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Diffstat (limited to 'src/ipcpd/unicast/pol/graph.c')
-rw-r--r--src/ipcpd/unicast/pol/graph.c695
1 files changed, 695 insertions, 0 deletions
diff --git a/src/ipcpd/unicast/pol/graph.c b/src/ipcpd/unicast/pol/graph.c
new file mode 100644
index 00000000..499dc2de
--- /dev/null
+++ b/src/ipcpd/unicast/pol/graph.c
@@ -0,0 +1,695 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Undirected graph structure
+ *
+ * Dimitri Staessens <dimitri.staessens@ugent.be>
+ * Sander Vrijders <sander.vrijders@ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#if defined(__linux__) || defined(__CYGWIN__)
+#define _DEFAULT_SOURCE
+#else
+#define _POSIX_C_SOURCE 200112L
+#endif
+
+#define OUROBOROS_PREFIX "graph"
+
+#include <ouroboros/logs.h>
+#include <ouroboros/errno.h>
+#include <ouroboros/list.h>
+
+#include "graph.h"
+#include "ipcp.h"
+
+#include <assert.h>
+#include <pthread.h>
+#include <stdlib.h>
+#include <limits.h>
+#include <string.h>
+
+struct edge {
+ struct list_head next;
+ struct vertex * nb;
+ qosspec_t qs;
+ int announced;
+};
+
+struct vertex {
+ struct list_head next;
+ uint64_t addr;
+ struct list_head edges;
+ int index;
+};
+
+struct graph {
+ size_t nr_vertices;
+ struct list_head vertices;
+ pthread_mutex_t lock;
+};
+
+static struct edge * find_edge_by_addr(struct vertex * vertex,
+ uint64_t dst_addr)
+{
+ struct list_head * p = NULL;
+
+ list_for_each(p, &vertex->edges) {
+ struct edge * e = list_entry(p, struct edge, next);
+ if (e->nb->addr == dst_addr)
+ return e;
+ }
+
+ return NULL;
+}
+
+static struct vertex * find_vertex_by_addr(struct graph * graph,
+ uint64_t addr)
+{
+ struct list_head * p = NULL;
+
+ list_for_each(p, &graph->vertices) {
+ struct vertex * e = list_entry(p, struct vertex, next);
+ if (e->addr == addr)
+ return e;
+ }
+
+ return NULL;
+}
+
+static struct edge * add_edge(struct vertex * vertex,
+ struct vertex * nb)
+{
+ struct edge * edge;
+
+ edge = malloc(sizeof(*edge));
+ if (edge == NULL)
+ return NULL;
+
+ list_head_init(&edge->next);
+ edge->nb = nb;
+ edge->announced = 0;
+
+ list_add(&edge->next, &vertex->edges);
+
+ return edge;
+}
+
+static void del_edge(struct edge * edge)
+{
+ list_del(&edge->next);
+ free(edge);
+}
+
+static struct vertex * add_vertex(struct graph * graph,
+ uint64_t addr)
+{
+ struct vertex * vertex;
+ struct list_head * p;
+ int i = 0;
+
+ vertex = malloc(sizeof(*vertex));
+ if (vertex == NULL)
+ return NULL;
+
+ list_head_init(&vertex->next);
+ list_head_init(&vertex->edges);
+ vertex->addr = addr;
+
+ /* Keep them ordered on address. */
+ list_for_each(p, &graph->vertices) {
+ struct vertex * v = list_entry(p, struct vertex, next);
+ if (v->addr > addr)
+ break;
+ i++;
+ }
+
+ vertex->index = i;
+
+ list_add_tail(&vertex->next, p);
+
+ /* Increase the index of the vertices to the right. */
+ list_for_each(p, &graph->vertices) {
+ struct vertex * v = list_entry(p, struct vertex, next);
+ if (v->addr > addr)
+ v->index++;
+ }
+
+ graph->nr_vertices++;
+
+ return vertex;
+}
+
+static void del_vertex(struct graph * graph,
+ struct vertex * vertex)
+{
+ struct list_head * p = NULL;
+ struct list_head * n = NULL;
+
+ list_del(&vertex->next);
+
+ /* Decrease the index of the vertices to the right. */
+ list_for_each(p, &graph->vertices) {
+ struct vertex * v = list_entry(p, struct vertex, next);
+ if (v->addr > vertex->addr)
+ v->index--;
+ }
+
+ list_for_each_safe(p, n, &vertex->edges) {
+ struct edge * e = list_entry(p, struct edge, next);
+ del_edge(e);
+ }
+
+ free(vertex);
+
+ graph->nr_vertices--;
+}
+
+struct graph * graph_create(void)
+{
+ struct graph * graph;
+
+ graph = malloc(sizeof(*graph));
+ if (graph == NULL)
+ return NULL;
+
+ if (pthread_mutex_init(&graph->lock, NULL)) {
+ free(graph);
+ return NULL;
+ }
+
+ graph->nr_vertices = 0;
+ list_head_init(&graph->vertices);
+
+ return graph;
+}
+
+void graph_destroy(struct graph * graph)
+{
+ struct list_head * p = NULL;
+ struct list_head * n = NULL;
+
+ assert(graph);
+
+ pthread_mutex_lock(&graph->lock);
+
+ list_for_each_safe(p, n, &graph->vertices) {
+ struct vertex * e = list_entry(p, struct vertex, next);
+ del_vertex(graph, e);
+ }
+
+ pthread_mutex_unlock(&graph->lock);
+
+ pthread_mutex_destroy(&graph->lock);
+
+ free(graph);
+}
+
+int graph_update_edge(struct graph * graph,
+ uint64_t s_addr,
+ uint64_t d_addr,
+ qosspec_t qs)
+{
+ struct vertex * v;
+ struct edge * e;
+ struct vertex * nb;
+ struct edge * nb_e;
+
+ assert(graph);
+
+ pthread_mutex_lock(&graph->lock);
+
+ v = find_vertex_by_addr(graph, s_addr);
+ if (v == NULL) {
+ v = add_vertex(graph, s_addr);
+ if (v == NULL) {
+ pthread_mutex_unlock(&graph->lock);
+ log_err("Failed to add vertex.");
+ return -ENOMEM;
+ }
+ }
+
+ nb = find_vertex_by_addr(graph, d_addr);
+ if (nb == NULL) {
+ nb = add_vertex(graph, d_addr);
+ if (nb == NULL) {
+ if (list_is_empty(&v->edges))
+ del_vertex(graph, v);
+ pthread_mutex_unlock(&graph->lock);
+ log_err("Failed to add vertex.");
+ return -ENOMEM;
+ }
+ }
+
+ e = find_edge_by_addr(v, d_addr);
+ if (e == NULL) {
+ e = add_edge(v, nb);
+ if (e == NULL) {
+ if (list_is_empty(&v->edges))
+ del_vertex(graph, v);
+ if (list_is_empty(&nb->edges))
+ del_vertex(graph, nb);
+ pthread_mutex_unlock(&graph->lock);
+ log_err("Failed to add edge.");
+ return -ENOMEM;
+ }
+ }
+
+ e->announced++;
+ e->qs = qs;
+
+ nb_e = find_edge_by_addr(nb, s_addr);
+ if (nb_e == NULL) {
+ nb_e = add_edge(nb, v);
+ if (nb_e == NULL) {
+ if (--e->announced == 0)
+ del_edge(e);
+ if (list_is_empty(&v->edges))
+ del_vertex(graph, v);
+ if (list_is_empty(&nb->edges))
+ del_vertex(graph, nb);
+ pthread_mutex_unlock(&graph->lock);
+ log_err("Failed to add edge.");
+ return -ENOMEM;
+ }
+ }
+
+ nb_e->announced++;
+ nb_e->qs = qs;
+
+ pthread_mutex_unlock(&graph->lock);
+
+ return 0;
+}
+
+int graph_del_edge(struct graph * graph,
+ uint64_t s_addr,
+ uint64_t d_addr)
+{
+ struct vertex * v;
+ struct edge * e;
+ struct vertex * nb;
+ struct edge * nb_e;
+
+ assert(graph);
+
+ pthread_mutex_lock(&graph->lock);
+
+ v = find_vertex_by_addr(graph, s_addr);
+ if (v == NULL) {
+ pthread_mutex_unlock(&graph->lock);
+ log_err("No such source vertex.");
+ return -1;
+ }
+
+ nb = find_vertex_by_addr(graph, d_addr);
+ if (nb == NULL) {
+ pthread_mutex_unlock(&graph->lock);
+ log_err("No such destination vertex.");
+ return -1;
+ }
+
+ e = find_edge_by_addr(v, d_addr);
+ if (e == NULL) {
+ pthread_mutex_unlock(&graph->lock);
+ log_err("No such source edge.");
+ return -1;
+ }
+
+ nb_e = find_edge_by_addr(nb, s_addr);
+ if (nb_e == NULL) {
+ pthread_mutex_unlock(&graph->lock);
+ log_err("No such destination edge.");
+ return -1;
+ }
+
+ if (--e->announced == 0)
+ del_edge(e);
+ if (--nb_e->announced == 0)
+ del_edge(nb_e);
+
+ /* Removing vertex if it was the last edge */
+ if (list_is_empty(&v->edges))
+ del_vertex(graph, v);
+ if (list_is_empty(&nb->edges))
+ del_vertex(graph, nb);
+
+ pthread_mutex_unlock(&graph->lock);
+
+ return 0;
+}
+
+static int get_min_vertex(struct graph * graph,
+ int * dist,
+ bool * used,
+ struct vertex ** v)
+{
+ int min = INT_MAX;
+ int index = -1;
+ int i = 0;
+ struct list_head * p = NULL;
+
+ *v = NULL;
+
+ list_for_each(p, &graph->vertices) {
+ if (!used[i] && dist[i] < min) {
+ min = dist[i];
+ index = i;
+ *v = list_entry(p, struct vertex, next);
+ }
+
+ i++;
+ }
+
+ if (index != -1)
+ used[index] = true;
+
+ return index;
+}
+
+static int dijkstra(struct graph * graph,
+ uint64_t src,
+ struct vertex *** nhops,
+ int ** dist)
+{
+ bool * used;
+ struct list_head * p = NULL;
+ int i = 0;
+ struct vertex * v = NULL;
+ struct edge * e = NULL;
+ int alt;
+
+ *nhops = malloc(sizeof(**nhops) * graph->nr_vertices);
+ if (*nhops == NULL)
+ goto fail_pnhops;
+
+ *dist = malloc(sizeof(**dist) * graph->nr_vertices);
+ if (*dist == NULL)
+ goto fail_pdist;
+
+ used = malloc(sizeof(*used) * graph->nr_vertices);
+ if (used == NULL)
+ goto fail_used;
+
+ /* Init the data structures */
+ memset(used, 0, sizeof(*used) * graph->nr_vertices);
+ memset(*nhops, 0, sizeof(**nhops) * graph->nr_vertices);
+ memset(*dist, 0, sizeof(**dist) * graph->nr_vertices);
+
+ list_for_each(p, &graph->vertices) {
+ v = list_entry(p, struct vertex, next);
+ (*dist)[i++] = (v->addr == src) ? 0 : INT_MAX;
+ }
+
+ /* Perform actual Dijkstra */
+ i = get_min_vertex(graph, *dist, used, &v);
+ while (v != NULL) {
+ list_for_each(p, &v->edges) {
+ e = list_entry(p, struct edge, next);
+
+ /* Only include it if both sides announced it. */
+ if (e->announced != 2)
+ continue;
+
+ /*
+ * NOTE: Current weight is just hop count.
+ * Method could be extended to use a different
+ * weight for a different QoS cube.
+ */
+ alt = (*dist)[i] + 1;
+ if (alt < (*dist)[e->nb->index]) {
+ (*dist)[e->nb->index] = alt;
+ if (v->addr == src)
+ (*nhops)[e->nb->index] = e->nb;
+ else
+ (*nhops)[e->nb->index] = (*nhops)[i];
+ }
+ }
+ i = get_min_vertex(graph, *dist, used, &v);
+ }
+
+ free(used);
+
+ return 0;
+
+ fail_used:
+ free(*dist);
+ fail_pdist:
+ free(*nhops);
+ fail_pnhops:
+ return -1;
+
+}
+
+static void free_routing_table(struct list_head * table)
+{
+ struct list_head * h;
+ struct list_head * p;
+ struct list_head * q;
+ struct list_head * i;
+
+ list_for_each_safe(p, h, table) {
+ struct routing_table * t =
+ list_entry(p, struct routing_table, next);
+ list_for_each_safe(q, i, &t->nhops) {
+ struct nhop * n =
+ list_entry(q, struct nhop, next);
+ list_del(&n->next);
+ free(n);
+ }
+ list_del(&t->next);
+ free(t);
+ }
+}
+
+void graph_free_routing_table(struct graph * graph,
+ struct list_head * table)
+{
+ assert(table);
+
+ pthread_mutex_lock(&graph->lock);
+
+ free_routing_table(table);
+
+ pthread_mutex_unlock(&graph->lock);
+}
+
+static int graph_routing_table_simple(struct graph * graph,
+ uint64_t s_addr,
+ struct list_head * table,
+ int ** dist)
+{
+ struct vertex ** nhops;
+ struct list_head * p;
+ int i = 0;
+ struct vertex * v;
+ struct routing_table * t;
+ struct nhop * n;
+
+ /* We need at least 2 vertices for a table */
+ if (graph->nr_vertices < 2)
+ goto fail_vertices;
+
+ if (dijkstra(graph, s_addr, &nhops, dist))
+ goto fail_vertices;
+
+ list_head_init(table);
+
+ /* Now construct the routing table from the nhops. */
+ list_for_each(p, &graph->vertices) {
+ v = list_entry(p, struct vertex, next);
+
+ /* This is the src */
+ if (nhops[i] == NULL) {
+ i++;
+ continue;
+ }
+
+ t = malloc(sizeof(*t));
+ if (t == NULL)
+ goto fail_t;
+
+ list_head_init(&t->nhops);
+
+ n = malloc(sizeof(*n));
+ if (n == NULL)
+ goto fail_n;
+
+ t->dst = v->addr;
+ n->nhop = nhops[i]->addr;
+
+ list_add(&n->next, &t->nhops);
+ list_add(&t->next, table);
+
+ i++;
+ }
+
+ free(nhops);
+
+ return 0;
+
+ fail_n:
+ free(t);
+ fail_t:
+ free_routing_table(table);
+ free(nhops);
+ free(*dist);
+ fail_vertices:
+ *dist = NULL;
+ return -1;
+}
+
+static int add_lfa_to_table(struct list_head * table,
+ uint64_t addr,
+ uint64_t lfa)
+{
+ struct list_head * p = NULL;
+ struct nhop * n;
+
+ n = malloc(sizeof(*n));
+ if (n == NULL)
+ return -1;
+
+ n->nhop = lfa;
+
+ list_for_each(p, table) {
+ struct routing_table * t =
+ list_entry(p, struct routing_table, next);
+ if (t->dst == addr) {
+ list_add_tail(&n->next, &t->nhops);
+ return 0;
+ }
+ }
+
+ free(n);
+
+ return -1;
+}
+
+int graph_routing_table(struct graph * graph,
+ enum routing_algo algo,
+ uint64_t s_addr,
+ struct list_head * table)
+{
+ int * s_dist;
+ int * n_dist[PROG_MAX_FLOWS];
+ uint64_t addrs[PROG_MAX_FLOWS];
+ int n_index[PROG_MAX_FLOWS];
+ struct list_head * p;
+ struct list_head * q;
+ struct vertex * v;
+ struct edge * e;
+ struct vertex ** nhops;
+ int i = 0;
+ int j = 0;
+ int k;
+
+ assert(graph);
+ assert(table);
+
+ pthread_mutex_lock(&graph->lock);
+
+ /* Get the simple next hops routing table. */
+ if (graph_routing_table_simple(graph, s_addr, table, &s_dist))
+ goto fail_table_simple;
+
+ /* Possibly augment the routing table. */
+ switch (algo) {
+ case ROUTING_SIMPLE:
+ break;
+ case ROUTING_LFA:
+ for (j = 0; j < PROG_MAX_FLOWS; j++) {
+ n_dist[j] = NULL;
+ n_index[j] = -1;
+ addrs[j] = -1;
+ }
+
+ list_for_each(p, &graph->vertices) {
+ v = list_entry(p, struct vertex, next);
+
+ if (v->addr != s_addr)
+ continue;
+
+ /*
+ * Get the distances for every neighbor
+ * of the source.
+ */
+ list_for_each(q, &v->edges) {
+ e = list_entry(q, struct edge, next);
+
+ addrs[i] = e->nb->addr;
+ n_index[i] = e->nb->index;
+ if (dijkstra(graph, e->nb->addr,
+ &nhops, &(n_dist[i++])))
+ goto fail_dijkstra;
+
+ free(nhops);
+ }
+
+ break;
+ }
+
+ /* Loop though all nodes to see if we have a LFA for them. */
+ list_for_each(p, &graph->vertices) {
+ v = list_entry(p, struct vertex, next);
+
+ if (v->addr == s_addr)
+ continue;
+
+ /*
+ * Check for every neighbor if
+ * dist(neighbor, destination) <
+ * dist(neighbor, source) + dist(source, destination).
+ */
+ for (j = 0; j < i; j++) {
+ /* Exclude ourselves. */
+ if (addrs[j] == v->addr)
+ continue;
+
+ if (n_dist[j][v->index] <
+ s_dist[n_index[j]] + s_dist[v->index])
+ if (add_lfa_to_table(table, v->addr,
+ addrs[j]))
+ goto fail_add_lfa;
+ }
+ }
+
+ for (j = 0; j < i; j++)
+ free(n_dist[j]);
+
+ break;
+ default:
+ log_err("Unsupported algorithm.");
+ goto fail_algo;
+ }
+
+ pthread_mutex_unlock(&graph->lock);
+
+ free(s_dist);
+
+ return 0;
+
+ fail_add_lfa:
+ for (k = j; k < i; k++)
+ free(n_dist[k]);
+ fail_dijkstra:
+ free_routing_table(table);
+ fail_algo:
+ free(s_dist);
+ fail_table_simple:
+ pthread_mutex_unlock(&graph->lock);
+
+ return -1;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-10 23:52:12 +0000