probe.c revision 1.4 
1/*	$OpenBSD: probe.c,v 1.4 2015/05/05 01:26:37 jsg Exp $ */
2
3/*
4 * Copyright (c) 2005, 2006 Esben Norby <norby@openbsd.org>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19#include <sys/types.h>
20#include <sys/socket.h>
21#include <netinet/in.h>
22#include <arpa/inet.h>
23#include <sys/time.h>
24#include <stdlib.h>
25#include <string.h>
26#include <event.h>
27
28#include "igmp.h"
29#include "dvmrpd.h"
30#include "dvmrp.h"
31#include "log.h"
32#include "dvmrpe.h"
33
34extern struct dvmrpd_conf	*deconf;
35
36/* DVMRP probe packet handling */
37int
38send_probe(struct iface *iface)
39{
40	struct sockaddr_in	 dst;
41	struct ibuf		*buf;
42	struct dvmrp_hdr	*dvmrp_hdr;
43	struct nbr		*nbr;
44	int			 ret = 0;
45
46	if (iface->passive)
47		return (0);
48
49	if ((buf = ibuf_open(iface->mtu - sizeof(struct ip))) == NULL)
50		fatal("send_probe");
51
52	/* DVMRP header */
53	if (gen_dvmrp_hdr(buf, iface, DVMRP_CODE_PROBE))
54		goto fail;
55
56	/* generation ID */
57	ibuf_add(buf, &iface->gen_id, sizeof(iface->gen_id));
58
59	/* generate neighbor list */
60	LIST_FOREACH(nbr, &iface->nbr_list, entry) {
61		if (nbr->state > NBR_STA_DOWN)
62			ibuf_add(buf, &nbr->id, sizeof(nbr->id));
63	}
64
65	/* set destination address */
66	dst.sin_family = AF_INET;
67	dst.sin_len = sizeof(struct sockaddr_in);
68	inet_aton(AllDVMRPRouters, &dst.sin_addr);
69
70	/* update chksum */
71	dvmrp_hdr = ibuf_seek(buf, 0, sizeof(*dvmrp_hdr));
72	dvmrp_hdr->chksum = in_cksum(buf->buf, buf->wpos);
73
74	ret = send_packet(iface, buf->buf, buf->wpos, &dst);
75	ibuf_free(buf);
76	return (ret);
77fail:
78	log_warn("send_probe");
79	ibuf_free(buf);
80	return (-1);
81}
82
83void
84recv_probe(struct iface *iface, struct in_addr src, u_int32_t src_ip,
85    u_int8_t capabilities, char *buf, u_int16_t len)
86{
87	struct nbr	*nbr = NULL;
88	u_int32_t	 gen_id;
89	u_int32_t	 nbr_id;
90
91	LIST_FOREACH(nbr, &iface->nbr_list, entry) {
92		if (nbr->id.s_addr == src_ip)
93			break;
94	}
95
96	memcpy(&gen_id, buf, sizeof(gen_id));
97	len -= sizeof(gen_id);
98	buf += sizeof(gen_id);
99
100	if (!nbr) {
101		nbr = nbr_new(src_ip, iface, 0);
102		nbr->gen_id = gen_id;
103		nbr->capabilities = capabilities;
104		nbr->addr = src;
105	}
106
107	nbr_fsm(nbr, NBR_EVT_PROBE_RCVD);
108
109	if ((nbr->gen_id != gen_id) || (nbr->capabilities != capabilities)) {
110		if (!nbr->compat)
111			nbr_fsm(nbr, NBR_EVT_1_WAY_RCVD);
112		nbr->gen_id = gen_id;
113		nbr->capabilities = capabilities;
114
115		/* XXX handle nbr change! */
116	}
117
118	while (len >= sizeof(nbr_id)) {
119		memcpy(&nbr_id, buf, sizeof(nbr_id));
120		if (nbr_id == iface->addr.s_addr) {
121			/* seen myself */
122			if (nbr->state < NBR_STA_2_WAY)
123			nbr_fsm(nbr, NBR_EVT_2_WAY_RCVD);
124			break;
125		}
126		buf += sizeof(nbr_id);
127		len -= sizeof(nbr_id);
128	}
129
130	if (len == 0) {
131		nbr_fsm(nbr, NBR_EVT_1_WAY_RCVD);
132		return;
133	}
134
135	/* XXX len correct?? */
136
137	return;
138}
139