1 /*
2  * H.323 connection tracking helper
3  *
4  * Copyright (c) 2006 Jing Min Zhao <zhaojingmin@users.sourceforge.net>
5  * Copyright (c) 2006-2012 Patrick McHardy <kaber@trash.net>
6  *
7  * This source code is licensed under General Public License version 2.
8  *
9  * Based on the 'brute force' H.323 connection tracking module by
10  * Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
11  *
12  * For more information, please see http://nath323.sourceforge.net/
13  */
14 
15 #include <linux/module.h>
16 #include <linux/moduleparam.h>
17 #include <linux/ctype.h>
18 #include <linux/inet.h>
19 #include <linux/in.h>
20 #include <linux/ip.h>
21 #include <linux/slab.h>
22 #include <linux/udp.h>
23 #include <linux/tcp.h>
24 #include <linux/skbuff.h>
25 #include <net/route.h>
26 #include <net/ip6_route.h>
27 
28 #include <net/netfilter/nf_conntrack.h>
29 #include <net/netfilter/nf_conntrack_core.h>
30 #include <net/netfilter/nf_conntrack_tuple.h>
31 #include <net/netfilter/nf_conntrack_expect.h>
32 #include <net/netfilter/nf_conntrack_ecache.h>
33 #include <net/netfilter/nf_conntrack_helper.h>
34 #include <net/netfilter/nf_conntrack_zones.h>
35 #include <linux/netfilter/nf_conntrack_h323.h>
36 
37 /* Parameters */
38 static unsigned int default_rrq_ttl __read_mostly = 300;
39 module_param(default_rrq_ttl, uint, 0600);
40 MODULE_PARM_DESC(default_rrq_ttl, "use this TTL if it's missing in RRQ");
41 
42 static int gkrouted_only __read_mostly = 1;
43 module_param(gkrouted_only, int, 0600);
44 MODULE_PARM_DESC(gkrouted_only, "only accept calls from gatekeeper");
45 
46 static bool callforward_filter __read_mostly = true;
47 module_param(callforward_filter, bool, 0600);
48 MODULE_PARM_DESC(callforward_filter, "only create call forwarding expectations "
49 				     "if both endpoints are on different sides "
50 				     "(determined by routing information)");
51 
52 /* Hooks for NAT */
53 int (*set_h245_addr_hook) (struct sk_buff *skb, unsigned int protoff,
54 			   unsigned char **data, int dataoff,
55 			   H245_TransportAddress *taddr,
56 			   union nf_inet_addr *addr, __be16 port)
57 			   __read_mostly;
58 int (*set_h225_addr_hook) (struct sk_buff *skb, unsigned int protoff,
59 			   unsigned char **data, int dataoff,
60 			   TransportAddress *taddr,
61 			   union nf_inet_addr *addr, __be16 port)
62 			   __read_mostly;
63 int (*set_sig_addr_hook) (struct sk_buff *skb,
64 			  struct nf_conn *ct,
65 			  enum ip_conntrack_info ctinfo,
66 			  unsigned int protoff, unsigned char **data,
67 			  TransportAddress *taddr, int count) __read_mostly;
68 int (*set_ras_addr_hook) (struct sk_buff *skb,
69 			  struct nf_conn *ct,
70 			  enum ip_conntrack_info ctinfo,
71 			  unsigned int protoff, unsigned char **data,
72 			  TransportAddress *taddr, int count) __read_mostly;
73 int (*nat_rtp_rtcp_hook) (struct sk_buff *skb,
74 			  struct nf_conn *ct,
75 			  enum ip_conntrack_info ctinfo,
76 			  unsigned int protoff,
77 			  unsigned char **data, int dataoff,
78 			  H245_TransportAddress *taddr,
79 			  __be16 port, __be16 rtp_port,
80 			  struct nf_conntrack_expect *rtp_exp,
81 			  struct nf_conntrack_expect *rtcp_exp) __read_mostly;
82 int (*nat_t120_hook) (struct sk_buff *skb,
83 		      struct nf_conn *ct,
84 		      enum ip_conntrack_info ctinfo,
85 		      unsigned int protoff,
86 		      unsigned char **data, int dataoff,
87 		      H245_TransportAddress *taddr, __be16 port,
88 		      struct nf_conntrack_expect *exp) __read_mostly;
89 int (*nat_h245_hook) (struct sk_buff *skb,
90 		      struct nf_conn *ct,
91 		      enum ip_conntrack_info ctinfo,
92 		      unsigned int protoff,
93 		      unsigned char **data, int dataoff,
94 		      TransportAddress *taddr, __be16 port,
95 		      struct nf_conntrack_expect *exp) __read_mostly;
96 int (*nat_callforwarding_hook) (struct sk_buff *skb,
97 				struct nf_conn *ct,
98 				enum ip_conntrack_info ctinfo,
99 				unsigned int protoff,
100 				unsigned char **data, int dataoff,
101 				TransportAddress *taddr, __be16 port,
102 				struct nf_conntrack_expect *exp) __read_mostly;
103 int (*nat_q931_hook) (struct sk_buff *skb,
104 		      struct nf_conn *ct,
105 		      enum ip_conntrack_info ctinfo,
106 		      unsigned int protoff,
107 		      unsigned char **data, TransportAddress *taddr, int idx,
108 		      __be16 port, struct nf_conntrack_expect *exp)
109 		      __read_mostly;
110 
111 static DEFINE_SPINLOCK(nf_h323_lock);
112 static char *h323_buffer;
113 
114 static struct nf_conntrack_helper nf_conntrack_helper_h245;
115 static struct nf_conntrack_helper nf_conntrack_helper_q931[];
116 static struct nf_conntrack_helper nf_conntrack_helper_ras[];
117 
118 /****************************************************************************/
119 static int get_tpkt_data(struct sk_buff *skb, unsigned int protoff,
120 			 struct nf_conn *ct, enum ip_conntrack_info ctinfo,
121 			 unsigned char **data, int *datalen, int *dataoff)
122 {
123 	struct nf_ct_h323_master *info = nfct_help_data(ct);
124 	int dir = CTINFO2DIR(ctinfo);
125 	const struct tcphdr *th;
126 	struct tcphdr _tcph;
127 	int tcpdatalen;
128 	int tcpdataoff;
129 	unsigned char *tpkt;
130 	int tpktlen;
131 	int tpktoff;
132 
133 	/* Get TCP header */
134 	th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph);
135 	if (th == NULL)
136 		return 0;
137 
138 	/* Get TCP data offset */
139 	tcpdataoff = protoff + th->doff * 4;
140 
141 	/* Get TCP data length */
142 	tcpdatalen = skb->len - tcpdataoff;
143 	if (tcpdatalen <= 0)	/* No TCP data */
144 		goto clear_out;
145 
146 	if (*data == NULL) {	/* first TPKT */
147 		/* Get first TPKT pointer */
148 		tpkt = skb_header_pointer(skb, tcpdataoff, tcpdatalen,
149 					  h323_buffer);
150 		BUG_ON(tpkt == NULL);
151 
152 		/* Validate TPKT identifier */
153 		if (tcpdatalen < 4 || tpkt[0] != 0x03 || tpkt[1] != 0) {
154 			/* Netmeeting sends TPKT header and data separately */
155 			if (info->tpkt_len[dir] > 0) {
156 				pr_debug("nf_ct_h323: previous packet "
157 					 "indicated separate TPKT data of %hu "
158 					 "bytes\n", info->tpkt_len[dir]);
159 				if (info->tpkt_len[dir] <= tcpdatalen) {
160 					/* Yes, there was a TPKT header
161 					 * received */
162 					*data = tpkt;
163 					*datalen = info->tpkt_len[dir];
164 					*dataoff = 0;
165 					goto out;
166 				}
167 
168 				/* Fragmented TPKT */
169 				pr_debug("nf_ct_h323: fragmented TPKT\n");
170 				goto clear_out;
171 			}
172 
173 			/* It is not even a TPKT */
174 			return 0;
175 		}
176 		tpktoff = 0;
177 	} else {		/* Next TPKT */
178 		tpktoff = *dataoff + *datalen;
179 		tcpdatalen -= tpktoff;
180 		if (tcpdatalen <= 4)	/* No more TPKT */
181 			goto clear_out;
182 		tpkt = *data + *datalen;
183 
184 		/* Validate TPKT identifier */
185 		if (tpkt[0] != 0x03 || tpkt[1] != 0)
186 			goto clear_out;
187 	}
188 
189 	/* Validate TPKT length */
190 	tpktlen = tpkt[2] * 256 + tpkt[3];
191 	if (tpktlen < 4)
192 		goto clear_out;
193 	if (tpktlen > tcpdatalen) {
194 		if (tcpdatalen == 4) {	/* Separate TPKT header */
195 			/* Netmeeting sends TPKT header and data separately */
196 			pr_debug("nf_ct_h323: separate TPKT header indicates "
197 				 "there will be TPKT data of %hu bytes\n",
198 				 tpktlen - 4);
199 			info->tpkt_len[dir] = tpktlen - 4;
200 			return 0;
201 		}
202 
203 		pr_debug("nf_ct_h323: incomplete TPKT (fragmented?)\n");
204 		goto clear_out;
205 	}
206 
207 	/* This is the encapsulated data */
208 	*data = tpkt + 4;
209 	*datalen = tpktlen - 4;
210 	*dataoff = tpktoff + 4;
211 
212       out:
213 	/* Clear TPKT length */
214 	info->tpkt_len[dir] = 0;
215 	return 1;
216 
217       clear_out:
218 	info->tpkt_len[dir] = 0;
219 	return 0;
220 }
221 
222 /****************************************************************************/
223 static int get_h245_addr(struct nf_conn *ct, const unsigned char *data,
224 			 H245_TransportAddress *taddr,
225 			 union nf_inet_addr *addr, __be16 *port)
226 {
227 	const unsigned char *p;
228 	int len;
229 
230 	if (taddr->choice != eH245_TransportAddress_unicastAddress)
231 		return 0;
232 
233 	switch (taddr->unicastAddress.choice) {
234 	case eUnicastAddress_iPAddress:
235 		if (nf_ct_l3num(ct) != AF_INET)
236 			return 0;
237 		p = data + taddr->unicastAddress.iPAddress.network;
238 		len = 4;
239 		break;
240 	case eUnicastAddress_iP6Address:
241 		if (nf_ct_l3num(ct) != AF_INET6)
242 			return 0;
243 		p = data + taddr->unicastAddress.iP6Address.network;
244 		len = 16;
245 		break;
246 	default:
247 		return 0;
248 	}
249 
250 	memcpy(addr, p, len);
251 	memset((void *)addr + len, 0, sizeof(*addr) - len);
252 	memcpy(port, p + len, sizeof(__be16));
253 
254 	return 1;
255 }
256 
257 /****************************************************************************/
258 static int expect_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct,
259 			   enum ip_conntrack_info ctinfo,
260 			   unsigned int protoff,
261 			   unsigned char **data, int dataoff,
262 			   H245_TransportAddress *taddr)
263 {
264 	int dir = CTINFO2DIR(ctinfo);
265 	int ret = 0;
266 	__be16 port;
267 	__be16 rtp_port, rtcp_port;
268 	union nf_inet_addr addr;
269 	struct nf_conntrack_expect *rtp_exp;
270 	struct nf_conntrack_expect *rtcp_exp;
271 	typeof(nat_rtp_rtcp_hook) nat_rtp_rtcp;
272 
273 	/* Read RTP or RTCP address */
274 	if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
275 	    memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
276 	    port == 0)
277 		return 0;
278 
279 	/* RTP port is even */
280 	rtp_port = port & ~htons(1);
281 	rtcp_port = port | htons(1);
282 
283 	/* Create expect for RTP */
284 	if ((rtp_exp = nf_ct_expect_alloc(ct)) == NULL)
285 		return -1;
286 	nf_ct_expect_init(rtp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
287 			  &ct->tuplehash[!dir].tuple.src.u3,
288 			  &ct->tuplehash[!dir].tuple.dst.u3,
289 			  IPPROTO_UDP, NULL, &rtp_port);
290 
291 	/* Create expect for RTCP */
292 	if ((rtcp_exp = nf_ct_expect_alloc(ct)) == NULL) {
293 		nf_ct_expect_put(rtp_exp);
294 		return -1;
295 	}
296 	nf_ct_expect_init(rtcp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
297 			  &ct->tuplehash[!dir].tuple.src.u3,
298 			  &ct->tuplehash[!dir].tuple.dst.u3,
299 			  IPPROTO_UDP, NULL, &rtcp_port);
300 
301 	if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
302 		   &ct->tuplehash[!dir].tuple.dst.u3,
303 		   sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
304 		   (nat_rtp_rtcp = rcu_dereference(nat_rtp_rtcp_hook)) &&
305 		   nf_ct_l3num(ct) == NFPROTO_IPV4 &&
306 		   ct->status & IPS_NAT_MASK) {
307 		/* NAT needed */
308 		ret = nat_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff,
309 				   taddr, port, rtp_port, rtp_exp, rtcp_exp);
310 	} else {		/* Conntrack only */
311 		if (nf_ct_expect_related(rtp_exp) == 0) {
312 			if (nf_ct_expect_related(rtcp_exp) == 0) {
313 				pr_debug("nf_ct_h323: expect RTP ");
314 				nf_ct_dump_tuple(&rtp_exp->tuple);
315 				pr_debug("nf_ct_h323: expect RTCP ");
316 				nf_ct_dump_tuple(&rtcp_exp->tuple);
317 			} else {
318 				nf_ct_unexpect_related(rtp_exp);
319 				ret = -1;
320 			}
321 		} else
322 			ret = -1;
323 	}
324 
325 	nf_ct_expect_put(rtp_exp);
326 	nf_ct_expect_put(rtcp_exp);
327 
328 	return ret;
329 }
330 
331 /****************************************************************************/
332 static int expect_t120(struct sk_buff *skb,
333 		       struct nf_conn *ct,
334 		       enum ip_conntrack_info ctinfo,
335 		       unsigned int protoff,
336 		       unsigned char **data, int dataoff,
337 		       H245_TransportAddress *taddr)
338 {
339 	int dir = CTINFO2DIR(ctinfo);
340 	int ret = 0;
341 	__be16 port;
342 	union nf_inet_addr addr;
343 	struct nf_conntrack_expect *exp;
344 	typeof(nat_t120_hook) nat_t120;
345 
346 	/* Read T.120 address */
347 	if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
348 	    memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
349 	    port == 0)
350 		return 0;
351 
352 	/* Create expect for T.120 connections */
353 	if ((exp = nf_ct_expect_alloc(ct)) == NULL)
354 		return -1;
355 	nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
356 			  &ct->tuplehash[!dir].tuple.src.u3,
357 			  &ct->tuplehash[!dir].tuple.dst.u3,
358 			  IPPROTO_TCP, NULL, &port);
359 	exp->flags = NF_CT_EXPECT_PERMANENT;	/* Accept multiple channels */
360 
361 	if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
362 		   &ct->tuplehash[!dir].tuple.dst.u3,
363 		   sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
364 	    (nat_t120 = rcu_dereference(nat_t120_hook)) &&
365 	    nf_ct_l3num(ct) == NFPROTO_IPV4 &&
366 	    ct->status & IPS_NAT_MASK) {
367 		/* NAT needed */
368 		ret = nat_t120(skb, ct, ctinfo, protoff, data, dataoff, taddr,
369 			       port, exp);
370 	} else {		/* Conntrack only */
371 		if (nf_ct_expect_related(exp) == 0) {
372 			pr_debug("nf_ct_h323: expect T.120 ");
373 			nf_ct_dump_tuple(&exp->tuple);
374 		} else
375 			ret = -1;
376 	}
377 
378 	nf_ct_expect_put(exp);
379 
380 	return ret;
381 }
382 
383 /****************************************************************************/
384 static int process_h245_channel(struct sk_buff *skb,
385 				struct nf_conn *ct,
386 				enum ip_conntrack_info ctinfo,
387 				unsigned int protoff,
388 				unsigned char **data, int dataoff,
389 				H2250LogicalChannelParameters *channel)
390 {
391 	int ret;
392 
393 	if (channel->options & eH2250LogicalChannelParameters_mediaChannel) {
394 		/* RTP */
395 		ret = expect_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff,
396 				      &channel->mediaChannel);
397 		if (ret < 0)
398 			return -1;
399 	}
400 
401 	if (channel->
402 	    options & eH2250LogicalChannelParameters_mediaControlChannel) {
403 		/* RTCP */
404 		ret = expect_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff,
405 				      &channel->mediaControlChannel);
406 		if (ret < 0)
407 			return -1;
408 	}
409 
410 	return 0;
411 }
412 
413 /****************************************************************************/
414 static int process_olc(struct sk_buff *skb, struct nf_conn *ct,
415 		       enum ip_conntrack_info ctinfo,
416 		       unsigned int protoff,
417 		       unsigned char **data, int dataoff,
418 		       OpenLogicalChannel *olc)
419 {
420 	int ret;
421 
422 	pr_debug("nf_ct_h323: OpenLogicalChannel\n");
423 
424 	if (olc->forwardLogicalChannelParameters.multiplexParameters.choice ==
425 	    eOpenLogicalChannel_forwardLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters)
426 	{
427 		ret = process_h245_channel(skb, ct, ctinfo,
428 					   protoff, data, dataoff,
429 					   &olc->
430 					   forwardLogicalChannelParameters.
431 					   multiplexParameters.
432 					   h2250LogicalChannelParameters);
433 		if (ret < 0)
434 			return -1;
435 	}
436 
437 	if ((olc->options &
438 	     eOpenLogicalChannel_reverseLogicalChannelParameters) &&
439 	    (olc->reverseLogicalChannelParameters.options &
440 	     eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters)
441 	    && (olc->reverseLogicalChannelParameters.multiplexParameters.
442 		choice ==
443 		eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
444 	{
445 		ret =
446 		    process_h245_channel(skb, ct, ctinfo,
447 					 protoff, data, dataoff,
448 					 &olc->
449 					 reverseLogicalChannelParameters.
450 					 multiplexParameters.
451 					 h2250LogicalChannelParameters);
452 		if (ret < 0)
453 			return -1;
454 	}
455 
456 	if ((olc->options & eOpenLogicalChannel_separateStack) &&
457 	    olc->forwardLogicalChannelParameters.dataType.choice ==
458 	    eDataType_data &&
459 	    olc->forwardLogicalChannelParameters.dataType.data.application.
460 	    choice == eDataApplicationCapability_application_t120 &&
461 	    olc->forwardLogicalChannelParameters.dataType.data.application.
462 	    t120.choice == eDataProtocolCapability_separateLANStack &&
463 	    olc->separateStack.networkAddress.choice ==
464 	    eNetworkAccessParameters_networkAddress_localAreaAddress) {
465 		ret = expect_t120(skb, ct, ctinfo, protoff, data, dataoff,
466 				  &olc->separateStack.networkAddress.
467 				  localAreaAddress);
468 		if (ret < 0)
469 			return -1;
470 	}
471 
472 	return 0;
473 }
474 
475 /****************************************************************************/
476 static int process_olca(struct sk_buff *skb, struct nf_conn *ct,
477 			enum ip_conntrack_info ctinfo,
478 			unsigned int protoff, unsigned char **data, int dataoff,
479 			OpenLogicalChannelAck *olca)
480 {
481 	H2250LogicalChannelAckParameters *ack;
482 	int ret;
483 
484 	pr_debug("nf_ct_h323: OpenLogicalChannelAck\n");
485 
486 	if ((olca->options &
487 	     eOpenLogicalChannelAck_reverseLogicalChannelParameters) &&
488 	    (olca->reverseLogicalChannelParameters.options &
489 	     eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters)
490 	    && (olca->reverseLogicalChannelParameters.multiplexParameters.
491 		choice ==
492 		eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
493 	{
494 		ret = process_h245_channel(skb, ct, ctinfo,
495 					   protoff, data, dataoff,
496 					   &olca->
497 					   reverseLogicalChannelParameters.
498 					   multiplexParameters.
499 					   h2250LogicalChannelParameters);
500 		if (ret < 0)
501 			return -1;
502 	}
503 
504 	if ((olca->options &
505 	     eOpenLogicalChannelAck_forwardMultiplexAckParameters) &&
506 	    (olca->forwardMultiplexAckParameters.choice ==
507 	     eOpenLogicalChannelAck_forwardMultiplexAckParameters_h2250LogicalChannelAckParameters))
508 	{
509 		ack = &olca->forwardMultiplexAckParameters.
510 		    h2250LogicalChannelAckParameters;
511 		if (ack->options &
512 		    eH2250LogicalChannelAckParameters_mediaChannel) {
513 			/* RTP */
514 			ret = expect_rtp_rtcp(skb, ct, ctinfo,
515 					      protoff, data, dataoff,
516 					      &ack->mediaChannel);
517 			if (ret < 0)
518 				return -1;
519 		}
520 
521 		if (ack->options &
522 		    eH2250LogicalChannelAckParameters_mediaControlChannel) {
523 			/* RTCP */
524 			ret = expect_rtp_rtcp(skb, ct, ctinfo,
525 					      protoff, data, dataoff,
526 					      &ack->mediaControlChannel);
527 			if (ret < 0)
528 				return -1;
529 		}
530 	}
531 
532 	if ((olca->options & eOpenLogicalChannelAck_separateStack) &&
533 		olca->separateStack.networkAddress.choice ==
534 		eNetworkAccessParameters_networkAddress_localAreaAddress) {
535 		ret = expect_t120(skb, ct, ctinfo, protoff, data, dataoff,
536 				  &olca->separateStack.networkAddress.
537 				  localAreaAddress);
538 		if (ret < 0)
539 			return -1;
540 	}
541 
542 	return 0;
543 }
544 
545 /****************************************************************************/
546 static int process_h245(struct sk_buff *skb, struct nf_conn *ct,
547 			enum ip_conntrack_info ctinfo,
548 			unsigned int protoff, unsigned char **data, int dataoff,
549 			MultimediaSystemControlMessage *mscm)
550 {
551 	switch (mscm->choice) {
552 	case eMultimediaSystemControlMessage_request:
553 		if (mscm->request.choice ==
554 		    eRequestMessage_openLogicalChannel) {
555 			return process_olc(skb, ct, ctinfo,
556 					   protoff, data, dataoff,
557 					   &mscm->request.openLogicalChannel);
558 		}
559 		pr_debug("nf_ct_h323: H.245 Request %d\n",
560 			 mscm->request.choice);
561 		break;
562 	case eMultimediaSystemControlMessage_response:
563 		if (mscm->response.choice ==
564 		    eResponseMessage_openLogicalChannelAck) {
565 			return process_olca(skb, ct, ctinfo,
566 					    protoff, data, dataoff,
567 					    &mscm->response.
568 					    openLogicalChannelAck);
569 		}
570 		pr_debug("nf_ct_h323: H.245 Response %d\n",
571 			 mscm->response.choice);
572 		break;
573 	default:
574 		pr_debug("nf_ct_h323: H.245 signal %d\n", mscm->choice);
575 		break;
576 	}
577 
578 	return 0;
579 }
580 
581 /****************************************************************************/
582 static int h245_help(struct sk_buff *skb, unsigned int protoff,
583 		     struct nf_conn *ct, enum ip_conntrack_info ctinfo)
584 {
585 	static MultimediaSystemControlMessage mscm;
586 	unsigned char *data = NULL;
587 	int datalen;
588 	int dataoff;
589 	int ret;
590 
591 	/* Until there's been traffic both ways, don't look in packets. */
592 	if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
593 		return NF_ACCEPT;
594 
595 	pr_debug("nf_ct_h245: skblen = %u\n", skb->len);
596 
597 	spin_lock_bh(&nf_h323_lock);
598 
599 	/* Process each TPKT */
600 	while (get_tpkt_data(skb, protoff, ct, ctinfo,
601 			     &data, &datalen, &dataoff)) {
602 		pr_debug("nf_ct_h245: TPKT len=%d ", datalen);
603 		nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
604 
605 		/* Decode H.245 signal */
606 		ret = DecodeMultimediaSystemControlMessage(data, datalen,
607 							   &mscm);
608 		if (ret < 0) {
609 			pr_debug("nf_ct_h245: decoding error: %s\n",
610 				 ret == H323_ERROR_BOUND ?
611 				 "out of bound" : "out of range");
612 			/* We don't drop when decoding error */
613 			break;
614 		}
615 
616 		/* Process H.245 signal */
617 		if (process_h245(skb, ct, ctinfo, protoff,
618 				 &data, dataoff, &mscm) < 0)
619 			goto drop;
620 	}
621 
622 	spin_unlock_bh(&nf_h323_lock);
623 	return NF_ACCEPT;
624 
625       drop:
626 	spin_unlock_bh(&nf_h323_lock);
627 	nf_ct_helper_log(skb, ct, "cannot process H.245 message");
628 	return NF_DROP;
629 }
630 
631 /****************************************************************************/
632 static const struct nf_conntrack_expect_policy h245_exp_policy = {
633 	.max_expected	= H323_RTP_CHANNEL_MAX * 4 + 2 /* T.120 */,
634 	.timeout	= 240,
635 };
636 
637 static struct nf_conntrack_helper nf_conntrack_helper_h245 __read_mostly = {
638 	.name			= "H.245",
639 	.me			= THIS_MODULE,
640 	.data_len		= sizeof(struct nf_ct_h323_master),
641 	.tuple.src.l3num	= AF_UNSPEC,
642 	.tuple.dst.protonum	= IPPROTO_UDP,
643 	.help			= h245_help,
644 	.expect_policy		= &h245_exp_policy,
645 };
646 
647 /****************************************************************************/
648 int get_h225_addr(struct nf_conn *ct, unsigned char *data,
649 		  TransportAddress *taddr,
650 		  union nf_inet_addr *addr, __be16 *port)
651 {
652 	const unsigned char *p;
653 	int len;
654 
655 	switch (taddr->choice) {
656 	case eTransportAddress_ipAddress:
657 		if (nf_ct_l3num(ct) != AF_INET)
658 			return 0;
659 		p = data + taddr->ipAddress.ip;
660 		len = 4;
661 		break;
662 	case eTransportAddress_ip6Address:
663 		if (nf_ct_l3num(ct) != AF_INET6)
664 			return 0;
665 		p = data + taddr->ip6Address.ip;
666 		len = 16;
667 		break;
668 	default:
669 		return 0;
670 	}
671 
672 	memcpy(addr, p, len);
673 	memset((void *)addr + len, 0, sizeof(*addr) - len);
674 	memcpy(port, p + len, sizeof(__be16));
675 
676 	return 1;
677 }
678 
679 /****************************************************************************/
680 static int expect_h245(struct sk_buff *skb, struct nf_conn *ct,
681 		       enum ip_conntrack_info ctinfo,
682 		       unsigned int protoff, unsigned char **data, int dataoff,
683 		       TransportAddress *taddr)
684 {
685 	int dir = CTINFO2DIR(ctinfo);
686 	int ret = 0;
687 	__be16 port;
688 	union nf_inet_addr addr;
689 	struct nf_conntrack_expect *exp;
690 	typeof(nat_h245_hook) nat_h245;
691 
692 	/* Read h245Address */
693 	if (!get_h225_addr(ct, *data, taddr, &addr, &port) ||
694 	    memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
695 	    port == 0)
696 		return 0;
697 
698 	/* Create expect for h245 connection */
699 	if ((exp = nf_ct_expect_alloc(ct)) == NULL)
700 		return -1;
701 	nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
702 			  &ct->tuplehash[!dir].tuple.src.u3,
703 			  &ct->tuplehash[!dir].tuple.dst.u3,
704 			  IPPROTO_TCP, NULL, &port);
705 	exp->helper = &nf_conntrack_helper_h245;
706 
707 	if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
708 		   &ct->tuplehash[!dir].tuple.dst.u3,
709 		   sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
710 	    (nat_h245 = rcu_dereference(nat_h245_hook)) &&
711 	    nf_ct_l3num(ct) == NFPROTO_IPV4 &&
712 	    ct->status & IPS_NAT_MASK) {
713 		/* NAT needed */
714 		ret = nat_h245(skb, ct, ctinfo, protoff, data, dataoff, taddr,
715 			       port, exp);
716 	} else {		/* Conntrack only */
717 		if (nf_ct_expect_related(exp) == 0) {
718 			pr_debug("nf_ct_q931: expect H.245 ");
719 			nf_ct_dump_tuple(&exp->tuple);
720 		} else
721 			ret = -1;
722 	}
723 
724 	nf_ct_expect_put(exp);
725 
726 	return ret;
727 }
728 
729 /* If the calling party is on the same side of the forward-to party,
730  * we don't need to track the second call */
731 static int callforward_do_filter(struct net *net,
732 				 const union nf_inet_addr *src,
733 				 const union nf_inet_addr *dst,
734 				 u_int8_t family)
735 {
736 	const struct nf_afinfo *afinfo;
737 	int ret = 0;
738 
739 	/* rcu_read_lock()ed by nf_hook_slow() */
740 	afinfo = nf_get_afinfo(family);
741 	if (!afinfo)
742 		return 0;
743 
744 	switch (family) {
745 	case AF_INET: {
746 		struct flowi4 fl1, fl2;
747 		struct rtable *rt1, *rt2;
748 
749 		memset(&fl1, 0, sizeof(fl1));
750 		fl1.daddr = src->ip;
751 
752 		memset(&fl2, 0, sizeof(fl2));
753 		fl2.daddr = dst->ip;
754 		if (!afinfo->route(net, (struct dst_entry **)&rt1,
755 				   flowi4_to_flowi(&fl1), false)) {
756 			if (!afinfo->route(net, (struct dst_entry **)&rt2,
757 					   flowi4_to_flowi(&fl2), false)) {
758 				if (rt_nexthop(rt1, fl1.daddr) ==
759 				    rt_nexthop(rt2, fl2.daddr) &&
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 #if IS_ENABLED(CONFIG_NF_CONNTRACK_IPV6)
769 	case AF_INET6: {
770 		struct flowi6 fl1, fl2;
771 		struct rt6_info *rt1, *rt2;
772 
773 		memset(&fl1, 0, sizeof(fl1));
774 		fl1.daddr = src->in6;
775 
776 		memset(&fl2, 0, sizeof(fl2));
777 		fl2.daddr = dst->in6;
778 		if (!afinfo->route(net, (struct dst_entry **)&rt1,
779 				   flowi6_to_flowi(&fl1), false)) {
780 			if (!afinfo->route(net, (struct dst_entry **)&rt2,
781 					   flowi6_to_flowi(&fl2), false)) {
782 				if (ipv6_addr_equal(rt6_nexthop(rt1, &fl1.daddr),
783 						    rt6_nexthop(rt2, &fl2.daddr)) &&
784 				    rt1->dst.dev == rt2->dst.dev)
785 					ret = 1;
786 				dst_release(&rt2->dst);
787 			}
788 			dst_release(&rt1->dst);
789 		}
790 		break;
791 	}
792 #endif
793 	}
794 	return ret;
795 
796 }
797 
798 /****************************************************************************/
799 static int expect_callforwarding(struct sk_buff *skb,
800 				 struct nf_conn *ct,
801 				 enum ip_conntrack_info ctinfo,
802 				 unsigned int protoff,
803 				 unsigned char **data, int dataoff,
804 				 TransportAddress *taddr)
805 {
806 	int dir = CTINFO2DIR(ctinfo);
807 	int ret = 0;
808 	__be16 port;
809 	union nf_inet_addr addr;
810 	struct nf_conntrack_expect *exp;
811 	struct net *net = nf_ct_net(ct);
812 	typeof(nat_callforwarding_hook) nat_callforwarding;
813 
814 	/* Read alternativeAddress */
815 	if (!get_h225_addr(ct, *data, taddr, &addr, &port) || port == 0)
816 		return 0;
817 
818 	/* If the calling party is on the same side of the forward-to party,
819 	 * we don't need to track the second call */
820 	if (callforward_filter &&
821 	    callforward_do_filter(net, &addr, &ct->tuplehash[!dir].tuple.src.u3,
822 				  nf_ct_l3num(ct))) {
823 		pr_debug("nf_ct_q931: Call Forwarding not tracked\n");
824 		return 0;
825 	}
826 
827 	/* Create expect for the second call leg */
828 	if ((exp = nf_ct_expect_alloc(ct)) == NULL)
829 		return -1;
830 	nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
831 			  &ct->tuplehash[!dir].tuple.src.u3, &addr,
832 			  IPPROTO_TCP, NULL, &port);
833 	exp->helper = nf_conntrack_helper_q931;
834 
835 	if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
836 		   &ct->tuplehash[!dir].tuple.dst.u3,
837 		   sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
838 	    (nat_callforwarding = rcu_dereference(nat_callforwarding_hook)) &&
839 	    nf_ct_l3num(ct) == NFPROTO_IPV4 &&
840 	    ct->status & IPS_NAT_MASK) {
841 		/* Need NAT */
842 		ret = nat_callforwarding(skb, ct, ctinfo,
843 					 protoff, data, dataoff,
844 					 taddr, port, exp);
845 	} else {		/* Conntrack only */
846 		if (nf_ct_expect_related(exp) == 0) {
847 			pr_debug("nf_ct_q931: expect Call Forwarding ");
848 			nf_ct_dump_tuple(&exp->tuple);
849 		} else
850 			ret = -1;
851 	}
852 
853 	nf_ct_expect_put(exp);
854 
855 	return ret;
856 }
857 
858 /****************************************************************************/
859 static int process_setup(struct sk_buff *skb, struct nf_conn *ct,
860 			 enum ip_conntrack_info ctinfo,
861 			 unsigned int protoff,
862 			 unsigned char **data, int dataoff,
863 			 Setup_UUIE *setup)
864 {
865 	int dir = CTINFO2DIR(ctinfo);
866 	int ret;
867 	int i;
868 	__be16 port;
869 	union nf_inet_addr addr;
870 	typeof(set_h225_addr_hook) set_h225_addr;
871 
872 	pr_debug("nf_ct_q931: Setup\n");
873 
874 	if (setup->options & eSetup_UUIE_h245Address) {
875 		ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
876 				  &setup->h245Address);
877 		if (ret < 0)
878 			return -1;
879 	}
880 
881 	set_h225_addr = rcu_dereference(set_h225_addr_hook);
882 	if ((setup->options & eSetup_UUIE_destCallSignalAddress) &&
883 	    (set_h225_addr) && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
884 	    ct->status & IPS_NAT_MASK &&
885 	    get_h225_addr(ct, *data, &setup->destCallSignalAddress,
886 			  &addr, &port) &&
887 	    memcmp(&addr, &ct->tuplehash[!dir].tuple.src.u3, sizeof(addr))) {
888 		pr_debug("nf_ct_q931: set destCallSignalAddress %pI6:%hu->%pI6:%hu\n",
889 			 &addr, ntohs(port), &ct->tuplehash[!dir].tuple.src.u3,
890 			 ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port));
891 		ret = set_h225_addr(skb, protoff, data, dataoff,
892 				    &setup->destCallSignalAddress,
893 				    &ct->tuplehash[!dir].tuple.src.u3,
894 				    ct->tuplehash[!dir].tuple.src.u.tcp.port);
895 		if (ret < 0)
896 			return -1;
897 	}
898 
899 	if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) &&
900 	    (set_h225_addr) && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
901 	    ct->status & IPS_NAT_MASK &&
902 	    get_h225_addr(ct, *data, &setup->sourceCallSignalAddress,
903 			  &addr, &port) &&
904 	    memcmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(addr))) {
905 		pr_debug("nf_ct_q931: set sourceCallSignalAddress %pI6:%hu->%pI6:%hu\n",
906 			 &addr, ntohs(port), &ct->tuplehash[!dir].tuple.dst.u3,
907 			 ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port));
908 		ret = set_h225_addr(skb, protoff, data, dataoff,
909 				    &setup->sourceCallSignalAddress,
910 				    &ct->tuplehash[!dir].tuple.dst.u3,
911 				    ct->tuplehash[!dir].tuple.dst.u.tcp.port);
912 		if (ret < 0)
913 			return -1;
914 	}
915 
916 	if (setup->options & eSetup_UUIE_fastStart) {
917 		for (i = 0; i < setup->fastStart.count; i++) {
918 			ret = process_olc(skb, ct, ctinfo,
919 					  protoff, data, dataoff,
920 					  &setup->fastStart.item[i]);
921 			if (ret < 0)
922 				return -1;
923 		}
924 	}
925 
926 	return 0;
927 }
928 
929 /****************************************************************************/
930 static int process_callproceeding(struct sk_buff *skb,
931 				  struct nf_conn *ct,
932 				  enum ip_conntrack_info ctinfo,
933 				  unsigned int protoff,
934 				  unsigned char **data, int dataoff,
935 				  CallProceeding_UUIE *callproc)
936 {
937 	int ret;
938 	int i;
939 
940 	pr_debug("nf_ct_q931: CallProceeding\n");
941 
942 	if (callproc->options & eCallProceeding_UUIE_h245Address) {
943 		ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
944 				  &callproc->h245Address);
945 		if (ret < 0)
946 			return -1;
947 	}
948 
949 	if (callproc->options & eCallProceeding_UUIE_fastStart) {
950 		for (i = 0; i < callproc->fastStart.count; i++) {
951 			ret = process_olc(skb, ct, ctinfo,
952 					  protoff, data, dataoff,
953 					  &callproc->fastStart.item[i]);
954 			if (ret < 0)
955 				return -1;
956 		}
957 	}
958 
959 	return 0;
960 }
961 
962 /****************************************************************************/
963 static int process_connect(struct sk_buff *skb, struct nf_conn *ct,
964 			   enum ip_conntrack_info ctinfo,
965 			   unsigned int protoff,
966 			   unsigned char **data, int dataoff,
967 			   Connect_UUIE *connect)
968 {
969 	int ret;
970 	int i;
971 
972 	pr_debug("nf_ct_q931: Connect\n");
973 
974 	if (connect->options & eConnect_UUIE_h245Address) {
975 		ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
976 				  &connect->h245Address);
977 		if (ret < 0)
978 			return -1;
979 	}
980 
981 	if (connect->options & eConnect_UUIE_fastStart) {
982 		for (i = 0; i < connect->fastStart.count; i++) {
983 			ret = process_olc(skb, ct, ctinfo,
984 					  protoff, data, dataoff,
985 					  &connect->fastStart.item[i]);
986 			if (ret < 0)
987 				return -1;
988 		}
989 	}
990 
991 	return 0;
992 }
993 
994 /****************************************************************************/
995 static int process_alerting(struct sk_buff *skb, struct nf_conn *ct,
996 			    enum ip_conntrack_info ctinfo,
997 			    unsigned int protoff,
998 			    unsigned char **data, int dataoff,
999 			    Alerting_UUIE *alert)
1000 {
1001 	int ret;
1002 	int i;
1003 
1004 	pr_debug("nf_ct_q931: Alerting\n");
1005 
1006 	if (alert->options & eAlerting_UUIE_h245Address) {
1007 		ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
1008 				  &alert->h245Address);
1009 		if (ret < 0)
1010 			return -1;
1011 	}
1012 
1013 	if (alert->options & eAlerting_UUIE_fastStart) {
1014 		for (i = 0; i < alert->fastStart.count; i++) {
1015 			ret = process_olc(skb, ct, ctinfo,
1016 					  protoff, data, dataoff,
1017 					  &alert->fastStart.item[i]);
1018 			if (ret < 0)
1019 				return -1;
1020 		}
1021 	}
1022 
1023 	return 0;
1024 }
1025 
1026 /****************************************************************************/
1027 static int process_facility(struct sk_buff *skb, struct nf_conn *ct,
1028 			    enum ip_conntrack_info ctinfo,
1029 			    unsigned int protoff,
1030 			    unsigned char **data, int dataoff,
1031 			    Facility_UUIE *facility)
1032 {
1033 	int ret;
1034 	int i;
1035 
1036 	pr_debug("nf_ct_q931: Facility\n");
1037 
1038 	if (facility->reason.choice == eFacilityReason_callForwarded) {
1039 		if (facility->options & eFacility_UUIE_alternativeAddress)
1040 			return expect_callforwarding(skb, ct, ctinfo,
1041 						     protoff, data, dataoff,
1042 						     &facility->
1043 						     alternativeAddress);
1044 		return 0;
1045 	}
1046 
1047 	if (facility->options & eFacility_UUIE_h245Address) {
1048 		ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
1049 				  &facility->h245Address);
1050 		if (ret < 0)
1051 			return -1;
1052 	}
1053 
1054 	if (facility->options & eFacility_UUIE_fastStart) {
1055 		for (i = 0; i < facility->fastStart.count; i++) {
1056 			ret = process_olc(skb, ct, ctinfo,
1057 					  protoff, data, dataoff,
1058 					  &facility->fastStart.item[i]);
1059 			if (ret < 0)
1060 				return -1;
1061 		}
1062 	}
1063 
1064 	return 0;
1065 }
1066 
1067 /****************************************************************************/
1068 static int process_progress(struct sk_buff *skb, struct nf_conn *ct,
1069 			    enum ip_conntrack_info ctinfo,
1070 			    unsigned int protoff,
1071 			    unsigned char **data, int dataoff,
1072 			    Progress_UUIE *progress)
1073 {
1074 	int ret;
1075 	int i;
1076 
1077 	pr_debug("nf_ct_q931: Progress\n");
1078 
1079 	if (progress->options & eProgress_UUIE_h245Address) {
1080 		ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
1081 				  &progress->h245Address);
1082 		if (ret < 0)
1083 			return -1;
1084 	}
1085 
1086 	if (progress->options & eProgress_UUIE_fastStart) {
1087 		for (i = 0; i < progress->fastStart.count; i++) {
1088 			ret = process_olc(skb, ct, ctinfo,
1089 					  protoff, data, dataoff,
1090 					  &progress->fastStart.item[i]);
1091 			if (ret < 0)
1092 				return -1;
1093 		}
1094 	}
1095 
1096 	return 0;
1097 }
1098 
1099 /****************************************************************************/
1100 static int process_q931(struct sk_buff *skb, struct nf_conn *ct,
1101 			enum ip_conntrack_info ctinfo,
1102 			unsigned int protoff, unsigned char **data, int dataoff,
1103 			Q931 *q931)
1104 {
1105 	H323_UU_PDU *pdu = &q931->UUIE.h323_uu_pdu;
1106 	int i;
1107 	int ret = 0;
1108 
1109 	switch (pdu->h323_message_body.choice) {
1110 	case eH323_UU_PDU_h323_message_body_setup:
1111 		ret = process_setup(skb, ct, ctinfo, protoff, data, dataoff,
1112 				    &pdu->h323_message_body.setup);
1113 		break;
1114 	case eH323_UU_PDU_h323_message_body_callProceeding:
1115 		ret = process_callproceeding(skb, ct, ctinfo,
1116 					     protoff, data, dataoff,
1117 					     &pdu->h323_message_body.
1118 					     callProceeding);
1119 		break;
1120 	case eH323_UU_PDU_h323_message_body_connect:
1121 		ret = process_connect(skb, ct, ctinfo, protoff, data, dataoff,
1122 				      &pdu->h323_message_body.connect);
1123 		break;
1124 	case eH323_UU_PDU_h323_message_body_alerting:
1125 		ret = process_alerting(skb, ct, ctinfo, protoff, data, dataoff,
1126 				       &pdu->h323_message_body.alerting);
1127 		break;
1128 	case eH323_UU_PDU_h323_message_body_facility:
1129 		ret = process_facility(skb, ct, ctinfo, protoff, data, dataoff,
1130 				       &pdu->h323_message_body.facility);
1131 		break;
1132 	case eH323_UU_PDU_h323_message_body_progress:
1133 		ret = process_progress(skb, ct, ctinfo, protoff, data, dataoff,
1134 				       &pdu->h323_message_body.progress);
1135 		break;
1136 	default:
1137 		pr_debug("nf_ct_q931: Q.931 signal %d\n",
1138 			 pdu->h323_message_body.choice);
1139 		break;
1140 	}
1141 
1142 	if (ret < 0)
1143 		return -1;
1144 
1145 	if (pdu->options & eH323_UU_PDU_h245Control) {
1146 		for (i = 0; i < pdu->h245Control.count; i++) {
1147 			ret = process_h245(skb, ct, ctinfo,
1148 					   protoff, data, dataoff,
1149 					   &pdu->h245Control.item[i]);
1150 			if (ret < 0)
1151 				return -1;
1152 		}
1153 	}
1154 
1155 	return 0;
1156 }
1157 
1158 /****************************************************************************/
1159 static int q931_help(struct sk_buff *skb, unsigned int protoff,
1160 		     struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1161 {
1162 	static Q931 q931;
1163 	unsigned char *data = NULL;
1164 	int datalen;
1165 	int dataoff;
1166 	int ret;
1167 
1168 	/* Until there's been traffic both ways, don't look in packets. */
1169 	if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
1170 		return NF_ACCEPT;
1171 
1172 	pr_debug("nf_ct_q931: skblen = %u\n", skb->len);
1173 
1174 	spin_lock_bh(&nf_h323_lock);
1175 
1176 	/* Process each TPKT */
1177 	while (get_tpkt_data(skb, protoff, ct, ctinfo,
1178 			     &data, &datalen, &dataoff)) {
1179 		pr_debug("nf_ct_q931: TPKT len=%d ", datalen);
1180 		nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1181 
1182 		/* Decode Q.931 signal */
1183 		ret = DecodeQ931(data, datalen, &q931);
1184 		if (ret < 0) {
1185 			pr_debug("nf_ct_q931: decoding error: %s\n",
1186 				 ret == H323_ERROR_BOUND ?
1187 				 "out of bound" : "out of range");
1188 			/* We don't drop when decoding error */
1189 			break;
1190 		}
1191 
1192 		/* Process Q.931 signal */
1193 		if (process_q931(skb, ct, ctinfo, protoff,
1194 				 &data, dataoff, &q931) < 0)
1195 			goto drop;
1196 	}
1197 
1198 	spin_unlock_bh(&nf_h323_lock);
1199 	return NF_ACCEPT;
1200 
1201       drop:
1202 	spin_unlock_bh(&nf_h323_lock);
1203 	nf_ct_helper_log(skb, ct, "cannot process Q.931 message");
1204 	return NF_DROP;
1205 }
1206 
1207 /****************************************************************************/
1208 static const struct nf_conntrack_expect_policy q931_exp_policy = {
1209 	/* T.120 and H.245 */
1210 	.max_expected		= H323_RTP_CHANNEL_MAX * 4 + 4,
1211 	.timeout		= 240,
1212 };
1213 
1214 static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = {
1215 	{
1216 		.name			= "Q.931",
1217 		.me			= THIS_MODULE,
1218 		.data_len		= sizeof(struct nf_ct_h323_master),
1219 		.tuple.src.l3num	= AF_INET,
1220 		.tuple.src.u.tcp.port	= cpu_to_be16(Q931_PORT),
1221 		.tuple.dst.protonum	= IPPROTO_TCP,
1222 		.help			= q931_help,
1223 		.expect_policy		= &q931_exp_policy,
1224 	},
1225 	{
1226 		.name			= "Q.931",
1227 		.me			= THIS_MODULE,
1228 		.tuple.src.l3num	= AF_INET6,
1229 		.tuple.src.u.tcp.port	= cpu_to_be16(Q931_PORT),
1230 		.tuple.dst.protonum	= IPPROTO_TCP,
1231 		.help			= q931_help,
1232 		.expect_policy		= &q931_exp_policy,
1233 	},
1234 };
1235 
1236 /****************************************************************************/
1237 static unsigned char *get_udp_data(struct sk_buff *skb, unsigned int protoff,
1238 				   int *datalen)
1239 {
1240 	const struct udphdr *uh;
1241 	struct udphdr _uh;
1242 	int dataoff;
1243 
1244 	uh = skb_header_pointer(skb, protoff, sizeof(_uh), &_uh);
1245 	if (uh == NULL)
1246 		return NULL;
1247 	dataoff = protoff + sizeof(_uh);
1248 	if (dataoff >= skb->len)
1249 		return NULL;
1250 	*datalen = skb->len - dataoff;
1251 	return skb_header_pointer(skb, dataoff, *datalen, h323_buffer);
1252 }
1253 
1254 /****************************************************************************/
1255 static struct nf_conntrack_expect *find_expect(struct nf_conn *ct,
1256 					       union nf_inet_addr *addr,
1257 					       __be16 port)
1258 {
1259 	struct net *net = nf_ct_net(ct);
1260 	struct nf_conntrack_expect *exp;
1261 	struct nf_conntrack_tuple tuple;
1262 
1263 	memset(&tuple.src.u3, 0, sizeof(tuple.src.u3));
1264 	tuple.src.u.tcp.port = 0;
1265 	memcpy(&tuple.dst.u3, addr, sizeof(tuple.dst.u3));
1266 	tuple.dst.u.tcp.port = port;
1267 	tuple.dst.protonum = IPPROTO_TCP;
1268 
1269 	exp = __nf_ct_expect_find(net, nf_ct_zone(ct), &tuple);
1270 	if (exp && exp->master == ct)
1271 		return exp;
1272 	return NULL;
1273 }
1274 
1275 /****************************************************************************/
1276 static int set_expect_timeout(struct nf_conntrack_expect *exp,
1277 			      unsigned int timeout)
1278 {
1279 	if (!exp || !del_timer(&exp->timeout))
1280 		return 0;
1281 
1282 	exp->timeout.expires = jiffies + timeout * HZ;
1283 	add_timer(&exp->timeout);
1284 
1285 	return 1;
1286 }
1287 
1288 /****************************************************************************/
1289 static int expect_q931(struct sk_buff *skb, struct nf_conn *ct,
1290 		       enum ip_conntrack_info ctinfo,
1291 		       unsigned int protoff, unsigned char **data,
1292 		       TransportAddress *taddr, int count)
1293 {
1294 	struct nf_ct_h323_master *info = nfct_help_data(ct);
1295 	int dir = CTINFO2DIR(ctinfo);
1296 	int ret = 0;
1297 	int i;
1298 	__be16 port;
1299 	union nf_inet_addr addr;
1300 	struct nf_conntrack_expect *exp;
1301 	typeof(nat_q931_hook) nat_q931;
1302 
1303 	/* Look for the first related address */
1304 	for (i = 0; i < count; i++) {
1305 		if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) &&
1306 		    memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3,
1307 			   sizeof(addr)) == 0 && port != 0)
1308 			break;
1309 	}
1310 
1311 	if (i >= count)		/* Not found */
1312 		return 0;
1313 
1314 	/* Create expect for Q.931 */
1315 	if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1316 		return -1;
1317 	nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1318 			  gkrouted_only ? /* only accept calls from GK? */
1319 				&ct->tuplehash[!dir].tuple.src.u3 : NULL,
1320 			  &ct->tuplehash[!dir].tuple.dst.u3,
1321 			  IPPROTO_TCP, NULL, &port);
1322 	exp->helper = nf_conntrack_helper_q931;
1323 	exp->flags = NF_CT_EXPECT_PERMANENT;	/* Accept multiple calls */
1324 
1325 	nat_q931 = rcu_dereference(nat_q931_hook);
1326 	if (nat_q931 && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1327 	    ct->status & IPS_NAT_MASK) {	/* Need NAT */
1328 		ret = nat_q931(skb, ct, ctinfo, protoff, data,
1329 			       taddr, i, port, exp);
1330 	} else {		/* Conntrack only */
1331 		if (nf_ct_expect_related(exp) == 0) {
1332 			pr_debug("nf_ct_ras: expect Q.931 ");
1333 			nf_ct_dump_tuple(&exp->tuple);
1334 
1335 			/* Save port for looking up expect in processing RCF */
1336 			info->sig_port[dir] = port;
1337 		} else
1338 			ret = -1;
1339 	}
1340 
1341 	nf_ct_expect_put(exp);
1342 
1343 	return ret;
1344 }
1345 
1346 /****************************************************************************/
1347 static int process_grq(struct sk_buff *skb, struct nf_conn *ct,
1348 		       enum ip_conntrack_info ctinfo,
1349 		       unsigned int protoff,
1350 		       unsigned char **data, GatekeeperRequest *grq)
1351 {
1352 	typeof(set_ras_addr_hook) set_ras_addr;
1353 
1354 	pr_debug("nf_ct_ras: GRQ\n");
1355 
1356 	set_ras_addr = rcu_dereference(set_ras_addr_hook);
1357 	if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1358 	    ct->status & IPS_NAT_MASK)	/* NATed */
1359 		return set_ras_addr(skb, ct, ctinfo, protoff, data,
1360 				    &grq->rasAddress, 1);
1361 	return 0;
1362 }
1363 
1364 /****************************************************************************/
1365 static int process_gcf(struct sk_buff *skb, struct nf_conn *ct,
1366 		       enum ip_conntrack_info ctinfo,
1367 		       unsigned int protoff,
1368 		       unsigned char **data, GatekeeperConfirm *gcf)
1369 {
1370 	int dir = CTINFO2DIR(ctinfo);
1371 	int ret = 0;
1372 	__be16 port;
1373 	union nf_inet_addr addr;
1374 	struct nf_conntrack_expect *exp;
1375 
1376 	pr_debug("nf_ct_ras: GCF\n");
1377 
1378 	if (!get_h225_addr(ct, *data, &gcf->rasAddress, &addr, &port))
1379 		return 0;
1380 
1381 	/* Registration port is the same as discovery port */
1382 	if (!memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1383 	    port == ct->tuplehash[dir].tuple.src.u.udp.port)
1384 		return 0;
1385 
1386 	/* Avoid RAS expectation loops. A GCF is never expected. */
1387 	if (test_bit(IPS_EXPECTED_BIT, &ct->status))
1388 		return 0;
1389 
1390 	/* Need new expect */
1391 	if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1392 		return -1;
1393 	nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1394 			  &ct->tuplehash[!dir].tuple.src.u3, &addr,
1395 			  IPPROTO_UDP, NULL, &port);
1396 	exp->helper = nf_conntrack_helper_ras;
1397 
1398 	if (nf_ct_expect_related(exp) == 0) {
1399 		pr_debug("nf_ct_ras: expect RAS ");
1400 		nf_ct_dump_tuple(&exp->tuple);
1401 	} else
1402 		ret = -1;
1403 
1404 	nf_ct_expect_put(exp);
1405 
1406 	return ret;
1407 }
1408 
1409 /****************************************************************************/
1410 static int process_rrq(struct sk_buff *skb, struct nf_conn *ct,
1411 		       enum ip_conntrack_info ctinfo,
1412 		       unsigned int protoff,
1413 		       unsigned char **data, RegistrationRequest *rrq)
1414 {
1415 	struct nf_ct_h323_master *info = nfct_help_data(ct);
1416 	int ret;
1417 	typeof(set_ras_addr_hook) set_ras_addr;
1418 
1419 	pr_debug("nf_ct_ras: RRQ\n");
1420 
1421 	ret = expect_q931(skb, ct, ctinfo, protoff, data,
1422 			  rrq->callSignalAddress.item,
1423 			  rrq->callSignalAddress.count);
1424 	if (ret < 0)
1425 		return -1;
1426 
1427 	set_ras_addr = rcu_dereference(set_ras_addr_hook);
1428 	if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1429 	    ct->status & IPS_NAT_MASK) {
1430 		ret = set_ras_addr(skb, ct, ctinfo, protoff, data,
1431 				   rrq->rasAddress.item,
1432 				   rrq->rasAddress.count);
1433 		if (ret < 0)
1434 			return -1;
1435 	}
1436 
1437 	if (rrq->options & eRegistrationRequest_timeToLive) {
1438 		pr_debug("nf_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive);
1439 		info->timeout = rrq->timeToLive;
1440 	} else
1441 		info->timeout = default_rrq_ttl;
1442 
1443 	return 0;
1444 }
1445 
1446 /****************************************************************************/
1447 static int process_rcf(struct sk_buff *skb, struct nf_conn *ct,
1448 		       enum ip_conntrack_info ctinfo,
1449 		       unsigned int protoff,
1450 		       unsigned char **data, RegistrationConfirm *rcf)
1451 {
1452 	struct nf_ct_h323_master *info = nfct_help_data(ct);
1453 	int dir = CTINFO2DIR(ctinfo);
1454 	int ret;
1455 	struct nf_conntrack_expect *exp;
1456 	typeof(set_sig_addr_hook) set_sig_addr;
1457 
1458 	pr_debug("nf_ct_ras: RCF\n");
1459 
1460 	set_sig_addr = rcu_dereference(set_sig_addr_hook);
1461 	if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1462 	    ct->status & IPS_NAT_MASK) {
1463 		ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1464 					rcf->callSignalAddress.item,
1465 					rcf->callSignalAddress.count);
1466 		if (ret < 0)
1467 			return -1;
1468 	}
1469 
1470 	if (rcf->options & eRegistrationConfirm_timeToLive) {
1471 		pr_debug("nf_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive);
1472 		info->timeout = rcf->timeToLive;
1473 	}
1474 
1475 	if (info->timeout > 0) {
1476 		pr_debug("nf_ct_ras: set RAS connection timeout to "
1477 			 "%u seconds\n", info->timeout);
1478 		nf_ct_refresh(ct, skb, info->timeout * HZ);
1479 
1480 		/* Set expect timeout */
1481 		spin_lock_bh(&nf_conntrack_expect_lock);
1482 		exp = find_expect(ct, &ct->tuplehash[dir].tuple.dst.u3,
1483 				  info->sig_port[!dir]);
1484 		if (exp) {
1485 			pr_debug("nf_ct_ras: set Q.931 expect "
1486 				 "timeout to %u seconds for",
1487 				 info->timeout);
1488 			nf_ct_dump_tuple(&exp->tuple);
1489 			set_expect_timeout(exp, info->timeout);
1490 		}
1491 		spin_unlock_bh(&nf_conntrack_expect_lock);
1492 	}
1493 
1494 	return 0;
1495 }
1496 
1497 /****************************************************************************/
1498 static int process_urq(struct sk_buff *skb, struct nf_conn *ct,
1499 		       enum ip_conntrack_info ctinfo,
1500 		       unsigned int protoff,
1501 		       unsigned char **data, UnregistrationRequest *urq)
1502 {
1503 	struct nf_ct_h323_master *info = nfct_help_data(ct);
1504 	int dir = CTINFO2DIR(ctinfo);
1505 	int ret;
1506 	typeof(set_sig_addr_hook) set_sig_addr;
1507 
1508 	pr_debug("nf_ct_ras: URQ\n");
1509 
1510 	set_sig_addr = rcu_dereference(set_sig_addr_hook);
1511 	if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1512 	    ct->status & IPS_NAT_MASK) {
1513 		ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1514 				   urq->callSignalAddress.item,
1515 				   urq->callSignalAddress.count);
1516 		if (ret < 0)
1517 			return -1;
1518 	}
1519 
1520 	/* Clear old expect */
1521 	nf_ct_remove_expectations(ct);
1522 	info->sig_port[dir] = 0;
1523 	info->sig_port[!dir] = 0;
1524 
1525 	/* Give it 30 seconds for UCF or URJ */
1526 	nf_ct_refresh(ct, skb, 30 * HZ);
1527 
1528 	return 0;
1529 }
1530 
1531 /****************************************************************************/
1532 static int process_arq(struct sk_buff *skb, struct nf_conn *ct,
1533 		       enum ip_conntrack_info ctinfo,
1534 		       unsigned int protoff,
1535 		       unsigned char **data, AdmissionRequest *arq)
1536 {
1537 	const struct nf_ct_h323_master *info = nfct_help_data(ct);
1538 	int dir = CTINFO2DIR(ctinfo);
1539 	__be16 port;
1540 	union nf_inet_addr addr;
1541 	typeof(set_h225_addr_hook) set_h225_addr;
1542 
1543 	pr_debug("nf_ct_ras: ARQ\n");
1544 
1545 	set_h225_addr = rcu_dereference(set_h225_addr_hook);
1546 	if ((arq->options & eAdmissionRequest_destCallSignalAddress) &&
1547 	    get_h225_addr(ct, *data, &arq->destCallSignalAddress,
1548 			  &addr, &port) &&
1549 	    !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1550 	    port == info->sig_port[dir] &&
1551 	    nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1552 	    set_h225_addr && ct->status & IPS_NAT_MASK) {
1553 		/* Answering ARQ */
1554 		return set_h225_addr(skb, protoff, data, 0,
1555 				     &arq->destCallSignalAddress,
1556 				     &ct->tuplehash[!dir].tuple.dst.u3,
1557 				     info->sig_port[!dir]);
1558 	}
1559 
1560 	if ((arq->options & eAdmissionRequest_srcCallSignalAddress) &&
1561 	    get_h225_addr(ct, *data, &arq->srcCallSignalAddress,
1562 			  &addr, &port) &&
1563 	    !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1564 	    set_h225_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1565 	    ct->status & IPS_NAT_MASK) {
1566 		/* Calling ARQ */
1567 		return set_h225_addr(skb, protoff, data, 0,
1568 				     &arq->srcCallSignalAddress,
1569 				     &ct->tuplehash[!dir].tuple.dst.u3,
1570 				     port);
1571 	}
1572 
1573 	return 0;
1574 }
1575 
1576 /****************************************************************************/
1577 static int process_acf(struct sk_buff *skb, struct nf_conn *ct,
1578 		       enum ip_conntrack_info ctinfo,
1579 		       unsigned int protoff,
1580 		       unsigned char **data, AdmissionConfirm *acf)
1581 {
1582 	int dir = CTINFO2DIR(ctinfo);
1583 	int ret = 0;
1584 	__be16 port;
1585 	union nf_inet_addr addr;
1586 	struct nf_conntrack_expect *exp;
1587 	typeof(set_sig_addr_hook) set_sig_addr;
1588 
1589 	pr_debug("nf_ct_ras: ACF\n");
1590 
1591 	if (!get_h225_addr(ct, *data, &acf->destCallSignalAddress,
1592 			   &addr, &port))
1593 		return 0;
1594 
1595 	if (!memcmp(&addr, &ct->tuplehash[dir].tuple.dst.u3, sizeof(addr))) {
1596 		/* Answering ACF */
1597 		set_sig_addr = rcu_dereference(set_sig_addr_hook);
1598 		if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1599 		    ct->status & IPS_NAT_MASK)
1600 			return set_sig_addr(skb, ct, ctinfo, protoff, data,
1601 					    &acf->destCallSignalAddress, 1);
1602 		return 0;
1603 	}
1604 
1605 	/* Need new expect */
1606 	if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1607 		return -1;
1608 	nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1609 			  &ct->tuplehash[!dir].tuple.src.u3, &addr,
1610 			  IPPROTO_TCP, NULL, &port);
1611 	exp->flags = NF_CT_EXPECT_PERMANENT;
1612 	exp->helper = nf_conntrack_helper_q931;
1613 
1614 	if (nf_ct_expect_related(exp) == 0) {
1615 		pr_debug("nf_ct_ras: expect Q.931 ");
1616 		nf_ct_dump_tuple(&exp->tuple);
1617 	} else
1618 		ret = -1;
1619 
1620 	nf_ct_expect_put(exp);
1621 
1622 	return ret;
1623 }
1624 
1625 /****************************************************************************/
1626 static int process_lrq(struct sk_buff *skb, struct nf_conn *ct,
1627 		       enum ip_conntrack_info ctinfo,
1628 		       unsigned int protoff,
1629 		       unsigned char **data, LocationRequest *lrq)
1630 {
1631 	typeof(set_ras_addr_hook) set_ras_addr;
1632 
1633 	pr_debug("nf_ct_ras: LRQ\n");
1634 
1635 	set_ras_addr = rcu_dereference(set_ras_addr_hook);
1636 	if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1637 	    ct->status & IPS_NAT_MASK)
1638 		return set_ras_addr(skb, ct, ctinfo, protoff, data,
1639 				    &lrq->replyAddress, 1);
1640 	return 0;
1641 }
1642 
1643 /****************************************************************************/
1644 static int process_lcf(struct sk_buff *skb, struct nf_conn *ct,
1645 		       enum ip_conntrack_info ctinfo,
1646 		       unsigned int protoff,
1647 		       unsigned char **data, LocationConfirm *lcf)
1648 {
1649 	int dir = CTINFO2DIR(ctinfo);
1650 	int ret = 0;
1651 	__be16 port;
1652 	union nf_inet_addr addr;
1653 	struct nf_conntrack_expect *exp;
1654 
1655 	pr_debug("nf_ct_ras: LCF\n");
1656 
1657 	if (!get_h225_addr(ct, *data, &lcf->callSignalAddress,
1658 			   &addr, &port))
1659 		return 0;
1660 
1661 	/* Need new expect for call signal */
1662 	if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1663 		return -1;
1664 	nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1665 			  &ct->tuplehash[!dir].tuple.src.u3, &addr,
1666 			  IPPROTO_TCP, NULL, &port);
1667 	exp->flags = NF_CT_EXPECT_PERMANENT;
1668 	exp->helper = nf_conntrack_helper_q931;
1669 
1670 	if (nf_ct_expect_related(exp) == 0) {
1671 		pr_debug("nf_ct_ras: expect Q.931 ");
1672 		nf_ct_dump_tuple(&exp->tuple);
1673 	} else
1674 		ret = -1;
1675 
1676 	nf_ct_expect_put(exp);
1677 
1678 	/* Ignore rasAddress */
1679 
1680 	return ret;
1681 }
1682 
1683 /****************************************************************************/
1684 static int process_irr(struct sk_buff *skb, struct nf_conn *ct,
1685 		       enum ip_conntrack_info ctinfo,
1686 		       unsigned int protoff,
1687 		       unsigned char **data, InfoRequestResponse *irr)
1688 {
1689 	int ret;
1690 	typeof(set_ras_addr_hook) set_ras_addr;
1691 	typeof(set_sig_addr_hook) set_sig_addr;
1692 
1693 	pr_debug("nf_ct_ras: IRR\n");
1694 
1695 	set_ras_addr = rcu_dereference(set_ras_addr_hook);
1696 	if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1697 	    ct->status & IPS_NAT_MASK) {
1698 		ret = set_ras_addr(skb, ct, ctinfo, protoff, data,
1699 				   &irr->rasAddress, 1);
1700 		if (ret < 0)
1701 			return -1;
1702 	}
1703 
1704 	set_sig_addr = rcu_dereference(set_sig_addr_hook);
1705 	if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1706 	    ct->status & IPS_NAT_MASK) {
1707 		ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1708 					irr->callSignalAddress.item,
1709 					irr->callSignalAddress.count);
1710 		if (ret < 0)
1711 			return -1;
1712 	}
1713 
1714 	return 0;
1715 }
1716 
1717 /****************************************************************************/
1718 static int process_ras(struct sk_buff *skb, struct nf_conn *ct,
1719 		       enum ip_conntrack_info ctinfo,
1720 		       unsigned int protoff,
1721 		       unsigned char **data, RasMessage *ras)
1722 {
1723 	switch (ras->choice) {
1724 	case eRasMessage_gatekeeperRequest:
1725 		return process_grq(skb, ct, ctinfo, protoff, data,
1726 				   &ras->gatekeeperRequest);
1727 	case eRasMessage_gatekeeperConfirm:
1728 		return process_gcf(skb, ct, ctinfo, protoff, data,
1729 				   &ras->gatekeeperConfirm);
1730 	case eRasMessage_registrationRequest:
1731 		return process_rrq(skb, ct, ctinfo, protoff, data,
1732 				   &ras->registrationRequest);
1733 	case eRasMessage_registrationConfirm:
1734 		return process_rcf(skb, ct, ctinfo, protoff, data,
1735 				   &ras->registrationConfirm);
1736 	case eRasMessage_unregistrationRequest:
1737 		return process_urq(skb, ct, ctinfo, protoff, data,
1738 				   &ras->unregistrationRequest);
1739 	case eRasMessage_admissionRequest:
1740 		return process_arq(skb, ct, ctinfo, protoff, data,
1741 				   &ras->admissionRequest);
1742 	case eRasMessage_admissionConfirm:
1743 		return process_acf(skb, ct, ctinfo, protoff, data,
1744 				   &ras->admissionConfirm);
1745 	case eRasMessage_locationRequest:
1746 		return process_lrq(skb, ct, ctinfo, protoff, data,
1747 				   &ras->locationRequest);
1748 	case eRasMessage_locationConfirm:
1749 		return process_lcf(skb, ct, ctinfo, protoff, data,
1750 				   &ras->locationConfirm);
1751 	case eRasMessage_infoRequestResponse:
1752 		return process_irr(skb, ct, ctinfo, protoff, data,
1753 				   &ras->infoRequestResponse);
1754 	default:
1755 		pr_debug("nf_ct_ras: RAS message %d\n", ras->choice);
1756 		break;
1757 	}
1758 
1759 	return 0;
1760 }
1761 
1762 /****************************************************************************/
1763 static int ras_help(struct sk_buff *skb, unsigned int protoff,
1764 		    struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1765 {
1766 	static RasMessage ras;
1767 	unsigned char *data;
1768 	int datalen = 0;
1769 	int ret;
1770 
1771 	pr_debug("nf_ct_ras: skblen = %u\n", skb->len);
1772 
1773 	spin_lock_bh(&nf_h323_lock);
1774 
1775 	/* Get UDP data */
1776 	data = get_udp_data(skb, protoff, &datalen);
1777 	if (data == NULL)
1778 		goto accept;
1779 	pr_debug("nf_ct_ras: RAS message len=%d ", datalen);
1780 	nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1781 
1782 	/* Decode RAS message */
1783 	ret = DecodeRasMessage(data, datalen, &ras);
1784 	if (ret < 0) {
1785 		pr_debug("nf_ct_ras: decoding error: %s\n",
1786 			 ret == H323_ERROR_BOUND ?
1787 			 "out of bound" : "out of range");
1788 		goto accept;
1789 	}
1790 
1791 	/* Process RAS message */
1792 	if (process_ras(skb, ct, ctinfo, protoff, &data, &ras) < 0)
1793 		goto drop;
1794 
1795       accept:
1796 	spin_unlock_bh(&nf_h323_lock);
1797 	return NF_ACCEPT;
1798 
1799       drop:
1800 	spin_unlock_bh(&nf_h323_lock);
1801 	nf_ct_helper_log(skb, ct, "cannot process RAS message");
1802 	return NF_DROP;
1803 }
1804 
1805 /****************************************************************************/
1806 static const struct nf_conntrack_expect_policy ras_exp_policy = {
1807 	.max_expected		= 32,
1808 	.timeout		= 240,
1809 };
1810 
1811 static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = {
1812 	{
1813 		.name			= "RAS",
1814 		.me			= THIS_MODULE,
1815 		.data_len		= sizeof(struct nf_ct_h323_master),
1816 		.tuple.src.l3num	= AF_INET,
1817 		.tuple.src.u.udp.port	= cpu_to_be16(RAS_PORT),
1818 		.tuple.dst.protonum	= IPPROTO_UDP,
1819 		.help			= ras_help,
1820 		.expect_policy		= &ras_exp_policy,
1821 	},
1822 	{
1823 		.name			= "RAS",
1824 		.me			= THIS_MODULE,
1825 		.data_len		= sizeof(struct nf_ct_h323_master),
1826 		.tuple.src.l3num	= AF_INET6,
1827 		.tuple.src.u.udp.port	= cpu_to_be16(RAS_PORT),
1828 		.tuple.dst.protonum	= IPPROTO_UDP,
1829 		.help			= ras_help,
1830 		.expect_policy		= &ras_exp_policy,
1831 	},
1832 };
1833 
1834 /****************************************************************************/
1835 static void __exit nf_conntrack_h323_fini(void)
1836 {
1837 	nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[1]);
1838 	nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1839 	nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1840 	nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1841 	nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1842 	kfree(h323_buffer);
1843 	pr_debug("nf_ct_h323: fini\n");
1844 }
1845 
1846 /****************************************************************************/
1847 static int __init nf_conntrack_h323_init(void)
1848 {
1849 	int ret;
1850 
1851 	h323_buffer = kmalloc(65536, GFP_KERNEL);
1852 	if (!h323_buffer)
1853 		return -ENOMEM;
1854 	ret = nf_conntrack_helper_register(&nf_conntrack_helper_h245);
1855 	if (ret < 0)
1856 		goto err1;
1857 	ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[0]);
1858 	if (ret < 0)
1859 		goto err2;
1860 	ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[1]);
1861 	if (ret < 0)
1862 		goto err3;
1863 	ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[0]);
1864 	if (ret < 0)
1865 		goto err4;
1866 	ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[1]);
1867 	if (ret < 0)
1868 		goto err5;
1869 	pr_debug("nf_ct_h323: init success\n");
1870 	return 0;
1871 
1872 err5:
1873 	nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1874 err4:
1875 	nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1876 err3:
1877 	nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1878 err2:
1879 	nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1880 err1:
1881 	kfree(h323_buffer);
1882 	return ret;
1883 }
1884 
1885 /****************************************************************************/
1886 module_init(nf_conntrack_h323_init);
1887 module_exit(nf_conntrack_h323_fini);
1888 
1889 EXPORT_SYMBOL_GPL(get_h225_addr);
1890 EXPORT_SYMBOL_GPL(set_h245_addr_hook);
1891 EXPORT_SYMBOL_GPL(set_h225_addr_hook);
1892 EXPORT_SYMBOL_GPL(set_sig_addr_hook);
1893 EXPORT_SYMBOL_GPL(set_ras_addr_hook);
1894 EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook);
1895 EXPORT_SYMBOL_GPL(nat_t120_hook);
1896 EXPORT_SYMBOL_GPL(nat_h245_hook);
1897 EXPORT_SYMBOL_GPL(nat_callforwarding_hook);
1898 EXPORT_SYMBOL_GPL(nat_q931_hook);
1899 
1900 MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>");
1901 MODULE_DESCRIPTION("H.323 connection tracking helper");
1902 MODULE_LICENSE("GPL");
1903 MODULE_ALIAS("ip_conntrack_h323");
1904 MODULE_ALIAS_NFCT_HELPER("RAS");
1905 MODULE_ALIAS_NFCT_HELPER("Q.931");
1906 MODULE_ALIAS_NFCT_HELPER("H.245");
1907