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[NETFILTER]: conntrack: add '_get' to {ip, nf}_conntrack_expect_find
[deliverable/linux.git] / net / ipv4 / netfilter / ip_conntrack_helper_h323.c
1 /*
2 * H.323 connection tracking helper
3 *
4 * Copyright (c) 2006 Jing Min Zhao <zhaojingmin@users.sourceforge.net>
5 *
6 * This source code is licensed under General Public License version 2.
7 *
8 * Based on the 'brute force' H.323 connection tracking module by
9 * Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
10 *
11 * For more information, please see http://nath323.sourceforge.net/
12 */
13
14 #include <linux/module.h>
15 #include <linux/netfilter.h>
16 #include <linux/ip.h>
17 #include <net/tcp.h>
18 #include <linux/netfilter_ipv4/ip_conntrack.h>
19 #include <linux/netfilter_ipv4/ip_conntrack_core.h>
20 #include <linux/netfilter_ipv4/ip_conntrack_helper.h>
21 #include <linux/netfilter_ipv4/ip_conntrack_tuple.h>
22 #include <linux/netfilter_ipv4/ip_conntrack_h323.h>
23 #include <linux/moduleparam.h>
24 #include <linux/ctype.h>
25 #include <linux/inet.h>
26
27 #if 0
28 #define DEBUGP printk
29 #else
30 #define DEBUGP(format, args...)
31 #endif
32
33 /* Parameters */
34 static unsigned int default_rrq_ttl = 300;
35 module_param(default_rrq_ttl, uint, 0600);
36 MODULE_PARM_DESC(default_rrq_ttl, "use this TTL if it's missing in RRQ");
37
38 static int gkrouted_only = 1;
39 module_param(gkrouted_only, int, 0600);
40 MODULE_PARM_DESC(gkrouted_only, "only accept calls from gatekeeper");
41
42 static int callforward_filter = 1;
43 module_param(callforward_filter, bool, 0600);
44 MODULE_PARM_DESC(callforward_filter, "only create call forwarding expectations "
45 "if both endpoints are on different sides "
46 "(determined by routing information)");
47
48 /* Hooks for NAT */
49 int (*set_h245_addr_hook) (struct sk_buff ** pskb,
50 unsigned char **data, int dataoff,
51 H245_TransportAddress * addr,
52 __be32 ip, u_int16_t port);
53 int (*set_h225_addr_hook) (struct sk_buff ** pskb,
54 unsigned char **data, int dataoff,
55 TransportAddress * addr,
56 __be32 ip, u_int16_t port);
57 int (*set_sig_addr_hook) (struct sk_buff ** pskb,
58 struct ip_conntrack * ct,
59 enum ip_conntrack_info ctinfo,
60 unsigned char **data,
61 TransportAddress * addr, int count);
62 int (*set_ras_addr_hook) (struct sk_buff ** pskb,
63 struct ip_conntrack * ct,
64 enum ip_conntrack_info ctinfo,
65 unsigned char **data,
66 TransportAddress * addr, int count);
67 int (*nat_rtp_rtcp_hook) (struct sk_buff ** pskb,
68 struct ip_conntrack * ct,
69 enum ip_conntrack_info ctinfo,
70 unsigned char **data, int dataoff,
71 H245_TransportAddress * addr,
72 u_int16_t port, u_int16_t rtp_port,
73 struct ip_conntrack_expect * rtp_exp,
74 struct ip_conntrack_expect * rtcp_exp);
75 int (*nat_t120_hook) (struct sk_buff ** pskb,
76 struct ip_conntrack * ct,
77 enum ip_conntrack_info ctinfo,
78 unsigned char **data, int dataoff,
79 H245_TransportAddress * addr, u_int16_t port,
80 struct ip_conntrack_expect * exp);
81 int (*nat_h245_hook) (struct sk_buff ** pskb,
82 struct ip_conntrack * ct,
83 enum ip_conntrack_info ctinfo,
84 unsigned char **data, int dataoff,
85 TransportAddress * addr, u_int16_t port,
86 struct ip_conntrack_expect * exp);
87 int (*nat_callforwarding_hook) (struct sk_buff ** pskb,
88 struct ip_conntrack * ct,
89 enum ip_conntrack_info ctinfo,
90 unsigned char **data, int dataoff,
91 TransportAddress * addr, u_int16_t port,
92 struct ip_conntrack_expect * exp);
93 int (*nat_q931_hook) (struct sk_buff ** pskb,
94 struct ip_conntrack * ct,
95 enum ip_conntrack_info ctinfo,
96 unsigned char **data, TransportAddress * addr, int idx,
97 u_int16_t port, struct ip_conntrack_expect * exp);
98
99
100 static DEFINE_SPINLOCK(ip_h323_lock);
101 static char *h323_buffer;
102
103 /****************************************************************************/
104 static int get_tpkt_data(struct sk_buff **pskb, struct ip_conntrack *ct,
105 enum ip_conntrack_info ctinfo,
106 unsigned char **data, int *datalen, int *dataoff)
107 {
108 struct ip_ct_h323_master *info = &ct->help.ct_h323_info;
109 int dir = CTINFO2DIR(ctinfo);
110 struct tcphdr _tcph, *th;
111 int tcpdatalen;
112 int tcpdataoff;
113 unsigned char *tpkt;
114 int tpktlen;
115 int tpktoff;
116
117 /* Get TCP header */
118 th = skb_header_pointer(*pskb, (*pskb)->nh.iph->ihl * 4,
119 sizeof(_tcph), &_tcph);
120 if (th == NULL)
121 return 0;
122
123 /* Get TCP data offset */
124 tcpdataoff = (*pskb)->nh.iph->ihl * 4 + th->doff * 4;
125
126 /* Get TCP data length */
127 tcpdatalen = (*pskb)->len - tcpdataoff;
128 if (tcpdatalen <= 0) /* No TCP data */
129 goto clear_out;
130
131 if (*data == NULL) { /* first TPKT */
132 /* Get first TPKT pointer */
133 tpkt = skb_header_pointer(*pskb, tcpdataoff, tcpdatalen,
134 h323_buffer);
135 BUG_ON(tpkt == NULL);
136
137 /* Validate TPKT identifier */
138 if (tcpdatalen < 4 || tpkt[0] != 0x03 || tpkt[1] != 0) {
139 /* Netmeeting sends TPKT header and data separately */
140 if (info->tpkt_len[dir] > 0) {
141 DEBUGP("ip_ct_h323: previous packet "
142 "indicated separate TPKT data of %hu "
143 "bytes\n", info->tpkt_len[dir]);
144 if (info->tpkt_len[dir] <= tcpdatalen) {
145 /* Yes, there was a TPKT header
146 * received */
147 *data = tpkt;
148 *datalen = info->tpkt_len[dir];
149 *dataoff = 0;
150 goto out;
151 }
152
153 /* Fragmented TPKT */
154 if (net_ratelimit())
155 printk("ip_ct_h323: "
156 "fragmented TPKT\n");
157 goto clear_out;
158 }
159
160 /* It is not even a TPKT */
161 return 0;
162 }
163 tpktoff = 0;
164 } else { /* Next TPKT */
165 tpktoff = *dataoff + *datalen;
166 tcpdatalen -= tpktoff;
167 if (tcpdatalen <= 4) /* No more TPKT */
168 goto clear_out;
169 tpkt = *data + *datalen;
170
171 /* Validate TPKT identifier */
172 if (tpkt[0] != 0x03 || tpkt[1] != 0)
173 goto clear_out;
174 }
175
176 /* Validate TPKT length */
177 tpktlen = tpkt[2] * 256 + tpkt[3];
178 if (tpktlen < 4)
179 goto clear_out;
180 if (tpktlen > tcpdatalen) {
181 if (tcpdatalen == 4) { /* Separate TPKT header */
182 /* Netmeeting sends TPKT header and data separately */
183 DEBUGP("ip_ct_h323: separate TPKT header indicates "
184 "there will be TPKT data of %hu bytes\n",
185 tpktlen - 4);
186 info->tpkt_len[dir] = tpktlen - 4;
187 return 0;
188 }
189
190 if (net_ratelimit())
191 printk("ip_ct_h323: incomplete TPKT (fragmented?)\n");
192 goto clear_out;
193 }
194
195 /* This is the encapsulated data */
196 *data = tpkt + 4;
197 *datalen = tpktlen - 4;
198 *dataoff = tpktoff + 4;
199
200 out:
201 /* Clear TPKT length */
202 info->tpkt_len[dir] = 0;
203 return 1;
204
205 clear_out:
206 info->tpkt_len[dir] = 0;
207 return 0;
208 }
209
210 /****************************************************************************/
211 static int get_h245_addr(unsigned char *data, H245_TransportAddress * addr,
212 __be32 * ip, u_int16_t * port)
213 {
214 unsigned char *p;
215
216 if (addr->choice != eH245_TransportAddress_unicastAddress ||
217 addr->unicastAddress.choice != eUnicastAddress_iPAddress)
218 return 0;
219
220 p = data + addr->unicastAddress.iPAddress.network;
221 *ip = htonl((p[0] << 24) | (p[1] << 16) | (p[2] << 8) | (p[3]));
222 *port = (p[4] << 8) | (p[5]);
223
224 return 1;
225 }
226
227 /****************************************************************************/
228 static int expect_rtp_rtcp(struct sk_buff **pskb, struct ip_conntrack *ct,
229 enum ip_conntrack_info ctinfo,
230 unsigned char **data, int dataoff,
231 H245_TransportAddress * addr)
232 {
233 int dir = CTINFO2DIR(ctinfo);
234 int ret = 0;
235 __be32 ip;
236 u_int16_t port;
237 u_int16_t rtp_port;
238 struct ip_conntrack_expect *rtp_exp;
239 struct ip_conntrack_expect *rtcp_exp;
240
241 /* Read RTP or RTCP address */
242 if (!get_h245_addr(*data, addr, &ip, &port) ||
243 ip != ct->tuplehash[dir].tuple.src.ip || port == 0)
244 return 0;
245
246 /* RTP port is even */
247 rtp_port = port & (~1);
248
249 /* Create expect for RTP */
250 if ((rtp_exp = ip_conntrack_expect_alloc(ct)) == NULL)
251 return -1;
252 rtp_exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip;
253 rtp_exp->tuple.src.u.udp.port = 0;
254 rtp_exp->tuple.dst.ip = ct->tuplehash[!dir].tuple.dst.ip;
255 rtp_exp->tuple.dst.u.udp.port = htons(rtp_port);
256 rtp_exp->tuple.dst.protonum = IPPROTO_UDP;
257 rtp_exp->mask.src.ip = htonl(0xFFFFFFFF);
258 rtp_exp->mask.src.u.udp.port = 0;
259 rtp_exp->mask.dst.ip = htonl(0xFFFFFFFF);
260 rtp_exp->mask.dst.u.udp.port = htons(0xFFFF);
261 rtp_exp->mask.dst.protonum = 0xFF;
262 rtp_exp->flags = 0;
263
264 /* Create expect for RTCP */
265 if ((rtcp_exp = ip_conntrack_expect_alloc(ct)) == NULL) {
266 ip_conntrack_expect_put(rtp_exp);
267 return -1;
268 }
269 rtcp_exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip;
270 rtcp_exp->tuple.src.u.udp.port = 0;
271 rtcp_exp->tuple.dst.ip = ct->tuplehash[!dir].tuple.dst.ip;
272 rtcp_exp->tuple.dst.u.udp.port = htons(rtp_port + 1);
273 rtcp_exp->tuple.dst.protonum = IPPROTO_UDP;
274 rtcp_exp->mask.src.ip = htonl(0xFFFFFFFF);
275 rtcp_exp->mask.src.u.udp.port = 0;
276 rtcp_exp->mask.dst.ip = htonl(0xFFFFFFFF);
277 rtcp_exp->mask.dst.u.udp.port = htons(0xFFFF);
278 rtcp_exp->mask.dst.protonum = 0xFF;
279 rtcp_exp->flags = 0;
280
281 if (ct->tuplehash[dir].tuple.src.ip !=
282 ct->tuplehash[!dir].tuple.dst.ip && nat_rtp_rtcp_hook) {
283 /* NAT needed */
284 ret = nat_rtp_rtcp_hook(pskb, ct, ctinfo, data, dataoff,
285 addr, port, rtp_port, rtp_exp,
286 rtcp_exp);
287 } else { /* Conntrack only */
288 rtp_exp->expectfn = NULL;
289 rtcp_exp->expectfn = NULL;
290
291 if (ip_conntrack_expect_related(rtp_exp) == 0) {
292 if (ip_conntrack_expect_related(rtcp_exp) == 0) {
293 DEBUGP("ip_ct_h323: expect RTP "
294 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
295 NIPQUAD(rtp_exp->tuple.src.ip),
296 ntohs(rtp_exp->tuple.src.u.udp.port),
297 NIPQUAD(rtp_exp->tuple.dst.ip),
298 ntohs(rtp_exp->tuple.dst.u.udp.port));
299 DEBUGP("ip_ct_h323: expect RTCP "
300 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
301 NIPQUAD(rtcp_exp->tuple.src.ip),
302 ntohs(rtcp_exp->tuple.src.u.udp.port),
303 NIPQUAD(rtcp_exp->tuple.dst.ip),
304 ntohs(rtcp_exp->tuple.dst.u.udp.port));
305 } else {
306 ip_conntrack_unexpect_related(rtp_exp);
307 ret = -1;
308 }
309 } else
310 ret = -1;
311 }
312
313 ip_conntrack_expect_put(rtp_exp);
314 ip_conntrack_expect_put(rtcp_exp);
315
316 return ret;
317 }
318
319 /****************************************************************************/
320 static int expect_t120(struct sk_buff **pskb,
321 struct ip_conntrack *ct,
322 enum ip_conntrack_info ctinfo,
323 unsigned char **data, int dataoff,
324 H245_TransportAddress * addr)
325 {
326 int dir = CTINFO2DIR(ctinfo);
327 int ret = 0;
328 __be32 ip;
329 u_int16_t port;
330 struct ip_conntrack_expect *exp = NULL;
331
332 /* Read T.120 address */
333 if (!get_h245_addr(*data, addr, &ip, &port) ||
334 ip != ct->tuplehash[dir].tuple.src.ip || port == 0)
335 return 0;
336
337 /* Create expect for T.120 connections */
338 if ((exp = ip_conntrack_expect_alloc(ct)) == NULL)
339 return -1;
340 exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip;
341 exp->tuple.src.u.tcp.port = 0;
342 exp->tuple.dst.ip = ct->tuplehash[!dir].tuple.dst.ip;
343 exp->tuple.dst.u.tcp.port = htons(port);
344 exp->tuple.dst.protonum = IPPROTO_TCP;
345 exp->mask.src.ip = htonl(0xFFFFFFFF);
346 exp->mask.src.u.tcp.port = 0;
347 exp->mask.dst.ip = htonl(0xFFFFFFFF);
348 exp->mask.dst.u.tcp.port = htons(0xFFFF);
349 exp->mask.dst.protonum = 0xFF;
350 exp->flags = IP_CT_EXPECT_PERMANENT; /* Accept multiple channels */
351
352 if (ct->tuplehash[dir].tuple.src.ip !=
353 ct->tuplehash[!dir].tuple.dst.ip && nat_t120_hook) {
354 /* NAT needed */
355 ret = nat_t120_hook(pskb, ct, ctinfo, data, dataoff, addr,
356 port, exp);
357 } else { /* Conntrack only */
358 exp->expectfn = NULL;
359 if (ip_conntrack_expect_related(exp) == 0) {
360 DEBUGP("ip_ct_h323: expect T.120 "
361 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
362 NIPQUAD(exp->tuple.src.ip),
363 ntohs(exp->tuple.src.u.tcp.port),
364 NIPQUAD(exp->tuple.dst.ip),
365 ntohs(exp->tuple.dst.u.tcp.port));
366 } else
367 ret = -1;
368 }
369
370 ip_conntrack_expect_put(exp);
371
372 return ret;
373 }
374
375 /****************************************************************************/
376 static int process_h245_channel(struct sk_buff **pskb,
377 struct ip_conntrack *ct,
378 enum ip_conntrack_info ctinfo,
379 unsigned char **data, int dataoff,
380 H2250LogicalChannelParameters * channel)
381 {
382 int ret;
383
384 if (channel->options & eH2250LogicalChannelParameters_mediaChannel) {
385 /* RTP */
386 ret = expect_rtp_rtcp(pskb, ct, ctinfo, data, dataoff,
387 &channel->mediaChannel);
388 if (ret < 0)
389 return -1;
390 }
391
392 if (channel->
393 options & eH2250LogicalChannelParameters_mediaControlChannel) {
394 /* RTCP */
395 ret = expect_rtp_rtcp(pskb, ct, ctinfo, data, dataoff,
396 &channel->mediaControlChannel);
397 if (ret < 0)
398 return -1;
399 }
400
401 return 0;
402 }
403
404 /****************************************************************************/
405 static int process_olc(struct sk_buff **pskb, struct ip_conntrack *ct,
406 enum ip_conntrack_info ctinfo,
407 unsigned char **data, int dataoff,
408 OpenLogicalChannel * olc)
409 {
410 int ret;
411
412 DEBUGP("ip_ct_h323: OpenLogicalChannel\n");
413
414 if (olc->forwardLogicalChannelParameters.multiplexParameters.choice ==
415 eOpenLogicalChannel_forwardLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters)
416 {
417 ret = process_h245_channel(pskb, ct, ctinfo, data, dataoff,
418 &olc->
419 forwardLogicalChannelParameters.
420 multiplexParameters.
421 h2250LogicalChannelParameters);
422 if (ret < 0)
423 return -1;
424 }
425
426 if ((olc->options &
427 eOpenLogicalChannel_reverseLogicalChannelParameters) &&
428 (olc->reverseLogicalChannelParameters.options &
429 eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters)
430 && (olc->reverseLogicalChannelParameters.multiplexParameters.
431 choice ==
432 eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
433 {
434 ret =
435 process_h245_channel(pskb, ct, ctinfo, data, dataoff,
436 &olc->
437 reverseLogicalChannelParameters.
438 multiplexParameters.
439 h2250LogicalChannelParameters);
440 if (ret < 0)
441 return -1;
442 }
443
444 if ((olc->options & eOpenLogicalChannel_separateStack) &&
445 olc->forwardLogicalChannelParameters.dataType.choice ==
446 eDataType_data &&
447 olc->forwardLogicalChannelParameters.dataType.data.application.
448 choice == eDataApplicationCapability_application_t120 &&
449 olc->forwardLogicalChannelParameters.dataType.data.application.
450 t120.choice == eDataProtocolCapability_separateLANStack &&
451 olc->separateStack.networkAddress.choice ==
452 eNetworkAccessParameters_networkAddress_localAreaAddress) {
453 ret = expect_t120(pskb, ct, ctinfo, data, dataoff,
454 &olc->separateStack.networkAddress.
455 localAreaAddress);
456 if (ret < 0)
457 return -1;
458 }
459
460 return 0;
461 }
462
463 /****************************************************************************/
464 static int process_olca(struct sk_buff **pskb, struct ip_conntrack *ct,
465 enum ip_conntrack_info ctinfo,
466 unsigned char **data, int dataoff,
467 OpenLogicalChannelAck * olca)
468 {
469 H2250LogicalChannelAckParameters *ack;
470 int ret;
471
472 DEBUGP("ip_ct_h323: OpenLogicalChannelAck\n");
473
474 if ((olca->options &
475 eOpenLogicalChannelAck_reverseLogicalChannelParameters) &&
476 (olca->reverseLogicalChannelParameters.options &
477 eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters)
478 && (olca->reverseLogicalChannelParameters.multiplexParameters.
479 choice ==
480 eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
481 {
482 ret = process_h245_channel(pskb, ct, ctinfo, data, dataoff,
483 &olca->
484 reverseLogicalChannelParameters.
485 multiplexParameters.
486 h2250LogicalChannelParameters);
487 if (ret < 0)
488 return -1;
489 }
490
491 if ((olca->options &
492 eOpenLogicalChannelAck_forwardMultiplexAckParameters) &&
493 (olca->forwardMultiplexAckParameters.choice ==
494 eOpenLogicalChannelAck_forwardMultiplexAckParameters_h2250LogicalChannelAckParameters))
495 {
496 ack = &olca->forwardMultiplexAckParameters.
497 h2250LogicalChannelAckParameters;
498 if (ack->options &
499 eH2250LogicalChannelAckParameters_mediaChannel) {
500 /* RTP */
501 ret = expect_rtp_rtcp(pskb, ct, ctinfo, data, dataoff,
502 &ack->mediaChannel);
503 if (ret < 0)
504 return -1;
505 }
506
507 if (ack->options &
508 eH2250LogicalChannelAckParameters_mediaControlChannel) {
509 /* RTCP */
510 ret = expect_rtp_rtcp(pskb, ct, ctinfo, data, dataoff,
511 &ack->mediaControlChannel);
512 if (ret < 0)
513 return -1;
514 }
515 }
516
517 return 0;
518 }
519
520 /****************************************************************************/
521 static int process_h245(struct sk_buff **pskb, struct ip_conntrack *ct,
522 enum ip_conntrack_info ctinfo,
523 unsigned char **data, int dataoff,
524 MultimediaSystemControlMessage * mscm)
525 {
526 switch (mscm->choice) {
527 case eMultimediaSystemControlMessage_request:
528 if (mscm->request.choice ==
529 eRequestMessage_openLogicalChannel) {
530 return process_olc(pskb, ct, ctinfo, data, dataoff,
531 &mscm->request.openLogicalChannel);
532 }
533 DEBUGP("ip_ct_h323: H.245 Request %d\n",
534 mscm->request.choice);
535 break;
536 case eMultimediaSystemControlMessage_response:
537 if (mscm->response.choice ==
538 eResponseMessage_openLogicalChannelAck) {
539 return process_olca(pskb, ct, ctinfo, data, dataoff,
540 &mscm->response.
541 openLogicalChannelAck);
542 }
543 DEBUGP("ip_ct_h323: H.245 Response %d\n",
544 mscm->response.choice);
545 break;
546 default:
547 DEBUGP("ip_ct_h323: H.245 signal %d\n", mscm->choice);
548 break;
549 }
550
551 return 0;
552 }
553
554 /****************************************************************************/
555 static int h245_help(struct sk_buff **pskb, struct ip_conntrack *ct,
556 enum ip_conntrack_info ctinfo)
557 {
558 static MultimediaSystemControlMessage mscm;
559 unsigned char *data = NULL;
560 int datalen;
561 int dataoff;
562 int ret;
563
564 /* Until there's been traffic both ways, don't look in packets. */
565 if (ctinfo != IP_CT_ESTABLISHED
566 && ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) {
567 return NF_ACCEPT;
568 }
569 DEBUGP("ip_ct_h245: skblen = %u\n", (*pskb)->len);
570
571 spin_lock_bh(&ip_h323_lock);
572
573 /* Process each TPKT */
574 while (get_tpkt_data(pskb, ct, ctinfo, &data, &datalen, &dataoff)) {
575 DEBUGP("ip_ct_h245: TPKT %u.%u.%u.%u->%u.%u.%u.%u, len=%d\n",
576 NIPQUAD((*pskb)->nh.iph->saddr),
577 NIPQUAD((*pskb)->nh.iph->daddr), datalen);
578
579 /* Decode H.245 signal */
580 ret = DecodeMultimediaSystemControlMessage(data, datalen,
581 &mscm);
582 if (ret < 0) {
583 if (net_ratelimit())
584 printk("ip_ct_h245: decoding error: %s\n",
585 ret == H323_ERROR_BOUND ?
586 "out of bound" : "out of range");
587 /* We don't drop when decoding error */
588 break;
589 }
590
591 /* Process H.245 signal */
592 if (process_h245(pskb, ct, ctinfo, &data, dataoff, &mscm) < 0)
593 goto drop;
594 }
595
596 spin_unlock_bh(&ip_h323_lock);
597 return NF_ACCEPT;
598
599 drop:
600 spin_unlock_bh(&ip_h323_lock);
601 if (net_ratelimit())
602 printk("ip_ct_h245: packet dropped\n");
603 return NF_DROP;
604 }
605
606 /****************************************************************************/
607 static struct ip_conntrack_helper ip_conntrack_helper_h245 = {
608 .name = "H.245",
609 .me = THIS_MODULE,
610 .max_expected = H323_RTP_CHANNEL_MAX * 4 + 2 /* T.120 */ ,
611 .timeout = 240,
612 .tuple = {.dst = {.protonum = IPPROTO_TCP}},
613 .mask = {.src = {.u = {0xFFFF}},
614 .dst = {.protonum = 0xFF}},
615 .help = h245_help
616 };
617
618 /****************************************************************************/
619 void ip_conntrack_h245_expect(struct ip_conntrack *new,
620 struct ip_conntrack_expect *this)
621 {
622 write_lock_bh(&ip_conntrack_lock);
623 new->helper = &ip_conntrack_helper_h245;
624 write_unlock_bh(&ip_conntrack_lock);
625 }
626
627 /****************************************************************************/
628 int get_h225_addr(unsigned char *data, TransportAddress * addr,
629 __be32 * ip, u_int16_t * port)
630 {
631 unsigned char *p;
632
633 if (addr->choice != eTransportAddress_ipAddress)
634 return 0;
635
636 p = data + addr->ipAddress.ip;
637 *ip = htonl((p[0] << 24) | (p[1] << 16) | (p[2] << 8) | (p[3]));
638 *port = (p[4] << 8) | (p[5]);
639
640 return 1;
641 }
642
643 /****************************************************************************/
644 static int expect_h245(struct sk_buff **pskb, struct ip_conntrack *ct,
645 enum ip_conntrack_info ctinfo,
646 unsigned char **data, int dataoff,
647 TransportAddress * addr)
648 {
649 int dir = CTINFO2DIR(ctinfo);
650 int ret = 0;
651 __be32 ip;
652 u_int16_t port;
653 struct ip_conntrack_expect *exp = NULL;
654
655 /* Read h245Address */
656 if (!get_h225_addr(*data, addr, &ip, &port) ||
657 ip != ct->tuplehash[dir].tuple.src.ip || port == 0)
658 return 0;
659
660 /* Create expect for h245 connection */
661 if ((exp = ip_conntrack_expect_alloc(ct)) == NULL)
662 return -1;
663 exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip;
664 exp->tuple.src.u.tcp.port = 0;
665 exp->tuple.dst.ip = ct->tuplehash[!dir].tuple.dst.ip;
666 exp->tuple.dst.u.tcp.port = htons(port);
667 exp->tuple.dst.protonum = IPPROTO_TCP;
668 exp->mask.src.ip = htonl(0xFFFFFFFF);
669 exp->mask.src.u.tcp.port = 0;
670 exp->mask.dst.ip = htonl(0xFFFFFFFF);
671 exp->mask.dst.u.tcp.port = htons(0xFFFF);
672 exp->mask.dst.protonum = 0xFF;
673 exp->flags = 0;
674
675 if (ct->tuplehash[dir].tuple.src.ip !=
676 ct->tuplehash[!dir].tuple.dst.ip && nat_h245_hook) {
677 /* NAT needed */
678 ret = nat_h245_hook(pskb, ct, ctinfo, data, dataoff, addr,
679 port, exp);
680 } else { /* Conntrack only */
681 exp->expectfn = ip_conntrack_h245_expect;
682
683 if (ip_conntrack_expect_related(exp) == 0) {
684 DEBUGP("ip_ct_q931: expect H.245 "
685 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
686 NIPQUAD(exp->tuple.src.ip),
687 ntohs(exp->tuple.src.u.tcp.port),
688 NIPQUAD(exp->tuple.dst.ip),
689 ntohs(exp->tuple.dst.u.tcp.port));
690 } else
691 ret = -1;
692 }
693
694 ip_conntrack_expect_put(exp);
695
696 return ret;
697 }
698
699 /* Forwarding declaration */
700 void ip_conntrack_q931_expect(struct ip_conntrack *new,
701 struct ip_conntrack_expect *this);
702
703 /****************************************************************************/
704 static int expect_callforwarding(struct sk_buff **pskb,
705 struct ip_conntrack *ct,
706 enum ip_conntrack_info ctinfo,
707 unsigned char **data, int dataoff,
708 TransportAddress * addr)
709 {
710 int dir = CTINFO2DIR(ctinfo);
711 int ret = 0;
712 __be32 ip;
713 u_int16_t port;
714 struct ip_conntrack_expect *exp = NULL;
715
716 /* Read alternativeAddress */
717 if (!get_h225_addr(*data, addr, &ip, &port) || port == 0)
718 return 0;
719
720 /* If the calling party is on the same side of the forward-to party,
721 * we don't need to track the second call */
722 if (callforward_filter) {
723 struct rtable *rt1, *rt2;
724 struct flowi fl1 = {
725 .fl4_dst = ip,
726 };
727 struct flowi fl2 = {
728 .fl4_dst = ct->tuplehash[!dir].tuple.src.ip,
729 };
730
731 if (ip_route_output_key(&rt1, &fl1) == 0) {
732 if (ip_route_output_key(&rt2, &fl2) == 0) {
733 if (rt1->rt_gateway == rt2->rt_gateway &&
734 rt1->u.dst.dev == rt2->u.dst.dev)
735 ret = 1;
736 dst_release(&rt2->u.dst);
737 }
738 dst_release(&rt1->u.dst);
739 }
740 if (ret) {
741 DEBUGP("ip_ct_q931: Call Forwarding not tracked\n");
742 return 0;
743 }
744 }
745
746 /* Create expect for the second call leg */
747 if ((exp = ip_conntrack_expect_alloc(ct)) == NULL)
748 return -1;
749 exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip;
750 exp->tuple.src.u.tcp.port = 0;
751 exp->tuple.dst.ip = ip;
752 exp->tuple.dst.u.tcp.port = htons(port);
753 exp->tuple.dst.protonum = IPPROTO_TCP;
754 exp->mask.src.ip = htonl(0xFFFFFFFF);
755 exp->mask.src.u.tcp.port = 0;
756 exp->mask.dst.ip = htonl(0xFFFFFFFF);
757 exp->mask.dst.u.tcp.port = htons(0xFFFF);
758 exp->mask.dst.protonum = 0xFF;
759 exp->flags = 0;
760
761 if (ct->tuplehash[dir].tuple.src.ip !=
762 ct->tuplehash[!dir].tuple.dst.ip && nat_callforwarding_hook) {
763 /* Need NAT */
764 ret = nat_callforwarding_hook(pskb, ct, ctinfo, data, dataoff,
765 addr, port, exp);
766 } else { /* Conntrack only */
767 exp->expectfn = ip_conntrack_q931_expect;
768
769 if (ip_conntrack_expect_related(exp) == 0) {
770 DEBUGP("ip_ct_q931: expect Call Forwarding "
771 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
772 NIPQUAD(exp->tuple.src.ip),
773 ntohs(exp->tuple.src.u.tcp.port),
774 NIPQUAD(exp->tuple.dst.ip),
775 ntohs(exp->tuple.dst.u.tcp.port));
776 } else
777 ret = -1;
778 }
779
780 ip_conntrack_expect_put(exp);
781
782 return ret;
783 }
784
785 /****************************************************************************/
786 static int process_setup(struct sk_buff **pskb, struct ip_conntrack *ct,
787 enum ip_conntrack_info ctinfo,
788 unsigned char **data, int dataoff,
789 Setup_UUIE * setup)
790 {
791 int dir = CTINFO2DIR(ctinfo);
792 int ret;
793 int i;
794 __be32 ip;
795 u_int16_t port;
796
797 DEBUGP("ip_ct_q931: Setup\n");
798
799 if (setup->options & eSetup_UUIE_h245Address) {
800 ret = expect_h245(pskb, ct, ctinfo, data, dataoff,
801 &setup->h245Address);
802 if (ret < 0)
803 return -1;
804 }
805
806 if ((setup->options & eSetup_UUIE_destCallSignalAddress) &&
807 (set_h225_addr_hook) &&
808 get_h225_addr(*data, &setup->destCallSignalAddress, &ip, &port) &&
809 ip != ct->tuplehash[!dir].tuple.src.ip) {
810 DEBUGP("ip_ct_q931: set destCallSignalAddress "
811 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
812 NIPQUAD(ip), port,
813 NIPQUAD(ct->tuplehash[!dir].tuple.src.ip),
814 ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port));
815 ret = set_h225_addr_hook(pskb, data, dataoff,
816 &setup->destCallSignalAddress,
817 ct->tuplehash[!dir].tuple.src.ip,
818 ntohs(ct->tuplehash[!dir].tuple.src.
819 u.tcp.port));
820 if (ret < 0)
821 return -1;
822 }
823
824 if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) &&
825 (set_h225_addr_hook) &&
826 get_h225_addr(*data, &setup->sourceCallSignalAddress, &ip, &port)
827 && ip != ct->tuplehash[!dir].tuple.dst.ip) {
828 DEBUGP("ip_ct_q931: set sourceCallSignalAddress "
829 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
830 NIPQUAD(ip), port,
831 NIPQUAD(ct->tuplehash[!dir].tuple.dst.ip),
832 ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port));
833 ret = set_h225_addr_hook(pskb, data, dataoff,
834 &setup->sourceCallSignalAddress,
835 ct->tuplehash[!dir].tuple.dst.ip,
836 ntohs(ct->tuplehash[!dir].tuple.dst.
837 u.tcp.port));
838 if (ret < 0)
839 return -1;
840 }
841
842 if (setup->options & eSetup_UUIE_fastStart) {
843 for (i = 0; i < setup->fastStart.count; i++) {
844 ret = process_olc(pskb, ct, ctinfo, data, dataoff,
845 &setup->fastStart.item[i]);
846 if (ret < 0)
847 return -1;
848 }
849 }
850
851 return 0;
852 }
853
854 /****************************************************************************/
855 static int process_callproceeding(struct sk_buff **pskb,
856 struct ip_conntrack *ct,
857 enum ip_conntrack_info ctinfo,
858 unsigned char **data, int dataoff,
859 CallProceeding_UUIE * callproc)
860 {
861 int ret;
862 int i;
863
864 DEBUGP("ip_ct_q931: CallProceeding\n");
865
866 if (callproc->options & eCallProceeding_UUIE_h245Address) {
867 ret = expect_h245(pskb, ct, ctinfo, data, dataoff,
868 &callproc->h245Address);
869 if (ret < 0)
870 return -1;
871 }
872
873 if (callproc->options & eCallProceeding_UUIE_fastStart) {
874 for (i = 0; i < callproc->fastStart.count; i++) {
875 ret = process_olc(pskb, ct, ctinfo, data, dataoff,
876 &callproc->fastStart.item[i]);
877 if (ret < 0)
878 return -1;
879 }
880 }
881
882 return 0;
883 }
884
885 /****************************************************************************/
886 static int process_connect(struct sk_buff **pskb, struct ip_conntrack *ct,
887 enum ip_conntrack_info ctinfo,
888 unsigned char **data, int dataoff,
889 Connect_UUIE * connect)
890 {
891 int ret;
892 int i;
893
894 DEBUGP("ip_ct_q931: Connect\n");
895
896 if (connect->options & eConnect_UUIE_h245Address) {
897 ret = expect_h245(pskb, ct, ctinfo, data, dataoff,
898 &connect->h245Address);
899 if (ret < 0)
900 return -1;
901 }
902
903 if (connect->options & eConnect_UUIE_fastStart) {
904 for (i = 0; i < connect->fastStart.count; i++) {
905 ret = process_olc(pskb, ct, ctinfo, data, dataoff,
906 &connect->fastStart.item[i]);
907 if (ret < 0)
908 return -1;
909 }
910 }
911
912 return 0;
913 }
914
915 /****************************************************************************/
916 static int process_alerting(struct sk_buff **pskb, struct ip_conntrack *ct,
917 enum ip_conntrack_info ctinfo,
918 unsigned char **data, int dataoff,
919 Alerting_UUIE * alert)
920 {
921 int ret;
922 int i;
923
924 DEBUGP("ip_ct_q931: Alerting\n");
925
926 if (alert->options & eAlerting_UUIE_h245Address) {
927 ret = expect_h245(pskb, ct, ctinfo, data, dataoff,
928 &alert->h245Address);
929 if (ret < 0)
930 return -1;
931 }
932
933 if (alert->options & eAlerting_UUIE_fastStart) {
934 for (i = 0; i < alert->fastStart.count; i++) {
935 ret = process_olc(pskb, ct, ctinfo, data, dataoff,
936 &alert->fastStart.item[i]);
937 if (ret < 0)
938 return -1;
939 }
940 }
941
942 return 0;
943 }
944
945 /****************************************************************************/
946 static int process_information(struct sk_buff **pskb,
947 struct ip_conntrack *ct,
948 enum ip_conntrack_info ctinfo,
949 unsigned char **data, int dataoff,
950 Information_UUIE * info)
951 {
952 int ret;
953 int i;
954
955 DEBUGP("ip_ct_q931: Information\n");
956
957 if (info->options & eInformation_UUIE_fastStart) {
958 for (i = 0; i < info->fastStart.count; i++) {
959 ret = process_olc(pskb, ct, ctinfo, data, dataoff,
960 &info->fastStart.item[i]);
961 if (ret < 0)
962 return -1;
963 }
964 }
965
966 return 0;
967 }
968
969 /****************************************************************************/
970 static int process_facility(struct sk_buff **pskb, struct ip_conntrack *ct,
971 enum ip_conntrack_info ctinfo,
972 unsigned char **data, int dataoff,
973 Facility_UUIE * facility)
974 {
975 int ret;
976 int i;
977
978 DEBUGP("ip_ct_q931: Facility\n");
979
980 if (facility->reason.choice == eFacilityReason_callForwarded) {
981 if (facility->options & eFacility_UUIE_alternativeAddress)
982 return expect_callforwarding(pskb, ct, ctinfo, data,
983 dataoff,
984 &facility->
985 alternativeAddress);
986 return 0;
987 }
988
989 if (facility->options & eFacility_UUIE_h245Address) {
990 ret = expect_h245(pskb, ct, ctinfo, data, dataoff,
991 &facility->h245Address);
992 if (ret < 0)
993 return -1;
994 }
995
996 if (facility->options & eFacility_UUIE_fastStart) {
997 for (i = 0; i < facility->fastStart.count; i++) {
998 ret = process_olc(pskb, ct, ctinfo, data, dataoff,
999 &facility->fastStart.item[i]);
1000 if (ret < 0)
1001 return -1;
1002 }
1003 }
1004
1005 return 0;
1006 }
1007
1008 /****************************************************************************/
1009 static int process_progress(struct sk_buff **pskb, struct ip_conntrack *ct,
1010 enum ip_conntrack_info ctinfo,
1011 unsigned char **data, int dataoff,
1012 Progress_UUIE * progress)
1013 {
1014 int ret;
1015 int i;
1016
1017 DEBUGP("ip_ct_q931: Progress\n");
1018
1019 if (progress->options & eProgress_UUIE_h245Address) {
1020 ret = expect_h245(pskb, ct, ctinfo, data, dataoff,
1021 &progress->h245Address);
1022 if (ret < 0)
1023 return -1;
1024 }
1025
1026 if (progress->options & eProgress_UUIE_fastStart) {
1027 for (i = 0; i < progress->fastStart.count; i++) {
1028 ret = process_olc(pskb, ct, ctinfo, data, dataoff,
1029 &progress->fastStart.item[i]);
1030 if (ret < 0)
1031 return -1;
1032 }
1033 }
1034
1035 return 0;
1036 }
1037
1038 /****************************************************************************/
1039 static int process_q931(struct sk_buff **pskb, struct ip_conntrack *ct,
1040 enum ip_conntrack_info ctinfo,
1041 unsigned char **data, int dataoff, Q931 * q931)
1042 {
1043 H323_UU_PDU *pdu = &q931->UUIE.h323_uu_pdu;
1044 int i;
1045 int ret = 0;
1046
1047 switch (pdu->h323_message_body.choice) {
1048 case eH323_UU_PDU_h323_message_body_setup:
1049 ret = process_setup(pskb, ct, ctinfo, data, dataoff,
1050 &pdu->h323_message_body.setup);
1051 break;
1052 case eH323_UU_PDU_h323_message_body_callProceeding:
1053 ret = process_callproceeding(pskb, ct, ctinfo, data, dataoff,
1054 &pdu->h323_message_body.
1055 callProceeding);
1056 break;
1057 case eH323_UU_PDU_h323_message_body_connect:
1058 ret = process_connect(pskb, ct, ctinfo, data, dataoff,
1059 &pdu->h323_message_body.connect);
1060 break;
1061 case eH323_UU_PDU_h323_message_body_alerting:
1062 ret = process_alerting(pskb, ct, ctinfo, data, dataoff,
1063 &pdu->h323_message_body.alerting);
1064 break;
1065 case eH323_UU_PDU_h323_message_body_information:
1066 ret = process_information(pskb, ct, ctinfo, data, dataoff,
1067 &pdu->h323_message_body.
1068 information);
1069 break;
1070 case eH323_UU_PDU_h323_message_body_facility:
1071 ret = process_facility(pskb, ct, ctinfo, data, dataoff,
1072 &pdu->h323_message_body.facility);
1073 break;
1074 case eH323_UU_PDU_h323_message_body_progress:
1075 ret = process_progress(pskb, ct, ctinfo, data, dataoff,
1076 &pdu->h323_message_body.progress);
1077 break;
1078 default:
1079 DEBUGP("ip_ct_q931: Q.931 signal %d\n",
1080 pdu->h323_message_body.choice);
1081 break;
1082 }
1083
1084 if (ret < 0)
1085 return -1;
1086
1087 if (pdu->options & eH323_UU_PDU_h245Control) {
1088 for (i = 0; i < pdu->h245Control.count; i++) {
1089 ret = process_h245(pskb, ct, ctinfo, data, dataoff,
1090 &pdu->h245Control.item[i]);
1091 if (ret < 0)
1092 return -1;
1093 }
1094 }
1095
1096 return 0;
1097 }
1098
1099 /****************************************************************************/
1100 static int q931_help(struct sk_buff **pskb, struct ip_conntrack *ct,
1101 enum ip_conntrack_info ctinfo)
1102 {
1103 static Q931 q931;
1104 unsigned char *data = NULL;
1105 int datalen;
1106 int dataoff;
1107 int ret;
1108
1109 /* Until there's been traffic both ways, don't look in packets. */
1110 if (ctinfo != IP_CT_ESTABLISHED
1111 && ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) {
1112 return NF_ACCEPT;
1113 }
1114 DEBUGP("ip_ct_q931: skblen = %u\n", (*pskb)->len);
1115
1116 spin_lock_bh(&ip_h323_lock);
1117
1118 /* Process each TPKT */
1119 while (get_tpkt_data(pskb, ct, ctinfo, &data, &datalen, &dataoff)) {
1120 DEBUGP("ip_ct_q931: TPKT %u.%u.%u.%u->%u.%u.%u.%u, len=%d\n",
1121 NIPQUAD((*pskb)->nh.iph->saddr),
1122 NIPQUAD((*pskb)->nh.iph->daddr), datalen);
1123
1124 /* Decode Q.931 signal */
1125 ret = DecodeQ931(data, datalen, &q931);
1126 if (ret < 0) {
1127 if (net_ratelimit())
1128 printk("ip_ct_q931: decoding error: %s\n",
1129 ret == H323_ERROR_BOUND ?
1130 "out of bound" : "out of range");
1131 /* We don't drop when decoding error */
1132 break;
1133 }
1134
1135 /* Process Q.931 signal */
1136 if (process_q931(pskb, ct, ctinfo, &data, dataoff, &q931) < 0)
1137 goto drop;
1138 }
1139
1140 spin_unlock_bh(&ip_h323_lock);
1141 return NF_ACCEPT;
1142
1143 drop:
1144 spin_unlock_bh(&ip_h323_lock);
1145 if (net_ratelimit())
1146 printk("ip_ct_q931: packet dropped\n");
1147 return NF_DROP;
1148 }
1149
1150 /****************************************************************************/
1151 static struct ip_conntrack_helper ip_conntrack_helper_q931 = {
1152 .name = "Q.931",
1153 .me = THIS_MODULE,
1154 .max_expected = H323_RTP_CHANNEL_MAX * 4 + 4 /* T.120 and H.245 */ ,
1155 .timeout = 240,
1156 .tuple = {.src = {.u = {.tcp = {.port = __constant_htons(Q931_PORT)}}},
1157 .dst = {.protonum = IPPROTO_TCP}},
1158 .mask = {.src = {.u = {0xFFFF}},
1159 .dst = {.protonum = 0xFF}},
1160 .help = q931_help
1161 };
1162
1163 /****************************************************************************/
1164 void ip_conntrack_q931_expect(struct ip_conntrack *new,
1165 struct ip_conntrack_expect *this)
1166 {
1167 write_lock_bh(&ip_conntrack_lock);
1168 new->helper = &ip_conntrack_helper_q931;
1169 write_unlock_bh(&ip_conntrack_lock);
1170 }
1171
1172 /****************************************************************************/
1173 static unsigned char *get_udp_data(struct sk_buff **pskb, int *datalen)
1174 {
1175 struct udphdr _uh, *uh;
1176 int dataoff;
1177
1178 uh = skb_header_pointer(*pskb, (*pskb)->nh.iph->ihl * 4, sizeof(_uh),
1179 &_uh);
1180 if (uh == NULL)
1181 return NULL;
1182 dataoff = (*pskb)->nh.iph->ihl * 4 + sizeof(_uh);
1183 if (dataoff >= (*pskb)->len)
1184 return NULL;
1185 *datalen = (*pskb)->len - dataoff;
1186 return skb_header_pointer(*pskb, dataoff, *datalen, h323_buffer);
1187 }
1188
1189 /****************************************************************************/
1190 static struct ip_conntrack_expect *find_expect(struct ip_conntrack *ct,
1191 __be32 ip, u_int16_t port)
1192 {
1193 struct ip_conntrack_expect *exp;
1194 struct ip_conntrack_tuple tuple;
1195
1196 tuple.src.ip = 0;
1197 tuple.src.u.tcp.port = 0;
1198 tuple.dst.ip = ip;
1199 tuple.dst.u.tcp.port = htons(port);
1200 tuple.dst.protonum = IPPROTO_TCP;
1201
1202 exp = __ip_conntrack_expect_find(&tuple);
1203 if (exp && exp->master == ct)
1204 return exp;
1205 return NULL;
1206 }
1207
1208 /****************************************************************************/
1209 static int set_expect_timeout(struct ip_conntrack_expect *exp,
1210 unsigned timeout)
1211 {
1212 if (!exp || !del_timer(&exp->timeout))
1213 return 0;
1214
1215 exp->timeout.expires = jiffies + timeout * HZ;
1216 add_timer(&exp->timeout);
1217
1218 return 1;
1219 }
1220
1221 /****************************************************************************/
1222 static int expect_q931(struct sk_buff **pskb, struct ip_conntrack *ct,
1223 enum ip_conntrack_info ctinfo,
1224 unsigned char **data,
1225 TransportAddress * addr, int count)
1226 {
1227 struct ip_ct_h323_master *info = &ct->help.ct_h323_info;
1228 int dir = CTINFO2DIR(ctinfo);
1229 int ret = 0;
1230 int i;
1231 __be32 ip;
1232 u_int16_t port;
1233 struct ip_conntrack_expect *exp;
1234
1235 /* Look for the first related address */
1236 for (i = 0; i < count; i++) {
1237 if (get_h225_addr(*data, &addr[i], &ip, &port) &&
1238 ip == ct->tuplehash[dir].tuple.src.ip && port != 0)
1239 break;
1240 }
1241
1242 if (i >= count) /* Not found */
1243 return 0;
1244
1245 /* Create expect for Q.931 */
1246 if ((exp = ip_conntrack_expect_alloc(ct)) == NULL)
1247 return -1;
1248 exp->tuple.src.ip = gkrouted_only ? /* only accept calls from GK? */
1249 ct->tuplehash[!dir].tuple.src.ip : 0;
1250 exp->tuple.src.u.tcp.port = 0;
1251 exp->tuple.dst.ip = ct->tuplehash[!dir].tuple.dst.ip;
1252 exp->tuple.dst.u.tcp.port = htons(port);
1253 exp->tuple.dst.protonum = IPPROTO_TCP;
1254 exp->mask.src.ip = gkrouted_only ? htonl(0xFFFFFFFF) : 0;
1255 exp->mask.src.u.tcp.port = 0;
1256 exp->mask.dst.ip = htonl(0xFFFFFFFF);
1257 exp->mask.dst.u.tcp.port = htons(0xFFFF);
1258 exp->mask.dst.protonum = 0xFF;
1259 exp->flags = IP_CT_EXPECT_PERMANENT; /* Accept multiple calls */
1260
1261 if (nat_q931_hook) { /* Need NAT */
1262 ret = nat_q931_hook(pskb, ct, ctinfo, data, addr, i,
1263 port, exp);
1264 } else { /* Conntrack only */
1265 exp->expectfn = ip_conntrack_q931_expect;
1266
1267 if (ip_conntrack_expect_related(exp) == 0) {
1268 DEBUGP("ip_ct_ras: expect Q.931 "
1269 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
1270 NIPQUAD(exp->tuple.src.ip),
1271 ntohs(exp->tuple.src.u.tcp.port),
1272 NIPQUAD(exp->tuple.dst.ip),
1273 ntohs(exp->tuple.dst.u.tcp.port));
1274
1275 /* Save port for looking up expect in processing RCF */
1276 info->sig_port[dir] = port;
1277 } else
1278 ret = -1;
1279 }
1280
1281 ip_conntrack_expect_put(exp);
1282
1283 return ret;
1284 }
1285
1286 /****************************************************************************/
1287 static int process_grq(struct sk_buff **pskb, struct ip_conntrack *ct,
1288 enum ip_conntrack_info ctinfo,
1289 unsigned char **data, GatekeeperRequest * grq)
1290 {
1291 DEBUGP("ip_ct_ras: GRQ\n");
1292
1293 if (set_ras_addr_hook) /* NATed */
1294 return set_ras_addr_hook(pskb, ct, ctinfo, data,
1295 &grq->rasAddress, 1);
1296 return 0;
1297 }
1298
1299 /* Declare before using */
1300 static void ip_conntrack_ras_expect(struct ip_conntrack *new,
1301 struct ip_conntrack_expect *this);
1302
1303 /****************************************************************************/
1304 static int process_gcf(struct sk_buff **pskb, struct ip_conntrack *ct,
1305 enum ip_conntrack_info ctinfo,
1306 unsigned char **data, GatekeeperConfirm * gcf)
1307 {
1308 int dir = CTINFO2DIR(ctinfo);
1309 int ret = 0;
1310 __be32 ip;
1311 u_int16_t port;
1312 struct ip_conntrack_expect *exp;
1313
1314 DEBUGP("ip_ct_ras: GCF\n");
1315
1316 if (!get_h225_addr(*data, &gcf->rasAddress, &ip, &port))
1317 return 0;
1318
1319 /* Registration port is the same as discovery port */
1320 if (ip == ct->tuplehash[dir].tuple.src.ip &&
1321 port == ntohs(ct->tuplehash[dir].tuple.src.u.udp.port))
1322 return 0;
1323
1324 /* Avoid RAS expectation loops. A GCF is never expected. */
1325 if (test_bit(IPS_EXPECTED_BIT, &ct->status))
1326 return 0;
1327
1328 /* Need new expect */
1329 if ((exp = ip_conntrack_expect_alloc(ct)) == NULL)
1330 return -1;
1331 exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip;
1332 exp->tuple.src.u.tcp.port = 0;
1333 exp->tuple.dst.ip = ip;
1334 exp->tuple.dst.u.tcp.port = htons(port);
1335 exp->tuple.dst.protonum = IPPROTO_UDP;
1336 exp->mask.src.ip = htonl(0xFFFFFFFF);
1337 exp->mask.src.u.tcp.port = 0;
1338 exp->mask.dst.ip = htonl(0xFFFFFFFF);
1339 exp->mask.dst.u.tcp.port = htons(0xFFFF);
1340 exp->mask.dst.protonum = 0xFF;
1341 exp->flags = 0;
1342 exp->expectfn = ip_conntrack_ras_expect;
1343 if (ip_conntrack_expect_related(exp) == 0) {
1344 DEBUGP("ip_ct_ras: expect RAS "
1345 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
1346 NIPQUAD(exp->tuple.src.ip),
1347 ntohs(exp->tuple.src.u.tcp.port),
1348 NIPQUAD(exp->tuple.dst.ip),
1349 ntohs(exp->tuple.dst.u.tcp.port));
1350 } else
1351 ret = -1;
1352
1353 ip_conntrack_expect_put(exp);
1354
1355 return ret;
1356 }
1357
1358 /****************************************************************************/
1359 static int process_rrq(struct sk_buff **pskb, struct ip_conntrack *ct,
1360 enum ip_conntrack_info ctinfo,
1361 unsigned char **data, RegistrationRequest * rrq)
1362 {
1363 struct ip_ct_h323_master *info = &ct->help.ct_h323_info;
1364 int ret;
1365
1366 DEBUGP("ip_ct_ras: RRQ\n");
1367
1368 ret = expect_q931(pskb, ct, ctinfo, data,
1369 rrq->callSignalAddress.item,
1370 rrq->callSignalAddress.count);
1371 if (ret < 0)
1372 return -1;
1373
1374 if (set_ras_addr_hook) {
1375 ret = set_ras_addr_hook(pskb, ct, ctinfo, data,
1376 rrq->rasAddress.item,
1377 rrq->rasAddress.count);
1378 if (ret < 0)
1379 return -1;
1380 }
1381
1382 if (rrq->options & eRegistrationRequest_timeToLive) {
1383 DEBUGP("ip_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive);
1384 info->timeout = rrq->timeToLive;
1385 } else
1386 info->timeout = default_rrq_ttl;
1387
1388 return 0;
1389 }
1390
1391 /****************************************************************************/
1392 static int process_rcf(struct sk_buff **pskb, struct ip_conntrack *ct,
1393 enum ip_conntrack_info ctinfo,
1394 unsigned char **data, RegistrationConfirm * rcf)
1395 {
1396 struct ip_ct_h323_master *info = &ct->help.ct_h323_info;
1397 int dir = CTINFO2DIR(ctinfo);
1398 int ret;
1399 struct ip_conntrack_expect *exp;
1400
1401 DEBUGP("ip_ct_ras: RCF\n");
1402
1403 if (set_sig_addr_hook) {
1404 ret = set_sig_addr_hook(pskb, ct, ctinfo, data,
1405 rcf->callSignalAddress.item,
1406 rcf->callSignalAddress.count);
1407 if (ret < 0)
1408 return -1;
1409 }
1410
1411 if (rcf->options & eRegistrationConfirm_timeToLive) {
1412 DEBUGP("ip_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive);
1413 info->timeout = rcf->timeToLive;
1414 }
1415
1416 if (info->timeout > 0) {
1417 DEBUGP
1418 ("ip_ct_ras: set RAS connection timeout to %u seconds\n",
1419 info->timeout);
1420 ip_ct_refresh(ct, *pskb, info->timeout * HZ);
1421
1422 /* Set expect timeout */
1423 read_lock_bh(&ip_conntrack_lock);
1424 exp = find_expect(ct, ct->tuplehash[dir].tuple.dst.ip,
1425 info->sig_port[!dir]);
1426 if (exp) {
1427 DEBUGP("ip_ct_ras: set Q.931 expect "
1428 "(%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu) "
1429 "timeout to %u seconds\n",
1430 NIPQUAD(exp->tuple.src.ip),
1431 ntohs(exp->tuple.src.u.tcp.port),
1432 NIPQUAD(exp->tuple.dst.ip),
1433 ntohs(exp->tuple.dst.u.tcp.port),
1434 info->timeout);
1435 set_expect_timeout(exp, info->timeout);
1436 }
1437 read_unlock_bh(&ip_conntrack_lock);
1438 }
1439
1440 return 0;
1441 }
1442
1443 /****************************************************************************/
1444 static int process_urq(struct sk_buff **pskb, struct ip_conntrack *ct,
1445 enum ip_conntrack_info ctinfo,
1446 unsigned char **data, UnregistrationRequest * urq)
1447 {
1448 struct ip_ct_h323_master *info = &ct->help.ct_h323_info;
1449 int dir = CTINFO2DIR(ctinfo);
1450 int ret;
1451
1452 DEBUGP("ip_ct_ras: URQ\n");
1453
1454 if (set_sig_addr_hook) {
1455 ret = set_sig_addr_hook(pskb, ct, ctinfo, data,
1456 urq->callSignalAddress.item,
1457 urq->callSignalAddress.count);
1458 if (ret < 0)
1459 return -1;
1460 }
1461
1462 /* Clear old expect */
1463 ip_ct_remove_expectations(ct);
1464 info->sig_port[dir] = 0;
1465 info->sig_port[!dir] = 0;
1466
1467 /* Give it 30 seconds for UCF or URJ */
1468 ip_ct_refresh(ct, *pskb, 30 * HZ);
1469
1470 return 0;
1471 }
1472
1473 /****************************************************************************/
1474 static int process_arq(struct sk_buff **pskb, struct ip_conntrack *ct,
1475 enum ip_conntrack_info ctinfo,
1476 unsigned char **data, AdmissionRequest * arq)
1477 {
1478 struct ip_ct_h323_master *info = &ct->help.ct_h323_info;
1479 int dir = CTINFO2DIR(ctinfo);
1480 __be32 ip;
1481 u_int16_t port;
1482
1483 DEBUGP("ip_ct_ras: ARQ\n");
1484
1485 if ((arq->options & eAdmissionRequest_destCallSignalAddress) &&
1486 get_h225_addr(*data, &arq->destCallSignalAddress, &ip, &port) &&
1487 ip == ct->tuplehash[dir].tuple.src.ip &&
1488 port == info->sig_port[dir] && set_h225_addr_hook) {
1489 /* Answering ARQ */
1490 return set_h225_addr_hook(pskb, data, 0,
1491 &arq->destCallSignalAddress,
1492 ct->tuplehash[!dir].tuple.dst.ip,
1493 info->sig_port[!dir]);
1494 }
1495
1496 if ((arq->options & eAdmissionRequest_srcCallSignalAddress) &&
1497 get_h225_addr(*data, &arq->srcCallSignalAddress, &ip, &port) &&
1498 ip == ct->tuplehash[dir].tuple.src.ip && set_h225_addr_hook) {
1499 /* Calling ARQ */
1500 return set_h225_addr_hook(pskb, data, 0,
1501 &arq->srcCallSignalAddress,
1502 ct->tuplehash[!dir].tuple.dst.ip,
1503 port);
1504 }
1505
1506 return 0;
1507 }
1508
1509 /****************************************************************************/
1510 static int process_acf(struct sk_buff **pskb, struct ip_conntrack *ct,
1511 enum ip_conntrack_info ctinfo,
1512 unsigned char **data, AdmissionConfirm * acf)
1513 {
1514 int dir = CTINFO2DIR(ctinfo);
1515 int ret = 0;
1516 __be32 ip;
1517 u_int16_t port;
1518 struct ip_conntrack_expect *exp;
1519
1520 DEBUGP("ip_ct_ras: ACF\n");
1521
1522 if (!get_h225_addr(*data, &acf->destCallSignalAddress, &ip, &port))
1523 return 0;
1524
1525 if (ip == ct->tuplehash[dir].tuple.dst.ip) { /* Answering ACF */
1526 if (set_sig_addr_hook)
1527 return set_sig_addr_hook(pskb, ct, ctinfo, data,
1528 &acf->destCallSignalAddress,
1529 1);
1530 return 0;
1531 }
1532
1533 /* Need new expect */
1534 if ((exp = ip_conntrack_expect_alloc(ct)) == NULL)
1535 return -1;
1536 exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip;
1537 exp->tuple.src.u.tcp.port = 0;
1538 exp->tuple.dst.ip = ip;
1539 exp->tuple.dst.u.tcp.port = htons(port);
1540 exp->tuple.dst.protonum = IPPROTO_TCP;
1541 exp->mask.src.ip = htonl(0xFFFFFFFF);
1542 exp->mask.src.u.tcp.port = 0;
1543 exp->mask.dst.ip = htonl(0xFFFFFFFF);
1544 exp->mask.dst.u.tcp.port = htons(0xFFFF);
1545 exp->mask.dst.protonum = 0xFF;
1546 exp->flags = IP_CT_EXPECT_PERMANENT;
1547 exp->expectfn = ip_conntrack_q931_expect;
1548
1549 if (ip_conntrack_expect_related(exp) == 0) {
1550 DEBUGP("ip_ct_ras: expect Q.931 "
1551 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
1552 NIPQUAD(exp->tuple.src.ip),
1553 ntohs(exp->tuple.src.u.tcp.port),
1554 NIPQUAD(exp->tuple.dst.ip),
1555 ntohs(exp->tuple.dst.u.tcp.port));
1556 } else
1557 ret = -1;
1558
1559 ip_conntrack_expect_put(exp);
1560
1561 return ret;
1562 }
1563
1564 /****************************************************************************/
1565 static int process_lrq(struct sk_buff **pskb, struct ip_conntrack *ct,
1566 enum ip_conntrack_info ctinfo,
1567 unsigned char **data, LocationRequest * lrq)
1568 {
1569 DEBUGP("ip_ct_ras: LRQ\n");
1570
1571 if (set_ras_addr_hook)
1572 return set_ras_addr_hook(pskb, ct, ctinfo, data,
1573 &lrq->replyAddress, 1);
1574 return 0;
1575 }
1576
1577 /****************************************************************************/
1578 static int process_lcf(struct sk_buff **pskb, struct ip_conntrack *ct,
1579 enum ip_conntrack_info ctinfo,
1580 unsigned char **data, LocationConfirm * lcf)
1581 {
1582 int dir = CTINFO2DIR(ctinfo);
1583 int ret = 0;
1584 __be32 ip;
1585 u_int16_t port;
1586 struct ip_conntrack_expect *exp = NULL;
1587
1588 DEBUGP("ip_ct_ras: LCF\n");
1589
1590 if (!get_h225_addr(*data, &lcf->callSignalAddress, &ip, &port))
1591 return 0;
1592
1593 /* Need new expect for call signal */
1594 if ((exp = ip_conntrack_expect_alloc(ct)) == NULL)
1595 return -1;
1596 exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip;
1597 exp->tuple.src.u.tcp.port = 0;
1598 exp->tuple.dst.ip = ip;
1599 exp->tuple.dst.u.tcp.port = htons(port);
1600 exp->tuple.dst.protonum = IPPROTO_TCP;
1601 exp->mask.src.ip = htonl(0xFFFFFFFF);
1602 exp->mask.src.u.tcp.port = 0;
1603 exp->mask.dst.ip = htonl(0xFFFFFFFF);
1604 exp->mask.dst.u.tcp.port = htons(0xFFFF);
1605 exp->mask.dst.protonum = 0xFF;
1606 exp->flags = IP_CT_EXPECT_PERMANENT;
1607 exp->expectfn = ip_conntrack_q931_expect;
1608
1609 if (ip_conntrack_expect_related(exp) == 0) {
1610 DEBUGP("ip_ct_ras: expect Q.931 "
1611 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
1612 NIPQUAD(exp->tuple.src.ip),
1613 ntohs(exp->tuple.src.u.tcp.port),
1614 NIPQUAD(exp->tuple.dst.ip),
1615 ntohs(exp->tuple.dst.u.tcp.port));
1616 } else
1617 ret = -1;
1618
1619 ip_conntrack_expect_put(exp);
1620
1621 /* Ignore rasAddress */
1622
1623 return ret;
1624 }
1625
1626 /****************************************************************************/
1627 static int process_irr(struct sk_buff **pskb, struct ip_conntrack *ct,
1628 enum ip_conntrack_info ctinfo,
1629 unsigned char **data, InfoRequestResponse * irr)
1630 {
1631 int ret;
1632
1633 DEBUGP("ip_ct_ras: IRR\n");
1634
1635 if (set_ras_addr_hook) {
1636 ret = set_ras_addr_hook(pskb, ct, ctinfo, data,
1637 &irr->rasAddress, 1);
1638 if (ret < 0)
1639 return -1;
1640 }
1641
1642 if (set_sig_addr_hook) {
1643 ret = set_sig_addr_hook(pskb, ct, ctinfo, data,
1644 irr->callSignalAddress.item,
1645 irr->callSignalAddress.count);
1646 if (ret < 0)
1647 return -1;
1648 }
1649
1650 return 0;
1651 }
1652
1653 /****************************************************************************/
1654 static int process_ras(struct sk_buff **pskb, struct ip_conntrack *ct,
1655 enum ip_conntrack_info ctinfo,
1656 unsigned char **data, RasMessage * ras)
1657 {
1658 switch (ras->choice) {
1659 case eRasMessage_gatekeeperRequest:
1660 return process_grq(pskb, ct, ctinfo, data,
1661 &ras->gatekeeperRequest);
1662 case eRasMessage_gatekeeperConfirm:
1663 return process_gcf(pskb, ct, ctinfo, data,
1664 &ras->gatekeeperConfirm);
1665 case eRasMessage_registrationRequest:
1666 return process_rrq(pskb, ct, ctinfo, data,
1667 &ras->registrationRequest);
1668 case eRasMessage_registrationConfirm:
1669 return process_rcf(pskb, ct, ctinfo, data,
1670 &ras->registrationConfirm);
1671 case eRasMessage_unregistrationRequest:
1672 return process_urq(pskb, ct, ctinfo, data,
1673 &ras->unregistrationRequest);
1674 case eRasMessage_admissionRequest:
1675 return process_arq(pskb, ct, ctinfo, data,
1676 &ras->admissionRequest);
1677 case eRasMessage_admissionConfirm:
1678 return process_acf(pskb, ct, ctinfo, data,
1679 &ras->admissionConfirm);
1680 case eRasMessage_locationRequest:
1681 return process_lrq(pskb, ct, ctinfo, data,
1682 &ras->locationRequest);
1683 case eRasMessage_locationConfirm:
1684 return process_lcf(pskb, ct, ctinfo, data,
1685 &ras->locationConfirm);
1686 case eRasMessage_infoRequestResponse:
1687 return process_irr(pskb, ct, ctinfo, data,
1688 &ras->infoRequestResponse);
1689 default:
1690 DEBUGP("ip_ct_ras: RAS message %d\n", ras->choice);
1691 break;
1692 }
1693
1694 return 0;
1695 }
1696
1697 /****************************************************************************/
1698 static int ras_help(struct sk_buff **pskb, struct ip_conntrack *ct,
1699 enum ip_conntrack_info ctinfo)
1700 {
1701 static RasMessage ras;
1702 unsigned char *data;
1703 int datalen = 0;
1704 int ret;
1705
1706 DEBUGP("ip_ct_ras: skblen = %u\n", (*pskb)->len);
1707
1708 spin_lock_bh(&ip_h323_lock);
1709
1710 /* Get UDP data */
1711 data = get_udp_data(pskb, &datalen);
1712 if (data == NULL)
1713 goto accept;
1714 DEBUGP("ip_ct_ras: RAS message %u.%u.%u.%u->%u.%u.%u.%u, len=%d\n",
1715 NIPQUAD((*pskb)->nh.iph->saddr),
1716 NIPQUAD((*pskb)->nh.iph->daddr), datalen);
1717
1718 /* Decode RAS message */
1719 ret = DecodeRasMessage(data, datalen, &ras);
1720 if (ret < 0) {
1721 if (net_ratelimit())
1722 printk("ip_ct_ras: decoding error: %s\n",
1723 ret == H323_ERROR_BOUND ?
1724 "out of bound" : "out of range");
1725 goto accept;
1726 }
1727
1728 /* Process RAS message */
1729 if (process_ras(pskb, ct, ctinfo, &data, &ras) < 0)
1730 goto drop;
1731
1732 accept:
1733 spin_unlock_bh(&ip_h323_lock);
1734 return NF_ACCEPT;
1735
1736 drop:
1737 spin_unlock_bh(&ip_h323_lock);
1738 if (net_ratelimit())
1739 printk("ip_ct_ras: packet dropped\n");
1740 return NF_DROP;
1741 }
1742
1743 /****************************************************************************/
1744 static struct ip_conntrack_helper ip_conntrack_helper_ras = {
1745 .name = "RAS",
1746 .me = THIS_MODULE,
1747 .max_expected = 32,
1748 .timeout = 240,
1749 .tuple = {.src = {.u = {.tcp = {.port = __constant_htons(RAS_PORT)}}},
1750 .dst = {.protonum = IPPROTO_UDP}},
1751 .mask = {.src = {.u = {0xFFFE}},
1752 .dst = {.protonum = 0xFF}},
1753 .help = ras_help,
1754 };
1755
1756 /****************************************************************************/
1757 static void ip_conntrack_ras_expect(struct ip_conntrack *new,
1758 struct ip_conntrack_expect *this)
1759 {
1760 write_lock_bh(&ip_conntrack_lock);
1761 new->helper = &ip_conntrack_helper_ras;
1762 write_unlock_bh(&ip_conntrack_lock);
1763 }
1764
1765 /****************************************************************************/
1766 /* Not __exit - called from init() */
1767 static void fini(void)
1768 {
1769 ip_conntrack_helper_unregister(&ip_conntrack_helper_ras);
1770 ip_conntrack_helper_unregister(&ip_conntrack_helper_q931);
1771 kfree(h323_buffer);
1772 DEBUGP("ip_ct_h323: fini\n");
1773 }
1774
1775 /****************************************************************************/
1776 static int __init init(void)
1777 {
1778 int ret;
1779
1780 h323_buffer = kmalloc(65536, GFP_KERNEL);
1781 if (!h323_buffer)
1782 return -ENOMEM;
1783 if ((ret = ip_conntrack_helper_register(&ip_conntrack_helper_q931)) ||
1784 (ret = ip_conntrack_helper_register(&ip_conntrack_helper_ras))) {
1785 fini();
1786 return ret;
1787 }
1788 DEBUGP("ip_ct_h323: init success\n");
1789 return 0;
1790 }
1791
1792 /****************************************************************************/
1793 module_init(init);
1794 module_exit(fini);
1795
1796 EXPORT_SYMBOL_GPL(get_h225_addr);
1797 EXPORT_SYMBOL_GPL(ip_conntrack_h245_expect);
1798 EXPORT_SYMBOL_GPL(ip_conntrack_q931_expect);
1799 EXPORT_SYMBOL_GPL(set_h245_addr_hook);
1800 EXPORT_SYMBOL_GPL(set_h225_addr_hook);
1801 EXPORT_SYMBOL_GPL(set_sig_addr_hook);
1802 EXPORT_SYMBOL_GPL(set_ras_addr_hook);
1803 EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook);
1804 EXPORT_SYMBOL_GPL(nat_t120_hook);
1805 EXPORT_SYMBOL_GPL(nat_h245_hook);
1806 EXPORT_SYMBOL_GPL(nat_callforwarding_hook);
1807 EXPORT_SYMBOL_GPL(nat_q931_hook);
1808
1809 MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>");
1810 MODULE_DESCRIPTION("H.323 connection tracking helper");
1811 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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