[IPV6] NDISC: Calculate packet length correctly for allocation.

MAX_HEADER does not include the ipv6 header length in it,
so we need to add it in explicitly.

With help from YOSHIFUJI Hideaki.

Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/ndisc.c

@@ -472,7 +472,9 @@ static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
 			inc_opt = 0;
 	}
 
-	skb = sock_alloc_send_skb(sk, MAX_HEADER + len + LL_RESERVED_SPACE(dev),
+	skb = sock_alloc_send_skb(sk,
+				  (MAX_HEADER + sizeof(struct ipv6hdr) +
+				   len + LL_RESERVED_SPACE(dev)),
 				  1, &err);
 
 	if (skb == NULL) {
@@ -561,7 +563,9 @@ void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
 	if (send_llinfo)
 		len += ndisc_opt_addr_space(dev);
 
-	skb = sock_alloc_send_skb(sk, MAX_HEADER + len + LL_RESERVED_SPACE(dev),
+	skb = sock_alloc_send_skb(sk,
+				  (MAX_HEADER + sizeof(struct ipv6hdr) +
+				   len + LL_RESERVED_SPACE(dev)),
 				  1, &err);
 	if (skb == NULL) {
 		ND_PRINTK0(KERN_ERR
@@ -636,7 +640,9 @@ void ndisc_send_rs(struct net_device *dev, struct in6_addr *saddr,
 	if (dev->addr_len)
 		len += ndisc_opt_addr_space(dev);
 
-        skb = sock_alloc_send_skb(sk, MAX_HEADER + len + LL_RESERVED_SPACE(dev),
+        skb = sock_alloc_send_skb(sk,
+				  (MAX_HEADER + sizeof(struct ipv6hdr) +
+				   len + LL_RESERVED_SPACE(dev)),
 				  1, &err);
 	if (skb == NULL) {
 		ND_PRINTK0(KERN_ERR
@@ -1446,7 +1452,9 @@ void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
 	rd_len &= ~0x7;
 	len += rd_len;
 
-	buff = sock_alloc_send_skb(sk, MAX_HEADER + len + LL_RESERVED_SPACE(dev),
+	buff = sock_alloc_send_skb(sk,
+				   (MAX_HEADER + sizeof(struct ipv6hdr) +
+				    len + LL_RESERVED_SPACE(dev)),
 				   1, &err);
 	if (buff == NULL) {
 		ND_PRINTK0(KERN_ERR