/* * BIRD -- OSPF * * (c) 1999 - 2003 Ondrej Filip * * Can be freely distributed and used under the terms of the GNU GPL. */ #include "ospf.h" void fill_ospf_pkt_hdr(struct ospf_iface *ifa, void *buf, u8 h_type) { struct ospf_packet *pkt; struct proto *p; p = (struct proto *) (ifa->proto); pkt = (struct ospf_packet *) buf; pkt->version = OSPF_VERSION; pkt->type = h_type; pkt->routerid = htonl(p->cf->global->router_id); pkt->areaid = htonl(ifa->an); pkt->autype = htons(ifa->autype); pkt->checksum = 0; } void ospf_tx_authenticate(struct ospf_iface *ifa, struct ospf_packet *pkt) { pkt->autype = htons(ifa->autype); memcpy(pkt->authetication, ifa->aukey, 8); return; } static int ospf_rx_authenticate(struct ospf_iface *ifa, struct ospf_packet *pkt) { int i; if (pkt->autype != htons(ifa->autype)) return 0; if (ifa->autype == AU_NONE) return 1; if (ifa->autype == AU_SIMPLE) { for (i = 0; i < 8; i++) { if (pkt->authetication[i] != ifa->aukey[i]) return 0; } return 1; } return 0; } void ospf_pkt_finalize(struct ospf_iface *ifa, struct ospf_packet *pkt) { ospf_tx_authenticate(ifa, pkt); /* Count checksum */ pkt->checksum = ipsum_calculate(pkt, sizeof(struct ospf_packet) - 8, (pkt + 1), ntohs(pkt->length) - sizeof(struct ospf_packet), NULL); } /** * ospf_rx_hook * @sk: socket we received the packet. Its ignored. * @size: size of the packet * * This is the entry point for messages from neighbors. Many checks (like * authentication, checksums, size) are done before the packet is passed to * non generic functions. */ int ospf_rx_hook(sock * sk, int size) { struct ospf_packet *ps; struct ospf_iface *ifa = (struct ospf_iface *) (sk->data); struct proto *p = (struct proto *) (ifa->proto); struct ospf_neighbor *n; char *mesg = "Bad OSPF packet from "; if (ifa->stub) return (1); DBG("%s: RX_Hook called on interface %s.\n", p->name, sk->iface->name); ps = (struct ospf_packet *) ipv4_skip_header(sk->rbuf, &size); if (ps == NULL) { log(L_ERR "%s%I - bad IP header", mesg, sk->faddr); return 1; } if ((unsigned) size < sizeof(struct ospf_packet)) { log(L_ERR "%s%I - too short (%u bytes)", mesg, sk->faddr, size); return 1; } if ((ntohs(ps->length) != size) || (size != (4 * (size / 4)))) { log(L_ERR "%s%I - size field does not match", mesg, sk->faddr); return 1; } if (ps->version != OSPF_VERSION) { log(L_ERR "%s%I - version %u", mesg, sk->faddr, ps->version); return 1; } if (!ipsum_verify(ps, 16, (void *) ps + sizeof(struct ospf_packet), ntohs(ps->length) - sizeof(struct ospf_packet), NULL)) { log(L_ERR "%s%I - bad checksum", mesg, sk->faddr); return 1; } if (!ospf_rx_authenticate(ifa, ps)) { log(L_ERR "%s%I - bad password", mesg, sk->faddr); return 1; } if (ntohl(ps->areaid) != ifa->an) { log(L_ERR "%s%I - other area %ld", mesg, sk->faddr, ps->areaid); return 1; } if (ntohl(ps->routerid) == p->cf->global->router_id) { log(L_ERR "%s%I - received my own router ID!", mesg, sk->faddr); return 1; } if (ntohl(ps->routerid) == 0) { log(L_ERR "%s%I - router id = 0.0.0.0", mesg, sk->faddr); return 1; } if ((unsigned) size > ifa->iface->mtu) { log(L_ERR "%s%I - received larger packet than MTU", mesg, sk->faddr); return 1; } n = find_neigh(ifa, ntohl(((struct ospf_packet *) ps)->routerid)); if(!n && (ps->type != HELLO_P)) { OSPF_TRACE(D_PACKETS, "Received non-hello packet from uknown neighbor (%I)", sk->faddr); return 1; } /* Dump packet pu8=(u8 *)(sk->rbuf+5*4); for(i=0;ilength);i+=4) DBG("%s: received %u,%u,%u,%u\n",p->name, pu8[i+0], pu8[i+1], pu8[i+2], pu8[i+3]); DBG("%s: received size: %u\n",p->name,size); */ switch (ps->type) { case HELLO_P: DBG("%s: Hello received.\n", p->name); ospf_hello_receive((struct ospf_hello_packet *) ps, ifa, n, sk->faddr); break; case DBDES_P: DBG("%s: Database description received.\n", p->name); ospf_dbdes_receive((struct ospf_dbdes_packet *) ps, ifa, n); break; case LSREQ_P: DBG("%s: Link state request received.\n", p->name); ospf_lsreq_receive((struct ospf_lsreq_packet *) ps, ifa, n); break; case LSUPD_P: DBG("%s: Link state update received.\n", p->name); ospf_lsupd_receive((struct ospf_lsupd_packet *) ps, ifa, n); break; case LSACK_P: DBG("%s: Link state ack received.\n", p->name); ospf_lsack_receive((struct ospf_lsack_packet *) ps, ifa, n); break; default: log(L_ERR "%s%I - wrong type %u", mesg, sk->faddr, ps->type); return 1; }; return 1; } void ospf_tx_hook(sock * sk) { struct ospf_iface *ifa; struct proto *p; ifa = (struct ospf_iface *) (sk->data); p = (struct proto *) (ifa->proto); DBG("%s: TX_Hook called on interface %s\n", p->name, sk->iface->name); } void ospf_err_hook(sock * sk, int err UNUSED) { struct ospf_iface *ifa; struct proto *p; ifa = (struct ospf_iface *) (sk->data); p = (struct proto *) (ifa->proto); DBG("%s: Err_Hook called on interface %s\n", p->name, sk->iface->name); } void sk_send_to_agt(sock * sk, u16 len, struct ospf_iface *ifa, u8 state) { struct ospf_neighbor *n; WALK_LIST(NODE n, ifa->neigh_list) if (n->state >= state) sk_send_to(sk, len, n->ip, OSPF_PROTO); } void sk_send_to_bdr(sock * sk, u16 len, struct ospf_iface *ifa) { if (ipa_compare(ifa->drip, ipa_from_u32(0)) != 0) sk_send_to(sk, len, ifa->drip, OSPF_PROTO); if (ipa_compare(ifa->bdrip, ipa_from_u32(0)) != 0) sk_send_to(sk, len, ifa->bdrip, OSPF_PROTO); }