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gerrit-public.fairphone.software / kernel / msm-4.9 / cd090eedd85256829f762677d0752a846c1b88b9 / . / net / ipv4 / netfilter / ip_conntrack_helper_h323.c
blob: daeb1395faa4db85096a108489b70645d9c9955b [file] [log] [blame]
Jing Min Zhao5e35941d2006-03-20 23:41:17 -0800[diff] [blame]1/*
2 * H.323 connection tracking helper
3 *
4 * Copyright (c) 2006 Jing Min Zhao <zhaojingmin@users.sourceforge.net>
5 *
6 * This source code is licensed under General Public License version 2.
7 *
8 * Based on the 'brute force' H.323 connection tracking module by
9 * Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
10 *
11 * For more information, please see http://nath323.sourceforge.net/
12 *
13 * Changes:
14 * 2006-02-01 - initial version 0.1
15 *
16 * 2006-02-20 - version 0.2
17 * 1. Changed source format to follow kernel conventions
18 * 2. Deleted some unnecessary structures
19 * 3. Minor fixes
20 *
21 * 2006-03-10 - version 0.3
22 * 1. Added support for multiple TPKTs in one packet (suggested by
23 * Patrick McHardy)
24 * 2. Avoid excessive stack usage (based on Patrick McHardy's patch)
25 * 3. Added support for non-linear skb (based on Patrick McHardy's patch)
26 * 4. Fixed missing H.245 module owner (Patrick McHardy)
27 * 5. Avoid long RAS expectation chains (Patrick McHardy)
28 * 6. Fixed incorrect __exit attribute (Patrick McHardy)
29 * 7. Eliminated unnecessary return code
30 * 8. Fixed incorrect use of NAT data from conntrack code (suggested by
31 * Patrick McHardy)
32 * 9. Fixed TTL calculation error in RCF
33 * 10. Added TTL support in RRQ
34 * 11. Better support for separate TPKT header and data
35 *
36 * 2006-03-15 - version 0.4
37 * 1. Added support for T.120 channels
38 * 2. Added parameter gkrouted_only (suggested by Patrick McHardy)
39 * 3. Splitted ASN.1 code and data (suggested by Patrick McHardy)
40 * 4. Sort ASN.1 data to avoid forwarding declarations (suggested by
41 * Patrick McHardy)
42 * 5. Reset next TPKT data length in get_tpkt_data()
43 */
44
45#include <linux/config.h>
46#include <linux/module.h>
47#include <linux/netfilter.h>
48#include <linux/ip.h>
49#include <net/tcp.h>
50#include <linux/netfilter_ipv4/ip_conntrack.h>
51#include <linux/netfilter_ipv4/ip_conntrack_core.h>
52#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
53#include <linux/netfilter_ipv4/ip_conntrack_tuple.h>
54#include <linux/netfilter_ipv4/ip_conntrack_h323.h>
55#include <linux/moduleparam.h>
56
57#include "ip_conntrack_helper_h323_asn1.h"
58
59#if 0
60#define DEBUGP printk
61#else
62#define DEBUGP(format, args...)
63#endif
64
65/* Parameters */
66static int gkrouted_only = 1;
67module_param(gkrouted_only, int, 0600);
68MODULE_PARM_DESC(gkrouted_only, "only accept calls from gatekeeper");
69
70/* Hooks for NAT */
71int (*set_h245_addr_hook) (struct sk_buff ** pskb,
72 unsigned char **data, int dataoff,
73 H245_TransportAddress * addr,
74 u_int32_t ip, u_int16_t port);
75int (*set_h225_addr_hook) (struct sk_buff ** pskb,
76 unsigned char **data, int dataoff,
77 TransportAddress * addr,
78 u_int32_t ip, u_int16_t port);
79int (*set_sig_addr_hook) (struct sk_buff ** pskb,
80 struct ip_conntrack * ct,
81 enum ip_conntrack_info ctinfo,
82 unsigned char **data,
83 TransportAddress * addr, int count);
84int (*set_ras_addr_hook) (struct sk_buff ** pskb,
85 struct ip_conntrack * ct,
86 enum ip_conntrack_info ctinfo,
87 unsigned char **data,
88 TransportAddress * addr, int count);
89int (*nat_rtp_rtcp_hook) (struct sk_buff ** pskb,
90 struct ip_conntrack * ct,
91 enum ip_conntrack_info ctinfo,
92 unsigned char **data, int dataoff,
93 H245_TransportAddress * addr,
94 u_int16_t port, u_int16_t rtp_port,
95 struct ip_conntrack_expect * rtp_exp,
96 struct ip_conntrack_expect * rtcp_exp);
97int (*nat_t120_hook) (struct sk_buff ** pskb,
98 struct ip_conntrack * ct,
99 enum ip_conntrack_info ctinfo,
100 unsigned char **data, int dataoff,
101 H245_TransportAddress * addr, u_int16_t port,
102 struct ip_conntrack_expect * exp);
103int (*nat_h245_hook) (struct sk_buff ** pskb,
104 struct ip_conntrack * ct,
105 enum ip_conntrack_info ctinfo,
106 unsigned char **data, int dataoff,
107 TransportAddress * addr, u_int16_t port,
108 struct ip_conntrack_expect * exp);
109int (*nat_q931_hook) (struct sk_buff ** pskb,
110 struct ip_conntrack * ct,
111 enum ip_conntrack_info ctinfo,
112 unsigned char **data, TransportAddress * addr, int idx,
113 u_int16_t port, struct ip_conntrack_expect * exp);
114
115
116static DEFINE_SPINLOCK(ip_h323_lock);
117static char *h323_buffer;
118
119/****************************************************************************/
120static int get_tpkt_data(struct sk_buff **pskb, struct ip_conntrack *ct,
121 enum ip_conntrack_info ctinfo,
122 unsigned char **data, int *datalen, int *dataoff)
123{
124 struct ip_ct_h323_master *info = &ct->help.ct_h323_info;
125 int dir = CTINFO2DIR(ctinfo);
126 struct tcphdr _tcph, *th;
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(*pskb, (*pskb)->nh.iph->ihl * 4,
135 sizeof(_tcph), &_tcph);
136 if (th == NULL)
137 return 0;
138
139 /* Get TCP data offset */
140 tcpdataoff = (*pskb)->nh.iph->ihl * 4 + th->doff * 4;
141
142 /* Get TCP data length */
143 tcpdatalen = (*pskb)->len - tcpdataoff;
144 if (tcpdatalen <= 0) /* No TCP data */
145 goto clear_out;
146
147 if (*data == NULL) { /* first TPKT */
148 /* Get first TPKT pointer */
149 tpkt = skb_header_pointer(*pskb, tcpdataoff, tcpdatalen,
150 h323_buffer);
151 BUG_ON(tpkt == NULL);
152
153 /* Validate TPKT identifier */
154 if (tcpdatalen < 4 || tpkt[0] != 0x03 || tpkt[1] != 0) {
155 /* Netmeeting sends TPKT header and data separately */
156 if (info->tpkt_len[dir] > 0) {
157 DEBUGP("ip_ct_h323: previous packet "
158 "indicated separate TPKT data of %hu "
159 "bytes\n", info->tpkt_len[dir]);
160 if (info->tpkt_len[dir] <= tcpdatalen) {
161 /* Yes, there was a TPKT header
162 * received */
163 *data = tpkt;
164 *datalen = info->tpkt_len[dir];
165 *dataoff = 0;
166 goto out;
167 }
168
169 /* Fragmented TPKT */
170 if (net_ratelimit())
171 printk("ip_ct_h323: "
172 "fragmented TPKT\n");
173 goto clear_out;
174 }
175
176 /* It is not even a TPKT */
177 return 0;
178 }
179 tpktoff = 0;
180 } else { /* Next TPKT */
181 tpktoff = *dataoff + *datalen;
182 tcpdatalen -= tpktoff;
183 if (tcpdatalen <= 4) /* No more TPKT */
184 goto clear_out;
185 tpkt = *data + *datalen;
186
187 /* Validate TPKT identifier */
188 if (tpkt[0] != 0x03 || tpkt[1] != 0)
189 goto clear_out;
190 }
191
192 /* Validate TPKT length */
193 tpktlen = tpkt[2] * 256 + tpkt[3];
194 if (tpktlen > tcpdatalen) {
195 if (tcpdatalen == 4) { /* Separate TPKT header */
196 /* Netmeeting sends TPKT header and data separately */
197 DEBUGP("ip_ct_h323: separate TPKT header indicates "
198 "there will be TPKT data of %hu bytes\n",
199 tpktlen - 4);
200 info->tpkt_len[dir] = tpktlen - 4;
201 return 0;
202 }
203
204 if (net_ratelimit())
205 printk("ip_ct_h323: incomplete TPKT (fragmented?)\n");
206 goto clear_out;
207 }
208
209 /* This is the encapsulated data */
210 *data = tpkt + 4;
211 *datalen = tpktlen - 4;
212 *dataoff = tpktoff + 4;
213
214 out:
215 /* Clear TPKT length */
216 info->tpkt_len[dir] = 0;
217 return 1;
218
219 clear_out:
220 info->tpkt_len[dir] = 0;
221 return 0;
222}
223
224/****************************************************************************/
225int get_h245_addr(unsigned char *data, H245_TransportAddress * addr,
226 u_int32_t * ip, u_int16_t * port)
227{
228 unsigned char *p;
229
230 if (addr->choice != eH245_TransportAddress_unicastAddress ||
231 addr->unicastAddress.choice != eUnicastAddress_iPAddress)
232 return 0;
233
234 p = data + addr->unicastAddress.iPAddress.network;
235 *ip = htonl((p[0] << 24) | (p[1] << 16) | (p[2] << 8) | (p[3]));
236 *port = (p[4] << 8) | (p[5]);
237
238 return 1;
239}
240
241/****************************************************************************/
242static int expect_rtp_rtcp(struct sk_buff **pskb, struct ip_conntrack *ct,
243 enum ip_conntrack_info ctinfo,
244 unsigned char **data, int dataoff,
245 H245_TransportAddress * addr)
246{
247 int dir = CTINFO2DIR(ctinfo);
248 int ret = 0;
249 u_int32_t ip;
250 u_int16_t port;
251 u_int16_t rtp_port;
252 struct ip_conntrack_expect *rtp_exp;
253 struct ip_conntrack_expect *rtcp_exp;
254
255 /* Read RTP or RTCP address */
256 if (!get_h245_addr(*data, addr, &ip, &port) ||
257 ip != ct->tuplehash[dir].tuple.src.ip || port == 0)
258 return 0;
259
260 /* RTP port is even */
261 rtp_port = port & (~1);
262
263 /* Create expect for RTP */
264 if ((rtp_exp = ip_conntrack_expect_alloc(ct)) == NULL)
265 return -1;
266 rtp_exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip;
267 rtp_exp->tuple.src.u.udp.port = 0;
268 rtp_exp->tuple.dst.ip = ct->tuplehash[!dir].tuple.dst.ip;
269 rtp_exp->tuple.dst.u.udp.port = htons(rtp_port);
270 rtp_exp->tuple.dst.protonum = IPPROTO_UDP;
271 rtp_exp->mask.src.ip = 0xFFFFFFFF;
272 rtp_exp->mask.src.u.udp.port = 0;
273 rtp_exp->mask.dst.ip = 0xFFFFFFFF;
274 rtp_exp->mask.dst.u.udp.port = 0xFFFF;
275 rtp_exp->mask.dst.protonum = 0xFF;
276 rtp_exp->flags = 0;
277
278 /* Create expect for RTCP */
279 if ((rtcp_exp = ip_conntrack_expect_alloc(ct)) == NULL) {
280 ip_conntrack_expect_put(rtp_exp);
281 return -1;
282 }
283 rtcp_exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip;
284 rtcp_exp->tuple.src.u.udp.port = 0;
285 rtcp_exp->tuple.dst.ip = ct->tuplehash[!dir].tuple.dst.ip;
286 rtcp_exp->tuple.dst.u.udp.port = htons(rtp_port + 1);
287 rtcp_exp->tuple.dst.protonum = IPPROTO_UDP;
288 rtcp_exp->mask.src.ip = 0xFFFFFFFF;
289 rtcp_exp->mask.src.u.udp.port = 0;
290 rtcp_exp->mask.dst.ip = 0xFFFFFFFF;
291 rtcp_exp->mask.dst.u.udp.port = 0xFFFF;
292 rtcp_exp->mask.dst.protonum = 0xFF;
293 rtcp_exp->flags = 0;
294
295 if (ct->tuplehash[dir].tuple.src.ip !=
296 ct->tuplehash[!dir].tuple.dst.ip && nat_rtp_rtcp_hook) {
297 /* NAT needed */
298 ret = nat_rtp_rtcp_hook(pskb, ct, ctinfo, data, dataoff,
299 addr, port, rtp_port, rtp_exp,
300 rtcp_exp);
301 } else { /* Conntrack only */
302 rtp_exp->expectfn = NULL;
303 rtcp_exp->expectfn = NULL;
304
305 if (ip_conntrack_expect_related(rtp_exp) == 0) {
306 if (ip_conntrack_expect_related(rtcp_exp) == 0) {
307 DEBUGP("ip_ct_h323: expect RTP "
308 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
309 NIPQUAD(rtp_exp->tuple.src.ip),
310 ntohs(rtp_exp->tuple.src.u.udp.port),
311 NIPQUAD(rtp_exp->tuple.dst.ip),
312 ntohs(rtp_exp->tuple.dst.u.udp.port));
313 DEBUGP("ip_ct_h323: expect RTCP "
314 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
315 NIPQUAD(rtcp_exp->tuple.src.ip),
316 ntohs(rtcp_exp->tuple.src.u.udp.port),
317 NIPQUAD(rtcp_exp->tuple.dst.ip),
318 ntohs(rtcp_exp->tuple.dst.u.udp.port));
319 } else {
320 ip_conntrack_unexpect_related(rtp_exp);
321 ret = -1;
322 }
323 } else
324 ret = -1;
325 }
326
327 ip_conntrack_expect_put(rtp_exp);
328 ip_conntrack_expect_put(rtcp_exp);
329
330 return ret;
331}
332
333/****************************************************************************/
334static int expect_t120(struct sk_buff **pskb,
335 struct ip_conntrack *ct,
336 enum ip_conntrack_info ctinfo,
337 unsigned char **data, int dataoff,
338 H245_TransportAddress * addr)
339{
340 int dir = CTINFO2DIR(ctinfo);
341 int ret = 0;
342 u_int32_t ip;
343 u_int16_t port;
344 struct ip_conntrack_expect *exp = NULL;
345
346 /* Read T.120 address */
347 if (!get_h245_addr(*data, addr, &ip, &port) ||
348 ip != ct->tuplehash[dir].tuple.src.ip || port == 0)
349 return 0;
350
351 /* Create expect for T.120 connections */
352 if ((exp = ip_conntrack_expect_alloc(ct)) == NULL)
353 return -1;
354 exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip;
355 exp->tuple.src.u.tcp.port = 0;
356 exp->tuple.dst.ip = ct->tuplehash[!dir].tuple.dst.ip;
357 exp->tuple.dst.u.tcp.port = htons(port);
358 exp->tuple.dst.protonum = IPPROTO_TCP;
359 exp->mask.src.ip = 0xFFFFFFFF;
360 exp->mask.src.u.tcp.port = 0;
361 exp->mask.dst.ip = 0xFFFFFFFF;
362 exp->mask.dst.u.tcp.port = 0xFFFF;
363 exp->mask.dst.protonum = 0xFF;
364 exp->flags = IP_CT_EXPECT_PERMANENT; /* Accept multiple channels */
365
366 if (ct->tuplehash[dir].tuple.src.ip !=
367 ct->tuplehash[!dir].tuple.dst.ip && nat_t120_hook) {
368 /* NAT needed */
369 ret = nat_t120_hook(pskb, ct, ctinfo, data, dataoff, addr,
370 port, exp);
371 } else { /* Conntrack only */
372 exp->expectfn = NULL;
373 if (ip_conntrack_expect_related(exp) == 0) {
374 DEBUGP("ip_ct_h323: expect T.120 "
375 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
376 NIPQUAD(exp->tuple.src.ip),
377 ntohs(exp->tuple.src.u.tcp.port),
378 NIPQUAD(exp->tuple.dst.ip),
379 ntohs(exp->tuple.dst.u.tcp.port));
380 } else
381 ret = -1;
382 }
383
384 ip_conntrack_expect_put(exp);
385
386 return ret;
387}
388
389/****************************************************************************/
390static int process_h245_channel(struct sk_buff **pskb,
391 struct ip_conntrack *ct,
392 enum ip_conntrack_info ctinfo,
393 unsigned char **data, int dataoff,
394 H2250LogicalChannelParameters * channel)
395{
396 int ret;
397
398 if (channel->options & eH2250LogicalChannelParameters_mediaChannel) {
399 /* RTP */
400 ret = expect_rtp_rtcp(pskb, ct, ctinfo, data, dataoff,
401 &channel->mediaChannel);
402 if (ret < 0)
403 return -1;
404 }
405
406 if (channel->
407 options & eH2250LogicalChannelParameters_mediaControlChannel) {
408 /* RTCP */
409 ret = expect_rtp_rtcp(pskb, ct, ctinfo, data, dataoff,
410 &channel->mediaControlChannel);
411 if (ret < 0)
412 return -1;
413 }
414
415 return 0;
416}
417
418/****************************************************************************/
419static int process_olc(struct sk_buff **pskb, struct ip_conntrack *ct,
420 enum ip_conntrack_info ctinfo,
421 unsigned char **data, int dataoff,
422 OpenLogicalChannel * olc)
423{
424 int ret;
425
426 DEBUGP("ip_ct_h323: OpenLogicalChannel\n");
427
428 if (olc->forwardLogicalChannelParameters.multiplexParameters.choice ==
429 eOpenLogicalChannel_forwardLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters)
430 {
431 ret = process_h245_channel(pskb, ct, ctinfo, data, dataoff,
432 &olc->
433 forwardLogicalChannelParameters.
434 multiplexParameters.
435 h2250LogicalChannelParameters);
436 if (ret < 0)
437 return -1;
438 }
439
440 if ((olc->options &
441 eOpenLogicalChannel_reverseLogicalChannelParameters) &&
442 (olc->reverseLogicalChannelParameters.options &
443 eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters)
444 && (olc->reverseLogicalChannelParameters.multiplexParameters.
445 choice ==
446 eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
447 {
448 ret =
449 process_h245_channel(pskb, ct, ctinfo, data, dataoff,
450 &olc->
451 reverseLogicalChannelParameters.
452 multiplexParameters.
453 h2250LogicalChannelParameters);
454 if (ret < 0)
455 return -1;
456 }
457
458 if ((olc->options & eOpenLogicalChannel_separateStack) &&
459 olc->forwardLogicalChannelParameters.dataType.choice ==
460 eDataType_data &&
461 olc->forwardLogicalChannelParameters.dataType.data.application.
462 choice == eDataApplicationCapability_application_t120 &&
463 olc->forwardLogicalChannelParameters.dataType.data.application.
464 t120.choice == eDataProtocolCapability_separateLANStack &&
465 olc->separateStack.networkAddress.choice ==
466 eNetworkAccessParameters_networkAddress_localAreaAddress) {
467 ret = expect_t120(pskb, ct, ctinfo, data, dataoff,
468 &olc->separateStack.networkAddress.
469 localAreaAddress);
470 if (ret < 0)
471 return -1;
472 }
473
474 return 0;
475}
476
477/****************************************************************************/
478static int process_olca(struct sk_buff **pskb, struct ip_conntrack *ct,
479 enum ip_conntrack_info ctinfo,
480 unsigned char **data, int dataoff,
481 OpenLogicalChannelAck * olca)
482{
483 H2250LogicalChannelAckParameters *ack;
484 int ret;
485
486 DEBUGP("ip_ct_h323: OpenLogicalChannelAck\n");
487
488 if ((olca->options &
489 eOpenLogicalChannelAck_reverseLogicalChannelParameters) &&
490 (olca->reverseLogicalChannelParameters.options &
491 eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters)
492 && (olca->reverseLogicalChannelParameters.multiplexParameters.
493 choice ==
494 eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
495 {
496 ret = process_h245_channel(pskb, ct, ctinfo, data, dataoff,
497 &olca->
498 reverseLogicalChannelParameters.
499 multiplexParameters.
500 h2250LogicalChannelParameters);
501 if (ret < 0)
502 return -1;
503 }
504
505 if ((olca->options &
506 eOpenLogicalChannelAck_forwardMultiplexAckParameters) &&
507 (olca->forwardMultiplexAckParameters.choice ==
508 eOpenLogicalChannelAck_forwardMultiplexAckParameters_h2250LogicalChannelAckParameters))
509 {
510 ack = &olca->forwardMultiplexAckParameters.
511 h2250LogicalChannelAckParameters;
512 if (ack->options &
513 eH2250LogicalChannelAckParameters_mediaChannel) {
514 /* RTP */
515 ret = expect_rtp_rtcp(pskb, ct, ctinfo, data, dataoff,
516 &ack->mediaChannel);
517 if (ret < 0)
518 return -1;
519 }
520
521 if (ack->options &
522 eH2250LogicalChannelAckParameters_mediaControlChannel) {
523 /* RTCP */
524 ret = expect_rtp_rtcp(pskb, ct, ctinfo, data, dataoff,
525 &ack->mediaControlChannel);
526 if (ret < 0)
527 return -1;
528 }
529 }
530
531 return 0;
532}
533
534/****************************************************************************/
535static int process_h245(struct sk_buff **pskb, struct ip_conntrack *ct,
536 enum ip_conntrack_info ctinfo,
537 unsigned char **data, int dataoff,
538 MultimediaSystemControlMessage * mscm)
539{
540 switch (mscm->choice) {
541 case eMultimediaSystemControlMessage_request:
542 if (mscm->request.choice ==
543 eRequestMessage_openLogicalChannel) {
544 return process_olc(pskb, ct, ctinfo, data, dataoff,
545 &mscm->request.openLogicalChannel);
546 }
547 DEBUGP("ip_ct_h323: H.245 Request %d\n",
548 mscm->request.choice);
549 break;
550 case eMultimediaSystemControlMessage_response:
551 if (mscm->response.choice ==
552 eResponseMessage_openLogicalChannelAck) {
553 return process_olca(pskb, ct, ctinfo, data, dataoff,
554 &mscm->response.
555 openLogicalChannelAck);
556 }
557 DEBUGP("ip_ct_h323: H.245 Response %d\n",
558 mscm->response.choice);
559 break;
560 default:
561 DEBUGP("ip_ct_h323: H.245 signal %d\n", mscm->choice);
562 break;
563 }
564
565 return 0;
566}
567
568/****************************************************************************/
569static int h245_help(struct sk_buff **pskb, struct ip_conntrack *ct,
570 enum ip_conntrack_info ctinfo)
571{
572 static MultimediaSystemControlMessage mscm;
573 unsigned char *data = NULL;
574 int datalen;
575 int dataoff;
576 int ret;
577
578 /* Until there's been traffic both ways, don't look in packets. */
579 if (ctinfo != IP_CT_ESTABLISHED
580 && ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) {
581 return NF_ACCEPT;
582 }
583 DEBUGP("ip_ct_h245: skblen = %u\n", (*pskb)->len);
584
585 spin_lock_bh(&ip_h323_lock);
586
587 /* Process each TPKT */
588 while (get_tpkt_data(pskb, ct, ctinfo, &data, &datalen, &dataoff)) {
589 DEBUGP("ip_ct_h245: TPKT %u.%u.%u.%u->%u.%u.%u.%u, len=%d\n",
590 NIPQUAD((*pskb)->nh.iph->saddr),
591 NIPQUAD((*pskb)->nh.iph->daddr), datalen);
592
593 /* Decode H.245 signal */
594 ret = DecodeMultimediaSystemControlMessage(data, datalen,
595 &mscm);
596 if (ret < 0) {
597 if (net_ratelimit())
598 printk("ip_ct_h245: decoding error: %s\n",
599 ret == H323_ERROR_BOUND ?
600 "out of bound" : "out of range");
601 /* We don't drop when decoding error */
602 break;
603 }
604
605 /* Process H.245 signal */
606 if (process_h245(pskb, ct, ctinfo, &data, dataoff, &mscm) < 0)
607 goto drop;
608 }
609
610 spin_unlock_bh(&ip_h323_lock);
611 return NF_ACCEPT;
612
613 drop:
614 spin_unlock_bh(&ip_h323_lock);
615 if (net_ratelimit())
616 printk("ip_ct_h245: packet dropped\n");
617 return NF_DROP;
618}
619
620/****************************************************************************/
621static struct ip_conntrack_helper ip_conntrack_helper_h245 = {
622 .name = "H.245",
623 .me = THIS_MODULE,
624 .max_expected = H323_RTP_CHANNEL_MAX * 4 + 2 /* T.120 */ ,
625 .timeout = 240,
626 .tuple = {.dst = {.protonum = IPPROTO_TCP}},
627 .mask = {.src = {.u = {0xFFFF}},
628 .dst = {.protonum = 0xFF}},
629 .help = h245_help
630};
631
632/****************************************************************************/
633void ip_conntrack_h245_expect(struct ip_conntrack *new,
634 struct ip_conntrack_expect *this)
635{
636 write_lock_bh(&ip_conntrack_lock);
637 new->helper = &ip_conntrack_helper_h245;
638 write_unlock_bh(&ip_conntrack_lock);
639}
640
641/****************************************************************************/
Patrick McHardy6a534ee2006-03-22 13:57:25 -0800[diff] [blame]642int get_h225_addr(unsigned char *data, TransportAddress * addr,
643 u_int32_t * ip, u_int16_t * port)
Jing Min Zhao5e35941d2006-03-20 23:41:17 -0800[diff] [blame]644{
645 unsigned char *p;
646
647 if (addr->choice != eTransportAddress_ipAddress)
648 return 0;
649
650 p = data + addr->ipAddress.ip;
651 *ip = htonl((p[0] << 24) | (p[1] << 16) | (p[2] << 8) | (p[3]));
652 *port = (p[4] << 8) | (p[5]);
653
654 return 1;
655}
656
657/****************************************************************************/
658static int expect_h245(struct sk_buff **pskb, struct ip_conntrack *ct,
659 enum ip_conntrack_info ctinfo,
660 unsigned char **data, int dataoff,
661 TransportAddress * addr)
662{
663 int dir = CTINFO2DIR(ctinfo);
664 int ret = 0;
665 u_int32_t ip;
666 u_int16_t port;
667 struct ip_conntrack_expect *exp = NULL;
668
669 /* Read h245Address */
670 if (!get_h225_addr(*data, addr, &ip, &port) ||
671 ip != ct->tuplehash[dir].tuple.src.ip || port == 0)
672 return 0;
673
674 /* Create expect for h245 connection */
675 if ((exp = ip_conntrack_expect_alloc(ct)) == NULL)
676 return -1;
677 exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip;
678 exp->tuple.src.u.tcp.port = 0;
679 exp->tuple.dst.ip = ct->tuplehash[!dir].tuple.dst.ip;
680 exp->tuple.dst.u.tcp.port = htons(port);
681 exp->tuple.dst.protonum = IPPROTO_TCP;
682 exp->mask.src.ip = 0xFFFFFFFF;
683 exp->mask.src.u.tcp.port = 0;
684 exp->mask.dst.ip = 0xFFFFFFFF;
685 exp->mask.dst.u.tcp.port = 0xFFFF;
686 exp->mask.dst.protonum = 0xFF;
687 exp->flags = 0;
688
689 if (ct->tuplehash[dir].tuple.src.ip !=
690 ct->tuplehash[!dir].tuple.dst.ip && nat_h245_hook) {
691 /* NAT needed */
692 ret = nat_h245_hook(pskb, ct, ctinfo, data, dataoff, addr,
693 port, exp);
694 } else { /* Conntrack only */
695 exp->expectfn = ip_conntrack_h245_expect;
696
697 if (ip_conntrack_expect_related(exp) == 0) {
698 DEBUGP("ip_ct_q931: expect H.245 "
699 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
700 NIPQUAD(exp->tuple.src.ip),
701 ntohs(exp->tuple.src.u.tcp.port),
702 NIPQUAD(exp->tuple.dst.ip),
703 ntohs(exp->tuple.dst.u.tcp.port));
704 } else
705 ret = -1;
706 }
707
708 ip_conntrack_expect_put(exp);
709
710 return ret;
711}
712
713/****************************************************************************/
714static int process_setup(struct sk_buff **pskb, struct ip_conntrack *ct,
715 enum ip_conntrack_info ctinfo,
716 unsigned char **data, int dataoff,
717 Setup_UUIE * setup)
718{
719 int dir = CTINFO2DIR(ctinfo);
720 int ret;
721 int i;
722 u_int32_t ip;
723 u_int16_t port;
724
725 DEBUGP("ip_ct_q931: Setup\n");
726
727 if (setup->options & eSetup_UUIE_h245Address) {
728 ret = expect_h245(pskb, ct, ctinfo, data, dataoff,
729 &setup->h245Address);
730 if (ret < 0)
731 return -1;
732 }
733
734 if ((setup->options & eSetup_UUIE_destCallSignalAddress) &&
735 (set_h225_addr_hook) &&
736 get_h225_addr(*data, &setup->destCallSignalAddress, &ip, &port) &&
737 ip != ct->tuplehash[!dir].tuple.src.ip) {
738 DEBUGP("ip_ct_q931: set destCallSignalAddress "
739 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
740 NIPQUAD(ip), port,
741 NIPQUAD(ct->tuplehash[!dir].tuple.src.ip),
742 ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port));
743 ret = set_h225_addr_hook(pskb, data, dataoff,
744 &setup->destCallSignalAddress,
745 ct->tuplehash[!dir].tuple.src.ip,
746 ntohs(ct->tuplehash[!dir].tuple.src.
747 u.tcp.port));
748 if (ret < 0)
749 return -1;
750 }
751
752 if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) &&
753 (set_h225_addr_hook) &&
754 get_h225_addr(*data, &setup->sourceCallSignalAddress, &ip, &port)
755 && ip != ct->tuplehash[!dir].tuple.dst.ip) {
756 DEBUGP("ip_ct_q931: set sourceCallSignalAddress "
757 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
758 NIPQUAD(ip), port,
759 NIPQUAD(ct->tuplehash[!dir].tuple.dst.ip),
760 ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port));
761 ret = set_h225_addr_hook(pskb, data, dataoff,
762 &setup->sourceCallSignalAddress,
763 ct->tuplehash[!dir].tuple.dst.ip,
764 ntohs(ct->tuplehash[!dir].tuple.dst.
765 u.tcp.port));
766 if (ret < 0)
767 return -1;
768 }
769
770 if (setup->options & eSetup_UUIE_fastStart) {
771 for (i = 0; i < setup->fastStart.count; i++) {
772 ret = process_olc(pskb, ct, ctinfo, data, dataoff,
773 &setup->fastStart.item[i]);
774 if (ret < 0)
775 return -1;
776 }
777 }
778
779 return 0;
780}
781
782/****************************************************************************/
783static int process_callproceeding(struct sk_buff **pskb,
784 struct ip_conntrack *ct,
785 enum ip_conntrack_info ctinfo,
786 unsigned char **data, int dataoff,
787 CallProceeding_UUIE * callproc)
788{
789 int ret;
790 int i;
791
792 DEBUGP("ip_ct_q931: CallProceeding\n");
793
794 if (callproc->options & eCallProceeding_UUIE_h245Address) {
795 ret = expect_h245(pskb, ct, ctinfo, data, dataoff,
796 &callproc->h245Address);
797 if (ret < 0)
798 return -1;
799 }
800
801 if (callproc->options & eCallProceeding_UUIE_fastStart) {
802 for (i = 0; i < callproc->fastStart.count; i++) {
803 ret = process_olc(pskb, ct, ctinfo, data, dataoff,
804 &callproc->fastStart.item[i]);
805 if (ret < 0)
806 return -1;
807 }
808 }
809
810 return 0;
811}
812
813/****************************************************************************/
814static int process_connect(struct sk_buff **pskb, struct ip_conntrack *ct,
815 enum ip_conntrack_info ctinfo,
816 unsigned char **data, int dataoff,
817 Connect_UUIE * connect)
818{
819 int ret;
820 int i;
821
822 DEBUGP("ip_ct_q931: Connect\n");
823
824 if (connect->options & eConnect_UUIE_h245Address) {
825 ret = expect_h245(pskb, ct, ctinfo, data, dataoff,
826 &connect->h245Address);
827 if (ret < 0)
828 return -1;
829 }
830
831 if (connect->options & eConnect_UUIE_fastStart) {
832 for (i = 0; i < connect->fastStart.count; i++) {
833 ret = process_olc(pskb, ct, ctinfo, data, dataoff,
834 &connect->fastStart.item[i]);
835 if (ret < 0)
836 return -1;
837 }
838 }
839
840 return 0;
841}
842
843/****************************************************************************/
844static int process_alerting(struct sk_buff **pskb, struct ip_conntrack *ct,
845 enum ip_conntrack_info ctinfo,
846 unsigned char **data, int dataoff,
847 Alerting_UUIE * alert)
848{
849 int ret;
850 int i;
851
852 DEBUGP("ip_ct_q931: Alerting\n");
853
854 if (alert->options & eAlerting_UUIE_h245Address) {
855 ret = expect_h245(pskb, ct, ctinfo, data, dataoff,
856 &alert->h245Address);
857 if (ret < 0)
858 return -1;
859 }
860
861 if (alert->options & eAlerting_UUIE_fastStart) {
862 for (i = 0; i < alert->fastStart.count; i++) {
863 ret = process_olc(pskb, ct, ctinfo, data, dataoff,
864 &alert->fastStart.item[i]);
865 if (ret < 0)
866 return -1;
867 }
868 }
869
870 return 0;
871}
872
873/****************************************************************************/
874static int process_information(struct sk_buff **pskb,
875 struct ip_conntrack *ct,
876 enum ip_conntrack_info ctinfo,
877 unsigned char **data, int dataoff,
878 Information_UUIE * info)
879{
880 int ret;
881 int i;
882
883 DEBUGP("ip_ct_q931: Information\n");
884
885 if (info->options & eInformation_UUIE_fastStart) {
886 for (i = 0; i < info->fastStart.count; i++) {
887 ret = process_olc(pskb, ct, ctinfo, data, dataoff,
888 &info->fastStart.item[i]);
889 if (ret < 0)
890 return -1;
891 }
892 }
893
894 return 0;
895}
896
897/****************************************************************************/
898static int process_facility(struct sk_buff **pskb, struct ip_conntrack *ct,
899 enum ip_conntrack_info ctinfo,
900 unsigned char **data, int dataoff,
901 Facility_UUIE * facility)
902{
903 int ret;
904 int i;
905
906 DEBUGP("ip_ct_q931: Facility\n");
907
908 if (facility->options & eFacility_UUIE_h245Address) {
909 ret = expect_h245(pskb, ct, ctinfo, data, dataoff,
910 &facility->h245Address);
911 if (ret < 0)
912 return -1;
913 }
914
915 if (facility->options & eFacility_UUIE_fastStart) {
916 for (i = 0; i < facility->fastStart.count; i++) {
917 ret = process_olc(pskb, ct, ctinfo, data, dataoff,
918 &facility->fastStart.item[i]);
919 if (ret < 0)
920 return -1;
921 }
922 }
923
924 return 0;
925}
926
927/****************************************************************************/
928static int process_progress(struct sk_buff **pskb, struct ip_conntrack *ct,
929 enum ip_conntrack_info ctinfo,
930 unsigned char **data, int dataoff,
931 Progress_UUIE * progress)
932{
933 int ret;
934 int i;
935
936 DEBUGP("ip_ct_q931: Progress\n");
937
938 if (progress->options & eProgress_UUIE_h245Address) {
939 ret = expect_h245(pskb, ct, ctinfo, data, dataoff,
940 &progress->h245Address);
941 if (ret < 0)
942 return -1;
943 }
944
945 if (progress->options & eProgress_UUIE_fastStart) {
946 for (i = 0; i < progress->fastStart.count; i++) {
947 ret = process_olc(pskb, ct, ctinfo, data, dataoff,
948 &progress->fastStart.item[i]);
949 if (ret < 0)
950 return -1;
951 }
952 }
953
954 return 0;
955}
956
957/****************************************************************************/
958static int process_q931(struct sk_buff **pskb, struct ip_conntrack *ct,
959 enum ip_conntrack_info ctinfo,
960 unsigned char **data, int dataoff, Q931 * q931)
961{
962 H323_UU_PDU *pdu = &q931->UUIE.h323_uu_pdu;
963 int i;
964 int ret = 0;
965
966 switch (pdu->h323_message_body.choice) {
967 case eH323_UU_PDU_h323_message_body_setup:
968 ret = process_setup(pskb, ct, ctinfo, data, dataoff,
969 &pdu->h323_message_body.setup);
970 break;
971 case eH323_UU_PDU_h323_message_body_callProceeding:
972 ret = process_callproceeding(pskb, ct, ctinfo, data, dataoff,
973 &pdu->h323_message_body.
974 callProceeding);
975 break;
976 case eH323_UU_PDU_h323_message_body_connect:
977 ret = process_connect(pskb, ct, ctinfo, data, dataoff,
978 &pdu->h323_message_body.connect);
979 break;
980 case eH323_UU_PDU_h323_message_body_alerting:
981 ret = process_alerting(pskb, ct, ctinfo, data, dataoff,
982 &pdu->h323_message_body.alerting);
983 break;
984 case eH323_UU_PDU_h323_message_body_information:
985 ret = process_information(pskb, ct, ctinfo, data, dataoff,
986 &pdu->h323_message_body.
987 information);
988 break;
989 case eH323_UU_PDU_h323_message_body_facility:
990 ret = process_facility(pskb, ct, ctinfo, data, dataoff,
991 &pdu->h323_message_body.facility);
992 break;
993 case eH323_UU_PDU_h323_message_body_progress:
994 ret = process_progress(pskb, ct, ctinfo, data, dataoff,
995 &pdu->h323_message_body.progress);
996 break;
997 default:
998 DEBUGP("ip_ct_q931: Q.931 signal %d\n",
999 pdu->h323_message_body.choice);
1000 break;
1001 }
1002
1003 if (ret < 0)
1004 return -1;
1005
1006 if (pdu->options & eH323_UU_PDU_h245Control) {
1007 for (i = 0; i < pdu->h245Control.count; i++) {
1008 ret = process_h245(pskb, ct, ctinfo, data, dataoff,
1009 &pdu->h245Control.item[i]);
1010 if (ret < 0)
1011 return -1;
1012 }
1013 }
1014
1015 return 0;
1016}
1017
1018/****************************************************************************/
1019static int q931_help(struct sk_buff **pskb, struct ip_conntrack *ct,
1020 enum ip_conntrack_info ctinfo)
1021{
1022 static Q931 q931;
1023 unsigned char *data = NULL;
1024 int datalen;
1025 int dataoff;
1026 int ret;
1027
1028 /* Until there's been traffic both ways, don't look in packets. */
1029 if (ctinfo != IP_CT_ESTABLISHED
1030 && ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) {
1031 return NF_ACCEPT;
1032 }
1033 DEBUGP("ip_ct_q931: skblen = %u\n", (*pskb)->len);
1034
1035 spin_lock_bh(&ip_h323_lock);
1036
1037 /* Process each TPKT */
1038 while (get_tpkt_data(pskb, ct, ctinfo, &data, &datalen, &dataoff)) {
1039 DEBUGP("ip_ct_q931: TPKT %u.%u.%u.%u->%u.%u.%u.%u, len=%d\n",
1040 NIPQUAD((*pskb)->nh.iph->saddr),
1041 NIPQUAD((*pskb)->nh.iph->daddr), datalen);
1042
1043 /* Decode Q.931 signal */
1044 ret = DecodeQ931(data, datalen, &q931);
1045 if (ret < 0) {
1046 if (net_ratelimit())
1047 printk("ip_ct_q931: decoding error: %s\n",
1048 ret == H323_ERROR_BOUND ?
1049 "out of bound" : "out of range");
1050 /* We don't drop when decoding error */
1051 break;
1052 }
1053
1054 /* Process Q.931 signal */
1055 if (process_q931(pskb, ct, ctinfo, &data, dataoff, &q931) < 0)
1056 goto drop;
1057 }
1058
1059 spin_unlock_bh(&ip_h323_lock);
1060 return NF_ACCEPT;
1061
1062 drop:
1063 spin_unlock_bh(&ip_h323_lock);
1064 if (net_ratelimit())
1065 printk("ip_ct_q931: packet dropped\n");
1066 return NF_DROP;
1067}
1068
1069/****************************************************************************/
1070static struct ip_conntrack_helper ip_conntrack_helper_q931 = {
1071 .name = "Q.931",
1072 .me = THIS_MODULE,
1073 .max_expected = H323_RTP_CHANNEL_MAX * 4 + 4 /* T.120 and H.245 */ ,
1074 .timeout = 240,
1075 .tuple = {.src = {.u = {__constant_htons(Q931_PORT)}},
1076 .dst = {.protonum = IPPROTO_TCP}},
1077 .mask = {.src = {.u = {0xFFFF}},
1078 .dst = {.protonum = 0xFF}},
1079 .help = q931_help
1080};
1081
1082/****************************************************************************/
1083void ip_conntrack_q931_expect(struct ip_conntrack *new,
1084 struct ip_conntrack_expect *this)
1085{
1086 write_lock_bh(&ip_conntrack_lock);
1087 new->helper = &ip_conntrack_helper_q931;
1088 write_unlock_bh(&ip_conntrack_lock);
1089}
1090
1091/****************************************************************************/
1092static unsigned char *get_udp_data(struct sk_buff **pskb, int *datalen)
1093{
1094 struct udphdr _uh, *uh;
1095 int dataoff;
1096
1097 uh = skb_header_pointer(*pskb, (*pskb)->nh.iph->ihl * 4, sizeof(_uh),
1098 &_uh);
1099 if (uh == NULL)
1100 return NULL;
1101 dataoff = (*pskb)->nh.iph->ihl * 4 + sizeof(_uh);
1102 if (dataoff >= (*pskb)->len)
1103 return NULL;
1104 *datalen = (*pskb)->len - dataoff;
1105 return skb_header_pointer(*pskb, dataoff, *datalen, h323_buffer);
1106}
1107
1108/****************************************************************************/
1109static struct ip_conntrack_expect *find_expect(struct ip_conntrack *ct,
1110 u_int32_t ip, u_int16_t port)
1111{
1112 struct ip_conntrack_expect *exp;
1113 struct ip_conntrack_tuple tuple;
1114
1115 tuple.src.ip = 0;
1116 tuple.src.u.tcp.port = 0;
1117 tuple.dst.ip = ip;
1118 tuple.dst.u.tcp.port = htons(port);
1119 tuple.dst.protonum = IPPROTO_TCP;
1120
1121 exp = __ip_conntrack_expect_find(&tuple);
1122 if (exp->master == ct)
1123 return exp;
1124 return NULL;
1125}
1126
1127/****************************************************************************/
1128static int set_expect_timeout(struct ip_conntrack_expect *exp,
1129 unsigned timeout)
1130{
1131 if (!exp || !del_timer(&exp->timeout))
1132 return 0;
1133
1134 exp->timeout.expires = jiffies + timeout * HZ;
1135 add_timer(&exp->timeout);
1136
1137 return 1;
1138}
1139
1140/****************************************************************************/
1141static int expect_q931(struct sk_buff **pskb, struct ip_conntrack *ct,
1142 enum ip_conntrack_info ctinfo,
1143 unsigned char **data,
1144 TransportAddress * addr, int count)
1145{
1146 struct ip_ct_h323_master *info = &ct->help.ct_h323_info;
1147 int dir = CTINFO2DIR(ctinfo);
1148 int ret = 0;
1149 int i;
1150 u_int32_t ip;
1151 u_int16_t port;
1152 struct ip_conntrack_expect *exp;
1153
1154 /* Look for the first related address */
1155 for (i = 0; i < count; i++) {
1156 if (get_h225_addr(*data, &addr[i], &ip, &port) &&
1157 ip == ct->tuplehash[dir].tuple.src.ip && port != 0)
1158 break;
1159 }
1160
1161 if (i >= count) /* Not found */
1162 return 0;
1163
1164 /* Create expect for Q.931 */
1165 if ((exp = ip_conntrack_expect_alloc(ct)) == NULL)
1166 return -1;
1167 exp->tuple.src.ip = gkrouted_only ? /* only accept calls from GK? */
1168 ct->tuplehash[!dir].tuple.src.ip : 0;
1169 exp->tuple.src.u.tcp.port = 0;
1170 exp->tuple.dst.ip = ct->tuplehash[!dir].tuple.dst.ip;
1171 exp->tuple.dst.u.tcp.port = htons(port);
1172 exp->tuple.dst.protonum = IPPROTO_TCP;
1173 exp->mask.src.ip = gkrouted_only ? 0xFFFFFFFF : 0;
1174 exp->mask.src.u.tcp.port = 0;
1175 exp->mask.dst.ip = 0xFFFFFFFF;
1176 exp->mask.dst.u.tcp.port = 0xFFFF;
1177 exp->mask.dst.protonum = 0xFF;
1178 exp->flags = IP_CT_EXPECT_PERMANENT; /* Accept multiple calls */
1179
1180 if (nat_q931_hook) { /* Need NAT */
1181 ret = nat_q931_hook(pskb, ct, ctinfo, data, addr, i,
1182 port, exp);
1183 } else { /* Conntrack only */
1184 exp->expectfn = ip_conntrack_q931_expect;
1185
1186 if (ip_conntrack_expect_related(exp) == 0) {
1187 DEBUGP("ip_ct_ras: expect Q.931 "
1188 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
1189 NIPQUAD(exp->tuple.src.ip),
1190 ntohs(exp->tuple.src.u.tcp.port),
1191 NIPQUAD(exp->tuple.dst.ip),
1192 ntohs(exp->tuple.dst.u.tcp.port));
1193
1194 /* Save port for looking up expect in processing RCF */
1195 info->sig_port[dir] = port;
1196 } else
1197 ret = -1;
1198 }
1199
1200 ip_conntrack_expect_put(exp);
1201
1202 return ret;
1203}
1204
1205/****************************************************************************/
1206static int process_grq(struct sk_buff **pskb, struct ip_conntrack *ct,
1207 enum ip_conntrack_info ctinfo,
1208 unsigned char **data, GatekeeperRequest * grq)
1209{
1210 DEBUGP("ip_ct_ras: GRQ\n");
1211
1212 if (set_ras_addr_hook) /* NATed */
1213 return set_ras_addr_hook(pskb, ct, ctinfo, data,
1214 &grq->rasAddress, 1);
1215 return 0;
1216}
1217
1218/* Declare before using */
1219static void ip_conntrack_ras_expect(struct ip_conntrack *new,
1220 struct ip_conntrack_expect *this);
1221
1222/****************************************************************************/
1223static int process_gcf(struct sk_buff **pskb, struct ip_conntrack *ct,
1224 enum ip_conntrack_info ctinfo,
1225 unsigned char **data, GatekeeperConfirm * gcf)
1226{
1227 int dir = CTINFO2DIR(ctinfo);
1228 int ret = 0;
1229 u_int32_t ip;
1230 u_int16_t port;
1231 struct ip_conntrack_expect *exp;
1232
1233 DEBUGP("ip_ct_ras: GCF\n");
1234
1235 if (!get_h225_addr(*data, &gcf->rasAddress, &ip, &port))
1236 return 0;
1237
1238 /* Registration port is the same as discovery port */
1239 if (ip == ct->tuplehash[dir].tuple.src.ip &&
1240 port == ntohs(ct->tuplehash[dir].tuple.src.u.udp.port))
1241 return 0;
1242
1243 /* Avoid RAS expectation loops. A GCF is never expected. */
1244 if (test_bit(IPS_EXPECTED_BIT, &ct->status))
1245 return 0;
1246
1247 /* Need new expect */
1248 if ((exp = ip_conntrack_expect_alloc(ct)) == NULL)
1249 return -1;
1250 exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip;
1251 exp->tuple.src.u.tcp.port = 0;
1252 exp->tuple.dst.ip = ip;
1253 exp->tuple.dst.u.tcp.port = htons(port);
1254 exp->tuple.dst.protonum = IPPROTO_UDP;
1255 exp->mask.src.ip = 0xFFFFFFFF;
1256 exp->mask.src.u.tcp.port = 0;
1257 exp->mask.dst.ip = 0xFFFFFFFF;
1258 exp->mask.dst.u.tcp.port = 0xFFFF;
1259 exp->mask.dst.protonum = 0xFF;
1260 exp->flags = 0;
1261 exp->expectfn = ip_conntrack_ras_expect;
1262 if (ip_conntrack_expect_related(exp) == 0) {
1263 DEBUGP("ip_ct_ras: expect RAS "
1264 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
1265 NIPQUAD(exp->tuple.src.ip),
1266 ntohs(exp->tuple.src.u.tcp.port),
1267 NIPQUAD(exp->tuple.dst.ip),
1268 ntohs(exp->tuple.dst.u.tcp.port));
1269 } else
1270 ret = -1;
1271
1272 ip_conntrack_expect_put(exp);
1273
1274 return ret;
1275}
1276
1277/****************************************************************************/
1278static int process_rrq(struct sk_buff **pskb, struct ip_conntrack *ct,
1279 enum ip_conntrack_info ctinfo,
1280 unsigned char **data, RegistrationRequest * rrq)
1281{
1282 struct ip_ct_h323_master *info = &ct->help.ct_h323_info;
1283 int ret;
1284
1285 DEBUGP("ip_ct_ras: RRQ\n");
1286
1287 ret = expect_q931(pskb, ct, ctinfo, data,
1288 rrq->callSignalAddress.item,
1289 rrq->callSignalAddress.count);
1290 if (ret < 0)
1291 return -1;
1292
1293 if (set_ras_addr_hook) {
1294 ret = set_ras_addr_hook(pskb, ct, ctinfo, data,
1295 rrq->rasAddress.item,
1296 rrq->rasAddress.count);
1297 if (ret < 0)
1298 return -1;
1299 }
1300
1301 if (rrq->options & eRegistrationRequest_timeToLive) {
1302 DEBUGP("ip_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive);
1303 info->timeout = rrq->timeToLive;
1304 } else
1305 info->timeout = 0;
1306
1307 return 0;
1308}
1309
1310/****************************************************************************/
1311static int process_rcf(struct sk_buff **pskb, struct ip_conntrack *ct,
1312 enum ip_conntrack_info ctinfo,
1313 unsigned char **data, RegistrationConfirm * rcf)
1314{
1315 struct ip_ct_h323_master *info = &ct->help.ct_h323_info;
1316 int dir = CTINFO2DIR(ctinfo);
1317 int ret;
1318 struct ip_conntrack_expect *exp;
1319
1320 DEBUGP("ip_ct_ras: RCF\n");
1321
1322 if (set_sig_addr_hook) {
1323 ret = set_sig_addr_hook(pskb, ct, ctinfo, data,
1324 rcf->callSignalAddress.item,
1325 rcf->callSignalAddress.count);
1326 if (ret < 0)
1327 return -1;
1328 }
1329
1330 if (rcf->options & eRegistrationConfirm_timeToLive) {
1331 DEBUGP("ip_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive);
1332 info->timeout = rcf->timeToLive;
1333 }
1334
1335 if (info->timeout > 0) {
1336 DEBUGP
1337 ("ip_ct_ras: set RAS connection timeout to %u seconds\n",
1338 info->timeout);
1339 ip_ct_refresh_acct(ct, ctinfo, NULL, info->timeout * HZ);
1340
1341 /* Set expect timeout */
1342 read_lock_bh(&ip_conntrack_lock);
1343 exp = find_expect(ct, ct->tuplehash[dir].tuple.dst.ip,
1344 info->sig_port[!dir]);
1345 if (exp) {
1346 DEBUGP("ip_ct_ras: set Q.931 expect "
1347 "(%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu) "
1348 "timeout to %u seconds\n",
1349 NIPQUAD(exp->tuple.src.ip),
1350 ntohs(exp->tuple.src.u.tcp.port),
1351 NIPQUAD(exp->tuple.dst.ip),
1352 ntohs(exp->tuple.dst.u.tcp.port),
1353 info->timeout);
1354 set_expect_timeout(exp, info->timeout);
1355 }
1356 read_unlock_bh(&ip_conntrack_lock);
1357 }
1358
1359 return 0;
1360}
1361
1362/****************************************************************************/
1363static int process_urq(struct sk_buff **pskb, struct ip_conntrack *ct,
1364 enum ip_conntrack_info ctinfo,
1365 unsigned char **data, UnregistrationRequest * urq)
1366{
1367 struct ip_ct_h323_master *info = &ct->help.ct_h323_info;
1368 int dir = CTINFO2DIR(ctinfo);
1369 int ret;
1370
1371 DEBUGP("ip_ct_ras: URQ\n");
1372
1373 if (set_sig_addr_hook) {
1374 ret = set_sig_addr_hook(pskb, ct, ctinfo, data,
1375 urq->callSignalAddress.item,
1376 urq->callSignalAddress.count);
1377 if (ret < 0)
1378 return -1;
1379 }
1380
1381 /* Clear old expect */
1382 ip_ct_remove_expectations(ct);
1383 info->sig_port[dir] = 0;
1384 info->sig_port[!dir] = 0;
1385
1386 /* Give it 30 seconds for UCF or URJ */
1387 ip_ct_refresh_acct(ct, ctinfo, NULL, 30 * HZ);
1388
1389 return 0;
1390}
1391
1392/****************************************************************************/
1393static int process_arq(struct sk_buff **pskb, struct ip_conntrack *ct,
1394 enum ip_conntrack_info ctinfo,
1395 unsigned char **data, AdmissionRequest * arq)
1396{
1397 struct ip_ct_h323_master *info = &ct->help.ct_h323_info;
1398 int dir = CTINFO2DIR(ctinfo);
1399 u_int32_t ip;
1400 u_int16_t port;
1401
1402 DEBUGP("ip_ct_ras: ARQ\n");
1403
1404 if ((arq->options & eAdmissionRequest_destCallSignalAddress) &&
1405 get_h225_addr(*data, &arq->destCallSignalAddress, &ip, &port) &&
1406 ip == ct->tuplehash[dir].tuple.src.ip &&
1407 port == info->sig_port[dir] && set_h225_addr_hook) {
1408 /* Answering ARQ */
1409 return set_h225_addr_hook(pskb, data, 0,
1410 &arq->destCallSignalAddress,
1411 ct->tuplehash[!dir].tuple.dst.ip,
1412 info->sig_port[!dir]);
1413 }
1414
1415 if ((arq->options & eAdmissionRequest_srcCallSignalAddress) &&
1416 get_h225_addr(*data, &arq->srcCallSignalAddress, &ip, &port) &&
1417 ip == ct->tuplehash[dir].tuple.src.ip && set_h225_addr_hook) {
1418 /* Calling ARQ */
1419 return set_h225_addr_hook(pskb, data, 0,
1420 &arq->srcCallSignalAddress,
1421 ct->tuplehash[!dir].tuple.dst.ip,
1422 port);
1423 }
1424
1425 return 0;
1426}
1427
1428/****************************************************************************/
1429static int process_acf(struct sk_buff **pskb, struct ip_conntrack *ct,
1430 enum ip_conntrack_info ctinfo,
1431 unsigned char **data, AdmissionConfirm * acf)
1432{
1433 int dir = CTINFO2DIR(ctinfo);
1434 int ret = 0;
1435 u_int32_t ip;
1436 u_int16_t port;
1437 struct ip_conntrack_expect *exp;
1438
1439 DEBUGP("ip_ct_ras: ACF\n");
1440
1441 if (!get_h225_addr(*data, &acf->destCallSignalAddress, &ip, &port))
1442 return 0;
1443
1444 if (ip == ct->tuplehash[dir].tuple.dst.ip) { /* Answering ACF */
1445 if (set_sig_addr_hook)
1446 return set_sig_addr_hook(pskb, ct, ctinfo, data,
1447 &acf->destCallSignalAddress,
1448 1);
1449 return 0;
1450 }
1451
1452 /* Need new expect */
1453 if ((exp = ip_conntrack_expect_alloc(ct)) == NULL)
1454 return -1;
1455 exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip;
1456 exp->tuple.src.u.tcp.port = 0;
1457 exp->tuple.dst.ip = ip;
1458 exp->tuple.dst.u.tcp.port = htons(port);
1459 exp->tuple.dst.protonum = IPPROTO_TCP;
1460 exp->mask.src.ip = 0xFFFFFFFF;
1461 exp->mask.src.u.tcp.port = 0;
1462 exp->mask.dst.ip = 0xFFFFFFFF;
1463 exp->mask.dst.u.tcp.port = 0xFFFF;
1464 exp->mask.dst.protonum = 0xFF;
1465 exp->flags = IP_CT_EXPECT_PERMANENT;
1466 exp->expectfn = ip_conntrack_q931_expect;
1467
1468 if (ip_conntrack_expect_related(exp) == 0) {
1469 DEBUGP("ip_ct_ras: expect Q.931 "
1470 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
1471 NIPQUAD(exp->tuple.src.ip),
1472 ntohs(exp->tuple.src.u.tcp.port),
1473 NIPQUAD(exp->tuple.dst.ip),
1474 ntohs(exp->tuple.dst.u.tcp.port));
1475 } else
1476 ret = -1;
1477
1478 ip_conntrack_expect_put(exp);
1479
1480 return ret;
1481}
1482
1483/****************************************************************************/
1484static int process_lrq(struct sk_buff **pskb, struct ip_conntrack *ct,
1485 enum ip_conntrack_info ctinfo,
1486 unsigned char **data, LocationRequest * lrq)
1487{
1488 DEBUGP("ip_ct_ras: LRQ\n");
1489
1490 if (set_ras_addr_hook)
1491 return set_ras_addr_hook(pskb, ct, ctinfo, data,
1492 &lrq->replyAddress, 1);
1493 return 0;
1494}
1495
1496/****************************************************************************/
1497static int process_lcf(struct sk_buff **pskb, struct ip_conntrack *ct,
1498 enum ip_conntrack_info ctinfo,
1499 unsigned char **data, LocationConfirm * lcf)
1500{
1501 int dir = CTINFO2DIR(ctinfo);
1502 int ret = 0;
1503 u_int32_t ip;
1504 u_int16_t port;
1505 struct ip_conntrack_expect *exp = NULL;
1506
1507 DEBUGP("ip_ct_ras: LCF\n");
1508
1509 if (!get_h225_addr(*data, &lcf->callSignalAddress, &ip, &port))
1510 return 0;
1511
1512 /* Need new expect for call signal */
1513 if ((exp = ip_conntrack_expect_alloc(ct)) == NULL)
1514 return -1;
1515 exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip;
1516 exp->tuple.src.u.tcp.port = 0;
1517 exp->tuple.dst.ip = ip;
1518 exp->tuple.dst.u.tcp.port = htons(port);
1519 exp->tuple.dst.protonum = IPPROTO_TCP;
1520 exp->mask.src.ip = 0xFFFFFFFF;
1521 exp->mask.src.u.tcp.port = 0;
1522 exp->mask.dst.ip = 0xFFFFFFFF;
1523 exp->mask.dst.u.tcp.port = 0xFFFF;
1524 exp->mask.dst.protonum = 0xFF;
1525 exp->flags = IP_CT_EXPECT_PERMANENT;
1526 exp->expectfn = ip_conntrack_q931_expect;
1527
1528 if (ip_conntrack_expect_related(exp) == 0) {
1529 DEBUGP("ip_ct_ras: expect Q.931 "
1530 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
1531 NIPQUAD(exp->tuple.src.ip),
1532 ntohs(exp->tuple.src.u.tcp.port),
1533 NIPQUAD(exp->tuple.dst.ip),
1534 ntohs(exp->tuple.dst.u.tcp.port));
1535 } else
1536 ret = -1;
1537
1538 ip_conntrack_expect_put(exp);
1539
1540 /* Ignore rasAddress */
1541
1542 return ret;
1543}
1544
1545/****************************************************************************/
1546static int process_irr(struct sk_buff **pskb, struct ip_conntrack *ct,
1547 enum ip_conntrack_info ctinfo,
1548 unsigned char **data, InfoRequestResponse * irr)
1549{
1550 int ret;
1551
1552 DEBUGP("ip_ct_ras: IRR\n");
1553
1554 if (set_ras_addr_hook) {
1555 ret = set_ras_addr_hook(pskb, ct, ctinfo, data,
1556 &irr->rasAddress, 1);
1557 if (ret < 0)
1558 return -1;
1559 }
1560
1561 if (set_sig_addr_hook) {
1562 ret = set_sig_addr_hook(pskb, ct, ctinfo, data,
1563 irr->callSignalAddress.item,
1564 irr->callSignalAddress.count);
1565 if (ret < 0)
1566 return -1;
1567 }
1568
1569 return 0;
1570}
1571
1572/****************************************************************************/
1573static int process_ras(struct sk_buff **pskb, struct ip_conntrack *ct,
1574 enum ip_conntrack_info ctinfo,
1575 unsigned char **data, RasMessage * ras)
1576{
1577 switch (ras->choice) {
1578 case eRasMessage_gatekeeperRequest:
1579 return process_grq(pskb, ct, ctinfo, data,
1580 &ras->gatekeeperRequest);
1581 case eRasMessage_gatekeeperConfirm:
1582 return process_gcf(pskb, ct, ctinfo, data,
1583 &ras->gatekeeperConfirm);
1584 case eRasMessage_registrationRequest:
1585 return process_rrq(pskb, ct, ctinfo, data,
1586 &ras->registrationRequest);
1587 case eRasMessage_registrationConfirm:
1588 return process_rcf(pskb, ct, ctinfo, data,
1589 &ras->registrationConfirm);
1590 case eRasMessage_unregistrationRequest:
1591 return process_urq(pskb, ct, ctinfo, data,
1592 &ras->unregistrationRequest);
1593 case eRasMessage_admissionRequest:
1594 return process_arq(pskb, ct, ctinfo, data,
1595 &ras->admissionRequest);
1596 case eRasMessage_admissionConfirm:
1597 return process_acf(pskb, ct, ctinfo, data,
1598 &ras->admissionConfirm);
1599 case eRasMessage_locationRequest:
1600 return process_lrq(pskb, ct, ctinfo, data,
1601 &ras->locationRequest);
1602 case eRasMessage_locationConfirm:
1603 return process_lcf(pskb, ct, ctinfo, data,
1604 &ras->locationConfirm);
1605 case eRasMessage_infoRequestResponse:
1606 return process_irr(pskb, ct, ctinfo, data,
1607 &ras->infoRequestResponse);
1608 default:
1609 DEBUGP("ip_ct_ras: RAS message %d\n", ras->choice);
1610 break;
1611 }
1612
1613 return 0;
1614}
1615
1616/****************************************************************************/
1617static int ras_help(struct sk_buff **pskb, struct ip_conntrack *ct,
1618 enum ip_conntrack_info ctinfo)
1619{
1620 static RasMessage ras;
1621 unsigned char *data;
1622 int datalen = 0;
1623 int ret;
1624
1625 DEBUGP("ip_ct_ras: skblen = %u\n", (*pskb)->len);
1626
1627 spin_lock_bh(&ip_h323_lock);
1628
1629 /* Get UDP data */
1630 data = get_udp_data(pskb, &datalen);
1631 if (data == NULL)
1632 goto accept;
1633 DEBUGP("ip_ct_ras: RAS message %u.%u.%u.%u->%u.%u.%u.%u, len=%d\n",
1634 NIPQUAD((*pskb)->nh.iph->saddr),
1635 NIPQUAD((*pskb)->nh.iph->daddr), datalen);
1636
1637 /* Decode RAS message */
1638 ret = DecodeRasMessage(data, datalen, &ras);
1639 if (ret < 0) {
1640 if (net_ratelimit())
1641 printk("ip_ct_ras: decoding error: %s\n",
1642 ret == H323_ERROR_BOUND ?
1643 "out of bound" : "out of range");
1644 goto accept;
1645 }
1646
1647 /* Process RAS message */
1648 if (process_ras(pskb, ct, ctinfo, &data, &ras) < 0)
1649 goto drop;
1650
1651 accept:
1652 spin_unlock_bh(&ip_h323_lock);
1653 return NF_ACCEPT;
1654
1655 drop:
1656 spin_unlock_bh(&ip_h323_lock);
1657 if (net_ratelimit())
1658 printk("ip_ct_ras: packet dropped\n");
1659 return NF_DROP;
1660}
1661
1662/****************************************************************************/
1663static struct ip_conntrack_helper ip_conntrack_helper_ras = {
1664 .name = "RAS",
1665 .me = THIS_MODULE,
1666 .max_expected = 32,
1667 .timeout = 240,
1668 .tuple = {.src = {.u = {__constant_htons(RAS_PORT)}},
1669 .dst = {.protonum = IPPROTO_UDP}},
1670 .mask = {.src = {.u = {0xFFFE}},
1671 .dst = {.protonum = 0xFF}},
1672 .help = ras_help,
1673};
1674
1675/****************************************************************************/
1676static void ip_conntrack_ras_expect(struct ip_conntrack *new,
1677 struct ip_conntrack_expect *this)
1678{
1679 write_lock_bh(&ip_conntrack_lock);
1680 new->helper = &ip_conntrack_helper_ras;
1681 write_unlock_bh(&ip_conntrack_lock);
1682}
1683
1684/****************************************************************************/
1685/* Not __exit - called from init() */
1686static void fini(void)
1687{
1688 ip_conntrack_helper_unregister(&ip_conntrack_helper_ras);
1689 ip_conntrack_helper_unregister(&ip_conntrack_helper_q931);
1690 kfree(h323_buffer);
1691 DEBUGP("ip_ct_h323: fini\n");
1692}
1693
1694/****************************************************************************/
1695static int __init init(void)
1696{
1697 int ret;
1698
1699 h323_buffer = kmalloc(65536, GFP_KERNEL);
1700 if (!h323_buffer)
1701 return -ENOMEM;
1702 if ((ret = ip_conntrack_helper_register(&ip_conntrack_helper_q931)) ||
1703 (ret = ip_conntrack_helper_register(&ip_conntrack_helper_ras))) {
1704 fini();
1705 return ret;
1706 }
1707
1708 DEBUGP("ip_ct_h323: init success\n");
1709 return 0;
1710}
1711
1712/****************************************************************************/
1713module_init(init);
1714module_exit(fini);
1715
1716EXPORT_SYMBOL(get_h245_addr);
1717EXPORT_SYMBOL(get_h225_addr);
1718EXPORT_SYMBOL(ip_conntrack_h245_expect);
1719EXPORT_SYMBOL(ip_conntrack_q931_expect);
1720EXPORT_SYMBOL(set_h245_addr_hook);
1721EXPORT_SYMBOL(set_h225_addr_hook);
1722EXPORT_SYMBOL(set_sig_addr_hook);
1723EXPORT_SYMBOL(set_ras_addr_hook);
1724EXPORT_SYMBOL(nat_rtp_rtcp_hook);
1725EXPORT_SYMBOL(nat_t120_hook);
1726EXPORT_SYMBOL(nat_h245_hook);
1727EXPORT_SYMBOL(nat_q931_hook);
1728
1729MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>");
1730MODULE_DESCRIPTION("H.323 connection tracking helper");
1731MODULE_LICENSE("GPL");