linux/net/netfilter/nf_conntrack_h323_main.c
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   1/*
   2 * H.323 connection tracking helper
   3 *
   4 * Copyright (c) 2006 Jing Min Zhao <zhaojingmin@users.sourceforge.net>
   5 *
   6 * This source code is licensed under General Public License version 2.
   7 *
   8 * Based on the 'brute force' H.323 connection tracking module by
   9 * Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
  10 *
  11 * For more information, please see http://nath323.sourceforge.net/
  12 */
  13
  14#include <linux/module.h>
  15#include <linux/moduleparam.h>
  16#include <linux/ctype.h>
  17#include <linux/inet.h>
  18#include <linux/in.h>
  19#include <linux/ip.h>
  20#include <linux/slab.h>
  21#include <linux/udp.h>
  22#include <linux/tcp.h>
  23#include <linux/skbuff.h>
  24#include <net/route.h>
  25#include <net/ip6_route.h>
  26
  27#include <net/netfilter/nf_conntrack.h>
  28#include <net/netfilter/nf_conntrack_core.h>
  29#include <net/netfilter/nf_conntrack_tuple.h>
  30#include <net/netfilter/nf_conntrack_expect.h>
  31#include <net/netfilter/nf_conntrack_ecache.h>
  32#include <net/netfilter/nf_conntrack_helper.h>
  33#include <net/netfilter/nf_conntrack_zones.h>
  34#include <linux/netfilter/nf_conntrack_h323.h>
  35
  36/* Parameters */
  37static unsigned int default_rrq_ttl __read_mostly = 300;
  38module_param(default_rrq_ttl, uint, 0600);
  39MODULE_PARM_DESC(default_rrq_ttl, "use this TTL if it's missing in RRQ");
  40
  41static int gkrouted_only __read_mostly = 1;
  42module_param(gkrouted_only, int, 0600);
  43MODULE_PARM_DESC(gkrouted_only, "only accept calls from gatekeeper");
  44
  45static bool callforward_filter __read_mostly = true;
  46module_param(callforward_filter, bool, 0600);
  47MODULE_PARM_DESC(callforward_filter, "only create call forwarding expectations "
  48                                     "if both endpoints are on different sides "
  49                                     "(determined by routing information)");
  50
  51/* Hooks for NAT */
  52int (*set_h245_addr_hook) (struct sk_buff *skb, unsigned int protoff,
  53                           unsigned char **data, int dataoff,
  54                           H245_TransportAddress *taddr,
  55                           union nf_inet_addr *addr, __be16 port)
  56                           __read_mostly;
  57int (*set_h225_addr_hook) (struct sk_buff *skb, unsigned int protoff,
  58                           unsigned char **data, int dataoff,
  59                           TransportAddress *taddr,
  60                           union nf_inet_addr *addr, __be16 port)
  61                           __read_mostly;
  62int (*set_sig_addr_hook) (struct sk_buff *skb,
  63                          struct nf_conn *ct,
  64                          enum ip_conntrack_info ctinfo,
  65                          unsigned int protoff, unsigned char **data,
  66                          TransportAddress *taddr, int count) __read_mostly;
  67int (*set_ras_addr_hook) (struct sk_buff *skb,
  68                          struct nf_conn *ct,
  69                          enum ip_conntrack_info ctinfo,
  70                          unsigned int protoff, unsigned char **data,
  71                          TransportAddress *taddr, int count) __read_mostly;
  72int (*nat_rtp_rtcp_hook) (struct sk_buff *skb,
  73                          struct nf_conn *ct,
  74                          enum ip_conntrack_info ctinfo,
  75                          unsigned int protoff,
  76                          unsigned char **data, int dataoff,
  77                          H245_TransportAddress *taddr,
  78                          __be16 port, __be16 rtp_port,
  79                          struct nf_conntrack_expect *rtp_exp,
  80                          struct nf_conntrack_expect *rtcp_exp) __read_mostly;
  81int (*nat_t120_hook) (struct sk_buff *skb,
  82                      struct nf_conn *ct,
  83                      enum ip_conntrack_info ctinfo,
  84                      unsigned int protoff,
  85                      unsigned char **data, int dataoff,
  86                      H245_TransportAddress *taddr, __be16 port,
  87                      struct nf_conntrack_expect *exp) __read_mostly;
  88int (*nat_h245_hook) (struct sk_buff *skb,
  89                      struct nf_conn *ct,
  90                      enum ip_conntrack_info ctinfo,
  91                      unsigned int protoff,
  92                      unsigned char **data, int dataoff,
  93                      TransportAddress *taddr, __be16 port,
  94                      struct nf_conntrack_expect *exp) __read_mostly;
  95int (*nat_callforwarding_hook) (struct sk_buff *skb,
  96                                struct nf_conn *ct,
  97                                enum ip_conntrack_info ctinfo,
  98                                unsigned int protoff,
  99                                unsigned char **data, int dataoff,
 100                                TransportAddress *taddr, __be16 port,
 101                                struct nf_conntrack_expect *exp) __read_mostly;
 102int (*nat_q931_hook) (struct sk_buff *skb,
 103                      struct nf_conn *ct,
 104                      enum ip_conntrack_info ctinfo,
 105                      unsigned int protoff,
 106                      unsigned char **data, TransportAddress *taddr, int idx,
 107                      __be16 port, struct nf_conntrack_expect *exp)
 108                      __read_mostly;
 109
 110static DEFINE_SPINLOCK(nf_h323_lock);
 111static char *h323_buffer;
 112
 113static struct nf_conntrack_helper nf_conntrack_helper_h245;
 114static struct nf_conntrack_helper nf_conntrack_helper_q931[];
 115static struct nf_conntrack_helper nf_conntrack_helper_ras[];
 116
 117/****************************************************************************/
 118static int get_tpkt_data(struct sk_buff *skb, unsigned int protoff,
 119                         struct nf_conn *ct, enum ip_conntrack_info ctinfo,
 120                         unsigned char **data, int *datalen, int *dataoff)
 121{
 122        struct nf_ct_h323_master *info = nfct_help_data(ct);
 123        int dir = CTINFO2DIR(ctinfo);
 124        const struct tcphdr *th;
 125        struct tcphdr _tcph;
 126        int tcpdatalen;
 127        int tcpdataoff;
 128        unsigned char *tpkt;
 129        int tpktlen;
 130        int tpktoff;
 131
 132        /* Get TCP header */
 133        th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph);
 134        if (th == NULL)
 135                return 0;
 136
 137        /* Get TCP data offset */
 138        tcpdataoff = protoff + th->doff * 4;
 139
 140        /* Get TCP data length */
 141        tcpdatalen = skb->len - tcpdataoff;
 142        if (tcpdatalen <= 0)    /* No TCP data */
 143                goto clear_out;
 144
 145        if (*data == NULL) {    /* first TPKT */
 146                /* Get first TPKT pointer */
 147                tpkt = skb_header_pointer(skb, tcpdataoff, tcpdatalen,
 148                                          h323_buffer);
 149                BUG_ON(tpkt == NULL);
 150
 151                /* Validate TPKT identifier */
 152                if (tcpdatalen < 4 || tpkt[0] != 0x03 || tpkt[1] != 0) {
 153                        /* Netmeeting sends TPKT header and data separately */
 154                        if (info->tpkt_len[dir] > 0) {
 155                                pr_debug("nf_ct_h323: previous packet "
 156                                         "indicated separate TPKT data of %hu "
 157                                         "bytes\n", info->tpkt_len[dir]);
 158                                if (info->tpkt_len[dir] <= tcpdatalen) {
 159                                        /* Yes, there was a TPKT header
 160                                         * received */
 161                                        *data = tpkt;
 162                                        *datalen = info->tpkt_len[dir];
 163                                        *dataoff = 0;
 164                                        goto out;
 165                                }
 166
 167                                /* Fragmented TPKT */
 168                                pr_debug("nf_ct_h323: fragmented TPKT\n");
 169                                goto clear_out;
 170                        }
 171
 172                        /* It is not even a TPKT */
 173                        return 0;
 174                }
 175                tpktoff = 0;
 176        } else {                /* Next TPKT */
 177                tpktoff = *dataoff + *datalen;
 178                tcpdatalen -= tpktoff;
 179                if (tcpdatalen <= 4)    /* No more TPKT */
 180                        goto clear_out;
 181                tpkt = *data + *datalen;
 182
 183                /* Validate TPKT identifier */
 184                if (tpkt[0] != 0x03 || tpkt[1] != 0)
 185                        goto clear_out;
 186        }
 187
 188        /* Validate TPKT length */
 189        tpktlen = tpkt[2] * 256 + tpkt[3];
 190        if (tpktlen < 4)
 191                goto clear_out;
 192        if (tpktlen > tcpdatalen) {
 193                if (tcpdatalen == 4) {  /* Separate TPKT header */
 194                        /* Netmeeting sends TPKT header and data separately */
 195                        pr_debug("nf_ct_h323: separate TPKT header indicates "
 196                                 "there will be TPKT data of %hu bytes\n",
 197                                 tpktlen - 4);
 198                        info->tpkt_len[dir] = tpktlen - 4;
 199                        return 0;
 200                }
 201
 202                pr_debug("nf_ct_h323: incomplete TPKT (fragmented?)\n");
 203                goto clear_out;
 204        }
 205
 206        /* This is the encapsulated data */
 207        *data = tpkt + 4;
 208        *datalen = tpktlen - 4;
 209        *dataoff = tpktoff + 4;
 210
 211      out:
 212        /* Clear TPKT length */
 213        info->tpkt_len[dir] = 0;
 214        return 1;
 215
 216      clear_out:
 217        info->tpkt_len[dir] = 0;
 218        return 0;
 219}
 220
 221/****************************************************************************/
 222static int get_h245_addr(struct nf_conn *ct, const unsigned char *data,
 223                         H245_TransportAddress *taddr,
 224                         union nf_inet_addr *addr, __be16 *port)
 225{
 226        const unsigned char *p;
 227        int len;
 228
 229        if (taddr->choice != eH245_TransportAddress_unicastAddress)
 230                return 0;
 231
 232        switch (taddr->unicastAddress.choice) {
 233        case eUnicastAddress_iPAddress:
 234                if (nf_ct_l3num(ct) != AF_INET)
 235                        return 0;
 236                p = data + taddr->unicastAddress.iPAddress.network;
 237                len = 4;
 238                break;
 239        case eUnicastAddress_iP6Address:
 240                if (nf_ct_l3num(ct) != AF_INET6)
 241                        return 0;
 242                p = data + taddr->unicastAddress.iP6Address.network;
 243                len = 16;
 244                break;
 245        default:
 246                return 0;
 247        }
 248
 249        memcpy(addr, p, len);
 250        memset((void *)addr + len, 0, sizeof(*addr) - len);
 251        memcpy(port, p + len, sizeof(__be16));
 252
 253        return 1;
 254}
 255
 256/****************************************************************************/
 257static int expect_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct,
 258                           enum ip_conntrack_info ctinfo,
 259                           unsigned int protoff,
 260                           unsigned char **data, int dataoff,
 261                           H245_TransportAddress *taddr)
 262{
 263        int dir = CTINFO2DIR(ctinfo);
 264        int ret = 0;
 265        __be16 port;
 266        __be16 rtp_port, rtcp_port;
 267        union nf_inet_addr addr;
 268        struct nf_conntrack_expect *rtp_exp;
 269        struct nf_conntrack_expect *rtcp_exp;
 270        typeof(nat_rtp_rtcp_hook) nat_rtp_rtcp;
 271
 272        /* Read RTP or RTCP address */
 273        if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
 274            memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 275            port == 0)
 276                return 0;
 277
 278        /* RTP port is even */
 279        rtp_port = port & ~htons(1);
 280        rtcp_port = port | htons(1);
 281
 282        /* Create expect for RTP */
 283        if ((rtp_exp = nf_ct_expect_alloc(ct)) == NULL)
 284                return -1;
 285        nf_ct_expect_init(rtp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 286                          &ct->tuplehash[!dir].tuple.src.u3,
 287                          &ct->tuplehash[!dir].tuple.dst.u3,
 288                          IPPROTO_UDP, NULL, &rtp_port);
 289
 290        /* Create expect for RTCP */
 291        if ((rtcp_exp = nf_ct_expect_alloc(ct)) == NULL) {
 292                nf_ct_expect_put(rtp_exp);
 293                return -1;
 294        }
 295        nf_ct_expect_init(rtcp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 296                          &ct->tuplehash[!dir].tuple.src.u3,
 297                          &ct->tuplehash[!dir].tuple.dst.u3,
 298                          IPPROTO_UDP, NULL, &rtcp_port);
 299
 300        if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 301                   &ct->tuplehash[!dir].tuple.dst.u3,
 302                   sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 303                   (nat_rtp_rtcp = rcu_dereference(nat_rtp_rtcp_hook)) &&
 304                   nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 305                   ct->status & IPS_NAT_MASK) {
 306                /* NAT needed */
 307                ret = nat_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff,
 308                                   taddr, port, rtp_port, rtp_exp, rtcp_exp);
 309        } else {                /* Conntrack only */
 310                if (nf_ct_expect_related(rtp_exp) == 0) {
 311                        if (nf_ct_expect_related(rtcp_exp) == 0) {
 312                                pr_debug("nf_ct_h323: expect RTP ");
 313                                nf_ct_dump_tuple(&rtp_exp->tuple);
 314                                pr_debug("nf_ct_h323: expect RTCP ");
 315                                nf_ct_dump_tuple(&rtcp_exp->tuple);
 316                        } else {
 317                                nf_ct_unexpect_related(rtp_exp);
 318                                ret = -1;
 319                        }
 320                } else
 321                        ret = -1;
 322        }
 323
 324        nf_ct_expect_put(rtp_exp);
 325        nf_ct_expect_put(rtcp_exp);
 326
 327        return ret;
 328}
 329
 330/****************************************************************************/
 331static int expect_t120(struct sk_buff *skb,
 332                       struct nf_conn *ct,
 333                       enum ip_conntrack_info ctinfo,
 334                       unsigned int protoff,
 335                       unsigned char **data, int dataoff,
 336                       H245_TransportAddress *taddr)
 337{
 338        int dir = CTINFO2DIR(ctinfo);
 339        int ret = 0;
 340        __be16 port;
 341        union nf_inet_addr addr;
 342        struct nf_conntrack_expect *exp;
 343        typeof(nat_t120_hook) nat_t120;
 344
 345        /* Read T.120 address */
 346        if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
 347            memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 348            port == 0)
 349                return 0;
 350
 351        /* Create expect for T.120 connections */
 352        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 353                return -1;
 354        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 355                          &ct->tuplehash[!dir].tuple.src.u3,
 356                          &ct->tuplehash[!dir].tuple.dst.u3,
 357                          IPPROTO_TCP, NULL, &port);
 358        exp->flags = NF_CT_EXPECT_PERMANENT;    /* Accept multiple channels */
 359
 360        if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 361                   &ct->tuplehash[!dir].tuple.dst.u3,
 362                   sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 363            (nat_t120 = rcu_dereference(nat_t120_hook)) &&
 364            nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 365            ct->status & IPS_NAT_MASK) {
 366                /* NAT needed */
 367                ret = nat_t120(skb, ct, ctinfo, protoff, data, dataoff, taddr,
 368                               port, exp);
 369        } else {                /* Conntrack only */
 370                if (nf_ct_expect_related(exp) == 0) {
 371                        pr_debug("nf_ct_h323: expect T.120 ");
 372                        nf_ct_dump_tuple(&exp->tuple);
 373                } else
 374                        ret = -1;
 375        }
 376
 377        nf_ct_expect_put(exp);
 378
 379        return ret;
 380}
 381
 382/****************************************************************************/
 383static int process_h245_channel(struct sk_buff *skb,
 384                                struct nf_conn *ct,
 385                                enum ip_conntrack_info ctinfo,
 386                                unsigned int protoff,
 387                                unsigned char **data, int dataoff,
 388                                H2250LogicalChannelParameters *channel)
 389{
 390        int ret;
 391
 392        if (channel->options & eH2250LogicalChannelParameters_mediaChannel) {
 393                /* RTP */
 394                ret = expect_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff,
 395                                      &channel->mediaChannel);
 396                if (ret < 0)
 397                        return -1;
 398        }
 399
 400        if (channel->
 401            options & eH2250LogicalChannelParameters_mediaControlChannel) {
 402                /* RTCP */
 403                ret = expect_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff,
 404                                      &channel->mediaControlChannel);
 405                if (ret < 0)
 406                        return -1;
 407        }
 408
 409        return 0;
 410}
 411
 412/****************************************************************************/
 413static int process_olc(struct sk_buff *skb, struct nf_conn *ct,
 414                       enum ip_conntrack_info ctinfo,
 415                       unsigned int protoff,
 416                       unsigned char **data, int dataoff,
 417                       OpenLogicalChannel *olc)
 418{
 419        int ret;
 420
 421        pr_debug("nf_ct_h323: OpenLogicalChannel\n");
 422
 423        if (olc->forwardLogicalChannelParameters.multiplexParameters.choice ==
 424            eOpenLogicalChannel_forwardLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters)
 425        {
 426                ret = process_h245_channel(skb, ct, ctinfo,
 427                                           protoff, data, dataoff,
 428                                           &olc->
 429                                           forwardLogicalChannelParameters.
 430                                           multiplexParameters.
 431                                           h2250LogicalChannelParameters);
 432                if (ret < 0)
 433                        return -1;
 434        }
 435
 436        if ((olc->options &
 437             eOpenLogicalChannel_reverseLogicalChannelParameters) &&
 438            (olc->reverseLogicalChannelParameters.options &
 439             eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters)
 440            && (olc->reverseLogicalChannelParameters.multiplexParameters.
 441                choice ==
 442                eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
 443        {
 444                ret =
 445                    process_h245_channel(skb, ct, ctinfo,
 446                                         protoff, data, dataoff,
 447                                         &olc->
 448                                         reverseLogicalChannelParameters.
 449                                         multiplexParameters.
 450                                         h2250LogicalChannelParameters);
 451                if (ret < 0)
 452                        return -1;
 453        }
 454
 455        if ((olc->options & eOpenLogicalChannel_separateStack) &&
 456            olc->forwardLogicalChannelParameters.dataType.choice ==
 457            eDataType_data &&
 458            olc->forwardLogicalChannelParameters.dataType.data.application.
 459            choice == eDataApplicationCapability_application_t120 &&
 460            olc->forwardLogicalChannelParameters.dataType.data.application.
 461            t120.choice == eDataProtocolCapability_separateLANStack &&
 462            olc->separateStack.networkAddress.choice ==
 463            eNetworkAccessParameters_networkAddress_localAreaAddress) {
 464                ret = expect_t120(skb, ct, ctinfo, protoff, data, dataoff,
 465                                  &olc->separateStack.networkAddress.
 466                                  localAreaAddress);
 467                if (ret < 0)
 468                        return -1;
 469        }
 470
 471        return 0;
 472}
 473
 474/****************************************************************************/
 475static int process_olca(struct sk_buff *skb, struct nf_conn *ct,
 476                        enum ip_conntrack_info ctinfo,
 477                        unsigned int protoff, unsigned char **data, int dataoff,
 478                        OpenLogicalChannelAck *olca)
 479{
 480        H2250LogicalChannelAckParameters *ack;
 481        int ret;
 482
 483        pr_debug("nf_ct_h323: OpenLogicalChannelAck\n");
 484
 485        if ((olca->options &
 486             eOpenLogicalChannelAck_reverseLogicalChannelParameters) &&
 487            (olca->reverseLogicalChannelParameters.options &
 488             eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters)
 489            && (olca->reverseLogicalChannelParameters.multiplexParameters.
 490                choice ==
 491                eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
 492        {
 493                ret = process_h245_channel(skb, ct, ctinfo,
 494                                           protoff, data, dataoff,
 495                                           &olca->
 496                                           reverseLogicalChannelParameters.
 497                                           multiplexParameters.
 498                                           h2250LogicalChannelParameters);
 499                if (ret < 0)
 500                        return -1;
 501        }
 502
 503        if ((olca->options &
 504             eOpenLogicalChannelAck_forwardMultiplexAckParameters) &&
 505            (olca->forwardMultiplexAckParameters.choice ==
 506             eOpenLogicalChannelAck_forwardMultiplexAckParameters_h2250LogicalChannelAckParameters))
 507        {
 508                ack = &olca->forwardMultiplexAckParameters.
 509                    h2250LogicalChannelAckParameters;
 510                if (ack->options &
 511                    eH2250LogicalChannelAckParameters_mediaChannel) {
 512                        /* RTP */
 513                        ret = expect_rtp_rtcp(skb, ct, ctinfo,
 514                                              protoff, data, dataoff,
 515                                              &ack->mediaChannel);
 516                        if (ret < 0)
 517                                return -1;
 518                }
 519
 520                if (ack->options &
 521                    eH2250LogicalChannelAckParameters_mediaControlChannel) {
 522                        /* RTCP */
 523                        ret = expect_rtp_rtcp(skb, ct, ctinfo,
 524                                              protoff, data, dataoff,
 525                                              &ack->mediaControlChannel);
 526                        if (ret < 0)
 527                                return -1;
 528                }
 529        }
 530
 531        if ((olca->options & eOpenLogicalChannelAck_separateStack) &&
 532                olca->separateStack.networkAddress.choice ==
 533                eNetworkAccessParameters_networkAddress_localAreaAddress) {
 534                ret = expect_t120(skb, ct, ctinfo, protoff, data, dataoff,
 535                                  &olca->separateStack.networkAddress.
 536                                  localAreaAddress);
 537                if (ret < 0)
 538                        return -1;
 539        }
 540
 541        return 0;
 542}
 543
 544/****************************************************************************/
 545static int process_h245(struct sk_buff *skb, struct nf_conn *ct,
 546                        enum ip_conntrack_info ctinfo,
 547                        unsigned int protoff, unsigned char **data, int dataoff,
 548                        MultimediaSystemControlMessage *mscm)
 549{
 550        switch (mscm->choice) {
 551        case eMultimediaSystemControlMessage_request:
 552                if (mscm->request.choice ==
 553                    eRequestMessage_openLogicalChannel) {
 554                        return process_olc(skb, ct, ctinfo,
 555                                           protoff, data, dataoff,
 556                                           &mscm->request.openLogicalChannel);
 557                }
 558                pr_debug("nf_ct_h323: H.245 Request %d\n",
 559                         mscm->request.choice);
 560                break;
 561        case eMultimediaSystemControlMessage_response:
 562                if (mscm->response.choice ==
 563                    eResponseMessage_openLogicalChannelAck) {
 564                        return process_olca(skb, ct, ctinfo,
 565                                            protoff, data, dataoff,
 566                                            &mscm->response.
 567                                            openLogicalChannelAck);
 568                }
 569                pr_debug("nf_ct_h323: H.245 Response %d\n",
 570                         mscm->response.choice);
 571                break;
 572        default:
 573                pr_debug("nf_ct_h323: H.245 signal %d\n", mscm->choice);
 574                break;
 575        }
 576
 577        return 0;
 578}
 579
 580/****************************************************************************/
 581static int h245_help(struct sk_buff *skb, unsigned int protoff,
 582                     struct nf_conn *ct, enum ip_conntrack_info ctinfo)
 583{
 584        static MultimediaSystemControlMessage mscm;
 585        unsigned char *data = NULL;
 586        int datalen;
 587        int dataoff;
 588        int ret;
 589
 590        /* Until there's been traffic both ways, don't look in packets. */
 591        if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
 592                return NF_ACCEPT;
 593
 594        pr_debug("nf_ct_h245: skblen = %u\n", skb->len);
 595
 596        spin_lock_bh(&nf_h323_lock);
 597
 598        /* Process each TPKT */
 599        while (get_tpkt_data(skb, protoff, ct, ctinfo,
 600                             &data, &datalen, &dataoff)) {
 601                pr_debug("nf_ct_h245: TPKT len=%d ", datalen);
 602                nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
 603
 604                /* Decode H.245 signal */
 605                ret = DecodeMultimediaSystemControlMessage(data, datalen,
 606                                                           &mscm);
 607                if (ret < 0) {
 608                        pr_debug("nf_ct_h245: decoding error: %s\n",
 609                                 ret == H323_ERROR_BOUND ?
 610                                 "out of bound" : "out of range");
 611                        /* We don't drop when decoding error */
 612                        break;
 613                }
 614
 615                /* Process H.245 signal */
 616                if (process_h245(skb, ct, ctinfo, protoff,
 617                                 &data, dataoff, &mscm) < 0)
 618                        goto drop;
 619        }
 620
 621        spin_unlock_bh(&nf_h323_lock);
 622        return NF_ACCEPT;
 623
 624      drop:
 625        spin_unlock_bh(&nf_h323_lock);
 626        net_info_ratelimited("nf_ct_h245: packet dropped\n");
 627        return NF_DROP;
 628}
 629
 630/****************************************************************************/
 631static const struct nf_conntrack_expect_policy h245_exp_policy = {
 632        .max_expected   = H323_RTP_CHANNEL_MAX * 4 + 2 /* T.120 */,
 633        .timeout        = 240,
 634};
 635
 636static struct nf_conntrack_helper nf_conntrack_helper_h245 __read_mostly = {
 637        .name                   = "H.245",
 638        .me                     = THIS_MODULE,
 639        .data_len               = sizeof(struct nf_ct_h323_master),
 640        .tuple.src.l3num        = AF_UNSPEC,
 641        .tuple.dst.protonum     = IPPROTO_UDP,
 642        .help                   = h245_help,
 643        .expect_policy          = &h245_exp_policy,
 644};
 645
 646/****************************************************************************/
 647int get_h225_addr(struct nf_conn *ct, unsigned char *data,
 648                  TransportAddress *taddr,
 649                  union nf_inet_addr *addr, __be16 *port)
 650{
 651        const unsigned char *p;
 652        int len;
 653
 654        switch (taddr->choice) {
 655        case eTransportAddress_ipAddress:
 656                if (nf_ct_l3num(ct) != AF_INET)
 657                        return 0;
 658                p = data + taddr->ipAddress.ip;
 659                len = 4;
 660                break;
 661        case eTransportAddress_ip6Address:
 662                if (nf_ct_l3num(ct) != AF_INET6)
 663                        return 0;
 664                p = data + taddr->ip6Address.ip;
 665                len = 16;
 666                break;
 667        default:
 668                return 0;
 669        }
 670
 671        memcpy(addr, p, len);
 672        memset((void *)addr + len, 0, sizeof(*addr) - len);
 673        memcpy(port, p + len, sizeof(__be16));
 674
 675        return 1;
 676}
 677
 678/****************************************************************************/
 679static int expect_h245(struct sk_buff *skb, struct nf_conn *ct,
 680                       enum ip_conntrack_info ctinfo,
 681                       unsigned int protoff, unsigned char **data, int dataoff,
 682                       TransportAddress *taddr)
 683{
 684        int dir = CTINFO2DIR(ctinfo);
 685        int ret = 0;
 686        __be16 port;
 687        union nf_inet_addr addr;
 688        struct nf_conntrack_expect *exp;
 689        typeof(nat_h245_hook) nat_h245;
 690
 691        /* Read h245Address */
 692        if (!get_h225_addr(ct, *data, taddr, &addr, &port) ||
 693            memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
 694            port == 0)
 695                return 0;
 696
 697        /* Create expect for h245 connection */
 698        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 699                return -1;
 700        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 701                          &ct->tuplehash[!dir].tuple.src.u3,
 702                          &ct->tuplehash[!dir].tuple.dst.u3,
 703                          IPPROTO_TCP, NULL, &port);
 704        exp->helper = &nf_conntrack_helper_h245;
 705
 706        if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 707                   &ct->tuplehash[!dir].tuple.dst.u3,
 708                   sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 709            (nat_h245 = rcu_dereference(nat_h245_hook)) &&
 710            nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 711            ct->status & IPS_NAT_MASK) {
 712                /* NAT needed */
 713                ret = nat_h245(skb, ct, ctinfo, protoff, data, dataoff, taddr,
 714                               port, exp);
 715        } else {                /* Conntrack only */
 716                if (nf_ct_expect_related(exp) == 0) {
 717                        pr_debug("nf_ct_q931: expect H.245 ");
 718                        nf_ct_dump_tuple(&exp->tuple);
 719                } else
 720                        ret = -1;
 721        }
 722
 723        nf_ct_expect_put(exp);
 724
 725        return ret;
 726}
 727
 728/* If the calling party is on the same side of the forward-to party,
 729 * we don't need to track the second call */
 730static int callforward_do_filter(const union nf_inet_addr *src,
 731                                 const union nf_inet_addr *dst,
 732                                 u_int8_t family)
 733{
 734        const struct nf_afinfo *afinfo;
 735        int ret = 0;
 736
 737        /* rcu_read_lock()ed by nf_hook_slow() */
 738        afinfo = nf_get_afinfo(family);
 739        if (!afinfo)
 740                return 0;
 741
 742        switch (family) {
 743        case AF_INET: {
 744                struct flowi4 fl1, fl2;
 745                struct rtable *rt1, *rt2;
 746
 747                memset(&fl1, 0, sizeof(fl1));
 748                fl1.daddr = src->ip;
 749
 750                memset(&fl2, 0, sizeof(fl2));
 751                fl2.daddr = dst->ip;
 752                if (!afinfo->route(&init_net, (struct dst_entry **)&rt1,
 753                                   flowi4_to_flowi(&fl1), false)) {
 754                        if (!afinfo->route(&init_net, (struct dst_entry **)&rt2,
 755                                           flowi4_to_flowi(&fl2), false)) {
 756                                if (rt_nexthop(rt1, fl1.daddr) ==
 757                                    rt_nexthop(rt2, fl2.daddr) &&
 758                                    rt1->dst.dev  == rt2->dst.dev)
 759                                        ret = 1;
 760                                dst_release(&rt2->dst);
 761                        }
 762                        dst_release(&rt1->dst);
 763                }
 764                break;
 765        }
 766#if IS_ENABLED(CONFIG_NF_CONNTRACK_IPV6)
 767        case AF_INET6: {
 768                struct flowi6 fl1, fl2;
 769                struct rt6_info *rt1, *rt2;
 770
 771                memset(&fl1, 0, sizeof(fl1));
 772                fl1.daddr = src->in6;
 773
 774                memset(&fl2, 0, sizeof(fl2));
 775                fl2.daddr = dst->in6;
 776                if (!afinfo->route(&init_net, (struct dst_entry **)&rt1,
 777                                   flowi6_to_flowi(&fl1), false)) {
 778                        if (!afinfo->route(&init_net, (struct dst_entry **)&rt2,
 779                                           flowi6_to_flowi(&fl2), false)) {
 780                                if (!memcmp(&rt1->rt6i_gateway, &rt2->rt6i_gateway,
 781                                            sizeof(rt1->rt6i_gateway)) &&
 782                                    rt1->dst.dev == rt2->dst.dev)
 783                                        ret = 1;
 784                                dst_release(&rt2->dst);
 785                        }
 786                        dst_release(&rt1->dst);
 787                }
 788                break;
 789        }
 790#endif
 791        }
 792        return ret;
 793
 794}
 795
 796/****************************************************************************/
 797static int expect_callforwarding(struct sk_buff *skb,
 798                                 struct nf_conn *ct,
 799                                 enum ip_conntrack_info ctinfo,
 800                                 unsigned int protoff,
 801                                 unsigned char **data, int dataoff,
 802                                 TransportAddress *taddr)
 803{
 804        int dir = CTINFO2DIR(ctinfo);
 805        int ret = 0;
 806        __be16 port;
 807        union nf_inet_addr addr;
 808        struct nf_conntrack_expect *exp;
 809        typeof(nat_callforwarding_hook) nat_callforwarding;
 810
 811        /* Read alternativeAddress */
 812        if (!get_h225_addr(ct, *data, taddr, &addr, &port) || port == 0)
 813                return 0;
 814
 815        /* If the calling party is on the same side of the forward-to party,
 816         * we don't need to track the second call */
 817        if (callforward_filter &&
 818            callforward_do_filter(&addr, &ct->tuplehash[!dir].tuple.src.u3,
 819                                  nf_ct_l3num(ct))) {
 820                pr_debug("nf_ct_q931: Call Forwarding not tracked\n");
 821                return 0;
 822        }
 823
 824        /* Create expect for the second call leg */
 825        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
 826                return -1;
 827        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
 828                          &ct->tuplehash[!dir].tuple.src.u3, &addr,
 829                          IPPROTO_TCP, NULL, &port);
 830        exp->helper = nf_conntrack_helper_q931;
 831
 832        if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
 833                   &ct->tuplehash[!dir].tuple.dst.u3,
 834                   sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 835            (nat_callforwarding = rcu_dereference(nat_callforwarding_hook)) &&
 836            nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 837            ct->status & IPS_NAT_MASK) {
 838                /* Need NAT */
 839                ret = nat_callforwarding(skb, ct, ctinfo,
 840                                         protoff, data, dataoff,
 841                                         taddr, port, exp);
 842        } else {                /* Conntrack only */
 843                if (nf_ct_expect_related(exp) == 0) {
 844                        pr_debug("nf_ct_q931: expect Call Forwarding ");
 845                        nf_ct_dump_tuple(&exp->tuple);
 846                } else
 847                        ret = -1;
 848        }
 849
 850        nf_ct_expect_put(exp);
 851
 852        return ret;
 853}
 854
 855/****************************************************************************/
 856static int process_setup(struct sk_buff *skb, struct nf_conn *ct,
 857                         enum ip_conntrack_info ctinfo,
 858                         unsigned int protoff,
 859                         unsigned char **data, int dataoff,
 860                         Setup_UUIE *setup)
 861{
 862        int dir = CTINFO2DIR(ctinfo);
 863        int ret;
 864        int i;
 865        __be16 port;
 866        union nf_inet_addr addr;
 867        typeof(set_h225_addr_hook) set_h225_addr;
 868
 869        pr_debug("nf_ct_q931: Setup\n");
 870
 871        if (setup->options & eSetup_UUIE_h245Address) {
 872                ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
 873                                  &setup->h245Address);
 874                if (ret < 0)
 875                        return -1;
 876        }
 877
 878        set_h225_addr = rcu_dereference(set_h225_addr_hook);
 879        if ((setup->options & eSetup_UUIE_destCallSignalAddress) &&
 880            (set_h225_addr) && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 881            ct->status & IPS_NAT_MASK &&
 882            get_h225_addr(ct, *data, &setup->destCallSignalAddress,
 883                          &addr, &port) &&
 884            memcmp(&addr, &ct->tuplehash[!dir].tuple.src.u3, sizeof(addr))) {
 885                pr_debug("nf_ct_q931: set destCallSignalAddress %pI6:%hu->%pI6:%hu\n",
 886                         &addr, ntohs(port), &ct->tuplehash[!dir].tuple.src.u3,
 887                         ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port));
 888                ret = set_h225_addr(skb, protoff, data, dataoff,
 889                                    &setup->destCallSignalAddress,
 890                                    &ct->tuplehash[!dir].tuple.src.u3,
 891                                    ct->tuplehash[!dir].tuple.src.u.tcp.port);
 892                if (ret < 0)
 893                        return -1;
 894        }
 895
 896        if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) &&
 897            (set_h225_addr) && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 898            ct->status & IPS_NAT_MASK &&
 899            get_h225_addr(ct, *data, &setup->sourceCallSignalAddress,
 900                          &addr, &port) &&
 901            memcmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(addr))) {
 902                pr_debug("nf_ct_q931: set sourceCallSignalAddress %pI6:%hu->%pI6:%hu\n",
 903                         &addr, ntohs(port), &ct->tuplehash[!dir].tuple.dst.u3,
 904                         ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port));
 905                ret = set_h225_addr(skb, protoff, data, dataoff,
 906                                    &setup->sourceCallSignalAddress,
 907                                    &ct->tuplehash[!dir].tuple.dst.u3,
 908                                    ct->tuplehash[!dir].tuple.dst.u.tcp.port);
 909                if (ret < 0)
 910                        return -1;
 911        }
 912
 913        if (setup->options & eSetup_UUIE_fastStart) {
 914                for (i = 0; i < setup->fastStart.count; i++) {
 915                        ret = process_olc(skb, ct, ctinfo,
 916                                          protoff, data, dataoff,
 917                                          &setup->fastStart.item[i]);
 918                        if (ret < 0)
 919                                return -1;
 920                }
 921        }
 922
 923        return 0;
 924}
 925
 926/****************************************************************************/
 927static int process_callproceeding(struct sk_buff *skb,
 928                                  struct nf_conn *ct,
 929                                  enum ip_conntrack_info ctinfo,
 930                                  unsigned int protoff,
 931                                  unsigned char **data, int dataoff,
 932                                  CallProceeding_UUIE *callproc)
 933{
 934        int ret;
 935        int i;
 936
 937        pr_debug("nf_ct_q931: CallProceeding\n");
 938
 939        if (callproc->options & eCallProceeding_UUIE_h245Address) {
 940                ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
 941                                  &callproc->h245Address);
 942                if (ret < 0)
 943                        return -1;
 944        }
 945
 946        if (callproc->options & eCallProceeding_UUIE_fastStart) {
 947                for (i = 0; i < callproc->fastStart.count; i++) {
 948                        ret = process_olc(skb, ct, ctinfo,
 949                                          protoff, data, dataoff,
 950                                          &callproc->fastStart.item[i]);
 951                        if (ret < 0)
 952                                return -1;
 953                }
 954        }
 955
 956        return 0;
 957}
 958
 959/****************************************************************************/
 960static int process_connect(struct sk_buff *skb, struct nf_conn *ct,
 961                           enum ip_conntrack_info ctinfo,
 962                           unsigned int protoff,
 963                           unsigned char **data, int dataoff,
 964                           Connect_UUIE *connect)
 965{
 966        int ret;
 967        int i;
 968
 969        pr_debug("nf_ct_q931: Connect\n");
 970
 971        if (connect->options & eConnect_UUIE_h245Address) {
 972                ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
 973                                  &connect->h245Address);
 974                if (ret < 0)
 975                        return -1;
 976        }
 977
 978        if (connect->options & eConnect_UUIE_fastStart) {
 979                for (i = 0; i < connect->fastStart.count; i++) {
 980                        ret = process_olc(skb, ct, ctinfo,
 981                                          protoff, data, dataoff,
 982                                          &connect->fastStart.item[i]);
 983                        if (ret < 0)
 984                                return -1;
 985                }
 986        }
 987
 988        return 0;
 989}
 990
 991/****************************************************************************/
 992static int process_alerting(struct sk_buff *skb, struct nf_conn *ct,
 993                            enum ip_conntrack_info ctinfo,
 994                            unsigned int protoff,
 995                            unsigned char **data, int dataoff,
 996                            Alerting_UUIE *alert)
 997{
 998        int ret;
 999        int i;
1000
1001        pr_debug("nf_ct_q931: Alerting\n");
1002
1003        if (alert->options & eAlerting_UUIE_h245Address) {
1004                ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
1005                                  &alert->h245Address);
1006                if (ret < 0)
1007                        return -1;
1008        }
1009
1010        if (alert->options & eAlerting_UUIE_fastStart) {
1011                for (i = 0; i < alert->fastStart.count; i++) {
1012                        ret = process_olc(skb, ct, ctinfo,
1013                                          protoff, data, dataoff,
1014                                          &alert->fastStart.item[i]);
1015                        if (ret < 0)
1016                                return -1;
1017                }
1018        }
1019
1020        return 0;
1021}
1022
1023/****************************************************************************/
1024static int process_facility(struct sk_buff *skb, struct nf_conn *ct,
1025                            enum ip_conntrack_info ctinfo,
1026                            unsigned int protoff,
1027                            unsigned char **data, int dataoff,
1028                            Facility_UUIE *facility)
1029{
1030        int ret;
1031        int i;
1032
1033        pr_debug("nf_ct_q931: Facility\n");
1034
1035        if (facility->reason.choice == eFacilityReason_callForwarded) {
1036                if (facility->options & eFacility_UUIE_alternativeAddress)
1037                        return expect_callforwarding(skb, ct, ctinfo,
1038                                                     protoff, data, dataoff,
1039                                                     &facility->
1040                                                     alternativeAddress);
1041                return 0;
1042        }
1043
1044        if (facility->options & eFacility_UUIE_h245Address) {
1045                ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
1046                                  &facility->h245Address);
1047                if (ret < 0)
1048                        return -1;
1049        }
1050
1051        if (facility->options & eFacility_UUIE_fastStart) {
1052                for (i = 0; i < facility->fastStart.count; i++) {
1053                        ret = process_olc(skb, ct, ctinfo,
1054                                          protoff, data, dataoff,
1055                                          &facility->fastStart.item[i]);
1056                        if (ret < 0)
1057                                return -1;
1058                }
1059        }
1060
1061        return 0;
1062}
1063
1064/****************************************************************************/
1065static int process_progress(struct sk_buff *skb, struct nf_conn *ct,
1066                            enum ip_conntrack_info ctinfo,
1067                            unsigned int protoff,
1068                            unsigned char **data, int dataoff,
1069                            Progress_UUIE *progress)
1070{
1071        int ret;
1072        int i;
1073
1074        pr_debug("nf_ct_q931: Progress\n");
1075
1076        if (progress->options & eProgress_UUIE_h245Address) {
1077                ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
1078                                  &progress->h245Address);
1079                if (ret < 0)
1080                        return -1;
1081        }
1082
1083        if (progress->options & eProgress_UUIE_fastStart) {
1084                for (i = 0; i < progress->fastStart.count; i++) {
1085                        ret = process_olc(skb, ct, ctinfo,
1086                                          protoff, data, dataoff,
1087                                          &progress->fastStart.item[i]);
1088                        if (ret < 0)
1089                                return -1;
1090                }
1091        }
1092
1093        return 0;
1094}
1095
1096/****************************************************************************/
1097static int process_q931(struct sk_buff *skb, struct nf_conn *ct,
1098                        enum ip_conntrack_info ctinfo,
1099                        unsigned int protoff, unsigned char **data, int dataoff,
1100                        Q931 *q931)
1101{
1102        H323_UU_PDU *pdu = &q931->UUIE.h323_uu_pdu;
1103        int i;
1104        int ret = 0;
1105
1106        switch (pdu->h323_message_body.choice) {
1107        case eH323_UU_PDU_h323_message_body_setup:
1108                ret = process_setup(skb, ct, ctinfo, protoff, data, dataoff,
1109                                    &pdu->h323_message_body.setup);
1110                break;
1111        case eH323_UU_PDU_h323_message_body_callProceeding:
1112                ret = process_callproceeding(skb, ct, ctinfo,
1113                                             protoff, data, dataoff,
1114                                             &pdu->h323_message_body.
1115                                             callProceeding);
1116                break;
1117        case eH323_UU_PDU_h323_message_body_connect:
1118                ret = process_connect(skb, ct, ctinfo, protoff, data, dataoff,
1119                                      &pdu->h323_message_body.connect);
1120                break;
1121        case eH323_UU_PDU_h323_message_body_alerting:
1122                ret = process_alerting(skb, ct, ctinfo, protoff, data, dataoff,
1123                                       &pdu->h323_message_body.alerting);
1124                break;
1125        case eH323_UU_PDU_h323_message_body_facility:
1126                ret = process_facility(skb, ct, ctinfo, protoff, data, dataoff,
1127                                       &pdu->h323_message_body.facility);
1128                break;
1129        case eH323_UU_PDU_h323_message_body_progress:
1130                ret = process_progress(skb, ct, ctinfo, protoff, data, dataoff,
1131                                       &pdu->h323_message_body.progress);
1132                break;
1133        default:
1134                pr_debug("nf_ct_q931: Q.931 signal %d\n",
1135                         pdu->h323_message_body.choice);
1136                break;
1137        }
1138
1139        if (ret < 0)
1140                return -1;
1141
1142        if (pdu->options & eH323_UU_PDU_h245Control) {
1143                for (i = 0; i < pdu->h245Control.count; i++) {
1144                        ret = process_h245(skb, ct, ctinfo,
1145                                           protoff, data, dataoff,
1146                                           &pdu->h245Control.item[i]);
1147                        if (ret < 0)
1148                                return -1;
1149                }
1150        }
1151
1152        return 0;
1153}
1154
1155/****************************************************************************/
1156static int q931_help(struct sk_buff *skb, unsigned int protoff,
1157                     struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1158{
1159        static Q931 q931;
1160        unsigned char *data = NULL;
1161        int datalen;
1162        int dataoff;
1163        int ret;
1164
1165        /* Until there's been traffic both ways, don't look in packets. */
1166        if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
1167                return NF_ACCEPT;
1168
1169        pr_debug("nf_ct_q931: skblen = %u\n", skb->len);
1170
1171        spin_lock_bh(&nf_h323_lock);
1172
1173        /* Process each TPKT */
1174        while (get_tpkt_data(skb, protoff, ct, ctinfo,
1175                             &data, &datalen, &dataoff)) {
1176                pr_debug("nf_ct_q931: TPKT len=%d ", datalen);
1177                nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1178
1179                /* Decode Q.931 signal */
1180                ret = DecodeQ931(data, datalen, &q931);
1181                if (ret < 0) {
1182                        pr_debug("nf_ct_q931: decoding error: %s\n",
1183                                 ret == H323_ERROR_BOUND ?
1184                                 "out of bound" : "out of range");
1185                        /* We don't drop when decoding error */
1186                        break;
1187                }
1188
1189                /* Process Q.931 signal */
1190                if (process_q931(skb, ct, ctinfo, protoff,
1191                                 &data, dataoff, &q931) < 0)
1192                        goto drop;
1193        }
1194
1195        spin_unlock_bh(&nf_h323_lock);
1196        return NF_ACCEPT;
1197
1198      drop:
1199        spin_unlock_bh(&nf_h323_lock);
1200        net_info_ratelimited("nf_ct_q931: packet dropped\n");
1201        return NF_DROP;
1202}
1203
1204/****************************************************************************/
1205static const struct nf_conntrack_expect_policy q931_exp_policy = {
1206        /* T.120 and H.245 */
1207        .max_expected           = H323_RTP_CHANNEL_MAX * 4 + 4,
1208        .timeout                = 240,
1209};
1210
1211static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = {
1212        {
1213                .name                   = "Q.931",
1214                .me                     = THIS_MODULE,
1215                .data_len               = sizeof(struct nf_ct_h323_master),
1216                .tuple.src.l3num        = AF_INET,
1217                .tuple.src.u.tcp.port   = cpu_to_be16(Q931_PORT),
1218                .tuple.dst.protonum     = IPPROTO_TCP,
1219                .help                   = q931_help,
1220                .expect_policy          = &q931_exp_policy,
1221        },
1222        {
1223                .name                   = "Q.931",
1224                .me                     = THIS_MODULE,
1225                .tuple.src.l3num        = AF_INET6,
1226                .tuple.src.u.tcp.port   = cpu_to_be16(Q931_PORT),
1227                .tuple.dst.protonum     = IPPROTO_TCP,
1228                .help                   = q931_help,
1229                .expect_policy          = &q931_exp_policy,
1230        },
1231};
1232
1233/****************************************************************************/
1234static unsigned char *get_udp_data(struct sk_buff *skb, unsigned int protoff,
1235                                   int *datalen)
1236{
1237        const struct udphdr *uh;
1238        struct udphdr _uh;
1239        int dataoff;
1240
1241        uh = skb_header_pointer(skb, protoff, sizeof(_uh), &_uh);
1242        if (uh == NULL)
1243                return NULL;
1244        dataoff = protoff + sizeof(_uh);
1245        if (dataoff >= skb->len)
1246                return NULL;
1247        *datalen = skb->len - dataoff;
1248        return skb_header_pointer(skb, dataoff, *datalen, h323_buffer);
1249}
1250
1251/****************************************************************************/
1252static struct nf_conntrack_expect *find_expect(struct nf_conn *ct,
1253                                               union nf_inet_addr *addr,
1254                                               __be16 port)
1255{
1256        struct net *net = nf_ct_net(ct);
1257        struct nf_conntrack_expect *exp;
1258        struct nf_conntrack_tuple tuple;
1259
1260        memset(&tuple.src.u3, 0, sizeof(tuple.src.u3));
1261        tuple.src.u.tcp.port = 0;
1262        memcpy(&tuple.dst.u3, addr, sizeof(tuple.dst.u3));
1263        tuple.dst.u.tcp.port = port;
1264        tuple.dst.protonum = IPPROTO_TCP;
1265
1266        exp = __nf_ct_expect_find(net, nf_ct_zone(ct), &tuple);
1267        if (exp && exp->master == ct)
1268                return exp;
1269        return NULL;
1270}
1271
1272/****************************************************************************/
1273static int set_expect_timeout(struct nf_conntrack_expect *exp,
1274                              unsigned int timeout)
1275{
1276        if (!exp || !del_timer(&exp->timeout))
1277                return 0;
1278
1279        exp->timeout.expires = jiffies + timeout * HZ;
1280        add_timer(&exp->timeout);
1281
1282        return 1;
1283}
1284
1285/****************************************************************************/
1286static int expect_q931(struct sk_buff *skb, struct nf_conn *ct,
1287                       enum ip_conntrack_info ctinfo,
1288                       unsigned int protoff, unsigned char **data,
1289                       TransportAddress *taddr, int count)
1290{
1291        struct nf_ct_h323_master *info = nfct_help_data(ct);
1292        int dir = CTINFO2DIR(ctinfo);
1293        int ret = 0;
1294        int i;
1295        __be16 port;
1296        union nf_inet_addr addr;
1297        struct nf_conntrack_expect *exp;
1298        typeof(nat_q931_hook) nat_q931;
1299
1300        /* Look for the first related address */
1301        for (i = 0; i < count; i++) {
1302                if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) &&
1303                    memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3,
1304                           sizeof(addr)) == 0 && port != 0)
1305                        break;
1306        }
1307
1308        if (i >= count)         /* Not found */
1309                return 0;
1310
1311        /* Create expect for Q.931 */
1312        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1313                return -1;
1314        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1315                          gkrouted_only ? /* only accept calls from GK? */
1316                                &ct->tuplehash[!dir].tuple.src.u3 : NULL,
1317                          &ct->tuplehash[!dir].tuple.dst.u3,
1318                          IPPROTO_TCP, NULL, &port);
1319        exp->helper = nf_conntrack_helper_q931;
1320        exp->flags = NF_CT_EXPECT_PERMANENT;    /* Accept multiple calls */
1321
1322        nat_q931 = rcu_dereference(nat_q931_hook);
1323        if (nat_q931 && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1324            ct->status & IPS_NAT_MASK) {        /* Need NAT */
1325                ret = nat_q931(skb, ct, ctinfo, protoff, data,
1326                               taddr, i, port, exp);
1327        } else {                /* Conntrack only */
1328                if (nf_ct_expect_related(exp) == 0) {
1329                        pr_debug("nf_ct_ras: expect Q.931 ");
1330                        nf_ct_dump_tuple(&exp->tuple);
1331
1332                        /* Save port for looking up expect in processing RCF */
1333                        info->sig_port[dir] = port;
1334                } else
1335                        ret = -1;
1336        }
1337
1338        nf_ct_expect_put(exp);
1339
1340        return ret;
1341}
1342
1343/****************************************************************************/
1344static int process_grq(struct sk_buff *skb, struct nf_conn *ct,
1345                       enum ip_conntrack_info ctinfo,
1346                       unsigned int protoff,
1347                       unsigned char **data, GatekeeperRequest *grq)
1348{
1349        typeof(set_ras_addr_hook) set_ras_addr;
1350
1351        pr_debug("nf_ct_ras: GRQ\n");
1352
1353        set_ras_addr = rcu_dereference(set_ras_addr_hook);
1354        if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1355            ct->status & IPS_NAT_MASK)  /* NATed */
1356                return set_ras_addr(skb, ct, ctinfo, protoff, data,
1357                                    &grq->rasAddress, 1);
1358        return 0;
1359}
1360
1361/****************************************************************************/
1362static int process_gcf(struct sk_buff *skb, struct nf_conn *ct,
1363                       enum ip_conntrack_info ctinfo,
1364                       unsigned int protoff,
1365                       unsigned char **data, GatekeeperConfirm *gcf)
1366{
1367        int dir = CTINFO2DIR(ctinfo);
1368        int ret = 0;
1369        __be16 port;
1370        union nf_inet_addr addr;
1371        struct nf_conntrack_expect *exp;
1372
1373        pr_debug("nf_ct_ras: GCF\n");
1374
1375        if (!get_h225_addr(ct, *data, &gcf->rasAddress, &addr, &port))
1376                return 0;
1377
1378        /* Registration port is the same as discovery port */
1379        if (!memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1380            port == ct->tuplehash[dir].tuple.src.u.udp.port)
1381                return 0;
1382
1383        /* Avoid RAS expectation loops. A GCF is never expected. */
1384        if (test_bit(IPS_EXPECTED_BIT, &ct->status))
1385                return 0;
1386
1387        /* Need new expect */
1388        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1389                return -1;
1390        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1391                          &ct->tuplehash[!dir].tuple.src.u3, &addr,
1392                          IPPROTO_UDP, NULL, &port);
1393        exp->helper = nf_conntrack_helper_ras;
1394
1395        if (nf_ct_expect_related(exp) == 0) {
1396                pr_debug("nf_ct_ras: expect RAS ");
1397                nf_ct_dump_tuple(&exp->tuple);
1398        } else
1399                ret = -1;
1400
1401        nf_ct_expect_put(exp);
1402
1403        return ret;
1404}
1405
1406/****************************************************************************/
1407static int process_rrq(struct sk_buff *skb, struct nf_conn *ct,
1408                       enum ip_conntrack_info ctinfo,
1409                       unsigned int protoff,
1410                       unsigned char **data, RegistrationRequest *rrq)
1411{
1412        struct nf_ct_h323_master *info = nfct_help_data(ct);
1413        int ret;
1414        typeof(set_ras_addr_hook) set_ras_addr;
1415
1416        pr_debug("nf_ct_ras: RRQ\n");
1417
1418        ret = expect_q931(skb, ct, ctinfo, protoff, data,
1419                          rrq->callSignalAddress.item,
1420                          rrq->callSignalAddress.count);
1421        if (ret < 0)
1422                return -1;
1423
1424        set_ras_addr = rcu_dereference(set_ras_addr_hook);
1425        if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1426            ct->status & IPS_NAT_MASK) {
1427                ret = set_ras_addr(skb, ct, ctinfo, protoff, data,
1428                                   rrq->rasAddress.item,
1429                                   rrq->rasAddress.count);
1430                if (ret < 0)
1431                        return -1;
1432        }
1433
1434        if (rrq->options & eRegistrationRequest_timeToLive) {
1435                pr_debug("nf_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive);
1436                info->timeout = rrq->timeToLive;
1437        } else
1438                info->timeout = default_rrq_ttl;
1439
1440        return 0;
1441}
1442
1443/****************************************************************************/
1444static int process_rcf(struct sk_buff *skb, struct nf_conn *ct,
1445                       enum ip_conntrack_info ctinfo,
1446                       unsigned int protoff,
1447                       unsigned char **data, RegistrationConfirm *rcf)
1448{
1449        struct nf_ct_h323_master *info = nfct_help_data(ct);
1450        int dir = CTINFO2DIR(ctinfo);
1451        int ret;
1452        struct nf_conntrack_expect *exp;
1453        typeof(set_sig_addr_hook) set_sig_addr;
1454
1455        pr_debug("nf_ct_ras: RCF\n");
1456
1457        set_sig_addr = rcu_dereference(set_sig_addr_hook);
1458        if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1459            ct->status & IPS_NAT_MASK) {
1460                ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1461                                        rcf->callSignalAddress.item,
1462                                        rcf->callSignalAddress.count);
1463                if (ret < 0)
1464                        return -1;
1465        }
1466
1467        if (rcf->options & eRegistrationConfirm_timeToLive) {
1468                pr_debug("nf_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive);
1469                info->timeout = rcf->timeToLive;
1470        }
1471
1472        if (info->timeout > 0) {
1473                pr_debug("nf_ct_ras: set RAS connection timeout to "
1474                         "%u seconds\n", info->timeout);
1475                nf_ct_refresh(ct, skb, info->timeout * HZ);
1476
1477                /* Set expect timeout */
1478                spin_lock_bh(&nf_conntrack_lock);
1479                exp = find_expect(ct, &ct->tuplehash[dir].tuple.dst.u3,
1480                                  info->sig_port[!dir]);
1481                if (exp) {
1482                        pr_debug("nf_ct_ras: set Q.931 expect "
1483                                 "timeout to %u seconds for",
1484                                 info->timeout);
1485                        nf_ct_dump_tuple(&exp->tuple);
1486                        set_expect_timeout(exp, info->timeout);
1487                }
1488                spin_unlock_bh(&nf_conntrack_lock);
1489        }
1490
1491        return 0;
1492}
1493
1494/****************************************************************************/
1495static int process_urq(struct sk_buff *skb, struct nf_conn *ct,
1496                       enum ip_conntrack_info ctinfo,
1497                       unsigned int protoff,
1498                       unsigned char **data, UnregistrationRequest *urq)
1499{
1500        struct nf_ct_h323_master *info = nfct_help_data(ct);
1501        int dir = CTINFO2DIR(ctinfo);
1502        int ret;
1503        typeof(set_sig_addr_hook) set_sig_addr;
1504
1505        pr_debug("nf_ct_ras: URQ\n");
1506
1507        set_sig_addr = rcu_dereference(set_sig_addr_hook);
1508        if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1509            ct->status & IPS_NAT_MASK) {
1510                ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1511                                   urq->callSignalAddress.item,
1512                                   urq->callSignalAddress.count);
1513                if (ret < 0)
1514                        return -1;
1515        }
1516
1517        /* Clear old expect */
1518        nf_ct_remove_expectations(ct);
1519        info->sig_port[dir] = 0;
1520        info->sig_port[!dir] = 0;
1521
1522        /* Give it 30 seconds for UCF or URJ */
1523        nf_ct_refresh(ct, skb, 30 * HZ);
1524
1525        return 0;
1526}
1527
1528/****************************************************************************/
1529static int process_arq(struct sk_buff *skb, struct nf_conn *ct,
1530                       enum ip_conntrack_info ctinfo,
1531                       unsigned int protoff,
1532                       unsigned char **data, AdmissionRequest *arq)
1533{
1534        const struct nf_ct_h323_master *info = nfct_help_data(ct);
1535        int dir = CTINFO2DIR(ctinfo);
1536        __be16 port;
1537        union nf_inet_addr addr;
1538        typeof(set_h225_addr_hook) set_h225_addr;
1539
1540        pr_debug("nf_ct_ras: ARQ\n");
1541
1542        set_h225_addr = rcu_dereference(set_h225_addr_hook);
1543        if ((arq->options & eAdmissionRequest_destCallSignalAddress) &&
1544            get_h225_addr(ct, *data, &arq->destCallSignalAddress,
1545                          &addr, &port) &&
1546            !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1547            port == info->sig_port[dir] &&
1548            nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1549            set_h225_addr && ct->status & IPS_NAT_MASK) {
1550                /* Answering ARQ */
1551                return set_h225_addr(skb, protoff, data, 0,
1552                                     &arq->destCallSignalAddress,
1553                                     &ct->tuplehash[!dir].tuple.dst.u3,
1554                                     info->sig_port[!dir]);
1555        }
1556
1557        if ((arq->options & eAdmissionRequest_srcCallSignalAddress) &&
1558            get_h225_addr(ct, *data, &arq->srcCallSignalAddress,
1559                          &addr, &port) &&
1560            !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1561            set_h225_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1562            ct->status & IPS_NAT_MASK) {
1563                /* Calling ARQ */
1564                return set_h225_addr(skb, protoff, data, 0,
1565                                     &arq->srcCallSignalAddress,
1566                                     &ct->tuplehash[!dir].tuple.dst.u3,
1567                                     port);
1568        }
1569
1570        return 0;
1571}
1572
1573/****************************************************************************/
1574static int process_acf(struct sk_buff *skb, struct nf_conn *ct,
1575                       enum ip_conntrack_info ctinfo,
1576                       unsigned int protoff,
1577                       unsigned char **data, AdmissionConfirm *acf)
1578{
1579        int dir = CTINFO2DIR(ctinfo);
1580        int ret = 0;
1581        __be16 port;
1582        union nf_inet_addr addr;
1583        struct nf_conntrack_expect *exp;
1584        typeof(set_sig_addr_hook) set_sig_addr;
1585
1586        pr_debug("nf_ct_ras: ACF\n");
1587
1588        if (!get_h225_addr(ct, *data, &acf->destCallSignalAddress,
1589                           &addr, &port))
1590                return 0;
1591
1592        if (!memcmp(&addr, &ct->tuplehash[dir].tuple.dst.u3, sizeof(addr))) {
1593                /* Answering ACF */
1594                set_sig_addr = rcu_dereference(set_sig_addr_hook);
1595                if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1596                    ct->status & IPS_NAT_MASK)
1597                        return set_sig_addr(skb, ct, ctinfo, protoff, data,
1598                                            &acf->destCallSignalAddress, 1);
1599                return 0;
1600        }
1601
1602        /* Need new expect */
1603        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1604                return -1;
1605        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1606                          &ct->tuplehash[!dir].tuple.src.u3, &addr,
1607                          IPPROTO_TCP, NULL, &port);
1608        exp->flags = NF_CT_EXPECT_PERMANENT;
1609        exp->helper = nf_conntrack_helper_q931;
1610
1611        if (nf_ct_expect_related(exp) == 0) {
1612                pr_debug("nf_ct_ras: expect Q.931 ");
1613                nf_ct_dump_tuple(&exp->tuple);
1614        } else
1615                ret = -1;
1616
1617        nf_ct_expect_put(exp);
1618
1619        return ret;
1620}
1621
1622/****************************************************************************/
1623static int process_lrq(struct sk_buff *skb, struct nf_conn *ct,
1624                       enum ip_conntrack_info ctinfo,
1625                       unsigned int protoff,
1626                       unsigned char **data, LocationRequest *lrq)
1627{
1628        typeof(set_ras_addr_hook) set_ras_addr;
1629
1630        pr_debug("nf_ct_ras: LRQ\n");
1631
1632        set_ras_addr = rcu_dereference(set_ras_addr_hook);
1633        if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1634            ct->status & IPS_NAT_MASK)
1635                return set_ras_addr(skb, ct, ctinfo, protoff, data,
1636                                    &lrq->replyAddress, 1);
1637        return 0;
1638}
1639
1640/****************************************************************************/
1641static int process_lcf(struct sk_buff *skb, struct nf_conn *ct,
1642                       enum ip_conntrack_info ctinfo,
1643                       unsigned int protoff,
1644                       unsigned char **data, LocationConfirm *lcf)
1645{
1646        int dir = CTINFO2DIR(ctinfo);
1647        int ret = 0;
1648        __be16 port;
1649        union nf_inet_addr addr;
1650        struct nf_conntrack_expect *exp;
1651
1652        pr_debug("nf_ct_ras: LCF\n");
1653
1654        if (!get_h225_addr(ct, *data, &lcf->callSignalAddress,
1655                           &addr, &port))
1656                return 0;
1657
1658        /* Need new expect for call signal */
1659        if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1660                return -1;
1661        nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1662                          &ct->tuplehash[!dir].tuple.src.u3, &addr,
1663                          IPPROTO_TCP, NULL, &port);
1664        exp->flags = NF_CT_EXPECT_PERMANENT;
1665        exp->helper = nf_conntrack_helper_q931;
1666
1667        if (nf_ct_expect_related(exp) == 0) {
1668                pr_debug("nf_ct_ras: expect Q.931 ");
1669                nf_ct_dump_tuple(&exp->tuple);
1670        } else
1671                ret = -1;
1672
1673        nf_ct_expect_put(exp);
1674
1675        /* Ignore rasAddress */
1676
1677        return ret;
1678}
1679
1680/****************************************************************************/
1681static int process_irr(struct sk_buff *skb, struct nf_conn *ct,
1682                       enum ip_conntrack_info ctinfo,
1683                       unsigned int protoff,
1684                       unsigned char **data, InfoRequestResponse *irr)
1685{
1686        int ret;
1687        typeof(set_ras_addr_hook) set_ras_addr;
1688        typeof(set_sig_addr_hook) set_sig_addr;
1689
1690        pr_debug("nf_ct_ras: IRR\n");
1691
1692        set_ras_addr = rcu_dereference(set_ras_addr_hook);
1693        if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1694            ct->status & IPS_NAT_MASK) {
1695                ret = set_ras_addr(skb, ct, ctinfo, protoff, data,
1696                                   &irr->rasAddress, 1);
1697                if (ret < 0)
1698                        return -1;
1699        }
1700
1701        set_sig_addr = rcu_dereference(set_sig_addr_hook);
1702        if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
1703            ct->status & IPS_NAT_MASK) {
1704                ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
1705                                        irr->callSignalAddress.item,
1706                                        irr->callSignalAddress.count);
1707                if (ret < 0)
1708                        return -1;
1709        }
1710
1711        return 0;
1712}
1713
1714/****************************************************************************/
1715static int process_ras(struct sk_buff *skb, struct nf_conn *ct,
1716                       enum ip_conntrack_info ctinfo,
1717                       unsigned int protoff,
1718                       unsigned char **data, RasMessage *ras)
1719{
1720        switch (ras->choice) {
1721        case eRasMessage_gatekeeperRequest:
1722                return process_grq(skb, ct, ctinfo, protoff, data,
1723                                   &ras->gatekeeperRequest);
1724        case eRasMessage_gatekeeperConfirm:
1725                return process_gcf(skb, ct, ctinfo, protoff, data,
1726                                   &ras->gatekeeperConfirm);
1727        case eRasMessage_registrationRequest:
1728                return process_rrq(skb, ct, ctinfo, protoff, data,
1729                                   &ras->registrationRequest);
1730        case eRasMessage_registrationConfirm:
1731                return process_rcf(skb, ct, ctinfo, protoff, data,
1732                                   &ras->registrationConfirm);
1733        case eRasMessage_unregistrationRequest:
1734                return process_urq(skb, ct, ctinfo, protoff, data,
1735                                   &ras->unregistrationRequest);
1736        case eRasMessage_admissionRequest:
1737                return process_arq(skb, ct, ctinfo, protoff, data,
1738                                   &ras->admissionRequest);
1739        case eRasMessage_admissionConfirm:
1740                return process_acf(skb, ct, ctinfo, protoff, data,
1741                                   &ras->admissionConfirm);
1742        case eRasMessage_locationRequest:
1743                return process_lrq(skb, ct, ctinfo, protoff, data,
1744                                   &ras->locationRequest);
1745        case eRasMessage_locationConfirm:
1746                return process_lcf(skb, ct, ctinfo, protoff, data,
1747                                   &ras->locationConfirm);
1748        case eRasMessage_infoRequestResponse:
1749                return process_irr(skb, ct, ctinfo, protoff, data,
1750                                   &ras->infoRequestResponse);
1751        default:
1752                pr_debug("nf_ct_ras: RAS message %d\n", ras->choice);
1753                break;
1754        }
1755
1756        return 0;
1757}
1758
1759/****************************************************************************/
1760static int ras_help(struct sk_buff *skb, unsigned int protoff,
1761                    struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1762{
1763        static RasMessage ras;
1764        unsigned char *data;
1765        int datalen = 0;
1766        int ret;
1767
1768        pr_debug("nf_ct_ras: skblen = %u\n", skb->len);
1769
1770        spin_lock_bh(&nf_h323_lock);
1771
1772        /* Get UDP data */
1773        data = get_udp_data(skb, protoff, &datalen);
1774        if (data == NULL)
1775                goto accept;
1776        pr_debug("nf_ct_ras: RAS message len=%d ", datalen);
1777        nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1778
1779        /* Decode RAS message */
1780        ret = DecodeRasMessage(data, datalen, &ras);
1781        if (ret < 0) {
1782                pr_debug("nf_ct_ras: decoding error: %s\n",
1783                         ret == H323_ERROR_BOUND ?
1784                         "out of bound" : "out of range");
1785                goto accept;
1786        }
1787
1788        /* Process RAS message */
1789        if (process_ras(skb, ct, ctinfo, protoff, &data, &ras) < 0)
1790                goto drop;
1791
1792      accept:
1793        spin_unlock_bh(&nf_h323_lock);
1794        return NF_ACCEPT;
1795
1796      drop:
1797        spin_unlock_bh(&nf_h323_lock);
1798        net_info_ratelimited("nf_ct_ras: packet dropped\n");
1799        return NF_DROP;
1800}
1801
1802/****************************************************************************/
1803static const struct nf_conntrack_expect_policy ras_exp_policy = {
1804        .max_expected           = 32,
1805        .timeout                = 240,
1806};
1807
1808static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = {
1809        {
1810                .name                   = "RAS",
1811                .me                     = THIS_MODULE,
1812                .data_len               = sizeof(struct nf_ct_h323_master),
1813                .tuple.src.l3num        = AF_INET,
1814                .tuple.src.u.udp.port   = cpu_to_be16(RAS_PORT),
1815                .tuple.dst.protonum     = IPPROTO_UDP,
1816                .help                   = ras_help,
1817                .expect_policy          = &ras_exp_policy,
1818        },
1819        {
1820                .name                   = "RAS",
1821                .me                     = THIS_MODULE,
1822                .data_len               = sizeof(struct nf_ct_h323_master),
1823                .tuple.src.l3num        = AF_INET6,
1824                .tuple.src.u.udp.port   = cpu_to_be16(RAS_PORT),
1825                .tuple.dst.protonum     = IPPROTO_UDP,
1826                .help                   = ras_help,
1827                .expect_policy          = &ras_exp_policy,
1828        },
1829};
1830
1831/****************************************************************************/
1832static void __exit nf_conntrack_h323_fini(void)
1833{
1834        nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[1]);
1835        nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1836        nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1837        nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1838        nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1839        kfree(h323_buffer);
1840        pr_debug("nf_ct_h323: fini\n");
1841}
1842
1843/****************************************************************************/
1844static int __init nf_conntrack_h323_init(void)
1845{
1846        int ret;
1847
1848        h323_buffer = kmalloc(65536, GFP_KERNEL);
1849        if (!h323_buffer)
1850                return -ENOMEM;
1851        ret = nf_conntrack_helper_register(&nf_conntrack_helper_h245);
1852        if (ret < 0)
1853                goto err1;
1854        ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[0]);
1855        if (ret < 0)
1856                goto err2;
1857        ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[1]);
1858        if (ret < 0)
1859                goto err3;
1860        ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[0]);
1861        if (ret < 0)
1862                goto err4;
1863        ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[1]);
1864        if (ret < 0)
1865                goto err5;
1866        pr_debug("nf_ct_h323: init success\n");
1867        return 0;
1868
1869err5:
1870        nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1871err4:
1872        nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1873err3:
1874        nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1875err2:
1876        nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1877err1:
1878        kfree(h323_buffer);
1879        return ret;
1880}
1881
1882/****************************************************************************/
1883module_init(nf_conntrack_h323_init);
1884module_exit(nf_conntrack_h323_fini);
1885
1886EXPORT_SYMBOL_GPL(get_h225_addr);
1887EXPORT_SYMBOL_GPL(set_h245_addr_hook);
1888EXPORT_SYMBOL_GPL(set_h225_addr_hook);
1889EXPORT_SYMBOL_GPL(set_sig_addr_hook);
1890EXPORT_SYMBOL_GPL(set_ras_addr_hook);
1891EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook);
1892EXPORT_SYMBOL_GPL(nat_t120_hook);
1893EXPORT_SYMBOL_GPL(nat_h245_hook);
1894EXPORT_SYMBOL_GPL(nat_callforwarding_hook);
1895EXPORT_SYMBOL_GPL(nat_q931_hook);
1896
1897MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>");
1898MODULE_DESCRIPTION("H.323 connection tracking helper");
1899MODULE_LICENSE("GPL");
1900MODULE_ALIAS("ip_conntrack_h323");
1901MODULE_ALIAS_NFCT_HELPER("RAS");
1902MODULE_ALIAS_NFCT_HELPER("Q.931");
1903MODULE_ALIAS_NFCT_HELPER("H.245");
1904
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