[NET]: Introduce RTA_TABLE/FRA_TABLE attributes

Introduce RTA_TABLE route attribute and FRA_TABLE routing rule attribute
to hold 32 bit routing table IDs. Usespace compatibility is provided by
continuing to accept and send the rtm_table field, but because of its
limited size it can only carry the low 8 bits of the table ID. This
implies that if larger IDs are used, _all_ userspace programs using them
need to use RTA_TABLE.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/decnet/dn_table.c b/net/decnet/dn_table.c
index 1601ee5..eca7c1e 100644
--- a/net/decnet/dn_table.c
+++ b/net/decnet/dn_table.c
@@ -278,6 +278,7 @@
         rtm->rtm_src_len = 0;
         rtm->rtm_tos = 0;
         rtm->rtm_table = tb_id;
+	RTA_PUT_U32(skb, RTA_TABLE, tb_id);
         rtm->rtm_flags = fi->fib_flags;
         rtm->rtm_scope = scope;
 	rtm->rtm_type  = type;