add pptp nat fix (should fix #571, needs to be tested)

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@5695 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 693 insertions, 687 deletions

diff --git a/target/linux/generic-2.4/patches/603-netfilter_nat_pptp.patch b/target/linux/generic-2.4/patches/603-netfilter_nat_pptp.patch
index 6a7a16fb9..ce2838f76 100644
--- a/target/linux/generic-2.4/patches/603-netfilter_nat_pptp.patch
+++ b/target/linux/generic-2.4/patches/603-netfilter_nat_pptp.patch
@@ -1,6 +1,6 @@
-diff -urN linux-2.4.29-old/include/linux/netfilter_ipv4/ip_conntrack.h linux-2.4.29-dev/include/linux/netfilter_ipv4/ip_conntrack.h
---- linux-2.4.29-old/include/linux/netfilter_ipv4/ip_conntrack.h	2005-04-02 19:04:11.000000000 +0200
-+++ linux-2.4.29-dev/include/linux/netfilter_ipv4/ip_conntrack.h	2005-04-02 19:41:05.000000000 +0200
+diff -urN linux.old/include/linux/netfilter_ipv4/ip_conntrack.h linux.dev/include/linux/netfilter_ipv4/ip_conntrack.h
+--- linux.old/include/linux/netfilter_ipv4/ip_conntrack.h	2006-12-06 00:31:46.000000000 +0100
++++ linux.dev/include/linux/netfilter_ipv4/ip_conntrack.h	2006-12-06 00:34:27.000000000 +0100
 @@ -50,16 +50,19 @@
  
  #include <linux/netfilter_ipv4/ip_conntrack_tcp.h>
@@ -55,9 +55,9 @@ diff -urN linux-2.4.29-old/include/linux/netfilter_ipv4/ip_conntrack.h linux-2.4
  };
  #endif
  
-diff -urN linux-2.4.29-old/include/linux/netfilter_ipv4/ip_conntrack_pptp.h linux-2.4.29-dev/include/linux/netfilter_ipv4/ip_conntrack_pptp.h
---- linux-2.4.29-old/include/linux/netfilter_ipv4/ip_conntrack_pptp.h	1970-01-01 01:00:00.000000000 +0100
-+++ linux-2.4.29-dev/include/linux/netfilter_ipv4/ip_conntrack_pptp.h	2005-04-02 19:09:07.000000000 +0200
+diff -urN linux.old/include/linux/netfilter_ipv4/ip_conntrack_pptp.h linux.dev/include/linux/netfilter_ipv4/ip_conntrack_pptp.h
+--- linux.old/include/linux/netfilter_ipv4/ip_conntrack_pptp.h	1970-01-01 01:00:00.000000000 +0100
++++ linux.dev/include/linux/netfilter_ipv4/ip_conntrack_pptp.h	2006-12-06 00:34:27.000000000 +0100
 @@ -0,0 +1,313 @@
 +/* PPTP constants and structs */
 +#ifndef _CONNTRACK_PPTP_H
@@ -372,9 +372,9 @@ diff -urN linux-2.4.29-old/include/linux/netfilter_ipv4/ip_conntrack_pptp.h linu
 +
 +#endif /* __KERNEL__ */
 +#endif /* _CONNTRACK_PPTP_H */
-diff -urN linux-2.4.29-old/include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h linux-2.4.29-dev/include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h
---- linux-2.4.29-old/include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h	1970-01-01 01:00:00.000000000 +0100
-+++ linux-2.4.29-dev/include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h	2005-04-02 19:10:45.000000000 +0200
+diff -urN linux.old/include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h linux.dev/include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h
+--- linux.old/include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h	1970-01-01 01:00:00.000000000 +0100
++++ linux.dev/include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h	2006-12-06 00:34:27.000000000 +0100
 @@ -0,0 +1,123 @@
 +#ifndef _CONNTRACK_PROTO_GRE_H
 +#define _CONNTRACK_PROTO_GRE_H
@@ -499,9 +499,9 @@ diff -urN linux-2.4.29-old/include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h
 +#endif /* __KERNEL__ */
 +
 +#endif /* _CONNTRACK_PROTO_GRE_H */
-diff -urN linux-2.4.29-old/include/linux/netfilter_ipv4/ip_conntrack_tuple.h linux-2.4.29-dev/include/linux/netfilter_ipv4/ip_conntrack_tuple.h
---- linux-2.4.29-old/include/linux/netfilter_ipv4/ip_conntrack_tuple.h	2003-11-28 19:26:21.000000000 +0100
-+++ linux-2.4.29-dev/include/linux/netfilter_ipv4/ip_conntrack_tuple.h	2005-04-02 19:07:18.000000000 +0200
+diff -urN linux.old/include/linux/netfilter_ipv4/ip_conntrack_tuple.h linux.dev/include/linux/netfilter_ipv4/ip_conntrack_tuple.h
+--- linux.old/include/linux/netfilter_ipv4/ip_conntrack_tuple.h	2003-11-28 19:26:21.000000000 +0100
++++ linux.dev/include/linux/netfilter_ipv4/ip_conntrack_tuple.h	2006-12-06 00:34:27.000000000 +0100
 @@ -14,7 +14,7 @@
  union ip_conntrack_manip_proto
  {
@@ -560,9 +560,9 @@ diff -urN linux-2.4.29-old/include/linux/netfilter_ipv4/ip_conntrack_tuple.h lin
  
  #define CTINFO2DIR(ctinfo) ((ctinfo) >= IP_CT_IS_REPLY ? IP_CT_DIR_REPLY : IP_CT_DIR_ORIGINAL)
  
-diff -urN linux-2.4.29-old/include/linux/netfilter_ipv4/ip_nat_pptp.h linux-2.4.29-dev/include/linux/netfilter_ipv4/ip_nat_pptp.h
---- linux-2.4.29-old/include/linux/netfilter_ipv4/ip_nat_pptp.h	1970-01-01 01:00:00.000000000 +0100
-+++ linux-2.4.29-dev/include/linux/netfilter_ipv4/ip_nat_pptp.h	2005-04-02 19:07:18.000000000 +0200
+diff -urN linux.old/include/linux/netfilter_ipv4/ip_nat_pptp.h linux.dev/include/linux/netfilter_ipv4/ip_nat_pptp.h
+--- linux.old/include/linux/netfilter_ipv4/ip_nat_pptp.h	1970-01-01 01:00:00.000000000 +0100
++++ linux.dev/include/linux/netfilter_ipv4/ip_nat_pptp.h	2006-12-06 00:34:27.000000000 +0100
 @@ -0,0 +1,11 @@
 +/* PPTP constants and structs */
 +#ifndef _NAT_PPTP_H
@@ -575,9 +575,9 @@ diff -urN linux-2.4.29-old/include/linux/netfilter_ipv4/ip_nat_pptp.h linux-2.4.
 +};
 +
 +#endif /* _NAT_PPTP_H */
-diff -urN linux-2.4.29-old/net/ipv4/netfilter/Config.in linux-2.4.29-dev/net/ipv4/netfilter/Config.in
---- linux-2.4.29-old/net/ipv4/netfilter/Config.in	2005-04-02 19:04:11.000000000 +0200
-+++ linux-2.4.29-dev/net/ipv4/netfilter/Config.in	2005-04-02 19:07:18.000000000 +0200
+diff -urN linux.old/net/ipv4/netfilter/Config.in linux.dev/net/ipv4/netfilter/Config.in
+--- linux.old/net/ipv4/netfilter/Config.in	2006-12-06 00:31:46.000000000 +0100
++++ linux.dev/net/ipv4/netfilter/Config.in	2006-12-06 00:34:27.000000000 +0100
 @@ -10,6 +10,8 @@
    dep_tristate '  Amanda protocol support' CONFIG_IP_NF_AMANDA $CONFIG_IP_NF_CONNTRACK
    dep_tristate '  TFTP protocol support' CONFIG_IP_NF_TFTP $CONFIG_IP_NF_CONNTRACK
@@ -587,7 +587,7 @@ diff -urN linux-2.4.29-old/net/ipv4/netfilter/Config.in linux-2.4.29-dev/net/ipv
  fi
  
  if [ "$CONFIG_EXPERIMENTAL" = "y" ]; then
-@@ -67,6 +69,20 @@
+@@ -64,6 +66,20 @@
        define_bool CONFIG_IP_NF_NAT_NEEDED y
        dep_tristate '    MASQUERADE target support' CONFIG_IP_NF_TARGET_MASQUERADE $CONFIG_IP_NF_NAT
        dep_tristate '    REDIRECT target support' CONFIG_IP_NF_TARGET_REDIRECT $CONFIG_IP_NF_NAT
@@ -608,10 +608,10 @@ diff -urN linux-2.4.29-old/net/ipv4/netfilter/Config.in linux-2.4.29-dev/net/ipv
        if [ "$CONFIG_IP_NF_AMANDA" = "m" ]; then
          define_tristate CONFIG_IP_NF_NAT_AMANDA m
        else
-diff -urN linux-2.4.29-old/net/ipv4/netfilter/ip_conntrack_core.c linux-2.4.29-dev/net/ipv4/netfilter/ip_conntrack_core.c
---- linux-2.4.29-old/net/ipv4/netfilter/ip_conntrack_core.c	2005-04-02 19:04:11.000000000 +0200
-+++ linux-2.4.29-dev/net/ipv4/netfilter/ip_conntrack_core.c	2005-04-02 19:07:18.000000000 +0200
-@@ -142,6 +142,8 @@
+diff -urN linux.old/net/ipv4/netfilter/ip_conntrack_core.c linux.dev/net/ipv4/netfilter/ip_conntrack_core.c
+--- linux.old/net/ipv4/netfilter/ip_conntrack_core.c	2006-12-06 00:31:46.000000000 +0100
++++ linux.dev/net/ipv4/netfilter/ip_conntrack_core.c	2006-12-06 00:34:27.000000000 +0100
+@@ -143,6 +143,8 @@
  	tuple->dst.ip = iph->daddr;
  	tuple->dst.protonum = iph->protocol;
  
@@ -620,7 +620,7 @@ diff -urN linux-2.4.29-old/net/ipv4/netfilter/ip_conntrack_core.c linux-2.4.29-d
  	ret = protocol->pkt_to_tuple((u_int32_t *)iph + iph->ihl,
  				     len - 4*iph->ihl,
  				     tuple);
-@@ -157,6 +159,8 @@
+@@ -158,6 +160,8 @@
  	inverse->dst.ip = orig->src.ip;
  	inverse->dst.protonum = orig->dst.protonum;
  
@@ -629,7 +629,7 @@ diff -urN linux-2.4.29-old/net/ipv4/netfilter/ip_conntrack_core.c linux-2.4.29-d
  	return protocol->invert_tuple(inverse, orig);
  }
  
-@@ -954,8 +958,8 @@
+@@ -970,8 +974,8 @@
  	 * so there is no need to use the tuple lock too */
  
  	DEBUGP("ip_conntrack_expect_related %p\n", related_to);
@@ -640,7 +640,7 @@ diff -urN linux-2.4.29-old/net/ipv4/netfilter/ip_conntrack_core.c linux-2.4.29-d
  
  	old = LIST_FIND(&ip_conntrack_expect_list, resent_expect,
  		        struct ip_conntrack_expect *, &expect->tuple, 
-@@ -1072,15 +1076,14 @@
+@@ -1089,15 +1093,14 @@
  
  	MUST_BE_READ_LOCKED(&ip_conntrack_lock);
  	WRITE_LOCK(&ip_conntrack_expect_tuple_lock);
@@ -660,9 +660,646 @@ diff -urN linux-2.4.29-old/net/ipv4/netfilter/ip_conntrack_core.c linux-2.4.29-d
  		    && LIST_FIND(&ip_conntrack_expect_list, expect_clash,
  			         struct ip_conntrack_expect *, newtuple, &expect->mask)) {
  			/* Force NAT to find an unused tuple */
-diff -urN linux-2.4.29-old/net/ipv4/netfilter/ip_conntrack_pptp_priv.h linux-2.4.29-dev/net/ipv4/netfilter/ip_conntrack_pptp_priv.h
---- linux-2.4.29-old/net/ipv4/netfilter/ip_conntrack_pptp_priv.h	1970-01-01 01:00:00.000000000 +0100
-+++ linux-2.4.29-dev/net/ipv4/netfilter/ip_conntrack_pptp_priv.h	2005-04-02 19:14:10.000000000 +0200
+diff -urN linux.old/net/ipv4/netfilter/ip_conntrack_pptp.c linux.dev/net/ipv4/netfilter/ip_conntrack_pptp.c
+--- linux.old/net/ipv4/netfilter/ip_conntrack_pptp.c	1970-01-01 01:00:00.000000000 +0100
++++ linux.dev/net/ipv4/netfilter/ip_conntrack_pptp.c	2006-12-06 00:34:27.000000000 +0100
+@@ -0,0 +1,633 @@
++/*
++ * ip_conntrack_pptp.c	- Version 1.9
++ *
++ * Connection tracking support for PPTP (Point to Point Tunneling Protocol).
++ * PPTP is a a protocol for creating virtual private networks.
++ * It is a specification defined by Microsoft and some vendors
++ * working with Microsoft.  PPTP is built on top of a modified
++ * version of the Internet Generic Routing Encapsulation Protocol.
++ * GRE is defined in RFC 1701 and RFC 1702.  Documentation of
++ * PPTP can be found in RFC 2637
++ *
++ * (C) 2000-2003 by Harald Welte <laforge@gnumonks.org>
++ *
++ * Development of this code funded by Astaro AG (http://www.astaro.com/)
++ *
++ * Limitations:
++ * 	 - We blindly assume that control connections are always
++ * 	   established in PNS->PAC direction.  This is a violation
++ * 	   of RFFC2673
++ *
++ * TODO: - finish support for multiple calls within one session
++ * 	   (needs expect reservations in newnat)
++ *	 - testing of incoming PPTP calls 
++ *
++ * Changes: 
++ * 	2002-02-05 - Version 1.3
++ * 	  - Call ip_conntrack_unexpect_related() from 
++ * 	    pptp_timeout_related() to destroy expectations in case
++ * 	    CALL_DISCONNECT_NOTIFY or tcp fin packet was seen
++ * 	    (Philip Craig <philipc@snapgear.com>)
++ * 	  - Add Version information at module loadtime
++ * 	2002-02-10 - Version 1.6
++ * 	  - move to C99 style initializers
++ * 	  - remove second expectation if first arrives
++ *
++ */
++
++#include <linux/config.h>
++#include <linux/module.h>
++#include <linux/netfilter.h>
++#include <linux/ip.h>
++#include <net/checksum.h>
++#include <net/tcp.h>
++
++#include <linux/netfilter_ipv4/lockhelp.h>
++#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
++#include <linux/netfilter_ipv4/ip_conntrack_proto_gre.h>
++#include <linux/netfilter_ipv4/ip_conntrack_pptp.h>
++
++#define IP_CT_PPTP_VERSION "1.9"
++
++MODULE_LICENSE("GPL");
++MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");
++MODULE_DESCRIPTION("Netfilter connection tracking helper module for PPTP");
++
++DECLARE_LOCK(ip_pptp_lock);
++
++#if 0
++#include "ip_conntrack_pptp_priv.h"
++#define DEBUGP(format, args...)	printk(KERN_DEBUG __FILE__ ":" __FUNCTION__ \
++					": " format, ## args)
++#else
++#define DEBUGP(format, args...)
++#endif
++
++#define SECS *HZ
++#define MINS * 60 SECS
++#define HOURS * 60 MINS
++#define DAYS * 24 HOURS
++
++#define PPTP_GRE_TIMEOUT 		(10 MINS)
++#define PPTP_GRE_STREAM_TIMEOUT 	(5 DAYS)
++
++static int pptp_expectfn(struct ip_conntrack *ct)
++{
++	struct ip_conntrack *master;
++	struct ip_conntrack_expect *exp;
++
++	DEBUGP("increasing timeouts\n");
++	/* increase timeout of GRE data channel conntrack entry */
++	ct->proto.gre.timeout = PPTP_GRE_TIMEOUT;
++	ct->proto.gre.stream_timeout = PPTP_GRE_STREAM_TIMEOUT;
++
++	master = master_ct(ct);
++	if (!master) {
++		DEBUGP(" no master!!!\n");
++		return 0;
++	}
++
++	exp = ct->master;
++	if (!exp) {
++		DEBUGP("no expectation!!\n");
++		return 0;
++	}
++
++	DEBUGP("completing tuples with ct info\n");
++	/* we can do this, since we're unconfirmed */
++	if (ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u.gre.key == 
++		htonl(master->help.ct_pptp_info.pac_call_id)) {	
++		/* assume PNS->PAC */
++		ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.gre.key = 
++			htonl(master->help.ct_pptp_info.pns_call_id);
++		ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.gre.key =
++			htonl(master->help.ct_pptp_info.pns_call_id);
++	} else {
++		/* assume PAC->PNS */
++		ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.gre.key =
++			htonl(master->help.ct_pptp_info.pac_call_id);
++		ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.gre.key =
++			htonl(master->help.ct_pptp_info.pac_call_id);
++	}
++	
++	/* delete other expectation */
++	if (exp->expected_list.next != &exp->expected_list) {
++		struct ip_conntrack_expect *other_exp;
++		struct list_head *cur_item, *next;
++
++		for (cur_item = master->sibling_list.next;
++		     cur_item != &master->sibling_list; cur_item = next) {
++			next = cur_item->next;
++			other_exp = list_entry(cur_item,
++					       struct ip_conntrack_expect,
++					       expected_list);
++			/* remove only if occurred at same sequence number */
++			if (other_exp != exp && other_exp->seq == exp->seq) {
++				DEBUGP("unexpecting other direction\n");
++				ip_ct_gre_keymap_destroy(other_exp);
++				ip_conntrack_unexpect_related(other_exp);
++			}
++		}
++	}
++
++	return 0;
++}
++
++/* timeout GRE data connections */
++static int pptp_timeout_related(struct ip_conntrack *ct)
++{
++	struct list_head *cur_item, *next;
++	struct ip_conntrack_expect *exp;
++
++	/* FIXME: do we have to lock something ? */
++	for (cur_item = ct->sibling_list.next;
++	    cur_item != &ct->sibling_list; cur_item = next) {
++		next = cur_item->next;
++		exp = list_entry(cur_item, struct ip_conntrack_expect,
++				 expected_list);
++
++		ip_ct_gre_keymap_destroy(exp);
++		if (!exp->sibling) {
++			ip_conntrack_unexpect_related(exp);
++			continue;
++		}
++
++		DEBUGP("setting timeout of conntrack %p to 0\n",
++			exp->sibling);
++		exp->sibling->proto.gre.timeout = 0;
++		exp->sibling->proto.gre.stream_timeout = 0;
++		ip_ct_refresh(exp->sibling, 0);
++	}
++
++	return 0;
++}
++
++/* expect GRE connections (PNS->PAC and PAC->PNS direction) */
++static inline int
++exp_gre(struct ip_conntrack *master,
++	u_int32_t seq,
++	u_int16_t callid,
++	u_int16_t peer_callid)
++{
++	struct ip_conntrack_expect exp;
++	struct ip_conntrack_tuple inv_tuple;
++
++	memset(&exp, 0, sizeof(exp));
++	/* tuple in original direction, PNS->PAC */
++	exp.tuple.src.ip = master->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
++	exp.tuple.src.u.gre.key = htonl(ntohs(peer_callid));
++	exp.tuple.dst.ip = master->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip;
++	exp.tuple.dst.u.gre.key = htonl(ntohs(callid));
++	exp.tuple.dst.protonum = IPPROTO_GRE;
++
++	exp.mask.src.ip = 0xffffffff;
++	exp.mask.src.u.all = 0;
++	exp.mask.dst.u.all = 0;
++	exp.mask.dst.u.gre.key = 0xffffffff;
++	exp.mask.dst.ip = 0xffffffff;
++	exp.mask.dst.protonum = 0xffff;
++			
++	exp.seq = seq;
++	exp.expectfn = pptp_expectfn;
++
++	exp.help.exp_pptp_info.pac_call_id = ntohs(callid);
++	exp.help.exp_pptp_info.pns_call_id = ntohs(peer_callid);
++
++	DEBUGP("calling expect_related ");
++	DUMP_TUPLE_RAW(&exp.tuple);
++	
++	/* Add GRE keymap entries */
++	if (ip_ct_gre_keymap_add(&exp, &exp.tuple, 0) != 0)
++		return 1;
++
++	invert_tuplepr(&inv_tuple, &exp.tuple);
++	if (ip_ct_gre_keymap_add(&exp, &inv_tuple, 1) != 0) {
++		ip_ct_gre_keymap_destroy(&exp);
++		return 1;
++	}
++	
++	if (ip_conntrack_expect_related(master, &exp) != 0) {
++		ip_ct_gre_keymap_destroy(&exp);
++		DEBUGP("cannot expect_related()\n");
++		return 1;
++	}
++
++	/* tuple in reply direction, PAC->PNS */
++	exp.tuple.src.ip = master->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip;
++	exp.tuple.src.u.gre.key = htonl(ntohs(callid));
++	exp.tuple.dst.ip = master->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip;
++	exp.tuple.dst.u.gre.key = htonl(ntohs(peer_callid));
++
++	DEBUGP("calling expect_related ");
++	DUMP_TUPLE_RAW(&exp.tuple);
++	
++	/* Add GRE keymap entries */
++	ip_ct_gre_keymap_add(&exp, &exp.tuple, 0);
++	invert_tuplepr(&inv_tuple, &exp.tuple);
++	ip_ct_gre_keymap_add(&exp, &inv_tuple, 1);
++	/* FIXME: cannot handle error correctly, since we need to free
++	 * the above keymap :( */
++	
++	if (ip_conntrack_expect_related(master, &exp) != 0) {
++		/* free the second pair of keypmaps */
++		ip_ct_gre_keymap_destroy(&exp);
++		DEBUGP("cannot expect_related():\n");
++		return 1;
++	}
++
++	return 0;
++}
++
++static inline int 
++pptp_inbound_pkt(struct tcphdr *tcph,
++		 struct pptp_pkt_hdr *pptph, 
++		 size_t datalen,
++		 struct ip_conntrack *ct,
++		 enum ip_conntrack_info ctinfo)
++{
++	struct PptpControlHeader *ctlh;
++        union pptp_ctrl_union pptpReq;
++	
++	struct ip_ct_pptp_master *info = &ct->help.ct_pptp_info;
++	u_int16_t msg, *cid, *pcid;
++	u_int32_t seq;	
++
++	ctlh = (struct PptpControlHeader *) 
++		((char *) pptph + sizeof(struct pptp_pkt_hdr));
++	pptpReq.rawreq = (void *) 
++		((char *) ctlh + sizeof(struct PptpControlHeader));
++
++	msg = ntohs(ctlh->messageType);
++	DEBUGP("inbound control message %s\n", strMName[msg]);
++
++	switch (msg) {
++	case PPTP_START_SESSION_REPLY:
++		/* server confirms new control session */
++		if (info->sstate < PPTP_SESSION_REQUESTED) {
++			DEBUGP("%s without START_SESS_REQUEST\n",
++				strMName[msg]);
++			break;
++		}
++		if (pptpReq.srep->resultCode == PPTP_START_OK)
++			info->sstate = PPTP_SESSION_CONFIRMED;
++		else 
++			info->sstate = PPTP_SESSION_ERROR;
++		break;
++
++	case PPTP_STOP_SESSION_REPLY:
++		/* server confirms end of control session */
++		if (info->sstate > PPTP_SESSION_STOPREQ) {
++			DEBUGP("%s without STOP_SESS_REQUEST\n",
++				strMName[msg]);
++			break;
++		}
++		if (pptpReq.strep->resultCode == PPTP_STOP_OK)
++			info->sstate = PPTP_SESSION_NONE;
++		else
++			info->sstate = PPTP_SESSION_ERROR;
++		break;
++
++	case PPTP_OUT_CALL_REPLY:
++		/* server accepted call, we now expect GRE frames */
++		if (info->sstate != PPTP_SESSION_CONFIRMED) {
++			DEBUGP("%s but no session\n", strMName[msg]);
++			break;
++		}
++		if (info->cstate != PPTP_CALL_OUT_REQ &&
++		    info->cstate != PPTP_CALL_OUT_CONF) {
++			DEBUGP("%s without OUTCALL_REQ\n", strMName[msg]);
++			break;
++		}
++		if (pptpReq.ocack->resultCode != PPTP_OUTCALL_CONNECT) {
++			info->cstate = PPTP_CALL_NONE;
++			break;
++		}
++
++		cid = &pptpReq.ocack->callID;
++		pcid = &pptpReq.ocack->peersCallID;
++
++		info->pac_call_id = ntohs(*cid);
++		
++		if (htons(info->pns_call_id) != *pcid) {
++			DEBUGP("%s for unknown callid %u\n",
++				strMName[msg], ntohs(*pcid));
++			break;
++		}
++
++		DEBUGP("%s, CID=%X, PCID=%X\n", strMName[msg], 
++			ntohs(*cid), ntohs(*pcid));
++		
++		info->cstate = PPTP_CALL_OUT_CONF;
++
++		seq = ntohl(tcph->seq) + ((void *)pcid - (void *)pptph);
++		if (exp_gre(ct, seq, *cid, *pcid) != 0)
++			printk("ip_conntrack_pptp: error during exp_gre\n");
++		break;
++
++	case PPTP_IN_CALL_REQUEST:
++		/* server tells us about incoming call request */
++		if (info->sstate != PPTP_SESSION_CONFIRMED) {
++			DEBUGP("%s but no session\n", strMName[msg]);
++			break;
++		}
++		pcid = &pptpReq.icack->peersCallID;
++		DEBUGP("%s, PCID=%X\n", strMName[msg], ntohs(*pcid));
++		info->cstate = PPTP_CALL_IN_REQ;
++		info->pac_call_id= ntohs(*pcid);
++		break;
++
++	case PPTP_IN_CALL_CONNECT:
++		/* server tells us about incoming call established */
++		if (info->sstate != PPTP_SESSION_CONFIRMED) {
++			DEBUGP("%s but no session\n", strMName[msg]);
++			break;
++		}
++		if (info->sstate != PPTP_CALL_IN_REP
++		    && info->sstate != PPTP_CALL_IN_CONF) {
++			DEBUGP("%s but never sent IN_CALL_REPLY\n",
++				strMName[msg]);
++			break;
++		}
++
++		pcid = &pptpReq.iccon->peersCallID;
++		cid = &info->pac_call_id;
++
++		if (info->pns_call_id != ntohs(*pcid)) {
++			DEBUGP("%s for unknown CallID %u\n", 
++				strMName[msg], ntohs(*cid));
++			break;
++		}
++
++		DEBUGP("%s, PCID=%X\n", strMName[msg], ntohs(*pcid));
++		info->cstate = PPTP_CALL_IN_CONF;
++
++		/* we expect a GRE connection from PAC to PNS */
++		seq = ntohl(tcph->seq) + ((void *)pcid - (void *)pptph);
++		if (exp_gre(ct, seq, *cid, *pcid) != 0)
++			printk("ip_conntrack_pptp: error during exp_gre\n");
++
++		break;
++
++	case PPTP_CALL_DISCONNECT_NOTIFY:
++		/* server confirms disconnect */
++		cid = &pptpReq.disc->callID;
++		DEBUGP("%s, CID=%X\n", strMName[msg], ntohs(*cid));
++		info->cstate = PPTP_CALL_NONE;
++
++		/* untrack this call id, unexpect GRE packets */
++		pptp_timeout_related(ct);
++		break;
++
++	case PPTP_WAN_ERROR_NOTIFY:
++		break;
++
++	case PPTP_ECHO_REQUEST:
++	case PPTP_ECHO_REPLY:
++		/* I don't have to explain these ;) */
++		break;
++	default:
++		DEBUGP("invalid %s (TY=%d)\n", (msg <= PPTP_MSG_MAX)
++			? strMName[msg]:strMName[0], msg);
++		break;
++	}
++
++	return NF_ACCEPT;
++
++}
++
++static inline int
++pptp_outbound_pkt(struct tcphdr *tcph,
++		  struct pptp_pkt_hdr *pptph,
++		  size_t datalen,
++		  struct ip_conntrack *ct,
++		  enum ip_conntrack_info ctinfo)
++{
++	struct PptpControlHeader *ctlh;
++        union pptp_ctrl_union pptpReq;
++	struct ip_ct_pptp_master *info = &ct->help.ct_pptp_info;
++	u_int16_t msg, *cid, *pcid;
++
++	ctlh = (struct PptpControlHeader *) ((void *) pptph + sizeof(*pptph));
++	pptpReq.rawreq = (void *) ((void *) ctlh + sizeof(*ctlh));
++
++	msg = ntohs(ctlh->messageType);
++	DEBUGP("outbound control message %s\n", strMName[msg]);
++
++	switch (msg) {
++	case PPTP_START_SESSION_REQUEST:
++		/* client requests for new control session */
++		if (info->sstate != PPTP_SESSION_NONE) {
++			DEBUGP("%s but we already have one",
++				strMName[msg]);
++		}
++		info->sstate = PPTP_SESSION_REQUESTED;
++		break;
++	case PPTP_STOP_SESSION_REQUEST:
++		/* client requests end of control session */
++		info->sstate = PPTP_SESSION_STOPREQ;
++		break;
++
++	case PPTP_OUT_CALL_REQUEST:
++		/* client initiating connection to server */
++		if (info->sstate != PPTP_SESSION_CONFIRMED) {
++			DEBUGP("%s but no session\n",
++				strMName[msg]);
++			break;
++		}
++		info->cstate = PPTP_CALL_OUT_REQ;
++		/* track PNS call id */
++		cid = &pptpReq.ocreq->callID;
++		DEBUGP("%s, CID=%X\n", strMName[msg], ntohs(*cid));
++		info->pns_call_id = ntohs(*cid);
++		break;
++	case PPTP_IN_CALL_REPLY:
++		/* client answers incoming call */
++		if (info->cstate != PPTP_CALL_IN_REQ
++		    && info->cstate != PPTP_CALL_IN_REP) {
++			DEBUGP("%s without incall_req\n", 
++				strMName[msg]);
++			break;
++		}
++		if (pptpReq.icack->resultCode != PPTP_INCALL_ACCEPT) {
++			info->cstate = PPTP_CALL_NONE;
++			break;
++		}
++		pcid = &pptpReq.icack->peersCallID;
++		if (info->pac_call_id != ntohs(*pcid)) {
++			DEBUGP("%s for unknown call %u\n", 
++				strMName[msg], ntohs(*pcid));
++			break;
++		}
++		DEBUGP("%s, CID=%X\n", strMName[msg], ntohs(*pcid));
++		/* part two of the three-way handshake */
++		info->cstate = PPTP_CALL_IN_REP;
++		info->pns_call_id = ntohs(pptpReq.icack->callID);
++		break;
++
++	case PPTP_CALL_CLEAR_REQUEST:
++		/* client requests hangup of call */
++		if (info->sstate != PPTP_SESSION_CONFIRMED) {
++			DEBUGP("CLEAR_CALL but no session\n");
++			break;
++		}
++		/* FUTURE: iterate over all calls and check if
++		 * call ID is valid.  We don't do this without newnat,
++		 * because we only know about last call */
++		info->cstate = PPTP_CALL_CLEAR_REQ;
++		break;
++	case PPTP_SET_LINK_INFO:
++		break;
++	case PPTP_ECHO_REQUEST:
++	case PPTP_ECHO_REPLY:
++		/* I don't have to explain these ;) */
++		break;
++	default:
++		DEBUGP("invalid %s (TY=%d)\n", (msg <= PPTP_MSG_MAX)? 
++			strMName[msg]:strMName[0], msg);
++		/* unknown: no need to create GRE masq table entry */
++		break;
++	}
++
++	return NF_ACCEPT;
++}
++
++
++/* track caller id inside control connection, call expect_related */
++static int 
++conntrack_pptp_help(const struct iphdr *iph, size_t len,
++		    struct ip_conntrack *ct, enum ip_conntrack_info ctinfo)
++
++{
++	struct pptp_pkt_hdr *pptph;
++	
++	struct tcphdr *tcph = (void *) iph + iph->ihl * 4;
++	u_int32_t tcplen = len - iph->ihl * 4;
++	u_int32_t datalen = tcplen - tcph->doff * 4;
++	void *datalimit;
++	int dir = CTINFO2DIR(ctinfo);
++	struct ip_ct_pptp_master *info = &ct->help.ct_pptp_info;
++
++	int oldsstate, oldcstate;
++	int ret;
++
++	/* don't do any tracking before tcp handshake complete */
++	if (ctinfo != IP_CT_ESTABLISHED 
++	    && ctinfo != IP_CT_ESTABLISHED+IP_CT_IS_REPLY) {
++		DEBUGP("ctinfo = %u, skipping\n", ctinfo);
++		return NF_ACCEPT;
++	}
++	
++	/* not a complete TCP header? */
++	if (tcplen < sizeof(struct tcphdr) || tcplen < tcph->doff * 4) {
++		DEBUGP("tcplen = %u\n", tcplen);
++		return NF_ACCEPT;
++	}
++
++	/* checksum invalid? */
++	if (tcp_v4_check(tcph, tcplen, iph->saddr, iph->daddr,
++			csum_partial((char *) tcph, tcplen, 0))) {
++		printk(KERN_NOTICE __FILE__ ": bad csum\n");
++		/* W2K PPTP server sends TCP packets with wrong checksum :(( */
++		//return NF_ACCEPT;
++	}
++
++	if (tcph->fin || tcph->rst) {
++		DEBUGP("RST/FIN received, timeouting GRE\n");
++		/* can't do this after real newnat */
++		info->cstate = PPTP_CALL_NONE;
++
++		/* untrack this call id, unexpect GRE packets */
++		pptp_timeout_related(ct);
++	}
++
++
++	pptph = (struct pptp_pkt_hdr *) ((void *) tcph + tcph->doff * 4);
++	datalimit = (void *) pptph + datalen;
++
++	/* not a full pptp packet header? */
++	if ((void *) pptph+sizeof(*pptph) >= datalimit) {
++		DEBUGP("no full PPTP header, can't track\n");
++		return NF_ACCEPT;
++	}
++	
++	/* if it's not a control message we can't do anything with it */
++        if (ntohs(pptph->packetType) != PPTP_PACKET_CONTROL ||
++	    ntohl(pptph->magicCookie) != PPTP_MAGIC_COOKIE) {
++		DEBUGP("not a control packet\n");
++		return NF_ACCEPT;
++	}
++
++	oldsstate = info->sstate;
++	oldcstate = info->cstate;
++
++	LOCK_BH(&ip_pptp_lock);
++
++	/* FIXME: We just blindly assume that the control connection is always
++	 * established from PNS->PAC.  However, RFC makes no guarantee */
++	if (dir == IP_CT_DIR_ORIGINAL)
++		/* client -> server (PNS -> PAC) */
++		ret = pptp_outbound_pkt(tcph, pptph, datalen, ct, ctinfo);
++	else
++		/* server -> client (PAC -> PNS) */
++		ret = pptp_inbound_pkt(tcph, pptph, datalen, ct, ctinfo);
++	DEBUGP("sstate: %d->%d, cstate: %d->%d\n",
++		oldsstate, info->sstate, oldcstate, info->cstate);
++	UNLOCK_BH(&ip_pptp_lock);
++
++	return ret;
++}
++
++/* control protocol helper */
++static struct ip_conntrack_helper pptp = { 
++	.list = { NULL, NULL },
++	.name = "pptp", 
++	.flags = IP_CT_HELPER_F_REUSE_EXPECT,
++	.me = THIS_MODULE,
++	.max_expected = 2,
++	.timeout = 0,
++	.tuple = { .src = { .ip = 0, 
++		 	    .u = { .tcp = { .port =  
++				    __constant_htons(PPTP_CONTROL_PORT) } } 
++			  }, 
++		   .dst = { .ip = 0, 
++			    .u = { .all = 0 },
++			    .protonum = IPPROTO_TCP
++			  } 
++		 },
++	.mask = { .src = { .ip = 0, 
++			   .u = { .tcp = { .port = 0xffff } } 
++			 }, 
++		  .dst = { .ip = 0, 
++			   .u = { .all = 0 },
++			   .protonum = 0xffff 
++		 	 } 
++		},
++	.help = conntrack_pptp_help
++};
++
++/* ip_conntrack_pptp initialization */
++static int __init init(void)
++{
++	int retcode;
++
++	DEBUGP(__FILE__ ": registering helper\n");
++	if ((retcode = ip_conntrack_helper_register(&pptp))) {
++                printk(KERN_ERR "Unable to register conntrack application "
++				"helper for pptp: %d\n", retcode);
++		return -EIO;
++	}
++
++	printk("ip_conntrack_pptp version %s loaded\n", IP_CT_PPTP_VERSION);
++	return 0;
++}
++
++static void __exit fini(void)
++{
++	ip_conntrack_helper_unregister(&pptp);
++	printk("ip_conntrack_pptp version %s unloaded\n", IP_CT_PPTP_VERSION);
++}
++
++module_init(init);
++module_exit(fini);
++
++EXPORT_SYMBOL(ip_pptp_lock);
+diff -urN linux.old/net/ipv4/netfilter/ip_conntrack_pptp_priv.h linux.dev/net/ipv4/netfilter/ip_conntrack_pptp_priv.h
+--- linux.old/net/ipv4/netfilter/ip_conntrack_pptp_priv.h	1970-01-01 01:00:00.000000000 +0100
++++ linux.dev/net/ipv4/netfilter/ip_conntrack_pptp_priv.h	2006-12-06 00:34:27.000000000 +0100
 @@ -0,0 +1,24 @@
 +#ifndef _IP_CT_PPTP_PRIV_H
 +#define _IP_CT_PPTP_PRIV_H
@@ -688,9 +1325,9 @@ diff -urN linux-2.4.29-old/net/ipv4/netfilter/ip_conntrack_pptp_priv.h linux-2.4
 +};
 +
 +#endif
-diff -urN linux-2.4.29-old/net/ipv4/netfilter/ip_conntrack_proto_gre.c linux-2.4.29-dev/net/ipv4/netfilter/ip_conntrack_proto_gre.c
---- linux-2.4.29-old/net/ipv4/netfilter/ip_conntrack_proto_gre.c	1970-01-01 01:00:00.000000000 +0100
-+++ linux-2.4.29-dev/net/ipv4/netfilter/ip_conntrack_proto_gre.c	2005-04-02 19:14:31.000000000 +0200
+diff -urN linux.old/net/ipv4/netfilter/ip_conntrack_proto_gre.c linux.dev/net/ipv4/netfilter/ip_conntrack_proto_gre.c
+--- linux.old/net/ipv4/netfilter/ip_conntrack_proto_gre.c	1970-01-01 01:00:00.000000000 +0100
++++ linux.dev/net/ipv4/netfilter/ip_conntrack_proto_gre.c	2006-12-06 00:34:27.000000000 +0100
 @@ -0,0 +1,333 @@
 +/*
 + * ip_conntrack_proto_gre.c - Version 1.2 
@@ -936,11 +1573,11 @@ diff -urN linux-2.4.29-old/net/ipv4/netfilter/ip_conntrack_proto_gre.c linux-2.4
 +	/* If we've seen traffic both ways, this is a GRE connection.
 +	 * Extend timeout. */
 +	if (ct->status & IPS_SEEN_REPLY) {
-+		ip_ct_refresh_acct(ct, ct->proto.gre.stream_timeout);
++		ip_ct_refresh(ct, ct->proto.gre.stream_timeout);
 +		/* Also, more likely to be important, and not a probe. */
 +		set_bit(IPS_ASSURED_BIT, &ct->status);
 +	} else
-+		ip_ct_refresh_acct(ct, ct->proto.gre.timeout);
++		ip_ct_refresh(ct, ct->proto.gre.timeout);
 +	
 +	return NF_ACCEPT;
 +}
@@ -1025,9 +1662,9 @@ diff -urN linux-2.4.29-old/net/ipv4/netfilter/ip_conntrack_proto_gre.c linux-2.4
 +
 +module_init(init);
 +module_exit(fini);
-diff -urN linux-2.4.29-old/net/ipv4/netfilter/ip_nat_core.c linux-2.4.29-dev/net/ipv4/netfilter/ip_nat_core.c
---- linux-2.4.29-old/net/ipv4/netfilter/ip_nat_core.c	2005-01-19 15:10:13.000000000 +0100
-+++ linux-2.4.29-dev/net/ipv4/netfilter/ip_nat_core.c	2005-04-02 19:07:18.000000000 +0200
+diff -urN linux.old/net/ipv4/netfilter/ip_nat_core.c linux.dev/net/ipv4/netfilter/ip_nat_core.c
+--- linux.old/net/ipv4/netfilter/ip_nat_core.c	2005-04-04 03:42:20.000000000 +0200
++++ linux.dev/net/ipv4/netfilter/ip_nat_core.c	2006-12-06 00:34:27.000000000 +0100
 @@ -424,7 +424,7 @@
  	*tuple = *orig_tuple;
  	while ((rptr = find_best_ips_proto_fast(tuple, mr, conntrack, hooknum))
@@ -1049,10 +1686,10 @@ diff -urN linux-2.4.29-old/net/ipv4/netfilter/ip_nat_core.c linux-2.4.29-dev/net
  #endif
  
  		/* We now have two tuples (SRCIP/SRCPT/DSTIP/DSTPT):
-diff -urN linux-2.4.29-old/net/ipv4/netfilter/ip_nat_pptp.c linux-2.4.29-dev/net/ipv4/netfilter/ip_nat_pptp.c
---- linux-2.4.29-old/net/ipv4/netfilter/ip_nat_pptp.c	1970-01-01 01:00:00.000000000 +0100
-+++ linux-2.4.29-dev/net/ipv4/netfilter/ip_nat_pptp.c	2005-04-02 19:14:52.000000000 +0200
-@@ -0,0 +1,475 @@
+diff -urN linux.old/net/ipv4/netfilter/ip_nat_pptp.c linux.dev/net/ipv4/netfilter/ip_nat_pptp.c
+--- linux.old/net/ipv4/netfilter/ip_nat_pptp.c	1970-01-01 01:00:00.000000000 +0100
++++ linux.dev/net/ipv4/netfilter/ip_nat_pptp.c	2006-12-06 00:34:38.000000000 +0100
+@@ -0,0 +1,482 @@
 +/*
 + * ip_nat_pptp.c	- Version 1.5
 + *
@@ -1341,8 +1978,12 @@ diff -urN linux-2.4.29-old/net/ipv4/netfilter/ip_nat_pptp.c linux-2.4.29-dev/net
 +		} else {
 +			DEBUGP("can't change expect\n");
 +		}
-+		ip_ct_gre_keymap_change(oldexp->proto.gre.keymap_orig, &t);
-+		ip_ct_gre_keymap_change(oldexp->proto.gre.keymap_reply, &inv_t);
++		if (oldexp->proto.gre.keymap_orig)
++			ip_ct_gre_keymap_change(oldexp->proto.gre.keymap_orig, 
++						&t);
++		if (oldexp->proto.gre.keymap_reply)
++			ip_ct_gre_keymap_change(oldexp->proto.gre.keymap_reply, 
++						&inv_t);
 +		break;
 +	case PPTP_IN_CALL_CONNECT:
 +		pcid = &pptpReq.iccon->peersCallID;
@@ -1375,6 +2016,9 @@ diff -urN linux-2.4.29-old/net/ipv4/netfilter/ip_nat_pptp.c linux-2.4.29-dev/net
 +	case PPTP_CALL_DISCONNECT_NOTIFY:
 +		pcid = &pptpReq.disc->callID;
 +		break;
++	case PPTP_SET_LINK_INFO:
++		pcid = &pptpReq.setlink->peersCallID;
++		break;
 +
 +	default:
 +		DEBUGP("unknown inbound packet %s\n",
@@ -1528,9 +2172,9 @@ diff -urN linux-2.4.29-old/net/ipv4/netfilter/ip_nat_pptp.c linux-2.4.29-dev/net
 +
 +module_init(init);
 +module_exit(fini);
-diff -urN linux-2.4.29-old/net/ipv4/netfilter/ip_nat_proto_gre.c linux-2.4.29-dev/net/ipv4/netfilter/ip_nat_proto_gre.c
---- linux-2.4.29-old/net/ipv4/netfilter/ip_nat_proto_gre.c	1970-01-01 01:00:00.000000000 +0100
-+++ linux-2.4.29-dev/net/ipv4/netfilter/ip_nat_proto_gre.c	2005-04-02 19:15:10.000000000 +0200
+diff -urN linux.old/net/ipv4/netfilter/ip_nat_proto_gre.c linux.dev/net/ipv4/netfilter/ip_nat_proto_gre.c
+--- linux.old/net/ipv4/netfilter/ip_nat_proto_gre.c	1970-01-01 01:00:00.000000000 +0100
++++ linux.dev/net/ipv4/netfilter/ip_nat_proto_gre.c	2006-12-06 00:34:27.000000000 +0100
 @@ -0,0 +1,202 @@
 +/*
 + * ip_nat_proto_gre.c - Version 1.2
@@ -1734,9 +2378,9 @@ diff -urN linux-2.4.29-old/net/ipv4/netfilter/ip_nat_proto_gre.c linux-2.4.29-de
 +
 +module_init(init);
 +module_exit(fini);
-diff -urN linux-2.4.29-old/net/ipv4/netfilter/Makefile linux-2.4.29-dev/net/ipv4/netfilter/Makefile
---- linux-2.4.29-old/net/ipv4/netfilter/Makefile	2005-04-02 19:04:11.000000000 +0200
-+++ linux-2.4.29-dev/net/ipv4/netfilter/Makefile	2005-04-02 19:07:18.000000000 +0200
+diff -urN linux.old/net/ipv4/netfilter/Makefile linux.dev/net/ipv4/netfilter/Makefile
+--- linux.old/net/ipv4/netfilter/Makefile	2006-12-06 00:31:46.000000000 +0100
++++ linux.dev/net/ipv4/netfilter/Makefile	2006-12-06 00:34:27.000000000 +0100
 @@ -36,23 +36,32 @@
  ifdef CONFIG_IP_NF_AMANDA
  	export-objs += ip_conntrack_amanda.o
@@ -1772,641 +2416,3 @@ diff -urN linux-2.4.29-old/net/ipv4/netfilter/Makefile linux-2.4.29-dev/net/ipv4
  
  # generic IP tables 
  obj-$(CONFIG_IP_NF_IPTABLES) += ip_tables.o
---- linux-2.4.32/net/ipv4/netfilter/ip_conntrack_pptp.c	1970-01-01 01:00:00.000000000 +0100
-+++ /home/florian//openwrt/trunk/openwrt/build_mipsel/linux/net/ipv4/netfilter/ip_conntrack_pptp.c	2006-02-04 18:23:27.000000000 +0100
-@@ -0,0 +1,635 @@
-+/*
-+ * ip_conntrack_pptp.c	- Version 1.9
-+ *
-+ * Connection tracking support for PPTP (Point to Point Tunneling Protocol).
-+ * PPTP is a a protocol for creating virtual private networks.
-+ * It is a specification defined by Microsoft and some vendors
-+ * working with Microsoft.  PPTP is built on top of a modified
-+ * version of the Internet Generic Routing Encapsulation Protocol.
-+ * GRE is defined in RFC 1701 and RFC 1702.  Documentation of
-+ * PPTP can be found in RFC 2637
-+ *
-+ * (C) 2000-2003 by Harald Welte <laforge@gnumonks.org>
-+ *
-+ * Development of this code funded by Astaro AG (http://www.astaro.com/)
-+ *
-+ * Limitations:
-+ * 	 - We blindly assume that control connections are always
-+ * 	   established in PNS->PAC direction.  This is a violation
-+ * 	   of RFFC2673
-+ *
-+ * TODO: - finish support for multiple calls within one session
-+ * 	   (needs expect reservations in newnat)
-+ *	 - testing of incoming PPTP calls 
-+ *
-+ * Changes: 
-+ * 	2002-02-05 - Version 1.3
-+ * 	  - Call ip_conntrack_unexpect_related() from 
-+ * 	    pptp_timeout_related() to destroy expectations in case
-+ * 	    CALL_DISCONNECT_NOTIFY or tcp fin packet was seen
-+ * 	    (Philip Craig <philipc@snapgear.com>)
-+ * 	  - Add Version information at module loadtime
-+ * 	2002-02-10 - Version 1.6
-+ * 	  - move to C99 style initializers
-+ * 	  - remove second expectation if first arrives
-+ *
-+ */
-+
-+#include <linux/config.h>
-+#include <linux/module.h>
-+#include <linux/netfilter.h>
-+#include <linux/ip.h>
-+#include <net/checksum.h>
-+#include <net/tcp.h>
-+
-+#include <linux/netfilter_ipv4/lockhelp.h>
-+#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
-+#include <linux/netfilter_ipv4/ip_conntrack_proto_gre.h>
-+#include <linux/netfilter_ipv4/ip_conntrack_pptp.h>
-+
-+#define IP_CT_PPTP_VERSION "1.9"
-+
-+MODULE_LICENSE("GPL");
-+MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");
-+MODULE_DESCRIPTION("Netfilter connection tracking helper module for PPTP");
-+
-+DECLARE_LOCK(ip_pptp_lock);
-+
-+#if 0
-+#include "ip_conntrack_pptp_priv.h"
-+#define DEBUGP(format, args...)	printk(KERN_DEBUG __FILE__ ":" __FUNCTION__ \
-+					": " format, ## args)
-+#else
-+#define DEBUGP(format, args...)
-+#endif
-+
-+#define SECS *HZ
-+#define MINS * 60 SECS
-+#define HOURS * 60 MINS
-+#define DAYS * 24 HOURS
-+
-+#define PPTP_GRE_TIMEOUT 		(10 MINS)
-+#define PPTP_GRE_STREAM_TIMEOUT 	(5 DAYS)
-+
-+static int pptp_expectfn(struct ip_conntrack *ct)
-+{
-+	struct ip_conntrack *master;
-+	struct ip_conntrack_expect *exp;
-+
-+	DEBUGP("increasing timeouts\n");
-+	/* increase timeout of GRE data channel conntrack entry */
-+	ct->proto.gre.timeout = PPTP_GRE_TIMEOUT;
-+	ct->proto.gre.stream_timeout = PPTP_GRE_STREAM_TIMEOUT;
-+
-+	master = master_ct(ct);
-+	if (!master) {
-+		DEBUGP(" no master!!!\n");
-+		return 0;
-+	}
-+
-+	exp = ct->master;
-+	if (!exp) {
-+		DEBUGP("no expectation!!\n");
-+		return 0;
-+	}
-+
-+	DEBUGP("completing tuples with ct info\n");
-+	/* we can do this, since we're unconfirmed */
-+	if (ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u.gre.key == 
-+		htonl(master->help.ct_pptp_info.pac_call_id)) {	
-+		/* assume PNS->PAC */
-+		ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.gre.key = 
-+			htonl(master->help.ct_pptp_info.pns_call_id);
-+		ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.gre.key =
-+			htonl(master->help.ct_pptp_info.pns_call_id);
-+	} else {
-+		/* assume PAC->PNS */
-+		ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.gre.key =
-+			htonl(master->help.ct_pptp_info.pac_call_id);
-+		ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.gre.key =
-+			htonl(master->help.ct_pptp_info.pac_call_id);
-+	}
-+	
-+	/* delete other expectation */
-+	if (exp->expected_list.next != &exp->expected_list) {
-+		struct ip_conntrack_expect *other_exp;
-+		struct list_head *cur_item, *next;
-+
-+		for (cur_item = master->sibling_list.next;
-+		     cur_item != &master->sibling_list; cur_item = next) {
-+			next = cur_item->next;
-+			other_exp = list_entry(cur_item,
-+					       struct ip_conntrack_expect,
-+					       expected_list);
-+			/* remove only if occurred at same sequence number */
-+			if (other_exp != exp && other_exp->seq == exp->seq) {
-+				DEBUGP("unexpecting other direction\n");
-+				ip_ct_gre_keymap_destroy(other_exp);
-+				ip_conntrack_unexpect_related(other_exp);
-+			}
-+		}
-+	}
-+
-+	return 0;
-+}
-+
-+/* timeout GRE data connections */
-+static int pptp_timeout_related(struct ip_conntrack *ct)
-+{
-+	struct list_head *cur_item, *next;
-+	struct ip_conntrack_expect *exp;
-+	enum ip_conntrack_info ctinfo;
-+	struct iphdr *iph;
-+
-+	/* FIXME: do we have to lock something ? */
-+	for (cur_item = ct->sibling_list.next;
-+	    cur_item != &ct->sibling_list; cur_item = next) {
-+		next = cur_item->next;
-+		exp = list_entry(cur_item, struct ip_conntrack_expect,
-+				 expected_list);
-+
-+		ip_ct_gre_keymap_destroy(exp);
-+		if (!exp->sibling) {
-+			ip_conntrack_unexpect_related(exp);
-+			continue;
-+		}
-+
-+		DEBUGP("setting timeout of conntrack %p to 0\n",
-+			exp->sibling);
-+		exp->sibling->proto.gre.timeout = 0;
-+		exp->sibling->proto.gre.stream_timeout = 0;
-+		ip_ct_refresh_acct(exp->sibling, ctinfo, iph, 0);
-+	}
-+
-+	return 0;
-+}
-+
-+/* expect GRE connections (PNS->PAC and PAC->PNS direction) */
-+static inline int
-+exp_gre(struct ip_conntrack *master,
-+	u_int32_t seq,
-+	u_int16_t callid,
-+	u_int16_t peer_callid)
-+{
-+	struct ip_conntrack_expect exp;
-+	struct ip_conntrack_tuple inv_tuple;
-+
-+	memset(&exp, 0, sizeof(exp));
-+	/* tuple in original direction, PNS->PAC */
-+	exp.tuple.src.ip = master->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
-+	exp.tuple.src.u.gre.key = htonl(ntohs(peer_callid));
-+	exp.tuple.dst.ip = master->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip;
-+	exp.tuple.dst.u.gre.key = htonl(ntohs(callid));
-+	exp.tuple.dst.protonum = IPPROTO_GRE;
-+
-+	exp.mask.src.ip = 0xffffffff;
-+	exp.mask.src.u.all = 0;
-+	exp.mask.dst.u.all = 0;
-+	exp.mask.dst.u.gre.key = 0xffffffff;
-+	exp.mask.dst.ip = 0xffffffff;
-+	exp.mask.dst.protonum = 0xffff;
-+			
-+	exp.seq = seq;
-+	exp.expectfn = pptp_expectfn;
-+
-+	exp.help.exp_pptp_info.pac_call_id = ntohs(callid);
-+	exp.help.exp_pptp_info.pns_call_id = ntohs(peer_callid);
-+
-+	DEBUGP("calling expect_related ");
-+	DUMP_TUPLE_RAW(&exp.tuple);
-+	
-+	/* Add GRE keymap entries */
-+	if (ip_ct_gre_keymap_add(&exp, &exp.tuple, 0) != 0)
-+		return 1;
-+
-+	invert_tuplepr(&inv_tuple, &exp.tuple);
-+	if (ip_ct_gre_keymap_add(&exp, &inv_tuple, 1) != 0) {
-+		ip_ct_gre_keymap_destroy(&exp);
-+		return 1;
-+	}
-+	
-+	if (ip_conntrack_expect_related(master, &exp) != 0) {
-+		ip_ct_gre_keymap_destroy(&exp);
-+		DEBUGP("cannot expect_related()\n");
-+		return 1;
-+	}
-+
-+	/* tuple in reply direction, PAC->PNS */
-+	exp.tuple.src.ip = master->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip;
-+	exp.tuple.src.u.gre.key = htonl(ntohs(callid));
-+	exp.tuple.dst.ip = master->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip;
-+	exp.tuple.dst.u.gre.key = htonl(ntohs(peer_callid));
-+
-+	DEBUGP("calling expect_related ");
-+	DUMP_TUPLE_RAW(&exp.tuple);
-+	
-+	/* Add GRE keymap entries */
-+	ip_ct_gre_keymap_add(&exp, &exp.tuple, 0);
-+	invert_tuplepr(&inv_tuple, &exp.tuple);
-+	ip_ct_gre_keymap_add(&exp, &inv_tuple, 1);
-+	/* FIXME: cannot handle error correctly, since we need to free
-+	 * the above keymap :( */
-+	
-+	if (ip_conntrack_expect_related(master, &exp) != 0) {
-+		/* free the second pair of keypmaps */
-+		ip_ct_gre_keymap_destroy(&exp);
-+		DEBUGP("cannot expect_related():\n");
-+		return 1;
-+	}
-+
-+	return 0;
-+}
-+
-+static inline int 
-+pptp_inbound_pkt(struct tcphdr *tcph,
-+		 struct pptp_pkt_hdr *pptph, 
-+		 size_t datalen,
-+		 struct ip_conntrack *ct,
-+		 enum ip_conntrack_info ctinfo)
-+{
-+	struct PptpControlHeader *ctlh;
-+        union pptp_ctrl_union pptpReq;
-+	
-+	struct ip_ct_pptp_master *info = &ct->help.ct_pptp_info;
-+	u_int16_t msg, *cid, *pcid;
-+	u_int32_t seq;	
-+
-+	ctlh = (struct PptpControlHeader *) 
-+		((char *) pptph + sizeof(struct pptp_pkt_hdr));
-+	pptpReq.rawreq = (void *) 
-+		((char *) ctlh + sizeof(struct PptpControlHeader));
-+
-+	msg = ntohs(ctlh->messageType);
-+	DEBUGP("inbound control message %s\n", strMName[msg]);
-+
-+	switch (msg) {
-+	case PPTP_START_SESSION_REPLY:
-+		/* server confirms new control session */
-+		if (info->sstate < PPTP_SESSION_REQUESTED) {
-+			DEBUGP("%s without START_SESS_REQUEST\n",
-+				strMName[msg]);
-+			break;
-+		}
-+		if (pptpReq.srep->resultCode == PPTP_START_OK)
-+			info->sstate = PPTP_SESSION_CONFIRMED;
-+		else 
-+			info->sstate = PPTP_SESSION_ERROR;
-+		break;
-+
-+	case PPTP_STOP_SESSION_REPLY:
-+		/* server confirms end of control session */
-+		if (info->sstate > PPTP_SESSION_STOPREQ) {
-+			DEBUGP("%s without STOP_SESS_REQUEST\n",
-+				strMName[msg]);
-+			break;
-+		}
-+		if (pptpReq.strep->resultCode == PPTP_STOP_OK)
-+			info->sstate = PPTP_SESSION_NONE;
-+		else
-+			info->sstate = PPTP_SESSION_ERROR;
-+		break;
-+
-+	case PPTP_OUT_CALL_REPLY:
-+		/* server accepted call, we now expect GRE frames */
-+		if (info->sstate != PPTP_SESSION_CONFIRMED) {
-+			DEBUGP("%s but no session\n", strMName[msg]);
-+			break;
-+		}
-+		if (info->cstate != PPTP_CALL_OUT_REQ &&
-+		    info->cstate != PPTP_CALL_OUT_CONF) {
-+			DEBUGP("%s without OUTCALL_REQ\n", strMName[msg]);
-+			break;
-+		}
-+		if (pptpReq.ocack->resultCode != PPTP_OUTCALL_CONNECT) {
-+			info->cstate = PPTP_CALL_NONE;
-+			break;
-+		}
-+
-+		cid = &pptpReq.ocack->callID;
-+		pcid = &pptpReq.ocack->peersCallID;
-+
-+		info->pac_call_id = ntohs(*cid);
-+		
-+		if (htons(info->pns_call_id) != *pcid) {
-+			DEBUGP("%s for unknown callid %u\n",
-+				strMName[msg], ntohs(*pcid));
-+			break;
-+		}
-+
-+		DEBUGP("%s, CID=%X, PCID=%X\n", strMName[msg], 
-+			ntohs(*cid), ntohs(*pcid));
-+		
-+		info->cstate = PPTP_CALL_OUT_CONF;
-+
-+		seq = ntohl(tcph->seq) + ((void *)pcid - (void *)pptph);
-+		if (exp_gre(ct, seq, *cid, *pcid) != 0)
-+			printk("ip_conntrack_pptp: error during exp_gre\n");
-+		break;
-+
-+	case PPTP_IN_CALL_REQUEST:
-+		/* server tells us about incoming call request */
-+		if (info->sstate != PPTP_SESSION_CONFIRMED) {
-+			DEBUGP("%s but no session\n", strMName[msg]);
-+			break;
-+		}
-+		pcid = &pptpReq.icack->peersCallID;
-+		DEBUGP("%s, PCID=%X\n", strMName[msg], ntohs(*pcid));
-+		info->cstate = PPTP_CALL_IN_REQ;
-+		info->pac_call_id= ntohs(*pcid);
-+		break;
-+
-+	case PPTP_IN_CALL_CONNECT:
-+		/* server tells us about incoming call established */
-+		if (info->sstate != PPTP_SESSION_CONFIRMED) {
-+			DEBUGP("%s but no session\n", strMName[msg]);
-+			break;
-+		}
-+		if (info->sstate != PPTP_CALL_IN_REP
-+		    && info->sstate != PPTP_CALL_IN_CONF) {
-+			DEBUGP("%s but never sent IN_CALL_REPLY\n",
-+				strMName[msg]);
-+			break;
-+		}
-+
-+		pcid = &pptpReq.iccon->peersCallID;
-+		cid = &info->pac_call_id;
-+
-+		if (info->pns_call_id != ntohs(*pcid)) {
-+			DEBUGP("%s for unknown CallID %u\n", 
-+				strMName[msg], ntohs(*cid));
-+			break;
-+		}
-+
-+		DEBUGP("%s, PCID=%X\n", strMName[msg], ntohs(*pcid));
-+		info->cstate = PPTP_CALL_IN_CONF;
-+
-+		/* we expect a GRE connection from PAC to PNS */
-+		seq = ntohl(tcph->seq) + ((void *)pcid - (void *)pptph);
-+		if (exp_gre(ct, seq, *cid, *pcid) != 0)
-+			printk("ip_conntrack_pptp: error during exp_gre\n");
-+
-+		break;
-+
-+	case PPTP_CALL_DISCONNECT_NOTIFY:
-+		/* server confirms disconnect */
-+		cid = &pptpReq.disc->callID;
-+		DEBUGP("%s, CID=%X\n", strMName[msg], ntohs(*cid));
-+		info->cstate = PPTP_CALL_NONE;
-+
-+		/* untrack this call id, unexpect GRE packets */
-+		pptp_timeout_related(ct);
-+		break;
-+
-+	case PPTP_WAN_ERROR_NOTIFY:
-+		break;
-+
-+	case PPTP_ECHO_REQUEST:
-+	case PPTP_ECHO_REPLY:
-+		/* I don't have to explain these ;) */
-+		break;
-+	default:
-+		DEBUGP("invalid %s (TY=%d)\n", (msg <= PPTP_MSG_MAX)
-+			? strMName[msg]:strMName[0], msg);
-+		break;
-+	}
-+
-+	return NF_ACCEPT;
-+
-+}
-+
-+static inline int
-+pptp_outbound_pkt(struct tcphdr *tcph,
-+		  struct pptp_pkt_hdr *pptph,
-+		  size_t datalen,
-+		  struct ip_conntrack *ct,
-+		  enum ip_conntrack_info ctinfo)
-+{
-+	struct PptpControlHeader *ctlh;
-+        union pptp_ctrl_union pptpReq;
-+	struct ip_ct_pptp_master *info = &ct->help.ct_pptp_info;
-+	u_int16_t msg, *cid, *pcid;
-+
-+	ctlh = (struct PptpControlHeader *) ((void *) pptph + sizeof(*pptph));
-+	pptpReq.rawreq = (void *) ((void *) ctlh + sizeof(*ctlh));
-+
-+	msg = ntohs(ctlh->messageType);
-+	DEBUGP("outbound control message %s\n", strMName[msg]);
-+
-+	switch (msg) {
-+	case PPTP_START_SESSION_REQUEST:
-+		/* client requests for new control session */
-+		if (info->sstate != PPTP_SESSION_NONE) {
-+			DEBUGP("%s but we already have one",
-+				strMName[msg]);
-+		}
-+		info->sstate = PPTP_SESSION_REQUESTED;
-+		break;
-+	case PPTP_STOP_SESSION_REQUEST:
-+		/* client requests end of control session */
-+		info->sstate = PPTP_SESSION_STOPREQ;
-+		break;
-+
-+	case PPTP_OUT_CALL_REQUEST:
-+		/* client initiating connection to server */
-+		if (info->sstate != PPTP_SESSION_CONFIRMED) {
-+			DEBUGP("%s but no session\n",
-+				strMName[msg]);
-+			break;
-+		}
-+		info->cstate = PPTP_CALL_OUT_REQ;
-+		/* track PNS call id */
-+		cid = &pptpReq.ocreq->callID;
-+		DEBUGP("%s, CID=%X\n", strMName[msg], ntohs(*cid));
-+		info->pns_call_id = ntohs(*cid);
-+		break;
-+	case PPTP_IN_CALL_REPLY:
-+		/* client answers incoming call */
-+		if (info->cstate != PPTP_CALL_IN_REQ
-+		    && info->cstate != PPTP_CALL_IN_REP) {
-+			DEBUGP("%s without incall_req\n", 
-+				strMName[msg]);
-+			break;
-+		}
-+		if (pptpReq.icack->resultCode != PPTP_INCALL_ACCEPT) {
-+			info->cstate = PPTP_CALL_NONE;
-+			break;
-+		}
-+		pcid = &pptpReq.icack->peersCallID;
-+		if (info->pac_call_id != ntohs(*pcid)) {
-+			DEBUGP("%s for unknown call %u\n", 
-+				strMName[msg], ntohs(*pcid));
-+			break;
-+		}
-+		DEBUGP("%s, CID=%X\n", strMName[msg], ntohs(*pcid));
-+		/* part two of the three-way handshake */
-+		info->cstate = PPTP_CALL_IN_REP;
-+		info->pns_call_id = ntohs(pptpReq.icack->callID);
-+		break;
-+
-+	case PPTP_CALL_CLEAR_REQUEST:
-+		/* client requests hangup of call */
-+		if (info->sstate != PPTP_SESSION_CONFIRMED) {
-+			DEBUGP("CLEAR_CALL but no session\n");
-+			break;
-+		}
-+		/* FUTURE: iterate over all calls and check if
-+		 * call ID is valid.  We don't do this without newnat,
-+		 * because we only know about last call */
-+		info->cstate = PPTP_CALL_CLEAR_REQ;
-+		break;
-+	case PPTP_SET_LINK_INFO:
-+		break;
-+	case PPTP_ECHO_REQUEST:
-+	case PPTP_ECHO_REPLY:
-+		/* I don't have to explain these ;) */
-+		break;
-+	default:
-+		DEBUGP("invalid %s (TY=%d)\n", (msg <= PPTP_MSG_MAX)? 
-+			strMName[msg]:strMName[0], msg);
-+		/* unknown: no need to create GRE masq table entry */
-+		break;
-+	}
-+
-+	return NF_ACCEPT;
-+}
-+
-+
-+/* track caller id inside control connection, call expect_related */
-+static int 
-+conntrack_pptp_help(const struct iphdr *iph, size_t len,
-+		    struct ip_conntrack *ct, enum ip_conntrack_info ctinfo)
-+
-+{
-+	struct pptp_pkt_hdr *pptph;
-+	
-+	struct tcphdr *tcph = (void *) iph + iph->ihl * 4;
-+	u_int32_t tcplen = len - iph->ihl * 4;
-+	u_int32_t datalen = tcplen - tcph->doff * 4;
-+	void *datalimit;
-+	int dir = CTINFO2DIR(ctinfo);
-+	struct ip_ct_pptp_master *info = &ct->help.ct_pptp_info;
-+
-+	int oldsstate, oldcstate;
-+	int ret;
-+
-+	/* don't do any tracking before tcp handshake complete */
-+	if (ctinfo != IP_CT_ESTABLISHED 
-+	    && ctinfo != IP_CT_ESTABLISHED+IP_CT_IS_REPLY) {
-+		DEBUGP("ctinfo = %u, skipping\n", ctinfo);
-+		return NF_ACCEPT;
-+	}
-+	
-+	/* not a complete TCP header? */
-+	if (tcplen < sizeof(struct tcphdr) || tcplen < tcph->doff * 4) {
-+		DEBUGP("tcplen = %u\n", tcplen);
-+		return NF_ACCEPT;
-+	}
-+
-+	/* checksum invalid? */
-+	if (tcp_v4_check(tcph, tcplen, iph->saddr, iph->daddr,
-+			csum_partial((char *) tcph, tcplen, 0))) {
-+		printk(KERN_NOTICE __FILE__ ": bad csum\n");
-+		/* W2K PPTP server sends TCP packets with wrong checksum :(( */
-+		//return NF_ACCEPT;
-+	}
-+
-+	if (tcph->fin || tcph->rst) {
-+		DEBUGP("RST/FIN received, timeouting GRE\n");
-+		/* can't do this after real newnat */
-+		info->cstate = PPTP_CALL_NONE;
-+
-+		/* untrack this call id, unexpect GRE packets */
-+		pptp_timeout_related(ct);
-+	}
-+
-+
-+	pptph = (struct pptp_pkt_hdr *) ((void *) tcph + tcph->doff * 4);
-+	datalimit = (void *) pptph + datalen;
-+
-+	/* not a full pptp packet header? */
-+	if ((void *) pptph+sizeof(*pptph) >= datalimit) {
-+		DEBUGP("no full PPTP header, can't track\n");
-+		return NF_ACCEPT;
-+	}
-+	
-+	/* if it's not a control message we can't do anything with it */
-+        if (ntohs(pptph->packetType) != PPTP_PACKET_CONTROL ||
-+	    ntohl(pptph->magicCookie) != PPTP_MAGIC_COOKIE) {
-+		DEBUGP("not a control packet\n");
-+		return NF_ACCEPT;
-+	}
-+
-+	oldsstate = info->sstate;
-+	oldcstate = info->cstate;
-+
-+	LOCK_BH(&ip_pptp_lock);
-+
-+	/* FIXME: We just blindly assume that the control connection is always
-+	 * established from PNS->PAC.  However, RFC makes no guarantee */
-+	if (dir == IP_CT_DIR_ORIGINAL)
-+		/* client -> server (PNS -> PAC) */
-+		ret = pptp_outbound_pkt(tcph, pptph, datalen, ct, ctinfo);
-+	else
-+		/* server -> client (PAC -> PNS) */
-+		ret = pptp_inbound_pkt(tcph, pptph, datalen, ct, ctinfo);
-+	DEBUGP("sstate: %d->%d, cstate: %d->%d\n",
-+		oldsstate, info->sstate, oldcstate, info->cstate);
-+	UNLOCK_BH(&ip_pptp_lock);
-+
-+	return ret;
-+}
-+
-+/* control protocol helper */
-+static struct ip_conntrack_helper pptp = { 
-+	.list = { NULL, NULL },
-+	.name = "pptp", 
-+	.flags = IP_CT_HELPER_F_REUSE_EXPECT,
-+	.me = THIS_MODULE,
-+	.max_expected = 2,
-+	.timeout = 0,
-+	.tuple = { .src = { .ip = 0, 
-+		 	    .u = { .tcp = { .port =  
-+				    __constant_htons(PPTP_CONTROL_PORT) } } 
-+			  }, 
-+		   .dst = { .ip = 0, 
-+			    .u = { .all = 0 },
-+			    .protonum = IPPROTO_TCP
-+			  } 
-+		 },
-+	.mask = { .src = { .ip = 0, 
-+			   .u = { .tcp = { .port = 0xffff } } 
-+			 }, 
-+		  .dst = { .ip = 0, 
-+			   .u = { .all = 0 },
-+			   .protonum = 0xffff 
-+		 	 } 
-+		},
-+	.help = conntrack_pptp_help
-+};
-+
-+/* ip_conntrack_pptp initialization */
-+static int __init init(void)
-+{
-+	int retcode;
-+
-+	DEBUGP(__FILE__ ": registering helper\n");
-+	if ((retcode = ip_conntrack_helper_register(&pptp))) {
-+                printk(KERN_ERR "Unable to register conntrack application "
-+				"helper for pptp: %d\n", retcode);
-+		return -EIO;
-+	}
-+
-+	printk("ip_conntrack_pptp version %s loaded\n", IP_CT_PPTP_VERSION);
-+	return 0;
-+}
-+
-+static void __exit fini(void)
-+{
-+	ip_conntrack_helper_unregister(&pptp);
-+	printk("ip_conntrack_pptp version %s unloaded\n", IP_CT_PPTP_VERSION);
-+}
-+
-+module_init(init);
-+module_exit(fini);
-+
-+EXPORT_SYMBOL(ip_pptp_lock);