xref: /openbsd/usr.sbin/dvmrpd/prune.c (revision 404b540a)
1 /*	$OpenBSD: prune.c,v 1.2 2009/03/14 15:32:55 michele 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/in_systm.h>
23 #include <netinet/ip.h>
24 #include <arpa/inet.h>
25 
26 #include <stdlib.h>
27 #include <strings.h>
28 
29 #include "igmp.h"
30 #include "dvmrpd.h"
31 #include "dvmrp.h"
32 #include "log.h"
33 #include "dvmrpe.h"
34 
35 /* DVMRP prune packet handling */
36 int
37 send_prune(struct nbr *nbr, struct prune *p)
38 {
39 	struct sockaddr_in	 dst;
40 	struct buf		*buf;
41 	struct dvmrp_hdr	*dvmrp_hdr;
42 	struct prune_hdr	 prune;
43 	int			 ret = 0;
44 
45 	log_debug("send_prune: interface %s nbr %s", nbr->iface->name,
46 	    inet_ntoa(nbr->addr));
47 
48 	if (nbr->iface->passive)
49 		return (0);
50 
51 	bzero(&prune, sizeof(prune));
52 
53 	dst.sin_family = AF_INET;
54 	dst.sin_len = sizeof(struct sockaddr_in);
55 	dst.sin_addr = nbr->addr;
56 
57 	if ((buf = buf_open(nbr->iface->mtu - sizeof(struct ip))) == NULL)
58 		fatal("send_prune");
59 
60 	/* DVMRP header */
61 	if (gen_dvmrp_hdr(buf, nbr->iface, DVMRP_CODE_PRUNE))
62 		goto fail;
63 
64 	prune.src_host_addr = p->origin.s_addr;
65 	prune.group_addr = p->group.s_addr;
66 
67 	/* XXX */
68 	prune.lifetime = htonl(MAX_PRUNE_LIFETIME);
69 	prune.src_netmask = p->netmask.s_addr;
70 
71 	buf_add(buf, &prune, sizeof(prune));
72 
73 	/* update chksum */
74 	dvmrp_hdr = buf_seek(buf, 0, sizeof(dvmrp_hdr));
75 	dvmrp_hdr->chksum = in_cksum(buf->buf, buf->wpos);
76 
77 	ret = send_packet(nbr->iface, buf->buf, buf->wpos, &dst);
78 	buf_free(buf);
79 
80 	return (ret);
81 fail:
82 	log_warn("send_prune");
83 	buf_free(buf);
84 	return (-1);
85 }
86 
87 void
88 recv_prune(struct nbr *nbr, char *buf, u_int16_t len)
89 {
90 	struct prune		 p;
91 	struct prune_hdr	*prune;
92 
93 	log_debug("recv_prune: neighbor ID %s", inet_ntoa(nbr->id));
94 
95 	if (len < PRUNE_MIN_LEN) {
96 		log_debug("recv_prune: packet malformed from %s",
97 		    inet_ntoa(nbr->id));
98 		return;
99 	}
100 
101 	bzero(&p, sizeof(p));
102 
103 	prune = (struct prune_hdr *)buf;
104 
105 	p.origin.s_addr = prune->src_host_addr;
106 	p.group.s_addr = prune->group_addr;
107 	p.lifetime = prune->lifetime;
108 
109 	if (len >= sizeof(*prune))
110 		p.netmask.s_addr = prune->src_netmask;
111 
112 	p.ifindex = nbr->iface->ifindex;
113 
114 	dvmrpe_imsg_compose_rde(IMSG_RECV_PRUNE, nbr->peerid, 0, &p, sizeof(p));
115 
116 	return;
117 }
118