net/netfilter/nf_conntrack_h323_main.c

   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 **pskb,
  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 **pskb,
  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 **pskb,
  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 **pskb,
  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 **pskb,
  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 **pskb,
  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 **pskb,
  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 **pskb,
  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 **pskb,
  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 **pskb, 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(*pskb, 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 = (*pskb)->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(*pskb, 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 **pskb, 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(pskb, 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 **pskb,
 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(pskb, 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 **pskb,
 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(pskb, 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(pskb, 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 **pskb, 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(pskb, 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(pskb, 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(pskb, 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 **pskb, 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(pskb, 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(pskb, 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(pskb, 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(pskb, 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 **pskb, 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(pskb, 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(pskb, 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 **pskb, 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", (*pskb)->len);
 578
 579         spin_lock_bh(&nf_h323_lock);
 580
 581         /* Process each TPKT */
 582         while (get_tpkt_data(pskb, 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(pskb, 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 **pskb, 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(pskb, 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         struct flowi fl1, fl2;
 712         int ret = 0;
 713
 714         memset(&fl1, 0, sizeof(fl1));
 715         memset(&fl2, 0, sizeof(fl2));
 716
 717         switch (family) {
 718         case AF_INET: {
 719                 struct rtable *rt1, *rt2;
 720
 721                 fl1.fl4_dst = src->ip;
 722                 fl2.fl4_dst = dst->ip;
 723                 if (ip_route_output_key(&rt1, &fl1) == 0) {
 724                         if (ip_route_output_key(&rt2, &fl2) == 0) {
 725                                 if (rt1->rt_gateway == rt2->rt_gateway &&
 726                                     rt1->u.dst.dev  == rt2->u.dst.dev)
 727                                         ret = 1;
 728                                 dst_release(&rt2->u.dst);
 729                         }
 730                         dst_release(&rt1->u.dst);
 731                 }
 732                 break;
 733         }
 734 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 735         case AF_INET6: {
 736                 struct rt6_info *rt1, *rt2;
 737
 738                 memcpy(&fl1.fl6_dst, src, sizeof(fl1.fl6_dst));
 739                 memcpy(&fl2.fl6_dst, dst, sizeof(fl2.fl6_dst));
 740                 rt1 = (struct rt6_info *)ip6_route_output(NULL, &fl1);
 741                 if (rt1) {
 742                         rt2 = (struct rt6_info *)ip6_route_output(NULL, &fl2);
 743                         if (rt2) {
 744                                 if (!memcmp(&rt1->rt6i_gateway, &rt2->rt6i_gateway,
 745                                             sizeof(rt1->rt6i_gateway)) &&
 746                                     rt1->u.dst.dev == rt2->u.dst.dev)
 747                                         ret = 1;
 748                                 dst_release(&rt2->u.dst);
 749                         }
 750                         dst_release(&rt1->u.dst);
 751                 }
 752                 break;
 753         }
 754 #endif
 755         }
 756         return ret;
 757
 758 }
 759
 760 /****************************************************************************/
 761 static int expect_callforwarding(struct sk_buff **pskb,
 762                                  struct nf_conn *ct,
 763                                  enum ip_conntrack_info ctinfo,
 764                                  unsigned char **data, int dataoff,
 765                                  TransportAddress *taddr)
 766 {
 767         int dir = CTINFO2DIR(ctinfo);
 768         int ret = 0;
 769         __be16 port;
 770         union nf_conntrack_address addr;
 771         struct nf_conntrack_expect *exp;
 772         typeof(nat_callforwarding_hook) nat_callforwarding;
 773
 774         /* Read alternativeAddress */
 775         if (!get_h225_addr(ct, *data, taddr, &addr, &port) || port == 0)
 776                 return 0;
 777
 778         /* If the calling party is on the same side of the forward-to party,
 779          * we don't need to track the second call */
 780         if (callforward_filter &&
 781             callforward_do_filter(&addr, &ct->tuplehash[!dir].tuple.src.u3,
 782                                   ct->tuplehash[!dir].tuple.src.l3num)) {
 783                 pr_debug("nf_ct_q931: Call Forwarding not tracked\n");
 784                 return 0;
 785         }
 786
 787         /* Create expect for the second call leg */
 788         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 789                 return -1;
 790         nf_ct_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
 791                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
 792                           IPPROTO_TCP, NULL, &port);
 793         exp->helper = nf_conntrack_helper_q931;
 794
 795         if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 796                    &ct->tuplehash[!dir].tuple.dst.u3,
 797                    sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 798             (nat_callforwarding = rcu_dereference(nat_callforwarding_hook)) &&
 799             ct->status & IPS_NAT_MASK) {
 800                 /* Need NAT */
 801                 ret = nat_callforwarding(pskb, ct, ctinfo, data, dataoff,
 802                                          taddr, port, exp);
 803         } else {                /* Conntrack only */
 804                 if (nf_ct_expect_related(exp) == 0) {
 805                         pr_debug("nf_ct_q931: expect Call Forwarding ");
 806                         NF_CT_DUMP_TUPLE(&exp->tuple);
 807                 } else
 808                         ret = -1;
 809         }
 810
 811         nf_ct_expect_put(exp);
 812
 813         return ret;
 814 }
 815
 816 /****************************************************************************/
 817 static int process_setup(struct sk_buff **pskb, struct nf_conn *ct,
 818                          enum ip_conntrack_info ctinfo,
 819                          unsigned char **data, int dataoff,
 820                          Setup_UUIE *setup)
 821 {
 822         int dir = CTINFO2DIR(ctinfo);
 823         int ret;
 824         int i;
 825         __be16 port;
 826         union nf_conntrack_address addr;
 827         typeof(set_h225_addr_hook) set_h225_addr;
 828
 829         pr_debug("nf_ct_q931: Setup\n");
 830
 831         if (setup->options & eSetup_UUIE_h245Address) {
 832                 ret = expect_h245(pskb, ct, ctinfo, data, dataoff,
 833                                   &setup->h245Address);
 834                 if (ret < 0)
 835                         return -1;
 836         }
 837
 838         set_h225_addr = rcu_dereference(set_h225_addr_hook);
 839         if ((setup->options & eSetup_UUIE_destCallSignalAddress) &&
 840             (set_h225_addr) && ct->status && IPS_NAT_MASK &&
 841             get_h225_addr(ct, *data, &setup->destCallSignalAddress,
 842                           &addr, &port) &&
 843             memcmp(&addr, &ct->tuplehash[!dir].tuple.src.u3, sizeof(addr))) {
 844                 pr_debug("nf_ct_q931: set destCallSignalAddress "
 845                          NIP6_FMT ":%hu->" NIP6_FMT ":%hu\n",
 846                          NIP6(*(struct in6_addr *)&addr), ntohs(port),
 847                          NIP6(*(struct in6_addr *)&ct->tuplehash[!dir].tuple.src.u3),
 848                          ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port));
 849                 ret = set_h225_addr(pskb, data, dataoff,
 850                                     &setup->destCallSignalAddress,
 851                                     &ct->tuplehash[!dir].tuple.src.u3,
 852                                     ct->tuplehash[!dir].tuple.src.u.tcp.port);
 853                 if (ret < 0)
 854                         return -1;
 855         }
 856
 857         if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) &&
 858             (set_h225_addr) && ct->status & IPS_NAT_MASK &&
 859             get_h225_addr(ct, *data, &setup->sourceCallSignalAddress,
 860                           &addr, &port) &&
 861             memcmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(addr))) {
 862                 pr_debug("nf_ct_q931: set sourceCallSignalAddress "
 863                          NIP6_FMT ":%hu->" NIP6_FMT ":%hu\n",
 864                          NIP6(*(struct in6_addr *)&addr), ntohs(port),
 865                          NIP6(*(struct in6_addr *)&ct->tuplehash[!dir].tuple.dst.u3),
 866                          ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port));
 867                 ret = set_h225_addr(pskb, data, dataoff,
 868                                     &setup->sourceCallSignalAddress,
 869                                     &ct->tuplehash[!dir].tuple.dst.u3,
 870                                     ct->tuplehash[!dir].tuple.dst.u.tcp.port);
 871                 if (ret < 0)
 872                         return -1;
 873         }
 874
 875         if (setup->options & eSetup_UUIE_fastStart) {
 876                 for (i = 0; i < setup->fastStart.count; i++) {
 877                         ret = process_olc(pskb, ct, ctinfo, data, dataoff,
 878                                           &setup->fastStart.item[i]);
 879                         if (ret < 0)
 880                                 return -1;
 881                 }
 882         }
 883
 884         return 0;
 885 }
 886
 887 /****************************************************************************/
 888 static int process_callproceeding(struct sk_buff **pskb,
 889                                   struct nf_conn *ct,
 890                                   enum ip_conntrack_info ctinfo,
 891                                   unsigned char **data, int dataoff,
 892                                   CallProceeding_UUIE *callproc)
 893 {
 894         int ret;
 895         int i;
 896
 897         pr_debug("nf_ct_q931: CallProceeding\n");
 898
 899         if (callproc->options & eCallProceeding_UUIE_h245Address) {
 900                 ret = expect_h245(pskb, ct, ctinfo, data, dataoff,
 901                                   &callproc->h245Address);
 902                 if (ret < 0)
 903                         return -1;
 904         }
 905
 906         if (callproc->options & eCallProceeding_UUIE_fastStart) {
 907                 for (i = 0; i < callproc->fastStart.count; i++) {
 908                         ret = process_olc(pskb, ct, ctinfo, data, dataoff,
 909                                           &callproc->fastStart.item[i]);
 910                         if (ret < 0)
 911                                 return -1;
 912                 }
 913         }
 914
 915         return 0;
 916 }
 917
 918 /****************************************************************************/
 919 static int process_connect(struct sk_buff **pskb, struct nf_conn *ct,
 920                            enum ip_conntrack_info ctinfo,
 921                            unsigned char **data, int dataoff,
 922                            Connect_UUIE *connect)
 923 {
 924         int ret;
 925         int i;
 926
 927         pr_debug("nf_ct_q931: Connect\n");
 928
 929         if (connect->options & eConnect_UUIE_h245Address) {
 930                 ret = expect_h245(pskb, ct, ctinfo, data, dataoff,
 931                                   &connect->h245Address);
 932                 if (ret < 0)
 933                         return -1;
 934         }
 935
 936         if (connect->options & eConnect_UUIE_fastStart) {
 937                 for (i = 0; i < connect->fastStart.count; i++) {
 938                         ret = process_olc(pskb, ct, ctinfo, data, dataoff,
 939                                           &connect->fastStart.item[i]);
 940                         if (ret < 0)
 941                                 return -1;
 942                 }
 943         }
 944
 945         return 0;
 946 }
 947
 948 /****************************************************************************/
 949 static int process_alerting(struct sk_buff **pskb, struct nf_conn *ct,
 950                             enum ip_conntrack_info ctinfo,
 951                             unsigned char **data, int dataoff,
 952                             Alerting_UUIE *alert)
 953 {
 954         int ret;
 955         int i;
 956
 957         pr_debug("nf_ct_q931: Alerting\n");
 958
 959         if (alert->options & eAlerting_UUIE_h245Address) {
 960                 ret = expect_h245(pskb, ct, ctinfo, data, dataoff,
 961                                   &alert->h245Address);
 962                 if (ret < 0)
 963                         return -1;
 964         }
 965
 966         if (alert->options & eAlerting_UUIE_fastStart) {
 967                 for (i = 0; i < alert->fastStart.count; i++) {
 968                         ret = process_olc(pskb, ct, ctinfo, data, dataoff,
 969                                           &alert->fastStart.item[i]);
 970                         if (ret < 0)
 971                                 return -1;
 972                 }
 973         }
 974
 975         return 0;
 976 }
 977
 978 /****************************************************************************/
 979 static int process_facility(struct sk_buff **pskb, struct nf_conn *ct,
 980                             enum ip_conntrack_info ctinfo,
 981                             unsigned char **data, int dataoff,
 982                             Facility_UUIE *facility)
 983 {
 984         int ret;
 985         int i;
 986
 987         pr_debug("nf_ct_q931: Facility\n");
 988
 989         if (facility->reason.choice == eFacilityReason_callForwarded) {
 990                 if (facility->options & eFacility_UUIE_alternativeAddress)
 991                         return expect_callforwarding(pskb, ct, ctinfo, data,
 992                                                      dataoff,
 993                                                      &facility->
 994                                                      alternativeAddress);
 995                 return 0;
 996         }
 997
 998         if (facility->options & eFacility_UUIE_h245Address) {
 999                 ret = expect_h245(pskb, ct, ctinfo, data, dataoff,
1000                                   &facility->h245Address);
1001                 if (ret < 0)
1002                         return -1;
1003         }
1004
1005         if (facility->options & eFacility_UUIE_fastStart) {
1006                 for (i = 0; i < facility->fastStart.count; i++) {
1007                         ret = process_olc(pskb, ct, ctinfo, data, dataoff,
1008                                           &facility->fastStart.item[i]);
1009                         if (ret < 0)
1010                                 return -1;
1011                 }
1012         }
1013
1014         return 0;
1015 }
1016
1017 /****************************************************************************/
1018 static int process_progress(struct sk_buff **pskb, struct nf_conn *ct,
1019                             enum ip_conntrack_info ctinfo,
1020                             unsigned char **data, int dataoff,
1021                             Progress_UUIE *progress)
1022 {
1023         int ret;
1024         int i;
1025
1026         pr_debug("nf_ct_q931: Progress\n");
1027
1028         if (progress->options & eProgress_UUIE_h245Address) {
1029                 ret = expect_h245(pskb, ct, ctinfo, data, dataoff,
1030                                   &progress->h245Address);
1031                 if (ret < 0)
1032                         return -1;
1033         }
1034
1035         if (progress->options & eProgress_UUIE_fastStart) {
1036                 for (i = 0; i < progress->fastStart.count; i++) {
1037                         ret = process_olc(pskb, ct, ctinfo, data, dataoff,
1038                                           &progress->fastStart.item[i]);
1039                         if (ret < 0)
1040                                 return -1;
1041                 }
1042         }
1043
1044         return 0;
1045 }
1046
1047 /****************************************************************************/
1048 static int process_q931(struct sk_buff **pskb, struct nf_conn *ct,
1049                         enum ip_conntrack_info ctinfo,
1050                         unsigned char **data, int dataoff, Q931 *q931)
1051 {
1052         H323_UU_PDU *pdu = &q931->UUIE.h323_uu_pdu;
1053         int i;
1054         int ret = 0;
1055
1056         switch (pdu->h323_message_body.choice) {
1057         case eH323_UU_PDU_h323_message_body_setup:
1058                 ret = process_setup(pskb, ct, ctinfo, data, dataoff,
1059                                     &pdu->h323_message_body.setup);
1060                 break;
1061         case eH323_UU_PDU_h323_message_body_callProceeding:
1062                 ret = process_callproceeding(pskb, ct, ctinfo, data, dataoff,
1063                                              &pdu->h323_message_body.
1064                                              callProceeding);
1065                 break;
1066         case eH323_UU_PDU_h323_message_body_connect:
1067                 ret = process_connect(pskb, ct, ctinfo, data, dataoff,
1068                                       &pdu->h323_message_body.connect);
1069                 break;
1070         case eH323_UU_PDU_h323_message_body_alerting:
1071                 ret = process_alerting(pskb, ct, ctinfo, data, dataoff,
1072                                        &pdu->h323_message_body.alerting);
1073                 break;
1074         case eH323_UU_PDU_h323_message_body_facility:
1075                 ret = process_facility(pskb, ct, ctinfo, data, dataoff,
1076                                        &pdu->h323_message_body.facility);
1077                 break;
1078         case eH323_UU_PDU_h323_message_body_progress:
1079                 ret = process_progress(pskb, ct, ctinfo, data, dataoff,
1080                                        &pdu->h323_message_body.progress);
1081                 break;
1082         default:
1083                 pr_debug("nf_ct_q931: Q.931 signal %d\n",
1084                          pdu->h323_message_body.choice);
1085                 break;
1086         }
1087
1088         if (ret < 0)
1089                 return -1;
1090
1091         if (pdu->options & eH323_UU_PDU_h245Control) {
1092                 for (i = 0; i < pdu->h245Control.count; i++) {
1093                         ret = process_h245(pskb, ct, ctinfo, data, dataoff,
1094                                            &pdu->h245Control.item[i]);
1095                         if (ret < 0)
1096                                 return -1;
1097                 }
1098         }
1099
1100         return 0;
1101 }
1102
1103 /****************************************************************************/
1104 static int q931_help(struct sk_buff **pskb, unsigned int protoff,
1105                      struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1106 {
1107         static Q931 q931;
1108         unsigned char *data = NULL;
1109         int datalen;
1110         int dataoff;
1111         int ret;
1112
1113         /* Until there's been traffic both ways, don't look in packets. */
1114         if (ctinfo != IP_CT_ESTABLISHED &&
1115             ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) {
1116                 return NF_ACCEPT;
1117         }
1118         pr_debug("nf_ct_q931: skblen = %u\n", (*pskb)->len);
1119
1120         spin_lock_bh(&nf_h323_lock);
1121
1122         /* Process each TPKT */
1123         while (get_tpkt_data(pskb, protoff, ct, ctinfo,
1124                              &data, &datalen, &dataoff)) {
1125                 pr_debug("nf_ct_q931: TPKT len=%d ", datalen);
1126                 NF_CT_DUMP_TUPLE(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1127
1128                 /* Decode Q.931 signal */
1129                 ret = DecodeQ931(data, datalen, &q931);
1130                 if (ret < 0) {
1131                         pr_debug("nf_ct_q931: decoding error: %s\n",
1132                                  ret == H323_ERROR_BOUND ?
1133                                  "out of bound" : "out of range");
1134                         /* We don't drop when decoding error */
1135                         break;
1136                 }
1137
1138                 /* Process Q.931 signal */
1139                 if (process_q931(pskb, ct, ctinfo, &data, dataoff, &q931) < 0)
1140                         goto drop;
1141         }
1142
1143         spin_unlock_bh(&nf_h323_lock);
1144         return NF_ACCEPT;
1145
1146       drop:
1147         spin_unlock_bh(&nf_h323_lock);
1148         if (net_ratelimit())
1149                 printk("nf_ct_q931: packet dropped\n");
1150         return NF_DROP;
1151 }
1152
1153 /****************************************************************************/
1154 static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = {
1155         {
1156                 .name                   = "Q.931",
1157                 .me                     = THIS_MODULE,
1158                                           /* T.120 and H.245 */
1159                 .max_expected           = H323_RTP_CHANNEL_MAX * 4 + 4,
1160                 .timeout                = 240,
1161                 .tuple.src.l3num        = AF_INET,
1162                 .tuple.src.u.tcp.port   = __constant_htons(Q931_PORT),
1163                 .tuple.dst.protonum     = IPPROTO_TCP,
1164                 .help                   = q931_help
1165         },
1166         {
1167                 .name                   = "Q.931",
1168                 .me                     = THIS_MODULE,
1169                                           /* T.120 and H.245 */
1170                 .max_expected           = H323_RTP_CHANNEL_MAX * 4 + 4,
1171                 .timeout                = 240,
1172                 .tuple.src.l3num        = AF_INET6,
1173                 .tuple.src.u.tcp.port   = __constant_htons(Q931_PORT),
1174                 .tuple.dst.protonum     = IPPROTO_TCP,
1175                 .help                   = q931_help
1176         },
1177 };
1178
1179 /****************************************************************************/
1180 static unsigned char *get_udp_data(struct sk_buff **pskb, unsigned int protoff,
1181                                    int *datalen)
1182 {
1183         struct udphdr _uh, *uh;
1184         int dataoff;
1185
1186         uh = skb_header_pointer(*pskb, protoff, sizeof(_uh), &_uh);
1187         if (uh == NULL)
1188                 return NULL;
1189         dataoff = protoff + sizeof(_uh);
1190         if (dataoff >= (*pskb)->len)
1191                 return NULL;
1192         *datalen = (*pskb)->len - dataoff;
1193         return skb_header_pointer(*pskb, dataoff, *datalen, h323_buffer);
1194 }
1195
1196 /****************************************************************************/
1197 static struct nf_conntrack_expect *find_expect(struct nf_conn *ct,
1198                                                union nf_conntrack_address *addr,
1199                                                __be16 port)
1200 {
1201         struct nf_conntrack_expect *exp;
1202         struct nf_conntrack_tuple tuple;
1203
1204         memset(&tuple.src.u3, 0, sizeof(tuple.src.u3));
1205         tuple.src.u.tcp.port = 0;
1206         memcpy(&tuple.dst.u3, addr, sizeof(tuple.dst.u3));
1207         tuple.dst.u.tcp.port = port;
1208         tuple.dst.protonum = IPPROTO_TCP;
1209
1210         exp = __nf_ct_expect_find(&tuple);
1211         if (exp && exp->master == ct)
1212                 return exp;
1213         return NULL;
1214 }
1215
1216 /****************************************************************************/
1217 static int set_expect_timeout(struct nf_conntrack_expect *exp,
1218                               unsigned timeout)
1219 {
1220         if (!exp || !del_timer(&exp->timeout))
1221                 return 0;
1222
1223         exp->timeout.expires = jiffies + timeout * HZ;
1224         add_timer(&exp->timeout);
1225
1226         return 1;
1227 }
1228
1229 /****************************************************************************/
1230 static int expect_q931(struct sk_buff **pskb, struct nf_conn *ct,
1231                        enum ip_conntrack_info ctinfo,
1232                        unsigned char **data,
1233                        TransportAddress *taddr, int count)
1234 {
1235         struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1236         int dir = CTINFO2DIR(ctinfo);
1237         int ret = 0;
1238         int i;
1239         __be16 port;
1240         union nf_conntrack_address addr;
1241         struct nf_conntrack_expect *exp;
1242         typeof(nat_q931_hook) nat_q931;
1243
1244         /* Look for the first related address */
1245         for (i = 0; i < count; i++) {
1246                 if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) &&
1247                     memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3,
1248                            sizeof(addr)) == 0 && port != 0)
1249                         break;
1250         }
1251
1252         if (i >= count)         /* Not found */
1253                 return 0;
1254
1255         /* Create expect for Q.931 */
1256         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1257                 return -1;
1258         nf_ct_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
1259                           gkrouted_only ? /* only accept calls from GK? */
1260                                 &ct->tuplehash[!dir].tuple.src.u3 : NULL,
1261                           &ct->tuplehash[!dir].tuple.dst.u3,
1262                           IPPROTO_TCP, NULL, &port);
1263         exp->helper = nf_conntrack_helper_q931;
1264         exp->flags = NF_CT_EXPECT_PERMANENT;    /* Accept multiple calls */
1265
1266         nat_q931 = rcu_dereference(nat_q931_hook);
1267         if (nat_q931 && ct->status & IPS_NAT_MASK) {    /* Need NAT */
1268                 ret = nat_q931(pskb, ct, ctinfo, data, taddr, i, port, exp);
1269         } else {                /* Conntrack only */
1270                 if (nf_ct_expect_related(exp) == 0) {
1271                         pr_debug("nf_ct_ras: expect Q.931 ");
1272                         NF_CT_DUMP_TUPLE(&exp->tuple);
1273
1274                         /* Save port for looking up expect in processing RCF */
1275                         info->sig_port[dir] = port;
1276                 } else
1277                         ret = -1;
1278         }
1279
1280         nf_ct_expect_put(exp);
1281
1282         return ret;
1283 }
1284
1285 /****************************************************************************/
1286 static int process_grq(struct sk_buff **pskb, struct nf_conn *ct,
1287                        enum ip_conntrack_info ctinfo,
1288                        unsigned char **data, GatekeeperRequest *grq)
1289 {
1290         typeof(set_ras_addr_hook) set_ras_addr;
1291
1292         pr_debug("nf_ct_ras: GRQ\n");
1293
1294         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1295         if (set_ras_addr && ct->status & IPS_NAT_MASK)  /* NATed */
1296                 return set_ras_addr(pskb, ct, ctinfo, data,
1297                                     &grq->rasAddress, 1);
1298         return 0;
1299 }
1300
1301 /****************************************************************************/
1302 static int process_gcf(struct sk_buff **pskb, struct nf_conn *ct,
1303                        enum ip_conntrack_info ctinfo,
1304                        unsigned char **data, GatekeeperConfirm *gcf)
1305 {
1306         int dir = CTINFO2DIR(ctinfo);
1307         int ret = 0;
1308         __be16 port;
1309         union nf_conntrack_address addr;
1310         struct nf_conntrack_expect *exp;
1311
1312         pr_debug("nf_ct_ras: GCF\n");
1313
1314         if (!get_h225_addr(ct, *data, &gcf->rasAddress, &addr, &port))
1315                 return 0;
1316
1317         /* Registration port is the same as discovery port */
1318         if (!memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1319             port == ct->tuplehash[dir].tuple.src.u.udp.port)
1320                 return 0;
1321
1322         /* Avoid RAS expectation loops. A GCF is never expected. */
1323         if (test_bit(IPS_EXPECTED_BIT, &ct->status))
1324                 return 0;
1325
1326         /* Need new expect */
1327         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1328                 return -1;
1329         nf_ct_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
1330                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1331                           IPPROTO_UDP, NULL, &port);
1332         exp->helper = nf_conntrack_helper_ras;
1333
1334         if (nf_ct_expect_related(exp) == 0) {
1335                 pr_debug("nf_ct_ras: expect RAS ");
1336                 NF_CT_DUMP_TUPLE(&exp->tuple);
1337         } else
1338                 ret = -1;
1339
1340         nf_ct_expect_put(exp);
1341
1342         return ret;
1343 }
1344
1345 /****************************************************************************/
1346 static int process_rrq(struct sk_buff **pskb, struct nf_conn *ct,
1347                        enum ip_conntrack_info ctinfo,
1348                        unsigned char **data, RegistrationRequest *rrq)
1349 {
1350         struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1351         int ret;
1352         typeof(set_ras_addr_hook) set_ras_addr;
1353
1354         pr_debug("nf_ct_ras: RRQ\n");
1355
1356         ret = expect_q931(pskb, ct, ctinfo, data,
1357                           rrq->callSignalAddress.item,
1358                           rrq->callSignalAddress.count);
1359         if (ret < 0)
1360                 return -1;
1361
1362         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1363         if (set_ras_addr && ct->status & IPS_NAT_MASK) {
1364                 ret = set_ras_addr(pskb, ct, ctinfo, data,
1365                                    rrq->rasAddress.item,
1366                                    rrq->rasAddress.count);
1367                 if (ret < 0)
1368                         return -1;
1369         }
1370
1371         if (rrq->options & eRegistrationRequest_timeToLive) {
1372                 pr_debug("nf_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive);
1373                 info->timeout = rrq->timeToLive;
1374         } else
1375                 info->timeout = default_rrq_ttl;
1376
1377         return 0;
1378 }
1379
1380 /****************************************************************************/
1381 static int process_rcf(struct sk_buff **pskb, struct nf_conn *ct,
1382                        enum ip_conntrack_info ctinfo,
1383                        unsigned char **data, RegistrationConfirm *rcf)
1384 {
1385         struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1386         int dir = CTINFO2DIR(ctinfo);
1387         int ret;
1388         struct nf_conntrack_expect *exp;
1389         typeof(set_sig_addr_hook) set_sig_addr;
1390
1391         pr_debug("nf_ct_ras: RCF\n");
1392
1393         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1394         if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1395                 ret = set_sig_addr(pskb, ct, ctinfo, data,
1396                                         rcf->callSignalAddress.item,
1397                                         rcf->callSignalAddress.count);
1398                 if (ret < 0)
1399                         return -1;
1400         }
1401
1402         if (rcf->options & eRegistrationConfirm_timeToLive) {
1403                 pr_debug("nf_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive);
1404                 info->timeout = rcf->timeToLive;
1405         }
1406
1407         if (info->timeout > 0) {
1408                 pr_debug("nf_ct_ras: set RAS connection timeout to "
1409                          "%u seconds\n", info->timeout);
1410                 nf_ct_refresh(ct, *pskb, info->timeout * HZ);
1411
1412                 /* Set expect timeout */
1413                 read_lock_bh(&nf_conntrack_lock);
1414                 exp = find_expect(ct, &ct->tuplehash[dir].tuple.dst.u3,
1415                                   info->sig_port[!dir]);
1416                 if (exp) {
1417                         pr_debug("nf_ct_ras: set Q.931 expect "
1418                                  "timeout to %u seconds for",
1419                                  info->timeout);
1420                         NF_CT_DUMP_TUPLE(&exp->tuple);
1421                         set_expect_timeout(exp, info->timeout);
1422                 }
1423                 read_unlock_bh(&nf_conntrack_lock);
1424         }
1425
1426         return 0;
1427 }
1428
1429 /****************************************************************************/
1430 static int process_urq(struct sk_buff **pskb, struct nf_conn *ct,
1431                        enum ip_conntrack_info ctinfo,
1432                        unsigned char **data, UnregistrationRequest *urq)
1433 {
1434         struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1435         int dir = CTINFO2DIR(ctinfo);
1436         int ret;
1437         typeof(set_sig_addr_hook) set_sig_addr;
1438
1439         pr_debug("nf_ct_ras: URQ\n");
1440
1441         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1442         if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1443                 ret = set_sig_addr(pskb, ct, ctinfo, data,
1444                                    urq->callSignalAddress.item,
1445                                    urq->callSignalAddress.count);
1446                 if (ret < 0)
1447                         return -1;
1448         }
1449
1450         /* Clear old expect */
1451         nf_ct_remove_expectations(ct);
1452         info->sig_port[dir] = 0;
1453         info->sig_port[!dir] = 0;
1454
1455         /* Give it 30 seconds for UCF or URJ */
1456         nf_ct_refresh(ct, *pskb, 30 * HZ);
1457
1458         return 0;
1459 }
1460
1461 /****************************************************************************/
1462 static int process_arq(struct sk_buff **pskb, struct nf_conn *ct,
1463                        enum ip_conntrack_info ctinfo,
1464                        unsigned char **data, AdmissionRequest *arq)
1465 {
1466         struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1467         int dir = CTINFO2DIR(ctinfo);
1468         __be16 port;
1469         union nf_conntrack_address addr;
1470         typeof(set_h225_addr_hook) set_h225_addr;
1471
1472         pr_debug("nf_ct_ras: ARQ\n");
1473
1474         set_h225_addr = rcu_dereference(set_h225_addr_hook);
1475         if ((arq->options & eAdmissionRequest_destCallSignalAddress) &&
1476             get_h225_addr(ct, *data, &arq->destCallSignalAddress,
1477                           &addr, &port) &&
1478             !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1479             port == info->sig_port[dir] &&
1480             set_h225_addr && ct->status & IPS_NAT_MASK) {
1481                 /* Answering ARQ */
1482                 return set_h225_addr(pskb, data, 0,
1483                                      &arq->destCallSignalAddress,
1484                                      &ct->tuplehash[!dir].tuple.dst.u3,
1485                                      info->sig_port[!dir]);
1486         }
1487
1488         if ((arq->options & eAdmissionRequest_srcCallSignalAddress) &&
1489             get_h225_addr(ct, *data, &arq->srcCallSignalAddress,
1490                           &addr, &port) &&
1491             !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1492             set_h225_addr && ct->status & IPS_NAT_MASK) {
1493                 /* Calling ARQ */
1494                 return set_h225_addr(pskb, data, 0,
1495                                      &arq->srcCallSignalAddress,
1496                                      &ct->tuplehash[!dir].tuple.dst.u3,
1497                                      port);
1498         }
1499
1500         return 0;
1501 }
1502
1503 /****************************************************************************/
1504 static int process_acf(struct sk_buff **pskb, struct nf_conn *ct,
1505                        enum ip_conntrack_info ctinfo,
1506                        unsigned char **data, AdmissionConfirm *acf)
1507 {
1508         int dir = CTINFO2DIR(ctinfo);
1509         int ret = 0;
1510         __be16 port;
1511         union nf_conntrack_address addr;
1512         struct nf_conntrack_expect *exp;
1513         typeof(set_sig_addr_hook) set_sig_addr;
1514
1515         pr_debug("nf_ct_ras: ACF\n");
1516
1517         if (!get_h225_addr(ct, *data, &acf->destCallSignalAddress,
1518                            &addr, &port))
1519                 return 0;
1520
1521         if (!memcmp(&addr, &ct->tuplehash[dir].tuple.dst.u3, sizeof(addr))) {
1522                 /* Answering ACF */
1523                 set_sig_addr = rcu_dereference(set_sig_addr_hook);
1524                 if (set_sig_addr && ct->status & IPS_NAT_MASK)
1525                         return set_sig_addr(pskb, ct, ctinfo, data,
1526                                             &acf->destCallSignalAddress, 1);
1527                 return 0;
1528         }
1529
1530         /* Need new expect */
1531         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1532                 return -1;
1533         nf_ct_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
1534                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1535                           IPPROTO_TCP, NULL, &port);
1536         exp->flags = NF_CT_EXPECT_PERMANENT;
1537         exp->helper = nf_conntrack_helper_q931;
1538
1539         if (nf_ct_expect_related(exp) == 0) {
1540                 pr_debug("nf_ct_ras: expect Q.931 ");
1541                 NF_CT_DUMP_TUPLE(&exp->tuple);
1542         } else
1543                 ret = -1;
1544
1545         nf_ct_expect_put(exp);
1546
1547         return ret;
1548 }
1549
1550 /****************************************************************************/
1551 static int process_lrq(struct sk_buff **pskb, struct nf_conn *ct,
1552                        enum ip_conntrack_info ctinfo,
1553                        unsigned char **data, LocationRequest *lrq)
1554 {
1555         typeof(set_ras_addr_hook) set_ras_addr;
1556
1557         pr_debug("nf_ct_ras: LRQ\n");
1558
1559         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1560         if (set_ras_addr && ct->status & IPS_NAT_MASK)
1561                 return set_ras_addr(pskb, ct, ctinfo, data,
1562                                     &lrq->replyAddress, 1);
1563         return 0;
1564 }
1565
1566 /****************************************************************************/
1567 static int process_lcf(struct sk_buff **pskb, struct nf_conn *ct,
1568                        enum ip_conntrack_info ctinfo,
1569                        unsigned char **data, LocationConfirm *lcf)
1570 {
1571         int dir = CTINFO2DIR(ctinfo);
1572         int ret = 0;
1573         __be16 port;
1574         union nf_conntrack_address addr;
1575         struct nf_conntrack_expect *exp;
1576
1577         pr_debug("nf_ct_ras: LCF\n");
1578
1579         if (!get_h225_addr(ct, *data, &lcf->callSignalAddress,
1580                            &addr, &port))
1581                 return 0;
1582
1583         /* Need new expect for call signal */
1584         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1585                 return -1;
1586         nf_ct_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
1587                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1588                           IPPROTO_TCP, NULL, &port);
1589         exp->flags = NF_CT_EXPECT_PERMANENT;
1590         exp->helper = nf_conntrack_helper_q931;
1591
1592         if (nf_ct_expect_related(exp) == 0) {
1593                 pr_debug("nf_ct_ras: expect Q.931 ");
1594                 NF_CT_DUMP_TUPLE(&exp->tuple);
1595         } else
1596                 ret = -1;
1597
1598         nf_ct_expect_put(exp);
1599
1600         /* Ignore rasAddress */
1601
1602         return ret;
1603 }
1604
1605 /****************************************************************************/
1606 static int process_irr(struct sk_buff **pskb, struct nf_conn *ct,
1607                        enum ip_conntrack_info ctinfo,
1608                        unsigned char **data, InfoRequestResponse *irr)
1609 {
1610         int ret;
1611         typeof(set_ras_addr_hook) set_ras_addr;
1612         typeof(set_sig_addr_hook) set_sig_addr;
1613
1614         pr_debug("nf_ct_ras: IRR\n");
1615
1616         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1617         if (set_ras_addr && ct->status & IPS_NAT_MASK) {
1618                 ret = set_ras_addr(pskb, ct, ctinfo, data,
1619                                    &irr->rasAddress, 1);
1620                 if (ret < 0)
1621                         return -1;
1622         }
1623
1624         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1625         if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1626                 ret = set_sig_addr(pskb, ct, ctinfo, data,
1627                                         irr->callSignalAddress.item,
1628                                         irr->callSignalAddress.count);
1629                 if (ret < 0)
1630                         return -1;
1631         }
1632
1633         return 0;
1634 }
1635
1636 /****************************************************************************/
1637 static int process_ras(struct sk_buff **pskb, struct nf_conn *ct,
1638                        enum ip_conntrack_info ctinfo,
1639                        unsigned char **data, RasMessage *ras)
1640 {
1641         switch (ras->choice) {
1642         case eRasMessage_gatekeeperRequest:
1643                 return process_grq(pskb, ct, ctinfo, data,
1644                                    &ras->gatekeeperRequest);
1645         case eRasMessage_gatekeeperConfirm:
1646                 return process_gcf(pskb, ct, ctinfo, data,
1647                                    &ras->gatekeeperConfirm);
1648         case eRasMessage_registrationRequest:
1649                 return process_rrq(pskb, ct, ctinfo, data,
1650                                    &ras->registrationRequest);
1651         case eRasMessage_registrationConfirm:
1652                 return process_rcf(pskb, ct, ctinfo, data,
1653                                    &ras->registrationConfirm);
1654         case eRasMessage_unregistrationRequest:
1655                 return process_urq(pskb, ct, ctinfo, data,
1656                                    &ras->unregistrationRequest);
1657         case eRasMessage_admissionRequest:
1658                 return process_arq(pskb, ct, ctinfo, data,
1659                                    &ras->admissionRequest);
1660         case eRasMessage_admissionConfirm:
1661                 return process_acf(pskb, ct, ctinfo, data,
1662                                    &ras->admissionConfirm);
1663         case eRasMessage_locationRequest:
1664                 return process_lrq(pskb, ct, ctinfo, data,
1665                                    &ras->locationRequest);
1666         case eRasMessage_locationConfirm:
1667                 return process_lcf(pskb, ct, ctinfo, data,
1668                                    &ras->locationConfirm);
1669         case eRasMessage_infoRequestResponse:
1670                 return process_irr(pskb, ct, ctinfo, data,
1671                                    &ras->infoRequestResponse);
1672         default:
1673                 pr_debug("nf_ct_ras: RAS message %d\n", ras->choice);
1674                 break;
1675         }
1676
1677         return 0;
1678 }
1679
1680 /****************************************************************************/
1681 static int ras_help(struct sk_buff **pskb, unsigned int protoff,
1682                     struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1683 {
1684         static RasMessage ras;
1685         unsigned char *data;
1686         int datalen = 0;
1687         int ret;
1688
1689         pr_debug("nf_ct_ras: skblen = %u\n", (*pskb)->len);
1690
1691         spin_lock_bh(&nf_h323_lock);
1692
1693         /* Get UDP data */
1694         data = get_udp_data(pskb, protoff, &datalen);
1695         if (data == NULL)
1696                 goto accept;
1697         pr_debug("nf_ct_ras: RAS message len=%d ", datalen);
1698         NF_CT_DUMP_TUPLE(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1699
1700         /* Decode RAS message */
1701         ret = DecodeRasMessage(data, datalen, &ras);
1702         if (ret < 0) {
1703                 pr_debug("nf_ct_ras: decoding error: %s\n",
1704                          ret == H323_ERROR_BOUND ?
1705                          "out of bound" : "out of range");
1706                 goto accept;
1707         }
1708
1709         /* Process RAS message */
1710         if (process_ras(pskb, ct, ctinfo, &data, &ras) < 0)
1711                 goto drop;
1712
1713       accept:
1714         spin_unlock_bh(&nf_h323_lock);
1715         return NF_ACCEPT;
1716
1717       drop:
1718         spin_unlock_bh(&nf_h323_lock);
1719         if (net_ratelimit())
1720                 printk("nf_ct_ras: packet dropped\n");
1721         return NF_DROP;
1722 }
1723
1724 /****************************************************************************/
1725 static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = {
1726         {
1727                 .name                   = "RAS",
1728                 .me                     = THIS_MODULE,
1729                 .max_expected           = 32,
1730                 .timeout                = 240,
1731                 .tuple.src.l3num        = AF_INET,
1732                 .tuple.src.u.udp.port   = __constant_htons(RAS_PORT),
1733                 .tuple.dst.protonum     = IPPROTO_UDP,
1734                 .help                   = ras_help,
1735         },
1736         {
1737                 .name                   = "RAS",
1738                 .me                     = THIS_MODULE,
1739                 .max_expected           = 32,
1740                 .timeout                = 240,
1741                 .tuple.src.l3num        = AF_INET6,
1742                 .tuple.src.u.udp.port   = __constant_htons(RAS_PORT),
1743                 .tuple.dst.protonum     = IPPROTO_UDP,
1744                 .help                   = ras_help,
1745         },
1746 };
1747
1748 /****************************************************************************/
1749 static void __exit nf_conntrack_h323_fini(void)
1750 {
1751         nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[1]);
1752         nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1753         nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1754         nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1755         kfree(h323_buffer);
1756         pr_debug("nf_ct_h323: fini\n");
1757 }
1758
1759 /****************************************************************************/
1760 static int __init nf_conntrack_h323_init(void)
1761 {
1762         int ret;
1763
1764         h323_buffer = kmalloc(65536, GFP_KERNEL);
1765         if (!h323_buffer)
1766                 return -ENOMEM;
1767         ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[0]);
1768         if (ret < 0)
1769                 goto err1;
1770         ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[1]);
1771         if (ret < 0)
1772                 goto err2;
1773         ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[0]);
1774         if (ret < 0)
1775                 goto err3;
1776         ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[1]);
1777         if (ret < 0)
1778                 goto err4;
1779         pr_debug("nf_ct_h323: init success\n");
1780         return 0;
1781
1782 err4:
1783         nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1784 err3:
1785         nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1786 err2:
1787         nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1788 err1:
1789         return ret;
1790 }
1791
1792 /****************************************************************************/
1793 module_init(nf_conntrack_h323_init);
1794 module_exit(nf_conntrack_h323_fini);
1795
1796 EXPORT_SYMBOL_GPL(get_h225_addr);
1797 EXPORT_SYMBOL_GPL(set_h245_addr_hook);
1798 EXPORT_SYMBOL_GPL(set_h225_addr_hook);
1799 EXPORT_SYMBOL_GPL(set_sig_addr_hook);
1800 EXPORT_SYMBOL_GPL(set_ras_addr_hook);
1801 EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook);
1802 EXPORT_SYMBOL_GPL(nat_t120_hook);
1803 EXPORT_SYMBOL_GPL(nat_h245_hook);
1804 EXPORT_SYMBOL_GPL(nat_callforwarding_hook);
1805 EXPORT_SYMBOL_GPL(nat_q931_hook);
1806
1807 MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>");
1808 MODULE_DESCRIPTION("H.323 connection tracking helper");
1809 MODULE_LICENSE("GPL");
1810 MODULE_ALIAS("ip_conntrack_h323");