net: xfrm: use skb_gso_validate_network_len() to check gso sizes

Replace skb_gso_network_seglen() with
skb_gso_validate_network_len(), as it considers the GSO_BY_FRAGS
case.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/xfrm4_output.c

@@ -30,7 +30,8 @@ static int xfrm4_tunnel_check_size(struct sk_buff *skb)
 
 	mtu = dst_mtu(skb_dst(skb));
 	if ((!skb_is_gso(skb) && skb->len > mtu) ||
-	    (skb_is_gso(skb) && skb_gso_network_seglen(skb) > ip_skb_dst_mtu(skb->sk, skb))) {
+	    (skb_is_gso(skb) &&
+	     !skb_gso_validate_network_len(skb, ip_skb_dst_mtu(skb->sk, skb)))) {
 		skb->protocol = htons(ETH_P_IP);
 
 		if (skb->sk)

net/ipv6/xfrm6_output.c

@@ -82,7 +82,7 @@ static int xfrm6_tunnel_check_size(struct sk_buff *skb)
 
 	if ((!skb_is_gso(skb) && skb->len > mtu) ||
 	    (skb_is_gso(skb) &&
-	     skb_gso_network_seglen(skb) > ip6_skb_dst_mtu(skb))) {
+	     !skb_gso_validate_network_len(skb, ip6_skb_dst_mtu(skb)))) {
 		skb->dev = dst->dev;
 		skb->protocol = htons(ETH_P_IPV6);