Merge branch 'erspan-always-reports-output-key-to-userspace'

Lorenzo Bianconi says:

====================
erspan: always reports output key to userspace

Erspan protocol relies on output key to set session id header field.
However TUNNEL_KEY bit is cleared in order to not add key field to
the external GRE header and so the configured o_key is not reported
to userspace.
Fix the issue adding TUNNEL_KEY bit to the o_flags parameter dumping
device info
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/ip_gre.c

@@ -1455,12 +1455,17 @@ static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
 {
 	struct ip_tunnel *t = netdev_priv(dev);
 	struct ip_tunnel_parm *p = &t->parms;
+	__be16 o_flags = p->o_flags;
+
+	if ((t->erspan_ver == 1 || t->erspan_ver == 2) &&
+	    !t->collect_md)
+		o_flags |= TUNNEL_KEY;
 
 	if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
 	    nla_put_be16(skb, IFLA_GRE_IFLAGS,
 			 gre_tnl_flags_to_gre_flags(p->i_flags)) ||
 	    nla_put_be16(skb, IFLA_GRE_OFLAGS,
-			 gre_tnl_flags_to_gre_flags(p->o_flags)) ||
+			 gre_tnl_flags_to_gre_flags(o_flags)) ||
 	    nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
 	    nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
 	    nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) ||

net/ipv6/ip6_gre.c

@@ -2098,12 +2098,17 @@ static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
 {
 	struct ip6_tnl *t = netdev_priv(dev);
 	struct __ip6_tnl_parm *p = &t->parms;
+	__be16 o_flags = p->o_flags;
+
+	if ((p->erspan_ver == 1 || p->erspan_ver == 2) &&
+	    !p->collect_md)
+		o_flags |= TUNNEL_KEY;
 
 	if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
 	    nla_put_be16(skb, IFLA_GRE_IFLAGS,
 			 gre_tnl_flags_to_gre_flags(p->i_flags)) ||
 	    nla_put_be16(skb, IFLA_GRE_OFLAGS,
-			 gre_tnl_flags_to_gre_flags(p->o_flags)) ||
+			 gre_tnl_flags_to_gre_flags(o_flags)) ||
 	    nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
 	    nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
 	    nla_put_in6_addr(skb, IFLA_GRE_LOCAL, &p->laddr) ||