ipcpd: normal: Make routing a policy

This makes the routing component into a policy since different
approaches may exist to do this, depending on how high the rank of the
DIF is.

7 files changed, 1276 insertions, 0 deletions

diff --git a/src/ipcpd/normal/pol/fso.proto b/src/ipcpd/normal/pol/fso.proto
new file mode 100644
index 00000000..32b281d6
--- /dev/null
+++ b/src/ipcpd/normal/pol/fso.proto
@@ -0,0 +1,29 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2017
+ *
+ * Flow State Object message
+ *
+ *    Dimitri Staessens <dimitri.staessens@intec.ugent.be>
+ *    Sander Vrijders   <sander.vrijders@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 version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+syntax = "proto2";
+
+message fso {
+        required uint64 s_addr = 1;
+        required uint64 d_addr = 2;
+        /* Add QoS parameters of link here */
+};
diff --git a/src/ipcpd/normal/pol/graph.c b/src/ipcpd/normal/pol/graph.c
new file mode 100644
index 00000000..78ed203d
--- /dev/null
+++ b/src/ipcpd/normal/pol/graph.c
@@ -0,0 +1,517 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2017
+ *
+ * Undirected graph structure
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#define OUROBOROS_PREFIX "graph"
+
+#include <ouroboros/config.h>
+#include <ouroboros/logs.h>
+#include <ouroboros/errno.h>
+#include <ouroboros/list.h>
+
+#include "graph.h"
+#include "ipcp.h"
+
+#include <assert.h>
+#include <pthread.h>
+#include <stdlib.h>
+#include <limits.h>
+
+struct edge {
+        struct list_head next;
+        struct vertex *  nb;
+        qosspec_t        qs;
+};
+
+struct vertex {
+        struct list_head next;
+        uint64_t         addr;
+        struct list_head edges;
+};
+
+struct graph {
+        size_t           nr_vertices;
+        struct list_head vertices;
+        pthread_mutex_t  lock;
+};
+
+static struct edge * find_edge_by_addr(struct vertex * vertex,
+                                       uint64_t        dst_addr)
+{
+        struct list_head * p = NULL;
+
+        list_for_each(p, &vertex->edges) {
+                struct edge * e = list_entry(p, struct edge, next);
+                if (e->nb->addr == dst_addr)
+                        return e;
+        }
+
+        return NULL;
+}
+
+static struct vertex * find_vertex_by_addr(struct graph * graph,
+                                           uint64_t       addr)
+{
+        struct list_head * p = NULL;
+
+        list_for_each(p, &graph->vertices) {
+                struct vertex * e = list_entry(p, struct vertex, next);
+                if (e->addr == addr)
+                        return e;
+        }
+
+        return NULL;
+}
+
+static struct edge * add_edge(struct vertex * vertex,
+                              struct vertex * nb)
+{
+        struct edge * edge;
+
+        edge = malloc(sizeof(*edge));
+        if (edge == NULL)
+                return NULL;
+
+        list_head_init(&edge->next);
+        edge->nb = nb;
+
+        list_add(&edge->next, &vertex->edges);
+
+        return edge;
+}
+
+static void del_edge(struct edge * edge)
+{
+       list_del(&edge->next);
+       free(edge);
+}
+
+static struct vertex * add_vertex(struct graph * graph,
+                                  uint64_t       addr)
+{
+        struct vertex *    vertex;
+        struct list_head * p;
+
+        vertex = malloc(sizeof(*vertex));
+        if (vertex == NULL)
+                return NULL;
+
+        list_head_init(&vertex->next);
+        list_head_init(&vertex->edges);
+        vertex->addr = addr;
+
+        list_for_each(p, &graph->vertices) {
+                struct vertex * v = list_entry(p, struct vertex, next);
+                if (v->addr > addr)
+                        break;
+        }
+
+        list_add_tail(&vertex->next, p);
+
+        graph->nr_vertices++;
+
+        return vertex;
+}
+
+static void del_vertex(struct graph * graph,
+                       struct vertex * vertex)
+{
+        struct list_head * p = NULL;
+        struct list_head * n = NULL;
+
+        list_del(&vertex->next);
+
+        list_for_each_safe(p, n, &vertex->edges) {
+                struct edge * e = list_entry(p, struct edge, next);
+                del_edge(e);
+        }
+
+        free(vertex);
+
+        graph->nr_vertices--;
+}
+
+struct graph * graph_create(void)
+{
+        struct graph * graph;
+
+        graph = malloc(sizeof(*graph));
+        if (graph == NULL)
+                return NULL;
+
+        if (pthread_mutex_init(&graph->lock, NULL)) {
+                free(graph);
+                return NULL;
+        }
+
+        graph->nr_vertices = 0;
+        list_head_init(&graph->vertices);
+
+        return graph;
+}
+
+void graph_destroy(struct graph * graph)
+{
+        struct list_head * p = NULL;
+        struct list_head * n = NULL;
+
+        assert(graph);
+
+        pthread_mutex_lock(&graph->lock);
+
+        list_for_each_safe(p, n, &graph->vertices) {
+                struct vertex * e = list_entry(p, struct vertex, next);
+                del_vertex(graph, e);
+        }
+
+        pthread_mutex_unlock(&graph->lock);
+
+        pthread_mutex_destroy(&graph->lock);
+
+        free(graph);
+}
+
+int graph_update_edge(struct graph * graph,
+                      uint64_t       s_addr,
+                      uint64_t       d_addr,
+                      qosspec_t      qs)
+{
+        struct vertex * v;
+        struct edge *   e;
+        struct vertex * nb;
+        struct edge *   nb_e;
+
+        assert(graph);
+
+        pthread_mutex_lock(&graph->lock);
+
+        v = find_vertex_by_addr(graph, s_addr);
+        if (v == NULL) {
+                v = add_vertex(graph, s_addr);
+                if (v == NULL) {
+                        pthread_mutex_unlock(&graph->lock);
+                        log_err("Failed to add vertex.");
+                        return -ENOMEM;
+                }
+        }
+
+        nb = find_vertex_by_addr(graph, d_addr);
+        if (nb == NULL) {
+                nb = add_vertex(graph, d_addr);
+                if (nb == NULL) {
+                        if (list_is_empty(&v->edges))
+                                del_vertex(graph, v);
+                        pthread_mutex_unlock(&graph->lock);
+                        log_err("Failed to add vertex.");
+                        return -ENOMEM;
+                }
+        }
+
+        e = find_edge_by_addr(v, d_addr);
+        if (e == NULL) {
+                e = add_edge(v, nb);
+                if (e == NULL) {
+                        if (list_is_empty(&v->edges))
+                            del_vertex(graph, v);
+                        if (list_is_empty(&nb->edges))
+                                del_vertex(graph, nb);
+                        pthread_mutex_unlock(&graph->lock);
+                        log_err("Failed to add edge.");
+                        return -ENOMEM;
+                }
+        }
+
+        e->qs = qs;
+
+        nb_e = find_edge_by_addr(nb, s_addr);
+        if (nb_e == NULL) {
+                nb_e = add_edge(nb, v);
+                if (nb_e == NULL) {
+                        del_edge(e);
+                        if (list_is_empty(&v->edges))
+                                del_vertex(graph, v);
+                        if (list_is_empty(&nb->edges))
+                                del_vertex(graph, nb);
+                        pthread_mutex_unlock(&graph->lock);
+                        log_err("Failed to add edge.");
+                        return -ENOMEM;
+                }
+        }
+
+        nb_e->qs = qs;
+
+        pthread_mutex_unlock(&graph->lock);
+
+        return 0;
+}
+
+int graph_del_edge(struct graph * graph,
+                   uint64_t       s_addr,
+                   uint64_t       d_addr)
+{
+        struct vertex * v;
+        struct edge *   e;
+        struct vertex * nb;
+        struct edge *   nb_e;
+
+        assert(graph);
+
+        pthread_mutex_lock(&graph->lock);
+
+        v = find_vertex_by_addr(graph, s_addr);
+        if (v == NULL) {
+                pthread_mutex_unlock(&graph->lock);
+                log_err("No such vertex.");
+                return -1;
+        }
+
+        nb = find_vertex_by_addr(graph, d_addr);
+        if (nb == NULL) {
+                pthread_mutex_unlock(&graph->lock);
+                log_err("No such vertex.");
+                return -1;
+        }
+
+        e = find_edge_by_addr(v, d_addr);
+        if (e == NULL) {
+                pthread_mutex_unlock(&graph->lock);
+                log_err("No such edge.");
+                return -1;
+        }
+
+        nb_e = find_edge_by_addr(nb, s_addr);
+        if (nb_e == NULL) {
+                pthread_mutex_unlock(&graph->lock);
+                log_err("No such edge.");
+                return -1;
+        }
+
+        del_edge(e);
+        del_edge(nb_e);
+
+        /* Removing vertex if it was the last edge */
+        if (list_is_empty(&v->edges))
+                del_vertex(graph, v);
+        if (list_is_empty(&nb->edges))
+                del_vertex(graph, nb);
+
+        pthread_mutex_unlock(&graph->lock);
+
+        return 0;
+}
+
+static int get_min_vertex(struct vertex ** vertices,
+                          int              nr_vertices,
+                          int *            dist,
+                          struct vertex ** v)
+{
+        int min = INT_MAX;
+        int index = -1;
+        int i;
+
+        *v = NULL;
+
+        for (i = 0; i < nr_vertices; i++) {
+                if (vertices[i] == NULL)
+                        continue;
+
+                if (dist[i] < min) {
+                        *v = vertices[i];
+                        min = dist[i];
+                        index = i;
+                }
+        }
+
+        if (index != -1)
+                vertices[index] = NULL;
+
+        return index;
+}
+
+static int get_vertex_number(struct vertex ** vertices,
+                             int              nr_vertices,
+                             struct vertex *  v)
+
+{
+        int i;
+
+        for (i = 0; i < nr_vertices; i++) {
+                if (vertices[i] == v)
+                        return i;
+        }
+
+        return -1;
+}
+
+static int get_vertex_index(struct graph *  graph,
+                            struct vertex * v)
+
+{
+        struct list_head * p = NULL;
+        struct vertex *    vertex;
+        int                i = 0;
+
+        list_for_each(p, &graph->vertices) {
+                vertex = list_entry(p, struct vertex, next);
+                if (vertex == v)
+                        return i;
+                i++;
+        }
+
+        return -1;
+}
+
+static struct vertex ** dijkstra(struct graph * graph,
+                                 uint64_t       src)
+{
+        int                dist[graph->nr_vertices];
+        struct vertex *    vertices[graph->nr_vertices];
+        struct list_head * p = NULL;
+        int                i = 0;
+        int                j = 0;
+        struct vertex *    v = NULL;
+        struct edge *      e = NULL;
+        int                alt;
+        struct vertex **   prev;
+
+        prev = malloc(sizeof(*prev) * graph->nr_vertices);
+        if (prev == NULL)
+                return NULL;
+
+        /* Init the data structures */
+        list_for_each(p, &graph->vertices) {
+                v = list_entry(p, struct vertex, next);
+                vertices[i] = v;
+                if (v->addr == src)
+                        dist[i] = 0;
+                else
+                        dist[i] = INT_MAX;
+                prev[i] = NULL;
+                i++;
+        }
+
+        /* Perform actual Dijkstra */
+        i = get_min_vertex(vertices, graph->nr_vertices, dist, &v);
+        while (v != NULL) {
+                list_for_each(p, &v->edges) {
+                        e = list_entry(p, struct edge, next);
+
+                        j = get_vertex_number(vertices,
+                                              graph->nr_vertices,
+                                              e->nb);
+                        if (j == -1)
+                                continue;
+
+                        /*
+                         * NOTE: Current weight is just hop count.
+                         * Method could be extended to use a different
+                         * weight for a different QoS cube.
+                         */
+                        alt = dist[i] + 1;
+                        if (alt < dist[j]) {
+                                dist[j] = alt;
+                                prev[j] = v;
+                        }
+                }
+                i = get_min_vertex(vertices, graph->nr_vertices, dist, &v);
+        }
+
+        return prev;
+}
+
+ssize_t graph_routing_table(struct graph *           graph,
+                            uint64_t                 s_addr,
+                            struct routing_table *** table)
+{
+        struct vertex **   prevs;
+        struct list_head * p = NULL;
+        int                i = 0;
+        int                index = 0;
+        int                j = 0;
+        int                k = 0;
+        struct vertex *    prev;
+        struct vertex *    nhop;
+        struct vertex *    v;
+
+        pthread_mutex_lock(&graph->lock);
+
+        if (graph->nr_vertices == 0) {
+                pthread_mutex_unlock(&graph->lock);
+                return 0;
+        }
+
+        prevs = dijkstra(graph, s_addr);
+        if (prevs == NULL) {
+                pthread_mutex_unlock(&graph->lock);
+                return -1;
+        }
+
+        *table = malloc(sizeof(**table) * (graph->nr_vertices - 1));
+        if (*table == NULL) {
+                pthread_mutex_unlock(&graph->lock);
+                free(prevs);
+                return -1;
+        }
+
+        /*
+         * Now loop through the list of predecessors
+         * to construct the routing table
+         */
+        list_for_each(p, &graph->vertices) {
+                v = list_entry(p, struct vertex, next);
+                prev = prevs[i];
+                nhop = v;
+
+                /* This is the src */
+                if (prev == NULL) {
+                        i++;
+                        continue;
+                }
+
+                index = get_vertex_index(graph, prev);
+                while (prevs[index] != NULL) {
+                        nhop = prev;
+                        prev = prevs[index];
+                        index = get_vertex_index(graph, prev);
+                }
+
+                (*table)[j] = malloc(sizeof(***table));
+                if ((*table)[j] == NULL) {
+                        pthread_mutex_unlock(&graph->lock);
+                        for (k = 0; k < j; ++k)
+                                free((*table)[k]);
+                        free(*table);
+                        free(prevs);
+                        return -1;
+                }
+
+                (*table)[j]->dst = v->addr;
+                (*table)[j]->nhop = nhop->addr;
+                j++;
+                i++;
+        }
+
+        pthread_mutex_unlock(&graph->lock);
+
+        free(prevs);
+
+        return j;
+}
diff --git a/src/ipcpd/normal/pol/graph.h b/src/ipcpd/normal/pol/graph.h
new file mode 100644
index 00000000..44496bc3
--- /dev/null
+++ b/src/ipcpd/normal/pol/graph.h
@@ -0,0 +1,53 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2017
+ *
+ * Undirected graph structure
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef OUROBOROS_IPCPD_NORMAL_GRAPH_H
+#define OUROBOROS_IPCPD_NORMAL_GRAPH_H
+
+#include <ouroboros/list.h>
+#include <ouroboros/qos.h>
+
+#include <inttypes.h>
+
+struct routing_table {
+        uint64_t dst;
+        uint64_t nhop;
+};
+
+struct graph * graph_create(void);
+
+void           graph_destroy(struct graph * graph);
+
+int            graph_update_edge(struct graph * graph,
+                                 uint64_t       s_addr,
+                                 uint64_t       d_addr,
+                                 qosspec_t      qs);
+
+int            graph_del_edge(struct graph * graph,
+                              uint64_t       s_addr,
+                              uint64_t       d_addr);
+
+ssize_t        graph_routing_table(struct graph *           graph,
+                                   uint64_t                 s_addr,
+                                   struct routing_table *** table);
+
+#endif /* OUROBOROS_IPCPD_NORMAL_GRAPH_H */
diff --git a/src/ipcpd/normal/pol/link_state.c b/src/ipcpd/normal/pol/link_state.c
new file mode 100644
index 00000000..3e0a63d6
--- /dev/null
+++ b/src/ipcpd/normal/pol/link_state.c
@@ -0,0 +1,360 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2017
+ *
+ * Link state routing policy
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#define OUROBOROS_PREFIX "link-state-routing"
+
+#include <ouroboros/config.h>
+#include <ouroboros/errno.h>
+#include <ouroboros/list.h>
+#include <ouroboros/logs.h>
+#include <ouroboros/rib.h>
+#include <ouroboros/rqueue.h>
+
+#include "ribmgr.h"
+#include "ribconfig.h"
+#include "graph.h"
+#include "neighbors.h"
+#include "ipcp.h"
+#include "pff.h"
+
+#include <assert.h>
+#include <stdlib.h>
+#include <inttypes.h>
+#include <string.h>
+#include <pthread.h>
+
+#include "fso.pb-c.h"
+typedef Fso fso_t;
+
+#define BUF_SIZE 256
+#define RECALC_TIME 4
+
+struct routing_i {
+        struct pff * pff;
+        pthread_t    calculator;
+};
+
+struct {
+        struct nbs *       nbs;
+        struct nb_notifier nb_notifier;
+
+        struct graph *     graph;
+
+        ro_set_t *         set;
+        rqueue_t *         queue;
+        pthread_t          rib_listener;
+} link_state;
+
+/* Take under neighbors lock */
+static int addr_to_fd(uint64_t addr)
+{
+        struct list_head * p = NULL;
+
+        list_for_each(p, &link_state.nbs->list) {
+                struct nb * e = list_entry(p, struct nb, next);
+                if (e->conn.conn_info.addr == addr)
+                        return e->conn.flow_info.fd;
+        }
+
+        return -1;
+}
+
+static void * calculate_pff(void * o)
+{
+        struct routing_i *      instance;
+        struct routing_table ** table;
+        ssize_t                 n_table;
+        int                     i;
+        int                     fd;
+
+        instance = (struct routing_i *) o;
+
+        while (true) {
+                table = NULL;
+                n_table = graph_routing_table(link_state.graph,
+                                              ipcpi.dt_addr, &table);
+                if (n_table < 0) {
+                        sleep(RECALC_TIME);
+                        continue;
+                }
+
+                pthread_mutex_lock(&link_state.nbs->list_lock);
+                pff_lock(instance->pff);
+
+                pff_flush(instance->pff);
+
+                for (i = 0; i < n_table; i++) {
+                        fd = addr_to_fd(table[i]->nhop);
+                        if (fd == -1)
+                                continue;
+
+                        pff_add(instance->pff, table[i]->dst, fd);
+                }
+
+                pff_unlock(instance->pff);
+                pthread_mutex_unlock(&link_state.nbs->list_lock);
+
+                freepp(struct routing_table, table, n_table);
+                sleep(RECALC_TIME);
+        }
+
+        return (void *) 0;
+}
+
+static int link_state_neighbor_event(enum nb_event event,
+                                     struct conn   conn)
+{
+        char      path[RIB_MAX_PATH_LEN + 1];
+        char      fso_name[RIB_MAX_PATH_LEN + 1];
+        fso_t     fso = FSO__INIT;
+        size_t    len;
+        uint8_t * data;
+
+        /* Only announce the flow if our address is bigger */
+        if (ipcpi.dt_addr < conn.conn_info.addr)
+                return 0;
+
+        path[0] = '\0';
+        sprintf(fso_name, "%" PRIu64 "-%" PRIu64,
+                ipcpi.dt_addr, conn.conn_info.addr);
+        rib_path_append(rib_path_append(path, ROUTING_NAME), fso_name);
+
+        switch (event) {
+        case NEIGHBOR_ADDED:
+                fso.s_addr = ipcpi.dt_addr;
+                fso.d_addr = conn.conn_info.addr;
+
+                len = fso__get_packed_size(&fso);
+                if (len == 0)
+                        return -1;
+
+                data = malloc(len);
+                if (data == NULL)
+                        return -1;
+
+                fso__pack(&fso, data);
+
+                if (rib_add(ROUTING_PATH, fso_name)) {
+                        log_err("Failed to add FSO.");
+                        free(data);
+                        return -1;
+                }
+
+                if (rib_put(path, data, len)) {
+                        log_err("Failed to put FSO in RIB.");
+                        rib_del(path);
+                        free(data);
+                        return -1;
+                }
+
+                log_dbg("Added %s to RIB.", path);
+
+                break;
+        case NEIGHBOR_REMOVED:
+                if (rib_del(path)) {
+                        log_err("Failed to remove FSO.");
+                        return -1;
+                }
+
+                log_dbg("Removed %s from RIB.", path);
+
+                break;
+        case NEIGHBOR_QOS_CHANGE:
+                log_info("Not currently supported.");
+                break;
+        default:
+                log_info("Unsupported event for routing.");
+                break;
+        }
+
+        return 0;
+}
+
+static int read_fso(char *  path,
+                    int32_t flag)
+{
+        ssize_t   len;
+        uint8_t   ro[BUF_SIZE];
+        fso_t *   fso;
+        qosspec_t qs;
+
+        memset(&qs, 0, sizeof(qs));
+
+        len = rib_read(path, ro, BUF_SIZE);
+        if (len < 0) {
+                log_err("Failed to read FSO.");
+                return -1;
+        }
+
+        fso = fso__unpack(NULL, len, ro);
+        if (fso == NULL) {
+                log_err("Failed to unpack.");
+                return -1;
+        }
+
+        if (flag & RO_MODIFY) {
+                if (graph_update_edge(link_state.graph,
+                                      fso->s_addr, fso->d_addr, qs)) {
+                        fso__free_unpacked(fso, NULL);
+                        return -1;
+                }
+        } else if (flag & RO_DELETE) {
+                if (graph_del_edge(link_state.graph, fso->s_addr, fso->d_addr)) {
+                        fso__free_unpacked(fso, NULL);
+                        return -1;
+                }
+        }
+
+        fso__free_unpacked(fso, NULL);
+
+        return 0;
+}
+
+static void * rib_listener(void * o)
+{
+        int32_t flag;
+        char    path[RIB_MAX_PATH_LEN + 1];
+        char ** children;
+        ssize_t len;
+        int     i;
+
+        (void) o;
+
+        if (ro_set_add(link_state.set, ROUTING_PATH, RO_MODIFY | RO_DELETE)) {
+                log_err("Failed to add to RO set");
+                return (void * ) -1;
+        }
+
+        len = rib_children(ROUTING_PATH, &children);
+        if (len < 0) {
+                log_err("Failed to retrieve children.");
+                return (void *) -1;
+        }
+
+        for (i = 0; i < len; i++) {
+                if (read_fso(children[i], RO_CREATE)) {
+                        log_err("Failed to parse FSO.");
+                        continue;
+                }
+        }
+
+        while (rib_event_wait(link_state.set, link_state.queue, NULL) == 0) {
+                path[0] = '\0';
+                flag = rqueue_next(link_state.queue, path);
+                if (flag < 0)
+                        continue;
+
+                if (read_fso(path, flag)) {
+                        log_err("Failed to parse FSO.");
+                        continue;
+                }
+        }
+
+        return (void *) 0;
+}
+
+struct routing_i * link_state_routing_i_create(struct pff * pff)
+{
+        struct routing_i * tmp;
+
+        assert(pff);
+
+        tmp = malloc(sizeof(*tmp));
+        if (tmp == NULL)
+                return NULL;
+
+        tmp->pff = pff;
+
+        pthread_create(&tmp->calculator, NULL, calculate_pff, (void *) tmp);
+
+        return tmp;
+}
+
+void link_state_routing_i_destroy(struct routing_i * instance)
+{
+        assert(instance);
+
+        pthread_cancel(instance->calculator);
+
+        pthread_join(instance->calculator, NULL);
+
+        free(instance);
+}
+
+int link_state_init(struct nbs * nbs)
+{
+        link_state.graph = graph_create();
+        if (link_state.graph == NULL)
+                return -1;
+
+        if (rib_add(RIB_ROOT, ROUTING_NAME)) {
+                graph_destroy(link_state.graph);
+                return -1;
+        }
+
+        link_state.nbs = nbs;
+
+        link_state.nb_notifier.notify_call = link_state_neighbor_event;
+        if (nbs_reg_notifier(link_state.nbs, &link_state.nb_notifier)) {
+                graph_destroy(link_state.graph);
+                rib_del(ROUTING_PATH);
+                return -1;
+        }
+
+        link_state.set = ro_set_create();
+        if (link_state.set == NULL) {
+                nbs_unreg_notifier(link_state.nbs, &link_state.nb_notifier);
+                graph_destroy(link_state.graph);
+                rib_del(ROUTING_PATH);
+                return -1;
+        }
+
+        link_state.queue = rqueue_create();
+        if (link_state.queue == NULL) {
+                ro_set_destroy(link_state.set);
+                nbs_unreg_notifier(link_state.nbs, &link_state.nb_notifier);
+                graph_destroy(link_state.graph);
+                rib_del(ROUTING_PATH);
+                return -1;
+        }
+
+        pthread_create(&link_state.rib_listener, NULL, rib_listener, NULL);
+
+        return 0;
+}
+
+void link_state_fini(void)
+{
+        pthread_cancel(link_state.rib_listener);
+
+        pthread_join(link_state.rib_listener, NULL);
+
+        rqueue_destroy(link_state.queue);
+
+        ro_set_destroy(link_state.set);
+
+        graph_destroy(link_state.graph);
+
+        rib_del(ROUTING_PATH);
+
+        nbs_unreg_notifier(link_state.nbs, &link_state.nb_notifier);
+}
diff --git a/src/ipcpd/normal/pol/link_state.h b/src/ipcpd/normal/pol/link_state.h
new file mode 100644
index 00000000..e78d0543
--- /dev/null
+++ b/src/ipcpd/normal/pol/link_state.h
@@ -0,0 +1,43 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2017
+ *
+ * Link state routing policy
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef OUROBOROS_IPCPD_NORMAL_POL_LINK_STATE_H
+#define OUROBOROS_IPCPD_NORMAL_POL_LINK_STATE_H
+
+#include "pol-routing-ops.h"
+
+int                link_state_init(struct nbs * nbs);
+
+void               link_state_fini(void);
+
+struct routing_i * link_state_routing_i_create(struct pff * pff);
+
+void               link_state_routing_i_destroy(struct routing_i * instance);
+
+struct pol_routing_ops link_state_ops = {
+        .init              = link_state_init,
+        .fini              = link_state_fini,
+        .routing_i_create  = link_state_routing_i_create,
+        .routing_i_destroy = link_state_routing_i_destroy
+};
+
+#endif /* OUROBOROS_IPCPD_NORMAL_POL_LINK_STATE_H */
diff --git a/src/ipcpd/normal/pol/tests/CMakeLists.txt b/src/ipcpd/normal/pol/tests/CMakeLists.txt
new file mode 100644
index 00000000..55ca425a
--- /dev/null
+++ b/src/ipcpd/normal/pol/tests/CMakeLists.txt
@@ -0,0 +1,34 @@
+get_filename_component(CURRENT_SOURCE_PARENT_DIR
+  ${CMAKE_CURRENT_SOURCE_DIR} DIRECTORY)
+get_filename_component(CURRENT_BINARY_PARENT_DIR
+  ${CMAKE_CURRENT_BINARY_DIR} DIRECTORY)
+
+include_directories(${CMAKE_CURRENT_SOURCE_DIR})
+include_directories(${CMAKE_CURRENT_BINARY_DIR})
+
+include_directories(${CURRENT_SOURCE_PARENT_DIR})
+include_directories(${CURRENT_BINARY_PARENT_DIR})
+
+include_directories(${CMAKE_SOURCE_DIR}/include)
+include_directories(${CMAKE_BINARY_DIR}/include)
+
+get_filename_component(PARENT_PATH ${CMAKE_CURRENT_SOURCE_DIR} DIRECTORY)
+get_filename_component(PARENT_DIR ${PARENT_PATH} NAME)
+
+create_test_sourcelist(${PARENT_DIR}_tests test_suite.c
+  # Add new tests here
+  graph_test.c
+  )
+
+add_executable(${PARENT_DIR}_test EXCLUDE_FROM_ALL ${${PARENT_DIR}_tests})
+target_link_libraries(${PARENT_DIR}_test ouroboros)
+
+add_dependencies(check ${PARENT_DIR}_test)
+
+set(tests_to_run ${${PARENT_DIR}_tests})
+remove(tests_to_run test_suite.c)
+
+foreach (test ${tests_to_run})
+  get_filename_component(test_name ${test} NAME_WE)
+  add_test(${test_name} ${C_TEST_PATH}/${PARENT_DIR}_test ${test_name})
+endforeach (test)
diff --git a/src/ipcpd/normal/pol/tests/graph_test.c b/src/ipcpd/normal/pol/tests/graph_test.c
new file mode 100644
index 00000000..3d433e34
--- /dev/null
+++ b/src/ipcpd/normal/pol/tests/graph_test.c
@@ -0,0 +1,240 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2017
+ *
+ * Test of the graph structure
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <ouroboros/config.h>
+#include <ouroboros/utils.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "graph.c"
+
+struct graph *          graph;
+struct routing_table ** table;
+ssize_t                 n_table;
+qosspec_t               qs;
+
+int graph_test_entries(int entries)
+{
+        n_table = graph_routing_table(graph, 1, &table);
+
+        if (n_table != entries) {
+                printf("Wrong number of entries.\n");
+                freepp(struct routing_table, table, n_table);
+                return -1;
+        }
+
+        freepp(struct routing_table, table, n_table);
+
+        return 0;
+}
+
+int graph_test_double_link(void)
+{
+        n_table = graph_routing_table(graph, 1, &table);
+        if (n_table < 0 || table == NULL) {
+                printf("Failed to get routing table.\n");
+                return -1;
+        }
+
+        if (n_table != 2) {
+                printf("Wrong number of entries.\n");
+                freepp(struct routing_table, table, n_table);
+                return -1;
+        }
+
+        if ((table[0]->dst != 2 && table[0]->nhop != 2) ||
+            (table[0]->dst != 3 && table[0]->nhop != 2)) {
+                printf("Wrong routing entry.\n");
+                freepp(struct routing_table, table, n_table);
+                return -1;
+        }
+
+        if ((table[1]->dst != 2 && table[1]->nhop != 2) ||
+            (table[0]->dst != 3 && table[0]->nhop != 2)) {
+                printf("Wrong routing entry.\n");
+                freepp(struct routing_table, table, n_table);
+                return -1;
+        }
+
+        freepp(struct routing_table, table, n_table);
+
+        return 0;
+}
+
+int graph_test_single_link(void)
+{
+        n_table = graph_routing_table(graph, 1, &table);
+        if (n_table < 0 || table == NULL) {
+                printf("Failed to get routing table.\n");
+                return -1;
+        }
+
+        if (n_table != 1) {
+                printf("Wrong number of entries.\n");
+                freepp(struct routing_table, table, n_table);
+                return -1;
+        }
+
+        if (table[0]->dst != 2 && table[0]->nhop != 2) {
+                printf("Wrong routing entry.\n");
+                freepp(struct routing_table, table, n_table);
+                return -1;
+        }
+
+        freepp(struct routing_table, table, n_table);
+
+        return 0;
+}
+
+int graph_test(int     argc,
+               char ** argv)
+{
+        int i;
+        int nhop;
+        int dst;
+
+        (void) argc;
+        (void) argv;
+
+        memset(&qs, 0, sizeof(qs));
+
+        graph = graph_create();
+        if (graph == NULL) {
+                printf("Failed to create graph.\n");
+                return -1;
+        }
+
+        graph_destroy(graph);
+
+        graph = graph_create();
+        if (graph == NULL) {
+                printf("Failed to create graph.\n");
+                return -1;
+        }
+
+        if (graph_update_edge(graph, 1, 2, qs)) {
+                printf("Failed to add edge.\n");
+                graph_destroy(graph);
+                return -1;
+        }
+
+        if (graph_test_single_link()) {
+                graph_destroy(graph);
+                return -1;
+        }
+
+        if (graph_update_edge(graph, 2, 3, qs)) {
+                printf("Failed to add edge.\n");
+                graph_destroy(graph);
+                return -1;
+        }
+
+        if (graph_test_double_link()) {
+                graph_destroy(graph);
+                return -1;
+        }
+
+        if (graph_del_edge(graph, 2, 3)) {
+                printf("Failed to delete edge.\n");
+                graph_destroy(graph);
+                return -1;
+        }
+
+        if (graph_test_single_link()) {
+                graph_destroy(graph);
+                return -1;
+        }
+
+        graph_update_edge(graph, 2, 3, qs);
+        graph_update_edge(graph, 1, 3, qs);
+
+        if (graph_test_entries(2)) {
+                graph_destroy(graph);
+                return -1;
+        }
+
+        graph_update_edge(graph, 3, 4, qs);
+        graph_update_edge(graph, 4, 5, qs);
+
+        if (graph_test_entries(4)) {
+                graph_destroy(graph);
+                return -1;
+        }
+
+        graph_update_edge(graph, 2, 6, qs);
+        graph_update_edge(graph, 6, 7, qs);
+        graph_update_edge(graph, 3, 7, qs);
+
+        if (graph_test_entries(6)) {
+                graph_destroy(graph);
+                return -1;
+        }
+
+        n_table = graph_routing_table(graph, 1, &table);
+
+        for (i = 0; i < 6; i++) {
+                nhop = table[i]->nhop;
+                dst = table[i]->dst;
+
+                if (dst == 3 && nhop != 3) {
+                        printf("Wrong entry.");
+                        freepp(struct routing_table, table, n_table);
+                        return -1;
+                }
+
+                if (dst == 2 && nhop != 2) {
+                        printf("Wrong entry.");
+                        freepp(struct routing_table, table, n_table);
+                        return -1;
+                }
+
+                if (dst == 6 && nhop != 2) {
+                        printf("Wrong entry.");
+                        freepp(struct routing_table, table, n_table);
+                        return -1;
+                }
+
+                if (dst == 4 && nhop != 3) {
+                        printf("Wrong entry.");
+                        freepp(struct routing_table, table, n_table);
+                        return -1;
+                }
+
+                if (dst == 5 && nhop != 3) {
+                        printf("Wrong entry.");
+                        freepp(struct routing_table, table, n_table);
+                        return -1;
+                }
+
+                if (dst == 7 && nhop != 3) {
+                        printf("Wrong entry.");
+                        freepp(struct routing_table, table, n_table);
+                        return -1;
+                }
+        }
+
+        freepp(struct routing_table, table, n_table);
+
+        return 0;
+}