ipcpd: normal: Add graph structure

This adds a graph structure which will be updated by routing when it
is notified about a new RIB event. The routing can then use this graph
as input for calculating the shortest path to a destination.

5 files changed, 365 insertions, 38 deletions

diff --git a/src/ipcpd/normal/CMakeLists.txt b/src/ipcpd/normal/CMakeLists.txt
index af99b3f9..39ced7bc 100644
--- a/src/ipcpd/normal/CMakeLists.txt
+++ b/src/ipcpd/normal/CMakeLists.txt
@@ -25,6 +25,7 @@ set(SOURCE_FILES
   fmgr.c
   frct.c
   gam.c
+  graph.c
   main.c
   neighbors.c
   pff.c
diff --git a/src/ipcpd/normal/graph.c b/src/ipcpd/normal/graph.c
new file mode 100644
index 00000000..85bb3fe2
--- /dev/null
+++ b/src/ipcpd/normal/graph.c
@@ -0,0 +1,277 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2017
+ *
+ * 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 <assert.h>
+#include <pthread.h>
+#include <stdlib.h>
+
+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->dst_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 int add_edge(struct vertex * vertex,
+                    uint64_t        dst_addr,
+                    qosspec_t       qs)
+{
+        struct edge * edge;
+
+        edge = malloc(sizeof(*edge));
+        if (edge == NULL)
+                return -ENOMEM;
+
+        list_head_init(&edge->next);
+        edge->dst_addr = dst_addr;
+        edge->qs = qs;
+
+        list_add(&edge->next, &vertex->edges);
+
+        return 0;
+}
+
+static void del_edge(struct edge * edge)
+{
+       list_del(&edge->next);
+       free(edge);
+}
+
+static int add_vertex(struct graph * graph,
+                      uint64_t       addr)
+{
+        struct vertex *    vertex;
+        struct list_head * p;
+
+        vertex = malloc(sizeof(*vertex));
+        if (vertex == NULL)
+                return -1;
+
+        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 0;
+}
+
+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);
+}
+
+int graph_add_edge(struct graph * graph,
+                   uint64_t       s_addr,
+                   uint64_t       d_addr,
+                   qosspec_t      qs)
+{
+        struct vertex * v;
+        struct edge * e;
+
+        assert(graph);
+
+        pthread_mutex_lock(&graph->lock);
+
+        v = find_vertex_by_addr(graph, s_addr);
+        if (v == NULL) {
+                if (add_vertex(graph, s_addr)) {
+                        pthread_mutex_unlock(&graph->lock);
+                        return -ENOMEM;
+                }
+        }
+
+        e = find_edge_by_addr(v, d_addr);
+        if (e != NULL) {
+                pthread_mutex_unlock(&graph->lock);
+                log_err("Edge already exists.");
+                return -1;
+        }
+
+        if (add_edge(v, d_addr, qs)) {
+                pthread_mutex_unlock(&graph->lock);
+                log_err("Failed to add edge.");
+                return -1;
+        }
+
+        pthread_mutex_unlock(&graph->lock);
+
+        return 0;
+}
+
+int graph_update_edge(struct graph * graph,
+                      uint64_t       s_addr,
+                      uint64_t       d_addr,
+                      qosspec_t      qs)
+{
+        struct vertex * v;
+        struct edge * 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;
+        }
+
+        e = find_edge_by_addr(v, d_addr);
+        if (e == NULL) {
+                pthread_mutex_unlock(&graph->lock);
+                log_err("No such edge.");
+                return -1;
+        }
+
+        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;
+
+        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;
+        }
+
+        e = find_edge_by_addr(v, d_addr);
+        if (e == NULL) {
+                pthread_mutex_unlock(&graph->lock);
+                log_err("No such edge.");
+                return -1;
+        }
+
+        del_edge(e);
+
+        /* Removing vertex if it was the last edge */
+        if (list_is_empty(&v->edges))
+               del_vertex(graph, v);
+
+        pthread_mutex_unlock(&graph->lock);
+
+        return 0;
+}
diff --git a/src/ipcpd/normal/graph.h b/src/ipcpd/normal/graph.h
new file mode 100644
index 00000000..9653efd7
--- /dev/null
+++ b/src/ipcpd/normal/graph.h
@@ -0,0 +1,67 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2017
+ *
+ * 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 edge {
+        struct list_head next;
+        uint64_t         dst_addr;
+        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;
+};
+
+struct graph * graph_create(void);
+
+void           graph_destroy(struct graph * graph);
+
+int            graph_add_edge(struct graph * graph,
+                              uint64_t       s_addr,
+                              uint64_t       d_addr,
+                              qosspec_t      qs);
+
+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);
+
+#endif /* OUROBOROS_IPCPD_NORMAL_GRAPH_H */
diff --git a/src/ipcpd/normal/routing.c b/src/ipcpd/normal/routing.c
index e699fd77..46c2be08 100644
--- a/src/ipcpd/normal/routing.c
+++ b/src/ipcpd/normal/routing.c
@@ -32,6 +32,7 @@
 #include "ribmgr.h"
 #include "ribconfig.h"
 #include "ipcp.h"
+#include "graph.h"
 
 #include <assert.h>
 #include <stdlib.h>
@@ -40,53 +41,25 @@
 
 #define ADDR_SIZE 30
 
-struct edge {
+struct routing_table_entry {
         struct list_head next;
-
-        uint64_t         addr;
-
-        qosspec_t        qs;
-};
-
-struct vertex {
-        struct list_head next;
-
-        uint64_t         addr;
-
-        struct list_head edges;
+        uint64_t         dst;
+        uint64_t         nhop;
 };
 
 struct routing_i {
         struct pff *     pff;
-        struct list_head vertices;
+        struct list_head routing_table;
 };
 
 struct {
         struct nbs *       nbs;
         struct nb_notifier nb_notifier;
-        char               fso_path[RIB_MAX_PATH_LEN + 1];
-} routing;
-
-#if 0
-/* FIXME: If zeroed since it is not used currently */
-static int add_vertex(struct routing * instance,
-                      uint64_t         addr)
-{
-        struct vertex *  vertex;
 
-        vertex = malloc(sizeof(*vertex));
-        if (vertex == NULL)
-                return -1;
-
-        list_head_init(&vertex->next);
-        list_head_init(&vertex->edges);
-        vertex->addr = addr;
-
-        list_add(&vertex->next, &instance->vertices);
+        char               fso_path[RIB_MAX_PATH_LEN + 1];
 
-        return 0;
-}
-#endif
+        struct graph *     graph;
+} routing;
 
 struct routing_i * routing_i_create(struct pff * pff)
 {
@@ -100,7 +73,7 @@ struct routing_i * routing_i_create(struct pff * pff)
 
         tmp->pff = pff;
 
-        list_head_init(&tmp->vertices);
+        list_head_init(&tmp->routing_table);
 
         return tmp;
 }
@@ -164,14 +137,21 @@ int routing_init(struct nbs * nbs)
 {
         char addr[ADDR_SIZE];
 
-        if (rib_add(RIB_ROOT, ROUTING_NAME))
+        routing.graph = graph_create();
+        if (routing.graph == NULL)
                 return -1;
 
+        if (rib_add(RIB_ROOT, ROUTING_NAME)) {
+                graph_destroy(routing.graph);
+                return -1;
+        }
+
         rib_path_append(routing.fso_path, ROUTING_NAME);
 
         snprintf(addr, ADDR_SIZE, "%" PRIx64, ipcpi.dt_addr);
 
         if (rib_add(routing.fso_path, addr)) {
+                graph_destroy(routing.graph);
                 rib_del(ROUTING_PATH);
                 return -1;
         }
@@ -182,6 +162,7 @@ int routing_init(struct nbs * nbs)
 
         routing.nb_notifier.notify_call = routing_neighbor_event;
         if (nbs_reg_notifier(routing.nbs, &routing.nb_notifier)) {
+                graph_destroy(routing.graph);
                 rib_del(ROUTING_PATH);
                 return -1;
         }
@@ -191,6 +172,8 @@ int routing_init(struct nbs * nbs)
 
 void routing_fini(void)
 {
+        graph_destroy(routing.graph);
+
         rib_del(ROUTING_PATH);
 
         nbs_unreg_notifier(routing.nbs, &routing.nb_notifier);
diff --git a/src/ipcpd/normal/routing.h b/src/ipcpd/normal/routing.h
index 20dc72f9..0794ef28 100644
--- a/src/ipcpd/normal/routing.h
+++ b/src/ipcpd/normal/routing.h
@@ -34,7 +34,6 @@
  * Routing will take a type in the future,
  * to allow different policies.
  */
-
 int                routing_init(struct nbs * nbs);
 
 void               routing_fini(void);