/* * BIRD -- OSPF * * (c) 1999--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_dbdes2_packet { struct ospf_packet hdr; union ospf_auth2 auth; u16 iface_mtu; u8 options; u8 imms; /* I, M, MS bits */ u32 ddseq; struct ospf_lsa_header lsas[]; }; struct ospf_dbdes3_packet { struct ospf_packet hdr; u32 options; u16 iface_mtu; u8 padding; u8 imms; /* I, M, MS bits */ u32 ddseq; struct ospf_lsa_header lsas[]; }; uint ospf_dbdes3_options(struct ospf_packet *pkt) { struct ospf_dbdes3_packet *ps = (void *) pkt; return ntohl(ps->options); } static inline uint ospf_dbdes_hdrlen(struct ospf_proto *p) { return ospf_is_v2(p) ? sizeof(struct ospf_dbdes2_packet) : sizeof(struct ospf_dbdes3_packet); } static void ospf_dbdes_body(struct ospf_proto *p, struct ospf_packet *pkt, struct ospf_lsa_header **body, uint *count) { uint plen = ntohs(pkt->length); uint hlen = ospf_dbdes_hdrlen(p); *body = ((void *) pkt) + hlen; *count = (plen - hlen) / sizeof(struct ospf_lsa_header); } static void ospf_dump_dbdes(struct ospf_proto *p, struct ospf_packet *pkt) { struct ospf_lsa_header *lsas; uint i, lsa_count; u32 pkt_ddseq; u16 pkt_iface_mtu; u8 pkt_imms; ASSERT(pkt->type == DBDES_P); ospf_dump_common(p, pkt); if (ospf_is_v2(p)) { struct ospf_dbdes2_packet *ps = (void *) pkt; pkt_iface_mtu = ntohs(ps->iface_mtu); pkt_imms = ps->imms; pkt_ddseq = ntohl(ps->ddseq); } else /* OSPFv3 */ { struct ospf_dbdes3_packet *ps = (void *) pkt; pkt_iface_mtu = ntohs(ps->iface_mtu); pkt_imms = ps->imms; pkt_ddseq = ntohl(ps->ddseq); } log(L_TRACE "%s: mtu %u", p->p.name, pkt_iface_mtu); log(L_TRACE "%s: imms %s%s%s", p->p.name, (pkt_imms & DBDES_I) ? "I " : "", (pkt_imms & DBDES_M) ? "M " : "", (pkt_imms & DBDES_MS) ? "MS" : ""); log(L_TRACE "%s: ddseq %u", p->p.name, pkt_ddseq); ospf_dbdes_body(p, pkt, &lsas, &lsa_count); for (i = 0; i < lsa_count; i++) ospf_dump_lsahdr(p, lsas + i); } static void ospf_prepare_dbdes(struct ospf_proto *p, struct ospf_neighbor *n) { struct ospf_iface *ifa = n->ifa; struct ospf_packet *pkt; uint length; u16 iface_mtu = (ifa->type == OSPF_IT_VLINK) ? 0 : ifa->iface->mtu; /* Update DBDES buffer */ if (n->ldd_bsize != ifa->tx_length) { mb_free(n->ldd_buffer); n->ldd_buffer = mb_allocz(n->pool, ifa->tx_length); n->ldd_bsize = ifa->tx_length; } pkt = n->ldd_buffer; ospf_pkt_fill_hdr(ifa, pkt, DBDES_P); if (ospf_is_v2(p)) { struct ospf_dbdes2_packet *ps = (void *) pkt; ps->iface_mtu = htons(iface_mtu); ps->options = ifa->oa->options & DBDES2_OPT_MASK; ps->imms = 0; /* Will be set later */ ps->ddseq = htonl(n->dds); length = sizeof(struct ospf_dbdes2_packet); } else /* OSPFv3 */ { struct ospf_dbdes3_packet *ps = (void *) pkt; u32 options = ifa->oa->options | (ifa->autype == OSPF_AUTH_CRYPT ? OPT_AT : 0); ps->options = htonl(options & DBDES3_OPT_MASK); ps->iface_mtu = htons(iface_mtu); ps->padding = 0; ps->imms = 0; /* Will be set later */ ps->ddseq = htonl(n->dds); length = sizeof(struct ospf_dbdes3_packet); } /* Prepare DBDES body */ if (!(n->myimms & DBDES_I) && (n->myimms & DBDES_M)) { struct ospf_lsa_header *lsas; struct top_hash_entry *en; uint i = 0, lsa_max; ospf_dbdes_body(p, pkt, &lsas, &lsa_max); en = (void *) s_get(&(n->dbsi)); while (i < lsa_max) { if (!SNODE_VALID(en)) { n->myimms &= ~DBDES_M; /* Unset More bit */ break; } if ((en->lsa.age < LSA_MAXAGE) && lsa_flooding_allowed(en->lsa_type, en->domain, ifa) && lsa_is_acceptable(en->lsa_type, n, p)) { lsa_hton_hdr(&(en->lsa), lsas + i); i++; } en = SNODE_NEXT(en); } s_put(&(n->dbsi), SNODE en); length += i * sizeof(struct ospf_lsa_header); } if (ospf_is_v2(p)) ((struct ospf_dbdes2_packet *) pkt)->imms = n->myimms; else ((struct ospf_dbdes3_packet *) pkt)->imms = n->myimms; pkt->length = htons(length); } static void ospf_do_send_dbdes(struct ospf_proto *p, struct ospf_neighbor *n) { struct ospf_iface *ifa = n->ifa; OSPF_PACKET(ospf_dump_dbdes, n->ldd_buffer, "DBDES packet sent to nbr %R on %s", n->rid, ifa->ifname); sk_set_tbuf(ifa->sk, n->ldd_buffer); ospf_send_to_nbr(ifa, n); sk_set_tbuf(ifa->sk, NULL); } /** * ospf_send_dbdes - transmit database description packet * @p: OSPF protocol instance * @n: neighbor * * Sending of a database description packet is described in 10.8 of RFC 2328. * Reception of each packet is acknowledged in the sequence number of another. * When I send a packet to a neighbor I keep a copy in a buffer. If the neighbor * does not reply, I don't create a new packet but just send the content * of the buffer. */ void ospf_send_dbdes(struct ospf_proto *p, struct ospf_neighbor *n) { /* RFC 2328 10.8 */ ASSERT((n->state == NEIGHBOR_EXSTART) || (n->state == NEIGHBOR_EXCHANGE)); if (!n->ifa->oa->rt && !p->gr_recovery) return; ospf_prepare_dbdes(p, n); ospf_do_send_dbdes(p, n); } void ospf_rxmt_dbdes(struct ospf_proto *p, struct ospf_neighbor *n) { ASSERT(n->state > NEIGHBOR_EXSTART); if (!n->ldd_buffer) { log(L_WARN "%s: No DBDES packet for retransmit", p->p.name); ospf_neigh_sm(n, INM_SEQMIS); return; } /* Send last packet */ ospf_do_send_dbdes(p, n); } void ospf_reset_ldd(struct ospf_proto *p UNUSED, struct ospf_neighbor *n) { mb_free(n->ldd_buffer); n->ldd_buffer = NULL; n->ldd_bsize = 0; } static int ospf_process_dbdes(struct ospf_proto *p, struct ospf_packet *pkt, struct ospf_neighbor *n) { struct ospf_iface *ifa = n->ifa; struct ospf_lsa_header *lsas, lsa; struct top_hash_entry *en, *req; const char *err_dsc = NULL; u32 lsa_type, lsa_domain; uint i, lsa_count; ospf_dbdes_body(p, pkt, &lsas, &lsa_count); for (i = 0; i < lsa_count; i++) { lsa_ntoh_hdr(lsas + i, &lsa); lsa_get_type_domain(&lsa, ifa, &lsa_type, &lsa_domain); /* RFC 2328 10.6 and RFC 5340 4.2.2 */ if (!lsa_type) DROP1("LSA of unknown type"); if (!oa_is_ext(ifa->oa) && (LSA_SCOPE(lsa_type) == LSA_SCOPE_AS)) DROP1("LSA with 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)) DROP1("rt-summary-LSA in stub area"); /* Not explicitly mentioned in RFC 5340 4.2.2 but makes sense */ if (LSA_SCOPE(lsa_type) == LSA_SCOPE_RES) DROP1("LSA with invalid scope"); /* RFC 3623 2.2 (2) special case - check for my router-LSA (GR recovery) */ if ((lsa_type == LSA_T_RT) && (lsa.rt == p->router_id)) n->got_my_rt_lsa = 1; en = ospf_hash_find(p->gr, lsa_domain, lsa.id, lsa.rt, lsa_type); if (!en || (lsa_comp(&lsa, &(en->lsa)) == CMP_NEWER)) { /* This should be splitted to ospf_lsa_lsrq_up() */ req = ospf_hash_get(n->lsrqh, lsa_domain, lsa.id, lsa.rt, lsa_type); if (!SNODE_VALID(req)) s_add_tail(&n->lsrql, SNODE req); if (!SNODE_VALID(n->lsrqi)) n->lsrqi = req; req->lsa = lsa; req->lsa_body = LSA_BODY_DUMMY; if (!tm_active(n->lsrq_timer)) tm_start(n->lsrq_timer, 0); } } return 0; drop: LOG_LSA1("Bad LSA (Type: %04x, Id: %R, Rt: %R) in DBDES", lsa_type, lsa.id, lsa.rt); LOG_LSA2(" received from nbr %R on %s - %s", n->rid, ifa->ifname, err_dsc); ospf_neigh_sm(n, INM_SEQMIS); return -1; } void ospf_receive_dbdes(struct ospf_packet *pkt, struct ospf_iface *ifa, struct ospf_neighbor *n) { struct ospf_proto *p = ifa->oa->po; const char *err_dsc = NULL; u32 rcv_ddseq, rcv_options; u16 rcv_iface_mtu; u8 rcv_imms; uint plen, err_val = 0; /* RFC 2328 10.6 */ plen = ntohs(pkt->length); if (plen < ospf_dbdes_hdrlen(p)) { LOG_PKT("Bad DBDES packet from nbr %R on %s - %s (%u)", n->rid, ifa->ifname, "too short", plen); return; } OSPF_PACKET(ospf_dump_dbdes, pkt, "DBDES packet received from nbr %R on %s", n->rid, ifa->ifname); ospf_neigh_sm(n, INM_HELLOREC); if (ospf_is_v2(p)) { struct ospf_dbdes2_packet *ps = (void *) pkt; rcv_iface_mtu = ntohs(ps->iface_mtu); rcv_options = ps->options; rcv_imms = ps->imms; rcv_ddseq = ntohl(ps->ddseq); } else /* OSPFv3 */ { struct ospf_dbdes3_packet *ps = (void *) pkt; rcv_options = ntohl(ps->options); rcv_iface_mtu = ntohs(ps->iface_mtu); rcv_imms = ps->imms; rcv_ddseq = ntohl(ps->ddseq); } /* Reject packets with non-matching MTU */ if ((ifa->type != OSPF_IT_VLINK) && (rcv_iface_mtu != ifa->iface->mtu) && (rcv_iface_mtu != 0) && (ifa->iface->mtu != 0)) { LOG_PKT("MTU mismatch with nbr %R on %s (remote %d, local %d)", n->rid, ifa->ifname, rcv_iface_mtu, ifa->iface->mtu); return; } switch (n->state) { case NEIGHBOR_DOWN: case NEIGHBOR_ATTEMPT: case NEIGHBOR_2WAY: OSPF_TRACE(D_PACKETS, "DBDES packet ignored - lesser state than ExStart"); return; case NEIGHBOR_INIT: ospf_neigh_sm(n, INM_2WAYREC); if (n->state != NEIGHBOR_EXSTART) return; /* fallthrough */ case NEIGHBOR_EXSTART: if (((rcv_imms & DBDES_IMMS) == DBDES_IMMS) && (n->rid > p->router_id) && (plen == ospf_dbdes_hdrlen(p))) { /* I'm slave! */ n->dds = rcv_ddseq; n->ddr = rcv_ddseq; n->options = rcv_options; n->myimms &= ~DBDES_MS; n->imms = rcv_imms; tm_stop(n->dbdes_timer); ospf_neigh_sm(n, INM_NEGDONE); ospf_send_dbdes(p, n); break; } if (!(rcv_imms & DBDES_I) && !(rcv_imms & DBDES_MS) && (n->rid < p->router_id) && (n->dds == rcv_ddseq)) { /* I'm master! */ n->options = rcv_options; n->ddr = rcv_ddseq - 1; /* It will be set corectly a few lines down */ n->imms = rcv_imms; ospf_neigh_sm(n, INM_NEGDONE); /* Continue to the NEIGHBOR_EXCHANGE case */ } else { DBG("%s: Nothing happend to %I (imms=%d)\n", p->name, n->ip, rcv_imms); break; } case NEIGHBOR_EXCHANGE: if ((rcv_imms == n->imms) && (rcv_options == n->options) && (rcv_ddseq == n->ddr)) goto duplicate; if ((rcv_imms & DBDES_MS) != (n->imms & DBDES_MS)) DROP("MS-bit mismatch", rcv_imms); if (rcv_imms & DBDES_I) DROP("I-bit mismatch", rcv_imms); if (rcv_options != n->options) DROP("options mismatch", rcv_options); n->ddr = rcv_ddseq; n->imms = rcv_imms; if (n->myimms & DBDES_MS) { /* MASTER */ if (rcv_ddseq != n->dds) DROP("DD sequence number mismatch", rcv_ddseq); n->dds++; if (ospf_process_dbdes(p, pkt, n) < 0) return; if (!(n->myimms & DBDES_M) && !(n->imms & DBDES_M)) { tm_stop(n->dbdes_timer); ospf_reset_ldd(p, n); ospf_neigh_sm(n, INM_EXDONE); break; } ospf_send_dbdes(p, n); tm_start(n->dbdes_timer, n->ifa->rxmtint S); } else { /* SLAVE */ if (rcv_ddseq != (n->dds + 1)) DROP("DD sequence number mismatch", rcv_ddseq); n->ddr = rcv_ddseq; n->dds = rcv_ddseq; if (ospf_process_dbdes(p, pkt, n) < 0) return; ospf_send_dbdes(p, n); if (!(n->myimms & DBDES_M) && !(n->imms & DBDES_M)) { /* Use dbdes timer to postpone freeing of Last DBDES packet buffer */ tm_start(n->dbdes_timer, n->ifa->deadint S); ospf_neigh_sm(n, INM_EXDONE); } } break; case NEIGHBOR_LOADING: case NEIGHBOR_FULL: if ((rcv_imms == n->imms) && (rcv_options == n->options) && (rcv_ddseq == n->ddr)) goto duplicate; DROP("too late for DD exchange", n->state); default: bug("Undefined interface state"); } return; duplicate: OSPF_TRACE(D_PACKETS, "DBDES packet is duplicate"); /* Slave should retransmit DBDES packet */ if (!(n->myimms & DBDES_MS)) ospf_rxmt_dbdes(p, n); return; drop: LOG_PKT("Bad DBDES packet from nbr %R on %s - %s (%u)", n->rid, ifa->ifname, err_dsc, err_val); ospf_neigh_sm(n, INM_SEQMIS); return; }