Merge branch 'nexthop-route-deletye-warning'

Nikolay Aleksandrov says:

====================
net: ipv4: fix nexthop route delete warning

The first patch fixes a warning that can be triggered by deleting a
nexthop route and specifying a device (more info in its commit msg).
And the second patch adds a selftest for that case.

Chose this way to fix it because we should match when deleting without
nh spec and should fail when deleting a nexthop route with old-style nh
spec because nexthop objects are managed separately, e.g.:
$ ip r show 1.2.3.4/32
1.2.3.4 nhid 12 via 192.168.11.2 dev dummy0

$ ip r del 1.2.3.4/32
$ ip r del 1.2.3.4/32 nhid 12
<both should work>

$ ip r del 1.2.3.4/32 dev dummy0
<should fail with ESRCH>

v2: addded more to patch 01's commit message
    adjusted the test comment in patch 02
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/fib_semantics.c

@@ -889,8 +889,13 @@ int fib_nh_match(struct net *net, struct fib_config *cfg, struct fib_info *fi,
 	}
 
 	if (cfg->fc_oif || cfg->fc_gw_family) {
-		struct fib_nh *nh = fib_info_nh(fi, 0);
+		struct fib_nh *nh;
+
+		/* cannot match on nexthop object attributes */
+		if (fi->nh)
+			return 1;
 
+		nh = fib_info_nh(fi, 0);
 		if (cfg->fc_encap) {
 			if (fib_encap_match(net, cfg->fc_encap_type,
 					    cfg->fc_encap, nh, cfg, extack))

tools/testing/selftests/net/fib_nexthops.sh

@@ -1208,6 +1208,20 @@ ipv4_fcnal()
 	set +e
 	check_nexthop "dev veth1" ""
 	log_test $? 0 "Nexthops removed on admin down"
+
+	# nexthop route delete warning: route add with nhid and delete
+	# using device
+	run_cmd "$IP li set dev veth1 up"
+	run_cmd "$IP nexthop add id 12 via 172.16.1.3 dev veth1"
+	out1=`dmesg | grep "WARNING:.*fib_nh_match.*" | wc -l`
+	run_cmd "$IP route add 172.16.101.1/32 nhid 12"
+	run_cmd "$IP route delete 172.16.101.1/32 dev veth1"
+	out2=`dmesg | grep "WARNING:.*fib_nh_match.*" | wc -l`
+	[ $out1 -eq $out2 ]
+	rc=$?
+	log_test $rc 0 "Delete nexthop route warning"
+	run_cmd "$IP ip route delete 172.16.101.1/32 nhid 12"
+	run_cmd "$IP ip nexthop del id 12"
 }
 
 ipv4_grp_fcnal()