/* * BIRD -- Routing Information Protocol (RIP) * * (c) 1998--1999 Pavel Machek * (c) 2004--2013 Ondrej Filip * (c) 2009--2015 Ondrej Zajicek * (c) 2009--2015 CZ.NIC z.s.p.o. * * Can be freely distributed and used under the terms of the GNU GPL. */ /** * DOC: Routing Information Protocol (RIP) * * The RIP protocol is implemented in two files: |rip.c| containing the protocol * logic, route management and the protocol glue with BIRD core, and |packets.c| * handling RIP packet processing, RX, TX and protocol sockets. * * Each instance of RIP is described by a structure &rip_proto, which contains * an internal RIP routing table, a list of protocol interfaces and the main * timer responsible for RIP routing table cleanup. * * RIP internal routing table contains incoming and outgoing routes. For each * network (represented by structure &rip_entry) there is one outgoing route * stored directly in &rip_entry and an one-way linked list of incoming routes * (structures &rip_rte). The list contains incoming routes from different RIP * neighbors, but only routes with the lowest metric are stored (i.e., all * stored incoming routes have the same metric). * * Note that RIP itself does not select outgoing route, that is done by the core * routing table. When a new incoming route is received, it is propagated to the * RIP table by rip_update_rte() and possibly stored in the list of incoming * routes. Then the change may be propagated to the core by rip_announce_rte(). * The core selects the best route and propagate it to RIP by rip_rt_notify(), * which updates outgoing route part of &rip_entry and possibly triggers route * propagation by rip_trigger_update(). * * RIP interfaces are represented by structures &rip_iface. A RIP interface * contains a per-interface socket, a list of associated neighbors, interface * configuration, and state information related to scheduled interface events * and running update sessions. RIP interfaces are added and removed based on * core interface notifications. * * There are two RIP interface events - regular updates and triggered updates. * Both are managed from the RIP interface timer (rip_iface_timer()). Regular * updates are called at fixed interval and propagate the whole routing table, * while triggered updates are scheduled by rip_trigger_update() due to some * routing table change and propagate only the routes modified since the time * they were scheduled. There are also unicast-destined requested updates, but * these are sent directly as a reaction to received RIP request message. The * update session is started by rip_send_table(). There may be at most one * active update session per interface, as the associated state (including the * fib iterator) is stored directly in &rip_iface structure. * * RIP neighbors are represented by structures &rip_neighbor. Compared to * neighbor handling in other routing protocols, RIP does not have explicit * neighbor discovery and adjacency maintenance, which makes the &rip_neighbor * related code a bit peculiar. RIP neighbors are interlinked with core neighbor * structures (&neighbor) and use core neighbor notifications to ensure that RIP * neighbors are timely removed. RIP neighbors are added based on received route * notifications and removed based on core neighbor and RIP interface events. * * RIP neighbors are linked by RIP routes and use counter to track the number of * associated routes, but when these RIP routes timeout, associated RIP neighbor * is still alive (with zero counter). When RIP neighbor is removed but still * has some associated routes, it is not freed, just changed to detached state * (core neighbors and RIP ifaces are unlinked), then during the main timer * cleanup phase the associated routes are removed and the &rip_neighbor * structure is finally freed. * * Supported standards: * RFC 1058 - RIPv1 * RFC 2453 - RIPv2 * RFC 2080 - RIPng * RFC 2091 - Triggered RIP for demand circuits * RFC 4822 - RIP cryptographic authentication */ #include #include "rip.h" #include "lib/macro.h" static inline void rip_lock_neighbor(struct rip_neighbor *n); static inline void rip_unlock_neighbor(struct rip_neighbor *n); static inline int rip_iface_link_up(struct rip_iface *ifa); static inline void rip_kick_timer(struct rip_proto *p); static inline void rip_iface_kick_timer(struct rip_iface *ifa); static void rip_iface_timer(timer *timer); static void rip_trigger_update(struct rip_proto *p); static struct ea_class ea_rip_metric, ea_rip_tag, ea_rip_from; /* * RIP routes */ static struct rip_rte * rip_add_rte(struct rip_proto *p, struct rip_rte **rp, struct rip_rte *src) { struct rip_rte *rt = sl_alloc(p->rte_slab); memcpy(rt, src, sizeof(struct rip_rte)); rt->next = *rp; *rp = rt; rip_lock_neighbor(rt->from); return rt; } static inline void rip_remove_rte(struct rip_proto *p UNUSED, struct rip_rte **rp) { struct rip_rte *rt = *rp; rip_unlock_neighbor(rt->from); *rp = rt->next; sl_free(rt); } static inline int rip_same_rte(struct rip_rte *a, struct rip_rte *b) { return a->metric == b->metric && a->tag == b->tag && ipa_equal(a->next_hop, b->next_hop); } static inline int rip_valid_rte(struct rip_rte *rt) { return rt->from->ifa != NULL; } struct rip_iface_adata { struct adata ad; struct iface *iface; }; /** * rip_announce_rte - announce route from RIP routing table to the core * @p: RIP instance * @en: related network * * The function takes a list of incoming routes from @en, prepare appropriate * &rte for the core and propagate it by rte_update(). */ static void rip_announce_rte(struct rip_proto *p, struct rip_entry *en) { struct rip_rte *rt = en->routes; /* Find first valid rte */ while (rt && !rip_valid_rte(rt)) rt = rt->next; if (rt) { /* Update */ rta a0 = { .dest = RTD_UNICAST, }; struct { ea_list l; eattr a[3]; } ea_block = { .l.count = ARRAY_SIZE(ea_block.a), .a = { EA_LITERAL_EMBEDDED(&ea_gen_preference, 0, p->p.main_channel->preference), EA_LITERAL_EMBEDDED(&ea_gen_source, 0, RTS_RIP), EA_LITERAL_EMBEDDED(&ea_rip_metric, 0, rt->metric), }, }; a0.eattrs = &ea_block.l; u16 rt_tag = rt->tag; struct iface *rt_from = NULL; if (p->ecmp) { /* ECMP route */ int num = 0; for (rt = en->routes; rt && (num < p->ecmp); rt = rt->next) if (rip_valid_rte(rt)) num++; struct nexthop_adata *nhad = (struct nexthop_adata *) tmp_alloc_adata((num+1) * sizeof(struct nexthop)); struct nexthop *nh = &nhad->nh; for (rt = en->routes; rt && (num < p->ecmp); rt = rt->next) { if (!rip_valid_rte(rt)) continue; *nh = (struct nexthop) { .gw = rt->next_hop, .iface = rt->from->ifa->iface, .weight = rt->from->ifa->cf->ecmp_weight, }; if (!rt_from) rt_from = rt->from->ifa->iface; nh = NEXTHOP_NEXT(nh); if (rt->tag != rt_tag) rt_tag = 0; } nhad->ad.length = ((void *) nh - (void *) nhad->ad.data); ea_set_attr(&a0.eattrs, EA_LITERAL_DIRECT_ADATA(&ea_gen_nexthop, 0, &(nexthop_sort(nhad, tmp_linpool)->ad))); } else { /* Unipath route */ rt_from = rt->from->ifa->iface; struct nexthop_adata nhad = { .nh.gw = rt->next_hop, .nh.iface = rt->from->ifa->iface, }; ea_set_attr_data(&a0.eattrs, &ea_gen_nexthop, 0, &nhad.ad.data, sizeof nhad - sizeof nhad.ad); ea_set_attr_data(&a0.eattrs, &ea_gen_from, 0, &rt->from->nbr->addr, sizeof(ip_addr)); } ea_set_attr_u32(&a0.eattrs, &ea_rip_tag, 0, rt_tag); struct rip_iface_adata riad = { .ad = { .length = sizeof(struct rip_iface_adata) - sizeof(struct adata) }, .iface = rt_from, }; ea_set_attr(&a0.eattrs, EA_LITERAL_DIRECT_ADATA(&ea_rip_from, 0, &riad.ad)); rte e0 = { .attrs = &a0, .src = p->p.main_source, }; rte_update(p->p.main_channel, en->n.addr, &e0, p->p.main_source); } else rte_update(p->p.main_channel, en->n.addr, NULL, p->p.main_source); } /** * rip_update_rte - enter a route update to RIP routing table * @p: RIP instance * @addr: network address * @new: a &rip_rte representing the new route * * The function is called by the RIP packet processing code whenever it receives * a reachable route. The appropriate routing table entry is found and the list * of incoming routes is updated. Eventually, the change is also propagated to * the core by rip_announce_rte(). Note that for unreachable routes, * rip_withdraw_rte() should be called instead of rip_update_rte(). */ void rip_update_rte(struct rip_proto *p, net_addr *n, struct rip_rte *new) { struct rip_entry *en = fib_get(&p->rtable, n); struct rip_rte *rt, **rp; int changed = 0; /* If the new route is better, remove all current routes */ if (en->routes && new->metric < en->routes->metric) while (en->routes) rip_remove_rte(p, &en->routes); /* Find the old route (also set rp for later) */ for (rp = &en->routes; rt = *rp; rp = &rt->next) if (rt->from == new->from) { if (rip_same_rte(rt, new)) { rt->expires = new->expires; return; } /* Remove the old route */ rip_remove_rte(p, rp); changed = 1; break; } /* If the new route is optimal, add it to the list */ if (!en->routes || new->metric == en->routes->metric) { rt = rip_add_rte(p, rp, new); changed = 1; } /* Announce change if on relevant position (the first or any for ECMP) */ if (changed && (rp == &en->routes || p->ecmp)) rip_announce_rte(p, en); } /** * rip_withdraw_rte - enter a route withdraw to RIP routing table * @p: RIP instance * @addr: network address * @from: a &rip_neighbor propagating the withdraw * * The function is called by the RIP packet processing code whenever it receives * an unreachable route. The incoming route for given network from nbr @from is * removed. Eventually, the change is also propagated by rip_announce_rte(). */ void rip_withdraw_rte(struct rip_proto *p, net_addr *n, struct rip_neighbor *from) { struct rip_entry *en = fib_find(&p->rtable, n); struct rip_rte *rt, **rp; if (!en) return; /* Find the old route */ for (rp = &en->routes; rt = *rp; rp = &rt->next) if (rt->from == from) break; if (!rt) return; /* Remove the old route */ rip_remove_rte(p, rp); /* Announce change if on relevant position */ if (rp == &en->routes || p->ecmp) rip_announce_rte(p, en); } /* * rip_rt_notify - core tells us about new route, so store * it into our data structures. */ static void rip_rt_notify(struct proto *P, struct channel *ch UNUSED, const net_addr *net, struct rte *new, const struct rte *old UNUSED) { struct rip_proto *p = (struct rip_proto *) P; struct rip_entry *en; int old_metric; if (new) { /* Update */ u32 rt_tag = ea_get_int(new->attrs->eattrs, &ea_rip_tag, 0); u32 rt_metric = ea_get_int(new->attrs->eattrs, &ea_rip_metric, 1); const eattr *rie = ea_find(new->attrs->eattrs, &ea_rip_from); struct iface *rt_from = rie ? ((struct rip_iface_adata *) rie->u.ptr)->iface : NULL; if (rt_metric > p->infinity) { log(L_WARN "%s: Invalid rip_metric value %u for route %N", p->p.name, rt_metric, net); rt_metric = p->infinity; } if (rt_tag > 0xffff) { log(L_WARN "%s: Invalid rip_tag value %u for route %N", p->p.name, rt_tag, net); rt_metric = p->infinity; rt_tag = 0; } /* * Note that we accept exported routes with infinity metric (this could * happen if rip_metric is modified in filters). Such entry has infinity * metric but is RIP_ENTRY_VALID and therefore is not subject to garbage * collection. */ en = fib_get(&p->rtable, net); old_metric = en->valid ? en->metric : -1; en->valid = RIP_ENTRY_VALID; en->metric = rt_metric; en->tag = rt_tag; en->from = (new->src->proto == P) ? rt_from : NULL; eattr *nhea = ea_find(new->attrs->eattrs, &ea_gen_nexthop); if (nhea) { struct nexthop_adata *nhad = (struct nexthop_adata *) nhea->u.ptr; en->iface = nhad->nh.iface; en->next_hop = nhad->nh.gw; } } else { /* Withdraw */ en = fib_find(&p->rtable, net); if (!en || en->valid != RIP_ENTRY_VALID) return; old_metric = en->metric; en->valid = RIP_ENTRY_STALE; en->metric = p->infinity; en->tag = 0; en->from = NULL; en->iface = NULL; en->next_hop = IPA_NONE; } /* Activate triggered updates */ if (en->metric != old_metric) { en->changed = current_time(); rip_trigger_update(p); } } void rip_flush_table(struct rip_proto *p, struct rip_neighbor *n) { btime expires = current_time() + n->ifa->cf->timeout_time; FIB_WALK(&p->rtable, struct rip_entry, en) { for (struct rip_rte *e = en->routes; e; e = e->next) if ((e->from == n) && (e->expires == TIME_INFINITY)) e->expires = expires; } FIB_WALK_END; } /* * RIP neighbors */ struct rip_neighbor * rip_get_neighbor(struct rip_proto *p, ip_addr *a, struct rip_iface *ifa) { neighbor *nbr = neigh_find(&p->p, *a, ifa->iface, 0); if (!nbr || (nbr->scope == SCOPE_HOST) || !rip_iface_link_up(ifa)) return NULL; if (nbr->data) return nbr->data; TRACE(D_EVENTS, "New neighbor %I on %s", *a, ifa->iface->name); struct rip_neighbor *n = mb_allocz(p->p.pool, sizeof(struct rip_neighbor)); n->ifa = ifa; n->nbr = nbr; nbr->data = n; n->csn = nbr->aux; add_tail(&ifa->neigh_list, NODE n); return n; } static void rip_remove_neighbor(struct rip_proto *p, struct rip_neighbor *n) { neighbor *nbr = n->nbr; TRACE(D_EVENTS, "Removing neighbor %I on %s", nbr->addr, nbr->ifreq->name); rem_node(NODE n); n->ifa = NULL; n->nbr = NULL; nbr->data = NULL; nbr->aux = n->csn; rfree(n->bfd_req); n->bfd_req = NULL; n->last_seen = 0; if (!n->uc) mb_free(n); /* Related routes are removed in rip_timer() */ rip_kick_timer(p); } static inline void rip_lock_neighbor(struct rip_neighbor *n) { n->uc++; } static inline void rip_unlock_neighbor(struct rip_neighbor *n) { n->uc--; if (!n->nbr && !n->uc) mb_free(n); } static void rip_neigh_notify(struct neighbor *nbr) { struct rip_proto *p = (struct rip_proto *) nbr->proto; struct rip_neighbor *n = nbr->data; if (!n) return; /* * We assume that rip_neigh_notify() is called before rip_if_notify() for * IF_CHANGE_DOWN and therefore n->ifa is still valid. We have no such * ordering assumption for IF_CHANGE_LINK, so we test link state of the * underlying iface instead of just rip_iface state. */ if ((nbr->scope <= 0) || !rip_iface_link_up(n->ifa)) rip_remove_neighbor(p, n); } static void rip_bfd_notify(struct bfd_request *req) { struct rip_neighbor *n = req->data; struct rip_proto *p = n->ifa->rip; if (req->down) { TRACE(D_EVENTS, "BFD session down for nbr %I on %s", n->nbr->addr, n->ifa->iface->name); rip_remove_neighbor(p, n); } } void rip_update_bfd(struct rip_proto *p, struct rip_neighbor *n) { int use_bfd = n->ifa->cf->bfd && n->last_seen; if (use_bfd && !n->bfd_req) { /* * For RIPv2, use the same address as rip_open_socket(). For RIPng, neighbor * should contain an address from the same prefix, thus also link-local. It * may cause problems if two link-local addresses are assigned to one iface. */ ip_addr saddr = rip_is_v2(p) ? n->ifa->sk->saddr : n->nbr->ifa->ip; n->bfd_req = bfd_request_session(p->p.pool, n->nbr->addr, saddr, n->nbr->iface, p->p.vrf, rip_bfd_notify, n, NULL); } if (!use_bfd && n->bfd_req) { rfree(n->bfd_req); n->bfd_req = NULL; } } /* * RIP interfaces */ static void rip_iface_start(struct rip_iface *ifa) { struct rip_proto *p = ifa->rip; TRACE(D_EVENTS, "Starting interface %s", ifa->iface->name); if (! ifa->cf->demand_circuit) { ifa->next_regular = current_time() + (random() % ifa->cf->update_time) + 100 MS; tm_set(ifa->timer, ifa->next_regular); } else { ifa->next_regular = TIME_INFINITY; } ifa->up = 1; if (ifa->cf->passive) return; rip_send_request(p, ifa); rip_send_table(p, ifa, ifa->addr, 0); } static void rip_iface_stop(struct rip_iface *ifa) { struct rip_proto *p = ifa->rip; struct rip_neighbor *n; TRACE(D_EVENTS, "Stopping interface %s", ifa->iface->name); rip_reset_tx_session(p, ifa); ifa->next_regular = 0; ifa->next_triggered = 0; ifa->want_triggered = 0; if (ifa->tx_pending) ifa->tx_seqnum++; ifa->tx_pending = 0; ifa->req_pending = 0; if (ifa->cf->demand_circuit && !ifa->cf->passive) rip_send_flush(p, ifa); WALK_LIST_FIRST(n, ifa->neigh_list) rip_remove_neighbor(p, n); tm_stop(ifa->timer); tm_stop(ifa->rxmt_timer); ifa->up = 0; } static inline int rip_iface_link_up(struct rip_iface *ifa) { return !ifa->cf->check_link || (ifa->iface->flags & IF_LINK_UP); } static void rip_iface_update_state(struct rip_iface *ifa) { int up = ifa->sk && rip_iface_link_up(ifa); if (up == ifa->up) return; if (up) rip_iface_start(ifa); else rip_iface_stop(ifa); } static void rip_iface_update_buffers(struct rip_iface *ifa) { if (!ifa->sk) return; uint rbsize = ifa->cf->rx_buffer ?: ifa->iface->mtu; uint tbsize = ifa->cf->tx_length ?: ifa->iface->mtu; rbsize = MAX(rbsize, tbsize); sk_set_rbsize(ifa->sk, rbsize); sk_set_tbsize(ifa->sk, tbsize); uint headers = (rip_is_v2(ifa->rip) ? IP4_HEADER_LENGTH : IP6_HEADER_LENGTH) + UDP_HEADER_LENGTH; ifa->tx_plen = tbsize - headers; if (ifa->cf->auth_type == RIP_AUTH_CRYPTO) ifa->tx_plen -= RIP_AUTH_TAIL_LENGTH + max_mac_length(ifa->cf->passwords); } static inline void rip_iface_update_bfd(struct rip_iface *ifa) { struct rip_proto *p = ifa->rip; struct rip_neighbor *n; WALK_LIST(n, ifa->neigh_list) rip_update_bfd(p, n); } static void rip_iface_locked(struct object_lock *lock) { struct rip_iface *ifa = lock->data; struct rip_proto *p = ifa->rip; if (!rip_open_socket(ifa)) { log(L_ERR "%s: Cannot open socket for %s", p->p.name, ifa->iface->name); return; } rip_iface_update_buffers(ifa); rip_iface_update_state(ifa); } static struct rip_iface * rip_find_iface(struct rip_proto *p, struct iface *what) { struct rip_iface *ifa; WALK_LIST(ifa, p->iface_list) if (ifa->iface == what) return ifa; return NULL; } static void rip_add_iface(struct rip_proto *p, struct iface *iface, struct rip_iface_config *ic) { struct rip_iface *ifa; TRACE(D_EVENTS, "Adding interface %s", iface->name); ifa = mb_allocz(p->p.pool, sizeof(struct rip_iface)); ifa->rip = p; ifa->iface = iface; ifa->cf = ic; if (ipa_nonzero(ic->address)) ifa->addr = ic->address; else if (ic->mode == RIP_IM_MULTICAST) ifa->addr = rip_is_v2(p) ? IP4_RIP_ROUTERS : IP6_RIP_ROUTERS; else /* Broadcast */ ifa->addr = iface->addr4->brd; /* * The above is just a workaround for BSD as it can't send broadcasts * to 255.255.255.255. BSD systems need the network broadcast address instead. * * TODO: move this to sysdep code */ init_list(&ifa->neigh_list); add_tail(&p->iface_list, NODE ifa); ifa->timer = tm_new_init(p->p.pool, rip_iface_timer, ifa, 0, 0); ifa->rxmt_timer = tm_new_init(p->p.pool, rip_rxmt_timeout, ifa, 0, 0); struct object_lock *lock = olock_new(p->p.pool); lock->type = OBJLOCK_UDP; lock->port = ic->port; lock->iface = iface; lock->data = ifa; lock->hook = rip_iface_locked; ifa->lock = lock; olock_acquire(lock); } static void rip_remove_iface(struct rip_proto *p, struct rip_iface *ifa) { rip_iface_stop(ifa); TRACE(D_EVENTS, "Removing interface %s", ifa->iface->name); rem_node(NODE ifa); rfree(ifa->sk); rfree(ifa->lock); rfree(ifa->timer); mb_free(ifa); } static int rip_reconfigure_iface(struct rip_proto *p, struct rip_iface *ifa, struct rip_iface_config *new) { struct rip_iface_config *old = ifa->cf; /* Change of these options would require to reset the iface socket */ if ((new->mode != old->mode) || (new->port != old->port) || (new->tx_tos != old->tx_tos) || (new->tx_priority != old->tx_priority) || (new->ttl_security != old->ttl_security) || (new->demand_circuit != old->demand_circuit)) return 0; TRACE(D_EVENTS, "Reconfiguring interface %s", ifa->iface->name); ifa->cf = new; rip_iface_update_buffers(ifa); if ((! ifa->cf->demand_circuit) && (ifa->next_regular > (current_time() + new->update_time))) ifa->next_regular = current_time() + (random() % new->update_time) + 100 MS; if (ifa->up && new->demand_circuit && (new->passive != old->passive)) { if (new->passive) rip_send_flush(p, ifa); else { rip_send_request(p, ifa); rip_send_table(p, ifa, ifa->addr, 0); } } if (new->check_link != old->check_link) rip_iface_update_state(ifa); if (new->bfd != old->bfd) rip_iface_update_bfd(ifa); if (ifa->up) rip_iface_kick_timer(ifa); return 1; } static void rip_reconfigure_ifaces(struct rip_proto *p, struct rip_config *cf) { struct iface *iface; WALK_LIST(iface, iface_list) { if (!(iface->flags & IF_UP)) continue; /* Ignore ifaces without appropriate address */ if (rip_is_v2(p) ? !iface->addr4 : !iface->llv6) continue; struct rip_iface *ifa = rip_find_iface(p, iface); struct rip_iface_config *ic = (void *) iface_patt_find(&cf->patt_list, iface, NULL); if (ifa && ic) { if (rip_reconfigure_iface(p, ifa, ic)) continue; /* Hard restart */ log(L_INFO "%s: Restarting interface %s", p->p.name, ifa->iface->name); rip_remove_iface(p, ifa); rip_add_iface(p, iface, ic); } if (ifa && !ic) rip_remove_iface(p, ifa); if (!ifa && ic) rip_add_iface(p, iface, ic); } } static void rip_if_notify(struct proto *P, unsigned flags, struct iface *iface) { struct rip_proto *p = (void *) P; struct rip_config *cf = (void *) P->cf; struct rip_iface *ifa = rip_find_iface(p, iface); if (iface->flags & IF_IGNORE) return; /* Add, remove or restart interface */ if (flags & (IF_CHANGE_UPDOWN | (rip_is_v2(p) ? IF_CHANGE_ADDR4 : IF_CHANGE_LLV6))) { if (ifa) rip_remove_iface(p, ifa); if (!(iface->flags & IF_UP)) return; /* Ignore ifaces without appropriate address */ if (rip_is_v2(p) ? !iface->addr4 : !iface->llv6) return; struct rip_iface_config *ic = (void *) iface_patt_find(&cf->patt_list, iface, NULL); if (ic) rip_add_iface(p, iface, ic); return; } if (!ifa) return; if (flags & IF_CHANGE_MTU) rip_iface_update_buffers(ifa); if (flags & IF_CHANGE_LINK) rip_iface_update_state(ifa); } /* * RIP timer events */ /** * rip_timer - RIP main timer hook * @t: timer * * The RIP main timer is responsible for routing table maintenance. Invalid or * expired routes (&rip_rte) are removed and garbage collection of stale routing * table entries (&rip_entry) is done. Changes are propagated to core tables, * route reload is also done here. Note that garbage collection uses a maximal * GC time, while interfaces maintain an illusion of per-interface GC times in * rip_send_response(). * * Keeping incoming routes and the selected outgoing route are two independent * functions, therefore after garbage collection some entries now considered * invalid (RIP_ENTRY_DUMMY) still may have non-empty list of incoming routes, * while some valid entries (representing an outgoing route) may have that list * empty. * * The main timer is not scheduled periodically but it uses the time of the * current next event and the minimal interval of any possible event to compute * the time of the next run. */ static void rip_timer(timer *t) { struct rip_proto *p = t->data; struct rip_config *cf = (void *) (p->p.cf); struct rip_iface *ifa; struct rip_neighbor *n, *nn; struct fib_iterator fit; btime now_ = current_time(); btime next = now_ + MIN(cf->min_timeout_time, cf->max_garbage_time); btime expires = 0; TRACE(D_EVENTS, "Main timer fired"); FIB_ITERATE_INIT(&fit, &p->rtable); loop: FIB_ITERATE_START(&p->rtable, &fit, struct rip_entry, en) { struct rip_rte *rt, **rp; int changed = 0; /* Checking received routes for timeout and for dead neighbors */ for (rp = &en->routes; rt = *rp; /* rp = &rt->next */) { if (!rip_valid_rte(rt) || (rt->expires <= now_)) { rip_remove_rte(p, rp); changed = 1; continue; } next = MIN(next, rt->expires); rp = &rt->next; } /* Propagating eventual change */ if (changed || p->rt_reload) { /* * We have to restart the iteration because there may be a cascade of * synchronous events rip_announce_rte() -> nest table change -> * rip_rt_notify() -> p->rtable change, invalidating hidden variables. */ FIB_ITERATE_PUT_NEXT(&fit, &p->rtable); rip_announce_rte(p, en); goto loop; } /* Checking stale entries for garbage collection timeout */ if (en->valid == RIP_ENTRY_STALE) { expires = en->changed + cf->max_garbage_time; if (expires <= now_) { // TRACE(D_EVENTS, "entry is too old: %N", en->n.addr); en->valid = 0; } else next = MIN(next, expires); } /* Remove empty nodes */ if (!en->valid && !en->routes) { FIB_ITERATE_PUT(&fit); fib_delete(&p->rtable, en); goto loop; } } FIB_ITERATE_END; p->rt_reload = 0; /* Handling neighbor expiration */ WALK_LIST(ifa, p->iface_list) { /* No expiration for demand circuit ifaces */ if (ifa->cf->demand_circuit) continue; WALK_LIST_DELSAFE(n, nn, ifa->neigh_list) if (n->last_seen) { expires = n->last_seen + n->ifa->cf->timeout_time; if (expires <= now_) rip_remove_neighbor(p, n); else next = MIN(next, expires); } } tm_start(p->timer, MAX(next - now_, 100 MS)); } static inline void rip_kick_timer(struct rip_proto *p) { if ((p->timer->expires > (current_time() + 100 MS))) tm_start(p->timer, 100 MS); } /** * rip_iface_timer - RIP interface timer hook * @t: timer * * RIP interface timers are responsible for scheduling both regular and * triggered updates. Fixed, delay-independent period is used for regular * updates, while minimal separating interval is enforced for triggered updates. * The function also ensures that a new update is not started when the old one * is still running. */ static void rip_iface_timer(timer *t) { struct rip_iface *ifa = t->data; struct rip_proto *p = ifa->rip; btime now_ = current_time(); btime period = ifa->cf->update_time; if (ifa->cf->passive) return; TRACE(D_EVENTS, "Interface timer fired for %s", ifa->iface->name); if (ifa->tx_active) { tm_start(ifa->timer, 100 MS); return; } if (now_ >= ifa->next_regular) { /* Send regular update, set timer for next period (or following one if necessay) */ TRACE(D_EVENTS, "Sending regular updates for %s", ifa->iface->name); rip_send_table(p, ifa, ifa->addr, 0); ifa->next_regular += period * (1 + ((now_ - ifa->next_regular) / period)); ifa->want_triggered = 0; p->triggered = 0; } else if (ifa->want_triggered && (now_ >= ifa->next_triggered)) { /* Send triggered update, enforce interval between triggered updates */ TRACE(D_EVENTS, "Sending triggered updates for %s", ifa->iface->name); rip_send_table(p, ifa, ifa->addr, ifa->want_triggered); ifa->next_triggered = now_ + MIN(5 S, period / 2); ifa->want_triggered = 0; p->triggered = 0; } if (ifa->want_triggered && (ifa->next_triggered < ifa->next_regular)) tm_set(ifa->timer, ifa->next_triggered); else if (ifa->next_regular != TIME_INFINITY) tm_set(ifa->timer, ifa->next_regular); } static inline void rip_iface_kick_timer(struct rip_iface *ifa) { if ((! tm_active(ifa->timer)) || (ifa->timer->expires > (current_time() + 100 MS))) tm_start(ifa->timer, 100 MS); } static void rip_trigger_update(struct rip_proto *p) { if (p->triggered) return; struct rip_iface *ifa; WALK_LIST(ifa, p->iface_list) { /* Interface not active */ if (! ifa->up) continue; /* Already scheduled */ if (ifa->want_triggered) continue; TRACE(D_EVENTS, "Scheduling triggered updates for %s", ifa->iface->name); ifa->want_triggered = current_time(); rip_iface_kick_timer(ifa); p->triggered = 1; } } /* * RIP protocol glue */ static void rip_reload_routes(struct channel *C) { struct rip_proto *p = (struct rip_proto *) C->proto; if (p->rt_reload) return; TRACE(D_EVENTS, "Scheduling route reload"); p->rt_reload = 1; rip_kick_timer(p); } static int rip_rte_better(struct rte *new, struct rte *old) { ASSERT_DIE(new->src == old->src); struct rip_proto *p = (struct rip_proto *) new->src->proto; u32 new_metric = ea_get_int(new->attrs->eattrs, &ea_rip_metric, p->infinity); u32 old_metric = ea_get_int(old->attrs->eattrs, &ea_rip_metric, p->infinity); return new_metric < old_metric; } static u32 rip_rte_igp_metric(const rte *rt) { return ea_get_int(rt->attrs->eattrs, &ea_rip_metric, IGP_METRIC_UNKNOWN); } static void rip_postconfig(struct proto_config *CF) { // struct rip_config *cf = (void *) CF; /* Define default channel */ if (! proto_cf_main_channel(CF)) channel_config_new(NULL, net_label[CF->net_type], CF->net_type, CF); } static struct proto * rip_init(struct proto_config *CF) { struct proto *P = proto_new(CF); P->main_channel = proto_add_channel(P, proto_cf_main_channel(CF)); P->if_notify = rip_if_notify; P->rt_notify = rip_rt_notify; P->neigh_notify = rip_neigh_notify; P->reload_routes = rip_reload_routes; P->rte_better = rip_rte_better; P->rte_igp_metric = rip_rte_igp_metric; return P; } static int rip_start(struct proto *P) { struct rip_proto *p = (void *) P; struct rip_config *cf = (void *) (P->cf); init_list(&p->iface_list); fib_init(&p->rtable, P->pool, cf->rip2 ? NET_IP4 : NET_IP6, sizeof(struct rip_entry), OFFSETOF(struct rip_entry, n), 0, NULL); p->rte_slab = sl_new(P->pool, sizeof(struct rip_rte)); p->timer = tm_new_init(P->pool, rip_timer, p, 0, 0); p->rip2 = cf->rip2; p->ecmp = cf->ecmp; p->infinity = cf->infinity; p->triggered = 0; p->log_pkt_tbf = (struct tbf){ .rate = 1, .burst = 5 }; p->log_rte_tbf = (struct tbf){ .rate = 4, .burst = 20 }; tm_start(p->timer, MIN(cf->min_timeout_time, cf->max_garbage_time)); return PS_UP; } static int rip_shutdown(struct proto *P) { struct rip_proto *p = (void *) P; TRACE(D_EVENTS, "Shutdown requested"); struct rip_iface *ifa; WALK_LIST(ifa, p->iface_list) rip_iface_stop(ifa); return PS_DOWN; } static int rip_reconfigure(struct proto *P, struct proto_config *CF) { struct rip_proto *p = (void *) P; struct rip_config *new = (void *) CF; // struct rip_config *old = (void *) (P->cf); if (new->rip2 != p->rip2) return 0; if (new->infinity != p->infinity) return 0; if (!proto_configure_channel(P, &P->main_channel, proto_cf_main_channel(CF))) return 0; TRACE(D_EVENTS, "Reconfiguring"); p->p.cf = CF; p->ecmp = new->ecmp; rip_reconfigure_ifaces(p, new); p->rt_reload = 1; rip_kick_timer(p); return 1; } static void rip_get_route_info(rte *rte, byte *buf) { struct rip_proto *p = (struct rip_proto *) rte->src->proto; u32 rt_metric = ea_get_int(rte->attrs->eattrs, &ea_rip_metric, p->infinity); u32 rt_tag = ea_get_int(rte->attrs->eattrs, &ea_rip_tag, 0); buf += bsprintf(buf, " (%d/%d)", rt_get_preference(rte), rt_metric); if (rt_tag) bsprintf(buf, " [%04x]", rt_tag); } static void rip_tag_format(const eattr *a, byte *buf, uint buflen) { bsnprintf(buf, buflen, "tag: %04x", a->u.data); } static struct ea_class ea_rip_metric = { .name = "rip_metric", .type = T_INT, }; static struct ea_class ea_rip_tag = { .name = "rip_tag", .type = T_INT, .format = rip_tag_format, }; static struct ea_class ea_rip_from = { .name = "rip_from", .type = T_IFACE, .readonly = 1, }; void rip_show_interfaces(struct proto *P, const char *iff) { struct rip_proto *p = (void *) P; struct rip_iface *ifa = NULL; struct rip_neighbor *n = NULL; if (p->p.proto_state != PS_UP) { cli_msg(-1021, "%s: is not up", p->p.name); return; } cli_msg(-1021, "%s:", p->p.name); cli_msg(-1021, "%-10s %-6s %6s %6s %7s", "Interface", "State", "Metric", "Nbrs", "Timer"); WALK_LIST(ifa, p->iface_list) { if (iff && !patmatch(iff, ifa->iface->name)) continue; int nbrs = 0; WALK_LIST(n, ifa->neigh_list) if (n->last_seen) nbrs++; btime now_ = current_time(); btime timer = ((ifa->next_regular < TIME_INFINITY) && (ifa->next_regular > now_)) ? (ifa->next_regular - now_) : 0; cli_msg(-1021, "%-10s %-6s %6u %6u %7t", ifa->iface->name, (ifa->up ? "Up" : "Down"), ifa->cf->metric, nbrs, timer); } } void rip_show_neighbors(struct proto *P, const char *iff) { struct rip_proto *p = (void *) P; struct rip_iface *ifa = NULL; struct rip_neighbor *n = NULL; if (p->p.proto_state != PS_UP) { cli_msg(-1022, "%s: is not up", p->p.name); return; } cli_msg(-1022, "%s:", p->p.name); cli_msg(-1022, "%-25s %-10s %6s %6s %7s", "IP address", "Interface", "Metric", "Routes", "Seen"); WALK_LIST(ifa, p->iface_list) { if (iff && !patmatch(iff, ifa->iface->name)) continue; WALK_LIST(n, ifa->neigh_list) { if (!n->last_seen) continue; btime timer = current_time() - n->last_seen; cli_msg(-1022, "%-25I %-10s %6u %6u %7t", n->nbr->addr, ifa->iface->name, ifa->cf->metric, n->uc, timer); } } } static void rip_dump(struct proto *P) { struct rip_proto *p = (struct rip_proto *) P; struct rip_iface *ifa; int i; i = 0; FIB_WALK(&p->rtable, struct rip_entry, en) { debug("RIP: entry #%d: %N via %I dev %s valid %d metric %d age %t\n", i++, en->n.addr, en->next_hop, en->iface ? en->iface->name : "(null)", en->valid, en->metric, current_time() - en->changed); for (struct rip_rte *e = en->routes; e; e = e->next) debug("RIP: via %I metric %d expires %t\n", e->next_hop, e->metric, e->expires - current_time()); } FIB_WALK_END; i = 0; WALK_LIST(ifa, p->iface_list) { debug("RIP: interface #%d: %s, %I, up = %d, busy = %d\n", i++, ifa->iface->name, ifa->sk ? ifa->sk->daddr : IPA_NONE, ifa->up, ifa->tx_active); } } struct protocol proto_rip = { .name = "RIP", .template = "rip%d", .preference = DEF_PREF_RIP, .channel_mask = NB_IP, .proto_size = sizeof(struct rip_proto), .config_size = sizeof(struct rip_config), .postconfig = rip_postconfig, .init = rip_init, .dump = rip_dump, .start = rip_start, .shutdown = rip_shutdown, .reconfigure = rip_reconfigure, .get_route_info = rip_get_route_info, }; void rip_build(void) { proto_build(&proto_rip); EA_REGISTER_ALL( &ea_rip_metric, &ea_rip_tag, &ea_rip_from ); }