/* * BIRD -- OSPF * * (c) 2000--2004 Ondrej Filip <feela@network.cz> * (c) 2009--2014 Ondrej Zajicek <santiago@crfreenet.org> * (c) 2009--2014 CZ.NIC z.s.p.o. * * Can be freely distributed and used under the terms of the GNU GPL. */ #include "ospf.h" /* struct ospf_lsupd_packet { struct ospf_packet hdr; // union ospf_auth auth; u32 lsa_count; void lsas[]; }; */ void ospf_dump_lsahdr(struct ospf_proto *p, struct ospf_lsa_header *lsa_n) { struct ospf_lsa_header lsa; u32 lsa_etype; lsa_ntoh_hdr(lsa_n, &lsa); lsa_etype = lsa_get_etype(&lsa, p); log(L_TRACE "%s: LSA Type: %04x, Id: %R, Rt: %R, Seq: %08x, Age: %u, Sum: %04x", p->p.name, lsa_etype, lsa.id, lsa.rt, lsa.sn, lsa.age, lsa.checksum); } void ospf_dump_common(struct ospf_proto *p, struct ospf_packet *pkt) { log(L_TRACE "%s: length %d", p->p.name, ntohs(pkt->length)); log(L_TRACE "%s: router %R", p->p.name, ntohl(pkt->routerid)); } static inline uint ospf_lsupd_hdrlen(struct ospf_proto *p) { return ospf_pkt_hdrlen(p) + 4; /* + u32 lsa count field */ } static inline u32 ospf_lsupd_get_lsa_count(struct ospf_packet *pkt, uint hdrlen) { u32 *c = ((void *) pkt) + hdrlen - 4; return ntohl(*c); } static inline void ospf_lsupd_set_lsa_count(struct ospf_packet *pkt, uint hdrlen, u32 val) { u32 *c = ((void *) pkt) + hdrlen - 4; *c = htonl(val); } static inline void ospf_lsupd_body(struct ospf_proto *p, struct ospf_packet *pkt, uint *offset, uint *lsa_count) { uint hlen = ospf_lsupd_hdrlen(p); *offset = hlen; *lsa_count = ospf_lsupd_get_lsa_count(pkt, hlen); } static void ospf_dump_lsupd(struct ospf_proto *p, struct ospf_packet *pkt) { uint offset, plen, i, lsa_count, lsa_len; ASSERT(pkt->type == LSUPD_P); ospf_dump_common(p, pkt); plen = ntohs(pkt->length); ospf_lsupd_body(p, pkt, &offset, &lsa_count); for (i = 0; i < lsa_count; i++) { if ((offset + sizeof(struct ospf_lsa_header)) > plen) goto invalid; struct ospf_lsa_header *lsa = ((void *) pkt) + offset; lsa_len = ntohs(lsa->length); if (((lsa_len % 4) != 0) || (lsa_len <= sizeof(struct ospf_lsa_header))) goto invalid; ospf_dump_lsahdr(p, lsa); offset += lsa_len; } return; invalid: log(L_TRACE "%s: LSA invalid", p->p.name); return; } static inline void ospf_lsa_lsrq_down(struct top_hash_entry *req, struct ospf_neighbor *n, struct ospf_neighbor *from) { if (req == n->lsrqi) n->lsrqi = SNODE_NEXT(req); s_rem_node(SNODE req); ospf_hash_delete(n->lsrqh, req); if (EMPTY_SLIST(n->lsrql)) { tm_stop(n->lsrq_timer); if (n->state == NEIGHBOR_LOADING) ospf_neigh_sm(n, INM_LOADDONE); } } static inline void ospf_lsa_lsrt_up(struct top_hash_entry *en, struct ospf_neighbor *n) { struct top_hash_entry *ret = ospf_hash_get_entry(n->lsrth, en); if (!SNODE_VALID(ret)) { en->ret_count++; s_add_tail(&n->lsrtl, SNODE ret); } ret->lsa = en->lsa; ret->lsa_body = LSA_BODY_DUMMY; if (!tm_active(n->lsrt_timer)) tm_start(n->lsrt_timer, n->ifa->rxmtint); } void ospf_lsa_lsrt_down_(struct top_hash_entry *en, struct ospf_neighbor *n, struct top_hash_entry *ret) { if (en) en->ret_count--; s_rem_node(SNODE ret); ospf_hash_delete(n->lsrth, ret); if (EMPTY_SLIST(n->lsrtl)) tm_stop(n->lsrt_timer); } static inline int ospf_lsa_lsrt_down(struct top_hash_entry *en, struct ospf_neighbor *n) { struct top_hash_entry *ret = ospf_hash_find_entry(n->lsrth, en); if (ret) ospf_lsa_lsrt_down_(en, n, ret); return ret != NULL; } void ospf_add_flushed_to_lsrt(struct ospf_proto *p, struct ospf_neighbor *n) { struct top_hash_entry *en; WALK_SLIST(en, p->lsal) if ((en->lsa.age == LSA_MAXAGE) && (en->lsa_body != NULL) && lsa_flooding_allowed(en->lsa_type, en->domain, n->ifa)) ospf_lsa_lsrt_up(en, n); /* If we found any flushed LSA, we send them ASAP */ if (tm_active(n->lsrt_timer)) tm_start(n->lsrt_timer, 0); } static int ospf_flood_lsupd(struct ospf_proto *p, struct top_hash_entry **lsa_list, uint lsa_count, uint lsa_min_count, struct ospf_iface *ifa); static void ospf_enqueue_lsa(struct ospf_proto *p, struct top_hash_entry *en, struct ospf_iface *ifa) { if (ifa->flood_queue_used == ifa->flood_queue_size) { /* If we already have full queue, we send some packets */ uint sent = ospf_flood_lsupd(p, ifa->flood_queue, ifa->flood_queue_used, ifa->flood_queue_used / 2, ifa); int i; for (i = 0; i < sent; i++) ifa->flood_queue[i]->ret_count--; ifa->flood_queue_used -= sent; memmove(ifa->flood_queue, ifa->flood_queue + sent, ifa->flood_queue_used * sizeof(void *)); bzero(ifa->flood_queue + ifa->flood_queue_used, sent * sizeof(void *)); } en->ret_count++; ifa->flood_queue[ifa->flood_queue_used] = en; ifa->flood_queue_used++; if (!ev_active(p->flood_event)) ev_schedule(p->flood_event); } void ospf_flood_event(void *ptr) { struct ospf_proto *p = ptr; struct ospf_iface *ifa; int i, count; WALK_LIST(ifa, p->iface_list) { if (ifa->flood_queue_used == 0) continue; count = ifa->flood_queue_used; ospf_flood_lsupd(p, ifa->flood_queue, count, count, ifa); for (i = 0; i < count; i++) ifa->flood_queue[i]->ret_count--; ifa->flood_queue_used = 0; bzero(ifa->flood_queue, count * sizeof(void *)); } } /** * ospf_flood_lsa - send LSA to the neighbors * @p: OSPF protocol instance * @en: LSA entry * @from: neighbor than sent this LSA (or NULL if LSA is local) * * return value - was the LSA flooded back? */ int ospf_flood_lsa(struct ospf_proto *p, struct top_hash_entry *en, struct ospf_neighbor *from) { struct ospf_iface *ifa; struct ospf_neighbor *n; /* RFC 2328 13.3 */ int back = 0; WALK_LIST(ifa, p->iface_list) { if (ifa->stub) continue; if (! lsa_flooding_allowed(en->lsa_type, en->domain, ifa)) continue; DBG("Wanted to flood LSA: Type: %u, ID: %R, RT: %R, SN: 0x%x, Age %u\n", hh->type, hh->id, hh->rt, hh->sn, hh->age); int used = 0; WALK_LIST(n, ifa->neigh_list) { /* 13.3 (1a) */ if (n->state < NEIGHBOR_EXCHANGE) continue; /* 13.3 (1b) */ if (n->state < NEIGHBOR_FULL) { struct top_hash_entry *req = ospf_hash_find_entry(n->lsrqh, en); if (req != NULL) { int cmp = lsa_comp(&en->lsa, &req->lsa); /* If same or newer, remove LSA from the link state request list */ if (cmp > CMP_OLDER) ospf_lsa_lsrq_down(req, n, from); /* If older or same, skip processing of this neighbor */ if (cmp < CMP_NEWER) continue; } } /* 13.3 (1c) */ if (n == from) continue; /* In OSPFv3, there should be check whether receiving router understand that type of LSA (for LSA types with U-bit == 0). But as we do not support any optional LSA types, this is not needed yet */ /* 13.3 (1d) - add LSA to the link state retransmission list */ ospf_lsa_lsrt_up(en, n); used = 1; } /* 13.3 (2) */ if (!used) continue; if (from && (from->ifa == ifa)) { /* 13.3 (3) */ if ((from->rid == ifa->drid) || (from->rid == ifa->bdrid)) continue; /* 13.3 (4) */ if (ifa->state == OSPF_IS_BACKUP) continue; back = 1; } /* 13.3 (5) - finally flood the packet */ ospf_enqueue_lsa(p, en, ifa); } return back; } static uint ospf_prepare_lsupd(struct ospf_proto *p, struct ospf_iface *ifa, struct top_hash_entry **lsa_list, uint lsa_count) { struct ospf_packet *pkt; uint hlen, pos, i, maxsize; pkt = ospf_tx_buffer(ifa); hlen = ospf_lsupd_hdrlen(p); maxsize = ospf_pkt_maxsize(ifa); ospf_pkt_fill_hdr(ifa, pkt, LSUPD_P); pos = hlen; for (i = 0; i < lsa_count; i++) { struct top_hash_entry *en = lsa_list[i]; uint len = en->lsa.length; if ((pos + len) > maxsize) { /* The packet if full, stop adding LSAs and sent it */ if (i > 0) break; /* LSA is larger than MTU, check buffer size */ if (ospf_iface_assure_bufsize(ifa, pos + len) < 0) { /* Cannot fit in a tx buffer, skip that */ log(L_ERR "%s: LSA too large to send on %s (Type: %04x, Id: %R, Rt: %R)", p->p.name, ifa->ifname, en->lsa_type, en->lsa.id, en->lsa.rt); break; } /* TX buffer could be reallocated */ pkt = ospf_tx_buffer(ifa); } struct ospf_lsa_header *buf = ((void *) pkt) + pos; lsa_hton_hdr(&en->lsa, buf); lsa_hton_body(en->lsa_body, ((void *) buf) + sizeof(struct ospf_lsa_header), len - sizeof(struct ospf_lsa_header)); buf->age = htons(MIN(en->lsa.age + ifa->inftransdelay, LSA_MAXAGE)); pos += len; } ospf_lsupd_set_lsa_count(pkt, hlen, i); pkt->length = htons(pos); return i; } static int ospf_flood_lsupd(struct ospf_proto *p, struct top_hash_entry **lsa_list, uint lsa_count, uint lsa_min_count, struct ospf_iface *ifa) { uint i, c; for (i = 0; i < lsa_min_count; i += c) { c = ospf_prepare_lsupd(p, ifa, lsa_list + i, lsa_count - i); if (!c) /* Too large LSA */ { i++; continue; } OSPF_PACKET(ospf_dump_lsupd, ospf_tx_buffer(ifa), "LSUPD packet flooded via %s", ifa->ifname); if (ifa->type == OSPF_IT_BCAST) { if ((ifa->state == OSPF_IS_DR) || (ifa->state == OSPF_IS_BACKUP)) ospf_send_to_all(ifa); else ospf_send_to_des(ifa); } else ospf_send_to_agt(ifa, NEIGHBOR_EXCHANGE); } return i; } int ospf_send_lsupd(struct ospf_proto *p, struct top_hash_entry **lsa_list, uint lsa_count, struct ospf_neighbor *n) { struct ospf_iface *ifa = n->ifa; uint i, c; for (i = 0; i < lsa_count; i += c) { c = ospf_prepare_lsupd(p, ifa, lsa_list + i, lsa_count - i); if (!c) /* Too large LSA */ { i++; continue; } OSPF_PACKET(ospf_dump_lsupd, ospf_tx_buffer(ifa), "LSUPD packet sent to nbr %R on %s", n->rid, ifa->ifname); ospf_send_to(ifa, n->ip); } return i; } void ospf_rxmt_lsupd(struct ospf_proto *p, struct ospf_neighbor *n) { uint max = 2 * n->ifa->flood_queue_size; struct top_hash_entry *entries[max]; struct top_hash_entry *ret, *nxt, *en; uint i = 0; /* ASSERT((n->state >= NEIGHBOR_EXCHANGE) && !EMPTY_SLIST(n->lsrtl)); */ WALK_SLIST_DELSAFE(ret, nxt, n->lsrtl) { if (i == max) break; en = ospf_hash_find_entry(p->gr, ret); if (!en) { /* Probably flushed LSA, this should not happen */ log(L_WARN "%s: LSA disappeared (Type: %04x, Id: %R, Rt: %R)", p->p.name, ret->lsa_type, ret->lsa.id, ret->lsa.rt); s_rem_node(SNODE ret); ospf_hash_delete(n->lsrth, ret); continue; } entries[i] = en; i++; } ospf_send_lsupd(p, entries, i, n); } static inline int ospf_addr_is_local(struct ospf_proto *p, struct ospf_area *oa, ip_addr ip) { struct ospf_iface *ifa; WALK_LIST(ifa, p->iface_list) if ((ifa->oa == oa) && ifa->addr && ipa_equal(ifa->addr->ip, ip)) return 1; return 0; } void ospf_receive_lsupd(struct ospf_packet *pkt, struct ospf_iface *ifa, struct ospf_neighbor *n) { struct ospf_proto *p = ifa->oa->po; const char *err_dsc = NULL; uint plen, err_val = 0; /* RFC 2328 13. */ plen = ntohs(pkt->length); if (plen < ospf_lsupd_hdrlen(p)) { LOG_PKT("Bad LSUPD packet from nbr %R on %s - %s (%u)", n->rid, ifa->ifname, "too short", plen); return; } OSPF_PACKET(ospf_dump_lsupd, pkt, "LSUPD packet received from nbr %R on %s", n->rid, ifa->ifname); if (n->state < NEIGHBOR_EXCHANGE) { OSPF_TRACE(D_PACKETS, "LSUPD packet ignored - lesser state than Exchange"); return; } ospf_neigh_sm(n, INM_HELLOREC); /* Questionable */ uint offset, i, lsa_count; ospf_lsupd_body(p, pkt, &offset, &lsa_count); for (i = 0; i < lsa_count; i++) { struct ospf_lsa_header lsa, *lsa_n; struct top_hash_entry *en; u32 lsa_len, lsa_type, lsa_domain; if ((offset + sizeof(struct ospf_lsa_header)) > plen) DROP("too short", plen); /* LSA header in network order */ lsa_n = ((void *) pkt) + offset; lsa_len = ntohs(lsa_n->length); offset += lsa_len; if (offset > plen) DROP("too short", plen); if (((lsa_len % 4) != 0) || (lsa_len <= sizeof(struct ospf_lsa_header))) DROP("invalid LSA length", lsa_len); /* LSA header in host order */ lsa_ntoh_hdr(lsa_n, &lsa); lsa_get_type_domain(&lsa, ifa, &lsa_type, &lsa_domain); DBG("Update Type: %04x, Id: %R, Rt: %R, Sn: 0x%08x, Age: %u, Sum: %u\n", lsa_type, lsa.id, lsa.rt, lsa.sn, lsa.age, lsa.checksum); /* RFC 2328 13. (1) - validate LSA checksum */ if ((lsa_n->checksum == 0) || (lsasum_check(lsa_n, NULL, 0) != 0)) SKIP("invalid checksum"); /* RFC 2328 13. (2) */ if (!lsa_type) SKIP("unknown type"); /* RFC 5340 4.5.1 (2) and RFC 2328 13. (3) */ if (!oa_is_ext(ifa->oa) && (LSA_SCOPE(lsa_type) == LSA_SCOPE_AS)) SKIP("AS scope in stub area"); /* Errata 3746 to RFC 2328 - rt-summary-LSAs forbidden in stub areas */ if (!oa_is_ext(ifa->oa) && (lsa_type == LSA_T_SUM_RT)) SKIP("rt-summary-LSA in stub area"); /* RFC 5340 4.5.1 (3) */ if (LSA_SCOPE(lsa_type) == LSA_SCOPE_RES) SKIP("invalid scope"); /* Find local copy of LSA in link state database */ en = ospf_hash_find(p->gr, lsa_domain, lsa.id, lsa.rt, lsa_type); #ifdef LOCAL_DEBUG if (en) DBG("I have Type: %04x, Id: %R, Rt: %R, Sn: 0x%08x, Age: %u, Sum: %u\n", en->lsa_type, en->lsa.id, en->lsa.rt, en->lsa.sn, en->lsa.age, en->lsa.checksum); #endif /* 13. (4) - ignore maxage LSA if i have no local copy */ if ((lsa.age == LSA_MAXAGE) && !en && (p->padj == 0)) { /* 13.5. - schedule ACKs (tbl 19, case 5) */ ospf_enqueue_lsack(n, lsa_n, ACKL_DIRECT); continue; } /* 13. (5) - received LSA is newer (or no local copy) */ if (!en || (lsa_comp(&lsa, &en->lsa) == CMP_NEWER)) { /* 13. (5a) - enforce minimum time between updates for received LSAs */ /* We also use this to ratelimit reactions to received self-originated LSAs */ if (en && ((now - en->inst_time) < MINLSARRIVAL)) { OSPF_TRACE(D_EVENTS, "Skipping LSA received in less that MinLSArrival"); continue; } /* Copy and validate LSA body */ int blen = lsa.length - sizeof(struct ospf_lsa_header); void *body = mb_alloc(p->p.pool, blen); lsa_ntoh_body(lsa_n + 1, body, blen); if (lsa_validate(&lsa, lsa_type, ospf_is_v2(p), body) == 0) { mb_free(body); SKIP("invalid body"); } /* 13. (5f) - handle self-originated LSAs, see also 13.4. */ if ((lsa.rt == p->router_id) || (ospf_is_v2(p) && (lsa_type == LSA_T_NET) && ospf_addr_is_local(p, ifa->oa, ipa_from_u32(lsa.id)))) { OSPF_TRACE(D_EVENTS, "Received unexpected self-originated LSA"); ospf_advance_lsa(p, en, &lsa, lsa_type, lsa_domain, body); continue; } /* 13. (5c) - remove old LSA from all retransmission lists * * We only need to remove it from the retransmission list of the neighbor * that send us the new LSA. The old LSA is automatically replaced in * retransmission lists by the new LSA. */ if (en) ospf_lsa_lsrt_down(en, n); #if 0 /* * Old code for removing LSA from all retransmission lists. Must be done * before (5b), otherwise it also removes the new entries from (5b). */ struct ospf_iface *ifi; struct ospf_neighbor *ni; WALK_LIST(ifi, p->iface_list) WALK_LIST(ni, ifi->neigh_list) if (ni->state > NEIGHBOR_EXSTART) ospf_lsa_lsrt_down(en, ni); #endif /* 13. (5d) - install new LSA into database */ en = ospf_install_lsa(p, &lsa, lsa_type, lsa_domain, body); /* RFC 5340 4.4.3 Events 6+7 - new Link LSA received */ if (lsa_type == LSA_T_LINK) ospf_notify_net_lsa(ifa); /* 13. (5b) - flood new LSA */ int flood_back = ospf_flood_lsa(p, en, n); /* 13.5. - schedule ACKs (tbl 19, cases 1+2) */ if (! flood_back) if ((ifa->state != OSPF_IS_BACKUP) || (n->rid == ifa->drid)) ospf_enqueue_lsack(n, lsa_n, ACKL_DELAY); /* FIXME: remove LSA entry if it is LSA_MAXAGE and it is possible? */ continue; } /* 13. (6) - received LSA is in Link state request list (but not newer) */ if (ospf_hash_find_entry(n->lsrqh, en) != NULL) DROP1("error in LSA database exchange"); /* 13. (7) - received LSA is same */ if (lsa_comp(&lsa, &en->lsa) == CMP_SAME) { /* Duplicate LSA, treat as implicit ACK */ int implicit_ack = ospf_lsa_lsrt_down(en, n); /* 13.5. - schedule ACKs (tbl 19, cases 3+4) */ if (implicit_ack) { if ((ifa->state == OSPF_IS_BACKUP) && (n->rid == ifa->drid)) ospf_enqueue_lsack(n, lsa_n, ACKL_DELAY); } else ospf_enqueue_lsack(n, lsa_n, ACKL_DIRECT); continue; } /* 13. (8) - received LSA is older */ { /* Seqnum is wrapping, wait until it is flushed */ if ((en->lsa.age == LSA_MAXAGE) && (en->lsa.sn == LSA_MAXSEQNO)) continue; /* Send newer local copy back to neighbor */ /* FIXME - check for MinLSArrival ? */ ospf_send_lsupd(p, &en, 1, n); continue; } skip: LOG_LSA1("Bad LSA (Type: %04x, Id: %R, Rt: %R) in LSUPD", lsa_type, lsa.id, lsa.rt); LOG_LSA2(" received from nbr %R on %s - %s", n->rid, ifa->ifname, err_dsc); } /* Send direct LSACKs */ ospf_send_lsack(p, n, ACKL_DIRECT); /* Send enqueued LSAs immediately, do not wait for flood_event */ if (ev_active(p->flood_event)) { ev_postpone(p->flood_event); ospf_flood_event(p); } /* * During loading, we should ask for another batch of LSAs. This is only * vaguely mentioned in RFC 2328. We send a new LSREQ if all requests sent in * the last packet were already answered and/or removed from the LS request * list and therefore lsrqi is pointing to the first node of the list. */ if (!EMPTY_SLIST(n->lsrql) && (n->lsrqi == SHEAD(n->lsrql))) { ospf_send_lsreq(p, n); tm_start(n->lsrq_timer, n->ifa->rxmtint); } return; drop: LOG_PKT("Bad LSUPD packet from nbr %R on %s - %s (%u)", n->rid, ifa->ifname, err_dsc, err_val); /* Malformed LSUPD - there is no defined error event, we abuse BadLSReq */ ospf_neigh_sm(n, INM_BADLSREQ); return; }