blob: f5f1a7edd8d182cf334fd5993f0c32b5af3c6b58 [file] [log] [blame]
paul718e3742002-12-13 20:15:29 +00001/* setsockopt functions
2 * Copyright (C) 1999 Kunihiro Ishiguro
3 *
4 * This file is part of GNU Zebra.
5 *
6 * GNU Zebra is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2, or (at your option) any
9 * later version.
10 *
11 * GNU Zebra is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with GNU Zebra; see the file COPYING. If not, write to the Free
18 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
19 * 02111-1307, USA.
20 */
21
22#include <zebra.h>
23#include "log.h"
paule6822762004-08-19 04:13:29 +000024#include "sockopt.h"
paul718e3742002-12-13 20:15:29 +000025
paul0b3acf42004-09-17 08:39:08 +000026int
27setsockopt_so_recvbuf (int sock, int size)
28{
29 int ret;
30
paulb89e60c2004-09-21 15:43:13 +000031 if ( (ret = setsockopt (sock, SOL_SOCKET, SO_RCVBUF, (char *)
ajsff29bb32004-11-19 18:29:22 +000032 &size, sizeof (int))) < 0)
33 zlog_err ("fd %d: can't setsockopt SO_RCVBUF to %d: %s",
ajsae5e24d2004-11-19 23:43:10 +000034 sock,size,safe_strerror(errno));
paul0b3acf42004-09-17 08:39:08 +000035
36 return ret;
37}
38
paul4f7baa02004-07-23 15:11:07 +000039static void *
40getsockopt_cmsg_data (struct msghdr *msgh, int level, int type)
41{
42 struct cmsghdr *cmsg;
43 void *ptr = NULL;
44
ajsb99760a2005-01-04 16:24:43 +000045 for (cmsg = ZCMSG_FIRSTHDR(msgh);
paul4f7baa02004-07-23 15:11:07 +000046 cmsg != NULL;
47 cmsg = CMSG_NXTHDR(msgh, cmsg))
48 if (cmsg->cmsg_level == level && cmsg->cmsg_type)
49 return (ptr = CMSG_DATA(cmsg));
paul9035efa2004-10-10 11:56:56 +000050
51 return NULL;
paul4f7baa02004-07-23 15:11:07 +000052}
53
paul718e3742002-12-13 20:15:29 +000054#ifdef HAVE_IPV6
55/* Set IPv6 packet info to the socket. */
56int
57setsockopt_ipv6_pktinfo (int sock, int val)
58{
59 int ret;
60
61#ifdef IPV6_RECVPKTINFO /*2292bis-01*/
62 ret = setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val));
63 if (ret < 0)
ajs6099b3b2004-11-20 02:06:59 +000064 zlog_warn ("can't setsockopt IPV6_RECVPKTINFO : %s", safe_strerror (errno));
paul718e3742002-12-13 20:15:29 +000065#else /*RFC2292*/
66 ret = setsockopt(sock, IPPROTO_IPV6, IPV6_PKTINFO, &val, sizeof(val));
67 if (ret < 0)
ajs6099b3b2004-11-20 02:06:59 +000068 zlog_warn ("can't setsockopt IPV6_PKTINFO : %s", safe_strerror (errno));
paul718e3742002-12-13 20:15:29 +000069#endif /* INIA_IPV6 */
70 return ret;
71}
72
73/* Set multicast hops val to the socket. */
74int
75setsockopt_ipv6_checksum (int sock, int val)
76{
77 int ret;
78
79#ifdef GNU_LINUX
80 ret = setsockopt(sock, IPPROTO_RAW, IPV6_CHECKSUM, &val, sizeof(val));
81#else
82 ret = setsockopt(sock, IPPROTO_IPV6, IPV6_CHECKSUM, &val, sizeof(val));
83#endif /* GNU_LINUX */
84 if (ret < 0)
85 zlog_warn ("can't setsockopt IPV6_CHECKSUM");
86 return ret;
87}
88
89/* Set multicast hops val to the socket. */
90int
91setsockopt_ipv6_multicast_hops (int sock, int val)
92{
93 int ret;
94
95 ret = setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &val, sizeof(val));
96 if (ret < 0)
97 zlog_warn ("can't setsockopt IPV6_MULTICAST_HOPS");
98 return ret;
99}
100
101/* Set multicast hops val to the socket. */
102int
103setsockopt_ipv6_unicast_hops (int sock, int val)
104{
105 int ret;
106
107 ret = setsockopt(sock, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &val, sizeof(val));
108 if (ret < 0)
109 zlog_warn ("can't setsockopt IPV6_UNICAST_HOPS");
110 return ret;
111}
112
113int
114setsockopt_ipv6_hoplimit (int sock, int val)
115{
116 int ret;
117
118#ifdef IPV6_RECVHOPLIMIT /*2292bis-01*/
119 ret = setsockopt (sock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &val, sizeof(val));
120 if (ret < 0)
121 zlog_warn ("can't setsockopt IPV6_RECVHOPLIMIT");
122#else /*RFC2292*/
123 ret = setsockopt (sock, IPPROTO_IPV6, IPV6_HOPLIMIT, &val, sizeof(val));
124 if (ret < 0)
125 zlog_warn ("can't setsockopt IPV6_HOPLIMIT");
126#endif
127 return ret;
128}
129
130/* Set multicast loop zero to the socket. */
131int
132setsockopt_ipv6_multicast_loop (int sock, int val)
133{
134 int ret;
135
136 ret = setsockopt (sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val,
137 sizeof (val));
138 if (ret < 0)
139 zlog_warn ("can't setsockopt IPV6_MULTICAST_LOOP");
140 return ret;
141}
142
paul4f7baa02004-07-23 15:11:07 +0000143static int
paule6822762004-08-19 04:13:29 +0000144getsockopt_ipv6_ifindex (struct msghdr *msgh)
paul4f7baa02004-07-23 15:11:07 +0000145{
146 struct in6_pktinfo *pktinfo;
147
148 pktinfo = getsockopt_cmsg_data (msgh, IPPROTO_IPV6, IPV6_PKTINFO);
149
150 return pktinfo->ipi6_ifindex;
151}
paul718e3742002-12-13 20:15:29 +0000152#endif /* HAVE_IPV6 */
153
154
gdtcc49eb52004-12-30 13:50:32 +0000155/*
156 * Process multicast socket options for IPv4 in an OS-dependent manner.
157 * Supported options are IP_MULTICAST_IF and IP_{ADD,DROP}_MEMBERSHIP.
158 *
159 * Many operating systems have a limit on the number of groups that
160 * can be joined per socket (where each group and local address
161 * counts). This impacts OSPF, which joins groups on each interface
162 * using a single socket. The limit is typically 20, derived from the
163 * original BSD multicast implementation. Some systems have
164 * mechanisms for increasing this limit.
ajsc188c372005-10-21 02:57:41 +0000165 *
166 * In many 4.4BSD-derived systems, multicast group operations are not
167 * allowed on interfaces that are not UP. Thus, a previous attempt to
168 * leave the group may have failed, leaving it still joined, and we
169 * drop/join quietly to recover. This may not be necessary, but aims to
170 * defend against unknown behavior in that we will still return an error
171 * if the second join fails. It is not clear how other systems
172 * (e.g. Linux, Solaris) behave when leaving groups on down interfaces,
173 * but this behavior should not be harmful if they behave the same way,
174 * allow leaves, or implicitly leave all groups joined to down interfaces.
gdtcc49eb52004-12-30 13:50:32 +0000175 */
paul718e3742002-12-13 20:15:29 +0000176int
177setsockopt_multicast_ipv4(int sock,
178 int optname,
Andrew J. Schorr97cabcf2007-07-06 17:00:24 +0000179 struct in_addr if_addr /* required */,
paul718e3742002-12-13 20:15:29 +0000180 unsigned int mcast_addr,
Andrew J. Schorr97cabcf2007-07-06 17:00:24 +0000181 unsigned int ifindex /* optional: if non-zero, may be
182 used instead of if_addr */)
paul718e3742002-12-13 20:15:29 +0000183{
184
paul42c98192005-05-07 02:22:51 +0000185#ifdef HAVE_STRUCT_IP_MREQN_IMR_IFINDEX
paul718e3742002-12-13 20:15:29 +0000186 /* This is better because it uses ifindex directly */
187 struct ip_mreqn mreqn;
ajsc188c372005-10-21 02:57:41 +0000188 int ret;
paul718e3742002-12-13 20:15:29 +0000189
190 switch (optname)
191 {
192 case IP_MULTICAST_IF:
193 case IP_ADD_MEMBERSHIP:
194 case IP_DROP_MEMBERSHIP:
195 memset (&mreqn, 0, sizeof(mreqn));
196
197 if (mcast_addr)
198 mreqn.imr_multiaddr.s_addr = mcast_addr;
199
200 if (ifindex)
201 mreqn.imr_ifindex = ifindex;
202 else
203 mreqn.imr_address = if_addr;
204
ajsc188c372005-10-21 02:57:41 +0000205 ret = setsockopt(sock, IPPROTO_IP, optname,
206 (void *)&mreqn, sizeof(mreqn));
207 if ((ret < 0) && (optname == IP_ADD_MEMBERSHIP) && (errno == EADDRINUSE))
208 {
209 /* see above: handle possible problem when interface comes back up */
210 char buf[2][INET_ADDRSTRLEN];
211 zlog_info("setsockopt_multicast_ipv4 attempting to drop and "
212 "re-add (fd %d, ifaddr %s, mcast %s, ifindex %u)",
213 sock,
214 inet_ntop(AF_INET, &if_addr, buf[0], sizeof(buf[0])),
215 inet_ntop(AF_INET, &mreqn.imr_multiaddr,
216 buf[1], sizeof(buf[1])), ifindex);
217 setsockopt(sock, IPPROTO_IP, IP_DROP_MEMBERSHIP,
218 (void *)&mreqn, sizeof(mreqn));
219 ret = setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
220 (void *)&mreqn, sizeof(mreqn));
221 }
222 return ret;
paul718e3742002-12-13 20:15:29 +0000223 break;
224
225 default:
226 /* Can out and give an understandable error */
227 errno = EINVAL;
228 return -1;
229 break;
230 }
231
232 /* Example defines for another OS, boilerplate off other code in this
233 function, AND handle optname as per other sections for consistency !! */
234 /* #elif defined(BOGON_NIX) && EXAMPLE_VERSION_CODE > -100000 */
235 /* Add your favourite OS here! */
236
237#else /* #if OS_TYPE */
gdtcc49eb52004-12-30 13:50:32 +0000238 /* standard BSD API */
paul718e3742002-12-13 20:15:29 +0000239
240 struct in_addr m;
241 struct ip_mreq mreq;
ajsc188c372005-10-21 02:57:41 +0000242 int ret;
paul718e3742002-12-13 20:15:29 +0000243
paul42c98192005-05-07 02:22:51 +0000244#ifdef HAVE_BSD_STRUCT_IP_MREQ_HACK
245 if (ifindex)
246 m.s_addr = htonl(ifindex);
247 else
248#endif
249 m = if_addr;
250
paul718e3742002-12-13 20:15:29 +0000251 switch (optname)
252 {
253 case IP_MULTICAST_IF:
paul718e3742002-12-13 20:15:29 +0000254 return setsockopt (sock, IPPROTO_IP, optname, (void *)&m, sizeof(m));
255 break;
256
257 case IP_ADD_MEMBERSHIP:
258 case IP_DROP_MEMBERSHIP:
259 memset (&mreq, 0, sizeof(mreq));
260 mreq.imr_multiaddr.s_addr = mcast_addr;
paul42c98192005-05-07 02:22:51 +0000261 mreq.imr_interface = m;
paul718e3742002-12-13 20:15:29 +0000262
ajsc188c372005-10-21 02:57:41 +0000263 ret = setsockopt (sock, IPPROTO_IP, optname, (void *)&mreq, sizeof(mreq));
264 if ((ret < 0) && (optname == IP_ADD_MEMBERSHIP) && (errno == EADDRINUSE))
265 {
266 /* see above: handle possible problem when interface comes back up */
267 char buf[2][INET_ADDRSTRLEN];
268 zlog_info("setsockopt_multicast_ipv4 attempting to drop and "
269 "re-add (fd %d, ifaddr %s, mcast %s, ifindex %u)",
270 sock,
271 inet_ntop(AF_INET, &if_addr, buf[0], sizeof(buf[0])),
272 inet_ntop(AF_INET, &mreq.imr_multiaddr,
273 buf[1], sizeof(buf[1])), ifindex);
274 setsockopt (sock, IPPROTO_IP, IP_DROP_MEMBERSHIP,
275 (void *)&mreq, sizeof(mreq));
276 ret = setsockopt (sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
277 (void *)&mreq, sizeof(mreq));
278 }
279 return ret;
paul718e3742002-12-13 20:15:29 +0000280 break;
281
282 default:
283 /* Can out and give an understandable error */
284 errno = EINVAL;
285 return -1;
286 break;
287 }
288#endif /* #if OS_TYPE */
289
290}
paul4f7baa02004-07-23 15:11:07 +0000291
292static int
paule6822762004-08-19 04:13:29 +0000293setsockopt_ipv4_ifindex (int sock, int val)
paul4f7baa02004-07-23 15:11:07 +0000294{
295 int ret;
296
297#if defined (IP_PKTINFO)
ajs1d75c8c2004-12-28 21:43:17 +0000298 if ((ret = setsockopt (sock, IPPROTO_IP, IP_PKTINFO, &val, sizeof (val))) < 0)
299 zlog_warn ("Can't set IP_PKTINFO option for fd %d to %d: %s",
300 sock,val,safe_strerror(errno));
paul4f7baa02004-07-23 15:11:07 +0000301#elif defined (IP_RECVIF)
ajs1d75c8c2004-12-28 21:43:17 +0000302 if ((ret = setsockopt (sock, IPPROTO_IP, IP_RECVIF, &val, sizeof (val))) < 0)
303 zlog_warn ("Can't set IP_RECVIF option for fd %d to %d: %s",
304 sock,val,safe_strerror(errno));
paul4f7baa02004-07-23 15:11:07 +0000305#else
306#warning "Neither IP_PKTINFO nor IP_RECVIF is available."
307#warning "Will not be able to receive link info."
308#warning "Things might be seriously broken.."
ajs1d75c8c2004-12-28 21:43:17 +0000309 /* XXX Does this ever happen? Should there be a zlog_warn message here? */
310 ret = -1;
paul4f7baa02004-07-23 15:11:07 +0000311#endif
paul4f7baa02004-07-23 15:11:07 +0000312 return ret;
313}
314
paule6822762004-08-19 04:13:29 +0000315int
316setsockopt_ifindex (int af, int sock, int val)
paul4f7baa02004-07-23 15:11:07 +0000317{
paule6822762004-08-19 04:13:29 +0000318 int ret = -1;
319
320 switch (af)
321 {
322 case AF_INET:
323 ret = setsockopt_ipv4_ifindex (sock, val);
324 break;
325#ifdef HAVE_IPV6
326 case AF_INET6:
327 ret = setsockopt_ipv6_pktinfo (sock, val);
328 break;
329#endif
330 default:
hassoe473b032004-09-26 16:08:11 +0000331 zlog_warn ("setsockopt_ifindex: unknown address family %d", af);
paule6822762004-08-19 04:13:29 +0000332 }
333 return ret;
334}
335
gdtd44debe2004-12-29 20:06:23 +0000336/*
337 * Requires: msgh is not NULL and points to a valid struct msghdr, which
338 * may or may not have control data about the incoming interface.
339 *
340 * Returns the interface index (small integer >= 1) if it can be
341 * determined, or else 0.
342 */
paule6822762004-08-19 04:13:29 +0000343static int
344getsockopt_ipv4_ifindex (struct msghdr *msgh)
345{
gdtd44debe2004-12-29 20:06:23 +0000346 /* XXX: initialize to zero? (Always overwritten, so just cosmetic.) */
paule6822762004-08-19 04:13:29 +0000347 int ifindex = -1;
gdt1d69fdf2004-12-29 18:53:30 +0000348
paule6822762004-08-19 04:13:29 +0000349#if defined(IP_PKTINFO)
350/* Linux pktinfo based ifindex retrieval */
paul4f7baa02004-07-23 15:11:07 +0000351 struct in_pktinfo *pktinfo;
paule6822762004-08-19 04:13:29 +0000352
353 pktinfo =
354 (struct in_pktinfo *)getsockopt_cmsg_data (msgh, IPPROTO_IP, IP_PKTINFO);
gdtd44debe2004-12-29 20:06:23 +0000355 /* XXX Can pktinfo be NULL? Clean up post 0.98. */
paule6822762004-08-19 04:13:29 +0000356 ifindex = pktinfo->ipi_ifindex;
357
358#elif defined(IP_RECVIF)
gdtd44debe2004-12-29 20:06:23 +0000359
360 /* retrieval based on IP_RECVIF */
361
paul4f7baa02004-07-23 15:11:07 +0000362#ifndef SUNOS_5
gdtd44debe2004-12-29 20:06:23 +0000363 /* BSD systems use a sockaddr_dl as the control message payload. */
paul4f7baa02004-07-23 15:11:07 +0000364 struct sockaddr_dl *sdl;
gdtd44debe2004-12-29 20:06:23 +0000365#else
366 /* SUNOS_5 uses an integer with the index. */
367 int *ifindex_p;
paul4f7baa02004-07-23 15:11:07 +0000368#endif /* SUNOS_5 */
gdt1d69fdf2004-12-29 18:53:30 +0000369
gdt33f92322004-07-23 16:14:32 +0000370#ifndef SUNOS_5
gdtd44debe2004-12-29 20:06:23 +0000371 /* BSD */
gdt33f92322004-07-23 16:14:32 +0000372 sdl =
paul4f7baa02004-07-23 15:11:07 +0000373 (struct sockaddr_dl *)getsockopt_cmsg_data (msgh, IPPROTO_IP, IP_RECVIF);
gdtd44debe2004-12-29 20:06:23 +0000374 if (sdl != NULL)
375 ifindex = sdl->sdl_index;
376 else
377 ifindex = 0;
378#else
379 /*
380 * Solaris. On Solaris 8, IP_RECVIF is defined, but the call to
381 * enable it fails with errno=99, and the struct msghdr has
382 * controllen 0.
383 */
384 ifindex_p = (uint_t *)getsockopt_cmsg_data (msgh, IPPROTO_IP, IP_RECVIF);
385 if (ifindex_p != NULL)
386 ifindex = *ifindex_p;
387 else
388 ifindex = 0;
paul4f7baa02004-07-23 15:11:07 +0000389#endif /* SUNOS_5 */
paule6822762004-08-19 04:13:29 +0000390
gdtd44debe2004-12-29 20:06:23 +0000391#else
392 /*
393 * Neither IP_PKTINFO nor IP_RECVIF defined - warn at compile time.
394 * XXX Decide if this is a core service, or if daemons have to cope.
395 * Since Solaris 8 and OpenBSD seem not to provide it, it seems that
396 * daemons have to cope.
397 */
398#warning "getsockopt_ipv4_ifindex: Neither IP_PKTINFO nor IP_RECVIF defined."
399#warning "Some daemons may fail to operate correctly!"
paul7d9c6e52004-10-22 10:54:39 +0000400 ifindex = 0;
gdtd44debe2004-12-29 20:06:23 +0000401
paule6822762004-08-19 04:13:29 +0000402#endif /* IP_PKTINFO */
gdtd44debe2004-12-29 20:06:23 +0000403
paul4f7baa02004-07-23 15:11:07 +0000404 return ifindex;
405}
406
407/* return ifindex, 0 if none found */
408int
paule6822762004-08-19 04:13:29 +0000409getsockopt_ifindex (int af, struct msghdr *msgh)
paul4f7baa02004-07-23 15:11:07 +0000410{
411 int ifindex = 0;
412
413 switch (af)
414 {
415 case AF_INET:
paule6822762004-08-19 04:13:29 +0000416 return (getsockopt_ipv4_ifindex (msgh));
paul4f7baa02004-07-23 15:11:07 +0000417 break;
418#ifdef HAVE_IPV6
419 case AF_INET6:
paule6822762004-08-19 04:13:29 +0000420 return (getsockopt_ipv6_ifindex (msgh));
paul4f7baa02004-07-23 15:11:07 +0000421 break;
422#endif
423 default:
hassoe473b032004-09-26 16:08:11 +0000424 zlog_warn ("getsockopt_ifindex: unknown address family %d", af);
paul4f7baa02004-07-23 15:11:07 +0000425 return (ifindex = 0);
426 }
427}
paul96e27c92004-10-05 14:33:43 +0000428
429/* swab iph between order system uses for IP_HDRINCL and host order */
430void
431sockopt_iphdrincl_swab_htosys (struct ip *iph)
432{
433 /* BSD and derived take iph in network order, except for
434 * ip_len and ip_off
435 */
436#ifndef HAVE_IP_HDRINCL_BSD_ORDER
437 iph->ip_len = htons(iph->ip_len);
438 iph->ip_off = htons(iph->ip_off);
439#endif /* HAVE_IP_HDRINCL_BSD_ORDER */
440
441 iph->ip_id = htons(iph->ip_id);
442}
443
444void
445sockopt_iphdrincl_swab_systoh (struct ip *iph)
446{
447#ifndef HAVE_IP_HDRINCL_BSD_ORDER
448 iph->ip_len = ntohs(iph->ip_len);
449 iph->ip_off = ntohs(iph->ip_off);
450#endif /* HAVE_IP_HDRINCL_BSD_ORDER */
451
452 iph->ip_id = ntohs(iph->ip_id);
453}