2 * Connection tracking support for PPTP (Point to Point Tunneling Protocol).
3 * PPTP is a a protocol for creating virtual private networks.
4 * It is a specification defined by Microsoft and some vendors
5 * working with Microsoft. PPTP is built on top of a modified
6 * version of the Internet Generic Routing Encapsulation Protocol.
7 * GRE is defined in RFC 1701 and RFC 1702. Documentation of
8 * PPTP can be found in RFC 2637
10 * (C) 2000-2005 by Harald Welte <laforge@gnumonks.org>
12 * Development of this code funded by Astaro AG (http://www.astaro.com/)
14 * (C) 2006-2012 Patrick McHardy <kaber@trash.net>
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
22 * - testing of incoming PPTP calls
25 #include <linux/module.h>
26 #include <linux/skbuff.h>
28 #include <linux/tcp.h>
30 #include <net/netfilter/nf_conntrack.h>
31 #include <net/netfilter/nf_conntrack_core.h>
32 #include <net/netfilter/nf_conntrack_helper.h>
33 #include <net/netfilter/nf_conntrack_zones.h>
34 #include <linux/netfilter/nf_conntrack_proto_gre.h>
35 #include <linux/netfilter/nf_conntrack_pptp.h>
37 #define NF_CT_PPTP_VERSION "3.1"
39 MODULE_LICENSE("GPL");
40 MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");
41 MODULE_DESCRIPTION("Netfilter connection tracking helper module for PPTP");
42 MODULE_ALIAS("ip_conntrack_pptp");
43 MODULE_ALIAS_NFCT_HELPER("pptp");
45 static DEFINE_SPINLOCK(nf_pptp_lock
);
48 (*nf_nat_pptp_hook_outbound
)(struct sk_buff
*skb
,
49 struct nf_conn
*ct
, enum ip_conntrack_info ctinfo
,
50 unsigned int protoff
, struct PptpControlHeader
*ctlh
,
51 union pptp_ctrl_union
*pptpReq
) __read_mostly
;
52 EXPORT_SYMBOL_GPL(nf_nat_pptp_hook_outbound
);
55 (*nf_nat_pptp_hook_inbound
)(struct sk_buff
*skb
,
56 struct nf_conn
*ct
, enum ip_conntrack_info ctinfo
,
57 unsigned int protoff
, struct PptpControlHeader
*ctlh
,
58 union pptp_ctrl_union
*pptpReq
) __read_mostly
;
59 EXPORT_SYMBOL_GPL(nf_nat_pptp_hook_inbound
);
62 (*nf_nat_pptp_hook_exp_gre
)(struct nf_conntrack_expect
*expect_orig
,
63 struct nf_conntrack_expect
*expect_reply
)
65 EXPORT_SYMBOL_GPL(nf_nat_pptp_hook_exp_gre
);
68 (*nf_nat_pptp_hook_expectfn
)(struct nf_conn
*ct
,
69 struct nf_conntrack_expect
*exp
) __read_mostly
;
70 EXPORT_SYMBOL_GPL(nf_nat_pptp_hook_expectfn
);
72 #if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
73 /* PptpControlMessageType names */
74 const char *const pptp_msg_name
[] = {
76 "START_SESSION_REQUEST",
77 "START_SESSION_REPLY",
78 "STOP_SESSION_REQUEST",
88 "CALL_DISCONNECT_NOTIFY",
92 EXPORT_SYMBOL(pptp_msg_name
);
96 #define MINS * 60 SECS
97 #define HOURS * 60 MINS
99 #define PPTP_GRE_TIMEOUT (10 MINS)
100 #define PPTP_GRE_STREAM_TIMEOUT (5 HOURS)
102 static void pptp_expectfn(struct nf_conn
*ct
,
103 struct nf_conntrack_expect
*exp
)
105 struct net
*net
= nf_ct_net(ct
);
106 typeof(nf_nat_pptp_hook_expectfn
) nf_nat_pptp_expectfn
;
107 pr_debug("increasing timeouts\n");
109 /* increase timeout of GRE data channel conntrack entry */
110 ct
->proto
.gre
.timeout
= PPTP_GRE_TIMEOUT
;
111 ct
->proto
.gre
.stream_timeout
= PPTP_GRE_STREAM_TIMEOUT
;
113 /* Can you see how rusty this code is, compared with the pre-2.6.11
114 * one? That's what happened to my shiny newnat of 2002 ;( -HW */
117 nf_nat_pptp_expectfn
= rcu_dereference(nf_nat_pptp_hook_expectfn
);
118 if (nf_nat_pptp_expectfn
&& ct
->master
->status
& IPS_NAT_MASK
)
119 nf_nat_pptp_expectfn(ct
, exp
);
121 struct nf_conntrack_tuple inv_t
;
122 struct nf_conntrack_expect
*exp_other
;
124 /* obviously this tuple inversion only works until you do NAT */
125 nf_ct_invert_tuplepr(&inv_t
, &exp
->tuple
);
126 pr_debug("trying to unexpect other dir: ");
127 nf_ct_dump_tuple(&inv_t
);
129 exp_other
= nf_ct_expect_find_get(net
, nf_ct_zone(ct
), &inv_t
);
131 /* delete other expectation. */
133 nf_ct_unexpect_related(exp_other
);
134 nf_ct_expect_put(exp_other
);
136 pr_debug("not found\n");
142 static int destroy_sibling_or_exp(struct net
*net
, struct nf_conn
*ct
,
143 const struct nf_conntrack_tuple
*t
)
145 const struct nf_conntrack_tuple_hash
*h
;
146 const struct nf_conntrack_zone
*zone
;
147 struct nf_conntrack_expect
*exp
;
148 struct nf_conn
*sibling
;
150 pr_debug("trying to timeout ct or exp for tuple ");
153 zone
= nf_ct_zone(ct
);
154 h
= nf_conntrack_find_get(net
, zone
, t
);
156 sibling
= nf_ct_tuplehash_to_ctrack(h
);
157 pr_debug("setting timeout of conntrack %p to 0\n", sibling
);
158 sibling
->proto
.gre
.timeout
= 0;
159 sibling
->proto
.gre
.stream_timeout
= 0;
160 if (del_timer(&sibling
->timeout
))
161 sibling
->timeout
.function((unsigned long)sibling
);
165 exp
= nf_ct_expect_find_get(net
, zone
, t
);
167 pr_debug("unexpect_related of expect %p\n", exp
);
168 nf_ct_unexpect_related(exp
);
169 nf_ct_expect_put(exp
);
176 /* timeout GRE data connections */
177 static void pptp_destroy_siblings(struct nf_conn
*ct
)
179 struct net
*net
= nf_ct_net(ct
);
180 const struct nf_ct_pptp_master
*ct_pptp_info
= nfct_help_data(ct
);
181 struct nf_conntrack_tuple t
;
183 nf_ct_gre_keymap_destroy(ct
);
185 /* try original (pns->pac) tuple */
186 memcpy(&t
, &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
, sizeof(t
));
187 t
.dst
.protonum
= IPPROTO_GRE
;
188 t
.src
.u
.gre
.key
= ct_pptp_info
->pns_call_id
;
189 t
.dst
.u
.gre
.key
= ct_pptp_info
->pac_call_id
;
190 if (!destroy_sibling_or_exp(net
, ct
, &t
))
191 pr_debug("failed to timeout original pns->pac ct/exp\n");
193 /* try reply (pac->pns) tuple */
194 memcpy(&t
, &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
, sizeof(t
));
195 t
.dst
.protonum
= IPPROTO_GRE
;
196 t
.src
.u
.gre
.key
= ct_pptp_info
->pac_call_id
;
197 t
.dst
.u
.gre
.key
= ct_pptp_info
->pns_call_id
;
198 if (!destroy_sibling_or_exp(net
, ct
, &t
))
199 pr_debug("failed to timeout reply pac->pns ct/exp\n");
202 /* expect GRE connections (PNS->PAC and PAC->PNS direction) */
203 static int exp_gre(struct nf_conn
*ct
, __be16 callid
, __be16 peer_callid
)
205 struct nf_conntrack_expect
*exp_orig
, *exp_reply
;
206 enum ip_conntrack_dir dir
;
208 typeof(nf_nat_pptp_hook_exp_gre
) nf_nat_pptp_exp_gre
;
210 exp_orig
= nf_ct_expect_alloc(ct
);
211 if (exp_orig
== NULL
)
214 exp_reply
= nf_ct_expect_alloc(ct
);
215 if (exp_reply
== NULL
)
218 /* original direction, PNS->PAC */
219 dir
= IP_CT_DIR_ORIGINAL
;
220 nf_ct_expect_init(exp_orig
, NF_CT_EXPECT_CLASS_DEFAULT
,
222 &ct
->tuplehash
[dir
].tuple
.src
.u3
,
223 &ct
->tuplehash
[dir
].tuple
.dst
.u3
,
224 IPPROTO_GRE
, &peer_callid
, &callid
);
225 exp_orig
->expectfn
= pptp_expectfn
;
227 /* reply direction, PAC->PNS */
228 dir
= IP_CT_DIR_REPLY
;
229 nf_ct_expect_init(exp_reply
, NF_CT_EXPECT_CLASS_DEFAULT
,
231 &ct
->tuplehash
[dir
].tuple
.src
.u3
,
232 &ct
->tuplehash
[dir
].tuple
.dst
.u3
,
233 IPPROTO_GRE
, &callid
, &peer_callid
);
234 exp_reply
->expectfn
= pptp_expectfn
;
236 nf_nat_pptp_exp_gre
= rcu_dereference(nf_nat_pptp_hook_exp_gre
);
237 if (nf_nat_pptp_exp_gre
&& ct
->status
& IPS_NAT_MASK
)
238 nf_nat_pptp_exp_gre(exp_orig
, exp_reply
);
239 if (nf_ct_expect_related(exp_orig
) != 0)
241 if (nf_ct_expect_related(exp_reply
) != 0)
242 goto out_unexpect_orig
;
244 /* Add GRE keymap entries */
245 if (nf_ct_gre_keymap_add(ct
, IP_CT_DIR_ORIGINAL
, &exp_orig
->tuple
) != 0)
246 goto out_unexpect_both
;
247 if (nf_ct_gre_keymap_add(ct
, IP_CT_DIR_REPLY
, &exp_reply
->tuple
) != 0) {
248 nf_ct_gre_keymap_destroy(ct
);
249 goto out_unexpect_both
;
254 nf_ct_expect_put(exp_reply
);
256 nf_ct_expect_put(exp_orig
);
261 nf_ct_unexpect_related(exp_reply
);
263 nf_ct_unexpect_related(exp_orig
);
268 pptp_inbound_pkt(struct sk_buff
*skb
, unsigned int protoff
,
269 struct PptpControlHeader
*ctlh
,
270 union pptp_ctrl_union
*pptpReq
,
273 enum ip_conntrack_info ctinfo
)
275 struct nf_ct_pptp_master
*info
= nfct_help_data(ct
);
277 __be16 cid
= 0, pcid
= 0;
278 typeof(nf_nat_pptp_hook_inbound
) nf_nat_pptp_inbound
;
280 msg
= ntohs(ctlh
->messageType
);
281 pr_debug("inbound control message %s\n", pptp_msg_name
[msg
]);
284 case PPTP_START_SESSION_REPLY
:
285 /* server confirms new control session */
286 if (info
->sstate
< PPTP_SESSION_REQUESTED
)
288 if (pptpReq
->srep
.resultCode
== PPTP_START_OK
)
289 info
->sstate
= PPTP_SESSION_CONFIRMED
;
291 info
->sstate
= PPTP_SESSION_ERROR
;
294 case PPTP_STOP_SESSION_REPLY
:
295 /* server confirms end of control session */
296 if (info
->sstate
> PPTP_SESSION_STOPREQ
)
298 if (pptpReq
->strep
.resultCode
== PPTP_STOP_OK
)
299 info
->sstate
= PPTP_SESSION_NONE
;
301 info
->sstate
= PPTP_SESSION_ERROR
;
304 case PPTP_OUT_CALL_REPLY
:
305 /* server accepted call, we now expect GRE frames */
306 if (info
->sstate
!= PPTP_SESSION_CONFIRMED
)
308 if (info
->cstate
!= PPTP_CALL_OUT_REQ
&&
309 info
->cstate
!= PPTP_CALL_OUT_CONF
)
312 cid
= pptpReq
->ocack
.callID
;
313 pcid
= pptpReq
->ocack
.peersCallID
;
314 if (info
->pns_call_id
!= pcid
)
316 pr_debug("%s, CID=%X, PCID=%X\n", pptp_msg_name
[msg
],
317 ntohs(cid
), ntohs(pcid
));
319 if (pptpReq
->ocack
.resultCode
== PPTP_OUTCALL_CONNECT
) {
320 info
->cstate
= PPTP_CALL_OUT_CONF
;
321 info
->pac_call_id
= cid
;
322 exp_gre(ct
, cid
, pcid
);
324 info
->cstate
= PPTP_CALL_NONE
;
327 case PPTP_IN_CALL_REQUEST
:
328 /* server tells us about incoming call request */
329 if (info
->sstate
!= PPTP_SESSION_CONFIRMED
)
332 cid
= pptpReq
->icreq
.callID
;
333 pr_debug("%s, CID=%X\n", pptp_msg_name
[msg
], ntohs(cid
));
334 info
->cstate
= PPTP_CALL_IN_REQ
;
335 info
->pac_call_id
= cid
;
338 case PPTP_IN_CALL_CONNECT
:
339 /* server tells us about incoming call established */
340 if (info
->sstate
!= PPTP_SESSION_CONFIRMED
)
342 if (info
->cstate
!= PPTP_CALL_IN_REP
&&
343 info
->cstate
!= PPTP_CALL_IN_CONF
)
346 pcid
= pptpReq
->iccon
.peersCallID
;
347 cid
= info
->pac_call_id
;
349 if (info
->pns_call_id
!= pcid
)
352 pr_debug("%s, PCID=%X\n", pptp_msg_name
[msg
], ntohs(pcid
));
353 info
->cstate
= PPTP_CALL_IN_CONF
;
355 /* we expect a GRE connection from PAC to PNS */
356 exp_gre(ct
, cid
, pcid
);
359 case PPTP_CALL_DISCONNECT_NOTIFY
:
360 /* server confirms disconnect */
361 cid
= pptpReq
->disc
.callID
;
362 pr_debug("%s, CID=%X\n", pptp_msg_name
[msg
], ntohs(cid
));
363 info
->cstate
= PPTP_CALL_NONE
;
365 /* untrack this call id, unexpect GRE packets */
366 pptp_destroy_siblings(ct
);
369 case PPTP_WAN_ERROR_NOTIFY
:
370 case PPTP_SET_LINK_INFO
:
371 case PPTP_ECHO_REQUEST
:
372 case PPTP_ECHO_REPLY
:
373 /* I don't have to explain these ;) */
380 nf_nat_pptp_inbound
= rcu_dereference(nf_nat_pptp_hook_inbound
);
381 if (nf_nat_pptp_inbound
&& ct
->status
& IPS_NAT_MASK
)
382 return nf_nat_pptp_inbound(skb
, ct
, ctinfo
,
383 protoff
, ctlh
, pptpReq
);
387 pr_debug("invalid %s: type=%d cid=%u pcid=%u "
388 "cstate=%d sstate=%d pns_cid=%u pac_cid=%u\n",
389 msg
<= PPTP_MSG_MAX
? pptp_msg_name
[msg
] : pptp_msg_name
[0],
390 msg
, ntohs(cid
), ntohs(pcid
), info
->cstate
, info
->sstate
,
391 ntohs(info
->pns_call_id
), ntohs(info
->pac_call_id
));
396 pptp_outbound_pkt(struct sk_buff
*skb
, unsigned int protoff
,
397 struct PptpControlHeader
*ctlh
,
398 union pptp_ctrl_union
*pptpReq
,
401 enum ip_conntrack_info ctinfo
)
403 struct nf_ct_pptp_master
*info
= nfct_help_data(ct
);
405 __be16 cid
= 0, pcid
= 0;
406 typeof(nf_nat_pptp_hook_outbound
) nf_nat_pptp_outbound
;
408 msg
= ntohs(ctlh
->messageType
);
409 pr_debug("outbound control message %s\n", pptp_msg_name
[msg
]);
412 case PPTP_START_SESSION_REQUEST
:
413 /* client requests for new control session */
414 if (info
->sstate
!= PPTP_SESSION_NONE
)
416 info
->sstate
= PPTP_SESSION_REQUESTED
;
419 case PPTP_STOP_SESSION_REQUEST
:
420 /* client requests end of control session */
421 info
->sstate
= PPTP_SESSION_STOPREQ
;
424 case PPTP_OUT_CALL_REQUEST
:
425 /* client initiating connection to server */
426 if (info
->sstate
!= PPTP_SESSION_CONFIRMED
)
428 info
->cstate
= PPTP_CALL_OUT_REQ
;
429 /* track PNS call id */
430 cid
= pptpReq
->ocreq
.callID
;
431 pr_debug("%s, CID=%X\n", pptp_msg_name
[msg
], ntohs(cid
));
432 info
->pns_call_id
= cid
;
435 case PPTP_IN_CALL_REPLY
:
436 /* client answers incoming call */
437 if (info
->cstate
!= PPTP_CALL_IN_REQ
&&
438 info
->cstate
!= PPTP_CALL_IN_REP
)
441 cid
= pptpReq
->icack
.callID
;
442 pcid
= pptpReq
->icack
.peersCallID
;
443 if (info
->pac_call_id
!= pcid
)
445 pr_debug("%s, CID=%X PCID=%X\n", pptp_msg_name
[msg
],
446 ntohs(cid
), ntohs(pcid
));
448 if (pptpReq
->icack
.resultCode
== PPTP_INCALL_ACCEPT
) {
449 /* part two of the three-way handshake */
450 info
->cstate
= PPTP_CALL_IN_REP
;
451 info
->pns_call_id
= cid
;
453 info
->cstate
= PPTP_CALL_NONE
;
456 case PPTP_CALL_CLEAR_REQUEST
:
457 /* client requests hangup of call */
458 if (info
->sstate
!= PPTP_SESSION_CONFIRMED
)
460 /* FUTURE: iterate over all calls and check if
461 * call ID is valid. We don't do this without newnat,
462 * because we only know about last call */
463 info
->cstate
= PPTP_CALL_CLEAR_REQ
;
466 case PPTP_SET_LINK_INFO
:
467 case PPTP_ECHO_REQUEST
:
468 case PPTP_ECHO_REPLY
:
469 /* I don't have to explain these ;) */
476 nf_nat_pptp_outbound
= rcu_dereference(nf_nat_pptp_hook_outbound
);
477 if (nf_nat_pptp_outbound
&& ct
->status
& IPS_NAT_MASK
)
478 return nf_nat_pptp_outbound(skb
, ct
, ctinfo
,
479 protoff
, ctlh
, pptpReq
);
483 pr_debug("invalid %s: type=%d cid=%u pcid=%u "
484 "cstate=%d sstate=%d pns_cid=%u pac_cid=%u\n",
485 msg
<= PPTP_MSG_MAX
? pptp_msg_name
[msg
] : pptp_msg_name
[0],
486 msg
, ntohs(cid
), ntohs(pcid
), info
->cstate
, info
->sstate
,
487 ntohs(info
->pns_call_id
), ntohs(info
->pac_call_id
));
491 static const unsigned int pptp_msg_size
[] = {
492 [PPTP_START_SESSION_REQUEST
] = sizeof(struct PptpStartSessionRequest
),
493 [PPTP_START_SESSION_REPLY
] = sizeof(struct PptpStartSessionReply
),
494 [PPTP_STOP_SESSION_REQUEST
] = sizeof(struct PptpStopSessionRequest
),
495 [PPTP_STOP_SESSION_REPLY
] = sizeof(struct PptpStopSessionReply
),
496 [PPTP_OUT_CALL_REQUEST
] = sizeof(struct PptpOutCallRequest
),
497 [PPTP_OUT_CALL_REPLY
] = sizeof(struct PptpOutCallReply
),
498 [PPTP_IN_CALL_REQUEST
] = sizeof(struct PptpInCallRequest
),
499 [PPTP_IN_CALL_REPLY
] = sizeof(struct PptpInCallReply
),
500 [PPTP_IN_CALL_CONNECT
] = sizeof(struct PptpInCallConnected
),
501 [PPTP_CALL_CLEAR_REQUEST
] = sizeof(struct PptpClearCallRequest
),
502 [PPTP_CALL_DISCONNECT_NOTIFY
] = sizeof(struct PptpCallDisconnectNotify
),
503 [PPTP_WAN_ERROR_NOTIFY
] = sizeof(struct PptpWanErrorNotify
),
504 [PPTP_SET_LINK_INFO
] = sizeof(struct PptpSetLinkInfo
),
507 /* track caller id inside control connection, call expect_related */
509 conntrack_pptp_help(struct sk_buff
*skb
, unsigned int protoff
,
510 struct nf_conn
*ct
, enum ip_conntrack_info ctinfo
)
513 int dir
= CTINFO2DIR(ctinfo
);
514 const struct nf_ct_pptp_master
*info
= nfct_help_data(ct
);
515 const struct tcphdr
*tcph
;
517 const struct pptp_pkt_hdr
*pptph
;
518 struct pptp_pkt_hdr _pptph
;
519 struct PptpControlHeader _ctlh
, *ctlh
;
520 union pptp_ctrl_union _pptpReq
, *pptpReq
;
521 unsigned int tcplen
= skb
->len
- protoff
;
522 unsigned int datalen
, reqlen
, nexthdr_off
;
523 int oldsstate
, oldcstate
;
527 /* don't do any tracking before tcp handshake complete */
528 if (ctinfo
!= IP_CT_ESTABLISHED
&& ctinfo
!= IP_CT_ESTABLISHED_REPLY
)
531 nexthdr_off
= protoff
;
532 tcph
= skb_header_pointer(skb
, nexthdr_off
, sizeof(_tcph
), &_tcph
);
534 nexthdr_off
+= tcph
->doff
* 4;
535 datalen
= tcplen
- tcph
->doff
* 4;
537 pptph
= skb_header_pointer(skb
, nexthdr_off
, sizeof(_pptph
), &_pptph
);
539 pr_debug("no full PPTP header, can't track\n");
542 nexthdr_off
+= sizeof(_pptph
);
543 datalen
-= sizeof(_pptph
);
545 /* if it's not a control message we can't do anything with it */
546 if (ntohs(pptph
->packetType
) != PPTP_PACKET_CONTROL
||
547 ntohl(pptph
->magicCookie
) != PPTP_MAGIC_COOKIE
) {
548 pr_debug("not a control packet\n");
552 ctlh
= skb_header_pointer(skb
, nexthdr_off
, sizeof(_ctlh
), &_ctlh
);
555 nexthdr_off
+= sizeof(_ctlh
);
556 datalen
-= sizeof(_ctlh
);
559 msg
= ntohs(ctlh
->messageType
);
560 if (msg
> 0 && msg
<= PPTP_MSG_MAX
&& reqlen
< pptp_msg_size
[msg
])
562 if (reqlen
> sizeof(*pptpReq
))
563 reqlen
= sizeof(*pptpReq
);
565 pptpReq
= skb_header_pointer(skb
, nexthdr_off
, reqlen
, &_pptpReq
);
569 oldsstate
= info
->sstate
;
570 oldcstate
= info
->cstate
;
572 spin_lock_bh(&nf_pptp_lock
);
574 /* FIXME: We just blindly assume that the control connection is always
575 * established from PNS->PAC. However, RFC makes no guarantee */
576 if (dir
== IP_CT_DIR_ORIGINAL
)
577 /* client -> server (PNS -> PAC) */
578 ret
= pptp_outbound_pkt(skb
, protoff
, ctlh
, pptpReq
, reqlen
, ct
,
581 /* server -> client (PAC -> PNS) */
582 ret
= pptp_inbound_pkt(skb
, protoff
, ctlh
, pptpReq
, reqlen
, ct
,
584 pr_debug("sstate: %d->%d, cstate: %d->%d\n",
585 oldsstate
, info
->sstate
, oldcstate
, info
->cstate
);
586 spin_unlock_bh(&nf_pptp_lock
);
591 static const struct nf_conntrack_expect_policy pptp_exp_policy
= {
596 /* control protocol helper */
597 static struct nf_conntrack_helper pptp __read_mostly
= {
600 .data_len
= sizeof(struct nf_ct_pptp_master
),
601 .tuple
.src
.l3num
= AF_INET
,
602 .tuple
.src
.u
.tcp
.port
= cpu_to_be16(PPTP_CONTROL_PORT
),
603 .tuple
.dst
.protonum
= IPPROTO_TCP
,
604 .help
= conntrack_pptp_help
,
605 .destroy
= pptp_destroy_siblings
,
606 .expect_policy
= &pptp_exp_policy
,
609 static int __init
nf_conntrack_pptp_init(void)
611 return nf_conntrack_helper_register(&pptp
);
614 static void __exit
nf_conntrack_pptp_fini(void)
616 nf_conntrack_helper_unregister(&pptp
);
619 module_init(nf_conntrack_pptp_init
);
620 module_exit(nf_conntrack_pptp_fini
);