gre: reject GUE and FOU in collect metadata mode

The collect metadata mode does not support GUE nor FOU. This might be implemented later; until then, we should reject such config. I think this is okay to be changed. It's unlikely anyone has such configuration (as it doesn't work anyway) and we may need a way to distinguish whether it's supported or not by the kernel later. For backwards compatibility with iproute2, it's not possible to just check the attribute presence (iproute2 always includes the attribute), the actual value has to be checked, too. Fixes: 2e15ea3 ("ip_gre: Add support to collect tunnel metadata.") Signed-off-by: Jiri Benc <[email protected]> Signed-off-by: David S. Miller <[email protected]>
ambv · Apr 28, 2016 · 946b636 · 946b636
1 parent 47ff580
commit 946b636
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
@@ -948,6 +948,11 @@ static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
 	if (flags & (GRE_VERSION|GRE_ROUTING))
 		return -EINVAL;
 
+	if (data[IFLA_GRE_COLLECT_METADATA] &&
+	    data[IFLA_GRE_ENCAP_TYPE] &&
+	    nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE)
+		return -EINVAL;
+
 	return 0;
 }