net/netfilter/nf_conntrack_h323_main.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * H.323 connection tracking helper
   4  *
   5  * Copyright (c) 2006 Jing Min Zhao <zhaojingmin@users.sourceforge.net>
   6  * Copyright (c) 2006-2012 Patrick McHardy <kaber@trash.net>
   7  *
   8  * Based on the 'brute force' H.323 connection tracking module by
   9  * Jozsef Kadlecsik <kadlec@netfilter.org>
  10  *
  11  * For more information, please see http://nath323.sourceforge.net/
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/moduleparam.h>
  16 #include <linux/ctype.h>
  17 #include <linux/inet.h>
  18 #include <linux/in.h>
  19 #include <linux/ip.h>
  20 #include <linux/slab.h>
  21 #include <linux/udp.h>
  22 #include <linux/tcp.h>
  23 #include <linux/skbuff.h>
  24 #include <net/route.h>
  25 #include <net/ip6_route.h>
  26 #include <linux/netfilter_ipv6.h>
  27
  28 #include <net/netfilter/nf_conntrack.h>
  29 #include <net/netfilter/nf_conntrack_core.h>
  30 #include <net/netfilter/nf_conntrack_tuple.h>
  31 #include <net/netfilter/nf_conntrack_expect.h>
  32 #include <net/netfilter/nf_conntrack_ecache.h>
  33 #include <net/netfilter/nf_conntrack_helper.h>
  34 #include <net/netfilter/nf_conntrack_zones.h>
  35 #include <linux/netfilter/nf_conntrack_h323.h>
  36
  37 /* Parameters */
  38 static unsigned int default_rrq_ttl __read_mostly = 300;
  39 module_param(default_rrq_ttl, uint, 0600);
  40 MODULE_PARM_DESC(default_rrq_ttl, "use this TTL if it's missing in RRQ");
  41
  42 static int gkrouted_only __read_mostly = 1;
  43 module_param(gkrouted_only, int, 0600);
  44 MODULE_PARM_DESC(gkrouted_only, "only accept calls from gatekeeper");
  45
  46 static bool callforward_filter __read_mostly = true;
  47 module_param(callforward_filter, bool, 0600);
  48 MODULE_PARM_DESC(callforward_filter, "only create call forwarding expectations "
  49                                      "if both endpoints are on different sides "
  50                                      "(determined by routing information)");
  51
  52 /* Hooks for NAT */
  53 int (*set_h245_addr_hook) (struct sk_buff *skb, unsigned int protoff,
  54                            unsigned char **data, int dataoff,
  55                            H245_TransportAddress *taddr,
  56                            union nf_inet_addr *addr, __be16 port)
  57                            __read_mostly;
  58 int (*set_h225_addr_hook) (struct sk_buff *skb, unsigned int protoff,
  59                            unsigned char **data, int dataoff,
  60                            TransportAddress *taddr,
  61                            union nf_inet_addr *addr, __be16 port)
  62                            __read_mostly;
  63 int (*set_sig_addr_hook) (struct sk_buff *skb,
  64                           struct nf_conn *ct,
  65                           enum ip_conntrack_info ctinfo,
  66                           unsigned int protoff, unsigned char **data,
  67                           TransportAddress *taddr, int count) __read_mostly;
  68 int (*set_ras_addr_hook) (struct sk_buff *skb,
  69                           struct nf_conn *ct,
  70                           enum ip_conntrack_info ctinfo,
  71                           unsigned int protoff, unsigned char **data,
  72                           TransportAddress *taddr, int count) __read_mostly;
  73 int (*nat_rtp_rtcp_hook) (struct sk_buff *skb,
  74                           struct nf_conn *ct,
  75                           enum ip_conntrack_info ctinfo,
  76                           unsigned int protoff,
  77                           unsigned char **data, int dataoff,
  78                           H245_TransportAddress *taddr,
  79                           __be16 port, __be16 rtp_port,
  80                           struct nf_conntrack_expect *rtp_exp,
  81                           struct nf_conntrack_expect *rtcp_exp) __read_mostly;
  82 int (*nat_t120_hook) (struct sk_buff *skb,
  83                       struct nf_conn *ct,
  84                       enum ip_conntrack_info ctinfo,
  85                       unsigned int protoff,
  86                       unsigned char **data, int dataoff,
  87                       H245_TransportAddress *taddr, __be16 port,
  88                       struct nf_conntrack_expect *exp) __read_mostly;
  89 int (*nat_h245_hook) (struct sk_buff *skb,
  90                       struct nf_conn *ct,
  91                       enum ip_conntrack_info ctinfo,
  92                       unsigned int protoff,
  93                       unsigned char **data, int dataoff,
  94                       TransportAddress *taddr, __be16 port,
  95                       struct nf_conntrack_expect *exp) __read_mostly;
  96 int (*nat_callforwarding_hook) (struct sk_buff *skb,
  97                                 struct nf_conn *ct,
  98                                 enum ip_conntrack_info ctinfo,
  99                                 unsigned int protoff,
 100                                 unsigned char **data, int dataoff,
 101                                 TransportAddress *taddr, __be16 port,
 102                                 struct nf_conntrack_expect *exp) __read_mostly;
 103 int (*nat_q931_hook) (struct sk_buff *skb,
 104                       struct nf_conn *ct,
 105                       enum ip_conntrack_info ctinfo,
 106                       unsigned int protoff,
 107                       unsigned char **data, TransportAddress *taddr, int idx,
 108                       __be16 port, struct nf_conntrack_expect *exp)
 109                       __read_mostly;
 110
 111 static DEFINE_SPINLOCK(nf_h323_lock);
 112 static char *h323_buffer;
 113
 114 static struct nf_conntrack_helper nf_conntrack_helper_h245;
 115 static struct nf_conntrack_helper nf_conntrack_helper_q931[];
 116 static struct nf_conntrack_helper nf_conntrack_helper_ras[];
 117
 118 static int get_tpkt_data(struct sk_buff *skb, unsigned int protoff,
 119                          struct nf_conn *ct, enum ip_conntrack_info ctinfo,
 120                          unsigned char **data, int *datalen, int *dataoff)
 121 {
 122         struct nf_ct_h323_master *info = nfct_help_data(ct);
 123         int dir = CTINFO2DIR(ctinfo);
 124         const struct tcphdr *th;
 125         struct tcphdr _tcph;
 126         int tcpdatalen;
 127         int tcpdataoff;
 128         unsigned char *tpkt;
 129         int tpktlen;
 130         int tpktoff;
 131
 132         /* Get TCP header */
 133         th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph);
 134         if (th == NULL)
 135                 return 0;
 136
 137         /* Get TCP data offset */
 138         tcpdataoff = protoff + th->doff * 4;
 139
 140         /* Get TCP data length */
 141         tcpdatalen = skb->len - tcpdataoff;
 142         if (tcpdatalen <= 0)    /* No TCP data */
 143                 goto clear_out;
 144
 145         if (*data == NULL) {    /* first TPKT */
 146                 /* Get first TPKT pointer */
 147                 tpkt = skb_header_pointer(skb, tcpdataoff, tcpdatalen,
 148                                           h323_buffer);
 149                 if (!tpkt)
 150                         goto clear_out;
 151
 152                 /* Validate TPKT identifier */
 153                 if (tcpdatalen < 4 || tpkt[0] != 0x03 || tpkt[1] != 0) {
 154                         /* Netmeeting sends TPKT header and data separately */
 155                         if (info->tpkt_len[dir] > 0) {
 156                                 pr_debug("nf_ct_h323: previous packet "
 157                                          "indicated separate TPKT data of %hu "
 158                                          "bytes\n", info->tpkt_len[dir]);
 159                                 if (info->tpkt_len[dir] <= tcpdatalen) {
 160                                         /* Yes, there was a TPKT header
 161                                          * received */
 162                                         *data = tpkt;
 163                                         *datalen = info->tpkt_len[dir];
 164                                         *dataoff = 0;
 165                                         goto out;
 166                                 }
 167
 168                                 /* Fragmented TPKT */
 169                                 pr_debug("nf_ct_h323: fragmented TPKT\n");
 170                                 goto clear_out;
 171                         }
 172
 173                         /* It is not even a TPKT */
 174                         return 0;
 175                 }
 176                 tpktoff = 0;
 177         } else {                /* Next TPKT */
 178                 tpktoff = *dataoff + *datalen;
 179                 tcpdatalen -= tpktoff;
 180                 if (tcpdatalen <= 4)    /* No more TPKT */
 181                         goto clear_out;
 182                 tpkt = *data + *datalen;
 183
 184                 /* Validate TPKT identifier */
 185                 if (tpkt[0] != 0x03 || tpkt[1] != 0)
 186                         goto clear_out;
 187         }
 188
 189         /* Validate TPKT length */
 190         tpktlen = tpkt[2] * 256 + tpkt[3];
 191         if (tpktlen < 4)
 192                 goto clear_out;
 193         if (tpktlen > tcpdatalen) {
 194                 if (tcpdatalen == 4) {  /* Separate TPKT header */
 195                         /* Netmeeting sends TPKT header and data separately */
 196                         pr_debug("nf_ct_h323: separate TPKT header indicates "
 197                                  "there will be TPKT data of %d bytes\n",
 198                                  tpktlen - 4);
 199                         info->tpkt_len[dir] = tpktlen - 4;
 200                         return 0;
 201                 }
 202
 203                 pr_debug("nf_ct_h323: incomplete TPKT (fragmented?)\n");
 204                 goto clear_out;
 205         }
 206
 207         /* This is the encapsulated data */
 208         *data = tpkt + 4;
 209         *datalen = tpktlen - 4;
 210         *dataoff = tpktoff + 4;
 211
 212       out:
 213         /* Clear TPKT length */
 214         info->tpkt_len[dir] = 0;
 215         return 1;
 216
 217       clear_out:
 218         info->tpkt_len[dir] = 0;
 219         return 0;
 220 }
 221
 222 static int get_h245_addr(struct nf_conn *ct, const unsigned char *data,
 223                          H245_TransportAddress *taddr,
 224                          union nf_inet_addr *addr, __be16 *port)
 225 {
 226         const unsigned char *p;
 227         int len;
 228
 229         if (taddr->choice != eH245_TransportAddress_unicastAddress)
 230                 return 0;
 231
 232         switch (taddr->unicastAddress.choice) {
 233         case eUnicastAddress_iPAddress:
 234                 if (nf_ct_l3num(ct) != AF_INET)
 235                         return 0;
 236                 p = data + taddr->unicastAddress.iPAddress.network;
 237                 len = 4;
 238                 break;
 239         case eUnicastAddress_iP6Address:
 240                 if (nf_ct_l3num(ct) != AF_INET6)
 241                         return 0;
 242                 p = data + taddr->unicastAddress.iP6Address.network;
 243                 len = 16;
 244                 break;
 245         default:
 246                 return 0;
 247         }
 248
 249         memcpy(addr, p, len);
 250         memset((void *)addr + len, 0, sizeof(*addr) - len);
 251         memcpy(port, p + len, sizeof(__be16));
 252
 253         return 1;
 254 }
 255
 256 static int expect_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct,
 257                            enum ip_conntrack_info ctinfo,
 258                            unsigned int protoff,
 259                            unsigned char **data, int dataoff,
 260                            H245_TransportAddress *taddr)
 261 {
 262         int dir = CTINFO2DIR(ctinfo);
 263         int ret = 0;
 264         __be16 port;
 265         __be16 rtp_port, rtcp_port;
 266         union nf_inet_addr addr;
 267         struct nf_conntrack_expect *rtp_exp;
 268         struct nf_conntrack_expect *rtcp_exp;
 269         typeof(nat_rtp_rtcp_hook) nat_rtp_rtcp;
 270
 271         /* Read RTP or RTCP address */
 272         if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
 273             memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 274             port == 0)
 275                 return 0;
 276
 277         /* RTP port is even */
 278         rtp_port = port & ~htons(1);
 279         rtcp_port = port | htons(1);
 280
 281         /* Create expect for RTP */
 282         if ((rtp_exp = nf_ct_expect_alloc(ct)) == NULL)
 283                 return -1;
 284         nf_ct_expect_init(rtp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 285                           &ct->tuplehash[!dir].tuple.src.u3,
 286                           &ct->tuplehash[!dir].tuple.dst.u3,
 287                           IPPROTO_UDP, NULL, &rtp_port);
 288
 289         /* Create expect for RTCP */
 290         if ((rtcp_exp = nf_ct_expect_alloc(ct)) == NULL) {
 291                 nf_ct_expect_put(rtp_exp);
 292                 return -1;
 293         }
 294         nf_ct_expect_init(rtcp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 295                           &ct->tuplehash[!dir].tuple.src.u3,
 296                           &ct->tuplehash[!dir].tuple.dst.u3,
 297                           IPPROTO_UDP, NULL, &rtcp_port);
 298
 299         if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 300                    &ct->tuplehash[!dir].tuple.dst.u3,
 301                    sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 302                    (nat_rtp_rtcp = rcu_dereference(nat_rtp_rtcp_hook)) &&
 303                    nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 304                    ct->status & IPS_NAT_MASK) {
 305                 /* NAT needed */
 306                 ret = nat_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff,
 307                                    taddr, port, rtp_port, rtp_exp, rtcp_exp);
 308         } else {                /* Conntrack only */
 309                 if (nf_ct_expect_related(rtp_exp, 0) == 0) {
 310                         if (nf_ct_expect_related(rtcp_exp, 0) == 0) {
 311                                 pr_debug("nf_ct_h323: expect RTP ");
 312                                 nf_ct_dump_tuple(&rtp_exp->tuple);
 313                                 pr_debug("nf_ct_h323: expect RTCP ");
 314                                 nf_ct_dump_tuple(&rtcp_exp->tuple);
 315                         } else {
 316                                 nf_ct_unexpect_related(rtp_exp);
 317                                 ret = -1;
 318                         }
 319                 } else
 320                         ret = -1;
 321         }
 322
 323         nf_ct_expect_put(rtp_exp);
 324         nf_ct_expect_put(rtcp_exp);
 325
 326         return ret;
 327 }
 328
 329 static int expect_t120(struct sk_buff *skb,
 330                        struct nf_conn *ct,
 331                        enum ip_conntrack_info ctinfo,
 332                        unsigned int protoff,
 333                        unsigned char **data, int dataoff,
 334                        H245_TransportAddress *taddr)
 335 {
 336         int dir = CTINFO2DIR(ctinfo);
 337         int ret = 0;
 338         __be16 port;
 339         union nf_inet_addr addr;
 340         struct nf_conntrack_expect *exp;
 341         typeof(nat_t120_hook) nat_t120;
 342
 343         /* Read T.120 address */
 344         if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
 345             memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 346             port == 0)
 347                 return 0;
 348
 349         /* Create expect for T.120 connections */
 350         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 351                 return -1;
 352         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 353                           &ct->tuplehash[!dir].tuple.src.u3,
 354                           &ct->tuplehash[!dir].tuple.dst.u3,
 355                           IPPROTO_TCP, NULL, &port);
 356         exp->flags = NF_CT_EXPECT_PERMANENT;    /* Accept multiple channels */
 357
 358         if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 359                    &ct->tuplehash[!dir].tuple.dst.u3,
 360                    sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 361             (nat_t120 = rcu_dereference(nat_t120_hook)) &&
 362             nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 363             ct->status & IPS_NAT_MASK) {
 364                 /* NAT needed */
 365                 ret = nat_t120(skb, ct, ctinfo, protoff, data, dataoff, taddr,
 366                                port, exp);
 367         } else {                /* Conntrack only */
 368                 if (nf_ct_expect_related(exp, 0) == 0) {
 369                         pr_debug("nf_ct_h323: expect T.120 ");
 370                         nf_ct_dump_tuple(&exp->tuple);
 371                 } else
 372                         ret = -1;
 373         }
 374
 375         nf_ct_expect_put(exp);
 376
 377         return ret;
 378 }
 379
 380 static int process_h245_channel(struct sk_buff *skb,
 381                                 struct nf_conn *ct,
 382                                 enum ip_conntrack_info ctinfo,
 383                                 unsigned int protoff,
 384                                 unsigned char **data, int dataoff,
 385                                 H2250LogicalChannelParameters *channel)
 386 {
 387         int ret;
 388
 389         if (channel->options & eH2250LogicalChannelParameters_mediaChannel) {
 390                 /* RTP */
 391                 ret = expect_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff,
 392                                       &channel->mediaChannel);
 393                 if (ret < 0)
 394                         return -1;
 395         }
 396
 397         if (channel->
 398             options & eH2250LogicalChannelParameters_mediaControlChannel) {
 399                 /* RTCP */
 400                 ret = expect_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff,
 401                                       &channel->mediaControlChannel);
 402                 if (ret < 0)
 403                         return -1;
 404         }
 405
 406         return 0;
 407 }
 408
 409 static int process_olc(struct sk_buff *skb, struct nf_conn *ct,
 410                        enum ip_conntrack_info ctinfo,
 411                        unsigned int protoff,
 412                        unsigned char **data, int dataoff,
 413                        OpenLogicalChannel *olc)
 414 {
 415         int ret;
 416
 417         pr_debug("nf_ct_h323: OpenLogicalChannel\n");
 418
 419         if (olc->forwardLogicalChannelParameters.multiplexParameters.choice ==
 420             eOpenLogicalChannel_forwardLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters)
 421         {
 422                 ret = process_h245_channel(skb, ct, ctinfo,
 423                                            protoff, data, dataoff,
 424                                            &olc->
 425                                            forwardLogicalChannelParameters.
 426                                            multiplexParameters.
 427                                            h2250LogicalChannelParameters);
 428                 if (ret < 0)
 429                         return -1;
 430         }
 431
 432         if ((olc->options &
 433              eOpenLogicalChannel_reverseLogicalChannelParameters) &&
 434             (olc->reverseLogicalChannelParameters.options &
 435              eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters)
 436             && (olc->reverseLogicalChannelParameters.multiplexParameters.
 437                 choice ==
 438                 eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
 439         {
 440                 ret =
 441                     process_h245_channel(skb, ct, ctinfo,
 442                                          protoff, data, dataoff,
 443                                          &olc->
 444                                          reverseLogicalChannelParameters.
 445                                          multiplexParameters.
 446                                          h2250LogicalChannelParameters);
 447                 if (ret < 0)
 448                         return -1;
 449         }
 450
 451         if ((olc->options & eOpenLogicalChannel_separateStack) &&
 452             olc->forwardLogicalChannelParameters.dataType.choice ==
 453             eDataType_data &&
 454             olc->forwardLogicalChannelParameters.dataType.data.application.
 455             choice == eDataApplicationCapability_application_t120 &&
 456             olc->forwardLogicalChannelParameters.dataType.data.application.
 457             t120.choice == eDataProtocolCapability_separateLANStack &&
 458             olc->separateStack.networkAddress.choice ==
 459             eNetworkAccessParameters_networkAddress_localAreaAddress) {
 460                 ret = expect_t120(skb, ct, ctinfo, protoff, data, dataoff,
 461                                   &olc->separateStack.networkAddress.
 462                                   localAreaAddress);
 463                 if (ret < 0)
 464                         return -1;
 465         }
 466
 467         return 0;
 468 }
 469
 470 static int process_olca(struct sk_buff *skb, struct nf_conn *ct,
 471                         enum ip_conntrack_info ctinfo,
 472                         unsigned int protoff, unsigned char **data, int dataoff,
 473                         OpenLogicalChannelAck *olca)
 474 {
 475         H2250LogicalChannelAckParameters *ack;
 476         int ret;
 477
 478         pr_debug("nf_ct_h323: OpenLogicalChannelAck\n");
 479
 480         if ((olca->options &
 481              eOpenLogicalChannelAck_reverseLogicalChannelParameters) &&
 482             (olca->reverseLogicalChannelParameters.options &
 483              eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters)
 484             && (olca->reverseLogicalChannelParameters.multiplexParameters.
 485                 choice ==
 486                 eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
 487         {
 488                 ret = process_h245_channel(skb, ct, ctinfo,
 489                                            protoff, data, dataoff,
 490                                            &olca->
 491                                            reverseLogicalChannelParameters.
 492                                            multiplexParameters.
 493                                            h2250LogicalChannelParameters);
 494                 if (ret < 0)
 495                         return -1;
 496         }
 497
 498         if ((olca->options &
 499              eOpenLogicalChannelAck_forwardMultiplexAckParameters) &&
 500             (olca->forwardMultiplexAckParameters.choice ==
 501              eOpenLogicalChannelAck_forwardMultiplexAckParameters_h2250LogicalChannelAckParameters))
 502         {
 503                 ack = &olca->forwardMultiplexAckParameters.
 504                     h2250LogicalChannelAckParameters;
 505                 if (ack->options &
 506                     eH2250LogicalChannelAckParameters_mediaChannel) {
 507                         /* RTP */
 508                         ret = expect_rtp_rtcp(skb, ct, ctinfo,
 509                                               protoff, data, dataoff,
 510                                               &ack->mediaChannel);
 511                         if (ret < 0)
 512                                 return -1;
 513                 }
 514
 515                 if (ack->options &
 516                     eH2250LogicalChannelAckParameters_mediaControlChannel) {
 517                         /* RTCP */
 518                         ret = expect_rtp_rtcp(skb, ct, ctinfo,
 519                                               protoff, data, dataoff,
 520                                               &ack->mediaControlChannel);
 521                         if (ret < 0)
 522                                 return -1;
 523                 }
 524         }
 525
 526         if ((olca->options & eOpenLogicalChannelAck_separateStack) &&
 527                 olca->separateStack.networkAddress.choice ==
 528                 eNetworkAccessParameters_networkAddress_localAreaAddress) {
 529                 ret = expect_t120(skb, ct, ctinfo, protoff, data, dataoff,
 530                                   &olca->separateStack.networkAddress.
 531                                   localAreaAddress);
 532                 if (ret < 0)
 533                         return -1;
 534         }
 535
 536         return 0;
 537 }
 538
 539 static int process_h245(struct sk_buff *skb, struct nf_conn *ct,
 540                         enum ip_conntrack_info ctinfo,
 541                         unsigned int protoff, unsigned char **data, int dataoff,
 542                         MultimediaSystemControlMessage *mscm)
 543 {
 544         switch (mscm->choice) {
 545         case eMultimediaSystemControlMessage_request:
 546                 if (mscm->request.choice ==
 547                     eRequestMessage_openLogicalChannel) {
 548                         return process_olc(skb, ct, ctinfo,
 549                                            protoff, data, dataoff,
 550                                            &mscm->request.openLogicalChannel);
 551                 }
 552                 pr_debug("nf_ct_h323: H.245 Request %d\n",
 553                          mscm->request.choice);
 554                 break;
 555         case eMultimediaSystemControlMessage_response:
 556                 if (mscm->response.choice ==
 557                     eResponseMessage_openLogicalChannelAck) {
 558                         return process_olca(skb, ct, ctinfo,
 559                                             protoff, data, dataoff,
 560                                             &mscm->response.
 561                                             openLogicalChannelAck);
 562                 }
 563                 pr_debug("nf_ct_h323: H.245 Response %d\n",
 564                          mscm->response.choice);
 565                 break;
 566         default:
 567                 pr_debug("nf_ct_h323: H.245 signal %d\n", mscm->choice);
 568                 break;
 569         }
 570
 571         return 0;
 572 }
 573
 574 static int h245_help(struct sk_buff *skb, unsigned int protoff,
 575                      struct nf_conn *ct, enum ip_conntrack_info ctinfo)
 576 {
 577         static MultimediaSystemControlMessage mscm;
 578         unsigned char *data = NULL;
 579         int datalen;
 580         int dataoff;
 581         int ret;
 582
 583         /* Until there's been traffic both ways, don't look in packets. */
 584         if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
 585                 return NF_ACCEPT;
 586
 587         pr_debug("nf_ct_h245: skblen = %u\n", skb->len);
 588
 589         spin_lock_bh(&nf_h323_lock);
 590
 591         /* Process each TPKT */
 592         while (get_tpkt_data(skb, protoff, ct, ctinfo,
 593                              &data, &datalen, &dataoff)) {
 594                 pr_debug("nf_ct_h245: TPKT len=%d ", datalen);
 595                 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
 596
 597                 /* Decode H.245 signal */
 598                 ret = DecodeMultimediaSystemControlMessage(data, datalen,
 599                                                            &mscm);
 600                 if (ret < 0) {
 601                         pr_debug("nf_ct_h245: decoding error: %s\n",
 602                                  ret == H323_ERROR_BOUND ?
 603                                  "out of bound" : "out of range");
 604                         /* We don't drop when decoding error */
 605                         break;
 606                 }
 607
 608                 /* Process H.245 signal */
 609                 if (process_h245(skb, ct, ctinfo, protoff,
 610                                  &data, dataoff, &mscm) < 0)
 611                         goto drop;
 612         }
 613
 614         spin_unlock_bh(&nf_h323_lock);
 615         return NF_ACCEPT;
 616
 617       drop:
 618         spin_unlock_bh(&nf_h323_lock);
 619         nf_ct_helper_log(skb, ct, "cannot process H.245 message");
 620         return NF_DROP;
 621 }
 622
 623 static const struct nf_conntrack_expect_policy h245_exp_policy = {
 624         .max_expected   = H323_RTP_CHANNEL_MAX * 4 + 2 /* T.120 */,
 625         .timeout        = 240,
 626 };
 627
 628 static struct nf_conntrack_helper nf_conntrack_helper_h245 __read_mostly = {
 629         .name                   = "H.245",
 630         .me                     = THIS_MODULE,
 631         .tuple.src.l3num        = AF_UNSPEC,
 632         .tuple.dst.protonum     = IPPROTO_UDP,
 633         .help                   = h245_help,
 634         .expect_policy          = &h245_exp_policy,
 635 };
 636
 637 int get_h225_addr(struct nf_conn *ct, unsigned char *data,
 638                   TransportAddress *taddr,
 639                   union nf_inet_addr *addr, __be16 *port)
 640 {
 641         const unsigned char *p;
 642         int len;
 643
 644         switch (taddr->choice) {
 645         case eTransportAddress_ipAddress:
 646                 if (nf_ct_l3num(ct) != AF_INET)
 647                         return 0;
 648                 p = data + taddr->ipAddress.ip;
 649                 len = 4;
 650                 break;
 651         case eTransportAddress_ip6Address:
 652                 if (nf_ct_l3num(ct) != AF_INET6)
 653                         return 0;
 654                 p = data + taddr->ip6Address.ip;
 655                 len = 16;
 656                 break;
 657         default:
 658                 return 0;
 659         }
 660
 661         memcpy(addr, p, len);
 662         memset((void *)addr + len, 0, sizeof(*addr) - len);
 663         memcpy(port, p + len, sizeof(__be16));
 664
 665         return 1;
 666 }
 667
 668 static int expect_h245(struct sk_buff *skb, struct nf_conn *ct,
 669                        enum ip_conntrack_info ctinfo,
 670                        unsigned int protoff, unsigned char **data, int dataoff,
 671                        TransportAddress *taddr)
 672 {
 673         int dir = CTINFO2DIR(ctinfo);
 674         int ret = 0;
 675         __be16 port;
 676         union nf_inet_addr addr;
 677         struct nf_conntrack_expect *exp;
 678         typeof(nat_h245_hook) nat_h245;
 679
 680         /* Read h245Address */
 681         if (!get_h225_addr(ct, *data, taddr, &addr, &port) ||
 682             memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 683             port == 0)
 684                 return 0;
 685
 686         /* Create expect for h245 connection */
 687         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 688                 return -1;
 689         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 690                           &ct->tuplehash[!dir].tuple.src.u3,
 691                           &ct->tuplehash[!dir].tuple.dst.u3,
 692                           IPPROTO_TCP, NULL, &port);
 693         exp->helper = &nf_conntrack_helper_h245;
 694
 695         if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 696                    &ct->tuplehash[!dir].tuple.dst.u3,
 697                    sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 698             (nat_h245 = rcu_dereference(nat_h245_hook)) &&
 699             nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 700             ct->status & IPS_NAT_MASK) {
 701                 /* NAT needed */
 702                 ret = nat_h245(skb, ct, ctinfo, protoff, data, dataoff, taddr,
 703                                port, exp);
 704         } else {                /* Conntrack only */
 705                 if (nf_ct_expect_related(exp, 0) == 0) {
 706                         pr_debug("nf_ct_q931: expect H.245 ");
 707                         nf_ct_dump_tuple(&exp->tuple);
 708                 } else
 709                         ret = -1;
 710         }
 711
 712         nf_ct_expect_put(exp);
 713
 714         return ret;
 715 }
 716
 717 /* If the calling party is on the same side of the forward-to party,
 718  * we don't need to track the second call
 719  */
 720 static int callforward_do_filter(struct net *net,
 721                                  const union nf_inet_addr *src,
 722                                  const union nf_inet_addr *dst,
 723                                  u_int8_t family)
 724 {
 725         int ret = 0;
 726
 727         switch (family) {
 728         case AF_INET: {
 729                 struct flowi4 fl1, fl2;
 730                 struct rtable *rt1, *rt2;
 731
 732                 memset(&fl1, 0, sizeof(fl1));
 733                 fl1.daddr = src->ip;
 734
 735                 memset(&fl2, 0, sizeof(fl2));
 736                 fl2.daddr = dst->ip;
 737                 if (!nf_ip_route(net, (struct dst_entry **)&rt1,
 738                                  flowi4_to_flowi(&fl1), false)) {
 739                         if (!nf_ip_route(net, (struct dst_entry **)&rt2,
 740                                          flowi4_to_flowi(&fl2), false)) {
 741                                 if (rt_nexthop(rt1, fl1.daddr) ==
 742                                     rt_nexthop(rt2, fl2.daddr) &&
 743                                     rt1->dst.dev  == rt2->dst.dev)
 744                                         ret = 1;
 745                                 dst_release(&rt2->dst);
 746                         }
 747                         dst_release(&rt1->dst);
 748                 }
 749                 break;
 750         }
 751 #if IS_ENABLED(CONFIG_IPV6)
 752         case AF_INET6: {
 753                 struct rt6_info *rt1, *rt2;
 754                 struct flowi6 fl1, fl2;
 755
 756                 memset(&fl1, 0, sizeof(fl1));
 757                 fl1.daddr = src->in6;
 758
 759                 memset(&fl2, 0, sizeof(fl2));
 760                 fl2.daddr = dst->in6;
 761                 if (!nf_ip6_route(net, (struct dst_entry **)&rt1,
 762                                   flowi6_to_flowi(&fl1), false)) {
 763                         if (!nf_ip6_route(net, (struct dst_entry **)&rt2,
 764                                           flowi6_to_flowi(&fl2), false)) {
 765                                 if (ipv6_addr_equal(rt6_nexthop(rt1, &fl1.daddr),
 766                                                     rt6_nexthop(rt2, &fl2.daddr)) &&
 767                                     rt1->dst.dev == rt2->dst.dev)
 768                                         ret = 1;
 769                                 dst_release(&rt2->dst);
 770                         }
 771                         dst_release(&rt1->dst);
 772                 }
 773                 break;
 774         }
 775 #endif
 776         }
 777         return ret;
 778
 779 }
 780
 781 static int expect_callforwarding(struct sk_buff *skb,
 782                                  struct nf_conn *ct,
 783                                  enum ip_conntrack_info ctinfo,
 784                                  unsigned int protoff,
 785                                  unsigned char **data, int dataoff,
 786                                  TransportAddress *taddr)
 787 {
 788         int dir = CTINFO2DIR(ctinfo);
 789         int ret = 0;
 790         __be16 port;
 791         union nf_inet_addr addr;
 792         struct nf_conntrack_expect *exp;
 793         struct net *net = nf_ct_net(ct);
 794         typeof(nat_callforwarding_hook) nat_callforwarding;
 795
 796         /* Read alternativeAddress */
 797         if (!get_h225_addr(ct, *data, taddr, &addr, &port) || port == 0)
 798                 return 0;
 799
 800         /* If the calling party is on the same side of the forward-to party,
 801          * we don't need to track the second call
 802          */
 803         if (callforward_filter &&
 804             callforward_do_filter(net, &addr, &ct->tuplehash[!dir].tuple.src.u3,
 805                                   nf_ct_l3num(ct))) {
 806                 pr_debug("nf_ct_q931: Call Forwarding not tracked\n");
 807                 return 0;
 808         }
 809
 810         /* Create expect for the second call leg */
 811         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 812                 return -1;
 813         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 814                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
 815                           IPPROTO_TCP, NULL, &port);
 816         exp->helper = nf_conntrack_helper_q931;
 817
 818         if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 819                    &ct->tuplehash[!dir].tuple.dst.u3,
 820                    sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 821             (nat_callforwarding = rcu_dereference(nat_callforwarding_hook)) &&
 822             nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 823             ct->status & IPS_NAT_MASK) {
 824                 /* Need NAT */
 825                 ret = nat_callforwarding(skb, ct, ctinfo,
 826                                          protoff, data, dataoff,
 827                                          taddr, port, exp);
 828         } else {                /* Conntrack only */
 829                 if (nf_ct_expect_related(exp, 0) == 0) {
 830                         pr_debug("nf_ct_q931: expect Call Forwarding ");
 831                         nf_ct_dump_tuple(&exp->tuple);
 832                 } else
 833                         ret = -1;
 834         }
 835
 836         nf_ct_expect_put(exp);
 837
 838         return ret;
 839 }
 840
 841 static int process_setup(struct sk_buff *skb, struct nf_conn *ct,
 842                          enum ip_conntrack_info ctinfo,
 843                          unsigned int protoff,
 844                          unsigned char **data, int dataoff,
 845                          Setup_UUIE *setup)
 846 {
 847         int dir = CTINFO2DIR(ctinfo);
 848         int ret;
 849         int i;
 850         __be16 port;
 851         union nf_inet_addr addr;
 852         typeof(set_h225_addr_hook) set_h225_addr;
 853
 854         pr_debug("nf_ct_q931: Setup\n");
 855
 856         if (setup->options & eSetup_UUIE_h245Address) {
 857                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
 858                                   &setup->h245Address);
 859                 if (ret < 0)
 860                         return -1;
 861         }
 862
 863         set_h225_addr = rcu_dereference(set_h225_addr_hook);
 864         if ((setup->options & eSetup_UUIE_destCallSignalAddress) &&
 865             (set_h225_addr) && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 866             ct->status & IPS_NAT_MASK &&
 867             get_h225_addr(ct, *data, &setup->destCallSignalAddress,
 868                           &addr, &port) &&
 869             memcmp(&addr, &ct->tuplehash[!dir].tuple.src.u3, sizeof(addr))) {
 870                 pr_debug("nf_ct_q931: set destCallSignalAddress %pI6:%hu->%pI6:%hu\n",
 871                          &addr, ntohs(port), &ct->tuplehash[!dir].tuple.src.u3,
 872                          ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port));
 873                 ret = set_h225_addr(skb, protoff, data, dataoff,
 874                                     &setup->destCallSignalAddress,
 875                                     &ct->tuplehash[!dir].tuple.src.u3,
 876                                     ct->tuplehash[!dir].tuple.src.u.tcp.port);
 877                 if (ret < 0)
 878                         return -1;
 879         }
 880
 881         if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) &&
 882             (set_h225_addr) && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 883             ct->status & IPS_NAT_MASK &&
 884             get_h225_addr(ct, *data, &setup->sourceCallSignalAddress,
 885                           &addr, &port) &&
 886             memcmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(addr))) {
 887                 pr_debug("nf_ct_q931: set sourceCallSignalAddress %pI6:%hu->%pI6:%hu\n",
 888                          &addr, ntohs(port), &ct->tuplehash[!dir].tuple.dst.u3,
 889                          ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port));
 890                 ret = set_h225_addr(skb, protoff, data, dataoff,
 891                                     &setup->sourceCallSignalAddress,
 892                                     &ct->tuplehash[!dir].tuple.dst.u3,
 893                                     ct->tuplehash[!dir].tuple.dst.u.tcp.port);
 894                 if (ret < 0)
 895                         return -1;
 896         }
 897
 898         if (setup->options & eSetup_UUIE_fastStart) {
 899                 for (i = 0; i < setup->fastStart.count; i++) {
 900                         ret = process_olc(skb, ct, ctinfo,
 901                                           protoff, data, dataoff,
 902                                           &setup->fastStart.item[i]);
 903                         if (ret < 0)
 904                                 return -1;
 905                 }
 906         }
 907
 908         return 0;
 909 }
 910
 911 static int process_callproceeding(struct sk_buff *skb,
 912                                   struct nf_conn *ct,
 913                                   enum ip_conntrack_info ctinfo,
 914                                   unsigned int protoff,
 915                                   unsigned char **data, int dataoff,
 916                                   CallProceeding_UUIE *callproc)
 917 {
 918         int ret;
 919         int i;
 920
 921         pr_debug("nf_ct_q931: CallProceeding\n");
 922
 923         if (callproc->options & eCallProceeding_UUIE_h245Address) {
 924                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
 925                                   &callproc->h245Address);
 926                 if (ret < 0)
 927                         return -1;
 928         }
 929
 930         if (callproc->options & eCallProceeding_UUIE_fastStart) {
 931                 for (i = 0; i < callproc->fastStart.count; i++) {
 932                         ret = process_olc(skb, ct, ctinfo,
 933                                           protoff, data, dataoff,
 934                                           &callproc->fastStart.item[i]);
 935                         if (ret < 0)
 936                                 return -1;
 937                 }
 938         }
 939
 940         return 0;
 941 }
 942
 943 static int process_connect(struct sk_buff *skb, struct nf_conn *ct,
 944                            enum ip_conntrack_info ctinfo,
 945                            unsigned int protoff,
 946                            unsigned char **data, int dataoff,
 947                            Connect_UUIE *connect)
 948 {
 949         int ret;
 950         int i;
 951
 952         pr_debug("nf_ct_q931: Connect\n");
 953
 954         if (connect->options & eConnect_UUIE_h245Address) {
 955                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
 956                                   &connect->h245Address);
 957                 if (ret < 0)
 958                         return -1;
 959         }
 960
 961         if (connect->options & eConnect_UUIE_fastStart) {
 962                 for (i = 0; i < connect->fastStart.count; i++) {
 963                         ret = process_olc(skb, ct, ctinfo,
 964                                           protoff, data, dataoff,
 965                                           &connect->fastStart.item[i]);
 966                         if (ret < 0)
 967                                 return -1;
 968                 }
 969         }
 970
 971         return 0;
 972 }
 973
 974 static int process_alerting(struct sk_buff *skb, struct nf_conn *ct,
 975                             enum ip_conntrack_info ctinfo,
 976                             unsigned int protoff,
 977                             unsigned char **data, int dataoff,
 978                             Alerting_UUIE *alert)
 979 {
 980         int ret;
 981         int i;
 982
 983         pr_debug("nf_ct_q931: Alerting\n");
 984
 985         if (alert->options & eAlerting_UUIE_h245Address) {
 986                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
 987                                   &alert->h245Address);
 988                 if (ret < 0)
 989                         return -1;
 990         }
 991
 992         if (alert->options & eAlerting_UUIE_fastStart) {
 993                 for (i = 0; i < alert->fastStart.count; i++) {
 994                         ret = process_olc(skb, ct, ctinfo,
 995                                           protoff, data, dataoff,
 996                                           &alert->fastStart.item[i]);
 997                         if (ret < 0)
 998                                 return -1;
 999                 }
1000         }
1001
1002         return 0;
1003 }
1004
1005 static int process_facility(struct sk_buff *skb, struct nf_conn *ct,
1006                             enum ip_conntrack_info ctinfo,
1007                             unsigned int protoff,
1008                             unsigned char **data, int dataoff,
1009                             Facility_UUIE *facility)
1010 {
1011         int ret;
1012         int i;
1013
1014         pr_debug("nf_ct_q931: Facility\n");
1015
1016         if (facility->reason.choice == eFacilityReason_callForwarded) {
1017                 if (facility->options & eFacility_UUIE_alternativeAddress)
1018                         return expect_callforwarding(skb, ct, ctinfo,
1019                                                      protoff, data, dataoff,
1020                                                      &facility->
1021                                                      alternativeAddress);
1022                 return 0;
1023         }
1024
1025         if (facility->options & eFacility_UUIE_h245Address) {
1026                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
1027                                   &facility->h245Address);
1028                 if (ret < 0)
1029                         return -1;
1030         }
1031
1032         if (facility->options & eFacility_UUIE_fastStart) {
1033                 for (i = 0; i < facility->fastStart.count; i++) {
1034                         ret = process_olc(skb, ct, ctinfo,
1035                                           protoff, data, dataoff,
1036                                           &facility->fastStart.item[i]);
1037                         if (ret < 0)
1038                                 return -1;
1039                 }
1040         }
1041
1042         return 0;
1043 }
1044
1045 static int process_progress(struct sk_buff *skb, struct nf_conn *ct,
1046                             enum ip_conntrack_info ctinfo,
1047                             unsigned int protoff,
1048                             unsigned char **data, int dataoff,
1049                             Progress_UUIE *progress)
1050 {
1051         int ret;
1052         int i;
1053
1054         pr_debug("nf_ct_q931: Progress\n");
1055
1056         if (progress->options & eProgress_UUIE_h245Address) {
1057                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
1058                                   &progress->h245Address);
1059                 if (ret < 0)
1060                         return -1;
1061         }
1062
1063         if (progress->options & eProgress_UUIE_fastStart) {
1064                 for (i = 0; i < progress->fastStart.count; i++) {
1065                         ret = process_olc(skb, ct, ctinfo,
1066                                           protoff, data, dataoff,
1067                                           &progress->fastStart.item[i]);
1068                         if (ret < 0)
1069                                 return -1;
1070                 }
1071         }
1072
1073         return 0;
1074 }
1075
1076 static int process_q931(struct sk_buff *skb, struct nf_conn *ct,
1077                         enum ip_conntrack_info ctinfo,
1078                         unsigned int protoff, unsigned char **data, int dataoff,
1079                         Q931 *q931)
1080 {
1081         H323_UU_PDU *pdu = &q931->UUIE.h323_uu_pdu;
1082         int i;
1083         int ret = 0;
1084
1085         switch (pdu->h323_message_body.choice) {
1086         case eH323_UU_PDU_h323_message_body_setup:
1087                 ret = process_setup(skb, ct, ctinfo, protoff, data, dataoff,
1088                                     &pdu->h323_message_body.setup);
1089                 break;
1090         case eH323_UU_PDU_h323_message_body_callProceeding:
1091                 ret = process_callproceeding(skb, ct, ctinfo,
1092                                              protoff, data, dataoff,
1093                                              &pdu->h323_message_body.
1094                                              callProceeding);
1095                 break;
1096         case eH323_UU_PDU_h323_message_body_connect:
1097                 ret = process_connect(skb, ct, ctinfo, protoff, data, dataoff,
1098                                       &pdu->h323_message_body.connect);
1099                 break;
1100         case eH323_UU_PDU_h323_message_body_alerting:
1101                 ret = process_alerting(skb, ct, ctinfo, protoff, data, dataoff,
1102                                        &pdu->h323_message_body.alerting);
1103                 break;
1104         case eH323_UU_PDU_h323_message_body_facility:
1105                 ret = process_facility(skb, ct, ctinfo, protoff, data, dataoff,
1106                                        &pdu->h323_message_body.facility);
1107                 break;
1108         case eH323_UU_PDU_h323_message_body_progress:
1109                 ret = process_progress(skb, ct, ctinfo, protoff, data, dataoff,
1110                                        &pdu->h323_message_body.progress);
1111                 break;
1112         default:
1113                 pr_debug("nf_ct_q931: Q.931 signal %d\n",
1114                          pdu->h323_message_body.choice);
1115                 break;
1116         }
1117
1118         if (ret < 0)
1119                 return -1;
1120
1121         if (pdu->options & eH323_UU_PDU_h245Control) {
1122                 for (i = 0; i < pdu->h245Control.count; i++) {
1123                         ret = process_h245(skb, ct, ctinfo,
1124                                            protoff, data, dataoff,
1125                                            &pdu->h245Control.item[i]);
1126                         if (ret < 0)
1127                                 return -1;
1128                 }
1129         }
1130
1131         return 0;
1132 }
1133
1134 static int q931_help(struct sk_buff *skb, unsigned int protoff,
1135                      struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1136 {
1137         static Q931 q931;
1138         unsigned char *data = NULL;
1139         int datalen;
1140         int dataoff;
1141         int ret;
1142
1143         /* Until there's been traffic both ways, don't look in packets. */
1144         if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
1145                 return NF_ACCEPT;
1146
1147         pr_debug("nf_ct_q931: skblen = %u\n", skb->len);
1148
1149         spin_lock_bh(&nf_h323_lock);
1150
1151         /* Process each TPKT */
1152         while (get_tpkt_data(skb, protoff, ct, ctinfo,
1153                              &data, &datalen, &dataoff)) {
1154                 pr_debug("nf_ct_q931: TPKT len=%d ", datalen);
1155                 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1156
1157                 /* Decode Q.931 signal */
1158                 ret = DecodeQ931(data, datalen, &q931);
1159                 if (ret < 0) {
1160                         pr_debug("nf_ct_q931: decoding error: %s\n",
1161                                  ret == H323_ERROR_BOUND ?
1162                                  "out of bound" : "out of range");
1163                         /* We don't drop when decoding error */
1164                         break;
1165                 }
1166
1167                 /* Process Q.931 signal */
1168                 if (process_q931(skb, ct, ctinfo, protoff,
1169                                  &data, dataoff, &q931) < 0)
1170                         goto drop;
1171         }
1172
1173         spin_unlock_bh(&nf_h323_lock);
1174         return NF_ACCEPT;
1175
1176       drop:
1177         spin_unlock_bh(&nf_h323_lock);
1178         nf_ct_helper_log(skb, ct, "cannot process Q.931 message");
1179         return NF_DROP;
1180 }
1181
1182 static const struct nf_conntrack_expect_policy q931_exp_policy = {
1183         /* T.120 and H.245 */
1184         .max_expected           = H323_RTP_CHANNEL_MAX * 4 + 4,
1185         .timeout                = 240,
1186 };
1187
1188 static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = {
1189         {
1190                 .name                   = "Q.931",
1191                 .me                     = THIS_MODULE,
1192                 .tuple.src.l3num        = AF_INET,
1193                 .tuple.src.u.tcp.port   = cpu_to_be16(Q931_PORT),
1194                 .tuple.dst.protonum     = IPPROTO_TCP,
1195                 .help                   = q931_help,
1196                 .expect_policy          = &q931_exp_policy,
1197         },
1198         {
1199                 .name                   = "Q.931",
1200                 .me                     = THIS_MODULE,
1201                 .tuple.src.l3num        = AF_INET6,
1202                 .tuple.src.u.tcp.port   = cpu_to_be16(Q931_PORT),
1203                 .tuple.dst.protonum     = IPPROTO_TCP,
1204                 .help                   = q931_help,
1205                 .expect_policy          = &q931_exp_policy,
1206         },
1207 };
1208
1209 static unsigned char *get_udp_data(struct sk_buff *skb, unsigned int protoff,
1210                                    int *datalen)
1211 {
1212         const struct udphdr *uh;
1213         struct udphdr _uh;
1214         int dataoff;
1215
1216         uh = skb_header_pointer(skb, protoff, sizeof(_uh), &_uh);
1217         if (uh == NULL)
1218                 return NULL;
1219         dataoff = protoff + sizeof(_uh);
1220         if (dataoff >= skb->len)
1221                 return NULL;
1222         *datalen = skb->len - dataoff;
1223         return skb_header_pointer(skb, dataoff, *datalen, h323_buffer);
1224 }
1225
1226 static struct nf_conntrack_expect *find_expect(struct nf_conn *ct,
1227                                                union nf_inet_addr *addr,
1228                                                __be16 port)
1229 {
1230         struct net *net = nf_ct_net(ct);
1231         struct nf_conntrack_expect *exp;
1232         struct nf_conntrack_tuple tuple;
1233
1234         memset(&tuple.src.u3, 0, sizeof(tuple.src.u3));
1235         tuple.src.u.tcp.port = 0;
1236         memcpy(&tuple.dst.u3, addr, sizeof(tuple.dst.u3));
1237         tuple.dst.u.tcp.port = port;
1238         tuple.dst.protonum = IPPROTO_TCP;
1239
1240         exp = __nf_ct_expect_find(net, nf_ct_zone(ct), &tuple);
1241         if (exp && exp->master == ct)
1242                 return exp;
1243         return NULL;
1244 }
1245
1246 static int expect_q931(struct sk_buff *skb, struct nf_conn *ct,
1247                        enum ip_conntrack_info ctinfo,
1248                        unsigned int protoff, unsigned char **data,
1249                        TransportAddress *taddr, int count)
1250 {
1251         struct nf_ct_h323_master *info = nfct_help_data(ct);
1252         int dir = CTINFO2DIR(ctinfo);
1253         int ret = 0;
1254         int i;
1255         __be16 port;
1256         union nf_inet_addr addr;
1257         struct nf_conntrack_expect *exp;
1258         typeof(nat_q931_hook) nat_q931;
1259
1260         /* Look for the first related address */
1261         for (i = 0; i < count; i++) {
1262                 if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) &&
1263                     memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3,
1264                            sizeof(addr)) == 0 && port != 0)
1265                         break;
1266         }
1267
1268         if (i >= count)         /* Not found */
1269                 return 0;
1270
1271         /* Create expect for Q.931 */
1272         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1273                 return -1;
1274         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1275                           gkrouted_only ? /* only accept calls from GK? */
1276                                 &ct->tuplehash[!dir].tuple.src.u3 : NULL,
1277                           &ct->tuplehash[!dir].tuple.dst.u3,
1278                           IPPROTO_TCP, NULL, &port);
1279         exp->helper = nf_conntrack_helper_q931;
1280         exp->flags = NF_CT_EXPECT_PERMANENT;    /* Accept multiple calls */
1281
1282         nat_q931 = rcu_dereference(nat_q931_hook);
1283         if (nat_q931 && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1284             ct->status & IPS_NAT_MASK) {        /* Need NAT */
1285                 ret = nat_q931(skb, ct, ctinfo, protoff, data,
1286                                taddr, i, port, exp);
1287         } else {                /* Conntrack only */
1288                 if (nf_ct_expect_related(exp, 0) == 0) {
1289                         pr_debug("nf_ct_ras: expect Q.931 ");
1290                         nf_ct_dump_tuple(&exp->tuple);
1291
1292                         /* Save port for looking up expect in processing RCF */
1293                         info->sig_port[dir] = port;
1294                 } else
1295                         ret = -1;
1296         }
1297
1298         nf_ct_expect_put(exp);
1299
1300         return ret;
1301 }
1302
1303 static int process_grq(struct sk_buff *skb, struct nf_conn *ct,
1304                        enum ip_conntrack_info ctinfo,
1305                        unsigned int protoff,
1306                        unsigned char **data, GatekeeperRequest *grq)
1307 {
1308         typeof(set_ras_addr_hook) set_ras_addr;
1309
1310         pr_debug("nf_ct_ras: GRQ\n");
1311
1312         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1313         if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1314             ct->status & IPS_NAT_MASK)  /* NATed */
1315                 return set_ras_addr(skb, ct, ctinfo, protoff, data,
1316                                     &grq->rasAddress, 1);
1317         return 0;
1318 }
1319
1320 static int process_gcf(struct sk_buff *skb, struct nf_conn *ct,
1321                        enum ip_conntrack_info ctinfo,
1322                        unsigned int protoff,
1323                        unsigned char **data, GatekeeperConfirm *gcf)
1324 {
1325         int dir = CTINFO2DIR(ctinfo);
1326         int ret = 0;
1327         __be16 port;
1328         union nf_inet_addr addr;
1329         struct nf_conntrack_expect *exp;
1330
1331         pr_debug("nf_ct_ras: GCF\n");
1332
1333         if (!get_h225_addr(ct, *data, &gcf->rasAddress, &addr, &port))
1334                 return 0;
1335
1336         /* Registration port is the same as discovery port */
1337         if (!memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1338             port == ct->tuplehash[dir].tuple.src.u.udp.port)
1339                 return 0;
1340
1341         /* Avoid RAS expectation loops. A GCF is never expected. */
1342         if (test_bit(IPS_EXPECTED_BIT, &ct->status))
1343                 return 0;
1344
1345         /* Need new expect */
1346         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1347                 return -1;
1348         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1349                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1350                           IPPROTO_UDP, NULL, &port);
1351         exp->helper = nf_conntrack_helper_ras;
1352
1353         if (nf_ct_expect_related(exp, 0) == 0) {
1354                 pr_debug("nf_ct_ras: expect RAS ");
1355                 nf_ct_dump_tuple(&exp->tuple);
1356         } else
1357                 ret = -1;
1358
1359         nf_ct_expect_put(exp);
1360
1361         return ret;
1362 }
1363
1364 static int process_rrq(struct sk_buff *skb, struct nf_conn *ct,
1365                        enum ip_conntrack_info ctinfo,
1366                        unsigned int protoff,
1367                        unsigned char **data, RegistrationRequest *rrq)
1368 {
1369         struct nf_ct_h323_master *info = nfct_help_data(ct);
1370         int ret;
1371         typeof(set_ras_addr_hook) set_ras_addr;
1372
1373         pr_debug("nf_ct_ras: RRQ\n");
1374
1375         ret = expect_q931(skb, ct, ctinfo, protoff, data,
1376                           rrq->callSignalAddress.item,
1377                           rrq->callSignalAddress.count);
1378         if (ret < 0)
1379                 return -1;
1380
1381         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1382         if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1383             ct->status & IPS_NAT_MASK) {
1384                 ret = set_ras_addr(skb, ct, ctinfo, protoff, data,
1385                                    rrq->rasAddress.item,
1386                                    rrq->rasAddress.count);
1387                 if (ret < 0)
1388                         return -1;
1389         }
1390
1391         if (rrq->options & eRegistrationRequest_timeToLive) {
1392                 pr_debug("nf_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive);
1393                 info->timeout = rrq->timeToLive;
1394         } else
1395                 info->timeout = default_rrq_ttl;
1396
1397         return 0;
1398 }
1399
1400 static int process_rcf(struct sk_buff *skb, struct nf_conn *ct,
1401                        enum ip_conntrack_info ctinfo,
1402                        unsigned int protoff,
1403                        unsigned char **data, RegistrationConfirm *rcf)
1404 {
1405         struct nf_ct_h323_master *info = nfct_help_data(ct);
1406         int dir = CTINFO2DIR(ctinfo);
1407         int ret;
1408         struct nf_conntrack_expect *exp;
1409         typeof(set_sig_addr_hook) set_sig_addr;
1410
1411         pr_debug("nf_ct_ras: RCF\n");
1412
1413         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1414         if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1415             ct->status & IPS_NAT_MASK) {
1416                 ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1417                                         rcf->callSignalAddress.item,
1418                                         rcf->callSignalAddress.count);
1419                 if (ret < 0)
1420                         return -1;
1421         }
1422
1423         if (rcf->options & eRegistrationConfirm_timeToLive) {
1424                 pr_debug("nf_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive);
1425                 info->timeout = rcf->timeToLive;
1426         }
1427
1428         if (info->timeout > 0) {
1429                 pr_debug("nf_ct_ras: set RAS connection timeout to "
1430                          "%u seconds\n", info->timeout);
1431                 nf_ct_refresh(ct, skb, info->timeout * HZ);
1432
1433                 /* Set expect timeout */
1434                 spin_lock_bh(&nf_conntrack_expect_lock);
1435                 exp = find_expect(ct, &ct->tuplehash[dir].tuple.dst.u3,
1436                                   info->sig_port[!dir]);
1437                 if (exp) {
1438                         pr_debug("nf_ct_ras: set Q.931 expect "
1439                                  "timeout to %u seconds for",
1440                                  info->timeout);
1441                         nf_ct_dump_tuple(&exp->tuple);
1442                         mod_timer_pending(&exp->timeout,
1443                                           jiffies + info->timeout * HZ);
1444                 }
1445                 spin_unlock_bh(&nf_conntrack_expect_lock);
1446         }
1447
1448         return 0;
1449 }
1450
1451 static int process_urq(struct sk_buff *skb, struct nf_conn *ct,
1452                        enum ip_conntrack_info ctinfo,
1453                        unsigned int protoff,
1454                        unsigned char **data, UnregistrationRequest *urq)
1455 {
1456         struct nf_ct_h323_master *info = nfct_help_data(ct);
1457         int dir = CTINFO2DIR(ctinfo);
1458         int ret;
1459         typeof(set_sig_addr_hook) set_sig_addr;
1460
1461         pr_debug("nf_ct_ras: URQ\n");
1462
1463         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1464         if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1465             ct->status & IPS_NAT_MASK) {
1466                 ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1467                                    urq->callSignalAddress.item,
1468                                    urq->callSignalAddress.count);
1469                 if (ret < 0)
1470                         return -1;
1471         }
1472
1473         /* Clear old expect */
1474         nf_ct_remove_expectations(ct);
1475         info->sig_port[dir] = 0;
1476         info->sig_port[!dir] = 0;
1477
1478         /* Give it 30 seconds for UCF or URJ */
1479         nf_ct_refresh(ct, skb, 30 * HZ);
1480
1481         return 0;
1482 }
1483
1484 static int process_arq(struct sk_buff *skb, struct nf_conn *ct,
1485                        enum ip_conntrack_info ctinfo,
1486                        unsigned int protoff,
1487                        unsigned char **data, AdmissionRequest *arq)
1488 {
1489         const struct nf_ct_h323_master *info = nfct_help_data(ct);
1490         int dir = CTINFO2DIR(ctinfo);
1491         __be16 port;
1492         union nf_inet_addr addr;
1493         typeof(set_h225_addr_hook) set_h225_addr;
1494
1495         pr_debug("nf_ct_ras: ARQ\n");
1496
1497         set_h225_addr = rcu_dereference(set_h225_addr_hook);
1498         if ((arq->options & eAdmissionRequest_destCallSignalAddress) &&
1499             get_h225_addr(ct, *data, &arq->destCallSignalAddress,
1500                           &addr, &port) &&
1501             !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1502             port == info->sig_port[dir] &&
1503             nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1504             set_h225_addr && ct->status & IPS_NAT_MASK) {
1505                 /* Answering ARQ */
1506                 return set_h225_addr(skb, protoff, data, 0,
1507                                      &arq->destCallSignalAddress,
1508                                      &ct->tuplehash[!dir].tuple.dst.u3,
1509                                      info->sig_port[!dir]);
1510         }
1511
1512         if ((arq->options & eAdmissionRequest_srcCallSignalAddress) &&
1513             get_h225_addr(ct, *data, &arq->srcCallSignalAddress,
1514                           &addr, &port) &&
1515             !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1516             set_h225_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1517             ct->status & IPS_NAT_MASK) {
1518                 /* Calling ARQ */
1519                 return set_h225_addr(skb, protoff, data, 0,
1520                                      &arq->srcCallSignalAddress,
1521                                      &ct->tuplehash[!dir].tuple.dst.u3,
1522                                      port);
1523         }
1524
1525         return 0;
1526 }
1527
1528 static int process_acf(struct sk_buff *skb, struct nf_conn *ct,
1529                        enum ip_conntrack_info ctinfo,
1530                        unsigned int protoff,
1531                        unsigned char **data, AdmissionConfirm *acf)
1532 {
1533         int dir = CTINFO2DIR(ctinfo);
1534         int ret = 0;
1535         __be16 port;
1536         union nf_inet_addr addr;
1537         struct nf_conntrack_expect *exp;
1538         typeof(set_sig_addr_hook) set_sig_addr;
1539
1540         pr_debug("nf_ct_ras: ACF\n");
1541
1542         if (!get_h225_addr(ct, *data, &acf->destCallSignalAddress,
1543                            &addr, &port))
1544                 return 0;
1545
1546         if (!memcmp(&addr, &ct->tuplehash[dir].tuple.dst.u3, sizeof(addr))) {
1547                 /* Answering ACF */
1548                 set_sig_addr = rcu_dereference(set_sig_addr_hook);
1549                 if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1550                     ct->status & IPS_NAT_MASK)
1551                         return set_sig_addr(skb, ct, ctinfo, protoff, data,
1552                                             &acf->destCallSignalAddress, 1);
1553                 return 0;
1554         }
1555
1556         /* Need new expect */
1557         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1558                 return -1;
1559         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1560                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1561                           IPPROTO_TCP, NULL, &port);
1562         exp->flags = NF_CT_EXPECT_PERMANENT;
1563         exp->helper = nf_conntrack_helper_q931;
1564
1565         if (nf_ct_expect_related(exp, 0) == 0) {
1566                 pr_debug("nf_ct_ras: expect Q.931 ");
1567                 nf_ct_dump_tuple(&exp->tuple);
1568         } else
1569                 ret = -1;
1570
1571         nf_ct_expect_put(exp);
1572
1573         return ret;
1574 }
1575
1576 static int process_lrq(struct sk_buff *skb, struct nf_conn *ct,
1577                        enum ip_conntrack_info ctinfo,
1578                        unsigned int protoff,
1579                        unsigned char **data, LocationRequest *lrq)
1580 {
1581         typeof(set_ras_addr_hook) set_ras_addr;
1582
1583         pr_debug("nf_ct_ras: LRQ\n");
1584
1585         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1586         if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1587             ct->status & IPS_NAT_MASK)
1588                 return set_ras_addr(skb, ct, ctinfo, protoff, data,
1589                                     &lrq->replyAddress, 1);
1590         return 0;
1591 }
1592
1593 static int process_lcf(struct sk_buff *skb, struct nf_conn *ct,
1594                        enum ip_conntrack_info ctinfo,
1595                        unsigned int protoff,
1596                        unsigned char **data, LocationConfirm *lcf)
1597 {
1598         int dir = CTINFO2DIR(ctinfo);
1599         int ret = 0;
1600         __be16 port;
1601         union nf_inet_addr addr;
1602         struct nf_conntrack_expect *exp;
1603
1604         pr_debug("nf_ct_ras: LCF\n");
1605
1606         if (!get_h225_addr(ct, *data, &lcf->callSignalAddress,
1607                            &addr, &port))
1608                 return 0;
1609
1610         /* Need new expect for call signal */
1611         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1612                 return -1;
1613         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1614                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1615                           IPPROTO_TCP, NULL, &port);
1616         exp->flags = NF_CT_EXPECT_PERMANENT;
1617         exp->helper = nf_conntrack_helper_q931;
1618
1619         if (nf_ct_expect_related(exp, 0) == 0) {
1620                 pr_debug("nf_ct_ras: expect Q.931 ");
1621                 nf_ct_dump_tuple(&exp->tuple);
1622         } else
1623                 ret = -1;
1624
1625         nf_ct_expect_put(exp);
1626
1627         /* Ignore rasAddress */
1628
1629         return ret;
1630 }
1631
1632 static int process_irr(struct sk_buff *skb, struct nf_conn *ct,
1633                        enum ip_conntrack_info ctinfo,
1634                        unsigned int protoff,
1635                        unsigned char **data, InfoRequestResponse *irr)
1636 {
1637         int ret;
1638         typeof(set_ras_addr_hook) set_ras_addr;
1639         typeof(set_sig_addr_hook) set_sig_addr;
1640
1641         pr_debug("nf_ct_ras: IRR\n");
1642
1643         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1644         if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1645             ct->status & IPS_NAT_MASK) {
1646                 ret = set_ras_addr(skb, ct, ctinfo, protoff, data,
1647                                    &irr->rasAddress, 1);
1648                 if (ret < 0)
1649                         return -1;
1650         }
1651
1652         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1653         if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1654             ct->status & IPS_NAT_MASK) {
1655                 ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1656                                         irr->callSignalAddress.item,
1657                                         irr->callSignalAddress.count);
1658                 if (ret < 0)
1659                         return -1;
1660         }
1661
1662         return 0;
1663 }
1664
1665 static int process_ras(struct sk_buff *skb, struct nf_conn *ct,
1666                        enum ip_conntrack_info ctinfo,
1667                        unsigned int protoff,
1668                        unsigned char **data, RasMessage *ras)
1669 {
1670         switch (ras->choice) {
1671         case eRasMessage_gatekeeperRequest:
1672                 return process_grq(skb, ct, ctinfo, protoff, data,
1673                                    &ras->gatekeeperRequest);
1674         case eRasMessage_gatekeeperConfirm:
1675                 return process_gcf(skb, ct, ctinfo, protoff, data,
1676                                    &ras->gatekeeperConfirm);
1677         case eRasMessage_registrationRequest:
1678                 return process_rrq(skb, ct, ctinfo, protoff, data,
1679                                    &ras->registrationRequest);
1680         case eRasMessage_registrationConfirm:
1681                 return process_rcf(skb, ct, ctinfo, protoff, data,
1682                                    &ras->registrationConfirm);
1683         case eRasMessage_unregistrationRequest:
1684                 return process_urq(skb, ct, ctinfo, protoff, data,
1685                                    &ras->unregistrationRequest);
1686         case eRasMessage_admissionRequest:
1687                 return process_arq(skb, ct, ctinfo, protoff, data,
1688                                    &ras->admissionRequest);
1689         case eRasMessage_admissionConfirm:
1690                 return process_acf(skb, ct, ctinfo, protoff, data,
1691                                    &ras->admissionConfirm);
1692         case eRasMessage_locationRequest:
1693                 return process_lrq(skb, ct, ctinfo, protoff, data,
1694                                    &ras->locationRequest);
1695         case eRasMessage_locationConfirm:
1696                 return process_lcf(skb, ct, ctinfo, protoff, data,
1697                                    &ras->locationConfirm);
1698         case eRasMessage_infoRequestResponse:
1699                 return process_irr(skb, ct, ctinfo, protoff, data,
1700                                    &ras->infoRequestResponse);
1701         default:
1702                 pr_debug("nf_ct_ras: RAS message %d\n", ras->choice);
1703                 break;
1704         }
1705
1706         return 0;
1707 }
1708
1709 static int ras_help(struct sk_buff *skb, unsigned int protoff,
1710                     struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1711 {
1712         static RasMessage ras;
1713         unsigned char *data;
1714         int datalen = 0;
1715         int ret;
1716
1717         pr_debug("nf_ct_ras: skblen = %u\n", skb->len);
1718
1719         spin_lock_bh(&nf_h323_lock);
1720
1721         /* Get UDP data */
1722         data = get_udp_data(skb, protoff, &datalen);
1723         if (data == NULL)
1724                 goto accept;
1725         pr_debug("nf_ct_ras: RAS message len=%d ", datalen);
1726         nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1727
1728         /* Decode RAS message */
1729         ret = DecodeRasMessage(data, datalen, &ras);
1730         if (ret < 0) {
1731                 pr_debug("nf_ct_ras: decoding error: %s\n",
1732                          ret == H323_ERROR_BOUND ?
1733                          "out of bound" : "out of range");
1734                 goto accept;
1735         }
1736
1737         /* Process RAS message */
1738         if (process_ras(skb, ct, ctinfo, protoff, &data, &ras) < 0)
1739                 goto drop;
1740
1741       accept:
1742         spin_unlock_bh(&nf_h323_lock);
1743         return NF_ACCEPT;
1744
1745       drop:
1746         spin_unlock_bh(&nf_h323_lock);
1747         nf_ct_helper_log(skb, ct, "cannot process RAS message");
1748         return NF_DROP;
1749 }
1750
1751 static const struct nf_conntrack_expect_policy ras_exp_policy = {
1752         .max_expected           = 32,
1753         .timeout                = 240,
1754 };
1755
1756 static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = {
1757         {
1758                 .name                   = "RAS",
1759                 .me                     = THIS_MODULE,
1760                 .tuple.src.l3num        = AF_INET,
1761                 .tuple.src.u.udp.port   = cpu_to_be16(RAS_PORT),
1762                 .tuple.dst.protonum     = IPPROTO_UDP,
1763                 .help                   = ras_help,
1764                 .expect_policy          = &ras_exp_policy,
1765         },
1766         {
1767                 .name                   = "RAS",
1768                 .me                     = THIS_MODULE,
1769                 .tuple.src.l3num        = AF_INET6,
1770                 .tuple.src.u.udp.port   = cpu_to_be16(RAS_PORT),
1771                 .tuple.dst.protonum     = IPPROTO_UDP,
1772                 .help                   = ras_help,
1773                 .expect_policy          = &ras_exp_policy,
1774         },
1775 };
1776
1777 static int __init h323_helper_init(void)
1778 {
1779         int ret;
1780
1781         ret = nf_conntrack_helper_register(&nf_conntrack_helper_h245);
1782         if (ret < 0)
1783                 return ret;
1784         ret = nf_conntrack_helpers_register(nf_conntrack_helper_q931,
1785                                         ARRAY_SIZE(nf_conntrack_helper_q931));
1786         if (ret < 0)
1787                 goto err1;
1788         ret = nf_conntrack_helpers_register(nf_conntrack_helper_ras,
1789                                         ARRAY_SIZE(nf_conntrack_helper_ras));
1790         if (ret < 0)
1791                 goto err2;
1792
1793         return 0;
1794 err2:
1795         nf_conntrack_helpers_unregister(nf_conntrack_helper_q931,
1796                                         ARRAY_SIZE(nf_conntrack_helper_q931));
1797 err1:
1798         nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1799         return ret;
1800 }
1801
1802 static void __exit h323_helper_exit(void)
1803 {
1804         nf_conntrack_helpers_unregister(nf_conntrack_helper_ras,
1805                                         ARRAY_SIZE(nf_conntrack_helper_ras));
1806         nf_conntrack_helpers_unregister(nf_conntrack_helper_q931,
1807                                         ARRAY_SIZE(nf_conntrack_helper_q931));
1808         nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1809 }
1810
1811 static void __exit nf_conntrack_h323_fini(void)
1812 {
1813         h323_helper_exit();
1814         kfree(h323_buffer);
1815         pr_debug("nf_ct_h323: fini\n");
1816 }
1817
1818 static int __init nf_conntrack_h323_init(void)
1819 {
1820         int ret;
1821
1822         NF_CT_HELPER_BUILD_BUG_ON(sizeof(struct nf_ct_h323_master));
1823
1824         h323_buffer = kmalloc(65536, GFP_KERNEL);
1825         if (!h323_buffer)
1826                 return -ENOMEM;
1827         ret = h323_helper_init();
1828         if (ret < 0)
1829                 goto err1;
1830         pr_debug("nf_ct_h323: init success\n");
1831         return 0;
1832 err1:
1833         kfree(h323_buffer);
1834         return ret;
1835 }
1836
1837 module_init(nf_conntrack_h323_init);
1838 module_exit(nf_conntrack_h323_fini);
1839
1840 EXPORT_SYMBOL_GPL(get_h225_addr);
1841 EXPORT_SYMBOL_GPL(set_h245_addr_hook);
1842 EXPORT_SYMBOL_GPL(set_h225_addr_hook);
1843 EXPORT_SYMBOL_GPL(set_sig_addr_hook);
1844 EXPORT_SYMBOL_GPL(set_ras_addr_hook);
1845 EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook);
1846 EXPORT_SYMBOL_GPL(nat_t120_hook);
1847 EXPORT_SYMBOL_GPL(nat_h245_hook);
1848 EXPORT_SYMBOL_GPL(nat_callforwarding_hook);
1849 EXPORT_SYMBOL_GPL(nat_q931_hook);
1850
1851 MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>");
1852 MODULE_DESCRIPTION("H.323 connection tracking helper");
1853 MODULE_LICENSE("GPL");
1854 MODULE_ALIAS("ip_conntrack_h323");
1855 MODULE_ALIAS_NFCT_HELPER("RAS");
1856 MODULE_ALIAS_NFCT_HELPER("Q.931");
1857 MODULE_ALIAS_NFCT_HELPER("H.245");