[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/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 06f4b23..2696ede 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -294,7 +294,8 @@
 		if (attr) {
 			if (RTA_PAYLOAD(attr) < 4)
 				return -EINVAL;
-			if (i != RTA_MULTIPATH && i != RTA_METRICS)
+			if (i != RTA_MULTIPATH && i != RTA_METRICS &&
+			    i != RTA_TABLE)
 				*rta = (struct rtattr*)RTA_DATA(attr);
 		}
 	}
@@ -310,7 +311,7 @@
 	if (inet_check_attr(r, rta))
 		return -EINVAL;
 
-	tb = fib_get_table(r->rtm_table);
+	tb = fib_get_table(rtm_get_table(rta, r->rtm_table));
 	if (tb)
 		return tb->tb_delete(tb, r, (struct kern_rta*)rta, nlh, &NETLINK_CB(skb));
 	return -ESRCH;
@@ -325,7 +326,7 @@
 	if (inet_check_attr(r, rta))
 		return -EINVAL;
 
-	tb = fib_new_table(r->rtm_table);
+	tb = fib_new_table(rtm_get_table(rta, r->rtm_table));
 	if (tb)
 		return tb->tb_insert(tb, r, (struct kern_rta*)rta, nlh, &NETLINK_CB(skb));
 	return -ENOBUFS;
diff --git a/net/ipv4/fib_rules.c b/net/ipv4/fib_rules.c
index 58fb91b..0330b9c 100644
--- a/net/ipv4/fib_rules.c
+++ b/net/ipv4/fib_rules.c
@@ -184,6 +184,7 @@
 	[FRA_DST]	= { .type = NLA_U32 },
 	[FRA_FWMARK]	= { .type = NLA_U32 },
 	[FRA_FLOW]	= { .type = NLA_U32 },
+	[FRA_TABLE]	= { .type = NLA_U32 },
 };
 
 static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index c7a112b..ab753df 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -953,6 +953,7 @@
 	rtm->rtm_src_len = 0;
 	rtm->rtm_tos = tos;
 	rtm->rtm_table = tb_id;
+	RTA_PUT_U32(skb, RTA_TABLE, tb_id);
 	rtm->rtm_type = type;
 	rtm->rtm_flags = fi->fib_flags;
 	rtm->rtm_scope = scope;
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index b873cbc..12128b8 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2652,6 +2652,7 @@
 	r->rtm_src_len	= 0;
 	r->rtm_tos	= rt->fl.fl4_tos;
 	r->rtm_table	= RT_TABLE_MAIN;
+	RTA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
 	r->rtm_type	= rt->rt_type;
 	r->rtm_scope	= RT_SCOPE_UNIVERSE;
 	r->rtm_protocol = RTPROT_UNSPEC;