1 /* 2 * H.323 connection tracking helper 3 * 4 * Copyright (c) 2006 Jing Min Zhao <zhaojingmin@users.sourceforge.net> 5 * Copyright (c) 2006-2012 Patrick McHardy <kaber@trash.net> 6 * 7 * This source code is licensed under General Public License version 2. 8 * 9 * Based on the 'brute force' H.323 connection tracking module by 10 * Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> 11 * 12 * For more information, please see http://nath323.sourceforge.net/ 13 */ 14 15 #include <linux/module.h> 16 #include <linux/moduleparam.h> 17 #include <linux/ctype.h> 18 #include <linux/inet.h> 19 #include <linux/in.h> 20 #include <linux/ip.h> 21 #include <linux/slab.h> 22 #include <linux/udp.h> 23 #include <linux/tcp.h> 24 #include <linux/skbuff.h> 25 #include <net/route.h> 26 #include <net/ip6_route.h> 27 #include <linux/netfilter_ipv6.h> 28 29 #include <net/netfilter/nf_conntrack.h> 30 #include <net/netfilter/nf_conntrack_core.h> 31 #include <net/netfilter/nf_conntrack_tuple.h> 32 #include <net/netfilter/nf_conntrack_expect.h> 33 #include <net/netfilter/nf_conntrack_ecache.h> 34 #include <net/netfilter/nf_conntrack_helper.h> 35 #include <net/netfilter/nf_conntrack_zones.h> 36 #include <linux/netfilter/nf_conntrack_h323.h> 37 38 /* Parameters */ 39 static unsigned int default_rrq_ttl __read_mostly = 300; 40 module_param(default_rrq_ttl, uint, 0600); 41 MODULE_PARM_DESC(default_rrq_ttl, "use this TTL if it's missing in RRQ"); 42 43 static int gkrouted_only __read_mostly = 1; 44 module_param(gkrouted_only, int, 0600); 45 MODULE_PARM_DESC(gkrouted_only, "only accept calls from gatekeeper"); 46 47 static bool callforward_filter __read_mostly = true; 48 module_param(callforward_filter, bool, 0600); 49 MODULE_PARM_DESC(callforward_filter, "only create call forwarding expectations " 50 "if both endpoints are on different sides " 51 "(determined by routing information)"); 52 53 /* Hooks for NAT */ 54 int (*set_h245_addr_hook) (struct sk_buff *skb, unsigned int protoff, 55 unsigned char **data, int dataoff, 56 H245_TransportAddress *taddr, 57 union nf_inet_addr *addr, __be16 port) 58 __read_mostly; 59 int (*set_h225_addr_hook) (struct sk_buff *skb, unsigned int protoff, 60 unsigned char **data, int dataoff, 61 TransportAddress *taddr, 62 union nf_inet_addr *addr, __be16 port) 63 __read_mostly; 64 int (*set_sig_addr_hook) (struct sk_buff *skb, 65 struct nf_conn *ct, 66 enum ip_conntrack_info ctinfo, 67 unsigned int protoff, unsigned char **data, 68 TransportAddress *taddr, int count) __read_mostly; 69 int (*set_ras_addr_hook) (struct sk_buff *skb, 70 struct nf_conn *ct, 71 enum ip_conntrack_info ctinfo, 72 unsigned int protoff, unsigned char **data, 73 TransportAddress *taddr, int count) __read_mostly; 74 int (*nat_rtp_rtcp_hook) (struct sk_buff *skb, 75 struct nf_conn *ct, 76 enum ip_conntrack_info ctinfo, 77 unsigned int protoff, 78 unsigned char **data, int dataoff, 79 H245_TransportAddress *taddr, 80 __be16 port, __be16 rtp_port, 81 struct nf_conntrack_expect *rtp_exp, 82 struct nf_conntrack_expect *rtcp_exp) __read_mostly; 83 int (*nat_t120_hook) (struct sk_buff *skb, 84 struct nf_conn *ct, 85 enum ip_conntrack_info ctinfo, 86 unsigned int protoff, 87 unsigned char **data, int dataoff, 88 H245_TransportAddress *taddr, __be16 port, 89 struct nf_conntrack_expect *exp) __read_mostly; 90 int (*nat_h245_hook) (struct sk_buff *skb, 91 struct nf_conn *ct, 92 enum ip_conntrack_info ctinfo, 93 unsigned int protoff, 94 unsigned char **data, int dataoff, 95 TransportAddress *taddr, __be16 port, 96 struct nf_conntrack_expect *exp) __read_mostly; 97 int (*nat_callforwarding_hook) (struct sk_buff *skb, 98 struct nf_conn *ct, 99 enum ip_conntrack_info ctinfo, 100 unsigned int protoff, 101 unsigned char **data, int dataoff, 102 TransportAddress *taddr, __be16 port, 103 struct nf_conntrack_expect *exp) __read_mostly; 104 int (*nat_q931_hook) (struct sk_buff *skb, 105 struct nf_conn *ct, 106 enum ip_conntrack_info ctinfo, 107 unsigned int protoff, 108 unsigned char **data, TransportAddress *taddr, int idx, 109 __be16 port, struct nf_conntrack_expect *exp) 110 __read_mostly; 111 112 static DEFINE_SPINLOCK(nf_h323_lock); 113 static char *h323_buffer; 114 115 static struct nf_conntrack_helper nf_conntrack_helper_h245; 116 static struct nf_conntrack_helper nf_conntrack_helper_q931[]; 117 static struct nf_conntrack_helper nf_conntrack_helper_ras[]; 118 119 static int get_tpkt_data(struct sk_buff *skb, unsigned int protoff, 120 struct nf_conn *ct, enum ip_conntrack_info ctinfo, 121 unsigned char **data, int *datalen, int *dataoff) 122 { 123 struct nf_ct_h323_master *info = nfct_help_data(ct); 124 int dir = CTINFO2DIR(ctinfo); 125 const struct tcphdr *th; 126 struct tcphdr _tcph; 127 int tcpdatalen; 128 int tcpdataoff; 129 unsigned char *tpkt; 130 int tpktlen; 131 int tpktoff; 132 133 /* Get TCP header */ 134 th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph); 135 if (th == NULL) 136 return 0; 137 138 /* Get TCP data offset */ 139 tcpdataoff = protoff + th->doff * 4; 140 141 /* Get TCP data length */ 142 tcpdatalen = skb->len - tcpdataoff; 143 if (tcpdatalen <= 0) /* No TCP data */ 144 goto clear_out; 145 146 if (*data == NULL) { /* first TPKT */ 147 /* Get first TPKT pointer */ 148 tpkt = skb_header_pointer(skb, tcpdataoff, tcpdatalen, 149 h323_buffer); 150 BUG_ON(tpkt == NULL); 151 152 /* Validate TPKT identifier */ 153 if (tcpdatalen < 4 || tpkt[0] != 0x03 || tpkt[1] != 0) { 154 /* Netmeeting sends TPKT header and data separately */ 155 if (info->tpkt_len[dir] > 0) { 156 pr_debug("nf_ct_h323: previous packet " 157 "indicated separate TPKT data of %hu " 158 "bytes\n", info->tpkt_len[dir]); 159 if (info->tpkt_len[dir] <= tcpdatalen) { 160 /* Yes, there was a TPKT header 161 * received */ 162 *data = tpkt; 163 *datalen = info->tpkt_len[dir]; 164 *dataoff = 0; 165 goto out; 166 } 167 168 /* Fragmented TPKT */ 169 pr_debug("nf_ct_h323: fragmented TPKT\n"); 170 goto clear_out; 171 } 172 173 /* It is not even a TPKT */ 174 return 0; 175 } 176 tpktoff = 0; 177 } else { /* Next TPKT */ 178 tpktoff = *dataoff + *datalen; 179 tcpdatalen -= tpktoff; 180 if (tcpdatalen <= 4) /* No more TPKT */ 181 goto clear_out; 182 tpkt = *data + *datalen; 183 184 /* Validate TPKT identifier */ 185 if (tpkt[0] != 0x03 || tpkt[1] != 0) 186 goto clear_out; 187 } 188 189 /* Validate TPKT length */ 190 tpktlen = tpkt[2] * 256 + tpkt[3]; 191 if (tpktlen < 4) 192 goto clear_out; 193 if (tpktlen > tcpdatalen) { 194 if (tcpdatalen == 4) { /* Separate TPKT header */ 195 /* Netmeeting sends TPKT header and data separately */ 196 pr_debug("nf_ct_h323: separate TPKT header indicates " 197 "there will be TPKT data of %hu bytes\n", 198 tpktlen - 4); 199 info->tpkt_len[dir] = tpktlen - 4; 200 return 0; 201 } 202 203 pr_debug("nf_ct_h323: incomplete TPKT (fragmented?)\n"); 204 goto clear_out; 205 } 206 207 /* This is the encapsulated data */ 208 *data = tpkt + 4; 209 *datalen = tpktlen - 4; 210 *dataoff = tpktoff + 4; 211 212 out: 213 /* Clear TPKT length */ 214 info->tpkt_len[dir] = 0; 215 return 1; 216 217 clear_out: 218 info->tpkt_len[dir] = 0; 219 return 0; 220 } 221 222 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) { 310 if (nf_ct_expect_related(rtcp_exp) == 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) { 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) { 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_NF_CONNTRACK_IPV6) 752 case AF_INET6: { 753 const struct nf_ipv6_ops *v6ops; 754 struct rt6_info *rt1, *rt2; 755 struct flowi6 fl1, fl2; 756 757 v6ops = nf_get_ipv6_ops(); 758 if (!v6ops) 759 return 0; 760 761 memset(&fl1, 0, sizeof(fl1)); 762 fl1.daddr = src->in6; 763 764 memset(&fl2, 0, sizeof(fl2)); 765 fl2.daddr = dst->in6; 766 if (!v6ops->route(net, (struct dst_entry **)&rt1, 767 flowi6_to_flowi(&fl1), false)) { 768 if (!v6ops->route(net, (struct dst_entry **)&rt2, 769 flowi6_to_flowi(&fl2), false)) { 770 if (ipv6_addr_equal(rt6_nexthop(rt1, &fl1.daddr), 771 rt6_nexthop(rt2, &fl2.daddr)) && 772 rt1->dst.dev == rt2->dst.dev) 773 ret = 1; 774 dst_release(&rt2->dst); 775 } 776 dst_release(&rt1->dst); 777 } 778 break; 779 } 780 #endif 781 } 782 return ret; 783 784 } 785 786 static int expect_callforwarding(struct sk_buff *skb, 787 struct nf_conn *ct, 788 enum ip_conntrack_info ctinfo, 789 unsigned int protoff, 790 unsigned char **data, int dataoff, 791 TransportAddress *taddr) 792 { 793 int dir = CTINFO2DIR(ctinfo); 794 int ret = 0; 795 __be16 port; 796 union nf_inet_addr addr; 797 struct nf_conntrack_expect *exp; 798 struct net *net = nf_ct_net(ct); 799 typeof(nat_callforwarding_hook) nat_callforwarding; 800 801 /* Read alternativeAddress */ 802 if (!get_h225_addr(ct, *data, taddr, &addr, &port) || port == 0) 803 return 0; 804 805 /* If the calling party is on the same side of the forward-to party, 806 * we don't need to track the second call 807 */ 808 if (callforward_filter && 809 callforward_do_filter(net, &addr, &ct->tuplehash[!dir].tuple.src.u3, 810 nf_ct_l3num(ct))) { 811 pr_debug("nf_ct_q931: Call Forwarding not tracked\n"); 812 return 0; 813 } 814 815 /* Create expect for the second call leg */ 816 if ((exp = nf_ct_expect_alloc(ct)) == NULL) 817 return -1; 818 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), 819 &ct->tuplehash[!dir].tuple.src.u3, &addr, 820 IPPROTO_TCP, NULL, &port); 821 exp->helper = nf_conntrack_helper_q931; 822 823 if (memcmp(&ct->tuplehash[dir].tuple.src.u3, 824 &ct->tuplehash[!dir].tuple.dst.u3, 825 sizeof(ct->tuplehash[dir].tuple.src.u3)) && 826 (nat_callforwarding = rcu_dereference(nat_callforwarding_hook)) && 827 nf_ct_l3num(ct) == NFPROTO_IPV4 && 828 ct->status & IPS_NAT_MASK) { 829 /* Need NAT */ 830 ret = nat_callforwarding(skb, ct, ctinfo, 831 protoff, data, dataoff, 832 taddr, port, exp); 833 } else { /* Conntrack only */ 834 if (nf_ct_expect_related(exp) == 0) { 835 pr_debug("nf_ct_q931: expect Call Forwarding "); 836 nf_ct_dump_tuple(&exp->tuple); 837 } else 838 ret = -1; 839 } 840 841 nf_ct_expect_put(exp); 842 843 return ret; 844 } 845 846 static int process_setup(struct sk_buff *skb, struct nf_conn *ct, 847 enum ip_conntrack_info ctinfo, 848 unsigned int protoff, 849 unsigned char **data, int dataoff, 850 Setup_UUIE *setup) 851 { 852 int dir = CTINFO2DIR(ctinfo); 853 int ret; 854 int i; 855 __be16 port; 856 union nf_inet_addr addr; 857 typeof(set_h225_addr_hook) set_h225_addr; 858 859 pr_debug("nf_ct_q931: Setup\n"); 860 861 if (setup->options & eSetup_UUIE_h245Address) { 862 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff, 863 &setup->h245Address); 864 if (ret < 0) 865 return -1; 866 } 867 868 set_h225_addr = rcu_dereference(set_h225_addr_hook); 869 if ((setup->options & eSetup_UUIE_destCallSignalAddress) && 870 (set_h225_addr) && nf_ct_l3num(ct) == NFPROTO_IPV4 && 871 ct->status & IPS_NAT_MASK && 872 get_h225_addr(ct, *data, &setup->destCallSignalAddress, 873 &addr, &port) && 874 memcmp(&addr, &ct->tuplehash[!dir].tuple.src.u3, sizeof(addr))) { 875 pr_debug("nf_ct_q931: set destCallSignalAddress %pI6:%hu->%pI6:%hu\n", 876 &addr, ntohs(port), &ct->tuplehash[!dir].tuple.src.u3, 877 ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port)); 878 ret = set_h225_addr(skb, protoff, data, dataoff, 879 &setup->destCallSignalAddress, 880 &ct->tuplehash[!dir].tuple.src.u3, 881 ct->tuplehash[!dir].tuple.src.u.tcp.port); 882 if (ret < 0) 883 return -1; 884 } 885 886 if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) && 887 (set_h225_addr) && nf_ct_l3num(ct) == NFPROTO_IPV4 && 888 ct->status & IPS_NAT_MASK && 889 get_h225_addr(ct, *data, &setup->sourceCallSignalAddress, 890 &addr, &port) && 891 memcmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(addr))) { 892 pr_debug("nf_ct_q931: set sourceCallSignalAddress %pI6:%hu->%pI6:%hu\n", 893 &addr, ntohs(port), &ct->tuplehash[!dir].tuple.dst.u3, 894 ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port)); 895 ret = set_h225_addr(skb, protoff, data, dataoff, 896 &setup->sourceCallSignalAddress, 897 &ct->tuplehash[!dir].tuple.dst.u3, 898 ct->tuplehash[!dir].tuple.dst.u.tcp.port); 899 if (ret < 0) 900 return -1; 901 } 902 903 if (setup->options & eSetup_UUIE_fastStart) { 904 for (i = 0; i < setup->fastStart.count; i++) { 905 ret = process_olc(skb, ct, ctinfo, 906 protoff, data, dataoff, 907 &setup->fastStart.item[i]); 908 if (ret < 0) 909 return -1; 910 } 911 } 912 913 return 0; 914 } 915 916 static int process_callproceeding(struct sk_buff *skb, 917 struct nf_conn *ct, 918 enum ip_conntrack_info ctinfo, 919 unsigned int protoff, 920 unsigned char **data, int dataoff, 921 CallProceeding_UUIE *callproc) 922 { 923 int ret; 924 int i; 925 926 pr_debug("nf_ct_q931: CallProceeding\n"); 927 928 if (callproc->options & eCallProceeding_UUIE_h245Address) { 929 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff, 930 &callproc->h245Address); 931 if (ret < 0) 932 return -1; 933 } 934 935 if (callproc->options & eCallProceeding_UUIE_fastStart) { 936 for (i = 0; i < callproc->fastStart.count; i++) { 937 ret = process_olc(skb, ct, ctinfo, 938 protoff, data, dataoff, 939 &callproc->fastStart.item[i]); 940 if (ret < 0) 941 return -1; 942 } 943 } 944 945 return 0; 946 } 947 948 static int process_connect(struct sk_buff *skb, struct nf_conn *ct, 949 enum ip_conntrack_info ctinfo, 950 unsigned int protoff, 951 unsigned char **data, int dataoff, 952 Connect_UUIE *connect) 953 { 954 int ret; 955 int i; 956 957 pr_debug("nf_ct_q931: Connect\n"); 958 959 if (connect->options & eConnect_UUIE_h245Address) { 960 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff, 961 &connect->h245Address); 962 if (ret < 0) 963 return -1; 964 } 965 966 if (connect->options & eConnect_UUIE_fastStart) { 967 for (i = 0; i < connect->fastStart.count; i++) { 968 ret = process_olc(skb, ct, ctinfo, 969 protoff, data, dataoff, 970 &connect->fastStart.item[i]); 971 if (ret < 0) 972 return -1; 973 } 974 } 975 976 return 0; 977 } 978 979 static int process_alerting(struct sk_buff *skb, struct nf_conn *ct, 980 enum ip_conntrack_info ctinfo, 981 unsigned int protoff, 982 unsigned char **data, int dataoff, 983 Alerting_UUIE *alert) 984 { 985 int ret; 986 int i; 987 988 pr_debug("nf_ct_q931: Alerting\n"); 989 990 if (alert->options & eAlerting_UUIE_h245Address) { 991 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff, 992 &alert->h245Address); 993 if (ret < 0) 994 return -1; 995 } 996 997 if (alert->options & eAlerting_UUIE_fastStart) { 998 for (i = 0; i < alert->fastStart.count; i++) { 999 ret = process_olc(skb, ct, ctinfo, 1000 protoff, data, dataoff, 1001 &alert->fastStart.item[i]); 1002 if (ret < 0) 1003 return -1; 1004 } 1005 } 1006 1007 return 0; 1008 } 1009 1010 static int process_facility(struct sk_buff *skb, struct nf_conn *ct, 1011 enum ip_conntrack_info ctinfo, 1012 unsigned int protoff, 1013 unsigned char **data, int dataoff, 1014 Facility_UUIE *facility) 1015 { 1016 int ret; 1017 int i; 1018 1019 pr_debug("nf_ct_q931: Facility\n"); 1020 1021 if (facility->reason.choice == eFacilityReason_callForwarded) { 1022 if (facility->options & eFacility_UUIE_alternativeAddress) 1023 return expect_callforwarding(skb, ct, ctinfo, 1024 protoff, data, dataoff, 1025 &facility-> 1026 alternativeAddress); 1027 return 0; 1028 } 1029 1030 if (facility->options & eFacility_UUIE_h245Address) { 1031 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff, 1032 &facility->h245Address); 1033 if (ret < 0) 1034 return -1; 1035 } 1036 1037 if (facility->options & eFacility_UUIE_fastStart) { 1038 for (i = 0; i < facility->fastStart.count; i++) { 1039 ret = process_olc(skb, ct, ctinfo, 1040 protoff, data, dataoff, 1041 &facility->fastStart.item[i]); 1042 if (ret < 0) 1043 return -1; 1044 } 1045 } 1046 1047 return 0; 1048 } 1049 1050 static int process_progress(struct sk_buff *skb, struct nf_conn *ct, 1051 enum ip_conntrack_info ctinfo, 1052 unsigned int protoff, 1053 unsigned char **data, int dataoff, 1054 Progress_UUIE *progress) 1055 { 1056 int ret; 1057 int i; 1058 1059 pr_debug("nf_ct_q931: Progress\n"); 1060 1061 if (progress->options & eProgress_UUIE_h245Address) { 1062 ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff, 1063 &progress->h245Address); 1064 if (ret < 0) 1065 return -1; 1066 } 1067 1068 if (progress->options & eProgress_UUIE_fastStart) { 1069 for (i = 0; i < progress->fastStart.count; i++) { 1070 ret = process_olc(skb, ct, ctinfo, 1071 protoff, data, dataoff, 1072 &progress->fastStart.item[i]); 1073 if (ret < 0) 1074 return -1; 1075 } 1076 } 1077 1078 return 0; 1079 } 1080 1081 static int process_q931(struct sk_buff *skb, struct nf_conn *ct, 1082 enum ip_conntrack_info ctinfo, 1083 unsigned int protoff, unsigned char **data, int dataoff, 1084 Q931 *q931) 1085 { 1086 H323_UU_PDU *pdu = &q931->UUIE.h323_uu_pdu; 1087 int i; 1088 int ret = 0; 1089 1090 switch (pdu->h323_message_body.choice) { 1091 case eH323_UU_PDU_h323_message_body_setup: 1092 ret = process_setup(skb, ct, ctinfo, protoff, data, dataoff, 1093 &pdu->h323_message_body.setup); 1094 break; 1095 case eH323_UU_PDU_h323_message_body_callProceeding: 1096 ret = process_callproceeding(skb, ct, ctinfo, 1097 protoff, data, dataoff, 1098 &pdu->h323_message_body. 1099 callProceeding); 1100 break; 1101 case eH323_UU_PDU_h323_message_body_connect: 1102 ret = process_connect(skb, ct, ctinfo, protoff, data, dataoff, 1103 &pdu->h323_message_body.connect); 1104 break; 1105 case eH323_UU_PDU_h323_message_body_alerting: 1106 ret = process_alerting(skb, ct, ctinfo, protoff, data, dataoff, 1107 &pdu->h323_message_body.alerting); 1108 break; 1109 case eH323_UU_PDU_h323_message_body_facility: 1110 ret = process_facility(skb, ct, ctinfo, protoff, data, dataoff, 1111 &pdu->h323_message_body.facility); 1112 break; 1113 case eH323_UU_PDU_h323_message_body_progress: 1114 ret = process_progress(skb, ct, ctinfo, protoff, data, dataoff, 1115 &pdu->h323_message_body.progress); 1116 break; 1117 default: 1118 pr_debug("nf_ct_q931: Q.931 signal %d\n", 1119 pdu->h323_message_body.choice); 1120 break; 1121 } 1122 1123 if (ret < 0) 1124 return -1; 1125 1126 if (pdu->options & eH323_UU_PDU_h245Control) { 1127 for (i = 0; i < pdu->h245Control.count; i++) { 1128 ret = process_h245(skb, ct, ctinfo, 1129 protoff, data, dataoff, 1130 &pdu->h245Control.item[i]); 1131 if (ret < 0) 1132 return -1; 1133 } 1134 } 1135 1136 return 0; 1137 } 1138 1139 static int q931_help(struct sk_buff *skb, unsigned int protoff, 1140 struct nf_conn *ct, enum ip_conntrack_info ctinfo) 1141 { 1142 static Q931 q931; 1143 unsigned char *data = NULL; 1144 int datalen; 1145 int dataoff; 1146 int ret; 1147 1148 /* Until there's been traffic both ways, don't look in packets. */ 1149 if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY) 1150 return NF_ACCEPT; 1151 1152 pr_debug("nf_ct_q931: skblen = %u\n", skb->len); 1153 1154 spin_lock_bh(&nf_h323_lock); 1155 1156 /* Process each TPKT */ 1157 while (get_tpkt_data(skb, protoff, ct, ctinfo, 1158 &data, &datalen, &dataoff)) { 1159 pr_debug("nf_ct_q931: TPKT len=%d ", datalen); 1160 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple); 1161 1162 /* Decode Q.931 signal */ 1163 ret = DecodeQ931(data, datalen, &q931); 1164 if (ret < 0) { 1165 pr_debug("nf_ct_q931: decoding error: %s\n", 1166 ret == H323_ERROR_BOUND ? 1167 "out of bound" : "out of range"); 1168 /* We don't drop when decoding error */ 1169 break; 1170 } 1171 1172 /* Process Q.931 signal */ 1173 if (process_q931(skb, ct, ctinfo, protoff, 1174 &data, dataoff, &q931) < 0) 1175 goto drop; 1176 } 1177 1178 spin_unlock_bh(&nf_h323_lock); 1179 return NF_ACCEPT; 1180 1181 drop: 1182 spin_unlock_bh(&nf_h323_lock); 1183 nf_ct_helper_log(skb, ct, "cannot process Q.931 message"); 1184 return NF_DROP; 1185 } 1186 1187 static const struct nf_conntrack_expect_policy q931_exp_policy = { 1188 /* T.120 and H.245 */ 1189 .max_expected = H323_RTP_CHANNEL_MAX * 4 + 4, 1190 .timeout = 240, 1191 }; 1192 1193 static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = { 1194 { 1195 .name = "Q.931", 1196 .me = THIS_MODULE, 1197 .tuple.src.l3num = AF_INET, 1198 .tuple.src.u.tcp.port = cpu_to_be16(Q931_PORT), 1199 .tuple.dst.protonum = IPPROTO_TCP, 1200 .help = q931_help, 1201 .expect_policy = &q931_exp_policy, 1202 }, 1203 { 1204 .name = "Q.931", 1205 .me = THIS_MODULE, 1206 .tuple.src.l3num = AF_INET6, 1207 .tuple.src.u.tcp.port = cpu_to_be16(Q931_PORT), 1208 .tuple.dst.protonum = IPPROTO_TCP, 1209 .help = q931_help, 1210 .expect_policy = &q931_exp_policy, 1211 }, 1212 }; 1213 1214 static unsigned char *get_udp_data(struct sk_buff *skb, unsigned int protoff, 1215 int *datalen) 1216 { 1217 const struct udphdr *uh; 1218 struct udphdr _uh; 1219 int dataoff; 1220 1221 uh = skb_header_pointer(skb, protoff, sizeof(_uh), &_uh); 1222 if (uh == NULL) 1223 return NULL; 1224 dataoff = protoff + sizeof(_uh); 1225 if (dataoff >= skb->len) 1226 return NULL; 1227 *datalen = skb->len - dataoff; 1228 return skb_header_pointer(skb, dataoff, *datalen, h323_buffer); 1229 } 1230 1231 static struct nf_conntrack_expect *find_expect(struct nf_conn *ct, 1232 union nf_inet_addr *addr, 1233 __be16 port) 1234 { 1235 struct net *net = nf_ct_net(ct); 1236 struct nf_conntrack_expect *exp; 1237 struct nf_conntrack_tuple tuple; 1238 1239 memset(&tuple.src.u3, 0, sizeof(tuple.src.u3)); 1240 tuple.src.u.tcp.port = 0; 1241 memcpy(&tuple.dst.u3, addr, sizeof(tuple.dst.u3)); 1242 tuple.dst.u.tcp.port = port; 1243 tuple.dst.protonum = IPPROTO_TCP; 1244 1245 exp = __nf_ct_expect_find(net, nf_ct_zone(ct), &tuple); 1246 if (exp && exp->master == ct) 1247 return exp; 1248 return NULL; 1249 } 1250 1251 static int expect_q931(struct sk_buff *skb, struct nf_conn *ct, 1252 enum ip_conntrack_info ctinfo, 1253 unsigned int protoff, unsigned char **data, 1254 TransportAddress *taddr, int count) 1255 { 1256 struct nf_ct_h323_master *info = nfct_help_data(ct); 1257 int dir = CTINFO2DIR(ctinfo); 1258 int ret = 0; 1259 int i; 1260 __be16 port; 1261 union nf_inet_addr addr; 1262 struct nf_conntrack_expect *exp; 1263 typeof(nat_q931_hook) nat_q931; 1264 1265 /* Look for the first related address */ 1266 for (i = 0; i < count; i++) { 1267 if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) && 1268 memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, 1269 sizeof(addr)) == 0 && port != 0) 1270 break; 1271 } 1272 1273 if (i >= count) /* Not found */ 1274 return 0; 1275 1276 /* Create expect for Q.931 */ 1277 if ((exp = nf_ct_expect_alloc(ct)) == NULL) 1278 return -1; 1279 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), 1280 gkrouted_only ? /* only accept calls from GK? */ 1281 &ct->tuplehash[!dir].tuple.src.u3 : NULL, 1282 &ct->tuplehash[!dir].tuple.dst.u3, 1283 IPPROTO_TCP, NULL, &port); 1284 exp->helper = nf_conntrack_helper_q931; 1285 exp->flags = NF_CT_EXPECT_PERMANENT; /* Accept multiple calls */ 1286 1287 nat_q931 = rcu_dereference(nat_q931_hook); 1288 if (nat_q931 && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1289 ct->status & IPS_NAT_MASK) { /* Need NAT */ 1290 ret = nat_q931(skb, ct, ctinfo, protoff, data, 1291 taddr, i, port, exp); 1292 } else { /* Conntrack only */ 1293 if (nf_ct_expect_related(exp) == 0) { 1294 pr_debug("nf_ct_ras: expect Q.931 "); 1295 nf_ct_dump_tuple(&exp->tuple); 1296 1297 /* Save port for looking up expect in processing RCF */ 1298 info->sig_port[dir] = port; 1299 } else 1300 ret = -1; 1301 } 1302 1303 nf_ct_expect_put(exp); 1304 1305 return ret; 1306 } 1307 1308 static int process_grq(struct sk_buff *skb, struct nf_conn *ct, 1309 enum ip_conntrack_info ctinfo, 1310 unsigned int protoff, 1311 unsigned char **data, GatekeeperRequest *grq) 1312 { 1313 typeof(set_ras_addr_hook) set_ras_addr; 1314 1315 pr_debug("nf_ct_ras: GRQ\n"); 1316 1317 set_ras_addr = rcu_dereference(set_ras_addr_hook); 1318 if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1319 ct->status & IPS_NAT_MASK) /* NATed */ 1320 return set_ras_addr(skb, ct, ctinfo, protoff, data, 1321 &grq->rasAddress, 1); 1322 return 0; 1323 } 1324 1325 static int process_gcf(struct sk_buff *skb, struct nf_conn *ct, 1326 enum ip_conntrack_info ctinfo, 1327 unsigned int protoff, 1328 unsigned char **data, GatekeeperConfirm *gcf) 1329 { 1330 int dir = CTINFO2DIR(ctinfo); 1331 int ret = 0; 1332 __be16 port; 1333 union nf_inet_addr addr; 1334 struct nf_conntrack_expect *exp; 1335 1336 pr_debug("nf_ct_ras: GCF\n"); 1337 1338 if (!get_h225_addr(ct, *data, &gcf->rasAddress, &addr, &port)) 1339 return 0; 1340 1341 /* Registration port is the same as discovery port */ 1342 if (!memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) && 1343 port == ct->tuplehash[dir].tuple.src.u.udp.port) 1344 return 0; 1345 1346 /* Avoid RAS expectation loops. A GCF is never expected. */ 1347 if (test_bit(IPS_EXPECTED_BIT, &ct->status)) 1348 return 0; 1349 1350 /* Need new expect */ 1351 if ((exp = nf_ct_expect_alloc(ct)) == NULL) 1352 return -1; 1353 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), 1354 &ct->tuplehash[!dir].tuple.src.u3, &addr, 1355 IPPROTO_UDP, NULL, &port); 1356 exp->helper = nf_conntrack_helper_ras; 1357 1358 if (nf_ct_expect_related(exp) == 0) { 1359 pr_debug("nf_ct_ras: expect RAS "); 1360 nf_ct_dump_tuple(&exp->tuple); 1361 } else 1362 ret = -1; 1363 1364 nf_ct_expect_put(exp); 1365 1366 return ret; 1367 } 1368 1369 static int process_rrq(struct sk_buff *skb, struct nf_conn *ct, 1370 enum ip_conntrack_info ctinfo, 1371 unsigned int protoff, 1372 unsigned char **data, RegistrationRequest *rrq) 1373 { 1374 struct nf_ct_h323_master *info = nfct_help_data(ct); 1375 int ret; 1376 typeof(set_ras_addr_hook) set_ras_addr; 1377 1378 pr_debug("nf_ct_ras: RRQ\n"); 1379 1380 ret = expect_q931(skb, ct, ctinfo, protoff, data, 1381 rrq->callSignalAddress.item, 1382 rrq->callSignalAddress.count); 1383 if (ret < 0) 1384 return -1; 1385 1386 set_ras_addr = rcu_dereference(set_ras_addr_hook); 1387 if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1388 ct->status & IPS_NAT_MASK) { 1389 ret = set_ras_addr(skb, ct, ctinfo, protoff, data, 1390 rrq->rasAddress.item, 1391 rrq->rasAddress.count); 1392 if (ret < 0) 1393 return -1; 1394 } 1395 1396 if (rrq->options & eRegistrationRequest_timeToLive) { 1397 pr_debug("nf_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive); 1398 info->timeout = rrq->timeToLive; 1399 } else 1400 info->timeout = default_rrq_ttl; 1401 1402 return 0; 1403 } 1404 1405 static int process_rcf(struct sk_buff *skb, struct nf_conn *ct, 1406 enum ip_conntrack_info ctinfo, 1407 unsigned int protoff, 1408 unsigned char **data, RegistrationConfirm *rcf) 1409 { 1410 struct nf_ct_h323_master *info = nfct_help_data(ct); 1411 int dir = CTINFO2DIR(ctinfo); 1412 int ret; 1413 struct nf_conntrack_expect *exp; 1414 typeof(set_sig_addr_hook) set_sig_addr; 1415 1416 pr_debug("nf_ct_ras: RCF\n"); 1417 1418 set_sig_addr = rcu_dereference(set_sig_addr_hook); 1419 if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1420 ct->status & IPS_NAT_MASK) { 1421 ret = set_sig_addr(skb, ct, ctinfo, protoff, data, 1422 rcf->callSignalAddress.item, 1423 rcf->callSignalAddress.count); 1424 if (ret < 0) 1425 return -1; 1426 } 1427 1428 if (rcf->options & eRegistrationConfirm_timeToLive) { 1429 pr_debug("nf_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive); 1430 info->timeout = rcf->timeToLive; 1431 } 1432 1433 if (info->timeout > 0) { 1434 pr_debug("nf_ct_ras: set RAS connection timeout to " 1435 "%u seconds\n", info->timeout); 1436 nf_ct_refresh(ct, skb, info->timeout * HZ); 1437 1438 /* Set expect timeout */ 1439 spin_lock_bh(&nf_conntrack_expect_lock); 1440 exp = find_expect(ct, &ct->tuplehash[dir].tuple.dst.u3, 1441 info->sig_port[!dir]); 1442 if (exp) { 1443 pr_debug("nf_ct_ras: set Q.931 expect " 1444 "timeout to %u seconds for", 1445 info->timeout); 1446 nf_ct_dump_tuple(&exp->tuple); 1447 mod_timer_pending(&exp->timeout, 1448 jiffies + info->timeout * HZ); 1449 } 1450 spin_unlock_bh(&nf_conntrack_expect_lock); 1451 } 1452 1453 return 0; 1454 } 1455 1456 static int process_urq(struct sk_buff *skb, struct nf_conn *ct, 1457 enum ip_conntrack_info ctinfo, 1458 unsigned int protoff, 1459 unsigned char **data, UnregistrationRequest *urq) 1460 { 1461 struct nf_ct_h323_master *info = nfct_help_data(ct); 1462 int dir = CTINFO2DIR(ctinfo); 1463 int ret; 1464 typeof(set_sig_addr_hook) set_sig_addr; 1465 1466 pr_debug("nf_ct_ras: URQ\n"); 1467 1468 set_sig_addr = rcu_dereference(set_sig_addr_hook); 1469 if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1470 ct->status & IPS_NAT_MASK) { 1471 ret = set_sig_addr(skb, ct, ctinfo, protoff, data, 1472 urq->callSignalAddress.item, 1473 urq->callSignalAddress.count); 1474 if (ret < 0) 1475 return -1; 1476 } 1477 1478 /* Clear old expect */ 1479 nf_ct_remove_expectations(ct); 1480 info->sig_port[dir] = 0; 1481 info->sig_port[!dir] = 0; 1482 1483 /* Give it 30 seconds for UCF or URJ */ 1484 nf_ct_refresh(ct, skb, 30 * HZ); 1485 1486 return 0; 1487 } 1488 1489 static int process_arq(struct sk_buff *skb, struct nf_conn *ct, 1490 enum ip_conntrack_info ctinfo, 1491 unsigned int protoff, 1492 unsigned char **data, AdmissionRequest *arq) 1493 { 1494 const struct nf_ct_h323_master *info = nfct_help_data(ct); 1495 int dir = CTINFO2DIR(ctinfo); 1496 __be16 port; 1497 union nf_inet_addr addr; 1498 typeof(set_h225_addr_hook) set_h225_addr; 1499 1500 pr_debug("nf_ct_ras: ARQ\n"); 1501 1502 set_h225_addr = rcu_dereference(set_h225_addr_hook); 1503 if ((arq->options & eAdmissionRequest_destCallSignalAddress) && 1504 get_h225_addr(ct, *data, &arq->destCallSignalAddress, 1505 &addr, &port) && 1506 !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) && 1507 port == info->sig_port[dir] && 1508 nf_ct_l3num(ct) == NFPROTO_IPV4 && 1509 set_h225_addr && ct->status & IPS_NAT_MASK) { 1510 /* Answering ARQ */ 1511 return set_h225_addr(skb, protoff, data, 0, 1512 &arq->destCallSignalAddress, 1513 &ct->tuplehash[!dir].tuple.dst.u3, 1514 info->sig_port[!dir]); 1515 } 1516 1517 if ((arq->options & eAdmissionRequest_srcCallSignalAddress) && 1518 get_h225_addr(ct, *data, &arq->srcCallSignalAddress, 1519 &addr, &port) && 1520 !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) && 1521 set_h225_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1522 ct->status & IPS_NAT_MASK) { 1523 /* Calling ARQ */ 1524 return set_h225_addr(skb, protoff, data, 0, 1525 &arq->srcCallSignalAddress, 1526 &ct->tuplehash[!dir].tuple.dst.u3, 1527 port); 1528 } 1529 1530 return 0; 1531 } 1532 1533 static int process_acf(struct sk_buff *skb, struct nf_conn *ct, 1534 enum ip_conntrack_info ctinfo, 1535 unsigned int protoff, 1536 unsigned char **data, AdmissionConfirm *acf) 1537 { 1538 int dir = CTINFO2DIR(ctinfo); 1539 int ret = 0; 1540 __be16 port; 1541 union nf_inet_addr addr; 1542 struct nf_conntrack_expect *exp; 1543 typeof(set_sig_addr_hook) set_sig_addr; 1544 1545 pr_debug("nf_ct_ras: ACF\n"); 1546 1547 if (!get_h225_addr(ct, *data, &acf->destCallSignalAddress, 1548 &addr, &port)) 1549 return 0; 1550 1551 if (!memcmp(&addr, &ct->tuplehash[dir].tuple.dst.u3, sizeof(addr))) { 1552 /* Answering ACF */ 1553 set_sig_addr = rcu_dereference(set_sig_addr_hook); 1554 if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1555 ct->status & IPS_NAT_MASK) 1556 return set_sig_addr(skb, ct, ctinfo, protoff, data, 1557 &acf->destCallSignalAddress, 1); 1558 return 0; 1559 } 1560 1561 /* Need new expect */ 1562 if ((exp = nf_ct_expect_alloc(ct)) == NULL) 1563 return -1; 1564 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), 1565 &ct->tuplehash[!dir].tuple.src.u3, &addr, 1566 IPPROTO_TCP, NULL, &port); 1567 exp->flags = NF_CT_EXPECT_PERMANENT; 1568 exp->helper = nf_conntrack_helper_q931; 1569 1570 if (nf_ct_expect_related(exp) == 0) { 1571 pr_debug("nf_ct_ras: expect Q.931 "); 1572 nf_ct_dump_tuple(&exp->tuple); 1573 } else 1574 ret = -1; 1575 1576 nf_ct_expect_put(exp); 1577 1578 return ret; 1579 } 1580 1581 static int process_lrq(struct sk_buff *skb, struct nf_conn *ct, 1582 enum ip_conntrack_info ctinfo, 1583 unsigned int protoff, 1584 unsigned char **data, LocationRequest *lrq) 1585 { 1586 typeof(set_ras_addr_hook) set_ras_addr; 1587 1588 pr_debug("nf_ct_ras: LRQ\n"); 1589 1590 set_ras_addr = rcu_dereference(set_ras_addr_hook); 1591 if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1592 ct->status & IPS_NAT_MASK) 1593 return set_ras_addr(skb, ct, ctinfo, protoff, data, 1594 &lrq->replyAddress, 1); 1595 return 0; 1596 } 1597 1598 static int process_lcf(struct sk_buff *skb, struct nf_conn *ct, 1599 enum ip_conntrack_info ctinfo, 1600 unsigned int protoff, 1601 unsigned char **data, LocationConfirm *lcf) 1602 { 1603 int dir = CTINFO2DIR(ctinfo); 1604 int ret = 0; 1605 __be16 port; 1606 union nf_inet_addr addr; 1607 struct nf_conntrack_expect *exp; 1608 1609 pr_debug("nf_ct_ras: LCF\n"); 1610 1611 if (!get_h225_addr(ct, *data, &lcf->callSignalAddress, 1612 &addr, &port)) 1613 return 0; 1614 1615 /* Need new expect for call signal */ 1616 if ((exp = nf_ct_expect_alloc(ct)) == NULL) 1617 return -1; 1618 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), 1619 &ct->tuplehash[!dir].tuple.src.u3, &addr, 1620 IPPROTO_TCP, NULL, &port); 1621 exp->flags = NF_CT_EXPECT_PERMANENT; 1622 exp->helper = nf_conntrack_helper_q931; 1623 1624 if (nf_ct_expect_related(exp) == 0) { 1625 pr_debug("nf_ct_ras: expect Q.931 "); 1626 nf_ct_dump_tuple(&exp->tuple); 1627 } else 1628 ret = -1; 1629 1630 nf_ct_expect_put(exp); 1631 1632 /* Ignore rasAddress */ 1633 1634 return ret; 1635 } 1636 1637 static int process_irr(struct sk_buff *skb, struct nf_conn *ct, 1638 enum ip_conntrack_info ctinfo, 1639 unsigned int protoff, 1640 unsigned char **data, InfoRequestResponse *irr) 1641 { 1642 int ret; 1643 typeof(set_ras_addr_hook) set_ras_addr; 1644 typeof(set_sig_addr_hook) set_sig_addr; 1645 1646 pr_debug("nf_ct_ras: IRR\n"); 1647 1648 set_ras_addr = rcu_dereference(set_ras_addr_hook); 1649 if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1650 ct->status & IPS_NAT_MASK) { 1651 ret = set_ras_addr(skb, ct, ctinfo, protoff, data, 1652 &irr->rasAddress, 1); 1653 if (ret < 0) 1654 return -1; 1655 } 1656 1657 set_sig_addr = rcu_dereference(set_sig_addr_hook); 1658 if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 && 1659 ct->status & IPS_NAT_MASK) { 1660 ret = set_sig_addr(skb, ct, ctinfo, protoff, data, 1661 irr->callSignalAddress.item, 1662 irr->callSignalAddress.count); 1663 if (ret < 0) 1664 return -1; 1665 } 1666 1667 return 0; 1668 } 1669 1670 static int process_ras(struct sk_buff *skb, struct nf_conn *ct, 1671 enum ip_conntrack_info ctinfo, 1672 unsigned int protoff, 1673 unsigned char **data, RasMessage *ras) 1674 { 1675 switch (ras->choice) { 1676 case eRasMessage_gatekeeperRequest: 1677 return process_grq(skb, ct, ctinfo, protoff, data, 1678 &ras->gatekeeperRequest); 1679 case eRasMessage_gatekeeperConfirm: 1680 return process_gcf(skb, ct, ctinfo, protoff, data, 1681 &ras->gatekeeperConfirm); 1682 case eRasMessage_registrationRequest: 1683 return process_rrq(skb, ct, ctinfo, protoff, data, 1684 &ras->registrationRequest); 1685 case eRasMessage_registrationConfirm: 1686 return process_rcf(skb, ct, ctinfo, protoff, data, 1687 &ras->registrationConfirm); 1688 case eRasMessage_unregistrationRequest: 1689 return process_urq(skb, ct, ctinfo, protoff, data, 1690 &ras->unregistrationRequest); 1691 case eRasMessage_admissionRequest: 1692 return process_arq(skb, ct, ctinfo, protoff, data, 1693 &ras->admissionRequest); 1694 case eRasMessage_admissionConfirm: 1695 return process_acf(skb, ct, ctinfo, protoff, data, 1696 &ras->admissionConfirm); 1697 case eRasMessage_locationRequest: 1698 return process_lrq(skb, ct, ctinfo, protoff, data, 1699 &ras->locationRequest); 1700 case eRasMessage_locationConfirm: 1701 return process_lcf(skb, ct, ctinfo, protoff, data, 1702 &ras->locationConfirm); 1703 case eRasMessage_infoRequestResponse: 1704 return process_irr(skb, ct, ctinfo, protoff, data, 1705 &ras->infoRequestResponse); 1706 default: 1707 pr_debug("nf_ct_ras: RAS message %d\n", ras->choice); 1708 break; 1709 } 1710 1711 return 0; 1712 } 1713 1714 static int ras_help(struct sk_buff *skb, unsigned int protoff, 1715 struct nf_conn *ct, enum ip_conntrack_info ctinfo) 1716 { 1717 static RasMessage ras; 1718 unsigned char *data; 1719 int datalen = 0; 1720 int ret; 1721 1722 pr_debug("nf_ct_ras: skblen = %u\n", skb->len); 1723 1724 spin_lock_bh(&nf_h323_lock); 1725 1726 /* Get UDP data */ 1727 data = get_udp_data(skb, protoff, &datalen); 1728 if (data == NULL) 1729 goto accept; 1730 pr_debug("nf_ct_ras: RAS message len=%d ", datalen); 1731 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple); 1732 1733 /* Decode RAS message */ 1734 ret = DecodeRasMessage(data, datalen, &ras); 1735 if (ret < 0) { 1736 pr_debug("nf_ct_ras: decoding error: %s\n", 1737 ret == H323_ERROR_BOUND ? 1738 "out of bound" : "out of range"); 1739 goto accept; 1740 } 1741 1742 /* Process RAS message */ 1743 if (process_ras(skb, ct, ctinfo, protoff, &data, &ras) < 0) 1744 goto drop; 1745 1746 accept: 1747 spin_unlock_bh(&nf_h323_lock); 1748 return NF_ACCEPT; 1749 1750 drop: 1751 spin_unlock_bh(&nf_h323_lock); 1752 nf_ct_helper_log(skb, ct, "cannot process RAS message"); 1753 return NF_DROP; 1754 } 1755 1756 static const struct nf_conntrack_expect_policy ras_exp_policy = { 1757 .max_expected = 32, 1758 .timeout = 240, 1759 }; 1760 1761 static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = { 1762 { 1763 .name = "RAS", 1764 .me = THIS_MODULE, 1765 .tuple.src.l3num = AF_INET, 1766 .tuple.src.u.udp.port = cpu_to_be16(RAS_PORT), 1767 .tuple.dst.protonum = IPPROTO_UDP, 1768 .help = ras_help, 1769 .expect_policy = &ras_exp_policy, 1770 }, 1771 { 1772 .name = "RAS", 1773 .me = THIS_MODULE, 1774 .tuple.src.l3num = AF_INET6, 1775 .tuple.src.u.udp.port = cpu_to_be16(RAS_PORT), 1776 .tuple.dst.protonum = IPPROTO_UDP, 1777 .help = ras_help, 1778 .expect_policy = &ras_exp_policy, 1779 }, 1780 }; 1781 1782 static int __init h323_helper_init(void) 1783 { 1784 int ret; 1785 1786 ret = nf_conntrack_helper_register(&nf_conntrack_helper_h245); 1787 if (ret < 0) 1788 return ret; 1789 ret = nf_conntrack_helpers_register(nf_conntrack_helper_q931, 1790 ARRAY_SIZE(nf_conntrack_helper_q931)); 1791 if (ret < 0) 1792 goto err1; 1793 ret = nf_conntrack_helpers_register(nf_conntrack_helper_ras, 1794 ARRAY_SIZE(nf_conntrack_helper_ras)); 1795 if (ret < 0) 1796 goto err2; 1797 1798 return 0; 1799 err2: 1800 nf_conntrack_helpers_unregister(nf_conntrack_helper_q931, 1801 ARRAY_SIZE(nf_conntrack_helper_q931)); 1802 err1: 1803 nf_conntrack_helper_unregister(&nf_conntrack_helper_h245); 1804 return ret; 1805 } 1806 1807 static void __exit h323_helper_exit(void) 1808 { 1809 nf_conntrack_helpers_unregister(nf_conntrack_helper_ras, 1810 ARRAY_SIZE(nf_conntrack_helper_ras)); 1811 nf_conntrack_helpers_unregister(nf_conntrack_helper_q931, 1812 ARRAY_SIZE(nf_conntrack_helper_q931)); 1813 nf_conntrack_helper_unregister(&nf_conntrack_helper_h245); 1814 } 1815 1816 static void __exit nf_conntrack_h323_fini(void) 1817 { 1818 h323_helper_exit(); 1819 kfree(h323_buffer); 1820 pr_debug("nf_ct_h323: fini\n"); 1821 } 1822 1823 static int __init nf_conntrack_h323_init(void) 1824 { 1825 int ret; 1826 1827 NF_CT_HELPER_BUILD_BUG_ON(sizeof(struct nf_ct_h323_master)); 1828 1829 h323_buffer = kmalloc(65536, GFP_KERNEL); 1830 if (!h323_buffer) 1831 return -ENOMEM; 1832 ret = h323_helper_init(); 1833 if (ret < 0) 1834 goto err1; 1835 pr_debug("nf_ct_h323: init success\n"); 1836 return 0; 1837 err1: 1838 kfree(h323_buffer); 1839 return ret; 1840 } 1841 1842 module_init(nf_conntrack_h323_init); 1843 module_exit(nf_conntrack_h323_fini); 1844 1845 EXPORT_SYMBOL_GPL(get_h225_addr); 1846 EXPORT_SYMBOL_GPL(set_h245_addr_hook); 1847 EXPORT_SYMBOL_GPL(set_h225_addr_hook); 1848 EXPORT_SYMBOL_GPL(set_sig_addr_hook); 1849 EXPORT_SYMBOL_GPL(set_ras_addr_hook); 1850 EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook); 1851 EXPORT_SYMBOL_GPL(nat_t120_hook); 1852 EXPORT_SYMBOL_GPL(nat_h245_hook); 1853 EXPORT_SYMBOL_GPL(nat_callforwarding_hook); 1854 EXPORT_SYMBOL_GPL(nat_q931_hook); 1855 1856 MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>"); 1857 MODULE_DESCRIPTION("H.323 connection tracking helper"); 1858 MODULE_LICENSE("GPL"); 1859 MODULE_ALIAS("ip_conntrack_h323"); 1860 MODULE_ALIAS_NFCT_HELPER("RAS"); 1861 MODULE_ALIAS_NFCT_HELPER("Q.931"); 1862 MODULE_ALIAS_NFCT_HELPER("H.245"); 1863