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 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 static int get_h245_addr(struct nf_conn *ct, const unsigned char *data, 222 H245_TransportAddress *taddr, 223 union nf_inet_addr *addr, __be16 *port) 224 { 225 const unsigned char *p; 226 int len; 227 228 if (taddr->choice != eH245_TransportAddress_unicastAddress) 229 return 0; 230 231 switch (taddr->unicastAddress.choice) { 232 case eUnicastAddress_iPAddress: 233 if (nf_ct_l3num(ct) != AF_INET) 234 return 0; 235 p = data + taddr->unicastAddress.iPAddress.network; 236 len = 4; 237 break; 238 case eUnicastAddress_iP6Address: 239 if (nf_ct_l3num(ct) != AF_INET6) 240 return 0; 241 p = data + taddr->unicastAddress.iP6Address.network; 242 len = 16; 243 break; 244 default: 245 return 0; 246 } 247 248 memcpy(addr, p, len); 249 memset((void *)addr + len, 0, sizeof(*addr) - len); 250 memcpy(port, p + len, sizeof(__be16)); 251 252 return 1; 253 } 254 255 static int expect_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct, 256 enum ip_conntrack_info ctinfo, 257 unsigned int protoff, 258 unsigned char **data, int dataoff, 259 H245_TransportAddress *taddr) 260 { 261 int dir = CTINFO2DIR(ctinfo); 262 int ret = 0; 263 __be16 port; 264 __be16 rtp_port, rtcp_port; 265 union nf_inet_addr addr; 266 struct nf_conntrack_expect *rtp_exp; 267 struct nf_conntrack_expect *rtcp_exp; 268 typeof(nat_rtp_rtcp_hook) nat_rtp_rtcp; 269 270 /* Read RTP or RTCP address */ 271 if (!get_h245_addr(ct, *data, taddr, &addr, &port) || 272 memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) || 273 port == 0) 274 return 0; 275 276 /* RTP port is even */ 277 rtp_port = port & ~htons(1); 278 rtcp_port = port | htons(1); 279 280 /* Create expect for RTP */ 281 if ((rtp_exp = nf_ct_expect_alloc(ct)) == NULL) 282 return -1; 283 nf_ct_expect_init(rtp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), 284 &ct->tuplehash[!dir].tuple.src.u3, 285 &ct->tuplehash[!dir].tuple.dst.u3, 286 IPPROTO_UDP, NULL, &rtp_port); 287 288 /* Create expect for RTCP */ 289 if ((rtcp_exp = nf_ct_expect_alloc(ct)) == NULL) { 290 nf_ct_expect_put(rtp_exp); 291 return -1; 292 } 293 nf_ct_expect_init(rtcp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), 294 &ct->tuplehash[!dir].tuple.src.u3, 295 &ct->tuplehash[!dir].tuple.dst.u3, 296 IPPROTO_UDP, NULL, &rtcp_port); 297 298 if (memcmp(&ct->tuplehash[dir].tuple.src.u3, 299 &ct->tuplehash[!dir].tuple.dst.u3, 300 sizeof(ct->tuplehash[dir].tuple.src.u3)) && 301 (nat_rtp_rtcp = rcu_dereference(nat_rtp_rtcp_hook)) && 302 nf_ct_l3num(ct) == NFPROTO_IPV4 && 303 ct->status & IPS_NAT_MASK) { 304 /* NAT needed */ 305 ret = nat_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff, 306 taddr, port, rtp_port, rtp_exp, rtcp_exp); 307 } else { /* Conntrack only */ 308 if (nf_ct_expect_related(rtp_exp, 0) == 0) { 309 if (nf_ct_expect_related(rtcp_exp, 0) == 0) { 310 pr_debug("nf_ct_h323: expect RTP "); 311 nf_ct_dump_tuple(&rtp_exp->tuple); 312 pr_debug("nf_ct_h323: expect RTCP "); 313 nf_ct_dump_tuple(&rtcp_exp->tuple); 314 } else { 315 nf_ct_unexpect_related(rtp_exp); 316 ret = -1; 317 } 318 } else 319 ret = -1; 320 } 321 322 nf_ct_expect_put(rtp_exp); 323 nf_ct_expect_put(rtcp_exp); 324 325 return ret; 326 } 327 328 static int expect_t120(struct sk_buff *skb, 329 struct nf_conn *ct, 330 enum ip_conntrack_info ctinfo, 331 unsigned int protoff, 332 unsigned char **data, int dataoff, 333 H245_TransportAddress *taddr) 334 { 335 int dir = CTINFO2DIR(ctinfo); 336 int ret = 0; 337 __be16 port; 338 union nf_inet_addr addr; 339 struct nf_conntrack_expect *exp; 340 typeof(nat_t120_hook) nat_t120; 341 342 /* Read T.120 address */ 343 if (!get_h245_addr(ct, *data, taddr, &addr, &port) || 344 memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) || 345 port == 0) 346 return 0; 347 348 /* Create expect for T.120 connections */ 349 if ((exp = nf_ct_expect_alloc(ct)) == NULL) 350 return -1; 351 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), 352 &ct->tuplehash[!dir].tuple.src.u3, 353 &ct->tuplehash[!dir].tuple.dst.u3, 354 IPPROTO_TCP, NULL, &port); 355 exp->flags = NF_CT_EXPECT_PERMANENT; /* Accept multiple channels */ 356 357 if (memcmp(&ct->tuplehash[dir].tuple.src.u3, 358 &ct->tuplehash[!dir].tuple.dst.u3, 359 sizeof(ct->tuplehash[dir].tuple.src.u3)) && 360 (nat_t120 = rcu_dereference(nat_t120_hook)) && 361 nf_ct_l3num(ct) == NFPROTO_IPV4 && 362 ct->status & IPS_NAT_MASK) { 363 /* NAT needed */ 364 ret = nat_t120(skb, ct, ctinfo, protoff, data, dataoff, taddr, 365 port, exp); 366 } else { /* Conntrack only */ 367 if (nf_ct_expect_related(exp, 0) == 0) { 368 pr_debug("nf_ct_h323: expect T.120 "); 369 nf_ct_dump_tuple(&exp->tuple); 370 } else 371 ret = -1; 372 } 373 374 nf_ct_expect_put(exp); 375 376 return ret; 377 } 378 379 static int process_h245_channel(struct sk_buff *skb, 380 struct nf_conn *ct, 381 enum ip_conntrack_info ctinfo, 382 unsigned int protoff, 383 unsigned char **data, int dataoff, 384 H2250LogicalChannelParameters *channel) 385 { 386 int ret; 387 388 if (channel->options & eH2250LogicalChannelParameters_mediaChannel) { 389 /* RTP */ 390 ret = expect_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff, 391 &channel->mediaChannel); 392 if (ret < 0) 393 return -1; 394 } 395 396 if (channel-> 397 options & eH2250LogicalChannelParameters_mediaControlChannel) { 398 /* RTCP */ 399 ret = expect_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff, 400 &channel->mediaControlChannel); 401 if (ret < 0) 402 return -1; 403 } 404 405 return 0; 406 } 407 408 static int process_olc(struct sk_buff *skb, struct nf_conn *ct, 409 enum ip_conntrack_info ctinfo, 410 unsigned int protoff, 411 unsigned char **data, int dataoff, 412 OpenLogicalChannel *olc) 413 { 414 int ret; 415 416 pr_debug("nf_ct_h323: OpenLogicalChannel\n"); 417 418 if (olc->forwardLogicalChannelParameters.multiplexParameters.choice == 419 eOpenLogicalChannel_forwardLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters) 420 { 421 ret = process_h245_channel(skb, ct, ctinfo, 422 protoff, data, dataoff, 423 &olc-> 424 forwardLogicalChannelParameters. 425 multiplexParameters. 426 h2250LogicalChannelParameters); 427 if (ret < 0) 428 return -1; 429 } 430 431 if ((olc->options & 432 eOpenLogicalChannel_reverseLogicalChannelParameters) && 433 (olc->reverseLogicalChannelParameters.options & 434 eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters) 435 && (olc->reverseLogicalChannelParameters.multiplexParameters. 436 choice == 437 eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters)) 438 { 439 ret = 440 process_h245_channel(skb, ct, ctinfo, 441 protoff, data, dataoff, 442 &olc-> 443 reverseLogicalChannelParameters. 444 multiplexParameters. 445 h2250LogicalChannelParameters); 446 if (ret < 0) 447 return -1; 448 } 449 450 if ((olc->options & eOpenLogicalChannel_separateStack) && 451 olc->forwardLogicalChannelParameters.dataType.choice == 452 eDataType_data && 453 olc->forwardLogicalChannelParameters.dataType.data.application. 454 choice == eDataApplicationCapability_application_t120 && 455 olc->forwardLogicalChannelParameters.dataType.data.application. 456 t120.choice == eDataProtocolCapability_separateLANStack && 457 olc->separateStack.networkAddress.choice == 458 eNetworkAccessParameters_networkAddress_localAreaAddress) { 459 ret = expect_t120(skb, ct, ctinfo, protoff, data, dataoff, 460 &olc->separateStack.networkAddress. 461 localAreaAddress); 462 if (ret < 0) 463 return -1; 464 } 465 466 return 0; 467 } 468 469 static int process_olca(struct sk_buff *skb, struct nf_conn *ct, 470 enum ip_conntrack_info ctinfo, 471 unsigned int protoff, unsigned char **data, int dataoff, 472 OpenLogicalChannelAck *olca) 473 { 474 H2250LogicalChannelAckParameters *ack; 475 int ret; 476 477 pr_debug("nf_ct_h323: OpenLogicalChannelAck\n"); 478 479 if ((olca->options & 480 eOpenLogicalChannelAck_reverseLogicalChannelParameters) && 481 (olca->reverseLogicalChannelParameters.options & 482 eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters) 483 && (olca->reverseLogicalChannelParameters.multiplexParameters. 484 choice == 485 eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters)) 486 { 487 ret = process_h245_channel(skb, ct, ctinfo, 488 protoff, data, dataoff, 489 &olca-> 490 reverseLogicalChannelParameters. 491 multiplexParameters. 492 h2250LogicalChannelParameters); 493 if (ret < 0) 494 return -1; 495 } 496 497 if ((olca->options & 498 eOpenLogicalChannelAck_forwardMultiplexAckParameters) && 499 (olca->forwardMultiplexAckParameters.choice == 500 eOpenLogicalChannelAck_forwardMultiplexAckParameters_h2250LogicalChannelAckParameters)) 501 { 502 ack = &olca->forwardMultiplexAckParameters. 503 h2250LogicalChannelAckParameters; 504 if (ack->options & 505 eH2250LogicalChannelAckParameters_mediaChannel) { 506 /* RTP */ 507 ret = expect_rtp_rtcp(skb, ct, ctinfo, 508 protoff, data, dataoff, 509 &ack->mediaChannel); 510 if (ret < 0) 511 return -1; 512 } 513 514 if (ack->options & 515 eH2250LogicalChannelAckParameters_mediaControlChannel) { 516 /* RTCP */ 517 ret = expect_rtp_rtcp(skb, ct, ctinfo, 518 protoff, data, dataoff, 519 &ack->mediaControlChannel); 520 if (ret < 0) 521 return -1; 522 } 523 } 524 525 if ((olca->options & eOpenLogicalChannelAck_separateStack) && 526 olca->separateStack.networkAddress.choice == 527 eNetworkAccessParameters_networkAddress_localAreaAddress) { 528 ret = expect_t120(skb, ct, ctinfo, protoff, data, dataoff, 529 &olca->separateStack.networkAddress. 530 localAreaAddress); 531 if (ret < 0) 532 return -1; 533 } 534 535 return 0; 536 } 537 538 static int process_h245(struct sk_buff *skb, struct nf_conn *ct, 539 enum ip_conntrack_info ctinfo, 540 unsigned int protoff, unsigned char **data, int dataoff, 541 MultimediaSystemControlMessage *mscm) 542 { 543 switch (mscm->choice) { 544 case eMultimediaSystemControlMessage_request: 545 if (mscm->request.choice == 546 eRequestMessage_openLogicalChannel) { 547 return process_olc(skb, ct, ctinfo, 548 protoff, data, dataoff, 549 &mscm->request.openLogicalChannel); 550 } 551 pr_debug("nf_ct_h323: H.245 Request %d\n", 552 mscm->request.choice); 553 break; 554 case eMultimediaSystemControlMessage_response: 555 if (mscm->response.choice == 556 eResponseMessage_openLogicalChannelAck) { 557 return process_olca(skb, ct, ctinfo, 558 protoff, data, dataoff, 559 &mscm->response. 560 openLogicalChannelAck); 561 } 562 pr_debug("nf_ct_h323: H.245 Response %d\n", 563 mscm->response.choice); 564 break; 565 default: 566 pr_debug("nf_ct_h323: H.245 signal %d\n", mscm->choice); 567 break; 568 } 569 570 return 0; 571 } 572 573 static int h245_help(struct sk_buff *skb, unsigned int protoff, 574 struct nf_conn *ct, enum ip_conntrack_info ctinfo) 575 { 576 static MultimediaSystemControlMessage mscm; 577 unsigned char *data = NULL; 578 int datalen; 579 int dataoff; 580 int ret; 581 582 /* Until there's been traffic both ways, don't look in packets. */ 583 if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY) 584 return NF_ACCEPT; 585 586 pr_debug("nf_ct_h245: skblen = %u\n", skb->len); 587 588 spin_lock_bh(&nf_h323_lock); 589 590 /* Process each TPKT */ 591 while (get_tpkt_data(skb, protoff, ct, ctinfo, 592 &data, &datalen, &dataoff)) { 593 pr_debug("nf_ct_h245: TPKT len=%d ", datalen); 594 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple); 595 596 /* Decode H.245 signal */ 597 ret = DecodeMultimediaSystemControlMessage(data, datalen, 598 &mscm); 599 if (ret < 0) { 600 pr_debug("nf_ct_h245: decoding error: %s\n", 601 ret == H323_ERROR_BOUND ? 602 "out of bound" : "out of range"); 603 /* We don't drop when decoding error */ 604 break; 605 } 606 607 /* Process H.245 signal */ 608 if (process_h245(skb, ct, ctinfo, protoff, 609 &data, dataoff, &mscm) < 0) 610 goto drop; 611 } 612 613 spin_unlock_bh(&nf_h323_lock); 614 return NF_ACCEPT; 615 616 drop: 617 spin_unlock_bh(&nf_h323_lock); 618 nf_ct_helper_log(skb, ct, "cannot process H.245 message"); 619 return NF_DROP; 620 } 621 622 static const struct nf_conntrack_expect_policy h245_exp_policy = { 623 .max_expected = H323_RTP_CHANNEL_MAX * 4 + 2 /* T.120 */, 624 .timeout = 240, 625 }; 626 627 static struct nf_conntrack_helper nf_conntrack_helper_h245 __read_mostly = { 628 .name = "H.245", 629 .me = THIS_MODULE, 630 .tuple.src.l3num = AF_UNSPEC, 631 .tuple.dst.protonum = IPPROTO_UDP, 632 .help = h245_help, 633 .expect_policy = &h245_exp_policy, 634 }; 635 636 int get_h225_addr(struct nf_conn *ct, unsigned char *data, 637 TransportAddress *taddr, 638 union nf_inet_addr *addr, __be16 *port) 639 { 640 const unsigned char *p; 641 int len; 642 643 switch (taddr->choice) { 644 case eTransportAddress_ipAddress: 645 if (nf_ct_l3num(ct) != AF_INET) 646 return 0; 647 p = data + taddr->ipAddress.ip; 648 len = 4; 649 break; 650 case eTransportAddress_ip6Address: 651 if (nf_ct_l3num(ct) != AF_INET6) 652 return 0; 653 p = data + taddr->ip6Address.ip; 654 len = 16; 655 break; 656 default: 657 return 0; 658 } 659 660 memcpy(addr, p, len); 661 memset((void *)addr + len, 0, sizeof(*addr) - len); 662 memcpy(port, p + len, sizeof(__be16)); 663 664 return 1; 665 } 666 667 static int expect_h245(struct sk_buff *skb, struct nf_conn *ct, 668 enum ip_conntrack_info ctinfo, 669 unsigned int protoff, unsigned char **data, int dataoff, 670 TransportAddress *taddr) 671 { 672 int dir = CTINFO2DIR(ctinfo); 673 int ret = 0; 674 __be16 port; 675 union nf_inet_addr addr; 676 struct nf_conntrack_expect *exp; 677 typeof(nat_h245_hook) nat_h245; 678 679 /* Read h245Address */ 680 if (!get_h225_addr(ct, *data, taddr, &addr, &port) || 681 memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) || 682 port == 0) 683 return 0; 684 685 /* Create expect for h245 connection */ 686 if ((exp = nf_ct_expect_alloc(ct)) == NULL) 687 return -1; 688 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), 689 &ct->tuplehash[!dir].tuple.src.u3, 690 &ct->tuplehash[!dir].tuple.dst.u3, 691 IPPROTO_TCP, NULL, &port); 692 exp->helper = &nf_conntrack_helper_h245; 693 694 if (memcmp(&ct->tuplehash[dir].tuple.src.u3, 695 &ct->tuplehash[!dir].tuple.dst.u3, 696 sizeof(ct->tuplehash[dir].tuple.src.u3)) && 697 (nat_h245 = rcu_dereference(nat_h245_hook)) && 698 nf_ct_l3num(ct) == NFPROTO_IPV4 && 699 ct->status & IPS_NAT_MASK) { 700 /* NAT needed */ 701 ret = nat_h245(skb, ct, ctinfo, protoff, data, dataoff, taddr, 702 port, exp); 703 } else { /* Conntrack only */ 704 if (nf_ct_expect_related(exp, 0) == 0) { 705 pr_debug("nf_ct_q931: expect H.245 "); 706 nf_ct_dump_tuple(&exp->tuple); 707 } else 708 ret = -1; 709 } 710 711 nf_ct_expect_put(exp); 712 713 return ret; 714 } 715 716 /* If the calling party is on the same side of the forward-to party, 717 * we don't need to track the second call 718 */ 719 static int callforward_do_filter(struct net *net, 720 const union nf_inet_addr *src, 721 const union nf_inet_addr *dst, 722 u_int8_t family) 723 { 724 int ret = 0; 725 726 switch (family) { 727 case AF_INET: { 728 struct flowi4 fl1, fl2; 729 struct rtable *rt1, *rt2; 730 731 memset(&fl1, 0, sizeof(fl1)); 732 fl1.daddr = src->ip; 733 734 memset(&fl2, 0, sizeof(fl2)); 735 fl2.daddr = dst->ip; 736 if (!nf_ip_route(net, (struct dst_entry **)&rt1, 737 flowi4_to_flowi(&fl1), false)) { 738 if (!nf_ip_route(net, (struct dst_entry **)&rt2, 739 flowi4_to_flowi(&fl2), false)) { 740 if (rt_nexthop(rt1, fl1.daddr) == 741 rt_nexthop(rt2, fl2.daddr) && 742 rt1->dst.dev == rt2->dst.dev) 743 ret = 1; 744 dst_release(&rt2->dst); 745 } 746 dst_release(&rt1->dst); 747 } 748 break; 749 } 750 #if IS_ENABLED(CONFIG_IPV6) 751 case AF_INET6: { 752 struct rt6_info *rt1, *rt2; 753 struct flowi6 fl1, fl2; 754 755 memset(&fl1, 0, sizeof(fl1)); 756 fl1.daddr = src->in6; 757 758 memset(&fl2, 0, sizeof(fl2)); 759 fl2.daddr = dst->in6; 760 if (!nf_ip6_route(net, (struct dst_entry **)&rt1, 761 flowi6_to_flowi(&fl1), false)) { 762 if (!nf_ip6_route(net, (struct dst_entry **)&rt2, 763 flowi6_to_flowi(&fl2), false)) { 764 if (ipv6_addr_equal(rt6_nexthop(rt1, &fl1.daddr), 765 rt6_nexthop(rt2, &fl2.daddr)) && 766 rt1->dst.dev == rt2->dst.dev) 767 ret = 1; 768 dst_release(&rt2->dst); 769 } 770 dst_release(&rt1->dst); 771 } 772 break; 773 } 774 #endif 775 } 776 return ret; 777 778 } 779 780 static int expect_callforwarding(struct sk_buff *skb, 781 struct nf_conn *ct, 782 enum ip_conntrack_info ctinfo, 783 unsigned int protoff, 784 unsigned char **data, int dataoff, 785 TransportAddress *taddr) 786 { 787 int dir = CTINFO2DIR(ctinfo); 788 int ret = 0; 789 __be16 port; 790 union nf_inet_addr addr; 791 struct nf_conntrack_expect *exp; 792 struct net *net = nf_ct_net(ct); 793 typeof(nat_callforwarding_hook) nat_callforwarding; 794 795 /* Read alternativeAddress */ 796 if (!get_h225_addr(ct, *data, taddr, &addr, &port) || port == 0) 797 return 0; 798 799 /* If the calling party is on the same side of the forward-to party, 800 * we don't need to track the second call 801 */ 802 if (callforward_filter && 803 callforward_do_filter(net, &addr, &ct->tuplehash[!dir].tuple.src.u3, 804 nf_ct_l3num(ct))) { 805 pr_debug("nf_ct_q931: Call Forwarding not tracked\n"); 806 return 0; 807 } 808 809 /* Create expect for the second call leg */ 810 if ((exp = nf_ct_expect_alloc(ct)) == NULL) 811 return -1; 812 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), 813 &ct->tuplehash[!dir].tuple.src.u3, &addr, 814 IPPROTO_TCP, NULL, &port); 815 exp->helper = nf_conntrack_helper_q931; 816 817 if (memcmp(&ct->tuplehash[dir].tuple.src.u3, 818 &ct->tuplehash[!dir].tuple.dst.u3, 819 sizeof(ct->tuplehash[dir].tuple.src.u3)) && 820 (nat_callforwarding = rcu_dereference(nat_callforwarding_hook)) && 821 nf_ct_l3num(ct) == NFPROTO_IPV4 && 822 ct->status & IPS_NAT_MASK) { 823 /* Need NAT */ 824 ret = nat_callforwarding(skb, ct, ctinfo, 825 protoff, data, dataoff, 826 taddr, port, exp); 827 } else { /* Conntrack only */ 828 if (nf_ct_expect_related(exp, 0) == 0) { 829 pr_debug("nf_ct_q931: expect Call Forwarding "); 830 nf_ct_dump_tuple(&exp->tuple); 831 } else 832 ret = -1; 833 } 834 835 nf_ct_expect_put(exp); 836 837 return ret; 838 } 839 840 static int process_setup(struct sk_buff *skb, struct nf_conn *ct, 841 enum ip_conntrack_info ctinfo, 842 unsigned int protoff, 843 unsigned char **data, int dataoff, 844 Setup_UUIE *setup) 845 { 846 int dir = CTINFO2DIR(ctinfo); 847 int ret; 848 int i; 849 __be16 port; 850 union nf_inet_addr addr; 851 typeof(set_h225_addr_hook) set_h225_addr; 852 853 pr_debug("nf_ct_q931: Setup\n"); 854 855 if (setup->options & eSetup_UUIE_h245Address) { 856 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff, 857 &setup->h245Address); 858 if (ret < 0) 859 return -1; 860 } 861 862 set_h225_addr = rcu_dereference(set_h225_addr_hook); 863 if ((setup->options & eSetup_UUIE_destCallSignalAddress) && 864 (set_h225_addr) && nf_ct_l3num(ct) == NFPROTO_IPV4 && 865 ct->status & IPS_NAT_MASK && 866 get_h225_addr(ct, *data, &setup->destCallSignalAddress, 867 &addr, &port) && 868 memcmp(&addr, &ct->tuplehash[!dir].tuple.src.u3, sizeof(addr))) { 869 pr_debug("nf_ct_q931: set destCallSignalAddress %pI6:%hu->%pI6:%hu\n", 870 &addr, ntohs(port), &ct->tuplehash[!dir].tuple.src.u3, 871 ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port)); 872 ret = set_h225_addr(skb, protoff, data, dataoff, 873 &setup->destCallSignalAddress, 874 &ct->tuplehash[!dir].tuple.src.u3, 875 ct->tuplehash[!dir].tuple.src.u.tcp.port); 876 if (ret < 0) 877 return -1; 878 } 879 880 if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) && 881 (set_h225_addr) && nf_ct_l3num(ct) == NFPROTO_IPV4 && 882 ct->status & IPS_NAT_MASK && 883 get_h225_addr(ct, *data, &setup->sourceCallSignalAddress, 884 &addr, &port) && 885 memcmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(addr))) { 886 pr_debug("nf_ct_q931: set sourceCallSignalAddress %pI6:%hu->%pI6:%hu\n", 887 &addr, ntohs(port), &ct->tuplehash[!dir].tuple.dst.u3, 888 ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port)); 889 ret = set_h225_addr(skb, protoff, data, dataoff, 890 &setup->sourceCallSignalAddress, 891 &ct->tuplehash[!dir].tuple.dst.u3, 892 ct->tuplehash[!dir].tuple.dst.u.tcp.port); 893 if (ret < 0) 894 return -1; 895 } 896 897 if (setup->options & eSetup_UUIE_fastStart) { 898 for (i = 0; i < setup->fastStart.count; i++) { 899 ret = process_olc(skb, ct, ctinfo, 900 protoff, data, dataoff, 901 &setup->fastStart.item[i]); 902 if (ret < 0) 903 return -1; 904 } 905 } 906 907 return 0; 908 } 909 910 static int process_callproceeding(struct sk_buff *skb, 911 struct nf_conn *ct, 912 enum ip_conntrack_info ctinfo, 913 unsigned int protoff, 914 unsigned char **data, int dataoff, 915 CallProceeding_UUIE *callproc) 916 { 917 int ret; 918 int i; 919 920 pr_debug("nf_ct_q931: CallProceeding\n"); 921 922 if (callproc->options & eCallProceeding_UUIE_h245Address) { 923 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff, 924 &callproc->h245Address); 925 if (ret < 0) 926 return -1; 927 } 928 929 if (callproc->options & eCallProceeding_UUIE_fastStart) { 930 for (i = 0; i < callproc->fastStart.count; i++) { 931 ret = process_olc(skb, ct, ctinfo, 932 protoff, data, dataoff, 933 &callproc->fastStart.item[i]); 934 if (ret < 0) 935 return -1; 936 } 937 } 938 939 return 0; 940 } 941 942 static int process_connect(struct sk_buff *skb, struct nf_conn *ct, 943 enum ip_conntrack_info ctinfo, 944 unsigned int protoff, 945 unsigned char **data, int dataoff, 946 Connect_UUIE *connect) 947 { 948 int ret; 949 int i; 950 951 pr_debug("nf_ct_q931: Connect\n"); 952 953 if (connect->options & eConnect_UUIE_h245Address) { 954 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff, 955 &connect->h245Address); 956 if (ret < 0) 957 return -1; 958 } 959 960 if (connect->options & eConnect_UUIE_fastStart) { 961 for (i = 0; i < connect->fastStart.count; i++) { 962 ret = process_olc(skb, ct, ctinfo, 963 protoff, data, dataoff, 964 &connect->fastStart.item[i]); 965 if (ret < 0) 966 return -1; 967 } 968 } 969 970 return 0; 971 } 972 973 static int process_alerting(struct sk_buff *skb, struct nf_conn *ct, 974 enum ip_conntrack_info ctinfo, 975 unsigned int protoff, 976 unsigned char **data, int dataoff, 977 Alerting_UUIE *alert) 978 { 979 int ret; 980 int i; 981 982 pr_debug("nf_ct_q931: Alerting\n"); 983 984 if (alert->options & eAlerting_UUIE_h245Address) { 985 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff, 986 &alert->h245Address); 987 if (ret < 0) 988 return -1; 989 } 990 991 if (alert->options & eAlerting_UUIE_fastStart) { 992 for (i = 0; i < alert->fastStart.count; i++) { 993 ret = process_olc(skb, ct, ctinfo, 994 protoff, data, dataoff, 995 &alert->fastStart.item[i]); 996 if (ret < 0) 997 return -1; 998 } 999 } 1000 1001 return 0; 1002 } 1003 1004 static int process_facility(struct sk_buff *skb, struct nf_conn *ct, 1005 enum ip_conntrack_info ctinfo, 1006 unsigned int protoff, 1007 unsigned char **data, int dataoff, 1008 Facility_UUIE *facility) 1009 { 1010 int ret; 1011 int i; 1012 1013 pr_debug("nf_ct_q931: Facility\n"); 1014 1015 if (facility->reason.choice == eFacilityReason_callForwarded) { 1016 if (facility->options & eFacility_UUIE_alternativeAddress) 1017 return expect_callforwarding(skb, ct, ctinfo, 1018 protoff, data, dataoff, 1019 &facility-> 1020 alternativeAddress); 1021 return 0; 1022 } 1023 1024 if (facility->options & eFacility_UUIE_h245Address) { 1025 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff, 1026 &facility->h245Address); 1027 if (ret < 0) 1028 return -1; 1029 } 1030 1031 if (facility->options & eFacility_UUIE_fastStart) { 1032 for (i = 0; i < facility->fastStart.count; i++) { 1033 ret = process_olc(skb, ct, ctinfo, 1034 protoff, data, dataoff, 1035 &facility->fastStart.item[i]); 1036 if (ret < 0) 1037 return -1; 1038 } 1039 } 1040 1041 return 0; 1042 } 1043 1044 static int process_progress(struct sk_buff *skb, struct nf_conn *ct, 1045 enum ip_conntrack_info ctinfo, 1046 unsigned int protoff, 1047 unsigned char **data, int dataoff, 1048 Progress_UUIE *progress) 1049 { 1050 int ret; 1051 int i; 1052 1053 pr_debug("nf_ct_q931: Progress\n"); 1054 1055 if (progress->options & eProgress_UUIE_h245Address) { 1056 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff, 1057 &progress->h245Address); 1058 if (ret < 0) 1059 return -1; 1060 } 1061 1062 if (progress->options & eProgress_UUIE_fastStart) { 1063 for (i = 0; i < progress->fastStart.count; i++) { 1064 ret = process_olc(skb, ct, ctinfo, 1065 protoff, data, dataoff, 1066 &progress->fastStart.item[i]); 1067 if (ret < 0) 1068 return -1; 1069 } 1070 } 1071 1072 return 0; 1073 } 1074 1075 static int process_q931(struct sk_buff *skb, struct nf_conn *ct, 1076 enum ip_conntrack_info ctinfo, 1077 unsigned int protoff, unsigned char **data, int dataoff, 1078 Q931 *q931) 1079 { 1080 H323_UU_PDU *pdu = &q931->UUIE.h323_uu_pdu; 1081 int i; 1082 int ret = 0; 1083 1084 switch (pdu->h323_message_body.choice) { 1085 case eH323_UU_PDU_h323_message_body_setup: 1086 ret = process_setup(skb, ct, ctinfo, protoff, data, dataoff, 1087 &pdu->h323_message_body.setup); 1088 break; 1089 case eH323_UU_PDU_h323_message_body_callProceeding: 1090 ret = process_callproceeding(skb, ct, ctinfo, 1091 protoff, data, dataoff, 1092 &pdu->h323_message_body. 1093 callProceeding); 1094 break; 1095 case eH323_UU_PDU_h323_message_body_connect: 1096 ret = process_connect(skb, ct, ctinfo, protoff, data, dataoff, 1097 &pdu->h323_message_body.connect); 1098 break; 1099 case eH323_UU_PDU_h323_message_body_alerting: 1100 ret = process_alerting(skb, ct, ctinfo, protoff, data, dataoff, 1101 &pdu->h323_message_body.alerting); 1102 break; 1103 case eH323_UU_PDU_h323_message_body_facility: 1104 ret = process_facility(skb, ct, ctinfo, protoff, data, dataoff, 1105 &pdu->h323_message_body.facility); 1106 break; 1107 case eH323_UU_PDU_h323_message_body_progress: 1108 ret = process_progress(skb, ct, ctinfo, protoff, data, dataoff, 1109 &pdu->h323_message_body.progress); 1110 break; 1111 default: 1112 pr_debug("nf_ct_q931: Q.931 signal %d\n", 1113 pdu->h323_message_body.choice); 1114 break; 1115 } 1116 1117 if (ret < 0) 1118 return -1; 1119 1120 if (pdu->options & eH323_UU_PDU_h245Control) { 1121 for (i = 0; i < pdu->h245Control.count; i++) { 1122 ret = process_h245(skb, ct, ctinfo, 1123 protoff, data, dataoff, 1124 &pdu->h245Control.item[i]); 1125 if (ret < 0) 1126 return -1; 1127 } 1128 } 1129 1130 return 0; 1131 } 1132 1133 static int q931_help(struct sk_buff *skb, unsigned int protoff, 1134 struct nf_conn *ct, enum ip_conntrack_info ctinfo) 1135 { 1136 static Q931 q931; 1137 unsigned char *data = NULL; 1138 int datalen; 1139 int dataoff; 1140 int ret; 1141 1142 /* Until there's been traffic both ways, don't look in packets. */ 1143 if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY) 1144 return NF_ACCEPT; 1145 1146 pr_debug("nf_ct_q931: skblen = %u\n", skb->len); 1147 1148 spin_lock_bh(&nf_h323_lock); 1149 1150 /* Process each TPKT */ 1151 while (get_tpkt_data(skb, protoff, ct, ctinfo, 1152 &data, &datalen, &dataoff)) { 1153 pr_debug("nf_ct_q931: TPKT len=%d ", datalen); 1154 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple); 1155 1156 /* Decode Q.931 signal */ 1157 ret = DecodeQ931(data, datalen, &q931); 1158 if (ret < 0) { 1159 pr_debug("nf_ct_q931: decoding error: %s\n", 1160 ret == H323_ERROR_BOUND ? 1161 "out of bound" : "out of range"); 1162 /* We don't drop when decoding error */ 1163 break; 1164 } 1165 1166 /* Process Q.931 signal */ 1167 if (process_q931(skb, ct, ctinfo, protoff, 1168 &data, dataoff, &q931) < 0) 1169 goto drop; 1170 } 1171 1172 spin_unlock_bh(&nf_h323_lock); 1173 return NF_ACCEPT; 1174 1175 drop: 1176 spin_unlock_bh(&nf_h323_lock); 1177 nf_ct_helper_log(skb, ct, "cannot process Q.931 message"); 1178 return NF_DROP; 1179 } 1180 1181 static const struct nf_conntrack_expect_policy q931_exp_policy = { 1182 /* T.120 and H.245 */ 1183 .max_expected = H323_RTP_CHANNEL_MAX * 4 + 4, 1184 .timeout = 240, 1185 }; 1186 1187 static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = { 1188 { 1189 .name = "Q.931", 1190 .me = THIS_MODULE, 1191 .tuple.src.l3num = AF_INET, 1192 .tuple.src.u.tcp.port = cpu_to_be16(Q931_PORT), 1193 .tuple.dst.protonum = IPPROTO_TCP, 1194 .help = q931_help, 1195 .expect_policy = &q931_exp_policy, 1196 }, 1197 { 1198 .name = "Q.931", 1199 .me = THIS_MODULE, 1200 .tuple.src.l3num = AF_INET6, 1201 .tuple.src.u.tcp.port = cpu_to_be16(Q931_PORT), 1202 .tuple.dst.protonum = IPPROTO_TCP, 1203 .help = q931_help, 1204 .expect_policy = &q931_exp_policy, 1205 }, 1206 }; 1207 1208 static unsigned char *get_udp_data(struct sk_buff *skb, unsigned int protoff, 1209 int *datalen) 1210 { 1211 const struct udphdr *uh; 1212 struct udphdr _uh; 1213 int dataoff; 1214 1215 uh = skb_header_pointer(skb, protoff, sizeof(_uh), &_uh); 1216 if (uh == NULL) 1217 return NULL; 1218 dataoff = protoff + sizeof(_uh); 1219 if (dataoff >= skb->len) 1220 return NULL; 1221 *datalen = skb->len - dataoff; 1222 return skb_header_pointer(skb, dataoff, *datalen, h323_buffer); 1223 } 1224 1225 static struct nf_conntrack_expect *find_expect(struct nf_conn *ct, 1226 union nf_inet_addr *addr, 1227 __be16 port) 1228 { 1229 struct net *net = nf_ct_net(ct); 1230 struct nf_conntrack_expect *exp; 1231 struct nf_conntrack_tuple tuple; 1232 1233 memset(&tuple.src.u3, 0, sizeof(tuple.src.u3)); 1234 tuple.src.u.tcp.port = 0; 1235 memcpy(&tuple.dst.u3, addr, sizeof(tuple.dst.u3)); 1236 tuple.dst.u.tcp.port = port; 1237 tuple.dst.protonum = IPPROTO_TCP; 1238 1239 exp = __nf_ct_expect_find(net, nf_ct_zone(ct), &tuple); 1240 if (exp && exp->master == ct) 1241 return exp; 1242 return NULL; 1243 } 1244 1245 static int expect_q931(struct sk_buff *skb, struct nf_conn *ct, 1246 enum ip_conntrack_info ctinfo, 1247 unsigned int protoff, unsigned char **data, 1248 TransportAddress *taddr, int count) 1249 { 1250 struct nf_ct_h323_master *info = nfct_help_data(ct); 1251 int dir = CTINFO2DIR(ctinfo); 1252 int ret = 0; 1253 int i; 1254 __be16 port; 1255 union nf_inet_addr addr; 1256 struct nf_conntrack_expect *exp; 1257 typeof(nat_q931_hook) nat_q931; 1258 1259 /* Look for the first related address */ 1260 for (i = 0; i < count; i++) { 1261 if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) && 1262 memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, 1263 sizeof(addr)) == 0 && port != 0) 1264 break; 1265 } 1266 1267 if (i >= count) /* Not found */ 1268 return 0; 1269 1270 /* Create expect for Q.931 */ 1271 if ((exp = nf_ct_expect_alloc(ct)) == NULL) 1272 return -1; 1273 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), 1274 gkrouted_only ? /* only accept calls from GK? */ 1275 &ct->tuplehash[!dir].tuple.src.u3 : NULL, 1276 &ct->tuplehash[!dir].tuple.dst.u3, 1277 IPPROTO_TCP, NULL, &port); 1278 exp->helper = nf_conntrack_helper_q931; 1279 exp->flags = NF_CT_EXPECT_PERMANENT; /* Accept multiple calls */ 1280 1281 nat_q931 = rcu_dereference(nat_q931_hook); 1282 if (nat_q931 && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1283 ct->status & IPS_NAT_MASK) { /* Need NAT */ 1284 ret = nat_q931(skb, ct, ctinfo, protoff, data, 1285 taddr, i, port, exp); 1286 } else { /* Conntrack only */ 1287 if (nf_ct_expect_related(exp, 0) == 0) { 1288 pr_debug("nf_ct_ras: expect Q.931 "); 1289 nf_ct_dump_tuple(&exp->tuple); 1290 1291 /* Save port for looking up expect in processing RCF */ 1292 info->sig_port[dir] = port; 1293 } else 1294 ret = -1; 1295 } 1296 1297 nf_ct_expect_put(exp); 1298 1299 return ret; 1300 } 1301 1302 static int process_grq(struct sk_buff *skb, struct nf_conn *ct, 1303 enum ip_conntrack_info ctinfo, 1304 unsigned int protoff, 1305 unsigned char **data, GatekeeperRequest *grq) 1306 { 1307 typeof(set_ras_addr_hook) set_ras_addr; 1308 1309 pr_debug("nf_ct_ras: GRQ\n"); 1310 1311 set_ras_addr = rcu_dereference(set_ras_addr_hook); 1312 if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1313 ct->status & IPS_NAT_MASK) /* NATed */ 1314 return set_ras_addr(skb, ct, ctinfo, protoff, data, 1315 &grq->rasAddress, 1); 1316 return 0; 1317 } 1318 1319 static int process_gcf(struct sk_buff *skb, struct nf_conn *ct, 1320 enum ip_conntrack_info ctinfo, 1321 unsigned int protoff, 1322 unsigned char **data, GatekeeperConfirm *gcf) 1323 { 1324 int dir = CTINFO2DIR(ctinfo); 1325 int ret = 0; 1326 __be16 port; 1327 union nf_inet_addr addr; 1328 struct nf_conntrack_expect *exp; 1329 1330 pr_debug("nf_ct_ras: GCF\n"); 1331 1332 if (!get_h225_addr(ct, *data, &gcf->rasAddress, &addr, &port)) 1333 return 0; 1334 1335 /* Registration port is the same as discovery port */ 1336 if (!memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) && 1337 port == ct->tuplehash[dir].tuple.src.u.udp.port) 1338 return 0; 1339 1340 /* Avoid RAS expectation loops. A GCF is never expected. */ 1341 if (test_bit(IPS_EXPECTED_BIT, &ct->status)) 1342 return 0; 1343 1344 /* Need new expect */ 1345 if ((exp = nf_ct_expect_alloc(ct)) == NULL) 1346 return -1; 1347 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), 1348 &ct->tuplehash[!dir].tuple.src.u3, &addr, 1349 IPPROTO_UDP, NULL, &port); 1350 exp->helper = nf_conntrack_helper_ras; 1351 1352 if (nf_ct_expect_related(exp, 0) == 0) { 1353 pr_debug("nf_ct_ras: expect RAS "); 1354 nf_ct_dump_tuple(&exp->tuple); 1355 } else 1356 ret = -1; 1357 1358 nf_ct_expect_put(exp); 1359 1360 return ret; 1361 } 1362 1363 static int process_rrq(struct sk_buff *skb, struct nf_conn *ct, 1364 enum ip_conntrack_info ctinfo, 1365 unsigned int protoff, 1366 unsigned char **data, RegistrationRequest *rrq) 1367 { 1368 struct nf_ct_h323_master *info = nfct_help_data(ct); 1369 int ret; 1370 typeof(set_ras_addr_hook) set_ras_addr; 1371 1372 pr_debug("nf_ct_ras: RRQ\n"); 1373 1374 ret = expect_q931(skb, ct, ctinfo, protoff, data, 1375 rrq->callSignalAddress.item, 1376 rrq->callSignalAddress.count); 1377 if (ret < 0) 1378 return -1; 1379 1380 set_ras_addr = rcu_dereference(set_ras_addr_hook); 1381 if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1382 ct->status & IPS_NAT_MASK) { 1383 ret = set_ras_addr(skb, ct, ctinfo, protoff, data, 1384 rrq->rasAddress.item, 1385 rrq->rasAddress.count); 1386 if (ret < 0) 1387 return -1; 1388 } 1389 1390 if (rrq->options & eRegistrationRequest_timeToLive) { 1391 pr_debug("nf_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive); 1392 info->timeout = rrq->timeToLive; 1393 } else 1394 info->timeout = default_rrq_ttl; 1395 1396 return 0; 1397 } 1398 1399 static int process_rcf(struct sk_buff *skb, struct nf_conn *ct, 1400 enum ip_conntrack_info ctinfo, 1401 unsigned int protoff, 1402 unsigned char **data, RegistrationConfirm *rcf) 1403 { 1404 struct nf_ct_h323_master *info = nfct_help_data(ct); 1405 int dir = CTINFO2DIR(ctinfo); 1406 int ret; 1407 struct nf_conntrack_expect *exp; 1408 typeof(set_sig_addr_hook) set_sig_addr; 1409 1410 pr_debug("nf_ct_ras: RCF\n"); 1411 1412 set_sig_addr = rcu_dereference(set_sig_addr_hook); 1413 if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1414 ct->status & IPS_NAT_MASK) { 1415 ret = set_sig_addr(skb, ct, ctinfo, protoff, data, 1416 rcf->callSignalAddress.item, 1417 rcf->callSignalAddress.count); 1418 if (ret < 0) 1419 return -1; 1420 } 1421 1422 if (rcf->options & eRegistrationConfirm_timeToLive) { 1423 pr_debug("nf_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive); 1424 info->timeout = rcf->timeToLive; 1425 } 1426 1427 if (info->timeout > 0) { 1428 pr_debug("nf_ct_ras: set RAS connection timeout to " 1429 "%u seconds\n", info->timeout); 1430 nf_ct_refresh(ct, skb, info->timeout * HZ); 1431 1432 /* Set expect timeout */ 1433 spin_lock_bh(&nf_conntrack_expect_lock); 1434 exp = find_expect(ct, &ct->tuplehash[dir].tuple.dst.u3, 1435 info->sig_port[!dir]); 1436 if (exp) { 1437 pr_debug("nf_ct_ras: set Q.931 expect " 1438 "timeout to %u seconds for", 1439 info->timeout); 1440 nf_ct_dump_tuple(&exp->tuple); 1441 mod_timer_pending(&exp->timeout, 1442 jiffies + info->timeout * HZ); 1443 } 1444 spin_unlock_bh(&nf_conntrack_expect_lock); 1445 } 1446 1447 return 0; 1448 } 1449 1450 static int process_urq(struct sk_buff *skb, struct nf_conn *ct, 1451 enum ip_conntrack_info ctinfo, 1452 unsigned int protoff, 1453 unsigned char **data, UnregistrationRequest *urq) 1454 { 1455 struct nf_ct_h323_master *info = nfct_help_data(ct); 1456 int dir = CTINFO2DIR(ctinfo); 1457 int ret; 1458 typeof(set_sig_addr_hook) set_sig_addr; 1459 1460 pr_debug("nf_ct_ras: URQ\n"); 1461 1462 set_sig_addr = rcu_dereference(set_sig_addr_hook); 1463 if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1464 ct->status & IPS_NAT_MASK) { 1465 ret = set_sig_addr(skb, ct, ctinfo, protoff, data, 1466 urq->callSignalAddress.item, 1467 urq->callSignalAddress.count); 1468 if (ret < 0) 1469 return -1; 1470 } 1471 1472 /* Clear old expect */ 1473 nf_ct_remove_expectations(ct); 1474 info->sig_port[dir] = 0; 1475 info->sig_port[!dir] = 0; 1476 1477 /* Give it 30 seconds for UCF or URJ */ 1478 nf_ct_refresh(ct, skb, 30 * HZ); 1479 1480 return 0; 1481 } 1482 1483 static int process_arq(struct sk_buff *skb, struct nf_conn *ct, 1484 enum ip_conntrack_info ctinfo, 1485 unsigned int protoff, 1486 unsigned char **data, AdmissionRequest *arq) 1487 { 1488 const struct nf_ct_h323_master *info = nfct_help_data(ct); 1489 int dir = CTINFO2DIR(ctinfo); 1490 __be16 port; 1491 union nf_inet_addr addr; 1492 typeof(set_h225_addr_hook) set_h225_addr; 1493 1494 pr_debug("nf_ct_ras: ARQ\n"); 1495 1496 set_h225_addr = rcu_dereference(set_h225_addr_hook); 1497 if ((arq->options & eAdmissionRequest_destCallSignalAddress) && 1498 get_h225_addr(ct, *data, &arq->destCallSignalAddress, 1499 &addr, &port) && 1500 !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) && 1501 port == info->sig_port[dir] && 1502 nf_ct_l3num(ct) == NFPROTO_IPV4 && 1503 set_h225_addr && ct->status & IPS_NAT_MASK) { 1504 /* Answering ARQ */ 1505 return set_h225_addr(skb, protoff, data, 0, 1506 &arq->destCallSignalAddress, 1507 &ct->tuplehash[!dir].tuple.dst.u3, 1508 info->sig_port[!dir]); 1509 } 1510 1511 if ((arq->options & eAdmissionRequest_srcCallSignalAddress) && 1512 get_h225_addr(ct, *data, &arq->srcCallSignalAddress, 1513 &addr, &port) && 1514 !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) && 1515 set_h225_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1516 ct->status & IPS_NAT_MASK) { 1517 /* Calling ARQ */ 1518 return set_h225_addr(skb, protoff, data, 0, 1519 &arq->srcCallSignalAddress, 1520 &ct->tuplehash[!dir].tuple.dst.u3, 1521 port); 1522 } 1523 1524 return 0; 1525 } 1526 1527 static int process_acf(struct sk_buff *skb, struct nf_conn *ct, 1528 enum ip_conntrack_info ctinfo, 1529 unsigned int protoff, 1530 unsigned char **data, AdmissionConfirm *acf) 1531 { 1532 int dir = CTINFO2DIR(ctinfo); 1533 int ret = 0; 1534 __be16 port; 1535 union nf_inet_addr addr; 1536 struct nf_conntrack_expect *exp; 1537 typeof(set_sig_addr_hook) set_sig_addr; 1538 1539 pr_debug("nf_ct_ras: ACF\n"); 1540 1541 if (!get_h225_addr(ct, *data, &acf->destCallSignalAddress, 1542 &addr, &port)) 1543 return 0; 1544 1545 if (!memcmp(&addr, &ct->tuplehash[dir].tuple.dst.u3, sizeof(addr))) { 1546 /* Answering ACF */ 1547 set_sig_addr = rcu_dereference(set_sig_addr_hook); 1548 if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1549 ct->status & IPS_NAT_MASK) 1550 return set_sig_addr(skb, ct, ctinfo, protoff, data, 1551 &acf->destCallSignalAddress, 1); 1552 return 0; 1553 } 1554 1555 /* Need new expect */ 1556 if ((exp = nf_ct_expect_alloc(ct)) == NULL) 1557 return -1; 1558 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), 1559 &ct->tuplehash[!dir].tuple.src.u3, &addr, 1560 IPPROTO_TCP, NULL, &port); 1561 exp->flags = NF_CT_EXPECT_PERMANENT; 1562 exp->helper = nf_conntrack_helper_q931; 1563 1564 if (nf_ct_expect_related(exp, 0) == 0) { 1565 pr_debug("nf_ct_ras: expect Q.931 "); 1566 nf_ct_dump_tuple(&exp->tuple); 1567 } else 1568 ret = -1; 1569 1570 nf_ct_expect_put(exp); 1571 1572 return ret; 1573 } 1574 1575 static int process_lrq(struct sk_buff *skb, struct nf_conn *ct, 1576 enum ip_conntrack_info ctinfo, 1577 unsigned int protoff, 1578 unsigned char **data, LocationRequest *lrq) 1579 { 1580 typeof(set_ras_addr_hook) set_ras_addr; 1581 1582 pr_debug("nf_ct_ras: LRQ\n"); 1583 1584 set_ras_addr = rcu_dereference(set_ras_addr_hook); 1585 if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1586 ct->status & IPS_NAT_MASK) 1587 return set_ras_addr(skb, ct, ctinfo, protoff, data, 1588 &lrq->replyAddress, 1); 1589 return 0; 1590 } 1591 1592 static int process_lcf(struct sk_buff *skb, struct nf_conn *ct, 1593 enum ip_conntrack_info ctinfo, 1594 unsigned int protoff, 1595 unsigned char **data, LocationConfirm *lcf) 1596 { 1597 int dir = CTINFO2DIR(ctinfo); 1598 int ret = 0; 1599 __be16 port; 1600 union nf_inet_addr addr; 1601 struct nf_conntrack_expect *exp; 1602 1603 pr_debug("nf_ct_ras: LCF\n"); 1604 1605 if (!get_h225_addr(ct, *data, &lcf->callSignalAddress, 1606 &addr, &port)) 1607 return 0; 1608 1609 /* Need new expect for call signal */ 1610 if ((exp = nf_ct_expect_alloc(ct)) == NULL) 1611 return -1; 1612 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), 1613 &ct->tuplehash[!dir].tuple.src.u3, &addr, 1614 IPPROTO_TCP, NULL, &port); 1615 exp->flags = NF_CT_EXPECT_PERMANENT; 1616 exp->helper = nf_conntrack_helper_q931; 1617 1618 if (nf_ct_expect_related(exp, 0) == 0) { 1619 pr_debug("nf_ct_ras: expect Q.931 "); 1620 nf_ct_dump_tuple(&exp->tuple); 1621 } else 1622 ret = -1; 1623 1624 nf_ct_expect_put(exp); 1625 1626 /* Ignore rasAddress */ 1627 1628 return ret; 1629 } 1630 1631 static int process_irr(struct sk_buff *skb, struct nf_conn *ct, 1632 enum ip_conntrack_info ctinfo, 1633 unsigned int protoff, 1634 unsigned char **data, InfoRequestResponse *irr) 1635 { 1636 int ret; 1637 typeof(set_ras_addr_hook) set_ras_addr; 1638 typeof(set_sig_addr_hook) set_sig_addr; 1639 1640 pr_debug("nf_ct_ras: IRR\n"); 1641 1642 set_ras_addr = rcu_dereference(set_ras_addr_hook); 1643 if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1644 ct->status & IPS_NAT_MASK) { 1645 ret = set_ras_addr(skb, ct, ctinfo, protoff, data, 1646 &irr->rasAddress, 1); 1647 if (ret < 0) 1648 return -1; 1649 } 1650 1651 set_sig_addr = rcu_dereference(set_sig_addr_hook); 1652 if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1653 ct->status & IPS_NAT_MASK) { 1654 ret = set_sig_addr(skb, ct, ctinfo, protoff, data, 1655 irr->callSignalAddress.item, 1656 irr->callSignalAddress.count); 1657 if (ret < 0) 1658 return -1; 1659 } 1660 1661 return 0; 1662 } 1663 1664 static int process_ras(struct sk_buff *skb, struct nf_conn *ct, 1665 enum ip_conntrack_info ctinfo, 1666 unsigned int protoff, 1667 unsigned char **data, RasMessage *ras) 1668 { 1669 switch (ras->choice) { 1670 case eRasMessage_gatekeeperRequest: 1671 return process_grq(skb, ct, ctinfo, protoff, data, 1672 &ras->gatekeeperRequest); 1673 case eRasMessage_gatekeeperConfirm: 1674 return process_gcf(skb, ct, ctinfo, protoff, data, 1675 &ras->gatekeeperConfirm); 1676 case eRasMessage_registrationRequest: 1677 return process_rrq(skb, ct, ctinfo, protoff, data, 1678 &ras->registrationRequest); 1679 case eRasMessage_registrationConfirm: 1680 return process_rcf(skb, ct, ctinfo, protoff, data, 1681 &ras->registrationConfirm); 1682 case eRasMessage_unregistrationRequest: 1683 return process_urq(skb, ct, ctinfo, protoff, data, 1684 &ras->unregistrationRequest); 1685 case eRasMessage_admissionRequest: 1686 return process_arq(skb, ct, ctinfo, protoff, data, 1687 &ras->admissionRequest); 1688 case eRasMessage_admissionConfirm: 1689 return process_acf(skb, ct, ctinfo, protoff, data, 1690 &ras->admissionConfirm); 1691 case eRasMessage_locationRequest: 1692 return process_lrq(skb, ct, ctinfo, protoff, data, 1693 &ras->locationRequest); 1694 case eRasMessage_locationConfirm: 1695 return process_lcf(skb, ct, ctinfo, protoff, data, 1696 &ras->locationConfirm); 1697 case eRasMessage_infoRequestResponse: 1698 return process_irr(skb, ct, ctinfo, protoff, data, 1699 &ras->infoRequestResponse); 1700 default: 1701 pr_debug("nf_ct_ras: RAS message %d\n", ras->choice); 1702 break; 1703 } 1704 1705 return 0; 1706 } 1707 1708 static int ras_help(struct sk_buff *skb, unsigned int protoff, 1709 struct nf_conn *ct, enum ip_conntrack_info ctinfo) 1710 { 1711 static RasMessage ras; 1712 unsigned char *data; 1713 int datalen = 0; 1714 int ret; 1715 1716 pr_debug("nf_ct_ras: skblen = %u\n", skb->len); 1717 1718 spin_lock_bh(&nf_h323_lock); 1719 1720 /* Get UDP data */ 1721 data = get_udp_data(skb, protoff, &datalen); 1722 if (data == NULL) 1723 goto accept; 1724 pr_debug("nf_ct_ras: RAS message len=%d ", datalen); 1725 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple); 1726 1727 /* Decode RAS message */ 1728 ret = DecodeRasMessage(data, datalen, &ras); 1729 if (ret < 0) { 1730 pr_debug("nf_ct_ras: decoding error: %s\n", 1731 ret == H323_ERROR_BOUND ? 1732 "out of bound" : "out of range"); 1733 goto accept; 1734 } 1735 1736 /* Process RAS message */ 1737 if (process_ras(skb, ct, ctinfo, protoff, &data, &ras) < 0) 1738 goto drop; 1739 1740 accept: 1741 spin_unlock_bh(&nf_h323_lock); 1742 return NF_ACCEPT; 1743 1744 drop: 1745 spin_unlock_bh(&nf_h323_lock); 1746 nf_ct_helper_log(skb, ct, "cannot process RAS message"); 1747 return NF_DROP; 1748 } 1749 1750 static const struct nf_conntrack_expect_policy ras_exp_policy = { 1751 .max_expected = 32, 1752 .timeout = 240, 1753 }; 1754 1755 static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = { 1756 { 1757 .name = "RAS", 1758 .me = THIS_MODULE, 1759 .tuple.src.l3num = AF_INET, 1760 .tuple.src.u.udp.port = cpu_to_be16(RAS_PORT), 1761 .tuple.dst.protonum = IPPROTO_UDP, 1762 .help = ras_help, 1763 .expect_policy = &ras_exp_policy, 1764 }, 1765 { 1766 .name = "RAS", 1767 .me = THIS_MODULE, 1768 .tuple.src.l3num = AF_INET6, 1769 .tuple.src.u.udp.port = cpu_to_be16(RAS_PORT), 1770 .tuple.dst.protonum = IPPROTO_UDP, 1771 .help = ras_help, 1772 .expect_policy = &ras_exp_policy, 1773 }, 1774 }; 1775 1776 static int __init h323_helper_init(void) 1777 { 1778 int ret; 1779 1780 ret = nf_conntrack_helper_register(&nf_conntrack_helper_h245); 1781 if (ret < 0) 1782 return ret; 1783 ret = nf_conntrack_helpers_register(nf_conntrack_helper_q931, 1784 ARRAY_SIZE(nf_conntrack_helper_q931)); 1785 if (ret < 0) 1786 goto err1; 1787 ret = nf_conntrack_helpers_register(nf_conntrack_helper_ras, 1788 ARRAY_SIZE(nf_conntrack_helper_ras)); 1789 if (ret < 0) 1790 goto err2; 1791 1792 return 0; 1793 err2: 1794 nf_conntrack_helpers_unregister(nf_conntrack_helper_q931, 1795 ARRAY_SIZE(nf_conntrack_helper_q931)); 1796 err1: 1797 nf_conntrack_helper_unregister(&nf_conntrack_helper_h245); 1798 return ret; 1799 } 1800 1801 static void __exit h323_helper_exit(void) 1802 { 1803 nf_conntrack_helpers_unregister(nf_conntrack_helper_ras, 1804 ARRAY_SIZE(nf_conntrack_helper_ras)); 1805 nf_conntrack_helpers_unregister(nf_conntrack_helper_q931, 1806 ARRAY_SIZE(nf_conntrack_helper_q931)); 1807 nf_conntrack_helper_unregister(&nf_conntrack_helper_h245); 1808 } 1809 1810 static void __exit nf_conntrack_h323_fini(void) 1811 { 1812 h323_helper_exit(); 1813 kfree(h323_buffer); 1814 pr_debug("nf_ct_h323: fini\n"); 1815 } 1816 1817 static int __init nf_conntrack_h323_init(void) 1818 { 1819 int ret; 1820 1821 NF_CT_HELPER_BUILD_BUG_ON(sizeof(struct nf_ct_h323_master)); 1822 1823 h323_buffer = kmalloc(65536, GFP_KERNEL); 1824 if (!h323_buffer) 1825 return -ENOMEM; 1826 ret = h323_helper_init(); 1827 if (ret < 0) 1828 goto err1; 1829 pr_debug("nf_ct_h323: init success\n"); 1830 return 0; 1831 err1: 1832 kfree(h323_buffer); 1833 return ret; 1834 } 1835 1836 module_init(nf_conntrack_h323_init); 1837 module_exit(nf_conntrack_h323_fini); 1838 1839 EXPORT_SYMBOL_GPL(get_h225_addr); 1840 EXPORT_SYMBOL_GPL(set_h245_addr_hook); 1841 EXPORT_SYMBOL_GPL(set_h225_addr_hook); 1842 EXPORT_SYMBOL_GPL(set_sig_addr_hook); 1843 EXPORT_SYMBOL_GPL(set_ras_addr_hook); 1844 EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook); 1845 EXPORT_SYMBOL_GPL(nat_t120_hook); 1846 EXPORT_SYMBOL_GPL(nat_h245_hook); 1847 EXPORT_SYMBOL_GPL(nat_callforwarding_hook); 1848 EXPORT_SYMBOL_GPL(nat_q931_hook); 1849 1850 MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>"); 1851 MODULE_DESCRIPTION("H.323 connection tracking helper"); 1852 MODULE_LICENSE("GPL"); 1853 MODULE_ALIAS("ip_conntrack_h323"); 1854 MODULE_ALIAS_NFCT_HELPER("RAS"); 1855 MODULE_ALIAS_NFCT_HELPER("Q.931"); 1856 MODULE_ALIAS_NFCT_HELPER("H.245"); 1857