path: root/packages/linux/linux-mtx-1-2.4.27/48-pptp.patch

diff -uNr linux_org/Documentation/Configure.help linux/Documentation/Configure.help
--- linux_org/Documentation/Configure.help	2006-10-27 14:08:20.000000000 +0200
+++ linux/Documentation/Configure.help	2006-10-27 14:11:52.000000000 +0200
@@ -2848,6 +2848,31 @@
   If you want to compile it as a module, say M here and read
   <file:Documentation/modules.txt>.  If unsure, say `Y'.
 
+PPTP conntrack and NAT support
+CONFIG_IP_NF_PPTP
+  This module adds support for PPTP (Point to Point Tunnelling Protocol, 
+  RFC2637) conncection tracking and NAT. 
+
+  If you are running PPTP sessions over a stateful firewall or NAT box,
+  you may want to enable this feature.  
+
+  Please note that not all PPTP modes of operation are supported yet.
+  For more info, read top of the file net/ipv4/netfilter/ip_conntrack_pptp.c
+
+  If you want to compile it as a module, say M here and read
+  Documentation/modules.txt.  If unsure, say `N'.
+
+GRE protocol conntrack and NAT support
+CONFIG_IP_NF_CT_PROTO_GRE
+  This module adds generic support for connection tracking and NAT of the
+  GRE protocol (RFC1701, RFC2784).  Please note that this will only work
+  with GRE connections using the key field of the GRE header.
+
+  You will need GRE support to enable PPTP support.
+
+  If you want to compile it as a module, say `M' here and read
+  Documentation/modules.txt.  If unsire, say `N'.
+
 User space queueing via NETLINK
 CONFIG_IP_NF_QUEUE
   Netfilter has the ability to queue packets to user space: the
diff -uNr linux_org/include/linux/netfilter_ipv4/ip_conntrack.h linux/include/linux/netfilter_ipv4/ip_conntrack.h
--- linux_org/include/linux/netfilter_ipv4/ip_conntrack.h	2004-11-24 12:13:57.000000000 +0100
+++ linux/include/linux/netfilter_ipv4/ip_conntrack.h	2006-10-27 14:11:52.000000000 +0200
@@ -50,19 +50,23 @@
 
 #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_gre gre;
 	struct ip_ct_tcp tcp;
 	struct ip_ct_icmp icmp;
 };
 
 union ip_conntrack_expect_proto {
 	/* insert expect proto private data here */
+	struct ip_ct_gre_expect gre;
 };
 
 /* Add protocol helper include file here */
+#include <linux/netfilter_ipv4/ip_conntrack_pptp.h>
 #include <linux/netfilter_ipv4/ip_conntrack_amanda.h>
 
 #include <linux/netfilter_ipv4/ip_conntrack_ftp.h>
@@ -71,6 +75,7 @@
 /* per expectation: application helper private data */
 union ip_conntrack_expect_help {
 	/* insert conntrack helper private data (expect) here */
+	struct ip_ct_pptp_expect exp_pptp_info;
 	struct ip_ct_amanda_expect exp_amanda_info;
 	struct ip_ct_ftp_expect exp_ftp_info;
 	struct ip_ct_irc_expect exp_irc_info;
@@ -85,16 +90,19 @@
 /* per conntrack: application helper private data */
 union ip_conntrack_help {
 	/* insert conntrack helper private data (master) here */
+	struct ip_ct_pptp_master ct_pptp_info;
 	struct ip_ct_ftp_master ct_ftp_info;
 	struct ip_ct_irc_master ct_irc_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 -uNr linux_org/include/linux/netfilter_ipv4/ip_conntrack_pptp.h linux/include/linux/netfilter_ipv4/ip_conntrack_pptp.h
--- linux_org/include/linux/netfilter_ipv4/ip_conntrack_pptp.h	1970-01-01 01:00:00.000000000 +0100
+++ linux/include/linux/netfilter_ipv4/ip_conntrack_pptp.h	2006-10-27 14:11:52.000000000 +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 PptpStopSessionReqest	*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 -uNr linux_org/include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h linux/include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h
--- linux_org/include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h	1970-01-01 01:00:00.000000000 +0100
+++ linux/include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h	2006-10-27 14:11:52.000000000 +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 -uNr linux_org/include/linux/netfilter_ipv4/ip_conntrack_tuple.h linux/include/linux/netfilter_ipv4/ip_conntrack_tuple.h
--- linux_org/include/linux/netfilter_ipv4/ip_conntrack_tuple.h	2003-11-17 02:07:46.000000000 +0100
+++ linux/include/linux/netfilter_ipv4/ip_conntrack_tuple.h	2006-10-27 14:11:52.000000000 +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_int64_t all;
 
 			struct {
 				u_int16_t port;
@@ -55,6 +58,11 @@
 			struct {
 				u_int8_t type, code;
 			} icmp;
+			struct {
+				u_int16_t protocol;
+				u_int8_t version;
+				u_int32_t key;
+			} gre;
 		} u;
 
 		/* The protocol. */
@@ -80,10 +88,16 @@
 #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 -uNr linux_org/include/linux/netfilter_ipv4/ip_conntrack_tuple.h.orig linux/include/linux/netfilter_ipv4/ip_conntrack_tuple.h.orig
--- linux_org/include/linux/netfilter_ipv4/ip_conntrack_tuple.h.orig	1970-01-01 01:00:00.000000000 +0100
+++ linux/include/linux/netfilter_ipv4/ip_conntrack_tuple.h.orig	2003-11-17 02:07:46.000000000 +0100
@@ -0,0 +1,139 @@
+#ifndef _IP_CONNTRACK_TUPLE_H
+#define _IP_CONNTRACK_TUPLE_H
+
+/* A `tuple' is a structure containing the information to uniquely
+  identify a connection.  ie. if two packets have the same tuple, they
+  are in the same connection; if not, they are not.
+
+  We divide the structure along "manipulatable" and
+  "non-manipulatable" lines, for the benefit of the NAT code.
+*/
+
+/* The protocol-specific manipulable parts of the tuple: always in
+   network order! */
+union ip_conntrack_manip_proto
+{
+	/* Add other protocols here. */
+	u_int16_t all;
+
+	struct {
+		u_int16_t port;
+	} tcp;
+	struct {
+		u_int16_t port;
+	} udp;
+	struct {
+		u_int16_t id;
+	} icmp;
+};
+
+/* The manipulable part of the tuple. */
+struct ip_conntrack_manip
+{
+	u_int32_t ip;
+	union ip_conntrack_manip_proto u;
+};
+
+/* This contains the information to distinguish a connection. */
+struct ip_conntrack_tuple
+{
+	struct ip_conntrack_manip src;
+
+	/* These are the parts of the tuple which are fixed. */
+	struct {
+		u_int32_t ip;
+		union {
+			/* Add other protocols here. */
+			u_int16_t all;
+
+			struct {
+				u_int16_t port;
+			} tcp;
+			struct {
+				u_int16_t port;
+			} udp;
+			struct {
+				u_int8_t type, code;
+			} icmp;
+		} u;
+
+		/* The protocol. */
+		u_int16_t protonum;
+	} dst;
+};
+
+/* This is optimized opposed to a memset of the whole structure.  Everything we
+ * really care about is the  source/destination unions */
+#define IP_CT_TUPLE_U_BLANK(tuple) 				\
+	do {							\
+		(tuple)->src.u.all = 0;				\
+		(tuple)->dst.u.all = 0;				\
+	} while (0)
+
+enum ip_conntrack_dir
+{
+	IP_CT_DIR_ORIGINAL,
+	IP_CT_DIR_REPLY,
+	IP_CT_DIR_MAX
+};
+
+#ifdef __KERNEL__
+
+#define DUMP_TUPLE(tp)						\
+DEBUGP("tuple %p: %u %u.%u.%u.%u:%hu -> %u.%u.%u.%u:%hu\n",	\
+       (tp), (tp)->dst.protonum,				\
+       NIPQUAD((tp)->src.ip), ntohs((tp)->src.u.all),		\
+       NIPQUAD((tp)->dst.ip), ntohs((tp)->dst.u.all))
+
+#define CTINFO2DIR(ctinfo) ((ctinfo) >= IP_CT_IS_REPLY ? IP_CT_DIR_REPLY : IP_CT_DIR_ORIGINAL)
+
+/* If we're the first tuple, it's the original dir. */
+#define DIRECTION(h) ((enum ip_conntrack_dir)(&(h)->ctrack->tuplehash[1] == (h)))
+
+/* Connections have two entries in the hash table: one for each way */
+struct ip_conntrack_tuple_hash
+{
+	struct list_head list;
+
+	struct ip_conntrack_tuple tuple;
+
+	/* this == &ctrack->tuplehash[DIRECTION(this)]. */
+	struct ip_conntrack *ctrack;
+};
+
+#endif /* __KERNEL__ */
+
+static inline int ip_ct_tuple_src_equal(const struct ip_conntrack_tuple *t1,
+				        const struct ip_conntrack_tuple *t2)
+{
+	return t1->src.ip == t2->src.ip
+		&& t1->src.u.all == t2->src.u.all;
+}
+
+static inline int ip_ct_tuple_dst_equal(const struct ip_conntrack_tuple *t1,
+				        const struct ip_conntrack_tuple *t2)
+{
+	return t1->dst.ip == t2->dst.ip
+		&& t1->dst.u.all == t2->dst.u.all
+		&& t1->dst.protonum == t2->dst.protonum;
+}
+
+static inline int ip_ct_tuple_equal(const struct ip_conntrack_tuple *t1,
+				    const struct ip_conntrack_tuple *t2)
+{
+	return ip_ct_tuple_src_equal(t1, t2) && ip_ct_tuple_dst_equal(t1, t2);
+}
+
+static inline int ip_ct_tuple_mask_cmp(const struct ip_conntrack_tuple *t,
+				       const struct ip_conntrack_tuple *tuple,
+				       const struct ip_conntrack_tuple *mask)
+{
+	return !(((t->src.ip ^ tuple->src.ip) & mask->src.ip)
+		 || ((t->dst.ip ^ tuple->dst.ip) & mask->dst.ip)
+		 || ((t->src.u.all ^ tuple->src.u.all) & mask->src.u.all)
+		 || ((t->dst.u.all ^ tuple->dst.u.all) & mask->dst.u.all)
+		 || ((t->dst.protonum ^ tuple->dst.protonum)
+		     & mask->dst.protonum));
+}
+
+#endif /* _IP_CONNTRACK_TUPLE_H */
diff -uNr linux_org/include/linux/netfilter_ipv4/ip_nat_pptp.h linux/include/linux/netfilter_ipv4/ip_nat_pptp.h
--- linux_org/include/linux/netfilter_ipv4/ip_nat_pptp.h	1970-01-01 01:00:00.000000000 +0100
+++ linux/include/linux/netfilter_ipv4/ip_nat_pptp.h	2006-10-27 14:11:52.000000000 +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 -uNr linux_org/net/ipv4/netfilter/Config.in linux/net/ipv4/netfilter/Config.in
--- linux_org/net/ipv4/netfilter/Config.in	2003-08-13 19:19:30.000000000 +0200
+++ linux/net/ipv4/netfilter/Config.in	2006-10-27 14:11:52.000000000 +0200
@@ -7,6 +7,11 @@
 tristate 'Connection tracking (required for masq/NAT)' CONFIG_IP_NF_CONNTRACK
 if [ "$CONFIG_IP_NF_CONNTRACK" != "n" ]; then
   dep_tristate '  FTP protocol support' CONFIG_IP_NF_FTP $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 $CONFIG_IP_NF_CONNTRACK
+  if [ "$CONFIG_IP_NF_PPTP" != "n" ]; then
+	bool   '    PPTP verbose debug' CONFIG_IP_NF_PPTP_DEBUG
+  fi
   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 $CONFIG_IP_NF_CONNTRACK
@@ -67,6 +72,20 @@
         fi
       fi
       bool '    NAT of local connections (READ HELP)' CONFIG_IP_NF_NAT_LOCAL
+      if [ "$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_EXPERIMENTAL" = "y" ]; then
         dep_tristate '    Basic SNMP-ALG support (EXPERIMENTAL)' CONFIG_IP_NF_NAT_SNMP_BASIC $CONFIG_IP_NF_NAT
       fi
diff -uNr linux_org/net/ipv4/netfilter/Makefile linux/net/ipv4/netfilter/Makefile
--- linux_org/net/ipv4/netfilter/Makefile	2003-08-13 19:19:30.000000000 +0200
+++ linux/net/ipv4/netfilter/Makefile	2006-10-27 14:11:52.000000000 +0200
@@ -30,8 +30,21 @@
 
 # connection tracking
 obj-$(CONFIG_IP_NF_CONNTRACK) += ip_conntrack.o
+ 
+# connection tracking protocol helpers
+obj-$(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
+
+# NAT protocol helpers
+obj-$(CONFIG_IP_NF_NAT_PROTO_GRE) += ip_nat_proto_gre.o
 
 # connection tracking helpers
+obj-$(CONFIG_IP_NF_PPTP) += ip_conntrack_pptp.o
+ifdef CONFIG_IP_NF_NAT_PPTP
+	export-objs += ip_conntrack_pptp.o
+endif
 obj-$(CONFIG_IP_NF_AMANDA) += ip_conntrack_amanda.o
 ifdef CONFIG_IP_NF_AMANDA
 	export-objs += ip_conntrack_amanda.o
@@ -49,6 +62,7 @@
 endif
 
 # NAT helpers 
+obj-$(CONFIG_IP_NF_NAT_PPTP) += ip_nat_pptp.o
 obj-$(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
diff -uNr linux_org/net/ipv4/netfilter/ip_conntrack_core.c linux/net/ipv4/netfilter/ip_conntrack_core.c
--- linux_org/net/ipv4/netfilter/ip_conntrack_core.c	2004-11-24 12:14:04.000000000 +0100
+++ linux/net/ipv4/netfilter/ip_conntrack_core.c	2006-10-27 14:11:52.000000000 +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);
 }
 
@@ -945,8 +949,8 @@
 	 * 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, 
@@ -1063,15 +1067,14 @@
 
 	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 -uNr linux_org/net/ipv4/netfilter/ip_conntrack_core.c.orig linux/net/ipv4/netfilter/ip_conntrack_core.c.orig
--- linux_org/net/ipv4/netfilter/ip_conntrack_core.c.orig	1970-01-01 01:00:00.000000000 +0100
+++ linux/net/ipv4/netfilter/ip_conntrack_core.c.orig	2004-11-24 12:14:04.000000000 +0100
@@ -0,0 +1,1446 @@
+/* Connection state tracking for netfilter.  This is separated from,
+   but required by, the NAT layer; it can also be used by an iptables
+   extension. */
+
+/* (c) 1999 Paul `Rusty' Russell.  Licenced under the GNU General
+ * Public Licence. 
+ *
+ * 23 Apr 2001: Harald Welte <laforge@gnumonks.org>
+ * 	- new API and handling of conntrack/nat helpers
+ * 	- now capable of multiple expectations for one master
+ * 16 Jul 2002: Harald Welte <laforge@gnumonks.org>
+ * 	- add usage/reference counts to ip_conntrack_expect
+ *	- export ip_conntrack[_expect]_{find_get,put} functions
+ * */
+
+#include <linux/version.h>
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/ip.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/proc_fs.h>
+#include <linux/vmalloc.h>
+#include <linux/brlock.h>
+#include <net/checksum.h>
+#include <linux/stddef.h>
+#include <linux/sysctl.h>
+#include <linux/slab.h>
+#include <linux/random.h>
+#include <linux/jhash.h>
+/* For ERR_PTR().  Yeah, I know... --RR */
+#include <linux/fs.h>
+
+/* This rwlock protects the main hash table, protocol/helper/expected
+   registrations, conntrack timers*/
+#define ASSERT_READ_LOCK(x) MUST_BE_READ_LOCKED(&ip_conntrack_lock)
+#define ASSERT_WRITE_LOCK(x) MUST_BE_WRITE_LOCKED(&ip_conntrack_lock)
+
+#include <linux/netfilter_ipv4/ip_conntrack.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/listhelp.h>
+
+#define IP_CONNTRACK_VERSION	"2.1"
+
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(format, args...)
+#endif
+
+DECLARE_RWLOCK(ip_conntrack_lock);
+DECLARE_RWLOCK(ip_conntrack_expect_tuple_lock);
+
+void (*ip_conntrack_destroyed)(struct ip_conntrack *conntrack) = NULL;
+LIST_HEAD(ip_conntrack_expect_list);
+LIST_HEAD(protocol_list);
+static LIST_HEAD(helpers);
+unsigned int ip_conntrack_htable_size = 0;
+int ip_conntrack_max = 0;
+static atomic_t ip_conntrack_count = ATOMIC_INIT(0);
+struct list_head *ip_conntrack_hash;
+static kmem_cache_t *ip_conntrack_cachep;
+
+extern struct ip_conntrack_protocol ip_conntrack_generic_protocol;
+
+static inline int proto_cmpfn(const struct ip_conntrack_protocol *curr,
+			      u_int8_t protocol)
+{
+	return protocol == curr->proto;
+}
+
+struct ip_conntrack_protocol *__ip_ct_find_proto(u_int8_t protocol)
+{
+	struct ip_conntrack_protocol *p;
+
+	MUST_BE_READ_LOCKED(&ip_conntrack_lock);
+	p = LIST_FIND(&protocol_list, proto_cmpfn,
+		      struct ip_conntrack_protocol *, protocol);
+	if (!p)
+		p = &ip_conntrack_generic_protocol;
+
+	return p;
+}
+
+struct ip_conntrack_protocol *ip_ct_find_proto(u_int8_t protocol)
+{
+	struct ip_conntrack_protocol *p;
+
+	READ_LOCK(&ip_conntrack_lock);
+	p = __ip_ct_find_proto(protocol);
+	READ_UNLOCK(&ip_conntrack_lock);
+	return p;
+}
+
+inline void 
+ip_conntrack_put(struct ip_conntrack *ct)
+{
+	IP_NF_ASSERT(ct);
+	IP_NF_ASSERT(ct->infos[0].master);
+	/* nf_conntrack_put wants to go via an info struct, so feed it
+           one at random. */
+	nf_conntrack_put(&ct->infos[0]);
+}
+
+static int ip_conntrack_hash_rnd_initted;
+static unsigned int ip_conntrack_hash_rnd;
+
+static u_int32_t
+hash_conntrack(const struct ip_conntrack_tuple *tuple)
+{
+#if 0
+	dump_tuple(tuple);
+#endif
+	return (jhash_3words(tuple->src.ip,
+	                     (tuple->dst.ip ^ tuple->dst.protonum),
+	                     (tuple->src.u.all | (tuple->dst.u.all << 16)),
+	                     ip_conntrack_hash_rnd) % ip_conntrack_htable_size);
+}
+
+inline int
+get_tuple(const struct iphdr *iph, size_t len,
+	  struct ip_conntrack_tuple *tuple,
+	  struct ip_conntrack_protocol *protocol)
+{
+	int ret;
+
+	/* Never happen */
+	if (iph->frag_off & htons(IP_OFFSET)) {
+		printk("ip_conntrack_core: Frag of proto %u.\n",
+		       iph->protocol);
+		return 0;
+	}
+	/* Guarantee 8 protocol bytes: if more wanted, use len param */
+	else if (iph->ihl * 4 + 8 > len)
+		return 0;
+
+	tuple->src.ip = iph->saddr;
+	tuple->dst.ip = iph->daddr;
+	tuple->dst.protonum = iph->protocol;
+
+	ret = protocol->pkt_to_tuple((u_int32_t *)iph + iph->ihl,
+				     len - 4*iph->ihl,
+				     tuple);
+	return ret;
+}
+
+static int
+invert_tuple(struct ip_conntrack_tuple *inverse,
+	     const struct ip_conntrack_tuple *orig,
+	     const struct ip_conntrack_protocol *protocol)
+{
+	inverse->src.ip = orig->dst.ip;
+	inverse->dst.ip = orig->src.ip;
+	inverse->dst.protonum = orig->dst.protonum;
+
+	return protocol->invert_tuple(inverse, orig);
+}
+
+
+/* ip_conntrack_expect helper functions */
+
+/* Compare tuple parts depending on mask. */
+static inline int expect_cmp(const struct ip_conntrack_expect *i,
+			     const struct ip_conntrack_tuple *tuple)
+{
+	MUST_BE_READ_LOCKED(&ip_conntrack_expect_tuple_lock);
+	return ip_ct_tuple_mask_cmp(tuple, &i->tuple, &i->mask);
+}
+
+static void
+destroy_expect(struct ip_conntrack_expect *exp)
+{
+	DEBUGP("destroy_expect(%p) use=%d\n", exp, atomic_read(&exp->use));
+	IP_NF_ASSERT(atomic_read(&exp->use) == 0);
+	IP_NF_ASSERT(!timer_pending(&exp->timeout));
+
+	kfree(exp);
+}
+
+inline void ip_conntrack_expect_put(struct ip_conntrack_expect *exp)
+{
+	IP_NF_ASSERT(exp);
+
+	if (atomic_dec_and_test(&exp->use)) {
+		/* usage count dropped to zero */
+		destroy_expect(exp);
+	}
+}
+
+static inline struct ip_conntrack_expect *
+__ip_ct_expect_find(const struct ip_conntrack_tuple *tuple)
+{
+	MUST_BE_READ_LOCKED(&ip_conntrack_lock);
+	MUST_BE_READ_LOCKED(&ip_conntrack_expect_tuple_lock);
+	return LIST_FIND(&ip_conntrack_expect_list, expect_cmp, 
+			 struct ip_conntrack_expect *, tuple);
+}
+
+/* Find a expectation corresponding to a tuple. */
+struct ip_conntrack_expect *
+ip_conntrack_expect_find_get(const struct ip_conntrack_tuple *tuple)
+{
+	struct ip_conntrack_expect *exp;
+
+	READ_LOCK(&ip_conntrack_lock);
+	READ_LOCK(&ip_conntrack_expect_tuple_lock);
+	exp = __ip_ct_expect_find(tuple);
+	if (exp)
+		atomic_inc(&exp->use);
+	READ_UNLOCK(&ip_conntrack_expect_tuple_lock);
+	READ_UNLOCK(&ip_conntrack_lock);
+
+	return exp;
+}
+
+/* remove one specific expectation from all lists and drop refcount,
+ * does _NOT_ delete the timer. */
+static void __unexpect_related(struct ip_conntrack_expect *expect)
+{
+	DEBUGP("unexpect_related(%p)\n", expect);
+	MUST_BE_WRITE_LOCKED(&ip_conntrack_lock);
+
+	/* we're not allowed to unexpect a confirmed expectation! */
+	IP_NF_ASSERT(!expect->sibling);
+
+	/* delete from global and local lists */
+	list_del(&expect->list);
+	list_del(&expect->expected_list);
+
+	/* decrement expect-count of master conntrack */
+	if (expect->expectant)
+		expect->expectant->expecting--;
+
+	ip_conntrack_expect_put(expect);
+}
+
+/* remove one specific expecatation from all lists, drop refcount
+ * and expire timer. 
+ * This function can _NOT_ be called for confirmed expects! */
+static void unexpect_related(struct ip_conntrack_expect *expect)
+{
+	IP_NF_ASSERT(expect->expectant);
+	IP_NF_ASSERT(expect->expectant->helper);
+	/* if we are supposed to have a timer, but we can't delete
+	 * it: race condition.  __unexpect_related will
+	 * be calledd by timeout function */
+	if (expect->expectant->helper->timeout
+	    && !del_timer(&expect->timeout))
+		return;
+
+	__unexpect_related(expect);
+}
+
+/* delete all unconfirmed expectations for this conntrack */
+static void remove_expectations(struct ip_conntrack *ct, int drop_refcount)
+{
+	struct list_head *exp_entry, *next;
+	struct ip_conntrack_expect *exp;
+
+	DEBUGP("remove_expectations(%p)\n", ct);
+
+	list_for_each_safe(exp_entry, next, &ct->sibling_list) {
+		exp = list_entry(exp_entry, struct ip_conntrack_expect,
+				 expected_list);
+
+		/* we skip established expectations, as we want to delete
+		 * the un-established ones only */
+		if (exp->sibling) {
+			DEBUGP("remove_expectations: skipping established %p of %p\n", exp->sibling, ct);
+			if (drop_refcount) {
+				/* Indicate that this expectations parent is dead */
+				ip_conntrack_put(exp->expectant);
+				exp->expectant = NULL;
+			}
+			continue;
+		}
+
+		IP_NF_ASSERT(list_inlist(&ip_conntrack_expect_list, exp));
+		IP_NF_ASSERT(exp->expectant == ct);
+
+		/* delete expectation from global and private lists */
+		unexpect_related(exp);
+	}
+}
+
+static void
+clean_from_lists(struct ip_conntrack *ct)
+{
+	unsigned int ho, hr;
+	
+	DEBUGP("clean_from_lists(%p)\n", ct);
+	MUST_BE_WRITE_LOCKED(&ip_conntrack_lock);
+
+	ho = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
+	hr = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
+	LIST_DELETE(&ip_conntrack_hash[ho], &ct->tuplehash[IP_CT_DIR_ORIGINAL]);
+	LIST_DELETE(&ip_conntrack_hash[hr], &ct->tuplehash[IP_CT_DIR_REPLY]);
+
+	/* Destroy all un-established, pending expectations */
+	remove_expectations(ct, 1);
+}
+
+static void
+destroy_conntrack(struct nf_conntrack *nfct)
+{
+	struct ip_conntrack *ct = (struct ip_conntrack *)nfct, *master = NULL;
+	struct ip_conntrack_protocol *proto;
+
+	DEBUGP("destroy_conntrack(%p)\n", ct);
+	IP_NF_ASSERT(atomic_read(&nfct->use) == 0);
+	IP_NF_ASSERT(!timer_pending(&ct->timeout));
+
+	/* To make sure we don't get any weird locking issues here:
+	 * destroy_conntrack() MUST NOT be called with a write lock
+	 * to ip_conntrack_lock!!! -HW */
+	proto = ip_ct_find_proto(ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.protonum);
+	if (proto && proto->destroy)
+		proto->destroy(ct);
+
+	if (ip_conntrack_destroyed)
+		ip_conntrack_destroyed(ct);
+
+	WRITE_LOCK(&ip_conntrack_lock);
+	/* Make sure don't leave any orphaned expectations lying around */
+	if (ct->expecting)
+		remove_expectations(ct, 1);
+
+	/* Delete our master expectation */
+	if (ct->master) {
+		if (ct->master->expectant) {
+			/* can't call __unexpect_related here,
+			 * since it would screw up expect_list */
+			list_del(&ct->master->expected_list);
+			master = ct->master->expectant;
+		}
+		kfree(ct->master);
+	}
+	WRITE_UNLOCK(&ip_conntrack_lock);
+
+	if (master)
+		ip_conntrack_put(master);
+
+	DEBUGP("destroy_conntrack: returning ct=%p to slab\n", ct);
+	kmem_cache_free(ip_conntrack_cachep, ct);
+	atomic_dec(&ip_conntrack_count);
+}
+
+static void death_by_timeout(unsigned long ul_conntrack)
+{
+	struct ip_conntrack *ct = (void *)ul_conntrack;
+
+	WRITE_LOCK(&ip_conntrack_lock);
+	clean_from_lists(ct);
+	WRITE_UNLOCK(&ip_conntrack_lock);
+	ip_conntrack_put(ct);
+}
+
+static inline int
+conntrack_tuple_cmp(const struct ip_conntrack_tuple_hash *i,
+		    const struct ip_conntrack_tuple *tuple,
+		    const struct ip_conntrack *ignored_conntrack)
+{
+	MUST_BE_READ_LOCKED(&ip_conntrack_lock);
+	return i->ctrack != ignored_conntrack
+		&& ip_ct_tuple_equal(tuple, &i->tuple);
+}
+
+static struct ip_conntrack_tuple_hash *
+__ip_conntrack_find(const struct ip_conntrack_tuple *tuple,
+		    const struct ip_conntrack *ignored_conntrack)
+{
+	struct ip_conntrack_tuple_hash *h;
+	unsigned int hash = hash_conntrack(tuple);
+
+	MUST_BE_READ_LOCKED(&ip_conntrack_lock);
+	h = LIST_FIND(&ip_conntrack_hash[hash],
+		      conntrack_tuple_cmp,
+		      struct ip_conntrack_tuple_hash *,
+		      tuple, ignored_conntrack);
+	return h;
+}
+
+/* Find a connection corresponding to a tuple. */
+struct ip_conntrack_tuple_hash *
+ip_conntrack_find_get(const struct ip_conntrack_tuple *tuple,
+		      const struct ip_conntrack *ignored_conntrack)
+{
+	struct ip_conntrack_tuple_hash *h;
+
+	READ_LOCK(&ip_conntrack_lock);
+	h = __ip_conntrack_find(tuple, ignored_conntrack);
+	if (h)
+		atomic_inc(&h->ctrack->ct_general.use);
+	READ_UNLOCK(&ip_conntrack_lock);
+
+	return h;
+}
+
+static inline struct ip_conntrack *
+__ip_conntrack_get(struct nf_ct_info *nfct, enum ip_conntrack_info *ctinfo)
+{
+	struct ip_conntrack *ct
+		= (struct ip_conntrack *)nfct->master;
+
+	/* ctinfo is the index of the nfct inside the conntrack */
+	*ctinfo = nfct - ct->infos;
+	IP_NF_ASSERT(*ctinfo >= 0 && *ctinfo < IP_CT_NUMBER);
+	return ct;
+}
+
+/* Return conntrack and conntrack_info given skb->nfct->master */
+struct ip_conntrack *
+ip_conntrack_get(struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
+{
+	if (skb->nfct) 
+		return __ip_conntrack_get(skb->nfct, ctinfo);
+	return NULL;
+}
+
+/* Confirm a connection given skb->nfct; places it in hash table */
+int
+__ip_conntrack_confirm(struct nf_ct_info *nfct)
+{
+	unsigned int hash, repl_hash;
+	struct ip_conntrack *ct;
+	enum ip_conntrack_info ctinfo;
+
+	ct = __ip_conntrack_get(nfct, &ctinfo);
+
+	/* ipt_REJECT uses ip_conntrack_attach to attach related
+	   ICMP/TCP RST packets in other direction.  Actual packet
+	   which created connection will be IP_CT_NEW or for an
+	   expected connection, IP_CT_RELATED. */
+	if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
+		return NF_ACCEPT;
+
+	hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
+	repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
+
+	/* We're not in hash table, and we refuse to set up related
+	   connections for unconfirmed conns.  But packet copies and
+	   REJECT will give spurious warnings here. */
+	/* IP_NF_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
+
+	/* No external references means noone else could have
+           confirmed us. */
+	IP_NF_ASSERT(!is_confirmed(ct));
+	DEBUGP("Confirming conntrack %p\n", ct);
+
+	WRITE_LOCK(&ip_conntrack_lock);
+	/* See if there's one in the list already, including reverse:
+           NAT could have grabbed it without realizing, since we're
+           not in the hash.  If there is, we lost race. */
+	if (!LIST_FIND(&ip_conntrack_hash[hash],
+		       conntrack_tuple_cmp,
+		       struct ip_conntrack_tuple_hash *,
+		       &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple, NULL)
+	    && !LIST_FIND(&ip_conntrack_hash[repl_hash],
+			  conntrack_tuple_cmp,
+			  struct ip_conntrack_tuple_hash *,
+			  &ct->tuplehash[IP_CT_DIR_REPLY].tuple, NULL)) {
+		list_prepend(&ip_conntrack_hash[hash],
+			     &ct->tuplehash[IP_CT_DIR_ORIGINAL]);
+		list_prepend(&ip_conntrack_hash[repl_hash],
+			     &ct->tuplehash[IP_CT_DIR_REPLY]);
+		/* Timer relative to confirmation time, not original
+		   setting time, otherwise we'd get timer wrap in
+		   weird delay cases. */
+		ct->timeout.expires += jiffies;
+		add_timer(&ct->timeout);
+		atomic_inc(&ct->ct_general.use);
+		set_bit(IPS_CONFIRMED_BIT, &ct->status);
+		WRITE_UNLOCK(&ip_conntrack_lock);
+		return NF_ACCEPT;
+	}
+
+	WRITE_UNLOCK(&ip_conntrack_lock);
+	return NF_DROP;
+}
+
+/* Returns true if a connection correspondings to the tuple (required
+   for NAT). */
+int
+ip_conntrack_tuple_taken(const struct ip_conntrack_tuple *tuple,
+			 const struct ip_conntrack *ignored_conntrack)
+{
+	struct ip_conntrack_tuple_hash *h;
+
+	READ_LOCK(&ip_conntrack_lock);
+	h = __ip_conntrack_find(tuple, ignored_conntrack);
+	READ_UNLOCK(&ip_conntrack_lock);
+
+	return h != NULL;
+}
+
+/* Returns conntrack if it dealt with ICMP, and filled in skb fields */
+struct ip_conntrack *
+icmp_error_track(struct sk_buff *skb,
+		 enum ip_conntrack_info *ctinfo,
+		 unsigned int hooknum)
+{
+	const struct iphdr *iph = skb->nh.iph;
+	struct icmphdr *hdr;
+	struct ip_conntrack_tuple innertuple, origtuple;
+	struct iphdr *inner;
+	size_t datalen;
+	struct ip_conntrack_protocol *innerproto;
+	struct ip_conntrack_tuple_hash *h;
+
+	IP_NF_ASSERT(iph->protocol == IPPROTO_ICMP);
+	IP_NF_ASSERT(skb->nfct == NULL);
+
+	hdr = (struct icmphdr *)((u_int32_t *)iph + iph->ihl);
+	inner = (struct iphdr *)(hdr + 1);
+	datalen = skb->len - iph->ihl*4 - sizeof(*hdr);
+
+	if (skb->len < iph->ihl * 4 + sizeof(*hdr) + sizeof(*iph)) {
+		DEBUGP("icmp_error_track: too short\n");
+		return NULL;
+	}
+
+	if (hdr->type != ICMP_DEST_UNREACH
+	    && hdr->type != ICMP_SOURCE_QUENCH
+	    && hdr->type != ICMP_TIME_EXCEEDED
+	    && hdr->type != ICMP_PARAMETERPROB
+	    && hdr->type != ICMP_REDIRECT)
+		return NULL;
+
+	/* Ignore ICMP's containing fragments (shouldn't happen) */
+	if (inner->frag_off & htons(IP_OFFSET)) {
+		DEBUGP("icmp_error_track: fragment of proto %u\n",
+		       inner->protocol);
+		return NULL;
+	}
+
+	/* Ignore it if the checksum's bogus. */
+	if (ip_compute_csum((unsigned char *)hdr, sizeof(*hdr) + datalen)) {
+		DEBUGP("icmp_error_track: bad csum\n");
+		return NULL;
+	}
+
+	innerproto = ip_ct_find_proto(inner->protocol);
+	/* Are they talking about one of our connections? */
+	if (inner->ihl * 4 + 8 > datalen
+	    || !get_tuple(inner, datalen, &origtuple, innerproto)) {
+		DEBUGP("icmp_error: ! get_tuple p=%u (%u*4+%u dlen=%u)\n",
+		       inner->protocol, inner->ihl, 8,
+		       datalen);
+		return NULL;
+	}
+
+	/* Ordinarily, we'd expect the inverted tupleproto, but it's
+	   been preserved inside the ICMP. */
+	if (!invert_tuple(&innertuple, &origtuple, innerproto)) {
+		DEBUGP("icmp_error_track: Can't invert tuple\n");
+		return NULL;
+	}
+
+	*ctinfo = IP_CT_RELATED;
+
+	h = ip_conntrack_find_get(&innertuple, NULL);
+	if (!h) {
+		/* Locally generated ICMPs will match inverted if they
+		   haven't been SNAT'ed yet */
+		/* FIXME: NAT code has to handle half-done double NAT --RR */
+		if (hooknum == NF_IP_LOCAL_OUT)
+			h = ip_conntrack_find_get(&origtuple, NULL);
+
+		if (!h) {
+			DEBUGP("icmp_error_track: no match\n");
+			return NULL;
+		}
+		/* Reverse direction from that found */
+		if (DIRECTION(h) != IP_CT_DIR_REPLY)
+			*ctinfo += IP_CT_IS_REPLY;
+	} else {
+		if (DIRECTION(h) == IP_CT_DIR_REPLY)
+			*ctinfo += IP_CT_IS_REPLY;
+	}
+
+	/* Update skb to refer to this connection */
+	skb->nfct = &h->ctrack->infos[*ctinfo];
+	return h->ctrack;
+}
+
+/* There's a small race here where we may free a just-assured
+   connection.  Too bad: we're in trouble anyway. */
+static inline int unreplied(const struct ip_conntrack_tuple_hash *i)
+{
+	return !(test_bit(IPS_ASSURED_BIT, &i->ctrack->status));
+}
+
+static int early_drop(struct list_head *chain)
+{
+	/* Traverse backwards: gives us oldest, which is roughly LRU */
+	struct ip_conntrack_tuple_hash *h;
+	int dropped = 0;
+
+	READ_LOCK(&ip_conntrack_lock);
+	h = LIST_FIND_B(chain, unreplied, struct ip_conntrack_tuple_hash *);
+	if (h)
+		atomic_inc(&h->ctrack->ct_general.use);
+	READ_UNLOCK(&ip_conntrack_lock);
+
+	if (!h)
+		return dropped;
+
+	if (del_timer(&h->ctrack->timeout)) {
+		death_by_timeout((unsigned long)h->ctrack);
+		dropped = 1;
+	}
+	ip_conntrack_put(h->ctrack);
+	return dropped;
+}
+
+static inline int helper_cmp(const struct ip_conntrack_helper *i,
+			     const struct ip_conntrack_tuple *rtuple)
+{
+	return ip_ct_tuple_mask_cmp(rtuple, &i->tuple, &i->mask);
+}
+
+struct ip_conntrack_helper *ip_ct_find_helper(const struct ip_conntrack_tuple *tuple)
+{
+	return LIST_FIND(&helpers, helper_cmp,
+			 struct ip_conntrack_helper *,
+			 tuple);
+}
+
+/* Allocate a new conntrack: we return -ENOMEM if classification
+   failed due to stress.  Otherwise it really is unclassifiable. */
+static struct ip_conntrack_tuple_hash *
+init_conntrack(const struct ip_conntrack_tuple *tuple,
+	       struct ip_conntrack_protocol *protocol,
+	       struct sk_buff *skb)
+{
+	struct ip_conntrack *conntrack;
+	struct ip_conntrack_tuple repl_tuple;
+	size_t hash;
+	struct ip_conntrack_expect *expected;
+	int i;
+	static unsigned int drop_next = 0;
+
+	if (!ip_conntrack_hash_rnd_initted) {
+		get_random_bytes(&ip_conntrack_hash_rnd, 4);
+		ip_conntrack_hash_rnd_initted = 1;
+	}
+
+	hash = hash_conntrack(tuple);
+
+	if (ip_conntrack_max &&
+	    atomic_read(&ip_conntrack_count) >= ip_conntrack_max) {
+		/* Try dropping from random chain, or else from the
+                   chain about to put into (in case they're trying to
+                   bomb one hash chain). */
+		unsigned int next = (drop_next++)%ip_conntrack_htable_size;
+
+		if (!early_drop(&ip_conntrack_hash[next])
+		    && !early_drop(&ip_conntrack_hash[hash])) {
+			if (net_ratelimit())
+				printk(KERN_WARNING
+				       "ip_conntrack: table full, dropping"
+				       " packet.\n");
+			return ERR_PTR(-ENOMEM);
+		}
+	}
+
+	if (!invert_tuple(&repl_tuple, tuple, protocol)) {
+		DEBUGP("Can't invert tuple.\n");
+		return NULL;
+	}
+
+	conntrack = kmem_cache_alloc(ip_conntrack_cachep, GFP_ATOMIC);
+	if (!conntrack) {
+		DEBUGP("Can't allocate conntrack.\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	memset(conntrack, 0, sizeof(*conntrack));
+	atomic_set(&conntrack->ct_general.use, 1);
+	conntrack->ct_general.destroy = destroy_conntrack;
+	conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *tuple;
+	conntrack->tuplehash[IP_CT_DIR_ORIGINAL].ctrack = conntrack;
+	conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = repl_tuple;
+	conntrack->tuplehash[IP_CT_DIR_REPLY].ctrack = conntrack;
+	for (i=0; i < IP_CT_NUMBER; i++)
+		conntrack->infos[i].master = &conntrack->ct_general;
+
+	if (!protocol->new(conntrack, skb->nh.iph, skb->len)) {
+		kmem_cache_free(ip_conntrack_cachep, conntrack);
+		return NULL;
+	}
+	/* Don't set timer yet: wait for confirmation */
+	init_timer(&conntrack->timeout);
+	conntrack->timeout.data = (unsigned long)conntrack;
+	conntrack->timeout.function = death_by_timeout;
+
+	INIT_LIST_HEAD(&conntrack->sibling_list);
+
+	WRITE_LOCK(&ip_conntrack_lock);
+	/* Need finding and deleting of expected ONLY if we win race */
+	READ_LOCK(&ip_conntrack_expect_tuple_lock);
+	expected = LIST_FIND(&ip_conntrack_expect_list, expect_cmp,
+			     struct ip_conntrack_expect *, tuple);
+	READ_UNLOCK(&ip_conntrack_expect_tuple_lock);
+
+	/* If master is not in hash table yet (ie. packet hasn't left
+	   this machine yet), how can other end know about expected?
+	   Hence these are not the droids you are looking for (if
+	   master ct never got confirmed, we'd hold a reference to it
+	   and weird things would happen to future packets). */
+	if (expected && !is_confirmed(expected->expectant))
+		expected = NULL;
+
+	/* Look up the conntrack helper for master connections only */
+	if (!expected)
+		conntrack->helper = ip_ct_find_helper(&repl_tuple);
+
+	/* If the expectation is dying, then this is a looser. */
+	if (expected
+	    && expected->expectant->helper->timeout
+	    && ! del_timer(&expected->timeout))
+		expected = NULL;
+
+	if (expected) {
+		DEBUGP("conntrack: expectation arrives ct=%p exp=%p\n",
+			conntrack, expected);
+		/* Welcome, Mr. Bond.  We've been expecting you... */
+		__set_bit(IPS_EXPECTED_BIT, &conntrack->status);
+		conntrack->master = expected;
+		expected->sibling = conntrack;
+		LIST_DELETE(&ip_conntrack_expect_list, expected);
+		expected->expectant->expecting--;
+		nf_conntrack_get(&master_ct(conntrack)->infos[0]);
+	}
+	atomic_inc(&ip_conntrack_count);
+	WRITE_UNLOCK(&ip_conntrack_lock);
+
+	if (expected && expected->expectfn)
+		expected->expectfn(conntrack);
+	return &conntrack->tuplehash[IP_CT_DIR_ORIGINAL];
+}
+
+/* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
+static inline struct ip_conntrack *
+resolve_normal_ct(struct sk_buff *skb,
+		  struct ip_conntrack_protocol *proto,
+		  int *set_reply,
+		  unsigned int hooknum,
+		  enum ip_conntrack_info *ctinfo)
+{
+	struct ip_conntrack_tuple tuple;
+	struct ip_conntrack_tuple_hash *h;
+
+	IP_NF_ASSERT((skb->nh.iph->frag_off & htons(IP_OFFSET)) == 0);
+
+	if (!get_tuple(skb->nh.iph, skb->len, &tuple, proto))
+		return NULL;
+
+	/* look for tuple match */
+	h = ip_conntrack_find_get(&tuple, NULL);
+	if (!h) {
+		h = init_conntrack(&tuple, proto, skb);
+		if (!h)
+			return NULL;
+		if (IS_ERR(h))
+			return (void *)h;
+	}
+
+	/* It exists; we have (non-exclusive) reference. */
+	if (DIRECTION(h) == IP_CT_DIR_REPLY) {
+		*ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY;
+		/* Please set reply bit if this packet OK */
+		*set_reply = 1;
+	} else {
+		/* Once we've had two way comms, always ESTABLISHED. */
+		if (test_bit(IPS_SEEN_REPLY_BIT, &h->ctrack->status)) {
+			DEBUGP("ip_conntrack_in: normal packet for %p\n",
+			       h->ctrack);
+		        *ctinfo = IP_CT_ESTABLISHED;
+		} else if (test_bit(IPS_EXPECTED_BIT, &h->ctrack->status)) {
+			DEBUGP("ip_conntrack_in: related packet for %p\n",
+			       h->ctrack);
+			*ctinfo = IP_CT_RELATED;
+		} else {
+			DEBUGP("ip_conntrack_in: new packet for %p\n",
+			       h->ctrack);
+			*ctinfo = IP_CT_NEW;
+		}
+		*set_reply = 0;
+	}
+	skb->nfct = &h->ctrack->infos[*ctinfo];
+	return h->ctrack;
+}
+
+/* Netfilter hook itself. */
+unsigned int ip_conntrack_in(unsigned int hooknum,
+			     struct sk_buff **pskb,
+			     const struct net_device *in,
+			     const struct net_device *out,
+			     int (*okfn)(struct sk_buff *))
+{
+	struct ip_conntrack *ct;
+	enum ip_conntrack_info ctinfo;
+	struct ip_conntrack_protocol *proto;
+	int set_reply;
+	int ret;
+
+	/* FIXME: Do this right please. --RR */
+	(*pskb)->nfcache |= NFC_UNKNOWN;
+
+/* Doesn't cover locally-generated broadcast, so not worth it. */
+#if 0
+	/* Ignore broadcast: no `connection'. */
+	if ((*pskb)->pkt_type == PACKET_BROADCAST) {
+		printk("Broadcast packet!\n");
+		return NF_ACCEPT;
+	} else if (((*pskb)->nh.iph->daddr & htonl(0x000000FF)) 
+		   == htonl(0x000000FF)) {
+		printk("Should bcast: %u.%u.%u.%u->%u.%u.%u.%u (sk=%p, ptype=%u)\n",
+		       NIPQUAD((*pskb)->nh.iph->saddr),
+		       NIPQUAD((*pskb)->nh.iph->daddr),
+		       (*pskb)->sk, (*pskb)->pkt_type);
+	}
+#endif
+
+	/* Previously seen (loopback)?  Ignore.  Do this before
+           fragment check. */
+	if ((*pskb)->nfct)
+		return NF_ACCEPT;
+
+	/* Gather fragments. */
+	if ((*pskb)->nh.iph->frag_off & htons(IP_MF|IP_OFFSET)) {
+		*pskb = ip_ct_gather_frags(*pskb);
+		if (!*pskb)
+			return NF_STOLEN;
+	}
+
+	proto = ip_ct_find_proto((*pskb)->nh.iph->protocol);
+
+	/* It may be an icmp error... */
+	if ((*pskb)->nh.iph->protocol == IPPROTO_ICMP 
+	    && icmp_error_track(*pskb, &ctinfo, hooknum))
+		return NF_ACCEPT;
+
+	if (!(ct = resolve_normal_ct(*pskb, proto,&set_reply,hooknum,&ctinfo)))
+		/* Not valid part of a connection */
+		return NF_ACCEPT;
+
+	if (IS_ERR(ct))
+		/* Too stressed to deal. */
+		return NF_DROP;
+
+	IP_NF_ASSERT((*pskb)->nfct);
+
+	ret = proto->packet(ct, (*pskb)->nh.iph, (*pskb)->len, ctinfo);
+	if (ret == -1) {
+		/* Invalid */
+		nf_conntrack_put((*pskb)->nfct);
+		(*pskb)->nfct = NULL;
+		return NF_ACCEPT;
+	}
+
+	if (ret != NF_DROP && ct->helper) {
+		ret = ct->helper->help((*pskb)->nh.iph, (*pskb)->len,
+				       ct, ctinfo);
+		if (ret == -1) {
+			/* Invalid */
+			nf_conntrack_put((*pskb)->nfct);
+			(*pskb)->nfct = NULL;
+			return NF_ACCEPT;
+		}
+	}
+	if (set_reply)
+		set_bit(IPS_SEEN_REPLY_BIT, &ct->status);
+
+	return ret;
+}
+
+int invert_tuplepr(struct ip_conntrack_tuple *inverse,
+		   const struct ip_conntrack_tuple *orig)
+{
+	return invert_tuple(inverse, orig, ip_ct_find_proto(orig->dst.protonum));
+}
+
+static inline int resent_expect(const struct ip_conntrack_expect *i,
+			        const struct ip_conntrack_tuple *tuple,
+			        const struct ip_conntrack_tuple *mask)
+{
+	DEBUGP("resent_expect\n");
+	DEBUGP("   tuple:   "); DUMP_TUPLE(&i->tuple);
+	DEBUGP("ct_tuple:   "); DUMP_TUPLE(&i->ct_tuple);
+	DEBUGP("test tuple: "); DUMP_TUPLE(tuple);
+	return (((i->ct_tuple.dst.protonum == 0 && ip_ct_tuple_equal(&i->tuple, tuple))
+	         || (i->ct_tuple.dst.protonum && ip_ct_tuple_equal(&i->ct_tuple, tuple)))
+		&& ip_ct_tuple_equal(&i->mask, mask));
+}
+
+/* Would two expected things clash? */
+static inline int expect_clash(const struct ip_conntrack_expect *i,
+			       const struct ip_conntrack_tuple *tuple,
+			       const struct ip_conntrack_tuple *mask)
+{
+	/* Part covered by intersection of masks must be unequal,
+           otherwise they clash */
+	struct ip_conntrack_tuple intersect_mask
+		= { { i->mask.src.ip & mask->src.ip,
+		      { i->mask.src.u.all & mask->src.u.all } },
+		    { i->mask.dst.ip & mask->dst.ip,
+		      { i->mask.dst.u.all & mask->dst.u.all },
+		      i->mask.dst.protonum & mask->dst.protonum } };
+
+	return ip_ct_tuple_mask_cmp(&i->tuple, tuple, &intersect_mask);
+}
+
+inline void ip_conntrack_unexpect_related(struct ip_conntrack_expect *expect)
+{
+	WRITE_LOCK(&ip_conntrack_lock);
+	unexpect_related(expect);
+	WRITE_UNLOCK(&ip_conntrack_lock);
+}
+	
+static void expectation_timed_out(unsigned long ul_expect)
+{
+	struct ip_conntrack_expect *expect = (void *) ul_expect;
+
+	DEBUGP("expectation %p timed out\n", expect);	
+	WRITE_LOCK(&ip_conntrack_lock);
+	__unexpect_related(expect);
+	WRITE_UNLOCK(&ip_conntrack_lock);
+}
+
+/* Add a related connection. */
+int ip_conntrack_expect_related(struct ip_conntrack *related_to,
+				struct ip_conntrack_expect *expect)
+{
+	struct ip_conntrack_expect *old, *new;
+	int ret = 0;
+
+	WRITE_LOCK(&ip_conntrack_lock);
+	/* Because of the write lock, no reader can walk the lists,
+	 * 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);
+
+	old = LIST_FIND(&ip_conntrack_expect_list, resent_expect,
+		        struct ip_conntrack_expect *, &expect->tuple, 
+			&expect->mask);
+	if (old) {
+		/* Helper private data may contain offsets but no pointers
+		   pointing into the payload - otherwise we should have to copy 
+		   the data filled out by the helper over the old one */
+		DEBUGP("expect_related: resent packet\n");
+		if (related_to->helper->timeout) {
+			if (!del_timer(&old->timeout)) {
+				/* expectation is dying. Fall through */
+				old = NULL;
+			} else {
+				old->timeout.expires = jiffies + 
+					related_to->helper->timeout * HZ;
+				add_timer(&old->timeout);
+			}
+		}
+
+		if (old) {
+			WRITE_UNLOCK(&ip_conntrack_lock);
+			return -EEXIST;
+		}
+	} else if (related_to->helper->max_expected && 
+		   related_to->expecting >= related_to->helper->max_expected) {
+		/* old == NULL */
+		if (!(related_to->helper->flags & 
+		      IP_CT_HELPER_F_REUSE_EXPECT)) {
+			WRITE_UNLOCK(&ip_conntrack_lock);
+ 		    	if (net_ratelimit())
+ 			    	printk(KERN_WARNING
+				       "ip_conntrack: max number of expected "
+				       "connections %i of %s reached for "
+				       "%u.%u.%u.%u->%u.%u.%u.%u\n",
+				       related_to->helper->max_expected,
+				       related_to->helper->name,
+ 		    	       	       NIPQUAD(related_to->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip),
+ 		    	       	       NIPQUAD(related_to->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip));
+			return -EPERM;
+		}
+		DEBUGP("ip_conntrack: max number of expected "
+		       "connections %i of %s reached for "
+		       "%u.%u.%u.%u->%u.%u.%u.%u, reusing\n",
+ 		       related_to->helper->max_expected,
+		       related_to->helper->name,
+		       NIPQUAD(related_to->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip),
+		       NIPQUAD(related_to->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip));
+ 
+		/* choose the the oldest expectation to evict */
+		list_for_each_entry(old, &related_to->sibling_list, 
+		                                      expected_list)
+			if (old->sibling == NULL)
+				break;
+
+		/* We cannot fail since related_to->expecting is the number
+		 * of unconfirmed expectations */
+		IP_NF_ASSERT(old && old->sibling == NULL);
+
+		/* newnat14 does not reuse the real allocated memory
+		 * structures but rather unexpects the old and
+		 * allocates a new.  unexpect_related will decrement
+		 * related_to->expecting. 
+		 */
+		unexpect_related(old);
+		ret = -EPERM;
+	} else if (LIST_FIND(&ip_conntrack_expect_list, expect_clash,
+			     struct ip_conntrack_expect *, &expect->tuple, 
+			     &expect->mask)) {
+		WRITE_UNLOCK(&ip_conntrack_lock);
+		DEBUGP("expect_related: busy!\n");
+		return -EBUSY;
+	}
+	
+	new = (struct ip_conntrack_expect *) 
+	      kmalloc(sizeof(struct ip_conntrack_expect), GFP_ATOMIC);
+	if (!new) {
+		WRITE_UNLOCK(&ip_conntrack_lock);
+		DEBUGP("expect_relaed: OOM allocating expect\n");
+		return -ENOMEM;
+	}
+	
+	DEBUGP("new expectation %p of conntrack %p\n", new, related_to);
+	memcpy(new, expect, sizeof(*expect));
+	new->expectant = related_to;
+	new->sibling = NULL;
+	atomic_set(&new->use, 1);
+	
+	/* add to expected list for this connection */	
+	list_add_tail(&new->expected_list, &related_to->sibling_list);
+	/* add to global list of expectations */
+	list_prepend(&ip_conntrack_expect_list, &new->list);
+	/* add and start timer if required */
+	if (related_to->helper->timeout) {
+		init_timer(&new->timeout);
+		new->timeout.data = (unsigned long)new;
+		new->timeout.function = expectation_timed_out;
+		new->timeout.expires = jiffies + 
+					related_to->helper->timeout * HZ;
+		add_timer(&new->timeout);
+	}
+	related_to->expecting++;
+
+	WRITE_UNLOCK(&ip_conntrack_lock);
+
+	return ret;
+}
+
+/* Change tuple in an existing expectation */
+int ip_conntrack_change_expect(struct ip_conntrack_expect *expect,
+			       struct ip_conntrack_tuple *newtuple)
+{
+	int ret;
+
+	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);
+	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) 
+		    && LIST_FIND(&ip_conntrack_expect_list, expect_clash,
+			         struct ip_conntrack_expect *, newtuple, &expect->mask)) {
+			/* Force NAT to find an unused tuple */
+			ret = -1;
+		} else {
+			memcpy(&expect->ct_tuple, &expect->tuple, sizeof(expect->tuple));
+			memcpy(&expect->tuple, newtuple, sizeof(expect->tuple));
+			ret = 0;
+		}
+	} else {
+		/* Resent packet */
+		DEBUGP("change expect: resent packet\n");
+		if (ip_ct_tuple_equal(&expect->tuple, newtuple)) {
+			ret = 0;
+		} else {
+			/* Force NAT to choose again the same port */
+			ret = -1;
+		}
+	}
+	WRITE_UNLOCK(&ip_conntrack_expect_tuple_lock);
+	
+	return ret;
+}
+
+/* Alter reply tuple (maybe alter helper).  If it's already taken,
+   return 0 and don't do alteration. */
+int ip_conntrack_alter_reply(struct ip_conntrack *conntrack,
+			     const struct ip_conntrack_tuple *newreply)
+{
+	WRITE_LOCK(&ip_conntrack_lock);
+	if (__ip_conntrack_find(newreply, conntrack)) {
+		WRITE_UNLOCK(&ip_conntrack_lock);
+		return 0;
+	}
+	/* Should be unconfirmed, so not in hash table yet */
+	IP_NF_ASSERT(!is_confirmed(conntrack));
+
+	DEBUGP("Altering reply tuple of %p to ", conntrack);
+	DUMP_TUPLE(newreply);
+
+	conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
+	if (!conntrack->master && list_empty(&conntrack->sibling_list))
+		conntrack->helper = ip_ct_find_helper(newreply);
+	WRITE_UNLOCK(&ip_conntrack_lock);
+
+	return 1;
+}
+
+int ip_conntrack_helper_register(struct ip_conntrack_helper *me)
+{
+	MOD_INC_USE_COUNT;
+
+	WRITE_LOCK(&ip_conntrack_lock);
+	list_prepend(&helpers, me);
+	WRITE_UNLOCK(&ip_conntrack_lock);
+
+	return 0;
+}
+
+static inline int unhelp(struct ip_conntrack_tuple_hash *i,
+			 const struct ip_conntrack_helper *me)
+{
+	if (i->ctrack->helper == me) {
+		/* Get rid of any expected. */
+		remove_expectations(i->ctrack, 0);
+		/* And *then* set helper to NULL */
+		i->ctrack->helper = NULL;
+	}
+	return 0;
+}
+
+void ip_conntrack_helper_unregister(struct ip_conntrack_helper *me)
+{
+	unsigned int i;
+
+	/* Need write lock here, to delete helper. */
+	WRITE_LOCK(&ip_conntrack_lock);
+	LIST_DELETE(&helpers, me);
+
+	/* Get rid of expecteds, set helpers to NULL. */
+	for (i = 0; i < ip_conntrack_htable_size; i++)
+		LIST_FIND_W(&ip_conntrack_hash[i], unhelp,
+			    struct ip_conntrack_tuple_hash *, me);
+	WRITE_UNLOCK(&ip_conntrack_lock);
+
+	/* Someone could be still looking at the helper in a bh. */
+	br_write_lock_bh(BR_NETPROTO_LOCK);
+	br_write_unlock_bh(BR_NETPROTO_LOCK);
+
+	MOD_DEC_USE_COUNT;
+}
+
+/* Refresh conntrack for this many jiffies. */
+void ip_ct_refresh(struct ip_conntrack *ct, unsigned long extra_jiffies)
+{
+	IP_NF_ASSERT(ct->timeout.data == (unsigned long)ct);
+
+	WRITE_LOCK(&ip_conntrack_lock);
+	/* If not in hash table, timer will not be active yet */
+	if (!is_confirmed(ct))
+		ct->timeout.expires = extra_jiffies;
+	else {
+		/* Need del_timer for race avoidance (may already be dying). */
+		if (del_timer(&ct->timeout)) {
+			ct->timeout.expires = jiffies + extra_jiffies;
+			add_timer(&ct->timeout);
+		}
+	}
+	WRITE_UNLOCK(&ip_conntrack_lock);
+}
+
+/* Returns new sk_buff, or NULL */
+struct sk_buff *
+ip_ct_gather_frags(struct sk_buff *skb)
+{
+	struct sock *sk = skb->sk;
+#ifdef CONFIG_NETFILTER_DEBUG
+	unsigned int olddebug = skb->nf_debug;
+#endif
+	if (sk) {
+		sock_hold(sk);
+		skb_orphan(skb);
+	}
+
+	local_bh_disable(); 
+	skb = ip_defrag(skb);
+	local_bh_enable();
+
+	if (!skb) {
+		if (sk) sock_put(sk);
+		return skb;
+	} else if (skb_is_nonlinear(skb) && skb_linearize(skb, GFP_ATOMIC) != 0) {
+		kfree_skb(skb);
+		if (sk) sock_put(sk);
+		return NULL;
+	}
+
+	if (sk) {
+		skb_set_owner_w(skb, sk);
+		sock_put(sk);
+	}
+
+	ip_send_check(skb->nh.iph);
+	skb->nfcache |= NFC_ALTERED;
+#ifdef CONFIG_NETFILTER_DEBUG
+	/* Packet path as if nothing had happened. */
+	skb->nf_debug = olddebug;
+#endif
+	return skb;
+}
+
+/* Used by ipt_REJECT. */
+static void ip_conntrack_attach(struct sk_buff *nskb, struct nf_ct_info *nfct)
+{
+	struct ip_conntrack *ct;
+	enum ip_conntrack_info ctinfo;
+
+	ct = __ip_conntrack_get(nfct, &ctinfo);
+
+	/* This ICMP is in reverse direction to the packet which
+           caused it */
+	if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
+		ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY;
+	else
+		ctinfo = IP_CT_RELATED;
+
+	/* Attach new skbuff, and increment count */
+	nskb->nfct = &ct->infos[ctinfo];
+	atomic_inc(&ct->ct_general.use);
+}
+
+static inline int
+do_kill(const struct ip_conntrack_tuple_hash *i,
+	int (*kill)(const struct ip_conntrack *i, void *data),
+	void *data)
+{
+	return kill(i->ctrack, data);
+}
+
+/* Bring out ya dead! */
+static struct ip_conntrack_tuple_hash *
+get_next_corpse(int (*kill)(const struct ip_conntrack *i, void *data),
+		void *data, unsigned int *bucket)
+{
+	struct ip_conntrack_tuple_hash *h = NULL;
+
+	READ_LOCK(&ip_conntrack_lock);
+	for (; !h && *bucket < ip_conntrack_htable_size; (*bucket)++) {
+		h = LIST_FIND(&ip_conntrack_hash[*bucket], do_kill,
+			      struct ip_conntrack_tuple_hash *, kill, data);
+	}
+	if (h)
+		atomic_inc(&h->ctrack->ct_general.use);
+	READ_UNLOCK(&ip_conntrack_lock);
+
+	return h;
+}
+
+void
+ip_ct_selective_cleanup(int (*kill)(const struct ip_conntrack *i, void *data),
+			void *data)
+{
+	struct ip_conntrack_tuple_hash *h;
+	unsigned int bucket = 0;
+
+	while ((h = get_next_corpse(kill, data, &bucket)) != NULL) {
+		/* Time to push up daises... */
+		if (del_timer(&h->ctrack->timeout))
+			death_by_timeout((unsigned long)h->ctrack);
+		/* ... else the timer will get him soon. */
+
+		ip_conntrack_put(h->ctrack);
+	}
+}
+
+/* Fast function for those who don't want to parse /proc (and I don't
+   blame them). */
+/* Reversing the socket's dst/src point of view gives us the reply
+   mapping. */
+static int
+getorigdst(struct sock *sk, int optval, void *user, int *len)
+{
+	struct ip_conntrack_tuple_hash *h;
+	struct ip_conntrack_tuple tuple;
+
+	IP_CT_TUPLE_U_BLANK(&tuple);
+	tuple.src.ip = sk->rcv_saddr;
+	tuple.src.u.tcp.port = sk->sport;
+	tuple.dst.ip = sk->daddr;
+	tuple.dst.u.tcp.port = sk->dport;
+	tuple.dst.protonum = IPPROTO_TCP;
+
+	/* We only do TCP at the moment: is there a better way? */
+	if (strcmp(sk->prot->name, "TCP") != 0) {
+		DEBUGP("SO_ORIGINAL_DST: Not a TCP socket\n");
+		return -ENOPROTOOPT;
+	}
+
+	if ((unsigned int) *len < sizeof(struct sockaddr_in)) {
+		DEBUGP("SO_ORIGINAL_DST: len %u not %u\n",
+		       *len, sizeof(struct sockaddr_in));
+		return -EINVAL;
+	}
+
+	h = ip_conntrack_find_get(&tuple, NULL);
+	if (h) {
+		struct sockaddr_in sin;
+
+		sin.sin_family = AF_INET;
+		sin.sin_port = h->ctrack->tuplehash[IP_CT_DIR_ORIGINAL]
+			.tuple.dst.u.tcp.port;
+		sin.sin_addr.s_addr = h->ctrack->tuplehash[IP_CT_DIR_ORIGINAL]
+			.tuple.dst.ip;
+
+		DEBUGP("SO_ORIGINAL_DST: %u.%u.%u.%u %u\n",
+		       NIPQUAD(sin.sin_addr.s_addr), ntohs(sin.sin_port));
+		ip_conntrack_put(h->ctrack);
+		if (copy_to_user(user, &sin, sizeof(sin)) != 0)
+			return -EFAULT;
+		else
+			return 0;
+	}
+	DEBUGP("SO_ORIGINAL_DST: Can't find %u.%u.%u.%u/%u-%u.%u.%u.%u/%u.\n",
+	       NIPQUAD(tuple.src.ip), ntohs(tuple.src.u.tcp.port),
+	       NIPQUAD(tuple.dst.ip), ntohs(tuple.dst.u.tcp.port));
+	return -ENOENT;
+}
+
+static struct nf_sockopt_ops so_getorigdst
+= { { NULL, NULL }, PF_INET,
+    0, 0, NULL, /* Setsockopts */
+    SO_ORIGINAL_DST, SO_ORIGINAL_DST+1, &getorigdst,
+    0, NULL };
+
+static int kill_all(const struct ip_conntrack *i, void *data)
+{
+	return 1;
+}
+
+/* Mishearing the voices in his head, our hero wonders how he's
+   supposed to kill the mall. */
+void ip_conntrack_cleanup(void)
+{
+	ip_ct_attach = NULL;
+	/* This makes sure all current packets have passed through
+           netfilter framework.  Roll on, two-stage module
+           delete... */
+	br_write_lock_bh(BR_NETPROTO_LOCK);
+	br_write_unlock_bh(BR_NETPROTO_LOCK);
+ 
+ i_see_dead_people:
+	ip_ct_selective_cleanup(kill_all, NULL);
+	if (atomic_read(&ip_conntrack_count) != 0) {
+		schedule();
+		goto i_see_dead_people;
+	}
+
+	kmem_cache_destroy(ip_conntrack_cachep);
+	vfree(ip_conntrack_hash);
+	nf_unregister_sockopt(&so_getorigdst);
+}
+
+static int hashsize = 0;
+MODULE_PARM(hashsize, "i");
+
+int __init ip_conntrack_init(void)
+{
+	unsigned int i;
+	int ret;
+
+	/* Idea from tcp.c: use 1/16384 of memory.  On i386: 32MB
+	 * machine has 256 buckets.  >= 1GB machines have 8192 buckets. */
+ 	if (hashsize) {
+ 		ip_conntrack_htable_size = hashsize;
+ 	} else {
+		ip_conntrack_htable_size
+			= (((num_physpages << PAGE_SHIFT) / 16384)
+			   / sizeof(struct list_head));
+		if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE))
+			ip_conntrack_htable_size = 8192;
+		if (ip_conntrack_htable_size < 16)
+			ip_conntrack_htable_size = 16;
+	}
+	ip_conntrack_max = 8 * ip_conntrack_htable_size;
+
+	printk("ip_conntrack version %s (%u buckets, %d max)"
+	       " - %Zd bytes per conntrack\n", IP_CONNTRACK_VERSION,
+	       ip_conntrack_htable_size, ip_conntrack_max,
+	       sizeof(struct ip_conntrack));
+
+	ret = nf_register_sockopt(&so_getorigdst);
+	if (ret != 0) {
+		printk(KERN_ERR "Unable to register netfilter socket option\n");
+		return ret;
+	}
+
+	ip_conntrack_hash = vmalloc(sizeof(struct list_head)
+				    * ip_conntrack_htable_size);
+	if (!ip_conntrack_hash) {
+		printk(KERN_ERR "Unable to create ip_conntrack_hash\n");
+		goto err_unreg_sockopt;
+	}
+
+	ip_conntrack_cachep = kmem_cache_create("ip_conntrack",
+	                                        sizeof(struct ip_conntrack), 0,
+	                                        SLAB_HWCACHE_ALIGN, NULL, NULL);
+	if (!ip_conntrack_cachep) {
+		printk(KERN_ERR "Unable to create ip_conntrack slab cache\n");
+		goto err_free_hash;
+	}
+	/* Don't NEED lock here, but good form anyway. */
+	WRITE_LOCK(&ip_conntrack_lock);
+	/* Sew in builtin protocols. */
+	list_append(&protocol_list, &ip_conntrack_protocol_tcp);
+	list_append(&protocol_list, &ip_conntrack_protocol_udp);
+	list_append(&protocol_list, &ip_conntrack_protocol_icmp);
+	WRITE_UNLOCK(&ip_conntrack_lock);
+
+	for (i = 0; i < ip_conntrack_htable_size; i++)
+		INIT_LIST_HEAD(&ip_conntrack_hash[i]);
+
+	/* For use by ipt_REJECT */
+	ip_ct_attach = ip_conntrack_attach;
+	return ret;
+
+err_free_hash:
+	vfree(ip_conntrack_hash);
+err_unreg_sockopt:
+	nf_unregister_sockopt(&so_getorigdst);
+
+	return -ENOMEM;
+}
diff -uNr linux_org/net/ipv4/netfilter/ip_conntrack_pptp.c linux/net/ipv4/netfilter/ip_conntrack_pptp.c
--- linux_org/net/ipv4/netfilter/ip_conntrack_pptp.c	1970-01-01 01:00:00.000000000 +0100
+++ linux/net/ipv4/netfilter/ip_conntrack_pptp.c	2006-10-27 14:11:52.000000000 +0200
@@ -0,0 +1,637 @@
+/*
+ * 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.u.gre.protocol = __constant_htons(GRE_PROTOCOL_PPTP);
+	exp.tuple.dst.u.gre.version = GRE_VERSION_PPTP;
+	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.u.gre.version = 0xff;
+	exp.mask.dst.u.gre.protocol = 0xffff;
+	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 -uNr linux_org/net/ipv4/netfilter/ip_conntrack_pptp_priv.h linux/net/ipv4/netfilter/ip_conntrack_pptp_priv.h
--- linux_org/net/ipv4/netfilter/ip_conntrack_pptp_priv.h	1970-01-01 01:00:00.000000000 +0100
+++ linux/net/ipv4/netfilter/ip_conntrack_pptp_priv.h	2006-10-27 14:11:52.000000000 +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 -uNr linux_org/net/ipv4/netfilter/ip_conntrack_proto_gre.c linux/net/ipv4/netfilter/ip_conntrack_proto_gre.c
--- linux_org/net/ipv4/netfilter/ip_conntrack_proto_gre.c	1970-01-01 01:00:00.000000000 +0100
+++ linux/net/ipv4/netfilter/ip_conntrack_proto_gre.c	2006-10-27 14:11:52.000000000 +0200
@@ -0,0 +1,343 @@
+/*
+ * 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), \
+			(x)->dst.u.gre.version, \
+			ntohs((x)->dst.u.gre.protocol))
+#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.protocol = orig->dst.u.gre.protocol;
+	tuple->dst.u.gre.version = orig->dst.u.gre.version;
+
+	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 */
+
+	tuple->dst.u.gre.version = grehdr->version; 
+	tuple->dst.u.gre.protocol = grehdr->protocol;
+
+	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",
+				tuple->dst.u.gre.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, "version=%d protocol=0x%04x srckey=0x%x dstkey=0x%x ", 
+			tuple->dst.u.gre.version,
+			ntohs(tuple->dst.u.gre.protocol),
+			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 -uNr linux_org/net/ipv4/netfilter/ip_nat_core.c linux/net/ipv4/netfilter/ip_nat_core.c
--- linux_org/net/ipv4/netfilter/ip_nat_core.c	2004-11-24 12:14:04.000000000 +0100
+++ linux/net/ipv4/netfilter/ip_nat_core.c	2006-10-27 14:11:52.000000000 +0200
@@ -430,7 +430,7 @@
 	*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. */
 
@@ -572,9 +572,9 @@
 		       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 -uNr linux_org/net/ipv4/netfilter/ip_nat_core.c.orig linux/net/ipv4/netfilter/ip_nat_core.c.orig
--- linux_org/net/ipv4/netfilter/ip_nat_core.c.orig	1970-01-01 01:00:00.000000000 +0100
+++ linux/net/ipv4/netfilter/ip_nat_core.c.orig	2004-11-24 12:14:04.000000000 +0100
@@ -0,0 +1,1014 @@
+/* NAT for netfilter; shared with compatibility layer. */
+
+/* (c) 1999 Paul `Rusty' Russell.  Licenced under the GNU General
+   Public Licence. */
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/timer.h>
+#include <linux/skbuff.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/brlock.h>
+#include <linux/vmalloc.h>
+#include <net/checksum.h>
+#include <net/icmp.h>
+#include <net/ip.h>
+#include <net/tcp.h>  /* For tcp_prot in getorigdst */
+
+#define ASSERT_READ_LOCK(x) MUST_BE_READ_LOCKED(&ip_nat_lock)
+#define ASSERT_WRITE_LOCK(x) MUST_BE_WRITE_LOCKED(&ip_nat_lock)
+
+#include <linux/netfilter_ipv4/ip_conntrack.h>
+#include <linux/netfilter_ipv4/ip_conntrack_core.h>
+#include <linux/netfilter_ipv4/ip_conntrack_protocol.h>
+#include <linux/netfilter_ipv4/ip_nat.h>
+#include <linux/netfilter_ipv4/ip_nat_protocol.h>
+#include <linux/netfilter_ipv4/ip_nat_core.h>
+#include <linux/netfilter_ipv4/ip_nat_helper.h>
+#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
+#include <linux/netfilter_ipv4/listhelp.h>
+
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(format, args...)
+#endif
+
+DECLARE_RWLOCK(ip_nat_lock);
+DECLARE_RWLOCK_EXTERN(ip_conntrack_lock);
+
+/* Calculated at init based on memory size */
+static unsigned int ip_nat_htable_size;
+
+static struct list_head *bysource;
+static struct list_head *byipsproto;
+LIST_HEAD(protos);
+LIST_HEAD(helpers);
+
+extern struct ip_nat_protocol unknown_nat_protocol;
+
+/* We keep extra hashes for each conntrack, for fast searching. */
+static inline size_t
+hash_by_ipsproto(u_int32_t src, u_int32_t dst, u_int16_t proto)
+{
+	/* Modified src and dst, to ensure we don't create two
+           identical streams. */
+	return (src + dst + proto) % ip_nat_htable_size;
+}
+
+static inline size_t
+hash_by_src(const struct ip_conntrack_manip *manip, u_int16_t proto)
+{
+	/* Original src, to ensure we map it consistently if poss. */
+	return (manip->ip + manip->u.all + proto) % ip_nat_htable_size;
+}
+
+/* Noone using conntrack by the time this called. */
+static void ip_nat_cleanup_conntrack(struct ip_conntrack *conn)
+{
+	struct ip_nat_info *info = &conn->nat.info;
+	unsigned int hs, hp;
+
+	if (!info->initialized)
+		return;
+
+	IP_NF_ASSERT(info->bysource.conntrack);
+	IP_NF_ASSERT(info->byipsproto.conntrack);
+
+	hs = hash_by_src(&conn->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src,
+	                 conn->tuplehash[IP_CT_DIR_ORIGINAL]
+	                 .tuple.dst.protonum);
+
+	hp = hash_by_ipsproto(conn->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip,
+	                      conn->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip,
+	                      conn->tuplehash[IP_CT_DIR_REPLY]
+	                      .tuple.dst.protonum);
+
+	WRITE_LOCK(&ip_nat_lock);
+	LIST_DELETE(&bysource[hs], &info->bysource);
+	LIST_DELETE(&byipsproto[hp], &info->byipsproto);
+	WRITE_UNLOCK(&ip_nat_lock);
+}
+
+/* We do checksum mangling, so if they were wrong before they're still
+ * wrong.  Also works for incomplete packets (eg. ICMP dest
+ * unreachables.) */
+u_int16_t
+ip_nat_cheat_check(u_int32_t oldvalinv, u_int32_t newval, u_int16_t oldcheck)
+{
+	u_int32_t diffs[] = { oldvalinv, newval };
+	return csum_fold(csum_partial((char *)diffs, sizeof(diffs),
+				      oldcheck^0xFFFF));
+}
+
+static inline int cmp_proto(const struct ip_nat_protocol *i, int proto)
+{
+	return i->protonum == proto;
+}
+
+struct ip_nat_protocol *
+find_nat_proto(u_int16_t protonum)
+{
+	struct ip_nat_protocol *i;
+
+	MUST_BE_READ_LOCKED(&ip_nat_lock);
+	i = LIST_FIND(&protos, cmp_proto, struct ip_nat_protocol *, protonum);
+	if (!i)
+		i = &unknown_nat_protocol;
+	return i;
+}
+
+/* Is this tuple already taken? (not by us) */
+int
+ip_nat_used_tuple(const struct ip_conntrack_tuple *tuple,
+		  const struct ip_conntrack *ignored_conntrack)
+{
+	/* Conntrack tracking doesn't keep track of outgoing tuples; only
+	   incoming ones.  NAT means they don't have a fixed mapping,
+	   so we invert the tuple and look for the incoming reply.
+
+	   We could keep a separate hash if this proves too slow. */
+	struct ip_conntrack_tuple reply;
+
+	invert_tuplepr(&reply, tuple);
+	return ip_conntrack_tuple_taken(&reply, ignored_conntrack);
+}
+
+/* Does tuple + the source manip come within the range mr */
+static int
+in_range(const struct ip_conntrack_tuple *tuple,
+	 const struct ip_conntrack_manip *manip,
+	 const struct ip_nat_multi_range *mr)
+{
+	struct ip_nat_protocol *proto = find_nat_proto(tuple->dst.protonum);
+	unsigned int i;
+	struct ip_conntrack_tuple newtuple = { *manip, tuple->dst };
+
+	for (i = 0; i < mr->rangesize; i++) {
+		/* If we are allowed to map IPs, then we must be in the
+		   range specified, otherwise we must be unchanged. */
+		if (mr->range[i].flags & IP_NAT_RANGE_MAP_IPS) {
+			if (ntohl(newtuple.src.ip) < ntohl(mr->range[i].min_ip)
+			    || (ntohl(newtuple.src.ip)
+				> ntohl(mr->range[i].max_ip)))
+				continue;
+		} else {
+			if (newtuple.src.ip != tuple->src.ip)
+				continue;
+		}
+
+		if ((mr->range[i].flags & IP_NAT_RANGE_PROTO_SPECIFIED)
+		    && proto->in_range(&newtuple, IP_NAT_MANIP_SRC,
+				       &mr->range[i].min, &mr->range[i].max))
+			return 1;
+	}
+	return 0;
+}
+
+static inline int
+src_cmp(const struct ip_nat_hash *i,
+	const struct ip_conntrack_tuple *tuple,
+	const struct ip_nat_multi_range *mr)
+{
+	return (i->conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum
+		== tuple->dst.protonum
+		&& i->conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip
+		== tuple->src.ip
+		&& i->conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.all
+		== tuple->src.u.all
+		&& in_range(tuple,
+			    &i->conntrack->tuplehash[IP_CT_DIR_ORIGINAL]
+			    .tuple.src,
+			    mr));
+}
+
+/* Only called for SRC manip */
+static struct ip_conntrack_manip *
+find_appropriate_src(const struct ip_conntrack_tuple *tuple,
+		     const struct ip_nat_multi_range *mr)
+{
+	unsigned int h = hash_by_src(&tuple->src, tuple->dst.protonum);
+	struct ip_nat_hash *i;
+
+	MUST_BE_READ_LOCKED(&ip_nat_lock);
+	i = LIST_FIND(&bysource[h], src_cmp, struct ip_nat_hash *, tuple, mr);
+	if (i)
+		return &i->conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src;
+	else
+		return NULL;
+}
+
+#ifdef CONFIG_IP_NF_NAT_LOCAL
+/* If it's really a local destination manip, it may need to do a
+   source manip too. */
+static int
+do_extra_mangle(u_int32_t var_ip, u_int32_t *other_ipp)
+{
+	struct rtable *rt;
+
+	/* FIXME: IPTOS_TOS(iph->tos) --RR */
+	if (ip_route_output(&rt, var_ip, 0, 0, 0) != 0) {
+		DEBUGP("do_extra_mangle: Can't get route to %u.%u.%u.%u\n",
+		       NIPQUAD(var_ip));
+		return 0;
+	}
+
+	*other_ipp = rt->rt_src;
+	ip_rt_put(rt);
+	return 1;
+}
+#endif
+
+/* Simple way to iterate through all. */
+static inline int fake_cmp(const struct ip_nat_hash *i,
+			   u_int32_t src, u_int32_t dst, u_int16_t protonum,
+			   unsigned int *score,
+			   const struct ip_conntrack *conntrack)
+{
+	/* Compare backwards: we're dealing with OUTGOING tuples, and
+           inside the conntrack is the REPLY tuple.  Don't count this
+           conntrack. */
+	if (i->conntrack != conntrack
+	    && i->conntrack->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip == dst
+	    && i->conntrack->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip == src
+	    && (i->conntrack->tuplehash[IP_CT_DIR_REPLY].tuple.dst.protonum
+		== protonum))
+		(*score)++;
+	return 0;
+}
+
+static inline unsigned int
+count_maps(u_int32_t src, u_int32_t dst, u_int16_t protonum,
+	   const struct ip_conntrack *conntrack)
+{
+	unsigned int score = 0;
+	unsigned int h;
+
+	MUST_BE_READ_LOCKED(&ip_nat_lock);
+	h = hash_by_ipsproto(src, dst, protonum);
+	LIST_FIND(&byipsproto[h], fake_cmp, struct ip_nat_hash *,
+	          src, dst, protonum, &score, conntrack);
+
+	return score;
+}
+
+/* For [FUTURE] fragmentation handling, we want the least-used
+   src-ip/dst-ip/proto triple.  Fairness doesn't come into it.  Thus
+   if the range specifies 1.2.3.4 ports 10000-10005 and 1.2.3.5 ports
+   1-65535, we don't do pro-rata allocation based on ports; we choose
+   the ip with the lowest src-ip/dst-ip/proto usage.
+
+   If an allocation then fails (eg. all 6 ports used in the 1.2.3.4
+   range), we eliminate that and try again.  This is not the most
+   efficient approach, but if you're worried about that, don't hand us
+   ranges you don't really have.  */
+static struct ip_nat_range *
+find_best_ips_proto(struct ip_conntrack_tuple *tuple,
+		    const struct ip_nat_multi_range *mr,
+		    const struct ip_conntrack *conntrack,
+		    unsigned int hooknum)
+{
+	unsigned int i;
+	struct {
+		const struct ip_nat_range *range;
+		unsigned int score;
+		struct ip_conntrack_tuple tuple;
+	} best = { NULL,  0xFFFFFFFF };
+	u_int32_t *var_ipp, *other_ipp, saved_ip, orig_dstip;
+	static unsigned int randomness = 0;
+
+	if (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC) {
+		var_ipp = &tuple->src.ip;
+		saved_ip = tuple->dst.ip;
+		other_ipp = &tuple->dst.ip;
+	} else {
+		var_ipp = &tuple->dst.ip;
+		saved_ip = tuple->src.ip;
+		other_ipp = &tuple->src.ip;
+	}
+	/* Don't do do_extra_mangle unless neccessary (overrides
+           explicit socket bindings, for example) */
+	orig_dstip = tuple->dst.ip;
+
+	IP_NF_ASSERT(mr->rangesize >= 1);
+	for (i = 0; i < mr->rangesize; i++) {
+		/* Host order */
+		u_int32_t minip, maxip, j;
+
+		/* Don't do ranges which are already eliminated. */
+		if (mr->range[i].flags & IP_NAT_RANGE_FULL) {
+			continue;
+		}
+
+		if (mr->range[i].flags & IP_NAT_RANGE_MAP_IPS) {
+			minip = ntohl(mr->range[i].min_ip);
+			maxip = ntohl(mr->range[i].max_ip);
+		} else
+			minip = maxip = ntohl(*var_ipp);
+
+		randomness++;
+		for (j = 0; j < maxip - minip + 1; j++) {
+			unsigned int score;
+
+			*var_ipp = htonl(minip + (randomness + j) 
+					 % (maxip - minip + 1));
+
+			/* Reset the other ip in case it was mangled by
+			 * do_extra_mangle last time. */
+			*other_ipp = saved_ip;
+
+#ifdef CONFIG_IP_NF_NAT_LOCAL
+			if (hooknum == NF_IP_LOCAL_OUT
+			    && *var_ipp != orig_dstip
+			    && !do_extra_mangle(*var_ipp, other_ipp)) {
+				DEBUGP("Range %u %u.%u.%u.%u rt failed!\n",
+				       i, NIPQUAD(*var_ipp));
+				/* Can't route?  This whole range part is
+				 * probably screwed, but keep trying
+				 * anyway. */
+				continue;
+			}
+#endif
+
+			/* Count how many others map onto this. */
+			score = count_maps(tuple->src.ip, tuple->dst.ip,
+					   tuple->dst.protonum, conntrack);
+			if (score < best.score) {
+				/* Optimization: doesn't get any better than
+				   this. */
+				if (score == 0)
+					return (struct ip_nat_range *)
+						&mr->range[i];
+
+				best.score = score;
+				best.tuple = *tuple;
+				best.range = &mr->range[i];
+			}
+		}
+	}
+	*tuple = best.tuple;
+
+	/* Discard const. */
+	return (struct ip_nat_range *)best.range;
+}
+
+/* Fast version doesn't iterate through hash chains, but only handles
+   common case of single IP address (null NAT, masquerade) */
+static struct ip_nat_range *
+find_best_ips_proto_fast(struct ip_conntrack_tuple *tuple,
+			 const struct ip_nat_multi_range *mr,
+			 const struct ip_conntrack *conntrack,
+			 unsigned int hooknum)
+{
+	if (mr->rangesize != 1
+	    || (mr->range[0].flags & IP_NAT_RANGE_FULL)
+	    || ((mr->range[0].flags & IP_NAT_RANGE_MAP_IPS)
+		&& mr->range[0].min_ip != mr->range[0].max_ip))
+		return find_best_ips_proto(tuple, mr, conntrack, hooknum);
+
+	if (mr->range[0].flags & IP_NAT_RANGE_MAP_IPS) {
+		if (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC)
+			tuple->src.ip = mr->range[0].min_ip;
+		else {
+			/* Only do extra mangle when required (breaks
+                           socket binding) */
+#ifdef CONFIG_IP_NF_NAT_LOCAL
+			if (tuple->dst.ip != mr->range[0].min_ip
+			    && hooknum == NF_IP_LOCAL_OUT
+			    && !do_extra_mangle(mr->range[0].min_ip,
+						&tuple->src.ip))
+				return NULL;
+#endif
+			tuple->dst.ip = mr->range[0].min_ip;
+		}
+	}
+
+	/* Discard const. */
+	return (struct ip_nat_range *)&mr->range[0];
+}
+
+static int
+get_unique_tuple(struct ip_conntrack_tuple *tuple,
+		 const struct ip_conntrack_tuple *orig_tuple,
+		 const struct ip_nat_multi_range *mrr,
+		 struct ip_conntrack *conntrack,
+		 unsigned int hooknum)
+{
+	struct ip_nat_protocol *proto
+		= find_nat_proto(orig_tuple->dst.protonum);
+	struct ip_nat_range *rptr;
+	unsigned int i;
+	int ret;
+
+	/* We temporarily use flags for marking full parts, but we
+	   always clean up afterwards */
+	struct ip_nat_multi_range *mr = (void *)mrr;
+
+	/* 1) If this srcip/proto/src-proto-part is currently mapped,
+	   and that same mapping gives a unique tuple within the given
+	   range, use that.
+
+	   This is only required for source (ie. NAT/masq) mappings.
+	   So far, we don't do local source mappings, so multiple
+	   manips not an issue.  */
+	if (hooknum == NF_IP_POST_ROUTING) {
+		struct ip_conntrack_manip *manip;
+
+		manip = find_appropriate_src(orig_tuple, mr);
+		if (manip) {
+			/* Apply same source manipulation. */
+			*tuple = ((struct ip_conntrack_tuple)
+				  { *manip, orig_tuple->dst });
+			DEBUGP("get_unique_tuple: Found current src map\n");
+			return 1;
+		}
+	}
+
+	/* 2) Select the least-used IP/proto combination in the given
+	   range.
+	*/
+	*tuple = *orig_tuple;
+	while ((rptr = find_best_ips_proto_fast(tuple, mr, conntrack, hooknum))
+	       != NULL) {
+		DEBUGP("Found best for "); DUMP_TUPLE(tuple);
+		/* 3) The per-protocol part of the manip is made to
+		   map into the range to make a unique tuple. */
+
+		/* Only bother mapping if it's not already in range
+		   and unique */
+		if ((!(rptr->flags & IP_NAT_RANGE_PROTO_SPECIFIED)
+		     || proto->in_range(tuple, HOOK2MANIP(hooknum),
+					&rptr->min, &rptr->max))
+		    && !ip_nat_used_tuple(tuple, conntrack)) {
+			ret = 1;
+			goto clear_fulls;
+		} else {
+			if (proto->unique_tuple(tuple, rptr,
+						HOOK2MANIP(hooknum),
+						conntrack)) {
+				/* Must be unique. */
+				IP_NF_ASSERT(!ip_nat_used_tuple(tuple,
+								conntrack));
+				ret = 1;
+				goto clear_fulls;
+			} else if (HOOK2MANIP(hooknum) == IP_NAT_MANIP_DST) {
+				/* Try implicit source NAT; protocol
+                                   may be able to play with ports to
+                                   make it unique. */
+				struct ip_nat_range r
+					= { IP_NAT_RANGE_MAP_IPS, 
+					    tuple->src.ip, tuple->src.ip,
+					    { 0 }, { 0 } };
+				DEBUGP("Trying implicit mapping\n");
+				if (proto->unique_tuple(tuple, &r,
+							IP_NAT_MANIP_SRC,
+							conntrack)) {
+					/* Must be unique. */
+					IP_NF_ASSERT(!ip_nat_used_tuple
+						     (tuple, conntrack));
+					ret = 1;
+					goto clear_fulls;
+				}
+			}
+			DEBUGP("Protocol can't get unique tuple %u.\n",
+			       hooknum);
+		}
+
+		/* Eliminate that from range, and try again. */
+		rptr->flags |= IP_NAT_RANGE_FULL;
+		*tuple = *orig_tuple;
+	}
+
+	ret = 0;
+
+ clear_fulls:
+	/* Clear full flags. */
+	IP_NF_ASSERT(mr->rangesize >= 1);
+	for (i = 0; i < mr->rangesize; i++)
+		mr->range[i].flags &= ~IP_NAT_RANGE_FULL;
+
+	return ret;
+}
+
+static inline int
+helper_cmp(const struct ip_nat_helper *helper,
+	   const struct ip_conntrack_tuple *tuple)
+{
+	return ip_ct_tuple_mask_cmp(tuple, &helper->tuple, &helper->mask);
+}
+
+/* Where to manip the reply packets (will be reverse manip). */
+static unsigned int opposite_hook[NF_IP_NUMHOOKS]
+= { [NF_IP_PRE_ROUTING] = NF_IP_POST_ROUTING,
+    [NF_IP_POST_ROUTING] = NF_IP_PRE_ROUTING,
+#ifdef CONFIG_IP_NF_NAT_LOCAL
+    [NF_IP_LOCAL_OUT] = NF_IP_LOCAL_IN,
+    [NF_IP_LOCAL_IN] = NF_IP_LOCAL_OUT,
+#endif
+};
+
+unsigned int
+ip_nat_setup_info(struct ip_conntrack *conntrack,
+		  const struct ip_nat_multi_range *mr,
+		  unsigned int hooknum)
+{
+	struct ip_conntrack_tuple new_tuple, inv_tuple, reply;
+	struct ip_conntrack_tuple orig_tp;
+	struct ip_nat_info *info = &conntrack->nat.info;
+	int in_hashes = info->initialized;
+
+	MUST_BE_WRITE_LOCKED(&ip_nat_lock);
+	IP_NF_ASSERT(hooknum == NF_IP_PRE_ROUTING
+		     || hooknum == NF_IP_POST_ROUTING
+		     || hooknum == NF_IP_LOCAL_IN
+		     || hooknum == NF_IP_LOCAL_OUT);
+	IP_NF_ASSERT(info->num_manips < IP_NAT_MAX_MANIPS);
+	IP_NF_ASSERT(!(info->initialized & (1 << HOOK2MANIP(hooknum))));
+
+	/* What we've got will look like inverse of reply. Normally
+	   this is what is in the conntrack, except for prior
+	   manipulations (future optimization: if num_manips == 0,
+	   orig_tp =
+	   conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple) */
+	invert_tuplepr(&orig_tp,
+		       &conntrack->tuplehash[IP_CT_DIR_REPLY].tuple);
+
+#if 0
+	{
+	unsigned int i;
+
+	DEBUGP("Hook %u (%s), ", hooknum,
+	       HOOK2MANIP(hooknum)==IP_NAT_MANIP_SRC ? "SRC" : "DST");
+	DUMP_TUPLE(&orig_tp);
+	DEBUGP("Range %p: ", mr);
+	for (i = 0; i < mr->rangesize; i++) {
+		DEBUGP("%u:%s%s%s %u.%u.%u.%u - %u.%u.%u.%u %u - %u\n",
+		       i,
+		       (mr->range[i].flags & IP_NAT_RANGE_MAP_IPS)
+		       ? " MAP_IPS" : "",
+		       (mr->range[i].flags
+			& IP_NAT_RANGE_PROTO_SPECIFIED)
+		       ? " PROTO_SPECIFIED" : "",
+		       (mr->range[i].flags & IP_NAT_RANGE_FULL)
+		       ? " FULL" : "",
+		       NIPQUAD(mr->range[i].min_ip),
+		       NIPQUAD(mr->range[i].max_ip),
+		       mr->range[i].min.all,
+		       mr->range[i].max.all);
+	}
+	}
+#endif
+
+	do {
+		if (!get_unique_tuple(&new_tuple, &orig_tp, mr, conntrack,
+				      hooknum)) {
+			DEBUGP("ip_nat_setup_info: Can't get unique for %p.\n",
+			       conntrack);
+			return NF_DROP;
+		}
+
+#if 0
+		DEBUGP("Hook %u (%s) %p\n", hooknum,
+		       HOOK2MANIP(hooknum)==IP_NAT_MANIP_SRC ? "SRC" : "DST",
+		       conntrack);
+		DEBUGP("Original: ");
+		DUMP_TUPLE(&orig_tp);
+		DEBUGP("New: ");
+		DUMP_TUPLE(&new_tuple);
+#endif
+
+		/* We now have two tuples (SRCIP/SRCPT/DSTIP/DSTPT):
+		   the original (A/B/C/D') and the mangled one (E/F/G/H').
+
+		   We're only allowed to work with the SRC per-proto
+		   part, so we create inverses of both to start, then
+		   derive the other fields we need.  */
+
+		/* Reply connection: simply invert the new tuple
+                   (G/H/E/F') */
+		invert_tuplepr(&reply, &new_tuple);
+
+		/* Alter conntrack table so it recognizes replies.
+                   If fail this race (reply tuple now used), repeat. */
+	} while (!ip_conntrack_alter_reply(conntrack, &reply));
+
+	/* FIXME: We can simply used existing conntrack reply tuple
+           here --RR */
+	/* Create inverse of original: C/D/A/B' */
+	invert_tuplepr(&inv_tuple, &orig_tp);
+
+	/* Has source changed?. */
+	if (!ip_ct_tuple_src_equal(&new_tuple, &orig_tp)) {
+		/* In this direction, a source manip. */
+		info->manips[info->num_manips++] =
+			((struct ip_nat_info_manip)
+			 { IP_CT_DIR_ORIGINAL, hooknum,
+			   IP_NAT_MANIP_SRC, new_tuple.src });
+
+		IP_NF_ASSERT(info->num_manips < IP_NAT_MAX_MANIPS);
+
+		/* In the reverse direction, a destination manip. */
+		info->manips[info->num_manips++] =
+			((struct ip_nat_info_manip)
+			 { IP_CT_DIR_REPLY, opposite_hook[hooknum],
+			   IP_NAT_MANIP_DST, orig_tp.src });
+		IP_NF_ASSERT(info->num_manips <= IP_NAT_MAX_MANIPS);
+	}
+
+	/* Has destination changed? */
+	if (!ip_ct_tuple_dst_equal(&new_tuple, &orig_tp)) {
+		/* In this direction, a destination manip */
+		info->manips[info->num_manips++] =
+			((struct ip_nat_info_manip)
+			 { IP_CT_DIR_ORIGINAL, hooknum,
+			   IP_NAT_MANIP_DST, reply.src });
+
+		IP_NF_ASSERT(info->num_manips < IP_NAT_MAX_MANIPS);
+
+		/* In the reverse direction, a source manip. */
+		info->manips[info->num_manips++] =
+			((struct ip_nat_info_manip)
+			 { IP_CT_DIR_REPLY, opposite_hook[hooknum],
+			   IP_NAT_MANIP_SRC, inv_tuple.src });
+		IP_NF_ASSERT(info->num_manips <= IP_NAT_MAX_MANIPS);
+	}
+
+	/* If there's a helper, assign it; based on new tuple. */
+	if (!conntrack->master)
+		info->helper = LIST_FIND(&helpers, helper_cmp, struct ip_nat_helper *,
+					 &reply);
+
+	/* It's done. */
+	info->initialized |= (1 << HOOK2MANIP(hooknum));
+
+	if (in_hashes) {
+		IP_NF_ASSERT(info->bysource.conntrack);
+		replace_in_hashes(conntrack, info);
+	} else {
+		place_in_hashes(conntrack, info);
+	}
+
+	return NF_ACCEPT;
+}
+
+void replace_in_hashes(struct ip_conntrack *conntrack,
+		       struct ip_nat_info *info)
+{
+	/* Source has changed, so replace in hashes. */
+	unsigned int srchash
+		= hash_by_src(&conntrack->tuplehash[IP_CT_DIR_ORIGINAL]
+			      .tuple.src,
+			      conntrack->tuplehash[IP_CT_DIR_ORIGINAL]
+			      .tuple.dst.protonum);
+	/* We place packet as seen OUTGOUNG in byips_proto hash
+           (ie. reverse dst and src of reply packet. */
+	unsigned int ipsprotohash
+		= hash_by_ipsproto(conntrack->tuplehash[IP_CT_DIR_REPLY]
+				   .tuple.dst.ip,
+				   conntrack->tuplehash[IP_CT_DIR_REPLY]
+				   .tuple.src.ip,
+				   conntrack->tuplehash[IP_CT_DIR_REPLY]
+				   .tuple.dst.protonum);
+
+	IP_NF_ASSERT(info->bysource.conntrack == conntrack);
+	MUST_BE_WRITE_LOCKED(&ip_nat_lock);
+
+	list_del(&info->bysource.list);
+	list_del(&info->byipsproto.list);
+
+	list_prepend(&bysource[srchash], &info->bysource);
+	list_prepend(&byipsproto[ipsprotohash], &info->byipsproto);
+}
+
+void place_in_hashes(struct ip_conntrack *conntrack,
+		     struct ip_nat_info *info)
+{
+	unsigned int srchash
+		= hash_by_src(&conntrack->tuplehash[IP_CT_DIR_ORIGINAL]
+			      .tuple.src,
+			      conntrack->tuplehash[IP_CT_DIR_ORIGINAL]
+			      .tuple.dst.protonum);
+	/* We place packet as seen OUTGOUNG in byips_proto hash
+           (ie. reverse dst and src of reply packet. */
+	unsigned int ipsprotohash
+		= hash_by_ipsproto(conntrack->tuplehash[IP_CT_DIR_REPLY]
+				   .tuple.dst.ip,
+				   conntrack->tuplehash[IP_CT_DIR_REPLY]
+				   .tuple.src.ip,
+				   conntrack->tuplehash[IP_CT_DIR_REPLY]
+				   .tuple.dst.protonum);
+
+	IP_NF_ASSERT(!info->bysource.conntrack);
+
+	MUST_BE_WRITE_LOCKED(&ip_nat_lock);
+	info->byipsproto.conntrack = conntrack;
+	info->bysource.conntrack = conntrack;
+
+	list_prepend(&bysource[srchash], &info->bysource);
+	list_prepend(&byipsproto[ipsprotohash], &info->byipsproto);
+}
+
+static void
+manip_pkt(u_int16_t proto, struct iphdr *iph, size_t len,
+	  const struct ip_conntrack_manip *manip,
+	  enum ip_nat_manip_type maniptype,
+	  __u32 *nfcache)
+{
+	*nfcache |= NFC_ALTERED;
+	find_nat_proto(proto)->manip_pkt(iph, len, manip, maniptype);
+
+	if (maniptype == IP_NAT_MANIP_SRC) {
+		iph->check = ip_nat_cheat_check(~iph->saddr, manip->ip,
+						iph->check);
+		iph->saddr = manip->ip;
+	} else {
+		iph->check = ip_nat_cheat_check(~iph->daddr, manip->ip,
+						iph->check);
+		iph->daddr = manip->ip;
+	}
+#if 0
+	if (ip_fast_csum((u8 *)iph, iph->ihl) != 0)
+		DEBUGP("IP: checksum on packet bad.\n");
+
+	if (proto == IPPROTO_TCP) {
+		void *th = (u_int32_t *)iph + iph->ihl;
+		if (tcp_v4_check(th, len - 4*iph->ihl, iph->saddr, iph->daddr,
+				 csum_partial((char *)th, len-4*iph->ihl, 0)))
+			DEBUGP("TCP: checksum on packet bad\n");
+	}
+#endif
+}
+
+static inline int exp_for_packet(struct ip_conntrack_expect *exp,
+			         struct sk_buff **pskb)
+{
+	struct ip_conntrack_protocol *proto;
+	int ret = 1;
+
+	MUST_BE_READ_LOCKED(&ip_conntrack_lock);
+	proto = __ip_ct_find_proto((*pskb)->nh.iph->protocol);
+	if (proto->exp_matches_pkt)
+		ret = proto->exp_matches_pkt(exp, pskb);
+
+	return ret;
+}
+
+/* Do packet manipulations according to binding. */
+unsigned int
+do_bindings(struct ip_conntrack *ct,
+	    enum ip_conntrack_info ctinfo,
+	    struct ip_nat_info *info,
+	    unsigned int hooknum,
+	    struct sk_buff **pskb)
+{
+	unsigned int i;
+	struct ip_nat_helper *helper;
+	enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+	int is_tcp = (*pskb)->nh.iph->protocol == IPPROTO_TCP;
+
+	/* Need nat lock to protect against modification, but neither
+	   conntrack (referenced) and helper (deleted with
+	   synchronize_bh()) can vanish. */
+	READ_LOCK(&ip_nat_lock);
+	for (i = 0; i < info->num_manips; i++) {
+		/* raw socket (tcpdump) may have clone of incoming
+                   skb: don't disturb it --RR */
+		if (skb_cloned(*pskb) && !(*pskb)->sk) {
+			struct sk_buff *nskb = skb_copy(*pskb, GFP_ATOMIC);
+			if (!nskb) {
+				READ_UNLOCK(&ip_nat_lock);
+				return NF_DROP;
+			}
+			kfree_skb(*pskb);
+			*pskb = nskb;
+		}
+
+		if (info->manips[i].direction == dir
+		    && info->manips[i].hooknum == hooknum) {
+			DEBUGP("Mangling %p: %s to %u.%u.%u.%u %u\n",
+			       *pskb,
+			       info->manips[i].maniptype == IP_NAT_MANIP_SRC
+			       ? "SRC" : "DST",
+			       NIPQUAD(info->manips[i].manip.ip),
+			       htons(info->manips[i].manip.u.all));
+			manip_pkt((*pskb)->nh.iph->protocol,
+				  (*pskb)->nh.iph,
+				  (*pskb)->len,
+				  &info->manips[i].manip,
+				  info->manips[i].maniptype,
+				  &(*pskb)->nfcache);
+		}
+	}
+	helper = info->helper;
+	READ_UNLOCK(&ip_nat_lock);
+
+	if (helper) {
+		struct ip_conntrack_expect *exp = NULL;
+		struct list_head *cur_item;
+		int ret = NF_ACCEPT;
+		int helper_called = 0;
+
+		DEBUGP("do_bindings: helper existing for (%p)\n", ct);
+
+		/* Always defragged for helpers */
+		IP_NF_ASSERT(!((*pskb)->nh.iph->frag_off
+			       & htons(IP_MF|IP_OFFSET)));
+
+		/* Have to grab read lock before sibling_list traversal */
+		READ_LOCK(&ip_conntrack_lock);
+		list_for_each_prev(cur_item, &ct->sibling_list) { 
+			exp = list_entry(cur_item, struct ip_conntrack_expect, 
+					 expected_list);
+					 
+			/* if this expectation is already established, skip */
+			if (exp->sibling)
+				continue;
+
+			if (exp_for_packet(exp, pskb)) {
+				/* FIXME: May be true multiple times in the
+				 * case of UDP!! */
+				DEBUGP("calling nat helper (exp=%p) for	packet\n", exp);
+				ret = helper->help(ct, exp, info, ctinfo, 
+						   hooknum, pskb);
+				if (ret != NF_ACCEPT) {
+					READ_UNLOCK(&ip_conntrack_lock);
+					return ret;
+				}
+				helper_called = 1;
+			}
+		}
+		/* Helper might want to manip the packet even when there is no
+		 * matching expectation for this packet */
+		if (!helper_called && helper->flags & IP_NAT_HELPER_F_ALWAYS) {
+			DEBUGP("calling nat helper for packet without expectation\n");
+			ret = helper->help(ct, NULL, info, ctinfo, 
+					   hooknum, pskb);
+			if (ret != NF_ACCEPT) {
+				READ_UNLOCK(&ip_conntrack_lock);
+				return ret;
+			}
+		}
+		READ_UNLOCK(&ip_conntrack_lock);
+		
+		/* Adjust sequence number only once per packet 
+		 * (helper is called at all hooks) */
+		if (is_tcp && (hooknum == NF_IP_POST_ROUTING
+			       || hooknum == NF_IP_LOCAL_IN)) {
+			DEBUGP("ip_nat_core: adjusting sequence number\n");
+			/* future: put this in a l4-proto specific function,
+			 * and call this function here. */
+			ip_nat_seq_adjust(*pskb, ct, ctinfo);
+		}
+
+		return ret;
+
+	} else 
+		return NF_ACCEPT;
+
+	/* not reached */
+}
+
+unsigned int
+icmp_reply_translation(struct sk_buff *skb,
+		       struct ip_conntrack *conntrack,
+		       unsigned int hooknum,
+		       int dir)
+{
+	struct iphdr *iph = skb->nh.iph;
+	struct icmphdr *hdr = (struct icmphdr *)((u_int32_t *)iph + iph->ihl);
+	struct iphdr *inner = (struct iphdr *)(hdr + 1);
+	size_t datalen = skb->len - ((void *)inner - (void *)iph);
+	unsigned int i;
+	struct ip_nat_info *info = &conntrack->nat.info;
+
+	IP_NF_ASSERT(skb->len >= iph->ihl*4 + sizeof(struct icmphdr));
+	/* Must be RELATED */
+	IP_NF_ASSERT(skb->nfct
+		     - ((struct ip_conntrack *)skb->nfct->master)->infos
+		     == IP_CT_RELATED
+		     || skb->nfct
+		     - ((struct ip_conntrack *)skb->nfct->master)->infos
+		     == IP_CT_RELATED+IP_CT_IS_REPLY);
+
+	/* Redirects on non-null nats must be dropped, else they'll
+           start talking to each other without our translation, and be
+           confused... --RR */
+	if (hdr->type == ICMP_REDIRECT) {
+		/* Don't care about races here. */
+		if (info->initialized
+		    != ((1 << IP_NAT_MANIP_SRC) | (1 << IP_NAT_MANIP_DST))
+		    || info->num_manips != 0)
+			return NF_DROP;
+	}
+
+	DEBUGP("icmp_reply_translation: translating error %p hook %u dir %s\n",
+	       skb, hooknum, dir == IP_CT_DIR_ORIGINAL ? "ORIG" : "REPLY");
+	/* Note: May not be from a NAT'd host, but probably safest to
+	   do translation always as if it came from the host itself
+	   (even though a "host unreachable" coming from the host
+	   itself is a bit weird).
+
+	   More explanation: some people use NAT for anonymizing.
+	   Also, CERT recommends dropping all packets from private IP
+	   addresses (although ICMP errors from internal links with
+	   such addresses are not too uncommon, as Alan Cox points
+	   out) */
+
+	READ_LOCK(&ip_nat_lock);
+	for (i = 0; i < info->num_manips; i++) {
+		DEBUGP("icmp_reply: manip %u dir %s hook %u\n",
+		       i, info->manips[i].direction == IP_CT_DIR_ORIGINAL ?
+		       "ORIG" : "REPLY", info->manips[i].hooknum);
+
+		if (info->manips[i].direction != dir)
+			continue;
+
+		/* Mapping the inner packet is just like a normal
+		   packet, except it was never src/dst reversed, so
+		   where we would normally apply a dst manip, we apply
+		   a src, and vice versa. */
+		if (info->manips[i].hooknum == hooknum) {
+			DEBUGP("icmp_reply: inner %s -> %u.%u.%u.%u %u\n",
+			       info->manips[i].maniptype == IP_NAT_MANIP_SRC
+			       ? "DST" : "SRC",
+			       NIPQUAD(info->manips[i].manip.ip),
+			       ntohs(info->manips[i].manip.u.udp.port));
+			manip_pkt(inner->protocol, inner,
+				  skb->len - ((void *)inner - (void *)iph),
+				  &info->manips[i].manip,
+				  !info->manips[i].maniptype,
+				  &skb->nfcache);
+			/* Outer packet needs to have IP header NATed like
+	                   it's a reply. */
+
+			/* Use mapping to map outer packet: 0 give no
+                           per-proto mapping */
+			DEBUGP("icmp_reply: outer %s -> %u.%u.%u.%u\n",
+			       info->manips[i].maniptype == IP_NAT_MANIP_SRC
+			       ? "SRC" : "DST",
+			       NIPQUAD(info->manips[i].manip.ip));
+			manip_pkt(0, iph, skb->len,
+				  &info->manips[i].manip,
+				  info->manips[i].maniptype,
+				  &skb->nfcache);
+		}
+	}
+	READ_UNLOCK(&ip_nat_lock);
+
+	/* Since we mangled inside ICMP packet, recalculate its
+	   checksum from scratch.  (Hence the handling of incorrect
+	   checksums in conntrack, so we don't accidentally fix one.)  */
+	hdr->checksum = 0;
+	hdr->checksum = ip_compute_csum((unsigned char *)hdr,
+					sizeof(*hdr) + datalen);
+
+	return NF_ACCEPT;
+}
+
+int __init ip_nat_init(void)
+{
+	size_t i;
+
+	/* Leave them the same for the moment. */
+	ip_nat_htable_size = ip_conntrack_htable_size;
+
+	/* One vmalloc for both hash tables */
+	bysource = vmalloc(sizeof(struct list_head) * ip_nat_htable_size*2);
+	if (!bysource) {
+		return -ENOMEM;
+	}
+	byipsproto = bysource + ip_nat_htable_size;
+
+	/* Sew in builtin protocols. */
+	WRITE_LOCK(&ip_nat_lock);
+	list_append(&protos, &ip_nat_protocol_tcp);
+	list_append(&protos, &ip_nat_protocol_udp);
+	list_append(&protos, &ip_nat_protocol_icmp);
+	WRITE_UNLOCK(&ip_nat_lock);
+
+	for (i = 0; i < ip_nat_htable_size; i++) {
+		INIT_LIST_HEAD(&bysource[i]);
+		INIT_LIST_HEAD(&byipsproto[i]);
+	}
+
+	/* FIXME: Man, this is a hack.  <SIGH> */
+	IP_NF_ASSERT(ip_conntrack_destroyed == NULL);
+	ip_conntrack_destroyed = &ip_nat_cleanup_conntrack;
+
+	return 0;
+}
+
+/* Clear NAT section of all conntracks, in case we're loaded again. */
+static int clean_nat(const struct ip_conntrack *i, void *data)
+{
+	memset((void *)&i->nat, 0, sizeof(i->nat));
+	return 0;
+}
+
+/* Not __exit: called from ip_nat_standalone.c:init_or_cleanup() --RR */
+void ip_nat_cleanup(void)
+{
+	ip_ct_selective_cleanup(&clean_nat, NULL);
+	ip_conntrack_destroyed = NULL;
+	vfree(bysource);
+}
diff -uNr linux_org/net/ipv4/netfilter/ip_nat_pptp.c linux/net/ipv4/netfilter/ip_nat_pptp.c
--- linux_org/net/ipv4/netfilter/ip_nat_pptp.c	1970-01-01 01:00:00.000000000 +0100
+++ linux/net/ipv4/netfilter/ip_nat_pptp.c	2006-10-27 14:11:52.000000000 +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);
diff -uNr linux_org/net/ipv4/netfilter/ip_nat_proto_gre.c linux/net/ipv4/netfilter/ip_nat_proto_gre.c
--- linux_org/net/ipv4/netfilter/ip_nat_proto_gre.c	1970-01-01 01:00:00.000000000 +0100
+++ linux/net/ipv4/netfilter/ip_nat_proto_gre.c	2006-10-27 14:11:52.000000000 +0200
@@ -0,0 +1,225 @@
+/*
+ * 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)) {
+
+		switch (tuple->dst.u.gre.version) {
+		case 0:
+			DEBUGP("NATing GRE version 0 (ct=%p)\n",
+				conntrack);
+			min = 1;
+			range_size = 0xffffffff;
+			break;
+		case GRE_VERSION_PPTP:
+			DEBUGP("%p: NATing GRE PPTP\n", 
+				conntrack);
+			min = 1;
+			range_size = 0xffff;
+			break;
+		default:
+			printk(KERN_WARNING "nat_gre: unknown GRE version\n");
+			return 0;
+			break;
+		}
+
+	} 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->dst.u.gre.version)
+		len += sprintf(buffer + len, "version=%d ",
+				ntohs(match->dst.u.gre.version));
+
+	if (mask->dst.u.gre.protocol)
+		len += sprintf(buffer + len, "protocol=0x%x ",
+				ntohs(match->dst.u.gre.protocol));
+
+	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);