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Diffstat (limited to 'src/ipcpd/normal/pol/graph.c')
-rw-r--r--src/ipcpd/normal/pol/graph.c517
1 files changed, 517 insertions, 0 deletions
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;
+}
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