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 *skb,
  51                            unsigned char **data, int dataoff,
  52                            H245_TransportAddress *taddr,
  53                            union nf_inet_addr *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_inet_addr *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         const struct tcphdr *th;
 118         struct tcphdr _tcph;
 119         int tcpdatalen;
 120         int tcpdataoff;
 121         unsigned char *tpkt;
 122         int tpktlen;
 123         int tpktoff;
 124
 125         /* Get TCP header */
 126         th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph);
 127         if (th == NULL)
 128                 return 0;
 129
 130         /* Get TCP data offset */
 131         tcpdataoff = protoff + th->doff * 4;
 132
 133         /* Get TCP data length */
 134         tcpdatalen = skb->len - tcpdataoff;
 135         if (tcpdatalen <= 0)    /* No TCP data */
 136                 goto clear_out;
 137
 138         if (*data == NULL) {    /* first TPKT */
 139                 /* Get first TPKT pointer */
 140                 tpkt = skb_header_pointer(skb, tcpdataoff, tcpdatalen,
 141                                           h323_buffer);
 142                 BUG_ON(tpkt == NULL);
 143
 144                 /* Validate TPKT identifier */
 145                 if (tcpdatalen < 4 || tpkt[0] != 0x03 || tpkt[1] != 0) {
 146                         /* Netmeeting sends TPKT header and data separately */
 147                         if (info->tpkt_len[dir] > 0) {
 148                                 pr_debug("nf_ct_h323: previous packet "
 149                                          "indicated separate TPKT data of %hu "
 150                                          "bytes\n", info->tpkt_len[dir]);
 151                                 if (info->tpkt_len[dir] <= tcpdatalen) {
 152                                         /* Yes, there was a TPKT header
 153                                          * received */
 154                                         *data = tpkt;
 155                                         *datalen = info->tpkt_len[dir];
 156                                         *dataoff = 0;
 157                                         goto out;
 158                                 }
 159
 160                                 /* Fragmented TPKT */
 161                                 pr_debug("nf_ct_h323: fragmented TPKT\n");
 162                                 goto clear_out;
 163                         }
 164
 165                         /* It is not even a TPKT */
 166                         return 0;
 167                 }
 168                 tpktoff = 0;
 169         } else {                /* Next TPKT */
 170                 tpktoff = *dataoff + *datalen;
 171                 tcpdatalen -= tpktoff;
 172                 if (tcpdatalen <= 4)    /* No more TPKT */
 173                         goto clear_out;
 174                 tpkt = *data + *datalen;
 175
 176                 /* Validate TPKT identifier */
 177                 if (tpkt[0] != 0x03 || tpkt[1] != 0)
 178                         goto clear_out;
 179         }
 180
 181         /* Validate TPKT length */
 182         tpktlen = tpkt[2] * 256 + tpkt[3];
 183         if (tpktlen < 4)
 184                 goto clear_out;
 185         if (tpktlen > tcpdatalen) {
 186                 if (tcpdatalen == 4) {  /* Separate TPKT header */
 187                         /* Netmeeting sends TPKT header and data separately */
 188                         pr_debug("nf_ct_h323: separate TPKT header indicates "
 189                                  "there will be TPKT data of %hu bytes\n",
 190                                  tpktlen - 4);
 191                         info->tpkt_len[dir] = tpktlen - 4;
 192                         return 0;
 193                 }
 194
 195                 if (net_ratelimit())
 196                         printk("nf_ct_h323: incomplete TPKT (fragmented?)\n");
 197                 goto clear_out;
 198         }
 199
 200         /* This is the encapsulated data */
 201         *data = tpkt + 4;
 202         *datalen = tpktlen - 4;
 203         *dataoff = tpktoff + 4;
 204
 205       out:
 206         /* Clear TPKT length */
 207         info->tpkt_len[dir] = 0;
 208         return 1;
 209
 210       clear_out:
 211         info->tpkt_len[dir] = 0;
 212         return 0;
 213 }
 214
 215 /****************************************************************************/
 216 static int get_h245_addr(struct nf_conn *ct, const unsigned char *data,
 217                          H245_TransportAddress *taddr,
 218                          union nf_inet_addr *addr, __be16 *port)
 219 {
 220         const unsigned char *p;
 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 (nf_ct_l3num(ct) != AF_INET)
 229                         return 0;
 230                 p = data + taddr->unicastAddress.iPAddress.network;
 231                 len = 4;
 232                 break;
 233         case eUnicastAddress_iP6Address:
 234                 if (nf_ct_l3num(ct) != 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_inet_addr 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, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 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, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 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_inet_addr 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, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 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 const struct nf_conntrack_expect_policy h245_exp_policy = {
 615         .max_expected   = H323_RTP_CHANNEL_MAX * 4 + 2 /* T.120 */,
 616         .timeout        = 240,
 617 };
 618
 619 static struct nf_conntrack_helper nf_conntrack_helper_h245 __read_mostly = {
 620         .name                   = "H.245",
 621         .me                     = THIS_MODULE,
 622         .tuple.src.l3num        = AF_UNSPEC,
 623         .tuple.dst.protonum     = IPPROTO_UDP,
 624         .help                   = h245_help,
 625         .expect_policy          = &h245_exp_policy,
 626 };
 627
 628 /****************************************************************************/
 629 int get_h225_addr(struct nf_conn *ct, unsigned char *data,
 630                   TransportAddress *taddr,
 631                   union nf_inet_addr *addr, __be16 *port)
 632 {
 633         const unsigned char *p;
 634         int len;
 635
 636         switch (taddr->choice) {
 637         case eTransportAddress_ipAddress:
 638                 if (nf_ct_l3num(ct) != AF_INET)
 639                         return 0;
 640                 p = data + taddr->ipAddress.ip;
 641                 len = 4;
 642                 break;
 643         case eTransportAddress_ip6Address:
 644                 if (nf_ct_l3num(ct) != AF_INET6)
 645                         return 0;
 646                 p = data + taddr->ip6Address.ip;
 647                 len = 16;
 648                 break;
 649         default:
 650                 return 0;
 651         }
 652
 653         memcpy(addr, p, len);
 654         memset((void *)addr + len, 0, sizeof(*addr) - len);
 655         memcpy(port, p + len, sizeof(__be16));
 656
 657         return 1;
 658 }
 659
 660 /****************************************************************************/
 661 static int expect_h245(struct sk_buff *skb, struct nf_conn *ct,
 662                        enum ip_conntrack_info ctinfo,
 663                        unsigned char **data, int dataoff,
 664                        TransportAddress *taddr)
 665 {
 666         int dir = CTINFO2DIR(ctinfo);
 667         int ret = 0;
 668         __be16 port;
 669         union nf_inet_addr addr;
 670         struct nf_conntrack_expect *exp;
 671         typeof(nat_h245_hook) nat_h245;
 672
 673         /* Read h245Address */
 674         if (!get_h225_addr(ct, *data, taddr, &addr, &port) ||
 675             memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 676             port == 0)
 677                 return 0;
 678
 679         /* Create expect for h245 connection */
 680         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 681                 return -1;
 682         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 683                           &ct->tuplehash[!dir].tuple.src.u3,
 684                           &ct->tuplehash[!dir].tuple.dst.u3,
 685                           IPPROTO_TCP, NULL, &port);
 686         exp->helper = &nf_conntrack_helper_h245;
 687
 688         if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 689                    &ct->tuplehash[!dir].tuple.dst.u3,
 690                    sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 691             (nat_h245 = rcu_dereference(nat_h245_hook)) &&
 692             ct->status & IPS_NAT_MASK) {
 693                 /* NAT needed */
 694                 ret = nat_h245(skb, ct, ctinfo, data, dataoff, taddr,
 695                                port, exp);
 696         } else {                /* Conntrack only */
 697                 if (nf_ct_expect_related(exp) == 0) {
 698                         pr_debug("nf_ct_q931: expect H.245 ");
 699                         nf_ct_dump_tuple(&exp->tuple);
 700                 } else
 701                         ret = -1;
 702         }
 703
 704         nf_ct_expect_put(exp);
 705
 706         return ret;
 707 }
 708
 709 /* If the calling party is on the same side of the forward-to party,
 710  * we don't need to track the second call */
 711 static int callforward_do_filter(const union nf_inet_addr *src,
 712                                  const union nf_inet_addr *dst, int family)
 713 {
 714         const struct nf_afinfo *afinfo;
 715         struct flowi fl1, fl2;
 716         int ret = 0;
 717
 718         /* rcu_read_lock()ed by nf_hook_slow() */
 719         afinfo = nf_get_afinfo(family);
 720         if (!afinfo)
 721                 return 0;
 722
 723         memset(&fl1, 0, sizeof(fl1));
 724         memset(&fl2, 0, sizeof(fl2));
 725
 726         switch (family) {
 727         case AF_INET: {
 728                 struct rtable *rt1, *rt2;
 729
 730                 fl1.fl4_dst = src->ip;
 731                 fl2.fl4_dst = dst->ip;
 732                 if (!afinfo->route((struct dst_entry **)&rt1, &fl1)) {
 733                         if (!afinfo->route((struct dst_entry **)&rt2, &fl2)) {
 734                                 if (rt1->rt_gateway == rt2->rt_gateway &&
 735                                     rt1->u.dst.dev  == rt2->u.dst.dev)
 736                                         ret = 1;
 737                                 dst_release(&rt2->u.dst);
 738                         }
 739                         dst_release(&rt1->u.dst);
 740                 }
 741                 break;
 742         }
 743 #if defined(CONFIG_NF_CONNTRACK_IPV6) || \
 744     defined(CONFIG_NF_CONNTRACK_IPV6_MODULE)
 745         case AF_INET6: {
 746                 struct rt6_info *rt1, *rt2;
 747
 748                 memcpy(&fl1.fl6_dst, src, sizeof(fl1.fl6_dst));
 749                 memcpy(&fl2.fl6_dst, dst, sizeof(fl2.fl6_dst));
 750                 if (!afinfo->route((struct dst_entry **)&rt1, &fl1)) {
 751                         if (!afinfo->route((struct dst_entry **)&rt2, &fl2)) {
 752                                 if (!memcmp(&rt1->rt6i_gateway, &rt2->rt6i_gateway,
 753                                             sizeof(rt1->rt6i_gateway)) &&
 754                                     rt1->u.dst.dev == rt2->u.dst.dev)
 755                                         ret = 1;
 756                                 dst_release(&rt2->u.dst);
 757                         }
 758                         dst_release(&rt1->u.dst);
 759                 }
 760                 break;
 761         }
 762 #endif
 763         }
 764         return ret;
 765
 766 }
 767
 768 /****************************************************************************/
 769 static int expect_callforwarding(struct sk_buff *skb,
 770                                  struct nf_conn *ct,
 771                                  enum ip_conntrack_info ctinfo,
 772                                  unsigned char **data, int dataoff,
 773                                  TransportAddress *taddr)
 774 {
 775         int dir = CTINFO2DIR(ctinfo);
 776         int ret = 0;
 777         __be16 port;
 778         union nf_inet_addr addr;
 779         struct nf_conntrack_expect *exp;
 780         typeof(nat_callforwarding_hook) nat_callforwarding;
 781
 782         /* Read alternativeAddress */
 783         if (!get_h225_addr(ct, *data, taddr, &addr, &port) || port == 0)
 784                 return 0;
 785
 786         /* If the calling party is on the same side of the forward-to party,
 787          * we don't need to track the second call */
 788         if (callforward_filter &&
 789             callforward_do_filter(&addr, &ct->tuplehash[!dir].tuple.src.u3,
 790                                   nf_ct_l3num(ct))) {
 791                 pr_debug("nf_ct_q931: Call Forwarding not tracked\n");
 792                 return 0;
 793         }
 794
 795         /* Create expect for the second call leg */
 796         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 797                 return -1;
 798         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 799                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
 800                           IPPROTO_TCP, NULL, &port);
 801         exp->helper = nf_conntrack_helper_q931;
 802
 803         if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 804                    &ct->tuplehash[!dir].tuple.dst.u3,
 805                    sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 806             (nat_callforwarding = rcu_dereference(nat_callforwarding_hook)) &&
 807             ct->status & IPS_NAT_MASK) {
 808                 /* Need NAT */
 809                 ret = nat_callforwarding(skb, ct, ctinfo, data, dataoff,
 810                                          taddr, port, exp);
 811         } else {                /* Conntrack only */
 812                 if (nf_ct_expect_related(exp) == 0) {
 813                         pr_debug("nf_ct_q931: expect Call Forwarding ");
 814                         nf_ct_dump_tuple(&exp->tuple);
 815                 } else
 816                         ret = -1;
 817         }
 818
 819         nf_ct_expect_put(exp);
 820
 821         return ret;
 822 }
 823
 824 /****************************************************************************/
 825 static int process_setup(struct sk_buff *skb, struct nf_conn *ct,
 826                          enum ip_conntrack_info ctinfo,
 827                          unsigned char **data, int dataoff,
 828                          Setup_UUIE *setup)
 829 {
 830         int dir = CTINFO2DIR(ctinfo);
 831         int ret;
 832         int i;
 833         __be16 port;
 834         union nf_inet_addr addr;
 835         typeof(set_h225_addr_hook) set_h225_addr;
 836
 837         pr_debug("nf_ct_q931: Setup\n");
 838
 839         if (setup->options & eSetup_UUIE_h245Address) {
 840                 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
 841                                   &setup->h245Address);
 842                 if (ret < 0)
 843                         return -1;
 844         }
 845
 846         set_h225_addr = rcu_dereference(set_h225_addr_hook);
 847         if ((setup->options & eSetup_UUIE_destCallSignalAddress) &&
 848             (set_h225_addr) && ct->status & IPS_NAT_MASK &&
 849             get_h225_addr(ct, *data, &setup->destCallSignalAddress,
 850                           &addr, &port) &&
 851             memcmp(&addr, &ct->tuplehash[!dir].tuple.src.u3, sizeof(addr))) {
 852                 pr_debug("nf_ct_q931: set destCallSignalAddress "
 853                          NIP6_FMT ":%hu->" NIP6_FMT ":%hu\n",
 854                          NIP6(*(struct in6_addr *)&addr), ntohs(port),
 855                          NIP6(*(struct in6_addr *)&ct->tuplehash[!dir].tuple.src.u3),
 856                          ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port));
 857                 ret = set_h225_addr(skb, data, dataoff,
 858                                     &setup->destCallSignalAddress,
 859                                     &ct->tuplehash[!dir].tuple.src.u3,
 860                                     ct->tuplehash[!dir].tuple.src.u.tcp.port);
 861                 if (ret < 0)
 862                         return -1;
 863         }
 864
 865         if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) &&
 866             (set_h225_addr) && ct->status & IPS_NAT_MASK &&
 867             get_h225_addr(ct, *data, &setup->sourceCallSignalAddress,
 868                           &addr, &port) &&
 869             memcmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(addr))) {
 870                 pr_debug("nf_ct_q931: set sourceCallSignalAddress "
 871                          NIP6_FMT ":%hu->" NIP6_FMT ":%hu\n",
 872                          NIP6(*(struct in6_addr *)&addr), ntohs(port),
 873                          NIP6(*(struct in6_addr *)&ct->tuplehash[!dir].tuple.dst.u3),
 874                          ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port));
 875                 ret = set_h225_addr(skb, data, dataoff,
 876                                     &setup->sourceCallSignalAddress,
 877                                     &ct->tuplehash[!dir].tuple.dst.u3,
 878                                     ct->tuplehash[!dir].tuple.dst.u.tcp.port);
 879                 if (ret < 0)
 880                         return -1;
 881         }
 882
 883         if (setup->options & eSetup_UUIE_fastStart) {
 884                 for (i = 0; i < setup->fastStart.count; i++) {
 885                         ret = process_olc(skb, ct, ctinfo, data, dataoff,
 886                                           &setup->fastStart.item[i]);
 887                         if (ret < 0)
 888                                 return -1;
 889                 }
 890         }
 891
 892         return 0;
 893 }
 894
 895 /****************************************************************************/
 896 static int process_callproceeding(struct sk_buff *skb,
 897                                   struct nf_conn *ct,
 898                                   enum ip_conntrack_info ctinfo,
 899                                   unsigned char **data, int dataoff,
 900                                   CallProceeding_UUIE *callproc)
 901 {
 902         int ret;
 903         int i;
 904
 905         pr_debug("nf_ct_q931: CallProceeding\n");
 906
 907         if (callproc->options & eCallProceeding_UUIE_h245Address) {
 908                 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
 909                                   &callproc->h245Address);
 910                 if (ret < 0)
 911                         return -1;
 912         }
 913
 914         if (callproc->options & eCallProceeding_UUIE_fastStart) {
 915                 for (i = 0; i < callproc->fastStart.count; i++) {
 916                         ret = process_olc(skb, ct, ctinfo, data, dataoff,
 917                                           &callproc->fastStart.item[i]);
 918                         if (ret < 0)
 919                                 return -1;
 920                 }
 921         }
 922
 923         return 0;
 924 }
 925
 926 /****************************************************************************/
 927 static int process_connect(struct sk_buff *skb, struct nf_conn *ct,
 928                            enum ip_conntrack_info ctinfo,
 929                            unsigned char **data, int dataoff,
 930                            Connect_UUIE *connect)
 931 {
 932         int ret;
 933         int i;
 934
 935         pr_debug("nf_ct_q931: Connect\n");
 936
 937         if (connect->options & eConnect_UUIE_h245Address) {
 938                 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
 939                                   &connect->h245Address);
 940                 if (ret < 0)
 941                         return -1;
 942         }
 943
 944         if (connect->options & eConnect_UUIE_fastStart) {
 945                 for (i = 0; i < connect->fastStart.count; i++) {
 946                         ret = process_olc(skb, ct, ctinfo, data, dataoff,
 947                                           &connect->fastStart.item[i]);
 948                         if (ret < 0)
 949                                 return -1;
 950                 }
 951         }
 952
 953         return 0;
 954 }
 955
 956 /****************************************************************************/
 957 static int process_alerting(struct sk_buff *skb, struct nf_conn *ct,
 958                             enum ip_conntrack_info ctinfo,
 959                             unsigned char **data, int dataoff,
 960                             Alerting_UUIE *alert)
 961 {
 962         int ret;
 963         int i;
 964
 965         pr_debug("nf_ct_q931: Alerting\n");
 966
 967         if (alert->options & eAlerting_UUIE_h245Address) {
 968                 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
 969                                   &alert->h245Address);
 970                 if (ret < 0)
 971                         return -1;
 972         }
 973
 974         if (alert->options & eAlerting_UUIE_fastStart) {
 975                 for (i = 0; i < alert->fastStart.count; i++) {
 976                         ret = process_olc(skb, ct, ctinfo, data, dataoff,
 977                                           &alert->fastStart.item[i]);
 978                         if (ret < 0)
 979                                 return -1;
 980                 }
 981         }
 982
 983         return 0;
 984 }
 985
 986 /****************************************************************************/
 987 static int process_facility(struct sk_buff *skb, struct nf_conn *ct,
 988                             enum ip_conntrack_info ctinfo,
 989                             unsigned char **data, int dataoff,
 990                             Facility_UUIE *facility)
 991 {
 992         int ret;
 993         int i;
 994
 995         pr_debug("nf_ct_q931: Facility\n");
 996
 997         if (facility->reason.choice == eFacilityReason_callForwarded) {
 998                 if (facility->options & eFacility_UUIE_alternativeAddress)
 999                         return expect_callforwarding(skb, ct, ctinfo, data,
1000                                                      dataoff,
1001                                                      &facility->
1002                                                      alternativeAddress);
1003                 return 0;
1004         }
1005
1006         if (facility->options & eFacility_UUIE_h245Address) {
1007                 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
1008                                   &facility->h245Address);
1009                 if (ret < 0)
1010                         return -1;
1011         }
1012
1013         if (facility->options & eFacility_UUIE_fastStart) {
1014                 for (i = 0; i < facility->fastStart.count; i++) {
1015                         ret = process_olc(skb, ct, ctinfo, data, dataoff,
1016                                           &facility->fastStart.item[i]);
1017                         if (ret < 0)
1018                                 return -1;
1019                 }
1020         }
1021
1022         return 0;
1023 }
1024
1025 /****************************************************************************/
1026 static int process_progress(struct sk_buff *skb, struct nf_conn *ct,
1027                             enum ip_conntrack_info ctinfo,
1028                             unsigned char **data, int dataoff,
1029                             Progress_UUIE *progress)
1030 {
1031         int ret;
1032         int i;
1033
1034         pr_debug("nf_ct_q931: Progress\n");
1035
1036         if (progress->options & eProgress_UUIE_h245Address) {
1037                 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
1038                                   &progress->h245Address);
1039                 if (ret < 0)
1040                         return -1;
1041         }
1042
1043         if (progress->options & eProgress_UUIE_fastStart) {
1044                 for (i = 0; i < progress->fastStart.count; i++) {
1045                         ret = process_olc(skb, ct, ctinfo, data, dataoff,
1046                                           &progress->fastStart.item[i]);
1047                         if (ret < 0)
1048                                 return -1;
1049                 }
1050         }
1051
1052         return 0;
1053 }
1054
1055 /****************************************************************************/
1056 static int process_q931(struct sk_buff *skb, struct nf_conn *ct,
1057                         enum ip_conntrack_info ctinfo,
1058                         unsigned char **data, int dataoff, Q931 *q931)
1059 {
1060         H323_UU_PDU *pdu = &q931->UUIE.h323_uu_pdu;
1061         int i;
1062         int ret = 0;
1063
1064         switch (pdu->h323_message_body.choice) {
1065         case eH323_UU_PDU_h323_message_body_setup:
1066                 ret = process_setup(skb, ct, ctinfo, data, dataoff,
1067                                     &pdu->h323_message_body.setup);
1068                 break;
1069         case eH323_UU_PDU_h323_message_body_callProceeding:
1070                 ret = process_callproceeding(skb, ct, ctinfo, data, dataoff,
1071                                              &pdu->h323_message_body.
1072                                              callProceeding);
1073                 break;
1074         case eH323_UU_PDU_h323_message_body_connect:
1075                 ret = process_connect(skb, ct, ctinfo, data, dataoff,
1076                                       &pdu->h323_message_body.connect);
1077                 break;
1078         case eH323_UU_PDU_h323_message_body_alerting:
1079                 ret = process_alerting(skb, ct, ctinfo, data, dataoff,
1080                                        &pdu->h323_message_body.alerting);
1081                 break;
1082         case eH323_UU_PDU_h323_message_body_facility:
1083                 ret = process_facility(skb, ct, ctinfo, data, dataoff,
1084                                        &pdu->h323_message_body.facility);
1085                 break;
1086         case eH323_UU_PDU_h323_message_body_progress:
1087                 ret = process_progress(skb, ct, ctinfo, data, dataoff,
1088                                        &pdu->h323_message_body.progress);
1089                 break;
1090         default:
1091                 pr_debug("nf_ct_q931: Q.931 signal %d\n",
1092                          pdu->h323_message_body.choice);
1093                 break;
1094         }
1095
1096         if (ret < 0)
1097                 return -1;
1098
1099         if (pdu->options & eH323_UU_PDU_h245Control) {
1100                 for (i = 0; i < pdu->h245Control.count; i++) {
1101                         ret = process_h245(skb, ct, ctinfo, data, dataoff,
1102                                            &pdu->h245Control.item[i]);
1103                         if (ret < 0)
1104                                 return -1;
1105                 }
1106         }
1107
1108         return 0;
1109 }
1110
1111 /****************************************************************************/
1112 static int q931_help(struct sk_buff *skb, unsigned int protoff,
1113                      struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1114 {
1115         static Q931 q931;
1116         unsigned char *data = NULL;
1117         int datalen;
1118         int dataoff;
1119         int ret;
1120
1121         /* Until there's been traffic both ways, don't look in packets. */
1122         if (ctinfo != IP_CT_ESTABLISHED &&
1123             ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) {
1124                 return NF_ACCEPT;
1125         }
1126         pr_debug("nf_ct_q931: skblen = %u\n", skb->len);
1127
1128         spin_lock_bh(&nf_h323_lock);
1129
1130         /* Process each TPKT */
1131         while (get_tpkt_data(skb, protoff, ct, ctinfo,
1132                              &data, &datalen, &dataoff)) {
1133                 pr_debug("nf_ct_q931: TPKT len=%d ", datalen);
1134                 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1135
1136                 /* Decode Q.931 signal */
1137                 ret = DecodeQ931(data, datalen, &q931);
1138                 if (ret < 0) {
1139                         pr_debug("nf_ct_q931: decoding error: %s\n",
1140                                  ret == H323_ERROR_BOUND ?
1141                                  "out of bound" : "out of range");
1142                         /* We don't drop when decoding error */
1143                         break;
1144                 }
1145
1146                 /* Process Q.931 signal */
1147                 if (process_q931(skb, ct, ctinfo, &data, dataoff, &q931) < 0)
1148                         goto drop;
1149         }
1150
1151         spin_unlock_bh(&nf_h323_lock);
1152         return NF_ACCEPT;
1153
1154       drop:
1155         spin_unlock_bh(&nf_h323_lock);
1156         if (net_ratelimit())
1157                 printk("nf_ct_q931: packet dropped\n");
1158         return NF_DROP;
1159 }
1160
1161 /****************************************************************************/
1162 static const struct nf_conntrack_expect_policy q931_exp_policy = {
1163         /* T.120 and H.245 */
1164         .max_expected           = H323_RTP_CHANNEL_MAX * 4 + 4,
1165         .timeout                = 240,
1166 };
1167
1168 static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = {
1169         {
1170                 .name                   = "Q.931",
1171                 .me                     = THIS_MODULE,
1172                 .tuple.src.l3num        = AF_INET,
1173                 .tuple.src.u.tcp.port   = __constant_htons(Q931_PORT),
1174                 .tuple.dst.protonum     = IPPROTO_TCP,
1175                 .help                   = q931_help,
1176                 .expect_policy          = &q931_exp_policy,
1177         },
1178         {
1179                 .name                   = "Q.931",
1180                 .me                     = THIS_MODULE,
1181                 .tuple.src.l3num        = AF_INET6,
1182                 .tuple.src.u.tcp.port   = __constant_htons(Q931_PORT),
1183                 .tuple.dst.protonum     = IPPROTO_TCP,
1184                 .help                   = q931_help,
1185                 .expect_policy          = &q931_exp_policy,
1186         },
1187 };
1188
1189 /****************************************************************************/
1190 static unsigned char *get_udp_data(struct sk_buff *skb, unsigned int protoff,
1191                                    int *datalen)
1192 {
1193         const struct udphdr *uh;
1194         struct udphdr _uh;
1195         int dataoff;
1196
1197         uh = skb_header_pointer(skb, protoff, sizeof(_uh), &_uh);
1198         if (uh == NULL)
1199                 return NULL;
1200         dataoff = protoff + sizeof(_uh);
1201         if (dataoff >= skb->len)
1202                 return NULL;
1203         *datalen = skb->len - dataoff;
1204         return skb_header_pointer(skb, dataoff, *datalen, h323_buffer);
1205 }
1206
1207 /****************************************************************************/
1208 static struct nf_conntrack_expect *find_expect(struct nf_conn *ct,
1209                                                union nf_inet_addr *addr,
1210                                                __be16 port)
1211 {
1212         struct nf_conntrack_expect *exp;
1213         struct nf_conntrack_tuple tuple;
1214
1215         memset(&tuple.src.u3, 0, sizeof(tuple.src.u3));
1216         tuple.src.u.tcp.port = 0;
1217         memcpy(&tuple.dst.u3, addr, sizeof(tuple.dst.u3));
1218         tuple.dst.u.tcp.port = port;
1219         tuple.dst.protonum = IPPROTO_TCP;
1220
1221         exp = __nf_ct_expect_find(&tuple);
1222         if (exp && exp->master == ct)
1223                 return exp;
1224         return NULL;
1225 }
1226
1227 /****************************************************************************/
1228 static int set_expect_timeout(struct nf_conntrack_expect *exp,
1229                               unsigned timeout)
1230 {
1231         if (!exp || !del_timer(&exp->timeout))
1232                 return 0;
1233
1234         exp->timeout.expires = jiffies + timeout * HZ;
1235         add_timer(&exp->timeout);
1236
1237         return 1;
1238 }
1239
1240 /****************************************************************************/
1241 static int expect_q931(struct sk_buff *skb, struct nf_conn *ct,
1242                        enum ip_conntrack_info ctinfo,
1243                        unsigned char **data,
1244                        TransportAddress *taddr, int count)
1245 {
1246         struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1247         int dir = CTINFO2DIR(ctinfo);
1248         int ret = 0;
1249         int i;
1250         __be16 port;
1251         union nf_inet_addr addr;
1252         struct nf_conntrack_expect *exp;
1253         typeof(nat_q931_hook) nat_q931;
1254
1255         /* Look for the first related address */
1256         for (i = 0; i < count; i++) {
1257                 if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) &&
1258                     memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3,
1259                            sizeof(addr)) == 0 && port != 0)
1260                         break;
1261         }
1262
1263         if (i >= count)         /* Not found */
1264                 return 0;
1265
1266         /* Create expect for Q.931 */
1267         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1268                 return -1;
1269         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1270                           gkrouted_only ? /* only accept calls from GK? */
1271                                 &ct->tuplehash[!dir].tuple.src.u3 : NULL,
1272                           &ct->tuplehash[!dir].tuple.dst.u3,
1273                           IPPROTO_TCP, NULL, &port);
1274         exp->helper = nf_conntrack_helper_q931;
1275         exp->flags = NF_CT_EXPECT_PERMANENT;    /* Accept multiple calls */
1276
1277         nat_q931 = rcu_dereference(nat_q931_hook);
1278         if (nat_q931 && ct->status & IPS_NAT_MASK) {    /* Need NAT */
1279                 ret = nat_q931(skb, ct, ctinfo, data, taddr, i, port, exp);
1280         } else {                /* Conntrack only */
1281                 if (nf_ct_expect_related(exp) == 0) {
1282                         pr_debug("nf_ct_ras: expect Q.931 ");
1283                         nf_ct_dump_tuple(&exp->tuple);
1284
1285                         /* Save port for looking up expect in processing RCF */
1286                         info->sig_port[dir] = port;
1287                 } else
1288                         ret = -1;
1289         }
1290
1291         nf_ct_expect_put(exp);
1292
1293         return ret;
1294 }
1295
1296 /****************************************************************************/
1297 static int process_grq(struct sk_buff *skb, struct nf_conn *ct,
1298                        enum ip_conntrack_info ctinfo,
1299                        unsigned char **data, GatekeeperRequest *grq)
1300 {
1301         typeof(set_ras_addr_hook) set_ras_addr;
1302
1303         pr_debug("nf_ct_ras: GRQ\n");
1304
1305         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1306         if (set_ras_addr && ct->status & IPS_NAT_MASK)  /* NATed */
1307                 return set_ras_addr(skb, ct, ctinfo, data,
1308                                     &grq->rasAddress, 1);
1309         return 0;
1310 }
1311
1312 /****************************************************************************/
1313 static int process_gcf(struct sk_buff *skb, struct nf_conn *ct,
1314                        enum ip_conntrack_info ctinfo,
1315                        unsigned char **data, GatekeeperConfirm *gcf)
1316 {
1317         int dir = CTINFO2DIR(ctinfo);
1318         int ret = 0;
1319         __be16 port;
1320         union nf_inet_addr addr;
1321         struct nf_conntrack_expect *exp;
1322
1323         pr_debug("nf_ct_ras: GCF\n");
1324
1325         if (!get_h225_addr(ct, *data, &gcf->rasAddress, &addr, &port))
1326                 return 0;
1327
1328         /* Registration port is the same as discovery port */
1329         if (!memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1330             port == ct->tuplehash[dir].tuple.src.u.udp.port)
1331                 return 0;
1332
1333         /* Avoid RAS expectation loops. A GCF is never expected. */
1334         if (test_bit(IPS_EXPECTED_BIT, &ct->status))
1335                 return 0;
1336
1337         /* Need new expect */
1338         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1339                 return -1;
1340         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1341                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1342                           IPPROTO_UDP, NULL, &port);
1343         exp->helper = nf_conntrack_helper_ras;
1344
1345         if (nf_ct_expect_related(exp) == 0) {
1346                 pr_debug("nf_ct_ras: expect RAS ");
1347                 nf_ct_dump_tuple(&exp->tuple);
1348         } else
1349                 ret = -1;
1350
1351         nf_ct_expect_put(exp);
1352
1353         return ret;
1354 }
1355
1356 /****************************************************************************/
1357 static int process_rrq(struct sk_buff *skb, struct nf_conn *ct,
1358                        enum ip_conntrack_info ctinfo,
1359                        unsigned char **data, RegistrationRequest *rrq)
1360 {
1361         struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1362         int ret;
1363         typeof(set_ras_addr_hook) set_ras_addr;
1364
1365         pr_debug("nf_ct_ras: RRQ\n");
1366
1367         ret = expect_q931(skb, ct, ctinfo, data,
1368                           rrq->callSignalAddress.item,
1369                           rrq->callSignalAddress.count);
1370         if (ret < 0)
1371                 return -1;
1372
1373         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1374         if (set_ras_addr && ct->status & IPS_NAT_MASK) {
1375                 ret = set_ras_addr(skb, ct, ctinfo, data,
1376                                    rrq->rasAddress.item,
1377                                    rrq->rasAddress.count);
1378                 if (ret < 0)
1379                         return -1;
1380         }
1381
1382         if (rrq->options & eRegistrationRequest_timeToLive) {
1383                 pr_debug("nf_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive);
1384                 info->timeout = rrq->timeToLive;
1385         } else
1386                 info->timeout = default_rrq_ttl;
1387
1388         return 0;
1389 }
1390
1391 /****************************************************************************/
1392 static int process_rcf(struct sk_buff *skb, struct nf_conn *ct,
1393                        enum ip_conntrack_info ctinfo,
1394                        unsigned char **data, RegistrationConfirm *rcf)
1395 {
1396         struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1397         int dir = CTINFO2DIR(ctinfo);
1398         int ret;
1399         struct nf_conntrack_expect *exp;
1400         typeof(set_sig_addr_hook) set_sig_addr;
1401
1402         pr_debug("nf_ct_ras: RCF\n");
1403
1404         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1405         if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1406                 ret = set_sig_addr(skb, ct, ctinfo, data,
1407                                         rcf->callSignalAddress.item,
1408                                         rcf->callSignalAddress.count);
1409                 if (ret < 0)
1410                         return -1;
1411         }
1412
1413         if (rcf->options & eRegistrationConfirm_timeToLive) {
1414                 pr_debug("nf_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive);
1415                 info->timeout = rcf->timeToLive;
1416         }
1417
1418         if (info->timeout > 0) {
1419                 pr_debug("nf_ct_ras: set RAS connection timeout to "
1420                          "%u seconds\n", info->timeout);
1421                 nf_ct_refresh(ct, skb, info->timeout * HZ);
1422
1423                 /* Set expect timeout */
1424                 spin_lock_bh(&nf_conntrack_lock);
1425                 exp = find_expect(ct, &ct->tuplehash[dir].tuple.dst.u3,
1426                                   info->sig_port[!dir]);
1427                 if (exp) {
1428                         pr_debug("nf_ct_ras: set Q.931 expect "
1429                                  "timeout to %u seconds for",
1430                                  info->timeout);
1431                         nf_ct_dump_tuple(&exp->tuple);
1432                         set_expect_timeout(exp, info->timeout);
1433                 }
1434                 spin_unlock_bh(&nf_conntrack_lock);
1435         }
1436
1437         return 0;
1438 }
1439
1440 /****************************************************************************/
1441 static int process_urq(struct sk_buff *skb, struct nf_conn *ct,
1442                        enum ip_conntrack_info ctinfo,
1443                        unsigned char **data, UnregistrationRequest *urq)
1444 {
1445         struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1446         int dir = CTINFO2DIR(ctinfo);
1447         int ret;
1448         typeof(set_sig_addr_hook) set_sig_addr;
1449
1450         pr_debug("nf_ct_ras: URQ\n");
1451
1452         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1453         if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1454                 ret = set_sig_addr(skb, ct, ctinfo, data,
1455                                    urq->callSignalAddress.item,
1456                                    urq->callSignalAddress.count);
1457                 if (ret < 0)
1458                         return -1;
1459         }
1460
1461         /* Clear old expect */
1462         nf_ct_remove_expectations(ct);
1463         info->sig_port[dir] = 0;
1464         info->sig_port[!dir] = 0;
1465
1466         /* Give it 30 seconds for UCF or URJ */
1467         nf_ct_refresh(ct, skb, 30 * HZ);
1468
1469         return 0;
1470 }
1471
1472 /****************************************************************************/
1473 static int process_arq(struct sk_buff *skb, struct nf_conn *ct,
1474                        enum ip_conntrack_info ctinfo,
1475                        unsigned char **data, AdmissionRequest *arq)
1476 {
1477         const struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1478         int dir = CTINFO2DIR(ctinfo);
1479         __be16 port;
1480         union nf_inet_addr addr;
1481         typeof(set_h225_addr_hook) set_h225_addr;
1482
1483         pr_debug("nf_ct_ras: ARQ\n");
1484
1485         set_h225_addr = rcu_dereference(set_h225_addr_hook);
1486         if ((arq->options & eAdmissionRequest_destCallSignalAddress) &&
1487             get_h225_addr(ct, *data, &arq->destCallSignalAddress,
1488                           &addr, &port) &&
1489             !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1490             port == info->sig_port[dir] &&
1491             set_h225_addr && ct->status & IPS_NAT_MASK) {
1492                 /* Answering ARQ */
1493                 return set_h225_addr(skb, data, 0,
1494                                      &arq->destCallSignalAddress,
1495                                      &ct->tuplehash[!dir].tuple.dst.u3,
1496                                      info->sig_port[!dir]);
1497         }
1498
1499         if ((arq->options & eAdmissionRequest_srcCallSignalAddress) &&
1500             get_h225_addr(ct, *data, &arq->srcCallSignalAddress,
1501                           &addr, &port) &&
1502             !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1503             set_h225_addr && ct->status & IPS_NAT_MASK) {
1504                 /* Calling ARQ */
1505                 return set_h225_addr(skb, data, 0,
1506                                      &arq->srcCallSignalAddress,
1507                                      &ct->tuplehash[!dir].tuple.dst.u3,
1508                                      port);
1509         }
1510
1511         return 0;
1512 }
1513
1514 /****************************************************************************/
1515 static int process_acf(struct sk_buff *skb, struct nf_conn *ct,
1516                        enum ip_conntrack_info ctinfo,
1517                        unsigned char **data, AdmissionConfirm *acf)
1518 {
1519         int dir = CTINFO2DIR(ctinfo);
1520         int ret = 0;
1521         __be16 port;
1522         union nf_inet_addr addr;
1523         struct nf_conntrack_expect *exp;
1524         typeof(set_sig_addr_hook) set_sig_addr;
1525
1526         pr_debug("nf_ct_ras: ACF\n");
1527
1528         if (!get_h225_addr(ct, *data, &acf->destCallSignalAddress,
1529                            &addr, &port))
1530                 return 0;
1531
1532         if (!memcmp(&addr, &ct->tuplehash[dir].tuple.dst.u3, sizeof(addr))) {
1533                 /* Answering ACF */
1534                 set_sig_addr = rcu_dereference(set_sig_addr_hook);
1535                 if (set_sig_addr && ct->status & IPS_NAT_MASK)
1536                         return set_sig_addr(skb, ct, ctinfo, data,
1537                                             &acf->destCallSignalAddress, 1);
1538                 return 0;
1539         }
1540
1541         /* Need new expect */
1542         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1543                 return -1;
1544         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1545                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1546                           IPPROTO_TCP, NULL, &port);
1547         exp->flags = NF_CT_EXPECT_PERMANENT;
1548         exp->helper = nf_conntrack_helper_q931;
1549
1550         if (nf_ct_expect_related(exp) == 0) {
1551                 pr_debug("nf_ct_ras: expect Q.931 ");
1552                 nf_ct_dump_tuple(&exp->tuple);
1553         } else
1554                 ret = -1;
1555
1556         nf_ct_expect_put(exp);
1557
1558         return ret;
1559 }
1560
1561 /****************************************************************************/
1562 static int process_lrq(struct sk_buff *skb, struct nf_conn *ct,
1563                        enum ip_conntrack_info ctinfo,
1564                        unsigned char **data, LocationRequest *lrq)
1565 {
1566         typeof(set_ras_addr_hook) set_ras_addr;
1567
1568         pr_debug("nf_ct_ras: LRQ\n");
1569
1570         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1571         if (set_ras_addr && ct->status & IPS_NAT_MASK)
1572                 return set_ras_addr(skb, ct, ctinfo, data,
1573                                     &lrq->replyAddress, 1);
1574         return 0;
1575 }
1576
1577 /****************************************************************************/
1578 static int process_lcf(struct sk_buff *skb, struct nf_conn *ct,
1579                        enum ip_conntrack_info ctinfo,
1580                        unsigned char **data, LocationConfirm *lcf)
1581 {
1582         int dir = CTINFO2DIR(ctinfo);
1583         int ret = 0;
1584         __be16 port;
1585         union nf_inet_addr addr;
1586         struct nf_conntrack_expect *exp;
1587
1588         pr_debug("nf_ct_ras: LCF\n");
1589
1590         if (!get_h225_addr(ct, *data, &lcf->callSignalAddress,
1591                            &addr, &port))
1592                 return 0;
1593
1594         /* Need new expect for call signal */
1595         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1596                 return -1;
1597         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1598                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1599                           IPPROTO_TCP, NULL, &port);
1600         exp->flags = NF_CT_EXPECT_PERMANENT;
1601         exp->helper = nf_conntrack_helper_q931;
1602
1603         if (nf_ct_expect_related(exp) == 0) {
1604                 pr_debug("nf_ct_ras: expect Q.931 ");
1605                 nf_ct_dump_tuple(&exp->tuple);
1606         } else
1607                 ret = -1;
1608
1609         nf_ct_expect_put(exp);
1610
1611         /* Ignore rasAddress */
1612
1613         return ret;
1614 }
1615
1616 /****************************************************************************/
1617 static int process_irr(struct sk_buff *skb, struct nf_conn *ct,
1618                        enum ip_conntrack_info ctinfo,
1619                        unsigned char **data, InfoRequestResponse *irr)
1620 {
1621         int ret;
1622         typeof(set_ras_addr_hook) set_ras_addr;
1623         typeof(set_sig_addr_hook) set_sig_addr;
1624
1625         pr_debug("nf_ct_ras: IRR\n");
1626
1627         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1628         if (set_ras_addr && ct->status & IPS_NAT_MASK) {
1629                 ret = set_ras_addr(skb, ct, ctinfo, data,
1630                                    &irr->rasAddress, 1);
1631                 if (ret < 0)
1632                         return -1;
1633         }
1634
1635         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1636         if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1637                 ret = set_sig_addr(skb, ct, ctinfo, data,
1638                                         irr->callSignalAddress.item,
1639                                         irr->callSignalAddress.count);
1640                 if (ret < 0)
1641                         return -1;
1642         }
1643
1644         return 0;
1645 }
1646
1647 /****************************************************************************/
1648 static int process_ras(struct sk_buff *skb, struct nf_conn *ct,
1649                        enum ip_conntrack_info ctinfo,
1650                        unsigned char **data, RasMessage *ras)
1651 {
1652         switch (ras->choice) {
1653         case eRasMessage_gatekeeperRequest:
1654                 return process_grq(skb, ct, ctinfo, data,
1655                                    &ras->gatekeeperRequest);
1656         case eRasMessage_gatekeeperConfirm:
1657                 return process_gcf(skb, ct, ctinfo, data,
1658                                    &ras->gatekeeperConfirm);
1659         case eRasMessage_registrationRequest:
1660                 return process_rrq(skb, ct, ctinfo, data,
1661                                    &ras->registrationRequest);
1662         case eRasMessage_registrationConfirm:
1663                 return process_rcf(skb, ct, ctinfo, data,
1664                                    &ras->registrationConfirm);
1665         case eRasMessage_unregistrationRequest:
1666                 return process_urq(skb, ct, ctinfo, data,
1667                                    &ras->unregistrationRequest);
1668         case eRasMessage_admissionRequest:
1669                 return process_arq(skb, ct, ctinfo, data,
1670                                    &ras->admissionRequest);
1671         case eRasMessage_admissionConfirm:
1672                 return process_acf(skb, ct, ctinfo, data,
1673                                    &ras->admissionConfirm);
1674         case eRasMessage_locationRequest:
1675                 return process_lrq(skb, ct, ctinfo, data,
1676                                    &ras->locationRequest);
1677         case eRasMessage_locationConfirm:
1678                 return process_lcf(skb, ct, ctinfo, data,
1679                                    &ras->locationConfirm);
1680         case eRasMessage_infoRequestResponse:
1681                 return process_irr(skb, ct, ctinfo, data,
1682                                    &ras->infoRequestResponse);
1683         default:
1684                 pr_debug("nf_ct_ras: RAS message %d\n", ras->choice);
1685                 break;
1686         }
1687
1688         return 0;
1689 }
1690
1691 /****************************************************************************/
1692 static int ras_help(struct sk_buff *skb, unsigned int protoff,
1693                     struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1694 {
1695         static RasMessage ras;
1696         unsigned char *data;
1697         int datalen = 0;
1698         int ret;
1699
1700         pr_debug("nf_ct_ras: skblen = %u\n", skb->len);
1701
1702         spin_lock_bh(&nf_h323_lock);
1703
1704         /* Get UDP data */
1705         data = get_udp_data(skb, protoff, &datalen);
1706         if (data == NULL)
1707                 goto accept;
1708         pr_debug("nf_ct_ras: RAS message len=%d ", datalen);
1709         nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1710
1711         /* Decode RAS message */
1712         ret = DecodeRasMessage(data, datalen, &ras);
1713         if (ret < 0) {
1714                 pr_debug("nf_ct_ras: decoding error: %s\n",
1715                          ret == H323_ERROR_BOUND ?
1716                          "out of bound" : "out of range");
1717                 goto accept;
1718         }
1719
1720         /* Process RAS message */
1721         if (process_ras(skb, ct, ctinfo, &data, &ras) < 0)
1722                 goto drop;
1723
1724       accept:
1725         spin_unlock_bh(&nf_h323_lock);
1726         return NF_ACCEPT;
1727
1728       drop:
1729         spin_unlock_bh(&nf_h323_lock);
1730         if (net_ratelimit())
1731                 printk("nf_ct_ras: packet dropped\n");
1732         return NF_DROP;
1733 }
1734
1735 /****************************************************************************/
1736 static const struct nf_conntrack_expect_policy ras_exp_policy = {
1737         .max_expected           = 32,
1738         .timeout                = 240,
1739 };
1740
1741 static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = {
1742         {
1743                 .name                   = "RAS",
1744                 .me                     = THIS_MODULE,
1745                 .tuple.src.l3num        = AF_INET,
1746                 .tuple.src.u.udp.port   = __constant_htons(RAS_PORT),
1747                 .tuple.dst.protonum     = IPPROTO_UDP,
1748                 .help                   = ras_help,
1749                 .expect_policy          = &ras_exp_policy,
1750         },
1751         {
1752                 .name                   = "RAS",
1753                 .me                     = THIS_MODULE,
1754                 .tuple.src.l3num        = AF_INET6,
1755                 .tuple.src.u.udp.port   = __constant_htons(RAS_PORT),
1756                 .tuple.dst.protonum     = IPPROTO_UDP,
1757                 .help                   = ras_help,
1758                 .expect_policy          = &ras_exp_policy,
1759         },
1760 };
1761
1762 /****************************************************************************/
1763 static void __exit nf_conntrack_h323_fini(void)
1764 {
1765         nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[1]);
1766         nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1767         nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1768         nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1769         nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1770         kfree(h323_buffer);
1771         pr_debug("nf_ct_h323: fini\n");
1772 }
1773
1774 /****************************************************************************/
1775 static int __init nf_conntrack_h323_init(void)
1776 {
1777         int ret;
1778
1779         h323_buffer = kmalloc(65536, GFP_KERNEL);
1780         if (!h323_buffer)
1781                 return -ENOMEM;
1782         ret = nf_conntrack_helper_register(&nf_conntrack_helper_h245);
1783         if (ret < 0)
1784                 goto err1;
1785         ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[0]);
1786         if (ret < 0)
1787                 goto err2;
1788         ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[1]);
1789         if (ret < 0)
1790                 goto err3;
1791         ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[0]);
1792         if (ret < 0)
1793                 goto err4;
1794         ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[1]);
1795         if (ret < 0)
1796                 goto err5;
1797         pr_debug("nf_ct_h323: init success\n");
1798         return 0;
1799
1800 err5:
1801         nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1802 err4:
1803         nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1804 err3:
1805         nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1806 err2:
1807         nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1808 err1:
1809         kfree(h323_buffer);
1810         return ret;
1811 }
1812
1813 /****************************************************************************/
1814 module_init(nf_conntrack_h323_init);
1815 module_exit(nf_conntrack_h323_fini);
1816
1817 EXPORT_SYMBOL_GPL(get_h225_addr);
1818 EXPORT_SYMBOL_GPL(set_h245_addr_hook);
1819 EXPORT_SYMBOL_GPL(set_h225_addr_hook);
1820 EXPORT_SYMBOL_GPL(set_sig_addr_hook);
1821 EXPORT_SYMBOL_GPL(set_ras_addr_hook);
1822 EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook);
1823 EXPORT_SYMBOL_GPL(nat_t120_hook);
1824 EXPORT_SYMBOL_GPL(nat_h245_hook);
1825 EXPORT_SYMBOL_GPL(nat_callforwarding_hook);
1826 EXPORT_SYMBOL_GPL(nat_q931_hook);
1827
1828 MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>");
1829 MODULE_DESCRIPTION("H.323 connection tracking helper");
1830 MODULE_LICENSE("GPL");
1831 MODULE_ALIAS("ip_conntrack_h323");