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Merge branch 'clk/mxs-for-3.6' of git://git.linaro.org/people/shawnguo/linux-2.6...
[deliverable/linux.git] / net / netfilter / nf_conntrack_h323_main.c
1 /*
2 * H.323 connection tracking helper
3 *
4 * Copyright (c) 2006 Jing Min Zhao <zhaojingmin@users.sourceforge.net>
5 *
6 * This source code is licensed under General Public License version 2.
7 *
8 * Based on the 'brute force' H.323 connection tracking module by
9 * Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
10 *
11 * For more information, please see http://nath323.sourceforge.net/
12 */
13
14 #include <linux/module.h>
15 #include <linux/moduleparam.h>
16 #include <linux/ctype.h>
17 #include <linux/inet.h>
18 #include <linux/in.h>
19 #include <linux/ip.h>
20 #include <linux/slab.h>
21 #include <linux/udp.h>
22 #include <linux/tcp.h>
23 #include <linux/skbuff.h>
24 #include <net/route.h>
25 #include <net/ip6_route.h>
26
27 #include <net/netfilter/nf_conntrack.h>
28 #include <net/netfilter/nf_conntrack_core.h>
29 #include <net/netfilter/nf_conntrack_tuple.h>
30 #include <net/netfilter/nf_conntrack_expect.h>
31 #include <net/netfilter/nf_conntrack_ecache.h>
32 #include <net/netfilter/nf_conntrack_helper.h>
33 #include <net/netfilter/nf_conntrack_zones.h>
34 #include <linux/netfilter/nf_conntrack_h323.h>
35
36 /* Parameters */
37 static unsigned int default_rrq_ttl __read_mostly = 300;
38 module_param(default_rrq_ttl, uint, 0600);
39 MODULE_PARM_DESC(default_rrq_ttl, "use this TTL if it's missing in RRQ");
40
41 static int gkrouted_only __read_mostly = 1;
42 module_param(gkrouted_only, int, 0600);
43 MODULE_PARM_DESC(gkrouted_only, "only accept calls from gatekeeper");
44
45 static bool callforward_filter __read_mostly = true;
46 module_param(callforward_filter, bool, 0600);
47 MODULE_PARM_DESC(callforward_filter, "only create call forwarding expectations "
48 "if both endpoints are on different sides "
49 "(determined by routing information)");
50
51 /* Hooks for NAT */
52 int (*set_h245_addr_hook) (struct sk_buff *skb,
53 unsigned char **data, int dataoff,
54 H245_TransportAddress *taddr,
55 union nf_inet_addr *addr, __be16 port)
56 __read_mostly;
57 int (*set_h225_addr_hook) (struct sk_buff *skb,
58 unsigned char **data, int dataoff,
59 TransportAddress *taddr,
60 union nf_inet_addr *addr, __be16 port)
61 __read_mostly;
62 int (*set_sig_addr_hook) (struct sk_buff *skb,
63 struct nf_conn *ct,
64 enum ip_conntrack_info ctinfo,
65 unsigned char **data,
66 TransportAddress *taddr, int count) __read_mostly;
67 int (*set_ras_addr_hook) (struct sk_buff *skb,
68 struct nf_conn *ct,
69 enum ip_conntrack_info ctinfo,
70 unsigned char **data,
71 TransportAddress *taddr, int count) __read_mostly;
72 int (*nat_rtp_rtcp_hook) (struct sk_buff *skb,
73 struct nf_conn *ct,
74 enum ip_conntrack_info ctinfo,
75 unsigned char **data, int dataoff,
76 H245_TransportAddress *taddr,
77 __be16 port, __be16 rtp_port,
78 struct nf_conntrack_expect *rtp_exp,
79 struct nf_conntrack_expect *rtcp_exp) __read_mostly;
80 int (*nat_t120_hook) (struct sk_buff *skb,
81 struct nf_conn *ct,
82 enum ip_conntrack_info ctinfo,
83 unsigned char **data, int dataoff,
84 H245_TransportAddress *taddr, __be16 port,
85 struct nf_conntrack_expect *exp) __read_mostly;
86 int (*nat_h245_hook) (struct sk_buff *skb,
87 struct nf_conn *ct,
88 enum ip_conntrack_info ctinfo,
89 unsigned char **data, int dataoff,
90 TransportAddress *taddr, __be16 port,
91 struct nf_conntrack_expect *exp) __read_mostly;
92 int (*nat_callforwarding_hook) (struct sk_buff *skb,
93 struct nf_conn *ct,
94 enum ip_conntrack_info ctinfo,
95 unsigned char **data, int dataoff,
96 TransportAddress *taddr, __be16 port,
97 struct nf_conntrack_expect *exp) __read_mostly;
98 int (*nat_q931_hook) (struct sk_buff *skb,
99 struct nf_conn *ct,
100 enum ip_conntrack_info ctinfo,
101 unsigned char **data, TransportAddress *taddr, int idx,
102 __be16 port, struct nf_conntrack_expect *exp)
103 __read_mostly;
104
105 static DEFINE_SPINLOCK(nf_h323_lock);
106 static char *h323_buffer;
107
108 static struct nf_conntrack_helper nf_conntrack_helper_h245;
109 static struct nf_conntrack_helper nf_conntrack_helper_q931[];
110 static struct nf_conntrack_helper nf_conntrack_helper_ras[];
111
112 /****************************************************************************/
113 static int get_tpkt_data(struct sk_buff *skb, unsigned int protoff,
114 struct nf_conn *ct, enum ip_conntrack_info ctinfo,
115 unsigned char **data, int *datalen, int *dataoff)
116 {
117 struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
118 int dir = CTINFO2DIR(ctinfo);
119 const struct tcphdr *th;
120 struct tcphdr _tcph;
121 int tcpdatalen;
122 int tcpdataoff;
123 unsigned char *tpkt;
124 int tpktlen;
125 int tpktoff;
126
127 /* Get TCP header */
128 th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph);
129 if (th == NULL)
130 return 0;
131
132 /* Get TCP data offset */
133 tcpdataoff = protoff + th->doff * 4;
134
135 /* Get TCP data length */
136 tcpdatalen = skb->len - tcpdataoff;
137 if (tcpdatalen <= 0) /* No TCP data */
138 goto clear_out;
139
140 if (*data == NULL) { /* first TPKT */
141 /* Get first TPKT pointer */
142 tpkt = skb_header_pointer(skb, tcpdataoff, tcpdatalen,
143 h323_buffer);
144 BUG_ON(tpkt == NULL);
145
146 /* Validate TPKT identifier */
147 if (tcpdatalen < 4 || tpkt[0] != 0x03 || tpkt[1] != 0) {
148 /* Netmeeting sends TPKT header and data separately */
149 if (info->tpkt_len[dir] > 0) {
150 pr_debug("nf_ct_h323: previous packet "
151 "indicated separate TPKT data of %hu "
152 "bytes\n", info->tpkt_len[dir]);
153 if (info->tpkt_len[dir] <= tcpdatalen) {
154 /* Yes, there was a TPKT header
155 * received */
156 *data = tpkt;
157 *datalen = info->tpkt_len[dir];
158 *dataoff = 0;
159 goto out;
160 }
161
162 /* Fragmented TPKT */
163 pr_debug("nf_ct_h323: fragmented TPKT\n");
164 goto clear_out;
165 }
166
167 /* It is not even a TPKT */
168 return 0;
169 }
170 tpktoff = 0;
171 } else { /* Next TPKT */
172 tpktoff = *dataoff + *datalen;
173 tcpdatalen -= tpktoff;
174 if (tcpdatalen <= 4) /* No more TPKT */
175 goto clear_out;
176 tpkt = *data + *datalen;
177
178 /* Validate TPKT identifier */
179 if (tpkt[0] != 0x03 || tpkt[1] != 0)
180 goto clear_out;
181 }
182
183 /* Validate TPKT length */
184 tpktlen = tpkt[2] * 256 + tpkt[3];
185 if (tpktlen < 4)
186 goto clear_out;
187 if (tpktlen > tcpdatalen) {
188 if (tcpdatalen == 4) { /* Separate TPKT header */
189 /* Netmeeting sends TPKT header and data separately */
190 pr_debug("nf_ct_h323: separate TPKT header indicates "
191 "there will be TPKT data of %hu bytes\n",
192 tpktlen - 4);
193 info->tpkt_len[dir] = tpktlen - 4;
194 return 0;
195 }
196
197 pr_debug("nf_ct_h323: incomplete TPKT (fragmented?)\n");
198 goto clear_out;
199 }
200
201 /* This is the encapsulated data */
202 *data = tpkt + 4;
203 *datalen = tpktlen - 4;
204 *dataoff = tpktoff + 4;
205
206 out:
207 /* Clear TPKT length */
208 info->tpkt_len[dir] = 0;
209 return 1;
210
211 clear_out:
212 info->tpkt_len[dir] = 0;
213 return 0;
214 }
215
216 /****************************************************************************/
217 static int get_h245_addr(struct nf_conn *ct, const unsigned char *data,
218 H245_TransportAddress *taddr,
219 union nf_inet_addr *addr, __be16 *port)
220 {
221 const unsigned char *p;
222 int len;
223
224 if (taddr->choice != eH245_TransportAddress_unicastAddress)
225 return 0;
226
227 switch (taddr->unicastAddress.choice) {
228 case eUnicastAddress_iPAddress:
229 if (nf_ct_l3num(ct) != AF_INET)
230 return 0;
231 p = data + taddr->unicastAddress.iPAddress.network;
232 len = 4;
233 break;
234 case eUnicastAddress_iP6Address:
235 if (nf_ct_l3num(ct) != AF_INET6)
236 return 0;
237 p = data + taddr->unicastAddress.iP6Address.network;
238 len = 16;
239 break;
240 default:
241 return 0;
242 }
243
244 memcpy(addr, p, len);
245 memset((void *)addr + len, 0, sizeof(*addr) - len);
246 memcpy(port, p + len, sizeof(__be16));
247
248 return 1;
249 }
250
251 /****************************************************************************/
252 static int expect_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct,
253 enum ip_conntrack_info ctinfo,
254 unsigned char **data, int dataoff,
255 H245_TransportAddress *taddr)
256 {
257 int dir = CTINFO2DIR(ctinfo);
258 int ret = 0;
259 __be16 port;
260 __be16 rtp_port, rtcp_port;
261 union nf_inet_addr addr;
262 struct nf_conntrack_expect *rtp_exp;
263 struct nf_conntrack_expect *rtcp_exp;
264 typeof(nat_rtp_rtcp_hook) nat_rtp_rtcp;
265
266 /* Read RTP or RTCP address */
267 if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
268 memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
269 port == 0)
270 return 0;
271
272 /* RTP port is even */
273 rtp_port = port & ~htons(1);
274 rtcp_port = port | htons(1);
275
276 /* Create expect for RTP */
277 if ((rtp_exp = nf_ct_expect_alloc(ct)) == NULL)
278 return -1;
279 nf_ct_expect_init(rtp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
280 &ct->tuplehash[!dir].tuple.src.u3,
281 &ct->tuplehash[!dir].tuple.dst.u3,
282 IPPROTO_UDP, NULL, &rtp_port);
283
284 /* Create expect for RTCP */
285 if ((rtcp_exp = nf_ct_expect_alloc(ct)) == NULL) {
286 nf_ct_expect_put(rtp_exp);
287 return -1;
288 }
289 nf_ct_expect_init(rtcp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
290 &ct->tuplehash[!dir].tuple.src.u3,
291 &ct->tuplehash[!dir].tuple.dst.u3,
292 IPPROTO_UDP, NULL, &rtcp_port);
293
294 if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
295 &ct->tuplehash[!dir].tuple.dst.u3,
296 sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
297 (nat_rtp_rtcp = rcu_dereference(nat_rtp_rtcp_hook)) &&
298 ct->status & IPS_NAT_MASK) {
299 /* NAT needed */
300 ret = nat_rtp_rtcp(skb, ct, ctinfo, data, dataoff,
301 taddr, port, rtp_port, rtp_exp, rtcp_exp);
302 } else { /* Conntrack only */
303 if (nf_ct_expect_related(rtp_exp) == 0) {
304 if (nf_ct_expect_related(rtcp_exp) == 0) {
305 pr_debug("nf_ct_h323: expect RTP ");
306 nf_ct_dump_tuple(&rtp_exp->tuple);
307 pr_debug("nf_ct_h323: expect RTCP ");
308 nf_ct_dump_tuple(&rtcp_exp->tuple);
309 } else {
310 nf_ct_unexpect_related(rtp_exp);
311 ret = -1;
312 }
313 } else
314 ret = -1;
315 }
316
317 nf_ct_expect_put(rtp_exp);
318 nf_ct_expect_put(rtcp_exp);
319
320 return ret;
321 }
322
323 /****************************************************************************/
324 static int expect_t120(struct sk_buff *skb,
325 struct nf_conn *ct,
326 enum ip_conntrack_info ctinfo,
327 unsigned char **data, int dataoff,
328 H245_TransportAddress *taddr)
329 {
330 int dir = CTINFO2DIR(ctinfo);
331 int ret = 0;
332 __be16 port;
333 union nf_inet_addr addr;
334 struct nf_conntrack_expect *exp;
335 typeof(nat_t120_hook) nat_t120;
336
337 /* Read T.120 address */
338 if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
339 memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
340 port == 0)
341 return 0;
342
343 /* Create expect for T.120 connections */
344 if ((exp = nf_ct_expect_alloc(ct)) == NULL)
345 return -1;
346 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
347 &ct->tuplehash[!dir].tuple.src.u3,
348 &ct->tuplehash[!dir].tuple.dst.u3,
349 IPPROTO_TCP, NULL, &port);
350 exp->flags = NF_CT_EXPECT_PERMANENT; /* Accept multiple channels */
351
352 if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
353 &ct->tuplehash[!dir].tuple.dst.u3,
354 sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
355 (nat_t120 = rcu_dereference(nat_t120_hook)) &&
356 ct->status & IPS_NAT_MASK) {
357 /* NAT needed */
358 ret = nat_t120(skb, ct, ctinfo, data, dataoff, taddr,
359 port, exp);
360 } else { /* Conntrack only */
361 if (nf_ct_expect_related(exp) == 0) {
362 pr_debug("nf_ct_h323: expect T.120 ");
363 nf_ct_dump_tuple(&exp->tuple);
364 } else
365 ret = -1;
366 }
367
368 nf_ct_expect_put(exp);
369
370 return ret;
371 }
372
373 /****************************************************************************/
374 static int process_h245_channel(struct sk_buff *skb,
375 struct nf_conn *ct,
376 enum ip_conntrack_info ctinfo,
377 unsigned char **data, int dataoff,
378 H2250LogicalChannelParameters *channel)
379 {
380 int ret;
381
382 if (channel->options & eH2250LogicalChannelParameters_mediaChannel) {
383 /* RTP */
384 ret = expect_rtp_rtcp(skb, ct, ctinfo, data, dataoff,
385 &channel->mediaChannel);
386 if (ret < 0)
387 return -1;
388 }
389
390 if (channel->
391 options & eH2250LogicalChannelParameters_mediaControlChannel) {
392 /* RTCP */
393 ret = expect_rtp_rtcp(skb, ct, ctinfo, data, dataoff,
394 &channel->mediaControlChannel);
395 if (ret < 0)
396 return -1;
397 }
398
399 return 0;
400 }
401
402 /****************************************************************************/
403 static int process_olc(struct sk_buff *skb, struct nf_conn *ct,
404 enum ip_conntrack_info ctinfo,
405 unsigned char **data, int dataoff,
406 OpenLogicalChannel *olc)
407 {
408 int ret;
409
410 pr_debug("nf_ct_h323: OpenLogicalChannel\n");
411
412 if (olc->forwardLogicalChannelParameters.multiplexParameters.choice ==
413 eOpenLogicalChannel_forwardLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters)
414 {
415 ret = process_h245_channel(skb, ct, ctinfo, data, dataoff,
416 &olc->
417 forwardLogicalChannelParameters.
418 multiplexParameters.
419 h2250LogicalChannelParameters);
420 if (ret < 0)
421 return -1;
422 }
423
424 if ((olc->options &
425 eOpenLogicalChannel_reverseLogicalChannelParameters) &&
426 (olc->reverseLogicalChannelParameters.options &
427 eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters)
428 && (olc->reverseLogicalChannelParameters.multiplexParameters.
429 choice ==
430 eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
431 {
432 ret =
433 process_h245_channel(skb, ct, ctinfo, data, dataoff,
434 &olc->
435 reverseLogicalChannelParameters.
436 multiplexParameters.
437 h2250LogicalChannelParameters);
438 if (ret < 0)
439 return -1;
440 }
441
442 if ((olc->options & eOpenLogicalChannel_separateStack) &&
443 olc->forwardLogicalChannelParameters.dataType.choice ==
444 eDataType_data &&
445 olc->forwardLogicalChannelParameters.dataType.data.application.
446 choice == eDataApplicationCapability_application_t120 &&
447 olc->forwardLogicalChannelParameters.dataType.data.application.
448 t120.choice == eDataProtocolCapability_separateLANStack &&
449 olc->separateStack.networkAddress.choice ==
450 eNetworkAccessParameters_networkAddress_localAreaAddress) {
451 ret = expect_t120(skb, ct, ctinfo, data, dataoff,
452 &olc->separateStack.networkAddress.
453 localAreaAddress);
454 if (ret < 0)
455 return -1;
456 }
457
458 return 0;
459 }
460
461 /****************************************************************************/
462 static int process_olca(struct sk_buff *skb, struct nf_conn *ct,
463 enum ip_conntrack_info ctinfo,
464 unsigned char **data, int dataoff,
465 OpenLogicalChannelAck *olca)
466 {
467 H2250LogicalChannelAckParameters *ack;
468 int ret;
469
470 pr_debug("nf_ct_h323: OpenLogicalChannelAck\n");
471
472 if ((olca->options &
473 eOpenLogicalChannelAck_reverseLogicalChannelParameters) &&
474 (olca->reverseLogicalChannelParameters.options &
475 eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters)
476 && (olca->reverseLogicalChannelParameters.multiplexParameters.
477 choice ==
478 eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
479 {
480 ret = process_h245_channel(skb, ct, ctinfo, data, dataoff,
481 &olca->
482 reverseLogicalChannelParameters.
483 multiplexParameters.
484 h2250LogicalChannelParameters);
485 if (ret < 0)
486 return -1;
487 }
488
489 if ((olca->options &
490 eOpenLogicalChannelAck_forwardMultiplexAckParameters) &&
491 (olca->forwardMultiplexAckParameters.choice ==
492 eOpenLogicalChannelAck_forwardMultiplexAckParameters_h2250LogicalChannelAckParameters))
493 {
494 ack = &olca->forwardMultiplexAckParameters.
495 h2250LogicalChannelAckParameters;
496 if (ack->options &
497 eH2250LogicalChannelAckParameters_mediaChannel) {
498 /* RTP */
499 ret = expect_rtp_rtcp(skb, ct, ctinfo, data, dataoff,
500 &ack->mediaChannel);
501 if (ret < 0)
502 return -1;
503 }
504
505 if (ack->options &
506 eH2250LogicalChannelAckParameters_mediaControlChannel) {
507 /* RTCP */
508 ret = expect_rtp_rtcp(skb, ct, ctinfo, data, dataoff,
509 &ack->mediaControlChannel);
510 if (ret < 0)
511 return -1;
512 }
513 }
514
515 if ((olca->options & eOpenLogicalChannelAck_separateStack) &&
516 olca->separateStack.networkAddress.choice ==
517 eNetworkAccessParameters_networkAddress_localAreaAddress) {
518 ret = expect_t120(skb, ct, ctinfo, data, dataoff,
519 &olca->separateStack.networkAddress.
520 localAreaAddress);
521 if (ret < 0)
522 return -1;
523 }
524
525 return 0;
526 }
527
528 /****************************************************************************/
529 static int process_h245(struct sk_buff *skb, struct nf_conn *ct,
530 enum ip_conntrack_info ctinfo,
531 unsigned char **data, int dataoff,
532 MultimediaSystemControlMessage *mscm)
533 {
534 switch (mscm->choice) {
535 case eMultimediaSystemControlMessage_request:
536 if (mscm->request.choice ==
537 eRequestMessage_openLogicalChannel) {
538 return process_olc(skb, ct, ctinfo, data, dataoff,
539 &mscm->request.openLogicalChannel);
540 }
541 pr_debug("nf_ct_h323: H.245 Request %d\n",
542 mscm->request.choice);
543 break;
544 case eMultimediaSystemControlMessage_response:
545 if (mscm->response.choice ==
546 eResponseMessage_openLogicalChannelAck) {
547 return process_olca(skb, ct, ctinfo, data, dataoff,
548 &mscm->response.
549 openLogicalChannelAck);
550 }
551 pr_debug("nf_ct_h323: H.245 Response %d\n",
552 mscm->response.choice);
553 break;
554 default:
555 pr_debug("nf_ct_h323: H.245 signal %d\n", mscm->choice);
556 break;
557 }
558
559 return 0;
560 }
561
562 /****************************************************************************/
563 static int h245_help(struct sk_buff *skb, unsigned int protoff,
564 struct nf_conn *ct, enum ip_conntrack_info ctinfo)
565 {
566 static MultimediaSystemControlMessage mscm;
567 unsigned char *data = NULL;
568 int datalen;
569 int dataoff;
570 int ret;
571
572 /* Until there's been traffic both ways, don't look in packets. */
573 if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
574 return NF_ACCEPT;
575
576 pr_debug("nf_ct_h245: skblen = %u\n", skb->len);
577
578 spin_lock_bh(&nf_h323_lock);
579
580 /* Process each TPKT */
581 while (get_tpkt_data(skb, protoff, ct, ctinfo,
582 &data, &datalen, &dataoff)) {
583 pr_debug("nf_ct_h245: TPKT len=%d ", datalen);
584 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
585
586 /* Decode H.245 signal */
587 ret = DecodeMultimediaSystemControlMessage(data, datalen,
588 &mscm);
589 if (ret < 0) {
590 pr_debug("nf_ct_h245: decoding error: %s\n",
591 ret == H323_ERROR_BOUND ?
592 "out of bound" : "out of range");
593 /* We don't drop when decoding error */
594 break;
595 }
596
597 /* Process H.245 signal */
598 if (process_h245(skb, ct, ctinfo, &data, dataoff, &mscm) < 0)
599 goto drop;
600 }
601
602 spin_unlock_bh(&nf_h323_lock);
603 return NF_ACCEPT;
604
605 drop:
606 spin_unlock_bh(&nf_h323_lock);
607 net_info_ratelimited("nf_ct_h245: packet dropped\n");
608 return NF_DROP;
609 }
610
611 /****************************************************************************/
612 static const struct nf_conntrack_expect_policy h245_exp_policy = {
613 .max_expected = H323_RTP_CHANNEL_MAX * 4 + 2 /* T.120 */,
614 .timeout = 240,
615 };
616
617 static struct nf_conntrack_helper nf_conntrack_helper_h245 __read_mostly = {
618 .name = "H.245",
619 .me = THIS_MODULE,
620 .tuple.src.l3num = AF_UNSPEC,
621 .tuple.dst.protonum = IPPROTO_UDP,
622 .help = h245_help,
623 .expect_policy = &h245_exp_policy,
624 };
625
626 /****************************************************************************/
627 int get_h225_addr(struct nf_conn *ct, unsigned char *data,
628 TransportAddress *taddr,
629 union nf_inet_addr *addr, __be16 *port)
630 {
631 const unsigned char *p;
632 int len;
633
634 switch (taddr->choice) {
635 case eTransportAddress_ipAddress:
636 if (nf_ct_l3num(ct) != AF_INET)
637 return 0;
638 p = data + taddr->ipAddress.ip;
639 len = 4;
640 break;
641 case eTransportAddress_ip6Address:
642 if (nf_ct_l3num(ct) != AF_INET6)
643 return 0;
644 p = data + taddr->ip6Address.ip;
645 len = 16;
646 break;
647 default:
648 return 0;
649 }
650
651 memcpy(addr, p, len);
652 memset((void *)addr + len, 0, sizeof(*addr) - len);
653 memcpy(port, p + len, sizeof(__be16));
654
655 return 1;
656 }
657
658 /****************************************************************************/
659 static int expect_h245(struct sk_buff *skb, struct nf_conn *ct,
660 enum ip_conntrack_info ctinfo,
661 unsigned char **data, int dataoff,
662 TransportAddress *taddr)
663 {
664 int dir = CTINFO2DIR(ctinfo);
665 int ret = 0;
666 __be16 port;
667 union nf_inet_addr addr;
668 struct nf_conntrack_expect *exp;
669 typeof(nat_h245_hook) nat_h245;
670
671 /* Read h245Address */
672 if (!get_h225_addr(ct, *data, taddr, &addr, &port) ||
673 memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
674 port == 0)
675 return 0;
676
677 /* Create expect for h245 connection */
678 if ((exp = nf_ct_expect_alloc(ct)) == NULL)
679 return -1;
680 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
681 &ct->tuplehash[!dir].tuple.src.u3,
682 &ct->tuplehash[!dir].tuple.dst.u3,
683 IPPROTO_TCP, NULL, &port);
684 exp->helper = &nf_conntrack_helper_h245;
685
686 if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
687 &ct->tuplehash[!dir].tuple.dst.u3,
688 sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
689 (nat_h245 = rcu_dereference(nat_h245_hook)) &&
690 ct->status & IPS_NAT_MASK) {
691 /* NAT needed */
692 ret = nat_h245(skb, ct, ctinfo, data, dataoff, taddr,
693 port, exp);
694 } else { /* Conntrack only */
695 if (nf_ct_expect_related(exp) == 0) {
696 pr_debug("nf_ct_q931: expect H.245 ");
697 nf_ct_dump_tuple(&exp->tuple);
698 } else
699 ret = -1;
700 }
701
702 nf_ct_expect_put(exp);
703
704 return ret;
705 }
706
707 /* If the calling party is on the same side of the forward-to party,
708 * we don't need to track the second call */
709 static int callforward_do_filter(const union nf_inet_addr *src,
710 const union nf_inet_addr *dst,
711 u_int8_t family)
712 {
713 const struct nf_afinfo *afinfo;
714 int ret = 0;
715
716 /* rcu_read_lock()ed by nf_hook_slow() */
717 afinfo = nf_get_afinfo(family);
718 if (!afinfo)
719 return 0;
720
721 switch (family) {
722 case AF_INET: {
723 struct flowi4 fl1, fl2;
724 struct rtable *rt1, *rt2;
725
726 memset(&fl1, 0, sizeof(fl1));
727 fl1.daddr = src->ip;
728
729 memset(&fl2, 0, sizeof(fl2));
730 fl2.daddr = dst->ip;
731 if (!afinfo->route(&init_net, (struct dst_entry **)&rt1,
732 flowi4_to_flowi(&fl1), false)) {
733 if (!afinfo->route(&init_net, (struct dst_entry **)&rt2,
734 flowi4_to_flowi(&fl2), false)) {
735 if (rt1->rt_gateway == rt2->rt_gateway &&
736 rt1->dst.dev == rt2->dst.dev)
737 ret = 1;
738 dst_release(&rt2->dst);
739 }
740 dst_release(&rt1->dst);
741 }
742 break;
743 }
744 #if IS_ENABLED(CONFIG_NF_CONNTRACK_IPV6)
745 case AF_INET6: {
746 struct flowi6 fl1, fl2;
747 struct rt6_info *rt1, *rt2;
748
749 memset(&fl1, 0, sizeof(fl1));
750 fl1.daddr = src->in6;
751
752 memset(&fl2, 0, sizeof(fl2));
753 fl2.daddr = dst->in6;
754 if (!afinfo->route(&init_net, (struct dst_entry **)&rt1,
755 flowi6_to_flowi(&fl1), false)) {
756 if (!afinfo->route(&init_net, (struct dst_entry **)&rt2,
757 flowi6_to_flowi(&fl2), false)) {
758 if (!memcmp(&rt1->rt6i_gateway, &rt2->rt6i_gateway,
759 sizeof(rt1->rt6i_gateway)) &&
760 rt1->dst.dev == rt2->dst.dev)
761 ret = 1;
762 dst_release(&rt2->dst);
763 }
764 dst_release(&rt1->dst);
765 }
766 break;
767 }
768 #endif
769 }
770 return ret;
771
772 }
773
774 /****************************************************************************/
775 static int expect_callforwarding(struct sk_buff *skb,
776 struct nf_conn *ct,
777 enum ip_conntrack_info ctinfo,
778 unsigned char **data, int dataoff,
779 TransportAddress *taddr)
780 {
781 int dir = CTINFO2DIR(ctinfo);
782 int ret = 0;
783 __be16 port;
784 union nf_inet_addr addr;
785 struct nf_conntrack_expect *exp;
786 typeof(nat_callforwarding_hook) nat_callforwarding;
787
788 /* Read alternativeAddress */
789 if (!get_h225_addr(ct, *data, taddr, &addr, &port) || port == 0)
790 return 0;
791
792 /* If the calling party is on the same side of the forward-to party,
793 * we don't need to track the second call */
794 if (callforward_filter &&
795 callforward_do_filter(&addr, &ct->tuplehash[!dir].tuple.src.u3,
796 nf_ct_l3num(ct))) {
797 pr_debug("nf_ct_q931: Call Forwarding not tracked\n");
798 return 0;
799 }
800
801 /* Create expect for the second call leg */
802 if ((exp = nf_ct_expect_alloc(ct)) == NULL)
803 return -1;
804 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
805 &ct->tuplehash[!dir].tuple.src.u3, &addr,
806 IPPROTO_TCP, NULL, &port);
807 exp->helper = nf_conntrack_helper_q931;
808
809 if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
810 &ct->tuplehash[!dir].tuple.dst.u3,
811 sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
812 (nat_callforwarding = rcu_dereference(nat_callforwarding_hook)) &&
813 ct->status & IPS_NAT_MASK) {
814 /* Need NAT */
815 ret = nat_callforwarding(skb, ct, ctinfo, data, dataoff,
816 taddr, port, exp);
817 } else { /* Conntrack only */
818 if (nf_ct_expect_related(exp) == 0) {
819 pr_debug("nf_ct_q931: expect Call Forwarding ");
820 nf_ct_dump_tuple(&exp->tuple);
821 } else
822 ret = -1;
823 }
824
825 nf_ct_expect_put(exp);
826
827 return ret;
828 }
829
830 /****************************************************************************/
831 static int process_setup(struct sk_buff *skb, struct nf_conn *ct,
832 enum ip_conntrack_info ctinfo,
833 unsigned char **data, int dataoff,
834 Setup_UUIE *setup)
835 {
836 int dir = CTINFO2DIR(ctinfo);
837 int ret;
838 int i;
839 __be16 port;
840 union nf_inet_addr addr;
841 typeof(set_h225_addr_hook) set_h225_addr;
842
843 pr_debug("nf_ct_q931: Setup\n");
844
845 if (setup->options & eSetup_UUIE_h245Address) {
846 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
847 &setup->h245Address);
848 if (ret < 0)
849 return -1;
850 }
851
852 set_h225_addr = rcu_dereference(set_h225_addr_hook);
853 if ((setup->options & eSetup_UUIE_destCallSignalAddress) &&
854 (set_h225_addr) && ct->status & IPS_NAT_MASK &&
855 get_h225_addr(ct, *data, &setup->destCallSignalAddress,
856 &addr, &port) &&
857 memcmp(&addr, &ct->tuplehash[!dir].tuple.src.u3, sizeof(addr))) {
858 pr_debug("nf_ct_q931: set destCallSignalAddress %pI6:%hu->%pI6:%hu\n",
859 &addr, ntohs(port), &ct->tuplehash[!dir].tuple.src.u3,
860 ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port));
861 ret = set_h225_addr(skb, data, dataoff,
862 &setup->destCallSignalAddress,
863 &ct->tuplehash[!dir].tuple.src.u3,
864 ct->tuplehash[!dir].tuple.src.u.tcp.port);
865 if (ret < 0)
866 return -1;
867 }
868
869 if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) &&
870 (set_h225_addr) && ct->status & IPS_NAT_MASK &&
871 get_h225_addr(ct, *data, &setup->sourceCallSignalAddress,
872 &addr, &port) &&
873 memcmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(addr))) {
874 pr_debug("nf_ct_q931: set sourceCallSignalAddress %pI6:%hu->%pI6:%hu\n",
875 &addr, ntohs(port), &ct->tuplehash[!dir].tuple.dst.u3,
876 ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port));
877 ret = set_h225_addr(skb, data, dataoff,
878 &setup->sourceCallSignalAddress,
879 &ct->tuplehash[!dir].tuple.dst.u3,
880 ct->tuplehash[!dir].tuple.dst.u.tcp.port);
881 if (ret < 0)
882 return -1;
883 }
884
885 if (setup->options & eSetup_UUIE_fastStart) {
886 for (i = 0; i < setup->fastStart.count; i++) {
887 ret = process_olc(skb, ct, ctinfo, data, dataoff,
888 &setup->fastStart.item[i]);
889 if (ret < 0)
890 return -1;
891 }
892 }
893
894 return 0;
895 }
896
897 /****************************************************************************/
898 static int process_callproceeding(struct sk_buff *skb,
899 struct nf_conn *ct,
900 enum ip_conntrack_info ctinfo,
901 unsigned char **data, int dataoff,
902 CallProceeding_UUIE *callproc)
903 {
904 int ret;
905 int i;
906
907 pr_debug("nf_ct_q931: CallProceeding\n");
908
909 if (callproc->options & eCallProceeding_UUIE_h245Address) {
910 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
911 &callproc->h245Address);
912 if (ret < 0)
913 return -1;
914 }
915
916 if (callproc->options & eCallProceeding_UUIE_fastStart) {
917 for (i = 0; i < callproc->fastStart.count; i++) {
918 ret = process_olc(skb, ct, ctinfo, data, dataoff,
919 &callproc->fastStart.item[i]);
920 if (ret < 0)
921 return -1;
922 }
923 }
924
925 return 0;
926 }
927
928 /****************************************************************************/
929 static int process_connect(struct sk_buff *skb, struct nf_conn *ct,
930 enum ip_conntrack_info ctinfo,
931 unsigned char **data, int dataoff,
932 Connect_UUIE *connect)
933 {
934 int ret;
935 int i;
936
937 pr_debug("nf_ct_q931: Connect\n");
938
939 if (connect->options & eConnect_UUIE_h245Address) {
940 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
941 &connect->h245Address);
942 if (ret < 0)
943 return -1;
944 }
945
946 if (connect->options & eConnect_UUIE_fastStart) {
947 for (i = 0; i < connect->fastStart.count; i++) {
948 ret = process_olc(skb, ct, ctinfo, data, dataoff,
949 &connect->fastStart.item[i]);
950 if (ret < 0)
951 return -1;
952 }
953 }
954
955 return 0;
956 }
957
958 /****************************************************************************/
959 static int process_alerting(struct sk_buff *skb, struct nf_conn *ct,
960 enum ip_conntrack_info ctinfo,
961 unsigned char **data, int dataoff,
962 Alerting_UUIE *alert)
963 {
964 int ret;
965 int i;
966
967 pr_debug("nf_ct_q931: Alerting\n");
968
969 if (alert->options & eAlerting_UUIE_h245Address) {
970 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
971 &alert->h245Address);
972 if (ret < 0)
973 return -1;
974 }
975
976 if (alert->options & eAlerting_UUIE_fastStart) {
977 for (i = 0; i < alert->fastStart.count; i++) {
978 ret = process_olc(skb, ct, ctinfo, data, dataoff,
979 &alert->fastStart.item[i]);
980 if (ret < 0)
981 return -1;
982 }
983 }
984
985 return 0;
986 }
987
988 /****************************************************************************/
989 static int process_facility(struct sk_buff *skb, struct nf_conn *ct,
990 enum ip_conntrack_info ctinfo,
991 unsigned char **data, int dataoff,
992 Facility_UUIE *facility)
993 {
994 int ret;
995 int i;
996
997 pr_debug("nf_ct_q931: Facility\n");
998
999 if (facility->reason.choice == eFacilityReason_callForwarded) {
1000 if (facility->options & eFacility_UUIE_alternativeAddress)
1001 return expect_callforwarding(skb, ct, ctinfo, data,
1002 dataoff,
1003 &facility->
1004 alternativeAddress);
1005 return 0;
1006 }
1007
1008 if (facility->options & eFacility_UUIE_h245Address) {
1009 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
1010 &facility->h245Address);
1011 if (ret < 0)
1012 return -1;
1013 }
1014
1015 if (facility->options & eFacility_UUIE_fastStart) {
1016 for (i = 0; i < facility->fastStart.count; i++) {
1017 ret = process_olc(skb, ct, ctinfo, data, dataoff,
1018 &facility->fastStart.item[i]);
1019 if (ret < 0)
1020 return -1;
1021 }
1022 }
1023
1024 return 0;
1025 }
1026
1027 /****************************************************************************/
1028 static int process_progress(struct sk_buff *skb, struct nf_conn *ct,
1029 enum ip_conntrack_info ctinfo,
1030 unsigned char **data, int dataoff,
1031 Progress_UUIE *progress)
1032 {
1033 int ret;
1034 int i;
1035
1036 pr_debug("nf_ct_q931: Progress\n");
1037
1038 if (progress->options & eProgress_UUIE_h245Address) {
1039 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
1040 &progress->h245Address);
1041 if (ret < 0)
1042 return -1;
1043 }
1044
1045 if (progress->options & eProgress_UUIE_fastStart) {
1046 for (i = 0; i < progress->fastStart.count; i++) {
1047 ret = process_olc(skb, ct, ctinfo, data, dataoff,
1048 &progress->fastStart.item[i]);
1049 if (ret < 0)
1050 return -1;
1051 }
1052 }
1053
1054 return 0;
1055 }
1056
1057 /****************************************************************************/
1058 static int process_q931(struct sk_buff *skb, struct nf_conn *ct,
1059 enum ip_conntrack_info ctinfo,
1060 unsigned char **data, int dataoff, Q931 *q931)
1061 {
1062 H323_UU_PDU *pdu = &q931->UUIE.h323_uu_pdu;
1063 int i;
1064 int ret = 0;
1065
1066 switch (pdu->h323_message_body.choice) {
1067 case eH323_UU_PDU_h323_message_body_setup:
1068 ret = process_setup(skb, ct, ctinfo, data, dataoff,
1069 &pdu->h323_message_body.setup);
1070 break;
1071 case eH323_UU_PDU_h323_message_body_callProceeding:
1072 ret = process_callproceeding(skb, ct, ctinfo, data, dataoff,
1073 &pdu->h323_message_body.
1074 callProceeding);
1075 break;
1076 case eH323_UU_PDU_h323_message_body_connect:
1077 ret = process_connect(skb, ct, ctinfo, data, dataoff,
1078 &pdu->h323_message_body.connect);
1079 break;
1080 case eH323_UU_PDU_h323_message_body_alerting:
1081 ret = process_alerting(skb, ct, ctinfo, data, dataoff,
1082 &pdu->h323_message_body.alerting);
1083 break;
1084 case eH323_UU_PDU_h323_message_body_facility:
1085 ret = process_facility(skb, ct, ctinfo, data, dataoff,
1086 &pdu->h323_message_body.facility);
1087 break;
1088 case eH323_UU_PDU_h323_message_body_progress:
1089 ret = process_progress(skb, ct, ctinfo, data, dataoff,
1090 &pdu->h323_message_body.progress);
1091 break;
1092 default:
1093 pr_debug("nf_ct_q931: Q.931 signal %d\n",
1094 pdu->h323_message_body.choice);
1095 break;
1096 }
1097
1098 if (ret < 0)
1099 return -1;
1100
1101 if (pdu->options & eH323_UU_PDU_h245Control) {
1102 for (i = 0; i < pdu->h245Control.count; i++) {
1103 ret = process_h245(skb, ct, ctinfo, data, dataoff,
1104 &pdu->h245Control.item[i]);
1105 if (ret < 0)
1106 return -1;
1107 }
1108 }
1109
1110 return 0;
1111 }
1112
1113 /****************************************************************************/
1114 static int q931_help(struct sk_buff *skb, unsigned int protoff,
1115 struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1116 {
1117 static Q931 q931;
1118 unsigned char *data = NULL;
1119 int datalen;
1120 int dataoff;
1121 int ret;
1122
1123 /* Until there's been traffic both ways, don't look in packets. */
1124 if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
1125 return NF_ACCEPT;
1126
1127 pr_debug("nf_ct_q931: skblen = %u\n", skb->len);
1128
1129 spin_lock_bh(&nf_h323_lock);
1130
1131 /* Process each TPKT */
1132 while (get_tpkt_data(skb, protoff, ct, ctinfo,
1133 &data, &datalen, &dataoff)) {
1134 pr_debug("nf_ct_q931: TPKT len=%d ", datalen);
1135 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1136
1137 /* Decode Q.931 signal */
1138 ret = DecodeQ931(data, datalen, &q931);
1139 if (ret < 0) {
1140 pr_debug("nf_ct_q931: decoding error: %s\n",
1141 ret == H323_ERROR_BOUND ?
1142 "out of bound" : "out of range");
1143 /* We don't drop when decoding error */
1144 break;
1145 }
1146
1147 /* Process Q.931 signal */
1148 if (process_q931(skb, ct, ctinfo, &data, dataoff, &q931) < 0)
1149 goto drop;
1150 }
1151
1152 spin_unlock_bh(&nf_h323_lock);
1153 return NF_ACCEPT;
1154
1155 drop:
1156 spin_unlock_bh(&nf_h323_lock);
1157 net_info_ratelimited("nf_ct_q931: packet dropped\n");
1158 return NF_DROP;
1159 }
1160
1161 /****************************************************************************/
1162 static const struct nf_conntrack_expect_policy q931_exp_policy = {
1163 /* T.120 and H.245 */
1164 .max_expected = H323_RTP_CHANNEL_MAX * 4 + 4,
1165 .timeout = 240,
1166 };
1167
1168 static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = {
1169 {
1170 .name = "Q.931",
1171 .me = THIS_MODULE,
1172 .tuple.src.l3num = AF_INET,
1173 .tuple.src.u.tcp.port = cpu_to_be16(Q931_PORT),
1174 .tuple.dst.protonum = IPPROTO_TCP,
1175 .help = q931_help,
1176 .expect_policy = &q931_exp_policy,
1177 },
1178 {
1179 .name = "Q.931",
1180 .me = THIS_MODULE,
1181 .tuple.src.l3num = AF_INET6,
1182 .tuple.src.u.tcp.port = cpu_to_be16(Q931_PORT),
1183 .tuple.dst.protonum = IPPROTO_TCP,
1184 .help = q931_help,
1185 .expect_policy = &q931_exp_policy,
1186 },
1187 };
1188
1189 /****************************************************************************/
1190 static unsigned char *get_udp_data(struct sk_buff *skb, unsigned int protoff,
1191 int *datalen)
1192 {
1193 const struct udphdr *uh;
1194 struct udphdr _uh;
1195 int dataoff;
1196
1197 uh = skb_header_pointer(skb, protoff, sizeof(_uh), &_uh);
1198 if (uh == NULL)
1199 return NULL;
1200 dataoff = protoff + sizeof(_uh);
1201 if (dataoff >= skb->len)
1202 return NULL;
1203 *datalen = skb->len - dataoff;
1204 return skb_header_pointer(skb, dataoff, *datalen, h323_buffer);
1205 }
1206
1207 /****************************************************************************/
1208 static struct nf_conntrack_expect *find_expect(struct nf_conn *ct,
1209 union nf_inet_addr *addr,
1210 __be16 port)
1211 {
1212 struct net *net = nf_ct_net(ct);
1213 struct nf_conntrack_expect *exp;
1214 struct nf_conntrack_tuple tuple;
1215
1216 memset(&tuple.src.u3, 0, sizeof(tuple.src.u3));
1217 tuple.src.u.tcp.port = 0;
1218 memcpy(&tuple.dst.u3, addr, sizeof(tuple.dst.u3));
1219 tuple.dst.u.tcp.port = port;
1220 tuple.dst.protonum = IPPROTO_TCP;
1221
1222 exp = __nf_ct_expect_find(net, nf_ct_zone(ct), &tuple);
1223 if (exp && exp->master == ct)
1224 return exp;
1225 return NULL;
1226 }
1227
1228 /****************************************************************************/
1229 static int set_expect_timeout(struct nf_conntrack_expect *exp,
1230 unsigned int timeout)
1231 {
1232 if (!exp || !del_timer(&exp->timeout))
1233 return 0;
1234
1235 exp->timeout.expires = jiffies + timeout * HZ;
1236 add_timer(&exp->timeout);
1237
1238 return 1;
1239 }
1240
1241 /****************************************************************************/
1242 static int expect_q931(struct sk_buff *skb, struct nf_conn *ct,
1243 enum ip_conntrack_info ctinfo,
1244 unsigned char **data,
1245 TransportAddress *taddr, int count)
1246 {
1247 struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1248 int dir = CTINFO2DIR(ctinfo);
1249 int ret = 0;
1250 int i;
1251 __be16 port;
1252 union nf_inet_addr addr;
1253 struct nf_conntrack_expect *exp;
1254 typeof(nat_q931_hook) nat_q931;
1255
1256 /* Look for the first related address */
1257 for (i = 0; i < count; i++) {
1258 if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) &&
1259 memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3,
1260 sizeof(addr)) == 0 && port != 0)
1261 break;
1262 }
1263
1264 if (i >= count) /* Not found */
1265 return 0;
1266
1267 /* Create expect for Q.931 */
1268 if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1269 return -1;
1270 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1271 gkrouted_only ? /* only accept calls from GK? */
1272 &ct->tuplehash[!dir].tuple.src.u3 : NULL,
1273 &ct->tuplehash[!dir].tuple.dst.u3,
1274 IPPROTO_TCP, NULL, &port);
1275 exp->helper = nf_conntrack_helper_q931;
1276 exp->flags = NF_CT_EXPECT_PERMANENT; /* Accept multiple calls */
1277
1278 nat_q931 = rcu_dereference(nat_q931_hook);
1279 if (nat_q931 && ct->status & IPS_NAT_MASK) { /* Need NAT */
1280 ret = nat_q931(skb, ct, ctinfo, data, taddr, i, port, exp);
1281 } else { /* Conntrack only */
1282 if (nf_ct_expect_related(exp) == 0) {
1283 pr_debug("nf_ct_ras: expect Q.931 ");
1284 nf_ct_dump_tuple(&exp->tuple);
1285
1286 /* Save port for looking up expect in processing RCF */
1287 info->sig_port[dir] = port;
1288 } else
1289 ret = -1;
1290 }
1291
1292 nf_ct_expect_put(exp);
1293
1294 return ret;
1295 }
1296
1297 /****************************************************************************/
1298 static int process_grq(struct sk_buff *skb, struct nf_conn *ct,
1299 enum ip_conntrack_info ctinfo,
1300 unsigned char **data, GatekeeperRequest *grq)
1301 {
1302 typeof(set_ras_addr_hook) set_ras_addr;
1303
1304 pr_debug("nf_ct_ras: GRQ\n");
1305
1306 set_ras_addr = rcu_dereference(set_ras_addr_hook);
1307 if (set_ras_addr && ct->status & IPS_NAT_MASK) /* NATed */
1308 return set_ras_addr(skb, ct, ctinfo, data,
1309 &grq->rasAddress, 1);
1310 return 0;
1311 }
1312
1313 /****************************************************************************/
1314 static int process_gcf(struct sk_buff *skb, struct nf_conn *ct,
1315 enum ip_conntrack_info ctinfo,
1316 unsigned char **data, GatekeeperConfirm *gcf)
1317 {
1318 int dir = CTINFO2DIR(ctinfo);
1319 int ret = 0;
1320 __be16 port;
1321 union nf_inet_addr addr;
1322 struct nf_conntrack_expect *exp;
1323
1324 pr_debug("nf_ct_ras: GCF\n");
1325
1326 if (!get_h225_addr(ct, *data, &gcf->rasAddress, &addr, &port))
1327 return 0;
1328
1329 /* Registration port is the same as discovery port */
1330 if (!memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1331 port == ct->tuplehash[dir].tuple.src.u.udp.port)
1332 return 0;
1333
1334 /* Avoid RAS expectation loops. A GCF is never expected. */
1335 if (test_bit(IPS_EXPECTED_BIT, &ct->status))
1336 return 0;
1337
1338 /* Need new expect */
1339 if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1340 return -1;
1341 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1342 &ct->tuplehash[!dir].tuple.src.u3, &addr,
1343 IPPROTO_UDP, NULL, &port);
1344 exp->helper = nf_conntrack_helper_ras;
1345
1346 if (nf_ct_expect_related(exp) == 0) {
1347 pr_debug("nf_ct_ras: expect RAS ");
1348 nf_ct_dump_tuple(&exp->tuple);
1349 } else
1350 ret = -1;
1351
1352 nf_ct_expect_put(exp);
1353
1354 return ret;
1355 }
1356
1357 /****************************************************************************/
1358 static int process_rrq(struct sk_buff *skb, struct nf_conn *ct,
1359 enum ip_conntrack_info ctinfo,
1360 unsigned char **data, RegistrationRequest *rrq)
1361 {
1362 struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1363 int ret;
1364 typeof(set_ras_addr_hook) set_ras_addr;
1365
1366 pr_debug("nf_ct_ras: RRQ\n");
1367
1368 ret = expect_q931(skb, ct, ctinfo, data,
1369 rrq->callSignalAddress.item,
1370 rrq->callSignalAddress.count);
1371 if (ret < 0)
1372 return -1;
1373
1374 set_ras_addr = rcu_dereference(set_ras_addr_hook);
1375 if (set_ras_addr && ct->status & IPS_NAT_MASK) {
1376 ret = set_ras_addr(skb, ct, ctinfo, data,
1377 rrq->rasAddress.item,
1378 rrq->rasAddress.count);
1379 if (ret < 0)
1380 return -1;
1381 }
1382
1383 if (rrq->options & eRegistrationRequest_timeToLive) {
1384 pr_debug("nf_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive);
1385 info->timeout = rrq->timeToLive;
1386 } else
1387 info->timeout = default_rrq_ttl;
1388
1389 return 0;
1390 }
1391
1392 /****************************************************************************/
1393 static int process_rcf(struct sk_buff *skb, struct nf_conn *ct,
1394 enum ip_conntrack_info ctinfo,
1395 unsigned char **data, RegistrationConfirm *rcf)
1396 {
1397 struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1398 int dir = CTINFO2DIR(ctinfo);
1399 int ret;
1400 struct nf_conntrack_expect *exp;
1401 typeof(set_sig_addr_hook) set_sig_addr;
1402
1403 pr_debug("nf_ct_ras: RCF\n");
1404
1405 set_sig_addr = rcu_dereference(set_sig_addr_hook);
1406 if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1407 ret = set_sig_addr(skb, ct, ctinfo, data,
1408 rcf->callSignalAddress.item,
1409 rcf->callSignalAddress.count);
1410 if (ret < 0)
1411 return -1;
1412 }
1413
1414 if (rcf->options & eRegistrationConfirm_timeToLive) {
1415 pr_debug("nf_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive);
1416 info->timeout = rcf->timeToLive;
1417 }
1418
1419 if (info->timeout > 0) {
1420 pr_debug("nf_ct_ras: set RAS connection timeout to "
1421 "%u seconds\n", info->timeout);
1422 nf_ct_refresh(ct, skb, info->timeout * HZ);
1423
1424 /* Set expect timeout */
1425 spin_lock_bh(&nf_conntrack_lock);
1426 exp = find_expect(ct, &ct->tuplehash[dir].tuple.dst.u3,
1427 info->sig_port[!dir]);
1428 if (exp) {
1429 pr_debug("nf_ct_ras: set Q.931 expect "
1430 "timeout to %u seconds for",
1431 info->timeout);
1432 nf_ct_dump_tuple(&exp->tuple);
1433 set_expect_timeout(exp, info->timeout);
1434 }
1435 spin_unlock_bh(&nf_conntrack_lock);
1436 }
1437
1438 return 0;
1439 }
1440
1441 /****************************************************************************/
1442 static int process_urq(struct sk_buff *skb, struct nf_conn *ct,
1443 enum ip_conntrack_info ctinfo,
1444 unsigned char **data, UnregistrationRequest *urq)
1445 {
1446 struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1447 int dir = CTINFO2DIR(ctinfo);
1448 int ret;
1449 typeof(set_sig_addr_hook) set_sig_addr;
1450
1451 pr_debug("nf_ct_ras: URQ\n");
1452
1453 set_sig_addr = rcu_dereference(set_sig_addr_hook);
1454 if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1455 ret = set_sig_addr(skb, ct, ctinfo, data,
1456 urq->callSignalAddress.item,
1457 urq->callSignalAddress.count);
1458 if (ret < 0)
1459 return -1;
1460 }
1461
1462 /* Clear old expect */
1463 nf_ct_remove_expectations(ct);
1464 info->sig_port[dir] = 0;
1465 info->sig_port[!dir] = 0;
1466
1467 /* Give it 30 seconds for UCF or URJ */
1468 nf_ct_refresh(ct, skb, 30 * HZ);
1469
1470 return 0;
1471 }
1472
1473 /****************************************************************************/
1474 static int process_arq(struct sk_buff *skb, struct nf_conn *ct,
1475 enum ip_conntrack_info ctinfo,
1476 unsigned char **data, AdmissionRequest *arq)
1477 {
1478 const struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1479 int dir = CTINFO2DIR(ctinfo);
1480 __be16 port;
1481 union nf_inet_addr addr;
1482 typeof(set_h225_addr_hook) set_h225_addr;
1483
1484 pr_debug("nf_ct_ras: ARQ\n");
1485
1486 set_h225_addr = rcu_dereference(set_h225_addr_hook);
1487 if ((arq->options & eAdmissionRequest_destCallSignalAddress) &&
1488 get_h225_addr(ct, *data, &arq->destCallSignalAddress,
1489 &addr, &port) &&
1490 !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1491 port == info->sig_port[dir] &&
1492 set_h225_addr && ct->status & IPS_NAT_MASK) {
1493 /* Answering ARQ */
1494 return set_h225_addr(skb, data, 0,
1495 &arq->destCallSignalAddress,
1496 &ct->tuplehash[!dir].tuple.dst.u3,
1497 info->sig_port[!dir]);
1498 }
1499
1500 if ((arq->options & eAdmissionRequest_srcCallSignalAddress) &&
1501 get_h225_addr(ct, *data, &arq->srcCallSignalAddress,
1502 &addr, &port) &&
1503 !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1504 set_h225_addr && ct->status & IPS_NAT_MASK) {
1505 /* Calling ARQ */
1506 return set_h225_addr(skb, data, 0,
1507 &arq->srcCallSignalAddress,
1508 &ct->tuplehash[!dir].tuple.dst.u3,
1509 port);
1510 }
1511
1512 return 0;
1513 }
1514
1515 /****************************************************************************/
1516 static int process_acf(struct sk_buff *skb, struct nf_conn *ct,
1517 enum ip_conntrack_info ctinfo,
1518 unsigned char **data, AdmissionConfirm *acf)
1519 {
1520 int dir = CTINFO2DIR(ctinfo);
1521 int ret = 0;
1522 __be16 port;
1523 union nf_inet_addr addr;
1524 struct nf_conntrack_expect *exp;
1525 typeof(set_sig_addr_hook) set_sig_addr;
1526
1527 pr_debug("nf_ct_ras: ACF\n");
1528
1529 if (!get_h225_addr(ct, *data, &acf->destCallSignalAddress,
1530 &addr, &port))
1531 return 0;
1532
1533 if (!memcmp(&addr, &ct->tuplehash[dir].tuple.dst.u3, sizeof(addr))) {
1534 /* Answering ACF */
1535 set_sig_addr = rcu_dereference(set_sig_addr_hook);
1536 if (set_sig_addr && ct->status & IPS_NAT_MASK)
1537 return set_sig_addr(skb, ct, ctinfo, data,
1538 &acf->destCallSignalAddress, 1);
1539 return 0;
1540 }
1541
1542 /* Need new expect */
1543 if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1544 return -1;
1545 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1546 &ct->tuplehash[!dir].tuple.src.u3, &addr,
1547 IPPROTO_TCP, NULL, &port);
1548 exp->flags = NF_CT_EXPECT_PERMANENT;
1549 exp->helper = nf_conntrack_helper_q931;
1550
1551 if (nf_ct_expect_related(exp) == 0) {
1552 pr_debug("nf_ct_ras: expect Q.931 ");
1553 nf_ct_dump_tuple(&exp->tuple);
1554 } else
1555 ret = -1;
1556
1557 nf_ct_expect_put(exp);
1558
1559 return ret;
1560 }
1561
1562 /****************************************************************************/
1563 static int process_lrq(struct sk_buff *skb, struct nf_conn *ct,
1564 enum ip_conntrack_info ctinfo,
1565 unsigned char **data, LocationRequest *lrq)
1566 {
1567 typeof(set_ras_addr_hook) set_ras_addr;
1568
1569 pr_debug("nf_ct_ras: LRQ\n");
1570
1571 set_ras_addr = rcu_dereference(set_ras_addr_hook);
1572 if (set_ras_addr && ct->status & IPS_NAT_MASK)
1573 return set_ras_addr(skb, ct, ctinfo, data,
1574 &lrq->replyAddress, 1);
1575 return 0;
1576 }
1577
1578 /****************************************************************************/
1579 static int process_lcf(struct sk_buff *skb, struct nf_conn *ct,
1580 enum ip_conntrack_info ctinfo,
1581 unsigned char **data, LocationConfirm *lcf)
1582 {
1583 int dir = CTINFO2DIR(ctinfo);
1584 int ret = 0;
1585 __be16 port;
1586 union nf_inet_addr addr;
1587 struct nf_conntrack_expect *exp;
1588
1589 pr_debug("nf_ct_ras: LCF\n");
1590
1591 if (!get_h225_addr(ct, *data, &lcf->callSignalAddress,
1592 &addr, &port))
1593 return 0;
1594
1595 /* Need new expect for call signal */
1596 if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1597 return -1;
1598 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1599 &ct->tuplehash[!dir].tuple.src.u3, &addr,
1600 IPPROTO_TCP, NULL, &port);
1601 exp->flags = NF_CT_EXPECT_PERMANENT;
1602 exp->helper = nf_conntrack_helper_q931;
1603
1604 if (nf_ct_expect_related(exp) == 0) {
1605 pr_debug("nf_ct_ras: expect Q.931 ");
1606 nf_ct_dump_tuple(&exp->tuple);
1607 } else
1608 ret = -1;
1609
1610 nf_ct_expect_put(exp);
1611
1612 /* Ignore rasAddress */
1613
1614 return ret;
1615 }
1616
1617 /****************************************************************************/
1618 static int process_irr(struct sk_buff *skb, struct nf_conn *ct,
1619 enum ip_conntrack_info ctinfo,
1620 unsigned char **data, InfoRequestResponse *irr)
1621 {
1622 int ret;
1623 typeof(set_ras_addr_hook) set_ras_addr;
1624 typeof(set_sig_addr_hook) set_sig_addr;
1625
1626 pr_debug("nf_ct_ras: IRR\n");
1627
1628 set_ras_addr = rcu_dereference(set_ras_addr_hook);
1629 if (set_ras_addr && ct->status & IPS_NAT_MASK) {
1630 ret = set_ras_addr(skb, ct, ctinfo, data,
1631 &irr->rasAddress, 1);
1632 if (ret < 0)
1633 return -1;
1634 }
1635
1636 set_sig_addr = rcu_dereference(set_sig_addr_hook);
1637 if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1638 ret = set_sig_addr(skb, ct, ctinfo, data,
1639 irr->callSignalAddress.item,
1640 irr->callSignalAddress.count);
1641 if (ret < 0)
1642 return -1;
1643 }
1644
1645 return 0;
1646 }
1647
1648 /****************************************************************************/
1649 static int process_ras(struct sk_buff *skb, struct nf_conn *ct,
1650 enum ip_conntrack_info ctinfo,
1651 unsigned char **data, RasMessage *ras)
1652 {
1653 switch (ras->choice) {
1654 case eRasMessage_gatekeeperRequest:
1655 return process_grq(skb, ct, ctinfo, data,
1656 &ras->gatekeeperRequest);
1657 case eRasMessage_gatekeeperConfirm:
1658 return process_gcf(skb, ct, ctinfo, data,
1659 &ras->gatekeeperConfirm);
1660 case eRasMessage_registrationRequest:
1661 return process_rrq(skb, ct, ctinfo, data,
1662 &ras->registrationRequest);
1663 case eRasMessage_registrationConfirm:
1664 return process_rcf(skb, ct, ctinfo, data,
1665 &ras->registrationConfirm);
1666 case eRasMessage_unregistrationRequest:
1667 return process_urq(skb, ct, ctinfo, data,
1668 &ras->unregistrationRequest);
1669 case eRasMessage_admissionRequest:
1670 return process_arq(skb, ct, ctinfo, data,
1671 &ras->admissionRequest);
1672 case eRasMessage_admissionConfirm:
1673 return process_acf(skb, ct, ctinfo, data,
1674 &ras->admissionConfirm);
1675 case eRasMessage_locationRequest:
1676 return process_lrq(skb, ct, ctinfo, data,
1677 &ras->locationRequest);
1678 case eRasMessage_locationConfirm:
1679 return process_lcf(skb, ct, ctinfo, data,
1680 &ras->locationConfirm);
1681 case eRasMessage_infoRequestResponse:
1682 return process_irr(skb, ct, ctinfo, data,
1683 &ras->infoRequestResponse);
1684 default:
1685 pr_debug("nf_ct_ras: RAS message %d\n", ras->choice);
1686 break;
1687 }
1688
1689 return 0;
1690 }
1691
1692 /****************************************************************************/
1693 static int ras_help(struct sk_buff *skb, unsigned int protoff,
1694 struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1695 {
1696 static RasMessage ras;
1697 unsigned char *data;
1698 int datalen = 0;
1699 int ret;
1700
1701 pr_debug("nf_ct_ras: skblen = %u\n", skb->len);
1702
1703 spin_lock_bh(&nf_h323_lock);
1704
1705 /* Get UDP data */
1706 data = get_udp_data(skb, protoff, &datalen);
1707 if (data == NULL)
1708 goto accept;
1709 pr_debug("nf_ct_ras: RAS message len=%d ", datalen);
1710 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1711
1712 /* Decode RAS message */
1713 ret = DecodeRasMessage(data, datalen, &ras);
1714 if (ret < 0) {
1715 pr_debug("nf_ct_ras: decoding error: %s\n",
1716 ret == H323_ERROR_BOUND ?
1717 "out of bound" : "out of range");
1718 goto accept;
1719 }
1720
1721 /* Process RAS message */
1722 if (process_ras(skb, ct, ctinfo, &data, &ras) < 0)
1723 goto drop;
1724
1725 accept:
1726 spin_unlock_bh(&nf_h323_lock);
1727 return NF_ACCEPT;
1728
1729 drop:
1730 spin_unlock_bh(&nf_h323_lock);
1731 net_info_ratelimited("nf_ct_ras: packet dropped\n");
1732 return NF_DROP;
1733 }
1734
1735 /****************************************************************************/
1736 static const struct nf_conntrack_expect_policy ras_exp_policy = {
1737 .max_expected = 32,
1738 .timeout = 240,
1739 };
1740
1741 static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = {
1742 {
1743 .name = "RAS",
1744 .me = THIS_MODULE,
1745 .tuple.src.l3num = AF_INET,
1746 .tuple.src.u.udp.port = cpu_to_be16(RAS_PORT),
1747 .tuple.dst.protonum = IPPROTO_UDP,
1748 .help = ras_help,
1749 .expect_policy = &ras_exp_policy,
1750 },
1751 {
1752 .name = "RAS",
1753 .me = THIS_MODULE,
1754 .tuple.src.l3num = AF_INET6,
1755 .tuple.src.u.udp.port = cpu_to_be16(RAS_PORT),
1756 .tuple.dst.protonum = IPPROTO_UDP,
1757 .help = ras_help,
1758 .expect_policy = &ras_exp_policy,
1759 },
1760 };
1761
1762 /****************************************************************************/
1763 static void __exit nf_conntrack_h323_fini(void)
1764 {
1765 nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[1]);
1766 nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1767 nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1768 nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1769 nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1770 kfree(h323_buffer);
1771 pr_debug("nf_ct_h323: fini\n");
1772 }
1773
1774 /****************************************************************************/
1775 static int __init nf_conntrack_h323_init(void)
1776 {
1777 int ret;
1778
1779 h323_buffer = kmalloc(65536, GFP_KERNEL);
1780 if (!h323_buffer)
1781 return -ENOMEM;
1782 ret = nf_conntrack_helper_register(&nf_conntrack_helper_h245);
1783 if (ret < 0)
1784 goto err1;
1785 ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[0]);
1786 if (ret < 0)
1787 goto err2;
1788 ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[1]);
1789 if (ret < 0)
1790 goto err3;
1791 ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[0]);
1792 if (ret < 0)
1793 goto err4;
1794 ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[1]);
1795 if (ret < 0)
1796 goto err5;
1797 pr_debug("nf_ct_h323: init success\n");
1798 return 0;
1799
1800 err5:
1801 nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1802 err4:
1803 nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1804 err3:
1805 nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1806 err2:
1807 nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1808 err1:
1809 kfree(h323_buffer);
1810 return ret;
1811 }
1812
1813 /****************************************************************************/
1814 module_init(nf_conntrack_h323_init);
1815 module_exit(nf_conntrack_h323_fini);
1816
1817 EXPORT_SYMBOL_GPL(get_h225_addr);
1818 EXPORT_SYMBOL_GPL(set_h245_addr_hook);
1819 EXPORT_SYMBOL_GPL(set_h225_addr_hook);
1820 EXPORT_SYMBOL_GPL(set_sig_addr_hook);
1821 EXPORT_SYMBOL_GPL(set_ras_addr_hook);
1822 EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook);
1823 EXPORT_SYMBOL_GPL(nat_t120_hook);
1824 EXPORT_SYMBOL_GPL(nat_h245_hook);
1825 EXPORT_SYMBOL_GPL(nat_callforwarding_hook);
1826 EXPORT_SYMBOL_GPL(nat_q931_hook);
1827
1828 MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>");
1829 MODULE_DESCRIPTION("H.323 connection tracking helper");
1830 MODULE_LICENSE("GPL");
1831 MODULE_ALIAS("ip_conntrack_h323");
1832 MODULE_ALIAS_NFCT_HELPER("RAS");
1833 MODULE_ALIAS_NFCT_HELPER("Q.931");
1834 MODULE_ALIAS_NFCT_HELPER("H.245");
Linux kernel - Deliverables
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