ipv6: Initial skb->dev and skb->protocol in ip6_output

Move the initialization of skb->dev and skb->protocol from
ip6_finish_output2 to ip6_output. This can make the skb->dev and
skb->protocol information avalaible to the CGROUP eBPF filter.
Signed-off-by: NChenbo Feng <fengc@google.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv6/ip6_output.c

@@ -67,9 +67,6 @@ static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff *
 	struct in6_addr *nexthop;
 	int ret;
 
-	skb->protocol = htons(ETH_P_IPV6);
-	skb->dev = dev;
-
 	if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) {
 		struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
 
@@ -154,6 +151,9 @@ int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 	struct net_device *dev = skb_dst(skb)->dev;
 	struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
 
+	skb->protocol = htons(ETH_P_IPV6);
+	skb->dev = dev;
+
 	if (unlikely(idev->cnf.disable_ipv6)) {
 		IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS);
 		kfree_skb(skb);