summaryrefslogtreecommitdiffstats
path: root/pimd/pim_sock.c
blob: 3476c177b74cfb85b8a2d955cf73b6a5f94d919b (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
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * PIM for Quagga
 * Copyright (C) 2008  Everton da Silva Marques
 */

#include <zebra.h>
#include <fcntl.h>

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/igmp.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <netdb.h>
#include <errno.h>

#include "log.h"
#include "privs.h"
#include "if.h"
#include "vrf.h"
#include "sockopt.h"
#include "lib_errors.h"
#include "network.h"

#include "pimd.h"
#include "pim_instance.h"
#include "pim_mroute.h"
#include "pim_iface.h"
#include "pim_sock.h"
#include "pim_str.h"

#if PIM_IPV == 4
#define setsockopt_iptos setsockopt_ipv4_tos
#define setsockopt_multicast_loop setsockopt_ipv4_multicast_loop
#else
#define setsockopt_iptos setsockopt_ipv6_tclass
#define setsockopt_multicast_loop setsockopt_ipv6_multicast_loop
#endif

int pim_socket_raw(int protocol)
{
	int fd;

	frr_with_privs(&pimd_privs) {
		fd = socket(PIM_AF, SOCK_RAW, protocol);
	}

	if (fd < 0) {
		zlog_warn("Could not create raw socket: errno=%d: %s", errno,
			  safe_strerror(errno));
		return PIM_SOCK_ERR_SOCKET;
	}

	return fd;
}

void pim_socket_ip_hdr(int fd)
{
	frr_with_privs(&pimd_privs) {
#if PIM_IPV == 4
		const int on = 1;

		if (setsockopt(fd, IPPROTO_IP, IP_HDRINCL, &on, sizeof(on)))
			zlog_err("%s: Could not turn on IP_HDRINCL option: %m",
				 __func__);
#endif
	}
}

/*
 * Given a socket and a interface,
 * Bind that socket to that interface
 */
int pim_socket_bind(int fd, struct interface *ifp)
{
	int ret = 0;

#ifdef SO_BINDTODEVICE
	frr_with_privs(&pimd_privs) {
		ret = setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, ifp->name,
				 strlen(ifp->name));
	}
#endif
	return ret;
}

#if PIM_IPV == 4
static inline int pim_setsockopt(int protocol, int fd, struct interface *ifp)
{
	int one = 1;
	int ttl = 1;

#if defined(HAVE_IP_PKTINFO)
	/* Linux and Solaris IP_PKTINFO */
	if (setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one)))
		zlog_warn("Could not set PKTINFO on socket fd=%d: %m", fd);
#elif defined(HAVE_IP_RECVDSTADDR)
	/* BSD IP_RECVDSTADDR */
	if (setsockopt(fd, IPPROTO_IP, IP_RECVDSTADDR, &one, sizeof(one)))
		zlog_warn("Could not set IP_RECVDSTADDR on socket fd=%d: %m",
			  fd);
#else
	flog_err(
		EC_LIB_DEVELOPMENT,
		"Missing IP_PKTINFO and IP_RECVDSTADDR: unable to get dst addr from recvmsg()");
	close(fd);
	return PIM_SOCK_ERR_DSTADDR;
#endif

	/* Set router alert (RFC 2113) for all IGMP messages (RFC
	 * 3376 4. Message Formats)*/
	if (protocol == IPPROTO_IGMP) {
		uint8_t ra[4];

		ra[0] = 148;
		ra[1] = 4;
		ra[2] = 0;
		ra[3] = 0;
		if (setsockopt(fd, IPPROTO_IP, IP_OPTIONS, ra, 4)) {
			zlog_warn(
				"Could not set Router Alert Option on socket fd=%d: %m",
				fd);
			close(fd);
			return PIM_SOCK_ERR_RA;
		}
	}

	if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl))) {
		zlog_warn("Could not set multicast TTL=%d on socket fd=%d: %m",
			  ttl, fd);
		close(fd);
		return PIM_SOCK_ERR_TTL;
	}

	if (setsockopt_ipv4_multicast_if(fd, PIMADDR_ANY, ifp->ifindex)) {
		zlog_warn(
			"Could not set Outgoing Interface Option on socket fd=%d: %m",
			fd);
		close(fd);
		return PIM_SOCK_ERR_IFACE;
	}

	return 0;
}
#else /* PIM_IPV != 4 */
static inline int pim_setsockopt(int protocol, int fd, struct interface *ifp)
{
	int ttl = 1;
	struct ipv6_mreq mreq = {};

	setsockopt_ipv6_pktinfo(fd, 1);
	setsockopt_ipv6_multicast_hops(fd, ttl);

	mreq.ipv6mr_interface = ifp->ifindex;
	if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &mreq,
		       sizeof(mreq))) {
		zlog_warn(
			"Could not set Outgoing Interface Option on socket fd=%d: %m",
			fd);
		close(fd);
		return PIM_SOCK_ERR_IFACE;
	}

	return 0;
}
#endif

int pim_reg_sock(void)
{
	int fd;
	long flags;

	frr_with_privs (&pimd_privs) {
		fd = socket(PIM_AF, SOCK_RAW, PIM_PROTO_REG);
	}

	if (fd < 0) {
		zlog_warn("Could not create raw socket: errno=%d: %s", errno,
			  safe_strerror(errno));
		return PIM_SOCK_ERR_SOCKET;
	}

	if (sockopt_reuseaddr(fd)) {
		close(fd);
		return PIM_SOCK_ERR_REUSE;
	}

	flags = fcntl(fd, F_GETFL, 0);
	if (flags < 0) {
		zlog_warn(
			"Could not get fcntl(F_GETFL,O_NONBLOCK) on socket fd=%d: errno=%d: %s",
			fd, errno, safe_strerror(errno));
		close(fd);
		return PIM_SOCK_ERR_NONBLOCK_GETFL;
	}

	if (fcntl(fd, F_SETFL, flags | O_NONBLOCK)) {
		zlog_warn(
			"Could not set fcntl(F_SETFL,O_NONBLOCK) on socket fd=%d: errno=%d: %s",
			fd, errno, safe_strerror(errno));
		close(fd);
		return PIM_SOCK_ERR_NONBLOCK_SETFL;
	}

	return fd;
}

int pim_socket_mcast(int protocol, pim_addr ifaddr, struct interface *ifp,
		     uint8_t loop)
{
	int fd;
	int ret;

	fd = pim_socket_raw(protocol);
	if (fd < 0) {
		zlog_warn("Could not create multicast socket: errno=%d: %s",
			  errno, safe_strerror(errno));
		return PIM_SOCK_ERR_SOCKET;
	}

	/* XXX: if SO_BINDTODEVICE isn't available, use IP_PKTINFO / IP_RECVIF
	 * to emulate behaviour?  Or change to only use 1 socket for all
	 * interfaces? */
	ret = pim_socket_bind(fd, ifp);
	if (ret) {
		close(fd);
		zlog_warn("Could not set fd: %d for interface: %s to device",
			  fd, ifp->name);
		return PIM_SOCK_ERR_BIND;
	}

	set_nonblocking(fd);
	sockopt_reuseaddr(fd);
	setsockopt_so_recvbuf(fd, 8 * 1024 * 1024);

	ret = pim_setsockopt(protocol, fd, ifp);
	if (ret) {
		zlog_warn("pim_setsockopt failed for interface: %s to device ",
			  ifp->name);
		return ret;
	}

	/* leftover common sockopts */
	if (setsockopt_multicast_loop(fd, loop)) {
		zlog_warn(
			"Could not %s Multicast Loopback Option on socket fd=%d: %m",
			loop ? "enable" : "disable", fd);
		close(fd);
		return PIM_SOCK_ERR_LOOP;
	}

	/* Set Tx socket DSCP byte */
	if (setsockopt_iptos(fd, IPTOS_PREC_INTERNETCONTROL))
		zlog_warn("can't set sockopt IP[V6]_TOS to socket %d: %m", fd);

	return fd;
}

int pim_socket_join(int fd, pim_addr group, pim_addr ifaddr, ifindex_t ifindex,
		    struct pim_interface *pim_ifp)
{
	int ret;

#if PIM_IPV == 4
	ret = setsockopt_ipv4_multicast(fd, IP_ADD_MEMBERSHIP, ifaddr,
					group.s_addr, ifindex);
#else
	struct ipv6_mreq opt;

	memcpy(&opt.ipv6mr_multiaddr, &group, 16);
	opt.ipv6mr_interface = ifindex;
	ret = setsockopt(fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, &opt, sizeof(opt));
#endif

	pim_ifp->igmp_ifstat_joins_sent++;

	if (ret) {
		flog_err(
			EC_LIB_SOCKET,
			"Failure socket joining fd=%d group %pPAs on interface address %pPAs: %m",
			fd, &group, &ifaddr);
		pim_ifp->igmp_ifstat_joins_failed++;
		return ret;
	}

	if (PIM_DEBUG_TRACE)
		zlog_debug(
			"Socket fd=%d joined group %pPAs on interface address %pPAs",
			fd, &group, &ifaddr);
	return ret;
}

#if PIM_IPV == 4
static void cmsg_getdstaddr(struct msghdr *mh, struct sockaddr_storage *dst,
			    ifindex_t *ifindex)
{
	struct cmsghdr *cmsg;
	struct sockaddr_in *dst4 = (struct sockaddr_in *)dst;

	for (cmsg = CMSG_FIRSTHDR(mh); cmsg != NULL;
	     cmsg = CMSG_NXTHDR(mh, cmsg)) {
#ifdef HAVE_IP_PKTINFO
		if ((cmsg->cmsg_level == IPPROTO_IP) &&
		    (cmsg->cmsg_type == IP_PKTINFO)) {
			struct in_pktinfo *i;

			i = (struct in_pktinfo *)CMSG_DATA(cmsg);
			if (dst4)
				dst4->sin_addr = i->ipi_addr;
			if (ifindex)
				*ifindex = i->ipi_ifindex;

			break;
		}
#endif

#ifdef HAVE_IP_RECVDSTADDR
		if ((cmsg->cmsg_level == IPPROTO_IP) &&
		    (cmsg->cmsg_type == IP_RECVDSTADDR)) {
			struct in_addr *i = (struct in_addr *)CMSG_DATA(cmsg);

			if (dst4)
				dst4->sin_addr = *i;

			break;
		}
#endif

#if defined(HAVE_IP_RECVIF) && defined(CMSG_IFINDEX)
		if (cmsg->cmsg_type == IP_RECVIF)
			if (ifindex)
				*ifindex = CMSG_IFINDEX(cmsg);
#endif
	}
}
#else  /* PIM_IPV != 4 */
static void cmsg_getdstaddr(struct msghdr *mh, struct sockaddr_storage *dst,
			    ifindex_t *ifindex)
{
	struct cmsghdr *cmsg;
	struct sockaddr_in6 *dst6 = (struct sockaddr_in6 *)dst;

	for (cmsg = CMSG_FIRSTHDR(mh); cmsg != NULL;
	     cmsg = CMSG_NXTHDR(mh, cmsg)) {
		if ((cmsg->cmsg_level == IPPROTO_IPV6) &&
		    (cmsg->cmsg_type == IPV6_PKTINFO)) {
			struct in6_pktinfo *i;

			i = (struct in6_pktinfo *)CMSG_DATA(cmsg);

			if (dst6)
				dst6->sin6_addr = i->ipi6_addr;
			if (ifindex)
				*ifindex = i->ipi6_ifindex;
			break;
		}
	}
}
#endif /* PIM_IPV != 4 */

int pim_socket_recvfromto(int fd, uint8_t *buf, size_t len,
			  struct sockaddr_storage *from, socklen_t *fromlen,
			  struct sockaddr_storage *to, socklen_t *tolen,
			  ifindex_t *ifindex)
{
	struct msghdr msgh;
	struct iovec iov;
	char cbuf[1000];
	int err;

	/*
	 * IP_PKTINFO / IP_RECVDSTADDR don't yield sin_port.
	 * Use getsockname() to get sin_port.
	 */
	if (to) {
		socklen_t to_len = sizeof(*to);

		pim_socket_getsockname(fd, (struct sockaddr *)to, &to_len);

		if (tolen)
			*tolen = sizeof(*to);
	}

	memset(&msgh, 0, sizeof(msgh));
	iov.iov_base = buf;
	iov.iov_len = len;
	msgh.msg_control = cbuf;
	msgh.msg_controllen = sizeof(cbuf);
	msgh.msg_name = from;
	msgh.msg_namelen = fromlen ? *fromlen : 0;
	msgh.msg_iov = &iov;
	msgh.msg_iovlen = 1;
	msgh.msg_flags = 0;

	err = recvmsg(fd, &msgh, 0);
	if (err < 0)
		return err;

	if (fromlen)
		*fromlen = msgh.msg_namelen;

	cmsg_getdstaddr(&msgh, to, ifindex);

	return err; /* len */
}

int pim_socket_getsockname(int fd, struct sockaddr *name, socklen_t *namelen)
{
	if (getsockname(fd, name, namelen)) {
		int e = errno;
		zlog_warn(
			"Could not get Socket Name for socket fd=%d: errno=%d: %s",
			fd, errno, safe_strerror(errno));
		errno = e;
		return PIM_SOCK_ERR_NAME;
	}

	return PIM_SOCK_ERR_NONE;
}