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/moduleparam.h>
16 #include <linux/ctype.h>
17 #include <linux/inet.h>
18 #include <linux/in.h>
19 #include <linux/ip.h>
20 #include <linux/udp.h>
21 #include <linux/tcp.h>
22 #include <linux/skbuff.h>
23 #include <net/route.h>
24 #include <net/ip6_route.h>
25
26 #include <net/netfilter/nf_conntrack.h>
27 #include <net/netfilter/nf_conntrack_core.h>
28 #include <net/netfilter/nf_conntrack_tuple.h>
29 #include <net/netfilter/nf_conntrack_expect.h>
30 #include <net/netfilter/nf_conntrack_ecache.h>
31 #include <net/netfilter/nf_conntrack_helper.h>
32 #include <linux/netfilter/nf_conntrack_h323.h>
33
34 /* Parameters */
35 static unsigned int default_rrq_ttl __read_mostly = 300;
36 module_param(default_rrq_ttl, uint, 0600);
37 MODULE_PARM_DESC(default_rrq_ttl, "use this TTL if it's missing in RRQ");
38
39 static int gkrouted_only __read_mostly = 1;
40 module_param(gkrouted_only, int, 0600);
41 MODULE_PARM_DESC(gkrouted_only, "only accept calls from gatekeeper");
42
43 static int callforward_filter __read_mostly = 1;
44 module_param(callforward_filter, bool, 0600);
45 MODULE_PARM_DESC(callforward_filter, "only create call forwarding expectations "
46 "if both endpoints are on different sides "
47 "(determined by routing information)");
48
49 /* Hooks for NAT */
50 int (*set_h245_addr_hook) (struct sk_buff *skb,
51 unsigned char **data, int dataoff,
52 H245_TransportAddress *taddr,
53 union nf_inet_addr *addr, __be16 port)
54 __read_mostly;
55 int (*set_h225_addr_hook) (struct sk_buff *skb,
56 unsigned char **data, int dataoff,
57 TransportAddress *taddr,
58 union nf_inet_addr *addr, __be16 port)
59 __read_mostly;
60 int (*set_sig_addr_hook) (struct sk_buff *skb,
61 struct nf_conn *ct,
62 enum ip_conntrack_info ctinfo,
63 unsigned char **data,
64 TransportAddress *taddr, int count) __read_mostly;
65 int (*set_ras_addr_hook) (struct sk_buff *skb,
66 struct nf_conn *ct,
67 enum ip_conntrack_info ctinfo,
68 unsigned char **data,
69 TransportAddress *taddr, int count) __read_mostly;
70 int (*nat_rtp_rtcp_hook) (struct sk_buff *skb,
71 struct nf_conn *ct,
72 enum ip_conntrack_info ctinfo,
73 unsigned char **data, int dataoff,
74 H245_TransportAddress *taddr,
75 __be16 port, __be16 rtp_port,
76 struct nf_conntrack_expect *rtp_exp,
77 struct nf_conntrack_expect *rtcp_exp) __read_mostly;
78 int (*nat_t120_hook) (struct sk_buff *skb,
79 struct nf_conn *ct,
80 enum ip_conntrack_info ctinfo,
81 unsigned char **data, int dataoff,
82 H245_TransportAddress *taddr, __be16 port,
83 struct nf_conntrack_expect *exp) __read_mostly;
84 int (*nat_h245_hook) (struct sk_buff *skb,
85 struct nf_conn *ct,
86 enum ip_conntrack_info ctinfo,
87 unsigned char **data, int dataoff,
88 TransportAddress *taddr, __be16 port,
89 struct nf_conntrack_expect *exp) __read_mostly;
90 int (*nat_callforwarding_hook) (struct sk_buff *skb,
91 struct nf_conn *ct,
92 enum ip_conntrack_info ctinfo,
93 unsigned char **data, int dataoff,
94 TransportAddress *taddr, __be16 port,
95 struct nf_conntrack_expect *exp) __read_mostly;
96 int (*nat_q931_hook) (struct sk_buff *skb,
97 struct nf_conn *ct,
98 enum ip_conntrack_info ctinfo,
99 unsigned char **data, TransportAddress *taddr, int idx,
100 __be16 port, struct nf_conntrack_expect *exp)
101 __read_mostly;
102
103 static DEFINE_SPINLOCK(nf_h323_lock);
104 static char *h323_buffer;
105
106 static struct nf_conntrack_helper nf_conntrack_helper_h245;
107 static struct nf_conntrack_helper nf_conntrack_helper_q931[];
108 static struct nf_conntrack_helper nf_conntrack_helper_ras[];
109
110 /****************************************************************************/
get_tpkt_data(struct sk_buff * skb,unsigned int protoff,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int * datalen,int * dataoff)111 static int get_tpkt_data(struct sk_buff *skb, unsigned int protoff,
112 struct nf_conn *ct, enum ip_conntrack_info ctinfo,
113 unsigned char **data, int *datalen, int *dataoff)
114 {
115 struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
116 int dir = CTINFO2DIR(ctinfo);
117 const struct tcphdr *th;
118 struct tcphdr _tcph;
119 int tcpdatalen;
120 int tcpdataoff;
121 unsigned char *tpkt;
122 int tpktlen;
123 int tpktoff;
124
125 /* Get TCP header */
126 th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph);
127 if (th == NULL)
128 return 0;
129
130 /* Get TCP data offset */
131 tcpdataoff = protoff + th->doff * 4;
132
133 /* Get TCP data length */
134 tcpdatalen = skb->len - tcpdataoff;
135 if (tcpdatalen <= 0) /* No TCP data */
136 goto clear_out;
137
138 if (*data == NULL) { /* first TPKT */
139 /* Get first TPKT pointer */
140 tpkt = skb_header_pointer(skb, tcpdataoff, tcpdatalen,
141 h323_buffer);
142 BUG_ON(tpkt == NULL);
143
144 /* Validate TPKT identifier */
145 if (tcpdatalen < 4 || tpkt[0] != 0x03 || tpkt[1] != 0) {
146 /* Netmeeting sends TPKT header and data separately */
147 if (info->tpkt_len[dir] > 0) {
148 pr_debug("nf_ct_h323: previous packet "
149 "indicated separate TPKT data of %hu "
150 "bytes\n", info->tpkt_len[dir]);
151 if (info->tpkt_len[dir] <= tcpdatalen) {
152 /* Yes, there was a TPKT header
153 * received */
154 *data = tpkt;
155 *datalen = info->tpkt_len[dir];
156 *dataoff = 0;
157 goto out;
158 }
159
160 /* Fragmented TPKT */
161 pr_debug("nf_ct_h323: fragmented TPKT\n");
162 goto clear_out;
163 }
164
165 /* It is not even a TPKT */
166 return 0;
167 }
168 tpktoff = 0;
169 } else { /* Next TPKT */
170 tpktoff = *dataoff + *datalen;
171 tcpdatalen -= tpktoff;
172 if (tcpdatalen <= 4) /* No more TPKT */
173 goto clear_out;
174 tpkt = *data + *datalen;
175
176 /* Validate TPKT identifier */
177 if (tpkt[0] != 0x03 || tpkt[1] != 0)
178 goto clear_out;
179 }
180
181 /* Validate TPKT length */
182 tpktlen = tpkt[2] * 256 + tpkt[3];
183 if (tpktlen < 4)
184 goto clear_out;
185 if (tpktlen > tcpdatalen) {
186 if (tcpdatalen == 4) { /* Separate TPKT header */
187 /* Netmeeting sends TPKT header and data separately */
188 pr_debug("nf_ct_h323: separate TPKT header indicates "
189 "there will be TPKT data of %hu bytes\n",
190 tpktlen - 4);
191 info->tpkt_len[dir] = tpktlen - 4;
192 return 0;
193 }
194
195 if (net_ratelimit())
196 printk("nf_ct_h323: incomplete TPKT (fragmented?)\n");
197 goto clear_out;
198 }
199
200 /* This is the encapsulated data */
201 *data = tpkt + 4;
202 *datalen = tpktlen - 4;
203 *dataoff = tpktoff + 4;
204
205 out:
206 /* Clear TPKT length */
207 info->tpkt_len[dir] = 0;
208 return 1;
209
210 clear_out:
211 info->tpkt_len[dir] = 0;
212 return 0;
213 }
214
215 /****************************************************************************/
get_h245_addr(struct nf_conn * ct,const unsigned char * data,H245_TransportAddress * taddr,union nf_inet_addr * addr,__be16 * port)216 static int get_h245_addr(struct nf_conn *ct, const unsigned char *data,
217 H245_TransportAddress *taddr,
218 union nf_inet_addr *addr, __be16 *port)
219 {
220 const unsigned char *p;
221 int len;
222
223 if (taddr->choice != eH245_TransportAddress_unicastAddress)
224 return 0;
225
226 switch (taddr->unicastAddress.choice) {
227 case eUnicastAddress_iPAddress:
228 if (nf_ct_l3num(ct) != AF_INET)
229 return 0;
230 p = data + taddr->unicastAddress.iPAddress.network;
231 len = 4;
232 break;
233 case eUnicastAddress_iP6Address:
234 if (nf_ct_l3num(ct) != AF_INET6)
235 return 0;
236 p = data + taddr->unicastAddress.iP6Address.network;
237 len = 16;
238 break;
239 default:
240 return 0;
241 }
242
243 memcpy(addr, p, len);
244 memset((void *)addr + len, 0, sizeof(*addr) - len);
245 memcpy(port, p + len, sizeof(__be16));
246
247 return 1;
248 }
249
250 /****************************************************************************/
expect_rtp_rtcp(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,H245_TransportAddress * taddr)251 static int expect_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct,
252 enum ip_conntrack_info ctinfo,
253 unsigned char **data, int dataoff,
254 H245_TransportAddress *taddr)
255 {
256 int dir = CTINFO2DIR(ctinfo);
257 int ret = 0;
258 __be16 port;
259 __be16 rtp_port, rtcp_port;
260 union nf_inet_addr addr;
261 struct nf_conntrack_expect *rtp_exp;
262 struct nf_conntrack_expect *rtcp_exp;
263 typeof(nat_rtp_rtcp_hook) nat_rtp_rtcp;
264
265 /* Read RTP or RTCP address */
266 if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
267 memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
268 port == 0)
269 return 0;
270
271 /* RTP port is even */
272 port &= htons(~1);
273 rtp_port = port;
274 rtcp_port = htons(ntohs(port) + 1);
275
276 /* Create expect for RTP */
277 if ((rtp_exp = nf_ct_expect_alloc(ct)) == NULL)
278 return -1;
279 nf_ct_expect_init(rtp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
280 &ct->tuplehash[!dir].tuple.src.u3,
281 &ct->tuplehash[!dir].tuple.dst.u3,
282 IPPROTO_UDP, NULL, &rtp_port);
283
284 /* Create expect for RTCP */
285 if ((rtcp_exp = nf_ct_expect_alloc(ct)) == NULL) {
286 nf_ct_expect_put(rtp_exp);
287 return -1;
288 }
289 nf_ct_expect_init(rtcp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
290 &ct->tuplehash[!dir].tuple.src.u3,
291 &ct->tuplehash[!dir].tuple.dst.u3,
292 IPPROTO_UDP, NULL, &rtcp_port);
293
294 if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
295 &ct->tuplehash[!dir].tuple.dst.u3,
296 sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
297 (nat_rtp_rtcp = rcu_dereference(nat_rtp_rtcp_hook)) &&
298 ct->status & IPS_NAT_MASK) {
299 /* NAT needed */
300 ret = nat_rtp_rtcp(skb, ct, ctinfo, data, dataoff,
301 taddr, port, rtp_port, rtp_exp, rtcp_exp);
302 } else { /* Conntrack only */
303 if (nf_ct_expect_related(rtp_exp) == 0) {
304 if (nf_ct_expect_related(rtcp_exp) == 0) {
305 pr_debug("nf_ct_h323: expect RTP ");
306 nf_ct_dump_tuple(&rtp_exp->tuple);
307 pr_debug("nf_ct_h323: expect RTCP ");
308 nf_ct_dump_tuple(&rtcp_exp->tuple);
309 } else {
310 nf_ct_unexpect_related(rtp_exp);
311 ret = -1;
312 }
313 } else
314 ret = -1;
315 }
316
317 nf_ct_expect_put(rtp_exp);
318 nf_ct_expect_put(rtcp_exp);
319
320 return ret;
321 }
322
323 /****************************************************************************/
expect_t120(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,H245_TransportAddress * taddr)324 static int expect_t120(struct sk_buff *skb,
325 struct nf_conn *ct,
326 enum ip_conntrack_info ctinfo,
327 unsigned char **data, int dataoff,
328 H245_TransportAddress *taddr)
329 {
330 int dir = CTINFO2DIR(ctinfo);
331 int ret = 0;
332 __be16 port;
333 union nf_inet_addr addr;
334 struct nf_conntrack_expect *exp;
335 typeof(nat_t120_hook) nat_t120;
336
337 /* Read T.120 address */
338 if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
339 memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
340 port == 0)
341 return 0;
342
343 /* Create expect for T.120 connections */
344 if ((exp = nf_ct_expect_alloc(ct)) == NULL)
345 return -1;
346 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
347 &ct->tuplehash[!dir].tuple.src.u3,
348 &ct->tuplehash[!dir].tuple.dst.u3,
349 IPPROTO_TCP, NULL, &port);
350 exp->flags = NF_CT_EXPECT_PERMANENT; /* Accept multiple channels */
351
352 if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
353 &ct->tuplehash[!dir].tuple.dst.u3,
354 sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
355 (nat_t120 = rcu_dereference(nat_t120_hook)) &&
356 ct->status & IPS_NAT_MASK) {
357 /* NAT needed */
358 ret = nat_t120(skb, ct, ctinfo, data, dataoff, taddr,
359 port, exp);
360 } else { /* Conntrack only */
361 if (nf_ct_expect_related(exp) == 0) {
362 pr_debug("nf_ct_h323: expect T.120 ");
363 nf_ct_dump_tuple(&exp->tuple);
364 } else
365 ret = -1;
366 }
367
368 nf_ct_expect_put(exp);
369
370 return ret;
371 }
372
373 /****************************************************************************/
process_h245_channel(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,H2250LogicalChannelParameters * channel)374 static int process_h245_channel(struct sk_buff *skb,
375 struct nf_conn *ct,
376 enum ip_conntrack_info ctinfo,
377 unsigned char **data, int dataoff,
378 H2250LogicalChannelParameters *channel)
379 {
380 int ret;
381
382 if (channel->options & eH2250LogicalChannelParameters_mediaChannel) {
383 /* RTP */
384 ret = expect_rtp_rtcp(skb, ct, ctinfo, data, dataoff,
385 &channel->mediaChannel);
386 if (ret < 0)
387 return -1;
388 }
389
390 if (channel->
391 options & eH2250LogicalChannelParameters_mediaControlChannel) {
392 /* RTCP */
393 ret = expect_rtp_rtcp(skb, ct, ctinfo, data, dataoff,
394 &channel->mediaControlChannel);
395 if (ret < 0)
396 return -1;
397 }
398
399 return 0;
400 }
401
402 /****************************************************************************/
process_olc(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,OpenLogicalChannel * olc)403 static int process_olc(struct sk_buff *skb, struct nf_conn *ct,
404 enum ip_conntrack_info ctinfo,
405 unsigned char **data, int dataoff,
406 OpenLogicalChannel *olc)
407 {
408 int ret;
409
410 pr_debug("nf_ct_h323: OpenLogicalChannel\n");
411
412 if (olc->forwardLogicalChannelParameters.multiplexParameters.choice ==
413 eOpenLogicalChannel_forwardLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters)
414 {
415 ret = process_h245_channel(skb, ct, ctinfo, data, dataoff,
416 &olc->
417 forwardLogicalChannelParameters.
418 multiplexParameters.
419 h2250LogicalChannelParameters);
420 if (ret < 0)
421 return -1;
422 }
423
424 if ((olc->options &
425 eOpenLogicalChannel_reverseLogicalChannelParameters) &&
426 (olc->reverseLogicalChannelParameters.options &
427 eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters)
428 && (olc->reverseLogicalChannelParameters.multiplexParameters.
429 choice ==
430 eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
431 {
432 ret =
433 process_h245_channel(skb, ct, ctinfo, data, dataoff,
434 &olc->
435 reverseLogicalChannelParameters.
436 multiplexParameters.
437 h2250LogicalChannelParameters);
438 if (ret < 0)
439 return -1;
440 }
441
442 if ((olc->options & eOpenLogicalChannel_separateStack) &&
443 olc->forwardLogicalChannelParameters.dataType.choice ==
444 eDataType_data &&
445 olc->forwardLogicalChannelParameters.dataType.data.application.
446 choice == eDataApplicationCapability_application_t120 &&
447 olc->forwardLogicalChannelParameters.dataType.data.application.
448 t120.choice == eDataProtocolCapability_separateLANStack &&
449 olc->separateStack.networkAddress.choice ==
450 eNetworkAccessParameters_networkAddress_localAreaAddress) {
451 ret = expect_t120(skb, ct, ctinfo, data, dataoff,
452 &olc->separateStack.networkAddress.
453 localAreaAddress);
454 if (ret < 0)
455 return -1;
456 }
457
458 return 0;
459 }
460
461 /****************************************************************************/
process_olca(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,OpenLogicalChannelAck * olca)462 static int process_olca(struct sk_buff *skb, struct nf_conn *ct,
463 enum ip_conntrack_info ctinfo,
464 unsigned char **data, int dataoff,
465 OpenLogicalChannelAck *olca)
466 {
467 H2250LogicalChannelAckParameters *ack;
468 int ret;
469
470 pr_debug("nf_ct_h323: OpenLogicalChannelAck\n");
471
472 if ((olca->options &
473 eOpenLogicalChannelAck_reverseLogicalChannelParameters) &&
474 (olca->reverseLogicalChannelParameters.options &
475 eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters)
476 && (olca->reverseLogicalChannelParameters.multiplexParameters.
477 choice ==
478 eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
479 {
480 ret = process_h245_channel(skb, ct, ctinfo, data, dataoff,
481 &olca->
482 reverseLogicalChannelParameters.
483 multiplexParameters.
484 h2250LogicalChannelParameters);
485 if (ret < 0)
486 return -1;
487 }
488
489 if ((olca->options &
490 eOpenLogicalChannelAck_forwardMultiplexAckParameters) &&
491 (olca->forwardMultiplexAckParameters.choice ==
492 eOpenLogicalChannelAck_forwardMultiplexAckParameters_h2250LogicalChannelAckParameters))
493 {
494 ack = &olca->forwardMultiplexAckParameters.
495 h2250LogicalChannelAckParameters;
496 if (ack->options &
497 eH2250LogicalChannelAckParameters_mediaChannel) {
498 /* RTP */
499 ret = expect_rtp_rtcp(skb, ct, ctinfo, data, dataoff,
500 &ack->mediaChannel);
501 if (ret < 0)
502 return -1;
503 }
504
505 if (ack->options &
506 eH2250LogicalChannelAckParameters_mediaControlChannel) {
507 /* RTCP */
508 ret = expect_rtp_rtcp(skb, ct, ctinfo, data, dataoff,
509 &ack->mediaControlChannel);
510 if (ret < 0)
511 return -1;
512 }
513 }
514
515 if ((olca->options & eOpenLogicalChannelAck_separateStack) &&
516 olca->separateStack.networkAddress.choice ==
517 eNetworkAccessParameters_networkAddress_localAreaAddress) {
518 ret = expect_t120(skb, ct, ctinfo, data, dataoff,
519 &olca->separateStack.networkAddress.
520 localAreaAddress);
521 if (ret < 0)
522 return -1;
523 }
524
525 return 0;
526 }
527
528 /****************************************************************************/
process_h245(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,MultimediaSystemControlMessage * mscm)529 static int process_h245(struct sk_buff *skb, struct nf_conn *ct,
530 enum ip_conntrack_info ctinfo,
531 unsigned char **data, int dataoff,
532 MultimediaSystemControlMessage *mscm)
533 {
534 switch (mscm->choice) {
535 case eMultimediaSystemControlMessage_request:
536 if (mscm->request.choice ==
537 eRequestMessage_openLogicalChannel) {
538 return process_olc(skb, ct, ctinfo, data, dataoff,
539 &mscm->request.openLogicalChannel);
540 }
541 pr_debug("nf_ct_h323: H.245 Request %d\n",
542 mscm->request.choice);
543 break;
544 case eMultimediaSystemControlMessage_response:
545 if (mscm->response.choice ==
546 eResponseMessage_openLogicalChannelAck) {
547 return process_olca(skb, ct, ctinfo, data, dataoff,
548 &mscm->response.
549 openLogicalChannelAck);
550 }
551 pr_debug("nf_ct_h323: H.245 Response %d\n",
552 mscm->response.choice);
553 break;
554 default:
555 pr_debug("nf_ct_h323: H.245 signal %d\n", mscm->choice);
556 break;
557 }
558
559 return 0;
560 }
561
562 /****************************************************************************/
h245_help(struct sk_buff * skb,unsigned int protoff,struct nf_conn * ct,enum ip_conntrack_info ctinfo)563 static int h245_help(struct sk_buff *skb, unsigned int protoff,
564 struct nf_conn *ct, enum ip_conntrack_info ctinfo)
565 {
566 static MultimediaSystemControlMessage mscm;
567 unsigned char *data = NULL;
568 int datalen;
569 int dataoff;
570 int ret;
571
572 /* Until there's been traffic both ways, don't look in packets. */
573 if (ctinfo != IP_CT_ESTABLISHED &&
574 ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) {
575 return NF_ACCEPT;
576 }
577 pr_debug("nf_ct_h245: skblen = %u\n", skb->len);
578
579 spin_lock_bh(&nf_h323_lock);
580
581 /* Process each TPKT */
582 while (get_tpkt_data(skb, protoff, ct, ctinfo,
583 &data, &datalen, &dataoff)) {
584 pr_debug("nf_ct_h245: TPKT len=%d ", datalen);
585 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
586
587 /* Decode H.245 signal */
588 ret = DecodeMultimediaSystemControlMessage(data, datalen,
589 &mscm);
590 if (ret < 0) {
591 pr_debug("nf_ct_h245: decoding error: %s\n",
592 ret == H323_ERROR_BOUND ?
593 "out of bound" : "out of range");
594 /* We don't drop when decoding error */
595 break;
596 }
597
598 /* Process H.245 signal */
599 if (process_h245(skb, ct, ctinfo, &data, dataoff, &mscm) < 0)
600 goto drop;
601 }
602
603 spin_unlock_bh(&nf_h323_lock);
604 return NF_ACCEPT;
605
606 drop:
607 spin_unlock_bh(&nf_h323_lock);
608 if (net_ratelimit())
609 printk("nf_ct_h245: packet dropped\n");
610 return NF_DROP;
611 }
612
613 /****************************************************************************/
614 static const struct nf_conntrack_expect_policy h245_exp_policy = {
615 .max_expected = H323_RTP_CHANNEL_MAX * 4 + 2 /* T.120 */,
616 .timeout = 240,
617 };
618
619 static struct nf_conntrack_helper nf_conntrack_helper_h245 __read_mostly = {
620 .name = "H.245",
621 .me = THIS_MODULE,
622 .tuple.src.l3num = AF_UNSPEC,
623 .tuple.dst.protonum = IPPROTO_UDP,
624 .help = h245_help,
625 .expect_policy = &h245_exp_policy,
626 };
627
628 /****************************************************************************/
get_h225_addr(struct nf_conn * ct,unsigned char * data,TransportAddress * taddr,union nf_inet_addr * addr,__be16 * port)629 int get_h225_addr(struct nf_conn *ct, unsigned char *data,
630 TransportAddress *taddr,
631 union nf_inet_addr *addr, __be16 *port)
632 {
633 const unsigned char *p;
634 int len;
635
636 switch (taddr->choice) {
637 case eTransportAddress_ipAddress:
638 if (nf_ct_l3num(ct) != AF_INET)
639 return 0;
640 p = data + taddr->ipAddress.ip;
641 len = 4;
642 break;
643 case eTransportAddress_ip6Address:
644 if (nf_ct_l3num(ct) != AF_INET6)
645 return 0;
646 p = data + taddr->ip6Address.ip;
647 len = 16;
648 break;
649 default:
650 return 0;
651 }
652
653 memcpy(addr, p, len);
654 memset((void *)addr + len, 0, sizeof(*addr) - len);
655 memcpy(port, p + len, sizeof(__be16));
656
657 return 1;
658 }
659
660 /****************************************************************************/
expect_h245(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,TransportAddress * taddr)661 static int expect_h245(struct sk_buff *skb, struct nf_conn *ct,
662 enum ip_conntrack_info ctinfo,
663 unsigned char **data, int dataoff,
664 TransportAddress *taddr)
665 {
666 int dir = CTINFO2DIR(ctinfo);
667 int ret = 0;
668 __be16 port;
669 union nf_inet_addr addr;
670 struct nf_conntrack_expect *exp;
671 typeof(nat_h245_hook) nat_h245;
672
673 /* Read h245Address */
674 if (!get_h225_addr(ct, *data, taddr, &addr, &port) ||
675 memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
676 port == 0)
677 return 0;
678
679 /* Create expect for h245 connection */
680 if ((exp = nf_ct_expect_alloc(ct)) == NULL)
681 return -1;
682 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
683 &ct->tuplehash[!dir].tuple.src.u3,
684 &ct->tuplehash[!dir].tuple.dst.u3,
685 IPPROTO_TCP, NULL, &port);
686 exp->helper = &nf_conntrack_helper_h245;
687
688 if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
689 &ct->tuplehash[!dir].tuple.dst.u3,
690 sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
691 (nat_h245 = rcu_dereference(nat_h245_hook)) &&
692 ct->status & IPS_NAT_MASK) {
693 /* NAT needed */
694 ret = nat_h245(skb, ct, ctinfo, data, dataoff, taddr,
695 port, exp);
696 } else { /* Conntrack only */
697 if (nf_ct_expect_related(exp) == 0) {
698 pr_debug("nf_ct_q931: expect H.245 ");
699 nf_ct_dump_tuple(&exp->tuple);
700 } else
701 ret = -1;
702 }
703
704 nf_ct_expect_put(exp);
705
706 return ret;
707 }
708
709 /* If the calling party is on the same side of the forward-to party,
710 * we don't need to track the second call */
callforward_do_filter(const union nf_inet_addr * src,const union nf_inet_addr * dst,u_int8_t family)711 static int callforward_do_filter(const union nf_inet_addr *src,
712 const union nf_inet_addr *dst,
713 u_int8_t family)
714 {
715 const struct nf_afinfo *afinfo;
716 struct flowi fl1, fl2;
717 int ret = 0;
718
719 /* rcu_read_lock()ed by nf_hook_slow() */
720 afinfo = nf_get_afinfo(family);
721 if (!afinfo)
722 return 0;
723
724 memset(&fl1, 0, sizeof(fl1));
725 memset(&fl2, 0, sizeof(fl2));
726
727 switch (family) {
728 case AF_INET: {
729 struct rtable *rt1, *rt2;
730
731 fl1.fl4_dst = src->ip;
732 fl2.fl4_dst = dst->ip;
733 if (!afinfo->route((struct dst_entry **)&rt1, &fl1)) {
734 if (!afinfo->route((struct dst_entry **)&rt2, &fl2)) {
735 if (rt1->rt_gateway == rt2->rt_gateway &&
736 rt1->u.dst.dev == rt2->u.dst.dev)
737 ret = 1;
738 dst_release(&rt2->u.dst);
739 }
740 dst_release(&rt1->u.dst);
741 }
742 break;
743 }
744 #if defined(CONFIG_NF_CONNTRACK_IPV6) || \
745 defined(CONFIG_NF_CONNTRACK_IPV6_MODULE)
746 case AF_INET6: {
747 struct rt6_info *rt1, *rt2;
748
749 memcpy(&fl1.fl6_dst, src, sizeof(fl1.fl6_dst));
750 memcpy(&fl2.fl6_dst, dst, sizeof(fl2.fl6_dst));
751 if (!afinfo->route((struct dst_entry **)&rt1, &fl1)) {
752 if (!afinfo->route((struct dst_entry **)&rt2, &fl2)) {
753 if (!memcmp(&rt1->rt6i_gateway, &rt2->rt6i_gateway,
754 sizeof(rt1->rt6i_gateway)) &&
755 rt1->u.dst.dev == rt2->u.dst.dev)
756 ret = 1;
757 dst_release(&rt2->u.dst);
758 }
759 dst_release(&rt1->u.dst);
760 }
761 break;
762 }
763 #endif
764 }
765 return ret;
766
767 }
768
769 /****************************************************************************/
expect_callforwarding(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,TransportAddress * taddr)770 static int expect_callforwarding(struct sk_buff *skb,
771 struct nf_conn *ct,
772 enum ip_conntrack_info ctinfo,
773 unsigned char **data, int dataoff,
774 TransportAddress *taddr)
775 {
776 int dir = CTINFO2DIR(ctinfo);
777 int ret = 0;
778 __be16 port;
779 union nf_inet_addr addr;
780 struct nf_conntrack_expect *exp;
781 typeof(nat_callforwarding_hook) nat_callforwarding;
782
783 /* Read alternativeAddress */
784 if (!get_h225_addr(ct, *data, taddr, &addr, &port) || port == 0)
785 return 0;
786
787 /* If the calling party is on the same side of the forward-to party,
788 * we don't need to track the second call */
789 if (callforward_filter &&
790 callforward_do_filter(&addr, &ct->tuplehash[!dir].tuple.src.u3,
791 nf_ct_l3num(ct))) {
792 pr_debug("nf_ct_q931: Call Forwarding not tracked\n");
793 return 0;
794 }
795
796 /* Create expect for the second call leg */
797 if ((exp = nf_ct_expect_alloc(ct)) == NULL)
798 return -1;
799 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
800 &ct->tuplehash[!dir].tuple.src.u3, &addr,
801 IPPROTO_TCP, NULL, &port);
802 exp->helper = nf_conntrack_helper_q931;
803
804 if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
805 &ct->tuplehash[!dir].tuple.dst.u3,
806 sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
807 (nat_callforwarding = rcu_dereference(nat_callforwarding_hook)) &&
808 ct->status & IPS_NAT_MASK) {
809 /* Need NAT */
810 ret = nat_callforwarding(skb, ct, ctinfo, data, dataoff,
811 taddr, port, exp);
812 } else { /* Conntrack only */
813 if (nf_ct_expect_related(exp) == 0) {
814 pr_debug("nf_ct_q931: expect Call Forwarding ");
815 nf_ct_dump_tuple(&exp->tuple);
816 } else
817 ret = -1;
818 }
819
820 nf_ct_expect_put(exp);
821
822 return ret;
823 }
824
825 /****************************************************************************/
process_setup(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,Setup_UUIE * setup)826 static int process_setup(struct sk_buff *skb, struct nf_conn *ct,
827 enum ip_conntrack_info ctinfo,
828 unsigned char **data, int dataoff,
829 Setup_UUIE *setup)
830 {
831 int dir = CTINFO2DIR(ctinfo);
832 int ret;
833 int i;
834 __be16 port;
835 union nf_inet_addr addr;
836 typeof(set_h225_addr_hook) set_h225_addr;
837
838 pr_debug("nf_ct_q931: Setup\n");
839
840 if (setup->options & eSetup_UUIE_h245Address) {
841 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
842 &setup->h245Address);
843 if (ret < 0)
844 return -1;
845 }
846
847 set_h225_addr = rcu_dereference(set_h225_addr_hook);
848 if ((setup->options & eSetup_UUIE_destCallSignalAddress) &&
849 (set_h225_addr) && ct->status & IPS_NAT_MASK &&
850 get_h225_addr(ct, *data, &setup->destCallSignalAddress,
851 &addr, &port) &&
852 memcmp(&addr, &ct->tuplehash[!dir].tuple.src.u3, sizeof(addr))) {
853 pr_debug("nf_ct_q931: set destCallSignalAddress %pI6:%hu->%pI6:%hu\n",
854 &addr, ntohs(port), &ct->tuplehash[!dir].tuple.src.u3,
855 ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port));
856 ret = set_h225_addr(skb, data, dataoff,
857 &setup->destCallSignalAddress,
858 &ct->tuplehash[!dir].tuple.src.u3,
859 ct->tuplehash[!dir].tuple.src.u.tcp.port);
860 if (ret < 0)
861 return -1;
862 }
863
864 if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) &&
865 (set_h225_addr) && ct->status & IPS_NAT_MASK &&
866 get_h225_addr(ct, *data, &setup->sourceCallSignalAddress,
867 &addr, &port) &&
868 memcmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(addr))) {
869 pr_debug("nf_ct_q931: set sourceCallSignalAddress %pI6:%hu->%pI6:%hu\n",
870 &addr, ntohs(port), &ct->tuplehash[!dir].tuple.dst.u3,
871 ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port));
872 ret = set_h225_addr(skb, data, dataoff,
873 &setup->sourceCallSignalAddress,
874 &ct->tuplehash[!dir].tuple.dst.u3,
875 ct->tuplehash[!dir].tuple.dst.u.tcp.port);
876 if (ret < 0)
877 return -1;
878 }
879
880 if (setup->options & eSetup_UUIE_fastStart) {
881 for (i = 0; i < setup->fastStart.count; i++) {
882 ret = process_olc(skb, ct, ctinfo, data, dataoff,
883 &setup->fastStart.item[i]);
884 if (ret < 0)
885 return -1;
886 }
887 }
888
889 return 0;
890 }
891
892 /****************************************************************************/
process_callproceeding(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,CallProceeding_UUIE * callproc)893 static int process_callproceeding(struct sk_buff *skb,
894 struct nf_conn *ct,
895 enum ip_conntrack_info ctinfo,
896 unsigned char **data, int dataoff,
897 CallProceeding_UUIE *callproc)
898 {
899 int ret;
900 int i;
901
902 pr_debug("nf_ct_q931: CallProceeding\n");
903
904 if (callproc->options & eCallProceeding_UUIE_h245Address) {
905 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
906 &callproc->h245Address);
907 if (ret < 0)
908 return -1;
909 }
910
911 if (callproc->options & eCallProceeding_UUIE_fastStart) {
912 for (i = 0; i < callproc->fastStart.count; i++) {
913 ret = process_olc(skb, ct, ctinfo, data, dataoff,
914 &callproc->fastStart.item[i]);
915 if (ret < 0)
916 return -1;
917 }
918 }
919
920 return 0;
921 }
922
923 /****************************************************************************/
process_connect(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,Connect_UUIE * connect)924 static int process_connect(struct sk_buff *skb, struct nf_conn *ct,
925 enum ip_conntrack_info ctinfo,
926 unsigned char **data, int dataoff,
927 Connect_UUIE *connect)
928 {
929 int ret;
930 int i;
931
932 pr_debug("nf_ct_q931: Connect\n");
933
934 if (connect->options & eConnect_UUIE_h245Address) {
935 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
936 &connect->h245Address);
937 if (ret < 0)
938 return -1;
939 }
940
941 if (connect->options & eConnect_UUIE_fastStart) {
942 for (i = 0; i < connect->fastStart.count; i++) {
943 ret = process_olc(skb, ct, ctinfo, data, dataoff,
944 &connect->fastStart.item[i]);
945 if (ret < 0)
946 return -1;
947 }
948 }
949
950 return 0;
951 }
952
953 /****************************************************************************/
process_alerting(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,Alerting_UUIE * alert)954 static int process_alerting(struct sk_buff *skb, struct nf_conn *ct,
955 enum ip_conntrack_info ctinfo,
956 unsigned char **data, int dataoff,
957 Alerting_UUIE *alert)
958 {
959 int ret;
960 int i;
961
962 pr_debug("nf_ct_q931: Alerting\n");
963
964 if (alert->options & eAlerting_UUIE_h245Address) {
965 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
966 &alert->h245Address);
967 if (ret < 0)
968 return -1;
969 }
970
971 if (alert->options & eAlerting_UUIE_fastStart) {
972 for (i = 0; i < alert->fastStart.count; i++) {
973 ret = process_olc(skb, ct, ctinfo, data, dataoff,
974 &alert->fastStart.item[i]);
975 if (ret < 0)
976 return -1;
977 }
978 }
979
980 return 0;
981 }
982
983 /****************************************************************************/
process_facility(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,Facility_UUIE * facility)984 static int process_facility(struct sk_buff *skb, struct nf_conn *ct,
985 enum ip_conntrack_info ctinfo,
986 unsigned char **data, int dataoff,
987 Facility_UUIE *facility)
988 {
989 int ret;
990 int i;
991
992 pr_debug("nf_ct_q931: Facility\n");
993
994 if (facility->reason.choice == eFacilityReason_callForwarded) {
995 if (facility->options & eFacility_UUIE_alternativeAddress)
996 return expect_callforwarding(skb, ct, ctinfo, data,
997 dataoff,
998 &facility->
999 alternativeAddress);
1000 return 0;
1001 }
1002
1003 if (facility->options & eFacility_UUIE_h245Address) {
1004 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
1005 &facility->h245Address);
1006 if (ret < 0)
1007 return -1;
1008 }
1009
1010 if (facility->options & eFacility_UUIE_fastStart) {
1011 for (i = 0; i < facility->fastStart.count; i++) {
1012 ret = process_olc(skb, ct, ctinfo, data, dataoff,
1013 &facility->fastStart.item[i]);
1014 if (ret < 0)
1015 return -1;
1016 }
1017 }
1018
1019 return 0;
1020 }
1021
1022 /****************************************************************************/
process_progress(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,Progress_UUIE * progress)1023 static int process_progress(struct sk_buff *skb, struct nf_conn *ct,
1024 enum ip_conntrack_info ctinfo,
1025 unsigned char **data, int dataoff,
1026 Progress_UUIE *progress)
1027 {
1028 int ret;
1029 int i;
1030
1031 pr_debug("nf_ct_q931: Progress\n");
1032
1033 if (progress->options & eProgress_UUIE_h245Address) {
1034 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
1035 &progress->h245Address);
1036 if (ret < 0)
1037 return -1;
1038 }
1039
1040 if (progress->options & eProgress_UUIE_fastStart) {
1041 for (i = 0; i < progress->fastStart.count; i++) {
1042 ret = process_olc(skb, ct, ctinfo, data, dataoff,
1043 &progress->fastStart.item[i]);
1044 if (ret < 0)
1045 return -1;
1046 }
1047 }
1048
1049 return 0;
1050 }
1051
1052 /****************************************************************************/
process_q931(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,Q931 * q931)1053 static int process_q931(struct sk_buff *skb, struct nf_conn *ct,
1054 enum ip_conntrack_info ctinfo,
1055 unsigned char **data, int dataoff, Q931 *q931)
1056 {
1057 H323_UU_PDU *pdu = &q931->UUIE.h323_uu_pdu;
1058 int i;
1059 int ret = 0;
1060
1061 switch (pdu->h323_message_body.choice) {
1062 case eH323_UU_PDU_h323_message_body_setup:
1063 ret = process_setup(skb, ct, ctinfo, data, dataoff,
1064 &pdu->h323_message_body.setup);
1065 break;
1066 case eH323_UU_PDU_h323_message_body_callProceeding:
1067 ret = process_callproceeding(skb, ct, ctinfo, data, dataoff,
1068 &pdu->h323_message_body.
1069 callProceeding);
1070 break;
1071 case eH323_UU_PDU_h323_message_body_connect:
1072 ret = process_connect(skb, ct, ctinfo, data, dataoff,
1073 &pdu->h323_message_body.connect);
1074 break;
1075 case eH323_UU_PDU_h323_message_body_alerting:
1076 ret = process_alerting(skb, ct, ctinfo, data, dataoff,
1077 &pdu->h323_message_body.alerting);
1078 break;
1079 case eH323_UU_PDU_h323_message_body_facility:
1080 ret = process_facility(skb, ct, ctinfo, data, dataoff,
1081 &pdu->h323_message_body.facility);
1082 break;
1083 case eH323_UU_PDU_h323_message_body_progress:
1084 ret = process_progress(skb, ct, ctinfo, data, dataoff,
1085 &pdu->h323_message_body.progress);
1086 break;
1087 default:
1088 pr_debug("nf_ct_q931: Q.931 signal %d\n",
1089 pdu->h323_message_body.choice);
1090 break;
1091 }
1092
1093 if (ret < 0)
1094 return -1;
1095
1096 if (pdu->options & eH323_UU_PDU_h245Control) {
1097 for (i = 0; i < pdu->h245Control.count; i++) {
1098 ret = process_h245(skb, ct, ctinfo, data, dataoff,
1099 &pdu->h245Control.item[i]);
1100 if (ret < 0)
1101 return -1;
1102 }
1103 }
1104
1105 return 0;
1106 }
1107
1108 /****************************************************************************/
q931_help(struct sk_buff * skb,unsigned int protoff,struct nf_conn * ct,enum ip_conntrack_info ctinfo)1109 static int q931_help(struct sk_buff *skb, unsigned int protoff,
1110 struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1111 {
1112 static Q931 q931;
1113 unsigned char *data = NULL;
1114 int datalen;
1115 int dataoff;
1116 int ret;
1117
1118 /* Until there's been traffic both ways, don't look in packets. */
1119 if (ctinfo != IP_CT_ESTABLISHED &&
1120 ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) {
1121 return NF_ACCEPT;
1122 }
1123 pr_debug("nf_ct_q931: skblen = %u\n", skb->len);
1124
1125 spin_lock_bh(&nf_h323_lock);
1126
1127 /* Process each TPKT */
1128 while (get_tpkt_data(skb, protoff, ct, ctinfo,
1129 &data, &datalen, &dataoff)) {
1130 pr_debug("nf_ct_q931: TPKT len=%d ", datalen);
1131 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1132
1133 /* Decode Q.931 signal */
1134 ret = DecodeQ931(data, datalen, &q931);
1135 if (ret < 0) {
1136 pr_debug("nf_ct_q931: decoding error: %s\n",
1137 ret == H323_ERROR_BOUND ?
1138 "out of bound" : "out of range");
1139 /* We don't drop when decoding error */
1140 break;
1141 }
1142
1143 /* Process Q.931 signal */
1144 if (process_q931(skb, ct, ctinfo, &data, dataoff, &q931) < 0)
1145 goto drop;
1146 }
1147
1148 spin_unlock_bh(&nf_h323_lock);
1149 return NF_ACCEPT;
1150
1151 drop:
1152 spin_unlock_bh(&nf_h323_lock);
1153 if (net_ratelimit())
1154 printk("nf_ct_q931: packet dropped\n");
1155 return NF_DROP;
1156 }
1157
1158 /****************************************************************************/
1159 static const struct nf_conntrack_expect_policy q931_exp_policy = {
1160 /* T.120 and H.245 */
1161 .max_expected = H323_RTP_CHANNEL_MAX * 4 + 4,
1162 .timeout = 240,
1163 };
1164
1165 static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = {
1166 {
1167 .name = "Q.931",
1168 .me = THIS_MODULE,
1169 .tuple.src.l3num = AF_INET,
1170 .tuple.src.u.tcp.port = __constant_htons(Q931_PORT),
1171 .tuple.dst.protonum = IPPROTO_TCP,
1172 .help = q931_help,
1173 .expect_policy = &q931_exp_policy,
1174 },
1175 {
1176 .name = "Q.931",
1177 .me = THIS_MODULE,
1178 .tuple.src.l3num = AF_INET6,
1179 .tuple.src.u.tcp.port = __constant_htons(Q931_PORT),
1180 .tuple.dst.protonum = IPPROTO_TCP,
1181 .help = q931_help,
1182 .expect_policy = &q931_exp_policy,
1183 },
1184 };
1185
1186 /****************************************************************************/
get_udp_data(struct sk_buff * skb,unsigned int protoff,int * datalen)1187 static unsigned char *get_udp_data(struct sk_buff *skb, unsigned int protoff,
1188 int *datalen)
1189 {
1190 const struct udphdr *uh;
1191 struct udphdr _uh;
1192 int dataoff;
1193
1194 uh = skb_header_pointer(skb, protoff, sizeof(_uh), &_uh);
1195 if (uh == NULL)
1196 return NULL;
1197 dataoff = protoff + sizeof(_uh);
1198 if (dataoff >= skb->len)
1199 return NULL;
1200 *datalen = skb->len - dataoff;
1201 return skb_header_pointer(skb, dataoff, *datalen, h323_buffer);
1202 }
1203
1204 /****************************************************************************/
find_expect(struct nf_conn * ct,union nf_inet_addr * addr,__be16 port)1205 static struct nf_conntrack_expect *find_expect(struct nf_conn *ct,
1206 union nf_inet_addr *addr,
1207 __be16 port)
1208 {
1209 struct net *net = nf_ct_net(ct);
1210 struct nf_conntrack_expect *exp;
1211 struct nf_conntrack_tuple tuple;
1212
1213 memset(&tuple.src.u3, 0, sizeof(tuple.src.u3));
1214 tuple.src.u.tcp.port = 0;
1215 memcpy(&tuple.dst.u3, addr, sizeof(tuple.dst.u3));
1216 tuple.dst.u.tcp.port = port;
1217 tuple.dst.protonum = IPPROTO_TCP;
1218
1219 exp = __nf_ct_expect_find(net, &tuple);
1220 if (exp && exp->master == ct)
1221 return exp;
1222 return NULL;
1223 }
1224
1225 /****************************************************************************/
set_expect_timeout(struct nf_conntrack_expect * exp,unsigned timeout)1226 static int set_expect_timeout(struct nf_conntrack_expect *exp,
1227 unsigned timeout)
1228 {
1229 if (!exp || !del_timer(&exp->timeout))
1230 return 0;
1231
1232 exp->timeout.expires = jiffies + timeout * HZ;
1233 add_timer(&exp->timeout);
1234
1235 return 1;
1236 }
1237
1238 /****************************************************************************/
expect_q931(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,TransportAddress * taddr,int count)1239 static int expect_q931(struct sk_buff *skb, struct nf_conn *ct,
1240 enum ip_conntrack_info ctinfo,
1241 unsigned char **data,
1242 TransportAddress *taddr, int count)
1243 {
1244 struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1245 int dir = CTINFO2DIR(ctinfo);
1246 int ret = 0;
1247 int i;
1248 __be16 port;
1249 union nf_inet_addr addr;
1250 struct nf_conntrack_expect *exp;
1251 typeof(nat_q931_hook) nat_q931;
1252
1253 /* Look for the first related address */
1254 for (i = 0; i < count; i++) {
1255 if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) &&
1256 memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3,
1257 sizeof(addr)) == 0 && port != 0)
1258 break;
1259 }
1260
1261 if (i >= count) /* Not found */
1262 return 0;
1263
1264 /* Create expect for Q.931 */
1265 if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1266 return -1;
1267 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1268 gkrouted_only ? /* only accept calls from GK? */
1269 &ct->tuplehash[!dir].tuple.src.u3 : NULL,
1270 &ct->tuplehash[!dir].tuple.dst.u3,
1271 IPPROTO_TCP, NULL, &port);
1272 exp->helper = nf_conntrack_helper_q931;
1273 exp->flags = NF_CT_EXPECT_PERMANENT; /* Accept multiple calls */
1274
1275 nat_q931 = rcu_dereference(nat_q931_hook);
1276 if (nat_q931 && ct->status & IPS_NAT_MASK) { /* Need NAT */
1277 ret = nat_q931(skb, ct, ctinfo, data, taddr, i, port, exp);
1278 } else { /* Conntrack only */
1279 if (nf_ct_expect_related(exp) == 0) {
1280 pr_debug("nf_ct_ras: expect Q.931 ");
1281 nf_ct_dump_tuple(&exp->tuple);
1282
1283 /* Save port for looking up expect in processing RCF */
1284 info->sig_port[dir] = port;
1285 } else
1286 ret = -1;
1287 }
1288
1289 nf_ct_expect_put(exp);
1290
1291 return ret;
1292 }
1293
1294 /****************************************************************************/
process_grq(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,GatekeeperRequest * grq)1295 static int process_grq(struct sk_buff *skb, struct nf_conn *ct,
1296 enum ip_conntrack_info ctinfo,
1297 unsigned char **data, GatekeeperRequest *grq)
1298 {
1299 typeof(set_ras_addr_hook) set_ras_addr;
1300
1301 pr_debug("nf_ct_ras: GRQ\n");
1302
1303 set_ras_addr = rcu_dereference(set_ras_addr_hook);
1304 if (set_ras_addr && ct->status & IPS_NAT_MASK) /* NATed */
1305 return set_ras_addr(skb, ct, ctinfo, data,
1306 &grq->rasAddress, 1);
1307 return 0;
1308 }
1309
1310 /****************************************************************************/
process_gcf(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,GatekeeperConfirm * gcf)1311 static int process_gcf(struct sk_buff *skb, struct nf_conn *ct,
1312 enum ip_conntrack_info ctinfo,
1313 unsigned char **data, GatekeeperConfirm *gcf)
1314 {
1315 int dir = CTINFO2DIR(ctinfo);
1316 int ret = 0;
1317 __be16 port;
1318 union nf_inet_addr addr;
1319 struct nf_conntrack_expect *exp;
1320
1321 pr_debug("nf_ct_ras: GCF\n");
1322
1323 if (!get_h225_addr(ct, *data, &gcf->rasAddress, &addr, &port))
1324 return 0;
1325
1326 /* Registration port is the same as discovery port */
1327 if (!memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1328 port == ct->tuplehash[dir].tuple.src.u.udp.port)
1329 return 0;
1330
1331 /* Avoid RAS expectation loops. A GCF is never expected. */
1332 if (test_bit(IPS_EXPECTED_BIT, &ct->status))
1333 return 0;
1334
1335 /* Need new expect */
1336 if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1337 return -1;
1338 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1339 &ct->tuplehash[!dir].tuple.src.u3, &addr,
1340 IPPROTO_UDP, NULL, &port);
1341 exp->helper = nf_conntrack_helper_ras;
1342
1343 if (nf_ct_expect_related(exp) == 0) {
1344 pr_debug("nf_ct_ras: expect RAS ");
1345 nf_ct_dump_tuple(&exp->tuple);
1346 } else
1347 ret = -1;
1348
1349 nf_ct_expect_put(exp);
1350
1351 return ret;
1352 }
1353
1354 /****************************************************************************/
process_rrq(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,RegistrationRequest * rrq)1355 static int process_rrq(struct sk_buff *skb, struct nf_conn *ct,
1356 enum ip_conntrack_info ctinfo,
1357 unsigned char **data, RegistrationRequest *rrq)
1358 {
1359 struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1360 int ret;
1361 typeof(set_ras_addr_hook) set_ras_addr;
1362
1363 pr_debug("nf_ct_ras: RRQ\n");
1364
1365 ret = expect_q931(skb, ct, ctinfo, data,
1366 rrq->callSignalAddress.item,
1367 rrq->callSignalAddress.count);
1368 if (ret < 0)
1369 return -1;
1370
1371 set_ras_addr = rcu_dereference(set_ras_addr_hook);
1372 if (set_ras_addr && ct->status & IPS_NAT_MASK) {
1373 ret = set_ras_addr(skb, ct, ctinfo, data,
1374 rrq->rasAddress.item,
1375 rrq->rasAddress.count);
1376 if (ret < 0)
1377 return -1;
1378 }
1379
1380 if (rrq->options & eRegistrationRequest_timeToLive) {
1381 pr_debug("nf_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive);
1382 info->timeout = rrq->timeToLive;
1383 } else
1384 info->timeout = default_rrq_ttl;
1385
1386 return 0;
1387 }
1388
1389 /****************************************************************************/
process_rcf(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,RegistrationConfirm * rcf)1390 static int process_rcf(struct sk_buff *skb, struct nf_conn *ct,
1391 enum ip_conntrack_info ctinfo,
1392 unsigned char **data, RegistrationConfirm *rcf)
1393 {
1394 struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1395 int dir = CTINFO2DIR(ctinfo);
1396 int ret;
1397 struct nf_conntrack_expect *exp;
1398 typeof(set_sig_addr_hook) set_sig_addr;
1399
1400 pr_debug("nf_ct_ras: RCF\n");
1401
1402 set_sig_addr = rcu_dereference(set_sig_addr_hook);
1403 if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1404 ret = set_sig_addr(skb, 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 pr_debug("nf_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive);
1413 info->timeout = rcf->timeToLive;
1414 }
1415
1416 if (info->timeout > 0) {
1417 pr_debug("nf_ct_ras: set RAS connection timeout to "
1418 "%u seconds\n", info->timeout);
1419 nf_ct_refresh(ct, skb, info->timeout * HZ);
1420
1421 /* Set expect timeout */
1422 spin_lock_bh(&nf_conntrack_lock);
1423 exp = find_expect(ct, &ct->tuplehash[dir].tuple.dst.u3,
1424 info->sig_port[!dir]);
1425 if (exp) {
1426 pr_debug("nf_ct_ras: set Q.931 expect "
1427 "timeout to %u seconds for",
1428 info->timeout);
1429 nf_ct_dump_tuple(&exp->tuple);
1430 set_expect_timeout(exp, info->timeout);
1431 }
1432 spin_unlock_bh(&nf_conntrack_lock);
1433 }
1434
1435 return 0;
1436 }
1437
1438 /****************************************************************************/
process_urq(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,UnregistrationRequest * urq)1439 static int process_urq(struct sk_buff *skb, struct nf_conn *ct,
1440 enum ip_conntrack_info ctinfo,
1441 unsigned char **data, UnregistrationRequest *urq)
1442 {
1443 struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1444 int dir = CTINFO2DIR(ctinfo);
1445 int ret;
1446 typeof(set_sig_addr_hook) set_sig_addr;
1447
1448 pr_debug("nf_ct_ras: URQ\n");
1449
1450 set_sig_addr = rcu_dereference(set_sig_addr_hook);
1451 if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1452 ret = set_sig_addr(skb, ct, ctinfo, data,
1453 urq->callSignalAddress.item,
1454 urq->callSignalAddress.count);
1455 if (ret < 0)
1456 return -1;
1457 }
1458
1459 /* Clear old expect */
1460 nf_ct_remove_expectations(ct);
1461 info->sig_port[dir] = 0;
1462 info->sig_port[!dir] = 0;
1463
1464 /* Give it 30 seconds for UCF or URJ */
1465 nf_ct_refresh(ct, skb, 30 * HZ);
1466
1467 return 0;
1468 }
1469
1470 /****************************************************************************/
process_arq(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,AdmissionRequest * arq)1471 static int process_arq(struct sk_buff *skb, struct nf_conn *ct,
1472 enum ip_conntrack_info ctinfo,
1473 unsigned char **data, AdmissionRequest *arq)
1474 {
1475 const struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1476 int dir = CTINFO2DIR(ctinfo);
1477 __be16 port;
1478 union nf_inet_addr addr;
1479 typeof(set_h225_addr_hook) set_h225_addr;
1480
1481 pr_debug("nf_ct_ras: ARQ\n");
1482
1483 set_h225_addr = rcu_dereference(set_h225_addr_hook);
1484 if ((arq->options & eAdmissionRequest_destCallSignalAddress) &&
1485 get_h225_addr(ct, *data, &arq->destCallSignalAddress,
1486 &addr, &port) &&
1487 !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1488 port == info->sig_port[dir] &&
1489 set_h225_addr && ct->status & IPS_NAT_MASK) {
1490 /* Answering ARQ */
1491 return set_h225_addr(skb, data, 0,
1492 &arq->destCallSignalAddress,
1493 &ct->tuplehash[!dir].tuple.dst.u3,
1494 info->sig_port[!dir]);
1495 }
1496
1497 if ((arq->options & eAdmissionRequest_srcCallSignalAddress) &&
1498 get_h225_addr(ct, *data, &arq->srcCallSignalAddress,
1499 &addr, &port) &&
1500 !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1501 set_h225_addr && ct->status & IPS_NAT_MASK) {
1502 /* Calling ARQ */
1503 return set_h225_addr(skb, data, 0,
1504 &arq->srcCallSignalAddress,
1505 &ct->tuplehash[!dir].tuple.dst.u3,
1506 port);
1507 }
1508
1509 return 0;
1510 }
1511
1512 /****************************************************************************/
process_acf(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,AdmissionConfirm * acf)1513 static int process_acf(struct sk_buff *skb, struct nf_conn *ct,
1514 enum ip_conntrack_info ctinfo,
1515 unsigned char **data, AdmissionConfirm *acf)
1516 {
1517 int dir = CTINFO2DIR(ctinfo);
1518 int ret = 0;
1519 __be16 port;
1520 union nf_inet_addr addr;
1521 struct nf_conntrack_expect *exp;
1522 typeof(set_sig_addr_hook) set_sig_addr;
1523
1524 pr_debug("nf_ct_ras: ACF\n");
1525
1526 if (!get_h225_addr(ct, *data, &acf->destCallSignalAddress,
1527 &addr, &port))
1528 return 0;
1529
1530 if (!memcmp(&addr, &ct->tuplehash[dir].tuple.dst.u3, sizeof(addr))) {
1531 /* Answering ACF */
1532 set_sig_addr = rcu_dereference(set_sig_addr_hook);
1533 if (set_sig_addr && ct->status & IPS_NAT_MASK)
1534 return set_sig_addr(skb, ct, ctinfo, data,
1535 &acf->destCallSignalAddress, 1);
1536 return 0;
1537 }
1538
1539 /* Need new expect */
1540 if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1541 return -1;
1542 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1543 &ct->tuplehash[!dir].tuple.src.u3, &addr,
1544 IPPROTO_TCP, NULL, &port);
1545 exp->flags = NF_CT_EXPECT_PERMANENT;
1546 exp->helper = nf_conntrack_helper_q931;
1547
1548 if (nf_ct_expect_related(exp) == 0) {
1549 pr_debug("nf_ct_ras: expect Q.931 ");
1550 nf_ct_dump_tuple(&exp->tuple);
1551 } else
1552 ret = -1;
1553
1554 nf_ct_expect_put(exp);
1555
1556 return ret;
1557 }
1558
1559 /****************************************************************************/
process_lrq(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,LocationRequest * lrq)1560 static int process_lrq(struct sk_buff *skb, struct nf_conn *ct,
1561 enum ip_conntrack_info ctinfo,
1562 unsigned char **data, LocationRequest *lrq)
1563 {
1564 typeof(set_ras_addr_hook) set_ras_addr;
1565
1566 pr_debug("nf_ct_ras: LRQ\n");
1567
1568 set_ras_addr = rcu_dereference(set_ras_addr_hook);
1569 if (set_ras_addr && ct->status & IPS_NAT_MASK)
1570 return set_ras_addr(skb, ct, ctinfo, data,
1571 &lrq->replyAddress, 1);
1572 return 0;
1573 }
1574
1575 /****************************************************************************/
process_lcf(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,LocationConfirm * lcf)1576 static int process_lcf(struct sk_buff *skb, struct nf_conn *ct,
1577 enum ip_conntrack_info ctinfo,
1578 unsigned char **data, LocationConfirm *lcf)
1579 {
1580 int dir = CTINFO2DIR(ctinfo);
1581 int ret = 0;
1582 __be16 port;
1583 union nf_inet_addr addr;
1584 struct nf_conntrack_expect *exp;
1585
1586 pr_debug("nf_ct_ras: LCF\n");
1587
1588 if (!get_h225_addr(ct, *data, &lcf->callSignalAddress,
1589 &addr, &port))
1590 return 0;
1591
1592 /* Need new expect for call signal */
1593 if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1594 return -1;
1595 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1596 &ct->tuplehash[!dir].tuple.src.u3, &addr,
1597 IPPROTO_TCP, NULL, &port);
1598 exp->flags = NF_CT_EXPECT_PERMANENT;
1599 exp->helper = nf_conntrack_helper_q931;
1600
1601 if (nf_ct_expect_related(exp) == 0) {
1602 pr_debug("nf_ct_ras: expect Q.931 ");
1603 nf_ct_dump_tuple(&exp->tuple);
1604 } else
1605 ret = -1;
1606
1607 nf_ct_expect_put(exp);
1608
1609 /* Ignore rasAddress */
1610
1611 return ret;
1612 }
1613
1614 /****************************************************************************/
process_irr(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,InfoRequestResponse * irr)1615 static int process_irr(struct sk_buff *skb, struct nf_conn *ct,
1616 enum ip_conntrack_info ctinfo,
1617 unsigned char **data, InfoRequestResponse *irr)
1618 {
1619 int ret;
1620 typeof(set_ras_addr_hook) set_ras_addr;
1621 typeof(set_sig_addr_hook) set_sig_addr;
1622
1623 pr_debug("nf_ct_ras: IRR\n");
1624
1625 set_ras_addr = rcu_dereference(set_ras_addr_hook);
1626 if (set_ras_addr && ct->status & IPS_NAT_MASK) {
1627 ret = set_ras_addr(skb, ct, ctinfo, data,
1628 &irr->rasAddress, 1);
1629 if (ret < 0)
1630 return -1;
1631 }
1632
1633 set_sig_addr = rcu_dereference(set_sig_addr_hook);
1634 if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1635 ret = set_sig_addr(skb, ct, ctinfo, data,
1636 irr->callSignalAddress.item,
1637 irr->callSignalAddress.count);
1638 if (ret < 0)
1639 return -1;
1640 }
1641
1642 return 0;
1643 }
1644
1645 /****************************************************************************/
process_ras(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,RasMessage * ras)1646 static int process_ras(struct sk_buff *skb, struct nf_conn *ct,
1647 enum ip_conntrack_info ctinfo,
1648 unsigned char **data, RasMessage *ras)
1649 {
1650 switch (ras->choice) {
1651 case eRasMessage_gatekeeperRequest:
1652 return process_grq(skb, ct, ctinfo, data,
1653 &ras->gatekeeperRequest);
1654 case eRasMessage_gatekeeperConfirm:
1655 return process_gcf(skb, ct, ctinfo, data,
1656 &ras->gatekeeperConfirm);
1657 case eRasMessage_registrationRequest:
1658 return process_rrq(skb, ct, ctinfo, data,
1659 &ras->registrationRequest);
1660 case eRasMessage_registrationConfirm:
1661 return process_rcf(skb, ct, ctinfo, data,
1662 &ras->registrationConfirm);
1663 case eRasMessage_unregistrationRequest:
1664 return process_urq(skb, ct, ctinfo, data,
1665 &ras->unregistrationRequest);
1666 case eRasMessage_admissionRequest:
1667 return process_arq(skb, ct, ctinfo, data,
1668 &ras->admissionRequest);
1669 case eRasMessage_admissionConfirm:
1670 return process_acf(skb, ct, ctinfo, data,
1671 &ras->admissionConfirm);
1672 case eRasMessage_locationRequest:
1673 return process_lrq(skb, ct, ctinfo, data,
1674 &ras->locationRequest);
1675 case eRasMessage_locationConfirm:
1676 return process_lcf(skb, ct, ctinfo, data,
1677 &ras->locationConfirm);
1678 case eRasMessage_infoRequestResponse:
1679 return process_irr(skb, ct, ctinfo, data,
1680 &ras->infoRequestResponse);
1681 default:
1682 pr_debug("nf_ct_ras: RAS message %d\n", ras->choice);
1683 break;
1684 }
1685
1686 return 0;
1687 }
1688
1689 /****************************************************************************/
ras_help(struct sk_buff * skb,unsigned int protoff,struct nf_conn * ct,enum ip_conntrack_info ctinfo)1690 static int ras_help(struct sk_buff *skb, unsigned int protoff,
1691 struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1692 {
1693 static RasMessage ras;
1694 unsigned char *data;
1695 int datalen = 0;
1696 int ret;
1697
1698 pr_debug("nf_ct_ras: skblen = %u\n", skb->len);
1699
1700 spin_lock_bh(&nf_h323_lock);
1701
1702 /* Get UDP data */
1703 data = get_udp_data(skb, protoff, &datalen);
1704 if (data == NULL)
1705 goto accept;
1706 pr_debug("nf_ct_ras: RAS message len=%d ", datalen);
1707 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1708
1709 /* Decode RAS message */
1710 ret = DecodeRasMessage(data, datalen, &ras);
1711 if (ret < 0) {
1712 pr_debug("nf_ct_ras: decoding error: %s\n",
1713 ret == H323_ERROR_BOUND ?
1714 "out of bound" : "out of range");
1715 goto accept;
1716 }
1717
1718 /* Process RAS message */
1719 if (process_ras(skb, ct, ctinfo, &data, &ras) < 0)
1720 goto drop;
1721
1722 accept:
1723 spin_unlock_bh(&nf_h323_lock);
1724 return NF_ACCEPT;
1725
1726 drop:
1727 spin_unlock_bh(&nf_h323_lock);
1728 if (net_ratelimit())
1729 printk("nf_ct_ras: packet dropped\n");
1730 return NF_DROP;
1731 }
1732
1733 /****************************************************************************/
1734 static const struct nf_conntrack_expect_policy ras_exp_policy = {
1735 .max_expected = 32,
1736 .timeout = 240,
1737 };
1738
1739 static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = {
1740 {
1741 .name = "RAS",
1742 .me = THIS_MODULE,
1743 .tuple.src.l3num = AF_INET,
1744 .tuple.src.u.udp.port = __constant_htons(RAS_PORT),
1745 .tuple.dst.protonum = IPPROTO_UDP,
1746 .help = ras_help,
1747 .expect_policy = &ras_exp_policy,
1748 },
1749 {
1750 .name = "RAS",
1751 .me = THIS_MODULE,
1752 .tuple.src.l3num = AF_INET6,
1753 .tuple.src.u.udp.port = __constant_htons(RAS_PORT),
1754 .tuple.dst.protonum = IPPROTO_UDP,
1755 .help = ras_help,
1756 .expect_policy = &ras_exp_policy,
1757 },
1758 };
1759
1760 /****************************************************************************/
nf_conntrack_h323_fini(void)1761 static void __exit nf_conntrack_h323_fini(void)
1762 {
1763 nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[1]);
1764 nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1765 nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1766 nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1767 nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1768 kfree(h323_buffer);
1769 pr_debug("nf_ct_h323: fini\n");
1770 }
1771
1772 /****************************************************************************/
nf_conntrack_h323_init(void)1773 static int __init nf_conntrack_h323_init(void)
1774 {
1775 int ret;
1776
1777 h323_buffer = kmalloc(65536, GFP_KERNEL);
1778 if (!h323_buffer)
1779 return -ENOMEM;
1780 ret = nf_conntrack_helper_register(&nf_conntrack_helper_h245);
1781 if (ret < 0)
1782 goto err1;
1783 ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[0]);
1784 if (ret < 0)
1785 goto err2;
1786 ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[1]);
1787 if (ret < 0)
1788 goto err3;
1789 ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[0]);
1790 if (ret < 0)
1791 goto err4;
1792 ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[1]);
1793 if (ret < 0)
1794 goto err5;
1795 pr_debug("nf_ct_h323: init success\n");
1796 return 0;
1797
1798 err5:
1799 nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1800 err4:
1801 nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1802 err3:
1803 nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1804 err2:
1805 nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1806 err1:
1807 kfree(h323_buffer);
1808 return ret;
1809 }
1810
1811 /****************************************************************************/
1812 module_init(nf_conntrack_h323_init);
1813 module_exit(nf_conntrack_h323_fini);
1814
1815 EXPORT_SYMBOL_GPL(get_h225_addr);
1816 EXPORT_SYMBOL_GPL(set_h245_addr_hook);
1817 EXPORT_SYMBOL_GPL(set_h225_addr_hook);
1818 EXPORT_SYMBOL_GPL(set_sig_addr_hook);
1819 EXPORT_SYMBOL_GPL(set_ras_addr_hook);
1820 EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook);
1821 EXPORT_SYMBOL_GPL(nat_t120_hook);
1822 EXPORT_SYMBOL_GPL(nat_h245_hook);
1823 EXPORT_SYMBOL_GPL(nat_callforwarding_hook);
1824 EXPORT_SYMBOL_GPL(nat_q931_hook);
1825
1826 MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>");
1827 MODULE_DESCRIPTION("H.323 connection tracking helper");
1828 MODULE_LICENSE("GPL");
1829 MODULE_ALIAS("ip_conntrack_h323");
1830 MODULE_ALIAS_NFCT_HELPER("h323");
1831