[PATCH] ip_tunnel: enclose a code block in macro IS_ENABLED(CONFIG_IPV6)

[Haishuang Yan]

For ipv6 case, enclose the code block in macro IS_ENABLED(CONFIG_IPV6).

Signed-off-by: Haishuang Yan <yanhaishuang@xxxxxxxxxxxxxxxxxxxx>
---
 net/ipv4/ip_tunnel.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index a69ed94..5f3c8de 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -665,10 +665,13 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
 		if (skb->protocol == htons(ETH_P_IP)) {
 			tos = inner_iph->tos;
 			connected = false;
-		} else if (skb->protocol == htons(ETH_P_IPV6)) {
+		}
+#if IS_ENABLED(CONFIG_IPV6)
+		else if (skb->protocol == htons(ETH_P_IPV6)) {
 			tos = ipv6_get_dsfield((const struct ipv6hdr *)inner_iph);
 			connected = false;
 		}
+#endif
 	}
 
 	init_tunnel_flow(&fl4, protocol, dst, tnl_params->saddr,
-- 
1.8.3.1