path: root/package/linux/kernel-patches/308-netfilter-nat-pptp

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