add pptp nat patch

git-svn-id: svn://svn.openwrt.org/openwrt/trunk/openwrt@529 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 2412 insertions, 0 deletions

diff --git a/package/linux/kernel-patches/308-netfilter-nat-pptp b/package/linux/kernel-patches/308-netfilter-nat-pptp
new file mode 100644
index 000000000..6c7d6e6f2
--- /dev/null
+++ b/package/linux/kernel-patches/308-netfilter-nat-pptp
@@ -0,0 +1,2412 @@
+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
+@@ -50,16 +50,19 @@
+ 
+ #include <linux/netfilter_ipv4/ip_conntrack_tcp.h>
+ #include <linux/netfilter_ipv4/ip_conntrack_icmp.h>
++#include <linux/netfilter_ipv4/ip_conntrack_proto_gre.h>
+ 
+ /* per conntrack: protocol private data */
+ union ip_conntrack_proto {
+ 	/* insert conntrack proto private data here */
+ 	struct ip_ct_tcp tcp;
+ 	struct ip_ct_icmp icmp;
++	struct ip_ct_gre gre;
+ };
+ 
+ union ip_conntrack_expect_proto {
+ 	/* insert expect proto private data here */
++	struct ip_ct_gre_expect gre;
+ };
+ 
+ /* Add protocol helper include file here */
+@@ -67,6 +70,7 @@
+ 
+ #include <linux/netfilter_ipv4/ip_conntrack_ftp.h>
+ #include <linux/netfilter_ipv4/ip_conntrack_irc.h>
++#include <linux/netfilter_ipv4/ip_conntrack_pptp.h>
+ 
+ /* per expectation: application helper private data */
+ union ip_conntrack_expect_help {
+@@ -74,6 +78,7 @@
+ 	struct ip_ct_amanda_expect exp_amanda_info;
+ 	struct ip_ct_ftp_expect exp_ftp_info;
+ 	struct ip_ct_irc_expect exp_irc_info;
++	struct ip_ct_pptp_expect exp_pptp_info;
+ 
+ #ifdef CONFIG_IP_NF_NAT_NEEDED
+ 	union {
+@@ -87,14 +92,17 @@
+ 	/* insert conntrack helper private data (master) here */
+ 	struct ip_ct_ftp_master ct_ftp_info;
+ 	struct ip_ct_irc_master ct_irc_info;
++	struct ip_ct_pptp_master ct_pptp_info;
+ };
+ 
+ #ifdef CONFIG_IP_NF_NAT_NEEDED
+ #include <linux/netfilter_ipv4/ip_nat.h>
++#include <linux/netfilter_ipv4/ip_nat_pptp.h>
+ 
+ /* per conntrack: nat application helper private data */
+ union ip_conntrack_nat_help {
+ 	/* insert nat helper private data here */
++	struct ip_nat_pptp nat_pptp_info;
+ };
+ #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
+@@ -0,0 +1,313 @@
++/* PPTP constants and structs */
++#ifndef _CONNTRACK_PPTP_H
++#define _CONNTRACK_PPTP_H
++
++/* state of the control session */
++enum pptp_ctrlsess_state {
++	PPTP_SESSION_NONE,			/* no session present */
++	PPTP_SESSION_ERROR,			/* some session error */
++	PPTP_SESSION_STOPREQ,			/* stop_sess request seen */
++	PPTP_SESSION_REQUESTED,			/* start_sess request seen */
++	PPTP_SESSION_CONFIRMED,			/* session established */
++};
++
++/* state of the call inside the control session */
++enum pptp_ctrlcall_state {
++	PPTP_CALL_NONE,
++	PPTP_CALL_ERROR,
++	PPTP_CALL_OUT_REQ,
++	PPTP_CALL_OUT_CONF,
++	PPTP_CALL_IN_REQ,
++	PPTP_CALL_IN_REP,
++	PPTP_CALL_IN_CONF,
++	PPTP_CALL_CLEAR_REQ,
++};
++
++
++/* conntrack private data */
++struct ip_ct_pptp_master {
++	enum pptp_ctrlsess_state sstate;	/* session state */
++
++	/* everything below is going to be per-expectation in newnat,
++	 * since there could be more than one call within one session */
++	enum pptp_ctrlcall_state cstate;	/* call state */
++	u_int16_t pac_call_id;			/* call id of PAC, host byte order */
++	u_int16_t pns_call_id;			/* call id of PNS, host byte order */
++};
++
++/* conntrack_expect private member */
++struct ip_ct_pptp_expect {
++	enum pptp_ctrlcall_state cstate; 	/* call state */
++	u_int16_t pac_call_id;			/* call id of PAC */
++	u_int16_t pns_call_id;			/* call id of PNS */
++};
++
++
++#ifdef __KERNEL__
++
++#include <linux/netfilter_ipv4/lockhelp.h>
++DECLARE_LOCK_EXTERN(ip_pptp_lock);
++
++#define IP_CONNTR_PPTP		PPTP_CONTROL_PORT
++
++union pptp_ctrl_union {
++                void				*rawreq;
++		struct PptpStartSessionRequest	*sreq;
++		struct PptpStartSessionReply	*srep;
++		struct PptpStopSessionRequest	*streq;
++		struct PptpStopSessionReply	*strep;
++                struct PptpOutCallRequest       *ocreq;
++                struct PptpOutCallReply         *ocack;
++                struct PptpInCallRequest        *icreq;
++                struct PptpInCallReply          *icack;
++                struct PptpInCallConnected      *iccon;
++		struct PptpClearCallRequest	*clrreq;
++                struct PptpCallDisconnectNotify *disc;
++                struct PptpWanErrorNotify       *wanerr;
++                struct PptpSetLinkInfo          *setlink;
++};
++
++
++
++#define PPTP_CONTROL_PORT	1723
++
++#define PPTP_PACKET_CONTROL	1
++#define PPTP_PACKET_MGMT	2
++
++#define PPTP_MAGIC_COOKIE	0x1a2b3c4d
++
++struct pptp_pkt_hdr {
++	__u16	packetLength;
++	__u16	packetType;
++	__u32	magicCookie;
++};
++
++/* PptpControlMessageType values */
++#define PPTP_START_SESSION_REQUEST	1
++#define PPTP_START_SESSION_REPLY	2
++#define PPTP_STOP_SESSION_REQUEST	3
++#define PPTP_STOP_SESSION_REPLY		4
++#define PPTP_ECHO_REQUEST		5
++#define PPTP_ECHO_REPLY			6
++#define PPTP_OUT_CALL_REQUEST		7
++#define PPTP_OUT_CALL_REPLY		8
++#define PPTP_IN_CALL_REQUEST		9
++#define PPTP_IN_CALL_REPLY		10
++#define PPTP_IN_CALL_CONNECT		11
++#define PPTP_CALL_CLEAR_REQUEST		12
++#define PPTP_CALL_DISCONNECT_NOTIFY	13
++#define PPTP_WAN_ERROR_NOTIFY		14
++#define PPTP_SET_LINK_INFO		15
++
++#define PPTP_MSG_MAX			15
++
++/* PptpGeneralError values */
++#define PPTP_ERROR_CODE_NONE		0
++#define PPTP_NOT_CONNECTED		1
++#define PPTP_BAD_FORMAT			2
++#define PPTP_BAD_VALUE			3
++#define PPTP_NO_RESOURCE		4
++#define PPTP_BAD_CALLID			5
++#define PPTP_REMOVE_DEVICE_ERROR	6
++
++struct PptpControlHeader {
++	__u16	messageType;
++	__u16	reserved;
++};
++
++/* FramingCapability Bitmap Values */
++#define PPTP_FRAME_CAP_ASYNC		0x1
++#define PPTP_FRAME_CAP_SYNC		0x2
++
++/* BearerCapability Bitmap Values */
++#define PPTP_BEARER_CAP_ANALOG		0x1
++#define PPTP_BEARER_CAP_DIGITAL		0x2
++
++struct PptpStartSessionRequest {
++	__u16	protocolVersion;
++	__u8	reserved1;
++	__u8	reserved2;
++	__u32	framingCapability;
++	__u32	bearerCapability;
++	__u16	maxChannels;
++	__u16	firmwareRevision;
++	__u8	hostName[64];
++	__u8	vendorString[64];
++};
++
++/* PptpStartSessionResultCode Values */
++#define PPTP_START_OK			1
++#define PPTP_START_GENERAL_ERROR	2
++#define PPTP_START_ALREADY_CONNECTED	3
++#define PPTP_START_NOT_AUTHORIZED	4
++#define PPTP_START_UNKNOWN_PROTOCOL	5
++
++struct PptpStartSessionReply {
++	__u16	protocolVersion;
++	__u8	resultCode;
++	__u8	generalErrorCode;
++	__u32	framingCapability;
++	__u32	bearerCapability;
++	__u16	maxChannels;
++	__u16	firmwareRevision;
++	__u8	hostName[64];
++	__u8	vendorString[64];
++};
++
++/* PptpStopReasons */
++#define PPTP_STOP_NONE			1
++#define PPTP_STOP_PROTOCOL		2
++#define PPTP_STOP_LOCAL_SHUTDOWN	3
++
++struct PptpStopSessionRequest {
++	__u8	reason;
++};
++
++/* PptpStopSessionResultCode */
++#define PPTP_STOP_OK			1
++#define PPTP_STOP_GENERAL_ERROR		2
++
++struct PptpStopSessionReply {
++	__u8	resultCode;
++	__u8	generalErrorCode;
++};
++
++struct PptpEchoRequest {
++	__u32 identNumber;
++};
++
++/* PptpEchoReplyResultCode */
++#define PPTP_ECHO_OK			1
++#define PPTP_ECHO_GENERAL_ERROR		2
++
++struct PptpEchoReply {
++	__u32	identNumber;
++	__u8	resultCode;
++	__u8	generalErrorCode;
++	__u16	reserved;
++};
++
++/* PptpFramingType */
++#define PPTP_ASYNC_FRAMING		1
++#define PPTP_SYNC_FRAMING		2
++#define PPTP_DONT_CARE_FRAMING		3
++
++/* PptpCallBearerType */
++#define PPTP_ANALOG_TYPE		1
++#define PPTP_DIGITAL_TYPE		2
++#define PPTP_DONT_CARE_BEARER_TYPE	3
++
++struct PptpOutCallRequest {
++	__u16	callID;
++	__u16	callSerialNumber;
++	__u32	minBPS;
++	__u32	maxBPS;
++	__u32	bearerType;
++	__u32	framingType;
++	__u16	packetWindow;
++	__u16	packetProcDelay;
++	__u16	reserved1;
++	__u16	phoneNumberLength;
++	__u16	reserved2;
++	__u8	phoneNumber[64];
++	__u8	subAddress[64];
++};
++
++/* PptpCallResultCode */
++#define PPTP_OUTCALL_CONNECT		1
++#define PPTP_OUTCALL_GENERAL_ERROR	2
++#define PPTP_OUTCALL_NO_CARRIER		3
++#define PPTP_OUTCALL_BUSY		4
++#define PPTP_OUTCALL_NO_DIAL_TONE	5
++#define PPTP_OUTCALL_TIMEOUT		6
++#define PPTP_OUTCALL_DONT_ACCEPT	7
++
++struct PptpOutCallReply {
++	__u16	callID;
++	__u16	peersCallID;
++	__u8	resultCode;
++	__u8	generalErrorCode;
++	__u16	causeCode;
++	__u32	connectSpeed;
++	__u16	packetWindow;
++	__u16	packetProcDelay;
++	__u32	physChannelID;
++};
++
++struct PptpInCallRequest {
++	__u16	callID;
++	__u16	callSerialNumber;
++	__u32	callBearerType;
++	__u32	physChannelID;
++	__u16	dialedNumberLength;
++	__u16	dialingNumberLength;
++	__u8	dialedNumber[64];
++	__u8	dialingNumber[64];
++	__u8	subAddress[64];
++};
++
++/* PptpInCallResultCode */
++#define PPTP_INCALL_ACCEPT		1
++#define PPTP_INCALL_GENERAL_ERROR	2
++#define PPTP_INCALL_DONT_ACCEPT		3
++
++struct PptpInCallReply {
++	__u16	callID;
++	__u16	peersCallID;
++	__u8	resultCode;
++	__u8	generalErrorCode;
++	__u16	packetWindow;
++	__u16	packetProcDelay;
++	__u16	reserved;
++};
++
++struct PptpInCallConnected {
++	__u16	peersCallID;
++	__u16	reserved;
++	__u32	connectSpeed;
++	__u16	packetWindow;
++	__u16	packetProcDelay;
++	__u32	callFramingType;
++};
++
++struct PptpClearCallRequest {
++	__u16	callID;
++	__u16	reserved;
++};
++
++struct PptpCallDisconnectNotify {
++	__u16	callID;
++	__u8	resultCode;
++	__u8	generalErrorCode;
++	__u16	causeCode;
++	__u16	reserved;
++	__u8	callStatistics[128];
++};
++
++struct PptpWanErrorNotify {
++	__u16	peersCallID;
++	__u16	reserved;
++	__u32	crcErrors;
++	__u32	framingErrors;
++	__u32	hardwareOverRuns;
++	__u32	bufferOverRuns;
++	__u32	timeoutErrors;
++	__u32	alignmentErrors;
++};
++
++struct PptpSetLinkInfo {
++	__u16	peersCallID;
++	__u16	reserved;
++	__u32	sendAccm;
++	__u32	recvAccm;
++};
++
++
++struct pptp_priv_data {
++	__u16	call_id;
++	__u16	mcall_id;
++	__u16	pcall_id;
++};
++
++#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
+@@ -0,0 +1,123 @@
++#ifndef _CONNTRACK_PROTO_GRE_H
++#define _CONNTRACK_PROTO_GRE_H
++#include <asm/byteorder.h>
++
++/* GRE PROTOCOL HEADER */
++
++/* GRE Version field */
++#define GRE_VERSION_1701	0x0
++#define GRE_VERSION_PPTP	0x1
++
++/* GRE Protocol field */
++#define GRE_PROTOCOL_PPTP	0x880B
++
++/* GRE Flags */
++#define GRE_FLAG_C		0x80
++#define GRE_FLAG_R		0x40
++#define GRE_FLAG_K		0x20
++#define GRE_FLAG_S		0x10
++#define GRE_FLAG_A		0x80
++
++#define GRE_IS_C(f)	((f)&GRE_FLAG_C)
++#define GRE_IS_R(f)	((f)&GRE_FLAG_R)
++#define GRE_IS_K(f)	((f)&GRE_FLAG_K)
++#define GRE_IS_S(f)	((f)&GRE_FLAG_S)
++#define GRE_IS_A(f)	((f)&GRE_FLAG_A)
++
++/* GRE is a mess: Four different standards */
++struct gre_hdr {
++#if defined(__LITTLE_ENDIAN_BITFIELD)
++	__u16	rec:3,
++		srr:1,
++		seq:1,
++		key:1,
++		routing:1,
++		csum:1,
++		version:3,
++		reserved:4,
++		ack:1;
++#elif defined(__BIG_ENDIAN_BITFIELD)
++	__u16	csum:1,
++		routing:1,
++		key:1,
++		seq:1,
++		srr:1,
++		rec:3,
++		ack:1,
++		reserved:4,
++		version:3;
++#else
++#error "Adjust your <asm/byteorder.h> defines"
++#endif
++	__u16	protocol;
++};
++
++/* modified GRE header for PPTP */
++struct gre_hdr_pptp {
++	__u8  flags;		/* bitfield */
++	__u8  version;		/* should be GRE_VERSION_PPTP */
++	__u16 protocol;		/* should be GRE_PROTOCOL_PPTP */
++	__u16 payload_len;	/* size of ppp payload, not inc. gre header */
++	__u16 call_id;		/* peer's call_id for this session */
++	__u32 seq;		/* sequence number.  Present if S==1 */
++	__u32 ack;		/* seq number of highest packet recieved by */
++				/*  sender in this session */
++};
++
++
++/* this is part of ip_conntrack */
++struct ip_ct_gre {
++	unsigned int stream_timeout;
++	unsigned int timeout;
++};
++
++/* this is part of ip_conntrack_expect */
++struct ip_ct_gre_expect {
++	struct ip_ct_gre_keymap *keymap_orig, *keymap_reply;
++};
++
++#ifdef __KERNEL__
++struct ip_conntrack_expect;
++
++/* structure for original <-> reply keymap */
++struct ip_ct_gre_keymap {
++	struct list_head list;
++
++	struct ip_conntrack_tuple tuple;
++};
++
++
++/* add new tuple->key_reply pair to keymap */
++int ip_ct_gre_keymap_add(struct ip_conntrack_expect *exp,
++			 struct ip_conntrack_tuple *t,
++			 int reply);
++
++/* change an existing keymap entry */
++void ip_ct_gre_keymap_change(struct ip_ct_gre_keymap *km,
++			     struct ip_conntrack_tuple *t);
++
++/* delete keymap entries */
++void ip_ct_gre_keymap_destroy(struct ip_conntrack_expect *exp);
++
++
++/* get pointer to gre key, if present */
++static inline u_int32_t *gre_key(struct gre_hdr *greh)
++{
++	if (!greh->key)
++		return NULL;
++	if (greh->csum || greh->routing)
++		return (u_int32_t *) (greh+sizeof(*greh)+4);
++	return (u_int32_t *) (greh+sizeof(*greh));
++}
++
++/* get pointer ot gre csum, if present */
++static inline u_int16_t *gre_csum(struct gre_hdr *greh)
++{
++	if (!greh->csum)
++		return NULL;
++	return (u_int16_t *) (greh+sizeof(*greh));
++}
++
++#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
+@@ -14,7 +14,7 @@
+ union ip_conntrack_manip_proto
+ {
+ 	/* Add other protocols here. */
+-	u_int16_t all;
++	u_int32_t all;
+ 
+ 	struct {
+ 		u_int16_t port;
+@@ -25,6 +25,9 @@
+ 	struct {
+ 		u_int16_t id;
+ 	} icmp;
++	struct {
++		u_int32_t key;
++	} gre;
+ };
+ 
+ /* The manipulable part of the tuple. */
+@@ -44,7 +47,7 @@
+ 		u_int32_t ip;
+ 		union {
+ 			/* Add other protocols here. */
+-			u_int16_t all;
++			u_int32_t all;
+ 
+ 			struct {
+ 				u_int16_t port;
+@@ -55,6 +58,9 @@
+ 			struct {
+ 				u_int8_t type, code;
+ 			} icmp;
++			struct {
++				u_int32_t key;
++			} gre;
+ 		} u;
+ 
+ 		/* The protocol. */
+@@ -80,10 +86,16 @@
+ #ifdef __KERNEL__
+ 
+ #define DUMP_TUPLE(tp)						\
+-DEBUGP("tuple %p: %u %u.%u.%u.%u:%hu -> %u.%u.%u.%u:%hu\n",	\
++DEBUGP("tuple %p: %u %u.%u.%u.%u:%u -> %u.%u.%u.%u:%u\n",	\
+        (tp), (tp)->dst.protonum,				\
+-       NIPQUAD((tp)->src.ip), ntohs((tp)->src.u.all),		\
+-       NIPQUAD((tp)->dst.ip), ntohs((tp)->dst.u.all))
++       NIPQUAD((tp)->src.ip), ntohl((tp)->src.u.all),		\
++       NIPQUAD((tp)->dst.ip), ntohl((tp)->dst.u.all))
++
++#define DUMP_TUPLE_RAW(x) 						\
++	DEBUGP("tuple %p: %u %u.%u.%u.%u:0x%08x -> %u.%u.%u.%u:0x%08x\n",\
++	(x), (x)->dst.protonum,						\
++	NIPQUAD((x)->src.ip), ntohl((x)->src.u.all), 			\
++	NIPQUAD((x)->dst.ip), ntohl((x)->dst.u.all))
+ 
+ #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
+@@ -0,0 +1,11 @@
++/* PPTP constants and structs */
++#ifndef _NAT_PPTP_H
++#define _NAT_PPTP_H
++
++/* conntrack private data */
++struct ip_nat_pptp {
++	u_int16_t pns_call_id;		/* NAT'ed PNS call id */
++	u_int16_t pac_call_id;		/* NAT'ed PAC call id */
++};
++
++#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
+@@ -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
+   dep_tristate '  IRC protocol support' CONFIG_IP_NF_IRC $CONFIG_IP_NF_CONNTRACK
++  dep_tristate '  GRE protocol support' CONFIG_IP_NF_CT_PROTO_GRE $CONFIG_IP_NF_CONNTRACK
++  dep_tristate '   PPTP protocol support' CONFIG_IP_NF_PPTP $CONFIG_IP_NF_CT_PROTO_GRE
+ fi
+ 
+ if [ "$CONFIG_EXPERIMENTAL" = "y" ]; then
+@@ -67,6 +69,20 @@
+       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 $CONFIG_IP_NF_NAT
++      if [ "$CONFIG_IP_NF_PPTP" = "m" ]; then
++        define_tristate CONFIG_IP_NF_NAT_PPTP m
++      else
++        if [ "$CONFIG_IP_NF_PPTP" = "y" ]; then
++          define_tristate CONFIG_IP_NF_NAT_PPTP $CONFIG_IP_NF_NAT
++        fi
++      fi
++      if [ "$CONFIG_IP_NF_CT_PROTO_GRE" = "m" ]; then
++        define_tristate CONFIG_IP_NF_NAT_PROTO_GRE m
++      else
++        if [ "$CONFIG_IP_NF_CT_PROTO_GRE" = "y" ]; then
++          define_tristate CONFIG_IP_NF_NAT_PROTO_GRE $CONFIG_IP_NF_NAT
++        fi
++      fi
+       if [ "$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 @@
+ 	tuple->dst.ip = iph->daddr;
+ 	tuple->dst.protonum = iph->protocol;
+ 
++	tuple->src.u.all = tuple->dst.u.all = 0;
++
+ 	ret = protocol->pkt_to_tuple((u_int32_t *)iph + iph->ihl,
+ 				     len - 4*iph->ihl,
+ 				     tuple);
+@@ -157,6 +159,8 @@
+ 	inverse->dst.ip = orig->src.ip;
+ 	inverse->dst.protonum = orig->dst.protonum;
+ 
++	inverse->src.u.all = inverse->dst.u.all = 0;
++
+ 	return protocol->invert_tuple(inverse, orig);
+ }
+ 
+@@ -954,8 +958,8 @@
+ 	 * so there is no need to use the tuple lock too */
+ 
+ 	DEBUGP("ip_conntrack_expect_related %p\n", related_to);
+-	DEBUGP("tuple: "); DUMP_TUPLE(&expect->tuple);
+-	DEBUGP("mask:  "); DUMP_TUPLE(&expect->mask);
++	DEBUGP("tuple: "); DUMP_TUPLE_RAW(&expect->tuple);
++	DEBUGP("mask:  "); DUMP_TUPLE_RAW(&expect->mask);
+ 
+ 	old = LIST_FIND(&ip_conntrack_expect_list, resent_expect,
+ 		        struct ip_conntrack_expect *, &expect->tuple, 
+@@ -1072,15 +1076,14 @@
+ 
+ 	MUST_BE_READ_LOCKED(&ip_conntrack_lock);
+ 	WRITE_LOCK(&ip_conntrack_expect_tuple_lock);
+-
+ 	DEBUGP("change_expect:\n");
+-	DEBUGP("exp tuple: "); DUMP_TUPLE(&expect->tuple);
+-	DEBUGP("exp mask:  "); DUMP_TUPLE(&expect->mask);
+-	DEBUGP("newtuple:  "); DUMP_TUPLE(newtuple);
++	DEBUGP("exp tuple: "); DUMP_TUPLE_RAW(&expect->tuple);
++	DEBUGP("exp mask:  "); DUMP_TUPLE_RAW(&expect->mask);
++	DEBUGP("newtuple:  "); DUMP_TUPLE_RAW(newtuple);
+ 	if (expect->ct_tuple.dst.protonum == 0) {
+ 		/* Never seen before */
+ 		DEBUGP("change expect: never seen before\n");
+-		if (!ip_ct_tuple_equal(&expect->tuple, newtuple) 
++		if (!ip_ct_tuple_mask_cmp(&expect->tuple, newtuple, &expect->mask)
+ 		    && 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.c linux-2.4.29-dev/net/ipv4/netfilter/ip_conntrack_pptp.c
+--- linux-2.4.29-old/net/ipv4/netfilter/ip_conntrack_pptp.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.4.29-dev/net/ipv4/netfilter/ip_conntrack_pptp.c	2005-04-02 19:13:21.000000000 +0200
+@@ -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-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
+@@ -0,0 +1,24 @@
++#ifndef _IP_CT_PPTP_PRIV_H
++#define _IP_CT_PPTP_PRIV_H
++
++/* PptpControlMessageType names */
++static const char *strMName[] = {
++	"UNKNOWN_MESSAGE",
++	"START_SESSION_REQUEST",
++	"START_SESSION_REPLY",
++	"STOP_SESSION_REQUEST",
++	"STOP_SESSION_REPLY",
++	"ECHO_REQUEST",
++	"ECHO_REPLY",
++	"OUT_CALL_REQUEST",
++	"OUT_CALL_REPLY",
++	"IN_CALL_REQUEST",
++	"IN_CALL_REPLY",
++	"IN_CALL_CONNECT",
++	"CALL_CLEAR_REQUEST",
++	"CALL_DISCONNECT_NOTIFY",
++	"WAN_ERROR_NOTIFY",
++	"SET_LINK_INFO"
++};
++
++#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
+@@ -0,0 +1,333 @@
++/*
++ * ip_conntrack_proto_gre.c - Version 1.2 
++ *
++ * Connection tracking protocol helper module for GRE.
++ *
++ * GRE is a generic encapsulation protocol, which is generally not very
++ * suited for NAT, as it has no protocol-specific part as port numbers.
++ *
++ * It has an optional key field, which may help us distinguishing two 
++ * connections between the same two hosts.
++ *
++ * GRE is defined in RFC 1701 and RFC 1702, as well as RFC 2784 
++ *
++ * PPTP is built on top of a modified version of GRE, and has a mandatory
++ * field called "CallID", which serves us for the same purpose as the key
++ * field in plain GRE.
++ *
++ * Documentation about 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/)
++ *
++ */
++
++#include <linux/config.h>
++#include <linux/module.h>
++#include <linux/types.h>
++#include <linux/timer.h>
++#include <linux/netfilter.h>
++#include <linux/ip.h>
++#include <linux/in.h>
++#include <linux/list.h>
++
++#include <linux/netfilter_ipv4/lockhelp.h>
++
++DECLARE_RWLOCK(ip_ct_gre_lock);
++#define ASSERT_READ_LOCK(x) MUST_BE_READ_LOCKED(&ip_ct_gre_lock)
++#define ASSERT_WRITE_LOCK(x) MUST_BE_WRITE_LOCKED(&ip_ct_gre_lock)
++
++#include <linux/netfilter_ipv4/listhelp.h>
++#include <linux/netfilter_ipv4/ip_conntrack_protocol.h>
++#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
++#include <linux/netfilter_ipv4/ip_conntrack_core.h>
++
++#include <linux/netfilter_ipv4/ip_conntrack_proto_gre.h>
++#include <linux/netfilter_ipv4/ip_conntrack_pptp.h>
++
++MODULE_LICENSE("GPL");
++MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");
++MODULE_DESCRIPTION("netfilter connection tracking protocol helper for GRE");
++
++/* shamelessly stolen from ip_conntrack_proto_udp.c */
++#define GRE_TIMEOUT		(30*HZ)
++#define GRE_STREAM_TIMEOUT	(180*HZ)
++
++#if 0
++#define DEBUGP(format, args...) printk(KERN_DEBUG __FILE__ ":" __FUNCTION__ \
++		                       ": " format, ## args)
++#define DUMP_TUPLE_GRE(x) printk("%u.%u.%u.%u:0x%x -> %u.%u.%u.%u:0x%x:%u:0x%x\n", \
++			NIPQUAD((x)->src.ip), ntohl((x)->src.u.gre.key), \
++			NIPQUAD((x)->dst.ip), ntohl((x)->dst.u.gre.key))
++#else
++#define DEBUGP(x, args...)
++#define DUMP_TUPLE_GRE(x)
++#endif
++				
++/* GRE KEYMAP HANDLING FUNCTIONS */
++static LIST_HEAD(gre_keymap_list);
++
++static inline int gre_key_cmpfn(const struct ip_ct_gre_keymap *km,
++				const struct ip_conntrack_tuple *t)
++{
++	return ((km->tuple.src.ip == t->src.ip) &&
++		(km->tuple.dst.ip == t->dst.ip) &&
++	        (km->tuple.dst.protonum == t->dst.protonum) &&
++	        (km->tuple.dst.u.all == t->dst.u.all));
++}
++
++/* look up the source key for a given tuple */
++static u_int32_t gre_keymap_lookup(struct ip_conntrack_tuple *t)
++{
++	struct ip_ct_gre_keymap *km;
++	u_int32_t key;
++
++	READ_LOCK(&ip_ct_gre_lock);
++	km = LIST_FIND(&gre_keymap_list, gre_key_cmpfn,
++			struct ip_ct_gre_keymap *, t);
++	if (!km) {
++		READ_UNLOCK(&ip_ct_gre_lock);
++		return 0;
++	}
++
++	key = km->tuple.src.u.gre.key;
++	READ_UNLOCK(&ip_ct_gre_lock);
++
++	return key;
++}
++
++/* add a single keymap entry, associate with specified expect */
++int ip_ct_gre_keymap_add(struct ip_conntrack_expect *exp,
++			 struct ip_conntrack_tuple *t, int reply)
++{
++	struct ip_ct_gre_keymap *km;
++
++	km = kmalloc(sizeof(*km), GFP_ATOMIC);
++	if (!km)
++		return -1;
++
++	/* initializing list head should be sufficient */
++	memset(km, 0, sizeof(*km));
++
++	memcpy(&km->tuple, t, sizeof(*t));
++
++	if (!reply)
++		exp->proto.gre.keymap_orig = km;
++	else
++		exp->proto.gre.keymap_reply = km;
++
++	DEBUGP("adding new entry %p: ", km);
++	DUMP_TUPLE_GRE(&km->tuple);
++
++	WRITE_LOCK(&ip_ct_gre_lock);
++	list_append(&gre_keymap_list, km);
++	WRITE_UNLOCK(&ip_ct_gre_lock);
++
++	return 0;
++}
++
++/* change the tuple of a keymap entry (used by nat helper) */
++void ip_ct_gre_keymap_change(struct ip_ct_gre_keymap *km,
++			     struct ip_conntrack_tuple *t)
++{
++	DEBUGP("changing entry %p to: ", km);
++	DUMP_TUPLE_GRE(t);
++
++	WRITE_LOCK(&ip_ct_gre_lock);
++	memcpy(&km->tuple, t, sizeof(km->tuple));
++	WRITE_UNLOCK(&ip_ct_gre_lock);
++}
++
++/* destroy the keymap entries associated with specified expect */
++void ip_ct_gre_keymap_destroy(struct ip_conntrack_expect *exp)
++{
++	DEBUGP("entering for exp %p\n", exp);
++	WRITE_LOCK(&ip_ct_gre_lock);
++	if (exp->proto.gre.keymap_orig) {
++		DEBUGP("removing %p from list\n", exp->proto.gre.keymap_orig);
++		list_del(&exp->proto.gre.keymap_orig->list);
++		kfree(exp->proto.gre.keymap_orig);
++		exp->proto.gre.keymap_orig = NULL;
++	}
++	if (exp->proto.gre.keymap_reply) {
++		DEBUGP("removing %p from list\n", exp->proto.gre.keymap_reply);
++		list_del(&exp->proto.gre.keymap_reply->list);
++		kfree(exp->proto.gre.keymap_reply);
++		exp->proto.gre.keymap_reply = NULL;
++	}
++	WRITE_UNLOCK(&ip_ct_gre_lock);
++}
++
++
++/* PUBLIC CONNTRACK PROTO HELPER FUNCTIONS */
++
++/* invert gre part of tuple */
++static int gre_invert_tuple(struct ip_conntrack_tuple *tuple,
++			    const struct ip_conntrack_tuple *orig)
++{
++	tuple->dst.u.gre.key = orig->src.u.gre.key;
++	tuple->src.u.gre.key = orig->dst.u.gre.key;
++
++	return 1;
++}
++
++/* gre hdr info to tuple */
++static int gre_pkt_to_tuple(const void *datah, size_t datalen,
++			    struct ip_conntrack_tuple *tuple)
++{
++	struct gre_hdr *grehdr = (struct gre_hdr *) datah;
++	struct gre_hdr_pptp *pgrehdr = (struct gre_hdr_pptp *) datah;
++	u_int32_t srckey;
++
++	/* core guarantees 8 protocol bytes, no need for size check */
++
++	switch (grehdr->version) {
++		case GRE_VERSION_1701:
++			if (!grehdr->key) {
++				DEBUGP("Can't track GRE without key\n");
++				return 0;
++			}
++			tuple->dst.u.gre.key = *(gre_key(grehdr));
++			break;
++
++		case GRE_VERSION_PPTP:
++			if (ntohs(grehdr->protocol) != GRE_PROTOCOL_PPTP) {
++				DEBUGP("GRE_VERSION_PPTP but unknown proto\n");
++				return 0;
++			}
++			tuple->dst.u.gre.key = htonl(ntohs(pgrehdr->call_id));
++			break;
++
++		default:
++			printk(KERN_WARNING "unknown GRE version %hu\n",
++				grehdr->version);
++			return 0;
++	}
++
++	srckey = gre_keymap_lookup(tuple);
++
++#if 0
++	DEBUGP("found src key %x for tuple ", ntohl(srckey));
++	DUMP_TUPLE_GRE(tuple);
++#endif
++	tuple->src.u.gre.key = srckey;
++
++	return 1;
++}
++
++/* print gre part of tuple */
++static unsigned int gre_print_tuple(char *buffer,
++				    const struct ip_conntrack_tuple *tuple)
++{
++	return sprintf(buffer, "srckey=0x%x dstkey=0x%x ", 
++			ntohl(tuple->src.u.gre.key),
++			ntohl(tuple->dst.u.gre.key));
++}
++
++/* print private data for conntrack */
++static unsigned int gre_print_conntrack(char *buffer,
++					const struct ip_conntrack *ct)
++{
++	return sprintf(buffer, "timeout=%u, stream_timeout=%u ",
++		       (ct->proto.gre.timeout / HZ),
++		       (ct->proto.gre.stream_timeout / HZ));
++}
++
++/* Returns verdict for packet, and may modify conntrack */
++static int gre_packet(struct ip_conntrack *ct,
++		      struct iphdr *iph, size_t len,
++		      enum ip_conntrack_info conntrackinfo)
++{
++	/* If we've seen traffic both ways, this is a GRE connection.
++	 * Extend timeout. */
++	if (ct->status & IPS_SEEN_REPLY) {
++		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(ct, ct->proto.gre.timeout);
++	
++	return NF_ACCEPT;
++}
++
++/* Called when a new connection for this protocol found. */
++static int gre_new(struct ip_conntrack *ct,
++		   struct iphdr *iph, size_t len)
++{ 
++	DEBUGP(": ");
++	DUMP_TUPLE_GRE(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
++
++	/* initialize to sane value.  Ideally a conntrack helper
++	 * (e.g. in case of pptp) is increasing them */
++	ct->proto.gre.stream_timeout = GRE_STREAM_TIMEOUT;
++	ct->proto.gre.timeout = GRE_TIMEOUT;
++
++	return 1;
++}
++
++/* Called when a conntrack entry has already been removed from the hashes
++ * and is about to be deleted from memory */
++static void gre_destroy(struct ip_conntrack *ct)
++{
++	struct ip_conntrack_expect *master = ct->master;
++
++	DEBUGP(" entering\n");
++
++	if (!master) {
++		DEBUGP("no master exp for ct %p\n", ct);
++		return;
++	}
++
++	ip_ct_gre_keymap_destroy(master);
++}
++
++/* protocol helper struct */
++static struct ip_conntrack_protocol gre = { { NULL, NULL }, IPPROTO_GRE,
++					    "gre", 
++					    gre_pkt_to_tuple,
++					    gre_invert_tuple,
++					    gre_print_tuple,
++					    gre_print_conntrack,
++					    gre_packet,
++					    gre_new,
++					    gre_destroy,
++					    NULL,
++					    THIS_MODULE };
++
++/* ip_conntrack_proto_gre initialization */
++static int __init init(void)
++{
++	int retcode;
++
++	if ((retcode = ip_conntrack_protocol_register(&gre))) {
++                printk(KERN_ERR "Unable to register conntrack protocol "
++			        "helper for gre: %d\n",	retcode);
++		return -EIO;
++	}
++
++	return 0;
++}
++
++static void __exit fini(void)
++{
++	struct list_head *pos, *n;
++
++	/* delete all keymap entries */
++	WRITE_LOCK(&ip_ct_gre_lock);
++	list_for_each_safe(pos, n, &gre_keymap_list) {
++		DEBUGP("deleting keymap %p at module unload time\n", pos);
++		list_del(pos);
++		kfree(pos);
++	}
++	WRITE_UNLOCK(&ip_ct_gre_lock);
++
++	ip_conntrack_protocol_unregister(&gre); 
++}
++
++EXPORT_SYMBOL(ip_ct_gre_keymap_add);
++EXPORT_SYMBOL(ip_ct_gre_keymap_change);
++EXPORT_SYMBOL(ip_ct_gre_keymap_destroy);
++
++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
+@@ -424,7 +424,7 @@
+ 	*tuple = *orig_tuple;
+ 	while ((rptr = find_best_ips_proto_fast(tuple, mr, conntrack, hooknum))
+ 	       != NULL) {
+-		DEBUGP("Found best for "); DUMP_TUPLE(tuple);
++		DEBUGP("Found best for "); DUMP_TUPLE_RAW(tuple);
+ 		/* 3) The per-protocol part of the manip is made to
+ 		   map into the range to make a unique tuple. */
+ 
+@@ -564,9 +564,9 @@
+ 		       HOOK2MANIP(hooknum)==IP_NAT_MANIP_SRC ? "SRC" : "DST",
+ 		       conntrack);
+ 		DEBUGP("Original: ");
+-		DUMP_TUPLE(&orig_tp);
++		DUMP_TUPLE_RAW(&orig_tp);
+ 		DEBUGP("New: ");
+-		DUMP_TUPLE(&new_tuple);
++		DUMP_TUPLE_RAW(&new_tuple);
+ #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 @@
++/*
++ * ip_nat_pptp.c	- Version 1.5
++ *
++ * NAT 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/)
++ *
++ * TODO: - Support for multiple calls within one session
++ * 	   (needs netfilter newnat code)
++ * 	 - NAT to a unique tuple, not to TCP source port
++ * 	   (needs netfilter tuple reservation)
++ *
++ * Changes:
++ *     2002-02-10 - Version 1.3
++ *       - Use ip_nat_mangle_tcp_packet() because of cloned skb's
++ *	   in local connections (Philip Craig <philipc@snapgear.com>)
++ *       - add checks for magicCookie and pptp version
++ *       - make argument list of pptp_{out,in}bound_packet() shorter
++ *       - move to C99 style initializers
++ *       - print version number at module loadtime
++ *     2003-09-22 - Version 1.5
++ *       - use SNATed tcp sourceport as callid, since we get called before
++ *         TCP header is mangled (Philip Craig <philipc@snapgear.com>)
++ * 
++ */
++
++#include <linux/config.h>
++#include <linux/module.h>
++#include <linux/ip.h>
++#include <linux/tcp.h>
++#include <net/tcp.h>
++#include <linux/netfilter_ipv4/ip_nat.h>
++#include <linux/netfilter_ipv4/ip_nat_rule.h>
++#include <linux/netfilter_ipv4/ip_nat_helper.h>
++#include <linux/netfilter_ipv4/ip_nat_pptp.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_NAT_PPTP_VERSION "1.5"
++
++MODULE_LICENSE("GPL");
++MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");
++MODULE_DESCRIPTION("Netfilter NAT helper module for PPTP");
++
++
++#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
++
++static unsigned int
++pptp_nat_expected(struct sk_buff **pskb,
++		  unsigned int hooknum,
++		  struct ip_conntrack *ct,
++		  struct ip_nat_info *info)
++{
++	struct ip_conntrack *master = master_ct(ct);
++	struct ip_nat_multi_range mr;
++	struct ip_ct_pptp_master *ct_pptp_info;
++	struct ip_nat_pptp *nat_pptp_info;
++	u_int32_t newip, newcid;
++	int ret;
++
++	IP_NF_ASSERT(info);
++	IP_NF_ASSERT(master);
++	IP_NF_ASSERT(!(info->initialized & (1 << HOOK2MANIP(hooknum))));
++
++	DEBUGP("we have a connection!\n");
++
++	LOCK_BH(&ip_pptp_lock);
++	ct_pptp_info = &master->help.ct_pptp_info;
++	nat_pptp_info = &master->nat.help.nat_pptp_info;
++
++	/* need to alter GRE tuple because conntrack expectfn() used 'wrong'
++	 * (unmanipulated) values */
++	if (HOOK2MANIP(hooknum) == IP_NAT_MANIP_DST) {
++		DEBUGP("completing tuples with NAT info \n");
++		/* we can do this, since we're unconfirmed */
++		if (ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u.gre.key ==
++			htonl(ct_pptp_info->pac_call_id)) {	
++			/* assume PNS->PAC */
++			ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.gre.key =
++				htonl(nat_pptp_info->pns_call_id);
++			ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.gre.key =
++				htonl(nat_pptp_info->pns_call_id);
++			newip = master->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip;
++			newcid = htonl(nat_pptp_info->pac_call_id);
++		} else {
++			/* assume PAC->PNS */
++			ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.gre.key =
++				htonl(nat_pptp_info->pac_call_id);
++			ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.gre.key =
++				htonl(nat_pptp_info->pac_call_id);
++			newip = master->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
++			newcid = htonl(nat_pptp_info->pns_call_id);
++		}
++	} else {
++		if (ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u.gre.key ==
++			htonl(ct_pptp_info->pac_call_id)) {	
++			/* assume PNS->PAC */
++			newip = master->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip;
++			newcid = htonl(ct_pptp_info->pns_call_id);
++		}
++		else {
++			/* assume PAC->PNS */
++			newip = master->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip;
++			newcid = htonl(ct_pptp_info->pac_call_id);
++		}
++	}
++
++	mr.rangesize = 1;
++	mr.range[0].flags = IP_NAT_RANGE_MAP_IPS | IP_NAT_RANGE_PROTO_SPECIFIED;
++	mr.range[0].min_ip = mr.range[0].max_ip = newip;
++	mr.range[0].min = mr.range[0].max = 
++		((union ip_conntrack_manip_proto ) { newcid }); 
++	DEBUGP("change ip to %u.%u.%u.%u\n", 
++		NIPQUAD(newip));
++	DEBUGP("change key to 0x%x\n", ntohl(newcid));
++	ret = ip_nat_setup_info(ct, &mr, hooknum);
++
++	UNLOCK_BH(&ip_pptp_lock);
++
++	return ret;
++
++}
++
++/* outbound packets == from PNS to PAC */
++static inline unsigned int
++pptp_outbound_pkt(struct sk_buff **pskb,
++		  struct ip_conntrack *ct,
++		  enum ip_conntrack_info ctinfo,
++		  struct ip_conntrack_expect *exp)
++
++{
++	struct iphdr *iph = (*pskb)->nh.iph;
++	struct tcphdr *tcph = (void *) iph + iph->ihl*4;
++	struct pptp_pkt_hdr *pptph = (struct pptp_pkt_hdr *) 
++					((void *)tcph + tcph->doff*4);
++
++	struct PptpControlHeader *ctlh;
++	union pptp_ctrl_union pptpReq;
++	struct ip_ct_pptp_master *ct_pptp_info = &ct->help.ct_pptp_info;
++	struct ip_nat_pptp *nat_pptp_info = &ct->nat.help.nat_pptp_info;
++
++	u_int16_t msg, *cid = NULL, new_callid;
++
++	/* FIXME: size checks !!! */
++	ctlh = (struct PptpControlHeader *) ((void *) pptph + sizeof(*pptph));
++	pptpReq.rawreq = (void *) ((void *) ctlh + sizeof(*ctlh));
++
++	new_callid = htons(ct_pptp_info->pns_call_id);
++	
++	switch (msg = ntohs(ctlh->messageType)) {
++		case PPTP_OUT_CALL_REQUEST:
++			cid = &pptpReq.ocreq->callID;
++			/* FIXME: ideally we would want to reserve a call ID
++			 * here.  current netfilter NAT core is not able to do
++			 * this :( For now we use TCP source port. This breaks
++			 * multiple calls within one control session */
++
++			/* save original call ID in nat_info */
++			nat_pptp_info->pns_call_id = ct_pptp_info->pns_call_id;
++
++			/* don't use tcph->source since we are at a DSTmanip
++			 * hook (e.g. PREROUTING) and pkt is not mangled yet */
++			new_callid = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.tcp.port;
++
++			/* save new call ID in ct info */
++			ct_pptp_info->pns_call_id = ntohs(new_callid);
++			break;
++		case PPTP_IN_CALL_REPLY:
++			cid = &pptpReq.icreq->callID;
++			break;
++		case PPTP_CALL_CLEAR_REQUEST:
++			cid = &pptpReq.clrreq->callID;
++			break;
++		default:
++			DEBUGP("unknown outbound packet 0x%04x:%s\n", msg,
++			      (msg <= PPTP_MSG_MAX)? strMName[msg]:strMName[0]);
++			/* fall through */
++
++		case PPTP_SET_LINK_INFO:
++			/* only need to NAT in case PAC is behind NAT box */
++		case PPTP_START_SESSION_REQUEST:
++		case PPTP_START_SESSION_REPLY:
++		case PPTP_STOP_SESSION_REQUEST:
++		case PPTP_STOP_SESSION_REPLY:
++		case PPTP_ECHO_REQUEST:
++		case PPTP_ECHO_REPLY:
++			/* no need to alter packet */
++			return NF_ACCEPT;
++	}
++
++	IP_NF_ASSERT(cid);
++
++	DEBUGP("altering call id from 0x%04x to 0x%04x\n",
++		ntohs(*cid), ntohs(new_callid));
++
++	/* mangle packet */
++	ip_nat_mangle_tcp_packet(pskb, ct, ctinfo, (void *)cid - (void *)pptph,
++				 sizeof(new_callid), (char *)&new_callid,
++				 sizeof(new_callid));
++
++	return NF_ACCEPT;
++}
++
++/* inbound packets == from PAC to PNS */
++static inline unsigned int
++pptp_inbound_pkt(struct sk_buff **pskb,
++		 struct ip_conntrack *ct,
++		 enum ip_conntrack_info ctinfo,
++		 struct ip_conntrack_expect *oldexp)
++{
++	struct iphdr *iph = (*pskb)->nh.iph;
++	struct tcphdr *tcph = (void *) iph + iph->ihl*4;
++	struct pptp_pkt_hdr *pptph = (struct pptp_pkt_hdr *) 
++					((void *)tcph + tcph->doff*4);
++
++	struct PptpControlHeader *ctlh;
++	union pptp_ctrl_union pptpReq;
++	struct ip_ct_pptp_master *ct_pptp_info = &ct->help.ct_pptp_info;
++	struct ip_nat_pptp *nat_pptp_info = &ct->nat.help.nat_pptp_info;
++
++	u_int16_t msg, new_cid = 0, new_pcid, *pcid = NULL, *cid = NULL;
++	u_int32_t old_dst_ip;
++
++	struct ip_conntrack_tuple t, inv_t;
++	struct ip_conntrack_tuple *orig_t, *reply_t;
++
++	/* FIXME: size checks !!! */
++	ctlh = (struct PptpControlHeader *) ((void *) pptph + sizeof(*pptph));
++	pptpReq.rawreq = (void *) ((void *) ctlh + sizeof(*ctlh));
++
++	new_pcid = htons(nat_pptp_info->pns_call_id);
++
++	switch (msg = ntohs(ctlh->messageType)) {
++	case PPTP_OUT_CALL_REPLY:
++		pcid = &pptpReq.ocack->peersCallID;	
++		cid = &pptpReq.ocack->callID;
++		if (!oldexp) {
++			DEBUGP("outcall but no expectation\n");
++			break;
++		}
++		old_dst_ip = oldexp->tuple.dst.ip;
++		t = oldexp->tuple;
++		invert_tuplepr(&inv_t, &t);
++
++		/* save original PAC call ID in nat_info */
++		nat_pptp_info->pac_call_id = ct_pptp_info->pac_call_id;
++
++		/* alter expectation */
++		orig_t = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
++		reply_t = &ct->tuplehash[IP_CT_DIR_REPLY].tuple;
++		if (t.src.ip == orig_t->src.ip && t.dst.ip == orig_t->dst.ip) {
++			/* expectation for PNS->PAC direction */
++			t.src.u.gre.key = htonl(nat_pptp_info->pns_call_id);
++			t.dst.u.gre.key = htonl(ct_pptp_info->pac_call_id);
++			inv_t.src.ip = reply_t->src.ip;
++			inv_t.dst.ip = reply_t->dst.ip;
++			inv_t.src.u.gre.key = htonl(nat_pptp_info->pac_call_id);
++			inv_t.dst.u.gre.key = htonl(ct_pptp_info->pns_call_id);
++		} else {
++			/* expectation for PAC->PNS direction */
++			t.src.u.gre.key = htonl(nat_pptp_info->pac_call_id);
++			t.dst.u.gre.key = htonl(ct_pptp_info->pns_call_id);
++			inv_t.src.ip = orig_t->src.ip;
++			inv_t.dst.ip = orig_t->dst.ip;
++			inv_t.src.u.gre.key = htonl(nat_pptp_info->pns_call_id);
++			inv_t.dst.u.gre.key = htonl(ct_pptp_info->pac_call_id);
++		}
++
++		if (!ip_conntrack_change_expect(oldexp, &t)) {
++			DEBUGP("successfully changed expect\n");
++		} 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);
++		break;
++	case PPTP_IN_CALL_CONNECT:
++		pcid = &pptpReq.iccon->peersCallID;
++		if (!oldexp)
++			break;
++		old_dst_ip = oldexp->tuple.dst.ip;
++		t = oldexp->tuple;
++
++		/* alter expectation, no need for callID */
++		if (t.dst.ip == ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip) {
++			/* expectation for PNS->PAC direction */
++			t.src.ip = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip;
++		} else {
++			/* expectation for PAC->PNS direction */
++			t.dst.ip = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip;
++		}
++
++		if (!ip_conntrack_change_expect(oldexp, &t)) {
++			DEBUGP("successfully changed expect\n");
++		} else {
++			DEBUGP("can't change expect\n");
++		}
++		break;
++	case PPTP_IN_CALL_REQUEST:
++		/* only need to nat in case PAC is behind NAT box */
++		break;
++	case PPTP_WAN_ERROR_NOTIFY:
++		pcid = &pptpReq.wanerr->peersCallID;
++		break;
++	case PPTP_CALL_DISCONNECT_NOTIFY:
++		pcid = &pptpReq.disc->callID;
++		break;
++
++	default:
++		DEBUGP("unknown inbound packet %s\n",
++			(msg <= PPTP_MSG_MAX)? strMName[msg]:strMName[0]);
++		/* fall through */
++
++	case PPTP_START_SESSION_REQUEST:
++	case PPTP_START_SESSION_REPLY:
++	case PPTP_STOP_SESSION_REQUEST:
++	case PPTP_STOP_SESSION_REPLY:
++	case PPTP_ECHO_REQUEST:
++	case PPTP_ECHO_REPLY:
++		/* no need to alter packet */
++		return NF_ACCEPT;
++	}
++
++	/* mangle packet */
++	IP_NF_ASSERT(pcid);
++	DEBUGP("altering peer call id from 0x%04x to 0x%04x\n",
++		ntohs(*pcid), ntohs(new_pcid));
++	ip_nat_mangle_tcp_packet(pskb, ct, ctinfo, (void *)pcid - (void *)pptph,
++				 sizeof(new_pcid), (char *)&new_pcid, 
++				 sizeof(new_pcid));
++
++	if (new_cid) {
++		IP_NF_ASSERT(cid);
++		DEBUGP("altering call id from 0x%04x to 0x%04x\n",
++			ntohs(*cid), ntohs(new_cid));
++		ip_nat_mangle_tcp_packet(pskb, ct, ctinfo, 
++					 (void *)cid - (void *)pptph, 
++					 sizeof(new_cid), (char *)&new_cid, 
++					 sizeof(new_cid));
++	}
++
++	/* great, at least we don't need to resize packets */
++	return NF_ACCEPT;
++}
++
++
++static unsigned int tcp_help(struct ip_conntrack *ct,
++			     struct ip_conntrack_expect *exp,
++			     struct ip_nat_info *info,
++			     enum ip_conntrack_info ctinfo,
++			     unsigned int hooknum, struct sk_buff **pskb)
++{
++	struct iphdr *iph = (*pskb)->nh.iph;
++	struct tcphdr *tcph = (void *) iph + iph->ihl*4;
++	unsigned int datalen = (*pskb)->len - iph->ihl*4 - tcph->doff*4;
++	struct pptp_pkt_hdr *pptph;
++
++	int dir;
++
++	DEBUGP("entering\n");
++
++	/* Only mangle things once: DST for original direction
++	   and SRC for reply direction. */
++	dir = CTINFO2DIR(ctinfo);
++	if (!((HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC
++	     && dir == IP_CT_DIR_ORIGINAL)
++	      || (HOOK2MANIP(hooknum) == IP_NAT_MANIP_DST
++		  && dir == IP_CT_DIR_REPLY))) {
++		DEBUGP("Not touching dir %s at hook %s\n",
++		       dir == IP_CT_DIR_ORIGINAL ? "ORIG" : "REPLY",
++		       hooknum == NF_IP_POST_ROUTING ? "POSTROUTING"
++		       : hooknum == NF_IP_PRE_ROUTING ? "PREROUTING"
++		       : hooknum == NF_IP_LOCAL_OUT ? "OUTPUT"
++		       : hooknum == NF_IP_LOCAL_IN ? "INPUT" : "???");
++		return NF_ACCEPT;
++	}
++
++	/* if packet is too small, just skip it */
++	if (datalen < sizeof(struct pptp_pkt_hdr)+
++		      sizeof(struct PptpControlHeader)) {
++		DEBUGP("pptp packet too short\n");
++		return NF_ACCEPT;	
++	}
++
++	pptph = (struct pptp_pkt_hdr *) ((void *)tcph + tcph->doff*4);
++
++	/* if it's not a control message, we can't handle it */
++	if (ntohs(pptph->packetType) != PPTP_PACKET_CONTROL ||
++	    ntohl(pptph->magicCookie) != PPTP_MAGIC_COOKIE) {
++		DEBUGP("not a pptp control packet\n");
++		return NF_ACCEPT;
++	}
++
++	LOCK_BH(&ip_pptp_lock);
++
++	if (dir == IP_CT_DIR_ORIGINAL) {
++		/* reuqests sent by client to server (PNS->PAC) */
++		pptp_outbound_pkt(pskb, ct, ctinfo, exp);
++	} else {
++		/* response from the server to the client (PAC->PNS) */
++		pptp_inbound_pkt(pskb, ct, ctinfo, exp);
++	}
++
++	UNLOCK_BH(&ip_pptp_lock);
++
++	return NF_ACCEPT;
++}
++
++/* nat helper struct for control connection */
++static struct ip_nat_helper pptp_tcp_helper = { 
++	.list = { NULL, NULL },
++	.name = "pptp", 
++	.flags = IP_NAT_HELPER_F_ALWAYS, 
++	.me = THIS_MODULE,
++	.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 = tcp_help, 
++	.expect = pptp_nat_expected 
++};
++
++			  
++static int __init init(void)
++{
++	DEBUGP("%s: registering NAT helper\n", __FILE__);
++	if (ip_nat_helper_register(&pptp_tcp_helper)) {
++		printk(KERN_ERR "Unable to register NAT application helper "
++				"for pptp\n");
++		return -EIO;
++	}
++
++	printk("ip_nat_pptp version %s loaded\n", IP_NAT_PPTP_VERSION);
++	return 0;
++}
++
++static void __exit fini(void)
++{
++	DEBUGP("cleanup_module\n" );
++	ip_nat_helper_unregister(&pptp_tcp_helper);
++	printk("ip_nat_pptp version %s unloaded\n", IP_NAT_PPTP_VERSION);
++}
++
++module_init(init);
++module_exit(fini);
+Binary files linux-2.4.29-old/net/ipv4/netfilter/.ip_nat_pptp.c.swp and linux-2.4.29-dev/net/ipv4/netfilter/.ip_nat_pptp.c.swp differ
+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
+@@ -0,0 +1,202 @@
++/*
++ * ip_nat_proto_gre.c - Version 1.2
++ *
++ * NAT protocol helper module for GRE.
++ *
++ * GRE is a generic encapsulation protocol, which is generally not very
++ * suited for NAT, as it has no protocol-specific part as port numbers.
++ *
++ * It has an optional key field, which may help us distinguishing two 
++ * connections between the same two hosts.
++ *
++ * GRE is defined in RFC 1701 and RFC 1702, as well as RFC 2784 
++ *
++ * PPTP is built on top of a modified version of GRE, and has a mandatory
++ * field called "CallID", which serves us for the same purpose as the key
++ * field in plain GRE.
++ *
++ * Documentation about 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/)
++ *
++ */
++
++#include <linux/config.h>
++#include <linux/module.h>
++#include <linux/ip.h>
++#include <linux/netfilter_ipv4/ip_nat.h>
++#include <linux/netfilter_ipv4/ip_nat_rule.h>
++#include <linux/netfilter_ipv4/ip_nat_protocol.h>
++#include <linux/netfilter_ipv4/ip_conntrack_proto_gre.h>
++
++MODULE_LICENSE("GPL");
++MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");
++MODULE_DESCRIPTION("Netfilter NAT protocol helper module for GRE");
++
++#if 0
++#define DEBUGP(format, args...) printk(KERN_DEBUG __FILE__ ":" __FUNCTION__ \
++				       ": " format, ## args)
++#else
++#define DEBUGP(x, args...)
++#endif
++
++/* is key in given range between min and max */
++static int
++gre_in_range(const struct ip_conntrack_tuple *tuple,
++	     enum ip_nat_manip_type maniptype,
++	     const union ip_conntrack_manip_proto *min,
++	     const union ip_conntrack_manip_proto *max)
++{
++	u_int32_t key;
++
++	if (maniptype == IP_NAT_MANIP_SRC)
++		key = tuple->src.u.gre.key;
++	else
++		key = tuple->dst.u.gre.key;
++
++	return ntohl(key) >= ntohl(min->gre.key)
++		&& ntohl(key) <= ntohl(max->gre.key);
++}
++
++/* generate unique tuple ... */
++static int 
++gre_unique_tuple(struct ip_conntrack_tuple *tuple,
++		 const struct ip_nat_range *range,
++		 enum ip_nat_manip_type maniptype,
++		 const struct ip_conntrack *conntrack)
++{
++	u_int32_t min, i, range_size;
++	u_int32_t key = 0, *keyptr;
++
++	if (maniptype == IP_NAT_MANIP_SRC)
++		keyptr = &tuple->src.u.gre.key;
++	else
++		keyptr = &tuple->dst.u.gre.key;
++
++	if (!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED)) {
++
++		DEBUGP("%p: NATing GRE PPTP\n", conntrack);
++		min = 1;
++		range_size = 0xffff;
++
++	} else {
++		min = ntohl(range->min.gre.key);
++		range_size = ntohl(range->max.gre.key) - min + 1;
++	}
++
++	DEBUGP("min = %u, range_size = %u\n", min, range_size); 
++
++	for (i = 0; i < range_size; i++, key++) {
++		*keyptr = htonl(min + key % range_size);
++		if (!ip_nat_used_tuple(tuple, conntrack))
++			return 1;
++	}
++
++	DEBUGP("%p: no NAT mapping\n", conntrack);
++
++	return 0;
++}
++
++/* manipulate a GRE packet according to maniptype */
++static void 
++gre_manip_pkt(struct iphdr *iph, size_t len, 
++	      const struct ip_conntrack_manip *manip,
++	      enum ip_nat_manip_type maniptype)
++{
++	struct gre_hdr *greh = (struct gre_hdr *)((u_int32_t *)iph+iph->ihl);
++	struct gre_hdr_pptp *pgreh = (struct gre_hdr_pptp *) greh;
++
++	/* we only have destination manip of a packet, since 'source key' 
++	 * is not present in the packet itself */
++	if (maniptype == IP_NAT_MANIP_DST) {
++		/* key manipulation is always dest */
++		switch (greh->version) {
++		case 0:
++			if (!greh->key) {
++				DEBUGP("can't nat GRE w/o key\n");
++				break;
++			}
++			if (greh->csum) {
++				/* FIXME: Never tested this code... */
++				*(gre_csum(greh)) = 
++					ip_nat_cheat_check(~*(gre_key(greh)),
++							manip->u.gre.key,
++							*(gre_csum(greh)));
++			}
++			*(gre_key(greh)) = manip->u.gre.key;
++			break;
++		case GRE_VERSION_PPTP:
++			DEBUGP("call_id -> 0x%04x\n", 
++				ntohl(manip->u.gre.key));
++			pgreh->call_id = htons(ntohl(manip->u.gre.key));
++			break;
++		default:
++			DEBUGP("can't nat unknown GRE version\n");
++			break;
++		}
++	}
++}
++
++/* print out a nat tuple */
++static unsigned int 
++gre_print(char *buffer, 
++	  const struct ip_conntrack_tuple *match,
++	  const struct ip_conntrack_tuple *mask)
++{
++	unsigned int len = 0;
++
++	if (mask->src.u.gre.key)
++		len += sprintf(buffer + len, "srckey=0x%x ", 
++				ntohl(match->src.u.gre.key));
++
++	if (mask->dst.u.gre.key)
++		len += sprintf(buffer + len, "dstkey=0x%x ",
++				ntohl(match->src.u.gre.key));
++
++	return len;
++}
++
++/* print a range of keys */
++static unsigned int 
++gre_print_range(char *buffer, const struct ip_nat_range *range)
++{
++	if (range->min.gre.key != 0 
++	    || range->max.gre.key != 0xFFFF) {
++		if (range->min.gre.key == range->max.gre.key)
++			return sprintf(buffer, "key 0x%x ",
++					ntohl(range->min.gre.key));
++		else
++			return sprintf(buffer, "keys 0x%u-0x%u ",
++					ntohl(range->min.gre.key),
++					ntohl(range->max.gre.key));
++	} else
++		return 0;
++}
++
++/* nat helper struct */
++static struct ip_nat_protocol gre = 
++	{ { NULL, NULL }, "GRE", IPPROTO_GRE,
++	  gre_manip_pkt,
++	  gre_in_range,
++	  gre_unique_tuple,
++	  gre_print,
++	  gre_print_range 
++	};
++				  
++static int __init init(void)
++{
++        if (ip_nat_protocol_register(&gre))
++                return -EIO;
++
++        return 0;
++}
++
++static void __exit fini(void)
++{
++        ip_nat_protocol_unregister(&gre);
++}
++
++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
+@@ -36,23 +36,32 @@
+ ifdef CONFIG_IP_NF_AMANDA
+ 	export-objs += ip_conntrack_amanda.o
+ endif
+-
+ obj-$(CONFIG_IP_NF_TFTP) += ip_conntrack_tftp.o
+ obj-$(CONFIG_IP_NF_FTP) += ip_conntrack_ftp.o
+ ifdef CONFIG_IP_NF_FTP
+ 	export-objs += ip_conntrack_ftp.o
+ endif
+-
+ obj-$(CONFIG_IP_NF_IRC) += ip_conntrack_irc.o
+ ifdef CONFIG_IP_NF_IRC
+ 	export-objs += ip_conntrack_irc.o
+ endif
++obj-$(CONFIG_IP_NF_CT_PROTO_GRE) += ip_conntrack_proto_gre.o
++ifdef CONFIG_IP_NF_CT_PROTO_GRE
++	export-objs += ip_conntrack_proto_gre.o
++endif
++obj-$(CONFIG_IP_NF_PPTP) += ip_conntrack_pptp.o
++ifdef CONFIG_IP_NF_NAT_PPTP
++	export-objs += ip_conntrack_pptp.o
++endif
++
+ 
+ # NAT helpers 
+ obj-$(CONFIG_IP_NF_NAT_AMANDA) += ip_nat_amanda.o
+ obj-$(CONFIG_IP_NF_NAT_TFTP) += ip_nat_tftp.o
+ obj-$(CONFIG_IP_NF_NAT_FTP) += ip_nat_ftp.o
+ obj-$(CONFIG_IP_NF_NAT_IRC) += ip_nat_irc.o
++obj-$(CONFIG_IP_NF_NAT_PROTO_GRE) += ip_nat_proto_gre.o
++obj-$(CONFIG_IP_NF_NAT_PPTP) += ip_nat_pptp.o
+ 
+ # generic IP tables 
+ obj-$(CONFIG_IP_NF_IPTABLES) += ip_tables.o