1 files changed, 34 insertions, 49 deletions

diff --git a/net/ipv6/mcast_snoop.c b/net/ipv6/mcast_snoop.c
index 9405b04eecc6..55e2ac179f28 100644
--- a/net/ipv6/mcast_snoop.c
+++ b/net/ipv6/mcast_snoop.c
@@ -41,6 +41,8 @@ static int ipv6_mc_check_ip6hdr(struct sk_buff *skb)
 	if (skb->len < len || len <= offset)
 		return -EINVAL;
 
+	skb_set_transport_header(skb, offset);
+
 	return 0;
 }
 
@@ -77,27 +79,27 @@ static int ipv6_mc_check_mld_reportv2(struct sk_buff *skb)
 
 	len += sizeof(struct mld2_report);
 
-	return pskb_may_pull(skb, len) ? 0 : -EINVAL;
+	return ipv6_mc_may_pull(skb, len) ? 0 : -EINVAL;
 }
 
 static int ipv6_mc_check_mld_query(struct sk_buff *skb)
 {
+	unsigned int transport_len = ipv6_transport_len(skb);
 	struct mld_msg *mld;
-	unsigned int len = skb_transport_offset(skb);
+	unsigned int len;
 
 	/* RFC2710+RFC3810 (MLDv1+MLDv2) require link-local source addresses */
 	if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL))
 		return -EINVAL;
 
-	len += sizeof(struct mld_msg);
-	if (skb->len < len)
-		return -EINVAL;
-
 	/* MLDv1? */
-	if (skb->len != len) {
+	if (transport_len != sizeof(struct mld_msg)) {
 		/* or MLDv2? */
-		len += sizeof(struct mld2_query) - sizeof(struct mld_msg);
-		if (skb->len < len || !pskb_may_pull(skb, len))
+		if (transport_len < sizeof(struct mld2_query))
+			return -EINVAL;
+
+		len = skb_transport_offset(skb) + sizeof(struct mld2_query);
+		if (!ipv6_mc_may_pull(skb, len))
 			return -EINVAL;
 	}
 
@@ -115,7 +117,13 @@ static int ipv6_mc_check_mld_query(struct sk_buff *skb)
 
 static int ipv6_mc_check_mld_msg(struct sk_buff *skb)
 {
-	struct mld_msg *mld = (struct mld_msg *)skb_transport_header(skb);
+	unsigned int len = skb_transport_offset(skb) + sizeof(struct mld_msg);
+	struct mld_msg *mld;
+
+	if (!ipv6_mc_may_pull(skb, len))
+		return -EINVAL;
+
+	mld = (struct mld_msg *)skb_transport_header(skb);
 
 	switch (mld->mld_type) {
 	case ICMPV6_MGM_REDUCTION:
@@ -136,49 +144,30 @@ static inline __sum16 ipv6_mc_validate_checksum(struct sk_buff *skb)
 	return skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo);
 }
 
-static int __ipv6_mc_check_mld(struct sk_buff *skb,
-			       struct sk_buff **skb_trimmed)
-
+int ipv6_mc_check_icmpv6(struct sk_buff *skb)
 {
-	struct sk_buff *skb_chk = NULL;
-	unsigned int transport_len;
-	unsigned int len = skb_transport_offset(skb) + sizeof(struct mld_msg);
-	int ret = -EINVAL;
+	unsigned int len = skb_transport_offset(skb) + sizeof(struct icmp6hdr);
+	unsigned int transport_len = ipv6_transport_len(skb);
+	struct sk_buff *skb_chk;
 
-	transport_len = ntohs(ipv6_hdr(skb)->payload_len);
-	transport_len -= skb_transport_offset(skb) - sizeof(struct ipv6hdr);
+	if (!ipv6_mc_may_pull(skb, len))
+		return -EINVAL;
 
 	skb_chk = skb_checksum_trimmed(skb, transport_len,
 				       ipv6_mc_validate_checksum);
 	if (!skb_chk)
-		goto err;
-
-	if (!pskb_may_pull(skb_chk, len))
-		goto err;
-
-	ret = ipv6_mc_check_mld_msg(skb_chk);
-	if (ret)
-		goto err;
-
-	if (skb_trimmed)
-		*skb_trimmed = skb_chk;
-	/* free now unneeded clone */
-	else if (skb_chk != skb)
-		kfree_skb(skb_chk);
-
-	ret = 0;
+		return -EINVAL;
 
-err:
-	if (ret && skb_chk && skb_chk != skb)
+	if (skb_chk != skb)
 		kfree_skb(skb_chk);
 
-	return ret;
+	return 0;
 }
+EXPORT_SYMBOL(ipv6_mc_check_icmpv6);
 
 /**
  * ipv6_mc_check_mld - checks whether this is a sane MLD packet
  * @skb: the skb to validate
- * @skb_trimmed: to store an skb pointer trimmed to IPv6 packet tail (optional)
  *
  * Checks whether an IPv6 packet is a valid MLD packet. If so sets
  * skb transport header accordingly and returns zero.
@@ -188,18 +177,10 @@ err:
  * -ENOMSG: IP header validation succeeded but it is not an MLD packet.
  * -ENOMEM: A memory allocation failure happened.
  *
- * Optionally, an skb pointer might be provided via skb_trimmed (or set it
- * to NULL): After parsing an MLD packet successfully it will point to
- * an skb which has its tail aligned to the IP packet end. This might
- * either be the originally provided skb or a trimmed, cloned version if
- * the skb frame had data beyond the IP packet. A cloned skb allows us
- * to leave the original skb and its full frame unchanged (which might be
- * desirable for layer 2 frame jugglers).
- *
  * Caller needs to set the skb network header and free any returned skb if it
  * differs from the provided skb.
  */
-int ipv6_mc_check_mld(struct sk_buff *skb, struct sk_buff **skb_trimmed)
+int ipv6_mc_check_mld(struct sk_buff *skb)
 {
 	int ret;
 
@@ -211,6 +192,10 @@ int ipv6_mc_check_mld(struct sk_buff *skb, struct sk_buff **skb_trimmed)
 	if (ret < 0)
 		return ret;
 
-	return __ipv6_mc_check_mld(skb, skb_trimmed);
+	ret = ipv6_mc_check_icmpv6(skb);
+	if (ret < 0)
+		return ret;
+
+	return ipv6_mc_check_mld_msg(skb);
 }
 EXPORT_SYMBOL(ipv6_mc_check_mld);