/* * BIRD -- OSPF * * (c) 1999 - 2000 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=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!=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_rx((struct ospf_hello_packet *)ps, p, 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_rx((struct ospf_lsack_packet *)ps, p, 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); }