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 * Copyright (c) 2006-2012 Patrick McHardy <kaber@trash.net>
   6 *
   7 * This source code is licensed under General Public License version 2.
   8 *
   9 * Based on the 'brute force' H.323 connection tracking module by
  10 * Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
  11 *
  12 * For more information, please see http://nath323.sourceforge.net/
  13 */
  14
  15#include <linux/module.h>
  16#include <linux/moduleparam.h>
  17#include <linux/ctype.h>
  18#include <linux/inet.h>
  19#include <linux/in.h>
  20#include <linux/ip.h>
  21#include <linux/slab.h>
  22#include <linux/udp.h>
  23#include <linux/tcp.h>
  24#include <linux/skbuff.h>
  25#include <net/route.h>
  26#include <net/ip6_route.h>
  27
  28#include <net/netfilter/nf_conntrack.h>
  29#include <net/netfilter/nf_conntrack_core.h>
  30#include <net/netfilter/nf_conntrack_tuple.h>
  31#include <net/netfilter/nf_conntrack_expect.h>
  32#include <net/netfilter/nf_conntrack_ecache.h>
  33#include <net/netfilter/nf_conntrack_helper.h>
  34#include <net/netfilter/nf_conntrack_zones.h>
  35#include <linux/netfilter/nf_conntrack_h323.h>
  36
  37/* Parameters */
  38static unsigned int default_rrq_ttl __read_mostly = 300;
  39module_param(default_rrq_ttl, uint, 0600);
  40MODULE_PARM_DESC(default_rrq_ttl, "use this TTL if it's missing in RRQ");
  41
  42static int gkrouted_only __read_mostly = 1;
  43module_param(gkrouted_only, int, 0600);
  44MODULE_PARM_DESC(gkrouted_only, "only accept calls from gatekeeper");
  45
  46static bool callforward_filter __read_mostly = true;
  47module_param(callforward_filter, bool, 0600);
  48MODULE_PARM_DESC(callforward_filter, "only create call forwarding expectations "
  49                                     "if both endpoints are on different sides "
  50                                     "(determined by routing information)");
  51
  52/* Hooks for NAT */
  53int (*set_h245_addr_hook) (struct sk_buff *skb, unsigned int protoff,
  54                           unsigned char **data, int dataoff,
  55                           H245_TransportAddress *taddr,
  56                           union nf_inet_addr *addr, __be16 port)
  57                           __read_mostly;
  58int (*set_h225_addr_hook) (struct sk_buff *skb, unsigned int protoff,
  59                           unsigned char **data, int dataoff,
  60                           TransportAddress *taddr,
  61                           union nf_inet_addr *addr, __be16 port)
  62                           __read_mostly;
  63int (*set_sig_addr_hook) (struct sk_buff *skb,
  64                          struct nf_conn *ct,
  65                          enum ip_conntrack_info ctinfo,
  66                          unsigned int protoff, unsigned char **data,
  67                          TransportAddress *taddr, int count) __read_mostly;
  68int (*set_ras_addr_hook) (struct sk_buff *skb,
  69                          struct nf_conn *ct,
  70                          enum ip_conntrack_info ctinfo,
  71                          unsigned int protoff, unsigned char **data,
  72                          TransportAddress *taddr, int count) __read_mostly;
  73int (*nat_rtp_rtcp_hook) (struct sk_buff *skb,
  74                          struct nf_conn *ct,
  75                          enum ip_conntrack_info ctinfo,
  76                          unsigned int protoff,
  77                          unsigned char **data, int dataoff,
  78                          H245_TransportAddress *taddr,
  79                          __be16 port, __be16 rtp_port,
  80                          struct nf_conntrack_expect *rtp_exp,
  81                          struct nf_conntrack_expect *rtcp_exp) __read_mostly;
  82int (*nat_t120_hook) (struct sk_buff *skb,
  83                      struct nf_conn *ct,
  84                      enum ip_conntrack_info ctinfo,
  85                      unsigned int protoff,
  86                      unsigned char **data, int dataoff,
  87                      H245_TransportAddress *taddr, __be16 port,
  88                      struct nf_conntrack_expect *exp) __read_mostly;
  89int (*nat_h245_hook) (struct sk_buff *skb,
  90                      struct nf_conn *ct,
  91                      enum ip_conntrack_info ctinfo,
  92                      unsigned int protoff,
  93                      unsigned char **data, int dataoff,
  94                      TransportAddress *taddr, __be16 port,
  95                      struct nf_conntrack_expect *exp) __read_mostly;
  96int (*nat_callforwarding_hook) (struct sk_buff *skb,
  97                                struct nf_conn *ct,
  98                                enum ip_conntrack_info ctinfo,
  99                                unsigned int protoff,
 100                                unsigned char **data, int dataoff,
 101                                TransportAddress *taddr, __be16 port,
 102                                struct nf_conntrack_expect *exp) __read_mostly;
 103int (*nat_q931_hook) (struct sk_buff *skb,
 104                      struct nf_conn *ct,
 105                      enum ip_conntrack_info ctinfo,
 106                      unsigned int protoff,
 107                      unsigned char **data, TransportAddress *taddr, int idx,
 108                      __be16 port, struct nf_conntrack_expect *exp)
 109                      __read_mostly;
 110
 111static DEFINE_SPINLOCK(nf_h323_lock);
 112static char *h323_buffer;
 113
 114static struct nf_conntrack_helper nf_conntrack_helper_h245;
 115static struct nf_conntrack_helper nf_conntrack_helper_q931[];
 116static struct nf_conntrack_helper nf_conntrack_helper_ras[];
 117
 118/****************************************************************************/
 119static int get_tpkt_data(struct sk_buff *skb, unsigned int protoff,
 120                         struct nf_conn *ct, enum ip_conntrack_info ctinfo,
 121                         unsigned char **data, int *datalen, int *dataoff)
 122{
 123        struct nf_ct_h323_master *info = nfct_help_data(ct);
 124        int dir = CTINFO2DIR(ctinfo);
 125        const struct tcphdr *th;
 126        struct tcphdr _tcph;
 127        int tcpdatalen;
 128        int tcpdataoff;
 129        unsigned char *tpkt;
 130        int tpktlen;
 131        int tpktoff;
 132
 133        /* Get TCP header */
 134        th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph);
 135        if (th == NULL)
 136                return 0;
 137
 138        /* Get TCP data offset */
 139        tcpdataoff = protoff + th->doff * 4;
 140
 141        /* Get TCP data length */
 142        tcpdatalen = skb->len - tcpdataoff;
 143        if (tcpdatalen <= 0)    /* No TCP data */
 144                goto clear_out;
 145
 146        if (*data == NULL) {    /* first TPKT */
 147                /* Get first TPKT pointer */
 148                tpkt = skb_header_pointer(skb, tcpdataoff, tcpdatalen,
 149                                          h323_buffer);
 150                BUG_ON(tpkt == NULL);
 151
 152                /* Validate TPKT identifier */
 153                if (tcpdatalen < 4 || tpkt[0] != 0x03 || tpkt[1] != 0) {
 154                        /* Netmeeting sends TPKT header and data separately */
 155                        if (info->tpkt_len[dir] > 0) {
 156                                pr_debug("nf_ct_h323: previous packet "
 157                                         "indicated separate TPKT data of %hu "
 158                                         "bytes\n", info->tpkt_len[dir]);
 159                                if (info->tpkt_len[dir] <= tcpdatalen) {
 160                                        /* Yes, there was a TPKT header
 161                                         * received */
 162                                        *data = tpkt;
 163                                        *datalen = info->tpkt_len[dir];
 164                                        *dataoff = 0;
 165                                        goto out;
 166                                }
 167
 168                                /* Fragmented TPKT */
 169                                pr_debug("nf_ct_h323: fragmented TPKT\n");
 170                                goto clear_out;
 171                        }
 172
 173                        /* It is not even a TPKT */
 174                        return 0;
 175                }
 176                tpktoff = 0;
 177        } else {                /* Next TPKT */
 178                tpktoff = *dataoff + *datalen;
 179                tcpdatalen -= tpktoff;
 180                if (tcpdatalen <= 4)    /* No more TPKT */
 181                        goto clear_out;
 182                tpkt = *data + *datalen;
 183
 184                /* Validate TPKT identifier */
 185                if (tpkt[0] != 0x03 || tpkt[1] != 0)
 186                        goto clear_out;
 187        }
 188
 189        /* Validate TPKT length */
 190        tpktlen = tpkt[2] * 256 + tpkt[3];
 191        if (tpktlen < 4)
 192                goto clear_out;
 193        if (tpktlen > tcpdatalen) {
 194                if (tcpdatalen == 4) {  /* Separate TPKT header */
 195                        /* Netmeeting sends TPKT header and data separately */
 196                        pr_debug("nf_ct_h323: separate TPKT header indicates "
 197                                 "there will be TPKT data of %hu bytes\n",
 198                                 tpktlen - 4);
 199                        info->tpkt_len[dir] = tpktlen - 4;
 200                        return 0;
 201                }
 202
 203                pr_debug("nf_ct_h323: incomplete TPKT (fragmented?)\n");
 204                goto clear_out;
 205        }
 206
 207        /* This is the encapsulated data */
 208        *data = tpkt + 4;
 209        *datalen = tpktlen - 4;
 210        *dataoff = tpktoff + 4;
 211
 212      out:
 213        /* Clear TPKT length */
 214        info->tpkt_len[dir] = 0;
 215        return 1;
 216
 217      clear_out:
 218        info->tpkt_len[dir] = 0;
 219        return 0;
 220}
 221
 222/****************************************************************************/
 223static int get_h245_addr(struct nf_conn *ct, const unsigned char *data,
 224                         H245_TransportAddress *taddr,
 225                         union nf_inet_addr *addr, __be16 *port)
 226{
 227        const unsigned char *p;
 228        int len;
 229
 230        if (taddr->choice != eH245_TransportAddress_unicastAddress)
 231                return 0;
 232
 233        switch (taddr->unicastAddress.choice) {
 234        case eUnicastAddress_iPAddress:
 235                if (nf_ct_l3num(ct) != AF_INET)
 236                        return 0;
 237                p = data + taddr->unicastAddress.iPAddress.network;
 238                len = 4;
 239                break;
 240        case eUnicastAddress_iP6Address:
 241                if (nf_ct_l3num(ct) != AF_INET6)
 242                        return 0;
 243                p = data + taddr->unicastAddress.iP6Address.network;
 244                len = 16;
 245                break;
 246        default:
 247                return 0;
 248        }
 249
 250        memcpy(addr, p, len);
 251        memset((void *)addr + len, 0, sizeof(*addr) - len);
 252        memcpy(port, p + len, sizeof(__be16));
 253
 254        return 1;
 255}
 256
 257/****************************************************************************/
 258static int expect_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct,
 259                           enum ip_conntrack_info ctinfo,
 260                           unsigned int protoff,
 261                           unsigned char **data, int dataoff,
 262                           H245_TransportAddress *taddr)
 263{
 264        int dir = CTINFO2DIR(ctinfo);
 265        int ret = 0;
 266        __be16 port;
 267        __be16 rtp_port, rtcp_port;
 268        union nf_inet_addr addr;
 269        struct nf_conntrack_expect *rtp_exp;
 270        struct nf_conntrack_expect *rtcp_exp;
 271        typeof(nat_rtp_rtcp_hook) nat_rtp_rtcp;
 272
 273        /* Read RTP or RTCP address */
 274        if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
 275            memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 276            port == 0)
 277                return 0;
 278
 279        /* RTP port is even */
 280        rtp_port = port & ~htons(1);
 281        rtcp_port = port | htons(1);
 282
 283        /* Create expect for RTP */
 284        if ((rtp_exp = nf_ct_expect_alloc(ct)) == NULL)
 285                return -1;
 286        nf_ct_expect_init(rtp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 287                          &ct->tuplehash[!dir].tuple.src.u3,
 288                          &ct->tuplehash[!dir].tuple.dst.u3,
 289                          IPPROTO_UDP, NULL, &rtp_port);
 290
 291        /* Create expect for RTCP */
 292        if ((rtcp_exp = nf_ct_expect_alloc(ct)) == NULL) {
 293                nf_ct_expect_put(rtp_exp);
 294                return -1;
 295        }
 296        nf_ct_expect_init(rtcp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 297                          &ct->tuplehash[!dir].tuple.src.u3,
 298                          &ct->tuplehash[!dir].tuple.dst.u3,
 299                          IPPROTO_UDP, NULL, &rtcp_port);
 300
 301        if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 302                   &ct->tuplehash[!dir].tuple.dst.u3,
 303                   sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 304                   (nat_rtp_rtcp = rcu_dereference(nat_rtp_rtcp_hook)) &&
 305                   nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 306                   ct->status & IPS_NAT_MASK) {
 307                /* NAT needed */
 308                ret = nat_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff,
 309                                   taddr, port, rtp_port, rtp_exp, rtcp_exp);
 310        } else {                /* Conntrack only */
 311                if (nf_ct_expect_related(rtp_exp) == 0) {
 312                        if (nf_ct_expect_related(rtcp_exp) == 0) {
 313                                pr_debug("nf_ct_h323: expect RTP ");
 314                                nf_ct_dump_tuple(&rtp_exp->tuple);
 315                                pr_debug("nf_ct_h323: expect RTCP ");
 316                                nf_ct_dump_tuple(&rtcp_exp->tuple);
 317                        } else {
 318                                nf_ct_unexpect_related(rtp_exp);
 319                                ret = -1;
 320                        }
 321                } else
 322                        ret = -1;
 323        }
 324
 325        nf_ct_expect_put(rtp_exp);
 326        nf_ct_expect_put(rtcp_exp);
 327
 328        return ret;
 329}
 330
 331/****************************************************************************/
 332static int expect_t120(struct sk_buff *skb,
 333                       struct nf_conn *ct,
 334                       enum ip_conntrack_info ctinfo,
 335                       unsigned int protoff,
 336                       unsigned char **data, int dataoff,
 337                       H245_TransportAddress *taddr)
 338{
 339        int dir = CTINFO2DIR(ctinfo);
 340        int ret = 0;
 341        __be16 port;
 342        union nf_inet_addr addr;
 343        struct nf_conntrack_expect *exp;
 344        typeof(nat_t120_hook) nat_t120;
 345
 346        /* Read T.120 address */
 347        if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
 348            memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 349            port == 0)
 350                return 0;
 351
 352        /* Create expect for T.120 connections */
 353        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 354                return -1;
 355        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 356                          &ct->tuplehash[!dir].tuple.src.u3,
 357                          &ct->tuplehash[!dir].tuple.dst.u3,
 358                          IPPROTO_TCP, NULL, &port);
 359        exp->flags = NF_CT_EXPECT_PERMANENT;    /* Accept multiple channels */
 360
 361        if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 362                   &ct->tuplehash[!dir].tuple.dst.u3,
 363                   sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 364            (nat_t120 = rcu_dereference(nat_t120_hook)) &&
 365            nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 366            ct->status & IPS_NAT_MASK) {
 367                /* NAT needed */
 368                ret = nat_t120(skb, ct, ctinfo, protoff, data, dataoff, taddr,
 369                               port, exp);
 370        } else {                /* Conntrack only */
 371                if (nf_ct_expect_related(exp) == 0) {
 372                        pr_debug("nf_ct_h323: expect T.120 ");
 373                        nf_ct_dump_tuple(&exp->tuple);
 374                } else
 375                        ret = -1;
 376        }
 377
 378        nf_ct_expect_put(exp);
 379
 380        return ret;
 381}
 382
 383/****************************************************************************/
 384static int process_h245_channel(struct sk_buff *skb,
 385                                struct nf_conn *ct,
 386                                enum ip_conntrack_info ctinfo,
 387                                unsigned int protoff,
 388                                unsigned char **data, int dataoff,
 389                                H2250LogicalChannelParameters *channel)
 390{
 391        int ret;
 392
 393        if (channel->options & eH2250LogicalChannelParameters_mediaChannel) {
 394                /* RTP */
 395                ret = expect_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff,
 396                                      &channel->mediaChannel);
 397                if (ret < 0)
 398                        return -1;
 399        }
 400
 401        if (channel->
 402            options & eH2250LogicalChannelParameters_mediaControlChannel) {
 403                /* RTCP */
 404                ret = expect_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff,
 405                                      &channel->mediaControlChannel);
 406                if (ret < 0)
 407                        return -1;
 408        }
 409
 410        return 0;
 411}
 412
 413/****************************************************************************/
 414static int process_olc(struct sk_buff *skb, struct nf_conn *ct,
 415                       enum ip_conntrack_info ctinfo,
 416                       unsigned int protoff,
 417                       unsigned char **data, int dataoff,
 418                       OpenLogicalChannel *olc)
 419{
 420        int ret;
 421
 422        pr_debug("nf_ct_h323: OpenLogicalChannel\n");
 423
 424        if (olc->forwardLogicalChannelParameters.multiplexParameters.choice ==
 425            eOpenLogicalChannel_forwardLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters)
 426        {
 427                ret = process_h245_channel(skb, ct, ctinfo,
 428                                           protoff, data, dataoff,
 429                                           &olc->
 430                                           forwardLogicalChannelParameters.
 431                                           multiplexParameters.
 432                                           h2250LogicalChannelParameters);
 433                if (ret < 0)
 434                        return -1;
 435        }
 436
 437        if ((olc->options &
 438             eOpenLogicalChannel_reverseLogicalChannelParameters) &&
 439            (olc->reverseLogicalChannelParameters.options &
 440             eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters)
 441            && (olc->reverseLogicalChannelParameters.multiplexParameters.
 442                choice ==
 443                eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
 444        {
 445                ret =
 446                    process_h245_channel(skb, ct, ctinfo,
 447                                         protoff, data, dataoff,
 448                                         &olc->
 449                                         reverseLogicalChannelParameters.
 450                                         multiplexParameters.
 451                                         h2250LogicalChannelParameters);
 452                if (ret < 0)
 453                        return -1;
 454        }
 455
 456        if ((olc->options & eOpenLogicalChannel_separateStack) &&
 457            olc->forwardLogicalChannelParameters.dataType.choice ==
 458            eDataType_data &&
 459            olc->forwardLogicalChannelParameters.dataType.data.application.
 460            choice == eDataApplicationCapability_application_t120 &&
 461            olc->forwardLogicalChannelParameters.dataType.data.application.
 462            t120.choice == eDataProtocolCapability_separateLANStack &&
 463            olc->separateStack.networkAddress.choice ==
 464            eNetworkAccessParameters_networkAddress_localAreaAddress) {
 465                ret = expect_t120(skb, ct, ctinfo, protoff, data, dataoff,
 466                                  &olc->separateStack.networkAddress.
 467                                  localAreaAddress);
 468                if (ret < 0)
 469                        return -1;
 470        }
 471
 472        return 0;
 473}
 474
 475/****************************************************************************/
 476static int process_olca(struct sk_buff *skb, struct nf_conn *ct,
 477                        enum ip_conntrack_info ctinfo,
 478                        unsigned int protoff, unsigned char **data, int dataoff,
 479                        OpenLogicalChannelAck *olca)
 480{
 481        H2250LogicalChannelAckParameters *ack;
 482        int ret;
 483
 484        pr_debug("nf_ct_h323: OpenLogicalChannelAck\n");
 485
 486        if ((olca->options &
 487             eOpenLogicalChannelAck_reverseLogicalChannelParameters) &&
 488            (olca->reverseLogicalChannelParameters.options &
 489             eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters)
 490            && (olca->reverseLogicalChannelParameters.multiplexParameters.
 491                choice ==
 492                eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
 493        {
 494                ret = process_h245_channel(skb, ct, ctinfo,
 495                                           protoff, data, dataoff,
 496                                           &olca->
 497                                           reverseLogicalChannelParameters.
 498                                           multiplexParameters.
 499                                           h2250LogicalChannelParameters);
 500                if (ret < 0)
 501                        return -1;
 502        }
 503
 504        if ((olca->options &
 505             eOpenLogicalChannelAck_forwardMultiplexAckParameters) &&
 506            (olca->forwardMultiplexAckParameters.choice ==
 507             eOpenLogicalChannelAck_forwardMultiplexAckParameters_h2250LogicalChannelAckParameters))
 508        {
 509                ack = &olca->forwardMultiplexAckParameters.
 510                    h2250LogicalChannelAckParameters;
 511                if (ack->options &
 512                    eH2250LogicalChannelAckParameters_mediaChannel) {
 513                        /* RTP */
 514                        ret = expect_rtp_rtcp(skb, ct, ctinfo,
 515                                              protoff, data, dataoff,
 516                                              &ack->mediaChannel);
 517                        if (ret < 0)
 518                                return -1;
 519                }
 520
 521                if (ack->options &
 522                    eH2250LogicalChannelAckParameters_mediaControlChannel) {
 523                        /* RTCP */
 524                        ret = expect_rtp_rtcp(skb, ct, ctinfo,
 525                                              protoff, data, dataoff,
 526                                              &ack->mediaControlChannel);
 527                        if (ret < 0)
 528                                return -1;
 529                }
 530        }
 531
 532        if ((olca->options & eOpenLogicalChannelAck_separateStack) &&
 533                olca->separateStack.networkAddress.choice ==
 534                eNetworkAccessParameters_networkAddress_localAreaAddress) {
 535                ret = expect_t120(skb, ct, ctinfo, protoff, data, dataoff,
 536                                  &olca->separateStack.networkAddress.
 537                                  localAreaAddress);
 538                if (ret < 0)
 539                        return -1;
 540        }
 541
 542        return 0;
 543}
 544
 545/****************************************************************************/
 546static int process_h245(struct sk_buff *skb, struct nf_conn *ct,
 547                        enum ip_conntrack_info ctinfo,
 548                        unsigned int protoff, unsigned char **data, int dataoff,
 549                        MultimediaSystemControlMessage *mscm)
 550{
 551        switch (mscm->choice) {
 552        case eMultimediaSystemControlMessage_request:
 553                if (mscm->request.choice ==
 554                    eRequestMessage_openLogicalChannel) {
 555                        return process_olc(skb, ct, ctinfo,
 556                                           protoff, data, dataoff,
 557                                           &mscm->request.openLogicalChannel);
 558                }
 559                pr_debug("nf_ct_h323: H.245 Request %d\n",
 560                         mscm->request.choice);
 561                break;
 562        case eMultimediaSystemControlMessage_response:
 563                if (mscm->response.choice ==
 564                    eResponseMessage_openLogicalChannelAck) {
 565                        return process_olca(skb, ct, ctinfo,
 566                                            protoff, data, dataoff,
 567                                            &mscm->response.
 568                                            openLogicalChannelAck);
 569                }
 570                pr_debug("nf_ct_h323: H.245 Response %d\n",
 571                         mscm->response.choice);
 572                break;
 573        default:
 574                pr_debug("nf_ct_h323: H.245 signal %d\n", mscm->choice);
 575                break;
 576        }
 577
 578        return 0;
 579}
 580
 581/****************************************************************************/
 582static int h245_help(struct sk_buff *skb, unsigned int protoff,
 583                     struct nf_conn *ct, enum ip_conntrack_info ctinfo)
 584{
 585        static MultimediaSystemControlMessage mscm;
 586        unsigned char *data = NULL;
 587        int datalen;
 588        int dataoff;
 589        int ret;
 590
 591        /* Until there's been traffic both ways, don't look in packets. */
 592        if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
 593                return NF_ACCEPT;
 594
 595        pr_debug("nf_ct_h245: skblen = %u\n", skb->len);
 596
 597        spin_lock_bh(&nf_h323_lock);
 598
 599        /* Process each TPKT */
 600        while (get_tpkt_data(skb, protoff, ct, ctinfo,
 601                             &data, &datalen, &dataoff)) {
 602                pr_debug("nf_ct_h245: TPKT len=%d ", datalen);
 603                nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
 604
 605                /* Decode H.245 signal */
 606                ret = DecodeMultimediaSystemControlMessage(data, datalen,
 607                                                           &mscm);
 608                if (ret < 0) {
 609                        pr_debug("nf_ct_h245: decoding error: %s\n",
 610                                 ret == H323_ERROR_BOUND ?
 611                                 "out of bound" : "out of range");
 612                        /* We don't drop when decoding error */
 613                        break;
 614                }
 615
 616                /* Process H.245 signal */
 617                if (process_h245(skb, ct, ctinfo, protoff,
 618                                 &data, dataoff, &mscm) < 0)
 619                        goto drop;
 620        }
 621
 622        spin_unlock_bh(&nf_h323_lock);
 623        return NF_ACCEPT;
 624
 625      drop:
 626        spin_unlock_bh(&nf_h323_lock);
 627        nf_ct_helper_log(skb, ct, "cannot process H.245 message");
 628        return NF_DROP;
 629}
 630
 631/****************************************************************************/
 632static const struct nf_conntrack_expect_policy h245_exp_policy = {
 633        .max_expected   = H323_RTP_CHANNEL_MAX * 4 + 2 /* T.120 */,
 634        .timeout        = 240,
 635};
 636
 637static struct nf_conntrack_helper nf_conntrack_helper_h245 __read_mostly = {
 638        .name                   = "H.245",
 639        .me                     = THIS_MODULE,
 640        .data_len               = sizeof(struct nf_ct_h323_master),
 641        .tuple.src.l3num        = AF_UNSPEC,
 642        .tuple.dst.protonum     = IPPROTO_UDP,
 643        .help                   = h245_help,
 644        .expect_policy          = &h245_exp_policy,
 645};
 646
 647/****************************************************************************/
 648int get_h225_addr(struct nf_conn *ct, unsigned char *data,
 649                  TransportAddress *taddr,
 650                  union nf_inet_addr *addr, __be16 *port)
 651{
 652        const unsigned char *p;
 653        int len;
 654
 655        switch (taddr->choice) {
 656        case eTransportAddress_ipAddress:
 657                if (nf_ct_l3num(ct) != AF_INET)
 658                        return 0;
 659                p = data + taddr->ipAddress.ip;
 660                len = 4;
 661                break;
 662        case eTransportAddress_ip6Address:
 663                if (nf_ct_l3num(ct) != AF_INET6)
 664                        return 0;
 665                p = data + taddr->ip6Address.ip;
 666                len = 16;
 667                break;
 668        default:
 669                return 0;
 670        }
 671
 672        memcpy(addr, p, len);
 673        memset((void *)addr + len, 0, sizeof(*addr) - len);
 674        memcpy(port, p + len, sizeof(__be16));
 675
 676        return 1;
 677}
 678
 679/****************************************************************************/
 680static int expect_h245(struct sk_buff *skb, struct nf_conn *ct,
 681                       enum ip_conntrack_info ctinfo,
 682                       unsigned int protoff, unsigned char **data, int dataoff,
 683                       TransportAddress *taddr)
 684{
 685        int dir = CTINFO2DIR(ctinfo);
 686        int ret = 0;
 687        __be16 port;
 688        union nf_inet_addr addr;
 689        struct nf_conntrack_expect *exp;
 690        typeof(nat_h245_hook) nat_h245;
 691
 692        /* Read h245Address */
 693        if (!get_h225_addr(ct, *data, taddr, &addr, &port) ||
 694            memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 695            port == 0)
 696                return 0;
 697
 698        /* Create expect for h245 connection */
 699        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 700                return -1;
 701        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 702                          &ct->tuplehash[!dir].tuple.src.u3,
 703                          &ct->tuplehash[!dir].tuple.dst.u3,
 704                          IPPROTO_TCP, NULL, &port);
 705        exp->helper = &nf_conntrack_helper_h245;
 706
 707        if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 708                   &ct->tuplehash[!dir].tuple.dst.u3,
 709                   sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 710            (nat_h245 = rcu_dereference(nat_h245_hook)) &&
 711            nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 712            ct->status & IPS_NAT_MASK) {
 713                /* NAT needed */
 714                ret = nat_h245(skb, ct, ctinfo, protoff, data, dataoff, taddr,
 715                               port, exp);
 716        } else {                /* Conntrack only */
 717                if (nf_ct_expect_related(exp) == 0) {
 718                        pr_debug("nf_ct_q931: expect H.245 ");
 719                        nf_ct_dump_tuple(&exp->tuple);
 720                } else
 721                        ret = -1;
 722        }
 723
 724        nf_ct_expect_put(exp);
 725
 726        return ret;
 727}
 728
 729/* If the calling party is on the same side of the forward-to party,
 730 * we don't need to track the second call */
 731static int callforward_do_filter(const union nf_inet_addr *src,
 732                                 const union nf_inet_addr *dst,
 733                                 u_int8_t family)
 734{
 735        const struct nf_afinfo *afinfo;
 736        int ret = 0;
 737
 738        /* rcu_read_lock()ed by nf_hook_slow() */
 739        afinfo = nf_get_afinfo(family);
 740        if (!afinfo)
 741                return 0;
 742
 743        switch (family) {
 744        case AF_INET: {
 745                struct flowi4 fl1, fl2;
 746                struct rtable *rt1, *rt2;
 747
 748                memset(&fl1, 0, sizeof(fl1));
 749                fl1.daddr = src->ip;
 750
 751                memset(&fl2, 0, sizeof(fl2));
 752                fl2.daddr = dst->ip;
 753                if (!afinfo->route(&init_net, (struct dst_entry **)&rt1,
 754                                   flowi4_to_flowi(&fl1), false)) {
 755                        if (!afinfo->route(&init_net, (struct dst_entry **)&rt2,
 756                                           flowi4_to_flowi(&fl2), false)) {
 757                                if (rt_nexthop(rt1, fl1.daddr) ==
 758                                    rt_nexthop(rt2, fl2.daddr) &&
 759                                    rt1->dst.dev  == rt2->dst.dev)
 760                                        ret = 1;
 761                                dst_release(&rt2->dst);
 762                        }
 763                        dst_release(&rt1->dst);
 764                }
 765                break;
 766        }
 767#if IS_ENABLED(CONFIG_NF_CONNTRACK_IPV6)
 768        case AF_INET6: {
 769                struct flowi6 fl1, fl2;
 770                struct rt6_info *rt1, *rt2;
 771
 772                memset(&fl1, 0, sizeof(fl1));
 773                fl1.daddr = src->in6;
 774
 775                memset(&fl2, 0, sizeof(fl2));
 776                fl2.daddr = dst->in6;
 777                if (!afinfo->route(&init_net, (struct dst_entry **)&rt1,
 778                                   flowi6_to_flowi(&fl1), false)) {
 779                        if (!afinfo->route(&init_net, (struct dst_entry **)&rt2,
 780                                           flowi6_to_flowi(&fl2), false)) {
 781                                if (!memcmp(&rt1->rt6i_gateway, &rt2->rt6i_gateway,
 782                                            sizeof(rt1->rt6i_gateway)) &&
 783                                    rt1->dst.dev == rt2->dst.dev)
 784                                        ret = 1;
 785                                dst_release(&rt2->dst);
 786                        }
 787                        dst_release(&rt1->dst);
 788                }
 789                break;
 790        }
 791#endif
 792        }
 793        return ret;
 794
 795}
 796
 797/****************************************************************************/
 798static int expect_callforwarding(struct sk_buff *skb,
 799                                 struct nf_conn *ct,
 800                                 enum ip_conntrack_info ctinfo,
 801                                 unsigned int protoff,
 802                                 unsigned char **data, int dataoff,
 803                                 TransportAddress *taddr)
 804{
 805        int dir = CTINFO2DIR(ctinfo);
 806        int ret = 0;
 807        __be16 port;
 808        union nf_inet_addr addr;
 809        struct nf_conntrack_expect *exp;
 810        typeof(nat_callforwarding_hook) nat_callforwarding;
 811
 812        /* Read alternativeAddress */
 813        if (!get_h225_addr(ct, *data, taddr, &addr, &port) || port == 0)
 814                return 0;
 815
 816        /* If the calling party is on the same side of the forward-to party,
 817         * we don't need to track the second call */
 818        if (callforward_filter &&
 819            callforward_do_filter(&addr, &ct->tuplehash[!dir].tuple.src.u3,
 820                                  nf_ct_l3num(ct))) {
 821                pr_debug("nf_ct_q931: Call Forwarding not tracked\n");
 822                return 0;
 823        }
 824
 825        /* Create expect for the second call leg */
 826        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 827                return -1;
 828        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 829                          &ct->tuplehash[!dir].tuple.src.u3, &addr,
 830                          IPPROTO_TCP, NULL, &port);
 831        exp->helper = nf_conntrack_helper_q931;
 832
 833        if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 834                   &ct->tuplehash[!dir].tuple.dst.u3,
 835                   sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 836            (nat_callforwarding = rcu_dereference(nat_callforwarding_hook)) &&
 837            nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 838            ct->status & IPS_NAT_MASK) {
 839                /* Need NAT */
 840                ret = nat_callforwarding(skb, ct, ctinfo,
 841                                         protoff, data, dataoff,
 842                                         taddr, port, exp);
 843        } else {                /* Conntrack only */
 844                if (nf_ct_expect_related(exp) == 0) {
 845                        pr_debug("nf_ct_q931: expect Call Forwarding ");
 846                        nf_ct_dump_tuple(&exp->tuple);
 847                } else
 848                        ret = -1;
 849        }
 850
 851        nf_ct_expect_put(exp);
 852
 853        return ret;
 854}
 855
 856/****************************************************************************/
 857static int process_setup(struct sk_buff *skb, struct nf_conn *ct,
 858                         enum ip_conntrack_info ctinfo,
 859                         unsigned int protoff,
 860                         unsigned char **data, int dataoff,
 861                         Setup_UUIE *setup)
 862{
 863        int dir = CTINFO2DIR(ctinfo);
 864        int ret;
 865        int i;
 866        __be16 port;
 867        union nf_inet_addr addr;
 868        typeof(set_h225_addr_hook) set_h225_addr;
 869
 870        pr_debug("nf_ct_q931: Setup\n");
 871
 872        if (setup->options & eSetup_UUIE_h245Address) {
 873                ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
 874                                  &setup->h245Address);
 875                if (ret < 0)
 876                        return -1;
 877        }
 878
 879        set_h225_addr = rcu_dereference(set_h225_addr_hook);
 880        if ((setup->options & eSetup_UUIE_destCallSignalAddress) &&
 881            (set_h225_addr) && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 882            ct->status & IPS_NAT_MASK &&
 883            get_h225_addr(ct, *data, &setup->destCallSignalAddress,
 884                          &addr, &port) &&
 885            memcmp(&addr, &ct->tuplehash[!dir].tuple.src.u3, sizeof(addr))) {
 886                pr_debug("nf_ct_q931: set destCallSignalAddress %pI6:%hu->%pI6:%hu\n",
 887                         &addr, ntohs(port), &ct->tuplehash[!dir].tuple.src.u3,
 888                         ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port));
 889                ret = set_h225_addr(skb, protoff, data, dataoff,
 890                                    &setup->destCallSignalAddress,
 891                                    &ct->tuplehash[!dir].tuple.src.u3,
 892                                    ct->tuplehash[!dir].tuple.src.u.tcp.port);
 893                if (ret < 0)
 894                        return -1;
 895        }
 896
 897        if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) &&
 898            (set_h225_addr) && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 899            ct->status & IPS_NAT_MASK &&
 900            get_h225_addr(ct, *data, &setup->sourceCallSignalAddress,
 901                          &addr, &port) &&
 902            memcmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(addr))) {
 903                pr_debug("nf_ct_q931: set sourceCallSignalAddress %pI6:%hu->%pI6:%hu\n",
 904                         &addr, ntohs(port), &ct->tuplehash[!dir].tuple.dst.u3,
 905                         ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port));
 906                ret = set_h225_addr(skb, protoff, data, dataoff,
 907                                    &setup->sourceCallSignalAddress,
 908                                    &ct->tuplehash[!dir].tuple.dst.u3,
 909                                    ct->tuplehash[!dir].tuple.dst.u.tcp.port);
 910                if (ret < 0)
 911                        return -1;
 912        }
 913
 914        if (setup->options & eSetup_UUIE_fastStart) {
 915                for (i = 0; i < setup->fastStart.count; i++) {
 916                        ret = process_olc(skb, ct, ctinfo,
 917                                          protoff, data, dataoff,
 918                                          &setup->fastStart.item[i]);
 919                        if (ret < 0)
 920                                return -1;
 921                }
 922        }
 923
 924        return 0;
 925}
 926
 927/****************************************************************************/
 928static int process_callproceeding(struct sk_buff *skb,
 929                                  struct nf_conn *ct,
 930                                  enum ip_conntrack_info ctinfo,
 931                                  unsigned int protoff,
 932                                  unsigned char **data, int dataoff,
 933                                  CallProceeding_UUIE *callproc)
 934{
 935        int ret;
 936        int i;
 937
 938        pr_debug("nf_ct_q931: CallProceeding\n");
 939
 940        if (callproc->options & eCallProceeding_UUIE_h245Address) {
 941                ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
 942                                  &callproc->h245Address);
 943                if (ret < 0)
 944                        return -1;
 945        }
 946
 947        if (callproc->options & eCallProceeding_UUIE_fastStart) {
 948                for (i = 0; i < callproc->fastStart.count; i++) {
 949                        ret = process_olc(skb, ct, ctinfo,
 950                                          protoff, data, dataoff,
 951                                          &callproc->fastStart.item[i]);
 952                        if (ret < 0)
 953                                return -1;
 954                }
 955        }
 956
 957        return 0;
 958}
 959
 960/****************************************************************************/
 961static int process_connect(struct sk_buff *skb, struct nf_conn *ct,
 962                           enum ip_conntrack_info ctinfo,
 963                           unsigned int protoff,
 964                           unsigned char **data, int dataoff,
 965                           Connect_UUIE *connect)
 966{
 967        int ret;
 968        int i;
 969
 970        pr_debug("nf_ct_q931: Connect\n");
 971
 972        if (connect->options & eConnect_UUIE_h245Address) {
 973                ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
 974                                  &connect->h245Address);
 975                if (ret < 0)
 976                        return -1;
 977        }
 978
 979        if (connect->options & eConnect_UUIE_fastStart) {
 980                for (i = 0; i < connect->fastStart.count; i++) {
 981                        ret = process_olc(skb, ct, ctinfo,
 982                                          protoff, data, dataoff,
 983                                          &connect->fastStart.item[i]);
 984                        if (ret < 0)
 985                                return -1;
 986                }
 987        }
 988
 989        return 0;
 990}
 991
 992/****************************************************************************/
 993static int process_alerting(struct sk_buff *skb, struct nf_conn *ct,
 994                            enum ip_conntrack_info ctinfo,
 995                            unsigned int protoff,
 996                            unsigned char **data, int dataoff,
 997                            Alerting_UUIE *alert)
 998{
 999        int ret;
1000        int i;
1001
1002        pr_debug("nf_ct_q931: Alerting\n");
1003
1004        if (alert->options & eAlerting_UUIE_h245Address) {
1005                ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
1006                                  &alert->h245Address);
1007                if (ret < 0)
1008                        return -1;
1009        }
1010
1011        if (alert->options & eAlerting_UUIE_fastStart) {
1012                for (i = 0; i < alert->fastStart.count; i++) {
1013                        ret = process_olc(skb, ct, ctinfo,
1014                                          protoff, data, dataoff,
1015                                          &alert->fastStart.item[i]);
1016                        if (ret < 0)
1017                                return -1;
1018                }
1019        }
1020
1021        return 0;
1022}
1023
1024/****************************************************************************/
1025static int process_facility(struct sk_buff *skb, struct nf_conn *ct,
1026                            enum ip_conntrack_info ctinfo,
1027                            unsigned int protoff,
1028                            unsigned char **data, int dataoff,
1029                            Facility_UUIE *facility)
1030{
1031        int ret;
1032        int i;
1033
1034        pr_debug("nf_ct_q931: Facility\n");
1035
1036        if (facility->reason.choice == eFacilityReason_callForwarded) {
1037                if (facility->options & eFacility_UUIE_alternativeAddress)
1038                        return expect_callforwarding(skb, ct, ctinfo,
1039                                                     protoff, data, dataoff,
1040                                                     &facility->
1041                                                     alternativeAddress);
1042                return 0;
1043        }
1044
1045        if (facility->options & eFacility_UUIE_h245Address) {
1046                ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
1047                                  &facility->h245Address);
1048                if (ret < 0)
1049                        return -1;
1050        }
1051
1052        if (facility->options & eFacility_UUIE_fastStart) {
1053                for (i = 0; i < facility->fastStart.count; i++) {
1054                        ret = process_olc(skb, ct, ctinfo,
1055                                          protoff, data, dataoff,
1056                                          &facility->fastStart.item[i]);
1057                        if (ret < 0)
1058                                return -1;
1059                }
1060        }
1061
1062        return 0;
1063}
1064
1065/****************************************************************************/
1066static int process_progress(struct sk_buff *skb, struct nf_conn *ct,
1067                            enum ip_conntrack_info ctinfo,
1068                            unsigned int protoff,
1069                            unsigned char **data, int dataoff,
1070                            Progress_UUIE *progress)
1071{
1072        int ret;
1073        int i;
1074
1075        pr_debug("nf_ct_q931: Progress\n");
1076
1077        if (progress->options & eProgress_UUIE_h245Address) {
1078                ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
1079                                  &progress->h245Address);
1080                if (ret < 0)
1081                        return -1;
1082        }
1083
1084        if (progress->options & eProgress_UUIE_fastStart) {
1085                for (i = 0; i < progress->fastStart.count; i++) {
1086                        ret = process_olc(skb, ct, ctinfo,
1087                                          protoff, data, dataoff,
1088                                          &progress->fastStart.item[i]);
1089                        if (ret < 0)
1090                                return -1;
1091                }
1092        }
1093
1094        return 0;
1095}
1096
1097/****************************************************************************/
1098static int process_q931(struct sk_buff *skb, struct nf_conn *ct,
1099                        enum ip_conntrack_info ctinfo,
1100                        unsigned int protoff, unsigned char **data, int dataoff,
1101                        Q931 *q931)
1102{
1103        H323_UU_PDU *pdu = &q931->UUIE.h323_uu_pdu;
1104        int i;
1105        int ret = 0;
1106
1107        switch (pdu->h323_message_body.choice) {
1108        case eH323_UU_PDU_h323_message_body_setup:
1109                ret = process_setup(skb, ct, ctinfo, protoff, data, dataoff,
1110                                    &pdu->h323_message_body.setup);
1111                break;
1112        case eH323_UU_PDU_h323_message_body_callProceeding:
1113                ret = process_callproceeding(skb, ct, ctinfo,
1114                                             protoff, data, dataoff,
1115                                             &pdu->h323_message_body.
1116                                             callProceeding);
1117                break;
1118        case eH323_UU_PDU_h323_message_body_connect:
1119                ret = process_connect(skb, ct, ctinfo, protoff, data, dataoff,
1120                                      &pdu->h323_message_body.connect);
1121                break;
1122        case eH323_UU_PDU_h323_message_body_alerting:
1123                ret = process_alerting(skb, ct, ctinfo, protoff, data, dataoff,
1124                                       &pdu->h323_message_body.alerting);
1125                break;
1126        case eH323_UU_PDU_h323_message_body_facility:
1127                ret = process_facility(skb, ct, ctinfo, protoff, data, dataoff,
1128                                       &pdu->h323_message_body.facility);
1129                break;
1130        case eH323_UU_PDU_h323_message_body_progress:
1131                ret = process_progress(skb, ct, ctinfo, protoff, data, dataoff,
1132                                       &pdu->h323_message_body.progress);
1133                break;
1134        default:
1135                pr_debug("nf_ct_q931: Q.931 signal %d\n",
1136                         pdu->h323_message_body.choice);
1137                break;
1138        }
1139
1140        if (ret < 0)
1141                return -1;
1142
1143        if (pdu->options & eH323_UU_PDU_h245Control) {
1144                for (i = 0; i < pdu->h245Control.count; i++) {
1145                        ret = process_h245(skb, ct, ctinfo,
1146                                           protoff, data, dataoff,
1147                                           &pdu->h245Control.item[i]);
1148                        if (ret < 0)
1149                                return -1;
1150                }
1151        }
1152
1153        return 0;
1154}
1155
1156/****************************************************************************/
1157static int q931_help(struct sk_buff *skb, unsigned int protoff,
1158                     struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1159{
1160        static Q931 q931;
1161        unsigned char *data = NULL;
1162        int datalen;
1163        int dataoff;
1164        int ret;
1165
1166        /* Until there's been traffic both ways, don't look in packets. */
1167        if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
1168                return NF_ACCEPT;
1169
1170        pr_debug("nf_ct_q931: skblen = %u\n", skb->len);
1171
1172        spin_lock_bh(&nf_h323_lock);
1173
1174        /* Process each TPKT */
1175        while (get_tpkt_data(skb, protoff, ct, ctinfo,
1176                             &data, &datalen, &dataoff)) {
1177                pr_debug("nf_ct_q931: TPKT len=%d ", datalen);
1178                nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1179
1180                /* Decode Q.931 signal */
1181                ret = DecodeQ931(data, datalen, &q931);
1182                if (ret < 0) {
1183                        pr_debug("nf_ct_q931: decoding error: %s\n",
1184                                 ret == H323_ERROR_BOUND ?
1185                                 "out of bound" : "out of range");
1186                        /* We don't drop when decoding error */
1187                        break;
1188                }
1189
1190                /* Process Q.931 signal */
1191                if (process_q931(skb, ct, ctinfo, protoff,
1192                                 &data, dataoff, &q931) < 0)
1193                        goto drop;
1194        }
1195
1196        spin_unlock_bh(&nf_h323_lock);
1197        return NF_ACCEPT;
1198
1199      drop:
1200        spin_unlock_bh(&nf_h323_lock);
1201        nf_ct_helper_log(skb, ct, "cannot process Q.931 message");
1202        return NF_DROP;
1203}
1204
1205/****************************************************************************/
1206static const struct nf_conntrack_expect_policy q931_exp_policy = {
1207        /* T.120 and H.245 */
1208        .max_expected           = H323_RTP_CHANNEL_MAX * 4 + 4,
1209        .timeout                = 240,
1210};
1211
1212static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = {
1213        {
1214                .name                   = "Q.931",
1215                .me                     = THIS_MODULE,
1216                .data_len               = sizeof(struct nf_ct_h323_master),
1217                .tuple.src.l3num        = AF_INET,
1218                .tuple.src.u.tcp.port   = cpu_to_be16(Q931_PORT),
1219                .tuple.dst.protonum     = IPPROTO_TCP,
1220                .help                   = q931_help,
1221                .expect_policy          = &q931_exp_policy,
1222        },
1223        {
1224                .name                   = "Q.931",
1225                .me                     = THIS_MODULE,
1226                .tuple.src.l3num        = AF_INET6,
1227                .tuple.src.u.tcp.port   = cpu_to_be16(Q931_PORT),
1228                .tuple.dst.protonum     = IPPROTO_TCP,
1229                .help                   = q931_help,
1230                .expect_policy          = &q931_exp_policy,
1231        },
1232};
1233
1234/****************************************************************************/
1235static unsigned char *get_udp_data(struct sk_buff *skb, unsigned int protoff,
1236                                   int *datalen)
1237{
1238        const struct udphdr *uh;
1239        struct udphdr _uh;
1240        int dataoff;
1241
1242        uh = skb_header_pointer(skb, protoff, sizeof(_uh), &_uh);
1243        if (uh == NULL)
1244                return NULL;
1245        dataoff = protoff + sizeof(_uh);
1246        if (dataoff >= skb->len)
1247                return NULL;
1248        *datalen = skb->len - dataoff;
1249        return skb_header_pointer(skb, dataoff, *datalen, h323_buffer);
1250}
1251
1252/****************************************************************************/
1253static struct nf_conntrack_expect *find_expect(struct nf_conn *ct,
1254                                               union nf_inet_addr *addr,
1255                                               __be16 port)
1256{
1257        struct net *net = nf_ct_net(ct);
1258        struct nf_conntrack_expect *exp;
1259        struct nf_conntrack_tuple tuple;
1260
1261        memset(&tuple.src.u3, 0, sizeof(tuple.src.u3));
1262        tuple.src.u.tcp.port = 0;
1263        memcpy(&tuple.dst.u3, addr, sizeof(tuple.dst.u3));
1264        tuple.dst.u.tcp.port = port;
1265        tuple.dst.protonum = IPPROTO_TCP;
1266
1267        exp = __nf_ct_expect_find(net, nf_ct_zone(ct), &tuple);
1268        if (exp && exp->master == ct)
1269                return exp;
1270        return NULL;
1271}
1272
1273/****************************************************************************/
1274static int set_expect_timeout(struct nf_conntrack_expect *exp,
1275                              unsigned int timeout)
1276{
1277        if (!exp || !del_timer(&exp->timeout))
1278                return 0;
1279
1280        exp->timeout.expires = jiffies + timeout * HZ;
1281        add_timer(&exp->timeout);
1282
1283        return 1;
1284}
1285
1286/****************************************************************************/
1287static int expect_q931(struct sk_buff *skb, struct nf_conn *ct,
1288                       enum ip_conntrack_info ctinfo,
1289                       unsigned int protoff, unsigned char **data,
1290                       TransportAddress *taddr, int count)
1291{
1292        struct nf_ct_h323_master *info = nfct_help_data(ct);
1293        int dir = CTINFO2DIR(ctinfo);
1294        int ret = 0;
1295        int i;
1296        __be16 port;
1297        union nf_inet_addr addr;
1298        struct nf_conntrack_expect *exp;
1299        typeof(nat_q931_hook) nat_q931;
1300
1301        /* Look for the first related address */
1302        for (i = 0; i < count; i++) {
1303                if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) &&
1304                    memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3,
1305                           sizeof(addr)) == 0 && port != 0)
1306                        break;
1307        }
1308
1309        if (i >= count)         /* Not found */
1310                return 0;
1311
1312        /* Create expect for Q.931 */
1313        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1314                return -1;
1315        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1316                          gkrouted_only ? /* only accept calls from GK? */
1317                                &ct->tuplehash[!dir].tuple.src.u3 : NULL,
1318                          &ct->tuplehash[!dir].tuple.dst.u3,
1319                          IPPROTO_TCP, NULL, &port);
1320        exp->helper = nf_conntrack_helper_q931;
1321        exp->flags = NF_CT_EXPECT_PERMANENT;    /* Accept multiple calls */
1322
1323        nat_q931 = rcu_dereference(nat_q931_hook);
1324        if (nat_q931 && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1325            ct->status & IPS_NAT_MASK) {        /* Need NAT */
1326                ret = nat_q931(skb, ct, ctinfo, protoff, data,
1327                               taddr, i, port, exp);
1328        } else {                /* Conntrack only */
1329                if (nf_ct_expect_related(exp) == 0) {
1330                        pr_debug("nf_ct_ras: expect Q.931 ");
1331                        nf_ct_dump_tuple(&exp->tuple);
1332
1333                        /* Save port for looking up expect in processing RCF */
1334                        info->sig_port[dir] = port;
1335                } else
1336                        ret = -1;
1337        }
1338
1339        nf_ct_expect_put(exp);
1340
1341        return ret;
1342}
1343
1344/****************************************************************************/
1345static int process_grq(struct sk_buff *skb, struct nf_conn *ct,
1346                       enum ip_conntrack_info ctinfo,
1347                       unsigned int protoff,
1348                       unsigned char **data, GatekeeperRequest *grq)
1349{
1350        typeof(set_ras_addr_hook) set_ras_addr;
1351
1352        pr_debug("nf_ct_ras: GRQ\n");
1353
1354        set_ras_addr = rcu_dereference(set_ras_addr_hook);
1355        if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1356            ct->status & IPS_NAT_MASK)  /* NATed */
1357                return set_ras_addr(skb, ct, ctinfo, protoff, data,
1358                                    &grq->rasAddress, 1);
1359        return 0;
1360}
1361
1362/****************************************************************************/
1363static int process_gcf(struct sk_buff *skb, struct nf_conn *ct,
1364                       enum ip_conntrack_info ctinfo,
1365                       unsigned int protoff,
1366                       unsigned char **data, GatekeeperConfirm *gcf)
1367{
1368        int dir = CTINFO2DIR(ctinfo);
1369        int ret = 0;
1370        __be16 port;
1371        union nf_inet_addr addr;
1372        struct nf_conntrack_expect *exp;
1373
1374        pr_debug("nf_ct_ras: GCF\n");
1375
1376        if (!get_h225_addr(ct, *data, &gcf->rasAddress, &addr, &port))
1377                return 0;
1378
1379        /* Registration port is the same as discovery port */
1380        if (!memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1381            port == ct->tuplehash[dir].tuple.src.u.udp.port)
1382                return 0;
1383
1384        /* Avoid RAS expectation loops. A GCF is never expected. */
1385        if (test_bit(IPS_EXPECTED_BIT, &ct->status))
1386                return 0;
1387
1388        /* Need new expect */
1389        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1390                return -1;
1391        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1392                          &ct->tuplehash[!dir].tuple.src.u3, &addr,
1393                          IPPROTO_UDP, NULL, &port);
1394        exp->helper = nf_conntrack_helper_ras;
1395
1396        if (nf_ct_expect_related(exp) == 0) {
1397                pr_debug("nf_ct_ras: expect RAS ");
1398                nf_ct_dump_tuple(&exp->tuple);
1399        } else
1400                ret = -1;
1401
1402        nf_ct_expect_put(exp);
1403
1404        return ret;
1405}
1406
1407/****************************************************************************/
1408static int process_rrq(struct sk_buff *skb, struct nf_conn *ct,
1409                       enum ip_conntrack_info ctinfo,
1410                       unsigned int protoff,
1411                       unsigned char **data, RegistrationRequest *rrq)
1412{
1413        struct nf_ct_h323_master *info = nfct_help_data(ct);
1414        int ret;
1415        typeof(set_ras_addr_hook) set_ras_addr;
1416
1417        pr_debug("nf_ct_ras: RRQ\n");
1418
1419        ret = expect_q931(skb, ct, ctinfo, protoff, data,
1420                          rrq->callSignalAddress.item,
1421                          rrq->callSignalAddress.count);
1422        if (ret < 0)
1423                return -1;
1424
1425        set_ras_addr = rcu_dereference(set_ras_addr_hook);
1426        if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1427            ct->status & IPS_NAT_MASK) {
1428                ret = set_ras_addr(skb, ct, ctinfo, protoff, data,
1429                                   rrq->rasAddress.item,
1430                                   rrq->rasAddress.count);
1431                if (ret < 0)
1432                        return -1;
1433        }
1434
1435        if (rrq->options & eRegistrationRequest_timeToLive) {
1436                pr_debug("nf_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive);
1437                info->timeout = rrq->timeToLive;
1438        } else
1439                info->timeout = default_rrq_ttl;
1440
1441        return 0;
1442}
1443
1444/****************************************************************************/
1445static int process_rcf(struct sk_buff *skb, struct nf_conn *ct,
1446                       enum ip_conntrack_info ctinfo,
1447                       unsigned int protoff,
1448                       unsigned char **data, RegistrationConfirm *rcf)
1449{
1450        struct nf_ct_h323_master *info = nfct_help_data(ct);
1451        int dir = CTINFO2DIR(ctinfo);
1452        int ret;
1453        struct nf_conntrack_expect *exp;
1454        typeof(set_sig_addr_hook) set_sig_addr;
1455
1456        pr_debug("nf_ct_ras: RCF\n");
1457
1458        set_sig_addr = rcu_dereference(set_sig_addr_hook);
1459        if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1460            ct->status & IPS_NAT_MASK) {
1461                ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1462                                        rcf->callSignalAddress.item,
1463                                        rcf->callSignalAddress.count);
1464                if (ret < 0)
1465                        return -1;
1466        }
1467
1468        if (rcf->options & eRegistrationConfirm_timeToLive) {
1469                pr_debug("nf_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive);
1470                info->timeout = rcf->timeToLive;
1471        }
1472
1473        if (info->timeout > 0) {
1474                pr_debug("nf_ct_ras: set RAS connection timeout to "
1475                         "%u seconds\n", info->timeout);
1476                nf_ct_refresh(ct, skb, info->timeout * HZ);
1477
1478                /* Set expect timeout */
1479                spin_lock_bh(&nf_conntrack_lock);
1480                exp = find_expect(ct, &ct->tuplehash[dir].tuple.dst.u3,
1481                                  info->sig_port[!dir]);
1482                if (exp) {
1483                        pr_debug("nf_ct_ras: set Q.931 expect "
1484                                 "timeout to %u seconds for",
1485                                 info->timeout);
1486                        nf_ct_dump_tuple(&exp->tuple);
1487                        set_expect_timeout(exp, info->timeout);
1488                }
1489                spin_unlock_bh(&nf_conntrack_lock);
1490        }
1491
1492        return 0;
1493}
1494
1495/****************************************************************************/
1496static int process_urq(struct sk_buff *skb, struct nf_conn *ct,
1497                       enum ip_conntrack_info ctinfo,
1498                       unsigned int protoff,
1499                       unsigned char **data, UnregistrationRequest *urq)
1500{
1501        struct nf_ct_h323_master *info = nfct_help_data(ct);
1502        int dir = CTINFO2DIR(ctinfo);
1503        int ret;
1504        typeof(set_sig_addr_hook) set_sig_addr;
1505
1506        pr_debug("nf_ct_ras: URQ\n");
1507
1508        set_sig_addr = rcu_dereference(set_sig_addr_hook);
1509        if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1510            ct->status & IPS_NAT_MASK) {
1511                ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1512                                   urq->callSignalAddress.item,
1513                                   urq->callSignalAddress.count);
1514                if (ret < 0)
1515                        return -1;
1516        }
1517
1518        /* Clear old expect */
1519        nf_ct_remove_expectations(ct);
1520        info->sig_port[dir] = 0;
1521        info->sig_port[!dir] = 0;
1522
1523        /* Give it 30 seconds for UCF or URJ */
1524        nf_ct_refresh(ct, skb, 30 * HZ);
1525
1526        return 0;
1527}
1528
1529/****************************************************************************/
1530static int process_arq(struct sk_buff *skb, struct nf_conn *ct,
1531                       enum ip_conntrack_info ctinfo,
1532                       unsigned int protoff,
1533                       unsigned char **data, AdmissionRequest *arq)
1534{
1535        const struct nf_ct_h323_master *info = nfct_help_data(ct);
1536        int dir = CTINFO2DIR(ctinfo);
1537        __be16 port;
1538        union nf_inet_addr addr;
1539        typeof(set_h225_addr_hook) set_h225_addr;
1540
1541        pr_debug("nf_ct_ras: ARQ\n");
1542
1543        set_h225_addr = rcu_dereference(set_h225_addr_hook);
1544        if ((arq->options & eAdmissionRequest_destCallSignalAddress) &&
1545            get_h225_addr(ct, *data, &arq->destCallSignalAddress,
1546                          &addr, &port) &&
1547            !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1548            port == info->sig_port[dir] &&
1549            nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1550            set_h225_addr && ct->status & IPS_NAT_MASK) {
1551                /* Answering ARQ */
1552                return set_h225_addr(skb, protoff, data, 0,
1553                                     &arq->destCallSignalAddress,
1554                                     &ct->tuplehash[!dir].tuple.dst.u3,
1555                                     info->sig_port[!dir]);
1556        }
1557
1558        if ((arq->options & eAdmissionRequest_srcCallSignalAddress) &&
1559            get_h225_addr(ct, *data, &arq->srcCallSignalAddress,
1560                          &addr, &port) &&
1561            !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1562            set_h225_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1563            ct->status & IPS_NAT_MASK) {
1564                /* Calling ARQ */
1565                return set_h225_addr(skb, protoff, data, 0,
1566                                     &arq->srcCallSignalAddress,
1567                                     &ct->tuplehash[!dir].tuple.dst.u3,
1568                                     port);
1569        }
1570
1571        return 0;
1572}
1573
1574/****************************************************************************/
1575static int process_acf(struct sk_buff *skb, struct nf_conn *ct,
1576                       enum ip_conntrack_info ctinfo,
1577                       unsigned int protoff,
1578                       unsigned char **data, AdmissionConfirm *acf)
1579{
1580        int dir = CTINFO2DIR(ctinfo);
1581        int ret = 0;
1582        __be16 port;
1583        union nf_inet_addr addr;
1584        struct nf_conntrack_expect *exp;
1585        typeof(set_sig_addr_hook) set_sig_addr;
1586
1587        pr_debug("nf_ct_ras: ACF\n");
1588
1589        if (!get_h225_addr(ct, *data, &acf->destCallSignalAddress,
1590                           &addr, &port))
1591                return 0;
1592
1593        if (!memcmp(&addr, &ct->tuplehash[dir].tuple.dst.u3, sizeof(addr))) {
1594                /* Answering ACF */
1595                set_sig_addr = rcu_dereference(set_sig_addr_hook);
1596                if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1597                    ct->status & IPS_NAT_MASK)
1598                        return set_sig_addr(skb, ct, ctinfo, protoff, data,
1599                                            &acf->destCallSignalAddress, 1);
1600                return 0;
1601        }
1602
1603        /* Need new expect */
1604        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1605                return -1;
1606        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1607                          &ct->tuplehash[!dir].tuple.src.u3, &addr,
1608                          IPPROTO_TCP, NULL, &port);
1609        exp->flags = NF_CT_EXPECT_PERMANENT;
1610        exp->helper = nf_conntrack_helper_q931;
1611
1612        if (nf_ct_expect_related(exp) == 0) {
1613                pr_debug("nf_ct_ras: expect Q.931 ");
1614                nf_ct_dump_tuple(&exp->tuple);
1615        } else
1616                ret = -1;
1617
1618        nf_ct_expect_put(exp);
1619
1620        return ret;
1621}
1622
1623/****************************************************************************/
1624static int process_lrq(struct sk_buff *skb, struct nf_conn *ct,
1625                       enum ip_conntrack_info ctinfo,
1626                       unsigned int protoff,
1627                       unsigned char **data, LocationRequest *lrq)
1628{
1629        typeof(set_ras_addr_hook) set_ras_addr;
1630
1631        pr_debug("nf_ct_ras: LRQ\n");
1632
1633        set_ras_addr = rcu_dereference(set_ras_addr_hook);
1634        if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1635            ct->status & IPS_NAT_MASK)
1636                return set_ras_addr(skb, ct, ctinfo, protoff, data,
1637                                    &lrq->replyAddress, 1);
1638        return 0;
1639}
1640
1641/****************************************************************************/
1642static int process_lcf(struct sk_buff *skb, struct nf_conn *ct,
1643                       enum ip_conntrack_info ctinfo,
1644                       unsigned int protoff,
1645                       unsigned char **data, LocationConfirm *lcf)
1646{
1647        int dir = CTINFO2DIR(ctinfo);
1648        int ret = 0;
1649        __be16 port;
1650        union nf_inet_addr addr;
1651        struct nf_conntrack_expect *exp;
1652
1653        pr_debug("nf_ct_ras: LCF\n");
1654
1655        if (!get_h225_addr(ct, *data, &lcf->callSignalAddress,
1656                           &addr, &port))
1657                return 0;
1658
1659        /* Need new expect for call signal */
1660        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1661                return -1;
1662        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1663                          &ct->tuplehash[!dir].tuple.src.u3, &addr,
1664                          IPPROTO_TCP, NULL, &port);
1665        exp->flags = NF_CT_EXPECT_PERMANENT;
1666        exp->helper = nf_conntrack_helper_q931;
1667
1668        if (nf_ct_expect_related(exp) == 0) {
1669                pr_debug("nf_ct_ras: expect Q.931 ");
1670                nf_ct_dump_tuple(&exp->tuple);
1671        } else
1672                ret = -1;
1673
1674        nf_ct_expect_put(exp);
1675
1676        /* Ignore rasAddress */
1677
1678        return ret;
1679}
1680
1681/****************************************************************************/
1682static int process_irr(struct sk_buff *skb, struct nf_conn *ct,
1683                       enum ip_conntrack_info ctinfo,
1684                       unsigned int protoff,
1685                       unsigned char **data, InfoRequestResponse *irr)
1686{
1687        int ret;
1688        typeof(set_ras_addr_hook) set_ras_addr;
1689        typeof(set_sig_addr_hook) set_sig_addr;
1690
1691        pr_debug("nf_ct_ras: IRR\n");
1692
1693        set_ras_addr = rcu_dereference(set_ras_addr_hook);
1694        if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1695            ct->status & IPS_NAT_MASK) {
1696                ret = set_ras_addr(skb, ct, ctinfo, protoff, data,
1697                                   &irr->rasAddress, 1);
1698                if (ret < 0)
1699                        return -1;
1700        }
1701
1702        set_sig_addr = rcu_dereference(set_sig_addr_hook);
1703        if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1704            ct->status & IPS_NAT_MASK) {
1705                ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1706                                        irr->callSignalAddress.item,
1707                                        irr->callSignalAddress.count);
1708                if (ret < 0)
1709                        return -1;
1710        }
1711
1712        return 0;
1713}
1714
1715/****************************************************************************/
1716static int process_ras(struct sk_buff *skb, struct nf_conn *ct,
1717                       enum ip_conntrack_info ctinfo,
1718                       unsigned int protoff,
1719                       unsigned char **data, RasMessage *ras)
1720{
1721        switch (ras->choice) {
1722        case eRasMessage_gatekeeperRequest:
1723                return process_grq(skb, ct, ctinfo, protoff, data,
1724                                   &ras->gatekeeperRequest);
1725        case eRasMessage_gatekeeperConfirm:
1726                return process_gcf(skb, ct, ctinfo, protoff, data,
1727                                   &ras->gatekeeperConfirm);
1728        case eRasMessage_registrationRequest:
1729                return process_rrq(skb, ct, ctinfo, protoff, data,
1730                                   &ras->registrationRequest);
1731        case eRasMessage_registrationConfirm:
1732                return process_rcf(skb, ct, ctinfo, protoff, data,
1733                                   &ras->registrationConfirm);
1734        case eRasMessage_unregistrationRequest:
1735                return process_urq(skb, ct, ctinfo, protoff, data,
1736                                   &ras->unregistrationRequest);
1737        case eRasMessage_admissionRequest:
1738                return process_arq(skb, ct, ctinfo, protoff, data,
1739                                   &ras->admissionRequest);
1740        case eRasMessage_admissionConfirm:
1741                return process_acf(skb, ct, ctinfo, protoff, data,
1742                                   &ras->admissionConfirm);
1743        case eRasMessage_locationRequest:
1744                return process_lrq(skb, ct, ctinfo, protoff, data,
1745                                   &ras->locationRequest);
1746        case eRasMessage_locationConfirm:
1747                return process_lcf(skb, ct, ctinfo, protoff, data,
1748                                   &ras->locationConfirm);
1749        case eRasMessage_infoRequestResponse:
1750                return process_irr(skb, ct, ctinfo, protoff, data,
1751                                   &ras->infoRequestResponse);
1752        default:
1753                pr_debug("nf_ct_ras: RAS message %d\n", ras->choice);
1754                break;
1755        }
1756
1757        return 0;
1758}
1759
1760/****************************************************************************/
1761static int ras_help(struct sk_buff *skb, unsigned int protoff,
1762                    struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1763{
1764        static RasMessage ras;
1765        unsigned char *data;
1766        int datalen = 0;
1767        int ret;
1768
1769        pr_debug("nf_ct_ras: skblen = %u\n", skb->len);
1770
1771        spin_lock_bh(&nf_h323_lock);
1772
1773        /* Get UDP data */
1774        data = get_udp_data(skb, protoff, &datalen);
1775        if (data == NULL)
1776                goto accept;
1777        pr_debug("nf_ct_ras: RAS message len=%d ", datalen);
1778        nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1779
1780        /* Decode RAS message */
1781        ret = DecodeRasMessage(data, datalen, &ras);
1782        if (ret < 0) {
1783                pr_debug("nf_ct_ras: decoding error: %s\n",
1784                         ret == H323_ERROR_BOUND ?
1785                         "out of bound" : "out of range");
1786                goto accept;
1787        }
1788
1789        /* Process RAS message */
1790        if (process_ras(skb, ct, ctinfo, protoff, &data, &ras) < 0)
1791                goto drop;
1792
1793      accept:
1794        spin_unlock_bh(&nf_h323_lock);
1795        return NF_ACCEPT;
1796
1797      drop:
1798        spin_unlock_bh(&nf_h323_lock);
1799        nf_ct_helper_log(skb, ct, "cannot process RAS message");
1800        return NF_DROP;
1801}
1802
1803/****************************************************************************/
1804static const struct nf_conntrack_expect_policy ras_exp_policy = {
1805        .max_expected           = 32,
1806        .timeout                = 240,
1807};
1808
1809static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = {
1810        {
1811                .name                   = "RAS",
1812                .me                     = THIS_MODULE,
1813                .data_len               = sizeof(struct nf_ct_h323_master),
1814                .tuple.src.l3num        = AF_INET,
1815                .tuple.src.u.udp.port   = cpu_to_be16(RAS_PORT),
1816                .tuple.dst.protonum     = IPPROTO_UDP,
1817                .help                   = ras_help,
1818                .expect_policy          = &ras_exp_policy,
1819        },
1820        {
1821                .name                   = "RAS",
1822                .me                     = THIS_MODULE,
1823                .data_len               = sizeof(struct nf_ct_h323_master),
1824                .tuple.src.l3num        = AF_INET6,
1825                .tuple.src.u.udp.port   = cpu_to_be16(RAS_PORT),
1826                .tuple.dst.protonum     = IPPROTO_UDP,
1827                .help                   = ras_help,
1828                .expect_policy          = &ras_exp_policy,
1829        },
1830};
1831
1832/****************************************************************************/
1833static void __exit nf_conntrack_h323_fini(void)
1834{
1835        nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[1]);
1836        nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1837        nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1838        nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1839        nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1840        kfree(h323_buffer);
1841        pr_debug("nf_ct_h323: fini\n");
1842}
1843
1844/****************************************************************************/
1845static int __init nf_conntrack_h323_init(void)
1846{
1847        int ret;
1848
1849        h323_buffer = kmalloc(65536, GFP_KERNEL);
1850        if (!h323_buffer)
1851                return -ENOMEM;
1852        ret = nf_conntrack_helper_register(&nf_conntrack_helper_h245);
1853        if (ret < 0)
1854                goto err1;
1855        ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[0]);
1856        if (ret < 0)
1857                goto err2;
1858        ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[1]);
1859        if (ret < 0)
1860                goto err3;
1861        ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[0]);
1862        if (ret < 0)
1863                goto err4;
1864        ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[1]);
1865        if (ret < 0)
1866                goto err5;
1867        pr_debug("nf_ct_h323: init success\n");
1868        return 0;
1869
1870err5:
1871        nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1872err4:
1873        nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1874err3:
1875        nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1876err2:
1877        nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1878err1:
1879        kfree(h323_buffer);
1880        return ret;
1881}
1882
1883/****************************************************************************/
1884module_init(nf_conntrack_h323_init);
1885module_exit(nf_conntrack_h323_fini);
1886
1887EXPORT_SYMBOL_GPL(get_h225_addr);
1888EXPORT_SYMBOL_GPL(set_h245_addr_hook);
1889EXPORT_SYMBOL_GPL(set_h225_addr_hook);
1890EXPORT_SYMBOL_GPL(set_sig_addr_hook);
1891EXPORT_SYMBOL_GPL(set_ras_addr_hook);
1892EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook);
1893EXPORT_SYMBOL_GPL(nat_t120_hook);
1894EXPORT_SYMBOL_GPL(nat_h245_hook);
1895EXPORT_SYMBOL_GPL(nat_callforwarding_hook);
1896EXPORT_SYMBOL_GPL(nat_q931_hook);
1897
1898MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>");
1899MODULE_DESCRIPTION("H.323 connection tracking helper");
1900MODULE_LICENSE("GPL");
1901MODULE_ALIAS("ip_conntrack_h323");
1902MODULE_ALIAS_NFCT_HELPER("RAS");
1903MODULE_ALIAS_NFCT_HELPER("Q.931");
1904MODULE_ALIAS_NFCT_HELPER("H.245");
1905
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