diff --git a/include/linux/netfilter/nf_conntrack_sip.h b/include/linux/netfilter/nf_conntrack_sip.h
index 8e5ce1ca7bfcd48276c5b17c8572824abb3f7ea1..9d0dbfb26300b7699741fb65370a979bd5cc2712 100644
--- a/include/linux/netfilter/nf_conntrack_sip.h
+++ b/include/linux/netfilter/nf_conntrack_sip.h
@@ -24,11 +24,13 @@ enum sip_header_pos {
 extern unsigned int (*nf_nat_sip_hook)(struct sk_buff *skb,
 				       enum ip_conntrack_info ctinfo,
 				       struct nf_conn *ct,
-				       const char **dptr);
+				       const char **dptr,
+				       unsigned int *datalen);
 extern unsigned int (*nf_nat_sdp_hook)(struct sk_buff *skb,
 				       enum ip_conntrack_info ctinfo,
 				       struct nf_conntrack_expect *exp,
-				       const char *dptr);
+				       const char **dptr,
+				       unsigned int *datalen);
 
 extern int ct_sip_get_info(const struct nf_conn *ct, const char *dptr,
                            size_t dlen, unsigned int *matchoff,
diff --git a/net/ipv4/netfilter/nf_nat_sip.c b/net/ipv4/netfilter/nf_nat_sip.c
index 84d8b4982cdfba51a9af7844f5604359dc054d02..e77122e65283ce132d0b94ad0a7a8a359ba4371e 100644
--- a/net/ipv4/netfilter/nf_nat_sip.c
+++ b/net/ipv4/netfilter/nf_nat_sip.c
@@ -60,15 +60,35 @@ static void addr_map_init(const struct nf_conn *ct, struct addr_map *map)
 	}
 }
 
+static unsigned int mangle_packet(struct sk_buff *skb,
+				  const char **dptr, unsigned int *datalen,
+				  unsigned int matchoff, unsigned int matchlen,
+				  const char *buffer, unsigned int buflen)
+{
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+
+	if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo, matchoff, matchlen,
+				      buffer, buflen))
+		return 0;
+
+	/* Reload data pointer and adjust datalen value */
+	*dptr = skb->data + ip_hdrlen(skb) + sizeof(struct udphdr);
+	*datalen += buflen - matchlen;
+	return 1;
+}
+
 static int map_sip_addr(struct sk_buff *skb, enum ip_conntrack_info ctinfo,
-			struct nf_conn *ct, const char **dptr, size_t dlen,
+			struct nf_conn *ct,
+			const char **dptr, unsigned int *datalen,
 			enum sip_header_pos pos, struct addr_map *map)
 {
 	enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
 	unsigned int matchlen, matchoff, addrlen;
 	char *addr;
 
-	if (ct_sip_get_info(ct, *dptr, dlen, &matchoff, &matchlen, pos) <= 0)
+	if (ct_sip_get_info(ct, *dptr, *datalen, &matchoff, &matchlen,
+			    pos) <= 0)
 		return 1;
 
 	if ((matchlen == map->addr[dir].srciplen ||
@@ -84,26 +104,19 @@ static int map_sip_addr(struct sk_buff *skb, enum ip_conntrack_info ctinfo,
 	} else
 		return 1;
 
-	if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo,
-				      matchoff, matchlen, addr, addrlen))
-		return 0;
-	*dptr = skb->data + ip_hdrlen(skb) + sizeof(struct udphdr);
-	return 1;
-
+	return mangle_packet(skb, dptr, datalen, matchoff, matchlen,
+			     addr, addrlen);
 }
 
 static unsigned int ip_nat_sip(struct sk_buff *skb,
 			       enum ip_conntrack_info ctinfo,
 			       struct nf_conn *ct,
-			       const char **dptr)
+			       const char **dptr, unsigned int *datalen)
 {
 	enum sip_header_pos pos;
 	struct addr_map map;
-	int dataoff, datalen;
 
-	dataoff = ip_hdrlen(skb) + sizeof(struct udphdr);
-	datalen = skb->len - dataoff;
-	if (datalen < sizeof("SIP/2.0") - 1)
+	if (*datalen < sizeof("SIP/2.0") - 1)
 		return NF_ACCEPT;
 
 	addr_map_init(ct, &map);
@@ -115,7 +128,7 @@ static unsigned int ip_nat_sip(struct sk_buff *skb,
 		 * The "userinfo" and "@" components of the SIP URI MUST NOT
 		 * be present.
 		 */
-		if (datalen >= sizeof("REGISTER") - 1 &&
+		if (*datalen >= sizeof("REGISTER") - 1 &&
 		    strncmp(*dptr, "REGISTER", sizeof("REGISTER") - 1) == 0)
 			pos = POS_REG_REQ_URI;
 		else
@@ -136,51 +149,45 @@ static unsigned int ip_nat_sip(struct sk_buff *skb,
 static unsigned int mangle_sip_packet(struct sk_buff *skb,
 				      enum ip_conntrack_info ctinfo,
 				      struct nf_conn *ct,
-				      const char **dptr, size_t dlen,
+				      const char **dptr, unsigned int *datalen,
 				      char *buffer, int bufflen,
 				      enum sip_header_pos pos)
 {
 	unsigned int matchlen, matchoff;
 
-	if (ct_sip_get_info(ct, *dptr, dlen, &matchoff, &matchlen, pos) <= 0)
-		return 0;
-
-	if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo,
-				      matchoff, matchlen, buffer, bufflen))
+	if (ct_sip_get_info(ct, *dptr, *datalen, &matchoff, &matchlen,
+			    pos) <= 0)
 		return 0;
 
-	/* We need to reload this. Thanks Patrick. */
-	*dptr = skb->data + ip_hdrlen(skb) + sizeof(struct udphdr);
-	return 1;
+	return mangle_packet(skb, dptr, datalen, matchoff, matchlen,
+			     buffer, bufflen);
 }
 
 static int mangle_content_len(struct sk_buff *skb,
 			      enum ip_conntrack_info ctinfo,
 			      struct nf_conn *ct,
-			      const char *dptr)
+			      const char **dptr, unsigned int *datalen)
 {
-	unsigned int dataoff, matchoff, matchlen;
+	unsigned int matchoff, matchlen;
 	char buffer[sizeof("65536")];
 	int bufflen;
 
-	dataoff = ip_hdrlen(skb) + sizeof(struct udphdr);
-
 	/* Get actual SDP length */
-	if (ct_sip_get_info(ct, dptr, skb->len - dataoff, &matchoff,
+	if (ct_sip_get_info(ct, *dptr, *datalen, &matchoff,
 			    &matchlen, POS_SDP_HEADER) > 0) {
 
 		/* since ct_sip_get_info() give us a pointer passing 'v='
 		   we need to add 2 bytes in this count. */
-		int c_len = skb->len - dataoff - matchoff + 2;
+		int c_len = *datalen - matchoff + 2;
 
 		/* Now, update SDP length */
-		if (ct_sip_get_info(ct, dptr, skb->len - dataoff, &matchoff,
+		if (ct_sip_get_info(ct, *dptr, *datalen, &matchoff,
 				    &matchlen, POS_CONTENT) > 0) {
 
 			bufflen = sprintf(buffer, "%u", c_len);
-			return nf_nat_mangle_udp_packet(skb, ct, ctinfo,
-							matchoff, matchlen,
-							buffer, bufflen);
+			return mangle_packet(skb, dptr, datalen,
+					     matchoff, matchlen,
+					     buffer, bufflen);
 		}
 	}
 	return 0;
@@ -190,30 +197,28 @@ static unsigned int mangle_sdp(struct sk_buff *skb,
 			       enum ip_conntrack_info ctinfo,
 			       struct nf_conn *ct,
 			       __be32 newip, u_int16_t port,
-			       const char *dptr)
+			       const char **dptr, unsigned int *datalen)
 {
 	char buffer[sizeof("nnn.nnn.nnn.nnn")];
-	unsigned int dataoff, bufflen;
-
-	dataoff = ip_hdrlen(skb) + sizeof(struct udphdr);
+	unsigned int bufflen;
 
 	/* Mangle owner and contact info. */
 	bufflen = sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(newip));
-	if (!mangle_sip_packet(skb, ctinfo, ct, &dptr, skb->len - dataoff,
+	if (!mangle_sip_packet(skb, ctinfo, ct, dptr, datalen,
 			       buffer, bufflen, POS_OWNER_IP4))
 		return 0;
 
-	if (!mangle_sip_packet(skb, ctinfo, ct, &dptr, skb->len - dataoff,
+	if (!mangle_sip_packet(skb, ctinfo, ct, dptr, datalen,
 			       buffer, bufflen, POS_CONNECTION_IP4))
 		return 0;
 
 	/* Mangle media port. */
 	bufflen = sprintf(buffer, "%u", port);
-	if (!mangle_sip_packet(skb, ctinfo, ct, &dptr, skb->len - dataoff,
+	if (!mangle_sip_packet(skb, ctinfo, ct, dptr, datalen,
 			       buffer, bufflen, POS_MEDIA))
 		return 0;
 
-	return mangle_content_len(skb, ctinfo, ct, dptr);
+	return mangle_content_len(skb, ctinfo, ct, dptr, datalen);
 }
 
 static void ip_nat_sdp_expect(struct nf_conn *ct,
@@ -242,7 +247,7 @@ static void ip_nat_sdp_expect(struct nf_conn *ct,
 static unsigned int ip_nat_sdp(struct sk_buff *skb,
 			       enum ip_conntrack_info ctinfo,
 			       struct nf_conntrack_expect *exp,
-			       const char *dptr)
+			       const char **dptr, unsigned int *datalen)
 {
 	struct nf_conn *ct = exp->master;
 	enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
@@ -275,7 +280,7 @@ static unsigned int ip_nat_sdp(struct sk_buff *skb,
 	if (port == 0)
 		return NF_DROP;
 
-	if (!mangle_sdp(skb, ctinfo, ct, newip, port, dptr)) {
+	if (!mangle_sdp(skb, ctinfo, ct, newip, port, dptr, datalen)) {
 		nf_ct_unexpect_related(exp);
 		return NF_DROP;
 	}
diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c
index 016e1c1aafe44a58ebeea68c41d31f6a60a4f10f..fa0d5599ff248046aa00149d7ff57a51896c6712 100644
--- a/net/netfilter/nf_conntrack_sip.c
+++ b/net/netfilter/nf_conntrack_sip.c
@@ -39,13 +39,15 @@ MODULE_PARM_DESC(sip_timeout, "timeout for the master SIP session");
 unsigned int (*nf_nat_sip_hook)(struct sk_buff *skb,
 				enum ip_conntrack_info ctinfo,
 				struct nf_conn *ct,
-				const char **dptr) __read_mostly;
+				const char **dptr,
+				unsigned int *datalen) __read_mostly;
 EXPORT_SYMBOL_GPL(nf_nat_sip_hook);
 
 unsigned int (*nf_nat_sdp_hook)(struct sk_buff *skb,
 				enum ip_conntrack_info ctinfo,
 				struct nf_conntrack_expect *exp,
-				const char *dptr) __read_mostly;
+				const char **dptr,
+				unsigned int *datalen) __read_mostly;
 EXPORT_SYMBOL_GPL(nf_nat_sdp_hook);
 
 static int digits_len(const struct nf_conn *, const char *, const char *, int *);
@@ -369,7 +371,7 @@ static int set_expected_rtp(struct sk_buff *skb,
 			    enum ip_conntrack_info ctinfo,
 			    union nf_inet_addr *addr,
 			    __be16 port,
-			    const char *dptr)
+			    const char **dptr, unsigned int *datalen)
 {
 	struct nf_conntrack_expect *exp;
 	enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
@@ -386,7 +388,7 @@ static int set_expected_rtp(struct sk_buff *skb,
 
 	nf_nat_sdp = rcu_dereference(nf_nat_sdp_hook);
 	if (nf_nat_sdp && ct->status & IPS_NAT_MASK)
-		ret = nf_nat_sdp(skb, ctinfo, exp, dptr);
+		ret = nf_nat_sdp(skb, ctinfo, exp, dptr, datalen);
 	else {
 		if (nf_ct_expect_related(exp) != 0)
 			ret = NF_DROP;
@@ -429,7 +431,7 @@ static int sip_help(struct sk_buff *skb,
 
 	nf_nat_sip = rcu_dereference(nf_nat_sip_hook);
 	if (nf_nat_sip && ct->status & IPS_NAT_MASK) {
-		if (!nf_nat_sip(skb, ctinfo, ct, &dptr)) {
+		if (!nf_nat_sip(skb, ctinfo, ct, &dptr, &datalen)) {
 			ret = NF_DROP;
 			goto out;
 		}
@@ -466,7 +468,7 @@ static int sip_help(struct sk_buff *skb,
 				goto out;
 			}
 			ret = set_expected_rtp(skb, ct, ctinfo, &addr,
-					       htons(port), dptr);
+					       htons(port), &dptr, &datalen);
 		}
 	}
 out: