1 /* $OpenBSD: probe.c,v 1.7 2024/08/21 09:18:47 florian 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
34 extern struct dvmrpd_conf *deconf;
35
36 /* DVMRP probe packet handling */
37 int
send_probe(struct iface * iface)38 send_probe(struct iface *iface)
39 {
40 struct sockaddr_in dst;
41 struct ibuf *buf;
42 struct nbr *nbr;
43 int ret = 0;
44
45 if (iface->passive)
46 return (0);
47
48 if ((buf = ibuf_open(iface->mtu - sizeof(struct ip))) == NULL)
49 fatal("send_probe");
50
51 /* DVMRP header */
52 if (gen_dvmrp_hdr(buf, iface, DVMRP_CODE_PROBE))
53 goto fail;
54
55 /* generation ID */
56 ibuf_add(buf, &iface->gen_id, sizeof(iface->gen_id));
57
58 /* generate neighbor list */
59 LIST_FOREACH(nbr, &iface->nbr_list, entry) {
60 if (nbr->state > NBR_STA_DOWN)
61 ibuf_add(buf, &nbr->id, sizeof(nbr->id));
62 }
63
64 /* set destination address */
65 dst.sin_family = AF_INET;
66 dst.sin_len = sizeof(struct sockaddr_in);
67 inet_pton(AF_INET, AllDVMRPRouters, &dst.sin_addr);
68
69 ret = send_packet(iface, buf, &dst);
70 ibuf_free(buf);
71 return (ret);
72 fail:
73 log_warn("send_probe");
74 ibuf_free(buf);
75 return (-1);
76 }
77
78 void
recv_probe(struct iface * iface,struct in_addr src,u_int32_t src_ip,u_int8_t capabilities,char * buf,u_int16_t len)79 recv_probe(struct iface *iface, struct in_addr src, u_int32_t src_ip,
80 u_int8_t capabilities, char *buf, u_int16_t len)
81 {
82 struct nbr *nbr = NULL;
83 u_int32_t gen_id;
84 u_int32_t nbr_id;
85
86 LIST_FOREACH(nbr, &iface->nbr_list, entry) {
87 if (nbr->id.s_addr == src_ip)
88 break;
89 }
90
91 memcpy(&gen_id, buf, sizeof(gen_id));
92 len -= sizeof(gen_id);
93 buf += sizeof(gen_id);
94
95 if (!nbr) {
96 nbr = nbr_new(src_ip, iface, 0);
97 nbr->gen_id = gen_id;
98 nbr->capabilities = capabilities;
99 nbr->addr = src;
100 }
101
102 nbr_fsm(nbr, NBR_EVT_PROBE_RCVD);
103
104 if ((nbr->gen_id != gen_id) || (nbr->capabilities != capabilities)) {
105 if (!nbr->compat)
106 nbr_fsm(nbr, NBR_EVT_1_WAY_RCVD);
107 nbr->gen_id = gen_id;
108 nbr->capabilities = capabilities;
109
110 /* XXX handle nbr change! */
111 }
112
113 while (len >= sizeof(nbr_id)) {
114 memcpy(&nbr_id, buf, sizeof(nbr_id));
115 if (nbr_id == iface->addr.s_addr) {
116 /* seen myself */
117 if (nbr->state < NBR_STA_2_WAY)
118 nbr_fsm(nbr, NBR_EVT_2_WAY_RCVD);
119 break;
120 }
121 buf += sizeof(nbr_id);
122 len -= sizeof(nbr_id);
123 }
124
125 if (len == 0) {
126 nbr_fsm(nbr, NBR_EVT_1_WAY_RCVD);
127 return;
128 }
129
130 /* XXX len correct?? */
131
132 return;
133 }
134