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
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
|
/* $FreeBSD$ */
/* $KAME: mld6.c,v 1.27 2001/04/04 05:17:30 itojun Exp $ */
/*
* Copyright (C) 1998 WIDE Project.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* Copyright (c) 1988 Stephen Deering.
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Stephen Deering of Stanford University.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)igmp.c 8.1 (Berkeley) 7/19/93
*/
#include "opt_inet.h"
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/protosw.h>
#include <sys/syslog.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet/icmp6.h>
#include <netinet6/mld6_var.h>
#include <net/net_osdep.h>
/*
* Protocol constants
*/
/* denotes that the MLD max response delay field specifies time in milliseconds */
#define MLD6_TIMER_SCALE 1000
/*
* time between repetitions of a node's initial report of interest in a
* multicast address(in seconds)
*/
#define MLD6_UNSOLICITED_REPORT_INTERVAL 10
static struct ip6_pktopts ip6_opts;
static int mld6_timers_are_running;
/* XXX: These are necessary for KAME's link-local hack */
static struct in6_addr mld6_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
static struct in6_addr mld6_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
static void mld6_sendpkt(struct in6_multi *, int, const struct in6_addr *);
void
mld6_init()
{
static u_int8_t hbh_buf[8];
struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf;
u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD);
mld6_timers_are_running = 0;
/* ip6h_nxt will be fill in later */
hbh->ip6h_len = 0; /* (8 >> 3) - 1 */
/* XXX: grotty hard coding... */
hbh_buf[2] = IP6OPT_PADN; /* 2 byte padding */
hbh_buf[3] = 0;
hbh_buf[4] = IP6OPT_RTALERT;
hbh_buf[5] = IP6OPT_RTALERT_LEN - 2;
bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t));
init_ip6pktopts(&ip6_opts);
ip6_opts.ip6po_hbh = hbh;
}
void
mld6_start_listening(in6m)
struct in6_multi *in6m;
{
int s = splnet();
/*
* RFC2710 page 10:
* The node never sends a Report or Done for the link-scope all-nodes
* address.
* MLD messages are never sent for multicast addresses whose scope is 0
* (reserved) or 1 (node-local).
*/
mld6_all_nodes_linklocal.s6_addr16[1] =
htons(in6m->in6m_ifp->if_index); /* XXX */
if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal) ||
IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) {
in6m->in6m_timer = 0;
in6m->in6m_state = MLD6_OTHERLISTENER;
} else {
mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL);
in6m->in6m_timer = MLD6_RANDOM_DELAY(
MLD6_UNSOLICITED_REPORT_INTERVAL * PR_FASTHZ);
in6m->in6m_state = MLD6_IREPORTEDLAST;
mld6_timers_are_running = 1;
}
splx(s);
}
void
mld6_stop_listening(in6m)
struct in6_multi *in6m;
{
mld6_all_nodes_linklocal.s6_addr16[1] =
htons(in6m->in6m_ifp->if_index); /* XXX */
mld6_all_routers_linklocal.s6_addr16[1] =
htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */
if (in6m->in6m_state == MLD6_IREPORTEDLAST &&
(!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal)) &&
IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_NODELOCAL)
mld6_sendpkt(in6m, MLD_LISTENER_DONE,
&mld6_all_routers_linklocal);
}
void
mld6_input(m, off)
struct mbuf *m;
int off;
{
struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
struct mld_hdr *mldh;
struct ifnet *ifp = m->m_pkthdr.rcvif;
struct in6_multi *in6m;
struct in6_ifaddr *ia;
struct ifmultiaddr *ifma;
int timer; /* timer value in the MLD query header */
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, off, sizeof(*mldh),);
mldh = (struct mld_hdr *)(mtod(m, caddr_t) + off);
#else
IP6_EXTHDR_GET(mldh, struct mld_hdr *, m, off, sizeof(*mldh));
if (mldh == NULL) {
icmp6stat.icp6s_tooshort++;
return;
}
#endif
/* source address validation */
ip6 = mtod(m, struct ip6_hdr *); /* in case mpullup */
if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) {
log(LOG_ERR,
"mld6_input: src %s is not link-local (grp=%s)\n",
ip6_sprintf(&ip6->ip6_src),
ip6_sprintf(&mldh->mld_addr));
/*
* spec (RFC2710) does not explicitly
* specify to discard the packet from a non link-local
* source address. But we believe it's expected to do so.
* XXX: do we have to allow :: as source?
*/
m_freem(m);
return;
}
/*
* In the MLD6 specification, there are 3 states and a flag.
*
* In Non-Listener state, we simply don't have a membership record.
* In Delaying Listener state, our timer is running (in6m->in6m_timer)
* In Idle Listener state, our timer is not running (in6m->in6m_timer==0)
*
* The flag is in6m->in6m_state, it is set to MLD6_OTHERLISTENER if
* we have heard a report from another member, or MLD6_IREPORTEDLAST
* if we sent the last report.
*/
switch(mldh->mld_type) {
case MLD_LISTENER_QUERY:
if (ifp->if_flags & IFF_LOOPBACK)
break;
if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) &&
!IN6_IS_ADDR_MULTICAST(&mldh->mld_addr))
break; /* print error or log stat? */
if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
mldh->mld_addr.s6_addr16[1] =
htons(ifp->if_index); /* XXX */
/*
* - Start the timers in all of our membership records
* that the query applies to for the interface on
* which the query arrived excl. those that belong
* to the "all-nodes" group (ff02::1).
* - Restart any timer that is already running but has
* A value longer than the requested timeout.
* - Use the value specified in the query message as
* the maximum timeout.
*/
IFP_TO_IA6(ifp, ia);
if (ia == NULL)
break;
/*
* XXX: System timer resolution is too low to handle Max
* Response Delay, so set 1 to the internal timer even if
* the calculated value equals to zero when Max Response
* Delay is positive.
*/
timer = ntohs(mldh->mld_maxdelay) * PR_FASTHZ / MLD6_TIMER_SCALE;
if (timer == 0 && mldh->mld_maxdelay)
timer = 1;
mld6_all_nodes_linklocal.s6_addr16[1] =
htons(ifp->if_index); /* XXX */
TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
if (ifma->ifma_addr->sa_family != AF_INET6)
continue;
in6m = (struct in6_multi *)ifma->ifma_protospec;
if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr,
&mld6_all_nodes_linklocal) ||
IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) <
IPV6_ADDR_SCOPE_LINKLOCAL)
continue;
if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) ||
IN6_ARE_ADDR_EQUAL(&mldh->mld_addr,
&in6m->in6m_addr))
{
if (timer == 0) {
/* send a report immediately */
mld6_sendpkt(in6m, MLD_LISTENER_REPORT,
NULL);
in6m->in6m_timer = 0; /* reset timer */
in6m->in6m_state = MLD6_IREPORTEDLAST;
}
else if (in6m->in6m_timer == 0 || /*idle state*/
in6m->in6m_timer > timer) {
in6m->in6m_timer =
MLD6_RANDOM_DELAY(timer);
mld6_timers_are_running = 1;
}
}
}
if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
break;
case MLD_LISTENER_REPORT:
/*
* For fast leave to work, we have to know that we are the
* last person to send a report for this group. Reports
* can potentially get looped back if we are a multicast
* router, so discard reports sourced by me.
* Note that it is impossible to check IFF_LOOPBACK flag of
* ifp for this purpose, since ip6_mloopback pass the physical
* interface to looutput.
*/
if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */
break;
if (!IN6_IS_ADDR_MULTICAST(&mldh->mld_addr))
break;
if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
mldh->mld_addr.s6_addr16[1] =
htons(ifp->if_index); /* XXX */
/*
* If we belong to the group being reported, stop
* our timer for that group.
*/
IN6_LOOKUP_MULTI(mldh->mld_addr, ifp, in6m);
if (in6m) {
in6m->in6m_timer = 0; /* transit to idle state */
in6m->in6m_state = MLD6_OTHERLISTENER; /* clear flag */
}
if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
break;
default: /* this is impossible */
log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld_type);
break;
}
m_freem(m);
}
void
mld6_fasttimeo()
{
struct in6_multi *in6m;
struct in6_multistep step;
int s;
/*
* Quick check to see if any work needs to be done, in order
* to minimize the overhead of fasttimo processing.
*/
if (!mld6_timers_are_running)
return;
s = splnet();
mld6_timers_are_running = 0;
IN6_FIRST_MULTI(step, in6m);
while (in6m != NULL) {
if (in6m->in6m_timer == 0) {
/* do nothing */
} else if (--in6m->in6m_timer == 0) {
mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL);
in6m->in6m_state = MLD6_IREPORTEDLAST;
} else {
mld6_timers_are_running = 1;
}
IN6_NEXT_MULTI(step, in6m);
}
splx(s);
}
static void
mld6_sendpkt(in6m, type, dst)
struct in6_multi *in6m;
int type;
const struct in6_addr *dst;
{
struct mbuf *mh, *md;
struct mld_hdr *mldh;
struct ip6_hdr *ip6;
struct ip6_moptions im6o;
struct in6_ifaddr *ia;
struct ifnet *ifp = in6m->in6m_ifp;
struct ifnet *outif = NULL;
/*
* At first, find a link local address on the outgoing interface
* to use as the source address of the MLD packet.
*/
if ((ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST))
== NULL)
return;
/*
* Allocate mbufs to store ip6 header and MLD header.
* We allocate 2 mbufs and make chain in advance because
* it is more convenient when inserting the hop-by-hop option later.
*/
MGETHDR(mh, M_DONTWAIT, MT_HEADER);
if (mh == NULL)
return;
MGET(md, M_DONTWAIT, MT_DATA);
if (md == NULL) {
m_free(mh);
return;
}
mh->m_next = md;
mh->m_pkthdr.rcvif = NULL;
mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr);
mh->m_len = sizeof(struct ip6_hdr);
MH_ALIGN(mh, sizeof(struct ip6_hdr));
/* fill in the ip6 header */
ip6 = mtod(mh, struct ip6_hdr *);
ip6->ip6_flow = 0;
ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
ip6->ip6_vfc |= IPV6_VERSION;
/* ip6_plen will be set later */
ip6->ip6_nxt = IPPROTO_ICMPV6;
/* ip6_hlim will be set by im6o.im6o_multicast_hlim */
ip6->ip6_src = ia->ia_addr.sin6_addr;
ip6->ip6_dst = dst ? *dst : in6m->in6m_addr;
/* fill in the MLD header */
md->m_len = sizeof(struct mld_hdr);
mldh = mtod(md, struct mld_hdr *);
mldh->mld_type = type;
mldh->mld_code = 0;
mldh->mld_cksum = 0;
/* XXX: we assume the function will not be called for query messages */
mldh->mld_maxdelay = 0;
mldh->mld_reserved = 0;
mldh->mld_addr = in6m->in6m_addr;
if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
mldh->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr),
sizeof(struct mld_hdr));
/* construct multicast option */
bzero(&im6o, sizeof(im6o));
im6o.im6o_multicast_ifp = ifp;
im6o.im6o_multicast_hlim = 1;
/*
* Request loopback of the report if we are acting as a multicast
* router, so that the process-level routing daemon can hear it.
*/
im6o.im6o_multicast_loop = (ip6_mrouter != NULL);
/* increment output statictics */
icmp6stat.icp6s_outhist[type]++;
ip6_output(mh, &ip6_opts, NULL, 0, &im6o, &outif, NULL);
if (outif) {
icmp6_ifstat_inc(outif, ifs6_out_msg);
switch (type) {
case MLD_LISTENER_QUERY:
icmp6_ifstat_inc(outif, ifs6_out_mldquery);
break;
case MLD_LISTENER_REPORT:
icmp6_ifstat_inc(outif, ifs6_out_mldreport);
break;
case MLD_LISTENER_DONE:
icmp6_ifstat_inc(outif, ifs6_out_mlddone);
break;
}
}
}
|