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 #define H323_MAX_SIZE 65535
  38
  39 /* Parameters */
  40 static unsigned int default_rrq_ttl __read_mostly = 300;
  41 module_param(default_rrq_ttl, uint, 0600);
  42 MODULE_PARM_DESC(default_rrq_ttl, "use this TTL if it's missing in RRQ");
  43
  44 static int gkrouted_only __read_mostly = 1;
  45 module_param(gkrouted_only, int, 0600);
  46 MODULE_PARM_DESC(gkrouted_only, "only accept calls from gatekeeper");
  47
  48 static bool callforward_filter __read_mostly = true;
  49 module_param(callforward_filter, bool, 0600);
  50 MODULE_PARM_DESC(callforward_filter, "only create call forwarding expectations "
  51                                      "if both endpoints are on different sides "
  52                                      "(determined by routing information)");
  53
  54 /* Hooks for NAT */
  55 int (*set_h245_addr_hook) (struct sk_buff *skb, unsigned int protoff,
  56                            unsigned char **data, int dataoff,
  57                            H245_TransportAddress *taddr,
  58                            union nf_inet_addr *addr, __be16 port)
  59                            __read_mostly;
  60 int (*set_h225_addr_hook) (struct sk_buff *skb, unsigned int protoff,
  61                            unsigned char **data, int dataoff,
  62                            TransportAddress *taddr,
  63                            union nf_inet_addr *addr, __be16 port)
  64                            __read_mostly;
  65 int (*set_sig_addr_hook) (struct sk_buff *skb,
  66                           struct nf_conn *ct,
  67                           enum ip_conntrack_info ctinfo,
  68                           unsigned int protoff, unsigned char **data,
  69                           TransportAddress *taddr, int count) __read_mostly;
  70 int (*set_ras_addr_hook) (struct sk_buff *skb,
  71                           struct nf_conn *ct,
  72                           enum ip_conntrack_info ctinfo,
  73                           unsigned int protoff, unsigned char **data,
  74                           TransportAddress *taddr, int count) __read_mostly;
  75 int (*nat_rtp_rtcp_hook) (struct sk_buff *skb,
  76                           struct nf_conn *ct,
  77                           enum ip_conntrack_info ctinfo,
  78                           unsigned int protoff,
  79                           unsigned char **data, int dataoff,
  80                           H245_TransportAddress *taddr,
  81                           __be16 port, __be16 rtp_port,
  82                           struct nf_conntrack_expect *rtp_exp,
  83                           struct nf_conntrack_expect *rtcp_exp) __read_mostly;
  84 int (*nat_t120_hook) (struct sk_buff *skb,
  85                       struct nf_conn *ct,
  86                       enum ip_conntrack_info ctinfo,
  87                       unsigned int protoff,
  88                       unsigned char **data, int dataoff,
  89                       H245_TransportAddress *taddr, __be16 port,
  90                       struct nf_conntrack_expect *exp) __read_mostly;
  91 int (*nat_h245_hook) (struct sk_buff *skb,
  92                       struct nf_conn *ct,
  93                       enum ip_conntrack_info ctinfo,
  94                       unsigned int protoff,
  95                       unsigned char **data, int dataoff,
  96                       TransportAddress *taddr, __be16 port,
  97                       struct nf_conntrack_expect *exp) __read_mostly;
  98 int (*nat_callforwarding_hook) (struct sk_buff *skb,
  99                                 struct nf_conn *ct,
 100                                 enum ip_conntrack_info ctinfo,
 101                                 unsigned int protoff,
 102                                 unsigned char **data, int dataoff,
 103                                 TransportAddress *taddr, __be16 port,
 104                                 struct nf_conntrack_expect *exp) __read_mostly;
 105 int (*nat_q931_hook) (struct sk_buff *skb,
 106                       struct nf_conn *ct,
 107                       enum ip_conntrack_info ctinfo,
 108                       unsigned int protoff,
 109                       unsigned char **data, TransportAddress *taddr, int idx,
 110                       __be16 port, struct nf_conntrack_expect *exp)
 111                       __read_mostly;
 112
 113 static DEFINE_SPINLOCK(nf_h323_lock);
 114 static char *h323_buffer;
 115
 116 static struct nf_conntrack_helper nf_conntrack_helper_h245;
 117 static struct nf_conntrack_helper nf_conntrack_helper_q931[];
 118 static struct nf_conntrack_helper nf_conntrack_helper_ras[];
 119
 120 static int get_tpkt_data(struct sk_buff *skb, unsigned int protoff,
 121                          struct nf_conn *ct, enum ip_conntrack_info ctinfo,
 122                          unsigned char **data, int *datalen, int *dataoff)
 123 {
 124         struct nf_ct_h323_master *info = nfct_help_data(ct);
 125         int dir = CTINFO2DIR(ctinfo);
 126         const struct tcphdr *th;
 127         struct tcphdr _tcph;
 128         int tcpdatalen;
 129         int tcpdataoff;
 130         unsigned char *tpkt;
 131         int tpktlen;
 132         int tpktoff;
 133
 134         /* Get TCP header */
 135         th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph);
 136         if (th == NULL)
 137                 return 0;
 138
 139         /* Get TCP data offset */
 140         tcpdataoff = protoff + th->doff * 4;
 141
 142         /* Get TCP data length */
 143         tcpdatalen = skb->len - tcpdataoff;
 144         if (tcpdatalen <= 0)    /* No TCP data */
 145                 goto clear_out;
 146
 147         if (tcpdatalen > H323_MAX_SIZE)
 148                 tcpdatalen = H323_MAX_SIZE;
 149
 150         if (*data == NULL) {    /* first TPKT */
 151                 /* Get first TPKT pointer */
 152                 tpkt = skb_header_pointer(skb, tcpdataoff, tcpdatalen,
 153                                           h323_buffer);
 154                 if (!tpkt)
 155                         goto clear_out;
 156
 157                 /* Validate TPKT identifier */
 158                 if (tcpdatalen < 4 || tpkt[0] != 0x03 || tpkt[1] != 0) {
 159                         /* Netmeeting sends TPKT header and data separately */
 160                         if (info->tpkt_len[dir] > 0) {
 161                                 pr_debug("nf_ct_h323: previous packet "
 162                                          "indicated separate TPKT data of %hu "
 163                                          "bytes\n", info->tpkt_len[dir]);
 164                                 if (info->tpkt_len[dir] <= tcpdatalen) {
 165                                         /* Yes, there was a TPKT header
 166                                          * received */
 167                                         *data = tpkt;
 168                                         *datalen = info->tpkt_len[dir];
 169                                         *dataoff = 0;
 170                                         goto out;
 171                                 }
 172
 173                                 /* Fragmented TPKT */
 174                                 pr_debug("nf_ct_h323: fragmented TPKT\n");
 175                                 goto clear_out;
 176                         }
 177
 178                         /* It is not even a TPKT */
 179                         return 0;
 180                 }
 181                 tpktoff = 0;
 182         } else {                /* Next TPKT */
 183                 tpktoff = *dataoff + *datalen;
 184                 tcpdatalen -= tpktoff;
 185                 if (tcpdatalen <= 4)    /* No more TPKT */
 186                         goto clear_out;
 187                 tpkt = *data + *datalen;
 188
 189                 /* Validate TPKT identifier */
 190                 if (tpkt[0] != 0x03 || tpkt[1] != 0)
 191                         goto clear_out;
 192         }
 193
 194         /* Validate TPKT length */
 195         tpktlen = tpkt[2] * 256 + tpkt[3];
 196         if (tpktlen < 4)
 197                 goto clear_out;
 198         if (tpktlen > tcpdatalen) {
 199                 if (tcpdatalen == 4) {  /* Separate TPKT header */
 200                         /* Netmeeting sends TPKT header and data separately */
 201                         pr_debug("nf_ct_h323: separate TPKT header indicates "
 202                                  "there will be TPKT data of %d bytes\n",
 203                                  tpktlen - 4);
 204                         info->tpkt_len[dir] = tpktlen - 4;
 205                         return 0;
 206                 }
 207
 208                 pr_debug("nf_ct_h323: incomplete TPKT (fragmented?)\n");
 209                 goto clear_out;
 210         }
 211
 212         /* This is the encapsulated data */
 213         *data = tpkt + 4;
 214         *datalen = tpktlen - 4;
 215         *dataoff = tpktoff + 4;
 216
 217       out:
 218         /* Clear TPKT length */
 219         info->tpkt_len[dir] = 0;
 220         return 1;
 221
 222       clear_out:
 223         info->tpkt_len[dir] = 0;
 224         return 0;
 225 }
 226
 227 static int get_h245_addr(struct nf_conn *ct, const unsigned char *data,
 228                          H245_TransportAddress *taddr,
 229                          union nf_inet_addr *addr, __be16 *port)
 230 {
 231         const unsigned char *p;
 232         int len;
 233
 234         if (taddr->choice != eH245_TransportAddress_unicastAddress)
 235                 return 0;
 236
 237         switch (taddr->unicastAddress.choice) {
 238         case eUnicastAddress_iPAddress:
 239                 if (nf_ct_l3num(ct) != AF_INET)
 240                         return 0;
 241                 p = data + taddr->unicastAddress.iPAddress.network;
 242                 len = 4;
 243                 break;
 244         case eUnicastAddress_iP6Address:
 245                 if (nf_ct_l3num(ct) != AF_INET6)
 246                         return 0;
 247                 p = data + taddr->unicastAddress.iP6Address.network;
 248                 len = 16;
 249                 break;
 250         default:
 251                 return 0;
 252         }
 253
 254         memcpy(addr, p, len);
 255         memset((void *)addr + len, 0, sizeof(*addr) - len);
 256         memcpy(port, p + len, sizeof(__be16));
 257
 258         return 1;
 259 }
 260
 261 static int expect_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct,
 262                            enum ip_conntrack_info ctinfo,
 263                            unsigned int protoff,
 264                            unsigned char **data, int dataoff,
 265                            H245_TransportAddress *taddr)
 266 {
 267         int dir = CTINFO2DIR(ctinfo);
 268         int ret = 0;
 269         __be16 port;
 270         __be16 rtp_port, rtcp_port;
 271         union nf_inet_addr addr;
 272         struct nf_conntrack_expect *rtp_exp;
 273         struct nf_conntrack_expect *rtcp_exp;
 274         typeof(nat_rtp_rtcp_hook) nat_rtp_rtcp;
 275
 276         /* Read RTP or RTCP address */
 277         if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
 278             memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 279             port == 0)
 280                 return 0;
 281
 282         /* RTP port is even */
 283         rtp_port = port & ~htons(1);
 284         rtcp_port = port | htons(1);
 285
 286         /* Create expect for RTP */
 287         if ((rtp_exp = nf_ct_expect_alloc(ct)) == NULL)
 288                 return -1;
 289         nf_ct_expect_init(rtp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 290                           &ct->tuplehash[!dir].tuple.src.u3,
 291                           &ct->tuplehash[!dir].tuple.dst.u3,
 292                           IPPROTO_UDP, NULL, &rtp_port);
 293
 294         /* Create expect for RTCP */
 295         if ((rtcp_exp = nf_ct_expect_alloc(ct)) == NULL) {
 296                 nf_ct_expect_put(rtp_exp);
 297                 return -1;
 298         }
 299         nf_ct_expect_init(rtcp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 300                           &ct->tuplehash[!dir].tuple.src.u3,
 301                           &ct->tuplehash[!dir].tuple.dst.u3,
 302                           IPPROTO_UDP, NULL, &rtcp_port);
 303
 304         if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 305                    &ct->tuplehash[!dir].tuple.dst.u3,
 306                    sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 307                    (nat_rtp_rtcp = rcu_dereference(nat_rtp_rtcp_hook)) &&
 308                    nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 309                    ct->status & IPS_NAT_MASK) {
 310                 /* NAT needed */
 311                 ret = nat_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff,
 312                                    taddr, port, rtp_port, rtp_exp, rtcp_exp);
 313         } else {                /* Conntrack only */
 314                 if (nf_ct_expect_related(rtp_exp, 0) == 0) {
 315                         if (nf_ct_expect_related(rtcp_exp, 0) == 0) {
 316                                 pr_debug("nf_ct_h323: expect RTP ");
 317                                 nf_ct_dump_tuple(&rtp_exp->tuple);
 318                                 pr_debug("nf_ct_h323: expect RTCP ");
 319                                 nf_ct_dump_tuple(&rtcp_exp->tuple);
 320                         } else {
 321                                 nf_ct_unexpect_related(rtp_exp);
 322                                 ret = -1;
 323                         }
 324                 } else
 325                         ret = -1;
 326         }
 327
 328         nf_ct_expect_put(rtp_exp);
 329         nf_ct_expect_put(rtcp_exp);
 330
 331         return ret;
 332 }
 333
 334 static int expect_t120(struct sk_buff *skb,
 335                        struct nf_conn *ct,
 336                        enum ip_conntrack_info ctinfo,
 337                        unsigned int protoff,
 338                        unsigned char **data, int dataoff,
 339                        H245_TransportAddress *taddr)
 340 {
 341         int dir = CTINFO2DIR(ctinfo);
 342         int ret = 0;
 343         __be16 port;
 344         union nf_inet_addr addr;
 345         struct nf_conntrack_expect *exp;
 346         typeof(nat_t120_hook) nat_t120;
 347
 348         /* Read T.120 address */
 349         if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
 350             memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 351             port == 0)
 352                 return 0;
 353
 354         /* Create expect for T.120 connections */
 355         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 356                 return -1;
 357         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 358                           &ct->tuplehash[!dir].tuple.src.u3,
 359                           &ct->tuplehash[!dir].tuple.dst.u3,
 360                           IPPROTO_TCP, NULL, &port);
 361         exp->flags = NF_CT_EXPECT_PERMANENT;    /* Accept multiple channels */
 362
 363         if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 364                    &ct->tuplehash[!dir].tuple.dst.u3,
 365                    sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 366             (nat_t120 = rcu_dereference(nat_t120_hook)) &&
 367             nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 368             ct->status & IPS_NAT_MASK) {
 369                 /* NAT needed */
 370                 ret = nat_t120(skb, ct, ctinfo, protoff, data, dataoff, taddr,
 371                                port, exp);
 372         } else {                /* Conntrack only */
 373                 if (nf_ct_expect_related(exp, 0) == 0) {
 374                         pr_debug("nf_ct_h323: expect T.120 ");
 375                         nf_ct_dump_tuple(&exp->tuple);
 376                 } else
 377                         ret = -1;
 378         }
 379
 380         nf_ct_expect_put(exp);
 381
 382         return ret;
 383 }
 384
 385 static int process_h245_channel(struct sk_buff *skb,
 386                                 struct nf_conn *ct,
 387                                 enum ip_conntrack_info ctinfo,
 388                                 unsigned int protoff,
 389                                 unsigned char **data, int dataoff,
 390                                 H2250LogicalChannelParameters *channel)
 391 {
 392         int ret;
 393
 394         if (channel->options & eH2250LogicalChannelParameters_mediaChannel) {
 395                 /* RTP */
 396                 ret = expect_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff,
 397                                       &channel->mediaChannel);
 398                 if (ret < 0)
 399                         return -1;
 400         }
 401
 402         if (channel->
 403             options & eH2250LogicalChannelParameters_mediaControlChannel) {
 404                 /* RTCP */
 405                 ret = expect_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff,
 406                                       &channel->mediaControlChannel);
 407                 if (ret < 0)
 408                         return -1;
 409         }
 410
 411         return 0;
 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 static int process_olca(struct sk_buff *skb, struct nf_conn *ct,
 476                         enum ip_conntrack_info ctinfo,
 477                         unsigned int protoff, unsigned char **data, int dataoff,
 478                         OpenLogicalChannelAck *olca)
 479 {
 480         H2250LogicalChannelAckParameters *ack;
 481         int ret;
 482
 483         pr_debug("nf_ct_h323: OpenLogicalChannelAck\n");
 484
 485         if ((olca->options &
 486              eOpenLogicalChannelAck_reverseLogicalChannelParameters) &&
 487             (olca->reverseLogicalChannelParameters.options &
 488              eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters)
 489             && (olca->reverseLogicalChannelParameters.multiplexParameters.
 490                 choice ==
 491                 eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
 492         {
 493                 ret = process_h245_channel(skb, ct, ctinfo,
 494                                            protoff, data, dataoff,
 495                                            &olca->
 496                                            reverseLogicalChannelParameters.
 497                                            multiplexParameters.
 498                                            h2250LogicalChannelParameters);
 499                 if (ret < 0)
 500                         return -1;
 501         }
 502
 503         if ((olca->options &
 504              eOpenLogicalChannelAck_forwardMultiplexAckParameters) &&
 505             (olca->forwardMultiplexAckParameters.choice ==
 506              eOpenLogicalChannelAck_forwardMultiplexAckParameters_h2250LogicalChannelAckParameters))
 507         {
 508                 ack = &olca->forwardMultiplexAckParameters.
 509                     h2250LogicalChannelAckParameters;
 510                 if (ack->options &
 511                     eH2250LogicalChannelAckParameters_mediaChannel) {
 512                         /* RTP */
 513                         ret = expect_rtp_rtcp(skb, ct, ctinfo,
 514                                               protoff, data, dataoff,
 515                                               &ack->mediaChannel);
 516                         if (ret < 0)
 517                                 return -1;
 518                 }
 519
 520                 if (ack->options &
 521                     eH2250LogicalChannelAckParameters_mediaControlChannel) {
 522                         /* RTCP */
 523                         ret = expect_rtp_rtcp(skb, ct, ctinfo,
 524                                               protoff, data, dataoff,
 525                                               &ack->mediaControlChannel);
 526                         if (ret < 0)
 527                                 return -1;
 528                 }
 529         }
 530
 531         if ((olca->options & eOpenLogicalChannelAck_separateStack) &&
 532                 olca->separateStack.networkAddress.choice ==
 533                 eNetworkAccessParameters_networkAddress_localAreaAddress) {
 534                 ret = expect_t120(skb, ct, ctinfo, protoff, data, dataoff,
 535                                   &olca->separateStack.networkAddress.
 536                                   localAreaAddress);
 537                 if (ret < 0)
 538                         return -1;
 539         }
 540
 541         return 0;
 542 }
 543
 544 static int process_h245(struct sk_buff *skb, struct nf_conn *ct,
 545                         enum ip_conntrack_info ctinfo,
 546                         unsigned int protoff, unsigned char **data, int dataoff,
 547                         MultimediaSystemControlMessage *mscm)
 548 {
 549         switch (mscm->choice) {
 550         case eMultimediaSystemControlMessage_request:
 551                 if (mscm->request.choice ==
 552                     eRequestMessage_openLogicalChannel) {
 553                         return process_olc(skb, ct, ctinfo,
 554                                            protoff, data, dataoff,
 555                                            &mscm->request.openLogicalChannel);
 556                 }
 557                 pr_debug("nf_ct_h323: H.245 Request %d\n",
 558                          mscm->request.choice);
 559                 break;
 560         case eMultimediaSystemControlMessage_response:
 561                 if (mscm->response.choice ==
 562                     eResponseMessage_openLogicalChannelAck) {
 563                         return process_olca(skb, ct, ctinfo,
 564                                             protoff, data, dataoff,
 565                                             &mscm->response.
 566                                             openLogicalChannelAck);
 567                 }
 568                 pr_debug("nf_ct_h323: H.245 Response %d\n",
 569                          mscm->response.choice);
 570                 break;
 571         default:
 572                 pr_debug("nf_ct_h323: H.245 signal %d\n", mscm->choice);
 573                 break;
 574         }
 575
 576         return 0;
 577 }
 578
 579 static int h245_help(struct sk_buff *skb, unsigned int protoff,
 580                      struct nf_conn *ct, enum ip_conntrack_info ctinfo)
 581 {
 582         static MultimediaSystemControlMessage mscm;
 583         unsigned char *data = NULL;
 584         int datalen;
 585         int dataoff;
 586         int ret;
 587
 588         /* Until there's been traffic both ways, don't look in packets. */
 589         if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
 590                 return NF_ACCEPT;
 591
 592         pr_debug("nf_ct_h245: skblen = %u\n", skb->len);
 593
 594         spin_lock_bh(&nf_h323_lock);
 595
 596         /* Process each TPKT */
 597         while (get_tpkt_data(skb, protoff, ct, ctinfo,
 598                              &data, &datalen, &dataoff)) {
 599                 pr_debug("nf_ct_h245: TPKT len=%d ", datalen);
 600                 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
 601
 602                 /* Decode H.245 signal */
 603                 ret = DecodeMultimediaSystemControlMessage(data, datalen,
 604                                                            &mscm);
 605                 if (ret < 0) {
 606                         pr_debug("nf_ct_h245: decoding error: %s\n",
 607                                  ret == H323_ERROR_BOUND ?
 608                                  "out of bound" : "out of range");
 609                         /* We don't drop when decoding error */
 610                         break;
 611                 }
 612
 613                 /* Process H.245 signal */
 614                 if (process_h245(skb, ct, ctinfo, protoff,
 615                                  &data, dataoff, &mscm) < 0)
 616                         goto drop;
 617         }
 618
 619         spin_unlock_bh(&nf_h323_lock);
 620         return NF_ACCEPT;
 621
 622       drop:
 623         spin_unlock_bh(&nf_h323_lock);
 624         nf_ct_helper_log(skb, ct, "cannot process H.245 message");
 625         return NF_DROP;
 626 }
 627
 628 static const struct nf_conntrack_expect_policy h245_exp_policy = {
 629         .max_expected   = H323_RTP_CHANNEL_MAX * 4 + 2 /* T.120 */,
 630         .timeout        = 240,
 631 };
 632
 633 static struct nf_conntrack_helper nf_conntrack_helper_h245 __read_mostly = {
 634         .name                   = "H.245",
 635         .me                     = THIS_MODULE,
 636         .tuple.src.l3num        = AF_UNSPEC,
 637         .tuple.dst.protonum     = IPPROTO_UDP,
 638         .help                   = h245_help,
 639         .expect_policy          = &h245_exp_policy,
 640 };
 641
 642 int get_h225_addr(struct nf_conn *ct, unsigned char *data,
 643                   TransportAddress *taddr,
 644                   union nf_inet_addr *addr, __be16 *port)
 645 {
 646         const unsigned char *p;
 647         int len;
 648
 649         switch (taddr->choice) {
 650         case eTransportAddress_ipAddress:
 651                 if (nf_ct_l3num(ct) != AF_INET)
 652                         return 0;
 653                 p = data + taddr->ipAddress.ip;
 654                 len = 4;
 655                 break;
 656         case eTransportAddress_ip6Address:
 657                 if (nf_ct_l3num(ct) != AF_INET6)
 658                         return 0;
 659                 p = data + taddr->ip6Address.ip;
 660                 len = 16;
 661                 break;
 662         default:
 663                 return 0;
 664         }
 665
 666         memcpy(addr, p, len);
 667         memset((void *)addr + len, 0, sizeof(*addr) - len);
 668         memcpy(port, p + len, sizeof(__be16));
 669
 670         return 1;
 671 }
 672
 673 static int expect_h245(struct sk_buff *skb, struct nf_conn *ct,
 674                        enum ip_conntrack_info ctinfo,
 675                        unsigned int protoff, unsigned char **data, int dataoff,
 676                        TransportAddress *taddr)
 677 {
 678         int dir = CTINFO2DIR(ctinfo);
 679         int ret = 0;
 680         __be16 port;
 681         union nf_inet_addr addr;
 682         struct nf_conntrack_expect *exp;
 683         typeof(nat_h245_hook) nat_h245;
 684
 685         /* Read h245Address */
 686         if (!get_h225_addr(ct, *data, taddr, &addr, &port) ||
 687             memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 688             port == 0)
 689                 return 0;
 690
 691         /* Create expect for h245 connection */
 692         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 693                 return -1;
 694         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 695                           &ct->tuplehash[!dir].tuple.src.u3,
 696                           &ct->tuplehash[!dir].tuple.dst.u3,
 697                           IPPROTO_TCP, NULL, &port);
 698         exp->helper = &nf_conntrack_helper_h245;
 699
 700         if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 701                    &ct->tuplehash[!dir].tuple.dst.u3,
 702                    sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 703             (nat_h245 = rcu_dereference(nat_h245_hook)) &&
 704             nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 705             ct->status & IPS_NAT_MASK) {
 706                 /* NAT needed */
 707                 ret = nat_h245(skb, ct, ctinfo, protoff, data, dataoff, taddr,
 708                                port, exp);
 709         } else {                /* Conntrack only */
 710                 if (nf_ct_expect_related(exp, 0) == 0) {
 711                         pr_debug("nf_ct_q931: expect H.245 ");
 712                         nf_ct_dump_tuple(&exp->tuple);
 713                 } else
 714                         ret = -1;
 715         }
 716
 717         nf_ct_expect_put(exp);
 718
 719         return ret;
 720 }
 721
 722 /* If the calling party is on the same side of the forward-to party,
 723  * we don't need to track the second call
 724  */
 725 static int callforward_do_filter(struct net *net,
 726                                  const union nf_inet_addr *src,
 727                                  const union nf_inet_addr *dst,
 728                                  u_int8_t family)
 729 {
 730         int ret = 0;
 731
 732         switch (family) {
 733         case AF_INET: {
 734                 struct flowi4 fl1, fl2;
 735                 struct rtable *rt1, *rt2;
 736
 737                 memset(&fl1, 0, sizeof(fl1));
 738                 fl1.daddr = src->ip;
 739
 740                 memset(&fl2, 0, sizeof(fl2));
 741                 fl2.daddr = dst->ip;
 742                 if (!nf_ip_route(net, (struct dst_entry **)&rt1,
 743                                  flowi4_to_flowi(&fl1), false)) {
 744                         if (!nf_ip_route(net, (struct dst_entry **)&rt2,
 745                                          flowi4_to_flowi(&fl2), false)) {
 746                                 if (rt_nexthop(rt1, fl1.daddr) ==
 747                                     rt_nexthop(rt2, fl2.daddr) &&
 748                                     rt1->dst.dev  == rt2->dst.dev)
 749                                         ret = 1;
 750                                 dst_release(&rt2->dst);
 751                         }
 752                         dst_release(&rt1->dst);
 753                 }
 754                 break;
 755         }
 756 #if IS_ENABLED(CONFIG_IPV6)
 757         case AF_INET6: {
 758                 struct rt6_info *rt1, *rt2;
 759                 struct flowi6 fl1, fl2;
 760
 761                 memset(&fl1, 0, sizeof(fl1));
 762                 fl1.daddr = src->in6;
 763
 764                 memset(&fl2, 0, sizeof(fl2));
 765                 fl2.daddr = dst->in6;
 766                 if (!nf_ip6_route(net, (struct dst_entry **)&rt1,
 767                                   flowi6_to_flowi(&fl1), false)) {
 768                         if (!nf_ip6_route(net, (struct dst_entry **)&rt2,
 769                                           flowi6_to_flowi(&fl2), false)) {
 770                                 if (ipv6_addr_equal(rt6_nexthop(rt1, &fl1.daddr),
 771                                                     rt6_nexthop(rt2, &fl2.daddr)) &&
 772                                     rt1->dst.dev == rt2->dst.dev)
 773                                         ret = 1;
 774                                 dst_release(&rt2->dst);
 775                         }
 776                         dst_release(&rt1->dst);
 777                 }
 778                 break;
 779         }
 780 #endif
 781         }
 782         return ret;
 783
 784 }
 785
 786 static int expect_callforwarding(struct sk_buff *skb,
 787                                  struct nf_conn *ct,
 788                                  enum ip_conntrack_info ctinfo,
 789                                  unsigned int protoff,
 790                                  unsigned char **data, int dataoff,
 791                                  TransportAddress *taddr)
 792 {
 793         int dir = CTINFO2DIR(ctinfo);
 794         int ret = 0;
 795         __be16 port;
 796         union nf_inet_addr addr;
 797         struct nf_conntrack_expect *exp;
 798         struct net *net = nf_ct_net(ct);
 799         typeof(nat_callforwarding_hook) nat_callforwarding;
 800
 801         /* Read alternativeAddress */
 802         if (!get_h225_addr(ct, *data, taddr, &addr, &port) || port == 0)
 803                 return 0;
 804
 805         /* If the calling party is on the same side of the forward-to party,
 806          * we don't need to track the second call
 807          */
 808         if (callforward_filter &&
 809             callforward_do_filter(net, &addr, &ct->tuplehash[!dir].tuple.src.u3,
 810                                   nf_ct_l3num(ct))) {
 811                 pr_debug("nf_ct_q931: Call Forwarding not tracked\n");
 812                 return 0;
 813         }
 814
 815         /* Create expect for the second call leg */
 816         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 817                 return -1;
 818         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 819                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
 820                           IPPROTO_TCP, NULL, &port);
 821         exp->helper = nf_conntrack_helper_q931;
 822
 823         if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 824                    &ct->tuplehash[!dir].tuple.dst.u3,
 825                    sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 826             (nat_callforwarding = rcu_dereference(nat_callforwarding_hook)) &&
 827             nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 828             ct->status & IPS_NAT_MASK) {
 829                 /* Need NAT */
 830                 ret = nat_callforwarding(skb, ct, ctinfo,
 831                                          protoff, data, dataoff,
 832                                          taddr, port, exp);
 833         } else {                /* Conntrack only */
 834                 if (nf_ct_expect_related(exp, 0) == 0) {
 835                         pr_debug("nf_ct_q931: expect Call Forwarding ");
 836                         nf_ct_dump_tuple(&exp->tuple);
 837                 } else
 838                         ret = -1;
 839         }
 840
 841         nf_ct_expect_put(exp);
 842
 843         return ret;
 844 }
 845
 846 static int process_setup(struct sk_buff *skb, struct nf_conn *ct,
 847                          enum ip_conntrack_info ctinfo,
 848                          unsigned int protoff,
 849                          unsigned char **data, int dataoff,
 850                          Setup_UUIE *setup)
 851 {
 852         int dir = CTINFO2DIR(ctinfo);
 853         int ret;
 854         int i;
 855         __be16 port;
 856         union nf_inet_addr addr;
 857         typeof(set_h225_addr_hook) set_h225_addr;
 858
 859         pr_debug("nf_ct_q931: Setup\n");
 860
 861         if (setup->options & eSetup_UUIE_h245Address) {
 862                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
 863                                   &setup->h245Address);
 864                 if (ret < 0)
 865                         return -1;
 866         }
 867
 868         set_h225_addr = rcu_dereference(set_h225_addr_hook);
 869         if ((setup->options & eSetup_UUIE_destCallSignalAddress) &&
 870             (set_h225_addr) && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 871             ct->status & IPS_NAT_MASK &&
 872             get_h225_addr(ct, *data, &setup->destCallSignalAddress,
 873                           &addr, &port) &&
 874             memcmp(&addr, &ct->tuplehash[!dir].tuple.src.u3, sizeof(addr))) {
 875                 pr_debug("nf_ct_q931: set destCallSignalAddress %pI6:%hu->%pI6:%hu\n",
 876                          &addr, ntohs(port), &ct->tuplehash[!dir].tuple.src.u3,
 877                          ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port));
 878                 ret = set_h225_addr(skb, protoff, data, dataoff,
 879                                     &setup->destCallSignalAddress,
 880                                     &ct->tuplehash[!dir].tuple.src.u3,
 881                                     ct->tuplehash[!dir].tuple.src.u.tcp.port);
 882                 if (ret < 0)
 883                         return -1;
 884         }
 885
 886         if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) &&
 887             (set_h225_addr) && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 888             ct->status & IPS_NAT_MASK &&
 889             get_h225_addr(ct, *data, &setup->sourceCallSignalAddress,
 890                           &addr, &port) &&
 891             memcmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(addr))) {
 892                 pr_debug("nf_ct_q931: set sourceCallSignalAddress %pI6:%hu->%pI6:%hu\n",
 893                          &addr, ntohs(port), &ct->tuplehash[!dir].tuple.dst.u3,
 894                          ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port));
 895                 ret = set_h225_addr(skb, protoff, data, dataoff,
 896                                     &setup->sourceCallSignalAddress,
 897                                     &ct->tuplehash[!dir].tuple.dst.u3,
 898                                     ct->tuplehash[!dir].tuple.dst.u.tcp.port);
 899                 if (ret < 0)
 900                         return -1;
 901         }
 902
 903         if (setup->options & eSetup_UUIE_fastStart) {
 904                 for (i = 0; i < setup->fastStart.count; i++) {
 905                         ret = process_olc(skb, ct, ctinfo,
 906                                           protoff, data, dataoff,
 907                                           &setup->fastStart.item[i]);
 908                         if (ret < 0)
 909                                 return -1;
 910                 }
 911         }
 912
 913         return 0;
 914 }
 915
 916 static int process_callproceeding(struct sk_buff *skb,
 917                                   struct nf_conn *ct,
 918                                   enum ip_conntrack_info ctinfo,
 919                                   unsigned int protoff,
 920                                   unsigned char **data, int dataoff,
 921                                   CallProceeding_UUIE *callproc)
 922 {
 923         int ret;
 924         int i;
 925
 926         pr_debug("nf_ct_q931: CallProceeding\n");
 927
 928         if (callproc->options & eCallProceeding_UUIE_h245Address) {
 929                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
 930                                   &callproc->h245Address);
 931                 if (ret < 0)
 932                         return -1;
 933         }
 934
 935         if (callproc->options & eCallProceeding_UUIE_fastStart) {
 936                 for (i = 0; i < callproc->fastStart.count; i++) {
 937                         ret = process_olc(skb, ct, ctinfo,
 938                                           protoff, data, dataoff,
 939                                           &callproc->fastStart.item[i]);
 940                         if (ret < 0)
 941                                 return -1;
 942                 }
 943         }
 944
 945         return 0;
 946 }
 947
 948 static int process_connect(struct sk_buff *skb, struct nf_conn *ct,
 949                            enum ip_conntrack_info ctinfo,
 950                            unsigned int protoff,
 951                            unsigned char **data, int dataoff,
 952                            Connect_UUIE *connect)
 953 {
 954         int ret;
 955         int i;
 956
 957         pr_debug("nf_ct_q931: Connect\n");
 958
 959         if (connect->options & eConnect_UUIE_h245Address) {
 960                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
 961                                   &connect->h245Address);
 962                 if (ret < 0)
 963                         return -1;
 964         }
 965
 966         if (connect->options & eConnect_UUIE_fastStart) {
 967                 for (i = 0; i < connect->fastStart.count; i++) {
 968                         ret = process_olc(skb, ct, ctinfo,
 969                                           protoff, data, dataoff,
 970                                           &connect->fastStart.item[i]);
 971                         if (ret < 0)
 972                                 return -1;
 973                 }
 974         }
 975
 976         return 0;
 977 }
 978
 979 static int process_alerting(struct sk_buff *skb, struct nf_conn *ct,
 980                             enum ip_conntrack_info ctinfo,
 981                             unsigned int protoff,
 982                             unsigned char **data, int dataoff,
 983                             Alerting_UUIE *alert)
 984 {
 985         int ret;
 986         int i;
 987
 988         pr_debug("nf_ct_q931: Alerting\n");
 989
 990         if (alert->options & eAlerting_UUIE_h245Address) {
 991                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
 992                                   &alert->h245Address);
 993                 if (ret < 0)
 994                         return -1;
 995         }
 996
 997         if (alert->options & eAlerting_UUIE_fastStart) {
 998                 for (i = 0; i < alert->fastStart.count; i++) {
 999                         ret = process_olc(skb, ct, ctinfo,
1000                                           protoff, data, dataoff,
1001                                           &alert->fastStart.item[i]);
1002                         if (ret < 0)
1003                                 return -1;
1004                 }
1005         }
1006
1007         return 0;
1008 }
1009
1010 static int process_facility(struct sk_buff *skb, struct nf_conn *ct,
1011                             enum ip_conntrack_info ctinfo,
1012                             unsigned int protoff,
1013                             unsigned char **data, int dataoff,
1014                             Facility_UUIE *facility)
1015 {
1016         int ret;
1017         int i;
1018
1019         pr_debug("nf_ct_q931: Facility\n");
1020
1021         if (facility->reason.choice == eFacilityReason_callForwarded) {
1022                 if (facility->options & eFacility_UUIE_alternativeAddress)
1023                         return expect_callforwarding(skb, ct, ctinfo,
1024                                                      protoff, data, dataoff,
1025                                                      &facility->
1026                                                      alternativeAddress);
1027                 return 0;
1028         }
1029
1030         if (facility->options & eFacility_UUIE_h245Address) {
1031                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
1032                                   &facility->h245Address);
1033                 if (ret < 0)
1034                         return -1;
1035         }
1036
1037         if (facility->options & eFacility_UUIE_fastStart) {
1038                 for (i = 0; i < facility->fastStart.count; i++) {
1039                         ret = process_olc(skb, ct, ctinfo,
1040                                           protoff, data, dataoff,
1041                                           &facility->fastStart.item[i]);
1042                         if (ret < 0)
1043                                 return -1;
1044                 }
1045         }
1046
1047         return 0;
1048 }
1049
1050 static int process_progress(struct sk_buff *skb, struct nf_conn *ct,
1051                             enum ip_conntrack_info ctinfo,
1052                             unsigned int protoff,
1053                             unsigned char **data, int dataoff,
1054                             Progress_UUIE *progress)
1055 {
1056         int ret;
1057         int i;
1058
1059         pr_debug("nf_ct_q931: Progress\n");
1060
1061         if (progress->options & eProgress_UUIE_h245Address) {
1062                 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
1063                                   &progress->h245Address);
1064                 if (ret < 0)
1065                         return -1;
1066         }
1067
1068         if (progress->options & eProgress_UUIE_fastStart) {
1069                 for (i = 0; i < progress->fastStart.count; i++) {
1070                         ret = process_olc(skb, ct, ctinfo,
1071                                           protoff, data, dataoff,
1072                                           &progress->fastStart.item[i]);
1073                         if (ret < 0)
1074                                 return -1;
1075                 }
1076         }
1077
1078         return 0;
1079 }
1080
1081 static int process_q931(struct sk_buff *skb, struct nf_conn *ct,
1082                         enum ip_conntrack_info ctinfo,
1083                         unsigned int protoff, unsigned char **data, int dataoff,
1084                         Q931 *q931)
1085 {
1086         H323_UU_PDU *pdu = &q931->UUIE.h323_uu_pdu;
1087         int i;
1088         int ret = 0;
1089
1090         switch (pdu->h323_message_body.choice) {
1091         case eH323_UU_PDU_h323_message_body_setup:
1092                 ret = process_setup(skb, ct, ctinfo, protoff, data, dataoff,
1093                                     &pdu->h323_message_body.setup);
1094                 break;
1095         case eH323_UU_PDU_h323_message_body_callProceeding:
1096                 ret = process_callproceeding(skb, ct, ctinfo,
1097                                              protoff, data, dataoff,
1098                                              &pdu->h323_message_body.
1099                                              callProceeding);
1100                 break;
1101         case eH323_UU_PDU_h323_message_body_connect:
1102                 ret = process_connect(skb, ct, ctinfo, protoff, data, dataoff,
1103                                       &pdu->h323_message_body.connect);
1104                 break;
1105         case eH323_UU_PDU_h323_message_body_alerting:
1106                 ret = process_alerting(skb, ct, ctinfo, protoff, data, dataoff,
1107                                        &pdu->h323_message_body.alerting);
1108                 break;
1109         case eH323_UU_PDU_h323_message_body_facility:
1110                 ret = process_facility(skb, ct, ctinfo, protoff, data, dataoff,
1111                                        &pdu->h323_message_body.facility);
1112                 break;
1113         case eH323_UU_PDU_h323_message_body_progress:
1114                 ret = process_progress(skb, ct, ctinfo, protoff, data, dataoff,
1115                                        &pdu->h323_message_body.progress);
1116                 break;
1117         default:
1118                 pr_debug("nf_ct_q931: Q.931 signal %d\n",
1119                          pdu->h323_message_body.choice);
1120                 break;
1121         }
1122
1123         if (ret < 0)
1124                 return -1;
1125
1126         if (pdu->options & eH323_UU_PDU_h245Control) {
1127                 for (i = 0; i < pdu->h245Control.count; i++) {
1128                         ret = process_h245(skb, ct, ctinfo,
1129                                            protoff, data, dataoff,
1130                                            &pdu->h245Control.item[i]);
1131                         if (ret < 0)
1132                                 return -1;
1133                 }
1134         }
1135
1136         return 0;
1137 }
1138
1139 static int q931_help(struct sk_buff *skb, unsigned int protoff,
1140                      struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1141 {
1142         static Q931 q931;
1143         unsigned char *data = NULL;
1144         int datalen;
1145         int dataoff;
1146         int ret;
1147
1148         /* Until there's been traffic both ways, don't look in packets. */
1149         if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
1150                 return NF_ACCEPT;
1151
1152         pr_debug("nf_ct_q931: skblen = %u\n", skb->len);
1153
1154         spin_lock_bh(&nf_h323_lock);
1155
1156         /* Process each TPKT */
1157         while (get_tpkt_data(skb, protoff, ct, ctinfo,
1158                              &data, &datalen, &dataoff)) {
1159                 pr_debug("nf_ct_q931: TPKT len=%d ", datalen);
1160                 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1161
1162                 /* Decode Q.931 signal */
1163                 ret = DecodeQ931(data, datalen, &q931);
1164                 if (ret < 0) {
1165                         pr_debug("nf_ct_q931: decoding error: %s\n",
1166                                  ret == H323_ERROR_BOUND ?
1167                                  "out of bound" : "out of range");
1168                         /* We don't drop when decoding error */
1169                         break;
1170                 }
1171
1172                 /* Process Q.931 signal */
1173                 if (process_q931(skb, ct, ctinfo, protoff,
1174                                  &data, dataoff, &q931) < 0)
1175                         goto drop;
1176         }
1177
1178         spin_unlock_bh(&nf_h323_lock);
1179         return NF_ACCEPT;
1180
1181       drop:
1182         spin_unlock_bh(&nf_h323_lock);
1183         nf_ct_helper_log(skb, ct, "cannot process Q.931 message");
1184         return NF_DROP;
1185 }
1186
1187 static const struct nf_conntrack_expect_policy q931_exp_policy = {
1188         /* T.120 and H.245 */
1189         .max_expected           = H323_RTP_CHANNEL_MAX * 4 + 4,
1190         .timeout                = 240,
1191 };
1192
1193 static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = {
1194         {
1195                 .name                   = "Q.931",
1196                 .me                     = THIS_MODULE,
1197                 .tuple.src.l3num        = AF_INET,
1198                 .tuple.src.u.tcp.port   = cpu_to_be16(Q931_PORT),
1199                 .tuple.dst.protonum     = IPPROTO_TCP,
1200                 .help                   = q931_help,
1201                 .expect_policy          = &q931_exp_policy,
1202         },
1203         {
1204                 .name                   = "Q.931",
1205                 .me                     = THIS_MODULE,
1206                 .tuple.src.l3num        = AF_INET6,
1207                 .tuple.src.u.tcp.port   = cpu_to_be16(Q931_PORT),
1208                 .tuple.dst.protonum     = IPPROTO_TCP,
1209                 .help                   = q931_help,
1210                 .expect_policy          = &q931_exp_policy,
1211         },
1212 };
1213
1214 static unsigned char *get_udp_data(struct sk_buff *skb, unsigned int protoff,
1215                                    int *datalen)
1216 {
1217         const struct udphdr *uh;
1218         struct udphdr _uh;
1219         int dataoff;
1220
1221         uh = skb_header_pointer(skb, protoff, sizeof(_uh), &_uh);
1222         if (uh == NULL)
1223                 return NULL;
1224         dataoff = protoff + sizeof(_uh);
1225         if (dataoff >= skb->len)
1226                 return NULL;
1227         *datalen = skb->len - dataoff;
1228         if (*datalen > H323_MAX_SIZE)
1229                 *datalen = H323_MAX_SIZE;
1230
1231         return skb_header_pointer(skb, dataoff, *datalen, h323_buffer);
1232 }
1233
1234 static struct nf_conntrack_expect *find_expect(struct nf_conn *ct,
1235                                                union nf_inet_addr *addr,
1236                                                __be16 port)
1237 {
1238         struct net *net = nf_ct_net(ct);
1239         struct nf_conntrack_expect *exp;
1240         struct nf_conntrack_tuple tuple;
1241
1242         memset(&tuple.src.u3, 0, sizeof(tuple.src.u3));
1243         tuple.src.u.tcp.port = 0;
1244         memcpy(&tuple.dst.u3, addr, sizeof(tuple.dst.u3));
1245         tuple.dst.u.tcp.port = port;
1246         tuple.dst.protonum = IPPROTO_TCP;
1247
1248         exp = __nf_ct_expect_find(net, nf_ct_zone(ct), &tuple);
1249         if (exp && exp->master == ct)
1250                 return exp;
1251         return NULL;
1252 }
1253
1254 static int expect_q931(struct sk_buff *skb, struct nf_conn *ct,
1255                        enum ip_conntrack_info ctinfo,
1256                        unsigned int protoff, unsigned char **data,
1257                        TransportAddress *taddr, int count)
1258 {
1259         struct nf_ct_h323_master *info = nfct_help_data(ct);
1260         int dir = CTINFO2DIR(ctinfo);
1261         int ret = 0;
1262         int i;
1263         __be16 port;
1264         union nf_inet_addr addr;
1265         struct nf_conntrack_expect *exp;
1266         typeof(nat_q931_hook) nat_q931;
1267
1268         /* Look for the first related address */
1269         for (i = 0; i < count; i++) {
1270                 if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) &&
1271                     memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3,
1272                            sizeof(addr)) == 0 && port != 0)
1273                         break;
1274         }
1275
1276         if (i >= count)         /* Not found */
1277                 return 0;
1278
1279         /* Create expect for Q.931 */
1280         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1281                 return -1;
1282         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1283                           gkrouted_only ? /* only accept calls from GK? */
1284                                 &ct->tuplehash[!dir].tuple.src.u3 : NULL,
1285                           &ct->tuplehash[!dir].tuple.dst.u3,
1286                           IPPROTO_TCP, NULL, &port);
1287         exp->helper = nf_conntrack_helper_q931;
1288         exp->flags = NF_CT_EXPECT_PERMANENT;    /* Accept multiple calls */
1289
1290         nat_q931 = rcu_dereference(nat_q931_hook);
1291         if (nat_q931 && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1292             ct->status & IPS_NAT_MASK) {        /* Need NAT */
1293                 ret = nat_q931(skb, ct, ctinfo, protoff, data,
1294                                taddr, i, port, exp);
1295         } else {                /* Conntrack only */
1296                 if (nf_ct_expect_related(exp, 0) == 0) {
1297                         pr_debug("nf_ct_ras: expect Q.931 ");
1298                         nf_ct_dump_tuple(&exp->tuple);
1299
1300                         /* Save port for looking up expect in processing RCF */
1301                         info->sig_port[dir] = port;
1302                 } else
1303                         ret = -1;
1304         }
1305
1306         nf_ct_expect_put(exp);
1307
1308         return ret;
1309 }
1310
1311 static int process_grq(struct sk_buff *skb, struct nf_conn *ct,
1312                        enum ip_conntrack_info ctinfo,
1313                        unsigned int protoff,
1314                        unsigned char **data, GatekeeperRequest *grq)
1315 {
1316         typeof(set_ras_addr_hook) set_ras_addr;
1317
1318         pr_debug("nf_ct_ras: GRQ\n");
1319
1320         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1321         if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1322             ct->status & IPS_NAT_MASK)  /* NATed */
1323                 return set_ras_addr(skb, ct, ctinfo, protoff, data,
1324                                     &grq->rasAddress, 1);
1325         return 0;
1326 }
1327
1328 static int process_gcf(struct sk_buff *skb, struct nf_conn *ct,
1329                        enum ip_conntrack_info ctinfo,
1330                        unsigned int protoff,
1331                        unsigned char **data, GatekeeperConfirm *gcf)
1332 {
1333         int dir = CTINFO2DIR(ctinfo);
1334         int ret = 0;
1335         __be16 port;
1336         union nf_inet_addr addr;
1337         struct nf_conntrack_expect *exp;
1338
1339         pr_debug("nf_ct_ras: GCF\n");
1340
1341         if (!get_h225_addr(ct, *data, &gcf->rasAddress, &addr, &port))
1342                 return 0;
1343
1344         /* Registration port is the same as discovery port */
1345         if (!memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1346             port == ct->tuplehash[dir].tuple.src.u.udp.port)
1347                 return 0;
1348
1349         /* Avoid RAS expectation loops. A GCF is never expected. */
1350         if (test_bit(IPS_EXPECTED_BIT, &ct->status))
1351                 return 0;
1352
1353         /* Need new expect */
1354         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1355                 return -1;
1356         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1357                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1358                           IPPROTO_UDP, NULL, &port);
1359         exp->helper = nf_conntrack_helper_ras;
1360
1361         if (nf_ct_expect_related(exp, 0) == 0) {
1362                 pr_debug("nf_ct_ras: expect RAS ");
1363                 nf_ct_dump_tuple(&exp->tuple);
1364         } else
1365                 ret = -1;
1366
1367         nf_ct_expect_put(exp);
1368
1369         return ret;
1370 }
1371
1372 static int process_rrq(struct sk_buff *skb, struct nf_conn *ct,
1373                        enum ip_conntrack_info ctinfo,
1374                        unsigned int protoff,
1375                        unsigned char **data, RegistrationRequest *rrq)
1376 {
1377         struct nf_ct_h323_master *info = nfct_help_data(ct);
1378         int ret;
1379         typeof(set_ras_addr_hook) set_ras_addr;
1380
1381         pr_debug("nf_ct_ras: RRQ\n");
1382
1383         ret = expect_q931(skb, ct, ctinfo, protoff, data,
1384                           rrq->callSignalAddress.item,
1385                           rrq->callSignalAddress.count);
1386         if (ret < 0)
1387                 return -1;
1388
1389         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1390         if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1391             ct->status & IPS_NAT_MASK) {
1392                 ret = set_ras_addr(skb, ct, ctinfo, protoff, data,
1393                                    rrq->rasAddress.item,
1394                                    rrq->rasAddress.count);
1395                 if (ret < 0)
1396                         return -1;
1397         }
1398
1399         if (rrq->options & eRegistrationRequest_timeToLive) {
1400                 pr_debug("nf_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive);
1401                 info->timeout = rrq->timeToLive;
1402         } else
1403                 info->timeout = default_rrq_ttl;
1404
1405         return 0;
1406 }
1407
1408 static int process_rcf(struct sk_buff *skb, struct nf_conn *ct,
1409                        enum ip_conntrack_info ctinfo,
1410                        unsigned int protoff,
1411                        unsigned char **data, RegistrationConfirm *rcf)
1412 {
1413         struct nf_ct_h323_master *info = nfct_help_data(ct);
1414         int dir = CTINFO2DIR(ctinfo);
1415         int ret;
1416         struct nf_conntrack_expect *exp;
1417         typeof(set_sig_addr_hook) set_sig_addr;
1418
1419         pr_debug("nf_ct_ras: RCF\n");
1420
1421         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1422         if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1423             ct->status & IPS_NAT_MASK) {
1424                 ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1425                                         rcf->callSignalAddress.item,
1426                                         rcf->callSignalAddress.count);
1427                 if (ret < 0)
1428                         return -1;
1429         }
1430
1431         if (rcf->options & eRegistrationConfirm_timeToLive) {
1432                 pr_debug("nf_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive);
1433                 info->timeout = rcf->timeToLive;
1434         }
1435
1436         if (info->timeout > 0) {
1437                 pr_debug("nf_ct_ras: set RAS connection timeout to "
1438                          "%u seconds\n", info->timeout);
1439                 nf_ct_refresh(ct, skb, info->timeout * HZ);
1440
1441                 /* Set expect timeout */
1442                 spin_lock_bh(&nf_conntrack_expect_lock);
1443                 exp = find_expect(ct, &ct->tuplehash[dir].tuple.dst.u3,
1444                                   info->sig_port[!dir]);
1445                 if (exp) {
1446                         pr_debug("nf_ct_ras: set Q.931 expect "
1447                                  "timeout to %u seconds for",
1448                                  info->timeout);
1449                         nf_ct_dump_tuple(&exp->tuple);
1450                         mod_timer_pending(&exp->timeout,
1451                                           jiffies + info->timeout * HZ);
1452                 }
1453                 spin_unlock_bh(&nf_conntrack_expect_lock);
1454         }
1455
1456         return 0;
1457 }
1458
1459 static int process_urq(struct sk_buff *skb, struct nf_conn *ct,
1460                        enum ip_conntrack_info ctinfo,
1461                        unsigned int protoff,
1462                        unsigned char **data, UnregistrationRequest *urq)
1463 {
1464         struct nf_ct_h323_master *info = nfct_help_data(ct);
1465         int dir = CTINFO2DIR(ctinfo);
1466         int ret;
1467         typeof(set_sig_addr_hook) set_sig_addr;
1468
1469         pr_debug("nf_ct_ras: URQ\n");
1470
1471         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1472         if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1473             ct->status & IPS_NAT_MASK) {
1474                 ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1475                                    urq->callSignalAddress.item,
1476                                    urq->callSignalAddress.count);
1477                 if (ret < 0)
1478                         return -1;
1479         }
1480
1481         /* Clear old expect */
1482         nf_ct_remove_expectations(ct);
1483         info->sig_port[dir] = 0;
1484         info->sig_port[!dir] = 0;
1485
1486         /* Give it 30 seconds for UCF or URJ */
1487         nf_ct_refresh(ct, skb, 30 * HZ);
1488
1489         return 0;
1490 }
1491
1492 static int process_arq(struct sk_buff *skb, struct nf_conn *ct,
1493                        enum ip_conntrack_info ctinfo,
1494                        unsigned int protoff,
1495                        unsigned char **data, AdmissionRequest *arq)
1496 {
1497         const struct nf_ct_h323_master *info = nfct_help_data(ct);
1498         int dir = CTINFO2DIR(ctinfo);
1499         __be16 port;
1500         union nf_inet_addr addr;
1501         typeof(set_h225_addr_hook) set_h225_addr;
1502
1503         pr_debug("nf_ct_ras: ARQ\n");
1504
1505         set_h225_addr = rcu_dereference(set_h225_addr_hook);
1506         if ((arq->options & eAdmissionRequest_destCallSignalAddress) &&
1507             get_h225_addr(ct, *data, &arq->destCallSignalAddress,
1508                           &addr, &port) &&
1509             !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1510             port == info->sig_port[dir] &&
1511             nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1512             set_h225_addr && ct->status & IPS_NAT_MASK) {
1513                 /* Answering ARQ */
1514                 return set_h225_addr(skb, protoff, data, 0,
1515                                      &arq->destCallSignalAddress,
1516                                      &ct->tuplehash[!dir].tuple.dst.u3,
1517                                      info->sig_port[!dir]);
1518         }
1519
1520         if ((arq->options & eAdmissionRequest_srcCallSignalAddress) &&
1521             get_h225_addr(ct, *data, &arq->srcCallSignalAddress,
1522                           &addr, &port) &&
1523             !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1524             set_h225_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1525             ct->status & IPS_NAT_MASK) {
1526                 /* Calling ARQ */
1527                 return set_h225_addr(skb, protoff, data, 0,
1528                                      &arq->srcCallSignalAddress,
1529                                      &ct->tuplehash[!dir].tuple.dst.u3,
1530                                      port);
1531         }
1532
1533         return 0;
1534 }
1535
1536 static int process_acf(struct sk_buff *skb, struct nf_conn *ct,
1537                        enum ip_conntrack_info ctinfo,
1538                        unsigned int protoff,
1539                        unsigned char **data, AdmissionConfirm *acf)
1540 {
1541         int dir = CTINFO2DIR(ctinfo);
1542         int ret = 0;
1543         __be16 port;
1544         union nf_inet_addr addr;
1545         struct nf_conntrack_expect *exp;
1546         typeof(set_sig_addr_hook) set_sig_addr;
1547
1548         pr_debug("nf_ct_ras: ACF\n");
1549
1550         if (!get_h225_addr(ct, *data, &acf->destCallSignalAddress,
1551                            &addr, &port))
1552                 return 0;
1553
1554         if (!memcmp(&addr, &ct->tuplehash[dir].tuple.dst.u3, sizeof(addr))) {
1555                 /* Answering ACF */
1556                 set_sig_addr = rcu_dereference(set_sig_addr_hook);
1557                 if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1558                     ct->status & IPS_NAT_MASK)
1559                         return set_sig_addr(skb, ct, ctinfo, protoff, data,
1560                                             &acf->destCallSignalAddress, 1);
1561                 return 0;
1562         }
1563
1564         /* Need new expect */
1565         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1566                 return -1;
1567         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1568                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1569                           IPPROTO_TCP, NULL, &port);
1570         exp->flags = NF_CT_EXPECT_PERMANENT;
1571         exp->helper = nf_conntrack_helper_q931;
1572
1573         if (nf_ct_expect_related(exp, 0) == 0) {
1574                 pr_debug("nf_ct_ras: expect Q.931 ");
1575                 nf_ct_dump_tuple(&exp->tuple);
1576         } else
1577                 ret = -1;
1578
1579         nf_ct_expect_put(exp);
1580
1581         return ret;
1582 }
1583
1584 static int process_lrq(struct sk_buff *skb, struct nf_conn *ct,
1585                        enum ip_conntrack_info ctinfo,
1586                        unsigned int protoff,
1587                        unsigned char **data, LocationRequest *lrq)
1588 {
1589         typeof(set_ras_addr_hook) set_ras_addr;
1590
1591         pr_debug("nf_ct_ras: LRQ\n");
1592
1593         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1594         if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1595             ct->status & IPS_NAT_MASK)
1596                 return set_ras_addr(skb, ct, ctinfo, protoff, data,
1597                                     &lrq->replyAddress, 1);
1598         return 0;
1599 }
1600
1601 static int process_lcf(struct sk_buff *skb, struct nf_conn *ct,
1602                        enum ip_conntrack_info ctinfo,
1603                        unsigned int protoff,
1604                        unsigned char **data, LocationConfirm *lcf)
1605 {
1606         int dir = CTINFO2DIR(ctinfo);
1607         int ret = 0;
1608         __be16 port;
1609         union nf_inet_addr addr;
1610         struct nf_conntrack_expect *exp;
1611
1612         pr_debug("nf_ct_ras: LCF\n");
1613
1614         if (!get_h225_addr(ct, *data, &lcf->callSignalAddress,
1615                            &addr, &port))
1616                 return 0;
1617
1618         /* Need new expect for call signal */
1619         if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1620                 return -1;
1621         nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1622                           &ct->tuplehash[!dir].tuple.src.u3, &addr,
1623                           IPPROTO_TCP, NULL, &port);
1624         exp->flags = NF_CT_EXPECT_PERMANENT;
1625         exp->helper = nf_conntrack_helper_q931;
1626
1627         if (nf_ct_expect_related(exp, 0) == 0) {
1628                 pr_debug("nf_ct_ras: expect Q.931 ");
1629                 nf_ct_dump_tuple(&exp->tuple);
1630         } else
1631                 ret = -1;
1632
1633         nf_ct_expect_put(exp);
1634
1635         /* Ignore rasAddress */
1636
1637         return ret;
1638 }
1639
1640 static int process_irr(struct sk_buff *skb, struct nf_conn *ct,
1641                        enum ip_conntrack_info ctinfo,
1642                        unsigned int protoff,
1643                        unsigned char **data, InfoRequestResponse *irr)
1644 {
1645         int ret;
1646         typeof(set_ras_addr_hook) set_ras_addr;
1647         typeof(set_sig_addr_hook) set_sig_addr;
1648
1649         pr_debug("nf_ct_ras: IRR\n");
1650
1651         set_ras_addr = rcu_dereference(set_ras_addr_hook);
1652         if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1653             ct->status & IPS_NAT_MASK) {
1654                 ret = set_ras_addr(skb, ct, ctinfo, protoff, data,
1655                                    &irr->rasAddress, 1);
1656                 if (ret < 0)
1657                         return -1;
1658         }
1659
1660         set_sig_addr = rcu_dereference(set_sig_addr_hook);
1661         if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1662             ct->status & IPS_NAT_MASK) {
1663                 ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1664                                         irr->callSignalAddress.item,
1665                                         irr->callSignalAddress.count);
1666                 if (ret < 0)
1667                         return -1;
1668         }
1669
1670         return 0;
1671 }
1672
1673 static int process_ras(struct sk_buff *skb, struct nf_conn *ct,
1674                        enum ip_conntrack_info ctinfo,
1675                        unsigned int protoff,
1676                        unsigned char **data, RasMessage *ras)
1677 {
1678         switch (ras->choice) {
1679         case eRasMessage_gatekeeperRequest:
1680                 return process_grq(skb, ct, ctinfo, protoff, data,
1681                                    &ras->gatekeeperRequest);
1682         case eRasMessage_gatekeeperConfirm:
1683                 return process_gcf(skb, ct, ctinfo, protoff, data,
1684                                    &ras->gatekeeperConfirm);
1685         case eRasMessage_registrationRequest:
1686                 return process_rrq(skb, ct, ctinfo, protoff, data,
1687                                    &ras->registrationRequest);
1688         case eRasMessage_registrationConfirm:
1689                 return process_rcf(skb, ct, ctinfo, protoff, data,
1690                                    &ras->registrationConfirm);
1691         case eRasMessage_unregistrationRequest:
1692                 return process_urq(skb, ct, ctinfo, protoff, data,
1693                                    &ras->unregistrationRequest);
1694         case eRasMessage_admissionRequest:
1695                 return process_arq(skb, ct, ctinfo, protoff, data,
1696                                    &ras->admissionRequest);
1697         case eRasMessage_admissionConfirm:
1698                 return process_acf(skb, ct, ctinfo, protoff, data,
1699                                    &ras->admissionConfirm);
1700         case eRasMessage_locationRequest:
1701                 return process_lrq(skb, ct, ctinfo, protoff, data,
1702                                    &ras->locationRequest);
1703         case eRasMessage_locationConfirm:
1704                 return process_lcf(skb, ct, ctinfo, protoff, data,
1705                                    &ras->locationConfirm);
1706         case eRasMessage_infoRequestResponse:
1707                 return process_irr(skb, ct, ctinfo, protoff, data,
1708                                    &ras->infoRequestResponse);
1709         default:
1710                 pr_debug("nf_ct_ras: RAS message %d\n", ras->choice);
1711                 break;
1712         }
1713
1714         return 0;
1715 }
1716
1717 static int ras_help(struct sk_buff *skb, unsigned int protoff,
1718                     struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1719 {
1720         static RasMessage ras;
1721         unsigned char *data;
1722         int datalen = 0;
1723         int ret;
1724
1725         pr_debug("nf_ct_ras: skblen = %u\n", skb->len);
1726
1727         spin_lock_bh(&nf_h323_lock);
1728
1729         /* Get UDP data */
1730         data = get_udp_data(skb, protoff, &datalen);
1731         if (data == NULL)
1732                 goto accept;
1733         pr_debug("nf_ct_ras: RAS message len=%d ", datalen);
1734         nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1735
1736         /* Decode RAS message */
1737         ret = DecodeRasMessage(data, datalen, &ras);
1738         if (ret < 0) {
1739                 pr_debug("nf_ct_ras: decoding error: %s\n",
1740                          ret == H323_ERROR_BOUND ?
1741                          "out of bound" : "out of range");
1742                 goto accept;
1743         }
1744
1745         /* Process RAS message */
1746         if (process_ras(skb, ct, ctinfo, protoff, &data, &ras) < 0)
1747                 goto drop;
1748
1749       accept:
1750         spin_unlock_bh(&nf_h323_lock);
1751         return NF_ACCEPT;
1752
1753       drop:
1754         spin_unlock_bh(&nf_h323_lock);
1755         nf_ct_helper_log(skb, ct, "cannot process RAS message");
1756         return NF_DROP;
1757 }
1758
1759 static const struct nf_conntrack_expect_policy ras_exp_policy = {
1760         .max_expected           = 32,
1761         .timeout                = 240,
1762 };
1763
1764 static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = {
1765         {
1766                 .name                   = "RAS",
1767                 .me                     = THIS_MODULE,
1768                 .tuple.src.l3num        = AF_INET,
1769                 .tuple.src.u.udp.port   = cpu_to_be16(RAS_PORT),
1770                 .tuple.dst.protonum     = IPPROTO_UDP,
1771                 .help                   = ras_help,
1772                 .expect_policy          = &ras_exp_policy,
1773         },
1774         {
1775                 .name                   = "RAS",
1776                 .me                     = THIS_MODULE,
1777                 .tuple.src.l3num        = AF_INET6,
1778                 .tuple.src.u.udp.port   = cpu_to_be16(RAS_PORT),
1779                 .tuple.dst.protonum     = IPPROTO_UDP,
1780                 .help                   = ras_help,
1781                 .expect_policy          = &ras_exp_policy,
1782         },
1783 };
1784
1785 static int __init h323_helper_init(void)
1786 {
1787         int ret;
1788
1789         ret = nf_conntrack_helper_register(&nf_conntrack_helper_h245);
1790         if (ret < 0)
1791                 return ret;
1792         ret = nf_conntrack_helpers_register(nf_conntrack_helper_q931,
1793                                         ARRAY_SIZE(nf_conntrack_helper_q931));
1794         if (ret < 0)
1795                 goto err1;
1796         ret = nf_conntrack_helpers_register(nf_conntrack_helper_ras,
1797                                         ARRAY_SIZE(nf_conntrack_helper_ras));
1798         if (ret < 0)
1799                 goto err2;
1800
1801         return 0;
1802 err2:
1803         nf_conntrack_helpers_unregister(nf_conntrack_helper_q931,
1804                                         ARRAY_SIZE(nf_conntrack_helper_q931));
1805 err1:
1806         nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1807         return ret;
1808 }
1809
1810 static void __exit h323_helper_exit(void)
1811 {
1812         nf_conntrack_helpers_unregister(nf_conntrack_helper_ras,
1813                                         ARRAY_SIZE(nf_conntrack_helper_ras));
1814         nf_conntrack_helpers_unregister(nf_conntrack_helper_q931,
1815                                         ARRAY_SIZE(nf_conntrack_helper_q931));
1816         nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1817 }
1818
1819 static void __exit nf_conntrack_h323_fini(void)
1820 {
1821         h323_helper_exit();
1822         kfree(h323_buffer);
1823         pr_debug("nf_ct_h323: fini\n");
1824 }
1825
1826 static int __init nf_conntrack_h323_init(void)
1827 {
1828         int ret;
1829
1830         NF_CT_HELPER_BUILD_BUG_ON(sizeof(struct nf_ct_h323_master));
1831
1832         h323_buffer = kmalloc(H323_MAX_SIZE + 1, GFP_KERNEL);
1833         if (!h323_buffer)
1834                 return -ENOMEM;
1835         ret = h323_helper_init();
1836         if (ret < 0)
1837                 goto err1;
1838         pr_debug("nf_ct_h323: init success\n");
1839         return 0;
1840 err1:
1841         kfree(h323_buffer);
1842         return ret;
1843 }
1844
1845 module_init(nf_conntrack_h323_init);
1846 module_exit(nf_conntrack_h323_fini);
1847
1848 EXPORT_SYMBOL_GPL(get_h225_addr);
1849 EXPORT_SYMBOL_GPL(set_h245_addr_hook);
1850 EXPORT_SYMBOL_GPL(set_h225_addr_hook);
1851 EXPORT_SYMBOL_GPL(set_sig_addr_hook);
1852 EXPORT_SYMBOL_GPL(set_ras_addr_hook);
1853 EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook);
1854 EXPORT_SYMBOL_GPL(nat_t120_hook);
1855 EXPORT_SYMBOL_GPL(nat_h245_hook);
1856 EXPORT_SYMBOL_GPL(nat_callforwarding_hook);
1857 EXPORT_SYMBOL_GPL(nat_q931_hook);
1858
1859 MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>");
1860 MODULE_DESCRIPTION("H.323 connection tracking helper");
1861 MODULE_LICENSE("GPL");
1862 MODULE_ALIAS("ip_conntrack_h323");
1863 MODULE_ALIAS_NFCT_HELPER("RAS");
1864 MODULE_ALIAS_NFCT_HELPER("Q.931");
1865 MODULE_ALIAS_NFCT_HELPER("H.245");