xref: /openbsd/usr.sbin/dvmrpd/prune.c (revision 3bef86f7)
1 /*	$OpenBSD: prune.c,v 1.7 2023/06/26 10:08:56 claudio 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 <netinet/ip.h>
23 #include <arpa/inet.h>
24 
25 #include <stdlib.h>
26 #include <string.h>
27 
28 #include "igmp.h"
29 #include "dvmrpd.h"
30 #include "dvmrp.h"
31 #include "log.h"
32 #include "dvmrpe.h"
33 
34 /* DVMRP prune packet handling */
35 int
36 send_prune(struct nbr *nbr, struct prune *p)
37 {
38 	struct sockaddr_in	 dst;
39 	struct ibuf		*buf;
40 	struct prune_hdr	 prune;
41 	int			 ret = 0;
42 
43 	log_debug("send_prune: interface %s nbr %s", nbr->iface->name,
44 	    inet_ntoa(nbr->addr));
45 
46 	if (nbr->iface->passive)
47 		return (0);
48 
49 	memset(&prune, 0, sizeof(prune));
50 
51 	dst.sin_family = AF_INET;
52 	dst.sin_len = sizeof(struct sockaddr_in);
53 	dst.sin_addr = nbr->addr;
54 
55 	if ((buf = ibuf_open(nbr->iface->mtu - sizeof(struct ip))) == NULL)
56 		fatal("send_prune");
57 
58 	/* DVMRP header */
59 	if (gen_dvmrp_hdr(buf, nbr->iface, DVMRP_CODE_PRUNE))
60 		goto fail;
61 
62 	prune.src_host_addr = p->origin.s_addr;
63 	prune.group_addr = p->group.s_addr;
64 
65 	/* XXX */
66 	prune.lifetime = htonl(MAX_PRUNE_LIFETIME);
67 	prune.src_netmask = p->netmask.s_addr;
68 
69 	ibuf_add(buf, &prune, sizeof(prune));
70 
71 	ret = send_packet(nbr->iface, buf, &dst);
72 	ibuf_free(buf);
73 
74 	return (ret);
75 fail:
76 	log_warn("send_prune");
77 	ibuf_free(buf);
78 	return (-1);
79 }
80 
81 void
82 recv_prune(struct nbr *nbr, char *buf, u_int16_t len)
83 {
84 	struct prune		 p;
85 	struct prune_hdr	*prune;
86 
87 	log_debug("recv_prune: neighbor ID %s", inet_ntoa(nbr->id));
88 
89 	if (len < PRUNE_MIN_LEN) {
90 		log_debug("recv_prune: packet malformed from %s",
91 		    inet_ntoa(nbr->id));
92 		return;
93 	}
94 
95 	memset(&p, 0, sizeof(p));
96 
97 	prune = (struct prune_hdr *)buf;
98 
99 	p.origin.s_addr = prune->src_host_addr;
100 	p.group.s_addr = prune->group_addr;
101 	p.lifetime = prune->lifetime;
102 
103 	if (len >= sizeof(*prune))
104 		p.netmask.s_addr = prune->src_netmask;
105 
106 	p.ifindex = nbr->iface->ifindex;
107 
108 	dvmrpe_imsg_compose_rde(IMSG_RECV_PRUNE, nbr->peerid, 0, &p, sizeof(p));
109 
110 	return;
111 }
112