Parallelize in_ifaddrhead operation
[dragonfly.git] / sys / netinet / igmp.c
CommitLineData
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1/*
2 * Copyright (c) 1988 Stephen Deering.
3 * Copyright (c) 1992, 1993
4 * The Regents of the University of California. All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * Stephen Deering of Stanford University.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed by the University of
20 * California, Berkeley and its contributors.
21 * 4. Neither the name of the University nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 *
37 * @(#)igmp.c 8.1 (Berkeley) 7/19/93
38 * $FreeBSD: src/sys/netinet/igmp.c,v 1.29.2.2 2003/01/23 21:06:44 sam Exp $
1b562c24 39 * $DragonFly: src/sys/netinet/igmp.c,v 1.14 2008/06/08 08:38:05 sephe Exp $
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40 */
41
42/*
43 * Internet Group Management Protocol (IGMP) routines.
44 *
45 * Written by Steve Deering, Stanford, May 1988.
46 * Modified by Rosen Sharma, Stanford, Aug 1994.
47 * Modified by Bill Fenner, Xerox PARC, Feb 1995.
48 * Modified to fully comply to IGMPv2 by Bill Fenner, Oct 1995.
49 *
50 * MULTICAST Revision: 3.5.1.4
51 */
52
53#include <sys/param.h>
54#include <sys/systm.h>
55#include <sys/malloc.h>
56#include <sys/mbuf.h>
57#include <sys/socket.h>
58#include <sys/protosw.h>
59#include <sys/kernel.h>
60#include <sys/sysctl.h>
3f9db7f8 61#include <sys/in_cksum.h>
1cae611f 62#include <sys/thread2.h>
984263bc 63
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64#include <machine/stdarg.h>
65
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66#include <net/if.h>
67#include <net/route.h>
68
69#include <netinet/in.h>
70#include <netinet/in_var.h>
71#include <netinet/in_systm.h>
72#include <netinet/ip.h>
73#include <netinet/ip_var.h>
74#include <netinet/igmp.h>
75#include <netinet/igmp_var.h>
76
77static MALLOC_DEFINE(M_IGMP, "igmp", "igmp state");
78
79static struct router_info *
42a7fc75 80 find_rti (struct ifnet *ifp);
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81
82static struct igmpstat igmpstat;
83
84SYSCTL_STRUCT(_net_inet_igmp, IGMPCTL_STATS, stats, CTLFLAG_RW,
85 &igmpstat, igmpstat, "");
86
87static int igmp_timers_are_running;
88static u_long igmp_all_hosts_group;
89static u_long igmp_all_rtrs_group;
90static struct mbuf *router_alert;
91static struct router_info *Head;
92
42a7fc75 93static void igmp_sendpkt (struct in_multi *, int, unsigned long);
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94
95void
f3f70f0d 96igmp_init(void)
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97{
98 struct ipoption *ra;
99
100 /*
101 * To avoid byte-swapping the same value over and over again.
102 */
103 igmp_all_hosts_group = htonl(INADDR_ALLHOSTS_GROUP);
104 igmp_all_rtrs_group = htonl(INADDR_ALLRTRS_GROUP);
105
106 igmp_timers_are_running = 0;
107
108 /*
109 * Construct a Router Alert option to use in outgoing packets
110 */
74f1caca 111 MGET(router_alert, MB_DONTWAIT, MT_DATA);
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112 ra = mtod(router_alert, struct ipoption *);
113 ra->ipopt_dst.s_addr = 0;
114 ra->ipopt_list[0] = IPOPT_RA; /* Router Alert Option */
115 ra->ipopt_list[1] = 0x04; /* 4 bytes long */
116 ra->ipopt_list[2] = 0x00;
117 ra->ipopt_list[3] = 0x00;
118 router_alert->m_len = sizeof(ra->ipopt_dst) + ra->ipopt_list[1];
119
120 Head = (struct router_info *) 0;
121}
122
123static struct router_info *
f3f70f0d 124find_rti(struct ifnet *ifp)
984263bc 125{
f23061d4 126 struct router_info *rti = Head;
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127
128#ifdef IGMP_DEBUG
a6ec04bc 129 kprintf("[igmp.c, _find_rti] --> entering \n");
984263bc 130#endif
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131 while (rti) {
132 if (rti->rti_ifp == ifp) {
984263bc 133#ifdef IGMP_DEBUG
a6ec04bc 134 kprintf("[igmp.c, _find_rti] --> found old entry \n");
984263bc 135#endif
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136 return rti;
137 }
138 rti = rti->rti_next;
139 }
ba4e3dbe 140 MALLOC(rti, struct router_info *, sizeof *rti, M_IGMP, M_INTWAIT);
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141 rti->rti_ifp = ifp;
142 rti->rti_type = IGMP_V2_ROUTER;
143 rti->rti_time = 0;
144 rti->rti_next = Head;
145 Head = rti;
984263bc 146#ifdef IGMP_DEBUG
a6ec04bc 147 kprintf("[igmp.c, _find_rti] --> created an entry \n");
984263bc 148#endif
f23061d4 149 return rti;
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150}
151
152void
a00138cb 153igmp_input(struct mbuf *m, ...)
984263bc 154{
a00138cb 155 int iphlen, off, proto;
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156 struct igmp *igmp;
157 struct ip *ip;
158 int igmplen;
159 struct ifnet *ifp = m->m_pkthdr.rcvif;
160 int minlen;
161 struct in_multi *inm;
162 struct in_ifaddr *ia;
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163 struct in_multistep step;
164 struct router_info *rti;
a00138cb 165 __va_list ap;
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166
167 int timer; /** timer value in the igmp query header **/
168
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169 __va_start(ap, m);
170 off = __va_arg(ap, int);
171 proto = __va_arg(ap, int);
172 __va_end(ap);
173
174 iphlen = off;
175
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176 ++igmpstat.igps_rcv_total;
177
178 ip = mtod(m, struct ip *);
179 igmplen = ip->ip_len;
180
181 /*
182 * Validate lengths
183 */
184 if (igmplen < IGMP_MINLEN) {
185 ++igmpstat.igps_rcv_tooshort;
186 m_freem(m);
187 return;
188 }
189 minlen = iphlen + IGMP_MINLEN;
190 if ((m->m_flags & M_EXT || m->m_len < minlen) &&
191 (m = m_pullup(m, minlen)) == 0) {
192 ++igmpstat.igps_rcv_tooshort;
193 return;
194 }
195
196 /*
197 * Validate checksum
198 */
199 m->m_data += iphlen;
200 m->m_len -= iphlen;
201 igmp = mtod(m, struct igmp *);
202 if (in_cksum(m, igmplen)) {
203 ++igmpstat.igps_rcv_badsum;
204 m_freem(m);
205 return;
206 }
207 m->m_data -= iphlen;
208 m->m_len += iphlen;
209
210 ip = mtod(m, struct ip *);
211 timer = igmp->igmp_code * PR_FASTHZ / IGMP_TIMER_SCALE;
212 if (timer == 0)
213 timer = 1;
214 rti = find_rti(ifp);
215
216 /*
217 * In the IGMPv2 specification, there are 3 states and a flag.
218 *
219 * In Non-Member state, we simply don't have a membership record.
220 * In Delaying Member state, our timer is running (inm->inm_timer)
221 * In Idle Member state, our timer is not running (inm->inm_timer==0)
222 *
223 * The flag is inm->inm_state, it is set to IGMP_OTHERMEMBER if
224 * we have heard a report from another member, or IGMP_IREPORTEDLAST
225 * if I sent the last report.
226 */
227 switch (igmp->igmp_type) {
228
229 case IGMP_MEMBERSHIP_QUERY:
230 ++igmpstat.igps_rcv_queries;
231
232 if (ifp->if_flags & IFF_LOOPBACK)
233 break;
234
235 if (igmp->igmp_code == 0) {
236 /*
237 * Old router. Remember that the querier on this
238 * interface is old, and set the timer to the
239 * value in RFC 1112.
240 */
241
242 rti->rti_type = IGMP_V1_ROUTER;
243 rti->rti_time = 0;
244
245 timer = IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ;
246
247 if (ip->ip_dst.s_addr != igmp_all_hosts_group ||
248 igmp->igmp_group.s_addr != 0) {
249 ++igmpstat.igps_rcv_badqueries;
250 m_freem(m);
251 return;
252 }
253 } else {
254 /*
255 * New router. Simply do the new validity check.
256 */
257
258 if (igmp->igmp_group.s_addr != 0 &&
259 !IN_MULTICAST(ntohl(igmp->igmp_group.s_addr))) {
260 ++igmpstat.igps_rcv_badqueries;
261 m_freem(m);
262 return;
263 }
264 }
265
266 /*
267 * - Start the timers in all of our membership records
268 * that the query applies to for the interface on
269 * which the query arrived excl. those that belong
270 * to the "all-hosts" group (224.0.0.1).
271 * - Restart any timer that is already running but has
272 * a value longer than the requested timeout.
273 * - Use the value specified in the query message as
274 * the maximum timeout.
275 */
276 IN_FIRST_MULTI(step, inm);
277 while (inm != NULL) {
278 if (inm->inm_ifp == ifp &&
279 inm->inm_addr.s_addr != igmp_all_hosts_group &&
280 (igmp->igmp_group.s_addr == 0 ||
281 igmp->igmp_group.s_addr == inm->inm_addr.s_addr)) {
282 if (inm->inm_timer == 0 ||
283 inm->inm_timer > timer) {
284 inm->inm_timer =
285 IGMP_RANDOM_DELAY(timer);
286 igmp_timers_are_running = 1;
287 }
288 }
289 IN_NEXT_MULTI(step, inm);
290 }
291
292 break;
293
294 case IGMP_V1_MEMBERSHIP_REPORT:
295 case IGMP_V2_MEMBERSHIP_REPORT:
296 /*
297 * For fast leave to work, we have to know that we are the
298 * last person to send a report for this group. Reports
299 * can potentially get looped back if we are a multicast
300 * router, so discard reports sourced by me.
301 */
1b562c24 302 ia = IFP_TO_IA(ifp);
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303 if (ia && ip->ip_src.s_addr == IA_SIN(ia)->sin_addr.s_addr)
304 break;
305
306 ++igmpstat.igps_rcv_reports;
307
308 if (ifp->if_flags & IFF_LOOPBACK)
309 break;
310
311 if (!IN_MULTICAST(ntohl(igmp->igmp_group.s_addr))) {
312 ++igmpstat.igps_rcv_badreports;
313 m_freem(m);
314 return;
315 }
316
317 /*
318 * KLUDGE: if the IP source address of the report has an
319 * unspecified (i.e., zero) subnet number, as is allowed for
320 * a booting host, replace it with the correct subnet number
321 * so that a process-level multicast routing demon can
322 * determine which subnet it arrived from. This is necessary
323 * to compensate for the lack of any way for a process to
324 * determine the arrival interface of an incoming packet.
325 */
326 if ((ntohl(ip->ip_src.s_addr) & IN_CLASSA_NET) == 0)
327 if (ia) ip->ip_src.s_addr = htonl(ia->ia_subnet);
328
329 /*
330 * If we belong to the group being reported, stop
331 * our timer for that group.
332 */
333 IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm);
334
335 if (inm != NULL) {
336 inm->inm_timer = 0;
337 ++igmpstat.igps_rcv_ourreports;
338
339 inm->inm_state = IGMP_OTHERMEMBER;
340 }
341
342 break;
343 }
344
345 /*
346 * Pass all valid IGMP packets up to any process(es) listening
347 * on a raw IGMP socket.
348 */
349 rip_input(m, off, proto);
350}
351
352void
f3f70f0d 353igmp_joingroup(struct in_multi *inm)
984263bc 354{
1cae611f 355 crit_enter();
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356 if (inm->inm_addr.s_addr == igmp_all_hosts_group
357 || inm->inm_ifp->if_flags & IFF_LOOPBACK) {
358 inm->inm_timer = 0;
359 inm->inm_state = IGMP_OTHERMEMBER;
360 } else {
361 inm->inm_rti = find_rti(inm->inm_ifp);
362 igmp_sendpkt(inm, inm->inm_rti->rti_type, 0);
363 inm->inm_timer = IGMP_RANDOM_DELAY(
364 IGMP_MAX_HOST_REPORT_DELAY*PR_FASTHZ);
365 inm->inm_state = IGMP_IREPORTEDLAST;
366 igmp_timers_are_running = 1;
367 }
1cae611f 368 crit_exit();
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369}
370
371void
f3f70f0d 372igmp_leavegroup(struct in_multi *inm)
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373{
374 if (inm->inm_state == IGMP_IREPORTEDLAST &&
375 inm->inm_addr.s_addr != igmp_all_hosts_group &&
376 !(inm->inm_ifp->if_flags & IFF_LOOPBACK) &&
377 inm->inm_rti->rti_type != IGMP_V1_ROUTER)
378 igmp_sendpkt(inm, IGMP_V2_LEAVE_GROUP, igmp_all_rtrs_group);
379}
380
381void
f3f70f0d 382igmp_fasttimo(void)
984263bc 383{
2256ba69 384 struct in_multi *inm;
984263bc 385 struct in_multistep step;
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386
387 /*
388 * Quick check to see if any work needs to be done, in order
389 * to minimize the overhead of fasttimo processing.
390 */
391
392 if (!igmp_timers_are_running)
393 return;
394
1cae611f 395 crit_enter();
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396 igmp_timers_are_running = 0;
397 IN_FIRST_MULTI(step, inm);
398 while (inm != NULL) {
399 if (inm->inm_timer == 0) {
400 /* do nothing */
401 } else if (--inm->inm_timer == 0) {
402 igmp_sendpkt(inm, inm->inm_rti->rti_type, 0);
403 inm->inm_state = IGMP_IREPORTEDLAST;
404 } else {
405 igmp_timers_are_running = 1;
406 }
407 IN_NEXT_MULTI(step, inm);
408 }
1cae611f 409 crit_exit();
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410}
411
412void
f3f70f0d 413igmp_slowtimo(void)
984263bc 414{
2256ba69 415 struct router_info *rti = Head;
984263bc 416
1cae611f 417 crit_enter();
984263bc 418#ifdef IGMP_DEBUG
a6ec04bc 419 kprintf("[igmp.c,_slowtimo] -- > entering \n");
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420#endif
421 while (rti) {
422 if (rti->rti_type == IGMP_V1_ROUTER) {
423 rti->rti_time++;
424 if (rti->rti_time >= IGMP_AGE_THRESHOLD) {
425 rti->rti_type = IGMP_V2_ROUTER;
426 }
427 }
428 rti = rti->rti_next;
429 }
430#ifdef IGMP_DEBUG
a6ec04bc 431 kprintf("[igmp.c,_slowtimo] -- > exiting \n");
984263bc 432#endif
1cae611f 433 crit_exit();
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434}
435
436static struct route igmprt;
437
438static void
f3f70f0d 439igmp_sendpkt(struct in_multi *inm, int type, unsigned long addr)
984263bc 440{
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441 struct mbuf *m;
442 struct igmp *igmp;
443 struct ip *ip;
444 struct ip_moptions imo;
984263bc 445
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446 MGETHDR(m, MB_DONTWAIT, MT_HEADER);
447 if (m == NULL)
448 return;
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449
450 m->m_pkthdr.rcvif = loif;
451 m->m_pkthdr.len = sizeof(struct ip) + IGMP_MINLEN;
452 MH_ALIGN(m, IGMP_MINLEN + sizeof(struct ip));
453 m->m_data += sizeof(struct ip);
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454 m->m_len = IGMP_MINLEN;
455 igmp = mtod(m, struct igmp *);
456 igmp->igmp_type = type;
457 igmp->igmp_code = 0;
458 igmp->igmp_group = inm->inm_addr;
459 igmp->igmp_cksum = 0;
460 igmp->igmp_cksum = in_cksum(m, IGMP_MINLEN);
461
462 m->m_data -= sizeof(struct ip);
463 m->m_len += sizeof(struct ip);
464 ip = mtod(m, struct ip *);
465 ip->ip_tos = 0;
466 ip->ip_len = sizeof(struct ip) + IGMP_MINLEN;
467 ip->ip_off = 0;
468 ip->ip_p = IPPROTO_IGMP;
469 ip->ip_src.s_addr = INADDR_ANY;
470 ip->ip_dst.s_addr = addr ? addr : igmp->igmp_group.s_addr;
471
472 imo.imo_multicast_ifp = inm->inm_ifp;
473 imo.imo_multicast_ttl = 1;
474 imo.imo_multicast_vif = -1;
475 /*
476 * Request loopback of the report if we are acting as a multicast
477 * router, so that the process-level routing demon can hear it.
478 */
479 imo.imo_multicast_loop = (ip_mrouter != NULL);
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480
481 /*
482 * XXX
483 * Do we have to worry about reentrancy here? Don't think so.
484 */
f23061d4 485 ip_output(m, router_alert, &igmprt, 0, &imo, NULL);
984263bc 486
f23061d4 487 ++igmpstat.igps_snd_reports;
984263bc 488}