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/slab.h>
21 #include <linux/udp.h>
22 #include <linux/tcp.h>
23 #include <linux/skbuff.h>
24 #include <net/route.h>
25 #include <net/ip6_route.h>
26
27 #include <net/netfilter/nf_conntrack.h>
28 #include <net/netfilter/nf_conntrack_core.h>
29 #include <net/netfilter/nf_conntrack_tuple.h>
30 #include <net/netfilter/nf_conntrack_expect.h>
31 #include <net/netfilter/nf_conntrack_ecache.h>
32 #include <net/netfilter/nf_conntrack_helper.h>
33 #include <net/netfilter/nf_conntrack_zones.h>
34 #include <linux/netfilter/nf_conntrack_h323.h>
35
36 /* Parameters */
37 static unsigned int default_rrq_ttl __read_mostly = 300;
38 module_param(default_rrq_ttl, uint, 0600);
39 MODULE_PARM_DESC(default_rrq_ttl, "use this TTL if it's missing in RRQ");
40
41 static int gkrouted_only __read_mostly = 1;
42 module_param(gkrouted_only, int, 0600);
43 MODULE_PARM_DESC(gkrouted_only, "only accept calls from gatekeeper");
44
45 static bool callforward_filter __read_mostly = true;
46 module_param(callforward_filter, bool, 0600);
47 MODULE_PARM_DESC(callforward_filter, "only create call forwarding expectations "
48 "if both endpoints are on different sides "
49 "(determined by routing information)");
50
51 /* Hooks for NAT */
52 int (*set_h245_addr_hook) (struct sk_buff *skb,
53 unsigned char **data, int dataoff,
54 H245_TransportAddress *taddr,
55 union nf_inet_addr *addr, __be16 port)
56 __read_mostly;
57 int (*set_h225_addr_hook) (struct sk_buff *skb,
58 unsigned char **data, int dataoff,
59 TransportAddress *taddr,
60 union nf_inet_addr *addr, __be16 port)
61 __read_mostly;
62 int (*set_sig_addr_hook) (struct sk_buff *skb,
63 struct nf_conn *ct,
64 enum ip_conntrack_info ctinfo,
65 unsigned char **data,
66 TransportAddress *taddr, int count) __read_mostly;
67 int (*set_ras_addr_hook) (struct sk_buff *skb,
68 struct nf_conn *ct,
69 enum ip_conntrack_info ctinfo,
70 unsigned char **data,
71 TransportAddress *taddr, int count) __read_mostly;
72 int (*nat_rtp_rtcp_hook) (struct sk_buff *skb,
73 struct nf_conn *ct,
74 enum ip_conntrack_info ctinfo,
75 unsigned char **data, int dataoff,
76 H245_TransportAddress *taddr,
77 __be16 port, __be16 rtp_port,
78 struct nf_conntrack_expect *rtp_exp,
79 struct nf_conntrack_expect *rtcp_exp) __read_mostly;
80 int (*nat_t120_hook) (struct sk_buff *skb,
81 struct nf_conn *ct,
82 enum ip_conntrack_info ctinfo,
83 unsigned char **data, int dataoff,
84 H245_TransportAddress *taddr, __be16 port,
85 struct nf_conntrack_expect *exp) __read_mostly;
86 int (*nat_h245_hook) (struct sk_buff *skb,
87 struct nf_conn *ct,
88 enum ip_conntrack_info ctinfo,
89 unsigned char **data, int dataoff,
90 TransportAddress *taddr, __be16 port,
91 struct nf_conntrack_expect *exp) __read_mostly;
92 int (*nat_callforwarding_hook) (struct sk_buff *skb,
93 struct nf_conn *ct,
94 enum ip_conntrack_info ctinfo,
95 unsigned char **data, int dataoff,
96 TransportAddress *taddr, __be16 port,
97 struct nf_conntrack_expect *exp) __read_mostly;
98 int (*nat_q931_hook) (struct sk_buff *skb,
99 struct nf_conn *ct,
100 enum ip_conntrack_info ctinfo,
101 unsigned char **data, TransportAddress *taddr, int idx,
102 __be16 port, struct nf_conntrack_expect *exp)
103 __read_mostly;
104
105 static DEFINE_SPINLOCK(nf_h323_lock);
106 static char *h323_buffer;
107
108 static struct nf_conntrack_helper nf_conntrack_helper_h245;
109 static struct nf_conntrack_helper nf_conntrack_helper_q931[];
110 static struct nf_conntrack_helper nf_conntrack_helper_ras[];
111
112 /****************************************************************************/
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)113 static int get_tpkt_data(struct sk_buff *skb, unsigned int protoff,
114 struct nf_conn *ct, enum ip_conntrack_info ctinfo,
115 unsigned char **data, int *datalen, int *dataoff)
116 {
117 struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
118 int dir = CTINFO2DIR(ctinfo);
119 const struct tcphdr *th;
120 struct tcphdr _tcph;
121 int tcpdatalen;
122 int tcpdataoff;
123 unsigned char *tpkt;
124 int tpktlen;
125 int tpktoff;
126
127 /* Get TCP header */
128 th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph);
129 if (th == NULL)
130 return 0;
131
132 /* Get TCP data offset */
133 tcpdataoff = protoff + th->doff * 4;
134
135 /* Get TCP data length */
136 tcpdatalen = skb->len - tcpdataoff;
137 if (tcpdatalen <= 0) /* No TCP data */
138 goto clear_out;
139
140 if (*data == NULL) { /* first TPKT */
141 /* Get first TPKT pointer */
142 tpkt = skb_header_pointer(skb, tcpdataoff, tcpdatalen,
143 h323_buffer);
144 BUG_ON(tpkt == NULL);
145
146 /* Validate TPKT identifier */
147 if (tcpdatalen < 4 || tpkt[0] != 0x03 || tpkt[1] != 0) {
148 /* Netmeeting sends TPKT header and data separately */
149 if (info->tpkt_len[dir] > 0) {
150 pr_debug("nf_ct_h323: previous packet "
151 "indicated separate TPKT data of %hu "
152 "bytes\n", info->tpkt_len[dir]);
153 if (info->tpkt_len[dir] <= tcpdatalen) {
154 /* Yes, there was a TPKT header
155 * received */
156 *data = tpkt;
157 *datalen = info->tpkt_len[dir];
158 *dataoff = 0;
159 goto out;
160 }
161
162 /* Fragmented TPKT */
163 pr_debug("nf_ct_h323: fragmented TPKT\n");
164 goto clear_out;
165 }
166
167 /* It is not even a TPKT */
168 return 0;
169 }
170 tpktoff = 0;
171 } else { /* Next TPKT */
172 tpktoff = *dataoff + *datalen;
173 tcpdatalen -= tpktoff;
174 if (tcpdatalen <= 4) /* No more TPKT */
175 goto clear_out;
176 tpkt = *data + *datalen;
177
178 /* Validate TPKT identifier */
179 if (tpkt[0] != 0x03 || tpkt[1] != 0)
180 goto clear_out;
181 }
182
183 /* Validate TPKT length */
184 tpktlen = tpkt[2] * 256 + tpkt[3];
185 if (tpktlen < 4)
186 goto clear_out;
187 if (tpktlen > tcpdatalen) {
188 if (tcpdatalen == 4) { /* Separate TPKT header */
189 /* Netmeeting sends TPKT header and data separately */
190 pr_debug("nf_ct_h323: separate TPKT header indicates "
191 "there will be TPKT data of %hu bytes\n",
192 tpktlen - 4);
193 info->tpkt_len[dir] = tpktlen - 4;
194 return 0;
195 }
196
197 pr_debug("nf_ct_h323: incomplete TPKT (fragmented?)\n");
198 goto clear_out;
199 }
200
201 /* This is the encapsulated data */
202 *data = tpkt + 4;
203 *datalen = tpktlen - 4;
204 *dataoff = tpktoff + 4;
205
206 out:
207 /* Clear TPKT length */
208 info->tpkt_len[dir] = 0;
209 return 1;
210
211 clear_out:
212 info->tpkt_len[dir] = 0;
213 return 0;
214 }
215
216 /****************************************************************************/
get_h245_addr(struct nf_conn * ct,const unsigned char * data,H245_TransportAddress * taddr,union nf_inet_addr * addr,__be16 * port)217 static int get_h245_addr(struct nf_conn *ct, const unsigned char *data,
218 H245_TransportAddress *taddr,
219 union nf_inet_addr *addr, __be16 *port)
220 {
221 const unsigned char *p;
222 int len;
223
224 if (taddr->choice != eH245_TransportAddress_unicastAddress)
225 return 0;
226
227 switch (taddr->unicastAddress.choice) {
228 case eUnicastAddress_iPAddress:
229 if (nf_ct_l3num(ct) != AF_INET)
230 return 0;
231 p = data + taddr->unicastAddress.iPAddress.network;
232 len = 4;
233 break;
234 case eUnicastAddress_iP6Address:
235 if (nf_ct_l3num(ct) != AF_INET6)
236 return 0;
237 p = data + taddr->unicastAddress.iP6Address.network;
238 len = 16;
239 break;
240 default:
241 return 0;
242 }
243
244 memcpy(addr, p, len);
245 memset((void *)addr + len, 0, sizeof(*addr) - len);
246 memcpy(port, p + len, sizeof(__be16));
247
248 return 1;
249 }
250
251 /****************************************************************************/
expect_rtp_rtcp(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,H245_TransportAddress * taddr)252 static int expect_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct,
253 enum ip_conntrack_info ctinfo,
254 unsigned char **data, int dataoff,
255 H245_TransportAddress *taddr)
256 {
257 int dir = CTINFO2DIR(ctinfo);
258 int ret = 0;
259 __be16 port;
260 __be16 rtp_port, rtcp_port;
261 union nf_inet_addr addr;
262 struct nf_conntrack_expect *rtp_exp;
263 struct nf_conntrack_expect *rtcp_exp;
264 typeof(nat_rtp_rtcp_hook) nat_rtp_rtcp;
265
266 /* Read RTP or RTCP address */
267 if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
268 memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
269 port == 0)
270 return 0;
271
272 /* RTP port is even */
273 port &= htons(~1);
274 rtp_port = port;
275 rtcp_port = htons(ntohs(port) + 1);
276
277 /* Create expect for RTP */
278 if ((rtp_exp = nf_ct_expect_alloc(ct)) == NULL)
279 return -1;
280 nf_ct_expect_init(rtp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
281 &ct->tuplehash[!dir].tuple.src.u3,
282 &ct->tuplehash[!dir].tuple.dst.u3,
283 IPPROTO_UDP, NULL, &rtp_port);
284
285 /* Create expect for RTCP */
286 if ((rtcp_exp = nf_ct_expect_alloc(ct)) == NULL) {
287 nf_ct_expect_put(rtp_exp);
288 return -1;
289 }
290 nf_ct_expect_init(rtcp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
291 &ct->tuplehash[!dir].tuple.src.u3,
292 &ct->tuplehash[!dir].tuple.dst.u3,
293 IPPROTO_UDP, NULL, &rtcp_port);
294
295 if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
296 &ct->tuplehash[!dir].tuple.dst.u3,
297 sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
298 (nat_rtp_rtcp = rcu_dereference(nat_rtp_rtcp_hook)) &&
299 ct->status & IPS_NAT_MASK) {
300 /* NAT needed */
301 ret = nat_rtp_rtcp(skb, ct, ctinfo, data, dataoff,
302 taddr, port, rtp_port, rtp_exp, rtcp_exp);
303 } else { /* Conntrack only */
304 if (nf_ct_expect_related(rtp_exp) == 0) {
305 if (nf_ct_expect_related(rtcp_exp) == 0) {
306 pr_debug("nf_ct_h323: expect RTP ");
307 nf_ct_dump_tuple(&rtp_exp->tuple);
308 pr_debug("nf_ct_h323: expect RTCP ");
309 nf_ct_dump_tuple(&rtcp_exp->tuple);
310 } else {
311 nf_ct_unexpect_related(rtp_exp);
312 ret = -1;
313 }
314 } else
315 ret = -1;
316 }
317
318 nf_ct_expect_put(rtp_exp);
319 nf_ct_expect_put(rtcp_exp);
320
321 return ret;
322 }
323
324 /****************************************************************************/
expect_t120(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,H245_TransportAddress * taddr)325 static int expect_t120(struct sk_buff *skb,
326 struct nf_conn *ct,
327 enum ip_conntrack_info ctinfo,
328 unsigned char **data, int dataoff,
329 H245_TransportAddress *taddr)
330 {
331 int dir = CTINFO2DIR(ctinfo);
332 int ret = 0;
333 __be16 port;
334 union nf_inet_addr addr;
335 struct nf_conntrack_expect *exp;
336 typeof(nat_t120_hook) nat_t120;
337
338 /* Read T.120 address */
339 if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
340 memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
341 port == 0)
342 return 0;
343
344 /* Create expect for T.120 connections */
345 if ((exp = nf_ct_expect_alloc(ct)) == NULL)
346 return -1;
347 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
348 &ct->tuplehash[!dir].tuple.src.u3,
349 &ct->tuplehash[!dir].tuple.dst.u3,
350 IPPROTO_TCP, NULL, &port);
351 exp->flags = NF_CT_EXPECT_PERMANENT; /* Accept multiple channels */
352
353 if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
354 &ct->tuplehash[!dir].tuple.dst.u3,
355 sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
356 (nat_t120 = rcu_dereference(nat_t120_hook)) &&
357 ct->status & IPS_NAT_MASK) {
358 /* NAT needed */
359 ret = nat_t120(skb, ct, ctinfo, data, dataoff, taddr,
360 port, exp);
361 } else { /* Conntrack only */
362 if (nf_ct_expect_related(exp) == 0) {
363 pr_debug("nf_ct_h323: expect T.120 ");
364 nf_ct_dump_tuple(&exp->tuple);
365 } else
366 ret = -1;
367 }
368
369 nf_ct_expect_put(exp);
370
371 return ret;
372 }
373
374 /****************************************************************************/
process_h245_channel(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,H2250LogicalChannelParameters * channel)375 static int process_h245_channel(struct sk_buff *skb,
376 struct nf_conn *ct,
377 enum ip_conntrack_info ctinfo,
378 unsigned char **data, int dataoff,
379 H2250LogicalChannelParameters *channel)
380 {
381 int ret;
382
383 if (channel->options & eH2250LogicalChannelParameters_mediaChannel) {
384 /* RTP */
385 ret = expect_rtp_rtcp(skb, ct, ctinfo, data, dataoff,
386 &channel->mediaChannel);
387 if (ret < 0)
388 return -1;
389 }
390
391 if (channel->
392 options & eH2250LogicalChannelParameters_mediaControlChannel) {
393 /* RTCP */
394 ret = expect_rtp_rtcp(skb, ct, ctinfo, data, dataoff,
395 &channel->mediaControlChannel);
396 if (ret < 0)
397 return -1;
398 }
399
400 return 0;
401 }
402
403 /****************************************************************************/
process_olc(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,OpenLogicalChannel * olc)404 static int process_olc(struct sk_buff *skb, struct nf_conn *ct,
405 enum ip_conntrack_info ctinfo,
406 unsigned char **data, int dataoff,
407 OpenLogicalChannel *olc)
408 {
409 int ret;
410
411 pr_debug("nf_ct_h323: OpenLogicalChannel\n");
412
413 if (olc->forwardLogicalChannelParameters.multiplexParameters.choice ==
414 eOpenLogicalChannel_forwardLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters)
415 {
416 ret = process_h245_channel(skb, ct, ctinfo, data, dataoff,
417 &olc->
418 forwardLogicalChannelParameters.
419 multiplexParameters.
420 h2250LogicalChannelParameters);
421 if (ret < 0)
422 return -1;
423 }
424
425 if ((olc->options &
426 eOpenLogicalChannel_reverseLogicalChannelParameters) &&
427 (olc->reverseLogicalChannelParameters.options &
428 eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters)
429 && (olc->reverseLogicalChannelParameters.multiplexParameters.
430 choice ==
431 eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
432 {
433 ret =
434 process_h245_channel(skb, ct, ctinfo, data, dataoff,
435 &olc->
436 reverseLogicalChannelParameters.
437 multiplexParameters.
438 h2250LogicalChannelParameters);
439 if (ret < 0)
440 return -1;
441 }
442
443 if ((olc->options & eOpenLogicalChannel_separateStack) &&
444 olc->forwardLogicalChannelParameters.dataType.choice ==
445 eDataType_data &&
446 olc->forwardLogicalChannelParameters.dataType.data.application.
447 choice == eDataApplicationCapability_application_t120 &&
448 olc->forwardLogicalChannelParameters.dataType.data.application.
449 t120.choice == eDataProtocolCapability_separateLANStack &&
450 olc->separateStack.networkAddress.choice ==
451 eNetworkAccessParameters_networkAddress_localAreaAddress) {
452 ret = expect_t120(skb, ct, ctinfo, data, dataoff,
453 &olc->separateStack.networkAddress.
454 localAreaAddress);
455 if (ret < 0)
456 return -1;
457 }
458
459 return 0;
460 }
461
462 /****************************************************************************/
process_olca(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,OpenLogicalChannelAck * olca)463 static int process_olca(struct sk_buff *skb, struct nf_conn *ct,
464 enum ip_conntrack_info ctinfo,
465 unsigned char **data, int dataoff,
466 OpenLogicalChannelAck *olca)
467 {
468 H2250LogicalChannelAckParameters *ack;
469 int ret;
470
471 pr_debug("nf_ct_h323: OpenLogicalChannelAck\n");
472
473 if ((olca->options &
474 eOpenLogicalChannelAck_reverseLogicalChannelParameters) &&
475 (olca->reverseLogicalChannelParameters.options &
476 eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters)
477 && (olca->reverseLogicalChannelParameters.multiplexParameters.
478 choice ==
479 eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
480 {
481 ret = process_h245_channel(skb, ct, ctinfo, data, dataoff,
482 &olca->
483 reverseLogicalChannelParameters.
484 multiplexParameters.
485 h2250LogicalChannelParameters);
486 if (ret < 0)
487 return -1;
488 }
489
490 if ((olca->options &
491 eOpenLogicalChannelAck_forwardMultiplexAckParameters) &&
492 (olca->forwardMultiplexAckParameters.choice ==
493 eOpenLogicalChannelAck_forwardMultiplexAckParameters_h2250LogicalChannelAckParameters))
494 {
495 ack = &olca->forwardMultiplexAckParameters.
496 h2250LogicalChannelAckParameters;
497 if (ack->options &
498 eH2250LogicalChannelAckParameters_mediaChannel) {
499 /* RTP */
500 ret = expect_rtp_rtcp(skb, ct, ctinfo, data, dataoff,
501 &ack->mediaChannel);
502 if (ret < 0)
503 return -1;
504 }
505
506 if (ack->options &
507 eH2250LogicalChannelAckParameters_mediaControlChannel) {
508 /* RTCP */
509 ret = expect_rtp_rtcp(skb, ct, ctinfo, data, dataoff,
510 &ack->mediaControlChannel);
511 if (ret < 0)
512 return -1;
513 }
514 }
515
516 if ((olca->options & eOpenLogicalChannelAck_separateStack) &&
517 olca->separateStack.networkAddress.choice ==
518 eNetworkAccessParameters_networkAddress_localAreaAddress) {
519 ret = expect_t120(skb, ct, ctinfo, data, dataoff,
520 &olca->separateStack.networkAddress.
521 localAreaAddress);
522 if (ret < 0)
523 return -1;
524 }
525
526 return 0;
527 }
528
529 /****************************************************************************/
process_h245(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,MultimediaSystemControlMessage * mscm)530 static int process_h245(struct sk_buff *skb, struct nf_conn *ct,
531 enum ip_conntrack_info ctinfo,
532 unsigned char **data, int dataoff,
533 MultimediaSystemControlMessage *mscm)
534 {
535 switch (mscm->choice) {
536 case eMultimediaSystemControlMessage_request:
537 if (mscm->request.choice ==
538 eRequestMessage_openLogicalChannel) {
539 return process_olc(skb, ct, ctinfo, data, dataoff,
540 &mscm->request.openLogicalChannel);
541 }
542 pr_debug("nf_ct_h323: H.245 Request %d\n",
543 mscm->request.choice);
544 break;
545 case eMultimediaSystemControlMessage_response:
546 if (mscm->response.choice ==
547 eResponseMessage_openLogicalChannelAck) {
548 return process_olca(skb, ct, ctinfo, data, dataoff,
549 &mscm->response.
550 openLogicalChannelAck);
551 }
552 pr_debug("nf_ct_h323: H.245 Response %d\n",
553 mscm->response.choice);
554 break;
555 default:
556 pr_debug("nf_ct_h323: H.245 signal %d\n", mscm->choice);
557 break;
558 }
559
560 return 0;
561 }
562
563 /****************************************************************************/
h245_help(struct sk_buff * skb,unsigned int protoff,struct nf_conn * ct,enum ip_conntrack_info ctinfo)564 static int h245_help(struct sk_buff *skb, unsigned int protoff,
565 struct nf_conn *ct, enum ip_conntrack_info ctinfo)
566 {
567 static MultimediaSystemControlMessage mscm;
568 unsigned char *data = NULL;
569 int datalen;
570 int dataoff;
571 int ret;
572
573 /* Until there's been traffic both ways, don't look in packets. */
574 if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_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 pr_info("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 int ret = 0;
717
718 /* rcu_read_lock()ed by nf_hook_slow() */
719 afinfo = nf_get_afinfo(family);
720 if (!afinfo)
721 return 0;
722
723 switch (family) {
724 case AF_INET: {
725 struct flowi4 fl1, fl2;
726 struct rtable *rt1, *rt2;
727
728 memset(&fl1, 0, sizeof(fl1));
729 fl1.daddr = src->ip;
730
731 memset(&fl2, 0, sizeof(fl2));
732 fl2.daddr = dst->ip;
733 if (!afinfo->route(&init_net, (struct dst_entry **)&rt1,
734 flowi4_to_flowi(&fl1), false)) {
735 if (!afinfo->route(&init_net, (struct dst_entry **)&rt2,
736 flowi4_to_flowi(&fl2), false)) {
737 if (rt1->rt_gateway == rt2->rt_gateway &&
738 rt1->dst.dev == rt2->dst.dev)
739 ret = 1;
740 dst_release(&rt2->dst);
741 }
742 dst_release(&rt1->dst);
743 }
744 break;
745 }
746 #if IS_ENABLED(CONFIG_NF_CONNTRACK_IPV6)
747 case AF_INET6: {
748 struct flowi6 fl1, fl2;
749 struct rt6_info *rt1, *rt2;
750
751 memset(&fl1, 0, sizeof(fl1));
752 fl1.daddr = src->in6;
753
754 memset(&fl2, 0, sizeof(fl2));
755 fl2.daddr = dst->in6;
756 if (!afinfo->route(&init_net, (struct dst_entry **)&rt1,
757 flowi6_to_flowi(&fl1), false)) {
758 if (!afinfo->route(&init_net, (struct dst_entry **)&rt2,
759 flowi6_to_flowi(&fl2), false)) {
760 if (!memcmp(&rt1->rt6i_gateway, &rt2->rt6i_gateway,
761 sizeof(rt1->rt6i_gateway)) &&
762 rt1->dst.dev == rt2->dst.dev)
763 ret = 1;
764 dst_release(&rt2->dst);
765 }
766 dst_release(&rt1->dst);
767 }
768 break;
769 }
770 #endif
771 }
772 return ret;
773
774 }
775
776 /****************************************************************************/
expect_callforwarding(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,TransportAddress * taddr)777 static int expect_callforwarding(struct sk_buff *skb,
778 struct nf_conn *ct,
779 enum ip_conntrack_info ctinfo,
780 unsigned char **data, int dataoff,
781 TransportAddress *taddr)
782 {
783 int dir = CTINFO2DIR(ctinfo);
784 int ret = 0;
785 __be16 port;
786 union nf_inet_addr addr;
787 struct nf_conntrack_expect *exp;
788 typeof(nat_callforwarding_hook) nat_callforwarding;
789
790 /* Read alternativeAddress */
791 if (!get_h225_addr(ct, *data, taddr, &addr, &port) || port == 0)
792 return 0;
793
794 /* If the calling party is on the same side of the forward-to party,
795 * we don't need to track the second call */
796 if (callforward_filter &&
797 callforward_do_filter(&addr, &ct->tuplehash[!dir].tuple.src.u3,
798 nf_ct_l3num(ct))) {
799 pr_debug("nf_ct_q931: Call Forwarding not tracked\n");
800 return 0;
801 }
802
803 /* Create expect for the second call leg */
804 if ((exp = nf_ct_expect_alloc(ct)) == NULL)
805 return -1;
806 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
807 &ct->tuplehash[!dir].tuple.src.u3, &addr,
808 IPPROTO_TCP, NULL, &port);
809 exp->helper = nf_conntrack_helper_q931;
810
811 if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
812 &ct->tuplehash[!dir].tuple.dst.u3,
813 sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
814 (nat_callforwarding = rcu_dereference(nat_callforwarding_hook)) &&
815 ct->status & IPS_NAT_MASK) {
816 /* Need NAT */
817 ret = nat_callforwarding(skb, ct, ctinfo, data, dataoff,
818 taddr, port, exp);
819 } else { /* Conntrack only */
820 if (nf_ct_expect_related(exp) == 0) {
821 pr_debug("nf_ct_q931: expect Call Forwarding ");
822 nf_ct_dump_tuple(&exp->tuple);
823 } else
824 ret = -1;
825 }
826
827 nf_ct_expect_put(exp);
828
829 return ret;
830 }
831
832 /****************************************************************************/
process_setup(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,Setup_UUIE * setup)833 static int process_setup(struct sk_buff *skb, struct nf_conn *ct,
834 enum ip_conntrack_info ctinfo,
835 unsigned char **data, int dataoff,
836 Setup_UUIE *setup)
837 {
838 int dir = CTINFO2DIR(ctinfo);
839 int ret;
840 int i;
841 __be16 port;
842 union nf_inet_addr addr;
843 typeof(set_h225_addr_hook) set_h225_addr;
844
845 pr_debug("nf_ct_q931: Setup\n");
846
847 if (setup->options & eSetup_UUIE_h245Address) {
848 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
849 &setup->h245Address);
850 if (ret < 0)
851 return -1;
852 }
853
854 set_h225_addr = rcu_dereference(set_h225_addr_hook);
855 if ((setup->options & eSetup_UUIE_destCallSignalAddress) &&
856 (set_h225_addr) && ct->status & IPS_NAT_MASK &&
857 get_h225_addr(ct, *data, &setup->destCallSignalAddress,
858 &addr, &port) &&
859 memcmp(&addr, &ct->tuplehash[!dir].tuple.src.u3, sizeof(addr))) {
860 pr_debug("nf_ct_q931: set destCallSignalAddress %pI6:%hu->%pI6:%hu\n",
861 &addr, ntohs(port), &ct->tuplehash[!dir].tuple.src.u3,
862 ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port));
863 ret = set_h225_addr(skb, data, dataoff,
864 &setup->destCallSignalAddress,
865 &ct->tuplehash[!dir].tuple.src.u3,
866 ct->tuplehash[!dir].tuple.src.u.tcp.port);
867 if (ret < 0)
868 return -1;
869 }
870
871 if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) &&
872 (set_h225_addr) && ct->status & IPS_NAT_MASK &&
873 get_h225_addr(ct, *data, &setup->sourceCallSignalAddress,
874 &addr, &port) &&
875 memcmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(addr))) {
876 pr_debug("nf_ct_q931: set sourceCallSignalAddress %pI6:%hu->%pI6:%hu\n",
877 &addr, ntohs(port), &ct->tuplehash[!dir].tuple.dst.u3,
878 ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port));
879 ret = set_h225_addr(skb, data, dataoff,
880 &setup->sourceCallSignalAddress,
881 &ct->tuplehash[!dir].tuple.dst.u3,
882 ct->tuplehash[!dir].tuple.dst.u.tcp.port);
883 if (ret < 0)
884 return -1;
885 }
886
887 if (setup->options & eSetup_UUIE_fastStart) {
888 for (i = 0; i < setup->fastStart.count; i++) {
889 ret = process_olc(skb, ct, ctinfo, data, dataoff,
890 &setup->fastStart.item[i]);
891 if (ret < 0)
892 return -1;
893 }
894 }
895
896 return 0;
897 }
898
899 /****************************************************************************/
process_callproceeding(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,CallProceeding_UUIE * callproc)900 static int process_callproceeding(struct sk_buff *skb,
901 struct nf_conn *ct,
902 enum ip_conntrack_info ctinfo,
903 unsigned char **data, int dataoff,
904 CallProceeding_UUIE *callproc)
905 {
906 int ret;
907 int i;
908
909 pr_debug("nf_ct_q931: CallProceeding\n");
910
911 if (callproc->options & eCallProceeding_UUIE_h245Address) {
912 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
913 &callproc->h245Address);
914 if (ret < 0)
915 return -1;
916 }
917
918 if (callproc->options & eCallProceeding_UUIE_fastStart) {
919 for (i = 0; i < callproc->fastStart.count; i++) {
920 ret = process_olc(skb, ct, ctinfo, data, dataoff,
921 &callproc->fastStart.item[i]);
922 if (ret < 0)
923 return -1;
924 }
925 }
926
927 return 0;
928 }
929
930 /****************************************************************************/
process_connect(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,Connect_UUIE * connect)931 static int process_connect(struct sk_buff *skb, struct nf_conn *ct,
932 enum ip_conntrack_info ctinfo,
933 unsigned char **data, int dataoff,
934 Connect_UUIE *connect)
935 {
936 int ret;
937 int i;
938
939 pr_debug("nf_ct_q931: Connect\n");
940
941 if (connect->options & eConnect_UUIE_h245Address) {
942 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
943 &connect->h245Address);
944 if (ret < 0)
945 return -1;
946 }
947
948 if (connect->options & eConnect_UUIE_fastStart) {
949 for (i = 0; i < connect->fastStart.count; i++) {
950 ret = process_olc(skb, ct, ctinfo, data, dataoff,
951 &connect->fastStart.item[i]);
952 if (ret < 0)
953 return -1;
954 }
955 }
956
957 return 0;
958 }
959
960 /****************************************************************************/
process_alerting(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,Alerting_UUIE * alert)961 static int process_alerting(struct sk_buff *skb, struct nf_conn *ct,
962 enum ip_conntrack_info ctinfo,
963 unsigned char **data, int dataoff,
964 Alerting_UUIE *alert)
965 {
966 int ret;
967 int i;
968
969 pr_debug("nf_ct_q931: Alerting\n");
970
971 if (alert->options & eAlerting_UUIE_h245Address) {
972 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
973 &alert->h245Address);
974 if (ret < 0)
975 return -1;
976 }
977
978 if (alert->options & eAlerting_UUIE_fastStart) {
979 for (i = 0; i < alert->fastStart.count; i++) {
980 ret = process_olc(skb, ct, ctinfo, data, dataoff,
981 &alert->fastStart.item[i]);
982 if (ret < 0)
983 return -1;
984 }
985 }
986
987 return 0;
988 }
989
990 /****************************************************************************/
process_facility(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,Facility_UUIE * facility)991 static int process_facility(struct sk_buff *skb, struct nf_conn *ct,
992 enum ip_conntrack_info ctinfo,
993 unsigned char **data, int dataoff,
994 Facility_UUIE *facility)
995 {
996 int ret;
997 int i;
998
999 pr_debug("nf_ct_q931: Facility\n");
1000
1001 if (facility->reason.choice == eFacilityReason_callForwarded) {
1002 if (facility->options & eFacility_UUIE_alternativeAddress)
1003 return expect_callforwarding(skb, ct, ctinfo, data,
1004 dataoff,
1005 &facility->
1006 alternativeAddress);
1007 return 0;
1008 }
1009
1010 if (facility->options & eFacility_UUIE_h245Address) {
1011 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
1012 &facility->h245Address);
1013 if (ret < 0)
1014 return -1;
1015 }
1016
1017 if (facility->options & eFacility_UUIE_fastStart) {
1018 for (i = 0; i < facility->fastStart.count; i++) {
1019 ret = process_olc(skb, ct, ctinfo, data, dataoff,
1020 &facility->fastStart.item[i]);
1021 if (ret < 0)
1022 return -1;
1023 }
1024 }
1025
1026 return 0;
1027 }
1028
1029 /****************************************************************************/
process_progress(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,Progress_UUIE * progress)1030 static int process_progress(struct sk_buff *skb, struct nf_conn *ct,
1031 enum ip_conntrack_info ctinfo,
1032 unsigned char **data, int dataoff,
1033 Progress_UUIE *progress)
1034 {
1035 int ret;
1036 int i;
1037
1038 pr_debug("nf_ct_q931: Progress\n");
1039
1040 if (progress->options & eProgress_UUIE_h245Address) {
1041 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
1042 &progress->h245Address);
1043 if (ret < 0)
1044 return -1;
1045 }
1046
1047 if (progress->options & eProgress_UUIE_fastStart) {
1048 for (i = 0; i < progress->fastStart.count; i++) {
1049 ret = process_olc(skb, ct, ctinfo, data, dataoff,
1050 &progress->fastStart.item[i]);
1051 if (ret < 0)
1052 return -1;
1053 }
1054 }
1055
1056 return 0;
1057 }
1058
1059 /****************************************************************************/
process_q931(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,int dataoff,Q931 * q931)1060 static int process_q931(struct sk_buff *skb, struct nf_conn *ct,
1061 enum ip_conntrack_info ctinfo,
1062 unsigned char **data, int dataoff, Q931 *q931)
1063 {
1064 H323_UU_PDU *pdu = &q931->UUIE.h323_uu_pdu;
1065 int i;
1066 int ret = 0;
1067
1068 switch (pdu->h323_message_body.choice) {
1069 case eH323_UU_PDU_h323_message_body_setup:
1070 ret = process_setup(skb, ct, ctinfo, data, dataoff,
1071 &pdu->h323_message_body.setup);
1072 break;
1073 case eH323_UU_PDU_h323_message_body_callProceeding:
1074 ret = process_callproceeding(skb, ct, ctinfo, data, dataoff,
1075 &pdu->h323_message_body.
1076 callProceeding);
1077 break;
1078 case eH323_UU_PDU_h323_message_body_connect:
1079 ret = process_connect(skb, ct, ctinfo, data, dataoff,
1080 &pdu->h323_message_body.connect);
1081 break;
1082 case eH323_UU_PDU_h323_message_body_alerting:
1083 ret = process_alerting(skb, ct, ctinfo, data, dataoff,
1084 &pdu->h323_message_body.alerting);
1085 break;
1086 case eH323_UU_PDU_h323_message_body_facility:
1087 ret = process_facility(skb, ct, ctinfo, data, dataoff,
1088 &pdu->h323_message_body.facility);
1089 break;
1090 case eH323_UU_PDU_h323_message_body_progress:
1091 ret = process_progress(skb, ct, ctinfo, data, dataoff,
1092 &pdu->h323_message_body.progress);
1093 break;
1094 default:
1095 pr_debug("nf_ct_q931: Q.931 signal %d\n",
1096 pdu->h323_message_body.choice);
1097 break;
1098 }
1099
1100 if (ret < 0)
1101 return -1;
1102
1103 if (pdu->options & eH323_UU_PDU_h245Control) {
1104 for (i = 0; i < pdu->h245Control.count; i++) {
1105 ret = process_h245(skb, ct, ctinfo, data, dataoff,
1106 &pdu->h245Control.item[i]);
1107 if (ret < 0)
1108 return -1;
1109 }
1110 }
1111
1112 return 0;
1113 }
1114
1115 /****************************************************************************/
q931_help(struct sk_buff * skb,unsigned int protoff,struct nf_conn * ct,enum ip_conntrack_info ctinfo)1116 static int q931_help(struct sk_buff *skb, unsigned int protoff,
1117 struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1118 {
1119 static Q931 q931;
1120 unsigned char *data = NULL;
1121 int datalen;
1122 int dataoff;
1123 int ret;
1124
1125 /* Until there's been traffic both ways, don't look in packets. */
1126 if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
1127 return NF_ACCEPT;
1128
1129 pr_debug("nf_ct_q931: skblen = %u\n", skb->len);
1130
1131 spin_lock_bh(&nf_h323_lock);
1132
1133 /* Process each TPKT */
1134 while (get_tpkt_data(skb, protoff, ct, ctinfo,
1135 &data, &datalen, &dataoff)) {
1136 pr_debug("nf_ct_q931: TPKT len=%d ", datalen);
1137 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1138
1139 /* Decode Q.931 signal */
1140 ret = DecodeQ931(data, datalen, &q931);
1141 if (ret < 0) {
1142 pr_debug("nf_ct_q931: decoding error: %s\n",
1143 ret == H323_ERROR_BOUND ?
1144 "out of bound" : "out of range");
1145 /* We don't drop when decoding error */
1146 break;
1147 }
1148
1149 /* Process Q.931 signal */
1150 if (process_q931(skb, ct, ctinfo, &data, dataoff, &q931) < 0)
1151 goto drop;
1152 }
1153
1154 spin_unlock_bh(&nf_h323_lock);
1155 return NF_ACCEPT;
1156
1157 drop:
1158 spin_unlock_bh(&nf_h323_lock);
1159 if (net_ratelimit())
1160 pr_info("nf_ct_q931: packet dropped\n");
1161 return NF_DROP;
1162 }
1163
1164 /****************************************************************************/
1165 static const struct nf_conntrack_expect_policy q931_exp_policy = {
1166 /* T.120 and H.245 */
1167 .max_expected = H323_RTP_CHANNEL_MAX * 4 + 4,
1168 .timeout = 240,
1169 };
1170
1171 static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = {
1172 {
1173 .name = "Q.931",
1174 .me = THIS_MODULE,
1175 .tuple.src.l3num = AF_INET,
1176 .tuple.src.u.tcp.port = cpu_to_be16(Q931_PORT),
1177 .tuple.dst.protonum = IPPROTO_TCP,
1178 .help = q931_help,
1179 .expect_policy = &q931_exp_policy,
1180 },
1181 {
1182 .name = "Q.931",
1183 .me = THIS_MODULE,
1184 .tuple.src.l3num = AF_INET6,
1185 .tuple.src.u.tcp.port = cpu_to_be16(Q931_PORT),
1186 .tuple.dst.protonum = IPPROTO_TCP,
1187 .help = q931_help,
1188 .expect_policy = &q931_exp_policy,
1189 },
1190 };
1191
1192 /****************************************************************************/
get_udp_data(struct sk_buff * skb,unsigned int protoff,int * datalen)1193 static unsigned char *get_udp_data(struct sk_buff *skb, unsigned int protoff,
1194 int *datalen)
1195 {
1196 const struct udphdr *uh;
1197 struct udphdr _uh;
1198 int dataoff;
1199
1200 uh = skb_header_pointer(skb, protoff, sizeof(_uh), &_uh);
1201 if (uh == NULL)
1202 return NULL;
1203 dataoff = protoff + sizeof(_uh);
1204 if (dataoff >= skb->len)
1205 return NULL;
1206 *datalen = skb->len - dataoff;
1207 return skb_header_pointer(skb, dataoff, *datalen, h323_buffer);
1208 }
1209
1210 /****************************************************************************/
find_expect(struct nf_conn * ct,union nf_inet_addr * addr,__be16 port)1211 static struct nf_conntrack_expect *find_expect(struct nf_conn *ct,
1212 union nf_inet_addr *addr,
1213 __be16 port)
1214 {
1215 struct net *net = nf_ct_net(ct);
1216 struct nf_conntrack_expect *exp;
1217 struct nf_conntrack_tuple tuple;
1218
1219 memset(&tuple.src.u3, 0, sizeof(tuple.src.u3));
1220 tuple.src.u.tcp.port = 0;
1221 memcpy(&tuple.dst.u3, addr, sizeof(tuple.dst.u3));
1222 tuple.dst.u.tcp.port = port;
1223 tuple.dst.protonum = IPPROTO_TCP;
1224
1225 exp = __nf_ct_expect_find(net, nf_ct_zone(ct), &tuple);
1226 if (exp && exp->master == ct)
1227 return exp;
1228 return NULL;
1229 }
1230
1231 /****************************************************************************/
set_expect_timeout(struct nf_conntrack_expect * exp,unsigned timeout)1232 static int set_expect_timeout(struct nf_conntrack_expect *exp,
1233 unsigned timeout)
1234 {
1235 if (!exp || !del_timer(&exp->timeout))
1236 return 0;
1237
1238 exp->timeout.expires = jiffies + timeout * HZ;
1239 add_timer(&exp->timeout);
1240
1241 return 1;
1242 }
1243
1244 /****************************************************************************/
expect_q931(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,TransportAddress * taddr,int count)1245 static int expect_q931(struct sk_buff *skb, struct nf_conn *ct,
1246 enum ip_conntrack_info ctinfo,
1247 unsigned char **data,
1248 TransportAddress *taddr, int count)
1249 {
1250 struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1251 int dir = CTINFO2DIR(ctinfo);
1252 int ret = 0;
1253 int i;
1254 __be16 port;
1255 union nf_inet_addr addr;
1256 struct nf_conntrack_expect *exp;
1257 typeof(nat_q931_hook) nat_q931;
1258
1259 /* Look for the first related address */
1260 for (i = 0; i < count; i++) {
1261 if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) &&
1262 memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3,
1263 sizeof(addr)) == 0 && port != 0)
1264 break;
1265 }
1266
1267 if (i >= count) /* Not found */
1268 return 0;
1269
1270 /* Create expect for Q.931 */
1271 if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1272 return -1;
1273 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1274 gkrouted_only ? /* only accept calls from GK? */
1275 &ct->tuplehash[!dir].tuple.src.u3 : NULL,
1276 &ct->tuplehash[!dir].tuple.dst.u3,
1277 IPPROTO_TCP, NULL, &port);
1278 exp->helper = nf_conntrack_helper_q931;
1279 exp->flags = NF_CT_EXPECT_PERMANENT; /* Accept multiple calls */
1280
1281 nat_q931 = rcu_dereference(nat_q931_hook);
1282 if (nat_q931 && ct->status & IPS_NAT_MASK) { /* Need NAT */
1283 ret = nat_q931(skb, ct, ctinfo, data, taddr, i, port, exp);
1284 } else { /* Conntrack only */
1285 if (nf_ct_expect_related(exp) == 0) {
1286 pr_debug("nf_ct_ras: expect Q.931 ");
1287 nf_ct_dump_tuple(&exp->tuple);
1288
1289 /* Save port for looking up expect in processing RCF */
1290 info->sig_port[dir] = port;
1291 } else
1292 ret = -1;
1293 }
1294
1295 nf_ct_expect_put(exp);
1296
1297 return ret;
1298 }
1299
1300 /****************************************************************************/
process_grq(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,GatekeeperRequest * grq)1301 static int process_grq(struct sk_buff *skb, struct nf_conn *ct,
1302 enum ip_conntrack_info ctinfo,
1303 unsigned char **data, GatekeeperRequest *grq)
1304 {
1305 typeof(set_ras_addr_hook) set_ras_addr;
1306
1307 pr_debug("nf_ct_ras: GRQ\n");
1308
1309 set_ras_addr = rcu_dereference(set_ras_addr_hook);
1310 if (set_ras_addr && ct->status & IPS_NAT_MASK) /* NATed */
1311 return set_ras_addr(skb, ct, ctinfo, data,
1312 &grq->rasAddress, 1);
1313 return 0;
1314 }
1315
1316 /****************************************************************************/
process_gcf(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,GatekeeperConfirm * gcf)1317 static int process_gcf(struct sk_buff *skb, struct nf_conn *ct,
1318 enum ip_conntrack_info ctinfo,
1319 unsigned char **data, GatekeeperConfirm *gcf)
1320 {
1321 int dir = CTINFO2DIR(ctinfo);
1322 int ret = 0;
1323 __be16 port;
1324 union nf_inet_addr addr;
1325 struct nf_conntrack_expect *exp;
1326
1327 pr_debug("nf_ct_ras: GCF\n");
1328
1329 if (!get_h225_addr(ct, *data, &gcf->rasAddress, &addr, &port))
1330 return 0;
1331
1332 /* Registration port is the same as discovery port */
1333 if (!memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1334 port == ct->tuplehash[dir].tuple.src.u.udp.port)
1335 return 0;
1336
1337 /* Avoid RAS expectation loops. A GCF is never expected. */
1338 if (test_bit(IPS_EXPECTED_BIT, &ct->status))
1339 return 0;
1340
1341 /* Need new expect */
1342 if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1343 return -1;
1344 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1345 &ct->tuplehash[!dir].tuple.src.u3, &addr,
1346 IPPROTO_UDP, NULL, &port);
1347 exp->helper = nf_conntrack_helper_ras;
1348
1349 if (nf_ct_expect_related(exp) == 0) {
1350 pr_debug("nf_ct_ras: expect RAS ");
1351 nf_ct_dump_tuple(&exp->tuple);
1352 } else
1353 ret = -1;
1354
1355 nf_ct_expect_put(exp);
1356
1357 return ret;
1358 }
1359
1360 /****************************************************************************/
process_rrq(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,RegistrationRequest * rrq)1361 static int process_rrq(struct sk_buff *skb, struct nf_conn *ct,
1362 enum ip_conntrack_info ctinfo,
1363 unsigned char **data, RegistrationRequest *rrq)
1364 {
1365 struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1366 int ret;
1367 typeof(set_ras_addr_hook) set_ras_addr;
1368
1369 pr_debug("nf_ct_ras: RRQ\n");
1370
1371 ret = expect_q931(skb, ct, ctinfo, data,
1372 rrq->callSignalAddress.item,
1373 rrq->callSignalAddress.count);
1374 if (ret < 0)
1375 return -1;
1376
1377 set_ras_addr = rcu_dereference(set_ras_addr_hook);
1378 if (set_ras_addr && ct->status & IPS_NAT_MASK) {
1379 ret = set_ras_addr(skb, ct, ctinfo, data,
1380 rrq->rasAddress.item,
1381 rrq->rasAddress.count);
1382 if (ret < 0)
1383 return -1;
1384 }
1385
1386 if (rrq->options & eRegistrationRequest_timeToLive) {
1387 pr_debug("nf_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive);
1388 info->timeout = rrq->timeToLive;
1389 } else
1390 info->timeout = default_rrq_ttl;
1391
1392 return 0;
1393 }
1394
1395 /****************************************************************************/
process_rcf(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,RegistrationConfirm * rcf)1396 static int process_rcf(struct sk_buff *skb, struct nf_conn *ct,
1397 enum ip_conntrack_info ctinfo,
1398 unsigned char **data, RegistrationConfirm *rcf)
1399 {
1400 struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1401 int dir = CTINFO2DIR(ctinfo);
1402 int ret;
1403 struct nf_conntrack_expect *exp;
1404 typeof(set_sig_addr_hook) set_sig_addr;
1405
1406 pr_debug("nf_ct_ras: RCF\n");
1407
1408 set_sig_addr = rcu_dereference(set_sig_addr_hook);
1409 if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1410 ret = set_sig_addr(skb, ct, ctinfo, data,
1411 rcf->callSignalAddress.item,
1412 rcf->callSignalAddress.count);
1413 if (ret < 0)
1414 return -1;
1415 }
1416
1417 if (rcf->options & eRegistrationConfirm_timeToLive) {
1418 pr_debug("nf_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive);
1419 info->timeout = rcf->timeToLive;
1420 }
1421
1422 if (info->timeout > 0) {
1423 pr_debug("nf_ct_ras: set RAS connection timeout to "
1424 "%u seconds\n", info->timeout);
1425 nf_ct_refresh(ct, skb, info->timeout * HZ);
1426
1427 /* Set expect timeout */
1428 spin_lock_bh(&nf_conntrack_lock);
1429 exp = find_expect(ct, &ct->tuplehash[dir].tuple.dst.u3,
1430 info->sig_port[!dir]);
1431 if (exp) {
1432 pr_debug("nf_ct_ras: set Q.931 expect "
1433 "timeout to %u seconds for",
1434 info->timeout);
1435 nf_ct_dump_tuple(&exp->tuple);
1436 set_expect_timeout(exp, info->timeout);
1437 }
1438 spin_unlock_bh(&nf_conntrack_lock);
1439 }
1440
1441 return 0;
1442 }
1443
1444 /****************************************************************************/
process_urq(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,UnregistrationRequest * urq)1445 static int process_urq(struct sk_buff *skb, struct nf_conn *ct,
1446 enum ip_conntrack_info ctinfo,
1447 unsigned char **data, UnregistrationRequest *urq)
1448 {
1449 struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1450 int dir = CTINFO2DIR(ctinfo);
1451 int ret;
1452 typeof(set_sig_addr_hook) set_sig_addr;
1453
1454 pr_debug("nf_ct_ras: URQ\n");
1455
1456 set_sig_addr = rcu_dereference(set_sig_addr_hook);
1457 if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1458 ret = set_sig_addr(skb, ct, ctinfo, data,
1459 urq->callSignalAddress.item,
1460 urq->callSignalAddress.count);
1461 if (ret < 0)
1462 return -1;
1463 }
1464
1465 /* Clear old expect */
1466 nf_ct_remove_expectations(ct);
1467 info->sig_port[dir] = 0;
1468 info->sig_port[!dir] = 0;
1469
1470 /* Give it 30 seconds for UCF or URJ */
1471 nf_ct_refresh(ct, skb, 30 * HZ);
1472
1473 return 0;
1474 }
1475
1476 /****************************************************************************/
process_arq(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,AdmissionRequest * arq)1477 static int process_arq(struct sk_buff *skb, struct nf_conn *ct,
1478 enum ip_conntrack_info ctinfo,
1479 unsigned char **data, AdmissionRequest *arq)
1480 {
1481 const struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1482 int dir = CTINFO2DIR(ctinfo);
1483 __be16 port;
1484 union nf_inet_addr addr;
1485 typeof(set_h225_addr_hook) set_h225_addr;
1486
1487 pr_debug("nf_ct_ras: ARQ\n");
1488
1489 set_h225_addr = rcu_dereference(set_h225_addr_hook);
1490 if ((arq->options & eAdmissionRequest_destCallSignalAddress) &&
1491 get_h225_addr(ct, *data, &arq->destCallSignalAddress,
1492 &addr, &port) &&
1493 !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1494 port == info->sig_port[dir] &&
1495 set_h225_addr && ct->status & IPS_NAT_MASK) {
1496 /* Answering ARQ */
1497 return set_h225_addr(skb, data, 0,
1498 &arq->destCallSignalAddress,
1499 &ct->tuplehash[!dir].tuple.dst.u3,
1500 info->sig_port[!dir]);
1501 }
1502
1503 if ((arq->options & eAdmissionRequest_srcCallSignalAddress) &&
1504 get_h225_addr(ct, *data, &arq->srcCallSignalAddress,
1505 &addr, &port) &&
1506 !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1507 set_h225_addr && ct->status & IPS_NAT_MASK) {
1508 /* Calling ARQ */
1509 return set_h225_addr(skb, data, 0,
1510 &arq->srcCallSignalAddress,
1511 &ct->tuplehash[!dir].tuple.dst.u3,
1512 port);
1513 }
1514
1515 return 0;
1516 }
1517
1518 /****************************************************************************/
process_acf(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,AdmissionConfirm * acf)1519 static int process_acf(struct sk_buff *skb, struct nf_conn *ct,
1520 enum ip_conntrack_info ctinfo,
1521 unsigned char **data, AdmissionConfirm *acf)
1522 {
1523 int dir = CTINFO2DIR(ctinfo);
1524 int ret = 0;
1525 __be16 port;
1526 union nf_inet_addr addr;
1527 struct nf_conntrack_expect *exp;
1528 typeof(set_sig_addr_hook) set_sig_addr;
1529
1530 pr_debug("nf_ct_ras: ACF\n");
1531
1532 if (!get_h225_addr(ct, *data, &acf->destCallSignalAddress,
1533 &addr, &port))
1534 return 0;
1535
1536 if (!memcmp(&addr, &ct->tuplehash[dir].tuple.dst.u3, sizeof(addr))) {
1537 /* Answering ACF */
1538 set_sig_addr = rcu_dereference(set_sig_addr_hook);
1539 if (set_sig_addr && ct->status & IPS_NAT_MASK)
1540 return set_sig_addr(skb, ct, ctinfo, data,
1541 &acf->destCallSignalAddress, 1);
1542 return 0;
1543 }
1544
1545 /* Need new expect */
1546 if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1547 return -1;
1548 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1549 &ct->tuplehash[!dir].tuple.src.u3, &addr,
1550 IPPROTO_TCP, NULL, &port);
1551 exp->flags = NF_CT_EXPECT_PERMANENT;
1552 exp->helper = nf_conntrack_helper_q931;
1553
1554 if (nf_ct_expect_related(exp) == 0) {
1555 pr_debug("nf_ct_ras: expect Q.931 ");
1556 nf_ct_dump_tuple(&exp->tuple);
1557 } else
1558 ret = -1;
1559
1560 nf_ct_expect_put(exp);
1561
1562 return ret;
1563 }
1564
1565 /****************************************************************************/
process_lrq(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,LocationRequest * lrq)1566 static int process_lrq(struct sk_buff *skb, struct nf_conn *ct,
1567 enum ip_conntrack_info ctinfo,
1568 unsigned char **data, LocationRequest *lrq)
1569 {
1570 typeof(set_ras_addr_hook) set_ras_addr;
1571
1572 pr_debug("nf_ct_ras: LRQ\n");
1573
1574 set_ras_addr = rcu_dereference(set_ras_addr_hook);
1575 if (set_ras_addr && ct->status & IPS_NAT_MASK)
1576 return set_ras_addr(skb, ct, ctinfo, data,
1577 &lrq->replyAddress, 1);
1578 return 0;
1579 }
1580
1581 /****************************************************************************/
process_lcf(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,LocationConfirm * lcf)1582 static int process_lcf(struct sk_buff *skb, struct nf_conn *ct,
1583 enum ip_conntrack_info ctinfo,
1584 unsigned char **data, LocationConfirm *lcf)
1585 {
1586 int dir = CTINFO2DIR(ctinfo);
1587 int ret = 0;
1588 __be16 port;
1589 union nf_inet_addr addr;
1590 struct nf_conntrack_expect *exp;
1591
1592 pr_debug("nf_ct_ras: LCF\n");
1593
1594 if (!get_h225_addr(ct, *data, &lcf->callSignalAddress,
1595 &addr, &port))
1596 return 0;
1597
1598 /* Need new expect for call signal */
1599 if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1600 return -1;
1601 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1602 &ct->tuplehash[!dir].tuple.src.u3, &addr,
1603 IPPROTO_TCP, NULL, &port);
1604 exp->flags = NF_CT_EXPECT_PERMANENT;
1605 exp->helper = nf_conntrack_helper_q931;
1606
1607 if (nf_ct_expect_related(exp) == 0) {
1608 pr_debug("nf_ct_ras: expect Q.931 ");
1609 nf_ct_dump_tuple(&exp->tuple);
1610 } else
1611 ret = -1;
1612
1613 nf_ct_expect_put(exp);
1614
1615 /* Ignore rasAddress */
1616
1617 return ret;
1618 }
1619
1620 /****************************************************************************/
process_irr(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,InfoRequestResponse * irr)1621 static int process_irr(struct sk_buff *skb, struct nf_conn *ct,
1622 enum ip_conntrack_info ctinfo,
1623 unsigned char **data, InfoRequestResponse *irr)
1624 {
1625 int ret;
1626 typeof(set_ras_addr_hook) set_ras_addr;
1627 typeof(set_sig_addr_hook) set_sig_addr;
1628
1629 pr_debug("nf_ct_ras: IRR\n");
1630
1631 set_ras_addr = rcu_dereference(set_ras_addr_hook);
1632 if (set_ras_addr && ct->status & IPS_NAT_MASK) {
1633 ret = set_ras_addr(skb, ct, ctinfo, data,
1634 &irr->rasAddress, 1);
1635 if (ret < 0)
1636 return -1;
1637 }
1638
1639 set_sig_addr = rcu_dereference(set_sig_addr_hook);
1640 if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1641 ret = set_sig_addr(skb, ct, ctinfo, data,
1642 irr->callSignalAddress.item,
1643 irr->callSignalAddress.count);
1644 if (ret < 0)
1645 return -1;
1646 }
1647
1648 return 0;
1649 }
1650
1651 /****************************************************************************/
process_ras(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,unsigned char ** data,RasMessage * ras)1652 static int process_ras(struct sk_buff *skb, struct nf_conn *ct,
1653 enum ip_conntrack_info ctinfo,
1654 unsigned char **data, RasMessage *ras)
1655 {
1656 switch (ras->choice) {
1657 case eRasMessage_gatekeeperRequest:
1658 return process_grq(skb, ct, ctinfo, data,
1659 &ras->gatekeeperRequest);
1660 case eRasMessage_gatekeeperConfirm:
1661 return process_gcf(skb, ct, ctinfo, data,
1662 &ras->gatekeeperConfirm);
1663 case eRasMessage_registrationRequest:
1664 return process_rrq(skb, ct, ctinfo, data,
1665 &ras->registrationRequest);
1666 case eRasMessage_registrationConfirm:
1667 return process_rcf(skb, ct, ctinfo, data,
1668 &ras->registrationConfirm);
1669 case eRasMessage_unregistrationRequest:
1670 return process_urq(skb, ct, ctinfo, data,
1671 &ras->unregistrationRequest);
1672 case eRasMessage_admissionRequest:
1673 return process_arq(skb, ct, ctinfo, data,
1674 &ras->admissionRequest);
1675 case eRasMessage_admissionConfirm:
1676 return process_acf(skb, ct, ctinfo, data,
1677 &ras->admissionConfirm);
1678 case eRasMessage_locationRequest:
1679 return process_lrq(skb, ct, ctinfo, data,
1680 &ras->locationRequest);
1681 case eRasMessage_locationConfirm:
1682 return process_lcf(skb, ct, ctinfo, data,
1683 &ras->locationConfirm);
1684 case eRasMessage_infoRequestResponse:
1685 return process_irr(skb, ct, ctinfo, data,
1686 &ras->infoRequestResponse);
1687 default:
1688 pr_debug("nf_ct_ras: RAS message %d\n", ras->choice);
1689 break;
1690 }
1691
1692 return 0;
1693 }
1694
1695 /****************************************************************************/
ras_help(struct sk_buff * skb,unsigned int protoff,struct nf_conn * ct,enum ip_conntrack_info ctinfo)1696 static int ras_help(struct sk_buff *skb, unsigned int protoff,
1697 struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1698 {
1699 static RasMessage ras;
1700 unsigned char *data;
1701 int datalen = 0;
1702 int ret;
1703
1704 pr_debug("nf_ct_ras: skblen = %u\n", skb->len);
1705
1706 spin_lock_bh(&nf_h323_lock);
1707
1708 /* Get UDP data */
1709 data = get_udp_data(skb, protoff, &datalen);
1710 if (data == NULL)
1711 goto accept;
1712 pr_debug("nf_ct_ras: RAS message len=%d ", datalen);
1713 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1714
1715 /* Decode RAS message */
1716 ret = DecodeRasMessage(data, datalen, &ras);
1717 if (ret < 0) {
1718 pr_debug("nf_ct_ras: decoding error: %s\n",
1719 ret == H323_ERROR_BOUND ?
1720 "out of bound" : "out of range");
1721 goto accept;
1722 }
1723
1724 /* Process RAS message */
1725 if (process_ras(skb, ct, ctinfo, &data, &ras) < 0)
1726 goto drop;
1727
1728 accept:
1729 spin_unlock_bh(&nf_h323_lock);
1730 return NF_ACCEPT;
1731
1732 drop:
1733 spin_unlock_bh(&nf_h323_lock);
1734 if (net_ratelimit())
1735 pr_info("nf_ct_ras: packet dropped\n");
1736 return NF_DROP;
1737 }
1738
1739 /****************************************************************************/
1740 static const struct nf_conntrack_expect_policy ras_exp_policy = {
1741 .max_expected = 32,
1742 .timeout = 240,
1743 };
1744
1745 static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = {
1746 {
1747 .name = "RAS",
1748 .me = THIS_MODULE,
1749 .tuple.src.l3num = AF_INET,
1750 .tuple.src.u.udp.port = cpu_to_be16(RAS_PORT),
1751 .tuple.dst.protonum = IPPROTO_UDP,
1752 .help = ras_help,
1753 .expect_policy = &ras_exp_policy,
1754 },
1755 {
1756 .name = "RAS",
1757 .me = THIS_MODULE,
1758 .tuple.src.l3num = AF_INET6,
1759 .tuple.src.u.udp.port = cpu_to_be16(RAS_PORT),
1760 .tuple.dst.protonum = IPPROTO_UDP,
1761 .help = ras_help,
1762 .expect_policy = &ras_exp_policy,
1763 },
1764 };
1765
1766 /****************************************************************************/
nf_conntrack_h323_fini(void)1767 static void __exit nf_conntrack_h323_fini(void)
1768 {
1769 nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[1]);
1770 nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1771 nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1772 nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1773 nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1774 kfree(h323_buffer);
1775 pr_debug("nf_ct_h323: fini\n");
1776 }
1777
1778 /****************************************************************************/
nf_conntrack_h323_init(void)1779 static int __init nf_conntrack_h323_init(void)
1780 {
1781 int ret;
1782
1783 h323_buffer = kmalloc(65536, GFP_KERNEL);
1784 if (!h323_buffer)
1785 return -ENOMEM;
1786 ret = nf_conntrack_helper_register(&nf_conntrack_helper_h245);
1787 if (ret < 0)
1788 goto err1;
1789 ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[0]);
1790 if (ret < 0)
1791 goto err2;
1792 ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[1]);
1793 if (ret < 0)
1794 goto err3;
1795 ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[0]);
1796 if (ret < 0)
1797 goto err4;
1798 ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[1]);
1799 if (ret < 0)
1800 goto err5;
1801 pr_debug("nf_ct_h323: init success\n");
1802 return 0;
1803
1804 err5:
1805 nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1806 err4:
1807 nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1808 err3:
1809 nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1810 err2:
1811 nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1812 err1:
1813 kfree(h323_buffer);
1814 return ret;
1815 }
1816
1817 /****************************************************************************/
1818 module_init(nf_conntrack_h323_init);
1819 module_exit(nf_conntrack_h323_fini);
1820
1821 EXPORT_SYMBOL_GPL(get_h225_addr);
1822 EXPORT_SYMBOL_GPL(set_h245_addr_hook);
1823 EXPORT_SYMBOL_GPL(set_h225_addr_hook);
1824 EXPORT_SYMBOL_GPL(set_sig_addr_hook);
1825 EXPORT_SYMBOL_GPL(set_ras_addr_hook);
1826 EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook);
1827 EXPORT_SYMBOL_GPL(nat_t120_hook);
1828 EXPORT_SYMBOL_GPL(nat_h245_hook);
1829 EXPORT_SYMBOL_GPL(nat_callforwarding_hook);
1830 EXPORT_SYMBOL_GPL(nat_q931_hook);
1831
1832 MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>");
1833 MODULE_DESCRIPTION("H.323 connection tracking helper");
1834 MODULE_LICENSE("GPL");
1835 MODULE_ALIAS("ip_conntrack_h323");
1836 MODULE_ALIAS_NFCT_HELPER("h323");
1837