ip6tnl/rtnl: add IFLA_IPTUN_PROTO on dump

IPv6 tunnels can have three mode: 4in6, 6in6 and xin6.
This information was missing in the netlink message.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 8db4d9b..929ba0b 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -1515,6 +1515,8 @@
 		nla_total_size(4) +
 		/* IFLA_IPTUN_FLAGS */
 		nla_total_size(4) +
+		/* IFLA_IPTUN_PROTO */
+		nla_total_size(1) +
 		0;
 }
 
@@ -1531,7 +1533,8 @@
 	    nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
 	    nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
 	    nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
-	    nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags))
+	    nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
+	    nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto))
 		goto nla_put_failure;
 	return 0;