From 11d2ecc140486949c8d81e984137263ca48d5799 Mon Sep 17 00:00:00 2001 From: Dimitri Staessens Date: Sat, 4 Dec 2021 15:35:36 +0100 Subject: ipcpd: Restructure policy code The policies were all in a single folder pol/, and have been moved to a folder per component/mechanism to keep things a bit more orderly. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders --- src/ipcpd/unicast/routing/graph.c | 849 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 849 insertions(+) create mode 100644 src/ipcpd/unicast/routing/graph.c (limited to 'src/ipcpd/unicast/routing/graph.c') diff --git a/src/ipcpd/unicast/routing/graph.c b/src/ipcpd/unicast/routing/graph.c new file mode 100644 index 00000000..6ea5c507 --- /dev/null +++ b/src/ipcpd/unicast/routing/graph.c @@ -0,0 +1,849 @@ +/* + * Ouroboros - Copyright (C) 2016 - 2021 + * + * Undirected graph structure + * + * Dimitri Staessens + * Sander Vrijders + * Nick Aerts + * + * 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 +#include +#include + +#include "graph.h" +#include "ipcp.h" + +#include +#include +#include +#include +#include + +struct vertex { + struct list_head next; + uint64_t addr; + struct list_head edges; + int index; +}; + +struct edge { + struct list_head next; + struct vertex * nb; + qosspec_t qs; + int announced; +}; + +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; + + assert(vertex); + + 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; + + assert(graph); + + 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; + + assert(vertex); + assert(nb); + + edge = malloc(sizeof(*edge)); + if (edge == NULL) + return NULL; + + edge->nb = nb; + edge->announced = 0; + + list_add(&edge->next, &vertex->edges); + + return edge; +} + +static void del_edge(struct edge * edge) +{ + assert(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; + + assert(graph); + + vertex = malloc(sizeof(*vertex)); + if (vertex == NULL) + return NULL; + + 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; + struct list_head * h; + + assert(graph); + assert(vertex); + + 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, h, &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; + + assert(v); + assert(graph); + assert(dist); + assert(used); + + *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; + + assert(graph); + assert(nhops); + assert(dist); + + *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; + + assert(table); + + 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; + + assert(graph); + assert(table); + assert(dist); + + /* 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; + struct nhop * n; + + assert(table); + + 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; +} + +static int graph_routing_table_lfa(struct graph * graph, + uint64_t s_addr, + struct list_head * table, + int ** 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; + int k; + + if (graph_routing_table_simple(graph, s_addr, table, dist)) + goto fail_table; + + 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] < + (*dist)[n_index[j]] + (*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]); + + return 0; + + fail_add_lfa: + for (k = j; k < i; k++) + free(n_dist[k]); + fail_dijkstra: + free_routing_table(table); + fail_table: + return -1; +} + +static int graph_routing_table_ecmp(struct graph * graph, + uint64_t s_addr, + struct list_head * table, + int ** dist) +{ + struct vertex ** nhops; + struct list_head * p; + struct list_head * h; + size_t i; + struct vertex * v; + struct vertex * src_v; + struct edge * e; + struct routing_table * t; + struct nhop * n; + struct list_head * forwarding; + + assert(graph); + assert(dist); + + if (graph-> nr_vertices < 2) + goto fail_vertices; + + forwarding = malloc(sizeof(*forwarding) * graph->nr_vertices); + if (forwarding == NULL) + goto fail_vertices; + + for (i = 0; i < graph->nr_vertices; ++i) + list_head_init(&forwarding[i]); + + if (dijkstra(graph, s_addr, &nhops, dist)) + goto fail_dijkstra; + + free(nhops); + + src_v = find_vertex_by_addr(graph, s_addr); + if (src_v == NULL) + goto fail_src_v; + + list_for_each(p, &src_v->edges) { + int * tmp_dist; + + e = list_entry(p, struct edge, next); + if (dijkstra(graph, e->nb->addr, &nhops, &tmp_dist)) + goto fail_src_v; + + free(nhops); + + list_for_each(h, &graph->vertices) { + v = list_entry(h, struct vertex, next); + if (tmp_dist[v->index] + 1 == (*dist)[v->index]) { + n = malloc(sizeof(*n)); + if (n == NULL) { + free(tmp_dist); + goto fail_src_v; + } + n->nhop = e->nb->addr; + list_add_tail(&n->next, &forwarding[v->index]); + } + } + + free(tmp_dist); + } + + list_head_init(table); + i = 0; + list_for_each(p, &graph->vertices) { + v = list_entry(p, struct vertex, next); + if (v->addr == s_addr) { + ++i; + continue; + } + + t = malloc(sizeof(*t)); + if (t == NULL) + goto fail_t; + + t->dst = v->addr; + + list_head_init(&t->nhops); + if (&forwarding[i] != forwarding[i].nxt) { + t->nhops.nxt = forwarding[i].nxt; + t->nhops.prv = forwarding[i].prv; + forwarding[i].prv->nxt = &t->nhops; + forwarding[i].nxt->prv = &t->nhops; + } + + list_add(&t->next, table); + ++i; + } + + free(*dist); + *dist = NULL; + free(forwarding); + + return 0; + + fail_t: + free_routing_table(table); + fail_src_v: + free(*dist); + fail_dijkstra: + free(forwarding); + fail_vertices: + *dist = NULL; + return -1; +} + +int graph_routing_table(struct graph * graph, + enum routing_algo algo, + uint64_t s_addr, + struct list_head * table) +{ + int * s_dist; + + assert(graph); + assert(table); + + pthread_mutex_lock(&graph->lock); + + switch (algo) { + case ROUTING_SIMPLE: + /* LFA uses the s_dist this returns. */ + if (graph_routing_table_simple(graph, s_addr, table, &s_dist)) + goto fail_table; + break; + case ROUTING_LFA: + if (graph_routing_table_lfa(graph, s_addr, table, &s_dist)) + goto fail_table; + break; + + case ROUTING_ECMP: + if (graph_routing_table_ecmp(graph, s_addr, table, &s_dist)) + goto fail_table; + break; + default: + log_err("Unsupported algorithm."); + goto fail_table; + } + + pthread_mutex_unlock(&graph->lock); + + free(s_dist); + + return 0; + + fail_table: + pthread_mutex_unlock(&graph->lock); + return -1; +} -- cgit v1.2.3