ipv6: Make ipv6_is_mld() inline and use it from ip6_mc_input().

Move generalized version of ipv6_is_mld() to header,
and use it from ip6_mc_input().
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/addrconf.h

@@ -150,7 +150,31 @@ extern void addrconf_dad_failure(struct inet6_ifaddr *ifp);
 extern bool ipv6_chk_mcast_addr(struct net_device *dev,
 				const struct in6_addr *group,
 				const struct in6_addr *src_addr);
-extern bool ipv6_is_mld(struct sk_buff *skb, int nexthdr);
+
+/*
+ * identify MLD packets for MLD filter exceptions
+ */
+static inline bool ipv6_is_mld(struct sk_buff *skb, int nexthdr, int offset)
+{
+	struct icmp6hdr *hdr;
+
+	if (nexthdr != IPPROTO_ICMPV6 ||
+	    !pskb_network_may_pull(skb, offset + sizeof(struct icmp6hdr)))
+		return false;
+
+	hdr = (struct icmp6hdr *)(skb_network_header(skb) + offset);
+
+	switch (hdr->icmp6_type) {
+	case ICMPV6_MGM_QUERY:
+	case ICMPV6_MGM_REPORT:
+	case ICMPV6_MGM_REDUCTION:
+	case ICMPV6_MLD2_REPORT:
+		return true;
+	default:
+		break;
+	}
+	return false;
+}
 
 extern void addrconf_prefix_rcv(struct net_device *dev,
 				u8 *opt, int len, bool sllao);

net/ipv6/ip6_input.c

@@ -212,7 +212,7 @@ static int ip6_input_finish(struct sk_buff *skb)
 			if (ipv6_addr_is_multicast(&hdr->daddr) &&
 			    !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
 			    &hdr->saddr) &&
-			    !ipv6_is_mld(skb, nexthdr))
+			    !ipv6_is_mld(skb, nexthdr, skb_network_header_len(skb)))
 				goto discard;
 		}
 		if (!(ipprot->flags & INET6_PROTO_NOPOLICY) &&
@@ -283,7 +283,6 @@ int ip6_mc_input(struct sk_buff *skb)
 		if (unlikely(opt->ra)) {
 			/* Check if this is a mld message */
 			u8 *ptr = skb_network_header(skb) + opt->ra;
-			struct icmp6hdr *icmp6;
 			u8 nexthdr = hdr->nexthdr;
 			__be16 frag_off;
 			int offset;
@@ -303,24 +302,10 @@ int ip6_mc_input(struct sk_buff *skb)
 				if (offset < 0)
 					goto out;
 
-				if (nexthdr != IPPROTO_ICMPV6)
+				if (!ipv6_is_mld(skb, nexthdr, offset))
 					goto out;
 
-				if (!pskb_may_pull(skb, (skb_network_header(skb) +
-						   offset + 1 - skb->data)))
-					goto out;
-
-				icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
-
-				switch (icmp6->icmp6_type) {
-				case ICMPV6_MGM_QUERY:
-				case ICMPV6_MGM_REPORT:
-				case ICMPV6_MGM_REDUCTION:
-				case ICMPV6_MLD2_REPORT:
-					deliver = true;
-					break;
-				}
-				goto out;
+				deliver = true;
 			}
 			/* unknown RA - process it normally */
 		}

net/ipv6/mcast.c

@@ -934,33 +934,6 @@ int ipv6_dev_mc_dec(struct net_device *dev, const struct in6_addr *addr)
 	return err;
 }
 
-/*
- * identify MLD packets for MLD filter exceptions
- */
-bool ipv6_is_mld(struct sk_buff *skb, int nexthdr)
-{
-	struct icmp6hdr *pic;
-
-	if (nexthdr != IPPROTO_ICMPV6)
-		return false;
-
-	if (!pskb_may_pull(skb, sizeof(struct icmp6hdr)))
-		return false;
-
-	pic = icmp6_hdr(skb);
-
-	switch (pic->icmp6_type) {
-	case ICMPV6_MGM_QUERY:
-	case ICMPV6_MGM_REPORT:
-	case ICMPV6_MGM_REDUCTION:
-	case ICMPV6_MLD2_REPORT:
-		return true;
-	default:
-		break;
-	}
-	return false;
-}
-
 /*
  *	check if the interface/address pair is valid
  */