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   1 /*
   2  * H.323 connection tracking helper
   3  *
   4  * Copyright (c) 2006 Jing Min Zhao <zhaojingmin@users.sourceforge.net>
   5  *
   6  * This source code is licensed under General Public License version 2.
   7  *
   8  * Based on the 'brute force' H.323 connection tracking module by
   9  * Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
  10  *
  11  * For more information, please see http://nath323.sourceforge.net/
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/moduleparam.h>
  16 #include <linux/ctype.h>
  17 #include <linux/inet.h>
  18 #include <linux/in.h>
  19 #include <linux/ip.h>
  20 #include <linux/udp.h>
  21 #include <linux/tcp.h>
  22 #include <linux/skbuff.h>
  23 #include <net/route.h>
  24 #include <net/ip6_route.h>
  25
  26 #include <net/netfilter/nf_conntrack.h>
  27 #include <net/netfilter/nf_conntrack_core.h>
  28 #include <net/netfilter/nf_conntrack_tuple.h>
  29 #include <net/netfilter/nf_conntrack_expect.h>
  30 #include <net/netfilter/nf_conntrack_ecache.h>
  31 #include <net/netfilter/nf_conntrack_helper.h>
  32 #include <linux/netfilter/nf_conntrack_h323.h>
  33
  34 /* Parameters */
  35 static unsigned int default_rrq_ttl __read_mostly = 300;
  36 module_param(default_rrq_ttl, uint, 0600);
  37 MODULE_PARM_DESC(default_rrq_ttl, "use this TTL if it's missing in RRQ");
  38
  39 static int gkrouted_only __read_mostly = 1;
  40 module_param(gkrouted_only, int, 0600);
  41 MODULE_PARM_DESC(gkrouted_only, "only accept calls from gatekeeper");
  42
  43 static int callforward_filter __read_mostly = 1;
  44 module_param(callforward_filter, bool, 0600);
  45 MODULE_PARM_DESC(callforward_filter, "only create call forwarding expectations "
  46                                      "if both endpoints are on different sides "
  47                                      "(determined by routing information)");
  48
  49 /* Hooks for NAT */
  50 int (*set_h245_addr_hook) (struct sk_buff *skb,
  51                            unsigned char **data, int dataoff,
  52                            H245_TransportAddress *taddr,
  53                            union nf_conntrack_address *addr, __be16 port)
  54                            __read_mostly;
  55 int (*set_h225_addr_hook) (struct sk_buff *skb,
  56                            unsigned char **data, int dataoff,
  57                            TransportAddress *taddr,
  58                            union nf_conntrack_address *addr, __be16 port)
  59                            __read_mostly;
  60 int (*set_sig_addr_hook) (struct sk_buff *skb,
  61                           struct nf_conn *ct,
  62                           enum ip_conntrack_info ctinfo,
  63                           unsigned char **data,
  64                           TransportAddress *taddr, int count) __read_mostly;
  65 int (*set_ras_addr_hook) (struct sk_buff *skb,
  66                           struct nf_conn *ct,
  67                           enum ip_conntrack_info ctinfo,
  68                           unsigned char **data,
  69                           TransportAddress *taddr, int count) __read_mostly;
  70 int (*nat_rtp_rtcp_hook) (struct sk_buff *skb,
  71                           struct nf_conn *ct,
  72                           enum ip_conntrack_info ctinfo,
  73                           unsigned char **data, int dataoff,
  74                           H245_TransportAddress *taddr,
  75                           __be16 port, __be16 rtp_port,
  76                           struct nf_conntrack_expect *rtp_exp,
  77                           struct nf_conntrack_expect *rtcp_exp) __read_mostly;
  78 int (*nat_t120_hook) (struct sk_buff *skb,
  79                       struct nf_conn *ct,
  80                       enum ip_conntrack_info ctinfo,
  81                       unsigned char **data, int dataoff,
  82                       H245_TransportAddress *taddr, __be16 port,
  83                       struct nf_conntrack_expect *exp) __read_mostly;
  84 int (*nat_h245_hook) (struct sk_buff *skb,
  85                       struct nf_conn *ct,
  86                       enum ip_conntrack_info ctinfo,
  87                       unsigned char **data, int dataoff,
  88                       TransportAddress *taddr, __be16 port,
  89                       struct nf_conntrack_expect *exp) __read_mostly;
  90 int (*nat_callforwarding_hook) (struct sk_buff *skb,
  91                                 struct nf_conn *ct,
  92                                 enum ip_conntrack_info ctinfo,
  93                                 unsigned char **data, int dataoff,
  94                                 TransportAddress *taddr, __be16 port,
  95                                 struct nf_conntrack_expect *exp) __read_mostly;
  96 int (*nat_q931_hook) (struct sk_buff *skb,
  97                       struct nf_conn *ct,
  98                       enum ip_conntrack_info ctinfo,
  99                       unsigned char **data, TransportAddress *taddr, int idx,
 100                       __be16 port, struct nf_conntrack_expect *exp)
 101                       __read_mostly;
 102
 103 static DEFINE_SPINLOCK(nf_h323_lock);
 104 static char *h323_buffer;
 105
 106 static struct nf_conntrack_helper nf_conntrack_helper_h245;
 107 static struct nf_conntrack_helper nf_conntrack_helper_q931[];
 108 static struct nf_conntrack_helper nf_conntrack_helper_ras[];
 109
 110 /****************************************************************************/
 111 static int get_tpkt_data(struct sk_buff *skb, unsigned int protoff,
 112                          struct nf_conn *ct, enum ip_conntrack_info ctinfo,
 113                          unsigned char **data, int *datalen, int *dataoff)
 114 {
 115         struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
 116         int dir = CTINFO2DIR(ctinfo);
 117         struct tcphdr _tcph, *th;
 118         int tcpdatalen;
 119         int tcpdataoff;
 120         unsigned char *tpkt;
 121         int tpktlen;
 122         int tpktoff;
 123
 124         /* Get TCP header */
 125         th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph);
 126         if (th == NULL)
 127                 return 0;
 128
 129         /* Get TCP data offset */
 130         tcpdataoff = protoff + th->doff * 4;
 131
 132         /* Get TCP data length */
 133         tcpdatalen = skb->len - tcpdataoff;
 134         if (tcpdatalen <= 0)    /* No TCP data */
 135                 goto clear_out;
 136
 137         if (*data == NULL) {    /* first TPKT */
 138                 /* Get first TPKT pointer */
 139                 tpkt = skb_header_pointer(skb, tcpdataoff, tcpdatalen,
 140                                           h323_buffer);
 141                 BUG_ON(tpkt == NULL);
 142
 143                 /* Validate TPKT identifier */
 144                 if (tcpdatalen < 4 || tpkt[0] != 0x03 || tpkt[1] != 0) {
 145                         /* Netmeeting sends TPKT header and data separately */
 146                         if (info->tpkt_len[dir] > 0) {
 147                                 pr_debug("nf_ct_h323: previous packet "
 148                                          "indicated separate TPKT data of %hu "
 149                                          "bytes\n", info->tpkt_len[dir]);
 150                                 if (info->tpkt_len[dir] <= tcpdatalen) {
 151                                         /* Yes, there was a TPKT header
 152                                          * received */
 153                                         *data = tpkt;
 154                                         *datalen = info->tpkt_len[dir];
 155                                         *dataoff = 0;
 156                                         goto out;
 157                                 }
 158
 159                                 /* Fragmented TPKT */
 160                                 pr_debug("nf_ct_h323: fragmented TPKT\n");
 161                                 goto clear_out;
 162                         }
 163
 164                         /* It is not even a TPKT */
 165                         return 0;
 166                 }
 167                 tpktoff = 0;
 168         } else {                /* Next TPKT */
 169                 tpktoff = *dataoff + *datalen;
 170                 tcpdatalen -= tpktoff;
 171                 if (tcpdatalen <= 4)    /* No more TPKT */
 172                         goto clear_out;
 173                 tpkt = *data + *datalen;
 174
 175                 /* Validate TPKT identifier */
 176                 if (tpkt[0] != 0x03 || tpkt[1] != 0)
 177                         goto clear_out;
 178         }
 179
 180         /* Validate TPKT length */
 181         tpktlen = tpkt[2] * 256 + tpkt[3];
 182         if (tpktlen < 4)
 183                 goto clear_out;
 184         if (tpktlen > tcpdatalen) {
 185                 if (tcpdatalen == 4) {  /* Separate TPKT header */
 186                         /* Netmeeting sends TPKT header and data separately */
 187                         pr_debug("nf_ct_h323: separate TPKT header indicates "
 188                                  "there will be TPKT data of %hu bytes\n",
 189                                  tpktlen - 4);
 190                         info->tpkt_len[dir] = tpktlen - 4;
 191                         return 0;
 192                 }
 193
 194                 if (net_ratelimit())
 195                         printk("nf_ct_h323: incomplete TPKT (fragmented?)\n");
 196                 goto clear_out;
 197         }
 198
 199         /* This is the encapsulated data */
 200         *data = tpkt + 4;
 201         *datalen = tpktlen - 4;
 202         *dataoff = tpktoff + 4;
 203
 204       out:
 205         /* Clear TPKT length */
 206         info->tpkt_len[dir] = 0;
 207         return 1;
 208
 209       clear_out:
 210         info->tpkt_len[dir] = 0;
 211         return 0;
 212 }
 213
 214 /****************************************************************************/
 215 static int get_h245_addr(struct nf_conn *ct, unsigned char *data,
 216                          H245_TransportAddress *taddr,
 217                          union nf_conntrack_address *addr, __be16 *port)
 218 {
 219         unsigned char *p;
 220         int family = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
 221         int len;
 222
 223         if (taddr->choice != eH245_TransportAddress_unicastAddress)
 224                 return 0;
 225
 226         switch (taddr->unicastAddress.choice) {
 227         case eUnicastAddress_iPAddress:
 228                 if (family != AF_INET)
 229                         return 0;
 230                 p = data + taddr->unicastAddress.iPAddress.network;
 231                 len = 4;
 232                 break;
 233         case eUnicastAddress_iP6Address:
 234                 if (family != AF_INET6)
 235                         return 0;
 236                 p = data + taddr->unicastAddress.iP6Address.network;
 237                 len = 16;
 238                 break;
 239         default:
 240                 return 0;
 241         }
 242
 243         memcpy(addr, p, len);
 244         memset((void *)addr + len, 0, sizeof(*addr) - len);
 245         memcpy(port, p + len, sizeof(__be16));
 246
 247         return 1;
 248 }
 249
 250 /****************************************************************************/
 251 static int expect_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct,
 252                            enum ip_conntrack_info ctinfo,
 253                            unsigned char **data, int dataoff,
 254                            H245_TransportAddress *taddr)
 255 {
 256         int dir = CTINFO2DIR(ctinfo);
 257         int ret = 0;
 258         __be16 port;
 259         __be16 rtp_port, rtcp_port;
 260         union nf_conntrack_address addr;
 261         struct nf_conntrack_expect *rtp_exp;
 262         struct nf_conntrack_expect *rtcp_exp;
 263         typeof(nat_rtp_rtcp_hook) nat_rtp_rtcp;
 264
 265         /* Read RTP or RTCP address */
 266         if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
 267             memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 268             port == 0)
 269                 return 0;
 270
 271         /* RTP port is even */
 272         port &= htons(~1);
 273         rtp_port = port;
 274         rtcp_port = htons(ntohs(port) + 1);
 275
 276         /* Create expect for RTP */
 277         if ((rtp_exp = nf_ct_expect_alloc(ct)) == NULL)
 278                 return -1;
 279         nf_ct_expect_init(rtp_exp, ct->tuplehash[!dir].tuple.src.l3num,
 280                           &ct->tuplehash[!dir].tuple.src.u3,
 281                           &ct->tuplehash[!dir].tuple.dst.u3,
 282                           IPPROTO_UDP, NULL, &rtp_port);
 283
 284         /* Create expect for RTCP */
 285         if ((rtcp_exp = nf_ct_expect_alloc(ct)) == NULL) {
 286                 nf_ct_expect_put(rtp_exp);
 287                 return -1;
 288         }
 289         nf_ct_expect_init(rtcp_exp, ct->tuplehash[!dir].tuple.src.l3num,
 290                           &ct->tuplehash[!dir].tuple.src.u3,
 291                           &ct->tuplehash[!dir].tuple.dst.u3,
 292                           IPPROTO_UDP, NULL, &rtcp_port);
 293
 294         if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 295                    &ct->tuplehash[!dir].tuple.dst.u3,
 296                    sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 297                    (nat_rtp_rtcp = rcu_dereference(nat_rtp_rtcp_hook)) &&
 298                    ct->status & IPS_NAT_MASK) {
 299                 /* NAT needed */
 300                 ret = nat_rtp_rtcp(skb, ct, ctinfo, data, dataoff,
 301                                    taddr, port, rtp_port, rtp_exp, rtcp_exp);
 302         } else {                /* Conntrack only */
 303                 if (nf_ct_expect_related(rtp_exp) == 0) {
 304                         if (nf_ct_expect_related(rtcp_exp) == 0) {
 305                                 pr_debug("nf_ct_h323: expect RTP ");
 306                                 NF_CT_DUMP_TUPLE(&rtp_exp->tuple);
 307                                 pr_debug("nf_ct_h323: expect RTCP ");
 308                                 NF_CT_DUMP_TUPLE(&rtcp_exp->tuple);
 309                         } else {
 310                                 nf_ct_unexpect_related(rtp_exp);
 311                                 ret = -1;
 312                         }
 313                 } else
 314                         ret = -1;
 315         }
 316
 317         nf_ct_expect_put(rtp_exp);
 318         nf_ct_expect_put(rtcp_exp);
 319
 320         return ret;
 321 }
 322
 323 /****************************************************************************/
 324 static int expect_t120(struct sk_buff *skb,
 325                        struct nf_conn *ct,
 326                        enum ip_conntrack_info ctinfo,
 327                        unsigned char **data, int dataoff,
 328                        H245_TransportAddress *taddr)
 329 {
 330         int dir = CTINFO2DIR(ctinfo);
 331         int ret = 0;
 332         __be16 port;
 333         union nf_conntrack_address addr;
 334         struct nf_conntrack_expect *exp;
 335         typeof(nat_t120_hook) nat_t120;
 336
 337         /* Read T.120 address */
 338         if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
 339             memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 340             port == 0)
 341                 return 0;
 342
 343         /* Create expect for T.120 connections */
 344         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 345                 return -1;
 346         nf_ct_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
 347                           &ct->tuplehash[!dir].tuple.src.u3,
 348                           &ct->tuplehash[!dir].tuple.dst.u3,
 349                           IPPROTO_TCP, NULL, &port);
 350         exp->flags = NF_CT_EXPECT_PERMANENT;    /* Accept multiple channels */
 351
 352         if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 353                    &ct->tuplehash[!dir].tuple.dst.u3,
 354                    sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 355             (nat_t120 = rcu_dereference(nat_t120_hook)) &&
 356             ct->status & IPS_NAT_MASK) {
 357                 /* NAT needed */
 358                 ret = nat_t120(skb, ct, ctinfo, data, dataoff, taddr,
 359                                port, exp);
 360         } else {                /* Conntrack only */
 361                 if (nf_ct_expect_related(exp) == 0) {
 362                         pr_debug("nf_ct_h323: expect T.120 ");
 363                         NF_CT_DUMP_TUPLE(&exp->tuple);
 364                 } else
 365                         ret = -1;
 366         }
 367
 368         nf_ct_expect_put(exp);
 369
 370         return ret;
 371 }
 372
 373 /****************************************************************************/
 374 static int process_h245_channel(struct sk_buff *skb,
 375                                 struct nf_conn *ct,
 376                                 enum ip_conntrack_info ctinfo,
 377                                 unsigned char **data, int dataoff,
 378                                 H2250LogicalChannelParameters *channel)
 379 {
 380         int ret;
 381
 382         if (channel->options & eH2250LogicalChannelParameters_mediaChannel) {
 383                 /* RTP */
 384                 ret = expect_rtp_rtcp(skb, ct, ctinfo, data, dataoff,
 385                                       &channel->mediaChannel);
 386                 if (ret < 0)
 387                         return -1;
 388         }
 389
 390         if (channel->
 391             options & eH2250LogicalChannelParameters_mediaControlChannel) {
 392                 /* RTCP */
 393                 ret = expect_rtp_rtcp(skb, ct, ctinfo, data, dataoff,
 394                                       &channel->mediaControlChannel);
 395                 if (ret < 0)
 396                         return -1;
 397         }
 398
 399         return 0;
 400 }
 401
 402 /****************************************************************************/
 403 static int process_olc(struct sk_buff *skb, struct nf_conn *ct,
 404                        enum ip_conntrack_info ctinfo,
 405                        unsigned char **data, int dataoff,
 406                        OpenLogicalChannel *olc)
 407 {
 408         int ret;
 409
 410         pr_debug("nf_ct_h323: OpenLogicalChannel\n");
 411
 412         if (olc->forwardLogicalChannelParameters.multiplexParameters.choice ==
 413             eOpenLogicalChannel_forwardLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters)
 414         {
 415                 ret = process_h245_channel(skb, ct, ctinfo, data, dataoff,
 416                                            &olc->
 417                                            forwardLogicalChannelParameters.
 418                                            multiplexParameters.
 419                                            h2250LogicalChannelParameters);
 420                 if (ret < 0)
 421                         return -1;
 422         }
 423
 424         if ((olc->options &
 425              eOpenLogicalChannel_reverseLogicalChannelParameters) &&
 426             (olc->reverseLogicalChannelParameters.options &
 427              eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters)
 428             && (olc->reverseLogicalChannelParameters.multiplexParameters.
 429                 choice ==
 430                 eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
 431         {
 432                 ret =
 433                     process_h245_channel(skb, ct, ctinfo, data, dataoff,
 434                                          &olc->
 435                                          reverseLogicalChannelParameters.
 436                                          multiplexParameters.
 437                                          h2250LogicalChannelParameters);
 438                 if (ret < 0)
 439                         return -1;
 440         }
 441
 442         if ((olc->options & eOpenLogicalChannel_separateStack) &&
 443             olc->forwardLogicalChannelParameters.dataType.choice ==
 444             eDataType_data &&
 445             olc->forwardLogicalChannelParameters.dataType.data.application.
 446             choice == eDataApplicationCapability_application_t120 &&
 447             olc->forwardLogicalChannelParameters.dataType.data.application.
 448             t120.choice == eDataProtocolCapability_separateLANStack &&
 449             olc->separateStack.networkAddress.choice ==
 450             eNetworkAccessParameters_networkAddress_localAreaAddress) {
 451                 ret = expect_t120(skb, ct, ctinfo, data, dataoff,
 452                                   &olc->separateStack.networkAddress.
 453                                   localAreaAddress);
 454                 if (ret < 0)
 455                         return -1;
 456         }
 457
 458         return 0;
 459 }
 460
 461 /****************************************************************************/
 462 static int process_olca(struct sk_buff *skb, struct nf_conn *ct,
 463                         enum ip_conntrack_info ctinfo,
 464                         unsigned char **data, int dataoff,
 465                         OpenLogicalChannelAck *olca)
 466 {
 467         H2250LogicalChannelAckParameters *ack;
 468         int ret;
 469
 470         pr_debug("nf_ct_h323: OpenLogicalChannelAck\n");
 471
 472         if ((olca->options &
 473              eOpenLogicalChannelAck_reverseLogicalChannelParameters) &&
 474             (olca->reverseLogicalChannelParameters.options &
 475              eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters)
 476             && (olca->reverseLogicalChannelParameters.multiplexParameters.
 477                 choice ==
 478                 eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
 479         {
 480                 ret = process_h245_channel(skb, ct, ctinfo, data, dataoff,
 481                                            &olca->
 482                                            reverseLogicalChannelParameters.
 483                                            multiplexParameters.
 484                                            h2250LogicalChannelParameters);
 485                 if (ret < 0)
 486                         return -1;
 487         }
 488
 489         if ((olca->options &
 490              eOpenLogicalChannelAck_forwardMultiplexAckParameters) &&
 491             (olca->forwardMultiplexAckParameters.choice ==
 492              eOpenLogicalChannelAck_forwardMultiplexAckParameters_h2250LogicalChannelAckParameters))
 493         {
 494                 ack = &olca->forwardMultiplexAckParameters.
 495                     h2250LogicalChannelAckParameters;
 496                 if (ack->options &
 497                     eH2250LogicalChannelAckParameters_mediaChannel) {
 498                         /* RTP */
 499                         ret = expect_rtp_rtcp(skb, ct, ctinfo, data, dataoff,
 500                                               &ack->mediaChannel);
 501                         if (ret < 0)
 502                                 return -1;
 503                 }
 504
 505                 if (ack->options &
 506                     eH2250LogicalChannelAckParameters_mediaControlChannel) {
 507                         /* RTCP */
 508                         ret = expect_rtp_rtcp(skb, ct, ctinfo, data, dataoff,
 509                                               &ack->mediaControlChannel);
 510                         if (ret < 0)
 511                                 return -1;
 512                 }
 513         }
 514
 515         if ((olca->options & eOpenLogicalChannelAck_separateStack) &&
 516                 olca->separateStack.networkAddress.choice ==
 517                 eNetworkAccessParameters_networkAddress_localAreaAddress) {
 518                 ret = expect_t120(skb, ct, ctinfo, data, dataoff,
 519                                   &olca->separateStack.networkAddress.
 520                                   localAreaAddress);
 521                 if (ret < 0)
 522                         return -1;
 523         }
 524
 525         return 0;
 526 }
 527
 528 /****************************************************************************/
 529 static int process_h245(struct sk_buff *skb, struct nf_conn *ct,
 530                         enum ip_conntrack_info ctinfo,
 531                         unsigned char **data, int dataoff,
 532                         MultimediaSystemControlMessage *mscm)
 533 {
 534         switch (mscm->choice) {
 535         case eMultimediaSystemControlMessage_request:
 536                 if (mscm->request.choice ==
 537                     eRequestMessage_openLogicalChannel) {
 538                         return process_olc(skb, ct, ctinfo, data, dataoff,
 539                                            &mscm->request.openLogicalChannel);
 540                 }
 541                 pr_debug("nf_ct_h323: H.245 Request %d\n",
 542                          mscm->request.choice);
 543                 break;
 544         case eMultimediaSystemControlMessage_response:
 545                 if (mscm->response.choice ==
 546                     eResponseMessage_openLogicalChannelAck) {
 547                         return process_olca(skb, ct, ctinfo, data, dataoff,
 548                                             &mscm->response.
 549                                             openLogicalChannelAck);
 550                 }
 551                 pr_debug("nf_ct_h323: H.245 Response %d\n",
 552                          mscm->response.choice);
 553                 break;
 554         default:
 555                 pr_debug("nf_ct_h323: H.245 signal %d\n", mscm->choice);
 556                 break;
 557         }
 558
 559         return 0;
 560 }
 561
 562 /****************************************************************************/
 563 static int h245_help(struct sk_buff *skb, unsigned int protoff,
 564                      struct nf_conn *ct, enum ip_conntrack_info ctinfo)
 565 {
 566         static MultimediaSystemControlMessage mscm;
 567         unsigned char *data = NULL;
 568         int datalen;
 569         int dataoff;
 570         int ret;
 571
 572         /* Until there's been traffic both ways, don't look in packets. */
 573         if (ctinfo != IP_CT_ESTABLISHED &&
 574             ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) {
 575                 return NF_ACCEPT;
 576         }
 577         pr_debug("nf_ct_h245: skblen = %u\n", skb->len);
 578
 579         spin_lock_bh(&nf_h323_lock);
 580
 581         /* Process each TPKT */
 582         while (get_tpkt_data(skb, protoff, ct, ctinfo,
 583                              &data, &datalen, &dataoff)) {
 584                 pr_debug("nf_ct_h245: TPKT len=%d ", datalen);
 585                 NF_CT_DUMP_TUPLE(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
 586
 587                 /* Decode H.245 signal */
 588                 ret = DecodeMultimediaSystemControlMessage(data, datalen,
 589                                                            &mscm);
 590                 if (ret < 0) {
 591                         pr_debug("nf_ct_h245: decoding error: %s\n",
 592                                  ret == H323_ERROR_BOUND ?
 593                                  "out of bound" : "out of range");
 594                         /* We don't drop when decoding error */
 595                         break;
 596                 }
 597
 598                 /* Process H.245 signal */
 599                 if (process_h245(skb, ct, ctinfo, &data, dataoff, &mscm) < 0)
 600                         goto drop;
 601         }
 602
 603         spin_unlock_bh(&nf_h323_lock);
 604         return NF_ACCEPT;
 605
 606       drop:
 607         spin_unlock_bh(&nf_h323_lock);
 608         if (net_ratelimit())
 609                 printk("nf_ct_h245: packet dropped\n");
 610         return NF_DROP;
 611 }
 612
 613 /****************************************************************************/
 614 static struct nf_conntrack_helper nf_conntrack_helper_h245 __read_mostly = {
 615         .name                   = "H.245",
 616         .me                     = THIS_MODULE,
 617         .max_expected           = H323_RTP_CHANNEL_MAX * 4 + 2 /* T.120 */,
 618         .timeout                = 240,
 619         .tuple.dst.protonum     = IPPROTO_UDP,
 620         .help                   = h245_help
 621 };
 622
 623 /****************************************************************************/
 624 int get_h225_addr(struct nf_conn *ct, unsigned char *data,
 625                   TransportAddress *taddr,
 626                   union nf_conntrack_address *addr, __be16 *port)
 627 {
 628         unsigned char *p;
 629         int family = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
 630         int len;
 631
 632         switch (taddr->choice) {
 633         case eTransportAddress_ipAddress:
 634                 if (family != AF_INET)
 635                         return 0;
 636                 p = data + taddr->ipAddress.ip;
 637                 len = 4;
 638                 break;
 639         case eTransportAddress_ip6Address:
 640                 if (family != AF_INET6)
 641                         return 0;
 642                 p = data + taddr->ip6Address.ip;
 643                 len = 16;
 644                 break;
 645         default:
 646                 return 0;
 647         }
 648
 649         memcpy(addr, p, len);
 650         memset((void *)addr + len, 0, sizeof(*addr) - len);
 651         memcpy(port, p + len, sizeof(__be16));
 652
 653         return 1;
 654 }
 655
 656 /****************************************************************************/
 657 static int expect_h245(struct sk_buff *skb, struct nf_conn *ct,
 658                        enum ip_conntrack_info ctinfo,
 659                        unsigned char **data, int dataoff,
 660                        TransportAddress *taddr)
 661 {
 662         int dir = CTINFO2DIR(ctinfo);
 663         int ret = 0;
 664         __be16 port;
 665         union nf_conntrack_address addr;
 666         struct nf_conntrack_expect *exp;
 667         typeof(nat_h245_hook) nat_h245;
 668
 669         /* Read h245Address */
 670         if (!get_h225_addr(ct, *data, taddr, &addr, &port) ||
 671             memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 672             port == 0)
 673                 return 0;
 674
 675         /* Create expect for h245 connection */
 676         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 677                 return -1;
 678         nf_ct_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
 679                           &ct->tuplehash[!dir].tuple.src.u3,
 680                           &ct->tuplehash[!dir].tuple.dst.u3,
 681                           IPPROTO_TCP, NULL, &port);
 682         exp->helper = &nf_conntrack_helper_h245;
 683
 684         if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 685                    &ct->tuplehash[!dir].tuple.dst.u3,
 686                    sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 687             (nat_h245 = rcu_dereference(nat_h245_hook)) &&
 688             ct->status & IPS_NAT_MASK) {
 689                 /* NAT needed */
 690                 ret = nat_h245(skb, ct, ctinfo, data, dataoff, taddr,
 691                                port, exp);
 692         } else {                /* Conntrack only */
 693                 if (nf_ct_expect_related(exp) == 0) {
 694                         pr_debug("nf_ct_q931: expect H.245 ");
 695                         NF_CT_DUMP_TUPLE(&exp->tuple);
 696                 } else
 697                         ret = -1;
 698         }
 699
 700         nf_ct_expect_put(exp);
 701
 702         return ret;
 703 }
 704
 705 /* If the calling party is on the same side of the forward-to party,
 706  * we don't need to track the second call */
 707 static int callforward_do_filter(union nf_conntrack_address *src,
 708                                  union nf_conntrack_address *dst,
 709                                  int family)
 710 {
 711         const struct nf_afinfo *afinfo;
 712         struct flowi fl1, fl2;
 713         int ret = 0;
 714
 715         /* rcu_read_lock()ed by nf_hook_slow() */
 716         afinfo = nf_get_afinfo(family);
 717         if (!afinfo)
 718                 return 0;
 719
 720         memset(&fl1, 0, sizeof(fl1));
 721         memset(&fl2, 0, sizeof(fl2));
 722
 723         switch (family) {
 724         case AF_INET: {
 725                 struct rtable *rt1, *rt2;
 726
 727                 fl1.fl4_dst = src->ip;
 728                 fl2.fl4_dst = dst->ip;
 729                 if (!afinfo->route((struct dst_entry **)&rt1, &fl1)) {
 730                         if (!afinfo->route((struct dst_entry **)&rt2, &fl2)) {
 731                                 if (rt1->rt_gateway == rt2->rt_gateway &&
 732                                     rt1->u.dst.dev  == rt2->u.dst.dev)
 733                                         ret = 1;
 734                                 dst_release(&rt2->u.dst);
 735                         }
 736                         dst_release(&rt1->u.dst);
 737                 }
 738                 break;
 739         }
 740 #if defined(CONFIG_NF_CONNTRACK_IPV6) || \
 741     defined(CONFIG_NF_CONNTRACK_IPV6_MODULE)
 742         case AF_INET6: {
 743                 struct rt6_info *rt1, *rt2;
 744
 745                 memcpy(&fl1.fl6_dst, src, sizeof(fl1.fl6_dst));
 746                 memcpy(&fl2.fl6_dst, dst, sizeof(fl2.fl6_dst));
 747                 if (!afinfo->route((struct dst_entry **)&rt1, &fl1)) {
 748                         if (!afinfo->route((struct dst_entry **)&rt2, &fl2)) {
 749                                 if (!memcmp(&rt1->rt6i_gateway, &rt2->rt6i_gateway,
 750                                             sizeof(rt1->rt6i_gateway)) &&
 751                                     rt1->u.dst.dev == rt2->u.dst.dev)
 752                                         ret = 1;
 753                                 dst_release(&rt2->u.dst);
 754                         }
 755                         dst_release(&rt1->u.dst);
 756                 }
 757                 break;
 758         }
 759 #endif
 760         }
 761         return ret;
 762
 763 }
 764
 765 /****************************************************************************/
 766 static int expect_callforwarding(struct sk_buff *skb,
 767                                  struct nf_conn *ct,
 768                                  enum ip_conntrack_info ctinfo,
 769                                  unsigned char **data, int dataoff,
 770                                  TransportAddress *taddr)
 771 {
 772         int dir = CTINFO2DIR(ctinfo);
 773         int ret = 0;
 774         __be16 port;
 775         union nf_conntrack_address addr;
 776         struct nf_conntrack_expect *exp;
 777         typeof(nat_callforwarding_hook) nat_callforwarding;
 778
 779         /* Read alternativeAddress */
 780         if (!get_h225_addr(ct, *data, taddr, &addr, &port) || port == 0)
 781                 return 0;
 782
 783         /* If the calling party is on the same side of the forward-to party,
 784          * we don't need to track the second call */
 785         if (callforward_filter &&
 786             callforward_do_filter(&addr, &ct->tuplehash[!dir].tuple.src.u3,
 787                                   ct->tuplehash[!dir].tuple.src.l3num)) {
 788                 pr_debug("nf_ct_q931: Call Forwarding not tracked\n");
 789                 return 0;
 790         }
 791
 792         /* Create expect for the second call leg */
 793         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 794                 return -1;
 795         nf_ct_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
 796                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
 797                           IPPROTO_TCP, NULL, &port);
 798         exp->helper = nf_conntrack_helper_q931;
 799
 800         if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 801                    &ct->tuplehash[!dir].tuple.dst.u3,
 802                    sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 803             (nat_callforwarding = rcu_dereference(nat_callforwarding_hook)) &&
 804             ct->status & IPS_NAT_MASK) {
 805                 /* Need NAT */
 806                 ret = nat_callforwarding(skb, ct, ctinfo, data, dataoff,
 807                                          taddr, port, exp);
 808         } else {                /* Conntrack only */
 809                 if (nf_ct_expect_related(exp) == 0) {
 810                         pr_debug("nf_ct_q931: expect Call Forwarding ");
 811                         NF_CT_DUMP_TUPLE(&exp->tuple);
 812                 } else
 813                         ret = -1;
 814         }
 815
 816         nf_ct_expect_put(exp);
 817
 818         return ret;
 819 }
 820
 821 /****************************************************************************/
 822 static int process_setup(struct sk_buff *skb, struct nf_conn *ct,
 823                          enum ip_conntrack_info ctinfo,
 824                          unsigned char **data, int dataoff,
 825                          Setup_UUIE *setup)
 826 {
 827         int dir = CTINFO2DIR(ctinfo);
 828         int ret;
 829         int i;
 830         __be16 port;
 831         union nf_conntrack_address addr;
 832         typeof(set_h225_addr_hook) set_h225_addr;
 833
 834         pr_debug("nf_ct_q931: Setup\n");
 835
 836         if (setup->options & eSetup_UUIE_h245Address) {
 837                 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
 838                                   &setup->h245Address);
 839                 if (ret < 0)
 840                         return -1;
 841         }
 842
 843         set_h225_addr = rcu_dereference(set_h225_addr_hook);
 844         if ((setup->options & eSetup_UUIE_destCallSignalAddress) &&
 845             (set_h225_addr) && ct->status && IPS_NAT_MASK &&
 846             get_h225_addr(ct, *data, &setup->destCallSignalAddress,
 847                           &addr, &port) &&
 848             memcmp(&addr, &ct->tuplehash[!dir].tuple.src.u3, sizeof(addr))) {
 849                 pr_debug("nf_ct_q931: set destCallSignalAddress "
 850                          NIP6_FMT ":%hu->" NIP6_FMT ":%hu\n",
 851                          NIP6(*(struct in6_addr *)&addr), ntohs(port),
 852                          NIP6(*(struct in6_addr *)&ct->tuplehash[!dir].tuple.src.u3),
 853                          ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port));
 854                 ret = set_h225_addr(skb, data, dataoff,
 855                                     &setup->destCallSignalAddress,
 856                                     &ct->tuplehash[!dir].tuple.src.u3,
 857                                     ct->tuplehash[!dir].tuple.src.u.tcp.port);
 858                 if (ret < 0)
 859                         return -1;
 860         }
 861
 862         if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) &&
 863             (set_h225_addr) && ct->status & IPS_NAT_MASK &&
 864             get_h225_addr(ct, *data, &setup->sourceCallSignalAddress,
 865                           &addr, &port) &&
 866             memcmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(addr))) {
 867                 pr_debug("nf_ct_q931: set sourceCallSignalAddress "
 868                          NIP6_FMT ":%hu->" NIP6_FMT ":%hu\n",
 869                          NIP6(*(struct in6_addr *)&addr), ntohs(port),
 870                          NIP6(*(struct in6_addr *)&ct->tuplehash[!dir].tuple.dst.u3),
 871                          ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port));
 872                 ret = set_h225_addr(skb, data, dataoff,
 873                                     &setup->sourceCallSignalAddress,
 874                                     &ct->tuplehash[!dir].tuple.dst.u3,
 875                                     ct->tuplehash[!dir].tuple.dst.u.tcp.port);
 876                 if (ret < 0)
 877                         return -1;
 878         }
 879
 880         if (setup->options & eSetup_UUIE_fastStart) {
 881                 for (i = 0; i < setup->fastStart.count; i++) {
 882                         ret = process_olc(skb, ct, ctinfo, data, dataoff,
 883                                           &setup->fastStart.item[i]);
 884                         if (ret < 0)
 885                                 return -1;
 886                 }
 887         }
 888
 889         return 0;
 890 }
 891
 892 /****************************************************************************/
 893 static int process_callproceeding(struct sk_buff *skb,
 894                                   struct nf_conn *ct,
 895                                   enum ip_conntrack_info ctinfo,
 896                                   unsigned char **data, int dataoff,
 897                                   CallProceeding_UUIE *callproc)
 898 {
 899         int ret;
 900         int i;
 901
 902         pr_debug("nf_ct_q931: CallProceeding\n");
 903
 904         if (callproc->options & eCallProceeding_UUIE_h245Address) {
 905                 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
 906                                   &callproc->h245Address);
 907                 if (ret < 0)
 908                         return -1;
 909         }
 910
 911         if (callproc->options & eCallProceeding_UUIE_fastStart) {
 912                 for (i = 0; i < callproc->fastStart.count; i++) {
 913                         ret = process_olc(skb, ct, ctinfo, data, dataoff,
 914                                           &callproc->fastStart.item[i]);
 915                         if (ret < 0)
 916                                 return -1;
 917                 }
 918         }
 919
 920         return 0;
 921 }
 922
 923 /****************************************************************************/
 924 static int process_connect(struct sk_buff *skb, struct nf_conn *ct,
 925                            enum ip_conntrack_info ctinfo,
 926                            unsigned char **data, int dataoff,
 927                            Connect_UUIE *connect)
 928 {
 929         int ret;
 930         int i;
 931
 932         pr_debug("nf_ct_q931: Connect\n");
 933
 934         if (connect->options & eConnect_UUIE_h245Address) {
 935                 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
 936                                   &connect->h245Address);
 937                 if (ret < 0)
 938                         return -1;
 939         }
 940
 941         if (connect->options & eConnect_UUIE_fastStart) {
 942                 for (i = 0; i < connect->fastStart.count; i++) {
 943                         ret = process_olc(skb, ct, ctinfo, data, dataoff,
 944                                           &connect->fastStart.item[i]);
 945                         if (ret < 0)
 946                                 return -1;
 947                 }
 948         }
 949
 950         return 0;
 951 }
 952
 953 /****************************************************************************/
 954 static int process_alerting(struct sk_buff *skb, struct nf_conn *ct,
 955                             enum ip_conntrack_info ctinfo,
 956                             unsigned char **data, int dataoff,
 957                             Alerting_UUIE *alert)
 958 {
 959         int ret;
 960         int i;
 961
 962         pr_debug("nf_ct_q931: Alerting\n");
 963
 964         if (alert->options & eAlerting_UUIE_h245Address) {
 965                 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
 966                                   &alert->h245Address);
 967                 if (ret < 0)
 968                         return -1;
 969         }
 970
 971         if (alert->options & eAlerting_UUIE_fastStart) {
 972                 for (i = 0; i < alert->fastStart.count; i++) {
 973                         ret = process_olc(skb, ct, ctinfo, data, dataoff,
 974                                           &alert->fastStart.item[i]);
 975                         if (ret < 0)
 976                                 return -1;
 977                 }
 978         }
 979
 980         return 0;
 981 }
 982
 983 /****************************************************************************/
 984 static int process_facility(struct sk_buff *skb, struct nf_conn *ct,
 985                             enum ip_conntrack_info ctinfo,
 986                             unsigned char **data, int dataoff,
 987                             Facility_UUIE *facility)
 988 {
 989         int ret;
 990         int i;
 991
 992         pr_debug("nf_ct_q931: Facility\n");
 993
 994         if (facility->reason.choice == eFacilityReason_callForwarded) {
 995                 if (facility->options & eFacility_UUIE_alternativeAddress)
 996                         return expect_callforwarding(skb, ct, ctinfo, data,
 997                                                      dataoff,
 998                                                      &facility->
 999                                                      alternativeAddress);
1000                 return 0;
1001         }
1002
1003         if (facility->options & eFacility_UUIE_h245Address) {
1004                 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
1005                                   &facility->h245Address);
1006                 if (ret < 0)
1007                         return -1;
1008         }
1009
1010         if (facility->options & eFacility_UUIE_fastStart) {
1011                 for (i = 0; i < facility->fastStart.count; i++) {
1012                         ret = process_olc(skb, ct, ctinfo, data, dataoff,
1013                                           &facility->fastStart.item[i]);
1014                         if (ret < 0)
1015                                 return -1;
1016                 }
1017         }
1018
1019         return 0;
1020 }
1021
1022 /****************************************************************************/
1023 static int process_progress(struct sk_buff *skb, struct nf_conn *ct,
1024                             enum ip_conntrack_info ctinfo,
1025                             unsigned char **data, int dataoff,
1026                             Progress_UUIE *progress)
1027 {
1028         int ret;
1029         int i;
1030
1031         pr_debug("nf_ct_q931: Progress\n");
1032
1033         if (progress->options & eProgress_UUIE_h245Address) {
1034                 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
1035                                   &progress->h245Address);
1036                 if (ret < 0)
1037                         return -1;
1038         }
1039
1040         if (progress->options & eProgress_UUIE_fastStart) {
1041                 for (i = 0; i < progress->fastStart.count; i++) {
1042                         ret = process_olc(skb, ct, ctinfo, data, dataoff,
1043                                           &progress->fastStart.item[i]);
1044                         if (ret < 0)
1045                                 return -1;
1046                 }
1047         }
1048
1049         return 0;
1050 }
1051
1052 /****************************************************************************/
1053 static int process_q931(struct sk_buff *skb, struct nf_conn *ct,
1054                         enum ip_conntrack_info ctinfo,
1055                         unsigned char **data, int dataoff, Q931 *q931)
1056 {
1057         H323_UU_PDU *pdu = &q931->UUIE.h323_uu_pdu;
1058         int i;
1059         int ret = 0;
1060
1061         switch (pdu->h323_message_body.choice) {
1062         case eH323_UU_PDU_h323_message_body_setup:
1063                 ret = process_setup(skb, ct, ctinfo, data, dataoff,
1064                                     &pdu->h323_message_body.setup);
1065                 break;
1066         case eH323_UU_PDU_h323_message_body_callProceeding:
1067                 ret = process_callproceeding(skb, ct, ctinfo, data, dataoff,
1068                                              &pdu->h323_message_body.
1069                                              callProceeding);
1070                 break;
1071         case eH323_UU_PDU_h323_message_body_connect:
1072                 ret = process_connect(skb, ct, ctinfo, data, dataoff,
1073                                       &pdu->h323_message_body.connect);
1074                 break;
1075         case eH323_UU_PDU_h323_message_body_alerting:
1076                 ret = process_alerting(skb, ct, ctinfo, data, dataoff,
1077                                        &pdu->h323_message_body.alerting);
1078                 break;
1079         case eH323_UU_PDU_h323_message_body_facility:
1080                 ret = process_facility(skb, ct, ctinfo, data, dataoff,
1081                                        &pdu->h323_message_body.facility);
1082                 break;
1083         case eH323_UU_PDU_h323_message_body_progress:
1084                 ret = process_progress(skb, ct, ctinfo, data, dataoff,
1085                                        &pdu->h323_message_body.progress);
1086                 break;
1087         default:
1088                 pr_debug("nf_ct_q931: Q.931 signal %d\n",
1089                          pdu->h323_message_body.choice);
1090                 break;
1091         }
1092
1093         if (ret < 0)
1094                 return -1;
1095
1096         if (pdu->options & eH323_UU_PDU_h245Control) {
1097                 for (i = 0; i < pdu->h245Control.count; i++) {
1098                         ret = process_h245(skb, ct, ctinfo, data, dataoff,
1099                                            &pdu->h245Control.item[i]);
1100                         if (ret < 0)
1101                                 return -1;
1102                 }
1103         }
1104
1105         return 0;
1106 }
1107
1108 /****************************************************************************/
1109 static int q931_help(struct sk_buff *skb, unsigned int protoff,
1110                      struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1111 {
1112         static Q931 q931;
1113         unsigned char *data = NULL;
1114         int datalen;
1115         int dataoff;
1116         int ret;
1117
1118         /* Until there's been traffic both ways, don't look in packets. */
1119         if (ctinfo != IP_CT_ESTABLISHED &&
1120             ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) {
1121                 return NF_ACCEPT;
1122         }
1123         pr_debug("nf_ct_q931: skblen = %u\n", skb->len);
1124
1125         spin_lock_bh(&nf_h323_lock);
1126
1127         /* Process each TPKT */
1128         while (get_tpkt_data(skb, protoff, ct, ctinfo,
1129                              &data, &datalen, &dataoff)) {
1130                 pr_debug("nf_ct_q931: TPKT len=%d ", datalen);
1131                 NF_CT_DUMP_TUPLE(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1132
1133                 /* Decode Q.931 signal */
1134                 ret = DecodeQ931(data, datalen, &q931);
1135                 if (ret < 0) {
1136                         pr_debug("nf_ct_q931: decoding error: %s\n",
1137                                  ret == H323_ERROR_BOUND ?
1138                                  "out of bound" : "out of range");
1139                         /* We don't drop when decoding error */
1140                         break;
1141                 }
1142
1143                 /* Process Q.931 signal */
1144                 if (process_q931(skb, ct, ctinfo, &data, dataoff, &q931) < 0)
1145                         goto drop;
1146         }
1147
1148         spin_unlock_bh(&nf_h323_lock);
1149         return NF_ACCEPT;
1150
1151       drop:
1152         spin_unlock_bh(&nf_h323_lock);
1153         if (net_ratelimit())
1154                 printk("nf_ct_q931: packet dropped\n");
1155         return NF_DROP;
1156 }
1157
1158 /****************************************************************************/
1159 static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = {
1160         {
1161                 .name                   = "Q.931",
1162                 .me                     = THIS_MODULE,
1163                                           /* T.120 and H.245 */
1164                 .max_expected           = H323_RTP_CHANNEL_MAX * 4 + 4,
1165                 .timeout                = 240,
1166                 .tuple.src.l3num        = AF_INET,
1167                 .tuple.src.u.tcp.port   = __constant_htons(Q931_PORT),
1168                 .tuple.dst.protonum     = IPPROTO_TCP,
1169                 .help                   = q931_help
1170         },
1171         {
1172                 .name                   = "Q.931",
1173                 .me                     = THIS_MODULE,
1174                                           /* T.120 and H.245 */
1175                 .max_expected           = H323_RTP_CHANNEL_MAX * 4 + 4,
1176                 .timeout                = 240,
1177                 .tuple.src.l3num        = AF_INET6,
1178                 .tuple.src.u.tcp.port   = __constant_htons(Q931_PORT),
1179                 .tuple.dst.protonum     = IPPROTO_TCP,
1180                 .help                   = q931_help
1181         },
1182 };
1183
1184 /****************************************************************************/
1185 static unsigned char *get_udp_data(struct sk_buff *skb, unsigned int protoff,
1186                                    int *datalen)
1187 {
1188         struct udphdr _uh, *uh;
1189         int dataoff;
1190
1191         uh = skb_header_pointer(skb, protoff, sizeof(_uh), &_uh);
1192         if (uh == NULL)
1193                 return NULL;
1194         dataoff = protoff + sizeof(_uh);
1195         if (dataoff >= skb->len)
1196                 return NULL;
1197         *datalen = skb->len - dataoff;
1198         return skb_header_pointer(skb, dataoff, *datalen, h323_buffer);
1199 }
1200
1201 /****************************************************************************/
1202 static struct nf_conntrack_expect *find_expect(struct nf_conn *ct,
1203                                                union nf_conntrack_address *addr,
1204                                                __be16 port)
1205 {
1206         struct nf_conntrack_expect *exp;
1207         struct nf_conntrack_tuple tuple;
1208
1209         memset(&tuple.src.u3, 0, sizeof(tuple.src.u3));
1210         tuple.src.u.tcp.port = 0;
1211         memcpy(&tuple.dst.u3, addr, sizeof(tuple.dst.u3));
1212         tuple.dst.u.tcp.port = port;
1213         tuple.dst.protonum = IPPROTO_TCP;
1214
1215         exp = __nf_ct_expect_find(&tuple);
1216         if (exp && exp->master == ct)
1217                 return exp;
1218         return NULL;
1219 }
1220
1221 /****************************************************************************/
1222 static int set_expect_timeout(struct nf_conntrack_expect *exp,
1223                               unsigned timeout)
1224 {
1225         if (!exp || !del_timer(&exp->timeout))
1226                 return 0;
1227
1228         exp->timeout.expires = jiffies + timeout * HZ;
1229         add_timer(&exp->timeout);
1230
1231         return 1;
1232 }
1233
1234 /****************************************************************************/
1235 static int expect_q931(struct sk_buff *skb, struct nf_conn *ct,
1236                        enum ip_conntrack_info ctinfo,
1237                        unsigned char **data,
1238                        TransportAddress *taddr, int count)
1239 {
1240         struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1241         int dir = CTINFO2DIR(ctinfo);
1242         int ret = 0;
1243         int i;
1244         __be16 port;
1245         union nf_conntrack_address addr;
1246         struct nf_conntrack_expect *exp;
1247         typeof(nat_q931_hook) nat_q931;
1248
1249         /* Look for the first related address */
1250         for (i = 0; i < count; i++) {
1251                 if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) &&
1252                     memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3,
1253                            sizeof(addr)) == 0 && port != 0)
1254                         break;
1255         }
1256
1257         if (i >= count)         /* Not found */
1258                 return 0;
1259
1260         /* Create expect for Q.931 */
1261         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1262                 return -1;
1263         nf_ct_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
1264                           gkrouted_only ? /* only accept calls from GK? */
1265                                 &ct->tuplehash[!dir].tuple.src.u3 : NULL,
1266                           &ct->tuplehash[!dir].tuple.dst.u3,
1267                           IPPROTO_TCP, NULL, &port);
1268         exp->helper = nf_conntrack_helper_q931;
1269         exp->flags = NF_CT_EXPECT_PERMANENT;    /* Accept multiple calls */
1270
1271         nat_q931 = rcu_dereference(nat_q931_hook);
1272         if (nat_q931 && ct->status & IPS_NAT_MASK) {    /* Need NAT */
1273                 ret = nat_q931(skb, ct, ctinfo, data, taddr, i, port, exp);
1274         } else {                /* Conntrack only */
1275                 if (nf_ct_expect_related(exp) == 0) {
1276                         pr_debug("nf_ct_ras: expect Q.931 ");
1277                         NF_CT_DUMP_TUPLE(&exp->tuple);
1278
1279                         /* Save port for looking up expect in processing RCF */
1280                         info->sig_port[dir] = port;
1281                 } else
1282                         ret = -1;
1283         }
1284
1285         nf_ct_expect_put(exp);
1286
1287         return ret;
1288 }
1289
1290 /****************************************************************************/
1291 static int process_grq(struct sk_buff *skb, struct nf_conn *ct,
1292                        enum ip_conntrack_info ctinfo,
1293                        unsigned char **data, GatekeeperRequest *grq)
1294 {
1295         typeof(set_ras_addr_hook) set_ras_addr;
1296
1297         pr_debug("nf_ct_ras: GRQ\n");
1298
1299         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1300         if (set_ras_addr && ct->status & IPS_NAT_MASK)  /* NATed */
1301                 return set_ras_addr(skb, ct, ctinfo, data,
1302                                     &grq->rasAddress, 1);
1303         return 0;
1304 }
1305
1306 /****************************************************************************/
1307 static int process_gcf(struct sk_buff *skb, struct nf_conn *ct,
1308                        enum ip_conntrack_info ctinfo,
1309                        unsigned char **data, GatekeeperConfirm *gcf)
1310 {
1311         int dir = CTINFO2DIR(ctinfo);
1312         int ret = 0;
1313         __be16 port;
1314         union nf_conntrack_address addr;
1315         struct nf_conntrack_expect *exp;
1316
1317         pr_debug("nf_ct_ras: GCF\n");
1318
1319         if (!get_h225_addr(ct, *data, &gcf->rasAddress, &addr, &port))
1320                 return 0;
1321
1322         /* Registration port is the same as discovery port */
1323         if (!memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1324             port == ct->tuplehash[dir].tuple.src.u.udp.port)
1325                 return 0;
1326
1327         /* Avoid RAS expectation loops. A GCF is never expected. */
1328         if (test_bit(IPS_EXPECTED_BIT, &ct->status))
1329                 return 0;
1330
1331         /* Need new expect */
1332         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1333                 return -1;
1334         nf_ct_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
1335                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1336                           IPPROTO_UDP, NULL, &port);
1337         exp->helper = nf_conntrack_helper_ras;
1338
1339         if (nf_ct_expect_related(exp) == 0) {
1340                 pr_debug("nf_ct_ras: expect RAS ");
1341                 NF_CT_DUMP_TUPLE(&exp->tuple);
1342         } else
1343                 ret = -1;
1344
1345         nf_ct_expect_put(exp);
1346
1347         return ret;
1348 }
1349
1350 /****************************************************************************/
1351 static int process_rrq(struct sk_buff *skb, struct nf_conn *ct,
1352                        enum ip_conntrack_info ctinfo,
1353                        unsigned char **data, RegistrationRequest *rrq)
1354 {
1355         struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1356         int ret;
1357         typeof(set_ras_addr_hook) set_ras_addr;
1358
1359         pr_debug("nf_ct_ras: RRQ\n");
1360
1361         ret = expect_q931(skb, ct, ctinfo, data,
1362                           rrq->callSignalAddress.item,
1363                           rrq->callSignalAddress.count);
1364         if (ret < 0)
1365                 return -1;
1366
1367         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1368         if (set_ras_addr && ct->status & IPS_NAT_MASK) {
1369                 ret = set_ras_addr(skb, ct, ctinfo, data,
1370                                    rrq->rasAddress.item,
1371                                    rrq->rasAddress.count);
1372                 if (ret < 0)
1373                         return -1;
1374         }
1375
1376         if (rrq->options & eRegistrationRequest_timeToLive) {
1377                 pr_debug("nf_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive);
1378                 info->timeout = rrq->timeToLive;
1379         } else
1380                 info->timeout = default_rrq_ttl;
1381
1382         return 0;
1383 }
1384
1385 /****************************************************************************/
1386 static int process_rcf(struct sk_buff *skb, struct nf_conn *ct,
1387                        enum ip_conntrack_info ctinfo,
1388                        unsigned char **data, RegistrationConfirm *rcf)
1389 {
1390         struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1391         int dir = CTINFO2DIR(ctinfo);
1392         int ret;
1393         struct nf_conntrack_expect *exp;
1394         typeof(set_sig_addr_hook) set_sig_addr;
1395
1396         pr_debug("nf_ct_ras: RCF\n");
1397
1398         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1399         if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1400                 ret = set_sig_addr(skb, ct, ctinfo, data,
1401                                         rcf->callSignalAddress.item,
1402                                         rcf->callSignalAddress.count);
1403                 if (ret < 0)
1404                         return -1;
1405         }
1406
1407         if (rcf->options & eRegistrationConfirm_timeToLive) {
1408                 pr_debug("nf_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive);
1409                 info->timeout = rcf->timeToLive;
1410         }
1411
1412         if (info->timeout > 0) {
1413                 pr_debug("nf_ct_ras: set RAS connection timeout to "
1414                          "%u seconds\n", info->timeout);
1415                 nf_ct_refresh(ct, skb, info->timeout * HZ);
1416
1417                 /* Set expect timeout */
1418                 read_lock_bh(&nf_conntrack_lock);
1419                 exp = find_expect(ct, &ct->tuplehash[dir].tuple.dst.u3,
1420                                   info->sig_port[!dir]);
1421                 if (exp) {
1422                         pr_debug("nf_ct_ras: set Q.931 expect "
1423                                  "timeout to %u seconds for",
1424                                  info->timeout);
1425                         NF_CT_DUMP_TUPLE(&exp->tuple);
1426                         set_expect_timeout(exp, info->timeout);
1427                 }
1428                 read_unlock_bh(&nf_conntrack_lock);
1429         }
1430
1431         return 0;
1432 }
1433
1434 /****************************************************************************/
1435 static int process_urq(struct sk_buff *skb, struct nf_conn *ct,
1436                        enum ip_conntrack_info ctinfo,
1437                        unsigned char **data, UnregistrationRequest *urq)
1438 {
1439         struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1440         int dir = CTINFO2DIR(ctinfo);
1441         int ret;
1442         typeof(set_sig_addr_hook) set_sig_addr;
1443
1444         pr_debug("nf_ct_ras: URQ\n");
1445
1446         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1447         if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1448                 ret = set_sig_addr(skb, ct, ctinfo, data,
1449                                    urq->callSignalAddress.item,
1450                                    urq->callSignalAddress.count);
1451                 if (ret < 0)
1452                         return -1;
1453         }
1454
1455         /* Clear old expect */
1456         nf_ct_remove_expectations(ct);
1457         info->sig_port[dir] = 0;
1458         info->sig_port[!dir] = 0;
1459
1460         /* Give it 30 seconds for UCF or URJ */
1461         nf_ct_refresh(ct, skb, 30 * HZ);
1462
1463         return 0;
1464 }
1465
1466 /****************************************************************************/
1467 static int process_arq(struct sk_buff *skb, struct nf_conn *ct,
1468                        enum ip_conntrack_info ctinfo,
1469                        unsigned char **data, AdmissionRequest *arq)
1470 {
1471         struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1472         int dir = CTINFO2DIR(ctinfo);
1473         __be16 port;
1474         union nf_conntrack_address addr;
1475         typeof(set_h225_addr_hook) set_h225_addr;
1476
1477         pr_debug("nf_ct_ras: ARQ\n");
1478
1479         set_h225_addr = rcu_dereference(set_h225_addr_hook);
1480         if ((arq->options & eAdmissionRequest_destCallSignalAddress) &&
1481             get_h225_addr(ct, *data, &arq->destCallSignalAddress,
1482                           &addr, &port) &&
1483             !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1484             port == info->sig_port[dir] &&
1485             set_h225_addr && ct->status & IPS_NAT_MASK) {
1486                 /* Answering ARQ */
1487                 return set_h225_addr(skb, data, 0,
1488                                      &arq->destCallSignalAddress,
1489                                      &ct->tuplehash[!dir].tuple.dst.u3,
1490                                      info->sig_port[!dir]);
1491         }
1492
1493         if ((arq->options & eAdmissionRequest_srcCallSignalAddress) &&
1494             get_h225_addr(ct, *data, &arq->srcCallSignalAddress,
1495                           &addr, &port) &&
1496             !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1497             set_h225_addr && ct->status & IPS_NAT_MASK) {
1498                 /* Calling ARQ */
1499                 return set_h225_addr(skb, data, 0,
1500                                      &arq->srcCallSignalAddress,
1501                                      &ct->tuplehash[!dir].tuple.dst.u3,
1502                                      port);
1503         }
1504
1505         return 0;
1506 }
1507
1508 /****************************************************************************/
1509 static int process_acf(struct sk_buff *skb, struct nf_conn *ct,
1510                        enum ip_conntrack_info ctinfo,
1511                        unsigned char **data, AdmissionConfirm *acf)
1512 {
1513         int dir = CTINFO2DIR(ctinfo);
1514         int ret = 0;
1515         __be16 port;
1516         union nf_conntrack_address addr;
1517         struct nf_conntrack_expect *exp;
1518         typeof(set_sig_addr_hook) set_sig_addr;
1519
1520         pr_debug("nf_ct_ras: ACF\n");
1521
1522         if (!get_h225_addr(ct, *data, &acf->destCallSignalAddress,
1523                            &addr, &port))
1524                 return 0;
1525
1526         if (!memcmp(&addr, &ct->tuplehash[dir].tuple.dst.u3, sizeof(addr))) {
1527                 /* Answering ACF */
1528                 set_sig_addr = rcu_dereference(set_sig_addr_hook);
1529                 if (set_sig_addr && ct->status & IPS_NAT_MASK)
1530                         return set_sig_addr(skb, ct, ctinfo, data,
1531                                             &acf->destCallSignalAddress, 1);
1532                 return 0;
1533         }
1534
1535         /* Need new expect */
1536         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1537                 return -1;
1538         nf_ct_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
1539                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1540                           IPPROTO_TCP, NULL, &port);
1541         exp->flags = NF_CT_EXPECT_PERMANENT;
1542         exp->helper = nf_conntrack_helper_q931;
1543
1544         if (nf_ct_expect_related(exp) == 0) {
1545                 pr_debug("nf_ct_ras: expect Q.931 ");
1546                 NF_CT_DUMP_TUPLE(&exp->tuple);
1547         } else
1548                 ret = -1;
1549
1550         nf_ct_expect_put(exp);
1551
1552         return ret;
1553 }
1554
1555 /****************************************************************************/
1556 static int process_lrq(struct sk_buff *skb, struct nf_conn *ct,
1557                        enum ip_conntrack_info ctinfo,
1558                        unsigned char **data, LocationRequest *lrq)
1559 {
1560         typeof(set_ras_addr_hook) set_ras_addr;
1561
1562         pr_debug("nf_ct_ras: LRQ\n");
1563
1564         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1565         if (set_ras_addr && ct->status & IPS_NAT_MASK)
1566                 return set_ras_addr(skb, ct, ctinfo, data,
1567                                     &lrq->replyAddress, 1);
1568         return 0;
1569 }
1570
1571 /****************************************************************************/
1572 static int process_lcf(struct sk_buff *skb, struct nf_conn *ct,
1573                        enum ip_conntrack_info ctinfo,
1574                        unsigned char **data, LocationConfirm *lcf)
1575 {
1576         int dir = CTINFO2DIR(ctinfo);
1577         int ret = 0;
1578         __be16 port;
1579         union nf_conntrack_address addr;
1580         struct nf_conntrack_expect *exp;
1581
1582         pr_debug("nf_ct_ras: LCF\n");
1583
1584         if (!get_h225_addr(ct, *data, &lcf->callSignalAddress,
1585                            &addr, &port))
1586                 return 0;
1587
1588         /* Need new expect for call signal */
1589         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1590                 return -1;
1591         nf_ct_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
1592                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1593                           IPPROTO_TCP, NULL, &port);
1594         exp->flags = NF_CT_EXPECT_PERMANENT;
1595         exp->helper = nf_conntrack_helper_q931;
1596
1597         if (nf_ct_expect_related(exp) == 0) {
1598                 pr_debug("nf_ct_ras: expect Q.931 ");
1599                 NF_CT_DUMP_TUPLE(&exp->tuple);
1600         } else
1601                 ret = -1;
1602
1603         nf_ct_expect_put(exp);
1604
1605         /* Ignore rasAddress */
1606
1607         return ret;
1608 }
1609
1610 /****************************************************************************/
1611 static int process_irr(struct sk_buff *skb, struct nf_conn *ct,
1612                        enum ip_conntrack_info ctinfo,
1613                        unsigned char **data, InfoRequestResponse *irr)
1614 {
1615         int ret;
1616         typeof(set_ras_addr_hook) set_ras_addr;
1617         typeof(set_sig_addr_hook) set_sig_addr;
1618
1619         pr_debug("nf_ct_ras: IRR\n");
1620
1621         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1622         if (set_ras_addr && ct->status & IPS_NAT_MASK) {
1623                 ret = set_ras_addr(skb, ct, ctinfo, data,
1624                                    &irr->rasAddress, 1);
1625                 if (ret < 0)
1626                         return -1;
1627         }
1628
1629         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1630         if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1631                 ret = set_sig_addr(skb, ct, ctinfo, data,
1632                                         irr->callSignalAddress.item,
1633                                         irr->callSignalAddress.count);
1634                 if (ret < 0)
1635                         return -1;
1636         }
1637
1638         return 0;
1639 }
1640
1641 /****************************************************************************/
1642 static int process_ras(struct sk_buff *skb, struct nf_conn *ct,
1643                        enum ip_conntrack_info ctinfo,
1644                        unsigned char **data, RasMessage *ras)
1645 {
1646         switch (ras->choice) {
1647         case eRasMessage_gatekeeperRequest:
1648                 return process_grq(skb, ct, ctinfo, data,
1649                                    &ras->gatekeeperRequest);
1650         case eRasMessage_gatekeeperConfirm:
1651                 return process_gcf(skb, ct, ctinfo, data,
1652                                    &ras->gatekeeperConfirm);
1653         case eRasMessage_registrationRequest:
1654                 return process_rrq(skb, ct, ctinfo, data,
1655                                    &ras->registrationRequest);
1656         case eRasMessage_registrationConfirm:
1657                 return process_rcf(skb, ct, ctinfo, data,
1658                                    &ras->registrationConfirm);
1659         case eRasMessage_unregistrationRequest:
1660                 return process_urq(skb, ct, ctinfo, data,
1661                                    &ras->unregistrationRequest);
1662         case eRasMessage_admissionRequest:
1663                 return process_arq(skb, ct, ctinfo, data,
1664                                    &ras->admissionRequest);
1665         case eRasMessage_admissionConfirm:
1666                 return process_acf(skb, ct, ctinfo, data,
1667                                    &ras->admissionConfirm);
1668         case eRasMessage_locationRequest:
1669                 return process_lrq(skb, ct, ctinfo, data,
1670                                    &ras->locationRequest);
1671         case eRasMessage_locationConfirm:
1672                 return process_lcf(skb, ct, ctinfo, data,
1673                                    &ras->locationConfirm);
1674         case eRasMessage_infoRequestResponse:
1675                 return process_irr(skb, ct, ctinfo, data,
1676                                    &ras->infoRequestResponse);
1677         default:
1678                 pr_debug("nf_ct_ras: RAS message %d\n", ras->choice);
1679                 break;
1680         }
1681
1682         return 0;
1683 }
1684
1685 /****************************************************************************/
1686 static int ras_help(struct sk_buff *skb, unsigned int protoff,
1687                     struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1688 {
1689         static RasMessage ras;
1690         unsigned char *data;
1691         int datalen = 0;
1692         int ret;
1693
1694         pr_debug("nf_ct_ras: skblen = %u\n", skb->len);
1695
1696         spin_lock_bh(&nf_h323_lock);
1697
1698         /* Get UDP data */
1699         data = get_udp_data(skb, protoff, &datalen);
1700         if (data == NULL)
1701                 goto accept;
1702         pr_debug("nf_ct_ras: RAS message len=%d ", datalen);
1703         NF_CT_DUMP_TUPLE(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1704
1705         /* Decode RAS message */
1706         ret = DecodeRasMessage(data, datalen, &ras);
1707         if (ret < 0) {
1708                 pr_debug("nf_ct_ras: decoding error: %s\n",
1709                          ret == H323_ERROR_BOUND ?
1710                          "out of bound" : "out of range");
1711                 goto accept;
1712         }
1713
1714         /* Process RAS message */
1715         if (process_ras(skb, ct, ctinfo, &data, &ras) < 0)
1716                 goto drop;
1717
1718       accept:
1719         spin_unlock_bh(&nf_h323_lock);
1720         return NF_ACCEPT;
1721
1722       drop:
1723         spin_unlock_bh(&nf_h323_lock);
1724         if (net_ratelimit())
1725                 printk("nf_ct_ras: packet dropped\n");
1726         return NF_DROP;
1727 }
1728
1729 /****************************************************************************/
1730 static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = {
1731         {
1732                 .name                   = "RAS",
1733                 .me                     = THIS_MODULE,
1734                 .max_expected           = 32,
1735                 .timeout                = 240,
1736                 .tuple.src.l3num        = AF_INET,
1737                 .tuple.src.u.udp.port   = __constant_htons(RAS_PORT),
1738                 .tuple.dst.protonum     = IPPROTO_UDP,
1739                 .help                   = ras_help,
1740         },
1741         {
1742                 .name                   = "RAS",
1743                 .me                     = THIS_MODULE,
1744                 .max_expected           = 32,
1745                 .timeout                = 240,
1746                 .tuple.src.l3num        = AF_INET6,
1747                 .tuple.src.u.udp.port   = __constant_htons(RAS_PORT),
1748                 .tuple.dst.protonum     = IPPROTO_UDP,
1749                 .help                   = ras_help,
1750         },
1751 };
1752
1753 /****************************************************************************/
1754 static void __exit nf_conntrack_h323_fini(void)
1755 {
1756         nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[1]);
1757         nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1758         nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1759         nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1760         kfree(h323_buffer);
1761         pr_debug("nf_ct_h323: fini\n");
1762 }
1763
1764 /****************************************************************************/
1765 static int __init nf_conntrack_h323_init(void)
1766 {
1767         int ret;
1768
1769         h323_buffer = kmalloc(65536, GFP_KERNEL);
1770         if (!h323_buffer)
1771                 return -ENOMEM;
1772         ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[0]);
1773         if (ret < 0)
1774                 goto err1;
1775         ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[1]);
1776         if (ret < 0)
1777                 goto err2;
1778         ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[0]);
1779         if (ret < 0)
1780                 goto err3;
1781         ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[1]);
1782         if (ret < 0)
1783                 goto err4;
1784         pr_debug("nf_ct_h323: init success\n");
1785         return 0;
1786
1787 err4:
1788         nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1789 err3:
1790         nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1791 err2:
1792         nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1793 err1:
1794         return ret;
1795 }
1796
1797 /****************************************************************************/
1798 module_init(nf_conntrack_h323_init);
1799 module_exit(nf_conntrack_h323_fini);
1800
1801 EXPORT_SYMBOL_GPL(get_h225_addr);
1802 EXPORT_SYMBOL_GPL(set_h245_addr_hook);
1803 EXPORT_SYMBOL_GPL(set_h225_addr_hook);
1804 EXPORT_SYMBOL_GPL(set_sig_addr_hook);
1805 EXPORT_SYMBOL_GPL(set_ras_addr_hook);
1806 EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook);
1807 EXPORT_SYMBOL_GPL(nat_t120_hook);
1808 EXPORT_SYMBOL_GPL(nat_h245_hook);
1809 EXPORT_SYMBOL_GPL(nat_callforwarding_hook);
1810 EXPORT_SYMBOL_GPL(nat_q931_hook);
1811
1812 MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>");
1813 MODULE_DESCRIPTION("H.323 connection tracking helper");
1814 MODULE_LICENSE("GPL");
1815 MODULE_ALIAS("ip_conntrack_h323");