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/* $OpenBSD: hello.c,v 1.3 2016/01/15 12:32:34 renato Exp $ */
/*
* Copyright (c) 2015 Renato Westphal <renato@openbsd.org>
*
* 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 <string.h>
#include <arpa/inet.h>
#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, NULL);
}
}
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