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.

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 <[email protected]>
+ *    Sander Vrijders   <[email protected]>
+ *
+ * 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;
+}