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Linux/net/netfilter/nf_conntrack_h323_main.c

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  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(const union nf_inet_addr *src,
732                                  const union nf_inet_addr *dst,
733                                  u_int8_t family)
734 {
735         const struct nf_afinfo *afinfo;
736         int ret = 0;
737 
738         /* rcu_read_lock()ed by nf_hook_slow() */
739         afinfo = nf_get_afinfo(family);
740         if (!afinfo)
741                 return 0;
742 
743         switch (family) {
744         case AF_INET: {
745                 struct flowi4 fl1, fl2;
746                 struct rtable *rt1, *rt2;
747 
748                 memset(&fl1, 0, sizeof(fl1));
749                 fl1.daddr = src->ip;
750 
751                 memset(&fl2, 0, sizeof(fl2));
752                 fl2.daddr = dst->ip;
753                 if (!afinfo->route(&init_net, (struct dst_entry **)&rt1,
754                                    flowi4_to_flowi(&fl1), false)) {
755                         if (!afinfo->route(&init_net, (struct dst_entry **)&rt2,
756                                            flowi4_to_flowi(&fl2), false)) {
757                                 if (rt_nexthop(rt1, fl1.daddr) ==
758                                     rt_nexthop(rt2, fl2.daddr) &&
759                                     rt1->dst.dev  == rt2->dst.dev)
760                                         ret = 1;
761                                 dst_release(&rt2->dst);
762                         }
763                         dst_release(&rt1->dst);
764                 }
765                 break;
766         }
767 #if IS_ENABLED(CONFIG_NF_CONNTRACK_IPV6)
768         case AF_INET6: {
769                 struct flowi6 fl1, fl2;
770                 struct rt6_info *rt1, *rt2;
771 
772                 memset(&fl1, 0, sizeof(fl1));
773                 fl1.daddr = src->in6;
774 
775                 memset(&fl2, 0, sizeof(fl2));
776                 fl2.daddr = dst->in6;
777                 if (!afinfo->route(&init_net, (struct dst_entry **)&rt1,
778                                    flowi6_to_flowi(&fl1), false)) {
779                         if (!afinfo->route(&init_net, (struct dst_entry **)&rt2,
780                                            flowi6_to_flowi(&fl2), false)) {
781                                 if (ipv6_addr_equal(rt6_nexthop(rt1),
782                                                     rt6_nexthop(rt2)) &&
783                                     rt1->dst.dev == rt2->dst.dev)
784                                         ret = 1;
785                                 dst_release(&rt2->dst);
786                         }
787                         dst_release(&rt1->dst);
788                 }
789                 break;
790         }
791 #endif
792         }
793         return ret;
794 
795 }
796 
797 /****************************************************************************/
798 static int expect_callforwarding(struct sk_buff *skb,
799                                  struct nf_conn *ct,
800                                  enum ip_conntrack_info ctinfo,
801                                  unsigned int protoff,
802                                  unsigned char **data, int dataoff,
803                                  TransportAddress *taddr)
804 {
805         int dir = CTINFO2DIR(ctinfo);
806         int ret = 0;
807         __be16 port;
808         union nf_inet_addr addr;
809         struct nf_conntrack_expect *exp;
810         typeof(nat_callforwarding_hook) nat_callforwarding;
811 
812         /* Read alternativeAddress */
813         if (!get_h225_addr(ct, *data, taddr, &addr, &port) || port == 0)
814                 return 0;
815 
816         /* If the calling party is on the same side of the forward-to party,
817          * we don't need to track the second call */
818         if (callforward_filter &&
819             callforward_do_filter(&addr, &ct->tuplehash[!dir].tuple.src.u3,
820                                   nf_ct_l3num(ct))) {
821                 pr_debug("nf_ct_q931: Call Forwarding not tracked\n");
822                 return 0;
823         }
824 
825         /* Create expect for the second call leg */
826         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
827                 return -1;
828         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
829                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
830                           IPPROTO_TCP, NULL, &port);
831         exp->helper = nf_conntrack_helper_q931;
832 
833         if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
834                    &ct->tuplehash[!dir].tuple.dst.u3,
835                    sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
836             (nat_callforwarding = rcu_dereference(nat_callforwarding_hook)) &&
837             nf_ct_l3num(ct) == NFPROTO_IPV4 &&
838             ct->status & IPS_NAT_MASK) {
839                 /* Need NAT */
840                 ret = nat_callforwarding(skb, ct, ctinfo,
841                                          protoff, data, dataoff,
842                                          taddr, port, exp);
843         } else {                /* Conntrack only */
844                 if (nf_ct_expect_related(exp) == 0) {
845                         pr_debug("nf_ct_q931: expect Call Forwarding ");
846                         nf_ct_dump_tuple(&exp->tuple);
847                 } else
848                         ret = -1;
849         }
850 
851         nf_ct_expect_put(exp);
852 
853         return ret;
854 }
855 
856 /****************************************************************************/
857 static int process_setup(struct sk_buff *skb, struct nf_conn *ct,
858                          enum ip_conntrack_info ctinfo,
859                          unsigned int protoff,
860                          unsigned char **data, int dataoff,
861                          Setup_UUIE *setup)
862 {
863         int dir = CTINFO2DIR(ctinfo);
864         int ret;
865         int i;
866         __be16 port;
867         union nf_inet_addr addr;
868         typeof(set_h225_addr_hook) set_h225_addr;
869 
870         pr_debug("nf_ct_q931: Setup\n");
871 
872         if (setup->options & eSetup_UUIE_h245Address) {
873                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
874                                   &setup->h245Address);
875                 if (ret < 0)
876                         return -1;
877         }
878 
879         set_h225_addr = rcu_dereference(set_h225_addr_hook);
880         if ((setup->options & eSetup_UUIE_destCallSignalAddress) &&
881             (set_h225_addr) && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
882             ct->status & IPS_NAT_MASK &&
883             get_h225_addr(ct, *data, &setup->destCallSignalAddress,
884                           &addr, &port) &&
885             memcmp(&addr, &ct->tuplehash[!dir].tuple.src.u3, sizeof(addr))) {
886                 pr_debug("nf_ct_q931: set destCallSignalAddress %pI6:%hu->%pI6:%hu\n",
887                          &addr, ntohs(port), &ct->tuplehash[!dir].tuple.src.u3,
888                          ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port));
889                 ret = set_h225_addr(skb, protoff, data, dataoff,
890                                     &setup->destCallSignalAddress,
891                                     &ct->tuplehash[!dir].tuple.src.u3,
892                                     ct->tuplehash[!dir].tuple.src.u.tcp.port);
893                 if (ret < 0)
894                         return -1;
895         }
896 
897         if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) &&
898             (set_h225_addr) && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
899             ct->status & IPS_NAT_MASK &&
900             get_h225_addr(ct, *data, &setup->sourceCallSignalAddress,
901                           &addr, &port) &&
902             memcmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(addr))) {
903                 pr_debug("nf_ct_q931: set sourceCallSignalAddress %pI6:%hu->%pI6:%hu\n",
904                          &addr, ntohs(port), &ct->tuplehash[!dir].tuple.dst.u3,
905                          ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port));
906                 ret = set_h225_addr(skb, protoff, data, dataoff,
907                                     &setup->sourceCallSignalAddress,
908                                     &ct->tuplehash[!dir].tuple.dst.u3,
909                                     ct->tuplehash[!dir].tuple.dst.u.tcp.port);
910                 if (ret < 0)
911                         return -1;
912         }
913 
914         if (setup->options & eSetup_UUIE_fastStart) {
915                 for (i = 0; i < setup->fastStart.count; i++) {
916                         ret = process_olc(skb, ct, ctinfo,
917                                           protoff, data, dataoff,
918                                           &setup->fastStart.item[i]);
919                         if (ret < 0)
920                                 return -1;
921                 }
922         }
923 
924         return 0;
925 }
926 
927 /****************************************************************************/
928 static int process_callproceeding(struct sk_buff *skb,
929                                   struct nf_conn *ct,
930                                   enum ip_conntrack_info ctinfo,
931                                   unsigned int protoff,
932                                   unsigned char **data, int dataoff,
933                                   CallProceeding_UUIE *callproc)
934 {
935         int ret;
936         int i;
937 
938         pr_debug("nf_ct_q931: CallProceeding\n");
939 
940         if (callproc->options & eCallProceeding_UUIE_h245Address) {
941                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
942                                   &callproc->h245Address);
943                 if (ret < 0)
944                         return -1;
945         }
946 
947         if (callproc->options & eCallProceeding_UUIE_fastStart) {
948                 for (i = 0; i < callproc->fastStart.count; i++) {
949                         ret = process_olc(skb, ct, ctinfo,
950                                           protoff, data, dataoff,
951                                           &callproc->fastStart.item[i]);
952                         if (ret < 0)
953                                 return -1;
954                 }
955         }
956 
957         return 0;
958 }
959 
960 /****************************************************************************/
961 static int process_connect(struct sk_buff *skb, struct nf_conn *ct,
962                            enum ip_conntrack_info ctinfo,
963                            unsigned int protoff,
964                            unsigned char **data, int dataoff,
965                            Connect_UUIE *connect)
966 {
967         int ret;
968         int i;
969 
970         pr_debug("nf_ct_q931: Connect\n");
971 
972         if (connect->options & eConnect_UUIE_h245Address) {
973                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
974                                   &connect->h245Address);
975                 if (ret < 0)
976                         return -1;
977         }
978 
979         if (connect->options & eConnect_UUIE_fastStart) {
980                 for (i = 0; i < connect->fastStart.count; i++) {
981                         ret = process_olc(skb, ct, ctinfo,
982                                           protoff, data, dataoff,
983                                           &connect->fastStart.item[i]);
984                         if (ret < 0)
985                                 return -1;
986                 }
987         }
988 
989         return 0;
990 }
991 
992 /****************************************************************************/
993 static int process_alerting(struct sk_buff *skb, struct nf_conn *ct,
994                             enum ip_conntrack_info ctinfo,
995                             unsigned int protoff,
996                             unsigned char **data, int dataoff,
997                             Alerting_UUIE *alert)
998 {
999         int ret;
1000         int i;
1001 
1002         pr_debug("nf_ct_q931: Alerting\n");
1003 
1004         if (alert->options & eAlerting_UUIE_h245Address) {
1005                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
1006                                   &alert->h245Address);
1007                 if (ret < 0)
1008                         return -1;
1009         }
1010 
1011         if (alert->options & eAlerting_UUIE_fastStart) {
1012                 for (i = 0; i < alert->fastStart.count; i++) {
1013                         ret = process_olc(skb, ct, ctinfo,
1014                                           protoff, data, dataoff,
1015                                           &alert->fastStart.item[i]);
1016                         if (ret < 0)
1017                                 return -1;
1018                 }
1019         }
1020 
1021         return 0;
1022 }
1023 
1024 /****************************************************************************/
1025 static int process_facility(struct sk_buff *skb, struct nf_conn *ct,
1026                             enum ip_conntrack_info ctinfo,
1027                             unsigned int protoff,
1028                             unsigned char **data, int dataoff,
1029                             Facility_UUIE *facility)
1030 {
1031         int ret;
1032         int i;
1033 
1034         pr_debug("nf_ct_q931: Facility\n");
1035 
1036         if (facility->reason.choice == eFacilityReason_callForwarded) {
1037                 if (facility->options & eFacility_UUIE_alternativeAddress)
1038                         return expect_callforwarding(skb, ct, ctinfo,
1039                                                      protoff, data, dataoff,
1040                                                      &facility->
1041                                                      alternativeAddress);
1042                 return 0;
1043         }
1044 
1045         if (facility->options & eFacility_UUIE_h245Address) {
1046                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
1047                                   &facility->h245Address);
1048                 if (ret < 0)
1049                         return -1;
1050         }
1051 
1052         if (facility->options & eFacility_UUIE_fastStart) {
1053                 for (i = 0; i < facility->fastStart.count; i++) {
1054                         ret = process_olc(skb, ct, ctinfo,
1055                                           protoff, data, dataoff,
1056                                           &facility->fastStart.item[i]);
1057                         if (ret < 0)
1058                                 return -1;
1059                 }
1060         }
1061 
1062         return 0;
1063 }
1064 
1065 /****************************************************************************/
1066 static int process_progress(struct sk_buff *skb, struct nf_conn *ct,
1067                             enum ip_conntrack_info ctinfo,
1068                             unsigned int protoff,
1069                             unsigned char **data, int dataoff,
1070                             Progress_UUIE *progress)
1071 {
1072         int ret;
1073         int i;
1074 
1075         pr_debug("nf_ct_q931: Progress\n");
1076 
1077         if (progress->options & eProgress_UUIE_h245Address) {
1078                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
1079                                   &progress->h245Address);
1080                 if (ret < 0)
1081                         return -1;
1082         }
1083 
1084         if (progress->options & eProgress_UUIE_fastStart) {
1085                 for (i = 0; i < progress->fastStart.count; i++) {
1086                         ret = process_olc(skb, ct, ctinfo,
1087                                           protoff, data, dataoff,
1088                                           &progress->fastStart.item[i]);
1089                         if (ret < 0)
1090                                 return -1;
1091                 }
1092         }
1093 
1094         return 0;
1095 }
1096 
1097 /****************************************************************************/
1098 static int process_q931(struct sk_buff *skb, struct nf_conn *ct,
1099                         enum ip_conntrack_info ctinfo,
1100                         unsigned int protoff, unsigned char **data, int dataoff,
1101                         Q931 *q931)
1102 {
1103         H323_UU_PDU *pdu = &q931->UUIE.h323_uu_pdu;
1104         int i;
1105         int ret = 0;
1106 
1107         switch (pdu->h323_message_body.choice) {
1108         case eH323_UU_PDU_h323_message_body_setup:
1109                 ret = process_setup(skb, ct, ctinfo, protoff, data, dataoff,
1110                                     &pdu->h323_message_body.setup);
1111                 break;
1112         case eH323_UU_PDU_h323_message_body_callProceeding:
1113                 ret = process_callproceeding(skb, ct, ctinfo,
1114                                              protoff, data, dataoff,
1115                                              &pdu->h323_message_body.
1116                                              callProceeding);
1117                 break;
1118         case eH323_UU_PDU_h323_message_body_connect:
1119                 ret = process_connect(skb, ct, ctinfo, protoff, data, dataoff,
1120                                       &pdu->h323_message_body.connect);
1121                 break;
1122         case eH323_UU_PDU_h323_message_body_alerting:
1123                 ret = process_alerting(skb, ct, ctinfo, protoff, data, dataoff,
1124                                        &pdu->h323_message_body.alerting);
1125                 break;
1126         case eH323_UU_PDU_h323_message_body_facility:
1127                 ret = process_facility(skb, ct, ctinfo, protoff, data, dataoff,
1128                                        &pdu->h323_message_body.facility);
1129                 break;
1130         case eH323_UU_PDU_h323_message_body_progress:
1131                 ret = process_progress(skb, ct, ctinfo, protoff, data, dataoff,
1132                                        &pdu->h323_message_body.progress);
1133                 break;
1134         default:
1135                 pr_debug("nf_ct_q931: Q.931 signal %d\n",
1136                          pdu->h323_message_body.choice);
1137                 break;
1138         }
1139 
1140         if (ret < 0)
1141                 return -1;
1142 
1143         if (pdu->options & eH323_UU_PDU_h245Control) {
1144                 for (i = 0; i < pdu->h245Control.count; i++) {
1145                         ret = process_h245(skb, ct, ctinfo,
1146                                            protoff, data, dataoff,
1147                                            &pdu->h245Control.item[i]);
1148                         if (ret < 0)
1149                                 return -1;
1150                 }
1151         }
1152 
1153         return 0;
1154 }
1155 
1156 /****************************************************************************/
1157 static int q931_help(struct sk_buff *skb, unsigned int protoff,
1158                      struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1159 {
1160         static Q931 q931;
1161         unsigned char *data = NULL;
1162         int datalen;
1163         int dataoff;
1164         int ret;
1165 
1166         /* Until there's been traffic both ways, don't look in packets. */
1167         if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
1168                 return NF_ACCEPT;
1169 
1170         pr_debug("nf_ct_q931: skblen = %u\n", skb->len);
1171 
1172         spin_lock_bh(&nf_h323_lock);
1173 
1174         /* Process each TPKT */
1175         while (get_tpkt_data(skb, protoff, ct, ctinfo,
1176                              &data, &datalen, &dataoff)) {
1177                 pr_debug("nf_ct_q931: TPKT len=%d ", datalen);
1178                 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1179 
1180                 /* Decode Q.931 signal */
1181                 ret = DecodeQ931(data, datalen, &q931);
1182                 if (ret < 0) {
1183                         pr_debug("nf_ct_q931: decoding error: %s\n",
1184                                  ret == H323_ERROR_BOUND ?
1185                                  "out of bound" : "out of range");
1186                         /* We don't drop when decoding error */
1187                         break;
1188                 }
1189 
1190                 /* Process Q.931 signal */
1191                 if (process_q931(skb, ct, ctinfo, protoff,
1192                                  &data, dataoff, &q931) < 0)
1193                         goto drop;
1194         }
1195 
1196         spin_unlock_bh(&nf_h323_lock);
1197         return NF_ACCEPT;
1198 
1199       drop:
1200         spin_unlock_bh(&nf_h323_lock);
1201         nf_ct_helper_log(skb, ct, "cannot process Q.931 message");
1202         return NF_DROP;
1203 }
1204 
1205 /****************************************************************************/
1206 static const struct nf_conntrack_expect_policy q931_exp_policy = {
1207         /* T.120 and H.245 */
1208         .max_expected           = H323_RTP_CHANNEL_MAX * 4 + 4,
1209         .timeout                = 240,
1210 };
1211 
1212 static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = {
1213         {
1214                 .name                   = "Q.931",
1215                 .me                     = THIS_MODULE,
1216                 .data_len               = sizeof(struct nf_ct_h323_master),
1217                 .tuple.src.l3num        = AF_INET,
1218                 .tuple.src.u.tcp.port   = cpu_to_be16(Q931_PORT),
1219                 .tuple.dst.protonum     = IPPROTO_TCP,
1220                 .help                   = q931_help,
1221                 .expect_policy          = &q931_exp_policy,
1222         },
1223         {
1224                 .name                   = "Q.931",
1225                 .me                     = THIS_MODULE,
1226                 .tuple.src.l3num        = AF_INET6,
1227                 .tuple.src.u.tcp.port   = cpu_to_be16(Q931_PORT),
1228                 .tuple.dst.protonum     = IPPROTO_TCP,
1229                 .help                   = q931_help,
1230                 .expect_policy          = &q931_exp_policy,
1231         },
1232 };
1233 
1234 /****************************************************************************/
1235 static unsigned char *get_udp_data(struct sk_buff *skb, unsigned int protoff,
1236                                    int *datalen)
1237 {
1238         const struct udphdr *uh;
1239         struct udphdr _uh;
1240         int dataoff;
1241 
1242         uh = skb_header_pointer(skb, protoff, sizeof(_uh), &_uh);
1243         if (uh == NULL)
1244                 return NULL;
1245         dataoff = protoff + sizeof(_uh);
1246         if (dataoff >= skb->len)
1247                 return NULL;
1248         *datalen = skb->len - dataoff;
1249         return skb_header_pointer(skb, dataoff, *datalen, h323_buffer);
1250 }
1251 
1252 /****************************************************************************/
1253 static struct nf_conntrack_expect *find_expect(struct nf_conn *ct,
1254                                                union nf_inet_addr *addr,
1255                                                __be16 port)
1256 {
1257         struct net *net = nf_ct_net(ct);
1258         struct nf_conntrack_expect *exp;
1259         struct nf_conntrack_tuple tuple;
1260 
1261         memset(&tuple.src.u3, 0, sizeof(tuple.src.u3));
1262         tuple.src.u.tcp.port = 0;
1263         memcpy(&tuple.dst.u3, addr, sizeof(tuple.dst.u3));
1264         tuple.dst.u.tcp.port = port;
1265         tuple.dst.protonum = IPPROTO_TCP;
1266 
1267         exp = __nf_ct_expect_find(net, nf_ct_zone(ct), &tuple);
1268         if (exp && exp->master == ct)
1269                 return exp;
1270         return NULL;
1271 }
1272 
1273 /****************************************************************************/
1274 static int set_expect_timeout(struct nf_conntrack_expect *exp,
1275                               unsigned int timeout)
1276 {
1277         if (!exp || !del_timer(&exp->timeout))
1278                 return 0;
1279 
1280         exp->timeout.expires = jiffies + timeout * HZ;
1281         add_timer(&exp->timeout);
1282 
1283         return 1;
1284 }
1285 
1286 /****************************************************************************/
1287 static int expect_q931(struct sk_buff *skb, struct nf_conn *ct,
1288                        enum ip_conntrack_info ctinfo,
1289                        unsigned int protoff, unsigned char **data,
1290                        TransportAddress *taddr, int count)
1291 {
1292         struct nf_ct_h323_master *info = nfct_help_data(ct);
1293         int dir = CTINFO2DIR(ctinfo);
1294         int ret = 0;
1295         int i;
1296         __be16 port;
1297         union nf_inet_addr addr;
1298         struct nf_conntrack_expect *exp;
1299         typeof(nat_q931_hook) nat_q931;
1300 
1301         /* Look for the first related address */
1302         for (i = 0; i < count; i++) {
1303                 if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) &&
1304                     memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3,
1305                            sizeof(addr)) == 0 && port != 0)
1306                         break;
1307         }
1308 
1309         if (i >= count)         /* Not found */
1310                 return 0;
1311 
1312         /* Create expect for Q.931 */
1313         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1314                 return -1;
1315         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1316                           gkrouted_only ? /* only accept calls from GK? */
1317                                 &ct->tuplehash[!dir].tuple.src.u3 : NULL,
1318                           &ct->tuplehash[!dir].tuple.dst.u3,
1319                           IPPROTO_TCP, NULL, &port);
1320         exp->helper = nf_conntrack_helper_q931;
1321         exp->flags = NF_CT_EXPECT_PERMANENT;    /* Accept multiple calls */
1322 
1323         nat_q931 = rcu_dereference(nat_q931_hook);
1324         if (nat_q931 && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1325             ct->status & IPS_NAT_MASK) {        /* Need NAT */
1326                 ret = nat_q931(skb, ct, ctinfo, protoff, data,
1327                                taddr, i, port, exp);
1328         } else {                /* Conntrack only */
1329                 if (nf_ct_expect_related(exp) == 0) {
1330                         pr_debug("nf_ct_ras: expect Q.931 ");
1331                         nf_ct_dump_tuple(&exp->tuple);
1332 
1333                         /* Save port for looking up expect in processing RCF */
1334                         info->sig_port[dir] = port;
1335                 } else
1336                         ret = -1;
1337         }
1338 
1339         nf_ct_expect_put(exp);
1340 
1341         return ret;
1342 }
1343 
1344 /****************************************************************************/
1345 static int process_grq(struct sk_buff *skb, struct nf_conn *ct,
1346                        enum ip_conntrack_info ctinfo,
1347                        unsigned int protoff,
1348                        unsigned char **data, GatekeeperRequest *grq)
1349 {
1350         typeof(set_ras_addr_hook) set_ras_addr;
1351 
1352         pr_debug("nf_ct_ras: GRQ\n");
1353 
1354         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1355         if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1356             ct->status & IPS_NAT_MASK)  /* NATed */
1357                 return set_ras_addr(skb, ct, ctinfo, protoff, data,
1358                                     &grq->rasAddress, 1);
1359         return 0;
1360 }
1361 
1362 /****************************************************************************/
1363 static int process_gcf(struct sk_buff *skb, struct nf_conn *ct,
1364                        enum ip_conntrack_info ctinfo,
1365                        unsigned int protoff,
1366                        unsigned char **data, GatekeeperConfirm *gcf)
1367 {
1368         int dir = CTINFO2DIR(ctinfo);
1369         int ret = 0;
1370         __be16 port;
1371         union nf_inet_addr addr;
1372         struct nf_conntrack_expect *exp;
1373 
1374         pr_debug("nf_ct_ras: GCF\n");
1375 
1376         if (!get_h225_addr(ct, *data, &gcf->rasAddress, &addr, &port))
1377                 return 0;
1378 
1379         /* Registration port is the same as discovery port */
1380         if (!memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1381             port == ct->tuplehash[dir].tuple.src.u.udp.port)
1382                 return 0;
1383 
1384         /* Avoid RAS expectation loops. A GCF is never expected. */
1385         if (test_bit(IPS_EXPECTED_BIT, &ct->status))
1386                 return 0;
1387 
1388         /* Need new expect */
1389         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1390                 return -1;
1391         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1392                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1393                           IPPROTO_UDP, NULL, &port);
1394         exp->helper = nf_conntrack_helper_ras;
1395 
1396         if (nf_ct_expect_related(exp) == 0) {
1397                 pr_debug("nf_ct_ras: expect RAS ");
1398                 nf_ct_dump_tuple(&exp->tuple);
1399         } else
1400                 ret = -1;
1401 
1402         nf_ct_expect_put(exp);
1403 
1404         return ret;
1405 }
1406 
1407 /****************************************************************************/
1408 static int process_rrq(struct sk_buff *skb, struct nf_conn *ct,
1409                        enum ip_conntrack_info ctinfo,
1410                        unsigned int protoff,
1411                        unsigned char **data, RegistrationRequest *rrq)
1412 {
1413         struct nf_ct_h323_master *info = nfct_help_data(ct);
1414         int ret;
1415         typeof(set_ras_addr_hook) set_ras_addr;
1416 
1417         pr_debug("nf_ct_ras: RRQ\n");
1418 
1419         ret = expect_q931(skb, ct, ctinfo, protoff, data,
1420                           rrq->callSignalAddress.item,
1421                           rrq->callSignalAddress.count);
1422         if (ret < 0)
1423                 return -1;
1424 
1425         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1426         if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1427             ct->status & IPS_NAT_MASK) {
1428                 ret = set_ras_addr(skb, ct, ctinfo, protoff, data,
1429                                    rrq->rasAddress.item,
1430                                    rrq->rasAddress.count);
1431                 if (ret < 0)
1432                         return -1;
1433         }
1434 
1435         if (rrq->options & eRegistrationRequest_timeToLive) {
1436                 pr_debug("nf_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive);
1437                 info->timeout = rrq->timeToLive;
1438         } else
1439                 info->timeout = default_rrq_ttl;
1440 
1441         return 0;
1442 }
1443 
1444 /****************************************************************************/
1445 static int process_rcf(struct sk_buff *skb, struct nf_conn *ct,
1446                        enum ip_conntrack_info ctinfo,
1447                        unsigned int protoff,
1448                        unsigned char **data, RegistrationConfirm *rcf)
1449 {
1450         struct nf_ct_h323_master *info = nfct_help_data(ct);
1451         int dir = CTINFO2DIR(ctinfo);
1452         int ret;
1453         struct nf_conntrack_expect *exp;
1454         typeof(set_sig_addr_hook) set_sig_addr;
1455 
1456         pr_debug("nf_ct_ras: RCF\n");
1457 
1458         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1459         if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1460             ct->status & IPS_NAT_MASK) {
1461                 ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1462                                         rcf->callSignalAddress.item,
1463                                         rcf->callSignalAddress.count);
1464                 if (ret < 0)
1465                         return -1;
1466         }
1467 
1468         if (rcf->options & eRegistrationConfirm_timeToLive) {
1469                 pr_debug("nf_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive);
1470                 info->timeout = rcf->timeToLive;
1471         }
1472 
1473         if (info->timeout > 0) {
1474                 pr_debug("nf_ct_ras: set RAS connection timeout to "
1475                          "%u seconds\n", info->timeout);
1476                 nf_ct_refresh(ct, skb, info->timeout * HZ);
1477 
1478                 /* Set expect timeout */
1479                 spin_lock_bh(&nf_conntrack_lock);
1480                 exp = find_expect(ct, &ct->tuplehash[dir].tuple.dst.u3,
1481                                   info->sig_port[!dir]);
1482                 if (exp) {
1483                         pr_debug("nf_ct_ras: set Q.931 expect "
1484                                  "timeout to %u seconds for",
1485                                  info->timeout);
1486                         nf_ct_dump_tuple(&exp->tuple);
1487                         set_expect_timeout(exp, info->timeout);
1488                 }
1489                 spin_unlock_bh(&nf_conntrack_lock);
1490         }
1491 
1492         return 0;
1493 }
1494 
1495 /****************************************************************************/
1496 static int process_urq(struct sk_buff *skb, struct nf_conn *ct,
1497                        enum ip_conntrack_info ctinfo,
1498                        unsigned int protoff,
1499                        unsigned char **data, UnregistrationRequest *urq)
1500 {
1501         struct nf_ct_h323_master *info = nfct_help_data(ct);
1502         int dir = CTINFO2DIR(ctinfo);
1503         int ret;
1504         typeof(set_sig_addr_hook) set_sig_addr;
1505 
1506         pr_debug("nf_ct_ras: URQ\n");
1507 
1508         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1509         if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1510             ct->status & IPS_NAT_MASK) {
1511                 ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1512                                    urq->callSignalAddress.item,
1513                                    urq->callSignalAddress.count);
1514                 if (ret < 0)
1515                         return -1;
1516         }
1517 
1518         /* Clear old expect */
1519         nf_ct_remove_expectations(ct);
1520         info->sig_port[dir] = 0;
1521         info->sig_port[!dir] = 0;
1522 
1523         /* Give it 30 seconds for UCF or URJ */
1524         nf_ct_refresh(ct, skb, 30 * HZ);
1525 
1526         return 0;
1527 }
1528 
1529 /****************************************************************************/
1530 static int process_arq(struct sk_buff *skb, struct nf_conn *ct,
1531                        enum ip_conntrack_info ctinfo,
1532                        unsigned int protoff,
1533                        unsigned char **data, AdmissionRequest *arq)
1534 {
1535         const struct nf_ct_h323_master *info = nfct_help_data(ct);
1536         int dir = CTINFO2DIR(ctinfo);
1537         __be16 port;
1538         union nf_inet_addr addr;
1539         typeof(set_h225_addr_hook) set_h225_addr;
1540 
1541         pr_debug("nf_ct_ras: ARQ\n");
1542 
1543         set_h225_addr = rcu_dereference(set_h225_addr_hook);
1544         if ((arq->options & eAdmissionRequest_destCallSignalAddress) &&
1545             get_h225_addr(ct, *data, &arq->destCallSignalAddress,
1546                           &addr, &port) &&
1547             !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1548             port == info->sig_port[dir] &&
1549             nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1550             set_h225_addr && ct->status & IPS_NAT_MASK) {
1551                 /* Answering ARQ */
1552                 return set_h225_addr(skb, protoff, data, 0,
1553                                      &arq->destCallSignalAddress,
1554                                      &ct->tuplehash[!dir].tuple.dst.u3,
1555                                      info->sig_port[!dir]);
1556         }
1557 
1558         if ((arq->options & eAdmissionRequest_srcCallSignalAddress) &&
1559             get_h225_addr(ct, *data, &arq->srcCallSignalAddress,
1560                           &addr, &port) &&
1561             !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1562             set_h225_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1563             ct->status & IPS_NAT_MASK) {
1564                 /* Calling ARQ */
1565                 return set_h225_addr(skb, protoff, data, 0,
1566                                      &arq->srcCallSignalAddress,
1567                                      &ct->tuplehash[!dir].tuple.dst.u3,
1568                                      port);
1569         }
1570 
1571         return 0;
1572 }
1573 
1574 /****************************************************************************/
1575 static int process_acf(struct sk_buff *skb, struct nf_conn *ct,
1576                        enum ip_conntrack_info ctinfo,
1577                        unsigned int protoff,
1578                        unsigned char **data, AdmissionConfirm *acf)
1579 {
1580         int dir = CTINFO2DIR(ctinfo);
1581         int ret = 0;
1582         __be16 port;
1583         union nf_inet_addr addr;
1584         struct nf_conntrack_expect *exp;
1585         typeof(set_sig_addr_hook) set_sig_addr;
1586 
1587         pr_debug("nf_ct_ras: ACF\n");
1588 
1589         if (!get_h225_addr(ct, *data, &acf->destCallSignalAddress,
1590                            &addr, &port))
1591                 return 0;
1592 
1593         if (!memcmp(&addr, &ct->tuplehash[dir].tuple.dst.u3, sizeof(addr))) {
1594                 /* Answering ACF */
1595                 set_sig_addr = rcu_dereference(set_sig_addr_hook);
1596                 if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1597                     ct->status & IPS_NAT_MASK)
1598                         return set_sig_addr(skb, ct, ctinfo, protoff, data,
1599                                             &acf->destCallSignalAddress, 1);
1600                 return 0;
1601         }
1602 
1603         /* Need new expect */
1604         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1605                 return -1;
1606         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1607                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1608                           IPPROTO_TCP, NULL, &port);
1609         exp->flags = NF_CT_EXPECT_PERMANENT;
1610         exp->helper = nf_conntrack_helper_q931;
1611 
1612         if (nf_ct_expect_related(exp) == 0) {
1613                 pr_debug("nf_ct_ras: expect Q.931 ");
1614                 nf_ct_dump_tuple(&exp->tuple);
1615         } else
1616                 ret = -1;
1617 
1618         nf_ct_expect_put(exp);
1619 
1620         return ret;
1621 }
1622 
1623 /****************************************************************************/
1624 static int process_lrq(struct sk_buff *skb, struct nf_conn *ct,
1625                        enum ip_conntrack_info ctinfo,
1626                        unsigned int protoff,
1627                        unsigned char **data, LocationRequest *lrq)
1628 {
1629         typeof(set_ras_addr_hook) set_ras_addr;
1630 
1631         pr_debug("nf_ct_ras: LRQ\n");
1632 
1633         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1634         if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1635             ct->status & IPS_NAT_MASK)
1636                 return set_ras_addr(skb, ct, ctinfo, protoff, data,
1637                                     &lrq->replyAddress, 1);
1638         return 0;
1639 }
1640 
1641 /****************************************************************************/
1642 static int process_lcf(struct sk_buff *skb, struct nf_conn *ct,
1643                        enum ip_conntrack_info ctinfo,
1644                        unsigned int protoff,
1645                        unsigned char **data, LocationConfirm *lcf)
1646 {
1647         int dir = CTINFO2DIR(ctinfo);
1648         int ret = 0;
1649         __be16 port;
1650         union nf_inet_addr addr;
1651         struct nf_conntrack_expect *exp;
1652 
1653         pr_debug("nf_ct_ras: LCF\n");
1654 
1655         if (!get_h225_addr(ct, *data, &lcf->callSignalAddress,
1656                            &addr, &port))
1657                 return 0;
1658 
1659         /* Need new expect for call signal */
1660         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1661                 return -1;
1662         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1663                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1664                           IPPROTO_TCP, NULL, &port);
1665         exp->flags = NF_CT_EXPECT_PERMANENT;
1666         exp->helper = nf_conntrack_helper_q931;
1667 
1668         if (nf_ct_expect_related(exp) == 0) {
1669                 pr_debug("nf_ct_ras: expect Q.931 ");
1670                 nf_ct_dump_tuple(&exp->tuple);
1671         } else
1672                 ret = -1;
1673 
1674         nf_ct_expect_put(exp);
1675 
1676         /* Ignore rasAddress */
1677 
1678         return ret;
1679 }
1680 
1681 /****************************************************************************/
1682 static int process_irr(struct sk_buff *skb, struct nf_conn *ct,
1683                        enum ip_conntrack_info ctinfo,
1684                        unsigned int protoff,
1685                        unsigned char **data, InfoRequestResponse *irr)
1686 {
1687         int ret;
1688         typeof(set_ras_addr_hook) set_ras_addr;
1689         typeof(set_sig_addr_hook) set_sig_addr;
1690 
1691         pr_debug("nf_ct_ras: IRR\n");
1692 
1693         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1694         if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1695             ct->status & IPS_NAT_MASK) {
1696                 ret = set_ras_addr(skb, ct, ctinfo, protoff, data,
1697                                    &irr->rasAddress, 1);
1698                 if (ret < 0)
1699                         return -1;
1700         }
1701 
1702         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1703         if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1704             ct->status & IPS_NAT_MASK) {
1705                 ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1706                                         irr->callSignalAddress.item,
1707                                         irr->callSignalAddress.count);
1708                 if (ret < 0)
1709                         return -1;
1710         }
1711 
1712         return 0;
1713 }
1714 
1715 /****************************************************************************/
1716 static int process_ras(struct sk_buff *skb, struct nf_conn *ct,
1717                        enum ip_conntrack_info ctinfo,
1718                        unsigned int protoff,
1719                        unsigned char **data, RasMessage *ras)
1720 {
1721         switch (ras->choice) {
1722         case eRasMessage_gatekeeperRequest:
1723                 return process_grq(skb, ct, ctinfo, protoff, data,
1724                                    &ras->gatekeeperRequest);
1725         case eRasMessage_gatekeeperConfirm:
1726                 return process_gcf(skb, ct, ctinfo, protoff, data,
1727                                    &ras->gatekeeperConfirm);
1728         case eRasMessage_registrationRequest:
1729                 return process_rrq(skb, ct, ctinfo, protoff, data,
1730                                    &ras->registrationRequest);
1731         case eRasMessage_registrationConfirm:
1732                 return process_rcf(skb, ct, ctinfo, protoff, data,
1733                                    &ras->registrationConfirm);
1734         case eRasMessage_unregistrationRequest:
1735                 return process_urq(skb, ct, ctinfo, protoff, data,
1736                                    &ras->unregistrationRequest);
1737         case eRasMessage_admissionRequest:
1738                 return process_arq(skb, ct, ctinfo, protoff, data,
1739                                    &ras->admissionRequest);
1740         case eRasMessage_admissionConfirm:
1741                 return process_acf(skb, ct, ctinfo, protoff, data,
1742                                    &ras->admissionConfirm);
1743         case eRasMessage_locationRequest:
1744                 return process_lrq(skb, ct, ctinfo, protoff, data,
1745                                    &ras->locationRequest);
1746         case eRasMessage_locationConfirm:
1747                 return process_lcf(skb, ct, ctinfo, protoff, data,
1748                                    &ras->locationConfirm);
1749         case eRasMessage_infoRequestResponse:
1750                 return process_irr(skb, ct, ctinfo, protoff, data,
1751                                    &ras->infoRequestResponse);
1752         default:
1753                 pr_debug("nf_ct_ras: RAS message %d\n", ras->choice);
1754                 break;
1755         }
1756 
1757         return 0;
1758 }
1759 
1760 /****************************************************************************/
1761 static int ras_help(struct sk_buff *skb, unsigned int protoff,
1762                     struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1763 {
1764         static RasMessage ras;
1765         unsigned char *data;
1766         int datalen = 0;
1767         int ret;
1768 
1769         pr_debug("nf_ct_ras: skblen = %u\n", skb->len);
1770 
1771         spin_lock_bh(&nf_h323_lock);
1772 
1773         /* Get UDP data */
1774         data = get_udp_data(skb, protoff, &datalen);
1775         if (data == NULL)
1776                 goto accept;
1777         pr_debug("nf_ct_ras: RAS message len=%d ", datalen);
1778         nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1779 
1780         /* Decode RAS message */
1781         ret = DecodeRasMessage(data, datalen, &ras);
1782         if (ret < 0) {
1783                 pr_debug("nf_ct_ras: decoding error: %s\n",
1784                          ret == H323_ERROR_BOUND ?
1785                          "out of bound" : "out of range");
1786                 goto accept;
1787         }
1788 
1789         /* Process RAS message */
1790         if (process_ras(skb, ct, ctinfo, protoff, &data, &ras) < 0)
1791                 goto drop;
1792 
1793       accept:
1794         spin_unlock_bh(&nf_h323_lock);
1795         return NF_ACCEPT;
1796 
1797       drop:
1798         spin_unlock_bh(&nf_h323_lock);
1799         nf_ct_helper_log(skb, ct, "cannot process RAS message");
1800         return NF_DROP;
1801 }
1802 
1803 /****************************************************************************/
1804 static const struct nf_conntrack_expect_policy ras_exp_policy = {
1805         .max_expected           = 32,
1806         .timeout                = 240,
1807 };
1808 
1809 static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = {
1810         {
1811                 .name                   = "RAS",
1812                 .me                     = THIS_MODULE,
1813                 .data_len               = sizeof(struct nf_ct_h323_master),
1814                 .tuple.src.l3num        = AF_INET,
1815                 .tuple.src.u.udp.port   = cpu_to_be16(RAS_PORT),
1816                 .tuple.dst.protonum     = IPPROTO_UDP,
1817                 .help                   = ras_help,
1818                 .expect_policy          = &ras_exp_policy,
1819         },
1820         {
1821                 .name                   = "RAS",
1822                 .me                     = THIS_MODULE,
1823                 .data_len               = sizeof(struct nf_ct_h323_master),
1824                 .tuple.src.l3num        = AF_INET6,
1825                 .tuple.src.u.udp.port   = cpu_to_be16(RAS_PORT),
1826                 .tuple.dst.protonum     = IPPROTO_UDP,
1827                 .help                   = ras_help,
1828                 .expect_policy          = &ras_exp_policy,
1829         },
1830 };
1831 
1832 /****************************************************************************/
1833 static void __exit nf_conntrack_h323_fini(void)
1834 {
1835         nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[1]);
1836         nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1837         nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1838         nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1839         nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1840         kfree(h323_buffer);
1841         pr_debug("nf_ct_h323: fini\n");
1842 }
1843 
1844 /****************************************************************************/
1845 static int __init nf_conntrack_h323_init(void)
1846 {
1847         int ret;
1848 
1849         h323_buffer = kmalloc(65536, GFP_KERNEL);
1850         if (!h323_buffer)
1851                 return -ENOMEM;
1852         ret = nf_conntrack_helper_register(&nf_conntrack_helper_h245);
1853         if (ret < 0)
1854                 goto err1;
1855         ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[0]);
1856         if (ret < 0)
1857                 goto err2;
1858         ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[1]);
1859         if (ret < 0)
1860                 goto err3;
1861         ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[0]);
1862         if (ret < 0)
1863                 goto err4;
1864         ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[1]);
1865         if (ret < 0)
1866                 goto err5;
1867         pr_debug("nf_ct_h323: init success\n");
1868         return 0;
1869 
1870 err5:
1871         nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1872 err4:
1873         nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1874 err3:
1875         nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1876 err2:
1877         nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1878 err1:
1879         kfree(h323_buffer);
1880         return ret;
1881 }
1882 
1883 /****************************************************************************/
1884 module_init(nf_conntrack_h323_init);
1885 module_exit(nf_conntrack_h323_fini);
1886 
1887 EXPORT_SYMBOL_GPL(get_h225_addr);
1888 EXPORT_SYMBOL_GPL(set_h245_addr_hook);
1889 EXPORT_SYMBOL_GPL(set_h225_addr_hook);
1890 EXPORT_SYMBOL_GPL(set_sig_addr_hook);
1891 EXPORT_SYMBOL_GPL(set_ras_addr_hook);
1892 EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook);
1893 EXPORT_SYMBOL_GPL(nat_t120_hook);
1894 EXPORT_SYMBOL_GPL(nat_h245_hook);
1895 EXPORT_SYMBOL_GPL(nat_callforwarding_hook);
1896 EXPORT_SYMBOL_GPL(nat_q931_hook);
1897 
1898 MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>");
1899 MODULE_DESCRIPTION("H.323 connection tracking helper");
1900 MODULE_LICENSE("GPL");
1901 MODULE_ALIAS("ip_conntrack_h323");
1902 MODULE_ALIAS_NFCT_HELPER("RAS");
1903 MODULE_ALIAS_NFCT_HELPER("Q.931");
1904 MODULE_ALIAS_NFCT_HELPER("H.245");
1905 

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