/* * BIRD -- Static Route Generator * * (c) 1998--2000 Martin Mares <mj@ucw.cz> * * Can be freely distributed and used under the terms of the GNU GPL. */ /** * DOC: Static * * The Static protocol is implemented in a straightforward way. It keeps a list * of static routes. Routes of dest RTD_UNICAST have associated sticky node in * the neighbor cache to be notified about gaining or losing the neighbor and * about interface-related events (e.g. link down). They may also have a BFD * request if associated with a BFD session. When a route is notified, * static_decide() is used to see whether the route activeness is changed. In * such case, the route is marked as dirty and scheduled to be announced or * withdrawn, which is done asynchronously from event hook. Routes of other * types (e.g. black holes) are announced all the time. * * Multipath routes are a bit tricky. To represent additional next hops, dummy * static_route nodes are used, which are chained using @mp_next field and link * to the master node by @mp_head field. Each next hop has a separate neighbor * entry and an activeness state, but the master node is used for most purposes. * Note that most functions DO NOT accept dummy nodes as arguments. * * The only other thing worth mentioning is that when asked for reconfiguration, * Static not only compares the two configurations, but it also calculates * difference between the lists of static routes and it just inserts the newly * added routes, removes the obsolete ones and reannounces changed ones. */ #undef LOCAL_DEBUG #include <stdlib.h> #include "nest/bird.h" #include "nest/iface.h" #include "nest/protocol.h" #include "nest/route.h" #include "nest/cli.h" #include "conf/conf.h" #include "filter/filter.h" #include "lib/string.h" #include "lib/alloca.h" #include "static.h" static linpool *static_lp; static inline rtable * p_igp_table(struct static_proto *p) { struct static_config *cf = (void *) p->p.cf; return cf->igp_table ? cf->igp_table->table : p->p.main_channel->table; } static void static_announce_rte(struct static_proto *p, struct static_route *r) { rta *a = allocz(RTA_MAX_SIZE); a->src = p->p.main_source; a->source = RTS_STATIC; a->scope = SCOPE_UNIVERSE; a->dest = r->dest; if (r->dest == RTD_UNICAST) { struct static_route *r2; struct nexthop *nhs = NULL; for (r2 = r; r2; r2 = r2->mp_next) { if (!r2->active) continue; struct nexthop *nh = allocz(NEXTHOP_MAX_SIZE); nh->gw = r2->via; nh->iface = r2->neigh->iface; nh->weight = r2->weight; nh->labels = r2->label_count; memcpy(nh->label, r2->label_stack, r2->label_count * sizeof(u32)); nexthop_insert(&nhs, nh); } if (!nhs) goto withdraw; nexthop_link(a, nhs); } if (r->dest == RTDX_RECURSIVE) { a->nh.labels_orig = a->nh.labels = r->label_count; memcpy(a->nh.label, r->label_stack, r->label_count * sizeof(u32)); rta_set_recursive_next_hop(p->p.main_channel->table, a, p_igp_table(p), r->via, IPA_NONE); } /* Already announced */ if (r->state == SRS_CLEAN) return; /* We skip rta_lookup() here */ rte *e = rte_get_temp(a); e->pflags = 0; if (r->cmds) f_eval_rte(r->cmds, &e, static_lp); rte_update(&p->p, r->net, e); r->state = SRS_CLEAN; if (r->cmds) lp_flush(static_lp); return; withdraw: if (r->state == SRS_DOWN) return; rte_update(&p->p, r->net, NULL); r->state = SRS_DOWN; } static void static_mark_rte(struct static_proto *p, struct static_route *r) { if (r->state == SRS_DIRTY) return; r->state = SRS_DIRTY; BUFFER_PUSH(p->marked) = r; if (!ev_active(p->event)) ev_schedule(p->event); } static void static_announce_marked(void *P) { struct static_proto *p = P; BUFFER_WALK(p->marked, r) static_announce_rte(P, r); BUFFER_FLUSH(p->marked); } static void static_bfd_notify(struct bfd_request *req); static void static_update_bfd(struct static_proto *p, struct static_route *r) { /* The @r is a RTD_UNICAST next hop, may be a dummy node */ struct neighbor *nb = r->neigh; int bfd_up = (nb->scope > 0) && r->use_bfd; if (bfd_up && !r->bfd_req) { // ip_addr local = ipa_nonzero(r->local) ? r->local : nb->ifa->ip; r->bfd_req = bfd_request_session(p->p.pool, r->via, nb->ifa->ip, nb->iface, static_bfd_notify, r); } if (!bfd_up && r->bfd_req) { rfree(r->bfd_req); r->bfd_req = NULL; } } static int static_decide(struct static_proto *p, struct static_route *r) { /* The @r is a RTD_UNICAST next hop, may be a dummy node */ struct static_config *cf = (void *) p->p.cf; uint old_active = r->active; if (r->neigh->scope < 0) goto fail; if (cf->check_link && !(r->neigh->iface->flags & IF_LINK_UP)) goto fail; if (r->bfd_req && (r->bfd_req->state != BFD_STATE_UP)) goto fail; r->active = 1; return !old_active; fail: r->active = 0; return old_active; } static void static_add_rte(struct static_proto *p, struct static_route *r) { if (r->dest == RTD_UNICAST) { struct static_route *r2; struct neighbor *n; for (r2 = r; r2; r2 = r2->mp_next) { n = ipa_nonzero(r2->via) ? neigh_find2(&p->p, &r2->via, r2->iface, NEF_STICKY) : neigh_find_iface(&p->p, r2->iface); if (!n) { log(L_WARN "Invalid next hop %I of static route %N", r2->via, r2->net); continue; } r2->neigh = n; r2->chain = n->data; n->data = r2; static_update_bfd(p, r2); static_decide(p, r2); } } static_announce_rte(p, r); } static void static_reset_rte(struct static_proto *p UNUSED, struct static_route *r) { struct static_route *r2; for (r2 = r; r2; r2 = r2->mp_next) { r2->neigh = NULL; r2->chain = NULL; r2->state = 0; r2->active = 0; rfree(r2->bfd_req); r2->bfd_req = NULL; } } static void static_remove_rte(struct static_proto *p, struct static_route *r) { if (r->state) rte_update(&p->p, r->net, NULL); static_reset_rte(p, r); } static inline int static_same_dest(struct static_route *x, struct static_route *y) { if (x->dest != y->dest) return 0; switch (x->dest) { case RTD_UNICAST: for (; x && y; x = x->mp_next, y = y->mp_next) { if (!ipa_equal(x->via, y->via) || (x->iface != y->iface) || (x->use_bfd != y->use_bfd) || (x->weight != y->weight) || (x->label_count != y->label_count)) return 0; for (int i = 0; i < x->label_count; i++) if (x->label_stack[i] != y->label_stack[i]) return 0; } return !x && !y; case RTDX_RECURSIVE: return ipa_equal(x->via, y->via); default: return 1; } } static inline int static_same_rte(struct static_route *or, struct static_route *nr) { /* Note that i_same() requires arguments in (new, old) order */ return static_same_dest(or, nr) && i_same(nr->cmds, or->cmds); } static void static_reconfigure_rte(struct static_proto *p, struct static_route *or, struct static_route *nr) { if ((or->state == SRS_CLEAN) && !static_same_rte(or, nr)) nr->state = SRS_DIRTY; else nr->state = or->state; static_add_rte(p, nr); static_reset_rte(p, or); } static void static_neigh_notify(struct neighbor *n) { struct static_proto *p = (void *) n->proto; struct static_route *r; DBG("Static: neighbor notify for %I: iface %p\n", n->addr, n->iface); for (r = n->data; r; r = r->chain) { static_update_bfd(p, r); if (static_decide(p, r)) static_mark_rte(p, r->mp_head); } } static void static_bfd_notify(struct bfd_request *req) { struct static_route *r = req->data; struct static_proto *p = (void *) r->neigh->proto; // if (req->down) TRACE(D_EVENTS, "BFD session down for nbr %I on %s", XXXX); if (static_decide(p, r)) static_mark_rte(p, r->mp_head); } static int static_rte_mergable(rte *pri UNUSED, rte *sec UNUSED) { return 1; } static void static_postconfig(struct proto_config *CF) { struct static_config *cf = (void *) CF; struct static_route *r; if (EMPTY_LIST(CF->channels)) cf_error("Channel not specified"); WALK_LIST(r, cf->routes) if (r->net && (r->net->type != CF->net_type)) cf_error("Route %N incompatible with channel type", r->net); } static struct proto * static_init(struct proto_config *CF) { struct proto *P = proto_new(CF); // struct static_proto *p = (void *) P; // struct static_config *cf = (void *) CF; P->main_channel = proto_add_channel(P, proto_cf_main_channel(CF)); P->neigh_notify = static_neigh_notify; P->rte_mergable = static_rte_mergable; return P; } static int static_start(struct proto *P) { struct static_proto *p = (void *) P; struct static_config *cf = (void *) P->cf; struct static_route *r; if (!static_lp) static_lp = lp_new(&root_pool, 1008); if (cf->igp_table) rt_lock_table(cf->igp_table->table); p->event = ev_new(p->p.pool); p->event->hook = static_announce_marked; p->event->data = p; BUFFER_INIT(p->marked, p->p.pool, 4); /* We have to go UP before routes could be installed */ proto_notify_state(P, PS_UP); WALK_LIST(r, cf->routes) static_add_rte(p, r); return PS_UP; } static int static_shutdown(struct proto *P) { struct static_proto *p = (void *) P; struct static_config *cf = (void *) P->cf; struct static_route *r; /* Just reset the flag, the routes will be flushed by the nest */ WALK_LIST(r, cf->routes) static_reset_rte(p, r); return PS_DOWN; } static void static_cleanup(struct proto *P) { struct static_config *cf = (void *) P->cf; if (cf->igp_table) rt_unlock_table(cf->igp_table->table); } static void static_dump_rte(struct static_route *r) { debug("%-1N: ", r->net); if (r->dest == RTD_UNICAST) if (r->iface && ipa_zero(r->via)) debug("dev %s\n", r->iface->name); else debug("via %I%J\n", r->via, r->iface); else debug("rtd %d\n", r->dest); } static void static_dump(struct proto *P) { struct static_config *c = (void *) P->cf; struct static_route *r; debug("Static routes:\n"); WALK_LIST(r, c->routes) static_dump_rte(r); } static inline rtable * cf_igp_table(struct static_config *cf) { return cf->igp_table ? cf->igp_table->table : NULL; } static inline int static_cmp_rte(const void *X, const void *Y) { struct static_route *x = *(void **)X, *y = *(void **)Y; return net_compare(x->net, y->net); } static int static_reconfigure(struct proto *P, struct proto_config *CF) { struct static_proto *p = (void *) P; struct static_config *o = (void *) P->cf; struct static_config *n = (void *) CF; struct static_route *r, *r2, *or, *nr; if (cf_igp_table(o) != cf_igp_table(n)) return 0; if (!proto_configure_channel(P, &P->main_channel, proto_cf_main_channel(CF))) return 0; p->p.cf = CF; /* Reset route lists in neighbor entries */ WALK_LIST(r, o->routes) for (r2 = r; r2; r2 = r2->mp_next) if (r2->neigh) r2->neigh->data = NULL; /* Reconfigure initial matching sequence */ for (or = HEAD(o->routes), nr = HEAD(n->routes); NODE_VALID(or) && NODE_VALID(nr) && net_equal(or->net, nr->net); or = NODE_NEXT(or), nr = NODE_NEXT(nr)) static_reconfigure_rte(p, or, nr); if (!NODE_VALID(or) && !NODE_VALID(nr)) return 1; /* Reconfigure remaining routes, sort them to find matching pairs */ struct static_route *or2, *nr2, **orbuf, **nrbuf; uint ornum = 0, nrnum = 0, orpos = 0, nrpos = 0, i; for (or2 = or; NODE_VALID(or2); or2 = NODE_NEXT(or2)) ornum++; for (nr2 = nr; NODE_VALID(nr2); nr2 = NODE_NEXT(nr2)) nrnum++; orbuf = xmalloc(ornum * sizeof(void *)); nrbuf = xmalloc(nrnum * sizeof(void *)); for (i = 0, or2 = or; i < ornum; i++, or2 = NODE_NEXT(or2)) orbuf[i] = or2; for (i = 0, nr2 = nr; i < nrnum; i++, nr2 = NODE_NEXT(nr2)) nrbuf[i] = nr2; qsort(orbuf, ornum, sizeof(struct static_route *), static_cmp_rte); qsort(nrbuf, nrnum, sizeof(struct static_route *), static_cmp_rte); while ((orpos < ornum) && (nrpos < nrnum)) { int x = net_compare(orbuf[orpos]->net, nrbuf[nrpos]->net); if (x < 0) static_remove_rte(p, orbuf[orpos++]); else if (x > 0) static_add_rte(p, nrbuf[nrpos++]); else static_reconfigure_rte(p, orbuf[orpos++], nrbuf[nrpos++]); } while (orpos < ornum) static_remove_rte(p, orbuf[orpos++]); while (nrpos < nrnum) static_add_rte(p, nrbuf[nrpos++]); xfree(orbuf); xfree(nrbuf); return 1; } static void static_copy_config(struct proto_config *dest, struct proto_config *src) { struct static_config *d = (struct static_config *) dest; struct static_config *s = (struct static_config *) src; struct static_route *srt, *snh; /* Copy route list */ init_list(&d->routes); WALK_LIST(srt, s->routes) { struct static_route *drt = NULL, *dnh = NULL, **dnp = &drt; for (snh = srt; snh; snh = snh->mp_next) { dnh = cfg_alloc(sizeof(struct static_route)); memcpy(dnh, snh, sizeof(struct static_route)); if (!drt) add_tail(&d->routes, &(dnh->n)); *dnp = dnh; dnp = &(dnh->mp_next); if (snh->mp_head) dnh->mp_head = drt; } } } static const char * rta_dest_names[] = { [RTD_NONE] = "", [RTD_UNICAST] = "unicast", [RTD_BLACKHOLE] = "blackhole", [RTD_UNREACHABLE] = "unreachable", [RTD_PROHIBIT] = "prohibited", }; static void static_show_rt(struct static_route *r) { switch (r->dest) { case RTD_UNICAST: { struct static_route *r2; cli_msg(-1009, "%N", r->net); for (r2 = r; r2; r2 = r2->mp_next) { if (r2->iface && ipa_zero(r2->via)) cli_msg(-1009, "\tdev %s%s%s", r2->iface->name, r2->bfd_req ? " (bfd)" : "", r2->active ? "" : " (dormant)"); else cli_msg(-1009, "\tvia %I%J%s%s", r2->via, r2->iface, r2->bfd_req ? " (bfd)" : "", r2->active ? "" : " (dormant)"); } break; } case RTD_NONE: case RTD_BLACKHOLE: case RTD_UNREACHABLE: case RTD_PROHIBIT: cli_msg(-1009, "%N\t%s", r->net, rta_dest_names[r->dest]); break; case RTDX_RECURSIVE: cli_msg(-1009, "%N\trecursive %I", r->net, r->via); break; } } void static_show(struct proto *P) { struct static_config *c = (void *) P->cf; struct static_route *r; WALK_LIST(r, c->routes) static_show_rt(r); cli_msg(0, ""); } struct protocol proto_static = { .name = "Static", .template = "static%d", .preference = DEF_PREF_STATIC, .channel_mask = NB_ANY, .proto_size = sizeof(struct static_proto), .config_size = sizeof(struct static_config), .postconfig = static_postconfig, .init = static_init, .dump = static_dump, .start = static_start, .shutdown = static_shutdown, .cleanup = static_cleanup, .reconfigure = static_reconfigure, .copy_config = static_copy_config };