2 * ip_conntrack_pptp.c - Version 3.0
4 * Connection tracking support for PPTP (Point to Point Tunneling Protocol).
5 * PPTP is a a protocol for creating virtual private networks.
6 * It is a specification defined by Microsoft and some vendors
7 * working with Microsoft. PPTP is built on top of a modified
8 * version of the Internet Generic Routing Encapsulation Protocol.
9 * GRE is defined in RFC 1701 and RFC 1702. Documentation of
10 * PPTP can be found in RFC 2637
12 * (C) 2000-2005 by Harald Welte <laforge@gnumonks.org>
14 * Development of this code funded by Astaro AG (http://www.astaro.com/)
17 * - We blindly assume that control connections are always
18 * established in PNS->PAC direction. This is a violation
20 * - We can only support one single call within each session
23 * - testing of incoming PPTP calls
26 * 2002-02-05 - Version 1.3
27 * - Call ip_conntrack_unexpect_related() from
28 * pptp_destroy_siblings() to destroy expectations in case
29 * CALL_DISCONNECT_NOTIFY or tcp fin packet was seen
30 * (Philip Craig <philipc@snapgear.com>)
31 * - Add Version information at module loadtime
32 * 2002-02-10 - Version 1.6
33 * - move to C99 style initializers
34 * - remove second expectation if first arrives
35 * 2004-10-22 - Version 2.0
36 * - merge Mandrake's 2.6.x port with recent 2.6.x API changes
37 * - fix lots of linear skb assumptions from Mandrake's port
38 * 2005-06-10 - Version 2.1
39 * - use ip_conntrack_expect_free() instead of kfree() on the
40 * expect's (which are from the slab for quite some time)
41 * 2005-06-10 - Version 3.0
42 * - port helper to post-2.6.11 API changes,
43 * funded by Oxcoda NetBox Blue (http://www.netboxblue.com/)
44 * 2005-07-30 - Version 3.1
45 * - port helper to 2.6.13 API changes
49 #include <linux/module.h>
50 #include <linux/netfilter.h>
52 #include <net/checksum.h>
55 #include <linux/netfilter_ipv4/ip_conntrack.h>
56 #include <linux/netfilter_ipv4/ip_conntrack_core.h>
57 #include <linux/netfilter_ipv4/ip_conntrack_helper.h>
58 #include <linux/netfilter_ipv4/ip_conntrack_proto_gre.h>
59 #include <linux/netfilter_ipv4/ip_conntrack_pptp.h>
61 #define IP_CT_PPTP_VERSION "3.1"
63 MODULE_LICENSE("GPL");
64 MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");
65 MODULE_DESCRIPTION("Netfilter connection tracking helper module for PPTP");
67 static DEFINE_SPINLOCK(ip_pptp_lock
);
70 (*ip_nat_pptp_hook_outbound
)(struct sk_buff
**pskb
,
71 struct ip_conntrack
*ct
,
72 enum ip_conntrack_info ctinfo
,
73 struct PptpControlHeader
*ctlh
,
74 union pptp_ctrl_union
*pptpReq
);
77 (*ip_nat_pptp_hook_inbound
)(struct sk_buff
**pskb
,
78 struct ip_conntrack
*ct
,
79 enum ip_conntrack_info ctinfo
,
80 struct PptpControlHeader
*ctlh
,
81 union pptp_ctrl_union
*pptpReq
);
84 (*ip_nat_pptp_hook_exp_gre
)(struct ip_conntrack_expect
*expect_orig
,
85 struct ip_conntrack_expect
*expect_reply
);
88 (*ip_nat_pptp_hook_expectfn
)(struct ip_conntrack
*ct
,
89 struct ip_conntrack_expect
*exp
);
92 /* PptpControlMessageType names */
93 const char *pptp_msg_name
[] = {
95 "START_SESSION_REQUEST",
96 "START_SESSION_REPLY",
97 "STOP_SESSION_REQUEST",
106 "CALL_CLEAR_REQUEST",
107 "CALL_DISCONNECT_NOTIFY",
111 EXPORT_SYMBOL(pptp_msg_name
);
112 #define DEBUGP(format, args...) printk(KERN_DEBUG "%s:%s: " format, __FILE__, __FUNCTION__, ## args)
114 #define DEBUGP(format, args...)
118 #define MINS * 60 SECS
119 #define HOURS * 60 MINS
121 #define PPTP_GRE_TIMEOUT (10 MINS)
122 #define PPTP_GRE_STREAM_TIMEOUT (5 HOURS)
124 static void pptp_expectfn(struct ip_conntrack
*ct
,
125 struct ip_conntrack_expect
*exp
)
127 DEBUGP("increasing timeouts\n");
129 /* increase timeout of GRE data channel conntrack entry */
130 ct
->proto
.gre
.timeout
= PPTP_GRE_TIMEOUT
;
131 ct
->proto
.gre
.stream_timeout
= PPTP_GRE_STREAM_TIMEOUT
;
133 /* Can you see how rusty this code is, compared with the pre-2.6.11
134 * one? That's what happened to my shiny newnat of 2002 ;( -HW */
136 if (!ip_nat_pptp_hook_expectfn
) {
137 struct ip_conntrack_tuple inv_t
;
138 struct ip_conntrack_expect
*exp_other
;
140 /* obviously this tuple inversion only works until you do NAT */
141 invert_tuplepr(&inv_t
, &exp
->tuple
);
142 DEBUGP("trying to unexpect other dir: ");
145 exp_other
= ip_conntrack_expect_find(&inv_t
);
147 /* delete other expectation. */
149 ip_conntrack_unexpect_related(exp_other
);
150 ip_conntrack_expect_put(exp_other
);
152 DEBUGP("not found\n");
155 /* we need more than simple inversion */
156 ip_nat_pptp_hook_expectfn(ct
, exp
);
160 static int destroy_sibling_or_exp(const struct ip_conntrack_tuple
*t
)
162 struct ip_conntrack_tuple_hash
*h
;
163 struct ip_conntrack_expect
*exp
;
165 DEBUGP("trying to timeout ct or exp for tuple ");
168 h
= ip_conntrack_find_get(t
, NULL
);
170 struct ip_conntrack
*sibling
= tuplehash_to_ctrack(h
);
171 DEBUGP("setting timeout of conntrack %p to 0\n", sibling
);
172 sibling
->proto
.gre
.timeout
= 0;
173 sibling
->proto
.gre
.stream_timeout
= 0;
174 if (del_timer(&sibling
->timeout
))
175 sibling
->timeout
.function((unsigned long)sibling
);
176 ip_conntrack_put(sibling
);
179 exp
= ip_conntrack_expect_find(t
);
181 DEBUGP("unexpect_related of expect %p\n", exp
);
182 ip_conntrack_unexpect_related(exp
);
183 ip_conntrack_expect_put(exp
);
192 /* timeout GRE data connections */
193 static void pptp_destroy_siblings(struct ip_conntrack
*ct
)
195 struct ip_conntrack_tuple t
;
197 /* Since ct->sibling_list has literally rusted away in 2.6.11,
198 * we now need another way to find out about our sibling
199 * contrack and expects... -HW */
201 /* try original (pns->pac) tuple */
202 memcpy(&t
, &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
, sizeof(t
));
203 t
.dst
.protonum
= IPPROTO_GRE
;
204 t
.src
.u
.gre
.key
= ct
->help
.ct_pptp_info
.pns_call_id
;
205 t
.dst
.u
.gre
.key
= ct
->help
.ct_pptp_info
.pac_call_id
;
207 if (!destroy_sibling_or_exp(&t
))
208 DEBUGP("failed to timeout original pns->pac ct/exp\n");
210 /* try reply (pac->pns) tuple */
211 memcpy(&t
, &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
, sizeof(t
));
212 t
.dst
.protonum
= IPPROTO_GRE
;
213 t
.src
.u
.gre
.key
= ct
->help
.ct_pptp_info
.pac_call_id
;
214 t
.dst
.u
.gre
.key
= ct
->help
.ct_pptp_info
.pns_call_id
;
216 if (!destroy_sibling_or_exp(&t
))
217 DEBUGP("failed to timeout reply pac->pns ct/exp\n");
220 /* expect GRE connections (PNS->PAC and PAC->PNS direction) */
222 exp_gre(struct ip_conntrack
*ct
,
226 struct ip_conntrack_expect
*exp_orig
, *exp_reply
;
229 exp_orig
= ip_conntrack_expect_alloc(ct
);
230 if (exp_orig
== NULL
)
233 exp_reply
= ip_conntrack_expect_alloc(ct
);
234 if (exp_reply
== NULL
)
237 /* original direction, PNS->PAC */
238 exp_orig
->tuple
.src
.ip
= ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
.src
.ip
;
239 exp_orig
->tuple
.src
.u
.gre
.key
= peer_callid
;
240 exp_orig
->tuple
.dst
.ip
= ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
.dst
.ip
;
241 exp_orig
->tuple
.dst
.u
.gre
.key
= callid
;
242 exp_orig
->tuple
.dst
.protonum
= IPPROTO_GRE
;
244 exp_orig
->mask
.src
.ip
= 0xffffffff;
245 exp_orig
->mask
.src
.u
.all
= 0;
246 exp_orig
->mask
.dst
.u
.gre
.key
= htons(0xffff);
247 exp_orig
->mask
.dst
.ip
= 0xffffffff;
248 exp_orig
->mask
.dst
.protonum
= 0xff;
250 exp_orig
->master
= ct
;
251 exp_orig
->expectfn
= pptp_expectfn
;
254 /* both expectations are identical apart from tuple */
255 memcpy(exp_reply
, exp_orig
, sizeof(*exp_reply
));
257 /* reply direction, PAC->PNS */
258 exp_reply
->tuple
.src
.ip
= ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
.src
.ip
;
259 exp_reply
->tuple
.src
.u
.gre
.key
= callid
;
260 exp_reply
->tuple
.dst
.ip
= ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
.dst
.ip
;
261 exp_reply
->tuple
.dst
.u
.gre
.key
= peer_callid
;
262 exp_reply
->tuple
.dst
.protonum
= IPPROTO_GRE
;
264 if (ip_nat_pptp_hook_exp_gre
)
265 ip_nat_pptp_hook_exp_gre(exp_orig
, exp_reply
);
266 if (ip_conntrack_expect_related(exp_orig
) != 0)
268 if (ip_conntrack_expect_related(exp_reply
) != 0)
269 goto out_unexpect_orig
;
271 /* Add GRE keymap entries */
272 if (ip_ct_gre_keymap_add(ct
, &exp_orig
->tuple
, 0) != 0)
273 goto out_unexpect_both
;
274 if (ip_ct_gre_keymap_add(ct
, &exp_reply
->tuple
, 1) != 0) {
275 ip_ct_gre_keymap_destroy(ct
);
276 goto out_unexpect_both
;
281 ip_conntrack_expect_put(exp_reply
);
283 ip_conntrack_expect_put(exp_orig
);
288 ip_conntrack_unexpect_related(exp_reply
);
290 ip_conntrack_unexpect_related(exp_orig
);
295 pptp_inbound_pkt(struct sk_buff
**pskb
,
296 struct PptpControlHeader
*ctlh
,
297 union pptp_ctrl_union
*pptpReq
,
299 struct ip_conntrack
*ct
,
300 enum ip_conntrack_info ctinfo
)
302 struct ip_ct_pptp_master
*info
= &ct
->help
.ct_pptp_info
;
306 msg
= ntohs(ctlh
->messageType
);
307 DEBUGP("inbound control message %s\n", pptp_msg_name
[msg
]);
310 case PPTP_START_SESSION_REPLY
:
311 /* server confirms new control session */
312 if (info
->sstate
< PPTP_SESSION_REQUESTED
) {
313 DEBUGP("%s without START_SESS_REQUEST\n",
317 if (pptpReq
->srep
.resultCode
== PPTP_START_OK
)
318 info
->sstate
= PPTP_SESSION_CONFIRMED
;
320 info
->sstate
= PPTP_SESSION_ERROR
;
323 case PPTP_STOP_SESSION_REPLY
:
324 /* server confirms end of control session */
325 if (info
->sstate
> PPTP_SESSION_STOPREQ
) {
326 DEBUGP("%s without STOP_SESS_REQUEST\n",
330 if (pptpReq
->strep
.resultCode
== PPTP_STOP_OK
)
331 info
->sstate
= PPTP_SESSION_NONE
;
333 info
->sstate
= PPTP_SESSION_ERROR
;
336 case PPTP_OUT_CALL_REPLY
:
337 /* server accepted call, we now expect GRE frames */
338 if (info
->sstate
!= PPTP_SESSION_CONFIRMED
) {
339 DEBUGP("%s but no session\n", pptp_msg_name
[msg
]);
342 if (info
->cstate
!= PPTP_CALL_OUT_REQ
&&
343 info
->cstate
!= PPTP_CALL_OUT_CONF
) {
344 DEBUGP("%s without OUTCALL_REQ\n", pptp_msg_name
[msg
]);
347 if (pptpReq
->ocack
.resultCode
!= PPTP_OUTCALL_CONNECT
) {
348 info
->cstate
= PPTP_CALL_NONE
;
352 cid
= pptpReq
->ocack
.callID
;
353 pcid
= pptpReq
->ocack
.peersCallID
;
355 info
->pac_call_id
= cid
;
357 if (info
->pns_call_id
!= pcid
) {
358 DEBUGP("%s for unknown callid %u\n",
359 pptp_msg_name
[msg
], ntohs(pcid
));
363 DEBUGP("%s, CID=%X, PCID=%X\n", pptp_msg_name
[msg
],
364 ntohs(cid
), ntohs(pcid
));
366 info
->cstate
= PPTP_CALL_OUT_CONF
;
368 exp_gre(ct
, cid
, pcid
);
371 case PPTP_IN_CALL_REQUEST
:
372 /* server tells us about incoming call request */
373 if (info
->sstate
!= PPTP_SESSION_CONFIRMED
) {
374 DEBUGP("%s but no session\n", pptp_msg_name
[msg
]);
377 pcid
= pptpReq
->icack
.peersCallID
;
378 DEBUGP("%s, PCID=%X\n", pptp_msg_name
[msg
], ntohs(pcid
));
379 info
->cstate
= PPTP_CALL_IN_REQ
;
380 info
->pac_call_id
= pcid
;
383 case PPTP_IN_CALL_CONNECT
:
384 /* server tells us about incoming call established */
385 if (info
->sstate
!= PPTP_SESSION_CONFIRMED
) {
386 DEBUGP("%s but no session\n", pptp_msg_name
[msg
]);
389 if (info
->cstate
!= PPTP_CALL_IN_REP
390 && info
->cstate
!= PPTP_CALL_IN_CONF
) {
391 DEBUGP("%s but never sent IN_CALL_REPLY\n",
396 pcid
= pptpReq
->iccon
.peersCallID
;
397 cid
= info
->pac_call_id
;
399 if (info
->pns_call_id
!= pcid
) {
400 DEBUGP("%s for unknown CallID %u\n",
401 pptp_msg_name
[msg
], ntohs(pcid
));
405 DEBUGP("%s, PCID=%X\n", pptp_msg_name
[msg
], ntohs(pcid
));
406 info
->cstate
= PPTP_CALL_IN_CONF
;
408 /* we expect a GRE connection from PAC to PNS */
409 exp_gre(ct
, cid
, pcid
);
412 case PPTP_CALL_DISCONNECT_NOTIFY
:
413 /* server confirms disconnect */
414 cid
= pptpReq
->disc
.callID
;
415 DEBUGP("%s, CID=%X\n", pptp_msg_name
[msg
], ntohs(cid
));
416 info
->cstate
= PPTP_CALL_NONE
;
418 /* untrack this call id, unexpect GRE packets */
419 pptp_destroy_siblings(ct
);
422 case PPTP_WAN_ERROR_NOTIFY
:
423 case PPTP_ECHO_REQUEST
:
424 case PPTP_ECHO_REPLY
:
425 /* I don't have to explain these ;) */
428 DEBUGP("invalid %s (TY=%d)\n", (msg
<= PPTP_MSG_MAX
)
429 ? pptp_msg_name
[msg
]:pptp_msg_name
[0], msg
);
434 if (ip_nat_pptp_hook_inbound
)
435 return ip_nat_pptp_hook_inbound(pskb
, ct
, ctinfo
, ctlh
,
443 pptp_outbound_pkt(struct sk_buff
**pskb
,
444 struct PptpControlHeader
*ctlh
,
445 union pptp_ctrl_union
*pptpReq
,
447 struct ip_conntrack
*ct
,
448 enum ip_conntrack_info ctinfo
)
450 struct ip_ct_pptp_master
*info
= &ct
->help
.ct_pptp_info
;
454 msg
= ntohs(ctlh
->messageType
);
455 DEBUGP("outbound control message %s\n", pptp_msg_name
[msg
]);
458 case PPTP_START_SESSION_REQUEST
:
459 /* client requests for new control session */
460 if (info
->sstate
!= PPTP_SESSION_NONE
) {
461 DEBUGP("%s but we already have one",
464 info
->sstate
= PPTP_SESSION_REQUESTED
;
466 case PPTP_STOP_SESSION_REQUEST
:
467 /* client requests end of control session */
468 info
->sstate
= PPTP_SESSION_STOPREQ
;
471 case PPTP_OUT_CALL_REQUEST
:
472 /* client initiating connection to server */
473 if (info
->sstate
!= PPTP_SESSION_CONFIRMED
) {
474 DEBUGP("%s but no session\n",
478 info
->cstate
= PPTP_CALL_OUT_REQ
;
479 /* track PNS call id */
480 cid
= pptpReq
->ocreq
.callID
;
481 DEBUGP("%s, CID=%X\n", pptp_msg_name
[msg
], ntohs(cid
));
482 info
->pns_call_id
= cid
;
484 case PPTP_IN_CALL_REPLY
:
485 /* client answers incoming call */
486 if (info
->cstate
!= PPTP_CALL_IN_REQ
487 && info
->cstate
!= PPTP_CALL_IN_REP
) {
488 DEBUGP("%s without incall_req\n",
492 if (pptpReq
->icack
.resultCode
!= PPTP_INCALL_ACCEPT
) {
493 info
->cstate
= PPTP_CALL_NONE
;
496 pcid
= pptpReq
->icack
.peersCallID
;
497 if (info
->pac_call_id
!= pcid
) {
498 DEBUGP("%s for unknown call %u\n",
499 pptp_msg_name
[msg
], ntohs(pcid
));
502 DEBUGP("%s, CID=%X\n", pptp_msg_name
[msg
], ntohs(pcid
));
503 /* part two of the three-way handshake */
504 info
->cstate
= PPTP_CALL_IN_REP
;
505 info
->pns_call_id
= pcid
;
508 case PPTP_CALL_CLEAR_REQUEST
:
509 /* client requests hangup of call */
510 if (info
->sstate
!= PPTP_SESSION_CONFIRMED
) {
511 DEBUGP("CLEAR_CALL but no session\n");
514 /* FUTURE: iterate over all calls and check if
515 * call ID is valid. We don't do this without newnat,
516 * because we only know about last call */
517 info
->cstate
= PPTP_CALL_CLEAR_REQ
;
519 case PPTP_SET_LINK_INFO
:
520 case PPTP_ECHO_REQUEST
:
521 case PPTP_ECHO_REPLY
:
522 /* I don't have to explain these ;) */
525 DEBUGP("invalid %s (TY=%d)\n", (msg
<= PPTP_MSG_MAX
)?
526 pptp_msg_name
[msg
]:pptp_msg_name
[0], msg
);
527 /* unknown: no need to create GRE masq table entry */
531 if (ip_nat_pptp_hook_outbound
)
532 return ip_nat_pptp_hook_outbound(pskb
, ct
, ctinfo
, ctlh
,
538 static const unsigned int pptp_msg_size
[] = {
539 [PPTP_START_SESSION_REQUEST
] = sizeof(struct PptpStartSessionRequest
),
540 [PPTP_START_SESSION_REPLY
] = sizeof(struct PptpStartSessionReply
),
541 [PPTP_STOP_SESSION_REQUEST
] = sizeof(struct PptpStopSessionRequest
),
542 [PPTP_STOP_SESSION_REPLY
] = sizeof(struct PptpStopSessionReply
),
543 [PPTP_OUT_CALL_REQUEST
] = sizeof(struct PptpOutCallRequest
),
544 [PPTP_OUT_CALL_REPLY
] = sizeof(struct PptpOutCallReply
),
545 [PPTP_IN_CALL_REQUEST
] = sizeof(struct PptpInCallRequest
),
546 [PPTP_IN_CALL_REPLY
] = sizeof(struct PptpInCallReply
),
547 [PPTP_IN_CALL_CONNECT
] = sizeof(struct PptpInCallConnected
),
548 [PPTP_CALL_CLEAR_REQUEST
] = sizeof(struct PptpClearCallRequest
),
549 [PPTP_CALL_DISCONNECT_NOTIFY
] = sizeof(struct PptpCallDisconnectNotify
),
550 [PPTP_WAN_ERROR_NOTIFY
] = sizeof(struct PptpWanErrorNotify
),
551 [PPTP_SET_LINK_INFO
] = sizeof(struct PptpSetLinkInfo
),
554 /* track caller id inside control connection, call expect_related */
556 conntrack_pptp_help(struct sk_buff
**pskb
,
557 struct ip_conntrack
*ct
, enum ip_conntrack_info ctinfo
)
560 int dir
= CTINFO2DIR(ctinfo
);
561 struct ip_ct_pptp_master
*info
= &ct
->help
.ct_pptp_info
;
562 struct tcphdr _tcph
, *tcph
;
563 struct pptp_pkt_hdr _pptph
, *pptph
;
564 struct PptpControlHeader _ctlh
, *ctlh
;
565 union pptp_ctrl_union _pptpReq
, *pptpReq
;
566 unsigned int tcplen
= (*pskb
)->len
- (*pskb
)->nh
.iph
->ihl
* 4;
567 unsigned int datalen
, reqlen
, nexthdr_off
;
568 int oldsstate
, oldcstate
;
572 /* don't do any tracking before tcp handshake complete */
573 if (ctinfo
!= IP_CT_ESTABLISHED
574 && ctinfo
!= IP_CT_ESTABLISHED
+IP_CT_IS_REPLY
) {
575 DEBUGP("ctinfo = %u, skipping\n", ctinfo
);
579 nexthdr_off
= (*pskb
)->nh
.iph
->ihl
*4;
580 tcph
= skb_header_pointer(*pskb
, nexthdr_off
, sizeof(_tcph
), &_tcph
);
582 nexthdr_off
+= tcph
->doff
* 4;
583 datalen
= tcplen
- tcph
->doff
* 4;
585 if (tcph
->fin
|| tcph
->rst
) {
586 DEBUGP("RST/FIN received, timeouting GRE\n");
587 /* can't do this after real newnat */
588 info
->cstate
= PPTP_CALL_NONE
;
590 /* untrack this call id, unexpect GRE packets */
591 pptp_destroy_siblings(ct
);
594 pptph
= skb_header_pointer(*pskb
, nexthdr_off
, sizeof(_pptph
), &_pptph
);
596 DEBUGP("no full PPTP header, can't track\n");
599 nexthdr_off
+= sizeof(_pptph
);
600 datalen
-= sizeof(_pptph
);
602 /* if it's not a control message we can't do anything with it */
603 if (ntohs(pptph
->packetType
) != PPTP_PACKET_CONTROL
||
604 ntohl(pptph
->magicCookie
) != PPTP_MAGIC_COOKIE
) {
605 DEBUGP("not a control packet\n");
609 ctlh
= skb_header_pointer(*pskb
, nexthdr_off
, sizeof(_ctlh
), &_ctlh
);
612 nexthdr_off
+= sizeof(_ctlh
);
613 datalen
-= sizeof(_ctlh
);
616 msg
= ntohs(ctlh
->messageType
);
617 if (msg
> 0 && msg
<= PPTP_MSG_MAX
&& reqlen
< pptp_msg_size
[msg
])
619 if (reqlen
> sizeof(*pptpReq
))
620 reqlen
= sizeof(*pptpReq
);
622 pptpReq
= skb_header_pointer(*pskb
, nexthdr_off
, reqlen
, &_pptpReq
);
626 oldsstate
= info
->sstate
;
627 oldcstate
= info
->cstate
;
629 spin_lock_bh(&ip_pptp_lock
);
631 /* FIXME: We just blindly assume that the control connection is always
632 * established from PNS->PAC. However, RFC makes no guarantee */
633 if (dir
== IP_CT_DIR_ORIGINAL
)
634 /* client -> server (PNS -> PAC) */
635 ret
= pptp_outbound_pkt(pskb
, ctlh
, pptpReq
, reqlen
, ct
,
638 /* server -> client (PAC -> PNS) */
639 ret
= pptp_inbound_pkt(pskb
, ctlh
, pptpReq
, reqlen
, ct
,
641 DEBUGP("sstate: %d->%d, cstate: %d->%d\n",
642 oldsstate
, info
->sstate
, oldcstate
, info
->cstate
);
643 spin_unlock_bh(&ip_pptp_lock
);
648 /* control protocol helper */
649 static struct ip_conntrack_helper pptp
= {
650 .list
= { NULL
, NULL
},
655 .tuple
= { .src
= { .ip
= 0,
656 .u
= { .tcp
= { .port
=
657 __constant_htons(PPTP_CONTROL_PORT
) } }
661 .protonum
= IPPROTO_TCP
664 .mask
= { .src
= { .ip
= 0,
665 .u
= { .tcp
= { .port
= __constant_htons(0xffff) } }
672 .help
= conntrack_pptp_help
675 extern void ip_ct_proto_gre_fini(void);
676 extern int __init
ip_ct_proto_gre_init(void);
678 /* ip_conntrack_pptp initialization */
679 static int __init
ip_conntrack_helper_pptp_init(void)
683 retcode
= ip_ct_proto_gre_init();
687 DEBUGP(" registering helper\n");
688 if ((retcode
= ip_conntrack_helper_register(&pptp
))) {
689 printk(KERN_ERR
"Unable to register conntrack application "
690 "helper for pptp: %d\n", retcode
);
691 ip_ct_proto_gre_fini();
695 printk("ip_conntrack_pptp version %s loaded\n", IP_CT_PPTP_VERSION
);
699 static void __exit
ip_conntrack_helper_pptp_fini(void)
701 ip_conntrack_helper_unregister(&pptp
);
702 ip_ct_proto_gre_fini();
703 printk("ip_conntrack_pptp version %s unloaded\n", IP_CT_PPTP_VERSION
);
706 module_init(ip_conntrack_helper_pptp_init
);
707 module_exit(ip_conntrack_helper_pptp_fini
);
709 EXPORT_SYMBOL(ip_nat_pptp_hook_outbound
);
710 EXPORT_SYMBOL(ip_nat_pptp_hook_inbound
);
711 EXPORT_SYMBOL(ip_nat_pptp_hook_exp_gre
);
712 EXPORT_SYMBOL(ip_nat_pptp_hook_expectfn
);