From 5d87cec1757c4e1c23ae778f2814363c1e39b43c Mon Sep 17 00:00:00 2001 From: Sander Vrijders Date: Mon, 15 May 2017 18:08:53 +0200 Subject: 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. --- src/ipcpd/normal/pol/graph.c | 517 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 517 insertions(+) create mode 100644 src/ipcpd/normal/pol/graph.c (limited to 'src/ipcpd/normal/pol/graph.c') 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 + * Sander Vrijders + * + * 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 +#include +#include +#include + +#include "graph.h" +#include "ipcp.h" + +#include +#include +#include +#include + +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; +} -- cgit v1.2.3