/* * BIRD -- Routing Table * * (c) 1998--2000 Martin Mares <mj@ucw.cz> * * Can be freely distributed and used under the terms of the GNU GPL. */ #undef LOCAL_DEBUG #include "nest/bird.h" #include "nest/route.h" #include "nest/protocol.h" #include "nest/cli.h" #include "nest/iface.h" #include "lib/resource.h" #include "lib/event.h" #include "lib/string.h" #include "conf/conf.h" #include "filter/filter.h" #include "lib/string.h" static slab *rte_slab; static linpool *rte_update_pool; static pool *rt_table_pool; static list routing_tables; static void rt_format_via(rte *e, byte *via); static void rte_init(struct fib_node *N) { net *n = (net *) N; N->flags = 0; n->routes = NULL; } rte * rte_find(net *net, struct proto *p) { rte *e = net->routes; while (e && e->attrs->proto != p) e = e->next; return e; } rte * rte_get_temp(rta *a) { rte *e = sl_alloc(rte_slab); e->attrs = a; e->flags = 0; e->pref = a->proto->preference; return e; } rte * rte_do_cow(rte *r) { rte *e = sl_alloc(rte_slab); memcpy(e, r, sizeof(rte)); e->attrs = rta_clone(r->attrs); e->flags = 0; return e; } static int /* Actually better or at least as good as */ rte_better(rte *new, rte *old) { int (*better)(rte *, rte *); if (!old) return 1; if (new->pref > old->pref) return 1; if (new->pref < old->pref) return 0; if (new->attrs->proto->proto != old->attrs->proto->proto) { /* * If the user has configured protocol preferences, so that two different protocols * have the same preference, try to break the tie by comparing addresses. Not too * useful, but keeps the ordering of routes unambiguous. */ return new->attrs->proto->proto > old->attrs->proto->proto; } if (better = new->attrs->proto->rte_better) return better(new, old); return 0; } static void rte_trace(struct proto *p, rte *e, int dir, char *msg) { byte via[STD_ADDRESS_P_LENGTH+32]; rt_format_via(e, via); log(L_TRACE "%s %c %s %I/%d %s", p->name, dir, msg, e->net->n.prefix, e->net->n.pxlen, via); } static inline void rte_trace_in(unsigned int flag, struct proto *p, rte *e, char *msg) { if (p->debug & flag) rte_trace(p, e, '>', msg); } static inline void rte_trace_out(unsigned int flag, struct proto *p, rte *e, char *msg) { if (p->debug & flag) rte_trace(p, e, '<', msg); } static inline void do_rte_announce(struct announce_hook *a, net *net, rte *new, rte *old, ea_list *tmpa, int class) { struct proto *p = a->proto; rte *new0 = new; rte *old0 = old; int ok; if (new) { if ((class & IADDR_SCOPE_MASK) < p->min_scope) { rte_trace_out(D_FILTERS, p, new, "out of scope"); new = NULL; } else if ((ok = p->import_control ? p->import_control(p, &new, &tmpa, rte_update_pool) : 0) < 0) { rte_trace_out(D_FILTERS, p, new, "rejected by protocol"); new = NULL; } else if (ok) rte_trace_out(D_FILTERS, p, new, "forced accept by protocol"); else if (p->out_filter == FILTER_REJECT || p->out_filter && f_run(p->out_filter, &new, &tmpa, rte_update_pool, FF_FORCE_TMPATTR) > F_ACCEPT) { rte_trace_out(D_FILTERS, p, new, "filtered out"); new = NULL; } } if (old && p->out_filter) { if (p->out_filter == FILTER_REJECT) old = NULL; else { ea_list *tmpb = p->make_tmp_attrs ? p->make_tmp_attrs(old, rte_update_pool) : NULL; ok = p->import_control ? p->import_control(p, &old, &tmpb, rte_update_pool) : 0; if (ok < 0 || (!ok && f_run(p->out_filter, &old, &tmpb, rte_update_pool, FF_FORCE_TMPATTR) > F_ACCEPT)) old = NULL; } } if (p->debug & D_ROUTES) { if (new && old) rte_trace_out(D_ROUTES, p, new, "replaced"); else if (new) rte_trace_out(D_ROUTES, p, new, "added"); else if (old) rte_trace_out(D_ROUTES, p, old, "removed"); } if (!new && !old) return; if (!new) p->rt_notify(p, net, NULL, old, NULL); else if (tmpa) { while (tmpa->next) tmpa = tmpa->next; tmpa->next = new->attrs->eattrs; p->rt_notify(p, net, new, old, tmpa); tmpa->next = NULL; } else p->rt_notify(p, net, new, old, new->attrs->eattrs); if (new && new != new0) /* Discard temporary rte's */ rte_free(new); if (old && old != old0) rte_free(old); } static void rte_announce(rtable *tab, net *net, rte *new, rte *old, ea_list *tmpa) { struct announce_hook *a; int class = ipa_classify(net->n.prefix); WALK_LIST(a, tab->hooks) { ASSERT(a->proto->core_state == FS_HAPPY || a->proto->core_state == FS_FEEDING); do_rte_announce(a, net, new, old, tmpa, class); } } static inline int rte_validate(rte *e) { int c; net *n = e->net; if (ipa_nonzero(ipa_and(n->n.prefix, ipa_not(ipa_mkmask(n->n.pxlen))))) { log(L_BUG "Ignoring bogus prefix %I/%d received via %s", n->n.prefix, n->n.pxlen, e->attrs->proto->name); return 0; } if (n->n.pxlen) { c = ipa_classify(n->n.prefix); if (c < 0 || !(c & IADDR_HOST)) { if (!ipa_nonzero(n->n.prefix)) { /* Various default routes */ #ifdef IPV6 if (n->n.pxlen == 96) #else if (n->n.pxlen <= 1) #endif return 1; } log(L_WARN "Ignoring bogus route %I/%d received via %s", n->n.prefix, n->n.pxlen, e->attrs->proto->name); return 0; } if ((c & IADDR_SCOPE_MASK) < e->attrs->proto->min_scope) { log(L_WARN "Ignoring %s scope route %I/%d received from %I via %s", ip_scope_text(c & IADDR_SCOPE_MASK), n->n.prefix, n->n.pxlen, e->attrs->from, e->attrs->proto->name); return 0; } } return 1; } void rte_free(rte *e) { if (e->attrs->aflags & RTAF_CACHED) rta_free(e->attrs); sl_free(rte_slab, e); } static inline void rte_free_quick(rte *e) { rta_free(e->attrs); sl_free(rte_slab, e); } static int rte_same(rte *x, rte *y) { return x->attrs == y->attrs && x->flags == y->flags && x->pflags == y->pflags && x->pref == y->pref && (!x->attrs->proto->rte_same || x->attrs->proto->rte_same(x, y)); } static void rte_recalculate(rtable *table, net *net, struct proto *p, rte *new, ea_list *tmpa) { rte *old_best = net->routes; rte *old = NULL; rte **k, *r, *s; k = &net->routes; /* Find and remove original route from the same protocol */ while (old = *k) { if (old->attrs->proto == p) { if (new && rte_same(old, new)) { /* No changes, ignore the new route */ rte_trace_in(D_ROUTES, p, new, "ignored"); rte_free_quick(new); old->lastmod = now; return; } *k = old->next; break; } k = &old->next; } if (new && rte_better(new, old_best)) /* It's a new optimal route => announce and relink it */ { rte_trace_in(D_ROUTES, p, new, "added [best]"); rte_announce(table, net, new, old_best, tmpa); new->next = net->routes; net->routes = new; } else { if (old == old_best) /* It has _replaced_ the old optimal route */ { r = new; /* Find new optimal route and announce it */ for(s=net->routes; s; s=s->next) if (rte_better(s, r)) r = s; rte_announce(table, net, r, old_best, tmpa); if (r) /* Re-link the new optimal route */ { k = &net->routes; while (s = *k) { if (s == r) { *k = r->next; break; } k = &s->next; } r->next = net->routes; net->routes = r; if (!r && table->gc_counter++ >= table->config->gc_max_ops && table->gc_time + table->config->gc_min_time <= now) ev_schedule(table->gc_event); } } if (new) /* Link in the new non-optimal route */ { new->next = old_best->next; old_best->next = new; rte_trace_in(D_ROUTES, p, new, "added"); } else if (old && (p->debug & D_ROUTES)) { if (old != old_best) rte_trace_in(D_ROUTES, p, old, "removed"); else if (net->routes) rte_trace_in(D_ROUTES, p, old, "removed [replaced]"); else rte_trace_in(D_ROUTES, p, old, "removed [sole]"); } } if (old) { if (p->rte_remove) p->rte_remove(net, old); rte_free_quick(old); } if (new) { new->lastmod = now; if (p->rte_insert) p->rte_insert(net, new); } } static int rte_update_nest_cnt; /* Nesting counter to allow recursive updates */ static inline void rte_update_lock(void) { rte_update_nest_cnt++; } static inline void rte_update_unlock(void) { if (!--rte_update_nest_cnt) lp_flush(rte_update_pool); } void rte_update(rtable *table, net *net, struct proto *p, rte *new) { ea_list *tmpa = NULL; rte_update_lock(); if (new) { if (!rte_validate(new)) { rte_trace_in(D_FILTERS, p, new, "invalid"); goto drop; } if (p->in_filter == FILTER_REJECT) { rte_trace_in(D_FILTERS, p, new, "filtered out"); goto drop; } if (p->make_tmp_attrs) tmpa = p->make_tmp_attrs(new, rte_update_pool); if (p->in_filter) { ea_list *old_tmpa = tmpa; int fr = f_run(p->in_filter, &new, &tmpa, rte_update_pool, 0); if (fr > F_ACCEPT) { rte_trace_in(D_FILTERS, p, new, "filtered out"); goto drop; } if (tmpa != old_tmpa && p->store_tmp_attrs) p->store_tmp_attrs(new, tmpa); } if (!(new->attrs->aflags & RTAF_CACHED)) /* Need to copy attributes */ new->attrs = rta_lookup(new->attrs); new->flags |= REF_COW; } rte_recalculate(table, net, p, new, tmpa); rte_update_unlock(); return; drop: rte_free(new); rte_update_unlock(); } void rte_discard(rtable *t, rte *old) /* Non-filtered route deletion, used during garbage collection */ { net *n = old->net; struct proto *p = old->attrs->proto; rte_update_lock(); rte_recalculate(t, n, p, NULL, NULL); rte_update_unlock(); } void rte_dump(rte *e) { net *n = e->net; if (n) debug("%1I/%2d ", n->n.prefix, n->n.pxlen); else debug("??? "); debug("KF=%02x PF=%02x pref=%d lm=%d ", n->n.flags, e->pflags, e->pref, now-e->lastmod); rta_dump(e->attrs); if (e->attrs->proto->proto->dump_attrs) e->attrs->proto->proto->dump_attrs(e); debug("\n"); } void rt_dump(rtable *t) { rte *e; net *n; struct announce_hook *a; debug("Dump of routing table <%s>\n", t->name); #ifdef DEBUGGING fib_check(&t->fib); #endif FIB_WALK(&t->fib, fn) { n = (net *) fn; for(e=n->routes; e; e=e->next) rte_dump(e); } FIB_WALK_END; WALK_LIST(a, t->hooks) debug("\tAnnounces routes to protocol %s\n", a->proto->name); debug("\n"); } void rt_dump_all(void) { rtable *t; WALK_LIST(t, routing_tables) rt_dump(t); } static void rt_gc(void *tab) { rtable *t = tab; DBG("Entered routing table garbage collector for %s after %d seconds and %d deletes\n", t->name, (int)(now - t->gc_time), t->gc_counter); rt_prune(t); } void rt_setup(pool *p, rtable *t, char *name, struct rtable_config *cf) { bzero(t, sizeof(*t)); fib_init(&t->fib, p, sizeof(net), 0, rte_init); t->name = name; t->config = cf; init_list(&t->hooks); if (cf) { t->gc_event = ev_new(p); t->gc_event->hook = rt_gc; t->gc_event->data = t; } } void rt_init(void) { rta_init(); rt_table_pool = rp_new(&root_pool, "Routing tables"); rte_update_pool = lp_new(rt_table_pool, 4080); rte_slab = sl_new(rt_table_pool, sizeof(rte)); init_list(&routing_tables); } void rt_prune(rtable *tab) { struct fib_iterator fit; int rcnt = 0, rdel = 0, ncnt = 0, ndel = 0; DBG("Pruning route table %s\n", tab->name); #ifdef DEBUGGING fib_check(&tab->fib); #endif FIB_ITERATE_INIT(&fit, &tab->fib); again: FIB_ITERATE_START(&tab->fib, &fit, f) { net *n = (net *) f; rte *e; ncnt++; rescan: for (e=n->routes; e; e=e->next, rcnt++) if (e->attrs->proto->core_state != FS_HAPPY && e->attrs->proto->core_state != FS_FEEDING) { rte_discard(tab, e); rdel++; goto rescan; } if (!n->routes) /* Orphaned FIB entry? */ { FIB_ITERATE_PUT(&fit, f); fib_delete(&tab->fib, f); ndel++; goto again; } } FIB_ITERATE_END(f); DBG("Pruned %d of %d routes and %d of %d networks\n", rcnt, rdel, ncnt, ndel); #ifdef DEBUGGING fib_check(&tab->fib); #endif tab->gc_counter = 0; tab->gc_time = now; } void rt_prune_all(void) { rtable *t; WALK_LIST(t, routing_tables) rt_prune(t); } struct rtable_config * rt_new_table(struct symbol *s) { struct rtable_config *c = cfg_allocz(sizeof(struct rtable_config)); cf_define_symbol(s, SYM_TABLE, c); c->name = s->name; add_tail(&new_config->tables, &c->n); c->gc_max_ops = 100; c->gc_min_time = 5; return c; } void rt_preconfig(struct config *c) { struct symbol *s = cf_find_symbol("master"); init_list(&c->tables); c->master_rtc = rt_new_table(s); } void rt_lock_table(rtable *r) { r->use_count++; } void rt_unlock_table(rtable *r) { if (!--r->use_count && r->deleted) { struct config *conf = r->deleted; DBG("Deleting routing table %s\n", r->name); rem_node(&r->n); fib_free(&r->fib); mb_free(r); config_del_obstacle(conf); } } void rt_commit(struct config *new, struct config *old) { struct rtable_config *o, *r; DBG("rt_commit:\n"); if (old) { WALK_LIST(o, old->tables) { rtable *ot = o->table; if (!ot->deleted) { struct symbol *sym = cf_find_symbol(o->name); if (sym && sym->class == SYM_TABLE && !new->shutdown) { DBG("\t%s: same\n", o->name); r = sym->def; r->table = ot; ot->name = r->name; ot->config = r; } else { DBG("\t%s: deleted\n", o->name); ot->deleted = old; config_add_obstacle(old); rt_lock_table(ot); rt_unlock_table(ot); } } } } WALK_LIST(r, new->tables) if (!r->table) { rtable *t = mb_alloc(rt_table_pool, sizeof(struct rtable)); DBG("\t%s: created\n", r->name); rt_setup(rt_table_pool, t, r->name, r); add_tail(&routing_tables, &t->n); r->table = t; } DBG("\tdone\n"); } int rt_feed_baby(struct proto *p) { struct announce_hook *h; struct fib_iterator *fit; int max_feed = 256; if (!p->feed_ahook) /* Need to initialize first */ { if (!p->ahooks) return 1; DBG("Announcing routes to new protocol %s\n", p->name); p->feed_ahook = p->ahooks; fit = p->feed_iterator = mb_alloc(p->pool, sizeof(struct fib_iterator)); goto next_hook; } fit = p->feed_iterator; again: h = p->feed_ahook; FIB_ITERATE_START(&h->table->fib, fit, fn) { net *n = (net *) fn; rte *e; if (max_feed <= 0) { FIB_ITERATE_PUT(fit, fn); return 0; } for(e=n->routes; e; e=e->next) { struct proto *q = e->attrs->proto; ea_list *tmpa; if (p->core_state != FS_FEEDING) return 1; /* In the meantime, the protocol fell down. */ rte_update_lock(); tmpa = q->make_tmp_attrs ? q->make_tmp_attrs(e, rte_update_pool) : NULL; do_rte_announce(h, n, e, NULL, tmpa, ipa_classify(n->n.prefix)); rte_update_unlock(); max_feed--; } } FIB_ITERATE_END(fn); p->feed_ahook = h->next; if (!p->feed_ahook) { mb_free(p->feed_iterator); p->feed_iterator = NULL; return 1; } next_hook: h = p->feed_ahook; FIB_ITERATE_INIT(fit, &h->table->fib); goto again; } void rt_feed_baby_abort(struct proto *p) { if (p->feed_ahook) { /* Unlink the iterator and exit */ fit_get(&p->feed_ahook->table->fib, p->feed_iterator); p->feed_ahook = NULL; } } /* * CLI commands */ static void rt_format_via(rte *e, byte *via) { rta *a = e->attrs; switch (a->dest) { case RTD_ROUTER: bsprintf(via, "via %I on %s", a->gw, a->iface->name); break; case RTD_DEVICE: bsprintf(via, "dev %s", a->iface->name); break; case RTD_BLACKHOLE: bsprintf(via, "blackhole"); break; case RTD_UNREACHABLE: bsprintf(via, "unreachable"); break; case RTD_PROHIBIT: bsprintf(via, "prohibited"); break; default: bsprintf(via, "???"); } } static void rt_show_rte(struct cli *c, byte *ia, rte *e, struct rt_show_data *d, ea_list *tmpa) { byte via[STD_ADDRESS_P_LENGTH+32], from[STD_ADDRESS_P_LENGTH+6]; byte tm[TM_RELTIME_BUFFER_SIZE], info[256]; rta *a = e->attrs; rt_format_via(e, via); tm_format_reltime(tm, e->lastmod); if (ipa_nonzero(a->from) && !ipa_equal(a->from, a->gw)) bsprintf(from, " from %I", a->from); else from[0] = 0; if (a->proto->proto->get_route_info || d->verbose) { /* Need to normalize the extended attributes */ ea_list *t = tmpa; t = ea_append(t, a->eattrs); tmpa = alloca(ea_scan(t)); ea_merge(t, tmpa); } if (a->proto->proto->get_route_info) a->proto->proto->get_route_info(e, info, tmpa); else bsprintf(info, " (%d)", e->pref); cli_printf(c, -1007, "%-18s %s [%s %s%s]%s", ia, via, a->proto->name, tm, from, info); if (d->verbose) rta_show(c, a, tmpa); } static void rt_show_net(struct cli *c, net *n, struct rt_show_data *d) { rte *e, *ee; byte ia[STD_ADDRESS_P_LENGTH+8]; int ok; bsprintf(ia, "%I/%d", n->n.prefix, n->n.pxlen); if (n->routes) d->net_counter++; for(e=n->routes; e; e=e->next) { struct ea_list *tmpa, *old_tmpa; struct proto *p0 = e->attrs->proto; struct proto *p1 = d->import_protocol; d->rt_counter++; ee = e; rte_update_lock(); /* We use the update buffer for filtering */ old_tmpa = tmpa = p0->make_tmp_attrs ? p0->make_tmp_attrs(e, rte_update_pool) : NULL; ok = (d->filter == FILTER_ACCEPT || f_run(d->filter, &e, &tmpa, rte_update_pool, FF_FORCE_TMPATTR) <= F_ACCEPT); if (ok && d->import_mode) { int ic = (p1->import_control ? p1->import_control(p1, &e, &tmpa, rte_update_pool) : 0); if (ic < 0) ok = 0; else if (!ic && d->import_mode > 1) { if (p1->out_filter == FILTER_REJECT || p1->out_filter && f_run(p1->out_filter, &e, &tmpa, rte_update_pool, FF_FORCE_TMPATTR) > F_ACCEPT) ok = 0; } } if (ok) { d->show_counter++; if (d->stats < 2) rt_show_rte(c, ia, e, d, tmpa); ia[0] = 0; } if (e != ee) rte_free(ee); rte_update_unlock(); if (d->primary_only) break; } } static void rt_show_cont(struct cli *c) { struct rt_show_data *d = c->rover; #ifdef DEBUGGING unsigned max = 4; #else unsigned max = 64; #endif struct fib *fib = &d->table->fib; struct fib_iterator *it = &d->fit; FIB_ITERATE_START(fib, it, f) { net *n = (net *) f; if (d->running_on_config && d->running_on_config != config) { cli_printf(c, 8004, "Stopped due to reconfiguration"); goto done; } if (d->import_protocol && d->import_protocol->core_state != FS_HAPPY && d->import_protocol->core_state != FS_FEEDING) { cli_printf(c, 8005, "Protocol is down"); goto done; } if (!max--) { FIB_ITERATE_PUT(it, f); return; } rt_show_net(c, n, d); } FIB_ITERATE_END(f); if (d->stats) cli_printf(c, 14, "%d of %d routes for %d networks", d->show_counter, d->rt_counter, d->net_counter); else cli_printf(c, 0, ""); done: c->cont = c->cleanup = NULL; } static void rt_show_cleanup(struct cli *c) { struct rt_show_data *d = c->rover; /* Unlink the iterator */ fit_get(&d->table->fib, &d->fit); } void rt_show(struct rt_show_data *d) { net *n; if (d->pxlen == 256) { FIB_ITERATE_INIT(&d->fit, &d->table->fib); this_cli->cont = rt_show_cont; this_cli->cleanup = rt_show_cleanup; this_cli->rover = d; } else { if (d->show_for) n = fib_route(&d->table->fib, d->prefix, d->pxlen); else n = fib_find(&d->table->fib, &d->prefix, d->pxlen); if (n) { rt_show_net(this_cli, n, d); cli_msg(0, ""); } else cli_msg(8001, "Network not in table"); } }