static void packet_input(int fd) #endif { rt_table_t *fwd_rt, *rev_rt, *next_hop_rt = NULL; struct in_addr dest_addr, src_addr; u_int8_t rreq_flags = 0; unsigned int ifindex; struct ip_data *ipd = NULL; int pkt_flags = 0; #ifdef NS_PORT ifindex = NS_IFINDEX; /* Always use ns interface */ fwd_rt = NULL; /* For broadcast we provide no next hop */ ipd = NULL; /* No ICMP messaging */ struct hdr_cmn *ch = HDR_CMN(p); struct hdr_ip *ih = HDR_IP(p); src_addr.s_addr = ih->saddr(); dest_addr.s_addr = ih->daddr(); /* If this is a TCP packet and we don't have a route, we should set the gratuituos flag in the RREQ. */ if (ch->ptype() == PT_TCP) { rreq_flags |= RREQ_GRATUITOUS; } #else int status; char buf[sizeof(struct nlmsghdr)+sizeof(ipq_packet_msg_t)+BUFSIZE]; char *dev_name; ipq_packet_msg_t *pkt; struct iphdr *ip; struct udphdr *udp; struct icmphdr *icmp = NULL; status = ipq_read(h, buf, sizeof(buf), -1); if (status < 0) { DEBUG(LOG_DEBUG, 0, "%s", ipq_errstr()); ipq_perror(NULL); return; } if (ipq_message_type(buf) == NLMSG_ERROR) { fprintf(stderr, "ERROR packet_input: Check that the ip_queue.o module is loaded.\n"); die(h); } pkt = ipq_get_packet(buf); #ifdef DEBUG_PACKET DEBUG(LOG_DEBUG, 0, "Protocol %u indev=%s outdev=%s\n", pkt->hw_protocol, pkt->indev_name, pkt->outdev_name); #endif if (pkt->hook == 0) dev_name = pkt->indev_name; else if (pkt->hook == 3) dev_name = pkt->outdev_name; else dev_name = NULL; /* We know from kaodv.c that this is an IP packet */ ip = (struct iphdr *) pkt->payload; dest_addr.s_addr = ip->daddr; src_addr.s_addr = ip->saddr; switch (ip->protocol) { /* Don't process AODV control packets (UDP on port 654). They are accounted for on the aodv socket */ case IPPROTO_UDP: udp = (struct udphdr *) ((char *) ip + (ip->ihl << 2)); if (ntohs(udp->dest) == AODV_PORT || ntohs(udp->source) == AODV_PORT) goto accept; break; /* If this is a TCP packet and we don't have a route, we should set the gratuituos flag in the RREQ. */ case IPPROTO_TCP: rreq_flags |= RREQ_GRATUITOUS; break; /* We set the gratuitous flag also on ICMP ECHO requests, since the destination will also need a route back for the reply... */ case IPPROTO_ICMP: icmp = (struct icmphdr *) ((char *) ip + (ip->ihl << 2)); if (icmp->type == ICMP_ECHO) rreq_flags |= RREQ_GRATUITOUS; #ifdef DEBUG_PACKET DEBUG(LOG_INFO, 0, "setting G flag for RREQ to %s", ip_to_str(dest_addr)); #endif break; #ifdef CONFIG_GATEWAY case IPPROTO_MIPE: if (internet_gw_mode) { ip = ip_pkt_decapsulate(ip); if (ip == NULL) { DEBUG(LOG_ERR, 0, "Decapsulation failed..."); exit(-1); } pkt_flags |= PKT_DEC; } break; #endif /* CONFIG_GATEWAY */ } #ifdef DEBUG_PACKET DEBUG(LOG_INFO, 0, "pkt to %s", ip_to_str(dest_addr)); #endif if (dev_name) { ifindex = name2index(dev_name); if (ifindex < 0) { DEBUG(LOG_ERR, 0, "name2index error!"); return; } } else ifindex = 0; #endif /* NS_PORT */ /* If the packet is not interesting we just let it go through... */ if (dest_addr.s_addr == AODV_BROADCAST || dest_addr.s_addr == DEV_IFINDEX(ifindex).broadcast.s_addr) { #ifdef NS_PORT /* Limit Non AODV broadcast packets (Rolf Winter * <[email protected]). */ ih->ttl() = ih->ttl() - 1; if(ih->ttl() < 1) Packet::free(p); else sendPacket(p, dest_addr, 0.0); return; #else goto accept; #endif } /* Find the entry of the neighboring node and the destination (if any). */ rev_rt = rt_table_find(src_addr); fwd_rt = rt_table_find(dest_addr); #ifdef CONFIG_GATEWAY /* Check if we have a route and it is an Internet destination (Should be * encapsulated and routed through the gateway). */ if (fwd_rt && (fwd_rt->state == VALID) && (fwd_rt->flags & RT_INET_DEST)) { /* The destination should be relayed through the IG */ rt_table_update_timeout(fwd_rt, ACTIVE_ROUTE_TIMEOUT); #ifdef NS_PORT p = pkt_encapsulate(p, fwd_rt->next_hop); if (p == NULL) { DEBUG(LOG_ERR, 0, "IP Encapsulation failed!"); return; } /* Update pointers to headers */ ch = HDR_CMN(p); ih = HDR_IP(p); #else ip = ip_pkt_encapsulate(ip, fwd_rt->next_hop, BUFSIZE); if (ip == NULL) { DEBUG(LOG_ERR, 0, "Minimal IP Encapsulation failed!"); exit(-1); } #endif dest_addr = fwd_rt->next_hop; fwd_rt = rt_table_find(dest_addr); pkt_flags |= PKT_ENC; } #endif /* CONFIG_GATEWAY */ /* UPDATE TIMERS on active forward and reverse routes... */ /* When forwarding a packet, we update the lifetime of the destination's routing table entry, as well as the entry for the next hop neighbor (if not the same). AODV draft 10, section 6.2. */ if (fwd_rt && fwd_rt->state == VALID && dest_addr.s_addr != DEV_IFINDEX(ifindex).ipaddr.s_addr) { rt_table_update_timeout(fwd_rt, ACTIVE_ROUTE_TIMEOUT); next_hop_rt = rt_table_find(fwd_rt->next_hop); if (next_hop_rt && next_hop_rt->state == VALID && next_hop_rt->dest_addr.s_addr != fwd_rt->dest_addr.s_addr) rt_table_update_timeout(next_hop_rt, ACTIVE_ROUTE_TIMEOUT); } /* Also update the reverse route and reverse next hop along the path back, since routes between originators and the destination are expected to be symmetric. */ if (rev_rt && rev_rt->state == VALID) { rt_table_update_timeout(rev_rt, ACTIVE_ROUTE_TIMEOUT); next_hop_rt = rt_table_find(rev_rt->next_hop); if (next_hop_rt && next_hop_rt->state == VALID && rev_rt && next_hop_rt->dest_addr.s_addr != rev_rt->dest_addr.s_addr) rt_table_update_timeout(next_hop_rt, ACTIVE_ROUTE_TIMEOUT); /* Update HELLO timer of next hop neighbor if active */ if (!llfeedback && next_hop_rt->hello_timer.used) { struct timeval now; gettimeofday(&now, NULL); hello_update_timeout(next_hop_rt, &now, ALLOWED_HELLO_LOSS * HELLO_INTERVAL); } } /* OK, the timeouts have been updated. Now see if either: 1. The packet is for this node -> ACCEPT. 2. The packet is not for this node -> Send RERR (someone want's this node to forward packets although there is no route) or Send RREQ. */ /* If the packet is destined for this node, then just accept it. */ if (memcmp(&dest_addr, &DEV_IFINDEX(ifindex).ipaddr, sizeof(struct in_addr)) == 0) { #ifdef NS_PORT ch->size() -= IP_HDR_LEN; // cut off IP header size 4/7/99 -dam target_->recv(p, (Handler*)0); p = 0; return; #else goto accept; #endif } if (!fwd_rt || fwd_rt->state == INVALID || (fwd_rt->hcnt == 1 && (fwd_rt->flags & RT_UNIDIR))) { /* Check if the route is marked for repair or is INVALID. In * that case, do a route discovery. */ if (fwd_rt && (fwd_rt->flags & RT_REPAIR)) goto route_discovery; /* If a packet is received on the NF_IP_PRE_ROUTING hook, i.e. inbound on the interface and we don't have a route to the destination, we should send an RERR to the source and then drop the package... */ /* NF_IP_PRE_ROUTING = 0 */ #ifdef NS_PORT #define PACKET_IS_INBOUND ch->direction() == hdr_cmn::UP #else #define PACKET_IS_INBOUND pkt->hook == 0 #endif if (PACKET_IS_INBOUND) { struct in_addr rerr_dest; RERR *rerr; #ifdef NS_PORT struct in_addr nh; nh.s_addr = ch->prev_hop_; DEBUG(LOG_DEBUG, 0, "No route, src=%s dest=%s prev_hop=%s - DROPPING!", ip_to_str(src_addr), ip_to_str(dest_addr), ip_to_str(nh)); #endif if (fwd_rt) { rerr = rerr_create(0, fwd_rt->dest_addr, fwd_rt->dest_seqno); rt_table_update_timeout(fwd_rt, DELETE_PERIOD); } else rerr = rerr_create(0, dest_addr, 0); DEBUG(LOG_DEBUG, 0, "Sending RERR to prev hop %s for unknown dest %s", ip_to_str(src_addr), ip_to_str(dest_addr)); /* Unicast the RERR to the source of the data transmission * if possible, otherwise we broadcast it. */ if (rev_rt && rev_rt->state == VALID) rerr_dest = rev_rt->next_hop; else rerr_dest.s_addr = AODV_BROADCAST; aodv_socket_send((AODV_msg *) rerr, rerr_dest, RERR_CALC_SIZE(rerr), 1, &DEV_IFINDEX(ifindex)); if (wait_on_reboot) { DEBUG(LOG_DEBUG, 0, "Wait on reboot timer reset."); timer_set_timeout(&worb_timer, DELETE_PERIOD); } #ifdef NS_PORT /* DEBUG(LOG_DEBUG, 0, "Dropping pkt uid=%d", ch->uid()); */ drop(p, DROP_RTR_NO_ROUTE); #else status = ipq_set_verdict(h, pkt->packet_id, NF_DROP, 0, NULL); if (status < 0) die(h); #endif return; } route_discovery: /* Buffer packets... Packets are queued by the ip_queue.o module already. We only need to save the handle id, and return the proper verdict when we know what to do... */ #ifdef NS_PORT packet_queue_add(p, dest_addr); #else packet_queue_add(pkt->packet_id, dest_addr, ip); #ifdef CONFIG_GATEWAY /* In gateway mode we handle packets in userspace */ ipq_set_verdict(h, pkt->packet_id, NF_DROP, 0, NULL); #endif /* Already seeking the destination? Then do not allocate any memory or generate a RREQ. */ if (seek_list_find(dest_addr)) return; /* If the request is generated locally by an application, we save the IP header + 64 bits of data for sending an ICMP Destination Host Unreachable in case we don't find a route... */ if (src_addr.s_addr == DEV_IFINDEX(ifindex).ipaddr.s_addr && ip && pkt->data_len >= (ip->ihl << 2) + 8) { ipd = (struct ip_data *) malloc(sizeof(struct ip_data)); if (ipd == NULL) { perror("Malloc for IP data failed!"); exit(-1); } /* IP header + 64 bits data (8 bytes) */ ipd->len = (ip->ihl << 2) + 8; memcpy(ipd->data, ip, ipd->len); } else ipd = NULL; #endif if (fwd_rt && (fwd_rt->flags & RT_REPAIR)) rreq_local_repair(fwd_rt, src_addr, ipd); else rreq_route_discovery(dest_addr, rreq_flags, ipd); return; } else { #ifdef NS_PORT /* DEBUG(LOG_DEBUG, 0, "Sending pkt uid=%d", ch->uid()); */ sendPacket(p, fwd_rt->next_hop, 0.0); #else accept: if (pkt_flags & PKT_ENC || (pkt_flags & PKT_DEC)) status = ipq_set_verdict(h, pkt->packet_id, NF_ACCEPT, ntohs(ip->tot_len), (unsigned char *)ip); else status = ipq_set_verdict(h, pkt->packet_id, NF_ACCEPT, 0, NULL); if (status < 0) die(h); #endif /* When forwarding data, make sure we are sending HELLO messages */ gettimeofday(&this_host.fwd_time, NULL); if (!llfeedback && optimized_hellos) hello_start(); } }
static void nl_callback(int sock) { int len, attrlen; socklen_t addrlen; struct nlmsghdr *nlm; struct nlmsgerr *nlmerr; char buf[BUFLEN]; struct in_addr dest_addr, src_addr; struct ifaddrmsg *ifm; struct rtattr *rta; kaodv_rt_msg_t *m; rt_table_t *rt, *fwd_rt, *rev_rt = NULL; addrlen = sizeof(peer); len = recvfrom(sock, buf, BUFLEN, 0, (struct sockaddr *)&peer, &addrlen); if (len <= 0) return; nlm = (struct nlmsghdr *)buf; switch (nlm->nlmsg_type) { case NLMSG_ERROR: nlmerr = NLMSG_DATA(nlm); if (nlmerr->error == 0) { DEBUG(LOG_DEBUG, 0, "NLMSG_ACK"); } else DEBUG(LOG_DEBUG, 0, "NLMSG_ERROR, error=%d", nlmerr->error); break; case RTM_NEWLINK: DEBUG(LOG_DEBUG, 0, "RTM_NEWADDR"); break; case RTM_NEWADDR: DEBUG(LOG_DEBUG, 0, "RTM_NEWADDR"); ifm = NLMSG_DATA(nlm); rta = (struct rtattr *)((char *)ifm + sizeof(ifm)); attrlen = nlm->nlmsg_len - sizeof(struct nlmsghdr) - sizeof(struct ifaddrmsg); for (; RTA_OK(rta, attrlen); rta = RTA_NEXT(rta, attrlen)) { if (rta->rta_type == IFA_ADDRESS) { struct in_addr ifaddr; memcpy(&ifaddr, RTA_DATA(rta), RTA_PAYLOAD(rta)); DEBUG(LOG_DEBUG, 0, "Interface index %d changed address to %s", ifm->ifa_index, ip_to_str(ifaddr)); } } break; case KAODVM_TIMEOUT: m = NLMSG_DATA(nlm); dest_addr.s_addr = m->dst; DEBUG(LOG_DEBUG, 0, "Got TIMEOUT msg from kernel for %s", ip_to_str(dest_addr)); rt = rt_table_find(dest_addr); if (rt && rt->state == VALID) route_expire_timeout(rt); else DEBUG(LOG_DEBUG, 0, "Got rt timeoute event but there is no route"); break; case KAODVM_NOROUTE: m = NLMSG_DATA(nlm); dest_addr.s_addr = m->dst; DEBUG(LOG_DEBUG, 0, "Got NOROUTE msg from kernel for %s", ip_to_str(dest_addr)); rreq_route_discovery(dest_addr, 0, NULL); break; case KAODVM_REPAIR: m = NLMSG_DATA(nlm); dest_addr.s_addr = m->dst; src_addr.s_addr = m->src; DEBUG(LOG_DEBUG, 0, "Got REPAIR msg from kernel for %s", ip_to_str(dest_addr)); fwd_rt = rt_table_find(dest_addr); if (fwd_rt) rreq_local_repair(fwd_rt, src_addr, NULL); break; case KAODVM_ROUTE_UPDATE: m = NLMSG_DATA(nlm); dest_addr.s_addr = m->dst; src_addr.s_addr = m->src; if (dest_addr.s_addr == AODV_BROADCAST || dest_addr.s_addr == DEV_IFINDEX(m->ifindex).broadcast.s_addr) return; fwd_rt = rt_table_find(dest_addr); rev_rt = rt_table_find(src_addr); rt_table_update_route_timeouts(fwd_rt, rev_rt); break; case KAODVM_SEND_RERR: m = NLMSG_DATA(nlm); dest_addr.s_addr = m->dst; src_addr.s_addr = m->src; if (dest_addr.s_addr == AODV_BROADCAST || dest_addr.s_addr == DEV_IFINDEX(m->ifindex).broadcast.s_addr) return; fwd_rt = rt_table_find(dest_addr); rev_rt = rt_table_find(src_addr); do { struct in_addr rerr_dest; RERR *rerr; DEBUG(LOG_DEBUG, 0, "Sending RERR for unsolicited message from %s to dest %s", ip_to_str(src_addr), ip_to_str(dest_addr)); if (fwd_rt) { rerr = rerr_create(0, fwd_rt->dest_addr, fwd_rt->dest_seqno); rt_table_update_timeout(fwd_rt, DELETE_PERIOD); } else rerr = rerr_create(0, dest_addr, 0); /* Unicast the RERR to the source of the data transmission * if possible, otherwise we broadcast it. */ if (rev_rt && rev_rt->state == VALID) rerr_dest = rev_rt->next_hop; else rerr_dest.s_addr = AODV_BROADCAST; aodv_socket_send((AODV_msg *) rerr, rerr_dest, RERR_CALC_SIZE(rerr), 1, &DEV_IFINDEX(m->ifindex)); if (wait_on_reboot) { DEBUG(LOG_DEBUG, 0, "Wait on reboot timer reset."); timer_set_timeout(&worb_timer, DELETE_PERIOD); } } while (0); break; default: DEBUG(LOG_DEBUG, 0, "Got mesg type=%d\n", nlm->nlmsg_type); } }