summaryrefslogtreecommitdiff
path: root/usr.sbin/ospf6d/packet.c
blob: 2f549e8246637a33bf6172034dae1ee238742257 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
/*	$OpenBSD: packet.c,v 1.6 2007/12/13 08:54:05 claudio Exp $ */

/*
 * Copyright (c) 2004, 2005 Esben Norby <norby@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/uio.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip6.h>
#include <arpa/inet.h>
#include <net/if_dl.h>

#include <errno.h>
#include <event.h>
#include <stdlib.h>
#include <string.h>

#include "ospf6d.h"
#include "ospf6.h"
#include "log.h"
#include "ospfe.h"

int		 ip_hdr_sanity_check(const struct ip6_hdr *, u_int16_t);
int		 ospf_hdr_sanity_check(struct ospf_hdr *, u_int16_t,
		    const struct iface *, struct in6_addr *);
struct iface	*find_iface(struct ospfd_conf *, unsigned int,
		    struct in6_addr *);

int
gen_ospf_hdr(struct buf *buf, struct iface *iface, u_int8_t type)
{
	struct ospf_hdr	ospf_hdr;

	bzero(&ospf_hdr, sizeof(ospf_hdr));
	ospf_hdr.version = OSPF6_VERSION;
	ospf_hdr.type = type;
	ospf_hdr.rtr_id = ospfe_router_id();
	if (iface->type != IF_TYPE_VIRTUALLINK)
		ospf_hdr.area_id = iface->area_id.s_addr;
	ospf_hdr.instance = DEFAULT_INSTANCE_ID;
	ospf_hdr.zero = 0;		/* must be zero */

	return (buf_add(buf, &ospf_hdr, sizeof(ospf_hdr)));
}

int
upd_ospf_hdr(struct buf *buf, struct iface *iface)
{
	struct ospf_hdr	*ospf_hdr;

	if ((ospf_hdr = buf_seek(buf, 0, sizeof(ospf_hdr))) == NULL)
		fatalx("upd_ospf_hdr: buf_seek failed");

	/* update length */
	if (buf->wpos > USHRT_MAX)
		fatalx("upd_ospf_hdr: resulting ospf packet too big");
	ospf_hdr->len = htons((u_int16_t)buf->wpos);
	ospf_hdr->chksum = 0; /* calculated via IPV6_CHECKSUM */

	return (0);
}

/* send and receive packets */
int
send_packet(struct iface *iface, void *pkt, size_t len,
    struct in6_addr *dst)
{
	struct sockaddr_in6	 sa6;

	/* setup buffer */
	bzero(&sa6, sizeof(sa6));

	sa6.sin6_family = AF_INET6;
	sa6.sin6_len = sizeof(sa6);
	sa6.sin6_addr = *dst;

	/* don't we all love link local scope and all the needed hacks for it */
	if (IN6_IS_ADDR_LINKLOCAL(dst) || IN6_IS_ADDR_MC_LINKLOCAL(dst))
		sa6.sin6_scope_id = iface->ifindex;

	/* set outgoing interface for multicast traffic */
	if (IN6_IS_ADDR_MULTICAST(dst))
		if (if_set_mcast(iface) == -1) {
			log_warn("send_packet: error setting multicast "
			    "interface, %s", iface->name);
			return (-1);
		}

	if (sendto(iface->fd, pkt, len, MSG_DONTROUTE, (struct sockaddr *)&sa6,
	    sizeof(sa6)) == -1) {
		log_warn("send_packet: error sending packet on interface %s",
		    iface->name);
		return (-1);
	}

	return (0);
}

void
recv_packet(int fd, short event, void *bula)
{
	char			 cbuf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
	struct msghdr		 msg;
	struct iovec		 iov;
	struct in6_addr		 addr, dest;
	struct sockaddr_in6	 src;
	struct ospfd_conf	*xconf = bula;
	struct ospf_hdr		*ospf_hdr;
	struct iface		*iface;
	struct nbr		*nbr = NULL;
	char			*buf;
	struct cmsghdr		*cmsg;
	ssize_t			 r;
	u_int16_t		 len;
	int			 l;
	unsigned int		 ifindex = 0;

	if (event != EV_READ)
		return;

	/* setup buffer */
	bzero(&msg, sizeof(msg));
	iov.iov_base = buf = pkt_ptr;
	iov.iov_len = READ_BUF_SIZE;
	msg.msg_name = &src;
	msg.msg_namelen = sizeof(src);
	msg.msg_iov = &iov;
	msg.msg_iovlen = 1;
	msg.msg_control = cbuf;
	msg.msg_controllen = sizeof(cbuf);

	if ((r = recvmsg(fd, &msg, 0)) == -1) {
		if (errno != EAGAIN && errno != EINTR)
			log_debug("recv_packet: read error: %s",
			    strerror(errno));
		return;
	}
	for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL;
	    cmsg = CMSG_NXTHDR(&msg, cmsg)) {
		if (cmsg->cmsg_level == IPPROTO_IPV6 &&
		    cmsg->cmsg_type == IPV6_PKTINFO) {
			ifindex = ((struct in6_pktinfo *)
			    CMSG_DATA(cmsg))->ipi6_ifindex;
			dest = ((struct in6_pktinfo *)
			    CMSG_DATA(cmsg))->ipi6_addr;
			break;
		}
	}

	/* find a matching interface */
	if ((iface = find_iface(xconf, ifindex, &src.sin6_addr)) == NULL) {
		/* XXX add a counter here */
		return;
	}
	/*
	 * Packet needs to be sent to AllSPFRouters or AllDRouters
	 * or to the address of the interface itself.
	 * AllDRouters is only valid for DR and BDR but this is checked later.
	 */
	inet_pton(AF_INET6, AllSPFRouters, &addr);

	if (!IN6_ARE_ADDR_EQUAL(&dest, &addr)) {
		inet_pton(AF_INET6, AllDRouters, &addr);
		if (!IN6_ARE_ADDR_EQUAL(&dest, &addr)) {
			if (!IN6_ARE_ADDR_EQUAL(&dest, &iface->addr)) {
				log_debug("recv_packet: packet sent to wrong "
				    "address %s, interface %s",
				    log_in6addr(&dest), iface->name);
				return;
			}
		}
	}

	len = (u_int16_t)r;
	/* OSPF header sanity checks */
	if (len < sizeof(*ospf_hdr)) {
		log_debug("recv_packet: bad packet size");
		return;
	}
	ospf_hdr = (struct ospf_hdr *)buf;

	if ((l = ospf_hdr_sanity_check(ospf_hdr, len, iface, &dest)) == -1)
		return;

	nbr = nbr_find_id(iface, ospf_hdr->rtr_id);
	if (ospf_hdr->type != PACKET_TYPE_HELLO && nbr == NULL) {
		log_debug("recv_packet: unknown neighbor ID");
		return;
	}

	buf += sizeof(*ospf_hdr);
	len = l - sizeof(*ospf_hdr);

	/* switch OSPF packet type */
	switch (ospf_hdr->type) {
	case PACKET_TYPE_HELLO:
		inet_pton(AF_INET6, AllDRouters, &addr);
		if (IN6_ARE_ADDR_EQUAL(&dest, &addr)) {
			log_debug("recv_packet: invalid destination IP "
			     "address");
			break;
		}

		recv_hello(iface, &src.sin6_addr, ospf_hdr->rtr_id, buf, len);
		break;
	case PACKET_TYPE_DD:
		recv_db_description(nbr, buf, len);
		break;
	case PACKET_TYPE_LS_REQUEST:
		recv_ls_req(nbr, buf, len);
		break;
	case PACKET_TYPE_LS_UPDATE:
		recv_ls_update(nbr, buf, len);
		break;
	case PACKET_TYPE_LS_ACK:
		recv_ls_ack(nbr, buf, len);
		break;
	default:
		log_debug("recv_packet: unknown OSPF packet type, interface %s",
		    iface->name);
	}
}

int
ospf_hdr_sanity_check(struct ospf_hdr *ospf_hdr, u_int16_t len,
    const struct iface *iface, struct in6_addr *dst)
{
	struct in6_addr		 addr;
	struct in_addr		 id;

	if (ospf_hdr->version != OSPF6_VERSION) {
		log_debug("recv_packet: invalid OSPF version %d",
		    ospf_hdr->version);
		return (-1);
	}

	if (ntohs(ospf_hdr->len) > len ||
	    len <= sizeof(struct ospf_hdr)) {
		log_debug("recv_packet: invalid OSPF packet length %d",
		    ntohs(ospf_hdr->len));
		return (-1);
	}

	if (iface->type != IF_TYPE_VIRTUALLINK) {
		if (ospf_hdr->area_id != iface->area_id.s_addr) {
			id.s_addr = ospf_hdr->area_id;
			log_debug("recv_packet: invalid area ID %s, "
			    "interface %s", inet_ntoa(id), iface->name);
			return (-1);
		}
	} else {
		if (ospf_hdr->area_id != 0) {
			id.s_addr = ospf_hdr->area_id;
			log_debug("recv_packet: invalid area ID %s, "
			    "interface %s", inet_ntoa(id), iface->name);
			return (-1);
		}
	}

	if (iface->type == IF_TYPE_BROADCAST || iface->type == IF_TYPE_NBMA) {
		if (inet_pton(AF_INET6, AllDRouters, &addr) == 0)
			fatalx("recv_packet: inet_pton");
		if (IN6_ARE_ADDR_EQUAL(dst, &addr) &&
		    (iface->state & IF_STA_DRORBDR) == 0) {
			log_debug("recv_packet: invalid destination IP in "
			    "state %s, interface %s",
			    if_state_name(iface->state), iface->name);
			return (-1);
		}
	}

	return (ntohs(ospf_hdr->len));
}

struct iface *
find_iface(struct ospfd_conf *xconf, unsigned int ifindex, struct in6_addr *src)
{
	struct area	*area;
	struct iface	*iface, *match = NULL;

	/*
	 * Returned interface needs to be active.
	 * Virtual-Links have higher precedence so the full interface
	 * list needs to be scanned for possible matches.
	 */
	LIST_FOREACH(area, &xconf->area_list, entry) {
		LIST_FOREACH(iface, &area->iface_list, entry) {
			switch (iface->type) {
			case IF_TYPE_VIRTUALLINK:
				if (IN6_ARE_ADDR_EQUAL(src, &iface->dst) &&
				    !(iface->cflags & F_IFACE_PASSIVE))
					return (iface);
				break;
			default:
				if (ifindex == iface->ifindex &&
				    !(iface->cflags & F_IFACE_PASSIVE))
					match = iface;
				break;
			}
		}
	}

	return (match);
}