netfilter: nf_nat: add protoff argument to packet mangling functions

For mangling IPv6 packets the protocol header offset needs to be known
by the NAT packet mangling functions. Add a so far unused protoff argument
and convert the conntrack and NAT helpers to use it in preparation of
IPv6 NAT.
Signed-off-by: Patrick McHardy <kaber@trash.net>

include/linux/netfilter/nf_conntrack_amanda.h

@@ -4,6 +4,7 @@
 
 extern unsigned int (*nf_nat_amanda_hook)(struct sk_buff *skb,
 					  enum ip_conntrack_info ctinfo,
+					  unsigned int protoff,
 					  unsigned int matchoff,
 					  unsigned int matchlen,
 					  struct nf_conntrack_expect *exp);

include/linux/netfilter/nf_conntrack_ftp.h

@@ -34,6 +34,7 @@ struct nf_conntrack_expect;
 extern unsigned int (*nf_nat_ftp_hook)(struct sk_buff *skb,
 				       enum ip_conntrack_info ctinfo,
 				       enum nf_ct_ftp_type type,
+				       unsigned int protoff,
 				       unsigned int matchoff,
 				       unsigned int matchlen,
 				       struct nf_conntrack_expect *exp);

include/linux/netfilter/nf_conntrack_h323.h

@@ -36,12 +36,12 @@ extern void nf_conntrack_h245_expect(struct nf_conn *new,
 				     struct nf_conntrack_expect *this);
 extern void nf_conntrack_q931_expect(struct nf_conn *new,
 				     struct nf_conntrack_expect *this);
-extern int (*set_h245_addr_hook) (struct sk_buff *skb,
+extern int (*set_h245_addr_hook) (struct sk_buff *skb, unsigned int protoff,
 				  unsigned char **data, int dataoff,
 				  H245_TransportAddress *taddr,
 				  union nf_inet_addr *addr,
 				  __be16 port);
-extern int (*set_h225_addr_hook) (struct sk_buff *skb,
+extern int (*set_h225_addr_hook) (struct sk_buff *skb, unsigned int protoff,
 				  unsigned char **data, int dataoff,
 				  TransportAddress *taddr,
 				  union nf_inet_addr *addr,
@@ -49,40 +49,45 @@ extern int (*set_h225_addr_hook) (struct sk_buff *skb,
 extern int (*set_sig_addr_hook) (struct sk_buff *skb,
 				 struct nf_conn *ct,
 				 enum ip_conntrack_info ctinfo,
-				 unsigned char **data,
+				 unsigned int protoff, unsigned char **data,
 				 TransportAddress *taddr, int count);
 extern int (*set_ras_addr_hook) (struct sk_buff *skb,
 				 struct nf_conn *ct,
 				 enum ip_conntrack_info ctinfo,
-				 unsigned char **data,
+				 unsigned int protoff, unsigned char **data,
 				 TransportAddress *taddr, int count);
 extern int (*nat_rtp_rtcp_hook) (struct sk_buff *skb,
 				 struct nf_conn *ct,
 				 enum ip_conntrack_info ctinfo,
-				 unsigned char **data, int dataoff,
+				 unsigned int protoff, unsigned char **data,
+				 int dataoff,
 				 H245_TransportAddress *taddr,
 				 __be16 port, __be16 rtp_port,
 				 struct nf_conntrack_expect *rtp_exp,
 				 struct nf_conntrack_expect *rtcp_exp);
 extern int (*nat_t120_hook) (struct sk_buff *skb, struct nf_conn *ct,
 			     enum ip_conntrack_info ctinfo,
+			     unsigned int protoff,
 			     unsigned char **data, int dataoff,
 			     H245_TransportAddress *taddr, __be16 port,
 			     struct nf_conntrack_expect *exp);
 extern int (*nat_h245_hook) (struct sk_buff *skb, struct nf_conn *ct,
 			     enum ip_conntrack_info ctinfo,
+			     unsigned int protoff,
 			     unsigned char **data, int dataoff,
 			     TransportAddress *taddr, __be16 port,
 			     struct nf_conntrack_expect *exp);
 extern int (*nat_callforwarding_hook) (struct sk_buff *skb,
 				       struct nf_conn *ct,
 				       enum ip_conntrack_info ctinfo,
+				       unsigned int protoff,
 				       unsigned char **data, int dataoff,
 				       TransportAddress *taddr,
 				       __be16 port,
 				       struct nf_conntrack_expect *exp);
 extern int (*nat_q931_hook) (struct sk_buff *skb, struct nf_conn *ct,
 			     enum ip_conntrack_info ctinfo,
+			     unsigned int protoff,
 			     unsigned char **data, TransportAddress *taddr,
 			     int idx, __be16 port,
 			     struct nf_conntrack_expect *exp);

include/linux/netfilter/nf_conntrack_irc.h

@@ -7,6 +7,7 @@
 
 extern unsigned int (*nf_nat_irc_hook)(struct sk_buff *skb,
 				       enum ip_conntrack_info ctinfo,
+				       unsigned int protoff,
 				       unsigned int matchoff,
 				       unsigned int matchlen,
 				       struct nf_conntrack_expect *exp);

include/linux/netfilter/nf_conntrack_pptp.h

@@ -303,12 +303,14 @@ struct nf_conntrack_expect;
 extern int
 (*nf_nat_pptp_hook_outbound)(struct sk_buff *skb,
 			     struct nf_conn *ct, enum ip_conntrack_info ctinfo,
+			     unsigned int protoff,
 			     struct PptpControlHeader *ctlh,
 			     union pptp_ctrl_union *pptpReq);
 
 extern int
 (*nf_nat_pptp_hook_inbound)(struct sk_buff *skb,
 			    struct nf_conn *ct, enum ip_conntrack_info ctinfo,
+			    unsigned int protoff,
 			    struct PptpControlHeader *ctlh,
 			    union pptp_ctrl_union *pptpReq);
 

include/linux/netfilter/nf_conntrack_sip.h

@@ -37,10 +37,12 @@ struct sdp_media_type {
 struct sip_handler {
 	const char	*method;
 	unsigned int	len;
-	int		(*request)(struct sk_buff *skb, unsigned int dataoff,
+	int		(*request)(struct sk_buff *skb, unsigned int protoff,
+				   unsigned int dataoff,
 				   const char **dptr, unsigned int *datalen,
 				   unsigned int cseq);
-	int		(*response)(struct sk_buff *skb, unsigned int dataoff,
+	int		(*response)(struct sk_buff *skb, unsigned int protoff,
+				    unsigned int dataoff,
 				    const char **dptr, unsigned int *datalen,
 				    unsigned int cseq, unsigned int code);
 };
@@ -105,11 +107,13 @@ enum sdp_header_types {
 };
 
 extern unsigned int (*nf_nat_sip_hook)(struct sk_buff *skb,
+				       unsigned int protoff,
 				       unsigned int dataoff,
 				       const char **dptr,
 				       unsigned int *datalen);
 extern void (*nf_nat_sip_seq_adjust_hook)(struct sk_buff *skb, s16 off);
 extern unsigned int (*nf_nat_sip_expect_hook)(struct sk_buff *skb,
+					      unsigned int protoff,
 					      unsigned int dataoff,
 					      const char **dptr,
 					      unsigned int *datalen,
@@ -117,6 +121,7 @@ extern unsigned int (*nf_nat_sip_expect_hook)(struct sk_buff *skb,
 					      unsigned int matchoff,
 					      unsigned int matchlen);
 extern unsigned int (*nf_nat_sdp_addr_hook)(struct sk_buff *skb,
+					    unsigned int protoff,
 					    unsigned int dataoff,
 					    const char **dptr,
 					    unsigned int *datalen,
@@ -125,6 +130,7 @@ extern unsigned int (*nf_nat_sdp_addr_hook)(struct sk_buff *skb,
 					    enum sdp_header_types term,
 					    const union nf_inet_addr *addr);
 extern unsigned int (*nf_nat_sdp_port_hook)(struct sk_buff *skb,
+					    unsigned int protoff,
 					    unsigned int dataoff,
 					    const char **dptr,
 					    unsigned int *datalen,
@@ -132,12 +138,14 @@ extern unsigned int (*nf_nat_sdp_port_hook)(struct sk_buff *skb,
 					    unsigned int matchlen,
 					    u_int16_t port);
 extern unsigned int (*nf_nat_sdp_session_hook)(struct sk_buff *skb,
+					       unsigned int protoff,
 					       unsigned int dataoff,
 					       const char **dptr,
 					       unsigned int *datalen,
 					       unsigned int sdpoff,
 					       const union nf_inet_addr *addr);
 extern unsigned int (*nf_nat_sdp_media_hook)(struct sk_buff *skb,
+					     unsigned int protoff,
 					     unsigned int dataoff,
 					     const char **dptr,
 					     unsigned int *datalen,

include/net/netfilter/nf_nat_helper.h

@@ -10,6 +10,7 @@ struct sk_buff;
 extern int __nf_nat_mangle_tcp_packet(struct sk_buff *skb,
 				      struct nf_conn *ct,
 				      enum ip_conntrack_info ctinfo,
+				      unsigned int protoff,
 				      unsigned int match_offset,
 				      unsigned int match_len,
 				      const char *rep_buffer,
@@ -18,12 +19,13 @@ extern int __nf_nat_mangle_tcp_packet(struct sk_buff *skb,
 static inline int nf_nat_mangle_tcp_packet(struct sk_buff *skb,
 					   struct nf_conn *ct,
 					   enum ip_conntrack_info ctinfo,
+					   unsigned int protoff,
 					   unsigned int match_offset,
 					   unsigned int match_len,
 					   const char *rep_buffer,
 					   unsigned int rep_len)
 {
-	return __nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
+	return __nf_nat_mangle_tcp_packet(skb, ct, ctinfo, protoff,
 					  match_offset, match_len,
 					  rep_buffer, rep_len, true);
 }
@@ -31,6 +33,7 @@ static inline int nf_nat_mangle_tcp_packet(struct sk_buff *skb,
 extern int nf_nat_mangle_udp_packet(struct sk_buff *skb,
 				    struct nf_conn *ct,
 				    enum ip_conntrack_info ctinfo,
+				    unsigned int protoff,
 				    unsigned int match_offset,
 				    unsigned int match_len,
 				    const char *rep_buffer,
@@ -41,10 +44,12 @@ extern void nf_nat_set_seq_adjust(struct nf_conn *ct,
 				  __be32 seq, s16 off);
 extern int nf_nat_seq_adjust(struct sk_buff *skb,
 			     struct nf_conn *ct,
-			     enum ip_conntrack_info ctinfo);
+			     enum ip_conntrack_info ctinfo,
+			     unsigned int protoff);
 extern int (*nf_nat_seq_adjust_hook)(struct sk_buff *skb,
 				     struct nf_conn *ct,
-				     enum ip_conntrack_info ctinfo);
+				     enum ip_conntrack_info ctinfo,
+				     unsigned int protoff);
 
 /* Setup NAT on this expected conntrack so it follows master, but goes
  * to port ct->master->saved_proto. */

net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c

@@ -31,7 +31,8 @@
 
 int (*nf_nat_seq_adjust_hook)(struct sk_buff *skb,
 			      struct nf_conn *ct,
-			      enum ip_conntrack_info ctinfo);
+			      enum ip_conntrack_info ctinfo,
+			      unsigned int protoff);
 EXPORT_SYMBOL_GPL(nf_nat_seq_adjust_hook);
 
 static bool ipv4_pkt_to_tuple(const struct sk_buff *skb, unsigned int nhoff,
@@ -149,7 +150,8 @@ static unsigned int ipv4_confirm(unsigned int hooknum,
 		typeof(nf_nat_seq_adjust_hook) seq_adjust;
 
 		seq_adjust = rcu_dereference(nf_nat_seq_adjust_hook);
-		if (!seq_adjust || !seq_adjust(skb, ct, ctinfo)) {
+		if (!seq_adjust ||
+		    !seq_adjust(skb, ct, ctinfo, ip_hdrlen(skb))) {
 			NF_CT_STAT_INC_ATOMIC(nf_ct_net(ct), drop);
 			return NF_DROP;
 		}

net/ipv4/netfilter/nf_nat_amanda.c

@@ -26,6 +26,7 @@ MODULE_ALIAS("ip_nat_amanda");
 
 static unsigned int help(struct sk_buff *skb,
 			 enum ip_conntrack_info ctinfo,
+			 unsigned int protoff,
 			 unsigned int matchoff,
 			 unsigned int matchlen,
 			 struct nf_conntrack_expect *exp)
@@ -61,7 +62,7 @@ static unsigned int help(struct sk_buff *skb,
 
 	sprintf(buffer, "%u", port);
 	ret = nf_nat_mangle_udp_packet(skb, exp->master, ctinfo,
-				       matchoff, matchlen,
+				       protoff, matchoff, matchlen,
 				       buffer, strlen(buffer));
 	if (ret != NF_ACCEPT)
 		nf_ct_unexpect_related(exp);

net/ipv4/netfilter/nf_nat_ftp.c

@@ -55,6 +55,7 @@ static int nf_nat_ftp_fmt_cmd(enum nf_ct_ftp_type type,
 static unsigned int nf_nat_ftp(struct sk_buff *skb,
 			       enum ip_conntrack_info ctinfo,
 			       enum nf_ct_ftp_type type,
+			       unsigned int protoff,
 			       unsigned int matchoff,
 			       unsigned int matchlen,
 			       struct nf_conntrack_expect *exp)
@@ -100,7 +101,7 @@ static unsigned int nf_nat_ftp(struct sk_buff *skb,
 
 	pr_debug("calling nf_nat_mangle_tcp_packet\n");
 
-	if (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo, matchoff,
+	if (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo, protoff, matchoff,
 				      matchlen, buffer, buflen))
 		goto out;
 

net/ipv4/netfilter/nf_nat_h323.c

@@ -21,7 +21,7 @@
 #include <linux/netfilter/nf_conntrack_h323.h>
 
 /****************************************************************************/
-static int set_addr(struct sk_buff *skb,
+static int set_addr(struct sk_buff *skb, unsigned int protoff,
 		    unsigned char **data, int dataoff,
 		    unsigned int addroff, __be32 ip, __be16 port)
 {
@@ -40,7 +40,7 @@ static int set_addr(struct sk_buff *skb,
 
 	if (ip_hdr(skb)->protocol == IPPROTO_TCP) {
 		if (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
-					      addroff, sizeof(buf),
+					      protoff, addroff, sizeof(buf),
 					      (char *) &buf, sizeof(buf))) {
 			net_notice_ratelimited("nf_nat_h323: nf_nat_mangle_tcp_packet error\n");
 			return -1;
@@ -54,7 +54,7 @@ static int set_addr(struct sk_buff *skb,
 		*data = skb->data + ip_hdrlen(skb) + th->doff * 4 + dataoff;
 	} else {
 		if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo,
-					      addroff, sizeof(buf),
+					      protoff, addroff, sizeof(buf),
 					      (char *) &buf, sizeof(buf))) {
 			net_notice_ratelimited("nf_nat_h323: nf_nat_mangle_udp_packet error\n");
 			return -1;
@@ -69,22 +69,22 @@ static int set_addr(struct sk_buff *skb,
 }
 
 /****************************************************************************/
-static int set_h225_addr(struct sk_buff *skb,
+static int set_h225_addr(struct sk_buff *skb, unsigned int protoff,
 			 unsigned char **data, int dataoff,
 			 TransportAddress *taddr,
 			 union nf_inet_addr *addr, __be16 port)
 {
-	return set_addr(skb, data, dataoff, taddr->ipAddress.ip,
+	return set_addr(skb, protoff, data, dataoff, taddr->ipAddress.ip,
 			addr->ip, port);
 }
 
 /****************************************************************************/
-static int set_h245_addr(struct sk_buff *skb,
+static int set_h245_addr(struct sk_buff *skb, unsigned protoff,
 			 unsigned char **data, int dataoff,
 			 H245_TransportAddress *taddr,
 			 union nf_inet_addr *addr, __be16 port)
 {
-	return set_addr(skb, data, dataoff,
+	return set_addr(skb, protoff, data, dataoff,
 			taddr->unicastAddress.iPAddress.network,
 			addr->ip, port);
 }
@@ -92,7 +92,7 @@ static int set_h245_addr(struct sk_buff *skb,
 /****************************************************************************/
 static int set_sig_addr(struct sk_buff *skb, struct nf_conn *ct,
 			enum ip_conntrack_info ctinfo,
-			unsigned char **data,
+			unsigned int protoff, unsigned char **data,
 			TransportAddress *taddr, int count)
 {
 	const struct nf_ct_h323_master *info = nfct_help_data(ct);
@@ -118,7 +118,8 @@ static int set_sig_addr(struct sk_buff *skb, struct nf_conn *ct,
 					 &addr.ip, port,
 					 &ct->tuplehash[!dir].tuple.dst.u3.ip,
 					 info->sig_port[!dir]);
-				return set_h225_addr(skb, data, 0, &taddr[i],
+				return set_h225_addr(skb, protoff, data, 0,
+						     &taddr[i],
 						     &ct->tuplehash[!dir].
 						     tuple.dst.u3,
 						     info->sig_port[!dir]);
@@ -129,7 +130,8 @@ static int set_sig_addr(struct sk_buff *skb, struct nf_conn *ct,
 					 &addr.ip, port,
 					 &ct->tuplehash[!dir].tuple.src.u3.ip,
 					 info->sig_port[!dir]);
-				return set_h225_addr(skb, data, 0, &taddr[i],
+				return set_h225_addr(skb, protoff, data, 0,
+						     &taddr[i],
 						     &ct->tuplehash[!dir].
 						     tuple.src.u3,
 						     info->sig_port[!dir]);
@@ -143,7 +145,7 @@ static int set_sig_addr(struct sk_buff *skb, struct nf_conn *ct,
 /****************************************************************************/
 static int set_ras_addr(struct sk_buff *skb, struct nf_conn *ct,
 			enum ip_conntrack_info ctinfo,
-			unsigned char **data,
+			unsigned int protoff, unsigned char **data,
 			TransportAddress *taddr, int count)
 {
 	int dir = CTINFO2DIR(ctinfo);
@@ -159,7 +161,7 @@ static int set_ras_addr(struct sk_buff *skb, struct nf_conn *ct,
 				 &addr.ip, ntohs(port),
 				 &ct->tuplehash[!dir].tuple.dst.u3.ip,
 				 ntohs(ct->tuplehash[!dir].tuple.dst.u.udp.port));
-			return set_h225_addr(skb, data, 0, &taddr[i],
+			return set_h225_addr(skb, protoff, data, 0, &taddr[i],
 					     &ct->tuplehash[!dir].tuple.dst.u3,
 					     ct->tuplehash[!dir].tuple.
 								dst.u.udp.port);
@@ -172,7 +174,7 @@ static int set_ras_addr(struct sk_buff *skb, struct nf_conn *ct,
 /****************************************************************************/
 static int nat_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct,
 			enum ip_conntrack_info ctinfo,
-			unsigned char **data, int dataoff,
+			unsigned int protoff, unsigned char **data, int dataoff,
 			H245_TransportAddress *taddr,
 			__be16 port, __be16 rtp_port,
 			struct nf_conntrack_expect *rtp_exp,
@@ -244,7 +246,7 @@ static int nat_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct,
 	}
 
 	/* Modify signal */
-	if (set_h245_addr(skb, data, dataoff, taddr,
+	if (set_h245_addr(skb, protoff, data, dataoff, taddr,
 			  &ct->tuplehash[!dir].tuple.dst.u3,
 			  htons((port & htons(1)) ? nated_port + 1 :
 						    nated_port)) == 0) {
@@ -275,7 +277,7 @@ static int nat_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct,
 /****************************************************************************/
 static int nat_t120(struct sk_buff *skb, struct nf_conn *ct,
 		    enum ip_conntrack_info ctinfo,
-		    unsigned char **data, int dataoff,
+		    unsigned int protoff, unsigned char **data, int dataoff,
 		    H245_TransportAddress *taddr, __be16 port,
 		    struct nf_conntrack_expect *exp)
 {
@@ -307,7 +309,7 @@ static int nat_t120(struct sk_buff *skb, struct nf_conn *ct,
 	}
 
 	/* Modify signal */
-	if (set_h245_addr(skb, data, dataoff, taddr,
+	if (set_h245_addr(skb, protoff, data, dataoff, taddr,
 			  &ct->tuplehash[!dir].tuple.dst.u3,
 			  htons(nated_port)) < 0) {
 		nf_ct_unexpect_related(exp);
@@ -326,7 +328,7 @@ static int nat_t120(struct sk_buff *skb, struct nf_conn *ct,
 /****************************************************************************/
 static int nat_h245(struct sk_buff *skb, struct nf_conn *ct,
 		    enum ip_conntrack_info ctinfo,
-		    unsigned char **data, int dataoff,
+		    unsigned int protoff, unsigned char **data, int dataoff,
 		    TransportAddress *taddr, __be16 port,
 		    struct nf_conntrack_expect *exp)
 {
@@ -363,7 +365,7 @@ static int nat_h245(struct sk_buff *skb, struct nf_conn *ct,
 	}
 
 	/* Modify signal */
-	if (set_h225_addr(skb, data, dataoff, taddr,
+	if (set_h225_addr(skb, protoff, data, dataoff, taddr,
 			  &ct->tuplehash[!dir].tuple.dst.u3,
 			  htons(nated_port)) == 0) {
 		/* Save ports */
@@ -416,7 +418,8 @@ static void ip_nat_q931_expect(struct nf_conn *new,
 /****************************************************************************/
 static int nat_q931(struct sk_buff *skb, struct nf_conn *ct,
 		    enum ip_conntrack_info ctinfo,
-		    unsigned char **data, TransportAddress *taddr, int idx,
+		    unsigned int protoff, unsigned char **data,
+		    TransportAddress *taddr, int idx,
 		    __be16 port, struct nf_conntrack_expect *exp)
 {
 	struct nf_ct_h323_master *info = nfct_help_data(ct);
@@ -453,7 +456,7 @@ static int nat_q931(struct sk_buff *skb, struct nf_conn *ct,
 	}
 
 	/* Modify signal */
-	if (set_h225_addr(skb, data, 0, &taddr[idx],
+	if (set_h225_addr(skb, protoff, data, 0, &taddr[idx],
 			  &ct->tuplehash[!dir].tuple.dst.u3,
 			  htons(nated_port)) == 0) {
 		/* Save ports */
@@ -464,7 +467,7 @@ static int nat_q931(struct sk_buff *skb, struct nf_conn *ct,
 		if (idx > 0 &&
 		    get_h225_addr(ct, *data, &taddr[0], &addr, &port) &&
 		    (ntohl(addr.ip) & 0xff000000) == 0x7f000000) {
-			set_h225_addr(skb, data, 0, &taddr[0],
+			set_h225_addr(skb, protoff, data, 0, &taddr[0],
 				      &ct->tuplehash[!dir].tuple.dst.u3,
 				      info->sig_port[!dir]);
 		}
@@ -507,6 +510,7 @@ static void ip_nat_callforwarding_expect(struct nf_conn *new,
 /****************************************************************************/
 static int nat_callforwarding(struct sk_buff *skb, struct nf_conn *ct,
 			      enum ip_conntrack_info ctinfo,
+			      unsigned int protoff,
 			      unsigned char **data, int dataoff,
 			      TransportAddress *taddr, __be16 port,
 			      struct nf_conntrack_expect *exp)
@@ -541,7 +545,7 @@ static int nat_callforwarding(struct sk_buff *skb, struct nf_conn *ct,
 	}
 
 	/* Modify signal */
-	if (!set_h225_addr(skb, data, dataoff, taddr,
+	if (!set_h225_addr(skb, protoff, data, dataoff, taddr,
 			   &ct->tuplehash[!dir].tuple.dst.u3,
 			   htons(nated_port)) == 0) {
 		nf_ct_unexpect_related(exp);

net/ipv4/netfilter/nf_nat_helper.c

@@ -206,6 +206,7 @@ static void nf_nat_csum(struct sk_buff *skb, const struct iphdr *iph, void *data
 int __nf_nat_mangle_tcp_packet(struct sk_buff *skb,
 			       struct nf_conn *ct,
 			       enum ip_conntrack_info ctinfo,
+			       unsigned int protoff,
 			       unsigned int match_offset,
 			       unsigned int match_len,
 			       const char *rep_buffer,
@@ -257,6 +258,7 @@ int
 nf_nat_mangle_udp_packet(struct sk_buff *skb,
 			 struct nf_conn *ct,
 			 enum ip_conntrack_info ctinfo,
+			 unsigned int protoff,
 			 unsigned int match_offset,
 			 unsigned int match_len,
 			 const char *rep_buffer,
@@ -387,7 +389,8 @@ nf_nat_sack_adjust(struct sk_buff *skb,
 int
 nf_nat_seq_adjust(struct sk_buff *skb,
 		  struct nf_conn *ct,
-		  enum ip_conntrack_info ctinfo)
+		  enum ip_conntrack_info ctinfo,
+		  unsigned int protoff)
 {
 	struct tcphdr *tcph;
 	int dir;
@@ -401,10 +404,10 @@ nf_nat_seq_adjust(struct sk_buff *skb,
 	this_way = &nat->seq[dir];
 	other_way = &nat->seq[!dir];
 
-	if (!skb_make_writable(skb, ip_hdrlen(skb) + sizeof(*tcph)))
+	if (!skb_make_writable(skb, protoff + sizeof(*tcph)))
 		return 0;
 
-	tcph = (void *)skb->data + ip_hdrlen(skb);
+	tcph = (void *)skb->data + protoff;
 	if (after(ntohl(tcph->seq), this_way->correction_pos))
 		seqoff = this_way->offset_after;
 	else

net/ipv4/netfilter/nf_nat_irc.c

@@ -29,6 +29,7 @@ MODULE_ALIAS("ip_nat_irc");
 
 static unsigned int help(struct sk_buff *skb,
 			 enum ip_conntrack_info ctinfo,
+			 unsigned int protoff,
 			 unsigned int matchoff,
 			 unsigned int matchlen,
 			 struct nf_conntrack_expect *exp)
@@ -66,7 +67,7 @@ static unsigned int help(struct sk_buff *skb,
 		 buffer, &ip, port);
 
 	ret = nf_nat_mangle_tcp_packet(skb, exp->master, ctinfo,
-				       matchoff, matchlen, buffer,
+				       protoff, matchoff, matchlen, buffer,
 				       strlen(buffer));
 	if (ret != NF_ACCEPT)
 		nf_ct_unexpect_related(exp);

net/ipv4/netfilter/nf_nat_pptp.c

@@ -113,6 +113,7 @@ static int
 pptp_outbound_pkt(struct sk_buff *skb,
 		  struct nf_conn *ct,
 		  enum ip_conntrack_info ctinfo,
+		  unsigned int protoff,
 		  struct PptpControlHeader *ctlh,
 		  union pptp_ctrl_union *pptpReq)
 
@@ -175,7 +176,7 @@ pptp_outbound_pkt(struct sk_buff *skb,
 		 ntohs(REQ_CID(pptpReq, cid_off)), ntohs(new_callid));
 
 	/* mangle packet */
-	if (nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
+	if (nf_nat_mangle_tcp_packet(skb, ct, ctinfo, protoff,
 				     cid_off + sizeof(struct pptp_pkt_hdr) +
 				     sizeof(struct PptpControlHeader),
 				     sizeof(new_callid), (char *)&new_callid,
@@ -216,6 +217,7 @@ static int
 pptp_inbound_pkt(struct sk_buff *skb,
 		 struct nf_conn *ct,
 		 enum ip_conntrack_info ctinfo,
+		 unsigned int protoff,
 		 struct PptpControlHeader *ctlh,
 		 union pptp_ctrl_union *pptpReq)
 {
@@ -268,7 +270,7 @@ pptp_inbound_pkt(struct sk_buff *skb,
 	pr_debug("altering peer call id from 0x%04x to 0x%04x\n",
 		 ntohs(REQ_CID(pptpReq, pcid_off)), ntohs(new_pcid));
 
-	if (nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
+	if (nf_nat_mangle_tcp_packet(skb, ct, ctinfo, protoff,
 				     pcid_off + sizeof(struct pptp_pkt_hdr) +
 				     sizeof(struct PptpControlHeader),
 				     sizeof(new_pcid), (char *)&new_pcid,

net/netfilter/ipvs/ip_vs_ftp.c

@@ -268,6 +268,7 @@ static int ip_vs_ftp_out(struct ip_vs_app *app, struct ip_vs_conn *cp,
 			 * packet.
 			 */
 			ret = nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
+						       iph->ihl * 4,
 						       start-data, end-start,
 						       buf, buf_len);
 			if (ret) {

net/netfilter/nf_conntrack_amanda.c

@@ -40,6 +40,7 @@ MODULE_PARM_DESC(ts_algo, "textsearch algorithm to use (default kmp)");
 
 unsigned int (*nf_nat_amanda_hook)(struct sk_buff *skb,
 				   enum ip_conntrack_info ctinfo,
+				   unsigned int protoff,
 				   unsigned int matchoff,
 				   unsigned int matchlen,
 				   struct nf_conntrack_expect *exp)
@@ -156,8 +157,8 @@ static int amanda_help(struct sk_buff *skb,
 		nf_nat_amanda = rcu_dereference(nf_nat_amanda_hook);
 		if (nf_nat_amanda && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 		    ct->status & IPS_NAT_MASK)
-			ret = nf_nat_amanda(skb, ctinfo, off - dataoff,
-					    len, exp);
+			ret = nf_nat_amanda(skb, ctinfo, protoff,
+					    off - dataoff, len, exp);
 		else if (nf_ct_expect_related(exp) != 0)
 			ret = NF_DROP;
 		nf_ct_expect_put(exp);

net/netfilter/nf_conntrack_ftp.c

@@ -48,6 +48,7 @@ module_param(loose, bool, 0600);
 unsigned int (*nf_nat_ftp_hook)(struct sk_buff *skb,
 				enum ip_conntrack_info ctinfo,
 				enum nf_ct_ftp_type type,
+				unsigned int protoff,
 				unsigned int matchoff,
 				unsigned int matchlen,
 				struct nf_conntrack_expect *exp);
@@ -490,7 +491,7 @@ static int help(struct sk_buff *skb,
 	if (nf_nat_ftp && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 	    ct->status & IPS_NAT_MASK)
 		ret = nf_nat_ftp(skb, ctinfo, search[dir][i].ftptype,
-				 matchoff, matchlen, exp);
+				 protoff, matchoff, matchlen, exp);
 	else {
 		/* Can't expect this?  Best to drop packet now. */
 		if (nf_ct_expect_related(exp) != 0)

net/netfilter/nf_conntrack_irc.c

@@ -33,6 +33,7 @@ static DEFINE_SPINLOCK(irc_buffer_lock);
 
 unsigned int (*nf_nat_irc_hook)(struct sk_buff *skb,
 				enum ip_conntrack_info ctinfo,
+				unsigned int protoff,
 				unsigned int matchoff,
 				unsigned int matchlen,
 				struct nf_conntrack_expect *exp) __read_mostly;
@@ -206,7 +207,7 @@ static int help(struct sk_buff *skb, unsigned int protoff,
 			nf_nat_irc = rcu_dereference(nf_nat_irc_hook);
 			if (nf_nat_irc && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 			    ct->status & IPS_NAT_MASK)
-				ret = nf_nat_irc(skb, ctinfo,
+				ret = nf_nat_irc(skb, ctinfo, protoff,
 						 addr_beg_p - ib_ptr,
 						 addr_end_p - addr_beg_p,
 						 exp);

net/netfilter/nf_conntrack_pptp.c

@@ -45,14 +45,14 @@ static DEFINE_SPINLOCK(nf_pptp_lock);
 int
 (*nf_nat_pptp_hook_outbound)(struct sk_buff *skb,
 			     struct nf_conn *ct, enum ip_conntrack_info ctinfo,
-			     struct PptpControlHeader *ctlh,
+			     unsigned int protoff, struct PptpControlHeader *ctlh,
 			     union pptp_ctrl_union *pptpReq) __read_mostly;
 EXPORT_SYMBOL_GPL(nf_nat_pptp_hook_outbound);
 
 int
 (*nf_nat_pptp_hook_inbound)(struct sk_buff *skb,
 			    struct nf_conn *ct, enum ip_conntrack_info ctinfo,
-			    struct PptpControlHeader *ctlh,
+			    unsigned int protoff, struct PptpControlHeader *ctlh,
 			    union pptp_ctrl_union *pptpReq) __read_mostly;
 EXPORT_SYMBOL_GPL(nf_nat_pptp_hook_inbound);
 
@@ -262,7 +262,7 @@ static int exp_gre(struct nf_conn *ct, __be16 callid, __be16 peer_callid)
 }
 
 static inline int
-pptp_inbound_pkt(struct sk_buff *skb,
+pptp_inbound_pkt(struct sk_buff *skb, unsigned int protoff,
 		 struct PptpControlHeader *ctlh,
 		 union pptp_ctrl_union *pptpReq,
 		 unsigned int reqlen,
@@ -376,7 +376,8 @@ pptp_inbound_pkt(struct sk_buff *skb,
 
 	nf_nat_pptp_inbound = rcu_dereference(nf_nat_pptp_hook_inbound);
 	if (nf_nat_pptp_inbound && ct->status & IPS_NAT_MASK)
-		return nf_nat_pptp_inbound(skb, ct, ctinfo, ctlh, pptpReq);
+		return nf_nat_pptp_inbound(skb, ct, ctinfo,
+					   protoff, ctlh, pptpReq);
 	return NF_ACCEPT;
 
 invalid:
@@ -389,7 +390,7 @@ pptp_inbound_pkt(struct sk_buff *skb,
 }
 
 static inline int
-pptp_outbound_pkt(struct sk_buff *skb,
+pptp_outbound_pkt(struct sk_buff *skb, unsigned int protoff,
 		  struct PptpControlHeader *ctlh,
 		  union pptp_ctrl_union *pptpReq,
 		  unsigned int reqlen,
@@ -471,7 +472,8 @@ pptp_outbound_pkt(struct sk_buff *skb,
 
 	nf_nat_pptp_outbound = rcu_dereference(nf_nat_pptp_hook_outbound);
 	if (nf_nat_pptp_outbound && ct->status & IPS_NAT_MASK)
-		return nf_nat_pptp_outbound(skb, ct, ctinfo, ctlh, pptpReq);
+		return nf_nat_pptp_outbound(skb, ct, ctinfo,
+					    protoff, ctlh, pptpReq);
 	return NF_ACCEPT;
 
 invalid:
@@ -570,11 +572,11 @@ conntrack_pptp_help(struct sk_buff *skb, unsigned int protoff,
 	 * established from PNS->PAC.  However, RFC makes no guarantee */
 	if (dir == IP_CT_DIR_ORIGINAL)
 		/* client -> server (PNS -> PAC) */
-		ret = pptp_outbound_pkt(skb, ctlh, pptpReq, reqlen, ct,
+		ret = pptp_outbound_pkt(skb, protoff, ctlh, pptpReq, reqlen, ct,
 					ctinfo);
 	else
 		/* server -> client (PAC -> PNS) */
-		ret = pptp_inbound_pkt(skb, ctlh, pptpReq, reqlen, ct,
+		ret = pptp_inbound_pkt(skb, protoff, ctlh, pptpReq, reqlen, ct,
 				       ctinfo);
 	pr_debug("sstate: %d->%d, cstate: %d->%d\n",
 		 oldsstate, info->sstate, oldcstate, info->cstate);