netfilter: br_netfilter: Unmask upper DSCP bits in br_nf_pre_routing_finish()

Unmask upper DSCP bits when calling ip_route_output() so that in the
future it could perform the FIB lookup according to the full DSCP value.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: idosch

net/bridge/br_netfilter_hooks.c

@@ -36,6 +36,7 @@
 #include <net/route.h>
 #include <net/netfilter/br_netfilter.h>
 #include <net/netns/generic.h>
+#include <net/inet_dscp.h>
 
 #include <linux/uaccess.h>
 #include "br_private.h"
@@ -402,7 +403,7 @@ static int br_nf_pre_routing_finish(struct net *net, struct sock *sk, struct sk_
 				goto free_skb;
 
 			rt = ip_route_output(net, iph->daddr, 0,
-					     RT_TOS(iph->tos), 0,
+					     iph->tos & INET_DSCP_MASK, 0,
 					     RT_SCOPE_UNIVERSE);
 			if (!IS_ERR(rt)) {
 				/* - Bridged-and-DNAT'ed traffic doesn't