net/netfilter/nf_conntrack_h323_main.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * H.323 connection tracking helper
   4  *
   5  * Copyright (c) 2006 Jing Min Zhao <zhaojingmin@users.sourceforge.net>
   6  * Copyright (c) 2006-2012 Patrick McHardy <kaber@trash.net>
   7  *
   8  * Based on the 'brute force' H.323 connection tracking module by
   9  * Jozsef Kadlecsik <kadlec@netfilter.org>
  10  *
  11  * For more information, please see http://nath323.sourceforge.net/
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/moduleparam.h>
  16 #include <linux/ctype.h>
  17 #include <linux/inet.h>
  18 #include <linux/in.h>
  19 #include <linux/ip.h>
  20 #include <linux/slab.h>
  21 #include <linux/udp.h>
  22 #include <linux/tcp.h>
  23 #include <linux/skbuff.h>
  24 #include <net/route.h>
  25 #include <net/ip6_route.h>
  26 #include <linux/netfilter_ipv6.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 static int get_tpkt_data(struct sk_buff *skb, unsigned int protoff,
 119                          struct nf_conn *ct, enum ip_conntrack_info ctinfo,
 120                          unsigned char **data, int *datalen, int *dataoff)
 121 {
 122         struct nf_ct_h323_master *info = nfct_help_data(ct);
 123         int dir = CTINFO2DIR(ctinfo);
 124         const struct tcphdr *th;
 125         struct tcphdr _tcph;
 126         int tcpdatalen;
 127         int tcpdataoff;
 128         unsigned char *tpkt;
 129         int tpktlen;
 130         int tpktoff;
 131
 132         /* Get TCP header */
 133         th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph);
 134         if (th == NULL)
 135                 return 0;
 136
 137         /* Get TCP data offset */
 138         tcpdataoff = protoff + th->doff * 4;
 139
 140         /* Get TCP data length */
 141         tcpdatalen = skb->len - tcpdataoff;
 142         if (tcpdatalen <= 0)    /* No TCP data */
 143                 goto clear_out;
 144
 145         if (*data == NULL) {    /* first TPKT */
 146                 /* Get first TPKT pointer */
 147                 tpkt = skb_header_pointer(skb, tcpdataoff, tcpdatalen,
 148                                           h323_buffer);
 149                 BUG_ON(tpkt == NULL);
 150
 151                 /* Validate TPKT identifier */
 152                 if (tcpdatalen < 4 || tpkt[0] != 0x03 || tpkt[1] != 0) {
 153                         /* Netmeeting sends TPKT header and data separately */
 154                         if (info->tpkt_len[dir] > 0) {
 155                                 pr_debug("nf_ct_h323: previous packet "
 156                                          "indicated separate TPKT data of %hu "
 157                                          "bytes\n", info->tpkt_len[dir]);
 158                                 if (info->tpkt_len[dir] <= tcpdatalen) {
 159                                         /* Yes, there was a TPKT header
 160                                          * received */
 161                                         *data = tpkt;
 162                                         *datalen = info->tpkt_len[dir];
 163                                         *dataoff = 0;
 164                                         goto out;
 165                                 }
 166
 167                                 /* Fragmented TPKT */
 168                                 pr_debug("nf_ct_h323: fragmented TPKT\n");
 169                                 goto clear_out;
 170                         }
 171
 172                         /* It is not even a TPKT */
 173                         return 0;
 174                 }
 175                 tpktoff = 0;
 176         } else {                /* Next TPKT */
 177                 tpktoff = *dataoff + *datalen;
 178                 tcpdatalen -= tpktoff;
 179                 if (tcpdatalen <= 4)    /* No more TPKT */
 180                         goto clear_out;
 181                 tpkt = *data + *datalen;
 182
 183                 /* Validate TPKT identifier */
 184                 if (tpkt[0] != 0x03 || tpkt[1] != 0)
 185                         goto clear_out;
 186         }
 187
 188         /* Validate TPKT length */
 189         tpktlen = tpkt[2] * 256 + tpkt[3];
 190         if (tpktlen < 4)
 191                 goto clear_out;
 192         if (tpktlen > tcpdatalen) {
 193                 if (tcpdatalen == 4) {  /* Separate TPKT header */
 194                         /* Netmeeting sends TPKT header and data separately */
 195                         pr_debug("nf_ct_h323: separate TPKT header indicates "
 196                                  "there will be TPKT data of %hu bytes\n",
 197                                  tpktlen - 4);
 198                         info->tpkt_len[dir] = tpktlen - 4;
 199                         return 0;
 200                 }
 201
 202                 pr_debug("nf_ct_h323: incomplete TPKT (fragmented?)\n");
 203                 goto clear_out;
 204         }
 205
 206         /* This is the encapsulated data */
 207         *data = tpkt + 4;
 208         *datalen = tpktlen - 4;
 209         *dataoff = tpktoff + 4;
 210
 211       out:
 212         /* Clear TPKT length */
 213         info->tpkt_len[dir] = 0;
 214         return 1;
 215
 216       clear_out:
 217         info->tpkt_len[dir] = 0;
 218         return 0;
 219 }
 220
 221 static int get_h245_addr(struct nf_conn *ct, const unsigned char *data,
 222                          H245_TransportAddress *taddr,
 223                          union nf_inet_addr *addr, __be16 *port)
 224 {
 225         const unsigned char *p;
 226         int len;
 227
 228         if (taddr->choice != eH245_TransportAddress_unicastAddress)
 229                 return 0;
 230
 231         switch (taddr->unicastAddress.choice) {
 232         case eUnicastAddress_iPAddress:
 233                 if (nf_ct_l3num(ct) != AF_INET)
 234                         return 0;
 235                 p = data + taddr->unicastAddress.iPAddress.network;
 236                 len = 4;
 237                 break;
 238         case eUnicastAddress_iP6Address:
 239                 if (nf_ct_l3num(ct) != AF_INET6)
 240                         return 0;
 241                 p = data + taddr->unicastAddress.iP6Address.network;
 242                 len = 16;
 243                 break;
 244         default:
 245                 return 0;
 246         }
 247
 248         memcpy(addr, p, len);
 249         memset((void *)addr + len, 0, sizeof(*addr) - len);
 250         memcpy(port, p + len, sizeof(__be16));
 251
 252         return 1;
 253 }
 254
 255 static int expect_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct,
 256                            enum ip_conntrack_info ctinfo,
 257                            unsigned int protoff,
 258                            unsigned char **data, int dataoff,
 259                            H245_TransportAddress *taddr)
 260 {
 261         int dir = CTINFO2DIR(ctinfo);
 262         int ret = 0;
 263         __be16 port;
 264         __be16 rtp_port, rtcp_port;
 265         union nf_inet_addr addr;
 266         struct nf_conntrack_expect *rtp_exp;
 267         struct nf_conntrack_expect *rtcp_exp;
 268         typeof(nat_rtp_rtcp_hook) nat_rtp_rtcp;
 269
 270         /* Read RTP or RTCP address */
 271         if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
 272             memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 273             port == 0)
 274                 return 0;
 275
 276         /* RTP port is even */
 277         rtp_port = port & ~htons(1);
 278         rtcp_port = port | htons(1);
 279
 280         /* Create expect for RTP */
 281         if ((rtp_exp = nf_ct_expect_alloc(ct)) == NULL)
 282                 return -1;
 283         nf_ct_expect_init(rtp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 284                           &ct->tuplehash[!dir].tuple.src.u3,
 285                           &ct->tuplehash[!dir].tuple.dst.u3,
 286                           IPPROTO_UDP, NULL, &rtp_port);
 287
 288         /* Create expect for RTCP */
 289         if ((rtcp_exp = nf_ct_expect_alloc(ct)) == NULL) {
 290                 nf_ct_expect_put(rtp_exp);
 291                 return -1;
 292         }
 293         nf_ct_expect_init(rtcp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 294                           &ct->tuplehash[!dir].tuple.src.u3,
 295                           &ct->tuplehash[!dir].tuple.dst.u3,
 296                           IPPROTO_UDP, NULL, &rtcp_port);
 297
 298         if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 299                    &ct->tuplehash[!dir].tuple.dst.u3,
 300                    sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 301                    (nat_rtp_rtcp = rcu_dereference(nat_rtp_rtcp_hook)) &&
 302                    nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 303                    ct->status & IPS_NAT_MASK) {
 304                 /* NAT needed */
 305                 ret = nat_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff,
 306                                    taddr, port, rtp_port, rtp_exp, rtcp_exp);
 307         } else {                /* Conntrack only */
 308                 if (nf_ct_expect_related(rtp_exp, 0) == 0) {
 309                         if (nf_ct_expect_related(rtcp_exp, 0) == 0) {
 310                                 pr_debug("nf_ct_h323: expect RTP ");
 311                                 nf_ct_dump_tuple(&rtp_exp->tuple);
 312                                 pr_debug("nf_ct_h323: expect RTCP ");
 313                                 nf_ct_dump_tuple(&rtcp_exp->tuple);
 314                         } else {
 315                                 nf_ct_unexpect_related(rtp_exp);
 316                                 ret = -1;
 317                         }
 318                 } else
 319                         ret = -1;
 320         }
 321
 322         nf_ct_expect_put(rtp_exp);
 323         nf_ct_expect_put(rtcp_exp);
 324
 325         return ret;
 326 }
 327
 328 static int expect_t120(struct sk_buff *skb,
 329                        struct nf_conn *ct,
 330                        enum ip_conntrack_info ctinfo,
 331                        unsigned int protoff,
 332                        unsigned char **data, int dataoff,
 333                        H245_TransportAddress *taddr)
 334 {
 335         int dir = CTINFO2DIR(ctinfo);
 336         int ret = 0;
 337         __be16 port;
 338         union nf_inet_addr addr;
 339         struct nf_conntrack_expect *exp;
 340         typeof(nat_t120_hook) nat_t120;
 341
 342         /* Read T.120 address */
 343         if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
 344             memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 345             port == 0)
 346                 return 0;
 347
 348         /* Create expect for T.120 connections */
 349         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 350                 return -1;
 351         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 352                           &ct->tuplehash[!dir].tuple.src.u3,
 353                           &ct->tuplehash[!dir].tuple.dst.u3,
 354                           IPPROTO_TCP, NULL, &port);
 355         exp->flags = NF_CT_EXPECT_PERMANENT;    /* Accept multiple channels */
 356
 357         if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 358                    &ct->tuplehash[!dir].tuple.dst.u3,
 359                    sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 360             (nat_t120 = rcu_dereference(nat_t120_hook)) &&
 361             nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 362             ct->status & IPS_NAT_MASK) {
 363                 /* NAT needed */
 364                 ret = nat_t120(skb, ct, ctinfo, protoff, data, dataoff, taddr,
 365                                port, exp);
 366         } else {                /* Conntrack only */
 367                 if (nf_ct_expect_related(exp, 0) == 0) {
 368                         pr_debug("nf_ct_h323: expect T.120 ");
 369                         nf_ct_dump_tuple(&exp->tuple);
 370                 } else
 371                         ret = -1;
 372         }
 373
 374         nf_ct_expect_put(exp);
 375
 376         return ret;
 377 }
 378
 379 static int process_h245_channel(struct sk_buff *skb,
 380                                 struct nf_conn *ct,
 381                                 enum ip_conntrack_info ctinfo,
 382                                 unsigned int protoff,
 383                                 unsigned char **data, int dataoff,
 384                                 H2250LogicalChannelParameters *channel)
 385 {
 386         int ret;
 387
 388         if (channel->options & eH2250LogicalChannelParameters_mediaChannel) {
 389                 /* RTP */
 390                 ret = expect_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff,
 391                                       &channel->mediaChannel);
 392                 if (ret < 0)
 393                         return -1;
 394         }
 395
 396         if (channel->
 397             options & eH2250LogicalChannelParameters_mediaControlChannel) {
 398                 /* RTCP */
 399                 ret = expect_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff,
 400                                       &channel->mediaControlChannel);
 401                 if (ret < 0)
 402                         return -1;
 403         }
 404
 405         return 0;
 406 }
 407
 408 static int process_olc(struct sk_buff *skb, struct nf_conn *ct,
 409                        enum ip_conntrack_info ctinfo,
 410                        unsigned int protoff,
 411                        unsigned char **data, int dataoff,
 412                        OpenLogicalChannel *olc)
 413 {
 414         int ret;
 415
 416         pr_debug("nf_ct_h323: OpenLogicalChannel\n");
 417
 418         if (olc->forwardLogicalChannelParameters.multiplexParameters.choice ==
 419             eOpenLogicalChannel_forwardLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters)
 420         {
 421                 ret = process_h245_channel(skb, ct, ctinfo,
 422                                            protoff, data, dataoff,
 423                                            &olc->
 424                                            forwardLogicalChannelParameters.
 425                                            multiplexParameters.
 426                                            h2250LogicalChannelParameters);
 427                 if (ret < 0)
 428                         return -1;
 429         }
 430
 431         if ((olc->options &
 432              eOpenLogicalChannel_reverseLogicalChannelParameters) &&
 433             (olc->reverseLogicalChannelParameters.options &
 434              eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters)
 435             && (olc->reverseLogicalChannelParameters.multiplexParameters.
 436                 choice ==
 437                 eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
 438         {
 439                 ret =
 440                     process_h245_channel(skb, ct, ctinfo,
 441                                          protoff, data, dataoff,
 442                                          &olc->
 443                                          reverseLogicalChannelParameters.
 444                                          multiplexParameters.
 445                                          h2250LogicalChannelParameters);
 446                 if (ret < 0)
 447                         return -1;
 448         }
 449
 450         if ((olc->options & eOpenLogicalChannel_separateStack) &&
 451             olc->forwardLogicalChannelParameters.dataType.choice ==
 452             eDataType_data &&
 453             olc->forwardLogicalChannelParameters.dataType.data.application.
 454             choice == eDataApplicationCapability_application_t120 &&
 455             olc->forwardLogicalChannelParameters.dataType.data.application.
 456             t120.choice == eDataProtocolCapability_separateLANStack &&
 457             olc->separateStack.networkAddress.choice ==
 458             eNetworkAccessParameters_networkAddress_localAreaAddress) {
 459                 ret = expect_t120(skb, ct, ctinfo, protoff, data, dataoff,
 460                                   &olc->separateStack.networkAddress.
 461                                   localAreaAddress);
 462                 if (ret < 0)
 463                         return -1;
 464         }
 465
 466         return 0;
 467 }
 468
 469 static int process_olca(struct sk_buff *skb, struct nf_conn *ct,
 470                         enum ip_conntrack_info ctinfo,
 471                         unsigned int protoff, unsigned char **data, int dataoff,
 472                         OpenLogicalChannelAck *olca)
 473 {
 474         H2250LogicalChannelAckParameters *ack;
 475         int ret;
 476
 477         pr_debug("nf_ct_h323: OpenLogicalChannelAck\n");
 478
 479         if ((olca->options &
 480              eOpenLogicalChannelAck_reverseLogicalChannelParameters) &&
 481             (olca->reverseLogicalChannelParameters.options &
 482              eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters)
 483             && (olca->reverseLogicalChannelParameters.multiplexParameters.
 484                 choice ==
 485                 eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
 486         {
 487                 ret = process_h245_channel(skb, ct, ctinfo,
 488                                            protoff, data, dataoff,
 489                                            &olca->
 490                                            reverseLogicalChannelParameters.
 491                                            multiplexParameters.
 492                                            h2250LogicalChannelParameters);
 493                 if (ret < 0)
 494                         return -1;
 495         }
 496
 497         if ((olca->options &
 498              eOpenLogicalChannelAck_forwardMultiplexAckParameters) &&
 499             (olca->forwardMultiplexAckParameters.choice ==
 500              eOpenLogicalChannelAck_forwardMultiplexAckParameters_h2250LogicalChannelAckParameters))
 501         {
 502                 ack = &olca->forwardMultiplexAckParameters.
 503                     h2250LogicalChannelAckParameters;
 504                 if (ack->options &
 505                     eH2250LogicalChannelAckParameters_mediaChannel) {
 506                         /* RTP */
 507                         ret = expect_rtp_rtcp(skb, ct, ctinfo,
 508                                               protoff, data, dataoff,
 509                                               &ack->mediaChannel);
 510                         if (ret < 0)
 511                                 return -1;
 512                 }
 513
 514                 if (ack->options &
 515                     eH2250LogicalChannelAckParameters_mediaControlChannel) {
 516                         /* RTCP */
 517                         ret = expect_rtp_rtcp(skb, ct, ctinfo,
 518                                               protoff, data, dataoff,
 519                                               &ack->mediaControlChannel);
 520                         if (ret < 0)
 521                                 return -1;
 522                 }
 523         }
 524
 525         if ((olca->options & eOpenLogicalChannelAck_separateStack) &&
 526                 olca->separateStack.networkAddress.choice ==
 527                 eNetworkAccessParameters_networkAddress_localAreaAddress) {
 528                 ret = expect_t120(skb, ct, ctinfo, protoff, data, dataoff,
 529                                   &olca->separateStack.networkAddress.
 530                                   localAreaAddress);
 531                 if (ret < 0)
 532                         return -1;
 533         }
 534
 535         return 0;
 536 }
 537
 538 static int process_h245(struct sk_buff *skb, struct nf_conn *ct,
 539                         enum ip_conntrack_info ctinfo,
 540                         unsigned int protoff, unsigned char **data, int dataoff,
 541                         MultimediaSystemControlMessage *mscm)
 542 {
 543         switch (mscm->choice) {
 544         case eMultimediaSystemControlMessage_request:
 545                 if (mscm->request.choice ==
 546                     eRequestMessage_openLogicalChannel) {
 547                         return process_olc(skb, ct, ctinfo,
 548                                            protoff, data, dataoff,
 549                                            &mscm->request.openLogicalChannel);
 550                 }
 551                 pr_debug("nf_ct_h323: H.245 Request %d\n",
 552                          mscm->request.choice);
 553                 break;
 554         case eMultimediaSystemControlMessage_response:
 555                 if (mscm->response.choice ==
 556                     eResponseMessage_openLogicalChannelAck) {
 557                         return process_olca(skb, ct, ctinfo,
 558                                             protoff, data, dataoff,
 559                                             &mscm->response.
 560                                             openLogicalChannelAck);
 561                 }
 562                 pr_debug("nf_ct_h323: H.245 Response %d\n",
 563                          mscm->response.choice);
 564                 break;
 565         default:
 566                 pr_debug("nf_ct_h323: H.245 signal %d\n", mscm->choice);
 567                 break;
 568         }
 569
 570         return 0;
 571 }
 572
 573 static int h245_help(struct sk_buff *skb, unsigned int protoff,
 574                      struct nf_conn *ct, enum ip_conntrack_info ctinfo)
 575 {
 576         static MultimediaSystemControlMessage mscm;
 577         unsigned char *data = NULL;
 578         int datalen;
 579         int dataoff;
 580         int ret;
 581
 582         /* Until there's been traffic both ways, don't look in packets. */
 583         if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
 584                 return NF_ACCEPT;
 585
 586         pr_debug("nf_ct_h245: skblen = %u\n", skb->len);
 587
 588         spin_lock_bh(&nf_h323_lock);
 589
 590         /* Process each TPKT */
 591         while (get_tpkt_data(skb, protoff, ct, ctinfo,
 592                              &data, &datalen, &dataoff)) {
 593                 pr_debug("nf_ct_h245: TPKT len=%d ", datalen);
 594                 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
 595
 596                 /* Decode H.245 signal */
 597                 ret = DecodeMultimediaSystemControlMessage(data, datalen,
 598                                                            &mscm);
 599                 if (ret < 0) {
 600                         pr_debug("nf_ct_h245: decoding error: %s\n",
 601                                  ret == H323_ERROR_BOUND ?
 602                                  "out of bound" : "out of range");
 603                         /* We don't drop when decoding error */
 604                         break;
 605                 }
 606
 607                 /* Process H.245 signal */
 608                 if (process_h245(skb, ct, ctinfo, protoff,
 609                                  &data, dataoff, &mscm) < 0)
 610                         goto drop;
 611         }
 612
 613         spin_unlock_bh(&nf_h323_lock);
 614         return NF_ACCEPT;
 615
 616       drop:
 617         spin_unlock_bh(&nf_h323_lock);
 618         nf_ct_helper_log(skb, ct, "cannot process H.245 message");
 619         return NF_DROP;
 620 }
 621
 622 static const struct nf_conntrack_expect_policy h245_exp_policy = {
 623         .max_expected   = H323_RTP_CHANNEL_MAX * 4 + 2 /* T.120 */,
 624         .timeout        = 240,
 625 };
 626
 627 static struct nf_conntrack_helper nf_conntrack_helper_h245 __read_mostly = {
 628         .name                   = "H.245",
 629         .me                     = THIS_MODULE,
 630         .tuple.src.l3num        = AF_UNSPEC,
 631         .tuple.dst.protonum     = IPPROTO_UDP,
 632         .help                   = h245_help,
 633         .expect_policy          = &h245_exp_policy,
 634 };
 635
 636 int get_h225_addr(struct nf_conn *ct, unsigned char *data,
 637                   TransportAddress *taddr,
 638                   union nf_inet_addr *addr, __be16 *port)
 639 {
 640         const unsigned char *p;
 641         int len;
 642
 643         switch (taddr->choice) {
 644         case eTransportAddress_ipAddress:
 645                 if (nf_ct_l3num(ct) != AF_INET)
 646                         return 0;
 647                 p = data + taddr->ipAddress.ip;
 648                 len = 4;
 649                 break;
 650         case eTransportAddress_ip6Address:
 651                 if (nf_ct_l3num(ct) != AF_INET6)
 652                         return 0;
 653                 p = data + taddr->ip6Address.ip;
 654                 len = 16;
 655                 break;
 656         default:
 657                 return 0;
 658         }
 659
 660         memcpy(addr, p, len);
 661         memset((void *)addr + len, 0, sizeof(*addr) - len);
 662         memcpy(port, p + len, sizeof(__be16));
 663
 664         return 1;
 665 }
 666
 667 static int expect_h245(struct sk_buff *skb, struct nf_conn *ct,
 668                        enum ip_conntrack_info ctinfo,
 669                        unsigned int protoff, unsigned char **data, int dataoff,
 670                        TransportAddress *taddr)
 671 {
 672         int dir = CTINFO2DIR(ctinfo);
 673         int ret = 0;
 674         __be16 port;
 675         union nf_inet_addr addr;
 676         struct nf_conntrack_expect *exp;
 677         typeof(nat_h245_hook) nat_h245;
 678
 679         /* Read h245Address */
 680         if (!get_h225_addr(ct, *data, taddr, &addr, &port) ||
 681             memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 682             port == 0)
 683                 return 0;
 684
 685         /* Create expect for h245 connection */
 686         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 687                 return -1;
 688         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 689                           &ct->tuplehash[!dir].tuple.src.u3,
 690                           &ct->tuplehash[!dir].tuple.dst.u3,
 691                           IPPROTO_TCP, NULL, &port);
 692         exp->helper = &nf_conntrack_helper_h245;
 693
 694         if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 695                    &ct->tuplehash[!dir].tuple.dst.u3,
 696                    sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 697             (nat_h245 = rcu_dereference(nat_h245_hook)) &&
 698             nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 699             ct->status & IPS_NAT_MASK) {
 700                 /* NAT needed */
 701                 ret = nat_h245(skb, ct, ctinfo, protoff, data, dataoff, taddr,
 702                                port, exp);
 703         } else {                /* Conntrack only */
 704                 if (nf_ct_expect_related(exp, 0) == 0) {
 705                         pr_debug("nf_ct_q931: expect H.245 ");
 706                         nf_ct_dump_tuple(&exp->tuple);
 707                 } else
 708                         ret = -1;
 709         }
 710
 711         nf_ct_expect_put(exp);
 712
 713         return ret;
 714 }
 715
 716 /* If the calling party is on the same side of the forward-to party,
 717  * we don't need to track the second call
 718  */
 719 static int callforward_do_filter(struct net *net,
 720                                  const union nf_inet_addr *src,
 721                                  const union nf_inet_addr *dst,
 722                                  u_int8_t family)
 723 {
 724         int ret = 0;
 725
 726         switch (family) {
 727         case AF_INET: {
 728                 struct flowi4 fl1, fl2;
 729                 struct rtable *rt1, *rt2;
 730
 731                 memset(&fl1, 0, sizeof(fl1));
 732                 fl1.daddr = src->ip;
 733
 734                 memset(&fl2, 0, sizeof(fl2));
 735                 fl2.daddr = dst->ip;
 736                 if (!nf_ip_route(net, (struct dst_entry **)&rt1,
 737                                  flowi4_to_flowi(&fl1), false)) {
 738                         if (!nf_ip_route(net, (struct dst_entry **)&rt2,
 739                                          flowi4_to_flowi(&fl2), false)) {
 740                                 if (rt_nexthop(rt1, fl1.daddr) ==
 741                                     rt_nexthop(rt2, fl2.daddr) &&
 742                                     rt1->dst.dev  == rt2->dst.dev)
 743                                         ret = 1;
 744                                 dst_release(&rt2->dst);
 745                         }
 746                         dst_release(&rt1->dst);
 747                 }
 748                 break;
 749         }
 750 #if IS_ENABLED(CONFIG_IPV6)
 751         case AF_INET6: {
 752                 struct rt6_info *rt1, *rt2;
 753                 struct flowi6 fl1, fl2;
 754
 755                 memset(&fl1, 0, sizeof(fl1));
 756                 fl1.daddr = src->in6;
 757
 758                 memset(&fl2, 0, sizeof(fl2));
 759                 fl2.daddr = dst->in6;
 760                 if (!nf_ip6_route(net, (struct dst_entry **)&rt1,
 761                                   flowi6_to_flowi(&fl1), false)) {
 762                         if (!nf_ip6_route(net, (struct dst_entry **)&rt2,
 763                                           flowi6_to_flowi(&fl2), false)) {
 764                                 if (ipv6_addr_equal(rt6_nexthop(rt1, &fl1.daddr),
 765                                                     rt6_nexthop(rt2, &fl2.daddr)) &&
 766                                     rt1->dst.dev == rt2->dst.dev)
 767                                         ret = 1;
 768                                 dst_release(&rt2->dst);
 769                         }
 770                         dst_release(&rt1->dst);
 771                 }
 772                 break;
 773         }
 774 #endif
 775         }
 776         return ret;
 777
 778 }
 779
 780 static int expect_callforwarding(struct sk_buff *skb,
 781                                  struct nf_conn *ct,
 782                                  enum ip_conntrack_info ctinfo,
 783                                  unsigned int protoff,
 784                                  unsigned char **data, int dataoff,
 785                                  TransportAddress *taddr)
 786 {
 787         int dir = CTINFO2DIR(ctinfo);
 788         int ret = 0;
 789         __be16 port;
 790         union nf_inet_addr addr;
 791         struct nf_conntrack_expect *exp;
 792         struct net *net = nf_ct_net(ct);
 793         typeof(nat_callforwarding_hook) nat_callforwarding;
 794
 795         /* Read alternativeAddress */
 796         if (!get_h225_addr(ct, *data, taddr, &addr, &port) || port == 0)
 797                 return 0;
 798
 799         /* If the calling party is on the same side of the forward-to party,
 800          * we don't need to track the second call
 801          */
 802         if (callforward_filter &&
 803             callforward_do_filter(net, &addr, &ct->tuplehash[!dir].tuple.src.u3,
 804                                   nf_ct_l3num(ct))) {
 805                 pr_debug("nf_ct_q931: Call Forwarding not tracked\n");
 806                 return 0;
 807         }
 808
 809         /* Create expect for the second call leg */
 810         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 811                 return -1;
 812         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 813                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
 814                           IPPROTO_TCP, NULL, &port);
 815         exp->helper = nf_conntrack_helper_q931;
 816
 817         if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 818                    &ct->tuplehash[!dir].tuple.dst.u3,
 819                    sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 820             (nat_callforwarding = rcu_dereference(nat_callforwarding_hook)) &&
 821             nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 822             ct->status & IPS_NAT_MASK) {
 823                 /* Need NAT */
 824                 ret = nat_callforwarding(skb, ct, ctinfo,
 825                                          protoff, data, dataoff,
 826                                          taddr, port, exp);
 827         } else {                /* Conntrack only */
 828                 if (nf_ct_expect_related(exp, 0) == 0) {
 829                         pr_debug("nf_ct_q931: expect Call Forwarding ");
 830                         nf_ct_dump_tuple(&exp->tuple);
 831                 } else
 832                         ret = -1;
 833         }
 834
 835         nf_ct_expect_put(exp);
 836
 837         return ret;
 838 }
 839
 840 static int process_setup(struct sk_buff *skb, struct nf_conn *ct,
 841                          enum ip_conntrack_info ctinfo,
 842                          unsigned int protoff,
 843                          unsigned char **data, int dataoff,
 844                          Setup_UUIE *setup)
 845 {
 846         int dir = CTINFO2DIR(ctinfo);
 847         int ret;
 848         int i;
 849         __be16 port;
 850         union nf_inet_addr addr;
 851         typeof(set_h225_addr_hook) set_h225_addr;
 852
 853         pr_debug("nf_ct_q931: Setup\n");
 854
 855         if (setup->options & eSetup_UUIE_h245Address) {
 856                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
 857                                   &setup->h245Address);
 858                 if (ret < 0)
 859                         return -1;
 860         }
 861
 862         set_h225_addr = rcu_dereference(set_h225_addr_hook);
 863         if ((setup->options & eSetup_UUIE_destCallSignalAddress) &&
 864             (set_h225_addr) && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 865             ct->status & IPS_NAT_MASK &&
 866             get_h225_addr(ct, *data, &setup->destCallSignalAddress,
 867                           &addr, &port) &&
 868             memcmp(&addr, &ct->tuplehash[!dir].tuple.src.u3, sizeof(addr))) {
 869                 pr_debug("nf_ct_q931: set destCallSignalAddress %pI6:%hu->%pI6:%hu\n",
 870                          &addr, ntohs(port), &ct->tuplehash[!dir].tuple.src.u3,
 871                          ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port));
 872                 ret = set_h225_addr(skb, protoff, data, dataoff,
 873                                     &setup->destCallSignalAddress,
 874                                     &ct->tuplehash[!dir].tuple.src.u3,
 875                                     ct->tuplehash[!dir].tuple.src.u.tcp.port);
 876                 if (ret < 0)
 877                         return -1;
 878         }
 879
 880         if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) &&
 881             (set_h225_addr) && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 882             ct->status & IPS_NAT_MASK &&
 883             get_h225_addr(ct, *data, &setup->sourceCallSignalAddress,
 884                           &addr, &port) &&
 885             memcmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(addr))) {
 886                 pr_debug("nf_ct_q931: set sourceCallSignalAddress %pI6:%hu->%pI6:%hu\n",
 887                          &addr, ntohs(port), &ct->tuplehash[!dir].tuple.dst.u3,
 888                          ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port));
 889                 ret = set_h225_addr(skb, protoff, data, dataoff,
 890                                     &setup->sourceCallSignalAddress,
 891                                     &ct->tuplehash[!dir].tuple.dst.u3,
 892                                     ct->tuplehash[!dir].tuple.dst.u.tcp.port);
 893                 if (ret < 0)
 894                         return -1;
 895         }
 896
 897         if (setup->options & eSetup_UUIE_fastStart) {
 898                 for (i = 0; i < setup->fastStart.count; i++) {
 899                         ret = process_olc(skb, ct, ctinfo,
 900                                           protoff, data, dataoff,
 901                                           &setup->fastStart.item[i]);
 902                         if (ret < 0)
 903                                 return -1;
 904                 }
 905         }
 906
 907         return 0;
 908 }
 909
 910 static int process_callproceeding(struct sk_buff *skb,
 911                                   struct nf_conn *ct,
 912                                   enum ip_conntrack_info ctinfo,
 913                                   unsigned int protoff,
 914                                   unsigned char **data, int dataoff,
 915                                   CallProceeding_UUIE *callproc)
 916 {
 917         int ret;
 918         int i;
 919
 920         pr_debug("nf_ct_q931: CallProceeding\n");
 921
 922         if (callproc->options & eCallProceeding_UUIE_h245Address) {
 923                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
 924                                   &callproc->h245Address);
 925                 if (ret < 0)
 926                         return -1;
 927         }
 928
 929         if (callproc->options & eCallProceeding_UUIE_fastStart) {
 930                 for (i = 0; i < callproc->fastStart.count; i++) {
 931                         ret = process_olc(skb, ct, ctinfo,
 932                                           protoff, data, dataoff,
 933                                           &callproc->fastStart.item[i]);
 934                         if (ret < 0)
 935                                 return -1;
 936                 }
 937         }
 938
 939         return 0;
 940 }
 941
 942 static int process_connect(struct sk_buff *skb, struct nf_conn *ct,
 943                            enum ip_conntrack_info ctinfo,
 944                            unsigned int protoff,
 945                            unsigned char **data, int dataoff,
 946                            Connect_UUIE *connect)
 947 {
 948         int ret;
 949         int i;
 950
 951         pr_debug("nf_ct_q931: Connect\n");
 952
 953         if (connect->options & eConnect_UUIE_h245Address) {
 954                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
 955                                   &connect->h245Address);
 956                 if (ret < 0)
 957                         return -1;
 958         }
 959
 960         if (connect->options & eConnect_UUIE_fastStart) {
 961                 for (i = 0; i < connect->fastStart.count; i++) {
 962                         ret = process_olc(skb, ct, ctinfo,
 963                                           protoff, data, dataoff,
 964                                           &connect->fastStart.item[i]);
 965                         if (ret < 0)
 966                                 return -1;
 967                 }
 968         }
 969
 970         return 0;
 971 }
 972
 973 static int process_alerting(struct sk_buff *skb, struct nf_conn *ct,
 974                             enum ip_conntrack_info ctinfo,
 975                             unsigned int protoff,
 976                             unsigned char **data, int dataoff,
 977                             Alerting_UUIE *alert)
 978 {
 979         int ret;
 980         int i;
 981
 982         pr_debug("nf_ct_q931: Alerting\n");
 983
 984         if (alert->options & eAlerting_UUIE_h245Address) {
 985                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
 986                                   &alert->h245Address);
 987                 if (ret < 0)
 988                         return -1;
 989         }
 990
 991         if (alert->options & eAlerting_UUIE_fastStart) {
 992                 for (i = 0; i < alert->fastStart.count; i++) {
 993                         ret = process_olc(skb, ct, ctinfo,
 994                                           protoff, data, dataoff,
 995                                           &alert->fastStart.item[i]);
 996                         if (ret < 0)
 997                                 return -1;
 998                 }
 999         }
1000
1001         return 0;
1002 }
1003
1004 static int process_facility(struct sk_buff *skb, struct nf_conn *ct,
1005                             enum ip_conntrack_info ctinfo,
1006                             unsigned int protoff,
1007                             unsigned char **data, int dataoff,
1008                             Facility_UUIE *facility)
1009 {
1010         int ret;
1011         int i;
1012
1013         pr_debug("nf_ct_q931: Facility\n");
1014
1015         if (facility->reason.choice == eFacilityReason_callForwarded) {
1016                 if (facility->options & eFacility_UUIE_alternativeAddress)
1017                         return expect_callforwarding(skb, ct, ctinfo,
1018                                                      protoff, data, dataoff,
1019                                                      &facility->
1020                                                      alternativeAddress);
1021                 return 0;
1022         }
1023
1024         if (facility->options & eFacility_UUIE_h245Address) {
1025                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
1026                                   &facility->h245Address);
1027                 if (ret < 0)
1028                         return -1;
1029         }
1030
1031         if (facility->options & eFacility_UUIE_fastStart) {
1032                 for (i = 0; i < facility->fastStart.count; i++) {
1033                         ret = process_olc(skb, ct, ctinfo,
1034                                           protoff, data, dataoff,
1035                                           &facility->fastStart.item[i]);
1036                         if (ret < 0)
1037                                 return -1;
1038                 }
1039         }
1040
1041         return 0;
1042 }
1043
1044 static int process_progress(struct sk_buff *skb, struct nf_conn *ct,
1045                             enum ip_conntrack_info ctinfo,
1046                             unsigned int protoff,
1047                             unsigned char **data, int dataoff,
1048                             Progress_UUIE *progress)
1049 {
1050         int ret;
1051         int i;
1052
1053         pr_debug("nf_ct_q931: Progress\n");
1054
1055         if (progress->options & eProgress_UUIE_h245Address) {
1056                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
1057                                   &progress->h245Address);
1058                 if (ret < 0)
1059                         return -1;
1060         }
1061
1062         if (progress->options & eProgress_UUIE_fastStart) {
1063                 for (i = 0; i < progress->fastStart.count; i++) {
1064                         ret = process_olc(skb, ct, ctinfo,
1065                                           protoff, data, dataoff,
1066                                           &progress->fastStart.item[i]);
1067                         if (ret < 0)
1068                                 return -1;
1069                 }
1070         }
1071
1072         return 0;
1073 }
1074
1075 static int process_q931(struct sk_buff *skb, struct nf_conn *ct,
1076                         enum ip_conntrack_info ctinfo,
1077                         unsigned int protoff, unsigned char **data, int dataoff,
1078                         Q931 *q931)
1079 {
1080         H323_UU_PDU *pdu = &q931->UUIE.h323_uu_pdu;
1081         int i;
1082         int ret = 0;
1083
1084         switch (pdu->h323_message_body.choice) {
1085         case eH323_UU_PDU_h323_message_body_setup:
1086                 ret = process_setup(skb, ct, ctinfo, protoff, data, dataoff,
1087                                     &pdu->h323_message_body.setup);
1088                 break;
1089         case eH323_UU_PDU_h323_message_body_callProceeding:
1090                 ret = process_callproceeding(skb, ct, ctinfo,
1091                                              protoff, data, dataoff,
1092                                              &pdu->h323_message_body.
1093                                              callProceeding);
1094                 break;
1095         case eH323_UU_PDU_h323_message_body_connect:
1096                 ret = process_connect(skb, ct, ctinfo, protoff, data, dataoff,
1097                                       &pdu->h323_message_body.connect);
1098                 break;
1099         case eH323_UU_PDU_h323_message_body_alerting:
1100                 ret = process_alerting(skb, ct, ctinfo, protoff, data, dataoff,
1101                                        &pdu->h323_message_body.alerting);
1102                 break;
1103         case eH323_UU_PDU_h323_message_body_facility:
1104                 ret = process_facility(skb, ct, ctinfo, protoff, data, dataoff,
1105                                        &pdu->h323_message_body.facility);
1106                 break;
1107         case eH323_UU_PDU_h323_message_body_progress:
1108                 ret = process_progress(skb, ct, ctinfo, protoff, data, dataoff,
1109                                        &pdu->h323_message_body.progress);
1110                 break;
1111         default:
1112                 pr_debug("nf_ct_q931: Q.931 signal %d\n",
1113                          pdu->h323_message_body.choice);
1114                 break;
1115         }
1116
1117         if (ret < 0)
1118                 return -1;
1119
1120         if (pdu->options & eH323_UU_PDU_h245Control) {
1121                 for (i = 0; i < pdu->h245Control.count; i++) {
1122                         ret = process_h245(skb, ct, ctinfo,
1123                                            protoff, data, dataoff,
1124                                            &pdu->h245Control.item[i]);
1125                         if (ret < 0)
1126                                 return -1;
1127                 }
1128         }
1129
1130         return 0;
1131 }
1132
1133 static int q931_help(struct sk_buff *skb, unsigned int protoff,
1134                      struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1135 {
1136         static Q931 q931;
1137         unsigned char *data = NULL;
1138         int datalen;
1139         int dataoff;
1140         int ret;
1141
1142         /* Until there's been traffic both ways, don't look in packets. */
1143         if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
1144                 return NF_ACCEPT;
1145
1146         pr_debug("nf_ct_q931: skblen = %u\n", skb->len);
1147
1148         spin_lock_bh(&nf_h323_lock);
1149
1150         /* Process each TPKT */
1151         while (get_tpkt_data(skb, protoff, ct, ctinfo,
1152                              &data, &datalen, &dataoff)) {
1153                 pr_debug("nf_ct_q931: TPKT len=%d ", datalen);
1154                 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1155
1156                 /* Decode Q.931 signal */
1157                 ret = DecodeQ931(data, datalen, &q931);
1158                 if (ret < 0) {
1159                         pr_debug("nf_ct_q931: decoding error: %s\n",
1160                                  ret == H323_ERROR_BOUND ?
1161                                  "out of bound" : "out of range");
1162                         /* We don't drop when decoding error */
1163                         break;
1164                 }
1165
1166                 /* Process Q.931 signal */
1167                 if (process_q931(skb, ct, ctinfo, protoff,
1168                                  &data, dataoff, &q931) < 0)
1169                         goto drop;
1170         }
1171
1172         spin_unlock_bh(&nf_h323_lock);
1173         return NF_ACCEPT;
1174
1175       drop:
1176         spin_unlock_bh(&nf_h323_lock);
1177         nf_ct_helper_log(skb, ct, "cannot process Q.931 message");
1178         return NF_DROP;
1179 }
1180
1181 static const struct nf_conntrack_expect_policy q931_exp_policy = {
1182         /* T.120 and H.245 */
1183         .max_expected           = H323_RTP_CHANNEL_MAX * 4 + 4,
1184         .timeout                = 240,
1185 };
1186
1187 static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = {
1188         {
1189                 .name                   = "Q.931",
1190                 .me                     = THIS_MODULE,
1191                 .tuple.src.l3num        = AF_INET,
1192                 .tuple.src.u.tcp.port   = cpu_to_be16(Q931_PORT),
1193                 .tuple.dst.protonum     = IPPROTO_TCP,
1194                 .help                   = q931_help,
1195                 .expect_policy          = &q931_exp_policy,
1196         },
1197         {
1198                 .name                   = "Q.931",
1199                 .me                     = THIS_MODULE,
1200                 .tuple.src.l3num        = AF_INET6,
1201                 .tuple.src.u.tcp.port   = cpu_to_be16(Q931_PORT),
1202                 .tuple.dst.protonum     = IPPROTO_TCP,
1203                 .help                   = q931_help,
1204                 .expect_policy          = &q931_exp_policy,
1205         },
1206 };
1207
1208 static unsigned char *get_udp_data(struct sk_buff *skb, unsigned int protoff,
1209                                    int *datalen)
1210 {
1211         const struct udphdr *uh;
1212         struct udphdr _uh;
1213         int dataoff;
1214
1215         uh = skb_header_pointer(skb, protoff, sizeof(_uh), &_uh);
1216         if (uh == NULL)
1217                 return NULL;
1218         dataoff = protoff + sizeof(_uh);
1219         if (dataoff >= skb->len)
1220                 return NULL;
1221         *datalen = skb->len - dataoff;
1222         return skb_header_pointer(skb, dataoff, *datalen, h323_buffer);
1223 }
1224
1225 static struct nf_conntrack_expect *find_expect(struct nf_conn *ct,
1226                                                union nf_inet_addr *addr,
1227                                                __be16 port)
1228 {
1229         struct net *net = nf_ct_net(ct);
1230         struct nf_conntrack_expect *exp;
1231         struct nf_conntrack_tuple tuple;
1232
1233         memset(&tuple.src.u3, 0, sizeof(tuple.src.u3));
1234         tuple.src.u.tcp.port = 0;
1235         memcpy(&tuple.dst.u3, addr, sizeof(tuple.dst.u3));
1236         tuple.dst.u.tcp.port = port;
1237         tuple.dst.protonum = IPPROTO_TCP;
1238
1239         exp = __nf_ct_expect_find(net, nf_ct_zone(ct), &tuple);
1240         if (exp && exp->master == ct)
1241                 return exp;
1242         return NULL;
1243 }
1244
1245 static int expect_q931(struct sk_buff *skb, struct nf_conn *ct,
1246                        enum ip_conntrack_info ctinfo,
1247                        unsigned int protoff, unsigned char **data,
1248                        TransportAddress *taddr, int count)
1249 {
1250         struct nf_ct_h323_master *info = nfct_help_data(ct);
1251         int dir = CTINFO2DIR(ctinfo);
1252         int ret = 0;
1253         int i;
1254         __be16 port;
1255         union nf_inet_addr addr;
1256         struct nf_conntrack_expect *exp;
1257         typeof(nat_q931_hook) nat_q931;
1258
1259         /* Look for the first related address */
1260         for (i = 0; i < count; i++) {
1261                 if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) &&
1262                     memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3,
1263                            sizeof(addr)) == 0 && port != 0)
1264                         break;
1265         }
1266
1267         if (i >= count)         /* Not found */
1268                 return 0;
1269
1270         /* Create expect for Q.931 */
1271         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1272                 return -1;
1273         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1274                           gkrouted_only ? /* only accept calls from GK? */
1275                                 &ct->tuplehash[!dir].tuple.src.u3 : NULL,
1276                           &ct->tuplehash[!dir].tuple.dst.u3,
1277                           IPPROTO_TCP, NULL, &port);
1278         exp->helper = nf_conntrack_helper_q931;
1279         exp->flags = NF_CT_EXPECT_PERMANENT;    /* Accept multiple calls */
1280
1281         nat_q931 = rcu_dereference(nat_q931_hook);
1282         if (nat_q931 && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1283             ct->status & IPS_NAT_MASK) {        /* Need NAT */
1284                 ret = nat_q931(skb, ct, ctinfo, protoff, data,
1285                                taddr, i, port, exp);
1286         } else {                /* Conntrack only */
1287                 if (nf_ct_expect_related(exp, 0) == 0) {
1288                         pr_debug("nf_ct_ras: expect Q.931 ");
1289                         nf_ct_dump_tuple(&exp->tuple);
1290
1291                         /* Save port for looking up expect in processing RCF */
1292                         info->sig_port[dir] = port;
1293                 } else
1294                         ret = -1;
1295         }
1296
1297         nf_ct_expect_put(exp);
1298
1299         return ret;
1300 }
1301
1302 static int process_grq(struct sk_buff *skb, struct nf_conn *ct,
1303                        enum ip_conntrack_info ctinfo,
1304                        unsigned int protoff,
1305                        unsigned char **data, GatekeeperRequest *grq)
1306 {
1307         typeof(set_ras_addr_hook) set_ras_addr;
1308
1309         pr_debug("nf_ct_ras: GRQ\n");
1310
1311         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1312         if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1313             ct->status & IPS_NAT_MASK)  /* NATed */
1314                 return set_ras_addr(skb, ct, ctinfo, protoff, data,
1315                                     &grq->rasAddress, 1);
1316         return 0;
1317 }
1318
1319 static int process_gcf(struct sk_buff *skb, struct nf_conn *ct,
1320                        enum ip_conntrack_info ctinfo,
1321                        unsigned int protoff,
1322                        unsigned char **data, GatekeeperConfirm *gcf)
1323 {
1324         int dir = CTINFO2DIR(ctinfo);
1325         int ret = 0;
1326         __be16 port;
1327         union nf_inet_addr addr;
1328         struct nf_conntrack_expect *exp;
1329
1330         pr_debug("nf_ct_ras: GCF\n");
1331
1332         if (!get_h225_addr(ct, *data, &gcf->rasAddress, &addr, &port))
1333                 return 0;
1334
1335         /* Registration port is the same as discovery port */
1336         if (!memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1337             port == ct->tuplehash[dir].tuple.src.u.udp.port)
1338                 return 0;
1339
1340         /* Avoid RAS expectation loops. A GCF is never expected. */
1341         if (test_bit(IPS_EXPECTED_BIT, &ct->status))
1342                 return 0;
1343
1344         /* Need new expect */
1345         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1346                 return -1;
1347         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1348                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1349                           IPPROTO_UDP, NULL, &port);
1350         exp->helper = nf_conntrack_helper_ras;
1351
1352         if (nf_ct_expect_related(exp, 0) == 0) {
1353                 pr_debug("nf_ct_ras: expect RAS ");
1354                 nf_ct_dump_tuple(&exp->tuple);
1355         } else
1356                 ret = -1;
1357
1358         nf_ct_expect_put(exp);
1359
1360         return ret;
1361 }
1362
1363 static int process_rrq(struct sk_buff *skb, struct nf_conn *ct,
1364                        enum ip_conntrack_info ctinfo,
1365                        unsigned int protoff,
1366                        unsigned char **data, RegistrationRequest *rrq)
1367 {
1368         struct nf_ct_h323_master *info = nfct_help_data(ct);
1369         int ret;
1370         typeof(set_ras_addr_hook) set_ras_addr;
1371
1372         pr_debug("nf_ct_ras: RRQ\n");
1373
1374         ret = expect_q931(skb, ct, ctinfo, protoff, data,
1375                           rrq->callSignalAddress.item,
1376                           rrq->callSignalAddress.count);
1377         if (ret < 0)
1378                 return -1;
1379
1380         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1381         if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1382             ct->status & IPS_NAT_MASK) {
1383                 ret = set_ras_addr(skb, ct, ctinfo, protoff, data,
1384                                    rrq->rasAddress.item,
1385                                    rrq->rasAddress.count);
1386                 if (ret < 0)
1387                         return -1;
1388         }
1389
1390         if (rrq->options & eRegistrationRequest_timeToLive) {
1391                 pr_debug("nf_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive);
1392                 info->timeout = rrq->timeToLive;
1393         } else
1394                 info->timeout = default_rrq_ttl;
1395
1396         return 0;
1397 }
1398
1399 static int process_rcf(struct sk_buff *skb, struct nf_conn *ct,
1400                        enum ip_conntrack_info ctinfo,
1401                        unsigned int protoff,
1402                        unsigned char **data, RegistrationConfirm *rcf)
1403 {
1404         struct nf_ct_h323_master *info = nfct_help_data(ct);
1405         int dir = CTINFO2DIR(ctinfo);
1406         int ret;
1407         struct nf_conntrack_expect *exp;
1408         typeof(set_sig_addr_hook) set_sig_addr;
1409
1410         pr_debug("nf_ct_ras: RCF\n");
1411
1412         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1413         if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1414             ct->status & IPS_NAT_MASK) {
1415                 ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1416                                         rcf->callSignalAddress.item,
1417                                         rcf->callSignalAddress.count);
1418                 if (ret < 0)
1419                         return -1;
1420         }
1421
1422         if (rcf->options & eRegistrationConfirm_timeToLive) {
1423                 pr_debug("nf_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive);
1424                 info->timeout = rcf->timeToLive;
1425         }
1426
1427         if (info->timeout > 0) {
1428                 pr_debug("nf_ct_ras: set RAS connection timeout to "
1429                          "%u seconds\n", info->timeout);
1430                 nf_ct_refresh(ct, skb, info->timeout * HZ);
1431
1432                 /* Set expect timeout */
1433                 spin_lock_bh(&nf_conntrack_expect_lock);
1434                 exp = find_expect(ct, &ct->tuplehash[dir].tuple.dst.u3,
1435                                   info->sig_port[!dir]);
1436                 if (exp) {
1437                         pr_debug("nf_ct_ras: set Q.931 expect "
1438                                  "timeout to %u seconds for",
1439                                  info->timeout);
1440                         nf_ct_dump_tuple(&exp->tuple);
1441                         mod_timer_pending(&exp->timeout,
1442                                           jiffies + info->timeout * HZ);
1443                 }
1444                 spin_unlock_bh(&nf_conntrack_expect_lock);
1445         }
1446
1447         return 0;
1448 }
1449
1450 static int process_urq(struct sk_buff *skb, struct nf_conn *ct,
1451                        enum ip_conntrack_info ctinfo,
1452                        unsigned int protoff,
1453                        unsigned char **data, UnregistrationRequest *urq)
1454 {
1455         struct nf_ct_h323_master *info = nfct_help_data(ct);
1456         int dir = CTINFO2DIR(ctinfo);
1457         int ret;
1458         typeof(set_sig_addr_hook) set_sig_addr;
1459
1460         pr_debug("nf_ct_ras: URQ\n");
1461
1462         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1463         if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1464             ct->status & IPS_NAT_MASK) {
1465                 ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1466                                    urq->callSignalAddress.item,
1467                                    urq->callSignalAddress.count);
1468                 if (ret < 0)
1469                         return -1;
1470         }
1471
1472         /* Clear old expect */
1473         nf_ct_remove_expectations(ct);
1474         info->sig_port[dir] = 0;
1475         info->sig_port[!dir] = 0;
1476
1477         /* Give it 30 seconds for UCF or URJ */
1478         nf_ct_refresh(ct, skb, 30 * HZ);
1479
1480         return 0;
1481 }
1482
1483 static int process_arq(struct sk_buff *skb, struct nf_conn *ct,
1484                        enum ip_conntrack_info ctinfo,
1485                        unsigned int protoff,
1486                        unsigned char **data, AdmissionRequest *arq)
1487 {
1488         const struct nf_ct_h323_master *info = nfct_help_data(ct);
1489         int dir = CTINFO2DIR(ctinfo);
1490         __be16 port;
1491         union nf_inet_addr addr;
1492         typeof(set_h225_addr_hook) set_h225_addr;
1493
1494         pr_debug("nf_ct_ras: ARQ\n");
1495
1496         set_h225_addr = rcu_dereference(set_h225_addr_hook);
1497         if ((arq->options & eAdmissionRequest_destCallSignalAddress) &&
1498             get_h225_addr(ct, *data, &arq->destCallSignalAddress,
1499                           &addr, &port) &&
1500             !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1501             port == info->sig_port[dir] &&
1502             nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1503             set_h225_addr && ct->status & IPS_NAT_MASK) {
1504                 /* Answering ARQ */
1505                 return set_h225_addr(skb, protoff, data, 0,
1506                                      &arq->destCallSignalAddress,
1507                                      &ct->tuplehash[!dir].tuple.dst.u3,
1508                                      info->sig_port[!dir]);
1509         }
1510
1511         if ((arq->options & eAdmissionRequest_srcCallSignalAddress) &&
1512             get_h225_addr(ct, *data, &arq->srcCallSignalAddress,
1513                           &addr, &port) &&
1514             !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1515             set_h225_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1516             ct->status & IPS_NAT_MASK) {
1517                 /* Calling ARQ */
1518                 return set_h225_addr(skb, protoff, data, 0,
1519                                      &arq->srcCallSignalAddress,
1520                                      &ct->tuplehash[!dir].tuple.dst.u3,
1521                                      port);
1522         }
1523
1524         return 0;
1525 }
1526
1527 static int process_acf(struct sk_buff *skb, struct nf_conn *ct,
1528                        enum ip_conntrack_info ctinfo,
1529                        unsigned int protoff,
1530                        unsigned char **data, AdmissionConfirm *acf)
1531 {
1532         int dir = CTINFO2DIR(ctinfo);
1533         int ret = 0;
1534         __be16 port;
1535         union nf_inet_addr addr;
1536         struct nf_conntrack_expect *exp;
1537         typeof(set_sig_addr_hook) set_sig_addr;
1538
1539         pr_debug("nf_ct_ras: ACF\n");
1540
1541         if (!get_h225_addr(ct, *data, &acf->destCallSignalAddress,
1542                            &addr, &port))
1543                 return 0;
1544
1545         if (!memcmp(&addr, &ct->tuplehash[dir].tuple.dst.u3, sizeof(addr))) {
1546                 /* Answering ACF */
1547                 set_sig_addr = rcu_dereference(set_sig_addr_hook);
1548                 if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1549                     ct->status & IPS_NAT_MASK)
1550                         return set_sig_addr(skb, ct, ctinfo, protoff, data,
1551                                             &acf->destCallSignalAddress, 1);
1552                 return 0;
1553         }
1554
1555         /* Need new expect */
1556         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1557                 return -1;
1558         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1559                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1560                           IPPROTO_TCP, NULL, &port);
1561         exp->flags = NF_CT_EXPECT_PERMANENT;
1562         exp->helper = nf_conntrack_helper_q931;
1563
1564         if (nf_ct_expect_related(exp, 0) == 0) {
1565                 pr_debug("nf_ct_ras: expect Q.931 ");
1566                 nf_ct_dump_tuple(&exp->tuple);
1567         } else
1568                 ret = -1;
1569
1570         nf_ct_expect_put(exp);
1571
1572         return ret;
1573 }
1574
1575 static int process_lrq(struct sk_buff *skb, struct nf_conn *ct,
1576                        enum ip_conntrack_info ctinfo,
1577                        unsigned int protoff,
1578                        unsigned char **data, LocationRequest *lrq)
1579 {
1580         typeof(set_ras_addr_hook) set_ras_addr;
1581
1582         pr_debug("nf_ct_ras: LRQ\n");
1583
1584         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1585         if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1586             ct->status & IPS_NAT_MASK)
1587                 return set_ras_addr(skb, ct, ctinfo, protoff, data,
1588                                     &lrq->replyAddress, 1);
1589         return 0;
1590 }
1591
1592 static int process_lcf(struct sk_buff *skb, struct nf_conn *ct,
1593                        enum ip_conntrack_info ctinfo,
1594                        unsigned int protoff,
1595                        unsigned char **data, LocationConfirm *lcf)
1596 {
1597         int dir = CTINFO2DIR(ctinfo);
1598         int ret = 0;
1599         __be16 port;
1600         union nf_inet_addr addr;
1601         struct nf_conntrack_expect *exp;
1602
1603         pr_debug("nf_ct_ras: LCF\n");
1604
1605         if (!get_h225_addr(ct, *data, &lcf->callSignalAddress,
1606                            &addr, &port))
1607                 return 0;
1608
1609         /* Need new expect for call signal */
1610         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1611                 return -1;
1612         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1613                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1614                           IPPROTO_TCP, NULL, &port);
1615         exp->flags = NF_CT_EXPECT_PERMANENT;
1616         exp->helper = nf_conntrack_helper_q931;
1617
1618         if (nf_ct_expect_related(exp, 0) == 0) {
1619                 pr_debug("nf_ct_ras: expect Q.931 ");
1620                 nf_ct_dump_tuple(&exp->tuple);
1621         } else
1622                 ret = -1;
1623
1624         nf_ct_expect_put(exp);
1625
1626         /* Ignore rasAddress */
1627
1628         return ret;
1629 }
1630
1631 static int process_irr(struct sk_buff *skb, struct nf_conn *ct,
1632                        enum ip_conntrack_info ctinfo,
1633                        unsigned int protoff,
1634                        unsigned char **data, InfoRequestResponse *irr)
1635 {
1636         int ret;
1637         typeof(set_ras_addr_hook) set_ras_addr;
1638         typeof(set_sig_addr_hook) set_sig_addr;
1639
1640         pr_debug("nf_ct_ras: IRR\n");
1641
1642         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1643         if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1644             ct->status & IPS_NAT_MASK) {
1645                 ret = set_ras_addr(skb, ct, ctinfo, protoff, data,
1646                                    &irr->rasAddress, 1);
1647                 if (ret < 0)
1648                         return -1;
1649         }
1650
1651         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1652         if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1653             ct->status & IPS_NAT_MASK) {
1654                 ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1655                                         irr->callSignalAddress.item,
1656                                         irr->callSignalAddress.count);
1657                 if (ret < 0)
1658                         return -1;
1659         }
1660
1661         return 0;
1662 }
1663
1664 static int process_ras(struct sk_buff *skb, struct nf_conn *ct,
1665                        enum ip_conntrack_info ctinfo,
1666                        unsigned int protoff,
1667                        unsigned char **data, RasMessage *ras)
1668 {
1669         switch (ras->choice) {
1670         case eRasMessage_gatekeeperRequest:
1671                 return process_grq(skb, ct, ctinfo, protoff, data,
1672                                    &ras->gatekeeperRequest);
1673         case eRasMessage_gatekeeperConfirm:
1674                 return process_gcf(skb, ct, ctinfo, protoff, data,
1675                                    &ras->gatekeeperConfirm);
1676         case eRasMessage_registrationRequest:
1677                 return process_rrq(skb, ct, ctinfo, protoff, data,
1678                                    &ras->registrationRequest);
1679         case eRasMessage_registrationConfirm:
1680                 return process_rcf(skb, ct, ctinfo, protoff, data,
1681                                    &ras->registrationConfirm);
1682         case eRasMessage_unregistrationRequest:
1683                 return process_urq(skb, ct, ctinfo, protoff, data,
1684                                    &ras->unregistrationRequest);
1685         case eRasMessage_admissionRequest:
1686                 return process_arq(skb, ct, ctinfo, protoff, data,
1687                                    &ras->admissionRequest);
1688         case eRasMessage_admissionConfirm:
1689                 return process_acf(skb, ct, ctinfo, protoff, data,
1690                                    &ras->admissionConfirm);
1691         case eRasMessage_locationRequest:
1692                 return process_lrq(skb, ct, ctinfo, protoff, data,
1693                                    &ras->locationRequest);
1694         case eRasMessage_locationConfirm:
1695                 return process_lcf(skb, ct, ctinfo, protoff, data,
1696                                    &ras->locationConfirm);
1697         case eRasMessage_infoRequestResponse:
1698                 return process_irr(skb, ct, ctinfo, protoff, data,
1699                                    &ras->infoRequestResponse);
1700         default:
1701                 pr_debug("nf_ct_ras: RAS message %d\n", ras->choice);
1702                 break;
1703         }
1704
1705         return 0;
1706 }
1707
1708 static int ras_help(struct sk_buff *skb, unsigned int protoff,
1709                     struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1710 {
1711         static RasMessage ras;
1712         unsigned char *data;
1713         int datalen = 0;
1714         int ret;
1715
1716         pr_debug("nf_ct_ras: skblen = %u\n", skb->len);
1717
1718         spin_lock_bh(&nf_h323_lock);
1719
1720         /* Get UDP data */
1721         data = get_udp_data(skb, protoff, &datalen);
1722         if (data == NULL)
1723                 goto accept;
1724         pr_debug("nf_ct_ras: RAS message len=%d ", datalen);
1725         nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1726
1727         /* Decode RAS message */
1728         ret = DecodeRasMessage(data, datalen, &ras);
1729         if (ret < 0) {
1730                 pr_debug("nf_ct_ras: decoding error: %s\n",
1731                          ret == H323_ERROR_BOUND ?
1732                          "out of bound" : "out of range");
1733                 goto accept;
1734         }
1735
1736         /* Process RAS message */
1737         if (process_ras(skb, ct, ctinfo, protoff, &data, &ras) < 0)
1738                 goto drop;
1739
1740       accept:
1741         spin_unlock_bh(&nf_h323_lock);
1742         return NF_ACCEPT;
1743
1744       drop:
1745         spin_unlock_bh(&nf_h323_lock);
1746         nf_ct_helper_log(skb, ct, "cannot process RAS message");
1747         return NF_DROP;
1748 }
1749
1750 static const struct nf_conntrack_expect_policy ras_exp_policy = {
1751         .max_expected           = 32,
1752         .timeout                = 240,
1753 };
1754
1755 static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = {
1756         {
1757                 .name                   = "RAS",
1758                 .me                     = THIS_MODULE,
1759                 .tuple.src.l3num        = AF_INET,
1760                 .tuple.src.u.udp.port   = cpu_to_be16(RAS_PORT),
1761                 .tuple.dst.protonum     = IPPROTO_UDP,
1762                 .help                   = ras_help,
1763                 .expect_policy          = &ras_exp_policy,
1764         },
1765         {
1766                 .name                   = "RAS",
1767                 .me                     = THIS_MODULE,
1768                 .tuple.src.l3num        = AF_INET6,
1769                 .tuple.src.u.udp.port   = cpu_to_be16(RAS_PORT),
1770                 .tuple.dst.protonum     = IPPROTO_UDP,
1771                 .help                   = ras_help,
1772                 .expect_policy          = &ras_exp_policy,
1773         },
1774 };
1775
1776 static int __init h323_helper_init(void)
1777 {
1778         int ret;
1779
1780         ret = nf_conntrack_helper_register(&nf_conntrack_helper_h245);
1781         if (ret < 0)
1782                 return ret;
1783         ret = nf_conntrack_helpers_register(nf_conntrack_helper_q931,
1784                                         ARRAY_SIZE(nf_conntrack_helper_q931));
1785         if (ret < 0)
1786                 goto err1;
1787         ret = nf_conntrack_helpers_register(nf_conntrack_helper_ras,
1788                                         ARRAY_SIZE(nf_conntrack_helper_ras));
1789         if (ret < 0)
1790                 goto err2;
1791
1792         return 0;
1793 err2:
1794         nf_conntrack_helpers_unregister(nf_conntrack_helper_q931,
1795                                         ARRAY_SIZE(nf_conntrack_helper_q931));
1796 err1:
1797         nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1798         return ret;
1799 }
1800
1801 static void __exit h323_helper_exit(void)
1802 {
1803         nf_conntrack_helpers_unregister(nf_conntrack_helper_ras,
1804                                         ARRAY_SIZE(nf_conntrack_helper_ras));
1805         nf_conntrack_helpers_unregister(nf_conntrack_helper_q931,
1806                                         ARRAY_SIZE(nf_conntrack_helper_q931));
1807         nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1808 }
1809
1810 static void __exit nf_conntrack_h323_fini(void)
1811 {
1812         h323_helper_exit();
1813         kfree(h323_buffer);
1814         pr_debug("nf_ct_h323: fini\n");
1815 }
1816
1817 static int __init nf_conntrack_h323_init(void)
1818 {
1819         int ret;
1820
1821         NF_CT_HELPER_BUILD_BUG_ON(sizeof(struct nf_ct_h323_master));
1822
1823         h323_buffer = kmalloc(65536, GFP_KERNEL);
1824         if (!h323_buffer)
1825                 return -ENOMEM;
1826         ret = h323_helper_init();
1827         if (ret < 0)
1828                 goto err1;
1829         pr_debug("nf_ct_h323: init success\n");
1830         return 0;
1831 err1:
1832         kfree(h323_buffer);
1833         return ret;
1834 }
1835
1836 module_init(nf_conntrack_h323_init);
1837 module_exit(nf_conntrack_h323_fini);
1838
1839 EXPORT_SYMBOL_GPL(get_h225_addr);
1840 EXPORT_SYMBOL_GPL(set_h245_addr_hook);
1841 EXPORT_SYMBOL_GPL(set_h225_addr_hook);
1842 EXPORT_SYMBOL_GPL(set_sig_addr_hook);
1843 EXPORT_SYMBOL_GPL(set_ras_addr_hook);
1844 EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook);
1845 EXPORT_SYMBOL_GPL(nat_t120_hook);
1846 EXPORT_SYMBOL_GPL(nat_h245_hook);
1847 EXPORT_SYMBOL_GPL(nat_callforwarding_hook);
1848 EXPORT_SYMBOL_GPL(nat_q931_hook);
1849
1850 MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>");
1851 MODULE_DESCRIPTION("H.323 connection tracking helper");
1852 MODULE_LICENSE("GPL");
1853 MODULE_ALIAS("ip_conntrack_h323");
1854 MODULE_ALIAS_NFCT_HELPER("RAS");
1855 MODULE_ALIAS_NFCT_HELPER("Q.931");
1856 MODULE_ALIAS_NFCT_HELPER("H.245");