/* $OpenBSD: hello.c,v 1.2 2015/10/05 01:59:33 renato Exp $ */ /* * Copyright (c) 2015 Renato Westphal * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include #include #include "eigrpd.h" #include "eigrp.h" #include "log.h" #include "eigrpe.h" /* hello packet handling */ void send_hello(struct eigrp_iface *ei, struct seq_addr_head *seq_addr_list, uint32_t mcast_seq, int peerterm) { struct eigrp *eigrp = ei->eigrp; struct ibuf *buf; uint8_t flags = 0; if ((buf = ibuf_dynamic(PKG_DEF_SIZE, IP_MAXPACKET - sizeof(struct ip))) == NULL) fatal("send_hello"); /* EIGRP header */ if (gen_eigrp_hdr(buf, EIGRP_OPC_HELLO, flags, 0, eigrp->as)) goto fail; if (gen_parameter_tlv(buf, ei, peerterm)) goto fail; if (gen_sw_version_tlv(buf)) goto fail; if (seq_addr_list && !TAILQ_EMPTY(seq_addr_list) && gen_sequence_tlv(buf, seq_addr_list)) goto fail; if (mcast_seq && gen_mcast_seq_tlv(buf, mcast_seq)) goto fail; /* send unreliably */ send_packet(ei, NULL, 0, buf); ibuf_free(buf); return; fail: log_warnx("%s: failed to send message", __func__); ibuf_free(buf); } void recv_hello(struct eigrp_iface *ei, union eigrpd_addr *src, struct nbr *nbr, struct tlv_parameter *tp) { /* * Some old Cisco routers seems to use the "parameters tlv" with all * K-values set to 255 (except k6) to inform that the neighbor has been * reset. The "peer termination" tlv described in the draft for the same * purpose is probably something introduced recently. Let's check for * this case to maintain backward compatibility. */ if (tp->kvalues[0] == 255 && tp->kvalues[1] == 255 && tp->kvalues[2] == 255 && tp->kvalues[3] == 255 && tp->kvalues[4] == 255 && tp->kvalues[5] == 0) { if (nbr) { log_debug("%s: peer temination", __func__); nbr_del(nbr); } return; } if (nbr == NULL) { if (memcmp(ei->eigrp->kvalues, tp->kvalues, 6) != 0) { log_debug("%s: k-values don't match (nbr %s)", __func__, log_addr(ei->eigrp->af, src)); return; } nbr = nbr_new(ei, src, ntohs(tp->holdtime), 0); /* send an expedited hello */ send_hello(ei, NULL, 0, 0); send_update(nbr->ei, nbr, EIGRP_HDR_FLAG_INIT, 0, NULL); } }