ipcp)->s_saddr)) < 0) {
+                 (struct sockaddr *) &udp_data.s_saddr,
+                 sizeof(udp_data.s_saddr)) < 0) {
                 LOG_ERR("Couldn't bind to %s.", ipstr);
                 close(fd);
                 return -1;
         }
 
-        pthread_rwlock_wrlock(&_ipcp->state_lock);
+        pthread_rwlock_wrlock(&ipcpi.state_lock);
 
-        if (ipcp_get_state(_ipcp) != IPCP_INIT) {
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+        if (ipcp_get_state() != IPCP_INIT) {
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 LOG_ERR("IPCP in wrong state.");
                 close(fd);
                 return -1;
         }
 
-        shim_data(_ipcp)->s_fd     = fd;
-        shim_data(_ipcp)->ip_addr  = conf->ip_addr;
-        shim_data(_ipcp)->dns_addr = conf->dns_addr;
+        udp_data.s_fd     = fd;
+        udp_data.ip_addr  = conf->ip_addr;
+        udp_data.dns_addr = conf->dns_addr;
 
-        FD_CLR(shim_data(_ipcp)->s_fd, &shim_data(_ipcp)->flow_fd_s);
+        FD_CLR(udp_data.s_fd, &udp_data.flow_fd_s);
 
-        ipcp_set_state(_ipcp, IPCP_ENROLLED);
+        ipcp_set_state(IPCP_ENROLLED);
 
-        pthread_create(&_ap_instance->handler,
+        pthread_create(&udp_data.handler,
                        NULL,
                        ipcp_udp_listener,
                        NULL);
-        pthread_create(&_ap_instance->sdu_reader,
+        pthread_create(&udp_data.sdu_reader,
                        NULL,
                        ipcp_udp_sdu_reader,
                        NULL);
 
-        pthread_create(&_ap_instance->sduloop,
+        pthread_create(&udp_data.sduloop,
                        NULL,
                        ipcp_udp_sdu_loop,
                        NULL);
 
-        pthread_rwlock_unlock(&_ipcp->state_lock);
-
-        LOG_DBG("Bootstrapped shim IPCP over UDP with api %d.",
-                getpid());
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
+        LOG_DBG("Bootstrapped shim IPCP over UDP with api %d.", getpid());
         LOG_DBG("Bound to IP address %s.", ipstr);
         LOG_DBG("DNS server address is %s.", dnsstr);
 
@@ -1059,10 +797,10 @@ static int ipcp_udp_name_reg(char * name)
                 return -1;
         }
 
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-        if (ipcp_data_add_reg_entry(_ipcp->data, name)) {
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+        if (ipcp_data_add_reg_entry(ipcpi.data, name)) {
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 LOG_ERR("Failed to add %s to local registry.", name);
                 return -1;
         }
@@ -1070,12 +808,12 @@ static int ipcp_udp_name_reg(char * name)
 #ifdef CONFIG_OUROBOROS_ENABLE_DNS
         /* register application with DNS server */
 
-        dns_addr = shim_data(_ipcp)->dns_addr;
+        dns_addr = udp_data.dns_addr;
 
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
         if (dns_addr != 0) {
-                ip_addr = shim_data(_ipcp)->ip_addr;
+                ip_addr = udp_data.ip_addr;
 
                 if (inet_ntop(AF_INET, &ip_addr,
                               ipstr, INET_ADDRSTRLEN) == NULL) {
@@ -1091,14 +829,14 @@ static int ipcp_udp_name_reg(char * name)
                         dnsstr, name, DNS_TTL, ipstr);
 
                 if (ddns_send(cmd)) {
-                        pthread_rwlock_rdlock(&_ipcp->state_lock);
-                        ipcp_data_del_reg_entry(_ipcp->data, name);
-                        pthread_rwlock_unlock(&_ipcp->state_lock);
+                        pthread_rwlock_rdlock(&ipcpi.state_lock);
+                        ipcp_data_del_reg_entry(ipcpi.data, name);
+                        pthread_rwlock_unlock(&ipcpi.state_lock);
                         return -1;
                 }
         }
 #else
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 #endif
         LOG_DBG("Registered %s.", name);
 
@@ -1122,11 +860,11 @@ static int ipcp_udp_name_unreg(char * name)
 #ifdef CONFIG_OUROBOROS_ENABLE_DNS
         /* unregister application with DNS server */
 
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-        dns_addr = shim_data(_ipcp)->dns_addr;
+        dns_addr = udp_data.dns_addr;
 
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
         if (dns_addr != 0) {
                 if (inet_ntop(AF_INET, &dns_addr, dnsstr, INET_ADDRSTRLEN)
@@ -1140,17 +878,16 @@ static int ipcp_udp_name_unreg(char * name)
         }
 #endif
 
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-        ipcp_data_del_reg_entry(_ipcp->data, name);
+        ipcp_data_del_reg_entry(ipcpi.data, name);
 
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
         return 0;
 }
 
-static int ipcp_udp_flow_alloc(pid_t         n_api,
-                               int           port_id,
+static int ipcp_udp_flow_alloc(int           fd,
                                char *        dst_name,
                                char *        src_ae_name,
                                enum qos_cube qos)
@@ -1158,15 +895,13 @@ static int ipcp_udp_flow_alloc(pid_t         n_api,
         struct sockaddr_in r_saddr; /* server address */
         struct sockaddr_in f_saddr; /* flow */
         socklen_t          f_saddr_len = sizeof(f_saddr);
-        int                fd;
+        int                skfd;
         struct hostent *   h;
         uint32_t           ip_addr = 0;
 #ifdef CONFIG_OUROBOROS_ENABLE_DNS
         uint32_t           dns_addr = 0;
 #endif
-        struct shm_ap_rbuff * rb;
-
-        LOG_INFO("Allocating flow to %s.", dst_name);
+        LOG_DBG("Allocating flow to %s.", dst_name);
 
         if (dst_name == NULL || src_ae_name == NULL)
                 return -1;
@@ -1179,11 +914,7 @@ static int ipcp_udp_flow_alloc(pid_t         n_api,
         if (qos != QOS_CUBE_BE)
                 LOG_DBG("QoS requested. UDP/IP can't do that.");
 
-        rb = shm_ap_rbuff_open_s(n_api);
-        if (rb == NULL)
-                return -1; /* -ENORBUFF */
-
-        fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
+        skfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
 
         /* this socket is for the flow */
         memset((char *) &f_saddr, 0, sizeof(f_saddr));
@@ -1191,31 +922,31 @@ static int ipcp_udp_flow_alloc(pid_t         n_api,
         f_saddr.sin_addr.s_addr = local_ip;
         f_saddr.sin_port        = 0;
 
-        if (bind(fd, (struct sockaddr *) &f_saddr, sizeof(f_saddr)) < 0) {
-                close(fd);
+        if (bind(skfd, (struct sockaddr *) &f_saddr, sizeof(f_saddr)) < 0) {
+                close(skfd);
                 return -1;
         }
 
-        if (getsockname(fd, (struct sockaddr *) &f_saddr, &f_saddr_len) < 0) {
+        if (getsockname(skfd, (struct sockaddr *) &f_saddr, &f_saddr_len) < 0) {
                 LOG_ERR("Could not get address from fd.");
-                close(fd);
+                close(skfd);
                 return -1;
         }
 
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-        if (ipcp_get_state(_ipcp) != IPCP_ENROLLED) {
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+        if (ipcp_get_state() != IPCP_ENROLLED) {
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 LOG_DBG("Won't allocate flow with non-enrolled IPCP.");
-                close(fd);
+                close(skfd);
                 return -1; /* -ENOTENROLLED */
         }
 
 #ifdef CONFIG_OUROBOROS_ENABLE_DNS
-        dns_addr = shim_data(_ipcp)->dns_addr;
+        dns_addr = udp_data.dns_addr;
 
         if (dns_addr != 0) {
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
 
                 ip_addr = ddns_resolve(dst_name, dns_addr);
                 if (ip_addr == 0) {
@@ -1224,11 +955,11 @@ static int ipcp_udp_flow_alloc(pid_t         n_api,
                         return -1;
                 }
 
-                pthread_rwlock_rdlock(&_ipcp->state_lock);
-                if (ipcp_get_state(_ipcp) != IPCP_ENROLLED) {
-                        pthread_rwlock_unlock(&_ipcp->state_lock);
+                pthread_rwlock_rdlock(&ipcpi.state_lock);
+                if (ipcp_get_state() != IPCP_ENROLLED) {
+                        pthread_rwlock_unlock(&ipcpi.state_lock);
                         LOG_DBG("Won't allocate flow with non-enrolled IPCP.");
-                        close(fd);
+                        close(skfd);
                         return -1; /* -ENOTENROLLED */
                 }
         } else {
@@ -1236,7 +967,7 @@ static int ipcp_udp_flow_alloc(pid_t         n_api,
                 h = gethostbyname(dst_name);
                 if (h == NULL) {
                         LOG_DBG("Could not resolve %s.", dst_name);
-                        close(fd);
+                        close(skfd);
                         return -1;
                 }
 
@@ -1251,60 +982,46 @@ static int ipcp_udp_flow_alloc(pid_t         n_api,
         r_saddr.sin_addr.s_addr = ip_addr;
         r_saddr.sin_port        = LISTEN_PORT;
 
-        if (connect(fd, (struct sockaddr *) &r_saddr, sizeof(r_saddr)) < 0) {
-                close(fd);
+        if (connect(skfd, (struct sockaddr *) &r_saddr, sizeof(r_saddr)) < 0) {
+                close(skfd);
                 return -1;
         }
 
-        pthread_rwlock_wrlock(&_ap_instance->flows_lock);
-
-        _ap_instance->flows[fd].port_id = port_id;
-        _ap_instance->flows[fd].state   = FLOW_PENDING;
-        _ap_instance->flows[fd].rb      = rb;
-
-        pthread_rwlock_unlock(&_ap_instance->flows_lock);
-        pthread_rwlock_rdlock(&_ap_instance->flows_lock);
+        pthread_rwlock_wrlock(&udp_data.flows_lock);
 
-        set_fd(fd);
+        udp_data.fd_to_uf[fd].udp  = f_saddr.sin_port;
+        udp_data.fd_to_uf[fd].skfd = skfd;
+        udp_data.uf_to_fd[skfd]    = fd;
 
-        pthread_rwlock_unlock(&_ap_instance->flows_lock);
-
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&udp_data.flows_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
         if (ipcp_udp_port_alloc(ip_addr,
                                 f_saddr.sin_port,
                                 dst_name,
                                 src_ae_name) < 0) {
-                pthread_rwlock_rdlock(&_ipcp->state_lock);
-                pthread_rwlock_rdlock(&_ap_instance->flows_lock);
-
-                clr_fd(fd);
-
-                pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                pthread_rwlock_wrlock(&_ap_instance->flows_lock);
+                pthread_rwlock_rdlock(&ipcpi.state_lock);
+                pthread_rwlock_wrlock(&udp_data.flows_lock);
 
-                _ap_instance->flows[fd].port_id = -1;
-                _ap_instance->flows[fd].state   = FLOW_NULL;
-                shm_ap_rbuff_close(_ap_instance->flows[fd].rb);
-                 _ap_instance->flows[fd].rb     = NULL;
+                udp_data.fd_to_uf[fd].udp  = -1;
+                udp_data.fd_to_uf[fd].skfd = -1;
+                udp_data.uf_to_fd[skfd]    = -1;
 
-                pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                close(fd);
+                pthread_rwlock_unlock(&udp_data.flows_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
+                close(skfd);
                 return -1;
         }
 
-        LOG_DBG("Flow pending on port_id %d.", port_id);
+        LOG_DBG("Flow pending on fd %d, UDP port %d.",
+                fd, ntohs(f_saddr.sin_port));
 
         return fd;
 }
 
-static int ipcp_udp_flow_alloc_resp(pid_t n_api,
-                                    int   port_id,
-                                    int   response)
+static int ipcp_udp_flow_alloc_resp(int fd, int response)
 {
-        struct shm_ap_rbuff * rb;
-        int fd = -1;
+        int skfd = -1;
         struct sockaddr_in f_saddr;
         struct sockaddr_in r_saddr;
         socklen_t len = sizeof(r_saddr);
@@ -1312,148 +1029,95 @@ static int ipcp_udp_flow_alloc_resp(pid_t n_api,
         if (response)
                 return 0;
 
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
-
-        /* awaken pending flow */
-
-        pthread_rwlock_wrlock(&_ap_instance->flows_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
+        pthread_rwlock_wrlock(&udp_data.flows_lock);
 
-        fd = port_id_to_fd(port_id);
-        if (fd < 0) {
-                pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                LOG_DBG("Could not find flow with port_id %d.", port_id);
-                return -1;
-        }
+        skfd = udp_data.fd_to_uf[fd].skfd;
 
-        if (_ap_instance->flows[fd].state != FLOW_PENDING) {
-                pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                LOG_DBG("Flow was not pending.");
+        if (getsockname(skfd, (struct sockaddr *) &f_saddr, &len) < 0) {
+                LOG_DBG("Socket with fd %d has no address.", skfd);
                 return -1;
         }
 
-        rb = shm_ap_rbuff_open_s(n_api);
-        if (rb == NULL) {
-                LOG_ERR("Could not open N + 1 ringbuffer.");
-                _ap_instance->flows[fd].state   = FLOW_NULL;
-                _ap_instance->flows[fd].port_id = -1;
-                pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+        if (getpeername(skfd, (struct sockaddr *) &r_saddr, &len) < 0) {
+                LOG_DBG("Socket with fd %d has no peer.", skfd);
                 return -1;
         }
 
-        if (getsockname(fd, (struct sockaddr *) &f_saddr, &len) < 0) {
-                LOG_DBG("Flow with port_id %d has no socket.", port_id);
-                return -1;
-        }
+        pthread_rwlock_unlock(&udp_data.flows_lock);
+        pthread_rwlock_rdlock(&udp_data.flows_lock);
 
-        if (getpeername(fd, (struct sockaddr *) &r_saddr, &len) < 0) {
-                LOG_DBG("Flow with port_id %d has no peer.", port_id);
-                return -1;
-        }
+        set_fd(skfd);
 
-        _ap_instance->flows[fd].state = FLOW_ALLOCATED;
-        _ap_instance->flows[fd].rb    = rb;
-
-        pthread_rwlock_unlock(&_ap_instance->flows_lock);
-        pthread_rwlock_rdlock(&_ap_instance->flows_lock);
-
-        set_fd(fd);
-
-        pthread_rwlock_unlock(&_ap_instance->flows_lock);
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&udp_data.flows_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
         if (ipcp_udp_port_alloc_resp(r_saddr.sin_addr.s_addr,
                                      f_saddr.sin_port,
                                      r_saddr.sin_port,
                                      response) < 0) {
-                pthread_rwlock_rdlock(&_ipcp->state_lock);
-                pthread_rwlock_rdlock(&_ap_instance->flows_lock);
-
-                clr_fd(fd);
-
-                pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                pthread_rwlock_wrlock(&_ap_instance->flows_lock);
-
-                _ap_instance->flows[fd].state = FLOW_NULL;
-                shm_ap_rbuff_close(_ap_instance->flows[fd].rb);
-                _ap_instance->flows[fd].rb    = NULL;
-
-                pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+                pthread_rwlock_rdlock(&ipcpi.state_lock);
+                pthread_rwlock_rdlock(&udp_data.flows_lock);
+                clr_fd(skfd);
+                pthread_rwlock_unlock(&udp_data.flows_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
 
                 return -1;
         }
 
-        LOG_DBG("Accepted flow, port_id %d on UDP fd %d.", port_id, fd);
+        LOG_DBG("Accepted flow, fd %d on UDP port %d.",
+                fd, ntohs(f_saddr.sin_port));
 
         return 0;
 }
 
-static int ipcp_udp_flow_dealloc(int port_id)
+static int ipcp_udp_flow_dealloc(int fd)
 {
-        int fd = -1;
+        int skfd = -1;
         int remote_udp = -1;
-        struct shm_ap_rbuff * rb;
         struct sockaddr_in    r_saddr;
         socklen_t             r_saddr_len = sizeof(r_saddr);
 
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
-        pthread_rwlock_rdlock(&_ap_instance->flows_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
+        pthread_rwlock_wrlock(&udp_data.flows_lock);
 
-        fd = port_id_to_fd(port_id);
-        if (fd < 0) {
-                pthread_rwlock_unlock(&_ap_instance->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                LOG_DBG("Could not find flow with port_id %d.", port_id);
-                return 0;
-        }
+        skfd = udp_data.fd_to_uf[fd].skfd;
 
-        clr_fd(fd);
+        udp_data.uf_to_fd[skfd]    = -1;
+        udp_data.fd_to_uf[fd].udp  = -1;
+        udp_data.fd_to_uf[fd].skfd = -1;
 
-        pthread_rwlock_unlock(&_ap_instance->flows_lock);
-        pthread_rwlock_wrlock(&_ap_instance->flows_lock);
+        pthread_rwlock_unlock(&udp_data.flows_lock);
+        pthread_rwlock_rdlock(&udp_data.flows_lock);
 
-        _ap_instance->flows[fd].state   = FLOW_NULL;
-        _ap_instance->flows[fd].port_id = -1;
-        rb = _ap_instance->flows[fd].rb;
-        _ap_instance->flows[fd].rb      = NULL;
+        clr_fd(skfd);
 
-        pthread_rwlock_unlock(&_ap_instance->flows_lock);
+        pthread_rwlock_unlock(&udp_data.flows_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
-        if (rb != NULL)
-                shm_ap_rbuff_close(rb);
-
-        if (getpeername(fd, (struct sockaddr *) &r_saddr, &r_saddr_len) < 0) {
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                LOG_DBG("Flow with port_id %d has no peer.", port_id);
-                close(fd);
+        if (getpeername(skfd, (struct sockaddr *) &r_saddr, &r_saddr_len) < 0) {
+                LOG_DBG("Socket with fd %d has no peer.", skfd);
+                close(skfd);
                 return 0;
         }
 
         remote_udp       = r_saddr.sin_port;
         r_saddr.sin_port = LISTEN_PORT;
 
-        if (connect(fd, (struct sockaddr *) &r_saddr, sizeof(r_saddr)) < 0) {
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                close(fd);
+        if (connect(skfd, (struct sockaddr *) &r_saddr, sizeof(r_saddr)) < 0) {
+                close(skfd);
                 return 0 ;
         }
 
-        if (ipcp_udp_port_dealloc(r_saddr.sin_addr.s_addr,
-                                  remote_udp) < 0) {
+        if (ipcp_udp_port_dealloc(r_saddr.sin_addr.s_addr, remote_udp) < 0) {
                 LOG_DBG("Could not notify remote.");
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                close(fd);
+                close(skfd);
                 return 0;
         }
 
-        pthread_rwlock_unlock(&_ipcp->state_lock);
-
-        close(fd);
+        close(skfd);
 
-        LOG_DBG("Flow with port_id %d deallocated.", port_id);
+        LOG_DBG("Flow with fd %d deallocated.", fd);
 
         return 0;
 }
@@ -1468,31 +1132,6 @@ static struct ipcp_ops udp_ops = {
         .ipcp_flow_dealloc    = ipcp_udp_flow_dealloc
 };
 
-static struct ipcp * ipcp_udp_create()
-{
-        struct ipcp * i;
-        struct ipcp_udp_data * data;
-
-        i = ipcp_instance_create();
-        if (i == NULL)
-                return NULL;
-
-        data = ipcp_udp_data_create();
-        if (data == NULL) {
-                free(i);
-                return NULL;
-        }
-
-        i->data = (struct ipcp_data *) data;
-        i->ops  = &udp_ops;
-
-        i->state = IPCP_INIT;
-
-        return i;
-}
-
-#ifndef MAKE_CHECK
-
 int main(int argc, char * argv[])
 {
         struct sigaction sig_act;
@@ -1508,7 +1147,9 @@ int main(int argc, char * argv[])
                 exit(EXIT_FAILURE);
         }
 
-        if (shim_ap_init() < 0) {
+        udp_data_init();
+
+        if (ap_init(NULL) < 0) {
                 close_logfile();
                 exit(EXIT_FAILURE);
         }
@@ -1528,17 +1169,13 @@ int main(int argc, char * argv[])
         sigaction(SIGHUP,  &sig_act, NULL);
         sigaction(SIGPIPE, &sig_act, NULL);
 
-        _ipcp = ipcp_udp_create();
-        if (_ipcp == NULL) {
-                LOG_ERR("Failed to create IPCP.");
+        pthread_sigmask(SIG_BLOCK, &sigset, NULL);
+
+        if (ipcp_init(THIS_TYPE, &udp_ops) < 0) {
                 close_logfile();
                 exit(EXIT_FAILURE);
         }
 
-        pthread_sigmask(SIG_BLOCK, &sigset, NULL);
-
-        pthread_create(&_ap_instance->mainloop, NULL, ipcp_main_loop, _ipcp);
-
         pthread_sigmask(SIG_UNBLOCK, &sigset, NULL);
 
         if (ipcp_create_r(getpid())) {
@@ -1547,24 +1184,21 @@ int main(int argc, char * argv[])
                 exit(EXIT_FAILURE);
         }
 
-        pthread_join(_ap_instance->mainloop, NULL);
+        ipcp_fini();
 
-        pthread_cancel(_ap_instance->handler);
-        pthread_cancel(_ap_instance->sdu_reader);
-        pthread_cancel(_ap_instance->sduloop);
+        pthread_cancel(udp_data.handler);
+        pthread_cancel(udp_data.sdu_reader);
+        pthread_cancel(udp_data.sduloop);
 
-        pthread_join(_ap_instance->sduloop, NULL);
-        pthread_join(_ap_instance->handler, NULL);
-        pthread_join(_ap_instance->sdu_reader, NULL);
+        pthread_join(udp_data.sduloop, NULL);
+        pthread_join(udp_data.handler, NULL);
+        pthread_join(udp_data.sdu_reader, NULL);
 
-        shim_ap_fini();
+        ap_fini();
 
-        ipcp_data_destroy(_ipcp->data);
-        free(_ipcp);
+        udp_data_fini();
 
         close_logfile();
 
         exit(EXIT_SUCCESS);
 }
-
-#endif /* MAKE_CHECK */