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  * Copyright (c) 2006-2012 Patrick McHardy <kaber@trash.net>
   6  *
   7  * This source code is licensed under General Public License version 2.
   8  *
   9  * Based on the 'brute force' H.323 connection tracking module by
  10  * Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
  11  *
  12  * For more information, please see http://nath323.sourceforge.net/
  13  */
  14
  15 #include <linux/module.h>
  16 #include <linux/moduleparam.h>
  17 #include <linux/ctype.h>
  18 #include <linux/inet.h>
  19 #include <linux/in.h>
  20 #include <linux/ip.h>
  21 #include <linux/slab.h>
  22 #include <linux/udp.h>
  23 #include <linux/tcp.h>
  24 #include <linux/skbuff.h>
  25 #include <net/route.h>
  26 #include <net/ip6_route.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 /****************************************************************************/
 119 static int get_tpkt_data(struct sk_buff *skb, unsigned int protoff,
 120                          struct nf_conn *ct, enum ip_conntrack_info ctinfo,
 121                          unsigned char **data, int *datalen, int *dataoff)
 122 {
 123         struct nf_ct_h323_master *info = nfct_help_data(ct);
 124         int dir = CTINFO2DIR(ctinfo);
 125         const struct tcphdr *th;
 126         struct tcphdr _tcph;
 127         int tcpdatalen;
 128         int tcpdataoff;
 129         unsigned char *tpkt;
 130         int tpktlen;
 131         int tpktoff;
 132
 133         /* Get TCP header */
 134         th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph);
 135         if (th == NULL)
 136                 return 0;
 137
 138         /* Get TCP data offset */
 139         tcpdataoff = protoff + th->doff * 4;
 140
 141         /* Get TCP data length */
 142         tcpdatalen = skb->len - tcpdataoff;
 143         if (tcpdatalen <= 0)    /* No TCP data */
 144                 goto clear_out;
 145
 146         if (*data == NULL) {    /* first TPKT */
 147                 /* Get first TPKT pointer */
 148                 tpkt = skb_header_pointer(skb, tcpdataoff, tcpdatalen,
 149                                           h323_buffer);
 150                 BUG_ON(tpkt == NULL);
 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 %hu 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 /****************************************************************************/
 223 static int get_h245_addr(struct nf_conn *ct, const unsigned char *data,
 224                          H245_TransportAddress *taddr,
 225                          union nf_inet_addr *addr, __be16 *port)
 226 {
 227         const unsigned char *p;
 228         int len;
 229
 230         if (taddr->choice != eH245_TransportAddress_unicastAddress)
 231                 return 0;
 232
 233         switch (taddr->unicastAddress.choice) {
 234         case eUnicastAddress_iPAddress:
 235                 if (nf_ct_l3num(ct) != AF_INET)
 236                         return 0;
 237                 p = data + taddr->unicastAddress.iPAddress.network;
 238                 len = 4;
 239                 break;
 240         case eUnicastAddress_iP6Address:
 241                 if (nf_ct_l3num(ct) != AF_INET6)
 242                         return 0;
 243                 p = data + taddr->unicastAddress.iP6Address.network;
 244                 len = 16;
 245                 break;
 246         default:
 247                 return 0;
 248         }
 249
 250         memcpy(addr, p, len);
 251         memset((void *)addr + len, 0, sizeof(*addr) - len);
 252         memcpy(port, p + len, sizeof(__be16));
 253
 254         return 1;
 255 }
 256
 257 /****************************************************************************/
 258 static int expect_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct,
 259                            enum ip_conntrack_info ctinfo,
 260                            unsigned int protoff,
 261                            unsigned char **data, int dataoff,
 262                            H245_TransportAddress *taddr)
 263 {
 264         int dir = CTINFO2DIR(ctinfo);
 265         int ret = 0;
 266         __be16 port;
 267         __be16 rtp_port, rtcp_port;
 268         union nf_inet_addr addr;
 269         struct nf_conntrack_expect *rtp_exp;
 270         struct nf_conntrack_expect *rtcp_exp;
 271         typeof(nat_rtp_rtcp_hook) nat_rtp_rtcp;
 272
 273         /* Read RTP or RTCP address */
 274         if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
 275             memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 276             port == 0)
 277                 return 0;
 278
 279         /* RTP port is even */
 280         rtp_port = port & ~htons(1);
 281         rtcp_port = port | htons(1);
 282
 283         /* Create expect for RTP */
 284         if ((rtp_exp = nf_ct_expect_alloc(ct)) == NULL)
 285                 return -1;
 286         nf_ct_expect_init(rtp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 287                           &ct->tuplehash[!dir].tuple.src.u3,
 288                           &ct->tuplehash[!dir].tuple.dst.u3,
 289                           IPPROTO_UDP, NULL, &rtp_port);
 290
 291         /* Create expect for RTCP */
 292         if ((rtcp_exp = nf_ct_expect_alloc(ct)) == NULL) {
 293                 nf_ct_expect_put(rtp_exp);
 294                 return -1;
 295         }
 296         nf_ct_expect_init(rtcp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 297                           &ct->tuplehash[!dir].tuple.src.u3,
 298                           &ct->tuplehash[!dir].tuple.dst.u3,
 299                           IPPROTO_UDP, NULL, &rtcp_port);
 300
 301         if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 302                    &ct->tuplehash[!dir].tuple.dst.u3,
 303                    sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 304                    (nat_rtp_rtcp = rcu_dereference(nat_rtp_rtcp_hook)) &&
 305                    nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 306                    ct->status & IPS_NAT_MASK) {
 307                 /* NAT needed */
 308                 ret = nat_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff,
 309                                    taddr, port, rtp_port, rtp_exp, rtcp_exp);
 310         } else {                /* Conntrack only */
 311                 if (nf_ct_expect_related(rtp_exp) == 0) {
 312                         if (nf_ct_expect_related(rtcp_exp) == 0) {
 313                                 pr_debug("nf_ct_h323: expect RTP ");
 314                                 nf_ct_dump_tuple(&rtp_exp->tuple);
 315                                 pr_debug("nf_ct_h323: expect RTCP ");
 316                                 nf_ct_dump_tuple(&rtcp_exp->tuple);
 317                         } else {
 318                                 nf_ct_unexpect_related(rtp_exp);
 319                                 ret = -1;
 320                         }
 321                 } else
 322                         ret = -1;
 323         }
 324
 325         nf_ct_expect_put(rtp_exp);
 326         nf_ct_expect_put(rtcp_exp);
 327
 328         return ret;
 329 }
 330
 331 /****************************************************************************/
 332 static int expect_t120(struct sk_buff *skb,
 333                        struct nf_conn *ct,
 334                        enum ip_conntrack_info ctinfo,
 335                        unsigned int protoff,
 336                        unsigned char **data, int dataoff,
 337                        H245_TransportAddress *taddr)
 338 {
 339         int dir = CTINFO2DIR(ctinfo);
 340         int ret = 0;
 341         __be16 port;
 342         union nf_inet_addr addr;
 343         struct nf_conntrack_expect *exp;
 344         typeof(nat_t120_hook) nat_t120;
 345
 346         /* Read T.120 address */
 347         if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
 348             memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 349             port == 0)
 350                 return 0;
 351
 352         /* Create expect for T.120 connections */
 353         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 354                 return -1;
 355         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 356                           &ct->tuplehash[!dir].tuple.src.u3,
 357                           &ct->tuplehash[!dir].tuple.dst.u3,
 358                           IPPROTO_TCP, NULL, &port);
 359         exp->flags = NF_CT_EXPECT_PERMANENT;    /* Accept multiple channels */
 360
 361         if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 362                    &ct->tuplehash[!dir].tuple.dst.u3,
 363                    sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 364             (nat_t120 = rcu_dereference(nat_t120_hook)) &&
 365             nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 366             ct->status & IPS_NAT_MASK) {
 367                 /* NAT needed */
 368                 ret = nat_t120(skb, ct, ctinfo, protoff, data, dataoff, taddr,
 369                                port, exp);
 370         } else {                /* Conntrack only */
 371                 if (nf_ct_expect_related(exp) == 0) {
 372                         pr_debug("nf_ct_h323: expect T.120 ");
 373                         nf_ct_dump_tuple(&exp->tuple);
 374                 } else
 375                         ret = -1;
 376         }
 377
 378         nf_ct_expect_put(exp);
 379
 380         return ret;
 381 }
 382
 383 /****************************************************************************/
 384 static int process_h245_channel(struct sk_buff *skb,
 385                                 struct nf_conn *ct,
 386                                 enum ip_conntrack_info ctinfo,
 387                                 unsigned int protoff,
 388                                 unsigned char **data, int dataoff,
 389                                 H2250LogicalChannelParameters *channel)
 390 {
 391         int ret;
 392
 393         if (channel->options & eH2250LogicalChannelParameters_mediaChannel) {
 394                 /* RTP */
 395                 ret = expect_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff,
 396                                       &channel->mediaChannel);
 397                 if (ret < 0)
 398                         return -1;
 399         }
 400
 401         if (channel->
 402             options & eH2250LogicalChannelParameters_mediaControlChannel) {
 403                 /* RTCP */
 404                 ret = expect_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff,
 405                                       &channel->mediaControlChannel);
 406                 if (ret < 0)
 407                         return -1;
 408         }
 409
 410         return 0;
 411 }
 412
 413 /****************************************************************************/
 414 static int process_olc(struct sk_buff *skb, struct nf_conn *ct,
 415                        enum ip_conntrack_info ctinfo,
 416                        unsigned int protoff,
 417                        unsigned char **data, int dataoff,
 418                        OpenLogicalChannel *olc)
 419 {
 420         int ret;
 421
 422         pr_debug("nf_ct_h323: OpenLogicalChannel\n");
 423
 424         if (olc->forwardLogicalChannelParameters.multiplexParameters.choice ==
 425             eOpenLogicalChannel_forwardLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters)
 426         {
 427                 ret = process_h245_channel(skb, ct, ctinfo,
 428                                            protoff, data, dataoff,
 429                                            &olc->
 430                                            forwardLogicalChannelParameters.
 431                                            multiplexParameters.
 432                                            h2250LogicalChannelParameters);
 433                 if (ret < 0)
 434                         return -1;
 435         }
 436
 437         if ((olc->options &
 438              eOpenLogicalChannel_reverseLogicalChannelParameters) &&
 439             (olc->reverseLogicalChannelParameters.options &
 440              eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters)
 441             && (olc->reverseLogicalChannelParameters.multiplexParameters.
 442                 choice ==
 443                 eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
 444         {
 445                 ret =
 446                     process_h245_channel(skb, ct, ctinfo,
 447                                          protoff, data, dataoff,
 448                                          &olc->
 449                                          reverseLogicalChannelParameters.
 450                                          multiplexParameters.
 451                                          h2250LogicalChannelParameters);
 452                 if (ret < 0)
 453                         return -1;
 454         }
 455
 456         if ((olc->options & eOpenLogicalChannel_separateStack) &&
 457             olc->forwardLogicalChannelParameters.dataType.choice ==
 458             eDataType_data &&
 459             olc->forwardLogicalChannelParameters.dataType.data.application.
 460             choice == eDataApplicationCapability_application_t120 &&
 461             olc->forwardLogicalChannelParameters.dataType.data.application.
 462             t120.choice == eDataProtocolCapability_separateLANStack &&
 463             olc->separateStack.networkAddress.choice ==
 464             eNetworkAccessParameters_networkAddress_localAreaAddress) {
 465                 ret = expect_t120(skb, ct, ctinfo, protoff, data, dataoff,
 466                                   &olc->separateStack.networkAddress.
 467                                   localAreaAddress);
 468                 if (ret < 0)
 469                         return -1;
 470         }
 471
 472         return 0;
 473 }
 474
 475 /****************************************************************************/
 476 static int process_olca(struct sk_buff *skb, struct nf_conn *ct,
 477                         enum ip_conntrack_info ctinfo,
 478                         unsigned int protoff, unsigned char **data, int dataoff,
 479                         OpenLogicalChannelAck *olca)
 480 {
 481         H2250LogicalChannelAckParameters *ack;
 482         int ret;
 483
 484         pr_debug("nf_ct_h323: OpenLogicalChannelAck\n");
 485
 486         if ((olca->options &
 487              eOpenLogicalChannelAck_reverseLogicalChannelParameters) &&
 488             (olca->reverseLogicalChannelParameters.options &
 489              eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters)
 490             && (olca->reverseLogicalChannelParameters.multiplexParameters.
 491                 choice ==
 492                 eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
 493         {
 494                 ret = process_h245_channel(skb, ct, ctinfo,
 495                                            protoff, data, dataoff,
 496                                            &olca->
 497                                            reverseLogicalChannelParameters.
 498                                            multiplexParameters.
 499                                            h2250LogicalChannelParameters);
 500                 if (ret < 0)
 501                         return -1;
 502         }
 503
 504         if ((olca->options &
 505              eOpenLogicalChannelAck_forwardMultiplexAckParameters) &&
 506             (olca->forwardMultiplexAckParameters.choice ==
 507              eOpenLogicalChannelAck_forwardMultiplexAckParameters_h2250LogicalChannelAckParameters))
 508         {
 509                 ack = &olca->forwardMultiplexAckParameters.
 510                     h2250LogicalChannelAckParameters;
 511                 if (ack->options &
 512                     eH2250LogicalChannelAckParameters_mediaChannel) {
 513                         /* RTP */
 514                         ret = expect_rtp_rtcp(skb, ct, ctinfo,
 515                                               protoff, data, dataoff,
 516                                               &ack->mediaChannel);
 517                         if (ret < 0)
 518                                 return -1;
 519                 }
 520
 521                 if (ack->options &
 522                     eH2250LogicalChannelAckParameters_mediaControlChannel) {
 523                         /* RTCP */
 524                         ret = expect_rtp_rtcp(skb, ct, ctinfo,
 525                                               protoff, data, dataoff,
 526                                               &ack->mediaControlChannel);
 527                         if (ret < 0)
 528                                 return -1;
 529                 }
 530         }
 531
 532         if ((olca->options & eOpenLogicalChannelAck_separateStack) &&
 533                 olca->separateStack.networkAddress.choice ==
 534                 eNetworkAccessParameters_networkAddress_localAreaAddress) {
 535                 ret = expect_t120(skb, ct, ctinfo, protoff, data, dataoff,
 536                                   &olca->separateStack.networkAddress.
 537                                   localAreaAddress);
 538                 if (ret < 0)
 539                         return -1;
 540         }
 541
 542         return 0;
 543 }
 544
 545 /****************************************************************************/
 546 static int process_h245(struct sk_buff *skb, struct nf_conn *ct,
 547                         enum ip_conntrack_info ctinfo,
 548                         unsigned int protoff, unsigned char **data, int dataoff,
 549                         MultimediaSystemControlMessage *mscm)
 550 {
 551         switch (mscm->choice) {
 552         case eMultimediaSystemControlMessage_request:
 553                 if (mscm->request.choice ==
 554                     eRequestMessage_openLogicalChannel) {
 555                         return process_olc(skb, ct, ctinfo,
 556                                            protoff, data, dataoff,
 557                                            &mscm->request.openLogicalChannel);
 558                 }
 559                 pr_debug("nf_ct_h323: H.245 Request %d\n",
 560                          mscm->request.choice);
 561                 break;
 562         case eMultimediaSystemControlMessage_response:
 563                 if (mscm->response.choice ==
 564                     eResponseMessage_openLogicalChannelAck) {
 565                         return process_olca(skb, ct, ctinfo,
 566                                             protoff, data, dataoff,
 567                                             &mscm->response.
 568                                             openLogicalChannelAck);
 569                 }
 570                 pr_debug("nf_ct_h323: H.245 Response %d\n",
 571                          mscm->response.choice);
 572                 break;
 573         default:
 574                 pr_debug("nf_ct_h323: H.245 signal %d\n", mscm->choice);
 575                 break;
 576         }
 577
 578         return 0;
 579 }
 580
 581 /****************************************************************************/
 582 static int h245_help(struct sk_buff *skb, unsigned int protoff,
 583                      struct nf_conn *ct, enum ip_conntrack_info ctinfo)
 584 {
 585         static MultimediaSystemControlMessage mscm;
 586         unsigned char *data = NULL;
 587         int datalen;
 588         int dataoff;
 589         int ret;
 590
 591         /* Until there's been traffic both ways, don't look in packets. */
 592         if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
 593                 return NF_ACCEPT;
 594
 595         pr_debug("nf_ct_h245: skblen = %u\n", skb->len);
 596
 597         spin_lock_bh(&nf_h323_lock);
 598
 599         /* Process each TPKT */
 600         while (get_tpkt_data(skb, protoff, ct, ctinfo,
 601                              &data, &datalen, &dataoff)) {
 602                 pr_debug("nf_ct_h245: TPKT len=%d ", datalen);
 603                 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
 604
 605                 /* Decode H.245 signal */
 606                 ret = DecodeMultimediaSystemControlMessage(data, datalen,
 607                                                            &mscm);
 608                 if (ret < 0) {
 609                         pr_debug("nf_ct_h245: decoding error: %s\n",
 610                                  ret == H323_ERROR_BOUND ?
 611                                  "out of bound" : "out of range");
 612                         /* We don't drop when decoding error */
 613                         break;
 614                 }
 615
 616                 /* Process H.245 signal */
 617                 if (process_h245(skb, ct, ctinfo, protoff,
 618                                  &data, dataoff, &mscm) < 0)
 619                         goto drop;
 620         }
 621
 622         spin_unlock_bh(&nf_h323_lock);
 623         return NF_ACCEPT;
 624
 625       drop:
 626         spin_unlock_bh(&nf_h323_lock);
 627         nf_ct_helper_log(skb, ct, "cannot process H.245 message");
 628         return NF_DROP;
 629 }
 630
 631 /****************************************************************************/
 632 static const struct nf_conntrack_expect_policy h245_exp_policy = {
 633         .max_expected   = H323_RTP_CHANNEL_MAX * 4 + 2 /* T.120 */,
 634         .timeout        = 240,
 635 };
 636
 637 static struct nf_conntrack_helper nf_conntrack_helper_h245 __read_mostly = {
 638         .name                   = "H.245",
 639         .me                     = THIS_MODULE,
 640         .data_len               = sizeof(struct nf_ct_h323_master),
 641         .tuple.src.l3num        = AF_UNSPEC,
 642         .tuple.dst.protonum     = IPPROTO_UDP,
 643         .help                   = h245_help,
 644         .expect_policy          = &h245_exp_policy,
 645 };
 646
 647 /****************************************************************************/
 648 int get_h225_addr(struct nf_conn *ct, unsigned char *data,
 649                   TransportAddress *taddr,
 650                   union nf_inet_addr *addr, __be16 *port)
 651 {
 652         const unsigned char *p;
 653         int len;
 654
 655         switch (taddr->choice) {
 656         case eTransportAddress_ipAddress:
 657                 if (nf_ct_l3num(ct) != AF_INET)
 658                         return 0;
 659                 p = data + taddr->ipAddress.ip;
 660                 len = 4;
 661                 break;
 662         case eTransportAddress_ip6Address:
 663                 if (nf_ct_l3num(ct) != AF_INET6)
 664                         return 0;
 665                 p = data + taddr->ip6Address.ip;
 666                 len = 16;
 667                 break;
 668         default:
 669                 return 0;
 670         }
 671
 672         memcpy(addr, p, len);
 673         memset((void *)addr + len, 0, sizeof(*addr) - len);
 674         memcpy(port, p + len, sizeof(__be16));
 675
 676         return 1;
 677 }
 678
 679 /****************************************************************************/
 680 static int expect_h245(struct sk_buff *skb, struct nf_conn *ct,
 681                        enum ip_conntrack_info ctinfo,
 682                        unsigned int protoff, unsigned char **data, int dataoff,
 683                        TransportAddress *taddr)
 684 {
 685         int dir = CTINFO2DIR(ctinfo);
 686         int ret = 0;
 687         __be16 port;
 688         union nf_inet_addr addr;
 689         struct nf_conntrack_expect *exp;
 690         typeof(nat_h245_hook) nat_h245;
 691
 692         /* Read h245Address */
 693         if (!get_h225_addr(ct, *data, taddr, &addr, &port) ||
 694             memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 695             port == 0)
 696                 return 0;
 697
 698         /* Create expect for h245 connection */
 699         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 700                 return -1;
 701         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 702                           &ct->tuplehash[!dir].tuple.src.u3,
 703                           &ct->tuplehash[!dir].tuple.dst.u3,
 704                           IPPROTO_TCP, NULL, &port);
 705         exp->helper = &nf_conntrack_helper_h245;
 706
 707         if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 708                    &ct->tuplehash[!dir].tuple.dst.u3,
 709                    sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 710             (nat_h245 = rcu_dereference(nat_h245_hook)) &&
 711             nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 712             ct->status & IPS_NAT_MASK) {
 713                 /* NAT needed */
 714                 ret = nat_h245(skb, ct, ctinfo, protoff, data, dataoff, taddr,
 715                                port, exp);
 716         } else {                /* Conntrack only */
 717                 if (nf_ct_expect_related(exp) == 0) {
 718                         pr_debug("nf_ct_q931: expect H.245 ");
 719                         nf_ct_dump_tuple(&exp->tuple);
 720                 } else
 721                         ret = -1;
 722         }
 723
 724         nf_ct_expect_put(exp);
 725
 726         return ret;
 727 }
 728
 729 /* If the calling party is on the same side of the forward-to party,
 730  * we don't need to track the second call */
 731 static int callforward_do_filter(const union nf_inet_addr *src,
 732                                  const union nf_inet_addr *dst,
 733                                  u_int8_t family)
 734 {
 735         const struct nf_afinfo *afinfo;
 736         int ret = 0;
 737
 738         /* rcu_read_lock()ed by nf_hook_slow() */
 739         afinfo = nf_get_afinfo(family);
 740         if (!afinfo)
 741                 return 0;
 742
 743         switch (family) {
 744         case AF_INET: {
 745                 struct flowi4 fl1, fl2;
 746                 struct rtable *rt1, *rt2;
 747
 748                 memset(&fl1, 0, sizeof(fl1));
 749                 fl1.daddr = src->ip;
 750
 751                 memset(&fl2, 0, sizeof(fl2));
 752                 fl2.daddr = dst->ip;
 753                 if (!afinfo->route(&init_net, (struct dst_entry **)&rt1,
 754                                    flowi4_to_flowi(&fl1), false)) {
 755                         if (!afinfo->route(&init_net, (struct dst_entry **)&rt2,
 756                                            flowi4_to_flowi(&fl2), false)) {
 757                                 if (rt_nexthop(rt1, fl1.daddr) ==
 758                                     rt_nexthop(rt2, fl2.daddr) &&
 759                                     rt1->dst.dev  == rt2->dst.dev)
 760                                         ret = 1;
 761                                 dst_release(&rt2->dst);
 762                         }
 763                         dst_release(&rt1->dst);
 764                 }
 765                 break;
 766         }
 767 #if IS_ENABLED(CONFIG_NF_CONNTRACK_IPV6)
 768         case AF_INET6: {
 769                 struct flowi6 fl1, fl2;
 770                 struct rt6_info *rt1, *rt2;
 771
 772                 memset(&fl1, 0, sizeof(fl1));
 773                 fl1.daddr = src->in6;
 774
 775                 memset(&fl2, 0, sizeof(fl2));
 776                 fl2.daddr = dst->in6;
 777                 if (!afinfo->route(&init_net, (struct dst_entry **)&rt1,
 778                                    flowi6_to_flowi(&fl1), false)) {
 779                         if (!afinfo->route(&init_net, (struct dst_entry **)&rt2,
 780                                            flowi6_to_flowi(&fl2), false)) {
 781                                 if (ipv6_addr_equal(rt6_nexthop(rt1),
 782                                                     rt6_nexthop(rt2)) &&
 783                                     rt1->dst.dev == rt2->dst.dev)
 784                                         ret = 1;
 785                                 dst_release(&rt2->dst);
 786                         }
 787                         dst_release(&rt1->dst);
 788                 }
 789                 break;
 790         }
 791 #endif
 792         }
 793         return ret;
 794
 795 }
 796
 797 /****************************************************************************/
 798 static int expect_callforwarding(struct sk_buff *skb,
 799                                  struct nf_conn *ct,
 800                                  enum ip_conntrack_info ctinfo,
 801                                  unsigned int protoff,
 802                                  unsigned char **data, int dataoff,
 803                                  TransportAddress *taddr)
 804 {
 805         int dir = CTINFO2DIR(ctinfo);
 806         int ret = 0;
 807         __be16 port;
 808         union nf_inet_addr addr;
 809         struct nf_conntrack_expect *exp;
 810         typeof(nat_callforwarding_hook) nat_callforwarding;
 811
 812         /* Read alternativeAddress */
 813         if (!get_h225_addr(ct, *data, taddr, &addr, &port) || port == 0)
 814                 return 0;
 815
 816         /* If the calling party is on the same side of the forward-to party,
 817          * we don't need to track the second call */
 818         if (callforward_filter &&
 819             callforward_do_filter(&addr, &ct->tuplehash[!dir].tuple.src.u3,
 820                                   nf_ct_l3num(ct))) {
 821                 pr_debug("nf_ct_q931: Call Forwarding not tracked\n");
 822                 return 0;
 823         }
 824
 825         /* Create expect for the second call leg */
 826         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 827                 return -1;
 828         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 829                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
 830                           IPPROTO_TCP, NULL, &port);
 831         exp->helper = nf_conntrack_helper_q931;
 832
 833         if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 834                    &ct->tuplehash[!dir].tuple.dst.u3,
 835                    sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 836             (nat_callforwarding = rcu_dereference(nat_callforwarding_hook)) &&
 837             nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 838             ct->status & IPS_NAT_MASK) {
 839                 /* Need NAT */
 840                 ret = nat_callforwarding(skb, ct, ctinfo,
 841                                          protoff, data, dataoff,
 842                                          taddr, port, exp);
 843         } else {                /* Conntrack only */
 844                 if (nf_ct_expect_related(exp) == 0) {
 845                         pr_debug("nf_ct_q931: expect Call Forwarding ");
 846                         nf_ct_dump_tuple(&exp->tuple);
 847                 } else
 848                         ret = -1;
 849         }
 850
 851         nf_ct_expect_put(exp);
 852
 853         return ret;
 854 }
 855
 856 /****************************************************************************/
 857 static int process_setup(struct sk_buff *skb, struct nf_conn *ct,
 858                          enum ip_conntrack_info ctinfo,
 859                          unsigned int protoff,
 860                          unsigned char **data, int dataoff,
 861                          Setup_UUIE *setup)
 862 {
 863         int dir = CTINFO2DIR(ctinfo);
 864         int ret;
 865         int i;
 866         __be16 port;
 867         union nf_inet_addr addr;
 868         typeof(set_h225_addr_hook) set_h225_addr;
 869
 870         pr_debug("nf_ct_q931: Setup\n");
 871
 872         if (setup->options & eSetup_UUIE_h245Address) {
 873                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
 874                                   &setup->h245Address);
 875                 if (ret < 0)
 876                         return -1;
 877         }
 878
 879         set_h225_addr = rcu_dereference(set_h225_addr_hook);
 880         if ((setup->options & eSetup_UUIE_destCallSignalAddress) &&
 881             (set_h225_addr) && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 882             ct->status & IPS_NAT_MASK &&
 883             get_h225_addr(ct, *data, &setup->destCallSignalAddress,
 884                           &addr, &port) &&
 885             memcmp(&addr, &ct->tuplehash[!dir].tuple.src.u3, sizeof(addr))) {
 886                 pr_debug("nf_ct_q931: set destCallSignalAddress %pI6:%hu->%pI6:%hu\n",
 887                          &addr, ntohs(port), &ct->tuplehash[!dir].tuple.src.u3,
 888                          ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port));
 889                 ret = set_h225_addr(skb, protoff, data, dataoff,
 890                                     &setup->destCallSignalAddress,
 891                                     &ct->tuplehash[!dir].tuple.src.u3,
 892                                     ct->tuplehash[!dir].tuple.src.u.tcp.port);
 893                 if (ret < 0)
 894                         return -1;
 895         }
 896
 897         if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) &&
 898             (set_h225_addr) && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 899             ct->status & IPS_NAT_MASK &&
 900             get_h225_addr(ct, *data, &setup->sourceCallSignalAddress,
 901                           &addr, &port) &&
 902             memcmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(addr))) {
 903                 pr_debug("nf_ct_q931: set sourceCallSignalAddress %pI6:%hu->%pI6:%hu\n",
 904                          &addr, ntohs(port), &ct->tuplehash[!dir].tuple.dst.u3,
 905                          ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port));
 906                 ret = set_h225_addr(skb, protoff, data, dataoff,
 907                                     &setup->sourceCallSignalAddress,
 908                                     &ct->tuplehash[!dir].tuple.dst.u3,
 909                                     ct->tuplehash[!dir].tuple.dst.u.tcp.port);
 910                 if (ret < 0)
 911                         return -1;
 912         }
 913
 914         if (setup->options & eSetup_UUIE_fastStart) {
 915                 for (i = 0; i < setup->fastStart.count; i++) {
 916                         ret = process_olc(skb, ct, ctinfo,
 917                                           protoff, data, dataoff,
 918                                           &setup->fastStart.item[i]);
 919                         if (ret < 0)
 920                                 return -1;
 921                 }
 922         }
 923
 924         return 0;
 925 }
 926
 927 /****************************************************************************/
 928 static int process_callproceeding(struct sk_buff *skb,
 929                                   struct nf_conn *ct,
 930                                   enum ip_conntrack_info ctinfo,
 931                                   unsigned int protoff,
 932                                   unsigned char **data, int dataoff,
 933                                   CallProceeding_UUIE *callproc)
 934 {
 935         int ret;
 936         int i;
 937
 938         pr_debug("nf_ct_q931: CallProceeding\n");
 939
 940         if (callproc->options & eCallProceeding_UUIE_h245Address) {
 941                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
 942                                   &callproc->h245Address);
 943                 if (ret < 0)
 944                         return -1;
 945         }
 946
 947         if (callproc->options & eCallProceeding_UUIE_fastStart) {
 948                 for (i = 0; i < callproc->fastStart.count; i++) {
 949                         ret = process_olc(skb, ct, ctinfo,
 950                                           protoff, data, dataoff,
 951                                           &callproc->fastStart.item[i]);
 952                         if (ret < 0)
 953                                 return -1;
 954                 }
 955         }
 956
 957         return 0;
 958 }
 959
 960 /****************************************************************************/
 961 static int process_connect(struct sk_buff *skb, struct nf_conn *ct,
 962                            enum ip_conntrack_info ctinfo,
 963                            unsigned int protoff,
 964                            unsigned char **data, int dataoff,
 965                            Connect_UUIE *connect)
 966 {
 967         int ret;
 968         int i;
 969
 970         pr_debug("nf_ct_q931: Connect\n");
 971
 972         if (connect->options & eConnect_UUIE_h245Address) {
 973                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
 974                                   &connect->h245Address);
 975                 if (ret < 0)
 976                         return -1;
 977         }
 978
 979         if (connect->options & eConnect_UUIE_fastStart) {
 980                 for (i = 0; i < connect->fastStart.count; i++) {
 981                         ret = process_olc(skb, ct, ctinfo,
 982                                           protoff, data, dataoff,
 983                                           &connect->fastStart.item[i]);
 984                         if (ret < 0)
 985                                 return -1;
 986                 }
 987         }
 988
 989         return 0;
 990 }
 991
 992 /****************************************************************************/
 993 static int process_alerting(struct sk_buff *skb, struct nf_conn *ct,
 994                             enum ip_conntrack_info ctinfo,
 995                             unsigned int protoff,
 996                             unsigned char **data, int dataoff,
 997                             Alerting_UUIE *alert)
 998 {
 999         int ret;
1000         int i;
1001
1002         pr_debug("nf_ct_q931: Alerting\n");
1003
1004         if (alert->options & eAlerting_UUIE_h245Address) {
1005                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
1006                                   &alert->h245Address);
1007                 if (ret < 0)
1008                         return -1;
1009         }
1010
1011         if (alert->options & eAlerting_UUIE_fastStart) {
1012                 for (i = 0; i < alert->fastStart.count; i++) {
1013                         ret = process_olc(skb, ct, ctinfo,
1014                                           protoff, data, dataoff,
1015                                           &alert->fastStart.item[i]);
1016                         if (ret < 0)
1017                                 return -1;
1018                 }
1019         }
1020
1021         return 0;
1022 }
1023
1024 /****************************************************************************/
1025 static int process_facility(struct sk_buff *skb, struct nf_conn *ct,
1026                             enum ip_conntrack_info ctinfo,
1027                             unsigned int protoff,
1028                             unsigned char **data, int dataoff,
1029                             Facility_UUIE *facility)
1030 {
1031         int ret;
1032         int i;
1033
1034         pr_debug("nf_ct_q931: Facility\n");
1035
1036         if (facility->reason.choice == eFacilityReason_callForwarded) {
1037                 if (facility->options & eFacility_UUIE_alternativeAddress)
1038                         return expect_callforwarding(skb, ct, ctinfo,
1039                                                      protoff, data, dataoff,
1040                                                      &facility->
1041                                                      alternativeAddress);
1042                 return 0;
1043         }
1044
1045         if (facility->options & eFacility_UUIE_h245Address) {
1046                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
1047                                   &facility->h245Address);
1048                 if (ret < 0)
1049                         return -1;
1050         }
1051
1052         if (facility->options & eFacility_UUIE_fastStart) {
1053                 for (i = 0; i < facility->fastStart.count; i++) {
1054                         ret = process_olc(skb, ct, ctinfo,
1055                                           protoff, data, dataoff,
1056                                           &facility->fastStart.item[i]);
1057                         if (ret < 0)
1058                                 return -1;
1059                 }
1060         }
1061
1062         return 0;
1063 }
1064
1065 /****************************************************************************/
1066 static int process_progress(struct sk_buff *skb, struct nf_conn *ct,
1067                             enum ip_conntrack_info ctinfo,
1068                             unsigned int protoff,
1069                             unsigned char **data, int dataoff,
1070                             Progress_UUIE *progress)
1071 {
1072         int ret;
1073         int i;
1074
1075         pr_debug("nf_ct_q931: Progress\n");
1076
1077         if (progress->options & eProgress_UUIE_h245Address) {
1078                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
1079                                   &progress->h245Address);
1080                 if (ret < 0)
1081                         return -1;
1082         }
1083
1084         if (progress->options & eProgress_UUIE_fastStart) {
1085                 for (i = 0; i < progress->fastStart.count; i++) {
1086                         ret = process_olc(skb, ct, ctinfo,
1087                                           protoff, data, dataoff,
1088                                           &progress->fastStart.item[i]);
1089                         if (ret < 0)
1090                                 return -1;
1091                 }
1092         }
1093
1094         return 0;
1095 }
1096
1097 /****************************************************************************/
1098 static int process_q931(struct sk_buff *skb, struct nf_conn *ct,
1099                         enum ip_conntrack_info ctinfo,
1100                         unsigned int protoff, unsigned char **data, int dataoff,
1101                         Q931 *q931)
1102 {
1103         H323_UU_PDU *pdu = &q931->UUIE.h323_uu_pdu;
1104         int i;
1105         int ret = 0;
1106
1107         switch (pdu->h323_message_body.choice) {
1108         case eH323_UU_PDU_h323_message_body_setup:
1109                 ret = process_setup(skb, ct, ctinfo, protoff, data, dataoff,
1110                                     &pdu->h323_message_body.setup);
1111                 break;
1112         case eH323_UU_PDU_h323_message_body_callProceeding:
1113                 ret = process_callproceeding(skb, ct, ctinfo,
1114                                              protoff, data, dataoff,
1115                                              &pdu->h323_message_body.
1116                                              callProceeding);
1117                 break;
1118         case eH323_UU_PDU_h323_message_body_connect:
1119                 ret = process_connect(skb, ct, ctinfo, protoff, data, dataoff,
1120                                       &pdu->h323_message_body.connect);
1121                 break;
1122         case eH323_UU_PDU_h323_message_body_alerting:
1123                 ret = process_alerting(skb, ct, ctinfo, protoff, data, dataoff,
1124                                        &pdu->h323_message_body.alerting);
1125                 break;
1126         case eH323_UU_PDU_h323_message_body_facility:
1127                 ret = process_facility(skb, ct, ctinfo, protoff, data, dataoff,
1128                                        &pdu->h323_message_body.facility);
1129                 break;
1130         case eH323_UU_PDU_h323_message_body_progress:
1131                 ret = process_progress(skb, ct, ctinfo, protoff, data, dataoff,
1132                                        &pdu->h323_message_body.progress);
1133                 break;
1134         default:
1135                 pr_debug("nf_ct_q931: Q.931 signal %d\n",
1136                          pdu->h323_message_body.choice);
1137                 break;
1138         }
1139
1140         if (ret < 0)
1141                 return -1;
1142
1143         if (pdu->options & eH323_UU_PDU_h245Control) {
1144                 for (i = 0; i < pdu->h245Control.count; i++) {
1145                         ret = process_h245(skb, ct, ctinfo,
1146                                            protoff, data, dataoff,
1147                                            &pdu->h245Control.item[i]);
1148                         if (ret < 0)
1149                                 return -1;
1150                 }
1151         }
1152
1153         return 0;
1154 }
1155
1156 /****************************************************************************/
1157 static int q931_help(struct sk_buff *skb, unsigned int protoff,
1158                      struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1159 {
1160         static Q931 q931;
1161         unsigned char *data = NULL;
1162         int datalen;
1163         int dataoff;
1164         int ret;
1165
1166         /* Until there's been traffic both ways, don't look in packets. */
1167         if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
1168                 return NF_ACCEPT;
1169
1170         pr_debug("nf_ct_q931: skblen = %u\n", skb->len);
1171
1172         spin_lock_bh(&nf_h323_lock);
1173
1174         /* Process each TPKT */
1175         while (get_tpkt_data(skb, protoff, ct, ctinfo,
1176                              &data, &datalen, &dataoff)) {
1177                 pr_debug("nf_ct_q931: TPKT len=%d ", datalen);
1178                 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1179
1180                 /* Decode Q.931 signal */
1181                 ret = DecodeQ931(data, datalen, &q931);
1182                 if (ret < 0) {
1183                         pr_debug("nf_ct_q931: decoding error: %s\n",
1184                                  ret == H323_ERROR_BOUND ?
1185                                  "out of bound" : "out of range");
1186                         /* We don't drop when decoding error */
1187                         break;
1188                 }
1189
1190                 /* Process Q.931 signal */
1191                 if (process_q931(skb, ct, ctinfo, protoff,
1192                                  &data, dataoff, &q931) < 0)
1193                         goto drop;
1194         }
1195
1196         spin_unlock_bh(&nf_h323_lock);
1197         return NF_ACCEPT;
1198
1199       drop:
1200         spin_unlock_bh(&nf_h323_lock);
1201         nf_ct_helper_log(skb, ct, "cannot process Q.931 message");
1202         return NF_DROP;
1203 }
1204
1205 /****************************************************************************/
1206 static const struct nf_conntrack_expect_policy q931_exp_policy = {
1207         /* T.120 and H.245 */
1208         .max_expected           = H323_RTP_CHANNEL_MAX * 4 + 4,
1209         .timeout                = 240,
1210 };
1211
1212 static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = {
1213         {
1214                 .name                   = "Q.931",
1215                 .me                     = THIS_MODULE,
1216                 .data_len               = sizeof(struct nf_ct_h323_master),
1217                 .tuple.src.l3num        = AF_INET,
1218                 .tuple.src.u.tcp.port   = cpu_to_be16(Q931_PORT),
1219                 .tuple.dst.protonum     = IPPROTO_TCP,
1220                 .help                   = q931_help,
1221                 .expect_policy          = &q931_exp_policy,
1222         },
1223         {
1224                 .name                   = "Q.931",
1225                 .me                     = THIS_MODULE,
1226                 .tuple.src.l3num        = AF_INET6,
1227                 .tuple.src.u.tcp.port   = cpu_to_be16(Q931_PORT),
1228                 .tuple.dst.protonum     = IPPROTO_TCP,
1229                 .help                   = q931_help,
1230                 .expect_policy          = &q931_exp_policy,
1231         },
1232 };
1233
1234 /****************************************************************************/
1235 static unsigned char *get_udp_data(struct sk_buff *skb, unsigned int protoff,
1236                                    int *datalen)
1237 {
1238         const struct udphdr *uh;
1239         struct udphdr _uh;
1240         int dataoff;
1241
1242         uh = skb_header_pointer(skb, protoff, sizeof(_uh), &_uh);
1243         if (uh == NULL)
1244                 return NULL;
1245         dataoff = protoff + sizeof(_uh);
1246         if (dataoff >= skb->len)
1247                 return NULL;
1248         *datalen = skb->len - dataoff;
1249         return skb_header_pointer(skb, dataoff, *datalen, h323_buffer);
1250 }
1251
1252 /****************************************************************************/
1253 static struct nf_conntrack_expect *find_expect(struct nf_conn *ct,
1254                                                union nf_inet_addr *addr,
1255                                                __be16 port)
1256 {
1257         struct net *net = nf_ct_net(ct);
1258         struct nf_conntrack_expect *exp;
1259         struct nf_conntrack_tuple tuple;
1260
1261         memset(&tuple.src.u3, 0, sizeof(tuple.src.u3));
1262         tuple.src.u.tcp.port = 0;
1263         memcpy(&tuple.dst.u3, addr, sizeof(tuple.dst.u3));
1264         tuple.dst.u.tcp.port = port;
1265         tuple.dst.protonum = IPPROTO_TCP;
1266
1267         exp = __nf_ct_expect_find(net, nf_ct_zone(ct), &tuple);
1268         if (exp && exp->master == ct)
1269                 return exp;
1270         return NULL;
1271 }
1272
1273 /****************************************************************************/
1274 static int set_expect_timeout(struct nf_conntrack_expect *exp,
1275                               unsigned int timeout)
1276 {
1277         if (!exp || !del_timer(&exp->timeout))
1278                 return 0;
1279
1280         exp->timeout.expires = jiffies + timeout * HZ;
1281         add_timer(&exp->timeout);
1282
1283         return 1;
1284 }
1285
1286 /****************************************************************************/
1287 static int expect_q931(struct sk_buff *skb, struct nf_conn *ct,
1288                        enum ip_conntrack_info ctinfo,
1289                        unsigned int protoff, unsigned char **data,
1290                        TransportAddress *taddr, int count)
1291 {
1292         struct nf_ct_h323_master *info = nfct_help_data(ct);
1293         int dir = CTINFO2DIR(ctinfo);
1294         int ret = 0;
1295         int i;
1296         __be16 port;
1297         union nf_inet_addr addr;
1298         struct nf_conntrack_expect *exp;
1299         typeof(nat_q931_hook) nat_q931;
1300
1301         /* Look for the first related address */
1302         for (i = 0; i < count; i++) {
1303                 if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) &&
1304                     memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3,
1305                            sizeof(addr)) == 0 && port != 0)
1306                         break;
1307         }
1308
1309         if (i >= count)         /* Not found */
1310                 return 0;
1311
1312         /* Create expect for Q.931 */
1313         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1314                 return -1;
1315         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1316                           gkrouted_only ? /* only accept calls from GK? */
1317                                 &ct->tuplehash[!dir].tuple.src.u3 : NULL,
1318                           &ct->tuplehash[!dir].tuple.dst.u3,
1319                           IPPROTO_TCP, NULL, &port);
1320         exp->helper = nf_conntrack_helper_q931;
1321         exp->flags = NF_CT_EXPECT_PERMANENT;    /* Accept multiple calls */
1322
1323         nat_q931 = rcu_dereference(nat_q931_hook);
1324         if (nat_q931 && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1325             ct->status & IPS_NAT_MASK) {        /* Need NAT */
1326                 ret = nat_q931(skb, ct, ctinfo, protoff, data,
1327                                taddr, i, port, exp);
1328         } else {                /* Conntrack only */
1329                 if (nf_ct_expect_related(exp) == 0) {
1330                         pr_debug("nf_ct_ras: expect Q.931 ");
1331                         nf_ct_dump_tuple(&exp->tuple);
1332
1333                         /* Save port for looking up expect in processing RCF */
1334                         info->sig_port[dir] = port;
1335                 } else
1336                         ret = -1;
1337         }
1338
1339         nf_ct_expect_put(exp);
1340
1341         return ret;
1342 }
1343
1344 /****************************************************************************/
1345 static int process_grq(struct sk_buff *skb, struct nf_conn *ct,
1346                        enum ip_conntrack_info ctinfo,
1347                        unsigned int protoff,
1348                        unsigned char **data, GatekeeperRequest *grq)
1349 {
1350         typeof(set_ras_addr_hook) set_ras_addr;
1351
1352         pr_debug("nf_ct_ras: GRQ\n");
1353
1354         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1355         if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1356             ct->status & IPS_NAT_MASK)  /* NATed */
1357                 return set_ras_addr(skb, ct, ctinfo, protoff, data,
1358                                     &grq->rasAddress, 1);
1359         return 0;
1360 }
1361
1362 /****************************************************************************/
1363 static int process_gcf(struct sk_buff *skb, struct nf_conn *ct,
1364                        enum ip_conntrack_info ctinfo,
1365                        unsigned int protoff,
1366                        unsigned char **data, GatekeeperConfirm *gcf)
1367 {
1368         int dir = CTINFO2DIR(ctinfo);
1369         int ret = 0;
1370         __be16 port;
1371         union nf_inet_addr addr;
1372         struct nf_conntrack_expect *exp;
1373
1374         pr_debug("nf_ct_ras: GCF\n");
1375
1376         if (!get_h225_addr(ct, *data, &gcf->rasAddress, &addr, &port))
1377                 return 0;
1378
1379         /* Registration port is the same as discovery port */
1380         if (!memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1381             port == ct->tuplehash[dir].tuple.src.u.udp.port)
1382                 return 0;
1383
1384         /* Avoid RAS expectation loops. A GCF is never expected. */
1385         if (test_bit(IPS_EXPECTED_BIT, &ct->status))
1386                 return 0;
1387
1388         /* Need new expect */
1389         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1390                 return -1;
1391         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1392                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1393                           IPPROTO_UDP, NULL, &port);
1394         exp->helper = nf_conntrack_helper_ras;
1395
1396         if (nf_ct_expect_related(exp) == 0) {
1397                 pr_debug("nf_ct_ras: expect RAS ");
1398                 nf_ct_dump_tuple(&exp->tuple);
1399         } else
1400                 ret = -1;
1401
1402         nf_ct_expect_put(exp);
1403
1404         return ret;
1405 }
1406
1407 /****************************************************************************/
1408 static int process_rrq(struct sk_buff *skb, struct nf_conn *ct,
1409                        enum ip_conntrack_info ctinfo,
1410                        unsigned int protoff,
1411                        unsigned char **data, RegistrationRequest *rrq)
1412 {
1413         struct nf_ct_h323_master *info = nfct_help_data(ct);
1414         int ret;
1415         typeof(set_ras_addr_hook) set_ras_addr;
1416
1417         pr_debug("nf_ct_ras: RRQ\n");
1418
1419         ret = expect_q931(skb, ct, ctinfo, protoff, data,
1420                           rrq->callSignalAddress.item,
1421                           rrq->callSignalAddress.count);
1422         if (ret < 0)
1423                 return -1;
1424
1425         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1426         if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1427             ct->status & IPS_NAT_MASK) {
1428                 ret = set_ras_addr(skb, ct, ctinfo, protoff, data,
1429                                    rrq->rasAddress.item,
1430                                    rrq->rasAddress.count);
1431                 if (ret < 0)
1432                         return -1;
1433         }
1434
1435         if (rrq->options & eRegistrationRequest_timeToLive) {
1436                 pr_debug("nf_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive);
1437                 info->timeout = rrq->timeToLive;
1438         } else
1439                 info->timeout = default_rrq_ttl;
1440
1441         return 0;
1442 }
1443
1444 /****************************************************************************/
1445 static int process_rcf(struct sk_buff *skb, struct nf_conn *ct,
1446                        enum ip_conntrack_info ctinfo,
1447                        unsigned int protoff,
1448                        unsigned char **data, RegistrationConfirm *rcf)
1449 {
1450         struct nf_ct_h323_master *info = nfct_help_data(ct);
1451         int dir = CTINFO2DIR(ctinfo);
1452         int ret;
1453         struct nf_conntrack_expect *exp;
1454         typeof(set_sig_addr_hook) set_sig_addr;
1455
1456         pr_debug("nf_ct_ras: RCF\n");
1457
1458         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1459         if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1460             ct->status & IPS_NAT_MASK) {
1461                 ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1462                                         rcf->callSignalAddress.item,
1463                                         rcf->callSignalAddress.count);
1464                 if (ret < 0)
1465                         return -1;
1466         }
1467
1468         if (rcf->options & eRegistrationConfirm_timeToLive) {
1469                 pr_debug("nf_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive);
1470                 info->timeout = rcf->timeToLive;
1471         }
1472
1473         if (info->timeout > 0) {
1474                 pr_debug("nf_ct_ras: set RAS connection timeout to "
1475                          "%u seconds\n", info->timeout);
1476                 nf_ct_refresh(ct, skb, info->timeout * HZ);
1477
1478                 /* Set expect timeout */
1479                 spin_lock_bh(&nf_conntrack_lock);
1480                 exp = find_expect(ct, &ct->tuplehash[dir].tuple.dst.u3,
1481                                   info->sig_port[!dir]);
1482                 if (exp) {
1483                         pr_debug("nf_ct_ras: set Q.931 expect "
1484                                  "timeout to %u seconds for",
1485                                  info->timeout);
1486                         nf_ct_dump_tuple(&exp->tuple);
1487                         set_expect_timeout(exp, info->timeout);
1488                 }
1489                 spin_unlock_bh(&nf_conntrack_lock);
1490         }
1491
1492         return 0;
1493 }
1494
1495 /****************************************************************************/
1496 static int process_urq(struct sk_buff *skb, struct nf_conn *ct,
1497                        enum ip_conntrack_info ctinfo,
1498                        unsigned int protoff,
1499                        unsigned char **data, UnregistrationRequest *urq)
1500 {
1501         struct nf_ct_h323_master *info = nfct_help_data(ct);
1502         int dir = CTINFO2DIR(ctinfo);
1503         int ret;
1504         typeof(set_sig_addr_hook) set_sig_addr;
1505
1506         pr_debug("nf_ct_ras: URQ\n");
1507
1508         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1509         if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1510             ct->status & IPS_NAT_MASK) {
1511                 ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1512                                    urq->callSignalAddress.item,
1513                                    urq->callSignalAddress.count);
1514                 if (ret < 0)
1515                         return -1;
1516         }
1517
1518         /* Clear old expect */
1519         nf_ct_remove_expectations(ct);
1520         info->sig_port[dir] = 0;
1521         info->sig_port[!dir] = 0;
1522
1523         /* Give it 30 seconds for UCF or URJ */
1524         nf_ct_refresh(ct, skb, 30 * HZ);
1525
1526         return 0;
1527 }
1528
1529 /****************************************************************************/
1530 static int process_arq(struct sk_buff *skb, struct nf_conn *ct,
1531                        enum ip_conntrack_info ctinfo,
1532                        unsigned int protoff,
1533                        unsigned char **data, AdmissionRequest *arq)
1534 {
1535         const struct nf_ct_h323_master *info = nfct_help_data(ct);
1536         int dir = CTINFO2DIR(ctinfo);
1537         __be16 port;
1538         union nf_inet_addr addr;
1539         typeof(set_h225_addr_hook) set_h225_addr;
1540
1541         pr_debug("nf_ct_ras: ARQ\n");
1542
1543         set_h225_addr = rcu_dereference(set_h225_addr_hook);
1544         if ((arq->options & eAdmissionRequest_destCallSignalAddress) &&
1545             get_h225_addr(ct, *data, &arq->destCallSignalAddress,
1546                           &addr, &port) &&
1547             !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1548             port == info->sig_port[dir] &&
1549             nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1550             set_h225_addr && ct->status & IPS_NAT_MASK) {
1551                 /* Answering ARQ */
1552                 return set_h225_addr(skb, protoff, data, 0,
1553                                      &arq->destCallSignalAddress,
1554                                      &ct->tuplehash[!dir].tuple.dst.u3,
1555                                      info->sig_port[!dir]);
1556         }
1557
1558         if ((arq->options & eAdmissionRequest_srcCallSignalAddress) &&
1559             get_h225_addr(ct, *data, &arq->srcCallSignalAddress,
1560                           &addr, &port) &&
1561             !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1562             set_h225_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1563             ct->status & IPS_NAT_MASK) {
1564                 /* Calling ARQ */
1565                 return set_h225_addr(skb, protoff, data, 0,
1566                                      &arq->srcCallSignalAddress,
1567                                      &ct->tuplehash[!dir].tuple.dst.u3,
1568                                      port);
1569         }
1570
1571         return 0;
1572 }
1573
1574 /****************************************************************************/
1575 static int process_acf(struct sk_buff *skb, struct nf_conn *ct,
1576                        enum ip_conntrack_info ctinfo,
1577                        unsigned int protoff,
1578                        unsigned char **data, AdmissionConfirm *acf)
1579 {
1580         int dir = CTINFO2DIR(ctinfo);
1581         int ret = 0;
1582         __be16 port;
1583         union nf_inet_addr addr;
1584         struct nf_conntrack_expect *exp;
1585         typeof(set_sig_addr_hook) set_sig_addr;
1586
1587         pr_debug("nf_ct_ras: ACF\n");
1588
1589         if (!get_h225_addr(ct, *data, &acf->destCallSignalAddress,
1590                            &addr, &port))
1591                 return 0;
1592
1593         if (!memcmp(&addr, &ct->tuplehash[dir].tuple.dst.u3, sizeof(addr))) {
1594                 /* Answering ACF */
1595                 set_sig_addr = rcu_dereference(set_sig_addr_hook);
1596                 if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1597                     ct->status & IPS_NAT_MASK)
1598                         return set_sig_addr(skb, ct, ctinfo, protoff, data,
1599                                             &acf->destCallSignalAddress, 1);
1600                 return 0;
1601         }
1602
1603         /* Need new expect */
1604         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1605                 return -1;
1606         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1607                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1608                           IPPROTO_TCP, NULL, &port);
1609         exp->flags = NF_CT_EXPECT_PERMANENT;
1610         exp->helper = nf_conntrack_helper_q931;
1611
1612         if (nf_ct_expect_related(exp) == 0) {
1613                 pr_debug("nf_ct_ras: expect Q.931 ");
1614                 nf_ct_dump_tuple(&exp->tuple);
1615         } else
1616                 ret = -1;
1617
1618         nf_ct_expect_put(exp);
1619
1620         return ret;
1621 }
1622
1623 /****************************************************************************/
1624 static int process_lrq(struct sk_buff *skb, struct nf_conn *ct,
1625                        enum ip_conntrack_info ctinfo,
1626                        unsigned int protoff,
1627                        unsigned char **data, LocationRequest *lrq)
1628 {
1629         typeof(set_ras_addr_hook) set_ras_addr;
1630
1631         pr_debug("nf_ct_ras: LRQ\n");
1632
1633         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1634         if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1635             ct->status & IPS_NAT_MASK)
1636                 return set_ras_addr(skb, ct, ctinfo, protoff, data,
1637                                     &lrq->replyAddress, 1);
1638         return 0;
1639 }
1640
1641 /****************************************************************************/
1642 static int process_lcf(struct sk_buff *skb, struct nf_conn *ct,
1643                        enum ip_conntrack_info ctinfo,
1644                        unsigned int protoff,
1645                        unsigned char **data, LocationConfirm *lcf)
1646 {
1647         int dir = CTINFO2DIR(ctinfo);
1648         int ret = 0;
1649         __be16 port;
1650         union nf_inet_addr addr;
1651         struct nf_conntrack_expect *exp;
1652
1653         pr_debug("nf_ct_ras: LCF\n");
1654
1655         if (!get_h225_addr(ct, *data, &lcf->callSignalAddress,
1656                            &addr, &port))
1657                 return 0;
1658
1659         /* Need new expect for call signal */
1660         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1661                 return -1;
1662         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1663                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1664                           IPPROTO_TCP, NULL, &port);
1665         exp->flags = NF_CT_EXPECT_PERMANENT;
1666         exp->helper = nf_conntrack_helper_q931;
1667
1668         if (nf_ct_expect_related(exp) == 0) {
1669                 pr_debug("nf_ct_ras: expect Q.931 ");
1670                 nf_ct_dump_tuple(&exp->tuple);
1671         } else
1672                 ret = -1;
1673
1674         nf_ct_expect_put(exp);
1675
1676         /* Ignore rasAddress */
1677
1678         return ret;
1679 }
1680
1681 /****************************************************************************/
1682 static int process_irr(struct sk_buff *skb, struct nf_conn *ct,
1683                        enum ip_conntrack_info ctinfo,
1684                        unsigned int protoff,
1685                        unsigned char **data, InfoRequestResponse *irr)
1686 {
1687         int ret;
1688         typeof(set_ras_addr_hook) set_ras_addr;
1689         typeof(set_sig_addr_hook) set_sig_addr;
1690
1691         pr_debug("nf_ct_ras: IRR\n");
1692
1693         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1694         if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1695             ct->status & IPS_NAT_MASK) {
1696                 ret = set_ras_addr(skb, ct, ctinfo, protoff, data,
1697                                    &irr->rasAddress, 1);
1698                 if (ret < 0)
1699                         return -1;
1700         }
1701
1702         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1703         if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1704             ct->status & IPS_NAT_MASK) {
1705                 ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1706                                         irr->callSignalAddress.item,
1707                                         irr->callSignalAddress.count);
1708                 if (ret < 0)
1709                         return -1;
1710         }
1711
1712         return 0;
1713 }
1714
1715 /****************************************************************************/
1716 static int process_ras(struct sk_buff *skb, struct nf_conn *ct,
1717                        enum ip_conntrack_info ctinfo,
1718                        unsigned int protoff,
1719                        unsigned char **data, RasMessage *ras)
1720 {
1721         switch (ras->choice) {
1722         case eRasMessage_gatekeeperRequest:
1723                 return process_grq(skb, ct, ctinfo, protoff, data,
1724                                    &ras->gatekeeperRequest);
1725         case eRasMessage_gatekeeperConfirm:
1726                 return process_gcf(skb, ct, ctinfo, protoff, data,
1727                                    &ras->gatekeeperConfirm);
1728         case eRasMessage_registrationRequest:
1729                 return process_rrq(skb, ct, ctinfo, protoff, data,
1730                                    &ras->registrationRequest);
1731         case eRasMessage_registrationConfirm:
1732                 return process_rcf(skb, ct, ctinfo, protoff, data,
1733                                    &ras->registrationConfirm);
1734         case eRasMessage_unregistrationRequest:
1735                 return process_urq(skb, ct, ctinfo, protoff, data,
1736                                    &ras->unregistrationRequest);
1737         case eRasMessage_admissionRequest:
1738                 return process_arq(skb, ct, ctinfo, protoff, data,
1739                                    &ras->admissionRequest);
1740         case eRasMessage_admissionConfirm:
1741                 return process_acf(skb, ct, ctinfo, protoff, data,
1742                                    &ras->admissionConfirm);
1743         case eRasMessage_locationRequest:
1744                 return process_lrq(skb, ct, ctinfo, protoff, data,
1745                                    &ras->locationRequest);
1746         case eRasMessage_locationConfirm:
1747                 return process_lcf(skb, ct, ctinfo, protoff, data,
1748                                    &ras->locationConfirm);
1749         case eRasMessage_infoRequestResponse:
1750                 return process_irr(skb, ct, ctinfo, protoff, data,
1751                                    &ras->infoRequestResponse);
1752         default:
1753                 pr_debug("nf_ct_ras: RAS message %d\n", ras->choice);
1754                 break;
1755         }
1756
1757         return 0;
1758 }
1759
1760 /****************************************************************************/
1761 static int ras_help(struct sk_buff *skb, unsigned int protoff,
1762                     struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1763 {
1764         static RasMessage ras;
1765         unsigned char *data;
1766         int datalen = 0;
1767         int ret;
1768
1769         pr_debug("nf_ct_ras: skblen = %u\n", skb->len);
1770
1771         spin_lock_bh(&nf_h323_lock);
1772
1773         /* Get UDP data */
1774         data = get_udp_data(skb, protoff, &datalen);
1775         if (data == NULL)
1776                 goto accept;
1777         pr_debug("nf_ct_ras: RAS message len=%d ", datalen);
1778         nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1779
1780         /* Decode RAS message */
1781         ret = DecodeRasMessage(data, datalen, &ras);
1782         if (ret < 0) {
1783                 pr_debug("nf_ct_ras: decoding error: %s\n",
1784                          ret == H323_ERROR_BOUND ?
1785                          "out of bound" : "out of range");
1786                 goto accept;
1787         }
1788
1789         /* Process RAS message */
1790         if (process_ras(skb, ct, ctinfo, protoff, &data, &ras) < 0)
1791                 goto drop;
1792
1793       accept:
1794         spin_unlock_bh(&nf_h323_lock);
1795         return NF_ACCEPT;
1796
1797       drop:
1798         spin_unlock_bh(&nf_h323_lock);
1799         nf_ct_helper_log(skb, ct, "cannot process RAS message");
1800         return NF_DROP;
1801 }
1802
1803 /****************************************************************************/
1804 static const struct nf_conntrack_expect_policy ras_exp_policy = {
1805         .max_expected           = 32,
1806         .timeout                = 240,
1807 };
1808
1809 static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = {
1810         {
1811                 .name                   = "RAS",
1812                 .me                     = THIS_MODULE,
1813                 .data_len               = sizeof(struct nf_ct_h323_master),
1814                 .tuple.src.l3num        = AF_INET,
1815                 .tuple.src.u.udp.port   = cpu_to_be16(RAS_PORT),
1816                 .tuple.dst.protonum     = IPPROTO_UDP,
1817                 .help                   = ras_help,
1818                 .expect_policy          = &ras_exp_policy,
1819         },
1820         {
1821                 .name                   = "RAS",
1822                 .me                     = THIS_MODULE,
1823                 .data_len               = sizeof(struct nf_ct_h323_master),
1824                 .tuple.src.l3num        = AF_INET6,
1825                 .tuple.src.u.udp.port   = cpu_to_be16(RAS_PORT),
1826                 .tuple.dst.protonum     = IPPROTO_UDP,
1827                 .help                   = ras_help,
1828                 .expect_policy          = &ras_exp_policy,
1829         },
1830 };
1831
1832 /****************************************************************************/
1833 static void __exit nf_conntrack_h323_fini(void)
1834 {
1835         nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[1]);
1836         nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1837         nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1838         nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1839         nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1840         kfree(h323_buffer);
1841         pr_debug("nf_ct_h323: fini\n");
1842 }
1843
1844 /****************************************************************************/
1845 static int __init nf_conntrack_h323_init(void)
1846 {
1847         int ret;
1848
1849         h323_buffer = kmalloc(65536, GFP_KERNEL);
1850         if (!h323_buffer)
1851                 return -ENOMEM;
1852         ret = nf_conntrack_helper_register(&nf_conntrack_helper_h245);
1853         if (ret < 0)
1854                 goto err1;
1855         ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[0]);
1856         if (ret < 0)
1857                 goto err2;
1858         ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[1]);
1859         if (ret < 0)
1860                 goto err3;
1861         ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[0]);
1862         if (ret < 0)
1863                 goto err4;
1864         ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[1]);
1865         if (ret < 0)
1866                 goto err5;
1867         pr_debug("nf_ct_h323: init success\n");
1868         return 0;
1869
1870 err5:
1871         nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1872 err4:
1873         nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1874 err3:
1875         nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1876 err2:
1877         nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1878 err1:
1879         kfree(h323_buffer);
1880         return ret;
1881 }
1882
1883 /****************************************************************************/
1884 module_init(nf_conntrack_h323_init);
1885 module_exit(nf_conntrack_h323_fini);
1886
1887 EXPORT_SYMBOL_GPL(get_h225_addr);
1888 EXPORT_SYMBOL_GPL(set_h245_addr_hook);
1889 EXPORT_SYMBOL_GPL(set_h225_addr_hook);
1890 EXPORT_SYMBOL_GPL(set_sig_addr_hook);
1891 EXPORT_SYMBOL_GPL(set_ras_addr_hook);
1892 EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook);
1893 EXPORT_SYMBOL_GPL(nat_t120_hook);
1894 EXPORT_SYMBOL_GPL(nat_h245_hook);
1895 EXPORT_SYMBOL_GPL(nat_callforwarding_hook);
1896 EXPORT_SYMBOL_GPL(nat_q931_hook);
1897
1898 MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>");
1899 MODULE_DESCRIPTION("H.323 connection tracking helper");
1900 MODULE_LICENSE("GPL");
1901 MODULE_ALIAS("ip_conntrack_h323");
1902 MODULE_ALIAS_NFCT_HELPER("RAS");
1903 MODULE_ALIAS_NFCT_HELPER("Q.931");
1904 MODULE_ALIAS_NFCT_HELPER("H.245");