linux/net/netfilter/nf_conntrack_h323_main.c
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   1/*
   2 * H.323 connection tracking helper
   3 *
   4 * Copyright (c) 2006 Jing Min Zhao <zhaojingmin@users.sourceforge.net>
   5 *
   6 * This source code is licensed under General Public License version 2.
   7 *
   8 * Based on the 'brute force' H.323 connection tracking module by
   9 * Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
  10 *
  11 * For more information, please see http://nath323.sourceforge.net/
  12 */
  13
  14#include <linux/module.h>
  15#include <linux/moduleparam.h>
  16#include <linux/ctype.h>
  17#include <linux/inet.h>
  18#include <linux/in.h>
  19#include <linux/ip.h>
  20#include <linux/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
  27#include <net/netfilter/nf_conntrack.h>
  28#include <net/netfilter/nf_conntrack_core.h>
  29#include <net/netfilter/nf_conntrack_tuple.h>
  30#include <net/netfilter/nf_conntrack_expect.h>
  31#include <net/netfilter/nf_conntrack_ecache.h>
  32#include <net/netfilter/nf_conntrack_helper.h>
  33#include <net/netfilter/nf_conntrack_zones.h>
  34#include <linux/netfilter/nf_conntrack_h323.h>
  35
  36/* Parameters */
  37static unsigned int default_rrq_ttl __read_mostly = 300;
  38module_param(default_rrq_ttl, uint, 0600);
  39MODULE_PARM_DESC(default_rrq_ttl, "use this TTL if it's missing in RRQ");
  40
  41static int gkrouted_only __read_mostly = 1;
  42module_param(gkrouted_only, int, 0600);
  43MODULE_PARM_DESC(gkrouted_only, "only accept calls from gatekeeper");
  44
  45static bool callforward_filter __read_mostly = true;
  46module_param(callforward_filter, bool, 0600);
  47MODULE_PARM_DESC(callforward_filter, "only create call forwarding expectations "
  48                                     "if both endpoints are on different sides "
  49                                     "(determined by routing information)");
  50
  51/* Hooks for NAT */
  52int (*set_h245_addr_hook) (struct sk_buff *skb,
  53                           unsigned char **data, int dataoff,
  54                           H245_TransportAddress *taddr,
  55                           union nf_inet_addr *addr, __be16 port)
  56                           __read_mostly;
  57int (*set_h225_addr_hook) (struct sk_buff *skb,
  58                           unsigned char **data, int dataoff,
  59                           TransportAddress *taddr,
  60                           union nf_inet_addr *addr, __be16 port)
  61                           __read_mostly;
  62int (*set_sig_addr_hook) (struct sk_buff *skb,
  63                          struct nf_conn *ct,
  64                          enum ip_conntrack_info ctinfo,
  65                          unsigned char **data,
  66                          TransportAddress *taddr, int count) __read_mostly;
  67int (*set_ras_addr_hook) (struct sk_buff *skb,
  68                          struct nf_conn *ct,
  69                          enum ip_conntrack_info ctinfo,
  70                          unsigned char **data,
  71                          TransportAddress *taddr, int count) __read_mostly;
  72int (*nat_rtp_rtcp_hook) (struct sk_buff *skb,
  73                          struct nf_conn *ct,
  74                          enum ip_conntrack_info ctinfo,
  75                          unsigned char **data, int dataoff,
  76                          H245_TransportAddress *taddr,
  77                          __be16 port, __be16 rtp_port,
  78                          struct nf_conntrack_expect *rtp_exp,
  79                          struct nf_conntrack_expect *rtcp_exp) __read_mostly;
  80int (*nat_t120_hook) (struct sk_buff *skb,
  81                      struct nf_conn *ct,
  82                      enum ip_conntrack_info ctinfo,
  83                      unsigned char **data, int dataoff,
  84                      H245_TransportAddress *taddr, __be16 port,
  85                      struct nf_conntrack_expect *exp) __read_mostly;
  86int (*nat_h245_hook) (struct sk_buff *skb,
  87                      struct nf_conn *ct,
  88                      enum ip_conntrack_info ctinfo,
  89                      unsigned char **data, int dataoff,
  90                      TransportAddress *taddr, __be16 port,
  91                      struct nf_conntrack_expect *exp) __read_mostly;
  92int (*nat_callforwarding_hook) (struct sk_buff *skb,
  93                                struct nf_conn *ct,
  94                                enum ip_conntrack_info ctinfo,
  95                                unsigned char **data, int dataoff,
  96                                TransportAddress *taddr, __be16 port,
  97                                struct nf_conntrack_expect *exp) __read_mostly;
  98int (*nat_q931_hook) (struct sk_buff *skb,
  99                      struct nf_conn *ct,
 100                      enum ip_conntrack_info ctinfo,
 101                      unsigned char **data, TransportAddress *taddr, int idx,
 102                      __be16 port, struct nf_conntrack_expect *exp)
 103                      __read_mostly;
 104
 105static DEFINE_SPINLOCK(nf_h323_lock);
 106static char *h323_buffer;
 107
 108static struct nf_conntrack_helper nf_conntrack_helper_h245;
 109static struct nf_conntrack_helper nf_conntrack_helper_q931[];
 110static struct nf_conntrack_helper nf_conntrack_helper_ras[];
 111
 112/****************************************************************************/
 113static int get_tpkt_data(struct sk_buff *skb, unsigned int protoff,
 114                         struct nf_conn *ct, enum ip_conntrack_info ctinfo,
 115                         unsigned char **data, int *datalen, int *dataoff)
 116{
 117        struct nf_ct_h323_master *info = nfct_help_data(ct);
 118        int dir = CTINFO2DIR(ctinfo);
 119        const struct tcphdr *th;
 120        struct tcphdr _tcph;
 121        int tcpdatalen;
 122        int tcpdataoff;
 123        unsigned char *tpkt;
 124        int tpktlen;
 125        int tpktoff;
 126
 127        /* Get TCP header */
 128        th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph);
 129        if (th == NULL)
 130                return 0;
 131
 132        /* Get TCP data offset */
 133        tcpdataoff = protoff + th->doff * 4;
 134
 135        /* Get TCP data length */
 136        tcpdatalen = skb->len - tcpdataoff;
 137        if (tcpdatalen <= 0)    /* No TCP data */
 138                goto clear_out;
 139
 140        if (*data == NULL) {    /* first TPKT */
 141                /* Get first TPKT pointer */
 142                tpkt = skb_header_pointer(skb, tcpdataoff, tcpdatalen,
 143                                          h323_buffer);
 144                BUG_ON(tpkt == NULL);
 145
 146                /* Validate TPKT identifier */
 147                if (tcpdatalen < 4 || tpkt[0] != 0x03 || tpkt[1] != 0) {
 148                        /* Netmeeting sends TPKT header and data separately */
 149                        if (info->tpkt_len[dir] > 0) {
 150                                pr_debug("nf_ct_h323: previous packet "
 151                                         "indicated separate TPKT data of %hu "
 152                                         "bytes\n", info->tpkt_len[dir]);
 153                                if (info->tpkt_len[dir] <= tcpdatalen) {
 154                                        /* Yes, there was a TPKT header
 155                                         * received */
 156                                        *data = tpkt;
 157                                        *datalen = info->tpkt_len[dir];
 158                                        *dataoff = 0;
 159                                        goto out;
 160                                }
 161
 162                                /* Fragmented TPKT */
 163                                pr_debug("nf_ct_h323: fragmented TPKT\n");
 164                                goto clear_out;
 165                        }
 166
 167                        /* It is not even a TPKT */
 168                        return 0;
 169                }
 170                tpktoff = 0;
 171        } else {                /* Next TPKT */
 172                tpktoff = *dataoff + *datalen;
 173                tcpdatalen -= tpktoff;
 174                if (tcpdatalen <= 4)    /* No more TPKT */
 175                        goto clear_out;
 176                tpkt = *data + *datalen;
 177
 178                /* Validate TPKT identifier */
 179                if (tpkt[0] != 0x03 || tpkt[1] != 0)
 180                        goto clear_out;
 181        }
 182
 183        /* Validate TPKT length */
 184        tpktlen = tpkt[2] * 256 + tpkt[3];
 185        if (tpktlen < 4)
 186                goto clear_out;
 187        if (tpktlen > tcpdatalen) {
 188                if (tcpdatalen == 4) {  /* Separate TPKT header */
 189                        /* Netmeeting sends TPKT header and data separately */
 190                        pr_debug("nf_ct_h323: separate TPKT header indicates "
 191                                 "there will be TPKT data of %hu bytes\n",
 192                                 tpktlen - 4);
 193                        info->tpkt_len[dir] = tpktlen - 4;
 194                        return 0;
 195                }
 196
 197                pr_debug("nf_ct_h323: incomplete TPKT (fragmented?)\n");
 198                goto clear_out;
 199        }
 200
 201        /* This is the encapsulated data */
 202        *data = tpkt + 4;
 203        *datalen = tpktlen - 4;
 204        *dataoff = tpktoff + 4;
 205
 206      out:
 207        /* Clear TPKT length */
 208        info->tpkt_len[dir] = 0;
 209        return 1;
 210
 211      clear_out:
 212        info->tpkt_len[dir] = 0;
 213        return 0;
 214}
 215
 216/****************************************************************************/
 217static int get_h245_addr(struct nf_conn *ct, const unsigned char *data,
 218                         H245_TransportAddress *taddr,
 219                         union nf_inet_addr *addr, __be16 *port)
 220{
 221        const unsigned char *p;
 222        int len;
 223
 224        if (taddr->choice != eH245_TransportAddress_unicastAddress)
 225                return 0;
 226
 227        switch (taddr->unicastAddress.choice) {
 228        case eUnicastAddress_iPAddress:
 229                if (nf_ct_l3num(ct) != AF_INET)
 230                        return 0;
 231                p = data + taddr->unicastAddress.iPAddress.network;
 232                len = 4;
 233                break;
 234        case eUnicastAddress_iP6Address:
 235                if (nf_ct_l3num(ct) != AF_INET6)
 236                        return 0;
 237                p = data + taddr->unicastAddress.iP6Address.network;
 238                len = 16;
 239                break;
 240        default:
 241                return 0;
 242        }
 243
 244        memcpy(addr, p, len);
 245        memset((void *)addr + len, 0, sizeof(*addr) - len);
 246        memcpy(port, p + len, sizeof(__be16));
 247
 248        return 1;
 249}
 250
 251/****************************************************************************/
 252static int expect_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct,
 253                           enum ip_conntrack_info ctinfo,
 254                           unsigned char **data, int dataoff,
 255                           H245_TransportAddress *taddr)
 256{
 257        int dir = CTINFO2DIR(ctinfo);
 258        int ret = 0;
 259        __be16 port;
 260        __be16 rtp_port, rtcp_port;
 261        union nf_inet_addr addr;
 262        struct nf_conntrack_expect *rtp_exp;
 263        struct nf_conntrack_expect *rtcp_exp;
 264        typeof(nat_rtp_rtcp_hook) nat_rtp_rtcp;
 265
 266        /* Read RTP or RTCP address */
 267        if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
 268            memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 269            port == 0)
 270                return 0;
 271
 272        /* RTP port is even */
 273        rtp_port = port & ~htons(1);
 274        rtcp_port = port | htons(1);
 275
 276        /* Create expect for RTP */
 277        if ((rtp_exp = nf_ct_expect_alloc(ct)) == NULL)
 278                return -1;
 279        nf_ct_expect_init(rtp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 280                          &ct->tuplehash[!dir].tuple.src.u3,
 281                          &ct->tuplehash[!dir].tuple.dst.u3,
 282                          IPPROTO_UDP, NULL, &rtp_port);
 283
 284        /* Create expect for RTCP */
 285        if ((rtcp_exp = nf_ct_expect_alloc(ct)) == NULL) {
 286                nf_ct_expect_put(rtp_exp);
 287                return -1;
 288        }
 289        nf_ct_expect_init(rtcp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 290                          &ct->tuplehash[!dir].tuple.src.u3,
 291                          &ct->tuplehash[!dir].tuple.dst.u3,
 292                          IPPROTO_UDP, NULL, &rtcp_port);
 293
 294        if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 295                   &ct->tuplehash[!dir].tuple.dst.u3,
 296                   sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 297                   (nat_rtp_rtcp = rcu_dereference(nat_rtp_rtcp_hook)) &&
 298                   ct->status & IPS_NAT_MASK) {
 299                /* NAT needed */
 300                ret = nat_rtp_rtcp(skb, ct, ctinfo, data, dataoff,
 301                                   taddr, port, rtp_port, rtp_exp, rtcp_exp);
 302        } else {                /* Conntrack only */
 303                if (nf_ct_expect_related(rtp_exp) == 0) {
 304                        if (nf_ct_expect_related(rtcp_exp) == 0) {
 305                                pr_debug("nf_ct_h323: expect RTP ");
 306                                nf_ct_dump_tuple(&rtp_exp->tuple);
 307                                pr_debug("nf_ct_h323: expect RTCP ");
 308                                nf_ct_dump_tuple(&rtcp_exp->tuple);
 309                        } else {
 310                                nf_ct_unexpect_related(rtp_exp);
 311                                ret = -1;
 312                        }
 313                } else
 314                        ret = -1;
 315        }
 316
 317        nf_ct_expect_put(rtp_exp);
 318        nf_ct_expect_put(rtcp_exp);
 319
 320        return ret;
 321}
 322
 323/****************************************************************************/
 324static int expect_t120(struct sk_buff *skb,
 325                       struct nf_conn *ct,
 326                       enum ip_conntrack_info ctinfo,
 327                       unsigned char **data, int dataoff,
 328                       H245_TransportAddress *taddr)
 329{
 330        int dir = CTINFO2DIR(ctinfo);
 331        int ret = 0;
 332        __be16 port;
 333        union nf_inet_addr addr;
 334        struct nf_conntrack_expect *exp;
 335        typeof(nat_t120_hook) nat_t120;
 336
 337        /* Read T.120 address */
 338        if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
 339            memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 340            port == 0)
 341                return 0;
 342
 343        /* Create expect for T.120 connections */
 344        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 345                return -1;
 346        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 347                          &ct->tuplehash[!dir].tuple.src.u3,
 348                          &ct->tuplehash[!dir].tuple.dst.u3,
 349                          IPPROTO_TCP, NULL, &port);
 350        exp->flags = NF_CT_EXPECT_PERMANENT;    /* Accept multiple channels */
 351
 352        if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 353                   &ct->tuplehash[!dir].tuple.dst.u3,
 354                   sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 355            (nat_t120 = rcu_dereference(nat_t120_hook)) &&
 356            ct->status & IPS_NAT_MASK) {
 357                /* NAT needed */
 358                ret = nat_t120(skb, ct, ctinfo, data, dataoff, taddr,
 359                               port, exp);
 360        } else {                /* Conntrack only */
 361                if (nf_ct_expect_related(exp) == 0) {
 362                        pr_debug("nf_ct_h323: expect T.120 ");
 363                        nf_ct_dump_tuple(&exp->tuple);
 364                } else
 365                        ret = -1;
 366        }
 367
 368        nf_ct_expect_put(exp);
 369
 370        return ret;
 371}
 372
 373/****************************************************************************/
 374static int process_h245_channel(struct sk_buff *skb,
 375                                struct nf_conn *ct,
 376                                enum ip_conntrack_info ctinfo,
 377                                unsigned char **data, int dataoff,
 378                                H2250LogicalChannelParameters *channel)
 379{
 380        int ret;
 381
 382        if (channel->options & eH2250LogicalChannelParameters_mediaChannel) {
 383                /* RTP */
 384                ret = expect_rtp_rtcp(skb, ct, ctinfo, data, dataoff,
 385                                      &channel->mediaChannel);
 386                if (ret < 0)
 387                        return -1;
 388        }
 389
 390        if (channel->
 391            options & eH2250LogicalChannelParameters_mediaControlChannel) {
 392                /* RTCP */
 393                ret = expect_rtp_rtcp(skb, ct, ctinfo, data, dataoff,
 394                                      &channel->mediaControlChannel);
 395                if (ret < 0)
 396                        return -1;
 397        }
 398
 399        return 0;
 400}
 401
 402/****************************************************************************/
 403static int process_olc(struct sk_buff *skb, struct nf_conn *ct,
 404                       enum ip_conntrack_info ctinfo,
 405                       unsigned char **data, int dataoff,
 406                       OpenLogicalChannel *olc)
 407{
 408        int ret;
 409
 410        pr_debug("nf_ct_h323: OpenLogicalChannel\n");
 411
 412        if (olc->forwardLogicalChannelParameters.multiplexParameters.choice ==
 413            eOpenLogicalChannel_forwardLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters)
 414        {
 415                ret = process_h245_channel(skb, ct, ctinfo, data, dataoff,
 416                                           &olc->
 417                                           forwardLogicalChannelParameters.
 418                                           multiplexParameters.
 419                                           h2250LogicalChannelParameters);
 420                if (ret < 0)
 421                        return -1;
 422        }
 423
 424        if ((olc->options &
 425             eOpenLogicalChannel_reverseLogicalChannelParameters) &&
 426            (olc->reverseLogicalChannelParameters.options &
 427             eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters)
 428            && (olc->reverseLogicalChannelParameters.multiplexParameters.
 429                choice ==
 430                eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
 431        {
 432                ret =
 433                    process_h245_channel(skb, ct, ctinfo, data, dataoff,
 434                                         &olc->
 435                                         reverseLogicalChannelParameters.
 436                                         multiplexParameters.
 437                                         h2250LogicalChannelParameters);
 438                if (ret < 0)
 439                        return -1;
 440        }
 441
 442        if ((olc->options & eOpenLogicalChannel_separateStack) &&
 443            olc->forwardLogicalChannelParameters.dataType.choice ==
 444            eDataType_data &&
 445            olc->forwardLogicalChannelParameters.dataType.data.application.
 446            choice == eDataApplicationCapability_application_t120 &&
 447            olc->forwardLogicalChannelParameters.dataType.data.application.
 448            t120.choice == eDataProtocolCapability_separateLANStack &&
 449            olc->separateStack.networkAddress.choice ==
 450            eNetworkAccessParameters_networkAddress_localAreaAddress) {
 451                ret = expect_t120(skb, ct, ctinfo, data, dataoff,
 452                                  &olc->separateStack.networkAddress.
 453                                  localAreaAddress);
 454                if (ret < 0)
 455                        return -1;
 456        }
 457
 458        return 0;
 459}
 460
 461/****************************************************************************/
 462static int process_olca(struct sk_buff *skb, struct nf_conn *ct,
 463                        enum ip_conntrack_info ctinfo,
 464                        unsigned char **data, int dataoff,
 465                        OpenLogicalChannelAck *olca)
 466{
 467        H2250LogicalChannelAckParameters *ack;
 468        int ret;
 469
 470        pr_debug("nf_ct_h323: OpenLogicalChannelAck\n");
 471
 472        if ((olca->options &
 473             eOpenLogicalChannelAck_reverseLogicalChannelParameters) &&
 474            (olca->reverseLogicalChannelParameters.options &
 475             eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters)
 476            && (olca->reverseLogicalChannelParameters.multiplexParameters.
 477                choice ==
 478                eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
 479        {
 480                ret = process_h245_channel(skb, ct, ctinfo, data, dataoff,
 481                                           &olca->
 482                                           reverseLogicalChannelParameters.
 483                                           multiplexParameters.
 484                                           h2250LogicalChannelParameters);
 485                if (ret < 0)
 486                        return -1;
 487        }
 488
 489        if ((olca->options &
 490             eOpenLogicalChannelAck_forwardMultiplexAckParameters) &&
 491            (olca->forwardMultiplexAckParameters.choice ==
 492             eOpenLogicalChannelAck_forwardMultiplexAckParameters_h2250LogicalChannelAckParameters))
 493        {
 494                ack = &olca->forwardMultiplexAckParameters.
 495                    h2250LogicalChannelAckParameters;
 496                if (ack->options &
 497                    eH2250LogicalChannelAckParameters_mediaChannel) {
 498                        /* RTP */
 499                        ret = expect_rtp_rtcp(skb, ct, ctinfo, data, dataoff,
 500                                              &ack->mediaChannel);
 501                        if (ret < 0)
 502                                return -1;
 503                }
 504
 505                if (ack->options &
 506                    eH2250LogicalChannelAckParameters_mediaControlChannel) {
 507                        /* RTCP */
 508                        ret = expect_rtp_rtcp(skb, ct, ctinfo, data, dataoff,
 509                                              &ack->mediaControlChannel);
 510                        if (ret < 0)
 511                                return -1;
 512                }
 513        }
 514
 515        if ((olca->options & eOpenLogicalChannelAck_separateStack) &&
 516                olca->separateStack.networkAddress.choice ==
 517                eNetworkAccessParameters_networkAddress_localAreaAddress) {
 518                ret = expect_t120(skb, ct, ctinfo, data, dataoff,
 519                                  &olca->separateStack.networkAddress.
 520                                  localAreaAddress);
 521                if (ret < 0)
 522                        return -1;
 523        }
 524
 525        return 0;
 526}
 527
 528/****************************************************************************/
 529static int process_h245(struct sk_buff *skb, struct nf_conn *ct,
 530                        enum ip_conntrack_info ctinfo,
 531                        unsigned char **data, int dataoff,
 532                        MultimediaSystemControlMessage *mscm)
 533{
 534        switch (mscm->choice) {
 535        case eMultimediaSystemControlMessage_request:
 536                if (mscm->request.choice ==
 537                    eRequestMessage_openLogicalChannel) {
 538                        return process_olc(skb, ct, ctinfo, data, dataoff,
 539                                           &mscm->request.openLogicalChannel);
 540                }
 541                pr_debug("nf_ct_h323: H.245 Request %d\n",
 542                         mscm->request.choice);
 543                break;
 544        case eMultimediaSystemControlMessage_response:
 545                if (mscm->response.choice ==
 546                    eResponseMessage_openLogicalChannelAck) {
 547                        return process_olca(skb, ct, ctinfo, data, dataoff,
 548                                            &mscm->response.
 549                                            openLogicalChannelAck);
 550                }
 551                pr_debug("nf_ct_h323: H.245 Response %d\n",
 552                         mscm->response.choice);
 553                break;
 554        default:
 555                pr_debug("nf_ct_h323: H.245 signal %d\n", mscm->choice);
 556                break;
 557        }
 558
 559        return 0;
 560}
 561
 562/****************************************************************************/
 563static int h245_help(struct sk_buff *skb, unsigned int protoff,
 564                     struct nf_conn *ct, enum ip_conntrack_info ctinfo)
 565{
 566        static MultimediaSystemControlMessage mscm;
 567        unsigned char *data = NULL;
 568        int datalen;
 569        int dataoff;
 570        int ret;
 571
 572        /* Until there's been traffic both ways, don't look in packets. */
 573        if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
 574                return NF_ACCEPT;
 575
 576        pr_debug("nf_ct_h245: skblen = %u\n", skb->len);
 577
 578        spin_lock_bh(&nf_h323_lock);
 579
 580        /* Process each TPKT */
 581        while (get_tpkt_data(skb, protoff, ct, ctinfo,
 582                             &data, &datalen, &dataoff)) {
 583                pr_debug("nf_ct_h245: TPKT len=%d ", datalen);
 584                nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
 585
 586                /* Decode H.245 signal */
 587                ret = DecodeMultimediaSystemControlMessage(data, datalen,
 588                                                           &mscm);
 589                if (ret < 0) {
 590                        pr_debug("nf_ct_h245: decoding error: %s\n",
 591                                 ret == H323_ERROR_BOUND ?
 592                                 "out of bound" : "out of range");
 593                        /* We don't drop when decoding error */
 594                        break;
 595                }
 596
 597                /* Process H.245 signal */
 598                if (process_h245(skb, ct, ctinfo, &data, dataoff, &mscm) < 0)
 599                        goto drop;
 600        }
 601
 602        spin_unlock_bh(&nf_h323_lock);
 603        return NF_ACCEPT;
 604
 605      drop:
 606        spin_unlock_bh(&nf_h323_lock);
 607        net_info_ratelimited("nf_ct_h245: packet dropped\n");
 608        return NF_DROP;
 609}
 610
 611/****************************************************************************/
 612static const struct nf_conntrack_expect_policy h245_exp_policy = {
 613        .max_expected   = H323_RTP_CHANNEL_MAX * 4 + 2 /* T.120 */,
 614        .timeout        = 240,
 615};
 616
 617static struct nf_conntrack_helper nf_conntrack_helper_h245 __read_mostly = {
 618        .name                   = "H.245",
 619        .me                     = THIS_MODULE,
 620        .data_len               = sizeof(struct nf_ct_h323_master),
 621        .tuple.src.l3num        = AF_UNSPEC,
 622        .tuple.dst.protonum     = IPPROTO_UDP,
 623        .help                   = h245_help,
 624        .expect_policy          = &h245_exp_policy,
 625};
 626
 627/****************************************************************************/
 628int get_h225_addr(struct nf_conn *ct, unsigned char *data,
 629                  TransportAddress *taddr,
 630                  union nf_inet_addr *addr, __be16 *port)
 631{
 632        const unsigned char *p;
 633        int len;
 634
 635        switch (taddr->choice) {
 636        case eTransportAddress_ipAddress:
 637                if (nf_ct_l3num(ct) != AF_INET)
 638                        return 0;
 639                p = data + taddr->ipAddress.ip;
 640                len = 4;
 641                break;
 642        case eTransportAddress_ip6Address:
 643                if (nf_ct_l3num(ct) != AF_INET6)
 644                        return 0;
 645                p = data + taddr->ip6Address.ip;
 646                len = 16;
 647                break;
 648        default:
 649                return 0;
 650        }
 651
 652        memcpy(addr, p, len);
 653        memset((void *)addr + len, 0, sizeof(*addr) - len);
 654        memcpy(port, p + len, sizeof(__be16));
 655
 656        return 1;
 657}
 658
 659/****************************************************************************/
 660static int expect_h245(struct sk_buff *skb, struct nf_conn *ct,
 661                       enum ip_conntrack_info ctinfo,
 662                       unsigned char **data, int dataoff,
 663                       TransportAddress *taddr)
 664{
 665        int dir = CTINFO2DIR(ctinfo);
 666        int ret = 0;
 667        __be16 port;
 668        union nf_inet_addr addr;
 669        struct nf_conntrack_expect *exp;
 670        typeof(nat_h245_hook) nat_h245;
 671
 672        /* Read h245Address */
 673        if (!get_h225_addr(ct, *data, taddr, &addr, &port) ||
 674            memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 675            port == 0)
 676                return 0;
 677
 678        /* Create expect for h245 connection */
 679        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 680                return -1;
 681        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 682                          &ct->tuplehash[!dir].tuple.src.u3,
 683                          &ct->tuplehash[!dir].tuple.dst.u3,
 684                          IPPROTO_TCP, NULL, &port);
 685        exp->helper = &nf_conntrack_helper_h245;
 686
 687        if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 688                   &ct->tuplehash[!dir].tuple.dst.u3,
 689                   sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 690            (nat_h245 = rcu_dereference(nat_h245_hook)) &&
 691            ct->status & IPS_NAT_MASK) {
 692                /* NAT needed */
 693                ret = nat_h245(skb, ct, ctinfo, data, dataoff, taddr,
 694                               port, exp);
 695        } else {                /* Conntrack only */
 696                if (nf_ct_expect_related(exp) == 0) {
 697                        pr_debug("nf_ct_q931: expect H.245 ");
 698                        nf_ct_dump_tuple(&exp->tuple);
 699                } else
 700                        ret = -1;
 701        }
 702
 703        nf_ct_expect_put(exp);
 704
 705        return ret;
 706}
 707
 708/* If the calling party is on the same side of the forward-to party,
 709 * we don't need to track the second call */
 710static int callforward_do_filter(const union nf_inet_addr *src,
 711                                 const union nf_inet_addr *dst,
 712                                 u_int8_t family)
 713{
 714        const struct nf_afinfo *afinfo;
 715        int ret = 0;
 716
 717        /* rcu_read_lock()ed by nf_hook_slow() */
 718        afinfo = nf_get_afinfo(family);
 719        if (!afinfo)
 720                return 0;
 721
 722        switch (family) {
 723        case AF_INET: {
 724                struct flowi4 fl1, fl2;
 725                struct rtable *rt1, *rt2;
 726
 727                memset(&fl1, 0, sizeof(fl1));
 728                fl1.daddr = src->ip;
 729
 730                memset(&fl2, 0, sizeof(fl2));
 731                fl2.daddr = dst->ip;
 732                if (!afinfo->route(&init_net, (struct dst_entry **)&rt1,
 733                                   flowi4_to_flowi(&fl1), false)) {
 734                        if (!afinfo->route(&init_net, (struct dst_entry **)&rt2,
 735                                           flowi4_to_flowi(&fl2), false)) {
 736                                if (rt1->rt_gateway == rt2->rt_gateway &&
 737                                    rt1->dst.dev  == rt2->dst.dev)
 738                                        ret = 1;
 739                                dst_release(&rt2->dst);
 740                        }
 741                        dst_release(&rt1->dst);
 742                }
 743                break;
 744        }
 745#if IS_ENABLED(CONFIG_NF_CONNTRACK_IPV6)
 746        case AF_INET6: {
 747                struct flowi6 fl1, fl2;
 748                struct rt6_info *rt1, *rt2;
 749
 750                memset(&fl1, 0, sizeof(fl1));
 751                fl1.daddr = src->in6;
 752
 753                memset(&fl2, 0, sizeof(fl2));
 754                fl2.daddr = dst->in6;
 755                if (!afinfo->route(&init_net, (struct dst_entry **)&rt1,
 756                                   flowi6_to_flowi(&fl1), false)) {
 757                        if (!afinfo->route(&init_net, (struct dst_entry **)&rt2,
 758                                           flowi6_to_flowi(&fl2), false)) {
 759                                if (!memcmp(&rt1->rt6i_gateway, &rt2->rt6i_gateway,
 760                                            sizeof(rt1->rt6i_gateway)) &&
 761                                    rt1->dst.dev == rt2->dst.dev)
 762                                        ret = 1;
 763                                dst_release(&rt2->dst);
 764                        }
 765                        dst_release(&rt1->dst);
 766                }
 767                break;
 768        }
 769#endif
 770        }
 771        return ret;
 772
 773}
 774
 775/****************************************************************************/
 776static int expect_callforwarding(struct sk_buff *skb,
 777                                 struct nf_conn *ct,
 778                                 enum ip_conntrack_info ctinfo,
 779                                 unsigned char **data, int dataoff,
 780                                 TransportAddress *taddr)
 781{
 782        int dir = CTINFO2DIR(ctinfo);
 783        int ret = 0;
 784        __be16 port;
 785        union nf_inet_addr addr;
 786        struct nf_conntrack_expect *exp;
 787        typeof(nat_callforwarding_hook) nat_callforwarding;
 788
 789        /* Read alternativeAddress */
 790        if (!get_h225_addr(ct, *data, taddr, &addr, &port) || port == 0)
 791                return 0;
 792
 793        /* If the calling party is on the same side of the forward-to party,
 794         * we don't need to track the second call */
 795        if (callforward_filter &&
 796            callforward_do_filter(&addr, &ct->tuplehash[!dir].tuple.src.u3,
 797                                  nf_ct_l3num(ct))) {
 798                pr_debug("nf_ct_q931: Call Forwarding not tracked\n");
 799                return 0;
 800        }
 801
 802        /* Create expect for the second call leg */
 803        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 804                return -1;
 805        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 806                          &ct->tuplehash[!dir].tuple.src.u3, &addr,
 807                          IPPROTO_TCP, NULL, &port);
 808        exp->helper = nf_conntrack_helper_q931;
 809
 810        if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 811                   &ct->tuplehash[!dir].tuple.dst.u3,
 812                   sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 813            (nat_callforwarding = rcu_dereference(nat_callforwarding_hook)) &&
 814            ct->status & IPS_NAT_MASK) {
 815                /* Need NAT */
 816                ret = nat_callforwarding(skb, ct, ctinfo, data, dataoff,
 817                                         taddr, port, exp);
 818        } else {                /* Conntrack only */
 819                if (nf_ct_expect_related(exp) == 0) {
 820                        pr_debug("nf_ct_q931: expect Call Forwarding ");
 821                        nf_ct_dump_tuple(&exp->tuple);
 822                } else
 823                        ret = -1;
 824        }
 825
 826        nf_ct_expect_put(exp);
 827
 828        return ret;
 829}
 830
 831/****************************************************************************/
 832static int process_setup(struct sk_buff *skb, struct nf_conn *ct,
 833                         enum ip_conntrack_info ctinfo,
 834                         unsigned char **data, int dataoff,
 835                         Setup_UUIE *setup)
 836{
 837        int dir = CTINFO2DIR(ctinfo);
 838        int ret;
 839        int i;
 840        __be16 port;
 841        union nf_inet_addr addr;
 842        typeof(set_h225_addr_hook) set_h225_addr;
 843
 844        pr_debug("nf_ct_q931: Setup\n");
 845
 846        if (setup->options & eSetup_UUIE_h245Address) {
 847                ret = expect_h245(skb, ct, ctinfo, data, dataoff,
 848                                  &setup->h245Address);
 849                if (ret < 0)
 850                        return -1;
 851        }
 852
 853        set_h225_addr = rcu_dereference(set_h225_addr_hook);
 854        if ((setup->options & eSetup_UUIE_destCallSignalAddress) &&
 855            (set_h225_addr) && ct->status & IPS_NAT_MASK &&
 856            get_h225_addr(ct, *data, &setup->destCallSignalAddress,
 857                          &addr, &port) &&
 858            memcmp(&addr, &ct->tuplehash[!dir].tuple.src.u3, sizeof(addr))) {
 859                pr_debug("nf_ct_q931: set destCallSignalAddress %pI6:%hu->%pI6:%hu\n",
 860                         &addr, ntohs(port), &ct->tuplehash[!dir].tuple.src.u3,
 861                         ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port));
 862                ret = set_h225_addr(skb, data, dataoff,
 863                                    &setup->destCallSignalAddress,
 864                                    &ct->tuplehash[!dir].tuple.src.u3,
 865                                    ct->tuplehash[!dir].tuple.src.u.tcp.port);
 866                if (ret < 0)
 867                        return -1;
 868        }
 869
 870        if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) &&
 871            (set_h225_addr) && ct->status & IPS_NAT_MASK &&
 872            get_h225_addr(ct, *data, &setup->sourceCallSignalAddress,
 873                          &addr, &port) &&
 874            memcmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(addr))) {
 875                pr_debug("nf_ct_q931: set sourceCallSignalAddress %pI6:%hu->%pI6:%hu\n",
 876                         &addr, ntohs(port), &ct->tuplehash[!dir].tuple.dst.u3,
 877                         ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port));
 878                ret = set_h225_addr(skb, data, dataoff,
 879                                    &setup->sourceCallSignalAddress,
 880                                    &ct->tuplehash[!dir].tuple.dst.u3,
 881                                    ct->tuplehash[!dir].tuple.dst.u.tcp.port);
 882                if (ret < 0)
 883                        return -1;
 884        }
 885
 886        if (setup->options & eSetup_UUIE_fastStart) {
 887                for (i = 0; i < setup->fastStart.count; i++) {
 888                        ret = process_olc(skb, ct, ctinfo, data, dataoff,
 889                                          &setup->fastStart.item[i]);
 890                        if (ret < 0)
 891                                return -1;
 892                }
 893        }
 894
 895        return 0;
 896}
 897
 898/****************************************************************************/
 899static int process_callproceeding(struct sk_buff *skb,
 900                                  struct nf_conn *ct,
 901                                  enum ip_conntrack_info ctinfo,
 902                                  unsigned char **data, int dataoff,
 903                                  CallProceeding_UUIE *callproc)
 904{
 905        int ret;
 906        int i;
 907
 908        pr_debug("nf_ct_q931: CallProceeding\n");
 909
 910        if (callproc->options & eCallProceeding_UUIE_h245Address) {
 911                ret = expect_h245(skb, ct, ctinfo, data, dataoff,
 912                                  &callproc->h245Address);
 913                if (ret < 0)
 914                        return -1;
 915        }
 916
 917        if (callproc->options & eCallProceeding_UUIE_fastStart) {
 918                for (i = 0; i < callproc->fastStart.count; i++) {
 919                        ret = process_olc(skb, ct, ctinfo, data, dataoff,
 920                                          &callproc->fastStart.item[i]);
 921                        if (ret < 0)
 922                                return -1;
 923                }
 924        }
 925
 926        return 0;
 927}
 928
 929/****************************************************************************/
 930static int process_connect(struct sk_buff *skb, struct nf_conn *ct,
 931                           enum ip_conntrack_info ctinfo,
 932                           unsigned char **data, int dataoff,
 933                           Connect_UUIE *connect)
 934{
 935        int ret;
 936        int i;
 937
 938        pr_debug("nf_ct_q931: Connect\n");
 939
 940        if (connect->options & eConnect_UUIE_h245Address) {
 941                ret = expect_h245(skb, ct, ctinfo, data, dataoff,
 942                                  &connect->h245Address);
 943                if (ret < 0)
 944                        return -1;
 945        }
 946
 947        if (connect->options & eConnect_UUIE_fastStart) {
 948                for (i = 0; i < connect->fastStart.count; i++) {
 949                        ret = process_olc(skb, ct, ctinfo, data, dataoff,
 950                                          &connect->fastStart.item[i]);
 951                        if (ret < 0)
 952                                return -1;
 953                }
 954        }
 955
 956        return 0;
 957}
 958
 959/****************************************************************************/
 960static int process_alerting(struct sk_buff *skb, struct nf_conn *ct,
 961                            enum ip_conntrack_info ctinfo,
 962                            unsigned char **data, int dataoff,
 963                            Alerting_UUIE *alert)
 964{
 965        int ret;
 966        int i;
 967
 968        pr_debug("nf_ct_q931: Alerting\n");
 969
 970        if (alert->options & eAlerting_UUIE_h245Address) {
 971                ret = expect_h245(skb, ct, ctinfo, data, dataoff,
 972                                  &alert->h245Address);
 973                if (ret < 0)
 974                        return -1;
 975        }
 976
 977        if (alert->options & eAlerting_UUIE_fastStart) {
 978                for (i = 0; i < alert->fastStart.count; i++) {
 979                        ret = process_olc(skb, ct, ctinfo, data, dataoff,
 980                                          &alert->fastStart.item[i]);
 981                        if (ret < 0)
 982                                return -1;
 983                }
 984        }
 985
 986        return 0;
 987}
 988
 989/****************************************************************************/
 990static int process_facility(struct sk_buff *skb, struct nf_conn *ct,
 991                            enum ip_conntrack_info ctinfo,
 992                            unsigned char **data, int dataoff,
 993                            Facility_UUIE *facility)
 994{
 995        int ret;
 996        int i;
 997
 998        pr_debug("nf_ct_q931: Facility\n");
 999
1000        if (facility->reason.choice == eFacilityReason_callForwarded) {
1001                if (facility->options & eFacility_UUIE_alternativeAddress)
1002                        return expect_callforwarding(skb, ct, ctinfo, data,
1003                                                     dataoff,
1004                                                     &facility->
1005                                                     alternativeAddress);
1006                return 0;
1007        }
1008
1009        if (facility->options & eFacility_UUIE_h245Address) {
1010                ret = expect_h245(skb, ct, ctinfo, data, dataoff,
1011                                  &facility->h245Address);
1012                if (ret < 0)
1013                        return -1;
1014        }
1015
1016        if (facility->options & eFacility_UUIE_fastStart) {
1017                for (i = 0; i < facility->fastStart.count; i++) {
1018                        ret = process_olc(skb, ct, ctinfo, data, dataoff,
1019                                          &facility->fastStart.item[i]);
1020                        if (ret < 0)
1021                                return -1;
1022                }
1023        }
1024
1025        return 0;
1026}
1027
1028/****************************************************************************/
1029static int process_progress(struct sk_buff *skb, struct nf_conn *ct,
1030                            enum ip_conntrack_info ctinfo,
1031                            unsigned char **data, int dataoff,
1032                            Progress_UUIE *progress)
1033{
1034        int ret;
1035        int i;
1036
1037        pr_debug("nf_ct_q931: Progress\n");
1038
1039        if (progress->options & eProgress_UUIE_h245Address) {
1040                ret = expect_h245(skb, ct, ctinfo, data, dataoff,
1041                                  &progress->h245Address);
1042                if (ret < 0)
1043                        return -1;
1044        }
1045
1046        if (progress->options & eProgress_UUIE_fastStart) {
1047                for (i = 0; i < progress->fastStart.count; i++) {
1048                        ret = process_olc(skb, ct, ctinfo, data, dataoff,
1049                                          &progress->fastStart.item[i]);
1050                        if (ret < 0)
1051                                return -1;
1052                }
1053        }
1054
1055        return 0;
1056}
1057
1058/****************************************************************************/
1059static int process_q931(struct sk_buff *skb, struct nf_conn *ct,
1060                        enum ip_conntrack_info ctinfo,
1061                        unsigned char **data, int dataoff, Q931 *q931)
1062{
1063        H323_UU_PDU *pdu = &q931->UUIE.h323_uu_pdu;
1064        int i;
1065        int ret = 0;
1066
1067        switch (pdu->h323_message_body.choice) {
1068        case eH323_UU_PDU_h323_message_body_setup:
1069                ret = process_setup(skb, ct, ctinfo, data, dataoff,
1070                                    &pdu->h323_message_body.setup);
1071                break;
1072        case eH323_UU_PDU_h323_message_body_callProceeding:
1073                ret = process_callproceeding(skb, ct, ctinfo, data, dataoff,
1074                                             &pdu->h323_message_body.
1075                                             callProceeding);
1076                break;
1077        case eH323_UU_PDU_h323_message_body_connect:
1078                ret = process_connect(skb, ct, ctinfo, data, dataoff,
1079                                      &pdu->h323_message_body.connect);
1080                break;
1081        case eH323_UU_PDU_h323_message_body_alerting:
1082                ret = process_alerting(skb, ct, ctinfo, data, dataoff,
1083                                       &pdu->h323_message_body.alerting);
1084                break;
1085        case eH323_UU_PDU_h323_message_body_facility:
1086                ret = process_facility(skb, ct, ctinfo, data, dataoff,
1087                                       &pdu->h323_message_body.facility);
1088                break;
1089        case eH323_UU_PDU_h323_message_body_progress:
1090                ret = process_progress(skb, ct, ctinfo, data, dataoff,
1091                                       &pdu->h323_message_body.progress);
1092                break;
1093        default:
1094                pr_debug("nf_ct_q931: Q.931 signal %d\n",
1095                         pdu->h323_message_body.choice);
1096                break;
1097        }
1098
1099        if (ret < 0)
1100                return -1;
1101
1102        if (pdu->options & eH323_UU_PDU_h245Control) {
1103                for (i = 0; i < pdu->h245Control.count; i++) {
1104                        ret = process_h245(skb, ct, ctinfo, data, dataoff,
1105                                           &pdu->h245Control.item[i]);
1106                        if (ret < 0)
1107                                return -1;
1108                }
1109        }
1110
1111        return 0;
1112}
1113
1114/****************************************************************************/
1115static int q931_help(struct sk_buff *skb, unsigned int protoff,
1116                     struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1117{
1118        static Q931 q931;
1119        unsigned char *data = NULL;
1120        int datalen;
1121        int dataoff;
1122        int ret;
1123
1124        /* Until there's been traffic both ways, don't look in packets. */
1125        if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
1126                return NF_ACCEPT;
1127
1128        pr_debug("nf_ct_q931: skblen = %u\n", skb->len);
1129
1130        spin_lock_bh(&nf_h323_lock);
1131
1132        /* Process each TPKT */
1133        while (get_tpkt_data(skb, protoff, ct, ctinfo,
1134                             &data, &datalen, &dataoff)) {
1135                pr_debug("nf_ct_q931: TPKT len=%d ", datalen);
1136                nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1137
1138                /* Decode Q.931 signal */
1139                ret = DecodeQ931(data, datalen, &q931);
1140                if (ret < 0) {
1141                        pr_debug("nf_ct_q931: decoding error: %s\n",
1142                                 ret == H323_ERROR_BOUND ?
1143                                 "out of bound" : "out of range");
1144                        /* We don't drop when decoding error */
1145                        break;
1146                }
1147
1148                /* Process Q.931 signal */
1149                if (process_q931(skb, ct, ctinfo, &data, dataoff, &q931) < 0)
1150                        goto drop;
1151        }
1152
1153        spin_unlock_bh(&nf_h323_lock);
1154        return NF_ACCEPT;
1155
1156      drop:
1157        spin_unlock_bh(&nf_h323_lock);
1158        net_info_ratelimited("nf_ct_q931: packet dropped\n");
1159        return NF_DROP;
1160}
1161
1162/****************************************************************************/
1163static const struct nf_conntrack_expect_policy q931_exp_policy = {
1164        /* T.120 and H.245 */
1165        .max_expected           = H323_RTP_CHANNEL_MAX * 4 + 4,
1166        .timeout                = 240,
1167};
1168
1169static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = {
1170        {
1171                .name                   = "Q.931",
1172                .me                     = THIS_MODULE,
1173                .data_len               = sizeof(struct nf_ct_h323_master),
1174                .tuple.src.l3num        = AF_INET,
1175                .tuple.src.u.tcp.port   = cpu_to_be16(Q931_PORT),
1176                .tuple.dst.protonum     = IPPROTO_TCP,
1177                .help                   = q931_help,
1178                .expect_policy          = &q931_exp_policy,
1179        },
1180        {
1181                .name                   = "Q.931",
1182                .me                     = THIS_MODULE,
1183                .tuple.src.l3num        = AF_INET6,
1184                .tuple.src.u.tcp.port   = cpu_to_be16(Q931_PORT),
1185                .tuple.dst.protonum     = IPPROTO_TCP,
1186                .help                   = q931_help,
1187                .expect_policy          = &q931_exp_policy,
1188        },
1189};
1190
1191/****************************************************************************/
1192static unsigned char *get_udp_data(struct sk_buff *skb, unsigned int protoff,
1193                                   int *datalen)
1194{
1195        const struct udphdr *uh;
1196        struct udphdr _uh;
1197        int dataoff;
1198
1199        uh = skb_header_pointer(skb, protoff, sizeof(_uh), &_uh);
1200        if (uh == NULL)
1201                return NULL;
1202        dataoff = protoff + sizeof(_uh);
1203        if (dataoff >= skb->len)
1204                return NULL;
1205        *datalen = skb->len - dataoff;
1206        return skb_header_pointer(skb, dataoff, *datalen, h323_buffer);
1207}
1208
1209/****************************************************************************/
1210static struct nf_conntrack_expect *find_expect(struct nf_conn *ct,
1211                                               union nf_inet_addr *addr,
1212                                               __be16 port)
1213{
1214        struct net *net = nf_ct_net(ct);
1215        struct nf_conntrack_expect *exp;
1216        struct nf_conntrack_tuple tuple;
1217
1218        memset(&tuple.src.u3, 0, sizeof(tuple.src.u3));
1219        tuple.src.u.tcp.port = 0;
1220        memcpy(&tuple.dst.u3, addr, sizeof(tuple.dst.u3));
1221        tuple.dst.u.tcp.port = port;
1222        tuple.dst.protonum = IPPROTO_TCP;
1223
1224        exp = __nf_ct_expect_find(net, nf_ct_zone(ct), &tuple);
1225        if (exp && exp->master == ct)
1226                return exp;
1227        return NULL;
1228}
1229
1230/****************************************************************************/
1231static int set_expect_timeout(struct nf_conntrack_expect *exp,
1232                              unsigned int timeout)
1233{
1234        if (!exp || !del_timer(&exp->timeout))
1235                return 0;
1236
1237        exp->timeout.expires = jiffies + timeout * HZ;
1238        add_timer(&exp->timeout);
1239
1240        return 1;
1241}
1242
1243/****************************************************************************/
1244static int expect_q931(struct sk_buff *skb, struct nf_conn *ct,
1245                       enum ip_conntrack_info ctinfo,
1246                       unsigned char **data,
1247                       TransportAddress *taddr, int count)
1248{
1249        struct nf_ct_h323_master *info = nfct_help_data(ct);
1250        int dir = CTINFO2DIR(ctinfo);
1251        int ret = 0;
1252        int i;
1253        __be16 port;
1254        union nf_inet_addr addr;
1255        struct nf_conntrack_expect *exp;
1256        typeof(nat_q931_hook) nat_q931;
1257
1258        /* Look for the first related address */
1259        for (i = 0; i < count; i++) {
1260                if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) &&
1261                    memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3,
1262                           sizeof(addr)) == 0 && port != 0)
1263                        break;
1264        }
1265
1266        if (i >= count)         /* Not found */
1267                return 0;
1268
1269        /* Create expect for Q.931 */
1270        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1271                return -1;
1272        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1273                          gkrouted_only ? /* only accept calls from GK? */
1274                                &ct->tuplehash[!dir].tuple.src.u3 : NULL,
1275                          &ct->tuplehash[!dir].tuple.dst.u3,
1276                          IPPROTO_TCP, NULL, &port);
1277        exp->helper = nf_conntrack_helper_q931;
1278        exp->flags = NF_CT_EXPECT_PERMANENT;    /* Accept multiple calls */
1279
1280        nat_q931 = rcu_dereference(nat_q931_hook);
1281        if (nat_q931 && ct->status & IPS_NAT_MASK) {    /* Need NAT */
1282                ret = nat_q931(skb, ct, ctinfo, data, taddr, i, port, exp);
1283        } else {                /* Conntrack only */
1284                if (nf_ct_expect_related(exp) == 0) {
1285                        pr_debug("nf_ct_ras: expect Q.931 ");
1286                        nf_ct_dump_tuple(&exp->tuple);
1287
1288                        /* Save port for looking up expect in processing RCF */
1289                        info->sig_port[dir] = port;
1290                } else
1291                        ret = -1;
1292        }
1293
1294        nf_ct_expect_put(exp);
1295
1296        return ret;
1297}
1298
1299/****************************************************************************/
1300static int process_grq(struct sk_buff *skb, struct nf_conn *ct,
1301                       enum ip_conntrack_info ctinfo,
1302                       unsigned char **data, GatekeeperRequest *grq)
1303{
1304        typeof(set_ras_addr_hook) set_ras_addr;
1305
1306        pr_debug("nf_ct_ras: GRQ\n");
1307
1308        set_ras_addr = rcu_dereference(set_ras_addr_hook);
1309        if (set_ras_addr && ct->status & IPS_NAT_MASK)  /* NATed */
1310                return set_ras_addr(skb, ct, ctinfo, data,
1311                                    &grq->rasAddress, 1);
1312        return 0;
1313}
1314
1315/****************************************************************************/
1316static int process_gcf(struct sk_buff *skb, struct nf_conn *ct,
1317                       enum ip_conntrack_info ctinfo,
1318                       unsigned char **data, GatekeeperConfirm *gcf)
1319{
1320        int dir = CTINFO2DIR(ctinfo);
1321        int ret = 0;
1322        __be16 port;
1323        union nf_inet_addr addr;
1324        struct nf_conntrack_expect *exp;
1325
1326        pr_debug("nf_ct_ras: GCF\n");
1327
1328        if (!get_h225_addr(ct, *data, &gcf->rasAddress, &addr, &port))
1329                return 0;
1330
1331        /* Registration port is the same as discovery port */
1332        if (!memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1333            port == ct->tuplehash[dir].tuple.src.u.udp.port)
1334                return 0;
1335
1336        /* Avoid RAS expectation loops. A GCF is never expected. */
1337        if (test_bit(IPS_EXPECTED_BIT, &ct->status))
1338                return 0;
1339
1340        /* Need new expect */
1341        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1342                return -1;
1343        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1344                          &ct->tuplehash[!dir].tuple.src.u3, &addr,
1345                          IPPROTO_UDP, NULL, &port);
1346        exp->helper = nf_conntrack_helper_ras;
1347
1348        if (nf_ct_expect_related(exp) == 0) {
1349                pr_debug("nf_ct_ras: expect RAS ");
1350                nf_ct_dump_tuple(&exp->tuple);
1351        } else
1352                ret = -1;
1353
1354        nf_ct_expect_put(exp);
1355
1356        return ret;
1357}
1358
1359/****************************************************************************/
1360static int process_rrq(struct sk_buff *skb, struct nf_conn *ct,
1361                       enum ip_conntrack_info ctinfo,
1362                       unsigned char **data, RegistrationRequest *rrq)
1363{
1364        struct nf_ct_h323_master *info = nfct_help_data(ct);
1365        int ret;
1366        typeof(set_ras_addr_hook) set_ras_addr;
1367
1368        pr_debug("nf_ct_ras: RRQ\n");
1369
1370        ret = expect_q931(skb, ct, ctinfo, data,
1371                          rrq->callSignalAddress.item,
1372                          rrq->callSignalAddress.count);
1373        if (ret < 0)
1374                return -1;
1375
1376        set_ras_addr = rcu_dereference(set_ras_addr_hook);
1377        if (set_ras_addr && ct->status & IPS_NAT_MASK) {
1378                ret = set_ras_addr(skb, ct, ctinfo, data,
1379                                   rrq->rasAddress.item,
1380                                   rrq->rasAddress.count);
1381                if (ret < 0)
1382                        return -1;
1383        }
1384
1385        if (rrq->options & eRegistrationRequest_timeToLive) {
1386                pr_debug("nf_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive);
1387                info->timeout = rrq->timeToLive;
1388        } else
1389                info->timeout = default_rrq_ttl;
1390
1391        return 0;
1392}
1393
1394/****************************************************************************/
1395static int process_rcf(struct sk_buff *skb, struct nf_conn *ct,
1396                       enum ip_conntrack_info ctinfo,
1397                       unsigned char **data, RegistrationConfirm *rcf)
1398{
1399        struct nf_ct_h323_master *info = nfct_help_data(ct);
1400        int dir = CTINFO2DIR(ctinfo);
1401        int ret;
1402        struct nf_conntrack_expect *exp;
1403        typeof(set_sig_addr_hook) set_sig_addr;
1404
1405        pr_debug("nf_ct_ras: RCF\n");
1406
1407        set_sig_addr = rcu_dereference(set_sig_addr_hook);
1408        if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1409                ret = set_sig_addr(skb, ct, ctinfo, data,
1410                                        rcf->callSignalAddress.item,
1411                                        rcf->callSignalAddress.count);
1412                if (ret < 0)
1413                        return -1;
1414        }
1415
1416        if (rcf->options & eRegistrationConfirm_timeToLive) {
1417                pr_debug("nf_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive);
1418                info->timeout = rcf->timeToLive;
1419        }
1420
1421        if (info->timeout > 0) {
1422                pr_debug("nf_ct_ras: set RAS connection timeout to "
1423                         "%u seconds\n", info->timeout);
1424                nf_ct_refresh(ct, skb, info->timeout * HZ);
1425
1426                /* Set expect timeout */
1427                spin_lock_bh(&nf_conntrack_lock);
1428                exp = find_expect(ct, &ct->tuplehash[dir].tuple.dst.u3,
1429                                  info->sig_port[!dir]);
1430                if (exp) {
1431                        pr_debug("nf_ct_ras: set Q.931 expect "
1432                                 "timeout to %u seconds for",
1433                                 info->timeout);
1434                        nf_ct_dump_tuple(&exp->tuple);
1435                        set_expect_timeout(exp, info->timeout);
1436                }
1437                spin_unlock_bh(&nf_conntrack_lock);
1438        }
1439
1440        return 0;
1441}
1442
1443/****************************************************************************/
1444static int process_urq(struct sk_buff *skb, struct nf_conn *ct,
1445                       enum ip_conntrack_info ctinfo,
1446                       unsigned char **data, UnregistrationRequest *urq)
1447{
1448        struct nf_ct_h323_master *info = nfct_help_data(ct);
1449        int dir = CTINFO2DIR(ctinfo);
1450        int ret;
1451        typeof(set_sig_addr_hook) set_sig_addr;
1452
1453        pr_debug("nf_ct_ras: URQ\n");
1454
1455        set_sig_addr = rcu_dereference(set_sig_addr_hook);
1456        if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1457                ret = set_sig_addr(skb, ct, ctinfo, data,
1458                                   urq->callSignalAddress.item,
1459                                   urq->callSignalAddress.count);
1460                if (ret < 0)
1461                        return -1;
1462        }
1463
1464        /* Clear old expect */
1465        nf_ct_remove_expectations(ct);
1466        info->sig_port[dir] = 0;
1467        info->sig_port[!dir] = 0;
1468
1469        /* Give it 30 seconds for UCF or URJ */
1470        nf_ct_refresh(ct, skb, 30 * HZ);
1471
1472        return 0;
1473}
1474
1475/****************************************************************************/
1476static int process_arq(struct sk_buff *skb, struct nf_conn *ct,
1477                       enum ip_conntrack_info ctinfo,
1478                       unsigned char **data, AdmissionRequest *arq)
1479{
1480        const struct nf_ct_h323_master *info = nfct_help_data(ct);
1481        int dir = CTINFO2DIR(ctinfo);
1482        __be16 port;
1483        union nf_inet_addr addr;
1484        typeof(set_h225_addr_hook) set_h225_addr;
1485
1486        pr_debug("nf_ct_ras: ARQ\n");
1487
1488        set_h225_addr = rcu_dereference(set_h225_addr_hook);
1489        if ((arq->options & eAdmissionRequest_destCallSignalAddress) &&
1490            get_h225_addr(ct, *data, &arq->destCallSignalAddress,
1491                          &addr, &port) &&
1492            !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1493            port == info->sig_port[dir] &&
1494            set_h225_addr && ct->status & IPS_NAT_MASK) {
1495                /* Answering ARQ */
1496                return set_h225_addr(skb, data, 0,
1497                                     &arq->destCallSignalAddress,
1498                                     &ct->tuplehash[!dir].tuple.dst.u3,
1499                                     info->sig_port[!dir]);
1500        }
1501
1502        if ((arq->options & eAdmissionRequest_srcCallSignalAddress) &&
1503            get_h225_addr(ct, *data, &arq->srcCallSignalAddress,
1504                          &addr, &port) &&
1505            !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1506            set_h225_addr && ct->status & IPS_NAT_MASK) {
1507                /* Calling ARQ */
1508                return set_h225_addr(skb, data, 0,
1509                                     &arq->srcCallSignalAddress,
1510                                     &ct->tuplehash[!dir].tuple.dst.u3,
1511                                     port);
1512        }
1513
1514        return 0;
1515}
1516
1517/****************************************************************************/
1518static int process_acf(struct sk_buff *skb, struct nf_conn *ct,
1519                       enum ip_conntrack_info ctinfo,
1520                       unsigned char **data, AdmissionConfirm *acf)
1521{
1522        int dir = CTINFO2DIR(ctinfo);
1523        int ret = 0;
1524        __be16 port;
1525        union nf_inet_addr addr;
1526        struct nf_conntrack_expect *exp;
1527        typeof(set_sig_addr_hook) set_sig_addr;
1528
1529        pr_debug("nf_ct_ras: ACF\n");
1530
1531        if (!get_h225_addr(ct, *data, &acf->destCallSignalAddress,
1532                           &addr, &port))
1533                return 0;
1534
1535        if (!memcmp(&addr, &ct->tuplehash[dir].tuple.dst.u3, sizeof(addr))) {
1536                /* Answering ACF */
1537                set_sig_addr = rcu_dereference(set_sig_addr_hook);
1538                if (set_sig_addr && ct->status & IPS_NAT_MASK)
1539                        return set_sig_addr(skb, ct, ctinfo, data,
1540                                            &acf->destCallSignalAddress, 1);
1541                return 0;
1542        }
1543
1544        /* Need new expect */
1545        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1546                return -1;
1547        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1548                          &ct->tuplehash[!dir].tuple.src.u3, &addr,
1549                          IPPROTO_TCP, NULL, &port);
1550        exp->flags = NF_CT_EXPECT_PERMANENT;
1551        exp->helper = nf_conntrack_helper_q931;
1552
1553        if (nf_ct_expect_related(exp) == 0) {
1554                pr_debug("nf_ct_ras: expect Q.931 ");
1555                nf_ct_dump_tuple(&exp->tuple);
1556        } else
1557                ret = -1;
1558
1559        nf_ct_expect_put(exp);
1560
1561        return ret;
1562}
1563
1564/****************************************************************************/
1565static int process_lrq(struct sk_buff *skb, struct nf_conn *ct,
1566                       enum ip_conntrack_info ctinfo,
1567                       unsigned char **data, LocationRequest *lrq)
1568{
1569        typeof(set_ras_addr_hook) set_ras_addr;
1570
1571        pr_debug("nf_ct_ras: LRQ\n");
1572
1573        set_ras_addr = rcu_dereference(set_ras_addr_hook);
1574        if (set_ras_addr && ct->status & IPS_NAT_MASK)
1575                return set_ras_addr(skb, ct, ctinfo, data,
1576                                    &lrq->replyAddress, 1);
1577        return 0;
1578}
1579
1580/****************************************************************************/
1581static int process_lcf(struct sk_buff *skb, struct nf_conn *ct,
1582                       enum ip_conntrack_info ctinfo,
1583                       unsigned char **data, LocationConfirm *lcf)
1584{
1585        int dir = CTINFO2DIR(ctinfo);
1586        int ret = 0;
1587        __be16 port;
1588        union nf_inet_addr addr;
1589        struct nf_conntrack_expect *exp;
1590
1591        pr_debug("nf_ct_ras: LCF\n");
1592
1593        if (!get_h225_addr(ct, *data, &lcf->callSignalAddress,
1594                           &addr, &port))
1595                return 0;
1596
1597        /* Need new expect for call signal */
1598        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1599                return -1;
1600        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1601                          &ct->tuplehash[!dir].tuple.src.u3, &addr,
1602                          IPPROTO_TCP, NULL, &port);
1603        exp->flags = NF_CT_EXPECT_PERMANENT;
1604        exp->helper = nf_conntrack_helper_q931;
1605
1606        if (nf_ct_expect_related(exp) == 0) {
1607                pr_debug("nf_ct_ras: expect Q.931 ");
1608                nf_ct_dump_tuple(&exp->tuple);
1609        } else
1610                ret = -1;
1611
1612        nf_ct_expect_put(exp);
1613
1614        /* Ignore rasAddress */
1615
1616        return ret;
1617}
1618
1619/****************************************************************************/
1620static int process_irr(struct sk_buff *skb, struct nf_conn *ct,
1621                       enum ip_conntrack_info ctinfo,
1622                       unsigned char **data, InfoRequestResponse *irr)
1623{
1624        int ret;
1625        typeof(set_ras_addr_hook) set_ras_addr;
1626        typeof(set_sig_addr_hook) set_sig_addr;
1627
1628        pr_debug("nf_ct_ras: IRR\n");
1629
1630        set_ras_addr = rcu_dereference(set_ras_addr_hook);
1631        if (set_ras_addr && ct->status & IPS_NAT_MASK) {
1632                ret = set_ras_addr(skb, ct, ctinfo, data,
1633                                   &irr->rasAddress, 1);
1634                if (ret < 0)
1635                        return -1;
1636        }
1637
1638        set_sig_addr = rcu_dereference(set_sig_addr_hook);
1639        if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1640                ret = set_sig_addr(skb, ct, ctinfo, data,
1641                                        irr->callSignalAddress.item,
1642                                        irr->callSignalAddress.count);
1643                if (ret < 0)
1644                        return -1;
1645        }
1646
1647        return 0;
1648}
1649
1650/****************************************************************************/
1651static int process_ras(struct sk_buff *skb, struct nf_conn *ct,
1652                       enum ip_conntrack_info ctinfo,
1653                       unsigned char **data, RasMessage *ras)
1654{
1655        switch (ras->choice) {
1656        case eRasMessage_gatekeeperRequest:
1657                return process_grq(skb, ct, ctinfo, data,
1658                                   &ras->gatekeeperRequest);
1659        case eRasMessage_gatekeeperConfirm:
1660                return process_gcf(skb, ct, ctinfo, data,
1661                                   &ras->gatekeeperConfirm);
1662        case eRasMessage_registrationRequest:
1663                return process_rrq(skb, ct, ctinfo, data,
1664                                   &ras->registrationRequest);
1665        case eRasMessage_registrationConfirm:
1666                return process_rcf(skb, ct, ctinfo, data,
1667                                   &ras->registrationConfirm);
1668        case eRasMessage_unregistrationRequest:
1669                return process_urq(skb, ct, ctinfo, data,
1670                                   &ras->unregistrationRequest);
1671        case eRasMessage_admissionRequest:
1672                return process_arq(skb, ct, ctinfo, data,
1673                                   &ras->admissionRequest);
1674        case eRasMessage_admissionConfirm:
1675                return process_acf(skb, ct, ctinfo, data,
1676                                   &ras->admissionConfirm);
1677        case eRasMessage_locationRequest:
1678                return process_lrq(skb, ct, ctinfo, data,
1679                                   &ras->locationRequest);
1680        case eRasMessage_locationConfirm:
1681                return process_lcf(skb, ct, ctinfo, data,
1682                                   &ras->locationConfirm);
1683        case eRasMessage_infoRequestResponse:
1684                return process_irr(skb, ct, ctinfo, data,
1685                                   &ras->infoRequestResponse);
1686        default:
1687                pr_debug("nf_ct_ras: RAS message %d\n", ras->choice);
1688                break;
1689        }
1690
1691        return 0;
1692}
1693
1694/****************************************************************************/
1695static int ras_help(struct sk_buff *skb, unsigned int protoff,
1696                    struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1697{
1698        static RasMessage ras;
1699        unsigned char *data;
1700        int datalen = 0;
1701        int ret;
1702
1703        pr_debug("nf_ct_ras: skblen = %u\n", skb->len);
1704
1705        spin_lock_bh(&nf_h323_lock);
1706
1707        /* Get UDP data */
1708        data = get_udp_data(skb, protoff, &datalen);
1709        if (data == NULL)
1710                goto accept;
1711        pr_debug("nf_ct_ras: RAS message len=%d ", datalen);
1712        nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1713
1714        /* Decode RAS message */
1715        ret = DecodeRasMessage(data, datalen, &ras);
1716        if (ret < 0) {
1717                pr_debug("nf_ct_ras: decoding error: %s\n",
1718                         ret == H323_ERROR_BOUND ?
1719                         "out of bound" : "out of range");
1720                goto accept;
1721        }
1722
1723        /* Process RAS message */
1724        if (process_ras(skb, ct, ctinfo, &data, &ras) < 0)
1725                goto drop;
1726
1727      accept:
1728        spin_unlock_bh(&nf_h323_lock);
1729        return NF_ACCEPT;
1730
1731      drop:
1732        spin_unlock_bh(&nf_h323_lock);
1733        net_info_ratelimited("nf_ct_ras: packet dropped\n");
1734        return NF_DROP;
1735}
1736
1737/****************************************************************************/
1738static const struct nf_conntrack_expect_policy ras_exp_policy = {
1739        .max_expected           = 32,
1740        .timeout                = 240,
1741};
1742
1743static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = {
1744        {
1745                .name                   = "RAS",
1746                .me                     = THIS_MODULE,
1747                .data_len               = sizeof(struct nf_ct_h323_master),
1748                .tuple.src.l3num        = AF_INET,
1749                .tuple.src.u.udp.port   = cpu_to_be16(RAS_PORT),
1750                .tuple.dst.protonum     = IPPROTO_UDP,
1751                .help                   = ras_help,
1752                .expect_policy          = &ras_exp_policy,
1753        },
1754        {
1755                .name                   = "RAS",
1756                .me                     = THIS_MODULE,
1757                .data_len               = sizeof(struct nf_ct_h323_master),
1758                .tuple.src.l3num        = AF_INET6,
1759                .tuple.src.u.udp.port   = cpu_to_be16(RAS_PORT),
1760                .tuple.dst.protonum     = IPPROTO_UDP,
1761                .help                   = ras_help,
1762                .expect_policy          = &ras_exp_policy,
1763        },
1764};
1765
1766/****************************************************************************/
1767static void __exit nf_conntrack_h323_fini(void)
1768{
1769        nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[1]);
1770        nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1771        nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1772        nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1773        nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1774        kfree(h323_buffer);
1775        pr_debug("nf_ct_h323: fini\n");
1776}
1777
1778/****************************************************************************/
1779static int __init nf_conntrack_h323_init(void)
1780{
1781        int ret;
1782
1783        h323_buffer = kmalloc(65536, GFP_KERNEL);
1784        if (!h323_buffer)
1785                return -ENOMEM;
1786        ret = nf_conntrack_helper_register(&nf_conntrack_helper_h245);
1787        if (ret < 0)
1788                goto err1;
1789        ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[0]);
1790        if (ret < 0)
1791                goto err2;
1792        ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[1]);
1793        if (ret < 0)
1794                goto err3;
1795        ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[0]);
1796        if (ret < 0)
1797                goto err4;
1798        ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[1]);
1799        if (ret < 0)
1800                goto err5;
1801        pr_debug("nf_ct_h323: init success\n");
1802        return 0;
1803
1804err5:
1805        nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1806err4:
1807        nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1808err3:
1809        nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1810err2:
1811        nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1812err1:
1813        kfree(h323_buffer);
1814        return ret;
1815}
1816
1817/****************************************************************************/
1818module_init(nf_conntrack_h323_init);
1819module_exit(nf_conntrack_h323_fini);
1820
1821EXPORT_SYMBOL_GPL(get_h225_addr);
1822EXPORT_SYMBOL_GPL(set_h245_addr_hook);
1823EXPORT_SYMBOL_GPL(set_h225_addr_hook);
1824EXPORT_SYMBOL_GPL(set_sig_addr_hook);
1825EXPORT_SYMBOL_GPL(set_ras_addr_hook);
1826EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook);
1827EXPORT_SYMBOL_GPL(nat_t120_hook);
1828EXPORT_SYMBOL_GPL(nat_h245_hook);
1829EXPORT_SYMBOL_GPL(nat_callforwarding_hook);
1830EXPORT_SYMBOL_GPL(nat_q931_hook);
1831
1832MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>");
1833MODULE_DESCRIPTION("H.323 connection tracking helper");
1834MODULE_LICENSE("GPL");
1835MODULE_ALIAS("ip_conntrack_h323");
1836MODULE_ALIAS_NFCT_HELPER("RAS");
1837MODULE_ALIAS_NFCT_HELPER("Q.931");
1838MODULE_ALIAS_NFCT_HELPER("H.245");
1839
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