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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(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_thresh */
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 expect_q931(struct sk_buff *skb, struct nf_conn *ct,
1277                        enum ip_conntrack_info ctinfo,
1278                        unsigned int protoff, unsigned char **data,
1279                        TransportAddress *taddr, int count)
1280 {
1281         struct nf_ct_h323_master *info = nfct_help_data(ct);
1282         int dir = CTINFO2DIR(ctinfo);
1283         int ret = 0;
1284         int i;
1285         __be16 port;
1286         union nf_inet_addr addr;
1287         struct nf_conntrack_expect *exp;
1288         typeof(nat_q931_hook) nat_q931;
1289 
1290         /* Look for the first related address */
1291         for (i = 0; i < count; i++) {
1292                 if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) &&
1293                     memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3,
1294                            sizeof(addr)) == 0 && port != 0)
1295                         break;
1296         }
1297 
1298         if (i >= count)         /* Not found */
1299                 return 0;
1300 
1301         /* Create expect for Q.931 */
1302         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1303                 return -1;
1304         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1305                           gkrouted_only ? /* only accept calls from GK? */
1306                                 &ct->tuplehash[!dir].tuple.src.u3 : NULL,
1307                           &ct->tuplehash[!dir].tuple.dst.u3,
1308                           IPPROTO_TCP, NULL, &port);
1309         exp->helper = nf_conntrack_helper_q931;
1310         exp->flags = NF_CT_EXPECT_PERMANENT;    /* Accept multiple calls */
1311 
1312         nat_q931 = rcu_dereference(nat_q931_hook);
1313         if (nat_q931 && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1314             ct->status & IPS_NAT_MASK) {        /* Need NAT */
1315                 ret = nat_q931(skb, ct, ctinfo, protoff, data,
1316                                taddr, i, port, exp);
1317         } else {                /* Conntrack only */
1318                 if (nf_ct_expect_related(exp) == 0) {
1319                         pr_debug("nf_ct_ras: expect Q.931 ");
1320                         nf_ct_dump_tuple(&exp->tuple);
1321 
1322                         /* Save port for looking up expect in processing RCF */
1323                         info->sig_port[dir] = port;
1324                 } else
1325                         ret = -1;
1326         }
1327 
1328         nf_ct_expect_put(exp);
1329 
1330         return ret;
1331 }
1332 
1333 /****************************************************************************/
1334 static int process_grq(struct sk_buff *skb, struct nf_conn *ct,
1335                        enum ip_conntrack_info ctinfo,
1336                        unsigned int protoff,
1337                        unsigned char **data, GatekeeperRequest *grq)
1338 {
1339         typeof(set_ras_addr_hook) set_ras_addr;
1340 
1341         pr_debug("nf_ct_ras: GRQ\n");
1342 
1343         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1344         if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1345             ct->status & IPS_NAT_MASK)  /* NATed */
1346                 return set_ras_addr(skb, ct, ctinfo, protoff, data,
1347                                     &grq->rasAddress, 1);
1348         return 0;
1349 }
1350 
1351 /****************************************************************************/
1352 static int process_gcf(struct sk_buff *skb, struct nf_conn *ct,
1353                        enum ip_conntrack_info ctinfo,
1354                        unsigned int protoff,
1355                        unsigned char **data, GatekeeperConfirm *gcf)
1356 {
1357         int dir = CTINFO2DIR(ctinfo);
1358         int ret = 0;
1359         __be16 port;
1360         union nf_inet_addr addr;
1361         struct nf_conntrack_expect *exp;
1362 
1363         pr_debug("nf_ct_ras: GCF\n");
1364 
1365         if (!get_h225_addr(ct, *data, &gcf->rasAddress, &addr, &port))
1366                 return 0;
1367 
1368         /* Registration port is the same as discovery port */
1369         if (!memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1370             port == ct->tuplehash[dir].tuple.src.u.udp.port)
1371                 return 0;
1372 
1373         /* Avoid RAS expectation loops. A GCF is never expected. */
1374         if (test_bit(IPS_EXPECTED_BIT, &ct->status))
1375                 return 0;
1376 
1377         /* Need new expect */
1378         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1379                 return -1;
1380         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1381                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1382                           IPPROTO_UDP, NULL, &port);
1383         exp->helper = nf_conntrack_helper_ras;
1384 
1385         if (nf_ct_expect_related(exp) == 0) {
1386                 pr_debug("nf_ct_ras: expect RAS ");
1387                 nf_ct_dump_tuple(&exp->tuple);
1388         } else
1389                 ret = -1;
1390 
1391         nf_ct_expect_put(exp);
1392 
1393         return ret;
1394 }
1395 
1396 /****************************************************************************/
1397 static int process_rrq(struct sk_buff *skb, struct nf_conn *ct,
1398                        enum ip_conntrack_info ctinfo,
1399                        unsigned int protoff,
1400                        unsigned char **data, RegistrationRequest *rrq)
1401 {
1402         struct nf_ct_h323_master *info = nfct_help_data(ct);
1403         int ret;
1404         typeof(set_ras_addr_hook) set_ras_addr;
1405 
1406         pr_debug("nf_ct_ras: RRQ\n");
1407 
1408         ret = expect_q931(skb, ct, ctinfo, protoff, data,
1409                           rrq->callSignalAddress.item,
1410                           rrq->callSignalAddress.count);
1411         if (ret < 0)
1412                 return -1;
1413 
1414         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1415         if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1416             ct->status & IPS_NAT_MASK) {
1417                 ret = set_ras_addr(skb, ct, ctinfo, protoff, data,
1418                                    rrq->rasAddress.item,
1419                                    rrq->rasAddress.count);
1420                 if (ret < 0)
1421                         return -1;
1422         }
1423 
1424         if (rrq->options & eRegistrationRequest_timeToLive) {
1425                 pr_debug("nf_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive);
1426                 info->timeout = rrq->timeToLive;
1427         } else
1428                 info->timeout = default_rrq_ttl;
1429 
1430         return 0;
1431 }
1432 
1433 /****************************************************************************/
1434 static int process_rcf(struct sk_buff *skb, struct nf_conn *ct,
1435                        enum ip_conntrack_info ctinfo,
1436                        unsigned int protoff,
1437                        unsigned char **data, RegistrationConfirm *rcf)
1438 {
1439         struct nf_ct_h323_master *info = nfct_help_data(ct);
1440         int dir = CTINFO2DIR(ctinfo);
1441         int ret;
1442         struct nf_conntrack_expect *exp;
1443         typeof(set_sig_addr_hook) set_sig_addr;
1444 
1445         pr_debug("nf_ct_ras: RCF\n");
1446 
1447         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1448         if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1449             ct->status & IPS_NAT_MASK) {
1450                 ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1451                                         rcf->callSignalAddress.item,
1452                                         rcf->callSignalAddress.count);
1453                 if (ret < 0)
1454                         return -1;
1455         }
1456 
1457         if (rcf->options & eRegistrationConfirm_timeToLive) {
1458                 pr_debug("nf_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive);
1459                 info->timeout = rcf->timeToLive;
1460         }
1461 
1462         if (info->timeout > 0) {
1463                 pr_debug("nf_ct_ras: set RAS connection timeout to "
1464                          "%u seconds\n", info->timeout);
1465                 nf_ct_refresh(ct, skb, info->timeout * HZ);
1466 
1467                 /* Set expect timeout */
1468                 spin_lock_bh(&nf_conntrack_expect_lock);
1469                 exp = find_expect(ct, &ct->tuplehash[dir].tuple.dst.u3,
1470                                   info->sig_port[!dir]);
1471                 if (exp) {
1472                         pr_debug("nf_ct_ras: set Q.931 expect "
1473                                  "timeout to %u seconds for",
1474                                  info->timeout);
1475                         nf_ct_dump_tuple(&exp->tuple);
1476                         mod_timer_pending(&exp->timeout,
1477                                           jiffies + info->timeout * HZ);
1478                 }
1479                 spin_unlock_bh(&nf_conntrack_expect_lock);
1480         }
1481 
1482         return 0;
1483 }
1484 
1485 /****************************************************************************/
1486 static int process_urq(struct sk_buff *skb, struct nf_conn *ct,
1487                        enum ip_conntrack_info ctinfo,
1488                        unsigned int protoff,
1489                        unsigned char **data, UnregistrationRequest *urq)
1490 {
1491         struct nf_ct_h323_master *info = nfct_help_data(ct);
1492         int dir = CTINFO2DIR(ctinfo);
1493         int ret;
1494         typeof(set_sig_addr_hook) set_sig_addr;
1495 
1496         pr_debug("nf_ct_ras: URQ\n");
1497 
1498         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1499         if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1500             ct->status & IPS_NAT_MASK) {
1501                 ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1502                                    urq->callSignalAddress.item,
1503                                    urq->callSignalAddress.count);
1504                 if (ret < 0)
1505                         return -1;
1506         }
1507 
1508         /* Clear old expect */
1509         nf_ct_remove_expectations(ct);
1510         info->sig_port[dir] = 0;
1511         info->sig_port[!dir] = 0;
1512 
1513         /* Give it 30 seconds for UCF or URJ */
1514         nf_ct_refresh(ct, skb, 30 * HZ);
1515 
1516         return 0;
1517 }
1518 
1519 /****************************************************************************/
1520 static int process_arq(struct sk_buff *skb, struct nf_conn *ct,
1521                        enum ip_conntrack_info ctinfo,
1522                        unsigned int protoff,
1523                        unsigned char **data, AdmissionRequest *arq)
1524 {
1525         const struct nf_ct_h323_master *info = nfct_help_data(ct);
1526         int dir = CTINFO2DIR(ctinfo);
1527         __be16 port;
1528         union nf_inet_addr addr;
1529         typeof(set_h225_addr_hook) set_h225_addr;
1530 
1531         pr_debug("nf_ct_ras: ARQ\n");
1532 
1533         set_h225_addr = rcu_dereference(set_h225_addr_hook);
1534         if ((arq->options & eAdmissionRequest_destCallSignalAddress) &&
1535             get_h225_addr(ct, *data, &arq->destCallSignalAddress,
1536                           &addr, &port) &&
1537             !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1538             port == info->sig_port[dir] &&
1539             nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1540             set_h225_addr && ct->status & IPS_NAT_MASK) {
1541                 /* Answering ARQ */
1542                 return set_h225_addr(skb, protoff, data, 0,
1543                                      &arq->destCallSignalAddress,
1544                                      &ct->tuplehash[!dir].tuple.dst.u3,
1545                                      info->sig_port[!dir]);
1546         }
1547 
1548         if ((arq->options & eAdmissionRequest_srcCallSignalAddress) &&
1549             get_h225_addr(ct, *data, &arq->srcCallSignalAddress,
1550                           &addr, &port) &&
1551             !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1552             set_h225_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1553             ct->status & IPS_NAT_MASK) {
1554                 /* Calling ARQ */
1555                 return set_h225_addr(skb, protoff, data, 0,
1556                                      &arq->srcCallSignalAddress,
1557                                      &ct->tuplehash[!dir].tuple.dst.u3,
1558                                      port);
1559         }
1560 
1561         return 0;
1562 }
1563 
1564 /****************************************************************************/
1565 static int process_acf(struct sk_buff *skb, struct nf_conn *ct,
1566                        enum ip_conntrack_info ctinfo,
1567                        unsigned int protoff,
1568                        unsigned char **data, AdmissionConfirm *acf)
1569 {
1570         int dir = CTINFO2DIR(ctinfo);
1571         int ret = 0;
1572         __be16 port;
1573         union nf_inet_addr addr;
1574         struct nf_conntrack_expect *exp;
1575         typeof(set_sig_addr_hook) set_sig_addr;
1576 
1577         pr_debug("nf_ct_ras: ACF\n");
1578 
1579         if (!get_h225_addr(ct, *data, &acf->destCallSignalAddress,
1580                            &addr, &port))
1581                 return 0;
1582 
1583         if (!memcmp(&addr, &ct->tuplehash[dir].tuple.dst.u3, sizeof(addr))) {
1584                 /* Answering ACF */
1585                 set_sig_addr = rcu_dereference(set_sig_addr_hook);
1586                 if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1587                     ct->status & IPS_NAT_MASK)
1588                         return set_sig_addr(skb, ct, ctinfo, protoff, data,
1589                                             &acf->destCallSignalAddress, 1);
1590                 return 0;
1591         }
1592 
1593         /* Need new expect */
1594         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1595                 return -1;
1596         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1597                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1598                           IPPROTO_TCP, NULL, &port);
1599         exp->flags = NF_CT_EXPECT_PERMANENT;
1600         exp->helper = nf_conntrack_helper_q931;
1601 
1602         if (nf_ct_expect_related(exp) == 0) {
1603                 pr_debug("nf_ct_ras: expect Q.931 ");
1604                 nf_ct_dump_tuple(&exp->tuple);
1605         } else
1606                 ret = -1;
1607 
1608         nf_ct_expect_put(exp);
1609 
1610         return ret;
1611 }
1612 
1613 /****************************************************************************/
1614 static int process_lrq(struct sk_buff *skb, struct nf_conn *ct,
1615                        enum ip_conntrack_info ctinfo,
1616                        unsigned int protoff,
1617                        unsigned char **data, LocationRequest *lrq)
1618 {
1619         typeof(set_ras_addr_hook) set_ras_addr;
1620 
1621         pr_debug("nf_ct_ras: LRQ\n");
1622 
1623         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1624         if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1625             ct->status & IPS_NAT_MASK)
1626                 return set_ras_addr(skb, ct, ctinfo, protoff, data,
1627                                     &lrq->replyAddress, 1);
1628         return 0;
1629 }
1630 
1631 /****************************************************************************/
1632 static int process_lcf(struct sk_buff *skb, struct nf_conn *ct,
1633                        enum ip_conntrack_info ctinfo,
1634                        unsigned int protoff,
1635                        unsigned char **data, LocationConfirm *lcf)
1636 {
1637         int dir = CTINFO2DIR(ctinfo);
1638         int ret = 0;
1639         __be16 port;
1640         union nf_inet_addr addr;
1641         struct nf_conntrack_expect *exp;
1642 
1643         pr_debug("nf_ct_ras: LCF\n");
1644 
1645         if (!get_h225_addr(ct, *data, &lcf->callSignalAddress,
1646                            &addr, &port))
1647                 return 0;
1648 
1649         /* Need new expect for call signal */
1650         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1651                 return -1;
1652         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1653                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1654                           IPPROTO_TCP, NULL, &port);
1655         exp->flags = NF_CT_EXPECT_PERMANENT;
1656         exp->helper = nf_conntrack_helper_q931;
1657 
1658         if (nf_ct_expect_related(exp) == 0) {
1659                 pr_debug("nf_ct_ras: expect Q.931 ");
1660                 nf_ct_dump_tuple(&exp->tuple);
1661         } else
1662                 ret = -1;
1663 
1664         nf_ct_expect_put(exp);
1665 
1666         /* Ignore rasAddress */
1667 
1668         return ret;
1669 }
1670 
1671 /****************************************************************************/
1672 static int process_irr(struct sk_buff *skb, struct nf_conn *ct,
1673                        enum ip_conntrack_info ctinfo,
1674                        unsigned int protoff,
1675                        unsigned char **data, InfoRequestResponse *irr)
1676 {
1677         int ret;
1678         typeof(set_ras_addr_hook) set_ras_addr;
1679         typeof(set_sig_addr_hook) set_sig_addr;
1680 
1681         pr_debug("nf_ct_ras: IRR\n");
1682 
1683         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1684         if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1685             ct->status & IPS_NAT_MASK) {
1686                 ret = set_ras_addr(skb, ct, ctinfo, protoff, data,
1687                                    &irr->rasAddress, 1);
1688                 if (ret < 0)
1689                         return -1;
1690         }
1691 
1692         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1693         if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1694             ct->status & IPS_NAT_MASK) {
1695                 ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1696                                         irr->callSignalAddress.item,
1697                                         irr->callSignalAddress.count);
1698                 if (ret < 0)
1699                         return -1;
1700         }
1701 
1702         return 0;
1703 }
1704 
1705 /****************************************************************************/
1706 static int process_ras(struct sk_buff *skb, struct nf_conn *ct,
1707                        enum ip_conntrack_info ctinfo,
1708                        unsigned int protoff,
1709                        unsigned char **data, RasMessage *ras)
1710 {
1711         switch (ras->choice) {
1712         case eRasMessage_gatekeeperRequest:
1713                 return process_grq(skb, ct, ctinfo, protoff, data,
1714                                    &ras->gatekeeperRequest);
1715         case eRasMessage_gatekeeperConfirm:
1716                 return process_gcf(skb, ct, ctinfo, protoff, data,
1717                                    &ras->gatekeeperConfirm);
1718         case eRasMessage_registrationRequest:
1719                 return process_rrq(skb, ct, ctinfo, protoff, data,
1720                                    &ras->registrationRequest);
1721         case eRasMessage_registrationConfirm:
1722                 return process_rcf(skb, ct, ctinfo, protoff, data,
1723                                    &ras->registrationConfirm);
1724         case eRasMessage_unregistrationRequest:
1725                 return process_urq(skb, ct, ctinfo, protoff, data,
1726                                    &ras->unregistrationRequest);
1727         case eRasMessage_admissionRequest:
1728                 return process_arq(skb, ct, ctinfo, protoff, data,
1729                                    &ras->admissionRequest);
1730         case eRasMessage_admissionConfirm:
1731                 return process_acf(skb, ct, ctinfo, protoff, data,
1732                                    &ras->admissionConfirm);
1733         case eRasMessage_locationRequest:
1734                 return process_lrq(skb, ct, ctinfo, protoff, data,
1735                                    &ras->locationRequest);
1736         case eRasMessage_locationConfirm:
1737                 return process_lcf(skb, ct, ctinfo, protoff, data,
1738                                    &ras->locationConfirm);
1739         case eRasMessage_infoRequestResponse:
1740                 return process_irr(skb, ct, ctinfo, protoff, data,
1741                                    &ras->infoRequestResponse);
1742         default:
1743                 pr_debug("nf_ct_ras: RAS message %d\n", ras->choice);
1744                 break;
1745         }
1746 
1747         return 0;
1748 }
1749 
1750 /****************************************************************************/
1751 static int ras_help(struct sk_buff *skb, unsigned int protoff,
1752                     struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1753 {
1754         static RasMessage ras;
1755         unsigned char *data;
1756         int datalen = 0;
1757         int ret;
1758 
1759         pr_debug("nf_ct_ras: skblen = %u\n", skb->len);
1760 
1761         spin_lock_bh(&nf_h323_lock);
1762 
1763         /* Get UDP data */
1764         data = get_udp_data(skb, protoff, &datalen);
1765         if (data == NULL)
1766                 goto accept;
1767         pr_debug("nf_ct_ras: RAS message len=%d ", datalen);
1768         nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1769 
1770         /* Decode RAS message */
1771         ret = DecodeRasMessage(data, datalen, &ras);
1772         if (ret < 0) {
1773                 pr_debug("nf_ct_ras: decoding error: %s\n",
1774                          ret == H323_ERROR_BOUND ?
1775                          "out of bound" : "out of range");
1776                 goto accept;
1777         }
1778 
1779         /* Process RAS message */
1780         if (process_ras(skb, ct, ctinfo, protoff, &data, &ras) < 0)
1781                 goto drop;
1782 
1783       accept:
1784         spin_unlock_bh(&nf_h323_lock);
1785         return NF_ACCEPT;
1786 
1787       drop:
1788         spin_unlock_bh(&nf_h323_lock);
1789         nf_ct_helper_log(skb, ct, "cannot process RAS message");
1790         return NF_DROP;
1791 }
1792 
1793 /****************************************************************************/
1794 static const struct nf_conntrack_expect_policy ras_exp_policy = {
1795         .max_expected           = 32,
1796         .timeout                = 240,
1797 };
1798 
1799 static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = {
1800         {
1801                 .name                   = "RAS",
1802                 .me                     = THIS_MODULE,
1803                 .data_len               = sizeof(struct nf_ct_h323_master),
1804                 .tuple.src.l3num        = AF_INET,
1805                 .tuple.src.u.udp.port   = cpu_to_be16(RAS_PORT),
1806                 .tuple.dst.protonum     = IPPROTO_UDP,
1807                 .help                   = ras_help,
1808                 .expect_policy          = &ras_exp_policy,
1809         },
1810         {
1811                 .name                   = "RAS",
1812                 .me                     = THIS_MODULE,
1813                 .data_len               = sizeof(struct nf_ct_h323_master),
1814                 .tuple.src.l3num        = AF_INET6,
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 
1822 /****************************************************************************/
1823 static void __exit nf_conntrack_h323_fini(void)
1824 {
1825         nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[1]);
1826         nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1827         nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1828         nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1829         nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1830         kfree(h323_buffer);
1831         pr_debug("nf_ct_h323: fini\n");
1832 }
1833 
1834 /****************************************************************************/
1835 static int __init nf_conntrack_h323_init(void)
1836 {
1837         int ret;
1838 
1839         h323_buffer = kmalloc(65536, GFP_KERNEL);
1840         if (!h323_buffer)
1841                 return -ENOMEM;
1842         ret = nf_conntrack_helper_register(&nf_conntrack_helper_h245);
1843         if (ret < 0)
1844                 goto err1;
1845         ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[0]);
1846         if (ret < 0)
1847                 goto err2;
1848         ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[1]);
1849         if (ret < 0)
1850                 goto err3;
1851         ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[0]);
1852         if (ret < 0)
1853                 goto err4;
1854         ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[1]);
1855         if (ret < 0)
1856                 goto err5;
1857         pr_debug("nf_ct_h323: init success\n");
1858         return 0;
1859 
1860 err5:
1861         nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1862 err4:
1863         nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1864 err3:
1865         nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1866 err2:
1867         nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1868 err1:
1869         kfree(h323_buffer);
1870         return ret;
1871 }
1872 
1873 /****************************************************************************/
1874 module_init(nf_conntrack_h323_init);
1875 module_exit(nf_conntrack_h323_fini);
1876 
1877 EXPORT_SYMBOL_GPL(get_h225_addr);
1878 EXPORT_SYMBOL_GPL(set_h245_addr_hook);
1879 EXPORT_SYMBOL_GPL(set_h225_addr_hook);
1880 EXPORT_SYMBOL_GPL(set_sig_addr_hook);
1881 EXPORT_SYMBOL_GPL(set_ras_addr_hook);
1882 EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook);
1883 EXPORT_SYMBOL_GPL(nat_t120_hook);
1884 EXPORT_SYMBOL_GPL(nat_h245_hook);
1885 EXPORT_SYMBOL_GPL(nat_callforwarding_hook);
1886 EXPORT_SYMBOL_GPL(nat_q931_hook);
1887 
1888 MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>");
1889 MODULE_DESCRIPTION("H.323 connection tracking helper");
1890 MODULE_LICENSE("GPL");
1891 MODULE_ALIAS("ip_conntrack_h323");
1892 MODULE_ALIAS_NFCT_HELPER("RAS");
1893 MODULE_ALIAS_NFCT_HELPER("Q.931");
1894 MODULE_ALIAS_NFCT_HELPER("H.245");
1895 

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