]> git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blob - net/netfilter/nf_conntrack_h323_main.c
projects / mirror_ubuntu-zesty-kernel.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Merge branch 'linus' into x86/nmi
[mirror_ubuntu-zesty-kernel.git] / net / netfilter / nf_conntrack_h323_main.c
1 /*
2 * H.323 connection tracking helper
3 *
4 * Copyright (c) 2006 Jing Min Zhao <zhaojingmin@users.sourceforge.net>
5 *
6 * This source code is licensed under General Public License version 2.
7 *
8 * Based on the 'brute force' H.323 connection tracking module by
9 * Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
10 *
11 * For more information, please see http://nath323.sourceforge.net/
12 */
13
14 #include <linux/module.h>
15 #include <linux/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 /****************************************************************************/
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 /****************************************************************************/
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 /****************************************************************************/
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 /****************************************************************************/
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 /****************************************************************************/
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 /****************************************************************************/
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 /****************************************************************************/
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 /****************************************************************************/
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 /****************************************************************************/
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 /****************************************************************************/
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 /****************************************************************************/
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 */
711 static int callforward_do_filter(const union nf_inet_addr *src,
712 const union nf_inet_addr *dst, int family)
713 {
714 const struct nf_afinfo *afinfo;
715 struct flowi fl1, fl2;
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 memset(&fl1, 0, sizeof(fl1));
724 memset(&fl2, 0, sizeof(fl2));
725
726 switch (family) {
727 case AF_INET: {
728 struct rtable *rt1, *rt2;
729
730 fl1.fl4_dst = src->ip;
731 fl2.fl4_dst = dst->ip;
732 if (!afinfo->route((struct dst_entry **)&rt1, &fl1)) {
733 if (!afinfo->route((struct dst_entry **)&rt2, &fl2)) {
734 if (rt1->rt_gateway == rt2->rt_gateway &&
735 rt1->u.dst.dev == rt2->u.dst.dev)
736 ret = 1;
737 dst_release(&rt2->u.dst);
738 }
739 dst_release(&rt1->u.dst);
740 }
741 break;
742 }
743 #if defined(CONFIG_NF_CONNTRACK_IPV6) || \
744 defined(CONFIG_NF_CONNTRACK_IPV6_MODULE)
745 case AF_INET6: {
746 struct rt6_info *rt1, *rt2;
747
748 memcpy(&fl1.fl6_dst, src, sizeof(fl1.fl6_dst));
749 memcpy(&fl2.fl6_dst, dst, sizeof(fl2.fl6_dst));
750 if (!afinfo->route((struct dst_entry **)&rt1, &fl1)) {
751 if (!afinfo->route((struct dst_entry **)&rt2, &fl2)) {
752 if (!memcmp(&rt1->rt6i_gateway, &rt2->rt6i_gateway,
753 sizeof(rt1->rt6i_gateway)) &&
754 rt1->u.dst.dev == rt2->u.dst.dev)
755 ret = 1;
756 dst_release(&rt2->u.dst);
757 }
758 dst_release(&rt1->u.dst);
759 }
760 break;
761 }
762 #endif
763 }
764 return ret;
765
766 }
767
768 /****************************************************************************/
769 static int expect_callforwarding(struct sk_buff *skb,
770 struct nf_conn *ct,
771 enum ip_conntrack_info ctinfo,
772 unsigned char **data, int dataoff,
773 TransportAddress *taddr)
774 {
775 int dir = CTINFO2DIR(ctinfo);
776 int ret = 0;
777 __be16 port;
778 union nf_inet_addr addr;
779 struct nf_conntrack_expect *exp;
780 typeof(nat_callforwarding_hook) nat_callforwarding;
781
782 /* Read alternativeAddress */
783 if (!get_h225_addr(ct, *data, taddr, &addr, &port) || port == 0)
784 return 0;
785
786 /* If the calling party is on the same side of the forward-to party,
787 * we don't need to track the second call */
788 if (callforward_filter &&
789 callforward_do_filter(&addr, &ct->tuplehash[!dir].tuple.src.u3,
790 nf_ct_l3num(ct))) {
791 pr_debug("nf_ct_q931: Call Forwarding not tracked\n");
792 return 0;
793 }
794
795 /* Create expect for the second call leg */
796 if ((exp = nf_ct_expect_alloc(ct)) == NULL)
797 return -1;
798 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
799 &ct->tuplehash[!dir].tuple.src.u3, &addr,
800 IPPROTO_TCP, NULL, &port);
801 exp->helper = nf_conntrack_helper_q931;
802
803 if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
804 &ct->tuplehash[!dir].tuple.dst.u3,
805 sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
806 (nat_callforwarding = rcu_dereference(nat_callforwarding_hook)) &&
807 ct->status & IPS_NAT_MASK) {
808 /* Need NAT */
809 ret = nat_callforwarding(skb, ct, ctinfo, data, dataoff,
810 taddr, port, exp);
811 } else { /* Conntrack only */
812 if (nf_ct_expect_related(exp) == 0) {
813 pr_debug("nf_ct_q931: expect Call Forwarding ");
814 nf_ct_dump_tuple(&exp->tuple);
815 } else
816 ret = -1;
817 }
818
819 nf_ct_expect_put(exp);
820
821 return ret;
822 }
823
824 /****************************************************************************/
825 static int process_setup(struct sk_buff *skb, struct nf_conn *ct,
826 enum ip_conntrack_info ctinfo,
827 unsigned char **data, int dataoff,
828 Setup_UUIE *setup)
829 {
830 int dir = CTINFO2DIR(ctinfo);
831 int ret;
832 int i;
833 __be16 port;
834 union nf_inet_addr addr;
835 typeof(set_h225_addr_hook) set_h225_addr;
836
837 pr_debug("nf_ct_q931: Setup\n");
838
839 if (setup->options & eSetup_UUIE_h245Address) {
840 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
841 &setup->h245Address);
842 if (ret < 0)
843 return -1;
844 }
845
846 set_h225_addr = rcu_dereference(set_h225_addr_hook);
847 if ((setup->options & eSetup_UUIE_destCallSignalAddress) &&
848 (set_h225_addr) && ct->status & IPS_NAT_MASK &&
849 get_h225_addr(ct, *data, &setup->destCallSignalAddress,
850 &addr, &port) &&
851 memcmp(&addr, &ct->tuplehash[!dir].tuple.src.u3, sizeof(addr))) {
852 pr_debug("nf_ct_q931: set destCallSignalAddress "
853 NIP6_FMT ":%hu->" NIP6_FMT ":%hu\n",
854 NIP6(*(struct in6_addr *)&addr), ntohs(port),
855 NIP6(*(struct in6_addr *)&ct->tuplehash[!dir].tuple.src.u3),
856 ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port));
857 ret = set_h225_addr(skb, data, dataoff,
858 &setup->destCallSignalAddress,
859 &ct->tuplehash[!dir].tuple.src.u3,
860 ct->tuplehash[!dir].tuple.src.u.tcp.port);
861 if (ret < 0)
862 return -1;
863 }
864
865 if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) &&
866 (set_h225_addr) && ct->status & IPS_NAT_MASK &&
867 get_h225_addr(ct, *data, &setup->sourceCallSignalAddress,
868 &addr, &port) &&
869 memcmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(addr))) {
870 pr_debug("nf_ct_q931: set sourceCallSignalAddress "
871 NIP6_FMT ":%hu->" NIP6_FMT ":%hu\n",
872 NIP6(*(struct in6_addr *)&addr), ntohs(port),
873 NIP6(*(struct in6_addr *)&ct->tuplehash[!dir].tuple.dst.u3),
874 ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port));
875 ret = set_h225_addr(skb, data, dataoff,
876 &setup->sourceCallSignalAddress,
877 &ct->tuplehash[!dir].tuple.dst.u3,
878 ct->tuplehash[!dir].tuple.dst.u.tcp.port);
879 if (ret < 0)
880 return -1;
881 }
882
883 if (setup->options & eSetup_UUIE_fastStart) {
884 for (i = 0; i < setup->fastStart.count; i++) {
885 ret = process_olc(skb, ct, ctinfo, data, dataoff,
886 &setup->fastStart.item[i]);
887 if (ret < 0)
888 return -1;
889 }
890 }
891
892 return 0;
893 }
894
895 /****************************************************************************/
896 static int process_callproceeding(struct sk_buff *skb,
897 struct nf_conn *ct,
898 enum ip_conntrack_info ctinfo,
899 unsigned char **data, int dataoff,
900 CallProceeding_UUIE *callproc)
901 {
902 int ret;
903 int i;
904
905 pr_debug("nf_ct_q931: CallProceeding\n");
906
907 if (callproc->options & eCallProceeding_UUIE_h245Address) {
908 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
909 &callproc->h245Address);
910 if (ret < 0)
911 return -1;
912 }
913
914 if (callproc->options & eCallProceeding_UUIE_fastStart) {
915 for (i = 0; i < callproc->fastStart.count; i++) {
916 ret = process_olc(skb, ct, ctinfo, data, dataoff,
917 &callproc->fastStart.item[i]);
918 if (ret < 0)
919 return -1;
920 }
921 }
922
923 return 0;
924 }
925
926 /****************************************************************************/
927 static int process_connect(struct sk_buff *skb, struct nf_conn *ct,
928 enum ip_conntrack_info ctinfo,
929 unsigned char **data, int dataoff,
930 Connect_UUIE *connect)
931 {
932 int ret;
933 int i;
934
935 pr_debug("nf_ct_q931: Connect\n");
936
937 if (connect->options & eConnect_UUIE_h245Address) {
938 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
939 &connect->h245Address);
940 if (ret < 0)
941 return -1;
942 }
943
944 if (connect->options & eConnect_UUIE_fastStart) {
945 for (i = 0; i < connect->fastStart.count; i++) {
946 ret = process_olc(skb, ct, ctinfo, data, dataoff,
947 &connect->fastStart.item[i]);
948 if (ret < 0)
949 return -1;
950 }
951 }
952
953 return 0;
954 }
955
956 /****************************************************************************/
957 static int process_alerting(struct sk_buff *skb, struct nf_conn *ct,
958 enum ip_conntrack_info ctinfo,
959 unsigned char **data, int dataoff,
960 Alerting_UUIE *alert)
961 {
962 int ret;
963 int i;
964
965 pr_debug("nf_ct_q931: Alerting\n");
966
967 if (alert->options & eAlerting_UUIE_h245Address) {
968 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
969 &alert->h245Address);
970 if (ret < 0)
971 return -1;
972 }
973
974 if (alert->options & eAlerting_UUIE_fastStart) {
975 for (i = 0; i < alert->fastStart.count; i++) {
976 ret = process_olc(skb, ct, ctinfo, data, dataoff,
977 &alert->fastStart.item[i]);
978 if (ret < 0)
979 return -1;
980 }
981 }
982
983 return 0;
984 }
985
986 /****************************************************************************/
987 static int process_facility(struct sk_buff *skb, struct nf_conn *ct,
988 enum ip_conntrack_info ctinfo,
989 unsigned char **data, int dataoff,
990 Facility_UUIE *facility)
991 {
992 int ret;
993 int i;
994
995 pr_debug("nf_ct_q931: Facility\n");
996
997 if (facility->reason.choice == eFacilityReason_callForwarded) {
998 if (facility->options & eFacility_UUIE_alternativeAddress)
999 return expect_callforwarding(skb, ct, ctinfo, data,
1000 dataoff,
1001 &facility->
1002 alternativeAddress);
1003 return 0;
1004 }
1005
1006 if (facility->options & eFacility_UUIE_h245Address) {
1007 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
1008 &facility->h245Address);
1009 if (ret < 0)
1010 return -1;
1011 }
1012
1013 if (facility->options & eFacility_UUIE_fastStart) {
1014 for (i = 0; i < facility->fastStart.count; i++) {
1015 ret = process_olc(skb, ct, ctinfo, data, dataoff,
1016 &facility->fastStart.item[i]);
1017 if (ret < 0)
1018 return -1;
1019 }
1020 }
1021
1022 return 0;
1023 }
1024
1025 /****************************************************************************/
1026 static int process_progress(struct sk_buff *skb, struct nf_conn *ct,
1027 enum ip_conntrack_info ctinfo,
1028 unsigned char **data, int dataoff,
1029 Progress_UUIE *progress)
1030 {
1031 int ret;
1032 int i;
1033
1034 pr_debug("nf_ct_q931: Progress\n");
1035
1036 if (progress->options & eProgress_UUIE_h245Address) {
1037 ret = expect_h245(skb, ct, ctinfo, data, dataoff,
1038 &progress->h245Address);
1039 if (ret < 0)
1040 return -1;
1041 }
1042
1043 if (progress->options & eProgress_UUIE_fastStart) {
1044 for (i = 0; i < progress->fastStart.count; i++) {
1045 ret = process_olc(skb, ct, ctinfo, data, dataoff,
1046 &progress->fastStart.item[i]);
1047 if (ret < 0)
1048 return -1;
1049 }
1050 }
1051
1052 return 0;
1053 }
1054
1055 /****************************************************************************/
1056 static int process_q931(struct sk_buff *skb, struct nf_conn *ct,
1057 enum ip_conntrack_info ctinfo,
1058 unsigned char **data, int dataoff, Q931 *q931)
1059 {
1060 H323_UU_PDU *pdu = &q931->UUIE.h323_uu_pdu;
1061 int i;
1062 int ret = 0;
1063
1064 switch (pdu->h323_message_body.choice) {
1065 case eH323_UU_PDU_h323_message_body_setup:
1066 ret = process_setup(skb, ct, ctinfo, data, dataoff,
1067 &pdu->h323_message_body.setup);
1068 break;
1069 case eH323_UU_PDU_h323_message_body_callProceeding:
1070 ret = process_callproceeding(skb, ct, ctinfo, data, dataoff,
1071 &pdu->h323_message_body.
1072 callProceeding);
1073 break;
1074 case eH323_UU_PDU_h323_message_body_connect:
1075 ret = process_connect(skb, ct, ctinfo, data, dataoff,
1076 &pdu->h323_message_body.connect);
1077 break;
1078 case eH323_UU_PDU_h323_message_body_alerting:
1079 ret = process_alerting(skb, ct, ctinfo, data, dataoff,
1080 &pdu->h323_message_body.alerting);
1081 break;
1082 case eH323_UU_PDU_h323_message_body_facility:
1083 ret = process_facility(skb, ct, ctinfo, data, dataoff,
1084 &pdu->h323_message_body.facility);
1085 break;
1086 case eH323_UU_PDU_h323_message_body_progress:
1087 ret = process_progress(skb, ct, ctinfo, data, dataoff,
1088 &pdu->h323_message_body.progress);
1089 break;
1090 default:
1091 pr_debug("nf_ct_q931: Q.931 signal %d\n",
1092 pdu->h323_message_body.choice);
1093 break;
1094 }
1095
1096 if (ret < 0)
1097 return -1;
1098
1099 if (pdu->options & eH323_UU_PDU_h245Control) {
1100 for (i = 0; i < pdu->h245Control.count; i++) {
1101 ret = process_h245(skb, ct, ctinfo, data, dataoff,
1102 &pdu->h245Control.item[i]);
1103 if (ret < 0)
1104 return -1;
1105 }
1106 }
1107
1108 return 0;
1109 }
1110
1111 /****************************************************************************/
1112 static int q931_help(struct sk_buff *skb, unsigned int protoff,
1113 struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1114 {
1115 static Q931 q931;
1116 unsigned char *data = NULL;
1117 int datalen;
1118 int dataoff;
1119 int ret;
1120
1121 /* Until there's been traffic both ways, don't look in packets. */
1122 if (ctinfo != IP_CT_ESTABLISHED &&
1123 ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) {
1124 return NF_ACCEPT;
1125 }
1126 pr_debug("nf_ct_q931: skblen = %u\n", skb->len);
1127
1128 spin_lock_bh(&nf_h323_lock);
1129
1130 /* Process each TPKT */
1131 while (get_tpkt_data(skb, protoff, ct, ctinfo,
1132 &data, &datalen, &dataoff)) {
1133 pr_debug("nf_ct_q931: TPKT len=%d ", datalen);
1134 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1135
1136 /* Decode Q.931 signal */
1137 ret = DecodeQ931(data, datalen, &q931);
1138 if (ret < 0) {
1139 pr_debug("nf_ct_q931: decoding error: %s\n",
1140 ret == H323_ERROR_BOUND ?
1141 "out of bound" : "out of range");
1142 /* We don't drop when decoding error */
1143 break;
1144 }
1145
1146 /* Process Q.931 signal */
1147 if (process_q931(skb, ct, ctinfo, &data, dataoff, &q931) < 0)
1148 goto drop;
1149 }
1150
1151 spin_unlock_bh(&nf_h323_lock);
1152 return NF_ACCEPT;
1153
1154 drop:
1155 spin_unlock_bh(&nf_h323_lock);
1156 if (net_ratelimit())
1157 printk("nf_ct_q931: packet dropped\n");
1158 return NF_DROP;
1159 }
1160
1161 /****************************************************************************/
1162 static const struct nf_conntrack_expect_policy q931_exp_policy = {
1163 /* T.120 and H.245 */
1164 .max_expected = H323_RTP_CHANNEL_MAX * 4 + 4,
1165 .timeout = 240,
1166 };
1167
1168 static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = {
1169 {
1170 .name = "Q.931",
1171 .me = THIS_MODULE,
1172 .tuple.src.l3num = AF_INET,
1173 .tuple.src.u.tcp.port = __constant_htons(Q931_PORT),
1174 .tuple.dst.protonum = IPPROTO_TCP,
1175 .help = q931_help,
1176 .expect_policy = &q931_exp_policy,
1177 },
1178 {
1179 .name = "Q.931",
1180 .me = THIS_MODULE,
1181 .tuple.src.l3num = AF_INET6,
1182 .tuple.src.u.tcp.port = __constant_htons(Q931_PORT),
1183 .tuple.dst.protonum = IPPROTO_TCP,
1184 .help = q931_help,
1185 .expect_policy = &q931_exp_policy,
1186 },
1187 };
1188
1189 /****************************************************************************/
1190 static unsigned char *get_udp_data(struct sk_buff *skb, unsigned int protoff,
1191 int *datalen)
1192 {
1193 const struct udphdr *uh;
1194 struct udphdr _uh;
1195 int dataoff;
1196
1197 uh = skb_header_pointer(skb, protoff, sizeof(_uh), &_uh);
1198 if (uh == NULL)
1199 return NULL;
1200 dataoff = protoff + sizeof(_uh);
1201 if (dataoff >= skb->len)
1202 return NULL;
1203 *datalen = skb->len - dataoff;
1204 return skb_header_pointer(skb, dataoff, *datalen, h323_buffer);
1205 }
1206
1207 /****************************************************************************/
1208 static struct nf_conntrack_expect *find_expect(struct nf_conn *ct,
1209 union nf_inet_addr *addr,
1210 __be16 port)
1211 {
1212 struct nf_conntrack_expect *exp;
1213 struct nf_conntrack_tuple tuple;
1214
1215 memset(&tuple.src.u3, 0, sizeof(tuple.src.u3));
1216 tuple.src.u.tcp.port = 0;
1217 memcpy(&tuple.dst.u3, addr, sizeof(tuple.dst.u3));
1218 tuple.dst.u.tcp.port = port;
1219 tuple.dst.protonum = IPPROTO_TCP;
1220
1221 exp = __nf_ct_expect_find(&tuple);
1222 if (exp && exp->master == ct)
1223 return exp;
1224 return NULL;
1225 }
1226
1227 /****************************************************************************/
1228 static int set_expect_timeout(struct nf_conntrack_expect *exp,
1229 unsigned timeout)
1230 {
1231 if (!exp || !del_timer(&exp->timeout))
1232 return 0;
1233
1234 exp->timeout.expires = jiffies + timeout * HZ;
1235 add_timer(&exp->timeout);
1236
1237 return 1;
1238 }
1239
1240 /****************************************************************************/
1241 static int expect_q931(struct sk_buff *skb, struct nf_conn *ct,
1242 enum ip_conntrack_info ctinfo,
1243 unsigned char **data,
1244 TransportAddress *taddr, int count)
1245 {
1246 struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1247 int dir = CTINFO2DIR(ctinfo);
1248 int ret = 0;
1249 int i;
1250 __be16 port;
1251 union nf_inet_addr addr;
1252 struct nf_conntrack_expect *exp;
1253 typeof(nat_q931_hook) nat_q931;
1254
1255 /* Look for the first related address */
1256 for (i = 0; i < count; i++) {
1257 if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) &&
1258 memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3,
1259 sizeof(addr)) == 0 && port != 0)
1260 break;
1261 }
1262
1263 if (i >= count) /* Not found */
1264 return 0;
1265
1266 /* Create expect for Q.931 */
1267 if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1268 return -1;
1269 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1270 gkrouted_only ? /* only accept calls from GK? */
1271 &ct->tuplehash[!dir].tuple.src.u3 : NULL,
1272 &ct->tuplehash[!dir].tuple.dst.u3,
1273 IPPROTO_TCP, NULL, &port);
1274 exp->helper = nf_conntrack_helper_q931;
1275 exp->flags = NF_CT_EXPECT_PERMANENT; /* Accept multiple calls */
1276
1277 nat_q931 = rcu_dereference(nat_q931_hook);
1278 if (nat_q931 && ct->status & IPS_NAT_MASK) { /* Need NAT */
1279 ret = nat_q931(skb, ct, ctinfo, data, taddr, i, port, exp);
1280 } else { /* Conntrack only */
1281 if (nf_ct_expect_related(exp) == 0) {
1282 pr_debug("nf_ct_ras: expect Q.931 ");
1283 nf_ct_dump_tuple(&exp->tuple);
1284
1285 /* Save port for looking up expect in processing RCF */
1286 info->sig_port[dir] = port;
1287 } else
1288 ret = -1;
1289 }
1290
1291 nf_ct_expect_put(exp);
1292
1293 return ret;
1294 }
1295
1296 /****************************************************************************/
1297 static int process_grq(struct sk_buff *skb, struct nf_conn *ct,
1298 enum ip_conntrack_info ctinfo,
1299 unsigned char **data, GatekeeperRequest *grq)
1300 {
1301 typeof(set_ras_addr_hook) set_ras_addr;
1302
1303 pr_debug("nf_ct_ras: GRQ\n");
1304
1305 set_ras_addr = rcu_dereference(set_ras_addr_hook);
1306 if (set_ras_addr && ct->status & IPS_NAT_MASK) /* NATed */
1307 return set_ras_addr(skb, ct, ctinfo, data,
1308 &grq->rasAddress, 1);
1309 return 0;
1310 }
1311
1312 /****************************************************************************/
1313 static int process_gcf(struct sk_buff *skb, struct nf_conn *ct,
1314 enum ip_conntrack_info ctinfo,
1315 unsigned char **data, GatekeeperConfirm *gcf)
1316 {
1317 int dir = CTINFO2DIR(ctinfo);
1318 int ret = 0;
1319 __be16 port;
1320 union nf_inet_addr addr;
1321 struct nf_conntrack_expect *exp;
1322
1323 pr_debug("nf_ct_ras: GCF\n");
1324
1325 if (!get_h225_addr(ct, *data, &gcf->rasAddress, &addr, &port))
1326 return 0;
1327
1328 /* Registration port is the same as discovery port */
1329 if (!memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1330 port == ct->tuplehash[dir].tuple.src.u.udp.port)
1331 return 0;
1332
1333 /* Avoid RAS expectation loops. A GCF is never expected. */
1334 if (test_bit(IPS_EXPECTED_BIT, &ct->status))
1335 return 0;
1336
1337 /* Need new expect */
1338 if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1339 return -1;
1340 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1341 &ct->tuplehash[!dir].tuple.src.u3, &addr,
1342 IPPROTO_UDP, NULL, &port);
1343 exp->helper = nf_conntrack_helper_ras;
1344
1345 if (nf_ct_expect_related(exp) == 0) {
1346 pr_debug("nf_ct_ras: expect RAS ");
1347 nf_ct_dump_tuple(&exp->tuple);
1348 } else
1349 ret = -1;
1350
1351 nf_ct_expect_put(exp);
1352
1353 return ret;
1354 }
1355
1356 /****************************************************************************/
1357 static int process_rrq(struct sk_buff *skb, struct nf_conn *ct,
1358 enum ip_conntrack_info ctinfo,
1359 unsigned char **data, RegistrationRequest *rrq)
1360 {
1361 struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1362 int ret;
1363 typeof(set_ras_addr_hook) set_ras_addr;
1364
1365 pr_debug("nf_ct_ras: RRQ\n");
1366
1367 ret = expect_q931(skb, ct, ctinfo, data,
1368 rrq->callSignalAddress.item,
1369 rrq->callSignalAddress.count);
1370 if (ret < 0)
1371 return -1;
1372
1373 set_ras_addr = rcu_dereference(set_ras_addr_hook);
1374 if (set_ras_addr && ct->status & IPS_NAT_MASK) {
1375 ret = set_ras_addr(skb, ct, ctinfo, data,
1376 rrq->rasAddress.item,
1377 rrq->rasAddress.count);
1378 if (ret < 0)
1379 return -1;
1380 }
1381
1382 if (rrq->options & eRegistrationRequest_timeToLive) {
1383 pr_debug("nf_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive);
1384 info->timeout = rrq->timeToLive;
1385 } else
1386 info->timeout = default_rrq_ttl;
1387
1388 return 0;
1389 }
1390
1391 /****************************************************************************/
1392 static int process_rcf(struct sk_buff *skb, struct nf_conn *ct,
1393 enum ip_conntrack_info ctinfo,
1394 unsigned char **data, RegistrationConfirm *rcf)
1395 {
1396 struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1397 int dir = CTINFO2DIR(ctinfo);
1398 int ret;
1399 struct nf_conntrack_expect *exp;
1400 typeof(set_sig_addr_hook) set_sig_addr;
1401
1402 pr_debug("nf_ct_ras: RCF\n");
1403
1404 set_sig_addr = rcu_dereference(set_sig_addr_hook);
1405 if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1406 ret = set_sig_addr(skb, ct, ctinfo, data,
1407 rcf->callSignalAddress.item,
1408 rcf->callSignalAddress.count);
1409 if (ret < 0)
1410 return -1;
1411 }
1412
1413 if (rcf->options & eRegistrationConfirm_timeToLive) {
1414 pr_debug("nf_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive);
1415 info->timeout = rcf->timeToLive;
1416 }
1417
1418 if (info->timeout > 0) {
1419 pr_debug("nf_ct_ras: set RAS connection timeout to "
1420 "%u seconds\n", info->timeout);
1421 nf_ct_refresh(ct, skb, info->timeout * HZ);
1422
1423 /* Set expect timeout */
1424 spin_lock_bh(&nf_conntrack_lock);
1425 exp = find_expect(ct, &ct->tuplehash[dir].tuple.dst.u3,
1426 info->sig_port[!dir]);
1427 if (exp) {
1428 pr_debug("nf_ct_ras: set Q.931 expect "
1429 "timeout to %u seconds for",
1430 info->timeout);
1431 nf_ct_dump_tuple(&exp->tuple);
1432 set_expect_timeout(exp, info->timeout);
1433 }
1434 spin_unlock_bh(&nf_conntrack_lock);
1435 }
1436
1437 return 0;
1438 }
1439
1440 /****************************************************************************/
1441 static int process_urq(struct sk_buff *skb, struct nf_conn *ct,
1442 enum ip_conntrack_info ctinfo,
1443 unsigned char **data, UnregistrationRequest *urq)
1444 {
1445 struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1446 int dir = CTINFO2DIR(ctinfo);
1447 int ret;
1448 typeof(set_sig_addr_hook) set_sig_addr;
1449
1450 pr_debug("nf_ct_ras: URQ\n");
1451
1452 set_sig_addr = rcu_dereference(set_sig_addr_hook);
1453 if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1454 ret = set_sig_addr(skb, ct, ctinfo, data,
1455 urq->callSignalAddress.item,
1456 urq->callSignalAddress.count);
1457 if (ret < 0)
1458 return -1;
1459 }
1460
1461 /* Clear old expect */
1462 nf_ct_remove_expectations(ct);
1463 info->sig_port[dir] = 0;
1464 info->sig_port[!dir] = 0;
1465
1466 /* Give it 30 seconds for UCF or URJ */
1467 nf_ct_refresh(ct, skb, 30 * HZ);
1468
1469 return 0;
1470 }
1471
1472 /****************************************************************************/
1473 static int process_arq(struct sk_buff *skb, struct nf_conn *ct,
1474 enum ip_conntrack_info ctinfo,
1475 unsigned char **data, AdmissionRequest *arq)
1476 {
1477 const struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
1478 int dir = CTINFO2DIR(ctinfo);
1479 __be16 port;
1480 union nf_inet_addr addr;
1481 typeof(set_h225_addr_hook) set_h225_addr;
1482
1483 pr_debug("nf_ct_ras: ARQ\n");
1484
1485 set_h225_addr = rcu_dereference(set_h225_addr_hook);
1486 if ((arq->options & eAdmissionRequest_destCallSignalAddress) &&
1487 get_h225_addr(ct, *data, &arq->destCallSignalAddress,
1488 &addr, &port) &&
1489 !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1490 port == info->sig_port[dir] &&
1491 set_h225_addr && ct->status & IPS_NAT_MASK) {
1492 /* Answering ARQ */
1493 return set_h225_addr(skb, data, 0,
1494 &arq->destCallSignalAddress,
1495 &ct->tuplehash[!dir].tuple.dst.u3,
1496 info->sig_port[!dir]);
1497 }
1498
1499 if ((arq->options & eAdmissionRequest_srcCallSignalAddress) &&
1500 get_h225_addr(ct, *data, &arq->srcCallSignalAddress,
1501 &addr, &port) &&
1502 !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
1503 set_h225_addr && ct->status & IPS_NAT_MASK) {
1504 /* Calling ARQ */
1505 return set_h225_addr(skb, data, 0,
1506 &arq->srcCallSignalAddress,
1507 &ct->tuplehash[!dir].tuple.dst.u3,
1508 port);
1509 }
1510
1511 return 0;
1512 }
1513
1514 /****************************************************************************/
1515 static int process_acf(struct sk_buff *skb, struct nf_conn *ct,
1516 enum ip_conntrack_info ctinfo,
1517 unsigned char **data, AdmissionConfirm *acf)
1518 {
1519 int dir = CTINFO2DIR(ctinfo);
1520 int ret = 0;
1521 __be16 port;
1522 union nf_inet_addr addr;
1523 struct nf_conntrack_expect *exp;
1524 typeof(set_sig_addr_hook) set_sig_addr;
1525
1526 pr_debug("nf_ct_ras: ACF\n");
1527
1528 if (!get_h225_addr(ct, *data, &acf->destCallSignalAddress,
1529 &addr, &port))
1530 return 0;
1531
1532 if (!memcmp(&addr, &ct->tuplehash[dir].tuple.dst.u3, sizeof(addr))) {
1533 /* Answering ACF */
1534 set_sig_addr = rcu_dereference(set_sig_addr_hook);
1535 if (set_sig_addr && ct->status & IPS_NAT_MASK)
1536 return set_sig_addr(skb, ct, ctinfo, data,
1537 &acf->destCallSignalAddress, 1);
1538 return 0;
1539 }
1540
1541 /* Need new expect */
1542 if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1543 return -1;
1544 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1545 &ct->tuplehash[!dir].tuple.src.u3, &addr,
1546 IPPROTO_TCP, NULL, &port);
1547 exp->flags = NF_CT_EXPECT_PERMANENT;
1548 exp->helper = nf_conntrack_helper_q931;
1549
1550 if (nf_ct_expect_related(exp) == 0) {
1551 pr_debug("nf_ct_ras: expect Q.931 ");
1552 nf_ct_dump_tuple(&exp->tuple);
1553 } else
1554 ret = -1;
1555
1556 nf_ct_expect_put(exp);
1557
1558 return ret;
1559 }
1560
1561 /****************************************************************************/
1562 static int process_lrq(struct sk_buff *skb, struct nf_conn *ct,
1563 enum ip_conntrack_info ctinfo,
1564 unsigned char **data, LocationRequest *lrq)
1565 {
1566 typeof(set_ras_addr_hook) set_ras_addr;
1567
1568 pr_debug("nf_ct_ras: LRQ\n");
1569
1570 set_ras_addr = rcu_dereference(set_ras_addr_hook);
1571 if (set_ras_addr && ct->status & IPS_NAT_MASK)
1572 return set_ras_addr(skb, ct, ctinfo, data,
1573 &lrq->replyAddress, 1);
1574 return 0;
1575 }
1576
1577 /****************************************************************************/
1578 static int process_lcf(struct sk_buff *skb, struct nf_conn *ct,
1579 enum ip_conntrack_info ctinfo,
1580 unsigned char **data, LocationConfirm *lcf)
1581 {
1582 int dir = CTINFO2DIR(ctinfo);
1583 int ret = 0;
1584 __be16 port;
1585 union nf_inet_addr addr;
1586 struct nf_conntrack_expect *exp;
1587
1588 pr_debug("nf_ct_ras: LCF\n");
1589
1590 if (!get_h225_addr(ct, *data, &lcf->callSignalAddress,
1591 &addr, &port))
1592 return 0;
1593
1594 /* Need new expect for call signal */
1595 if ((exp = nf_ct_expect_alloc(ct)) == NULL)
1596 return -1;
1597 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
1598 &ct->tuplehash[!dir].tuple.src.u3, &addr,
1599 IPPROTO_TCP, NULL, &port);
1600 exp->flags = NF_CT_EXPECT_PERMANENT;
1601 exp->helper = nf_conntrack_helper_q931;
1602
1603 if (nf_ct_expect_related(exp) == 0) {
1604 pr_debug("nf_ct_ras: expect Q.931 ");
1605 nf_ct_dump_tuple(&exp->tuple);
1606 } else
1607 ret = -1;
1608
1609 nf_ct_expect_put(exp);
1610
1611 /* Ignore rasAddress */
1612
1613 return ret;
1614 }
1615
1616 /****************************************************************************/
1617 static int process_irr(struct sk_buff *skb, struct nf_conn *ct,
1618 enum ip_conntrack_info ctinfo,
1619 unsigned char **data, InfoRequestResponse *irr)
1620 {
1621 int ret;
1622 typeof(set_ras_addr_hook) set_ras_addr;
1623 typeof(set_sig_addr_hook) set_sig_addr;
1624
1625 pr_debug("nf_ct_ras: IRR\n");
1626
1627 set_ras_addr = rcu_dereference(set_ras_addr_hook);
1628 if (set_ras_addr && ct->status & IPS_NAT_MASK) {
1629 ret = set_ras_addr(skb, ct, ctinfo, data,
1630 &irr->rasAddress, 1);
1631 if (ret < 0)
1632 return -1;
1633 }
1634
1635 set_sig_addr = rcu_dereference(set_sig_addr_hook);
1636 if (set_sig_addr && ct->status & IPS_NAT_MASK) {
1637 ret = set_sig_addr(skb, ct, ctinfo, data,
1638 irr->callSignalAddress.item,
1639 irr->callSignalAddress.count);
1640 if (ret < 0)
1641 return -1;
1642 }
1643
1644 return 0;
1645 }
1646
1647 /****************************************************************************/
1648 static int process_ras(struct sk_buff *skb, struct nf_conn *ct,
1649 enum ip_conntrack_info ctinfo,
1650 unsigned char **data, RasMessage *ras)
1651 {
1652 switch (ras->choice) {
1653 case eRasMessage_gatekeeperRequest:
1654 return process_grq(skb, ct, ctinfo, data,
1655 &ras->gatekeeperRequest);
1656 case eRasMessage_gatekeeperConfirm:
1657 return process_gcf(skb, ct, ctinfo, data,
1658 &ras->gatekeeperConfirm);
1659 case eRasMessage_registrationRequest:
1660 return process_rrq(skb, ct, ctinfo, data,
1661 &ras->registrationRequest);
1662 case eRasMessage_registrationConfirm:
1663 return process_rcf(skb, ct, ctinfo, data,
1664 &ras->registrationConfirm);
1665 case eRasMessage_unregistrationRequest:
1666 return process_urq(skb, ct, ctinfo, data,
1667 &ras->unregistrationRequest);
1668 case eRasMessage_admissionRequest:
1669 return process_arq(skb, ct, ctinfo, data,
1670 &ras->admissionRequest);
1671 case eRasMessage_admissionConfirm:
1672 return process_acf(skb, ct, ctinfo, data,
1673 &ras->admissionConfirm);
1674 case eRasMessage_locationRequest:
1675 return process_lrq(skb, ct, ctinfo, data,
1676 &ras->locationRequest);
1677 case eRasMessage_locationConfirm:
1678 return process_lcf(skb, ct, ctinfo, data,
1679 &ras->locationConfirm);
1680 case eRasMessage_infoRequestResponse:
1681 return process_irr(skb, ct, ctinfo, data,
1682 &ras->infoRequestResponse);
1683 default:
1684 pr_debug("nf_ct_ras: RAS message %d\n", ras->choice);
1685 break;
1686 }
1687
1688 return 0;
1689 }
1690
1691 /****************************************************************************/
1692 static int ras_help(struct sk_buff *skb, unsigned int protoff,
1693 struct nf_conn *ct, enum ip_conntrack_info ctinfo)
1694 {
1695 static RasMessage ras;
1696 unsigned char *data;
1697 int datalen = 0;
1698 int ret;
1699
1700 pr_debug("nf_ct_ras: skblen = %u\n", skb->len);
1701
1702 spin_lock_bh(&nf_h323_lock);
1703
1704 /* Get UDP data */
1705 data = get_udp_data(skb, protoff, &datalen);
1706 if (data == NULL)
1707 goto accept;
1708 pr_debug("nf_ct_ras: RAS message len=%d ", datalen);
1709 nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
1710
1711 /* Decode RAS message */
1712 ret = DecodeRasMessage(data, datalen, &ras);
1713 if (ret < 0) {
1714 pr_debug("nf_ct_ras: decoding error: %s\n",
1715 ret == H323_ERROR_BOUND ?
1716 "out of bound" : "out of range");
1717 goto accept;
1718 }
1719
1720 /* Process RAS message */
1721 if (process_ras(skb, ct, ctinfo, &data, &ras) < 0)
1722 goto drop;
1723
1724 accept:
1725 spin_unlock_bh(&nf_h323_lock);
1726 return NF_ACCEPT;
1727
1728 drop:
1729 spin_unlock_bh(&nf_h323_lock);
1730 if (net_ratelimit())
1731 printk("nf_ct_ras: packet dropped\n");
1732 return NF_DROP;
1733 }
1734
1735 /****************************************************************************/
1736 static const struct nf_conntrack_expect_policy ras_exp_policy = {
1737 .max_expected = 32,
1738 .timeout = 240,
1739 };
1740
1741 static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = {
1742 {
1743 .name = "RAS",
1744 .me = THIS_MODULE,
1745 .tuple.src.l3num = AF_INET,
1746 .tuple.src.u.udp.port = __constant_htons(RAS_PORT),
1747 .tuple.dst.protonum = IPPROTO_UDP,
1748 .help = ras_help,
1749 .expect_policy = &ras_exp_policy,
1750 },
1751 {
1752 .name = "RAS",
1753 .me = THIS_MODULE,
1754 .tuple.src.l3num = AF_INET6,
1755 .tuple.src.u.udp.port = __constant_htons(RAS_PORT),
1756 .tuple.dst.protonum = IPPROTO_UDP,
1757 .help = ras_help,
1758 .expect_policy = &ras_exp_policy,
1759 },
1760 };
1761
1762 /****************************************************************************/
1763 static void __exit nf_conntrack_h323_fini(void)
1764 {
1765 nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[1]);
1766 nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1767 nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1768 nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1769 nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1770 kfree(h323_buffer);
1771 pr_debug("nf_ct_h323: fini\n");
1772 }
1773
1774 /****************************************************************************/
1775 static int __init nf_conntrack_h323_init(void)
1776 {
1777 int ret;
1778
1779 h323_buffer = kmalloc(65536, GFP_KERNEL);
1780 if (!h323_buffer)
1781 return -ENOMEM;
1782 ret = nf_conntrack_helper_register(&nf_conntrack_helper_h245);
1783 if (ret < 0)
1784 goto err1;
1785 ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[0]);
1786 if (ret < 0)
1787 goto err2;
1788 ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[1]);
1789 if (ret < 0)
1790 goto err3;
1791 ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[0]);
1792 if (ret < 0)
1793 goto err4;
1794 ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[1]);
1795 if (ret < 0)
1796 goto err5;
1797 pr_debug("nf_ct_h323: init success\n");
1798 return 0;
1799
1800 err5:
1801 nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
1802 err4:
1803 nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
1804 err3:
1805 nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
1806 err2:
1807 nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
1808 err1:
1809 kfree(h323_buffer);
1810 return ret;
1811 }
1812
1813 /****************************************************************************/
1814 module_init(nf_conntrack_h323_init);
1815 module_exit(nf_conntrack_h323_fini);
1816
1817 EXPORT_SYMBOL_GPL(get_h225_addr);
1818 EXPORT_SYMBOL_GPL(set_h245_addr_hook);
1819 EXPORT_SYMBOL_GPL(set_h225_addr_hook);
1820 EXPORT_SYMBOL_GPL(set_sig_addr_hook);
1821 EXPORT_SYMBOL_GPL(set_ras_addr_hook);
1822 EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook);
1823 EXPORT_SYMBOL_GPL(nat_t120_hook);
1824 EXPORT_SYMBOL_GPL(nat_h245_hook);
1825 EXPORT_SYMBOL_GPL(nat_callforwarding_hook);
1826 EXPORT_SYMBOL_GPL(nat_q931_hook);
1827
1828 MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>");
1829 MODULE_DESCRIPTION("H.323 connection tracking helper");
1830 MODULE_LICENSE("GPL");
1831 MODULE_ALIAS("ip_conntrack_h323");
ubuntu-zesty-kernel mirror