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/udp.h>
  21#include <linux/tcp.h>
  22#include <linux/skbuff.h>
  23#include <net/route.h>
  24#include <net/ip6_route.h>
  25
  26#include <net/netfilter/nf_conntrack.h>
  27#include <net/netfilter/nf_conntrack_core.h>
  28#include <net/netfilter/nf_conntrack_tuple.h>
  29#include <net/netfilter/nf_conntrack_expect.h>
  30#include <net/netfilter/nf_conntrack_ecache.h>
  31#include <net/netfilter/nf_conntrack_helper.h>
  32#include <linux/netfilter/nf_conntrack_h323.h>
  33
  34/* Parameters */
  35static unsigned int default_rrq_ttl __read_mostly = 300;
  36module_param(default_rrq_ttl, uint, 0600);
  37MODULE_PARM_DESC(default_rrq_ttl, "use this TTL if it's missing in RRQ");
  38
  39static int gkrouted_only __read_mostly = 1;
  40module_param(gkrouted_only, int, 0600);
  41MODULE_PARM_DESC(gkrouted_only, "only accept calls from gatekeeper");
  42
  43static int callforward_filter __read_mostly = 1;
  44module_param(callforward_filter, bool, 0600);
  45MODULE_PARM_DESC(callforward_filter, "only create call forwarding expectations "
  46                                     "if both endpoints are on different sides "
  47                                     "(determined by routing information)");
  48
  49/* Hooks for NAT */
  50int (*set_h245_addr_hook) (struct sk_buff *skb,
  51                           unsigned char **data, int dataoff,
  52                           H245_TransportAddress *taddr,
  53                           union nf_inet_addr *addr, __be16 port)
  54                           __read_mostly;
  55int (*set_h225_addr_hook) (struct sk_buff *skb,
  56                           unsigned char **data, int dataoff,
  57                           TransportAddress *taddr,
  58                           union nf_inet_addr *addr, __be16 port)
  59                           __read_mostly;
  60int (*set_sig_addr_hook) (struct sk_buff *skb,
  61                          struct nf_conn *ct,
  62                          enum ip_conntrack_info ctinfo,
  63                          unsigned char **data,
  64                          TransportAddress *taddr, int count) __read_mostly;
  65int (*set_ras_addr_hook) (struct sk_buff *skb,
  66                          struct nf_conn *ct,
  67                          enum ip_conntrack_info ctinfo,
  68                          unsigned char **data,
  69                          TransportAddress *taddr, int count) __read_mostly;
  70int (*nat_rtp_rtcp_hook) (struct sk_buff *skb,
  71                          struct nf_conn *ct,
  72                          enum ip_conntrack_info ctinfo,
  73                          unsigned char **data, int dataoff,
  74                          H245_TransportAddress *taddr,
  75                          __be16 port, __be16 rtp_port,
  76                          struct nf_conntrack_expect *rtp_exp,
  77                          struct nf_conntrack_expect *rtcp_exp) __read_mostly;
  78int (*nat_t120_hook) (struct sk_buff *skb,
  79                      struct nf_conn *ct,
  80                      enum ip_conntrack_info ctinfo,
  81                      unsigned char **data, int dataoff,
  82                      H245_TransportAddress *taddr, __be16 port,
  83                      struct nf_conntrack_expect *exp) __read_mostly;
  84int (*nat_h245_hook) (struct sk_buff *skb,
  85                      struct nf_conn *ct,
  86                      enum ip_conntrack_info ctinfo,
  87                      unsigned char **data, int dataoff,
  88                      TransportAddress *taddr, __be16 port,
  89                      struct nf_conntrack_expect *exp) __read_mostly;
  90int (*nat_callforwarding_hook) (struct sk_buff *skb,
  91                                struct nf_conn *ct,
  92                                enum ip_conntrack_info ctinfo,
  93                                unsigned char **data, int dataoff,
  94                                TransportAddress *taddr, __be16 port,
  95                                struct nf_conntrack_expect *exp) __read_mostly;
  96int (*nat_q931_hook) (struct sk_buff *skb,
  97                      struct nf_conn *ct,
  98                      enum ip_conntrack_info ctinfo,
  99                      unsigned char **data, TransportAddress *taddr, int idx,
 100                      __be16 port, struct nf_conntrack_expect *exp)
 101                      __read_mostly;
 102
 103static DEFINE_SPINLOCK(nf_h323_lock);
 104static char *h323_buffer;
 105
 106static struct nf_conntrack_helper nf_conntrack_helper_h245;
 107static struct nf_conntrack_helper nf_conntrack_helper_q931[];
 108static struct nf_conntrack_helper nf_conntrack_helper_ras[];
 109
 110/****************************************************************************/
 111static int get_tpkt_data(struct sk_buff *skb, unsigned int protoff,
 112                         struct nf_conn *ct, enum ip_conntrack_info ctinfo,
 113                         unsigned char **data, int *datalen, int *dataoff)
 114{
 115        struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
 116        int dir = CTINFO2DIR(ctinfo);
 117        const struct tcphdr *th;
 118        struct tcphdr _tcph;
 119        int tcpdatalen;
 120        int tcpdataoff;
 121        unsigned char *tpkt;
 122        int tpktlen;
 123        int tpktoff;
 124
 125        /* Get TCP header */
 126        th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph);
 127        if (th == NULL)
 128                return 0;
 129
 130        /* Get TCP data offset */
 131        tcpdataoff = protoff + th->doff * 4;
 132
 133        /* Get TCP data length */
 134        tcpdatalen = skb->len - tcpdataoff;
 135        if (tcpdatalen <= 0)    /* No TCP data */
 136                goto clear_out;
 137
 138        if (*data == NULL) {    /* first TPKT */
 139                /* Get first TPKT pointer */
 140                tpkt = skb_header_pointer(skb, tcpdataoff, tcpdatalen,
 141                                          h323_buffer);
 142                BUG_ON(tpkt == NULL);
 143
 144                /* Validate TPKT identifier */
 145                if (tcpdatalen < 4 || tpkt[0] != 0x03 || tpkt[1] != 0) {
 146                        /* Netmeeting sends TPKT header and data separately */
 147                        if (info->tpkt_len[dir] > 0) {
 148                                pr_debug("nf_ct_h323: previous packet "
 149                                         "indicated separate TPKT data of %hu "
 150                                         "bytes\n", info->tpkt_len[dir]);
 151                                if (info->tpkt_len[dir] <= tcpdatalen) {
 152                                        /* Yes, there was a TPKT header
 153                                         * received */
 154                                        *data = tpkt;
 155                                        *datalen = info->tpkt_len[dir];
 156                                        *dataoff = 0;
 157                                        goto out;
 158                                }
 159
 160                                /* Fragmented TPKT */
 161                                pr_debug("nf_ct_h323: fragmented TPKT\n");
 162                                goto clear_out;
 163                        }
 164
 165                        /* It is not even a TPKT */
 166                        return 0;
 167                }
 168                tpktoff = 0;
 169        } else {                /* Next TPKT */
 170                tpktoff = *dataoff + *datalen;
 171                tcpdatalen -= tpktoff;
 172                if (tcpdatalen <= 4)    /* No more TPKT */
 173                        goto clear_out;
 174                tpkt = *data + *datalen;
 175
 176                /* Validate TPKT identifier */
 177                if (tpkt[0] != 0x03 || tpkt[1] != 0)
 178                        goto clear_out;
 179        }
 180
 181        /* Validate TPKT length */
 182        tpktlen = tpkt[2] * 256 + tpkt[3];
 183        if (tpktlen < 4)
 184                goto clear_out;
 185        if (tpktlen > tcpdatalen) {
 186                if (tcpdatalen == 4) {  /* Separate TPKT header */
 187                        /* Netmeeting sends TPKT header and data separately */
 188                        pr_debug("nf_ct_h323: separate TPKT header indicates "
 189                                 "there will be TPKT data of %hu bytes\n",
 190                                 tpktlen - 4);
 191                        info->tpkt_len[dir] = tpktlen - 4;
 192                        return 0;
 193                }
 194
 195                if (net_ratelimit())
 196                        printk("nf_ct_h323: incomplete TPKT (fragmented?)\n");
 197                goto clear_out;
 198        }
 199
 200        /* This is the encapsulated data */
 201        *data = tpkt + 4;
 202        *datalen = tpktlen - 4;
 203        *dataoff = tpktoff + 4;
 204
 205      out:
 206        /* Clear TPKT length */
 207        info->tpkt_len[dir] = 0;
 208        return 1;
 209
 210      clear_out:
 211        info->tpkt_len[dir] = 0;
 212        return 0;
 213}
 214
 215/****************************************************************************/
 216static int get_h245_addr(struct nf_conn *ct, const unsigned char *data,
 217                         H245_TransportAddress *taddr,
 218                         union nf_inet_addr *addr, __be16 *port)
 219{
 220        const unsigned char *p;
 221        int len;
 222
 223        if (taddr->choice != eH245_TransportAddress_unicastAddress)
 224                return 0;
 225
 226        switch (taddr->unicastAddress.choice) {
 227        case eUnicastAddress_iPAddress:
 228                if (nf_ct_l3num(ct) != AF_INET)
 229                        return 0;
 230                p = data + taddr->unicastAddress.iPAddress.network;
 231                len = 4;
 232                break;
 233        case eUnicastAddress_iP6Address:
 234                if (nf_ct_l3num(ct) != AF_INET6)
 235                        return 0;
 236                p = data + taddr->unicastAddress.iP6Address.network;
 237                len = 16;
 238                break;
 239        default:
 240                return 0;
 241        }
 242
 243        memcpy(addr, p, len);
 244        memset((void *)addr + len, 0, sizeof(*addr) - len);
 245        memcpy(port, p + len, sizeof(__be16));
 246
 247        return 1;
 248}
 249
 250/****************************************************************************/
 251static int expect_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct,
 252                           enum ip_conntrack_info ctinfo,
 253                           unsigned char **data, int dataoff,
 254                           H245_TransportAddress *taddr)
 255{
 256        int dir = CTINFO2DIR(ctinfo);
 257        int ret = 0;
 258        __be16 port;
 259        __be16 rtp_port, rtcp_port;
 260        union nf_inet_addr addr;
 261        struct nf_conntrack_expect *rtp_exp;
 262        struct nf_conntrack_expect *rtcp_exp;
 263        typeof(nat_rtp_rtcp_hook) nat_rtp_rtcp;
 264
 265        /* Read RTP or RTCP address */
 266        if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
 267            memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 268            port == 0)
 269                return 0;
 270
 271        /* RTP port is even */
 272        port &= htons(~1);
 273        rtp_port = port;
 274        rtcp_port = htons(ntohs(port) + 1);
 275
 276        /* Create expect for RTP */
 277        if ((rtp_exp = nf_ct_expect_alloc(ct)) == NULL)
 278                return -1;
 279        nf_ct_expect_init(rtp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 280                          &ct->tuplehash[!dir].tuple.src.u3,
 281                          &ct->tuplehash[!dir].tuple.dst.u3,
 282                          IPPROTO_UDP, NULL, &rtp_port);
 283
 284        /* Create expect for RTCP */
 285        if ((rtcp_exp = nf_ct_expect_alloc(ct)) == NULL) {
 286                nf_ct_expect_put(rtp_exp);
 287                return -1;
 288        }
 289        nf_ct_expect_init(rtcp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 290                          &ct->tuplehash[!dir].tuple.src.u3,
 291                          &ct->tuplehash[!dir].tuple.dst.u3,
 292                          IPPROTO_UDP, NULL, &rtcp_port);
 293
 294        if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 295                   &ct->tuplehash[!dir].tuple.dst.u3,
 296                   sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 297                   (nat_rtp_rtcp = rcu_dereference(nat_rtp_rtcp_hook)) &&
 298                   ct->status & IPS_NAT_MASK) {
 299                /* NAT needed */
 300                ret = nat_rtp_rtcp(skb, ct, ctinfo, data, dataoff,
 301                                   taddr, port, rtp_port, rtp_exp, rtcp_exp);
 302        } else {                /* Conntrack only */
 303                if (nf_ct_expect_related(rtp_exp) == 0) {
 304                        if (nf_ct_expect_related(rtcp_exp) == 0) {
 305                                pr_debug("nf_ct_h323: expect RTP ");
 306                                nf_ct_dump_tuple(&rtp_exp->tuple);
 307                                pr_debug("nf_ct_h323: expect RTCP ");
 308                                nf_ct_dump_tuple(&rtcp_exp->tuple);
 309                        } else {
 310                                nf_ct_unexpect_related(rtp_exp);
 311                                ret = -1;
 312                        }
 313                } else
 314                        ret = -1;
 315        }
 316
 317        nf_ct_expect_put(rtp_exp);
 318        nf_ct_expect_put(rtcp_exp);
 319
 320        return ret;
 321}
 322
 323/****************************************************************************/
 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 &&
 574            ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) {
 575                return NF_ACCEPT;
 576        }
 577        pr_debug("nf_ct_h245: skblen = %u\n", skb->len);
 578
 579        spin_lock_bh(&nf_h323_lock);
 580
 581        /* Process each TPKT */
 582        while (get_tpkt_data(skb, protoff, ct, ctinfo,
 583                             &data, &datalen, &dataoff)) {
 584                pr_debug("nf_ct_h245: TPKT len=%d ", datalen);
 585                nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
 586
 587                /* Decode H.245 signal */
 588                ret = DecodeMultimediaSystemControlMessage(data, datalen,
 589                                                           &mscm);
 590                if (ret < 0) {
 591                        pr_debug("nf_ct_h245: decoding error: %s\n",
 592                                 ret == H323_ERROR_BOUND ?
 593                                 "out of bound" : "out of range");
 594                        /* We don't drop when decoding error */
 595                        break;
 596                }
 597
 598                /* Process H.245 signal */
 599                if (process_h245(skb, ct, ctinfo, &data, dataoff, &mscm) < 0)
 600                        goto drop;
 601        }
 602
 603        spin_unlock_bh(&nf_h323_lock);
 604        return NF_ACCEPT;
 605
 606      drop:
 607        spin_unlock_bh(&nf_h323_lock);
 608        if (net_ratelimit())
 609                printk("nf_ct_h245: packet dropped\n");
 610        return NF_DROP;
 611}
 612
 613/****************************************************************************/
 614static const struct nf_conntrack_expect_policy h245_exp_policy = {
 615        .max_expected   = H323_RTP_CHANNEL_MAX * 4 + 2 /* T.120 */,
 616        .timeout        = 240,
 617};
 618
 619static struct nf_conntrack_helper nf_conntrack_helper_h245 __read_mostly = {
 620        .name                   = "H.245",
 621        .me                     = THIS_MODULE,
 622        .tuple.src.l3num        = AF_UNSPEC,
 623        .tuple.dst.protonum     = IPPROTO_UDP,
 624        .help                   = h245_help,
 625        .expect_policy          = &h245_exp_policy,
 626};
 627
 628/****************************************************************************/
 629int get_h225_addr(struct nf_conn *ct, unsigned char *data,
 630                  TransportAddress *taddr,
 631                  union nf_inet_addr *addr, __be16 *port)
 632{
 633        const unsigned char *p;
 634        int len;
 635
 636        switch (taddr->choice) {
 637        case eTransportAddress_ipAddress:
 638                if (nf_ct_l3num(ct) != AF_INET)
 639                        return 0;
 640                p = data + taddr->ipAddress.ip;
 641                len = 4;
 642                break;
 643        case eTransportAddress_ip6Address:
 644                if (nf_ct_l3num(ct) != AF_INET6)
 645                        return 0;
 646                p = data + taddr->ip6Address.ip;
 647                len = 16;
 648                break;
 649        default:
 650                return 0;
 651        }
 652
 653        memcpy(addr, p, len);
 654        memset((void *)addr + len, 0, sizeof(*addr) - len);
 655        memcpy(port, p + len, sizeof(__be16));
 656
 657        return 1;
 658}
 659
 660/****************************************************************************/
 661static int expect_h245(struct sk_buff *skb, struct nf_conn *ct,
 662                       enum ip_conntrack_info ctinfo,
 663                       unsigned char **data, int dataoff,
 664                       TransportAddress *taddr)
 665{
 666        int dir = CTINFO2DIR(ctinfo);
 667        int ret = 0;
 668        __be16 port;
 669        union nf_inet_addr addr;
 670        struct nf_conntrack_expect *exp;
 671        typeof(nat_h245_hook) nat_h245;
 672
 673        /* Read h245Address */
 674        if (!get_h225_addr(ct, *data, taddr, &addr, &port) ||
 675            memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 676            port == 0)
 677                return 0;
 678
 679        /* Create expect for h245 connection */
 680        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 681                return -1;
 682        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 683                          &ct->tuplehash[!dir].tuple.src.u3,
 684                          &ct->tuplehash[!dir].tuple.dst.u3,
 685                          IPPROTO_TCP, NULL, &port);
 686        exp->helper = &nf_conntrack_helper_h245;
 687
 688        if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 689                   &ct->tuplehash[!dir].tuple.dst.u3,
 690                   sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 691            (nat_h245 = rcu_dereference(nat_h245_hook)) &&
 692            ct->status & IPS_NAT_MASK) {
 693                /* NAT needed */
 694                ret = nat_h245(skb, ct, ctinfo, data, dataoff, taddr,
 695                               port, exp);
 696        } else {                /* Conntrack only */
 697                if (nf_ct_expect_related(exp) == 0) {
 698                        pr_debug("nf_ct_q931: expect H.245 ");
 699                        nf_ct_dump_tuple(&exp->tuple);
 700                } else
 701                        ret = -1;
 702        }
 703
 704        nf_ct_expect_put(exp);
 705
 706        return ret;
 707}
 708
 709/* If the calling party is on the same side of the forward-to party,
 710 * we don't need to track the second call */
 711static int callforward_do_filter(const union nf_inet_addr *src,
 712                                 const union nf_inet_addr *dst,
 713                                 u_int8_t family)
 714{
 715        const struct nf_afinfo *afinfo;
 716        struct flowi fl1, fl2;
 717        int ret = 0;
 718
 719        /* rcu_read_lock()ed by nf_hook_slow() */
 720        afinfo = nf_get_afinfo(family);
 721        if (!afinfo)
 722                return 0;
 723
 724        memset(&fl1, 0, sizeof(fl1));
 725        memset(&fl2, 0, sizeof(fl2));
 726
 727        switch (family) {
 728        case AF_INET: {
 729                struct rtable *rt1, *rt2;
 730
 731                fl1.fl4_dst = src->ip;
 732                fl2.fl4_dst = dst->ip;
 733                if (!afinfo->route((struct dst_entry **)&rt1, &fl1)) {
 734                        if (!afinfo->route((struct dst_entry **)&rt2, &fl2)) {
 735                                if (rt1->rt_gateway == rt2->rt_gateway &&
 736                                    rt1->u.dst.dev  == rt2->u.dst.dev)
 737                                        ret = 1;
 738                                dst_release(&rt2->u.dst);
 739                        }
 740                        dst_release(&rt1->u.dst);
 741                }
 742                break;
 743        }
 744#if defined(CONFIG_NF_CONNTRACK_IPV6) || \
 745    defined(CONFIG_NF_CONNTRACK_IPV6_MODULE)
 746        case AF_INET6: {
 747                struct rt6_info *rt1, *rt2;
 748
 749                memcpy(&fl1.fl6_dst, src, sizeof(fl1.fl6_dst));
 750                memcpy(&fl2.fl6_dst, dst, sizeof(fl2.fl6_dst));
 751                if (!afinfo->route((struct dst_entry **)&rt1, &fl1)) {
 752                        if (!afinfo->route((struct dst_entry **)&rt2, &fl2)) {
 753                                if (!memcmp(&rt1->rt6i_gateway, &rt2->rt6i_gateway,
 754                                            sizeof(rt1->rt6i_gateway)) &&
 755                                    rt1->u.dst.dev == rt2->u.dst.dev)
 756                                        ret = 1;
 757                                dst_release(&rt2->u.dst);
 758                        }
 759                        dst_release(&rt1->u.dst);
 760                }
 761                break;
 762        }
 763#endif
 764        }
 765        return ret;
 766
 767}
 768
 769/****************************************************************************/
 770static int expect_callforwarding(struct sk_buff *skb,
 771                                 struct nf_conn *ct,
 772                                 enum ip_conntrack_info ctinfo,
 773                                 unsigned char **data, int dataoff,
 774                                 TransportAddress *taddr)
 775{
 776        int dir = CTINFO2DIR(ctinfo);
 777        int ret = 0;
 778        __be16 port;
 779        union nf_inet_addr addr;
 780        struct nf_conntrack_expect *exp;
 781        typeof(nat_callforwarding_hook) nat_callforwarding;
 782
 783        /* Read alternativeAddress */
 784        if (!get_h225_addr(ct, *data, taddr, &addr, &port) || port == 0)
 785                return 0;
 786
 787        /* If the calling party is on the same side of the forward-to party,
 788         * we don't need to track the second call */
 789        if (callforward_filter &&
 790            callforward_do_filter(&addr, &ct->tuplehash[!dir].tuple.src.u3,
 791                                  nf_ct_l3num(ct))) {
 792                pr_debug("nf_ct_q931: Call Forwarding not tracked\n");
 793                return 0;
 794        }
 795
 796        /* Create expect for the second call leg */
 797        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 798                return -1;
 799        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 800                          &ct->tuplehash[!dir].tuple.src.u3, &addr,
 801                          IPPROTO_TCP, NULL, &port);
 802        exp->helper = nf_conntrack_helper_q931;
 803
 804        if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 805                   &ct->tuplehash[!dir].tuple.dst.u3,
 806                   sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 807            (nat_callforwarding = rcu_dereference(nat_callforwarding_hook)) &&
 808            ct->status & IPS_NAT_MASK) {
 809                /* Need NAT */
 810                ret = nat_callforwarding(skb, ct, ctinfo, data, dataoff,
 811                                         taddr, port, exp);
 812        } else {                /* Conntrack only */
 813                if (nf_ct_expect_related(exp) == 0) {
 814                        pr_debug("nf_ct_q931: expect Call Forwarding ");
 815                        nf_ct_dump_tuple(&exp->tuple);
 816                } else
 817                        ret = -1;
 818        }
 819
 820        nf_ct_expect_put(exp);
 821
 822        return ret;
 823}
 824
 825/****************************************************************************/
 826static int process_setup(struct sk_buff *skb, struct nf_conn *ct,
 827                         enum ip_conntrack_info ctinfo,
 828                         unsigned char **data, int dataoff,
 829                         Setup_UUIE *setup)
 830{
 831        int dir = CTINFO2DIR(ctinfo);
 832        int ret;
 833        int i;
 834        __be16 port;
 835        union nf_inet_addr addr;
 836        typeof(set_h225_addr_hook) set_h225_addr;
 837
 838        pr_debug("nf_ct_q931: Setup\n");
 839
 840        if (setup->options & eSetup_UUIE_h245Address) {
 841                ret = expect_h245(skb, ct, ctinfo, data, dataoff,
 842                                  &setup->h245Address);
 843                if (ret < 0)
 844                        return -1;
 845        }
 846
 847        set_h225_addr = rcu_dereference(set_h225_addr_hook);
 848        if ((setup->options & eSetup_UUIE_destCallSignalAddress) &&
 849            (set_h225_addr) && ct->status & IPS_NAT_MASK &&
 850            get_h225_addr(ct, *data, &setup->destCallSignalAddress,
 851                          &addr, &port) &&
 852            memcmp(&addr, &ct->tuplehash[!dir].tuple.src.u3, sizeof(addr))) {
 853                pr_debug("nf_ct_q931: set destCallSignalAddress "
 854                         NIP6_FMT ":%hu->" NIP6_FMT ":%hu\n",
 855                         NIP6(*(struct in6_addr *)&addr), ntohs(port),
 856                         NIP6(*(struct in6_addr *)&ct->tuplehash[!dir].tuple.src.u3),
 857                         ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port));
 858                ret = set_h225_addr(skb, data, dataoff,
 859                                    &setup->destCallSignalAddress,
 860                                    &ct->tuplehash[!dir].tuple.src.u3,
 861                                    ct->tuplehash[!dir].tuple.src.u.tcp.port);
 862                if (ret < 0)
 863                        return -1;
 864        }
 865
 866        if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) &&
 867            (set_h225_addr) && ct->status & IPS_NAT_MASK &&
 868            get_h225_addr(ct, *data, &setup->sourceCallSignalAddress,
 869                          &addr, &port) &&
 870            memcmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(addr))) {
 871                pr_debug("nf_ct_q931: set sourceCallSignalAddress "
 872                         NIP6_FMT ":%hu->" NIP6_FMT ":%hu\n",
 873                         NIP6(*(struct in6_addr *)&addr), ntohs(port),
 874                         NIP6(*(struct in6_addr *)&ct->tuplehash[!dir].tuple.dst.u3),
 875                         ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port));
 876                ret = set_h225_addr(skb, data, dataoff,
 877                                    &setup->sourceCallSignalAddress,
 878                                    &ct->tuplehash[!dir].tuple.dst.u3,
 879                                    ct->tuplehash[!dir].tuple.dst.u.tcp.port);
 880                if (ret < 0)
 881                        return -1;
 882        }
 883
 884        if (setup->options & eSetup_UUIE_fastStart) {
 885                for (i = 0; i < setup->fastStart.count; i++) {
 886                        ret = process_olc(skb, ct, ctinfo, data, dataoff,
 887                                          &setup->fastStart.item[i]);
 888                        if (ret < 0)
 889                                return -1;
 890                }
 891        }
 892
 893        return 0;
 894}
 895
 896/****************************************************************************/
 897static int process_callproceeding(struct sk_buff *skb,
 898                                  struct nf_conn *ct,
 899                                  enum ip_conntrack_info ctinfo,
 900                                  unsigned char **data, int dataoff,
 901                                  CallProceeding_UUIE *callproc)
 902{
 903        int ret;
 904        int i;
 905
 906        pr_debug("nf_ct_q931: CallProceeding\n");
 907
 908        if (callproc->options & eCallProceeding_UUIE_h245Address) {
 909                ret = expect_h245(skb, ct, ctinfo, data, dataoff,
 910                                  &callproc->h245Address);
 911                if (ret < 0)
 912                        return -1;
 913        }
 914
 915        if (callproc->options & eCallProceeding_UUIE_fastStart) {
 916                for (i = 0; i < callproc->fastStart.count; i++) {
 917                        ret = process_olc(skb, ct, ctinfo, data, dataoff,
 918                                          &callproc->fastStart.item[i]);
 919                        if (ret < 0)
 920                                return -1;
 921                }
 922        }
 923
 924        return 0;
 925}
 926
 927/****************************************************************************/
 928static int process_connect(struct sk_buff *skb, struct nf_conn *ct,
 929                           enum ip_conntrack_info ctinfo,
 930                           unsigned char **data, int dataoff,
 931                           Connect_UUIE *connect)
 932{
 933        int ret;
 934        int i;
 935
 936        pr_debug("nf_ct_q931: Connect\n");
 937
 938        if (connect->options & eConnect_UUIE_h245Address) {
 939                ret = expect_h245(skb, ct, ctinfo, data, dataoff,
 940                                  &connect->h245Address);
 941                if (ret < 0)
 942                        return -1;
 943        }
 944
 945        if (connect->options & eConnect_UUIE_fastStart) {
 946                for (i = 0; i < connect->fastStart.count; i++) {
 947                        ret = process_olc(skb, ct, ctinfo, data, dataoff,
 948                                          &connect->fastStart.item[i]);
 949                        if (ret < 0)
 950                                return -1;
 951                }
 952        }
 953
 954        return 0;
 955}
 956
 957/****************************************************************************/
 958static int process_alerting(struct sk_buff *skb, struct nf_conn *ct,
 959                            enum ip_conntrack_info ctinfo,
 960                            unsigned char **data, int dataoff,
 961                            Alerting_UUIE *alert)
 962{
 963        int ret;
 964        int i;
 965
 966        pr_debug("nf_ct_q931: Alerting\n");
 967
 968        if (alert->options & eAlerting_UUIE_h245Address) {
 969                ret = expect_h245(skb, ct, ctinfo, data, dataoff,
 970                                  &alert->h245Address);
 971                if (ret < 0)
 972                        return -1;
 973        }
 974
 975        if (alert->options & eAlerting_UUIE_fastStart) {
 976                for (i = 0; i < alert->fastStart.count; i++) {
 977                        ret = process_olc(skb, ct, ctinfo, data, dataoff,
 978                                          &alert->fastStart.item[i]);
 979                        if (ret < 0)
 980                                return -1;
 981                }
 982        }
 983
 984        return 0;
 985}
 986
 987/****************************************************************************/
 988static int process_facility(struct sk_buff *skb, struct nf_conn *ct,
 989                            enum ip_conntrack_info ctinfo,
 990                            unsigned char **data, int dataoff,
 991                            Facility_UUIE *facility)
 992{
 993        int ret;
 994        int i;
 995
 996        pr_debug("nf_ct_q931: Facility\n");
 997
 998        if (facility->reason.choice == eFacilityReason_callForwarded) {
 999                if (facility->options & eFacility_UUIE_alternativeAddress)
1000                        return expect_callforwarding(skb, ct, ctinfo, data,
1001                                                     dataoff,
1002                                                     &facility->
1003                                                     alternativeAddress);
1004                return 0;
1005        }
1006
1007        if (facility->options & eFacility_UUIE_h245Address) {
1008                ret = expect_h245(skb, ct, ctinfo, data, dataoff,
1009                                  &facility->h245Address);
1010                if (ret < 0)
1011                        return -1;
1012        }
1013
1014        if (facility->options & eFacility_UUIE_fastStart) {
1015                for (i = 0; i < facility->fastStart.count; i++) {
1016                        ret = process_olc(skb, ct, ctinfo, data, dataoff,
1017                                          &facility->fastStart.item[i]);
1018                        if (ret < 0)
1019                                return -1;
1020                }
1021        }
1022
1023        return 0;
1024}
1025
1026/****************************************************************************/
1027static int process_progress(struct sk_buff *skb, struct nf_conn *ct,
1028                            enum ip_conntrack_info ctinfo,
1029                            unsigned char **data, int dataoff,
1030                            Progress_UUIE *progress)
1031{
1032        int ret;
1033        int i;
1034
1035        pr_debug("nf_ct_q931: Progress\n");
1036
1037        if (progress->options & eProgress_UUIE_h245Address) {
1038                ret = expect_h245(skb, ct, ctinfo, data, dataoff,
1039                                  &progress->h245Address);
1040                if (ret < 0)
1041                        return -1;
1042        }
1043
1044        if (progress->options & eProgress_UUIE_fastStart) {
1045                for (i = 0; i < progress->fastStart.count; i++) {
1046                        ret = process_olc(skb, ct, ctinfo, data, dataoff,
1047                                          &progress->fastStart.item[i]);
1048                        if (ret < 0)
1049                                return -1;
1050                }
1051        }
1052
1053        return 0;
1054}
1055
1056/****************************************************************************/
1057static int process_q931(struct sk_buff *skb, struct nf_conn *ct,
1058                        enum ip_conntrack_info ctinfo,
1059                        unsigned char **data, int dataoff, Q931 *q931)
1060{
1061        H323_UU_PDU *pdu = &q931->UUIE.h323_uu_pdu;
1062        int i;
1063        int ret = 0;
1064
1065        switch (pdu->h323_message_body.choice) {
1066        case eH323_UU_PDU_h323_message_body_setup:
1067                ret = process_setup(skb, ct, ctinfo, data, dataoff,
1068                                    &pdu->h323_message_body.setup);
1069                break;
1070        case eH323_UU_PDU_h323_message_body_callProceeding:
1071                ret = process_callproceeding(skb, ct, ctinfo, data, dataoff,
1072                                             &pdu->h323_message_body.
1073                                             callProceeding);
1074                break;
1075        case eH323_UU_PDU_h323_message_body_connect:
1076                ret = process_connect(skb, ct, ctinfo, data, dataoff,
1077                                      &pdu->h323_message_body.connect);
1078                break;
1079        case eH323_UU_PDU_h323_message_body_alerting:
1080                ret = process_alerting(skb, ct, ctinfo, data, dataoff,
1081                                       &pdu->h323_message_body.alerting);
1082                break;
1083        case eH323_UU_PDU_h323_message_body_facility:
1084                ret = process_facility(skb, ct, ctinfo, data, dataoff,
1085                                       &pdu->h323_message_body.facility);
1086                break;
1087        case eH323_UU_PDU_h323_message_body_progress:
1088                ret = process_progress(skb, ct, ctinfo, data, dataoff,
1089                                       &pdu->h323_message_body.progress);
1090                break;
1091        default:
1092                pr_debug("nf_ct_q931: Q.931 signal %d\n",
1093                         pdu->h323_message_body.choice);
1094                break;
1095        }
1096
1097        if (ret < 0)
1098                return -1;
1099
1100        if (pdu->options & eH323_UU_PDU_h245Control) {
1101                for (i = 0; i < pdu->h245Control.count; i++) {
1102                        ret = process_h245(skb, ct, ctinfo, data, dataoff,
1103                                           &pdu->h245Control.item[i]);
1104                        if (ret < 0)
1105                                return -1;
1106                }
1107        }
1108
1109        return 0;
1110}
1111
1112/****************************************************************************/
1113static int q931_help(struct sk_buff *skb, unsigned int protoff,
1114                     struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1115{
1116        static Q931 q931;
1117        unsigned char *data = NULL;
1118        int datalen;
1119        int dataoff;
1120        int ret;
1121
1122        /* Until there's been traffic both ways, don't look in packets. */
1123        if (ctinfo != IP_CT_ESTABLISHED &&
1124            ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) {
1125                return NF_ACCEPT;
1126        }
1127        pr_debug("nf_ct_q931: skblen = %u\n", skb->len);
1128
1129        spin_lock_bh(&nf_h323_lock);
1130
1131        /* Process each TPKT */
1132        while (get_tpkt_data(skb, protoff, ct, ctinfo,
1133                             &data, &datalen, &dataoff)) {
1134                pr_debug("nf_ct_q931: TPKT len=%d ", datalen);
1135                nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1136
1137                /* Decode Q.931 signal */
1138                ret = DecodeQ931(data, datalen, &q931);
1139                if (ret < 0) {
1140                        pr_debug("nf_ct_q931: decoding error: %s\n",
1141                                 ret == H323_ERROR_BOUND ?
1142                                 "out of bound" : "out of range");
1143                        /* We don't drop when decoding error */
1144                        break;
1145                }
1146
1147                /* Process Q.931 signal */
1148                if (process_q931(skb, ct, ctinfo, &data, dataoff, &q931) < 0)
1149                        goto drop;
1150        }
1151
1152        spin_unlock_bh(&nf_h323_lock);
1153        return NF_ACCEPT;
1154
1155      drop:
1156        spin_unlock_bh(&nf_h323_lock);
1157        if (net_ratelimit())
1158                printk("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                .tuple.src.l3num        = AF_INET,
1174                .tuple.src.u.tcp.port   = __constant_htons(Q931_PORT),
1175                .tuple.dst.protonum     = IPPROTO_TCP,
1176                .help                   = q931_help,
1177                .expect_policy          = &q931_exp_policy,
1178        },
1179        {
1180                .name                   = "Q.931",
1181                .me                     = THIS_MODULE,
1182                .tuple.src.l3num        = AF_INET6,
1183                .tuple.src.u.tcp.port   = __constant_htons(Q931_PORT),
1184                .tuple.dst.protonum     = IPPROTO_TCP,
1185                .help                   = q931_help,
1186                .expect_policy          = &q931_exp_policy,
1187        },
1188};
1189
1190/****************************************************************************/
1191static unsigned char *get_udp_data(struct sk_buff *skb, unsigned int protoff,
1192                                   int *datalen)
1193{
1194        const struct udphdr *uh;
1195        struct udphdr _uh;
1196        int dataoff;
1197
1198        uh = skb_header_pointer(skb, protoff, sizeof(_uh), &_uh);
1199        if (uh == NULL)
1200                return NULL;
1201        dataoff = protoff + sizeof(_uh);
1202        if (dataoff >= skb->len)
1203                return NULL;
1204        *datalen = skb->len - dataoff;
1205        return skb_header_pointer(skb, dataoff, *datalen, h323_buffer);
1206}
1207
1208/****************************************************************************/
1209static struct nf_conntrack_expect *find_expect(struct nf_conn *ct,
1210                                               union nf_inet_addr *addr,
1211                                               __be16 port)
1212{
1213        struct net *net = nf_ct_net(ct);
1214        struct nf_conntrack_expect *exp;
1215        struct nf_conntrack_tuple tuple;
1216
1217        memset(&tuple.src.u3, 0, sizeof(tuple.src.u3));
1218        tuple.src.u.tcp.port = 0;
1219        memcpy(&tuple.dst.u3, addr, sizeof(tuple.dst.u3));
1220        tuple.dst.u.tcp.port = port;
1221        tuple.dst.protonum = IPPROTO_TCP;
1222
1223        exp = __nf_ct_expect_find(net, &tuple);
1224        if (exp && exp->master == ct)
1225                return exp;
1226        return NULL;
1227}
1228
1229/****************************************************************************/
1230static int set_expect_timeout(struct nf_conntrack_expect *exp,
1231                              unsigned timeout)
1232{
1233        if (!exp || !del_timer(&exp->timeout))
1234                return 0;
1235
1236        exp->timeout.expires = jiffies + timeout * HZ;
1237        add_timer(&exp->timeout);
1238
1239        return 1;
1240}
1241
1242/****************************************************************************/
1243static int expect_q931(struct sk_buff *skb, struct nf_conn *ct,
1244                       enum ip_conntrack_info ctinfo,
1245                       unsigned char **data,
1246                       TransportAddress *taddr, int count)
1247{
1248        struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1249        int dir = CTINFO2DIR(ctinfo);
1250        int ret = 0;
1251        int i;
1252        __be16 port;
1253        union nf_inet_addr addr;
1254        struct nf_conntrack_expect *exp;
1255        typeof(nat_q931_hook) nat_q931;
1256
1257        /* Look for the first related address */
1258        for (i = 0; i < count; i++) {
1259                if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) &&
1260                    memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3,
1261                           sizeof(addr)) == 0 && port != 0)
1262                        break;
1263        }
1264
1265        if (i >= count)         /* Not found */
1266                return 0;
1267
1268        /* Create expect for Q.931 */
1269        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1270                return -1;
1271        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1272                          gkrouted_only ? /* only accept calls from GK? */
1273                                &ct->tuplehash[!dir].tuple.src.u3 : NULL,
1274                          &ct->tuplehash[!dir].tuple.dst.u3,
1275                          IPPROTO_TCP, NULL, &port);
1276        exp->helper = nf_conntrack_helper_q931;
1277        exp->flags = NF_CT_EXPECT_PERMANENT;    /* Accept multiple calls */
1278
1279        nat_q931 = rcu_dereference(nat_q931_hook);
1280        if (nat_q931 && ct->status & IPS_NAT_MASK) {    /* Need NAT */
1281                ret = nat_q931(skb, ct, ctinfo, data, taddr, i, port, exp);
1282        } else {                /* Conntrack only */
1283                if (nf_ct_expect_related(exp) == 0) {
1284                        pr_debug("nf_ct_ras: expect Q.931 ");
1285                        nf_ct_dump_tuple(&exp->tuple);
1286
1287                        /* Save port for looking up expect in processing RCF */
1288                        info->sig_port[dir] = port;
1289                } else
1290                        ret = -1;
1291        }
1292
1293        nf_ct_expect_put(exp);
1294
1295        return ret;
1296}
1297
1298/****************************************************************************/
1299static int process_grq(struct sk_buff *skb, struct nf_conn *ct,
1300                       enum ip_conntrack_info ctinfo,
1301                       unsigned char **data, GatekeeperRequest *grq)
1302{
1303        typeof(set_ras_addr_hook) set_ras_addr;
1304
1305        pr_debug("nf_ct_ras: GRQ\n");
1306
1307        set_ras_addr = rcu_dereference(set_ras_addr_hook);
1308        if (set_ras_addr && ct->status & IPS_NAT_MASK)  /* NATed */
1309                return set_ras_addr(skb, ct, ctinfo, data,
1310                                    &grq->rasAddress, 1);
1311        return 0;
1312}
1313
1314/****************************************************************************/
1315static int process_gcf(struct sk_buff *skb, struct nf_conn *ct,
1316                       enum ip_conntrack_info ctinfo,
1317                       unsigned char **data, GatekeeperConfirm *gcf)
1318{
1319        int dir = CTINFO2DIR(ctinfo);
1320        int ret = 0;
1321        __be16 port;
1322        union nf_inet_addr addr;
1323        struct nf_conntrack_expect *exp;
1324
1325        pr_debug("nf_ct_ras: GCF\n");
1326
1327        if (!get_h225_addr(ct, *data, &gcf->rasAddress, &addr, &port))
1328                return 0;
1329
1330        /* Registration port is the same as discovery port */
1331        if (!memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1332            port == ct->tuplehash[dir].tuple.src.u.udp.port)
1333                return 0;
1334
1335        /* Avoid RAS expectation loops. A GCF is never expected. */
1336        if (test_bit(IPS_EXPECTED_BIT, &ct->status))
1337                return 0;
1338
1339        /* Need new expect */
1340        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1341                return -1;
1342        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1343                          &ct->tuplehash[!dir].tuple.src.u3, &addr,
1344                          IPPROTO_UDP, NULL, &port);
1345        exp->helper = nf_conntrack_helper_ras;
1346
1347        if (nf_ct_expect_related(exp) == 0) {
1348                pr_debug("nf_ct_ras: expect RAS ");
1349                nf_ct_dump_tuple(&exp->tuple);
1350        } else
1351                ret = -1;
1352
1353        nf_ct_expect_put(exp);
1354
1355        return ret;
1356}
1357
1358/****************************************************************************/
1359static int process_rrq(struct sk_buff *skb, struct nf_conn *ct,
1360                       enum ip_conntrack_info ctinfo,
1361                       unsigned char **data, RegistrationRequest *rrq)
1362{
1363        struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1364        int ret;
1365        typeof(set_ras_addr_hook) set_ras_addr;
1366
1367        pr_debug("nf_ct_ras: RRQ\n");
1368
1369        ret = expect_q931(skb, ct, ctinfo, data,
1370                          rrq->callSignalAddress.item,
1371                          rrq->callSignalAddress.count);
1372        if (ret < 0)
1373                return -1;
1374
1375        set_ras_addr = rcu_dereference(set_ras_addr_hook);
1376        if (set_ras_addr && ct->status & IPS_NAT_MASK) {
1377                ret = set_ras_addr(skb, ct, ctinfo, data,
1378                                   rrq->rasAddress.item,
1379                                   rrq->rasAddress.count);
1380                if (ret < 0)
1381                        return -1;
1382        }
1383
1384        if (rrq->options & eRegistrationRequest_timeToLive) {
1385                pr_debug("nf_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive);
1386                info->timeout = rrq->timeToLive;
1387        } else
1388                info->timeout = default_rrq_ttl;
1389
1390        return 0;
1391}
1392
1393/****************************************************************************/
1394static int process_rcf(struct sk_buff *skb, struct nf_conn *ct,
1395                       enum ip_conntrack_info ctinfo,
1396                       unsigned char **data, RegistrationConfirm *rcf)
1397{
1398        struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1399        int dir = CTINFO2DIR(ctinfo);
1400        int ret;
1401        struct nf_conntrack_expect *exp;
1402        typeof(set_sig_addr_hook) set_sig_addr;
1403
1404        pr_debug("nf_ct_ras: RCF\n");
1405
1406        set_sig_addr = rcu_dereference(set_sig_addr_hook);
1407        if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1408                ret = set_sig_addr(skb, ct, ctinfo, data,
1409                                        rcf->callSignalAddress.item,
1410                                        rcf->callSignalAddress.count);
1411                if (ret < 0)
1412                        return -1;
1413        }
1414
1415        if (rcf->options & eRegistrationConfirm_timeToLive) {
1416                pr_debug("nf_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive);
1417                info->timeout = rcf->timeToLive;
1418        }
1419
1420        if (info->timeout > 0) {
1421                pr_debug("nf_ct_ras: set RAS connection timeout to "
1422                         "%u seconds\n", info->timeout);
1423                nf_ct_refresh(ct, skb, info->timeout * HZ);
1424
1425                /* Set expect timeout */
1426                spin_lock_bh(&nf_conntrack_lock);
1427                exp = find_expect(ct, &ct->tuplehash[dir].tuple.dst.u3,
1428                                  info->sig_port[!dir]);
1429                if (exp) {
1430                        pr_debug("nf_ct_ras: set Q.931 expect "
1431                                 "timeout to %u seconds for",
1432                                 info->timeout);
1433                        nf_ct_dump_tuple(&exp->tuple);
1434                        set_expect_timeout(exp, info->timeout);
1435                }
1436                spin_unlock_bh(&nf_conntrack_lock);
1437        }
1438
1439        return 0;
1440}
1441
1442/****************************************************************************/
1443static int process_urq(struct sk_buff *skb, struct nf_conn *ct,
1444                       enum ip_conntrack_info ctinfo,
1445                       unsigned char **data, UnregistrationRequest *urq)
1446{
1447        struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1448        int dir = CTINFO2DIR(ctinfo);
1449        int ret;
1450        typeof(set_sig_addr_hook) set_sig_addr;
1451
1452        pr_debug("nf_ct_ras: URQ\n");
1453
1454        set_sig_addr = rcu_dereference(set_sig_addr_hook);
1455        if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1456                ret = set_sig_addr(skb, ct, ctinfo, data,
1457                                   urq->callSignalAddress.item,
1458                                   urq->callSignalAddress.count);
1459                if (ret < 0)
1460                        return -1;
1461        }
1462
1463        /* Clear old expect */
1464        nf_ct_remove_expectations(ct);
1465        info->sig_port[dir] = 0;
1466        info->sig_port[!dir] = 0;
1467
1468        /* Give it 30 seconds for UCF or URJ */
1469        nf_ct_refresh(ct, skb, 30 * HZ);
1470
1471        return 0;
1472}
1473
1474/****************************************************************************/
1475static int process_arq(struct sk_buff *skb, struct nf_conn *ct,
1476                       enum ip_conntrack_info ctinfo,
1477                       unsigned char **data, AdmissionRequest *arq)
1478{
1479        const struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1480        int dir = CTINFO2DIR(ctinfo);
1481        __be16 port;
1482        union nf_inet_addr addr;
1483        typeof(set_h225_addr_hook) set_h225_addr;
1484
1485        pr_debug("nf_ct_ras: ARQ\n");
1486
1487        set_h225_addr = rcu_dereference(set_h225_addr_hook);
1488        if ((arq->options & eAdmissionRequest_destCallSignalAddress) &&
1489            get_h225_addr(ct, *data, &arq->destCallSignalAddress,
1490                          &addr, &port) &&
1491            !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1492            port == info->sig_port[dir] &&
1493            set_h225_addr && ct->status & IPS_NAT_MASK) {
1494                /* Answering ARQ */
1495                return set_h225_addr(skb, data, 0,
1496                                     &arq->destCallSignalAddress,
1497                                     &ct->tuplehash[!dir].tuple.dst.u3,
1498                                     info->sig_port[!dir]);
1499        }
1500
1501        if ((arq->options & eAdmissionRequest_srcCallSignalAddress) &&
1502            get_h225_addr(ct, *data, &arq->srcCallSignalAddress,
1503                          &addr, &port) &&
1504            !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1505            set_h225_addr && ct->status & IPS_NAT_MASK) {
1506                /* Calling ARQ */
1507                return set_h225_addr(skb, data, 0,
1508                                     &arq->srcCallSignalAddress,
1509                                     &ct->tuplehash[!dir].tuple.dst.u3,
1510                                     port);
1511        }
1512
1513        return 0;
1514}
1515
1516/****************************************************************************/
1517static int process_acf(struct sk_buff *skb, struct nf_conn *ct,
1518                       enum ip_conntrack_info ctinfo,
1519                       unsigned char **data, AdmissionConfirm *acf)
1520{
1521        int dir = CTINFO2DIR(ctinfo);
1522        int ret = 0;
1523        __be16 port;
1524        union nf_inet_addr addr;
1525        struct nf_conntrack_expect *exp;
1526        typeof(set_sig_addr_hook) set_sig_addr;
1527
1528        pr_debug("nf_ct_ras: ACF\n");
1529
1530        if (!get_h225_addr(ct, *data, &acf->destCallSignalAddress,
1531                           &addr, &port))
1532                return 0;
1533
1534        if (!memcmp(&addr, &ct->tuplehash[dir].tuple.dst.u3, sizeof(addr))) {
1535                /* Answering ACF */
1536                set_sig_addr = rcu_dereference(set_sig_addr_hook);
1537                if (set_sig_addr && ct->status & IPS_NAT_MASK)
1538                        return set_sig_addr(skb, ct, ctinfo, data,
1539                                            &acf->destCallSignalAddress, 1);
1540                return 0;
1541        }
1542
1543        /* Need new expect */
1544        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1545                return -1;
1546        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1547                          &ct->tuplehash[!dir].tuple.src.u3, &addr,
1548                          IPPROTO_TCP, NULL, &port);
1549        exp->flags = NF_CT_EXPECT_PERMANENT;
1550        exp->helper = nf_conntrack_helper_q931;
1551
1552        if (nf_ct_expect_related(exp) == 0) {
1553                pr_debug("nf_ct_ras: expect Q.931 ");
1554                nf_ct_dump_tuple(&exp->tuple);
1555        } else
1556                ret = -1;
1557
1558        nf_ct_expect_put(exp);
1559
1560        return ret;
1561}
1562
1563/****************************************************************************/
1564static int process_lrq(struct sk_buff *skb, struct nf_conn *ct,
1565                       enum ip_conntrack_info ctinfo,
1566                       unsigned char **data, LocationRequest *lrq)
1567{
1568        typeof(set_ras_addr_hook) set_ras_addr;
1569
1570        pr_debug("nf_ct_ras: LRQ\n");
1571
1572        set_ras_addr = rcu_dereference(set_ras_addr_hook);
1573        if (set_ras_addr && ct->status & IPS_NAT_MASK)
1574                return set_ras_addr(skb, ct, ctinfo, data,
1575                                    &lrq->replyAddress, 1);
1576        return 0;
1577}
1578
1579/****************************************************************************/
1580static int process_lcf(struct sk_buff *skb, struct nf_conn *ct,
1581                       enum ip_conntrack_info ctinfo,
1582                       unsigned char **data, LocationConfirm *lcf)
1583{
1584        int dir = CTINFO2DIR(ctinfo);
1585        int ret = 0;
1586        __be16 port;
1587        union nf_inet_addr addr;
1588        struct nf_conntrack_expect *exp;
1589
1590        pr_debug("nf_ct_ras: LCF\n");
1591
1592        if (!get_h225_addr(ct, *data, &lcf->callSignalAddress,
1593                           &addr, &port))
1594                return 0;
1595
1596        /* Need new expect for call signal */
1597        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1598                return -1;
1599        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1600                          &ct->tuplehash[!dir].tuple.src.u3, &addr,
1601                          IPPROTO_TCP, NULL, &port);
1602        exp->flags = NF_CT_EXPECT_PERMANENT;
1603        exp->helper = nf_conntrack_helper_q931;
1604
1605        if (nf_ct_expect_related(exp) == 0) {
1606                pr_debug("nf_ct_ras: expect Q.931 ");
1607                nf_ct_dump_tuple(&exp->tuple);
1608        } else
1609                ret = -1;
1610
1611        nf_ct_expect_put(exp);
1612
1613        /* Ignore rasAddress */
1614
1615        return ret;
1616}
1617
1618/****************************************************************************/
1619static int process_irr(struct sk_buff *skb, struct nf_conn *ct,
1620                       enum ip_conntrack_info ctinfo,
1621                       unsigned char **data, InfoRequestResponse *irr)
1622{
1623        int ret;
1624        typeof(set_ras_addr_hook) set_ras_addr;
1625        typeof(set_sig_addr_hook) set_sig_addr;
1626
1627        pr_debug("nf_ct_ras: IRR\n");
1628
1629        set_ras_addr = rcu_dereference(set_ras_addr_hook);
1630        if (set_ras_addr && ct->status & IPS_NAT_MASK) {
1631                ret = set_ras_addr(skb, ct, ctinfo, data,
1632                                   &irr->rasAddress, 1);
1633                if (ret < 0)
1634                        return -1;
1635        }
1636
1637        set_sig_addr = rcu_dereference(set_sig_addr_hook);
1638        if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1639                ret = set_sig_addr(skb, ct, ctinfo, data,
1640                                        irr->callSignalAddress.item,
1641                                        irr->callSignalAddress.count);
1642                if (ret < 0)
1643                        return -1;
1644        }
1645
1646        return 0;
1647}
1648
1649/****************************************************************************/
1650static int process_ras(struct sk_buff *skb, struct nf_conn *ct,
1651                       enum ip_conntrack_info ctinfo,
1652                       unsigned char **data, RasMessage *ras)
1653{
1654        switch (ras->choice) {
1655        case eRasMessage_gatekeeperRequest:
1656                return process_grq(skb, ct, ctinfo, data,
1657                                   &ras->gatekeeperRequest);
1658        case eRasMessage_gatekeeperConfirm:
1659                return process_gcf(skb, ct, ctinfo, data,
1660                                   &ras->gatekeeperConfirm);
1661        case eRasMessage_registrationRequest:
1662                return process_rrq(skb, ct, ctinfo, data,
1663                                   &ras->registrationRequest);
1664        case eRasMessage_registrationConfirm:
1665                return process_rcf(skb, ct, ctinfo, data,
1666                                   &ras->registrationConfirm);
1667        case eRasMessage_unregistrationRequest:
1668                return process_urq(skb, ct, ctinfo, data,
1669                                   &ras->unregistrationRequest);
1670        case eRasMessage_admissionRequest:
1671                return process_arq(skb, ct, ctinfo, data,
1672                                   &ras->admissionRequest);
1673        case eRasMessage_admissionConfirm:
1674                return process_acf(skb, ct, ctinfo, data,
1675                                   &ras->admissionConfirm);
1676        case eRasMessage_locationRequest:
1677                return process_lrq(skb, ct, ctinfo, data,
1678                                   &ras->locationRequest);
1679        case eRasMessage_locationConfirm:
1680                return process_lcf(skb, ct, ctinfo, data,
1681                                   &ras->locationConfirm);
1682        case eRasMessage_infoRequestResponse:
1683                return process_irr(skb, ct, ctinfo, data,
1684                                   &ras->infoRequestResponse);
1685        default:
1686                pr_debug("nf_ct_ras: RAS message %d\n", ras->choice);
1687                break;
1688        }
1689
1690        return 0;
1691}
1692
1693/****************************************************************************/
1694static int ras_help(struct sk_buff *skb, unsigned int protoff,
1695                    struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1696{
1697        static RasMessage ras;
1698        unsigned char *data;
1699        int datalen = 0;
1700        int ret;
1701
1702        pr_debug("nf_ct_ras: skblen = %u\n", skb->len);
1703
1704        spin_lock_bh(&nf_h323_lock);
1705
1706        /* Get UDP data */
1707        data = get_udp_data(skb, protoff, &datalen);
1708        if (data == NULL)
1709                goto accept;
1710        pr_debug("nf_ct_ras: RAS message len=%d ", datalen);
1711        nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1712
1713        /* Decode RAS message */
1714        ret = DecodeRasMessage(data, datalen, &ras);
1715        if (ret < 0) {
1716                pr_debug("nf_ct_ras: decoding error: %s\n",
1717                         ret == H323_ERROR_BOUND ?
1718                         "out of bound" : "out of range");
1719                goto accept;
1720        }
1721
1722        /* Process RAS message */
1723        if (process_ras(skb, ct, ctinfo, &data, &ras) < 0)
1724                goto drop;
1725
1726      accept:
1727        spin_unlock_bh(&nf_h323_lock);
1728        return NF_ACCEPT;
1729
1730      drop:
1731        spin_unlock_bh(&nf_h323_lock);
1732        if (net_ratelimit())
1733                printk("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                .tuple.src.l3num        = AF_INET,
1748                .tuple.src.u.udp.port   = __constant_htons(RAS_PORT),
1749                .tuple.dst.protonum     = IPPROTO_UDP,
1750                .help                   = ras_help,
1751                .expect_policy          = &ras_exp_policy,
1752        },
1753        {
1754                .name                   = "RAS",
1755                .me                     = THIS_MODULE,
1756                .tuple.src.l3num        = AF_INET6,
1757                .tuple.src.u.udp.port   = __constant_htons(RAS_PORT),
1758                .tuple.dst.protonum     = IPPROTO_UDP,
1759                .help                   = ras_help,
1760                .expect_policy          = &ras_exp_policy,
1761        },
1762};
1763
1764/****************************************************************************/
1765static void __exit nf_conntrack_h323_fini(void)
1766{
1767        nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[1]);
1768        nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1769        nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1770        nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1771        nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1772        kfree(h323_buffer);
1773        pr_debug("nf_ct_h323: fini\n");
1774}
1775
1776/****************************************************************************/
1777static int __init nf_conntrack_h323_init(void)
1778{
1779        int ret;
1780
1781        h323_buffer = kmalloc(65536, GFP_KERNEL);
1782        if (!h323_buffer)
1783                return -ENOMEM;
1784        ret = nf_conntrack_helper_register(&nf_conntrack_helper_h245);
1785        if (ret < 0)
1786                goto err1;
1787        ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[0]);
1788        if (ret < 0)
1789                goto err2;
1790        ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[1]);
1791        if (ret < 0)
1792                goto err3;
1793        ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[0]);
1794        if (ret < 0)
1795                goto err4;
1796        ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[1]);
1797        if (ret < 0)
1798                goto err5;
1799        pr_debug("nf_ct_h323: init success\n");
1800        return 0;
1801
1802err5:
1803        nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1804err4:
1805        nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1806err3:
1807        nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1808err2:
1809        nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1810err1:
1811        kfree(h323_buffer);
1812        return ret;
1813}
1814
1815/****************************************************************************/
1816module_init(nf_conntrack_h323_init);
1817module_exit(nf_conntrack_h323_fini);
1818
1819EXPORT_SYMBOL_GPL(get_h225_addr);
1820EXPORT_SYMBOL_GPL(set_h245_addr_hook);
1821EXPORT_SYMBOL_GPL(set_h225_addr_hook);
1822EXPORT_SYMBOL_GPL(set_sig_addr_hook);
1823EXPORT_SYMBOL_GPL(set_ras_addr_hook);
1824EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook);
1825EXPORT_SYMBOL_GPL(nat_t120_hook);
1826EXPORT_SYMBOL_GPL(nat_h245_hook);
1827EXPORT_SYMBOL_GPL(nat_callforwarding_hook);
1828EXPORT_SYMBOL_GPL(nat_q931_hook);
1829
1830MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>");
1831MODULE_DESCRIPTION("H.323 connection tracking helper");
1832MODULE_LICENSE("GPL");
1833MODULE_ALIAS("ip_conntrack_h323");
1834