1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * H.323 connection tracking helper 4 * 5 * Copyright (c) 2006 Jing Min Zhao <zhaojingmin@users.sourceforge.net> 6 * Copyright (c) 2006-2012 Patrick McHardy <kaber@trash.net> 7 * 8 * Based on the 'brute force' H.323 connection tracking module by 9 * Jozsef Kadlecsik <kadlec@netfilter.org> 10 * 11 * For more information, please see http://nath323.sourceforge.net/ 12 */ 13 14 #include <linux/module.h> 15 #include <linux/moduleparam.h> 16 #include <linux/ctype.h> 17 #include <linux/inet.h> 18 #include <linux/in.h> 19 #include <linux/ip.h> 20 #include <linux/slab.h> 21 #include <linux/udp.h> 22 #include <linux/tcp.h> 23 #include <linux/skbuff.h> 24 #include <net/route.h> 25 #include <net/ip6_route.h> 26 #include <linux/netfilter_ipv6.h> 27 28 #include <net/netfilter/nf_conntrack.h> 29 #include <net/netfilter/nf_conntrack_core.h> 30 #include <net/netfilter/nf_conntrack_tuple.h> 31 #include <net/netfilter/nf_conntrack_expect.h> 32 #include <net/netfilter/nf_conntrack_ecache.h> 33 #include <net/netfilter/nf_conntrack_helper.h> 34 #include <net/netfilter/nf_conntrack_zones.h> 35 #include <linux/netfilter/nf_conntrack_h323.h> 36 37 /* Parameters */ 38 static unsigned int default_rrq_ttl __read_mostly = 300; 39 module_param(default_rrq_ttl, uint, 0600); 40 MODULE_PARM_DESC(default_rrq_ttl, "use this TTL if it's missing in RRQ"); 41 42 static int gkrouted_only __read_mostly = 1; 43 module_param(gkrouted_only, int, 0600); 44 MODULE_PARM_DESC(gkrouted_only, "only accept calls from gatekeeper"); 45 46 static bool callforward_filter __read_mostly = true; 47 module_param(callforward_filter, bool, 0600); 48 MODULE_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 */ 53 int (*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; 58 int (*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; 63 int (*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; 68 int (*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; 73 int (*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; 82 int (*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; 89 int (*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; 96 int (*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; 103 int (*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; 110 111 static DEFINE_SPINLOCK(nf_h323_lock); 112 static char *h323_buffer; 113 114 static struct nf_conntrack_helper nf_conntrack_helper_h245; 115 static struct nf_conntrack_helper nf_conntrack_helper_q931[]; 116 static struct nf_conntrack_helper nf_conntrack_helper_ras[]; 117 118 static 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 if (!tpkt) 150 goto clear_out; 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 %d 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 static 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 static int expect_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct, 257 enum ip_conntrack_info ctinfo, 258 unsigned int protoff, 259 unsigned char **data, int dataoff, 260 H245_TransportAddress *taddr) 261 { 262 int dir = CTINFO2DIR(ctinfo); 263 int ret = 0; 264 __be16 port; 265 __be16 rtp_port, rtcp_port; 266 union nf_inet_addr addr; 267 struct nf_conntrack_expect *rtp_exp; 268 struct nf_conntrack_expect *rtcp_exp; 269 typeof(nat_rtp_rtcp_hook) nat_rtp_rtcp; 270 271 /* Read RTP or RTCP address */ 272 if (!get_h245_addr(ct, *data, taddr, &addr, &port) || 273 memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) || 274 port == 0) 275 return 0; 276 277 /* RTP port is even */ 278 rtp_port = port & ~htons(1); 279 rtcp_port = port | htons(1); 280 281 /* Create expect for RTP */ 282 if ((rtp_exp = nf_ct_expect_alloc(ct)) == NULL) 283 return -1; 284 nf_ct_expect_init(rtp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), 285 &ct->tuplehash[!dir].tuple.src.u3, 286 &ct->tuplehash[!dir].tuple.dst.u3, 287 IPPROTO_UDP, NULL, &rtp_port); 288 289 /* Create expect for RTCP */ 290 if ((rtcp_exp = nf_ct_expect_alloc(ct)) == NULL) { 291 nf_ct_expect_put(rtp_exp); 292 return -1; 293 } 294 nf_ct_expect_init(rtcp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), 295 &ct->tuplehash[!dir].tuple.src.u3, 296 &ct->tuplehash[!dir].tuple.dst.u3, 297 IPPROTO_UDP, NULL, &rtcp_port); 298 299 if (memcmp(&ct->tuplehash[dir].tuple.src.u3, 300 &ct->tuplehash[!dir].tuple.dst.u3, 301 sizeof(ct->tuplehash[dir].tuple.src.u3)) && 302 (nat_rtp_rtcp = rcu_dereference(nat_rtp_rtcp_hook)) && 303 nf_ct_l3num(ct) == NFPROTO_IPV4 && 304 ct->status & IPS_NAT_MASK) { 305 /* NAT needed */ 306 ret = nat_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff, 307 taddr, port, rtp_port, rtp_exp, rtcp_exp); 308 } else { /* Conntrack only */ 309 if (nf_ct_expect_related(rtp_exp, 0) == 0) { 310 if (nf_ct_expect_related(rtcp_exp, 0) == 0) { 311 pr_debug("nf_ct_h323: expect RTP "); 312 nf_ct_dump_tuple(&rtp_exp->tuple); 313 pr_debug("nf_ct_h323: expect RTCP "); 314 nf_ct_dump_tuple(&rtcp_exp->tuple); 315 } else { 316 nf_ct_unexpect_related(rtp_exp); 317 ret = -1; 318 } 319 } else 320 ret = -1; 321 } 322 323 nf_ct_expect_put(rtp_exp); 324 nf_ct_expect_put(rtcp_exp); 325 326 return ret; 327 } 328 329 static int expect_t120(struct sk_buff *skb, 330 struct nf_conn *ct, 331 enum ip_conntrack_info ctinfo, 332 unsigned int protoff, 333 unsigned char **data, int dataoff, 334 H245_TransportAddress *taddr) 335 { 336 int dir = CTINFO2DIR(ctinfo); 337 int ret = 0; 338 __be16 port; 339 union nf_inet_addr addr; 340 struct nf_conntrack_expect *exp; 341 typeof(nat_t120_hook) nat_t120; 342 343 /* Read T.120 address */ 344 if (!get_h245_addr(ct, *data, taddr, &addr, &port) || 345 memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) || 346 port == 0) 347 return 0; 348 349 /* Create expect for T.120 connections */ 350 if ((exp = nf_ct_expect_alloc(ct)) == NULL) 351 return -1; 352 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), 353 &ct->tuplehash[!dir].tuple.src.u3, 354 &ct->tuplehash[!dir].tuple.dst.u3, 355 IPPROTO_TCP, NULL, &port); 356 exp->flags = NF_CT_EXPECT_PERMANENT; /* Accept multiple channels */ 357 358 if (memcmp(&ct->tuplehash[dir].tuple.src.u3, 359 &ct->tuplehash[!dir].tuple.dst.u3, 360 sizeof(ct->tuplehash[dir].tuple.src.u3)) && 361 (nat_t120 = rcu_dereference(nat_t120_hook)) && 362 nf_ct_l3num(ct) == NFPROTO_IPV4 && 363 ct->status & IPS_NAT_MASK) { 364 /* NAT needed */ 365 ret = nat_t120(skb, ct, ctinfo, protoff, data, dataoff, taddr, 366 port, exp); 367 } else { /* Conntrack only */ 368 if (nf_ct_expect_related(exp, 0) == 0) { 369 pr_debug("nf_ct_h323: expect T.120 "); 370 nf_ct_dump_tuple(&exp->tuple); 371 } else 372 ret = -1; 373 } 374 375 nf_ct_expect_put(exp); 376 377 return ret; 378 } 379 380 static int process_h245_channel(struct sk_buff *skb, 381 struct nf_conn *ct, 382 enum ip_conntrack_info ctinfo, 383 unsigned int protoff, 384 unsigned char **data, int dataoff, 385 H2250LogicalChannelParameters *channel) 386 { 387 int ret; 388 389 if (channel->options & eH2250LogicalChannelParameters_mediaChannel) { 390 /* RTP */ 391 ret = expect_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff, 392 &channel->mediaChannel); 393 if (ret < 0) 394 return -1; 395 } 396 397 if (channel-> 398 options & eH2250LogicalChannelParameters_mediaControlChannel) { 399 /* RTCP */ 400 ret = expect_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff, 401 &channel->mediaControlChannel); 402 if (ret < 0) 403 return -1; 404 } 405 406 return 0; 407 } 408 409 static int process_olc(struct sk_buff *skb, struct nf_conn *ct, 410 enum ip_conntrack_info ctinfo, 411 unsigned int protoff, 412 unsigned char **data, int dataoff, 413 OpenLogicalChannel *olc) 414 { 415 int ret; 416 417 pr_debug("nf_ct_h323: OpenLogicalChannel\n"); 418 419 if (olc->forwardLogicalChannelParameters.multiplexParameters.choice == 420 eOpenLogicalChannel_forwardLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters) 421 { 422 ret = process_h245_channel(skb, ct, ctinfo, 423 protoff, data, dataoff, 424 &olc-> 425 forwardLogicalChannelParameters. 426 multiplexParameters. 427 h2250LogicalChannelParameters); 428 if (ret < 0) 429 return -1; 430 } 431 432 if ((olc->options & 433 eOpenLogicalChannel_reverseLogicalChannelParameters) && 434 (olc->reverseLogicalChannelParameters.options & 435 eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters) 436 && (olc->reverseLogicalChannelParameters.multiplexParameters. 437 choice == 438 eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters)) 439 { 440 ret = 441 process_h245_channel(skb, ct, ctinfo, 442 protoff, data, dataoff, 443 &olc-> 444 reverseLogicalChannelParameters. 445 multiplexParameters. 446 h2250LogicalChannelParameters); 447 if (ret < 0) 448 return -1; 449 } 450 451 if ((olc->options & eOpenLogicalChannel_separateStack) && 452 olc->forwardLogicalChannelParameters.dataType.choice == 453 eDataType_data && 454 olc->forwardLogicalChannelParameters.dataType.data.application. 455 choice == eDataApplicationCapability_application_t120 && 456 olc->forwardLogicalChannelParameters.dataType.data.application. 457 t120.choice == eDataProtocolCapability_separateLANStack && 458 olc->separateStack.networkAddress.choice == 459 eNetworkAccessParameters_networkAddress_localAreaAddress) { 460 ret = expect_t120(skb, ct, ctinfo, protoff, data, dataoff, 461 &olc->separateStack.networkAddress. 462 localAreaAddress); 463 if (ret < 0) 464 return -1; 465 } 466 467 return 0; 468 } 469 470 static int process_olca(struct sk_buff *skb, struct nf_conn *ct, 471 enum ip_conntrack_info ctinfo, 472 unsigned int protoff, unsigned char **data, int dataoff, 473 OpenLogicalChannelAck *olca) 474 { 475 H2250LogicalChannelAckParameters *ack; 476 int ret; 477 478 pr_debug("nf_ct_h323: OpenLogicalChannelAck\n"); 479 480 if ((olca->options & 481 eOpenLogicalChannelAck_reverseLogicalChannelParameters) && 482 (olca->reverseLogicalChannelParameters.options & 483 eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters) 484 && (olca->reverseLogicalChannelParameters.multiplexParameters. 485 choice == 486 eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters)) 487 { 488 ret = process_h245_channel(skb, ct, ctinfo, 489 protoff, data, dataoff, 490 &olca-> 491 reverseLogicalChannelParameters. 492 multiplexParameters. 493 h2250LogicalChannelParameters); 494 if (ret < 0) 495 return -1; 496 } 497 498 if ((olca->options & 499 eOpenLogicalChannelAck_forwardMultiplexAckParameters) && 500 (olca->forwardMultiplexAckParameters.choice == 501 eOpenLogicalChannelAck_forwardMultiplexAckParameters_h2250LogicalChannelAckParameters)) 502 { 503 ack = &olca->forwardMultiplexAckParameters. 504 h2250LogicalChannelAckParameters; 505 if (ack->options & 506 eH2250LogicalChannelAckParameters_mediaChannel) { 507 /* RTP */ 508 ret = expect_rtp_rtcp(skb, ct, ctinfo, 509 protoff, data, dataoff, 510 &ack->mediaChannel); 511 if (ret < 0) 512 return -1; 513 } 514 515 if (ack->options & 516 eH2250LogicalChannelAckParameters_mediaControlChannel) { 517 /* RTCP */ 518 ret = expect_rtp_rtcp(skb, ct, ctinfo, 519 protoff, data, dataoff, 520 &ack->mediaControlChannel); 521 if (ret < 0) 522 return -1; 523 } 524 } 525 526 if ((olca->options & eOpenLogicalChannelAck_separateStack) && 527 olca->separateStack.networkAddress.choice == 528 eNetworkAccessParameters_networkAddress_localAreaAddress) { 529 ret = expect_t120(skb, ct, ctinfo, protoff, data, dataoff, 530 &olca->separateStack.networkAddress. 531 localAreaAddress); 532 if (ret < 0) 533 return -1; 534 } 535 536 return 0; 537 } 538 539 static int process_h245(struct sk_buff *skb, struct nf_conn *ct, 540 enum ip_conntrack_info ctinfo, 541 unsigned int protoff, unsigned char **data, int dataoff, 542 MultimediaSystemControlMessage *mscm) 543 { 544 switch (mscm->choice) { 545 case eMultimediaSystemControlMessage_request: 546 if (mscm->request.choice == 547 eRequestMessage_openLogicalChannel) { 548 return process_olc(skb, ct, ctinfo, 549 protoff, data, dataoff, 550 &mscm->request.openLogicalChannel); 551 } 552 pr_debug("nf_ct_h323: H.245 Request %d\n", 553 mscm->request.choice); 554 break; 555 case eMultimediaSystemControlMessage_response: 556 if (mscm->response.choice == 557 eResponseMessage_openLogicalChannelAck) { 558 return process_olca(skb, ct, ctinfo, 559 protoff, data, dataoff, 560 &mscm->response. 561 openLogicalChannelAck); 562 } 563 pr_debug("nf_ct_h323: H.245 Response %d\n", 564 mscm->response.choice); 565 break; 566 default: 567 pr_debug("nf_ct_h323: H.245 signal %d\n", mscm->choice); 568 break; 569 } 570 571 return 0; 572 } 573 574 static int h245_help(struct sk_buff *skb, unsigned int protoff, 575 struct nf_conn *ct, enum ip_conntrack_info ctinfo) 576 { 577 static MultimediaSystemControlMessage mscm; 578 unsigned char *data = NULL; 579 int datalen; 580 int dataoff; 581 int ret; 582 583 /* Until there's been traffic both ways, don't look in packets. */ 584 if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY) 585 return NF_ACCEPT; 586 587 pr_debug("nf_ct_h245: skblen = %u\n", skb->len); 588 589 spin_lock_bh(&nf_h323_lock); 590 591 /* Process each TPKT */ 592 while (get_tpkt_data(skb, protoff, ct, ctinfo, 593 &data, &datalen, &dataoff)) { 594 pr_debug("nf_ct_h245: TPKT len=%d ", datalen); 595 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple); 596 597 /* Decode H.245 signal */ 598 ret = DecodeMultimediaSystemControlMessage(data, datalen, 599 &mscm); 600 if (ret < 0) { 601 pr_debug("nf_ct_h245: decoding error: %s\n", 602 ret == H323_ERROR_BOUND ? 603 "out of bound" : "out of range"); 604 /* We don't drop when decoding error */ 605 break; 606 } 607 608 /* Process H.245 signal */ 609 if (process_h245(skb, ct, ctinfo, protoff, 610 &data, dataoff, &mscm) < 0) 611 goto drop; 612 } 613 614 spin_unlock_bh(&nf_h323_lock); 615 return NF_ACCEPT; 616 617 drop: 618 spin_unlock_bh(&nf_h323_lock); 619 nf_ct_helper_log(skb, ct, "cannot process H.245 message"); 620 return NF_DROP; 621 } 622 623 static const struct nf_conntrack_expect_policy h245_exp_policy = { 624 .max_expected = H323_RTP_CHANNEL_MAX * 4 + 2 /* T.120 */, 625 .timeout = 240, 626 }; 627 628 static struct nf_conntrack_helper nf_conntrack_helper_h245 __read_mostly = { 629 .name = "H.245", 630 .me = THIS_MODULE, 631 .tuple.src.l3num = AF_UNSPEC, 632 .tuple.dst.protonum = IPPROTO_UDP, 633 .help = h245_help, 634 .expect_policy = &h245_exp_policy, 635 }; 636 637 int get_h225_addr(struct nf_conn *ct, unsigned char *data, 638 TransportAddress *taddr, 639 union nf_inet_addr *addr, __be16 *port) 640 { 641 const unsigned char *p; 642 int len; 643 644 switch (taddr->choice) { 645 case eTransportAddress_ipAddress: 646 if (nf_ct_l3num(ct) != AF_INET) 647 return 0; 648 p = data + taddr->ipAddress.ip; 649 len = 4; 650 break; 651 case eTransportAddress_ip6Address: 652 if (nf_ct_l3num(ct) != AF_INET6) 653 return 0; 654 p = data + taddr->ip6Address.ip; 655 len = 16; 656 break; 657 default: 658 return 0; 659 } 660 661 memcpy(addr, p, len); 662 memset((void *)addr + len, 0, sizeof(*addr) - len); 663 memcpy(port, p + len, sizeof(__be16)); 664 665 return 1; 666 } 667 668 static int expect_h245(struct sk_buff *skb, struct nf_conn *ct, 669 enum ip_conntrack_info ctinfo, 670 unsigned int protoff, unsigned char **data, int dataoff, 671 TransportAddress *taddr) 672 { 673 int dir = CTINFO2DIR(ctinfo); 674 int ret = 0; 675 __be16 port; 676 union nf_inet_addr addr; 677 struct nf_conntrack_expect *exp; 678 typeof(nat_h245_hook) nat_h245; 679 680 /* Read h245Address */ 681 if (!get_h225_addr(ct, *data, taddr, &addr, &port) || 682 memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) || 683 port == 0) 684 return 0; 685 686 /* Create expect for h245 connection */ 687 if ((exp = nf_ct_expect_alloc(ct)) == NULL) 688 return -1; 689 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), 690 &ct->tuplehash[!dir].tuple.src.u3, 691 &ct->tuplehash[!dir].tuple.dst.u3, 692 IPPROTO_TCP, NULL, &port); 693 exp->helper = &nf_conntrack_helper_h245; 694 695 if (memcmp(&ct->tuplehash[dir].tuple.src.u3, 696 &ct->tuplehash[!dir].tuple.dst.u3, 697 sizeof(ct->tuplehash[dir].tuple.src.u3)) && 698 (nat_h245 = rcu_dereference(nat_h245_hook)) && 699 nf_ct_l3num(ct) == NFPROTO_IPV4 && 700 ct->status & IPS_NAT_MASK) { 701 /* NAT needed */ 702 ret = nat_h245(skb, ct, ctinfo, protoff, data, dataoff, taddr, 703 port, exp); 704 } else { /* Conntrack only */ 705 if (nf_ct_expect_related(exp, 0) == 0) { 706 pr_debug("nf_ct_q931: expect H.245 "); 707 nf_ct_dump_tuple(&exp->tuple); 708 } else 709 ret = -1; 710 } 711 712 nf_ct_expect_put(exp); 713 714 return ret; 715 } 716 717 /* If the calling party is on the same side of the forward-to party, 718 * we don't need to track the second call 719 */ 720 static int callforward_do_filter(struct net *net, 721 const union nf_inet_addr *src, 722 const union nf_inet_addr *dst, 723 u_int8_t family) 724 { 725 int ret = 0; 726 727 switch (family) { 728 case AF_INET: { 729 struct flowi4 fl1, fl2; 730 struct rtable *rt1, *rt2; 731 732 memset(&fl1, 0, sizeof(fl1)); 733 fl1.daddr = src->ip; 734 735 memset(&fl2, 0, sizeof(fl2)); 736 fl2.daddr = dst->ip; 737 if (!nf_ip_route(net, (struct dst_entry **)&rt1, 738 flowi4_to_flowi(&fl1), false)) { 739 if (!nf_ip_route(net, (struct dst_entry **)&rt2, 740 flowi4_to_flowi(&fl2), false)) { 741 if (rt_nexthop(rt1, fl1.daddr) == 742 rt_nexthop(rt2, fl2.daddr) && 743 rt1->dst.dev == rt2->dst.dev) 744 ret = 1; 745 dst_release(&rt2->dst); 746 } 747 dst_release(&rt1->dst); 748 } 749 break; 750 } 751 #if IS_ENABLED(CONFIG_IPV6) 752 case AF_INET6: { 753 struct rt6_info *rt1, *rt2; 754 struct flowi6 fl1, fl2; 755 756 memset(&fl1, 0, sizeof(fl1)); 757 fl1.daddr = src->in6; 758 759 memset(&fl2, 0, sizeof(fl2)); 760 fl2.daddr = dst->in6; 761 if (!nf_ip6_route(net, (struct dst_entry **)&rt1, 762 flowi6_to_flowi(&fl1), false)) { 763 if (!nf_ip6_route(net, (struct dst_entry **)&rt2, 764 flowi6_to_flowi(&fl2), false)) { 765 if (ipv6_addr_equal(rt6_nexthop(rt1, &fl1.daddr), 766 rt6_nexthop(rt2, &fl2.daddr)) && 767 rt1->dst.dev == rt2->dst.dev) 768 ret = 1; 769 dst_release(&rt2->dst); 770 } 771 dst_release(&rt1->dst); 772 } 773 break; 774 } 775 #endif 776 } 777 return ret; 778 779 } 780 781 static int expect_callforwarding(struct sk_buff *skb, 782 struct nf_conn *ct, 783 enum ip_conntrack_info ctinfo, 784 unsigned int protoff, 785 unsigned char **data, int dataoff, 786 TransportAddress *taddr) 787 { 788 int dir = CTINFO2DIR(ctinfo); 789 int ret = 0; 790 __be16 port; 791 union nf_inet_addr addr; 792 struct nf_conntrack_expect *exp; 793 struct net *net = nf_ct_net(ct); 794 typeof(nat_callforwarding_hook) nat_callforwarding; 795 796 /* Read alternativeAddress */ 797 if (!get_h225_addr(ct, *data, taddr, &addr, &port) || port == 0) 798 return 0; 799 800 /* If the calling party is on the same side of the forward-to party, 801 * we don't need to track the second call 802 */ 803 if (callforward_filter && 804 callforward_do_filter(net, &addr, &ct->tuplehash[!dir].tuple.src.u3, 805 nf_ct_l3num(ct))) { 806 pr_debug("nf_ct_q931: Call Forwarding not tracked\n"); 807 return 0; 808 } 809 810 /* Create expect for the second call leg */ 811 if ((exp = nf_ct_expect_alloc(ct)) == NULL) 812 return -1; 813 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), 814 &ct->tuplehash[!dir].tuple.src.u3, &addr, 815 IPPROTO_TCP, NULL, &port); 816 exp->helper = nf_conntrack_helper_q931; 817 818 if (memcmp(&ct->tuplehash[dir].tuple.src.u3, 819 &ct->tuplehash[!dir].tuple.dst.u3, 820 sizeof(ct->tuplehash[dir].tuple.src.u3)) && 821 (nat_callforwarding = rcu_dereference(nat_callforwarding_hook)) && 822 nf_ct_l3num(ct) == NFPROTO_IPV4 && 823 ct->status & IPS_NAT_MASK) { 824 /* Need NAT */ 825 ret = nat_callforwarding(skb, ct, ctinfo, 826 protoff, data, dataoff, 827 taddr, port, exp); 828 } else { /* Conntrack only */ 829 if (nf_ct_expect_related(exp, 0) == 0) { 830 pr_debug("nf_ct_q931: expect Call Forwarding "); 831 nf_ct_dump_tuple(&exp->tuple); 832 } else 833 ret = -1; 834 } 835 836 nf_ct_expect_put(exp); 837 838 return ret; 839 } 840 841 static int process_setup(struct sk_buff *skb, struct nf_conn *ct, 842 enum ip_conntrack_info ctinfo, 843 unsigned int protoff, 844 unsigned char **data, int dataoff, 845 Setup_UUIE *setup) 846 { 847 int dir = CTINFO2DIR(ctinfo); 848 int ret; 849 int i; 850 __be16 port; 851 union nf_inet_addr addr; 852 typeof(set_h225_addr_hook) set_h225_addr; 853 854 pr_debug("nf_ct_q931: Setup\n"); 855 856 if (setup->options & eSetup_UUIE_h245Address) { 857 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff, 858 &setup->h245Address); 859 if (ret < 0) 860 return -1; 861 } 862 863 set_h225_addr = rcu_dereference(set_h225_addr_hook); 864 if ((setup->options & eSetup_UUIE_destCallSignalAddress) && 865 (set_h225_addr) && nf_ct_l3num(ct) == NFPROTO_IPV4 && 866 ct->status & IPS_NAT_MASK && 867 get_h225_addr(ct, *data, &setup->destCallSignalAddress, 868 &addr, &port) && 869 memcmp(&addr, &ct->tuplehash[!dir].tuple.src.u3, sizeof(addr))) { 870 pr_debug("nf_ct_q931: set destCallSignalAddress %pI6:%hu->%pI6:%hu\n", 871 &addr, ntohs(port), &ct->tuplehash[!dir].tuple.src.u3, 872 ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port)); 873 ret = set_h225_addr(skb, protoff, data, dataoff, 874 &setup->destCallSignalAddress, 875 &ct->tuplehash[!dir].tuple.src.u3, 876 ct->tuplehash[!dir].tuple.src.u.tcp.port); 877 if (ret < 0) 878 return -1; 879 } 880 881 if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) && 882 (set_h225_addr) && nf_ct_l3num(ct) == NFPROTO_IPV4 && 883 ct->status & IPS_NAT_MASK && 884 get_h225_addr(ct, *data, &setup->sourceCallSignalAddress, 885 &addr, &port) && 886 memcmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(addr))) { 887 pr_debug("nf_ct_q931: set sourceCallSignalAddress %pI6:%hu->%pI6:%hu\n", 888 &addr, ntohs(port), &ct->tuplehash[!dir].tuple.dst.u3, 889 ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port)); 890 ret = set_h225_addr(skb, protoff, data, dataoff, 891 &setup->sourceCallSignalAddress, 892 &ct->tuplehash[!dir].tuple.dst.u3, 893 ct->tuplehash[!dir].tuple.dst.u.tcp.port); 894 if (ret < 0) 895 return -1; 896 } 897 898 if (setup->options & eSetup_UUIE_fastStart) { 899 for (i = 0; i < setup->fastStart.count; i++) { 900 ret = process_olc(skb, ct, ctinfo, 901 protoff, data, dataoff, 902 &setup->fastStart.item[i]); 903 if (ret < 0) 904 return -1; 905 } 906 } 907 908 return 0; 909 } 910 911 static int process_callproceeding(struct sk_buff *skb, 912 struct nf_conn *ct, 913 enum ip_conntrack_info ctinfo, 914 unsigned int protoff, 915 unsigned char **data, int dataoff, 916 CallProceeding_UUIE *callproc) 917 { 918 int ret; 919 int i; 920 921 pr_debug("nf_ct_q931: CallProceeding\n"); 922 923 if (callproc->options & eCallProceeding_UUIE_h245Address) { 924 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff, 925 &callproc->h245Address); 926 if (ret < 0) 927 return -1; 928 } 929 930 if (callproc->options & eCallProceeding_UUIE_fastStart) { 931 for (i = 0; i < callproc->fastStart.count; i++) { 932 ret = process_olc(skb, ct, ctinfo, 933 protoff, data, dataoff, 934 &callproc->fastStart.item[i]); 935 if (ret < 0) 936 return -1; 937 } 938 } 939 940 return 0; 941 } 942 943 static int process_connect(struct sk_buff *skb, struct nf_conn *ct, 944 enum ip_conntrack_info ctinfo, 945 unsigned int protoff, 946 unsigned char **data, int dataoff, 947 Connect_UUIE *connect) 948 { 949 int ret; 950 int i; 951 952 pr_debug("nf_ct_q931: Connect\n"); 953 954 if (connect->options & eConnect_UUIE_h245Address) { 955 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff, 956 &connect->h245Address); 957 if (ret < 0) 958 return -1; 959 } 960 961 if (connect->options & eConnect_UUIE_fastStart) { 962 for (i = 0; i < connect->fastStart.count; i++) { 963 ret = process_olc(skb, ct, ctinfo, 964 protoff, data, dataoff, 965 &connect->fastStart.item[i]); 966 if (ret < 0) 967 return -1; 968 } 969 } 970 971 return 0; 972 } 973 974 static int process_alerting(struct sk_buff *skb, struct nf_conn *ct, 975 enum ip_conntrack_info ctinfo, 976 unsigned int protoff, 977 unsigned char **data, int dataoff, 978 Alerting_UUIE *alert) 979 { 980 int ret; 981 int i; 982 983 pr_debug("nf_ct_q931: Alerting\n"); 984 985 if (alert->options & eAlerting_UUIE_h245Address) { 986 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff, 987 &alert->h245Address); 988 if (ret < 0) 989 return -1; 990 } 991 992 if (alert->options & eAlerting_UUIE_fastStart) { 993 for (i = 0; i < alert->fastStart.count; i++) { 994 ret = process_olc(skb, ct, ctinfo, 995 protoff, data, dataoff, 996 &alert->fastStart.item[i]); 997 if (ret < 0) 998 return -1; 999 } 1000 } 1001 1002 return 0; 1003 } 1004 1005 static int process_facility(struct sk_buff *skb, struct nf_conn *ct, 1006 enum ip_conntrack_info ctinfo, 1007 unsigned int protoff, 1008 unsigned char **data, int dataoff, 1009 Facility_UUIE *facility) 1010 { 1011 int ret; 1012 int i; 1013 1014 pr_debug("nf_ct_q931: Facility\n"); 1015 1016 if (facility->reason.choice == eFacilityReason_callForwarded) { 1017 if (facility->options & eFacility_UUIE_alternativeAddress) 1018 return expect_callforwarding(skb, ct, ctinfo, 1019 protoff, data, dataoff, 1020 &facility-> 1021 alternativeAddress); 1022 return 0; 1023 } 1024 1025 if (facility->options & eFacility_UUIE_h245Address) { 1026 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff, 1027 &facility->h245Address); 1028 if (ret < 0) 1029 return -1; 1030 } 1031 1032 if (facility->options & eFacility_UUIE_fastStart) { 1033 for (i = 0; i < facility->fastStart.count; i++) { 1034 ret = process_olc(skb, ct, ctinfo, 1035 protoff, data, dataoff, 1036 &facility->fastStart.item[i]); 1037 if (ret < 0) 1038 return -1; 1039 } 1040 } 1041 1042 return 0; 1043 } 1044 1045 static int process_progress(struct sk_buff *skb, struct nf_conn *ct, 1046 enum ip_conntrack_info ctinfo, 1047 unsigned int protoff, 1048 unsigned char **data, int dataoff, 1049 Progress_UUIE *progress) 1050 { 1051 int ret; 1052 int i; 1053 1054 pr_debug("nf_ct_q931: Progress\n"); 1055 1056 if (progress->options & eProgress_UUIE_h245Address) { 1057 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff, 1058 &progress->h245Address); 1059 if (ret < 0) 1060 return -1; 1061 } 1062 1063 if (progress->options & eProgress_UUIE_fastStart) { 1064 for (i = 0; i < progress->fastStart.count; i++) { 1065 ret = process_olc(skb, ct, ctinfo, 1066 protoff, data, dataoff, 1067 &progress->fastStart.item[i]); 1068 if (ret < 0) 1069 return -1; 1070 } 1071 } 1072 1073 return 0; 1074 } 1075 1076 static int process_q931(struct sk_buff *skb, struct nf_conn *ct, 1077 enum ip_conntrack_info ctinfo, 1078 unsigned int protoff, unsigned char **data, int dataoff, 1079 Q931 *q931) 1080 { 1081 H323_UU_PDU *pdu = &q931->UUIE.h323_uu_pdu; 1082 int i; 1083 int ret = 0; 1084 1085 switch (pdu->h323_message_body.choice) { 1086 case eH323_UU_PDU_h323_message_body_setup: 1087 ret = process_setup(skb, ct, ctinfo, protoff, data, dataoff, 1088 &pdu->h323_message_body.setup); 1089 break; 1090 case eH323_UU_PDU_h323_message_body_callProceeding: 1091 ret = process_callproceeding(skb, ct, ctinfo, 1092 protoff, data, dataoff, 1093 &pdu->h323_message_body. 1094 callProceeding); 1095 break; 1096 case eH323_UU_PDU_h323_message_body_connect: 1097 ret = process_connect(skb, ct, ctinfo, protoff, data, dataoff, 1098 &pdu->h323_message_body.connect); 1099 break; 1100 case eH323_UU_PDU_h323_message_body_alerting: 1101 ret = process_alerting(skb, ct, ctinfo, protoff, data, dataoff, 1102 &pdu->h323_message_body.alerting); 1103 break; 1104 case eH323_UU_PDU_h323_message_body_facility: 1105 ret = process_facility(skb, ct, ctinfo, protoff, data, dataoff, 1106 &pdu->h323_message_body.facility); 1107 break; 1108 case eH323_UU_PDU_h323_message_body_progress: 1109 ret = process_progress(skb, ct, ctinfo, protoff, data, dataoff, 1110 &pdu->h323_message_body.progress); 1111 break; 1112 default: 1113 pr_debug("nf_ct_q931: Q.931 signal %d\n", 1114 pdu->h323_message_body.choice); 1115 break; 1116 } 1117 1118 if (ret < 0) 1119 return -1; 1120 1121 if (pdu->options & eH323_UU_PDU_h245Control) { 1122 for (i = 0; i < pdu->h245Control.count; i++) { 1123 ret = process_h245(skb, ct, ctinfo, 1124 protoff, data, dataoff, 1125 &pdu->h245Control.item[i]); 1126 if (ret < 0) 1127 return -1; 1128 } 1129 } 1130 1131 return 0; 1132 } 1133 1134 static int q931_help(struct sk_buff *skb, unsigned int protoff, 1135 struct nf_conn *ct, enum ip_conntrack_info ctinfo) 1136 { 1137 static Q931 q931; 1138 unsigned char *data = NULL; 1139 int datalen; 1140 int dataoff; 1141 int ret; 1142 1143 /* Until there's been traffic both ways, don't look in packets. */ 1144 if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY) 1145 return NF_ACCEPT; 1146 1147 pr_debug("nf_ct_q931: skblen = %u\n", skb->len); 1148 1149 spin_lock_bh(&nf_h323_lock); 1150 1151 /* Process each TPKT */ 1152 while (get_tpkt_data(skb, protoff, ct, ctinfo, 1153 &data, &datalen, &dataoff)) { 1154 pr_debug("nf_ct_q931: TPKT len=%d ", datalen); 1155 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple); 1156 1157 /* Decode Q.931 signal */ 1158 ret = DecodeQ931(data, datalen, &q931); 1159 if (ret < 0) { 1160 pr_debug("nf_ct_q931: decoding error: %s\n", 1161 ret == H323_ERROR_BOUND ? 1162 "out of bound" : "out of range"); 1163 /* We don't drop when decoding error */ 1164 break; 1165 } 1166 1167 /* Process Q.931 signal */ 1168 if (process_q931(skb, ct, ctinfo, protoff, 1169 &data, dataoff, &q931) < 0) 1170 goto drop; 1171 } 1172 1173 spin_unlock_bh(&nf_h323_lock); 1174 return NF_ACCEPT; 1175 1176 drop: 1177 spin_unlock_bh(&nf_h323_lock); 1178 nf_ct_helper_log(skb, ct, "cannot process Q.931 message"); 1179 return NF_DROP; 1180 } 1181 1182 static const struct nf_conntrack_expect_policy q931_exp_policy = { 1183 /* T.120 and H.245 */ 1184 .max_expected = H323_RTP_CHANNEL_MAX * 4 + 4, 1185 .timeout = 240, 1186 }; 1187 1188 static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = { 1189 { 1190 .name = "Q.931", 1191 .me = THIS_MODULE, 1192 .tuple.src.l3num = AF_INET, 1193 .tuple.src.u.tcp.port = cpu_to_be16(Q931_PORT), 1194 .tuple.dst.protonum = IPPROTO_TCP, 1195 .help = q931_help, 1196 .expect_policy = &q931_exp_policy, 1197 }, 1198 { 1199 .name = "Q.931", 1200 .me = THIS_MODULE, 1201 .tuple.src.l3num = AF_INET6, 1202 .tuple.src.u.tcp.port = cpu_to_be16(Q931_PORT), 1203 .tuple.dst.protonum = IPPROTO_TCP, 1204 .help = q931_help, 1205 .expect_policy = &q931_exp_policy, 1206 }, 1207 }; 1208 1209 static unsigned char *get_udp_data(struct sk_buff *skb, unsigned int protoff, 1210 int *datalen) 1211 { 1212 const struct udphdr *uh; 1213 struct udphdr _uh; 1214 int dataoff; 1215 1216 uh = skb_header_pointer(skb, protoff, sizeof(_uh), &_uh); 1217 if (uh == NULL) 1218 return NULL; 1219 dataoff = protoff + sizeof(_uh); 1220 if (dataoff >= skb->len) 1221 return NULL; 1222 *datalen = skb->len - dataoff; 1223 return skb_header_pointer(skb, dataoff, *datalen, h323_buffer); 1224 } 1225 1226 static struct nf_conntrack_expect *find_expect(struct nf_conn *ct, 1227 union nf_inet_addr *addr, 1228 __be16 port) 1229 { 1230 struct net *net = nf_ct_net(ct); 1231 struct nf_conntrack_expect *exp; 1232 struct nf_conntrack_tuple tuple; 1233 1234 memset(&tuple.src.u3, 0, sizeof(tuple.src.u3)); 1235 tuple.src.u.tcp.port = 0; 1236 memcpy(&tuple.dst.u3, addr, sizeof(tuple.dst.u3)); 1237 tuple.dst.u.tcp.port = port; 1238 tuple.dst.protonum = IPPROTO_TCP; 1239 1240 exp = __nf_ct_expect_find(net, nf_ct_zone(ct), &tuple); 1241 if (exp && exp->master == ct) 1242 return exp; 1243 return NULL; 1244 } 1245 1246 static int expect_q931(struct sk_buff *skb, struct nf_conn *ct, 1247 enum ip_conntrack_info ctinfo, 1248 unsigned int protoff, unsigned char **data, 1249 TransportAddress *taddr, int count) 1250 { 1251 struct nf_ct_h323_master *info = nfct_help_data(ct); 1252 int dir = CTINFO2DIR(ctinfo); 1253 int ret = 0; 1254 int i; 1255 __be16 port; 1256 union nf_inet_addr addr; 1257 struct nf_conntrack_expect *exp; 1258 typeof(nat_q931_hook) nat_q931; 1259 1260 /* Look for the first related address */ 1261 for (i = 0; i < count; i++) { 1262 if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) && 1263 memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, 1264 sizeof(addr)) == 0 && port != 0) 1265 break; 1266 } 1267 1268 if (i >= count) /* Not found */ 1269 return 0; 1270 1271 /* Create expect for Q.931 */ 1272 if ((exp = nf_ct_expect_alloc(ct)) == NULL) 1273 return -1; 1274 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), 1275 gkrouted_only ? /* only accept calls from GK? */ 1276 &ct->tuplehash[!dir].tuple.src.u3 : NULL, 1277 &ct->tuplehash[!dir].tuple.dst.u3, 1278 IPPROTO_TCP, NULL, &port); 1279 exp->helper = nf_conntrack_helper_q931; 1280 exp->flags = NF_CT_EXPECT_PERMANENT; /* Accept multiple calls */ 1281 1282 nat_q931 = rcu_dereference(nat_q931_hook); 1283 if (nat_q931 && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1284 ct->status & IPS_NAT_MASK) { /* Need NAT */ 1285 ret = nat_q931(skb, ct, ctinfo, protoff, data, 1286 taddr, i, port, exp); 1287 } else { /* Conntrack only */ 1288 if (nf_ct_expect_related(exp, 0) == 0) { 1289 pr_debug("nf_ct_ras: expect Q.931 "); 1290 nf_ct_dump_tuple(&exp->tuple); 1291 1292 /* Save port for looking up expect in processing RCF */ 1293 info->sig_port[dir] = port; 1294 } else 1295 ret = -1; 1296 } 1297 1298 nf_ct_expect_put(exp); 1299 1300 return ret; 1301 } 1302 1303 static int process_grq(struct sk_buff *skb, struct nf_conn *ct, 1304 enum ip_conntrack_info ctinfo, 1305 unsigned int protoff, 1306 unsigned char **data, GatekeeperRequest *grq) 1307 { 1308 typeof(set_ras_addr_hook) set_ras_addr; 1309 1310 pr_debug("nf_ct_ras: GRQ\n"); 1311 1312 set_ras_addr = rcu_dereference(set_ras_addr_hook); 1313 if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1314 ct->status & IPS_NAT_MASK) /* NATed */ 1315 return set_ras_addr(skb, ct, ctinfo, protoff, data, 1316 &grq->rasAddress, 1); 1317 return 0; 1318 } 1319 1320 static int process_gcf(struct sk_buff *skb, struct nf_conn *ct, 1321 enum ip_conntrack_info ctinfo, 1322 unsigned int protoff, 1323 unsigned char **data, GatekeeperConfirm *gcf) 1324 { 1325 int dir = CTINFO2DIR(ctinfo); 1326 int ret = 0; 1327 __be16 port; 1328 union nf_inet_addr addr; 1329 struct nf_conntrack_expect *exp; 1330 1331 pr_debug("nf_ct_ras: GCF\n"); 1332 1333 if (!get_h225_addr(ct, *data, &gcf->rasAddress, &addr, &port)) 1334 return 0; 1335 1336 /* Registration port is the same as discovery port */ 1337 if (!memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) && 1338 port == ct->tuplehash[dir].tuple.src.u.udp.port) 1339 return 0; 1340 1341 /* Avoid RAS expectation loops. A GCF is never expected. */ 1342 if (test_bit(IPS_EXPECTED_BIT, &ct->status)) 1343 return 0; 1344 1345 /* Need new expect */ 1346 if ((exp = nf_ct_expect_alloc(ct)) == NULL) 1347 return -1; 1348 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), 1349 &ct->tuplehash[!dir].tuple.src.u3, &addr, 1350 IPPROTO_UDP, NULL, &port); 1351 exp->helper = nf_conntrack_helper_ras; 1352 1353 if (nf_ct_expect_related(exp, 0) == 0) { 1354 pr_debug("nf_ct_ras: expect RAS "); 1355 nf_ct_dump_tuple(&exp->tuple); 1356 } else 1357 ret = -1; 1358 1359 nf_ct_expect_put(exp); 1360 1361 return ret; 1362 } 1363 1364 static int process_rrq(struct sk_buff *skb, struct nf_conn *ct, 1365 enum ip_conntrack_info ctinfo, 1366 unsigned int protoff, 1367 unsigned char **data, RegistrationRequest *rrq) 1368 { 1369 struct nf_ct_h323_master *info = nfct_help_data(ct); 1370 int ret; 1371 typeof(set_ras_addr_hook) set_ras_addr; 1372 1373 pr_debug("nf_ct_ras: RRQ\n"); 1374 1375 ret = expect_q931(skb, ct, ctinfo, protoff, data, 1376 rrq->callSignalAddress.item, 1377 rrq->callSignalAddress.count); 1378 if (ret < 0) 1379 return -1; 1380 1381 set_ras_addr = rcu_dereference(set_ras_addr_hook); 1382 if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1383 ct->status & IPS_NAT_MASK) { 1384 ret = set_ras_addr(skb, ct, ctinfo, protoff, data, 1385 rrq->rasAddress.item, 1386 rrq->rasAddress.count); 1387 if (ret < 0) 1388 return -1; 1389 } 1390 1391 if (rrq->options & eRegistrationRequest_timeToLive) { 1392 pr_debug("nf_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive); 1393 info->timeout = rrq->timeToLive; 1394 } else 1395 info->timeout = default_rrq_ttl; 1396 1397 return 0; 1398 } 1399 1400 static int process_rcf(struct sk_buff *skb, struct nf_conn *ct, 1401 enum ip_conntrack_info ctinfo, 1402 unsigned int protoff, 1403 unsigned char **data, RegistrationConfirm *rcf) 1404 { 1405 struct nf_ct_h323_master *info = nfct_help_data(ct); 1406 int dir = CTINFO2DIR(ctinfo); 1407 int ret; 1408 struct nf_conntrack_expect *exp; 1409 typeof(set_sig_addr_hook) set_sig_addr; 1410 1411 pr_debug("nf_ct_ras: RCF\n"); 1412 1413 set_sig_addr = rcu_dereference(set_sig_addr_hook); 1414 if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1415 ct->status & IPS_NAT_MASK) { 1416 ret = set_sig_addr(skb, ct, ctinfo, protoff, data, 1417 rcf->callSignalAddress.item, 1418 rcf->callSignalAddress.count); 1419 if (ret < 0) 1420 return -1; 1421 } 1422 1423 if (rcf->options & eRegistrationConfirm_timeToLive) { 1424 pr_debug("nf_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive); 1425 info->timeout = rcf->timeToLive; 1426 } 1427 1428 if (info->timeout > 0) { 1429 pr_debug("nf_ct_ras: set RAS connection timeout to " 1430 "%u seconds\n", info->timeout); 1431 nf_ct_refresh(ct, skb, info->timeout * HZ); 1432 1433 /* Set expect timeout */ 1434 spin_lock_bh(&nf_conntrack_expect_lock); 1435 exp = find_expect(ct, &ct->tuplehash[dir].tuple.dst.u3, 1436 info->sig_port[!dir]); 1437 if (exp) { 1438 pr_debug("nf_ct_ras: set Q.931 expect " 1439 "timeout to %u seconds for", 1440 info->timeout); 1441 nf_ct_dump_tuple(&exp->tuple); 1442 mod_timer_pending(&exp->timeout, 1443 jiffies + info->timeout * HZ); 1444 } 1445 spin_unlock_bh(&nf_conntrack_expect_lock); 1446 } 1447 1448 return 0; 1449 } 1450 1451 static int process_urq(struct sk_buff *skb, struct nf_conn *ct, 1452 enum ip_conntrack_info ctinfo, 1453 unsigned int protoff, 1454 unsigned char **data, UnregistrationRequest *urq) 1455 { 1456 struct nf_ct_h323_master *info = nfct_help_data(ct); 1457 int dir = CTINFO2DIR(ctinfo); 1458 int ret; 1459 typeof(set_sig_addr_hook) set_sig_addr; 1460 1461 pr_debug("nf_ct_ras: URQ\n"); 1462 1463 set_sig_addr = rcu_dereference(set_sig_addr_hook); 1464 if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1465 ct->status & IPS_NAT_MASK) { 1466 ret = set_sig_addr(skb, ct, ctinfo, protoff, data, 1467 urq->callSignalAddress.item, 1468 urq->callSignalAddress.count); 1469 if (ret < 0) 1470 return -1; 1471 } 1472 1473 /* Clear old expect */ 1474 nf_ct_remove_expectations(ct); 1475 info->sig_port[dir] = 0; 1476 info->sig_port[!dir] = 0; 1477 1478 /* Give it 30 seconds for UCF or URJ */ 1479 nf_ct_refresh(ct, skb, 30 * HZ); 1480 1481 return 0; 1482 } 1483 1484 static int process_arq(struct sk_buff *skb, struct nf_conn *ct, 1485 enum ip_conntrack_info ctinfo, 1486 unsigned int protoff, 1487 unsigned char **data, AdmissionRequest *arq) 1488 { 1489 const struct nf_ct_h323_master *info = nfct_help_data(ct); 1490 int dir = CTINFO2DIR(ctinfo); 1491 __be16 port; 1492 union nf_inet_addr addr; 1493 typeof(set_h225_addr_hook) set_h225_addr; 1494 1495 pr_debug("nf_ct_ras: ARQ\n"); 1496 1497 set_h225_addr = rcu_dereference(set_h225_addr_hook); 1498 if ((arq->options & eAdmissionRequest_destCallSignalAddress) && 1499 get_h225_addr(ct, *data, &arq->destCallSignalAddress, 1500 &addr, &port) && 1501 !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) && 1502 port == info->sig_port[dir] && 1503 nf_ct_l3num(ct) == NFPROTO_IPV4 && 1504 set_h225_addr && ct->status & IPS_NAT_MASK) { 1505 /* Answering ARQ */ 1506 return set_h225_addr(skb, protoff, data, 0, 1507 &arq->destCallSignalAddress, 1508 &ct->tuplehash[!dir].tuple.dst.u3, 1509 info->sig_port[!dir]); 1510 } 1511 1512 if ((arq->options & eAdmissionRequest_srcCallSignalAddress) && 1513 get_h225_addr(ct, *data, &arq->srcCallSignalAddress, 1514 &addr, &port) && 1515 !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) && 1516 set_h225_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1517 ct->status & IPS_NAT_MASK) { 1518 /* Calling ARQ */ 1519 return set_h225_addr(skb, protoff, data, 0, 1520 &arq->srcCallSignalAddress, 1521 &ct->tuplehash[!dir].tuple.dst.u3, 1522 port); 1523 } 1524 1525 return 0; 1526 } 1527 1528 static int process_acf(struct sk_buff *skb, struct nf_conn *ct, 1529 enum ip_conntrack_info ctinfo, 1530 unsigned int protoff, 1531 unsigned char **data, AdmissionConfirm *acf) 1532 { 1533 int dir = CTINFO2DIR(ctinfo); 1534 int ret = 0; 1535 __be16 port; 1536 union nf_inet_addr addr; 1537 struct nf_conntrack_expect *exp; 1538 typeof(set_sig_addr_hook) set_sig_addr; 1539 1540 pr_debug("nf_ct_ras: ACF\n"); 1541 1542 if (!get_h225_addr(ct, *data, &acf->destCallSignalAddress, 1543 &addr, &port)) 1544 return 0; 1545 1546 if (!memcmp(&addr, &ct->tuplehash[dir].tuple.dst.u3, sizeof(addr))) { 1547 /* Answering ACF */ 1548 set_sig_addr = rcu_dereference(set_sig_addr_hook); 1549 if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1550 ct->status & IPS_NAT_MASK) 1551 return set_sig_addr(skb, ct, ctinfo, protoff, data, 1552 &acf->destCallSignalAddress, 1); 1553 return 0; 1554 } 1555 1556 /* Need new expect */ 1557 if ((exp = nf_ct_expect_alloc(ct)) == NULL) 1558 return -1; 1559 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), 1560 &ct->tuplehash[!dir].tuple.src.u3, &addr, 1561 IPPROTO_TCP, NULL, &port); 1562 exp->flags = NF_CT_EXPECT_PERMANENT; 1563 exp->helper = nf_conntrack_helper_q931; 1564 1565 if (nf_ct_expect_related(exp, 0) == 0) { 1566 pr_debug("nf_ct_ras: expect Q.931 "); 1567 nf_ct_dump_tuple(&exp->tuple); 1568 } else 1569 ret = -1; 1570 1571 nf_ct_expect_put(exp); 1572 1573 return ret; 1574 } 1575 1576 static int process_lrq(struct sk_buff *skb, struct nf_conn *ct, 1577 enum ip_conntrack_info ctinfo, 1578 unsigned int protoff, 1579 unsigned char **data, LocationRequest *lrq) 1580 { 1581 typeof(set_ras_addr_hook) set_ras_addr; 1582 1583 pr_debug("nf_ct_ras: LRQ\n"); 1584 1585 set_ras_addr = rcu_dereference(set_ras_addr_hook); 1586 if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1587 ct->status & IPS_NAT_MASK) 1588 return set_ras_addr(skb, ct, ctinfo, protoff, data, 1589 &lrq->replyAddress, 1); 1590 return 0; 1591 } 1592 1593 static int process_lcf(struct sk_buff *skb, struct nf_conn *ct, 1594 enum ip_conntrack_info ctinfo, 1595 unsigned int protoff, 1596 unsigned char **data, LocationConfirm *lcf) 1597 { 1598 int dir = CTINFO2DIR(ctinfo); 1599 int ret = 0; 1600 __be16 port; 1601 union nf_inet_addr addr; 1602 struct nf_conntrack_expect *exp; 1603 1604 pr_debug("nf_ct_ras: LCF\n"); 1605 1606 if (!get_h225_addr(ct, *data, &lcf->callSignalAddress, 1607 &addr, &port)) 1608 return 0; 1609 1610 /* Need new expect for call signal */ 1611 if ((exp = nf_ct_expect_alloc(ct)) == NULL) 1612 return -1; 1613 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), 1614 &ct->tuplehash[!dir].tuple.src.u3, &addr, 1615 IPPROTO_TCP, NULL, &port); 1616 exp->flags = NF_CT_EXPECT_PERMANENT; 1617 exp->helper = nf_conntrack_helper_q931; 1618 1619 if (nf_ct_expect_related(exp, 0) == 0) { 1620 pr_debug("nf_ct_ras: expect Q.931 "); 1621 nf_ct_dump_tuple(&exp->tuple); 1622 } else 1623 ret = -1; 1624 1625 nf_ct_expect_put(exp); 1626 1627 /* Ignore rasAddress */ 1628 1629 return ret; 1630 } 1631 1632 static int process_irr(struct sk_buff *skb, struct nf_conn *ct, 1633 enum ip_conntrack_info ctinfo, 1634 unsigned int protoff, 1635 unsigned char **data, InfoRequestResponse *irr) 1636 { 1637 int ret; 1638 typeof(set_ras_addr_hook) set_ras_addr; 1639 typeof(set_sig_addr_hook) set_sig_addr; 1640 1641 pr_debug("nf_ct_ras: IRR\n"); 1642 1643 set_ras_addr = rcu_dereference(set_ras_addr_hook); 1644 if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1645 ct->status & IPS_NAT_MASK) { 1646 ret = set_ras_addr(skb, ct, ctinfo, protoff, data, 1647 &irr->rasAddress, 1); 1648 if (ret < 0) 1649 return -1; 1650 } 1651 1652 set_sig_addr = rcu_dereference(set_sig_addr_hook); 1653 if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1654 ct->status & IPS_NAT_MASK) { 1655 ret = set_sig_addr(skb, ct, ctinfo, protoff, data, 1656 irr->callSignalAddress.item, 1657 irr->callSignalAddress.count); 1658 if (ret < 0) 1659 return -1; 1660 } 1661 1662 return 0; 1663 } 1664 1665 static int process_ras(struct sk_buff *skb, struct nf_conn *ct, 1666 enum ip_conntrack_info ctinfo, 1667 unsigned int protoff, 1668 unsigned char **data, RasMessage *ras) 1669 { 1670 switch (ras->choice) { 1671 case eRasMessage_gatekeeperRequest: 1672 return process_grq(skb, ct, ctinfo, protoff, data, 1673 &ras->gatekeeperRequest); 1674 case eRasMessage_gatekeeperConfirm: 1675 return process_gcf(skb, ct, ctinfo, protoff, data, 1676 &ras->gatekeeperConfirm); 1677 case eRasMessage_registrationRequest: 1678 return process_rrq(skb, ct, ctinfo, protoff, data, 1679 &ras->registrationRequest); 1680 case eRasMessage_registrationConfirm: 1681 return process_rcf(skb, ct, ctinfo, protoff, data, 1682 &ras->registrationConfirm); 1683 case eRasMessage_unregistrationRequest: 1684 return process_urq(skb, ct, ctinfo, protoff, data, 1685 &ras->unregistrationRequest); 1686 case eRasMessage_admissionRequest: 1687 return process_arq(skb, ct, ctinfo, protoff, data, 1688 &ras->admissionRequest); 1689 case eRasMessage_admissionConfirm: 1690 return process_acf(skb, ct, ctinfo, protoff, data, 1691 &ras->admissionConfirm); 1692 case eRasMessage_locationRequest: 1693 return process_lrq(skb, ct, ctinfo, protoff, data, 1694 &ras->locationRequest); 1695 case eRasMessage_locationConfirm: 1696 return process_lcf(skb, ct, ctinfo, protoff, data, 1697 &ras->locationConfirm); 1698 case eRasMessage_infoRequestResponse: 1699 return process_irr(skb, ct, ctinfo, protoff, data, 1700 &ras->infoRequestResponse); 1701 default: 1702 pr_debug("nf_ct_ras: RAS message %d\n", ras->choice); 1703 break; 1704 } 1705 1706 return 0; 1707 } 1708 1709 static int ras_help(struct sk_buff *skb, unsigned int protoff, 1710 struct nf_conn *ct, enum ip_conntrack_info ctinfo) 1711 { 1712 static RasMessage ras; 1713 unsigned char *data; 1714 int datalen = 0; 1715 int ret; 1716 1717 pr_debug("nf_ct_ras: skblen = %u\n", skb->len); 1718 1719 spin_lock_bh(&nf_h323_lock); 1720 1721 /* Get UDP data */ 1722 data = get_udp_data(skb, protoff, &datalen); 1723 if (data == NULL) 1724 goto accept; 1725 pr_debug("nf_ct_ras: RAS message len=%d ", datalen); 1726 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple); 1727 1728 /* Decode RAS message */ 1729 ret = DecodeRasMessage(data, datalen, &ras); 1730 if (ret < 0) { 1731 pr_debug("nf_ct_ras: decoding error: %s\n", 1732 ret == H323_ERROR_BOUND ? 1733 "out of bound" : "out of range"); 1734 goto accept; 1735 } 1736 1737 /* Process RAS message */ 1738 if (process_ras(skb, ct, ctinfo, protoff, &data, &ras) < 0) 1739 goto drop; 1740 1741 accept: 1742 spin_unlock_bh(&nf_h323_lock); 1743 return NF_ACCEPT; 1744 1745 drop: 1746 spin_unlock_bh(&nf_h323_lock); 1747 nf_ct_helper_log(skb, ct, "cannot process RAS message"); 1748 return NF_DROP; 1749 } 1750 1751 static const struct nf_conntrack_expect_policy ras_exp_policy = { 1752 .max_expected = 32, 1753 .timeout = 240, 1754 }; 1755 1756 static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = { 1757 { 1758 .name = "RAS", 1759 .me = THIS_MODULE, 1760 .tuple.src.l3num = AF_INET, 1761 .tuple.src.u.udp.port = cpu_to_be16(RAS_PORT), 1762 .tuple.dst.protonum = IPPROTO_UDP, 1763 .help = ras_help, 1764 .expect_policy = &ras_exp_policy, 1765 }, 1766 { 1767 .name = "RAS", 1768 .me = THIS_MODULE, 1769 .tuple.src.l3num = AF_INET6, 1770 .tuple.src.u.udp.port = cpu_to_be16(RAS_PORT), 1771 .tuple.dst.protonum = IPPROTO_UDP, 1772 .help = ras_help, 1773 .expect_policy = &ras_exp_policy, 1774 }, 1775 }; 1776 1777 static int __init h323_helper_init(void) 1778 { 1779 int ret; 1780 1781 ret = nf_conntrack_helper_register(&nf_conntrack_helper_h245); 1782 if (ret < 0) 1783 return ret; 1784 ret = nf_conntrack_helpers_register(nf_conntrack_helper_q931, 1785 ARRAY_SIZE(nf_conntrack_helper_q931)); 1786 if (ret < 0) 1787 goto err1; 1788 ret = nf_conntrack_helpers_register(nf_conntrack_helper_ras, 1789 ARRAY_SIZE(nf_conntrack_helper_ras)); 1790 if (ret < 0) 1791 goto err2; 1792 1793 return 0; 1794 err2: 1795 nf_conntrack_helpers_unregister(nf_conntrack_helper_q931, 1796 ARRAY_SIZE(nf_conntrack_helper_q931)); 1797 err1: 1798 nf_conntrack_helper_unregister(&nf_conntrack_helper_h245); 1799 return ret; 1800 } 1801 1802 static void __exit h323_helper_exit(void) 1803 { 1804 nf_conntrack_helpers_unregister(nf_conntrack_helper_ras, 1805 ARRAY_SIZE(nf_conntrack_helper_ras)); 1806 nf_conntrack_helpers_unregister(nf_conntrack_helper_q931, 1807 ARRAY_SIZE(nf_conntrack_helper_q931)); 1808 nf_conntrack_helper_unregister(&nf_conntrack_helper_h245); 1809 } 1810 1811 static void __exit nf_conntrack_h323_fini(void) 1812 { 1813 h323_helper_exit(); 1814 kfree(h323_buffer); 1815 pr_debug("nf_ct_h323: fini\n"); 1816 } 1817 1818 static int __init nf_conntrack_h323_init(void) 1819 { 1820 int ret; 1821 1822 NF_CT_HELPER_BUILD_BUG_ON(sizeof(struct nf_ct_h323_master)); 1823 1824 h323_buffer = kmalloc(65536, GFP_KERNEL); 1825 if (!h323_buffer) 1826 return -ENOMEM; 1827 ret = h323_helper_init(); 1828 if (ret < 0) 1829 goto err1; 1830 pr_debug("nf_ct_h323: init success\n"); 1831 return 0; 1832 err1: 1833 kfree(h323_buffer); 1834 return ret; 1835 } 1836 1837 module_init(nf_conntrack_h323_init); 1838 module_exit(nf_conntrack_h323_fini); 1839 1840 EXPORT_SYMBOL_GPL(get_h225_addr); 1841 EXPORT_SYMBOL_GPL(set_h245_addr_hook); 1842 EXPORT_SYMBOL_GPL(set_h225_addr_hook); 1843 EXPORT_SYMBOL_GPL(set_sig_addr_hook); 1844 EXPORT_SYMBOL_GPL(set_ras_addr_hook); 1845 EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook); 1846 EXPORT_SYMBOL_GPL(nat_t120_hook); 1847 EXPORT_SYMBOL_GPL(nat_h245_hook); 1848 EXPORT_SYMBOL_GPL(nat_callforwarding_hook); 1849 EXPORT_SYMBOL_GPL(nat_q931_hook); 1850 1851 MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>"); 1852 MODULE_DESCRIPTION("H.323 connection tracking helper"); 1853 MODULE_LICENSE("GPL"); 1854 MODULE_ALIAS("ip_conntrack_h323"); 1855 MODULE_ALIAS_NFCT_HELPER("RAS"); 1856 MODULE_ALIAS_NFCT_HELPER("Q.931"); 1857 MODULE_ALIAS_NFCT_HELPER("H.245"); 1858