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>
diff --git a/net/ipv4/netfilter/nf_nat_h323.c b/net/ipv4/netfilter/nf_nat_h323.c
index c6784a1..d2c228d 100644
--- a/net/ipv4/netfilter/nf_nat_h323.c
+++ b/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 @@
 
 	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 @@
 		*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_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_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 @@
 					 &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 @@
 					 &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_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 @@
 				 &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 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 @@
 	}
 
 	/* 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_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 @@
 	}
 
 	/* 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_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 @@
 	}
 
 	/* 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 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 @@
 	}
 
 	/* 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 @@
 		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 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 @@
 	}
 
 	/* 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);