probe.c revision 1.2 
1/*	$OpenBSD: probe.c,v 1.2 2010/05/26 13:56:07 nicm 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 <sys/socket.h>
25#include <stdlib.h>
26#include <string.h>
27#include <event.h>
28
29#include "igmp.h"
30#include "dvmrpd.h"
31#include "dvmrp.h"
32#include "log.h"
33#include "dvmrpe.h"
34
35extern struct dvmrpd_conf	*deconf;
36
37/* DVMRP probe packet handling */
38int
39send_probe(struct iface *iface)
40{
41	struct sockaddr_in	 dst;
42	struct ibuf		*buf;
43	struct dvmrp_hdr	*dvmrp_hdr;
44	struct nbr		*nbr;
45	int			 ret = 0;
46
47	if (iface->passive)
48		return (0);
49
50	if ((buf = ibuf_open(iface->mtu - sizeof(struct ip))) == NULL)
51		fatal("send_probe");
52
53	/* DVMRP header */
54	if (gen_dvmrp_hdr(buf, iface, DVMRP_CODE_PROBE))
55		goto fail;
56
57	/* generation ID */
58	ibuf_add(buf, &iface->gen_id, sizeof(iface->gen_id));
59
60	/* generate neighbor list */
61	LIST_FOREACH(nbr, &iface->nbr_list, entry) {
62		if (nbr->state > NBR_STA_DOWN)
63			ibuf_add(buf, &nbr->id, sizeof(nbr->id));
64	}
65
66	/* set destination address */
67	dst.sin_family = AF_INET;
68	dst.sin_len = sizeof(struct sockaddr_in);
69	inet_aton(AllDVMRPRouters, &dst.sin_addr);
70
71	/* update chksum */
72	dvmrp_hdr = ibuf_seek(buf, 0, sizeof(dvmrp_hdr));
73	dvmrp_hdr->chksum = in_cksum(buf->buf, buf->wpos);
74
75	ret = send_packet(iface, buf->buf, buf->wpos, &dst);
76	ibuf_free(buf);
77	return (ret);
78fail:
79	log_warn("send_probe");
80	ibuf_free(buf);
81	return (-1);
82}
83
84void
85recv_probe(struct iface *iface, struct in_addr src, u_int32_t src_ip,
86    u_int8_t capabilities, char *buf, u_int16_t len)
87{
88	struct nbr	*nbr = NULL;
89	u_int32_t	 gen_id;
90	u_int32_t	 nbr_id;
91
92	LIST_FOREACH(nbr, &iface->nbr_list, entry) {
93		if (nbr->id.s_addr == src_ip)
94			break;
95	}
96
97	memcpy(&gen_id, buf, sizeof(gen_id));
98	len -= sizeof(gen_id);
99	buf += sizeof(gen_id);
100
101	if (!nbr) {
102		nbr = nbr_new(src_ip, iface, 0);
103		nbr->gen_id = gen_id;
104		nbr->capabilities = capabilities;
105		nbr->addr = src;
106	}
107
108	nbr_fsm(nbr, NBR_EVT_PROBE_RCVD);
109
110	if ((nbr->gen_id != gen_id) || (nbr->capabilities != capabilities)) {
111		if (!nbr->compat)
112			nbr_fsm(nbr, NBR_EVT_1_WAY_RCVD);
113		nbr->gen_id = gen_id;
114		nbr->capabilities = capabilities;
115
116		/* XXX handle nbr change! */
117	}
118
119	while (len >= sizeof(nbr_id)) {
120		memcpy(&nbr_id, buf, sizeof(nbr_id));
121		if (nbr_id == iface->addr.s_addr) {
122			/* seen myself */
123			if (nbr->state < NBR_STA_2_WAY)
124			nbr_fsm(nbr, NBR_EVT_2_WAY_RCVD);
125			break;
126		}
127		buf += sizeof(nbr_id);
128		len -= sizeof(nbr_id);
129	}
130
131	if (len == 0) {
132		nbr_fsm(nbr, NBR_EVT_1_WAY_RCVD);
133		return;
134	}
135
136	/* XXX len correct?? */
137
138	return;
139}
140