/* * 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) { int i; pkt->autype = htons (ifa->autype); memcpy (pkt->authetication, ifa->aukey, 8); return; } 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) { #ifndef IPV6 struct ospf_packet *ps; struct ospf_iface *ifa = (struct ospf_iface *) (sk->data); struct proto *p = (struct proto *) (ifa->proto); int i; u8 *pu8; 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 ("%s: Bad OSPF packet received: bad IP header", p->name); log ("%s: Discarding", p->name); return (1); } if ((unsigned) size < sizeof (struct ospf_packet)) { log ("%s: Bad OSPF packet received: too short (%u bytes)", p->name, size); log ("%s: Discarding", p->name); return (1); } if ((ntohs (ps->length) != size) || (size != (4 * (size / 4)))) { log ("%s: Bad OSPF packet received: size field does not match", p->name); log ("%s: Discarding", p->name); return (1); } if (ps->version != OSPF_VERSION) { log ("%s: Bad OSPF packet received: version %u", p->name, ps->version); log ("%s: Discarding", p->name); return (1); } if (!ipsum_verify (ps, 16, (void *) ps + sizeof (struct ospf_packet), ntohs (ps->length) - sizeof (struct ospf_packet), NULL)) { log ("%s: Bad OSPF packet received: bad checksum", p->name); log ("%s: Discarding", p->name); return (1); } if (!ospf_rx_authenticate (ifa, ps)) { log ("%s: Bad OSPF packet received: bad password", p->name); return (1); } if (ntohl (ps->areaid) != ifa->an) { log ("%s: Bad OSPF packet received: other area %ld", p->name, ps->areaid); log ("%s: Discarding", p->name); return (1); } if (ntohl (ps->routerid) == p->cf->global->router_id) { log ("%s: Bad OSPF packet received: received my own router ID!", p->name); log ("%s: Discarding", p->name); return (1); } if (ntohl (ps->routerid) == 0) { log ("%s: Bad OSPF packet received: Id 0.0.0.0 is not allowed.", p->name); log ("%s: Discarding", p->name); 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, size, sk->faddr); break; case DBDES_P: DBG ("%s: Database description received.\n", p->name); ospf_dbdes_rx ((struct ospf_dbdes_packet *) ps, p, ifa, size); break; case LSREQ_P: DBG ("%s: Link state request received.\n", p->name); ospf_lsreq_rx ((struct ospf_lsreq_packet *) ps, p, ifa, size); break; case LSUPD_P: DBG ("%s: Link state update received.\n", p->name); ospf_lsupd_rx ((struct ospf_lsupd_packet *) ps, p, ifa, size); break; case LSACK_P: DBG ("%s: Link state ack received.\n", p->name); ospf_lsack_receive((struct ospf_lsack_packet *) ps, ifa, size); break; default: log ("%s: Bad packet received: wrong type %u", p->name, ps->type); log ("%s: Discarding\n", p->name); return (1); }; #else #error RX_Hook does not work for IPv6 now. #endif 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) { 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) { struct ospf_neighbor *n; 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); }