Merge branch 'ipv4-two-bug-fixes'

Ido Schimmel says:

====================
ipv4: Two small fixes for bugs in IPv4 routing code.

A variation of the second bug was reported by an FRR 5.0 (released
06/18) user as this version was setting a table ID of 0 for the
default VRF, unlike iproute2 and newer FRR versions.

The first bug was discovered while fixing the second.

Both bugs are not regressions (never worked) and are not critical
in my opinion, so the fixes can be applied to net-next, if desired.

No regressions in other tests:

 # ./fib_tests.sh
 ...
 Tests passed: 191
 Tests failed:   0
====================

Link: https://lore.kernel.org/r/20221204075045.3780097-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

3 files changed, 41 insertions, 0 deletions

diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index f361d3d56be2..b5736ef16ed2 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -841,6 +841,9 @@ static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
 		return -EINVAL;
 	}
 
+	if (!cfg->fc_table)
+		cfg->fc_table = RT_TABLE_MAIN;
+
 	return 0;
 errout:
 	return err;
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 19a662003eef..ce9ff3c62e84 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -423,6 +423,7 @@ static struct fib_info *fib_find_info(struct fib_info *nfi)
 		    nfi->fib_prefsrc == fi->fib_prefsrc &&
 		    nfi->fib_priority == fi->fib_priority &&
 		    nfi->fib_type == fi->fib_type &&
+		    nfi->fib_tb_id == fi->fib_tb_id &&
 		    memcmp(nfi->fib_metrics, fi->fib_metrics,
 			   sizeof(u32) * RTAX_MAX) == 0 &&
 		    !((nfi->fib_flags ^ fi->fib_flags) & ~RTNH_COMPARE_MASK) &&
diff --git a/tools/testing/selftests/net/fib_tests.sh b/tools/testing/selftests/net/fib_tests.sh
index 2271a8727f62..5637b5dadabd 100755
--- a/tools/testing/selftests/net/fib_tests.sh
+++ b/tools/testing/selftests/net/fib_tests.sh
@@ -1711,13 +1711,21 @@ ipv4_del_addr_test()
 
 	$IP addr add dev dummy1 172.16.104.1/24
 	$IP addr add dev dummy1 172.16.104.11/24
+	$IP addr add dev dummy1 172.16.104.12/24
+	$IP addr add dev dummy1 172.16.104.13/24
 	$IP addr add dev dummy2 172.16.104.1/24
 	$IP addr add dev dummy2 172.16.104.11/24
+	$IP addr add dev dummy2 172.16.104.12/24
 	$IP route add 172.16.105.0/24 via 172.16.104.2 src 172.16.104.11
+	$IP route add 172.16.106.0/24 dev lo src 172.16.104.12
+	$IP route add table 0 172.16.107.0/24 via 172.16.104.2 src 172.16.104.13
 	$IP route add vrf red 172.16.105.0/24 via 172.16.104.2 src 172.16.104.11
+	$IP route add vrf red 172.16.106.0/24 dev lo src 172.16.104.12
 	set +e
 
 	# removing address from device in vrf should only remove route from vrf table
+	echo "    Regular FIB info"
+
 	$IP addr del dev dummy2 172.16.104.11/24
 	$IP ro ls vrf red | grep -q 172.16.105.0/24
 	log_test $? 1 "Route removed from VRF when source address deleted"
@@ -1735,6 +1743,35 @@ ipv4_del_addr_test()
 	$IP ro ls vrf red | grep -q 172.16.105.0/24
 	log_test $? 0 "Route in VRF is not removed by address delete"
 
+	# removing address from device in vrf should only remove route from vrf
+	# table even when the associated fib info only differs in table ID
+	echo "    Identical FIB info with different table ID"
+
+	$IP addr del dev dummy2 172.16.104.12/24
+	$IP ro ls vrf red | grep -q 172.16.106.0/24
+	log_test $? 1 "Route removed from VRF when source address deleted"
+
+	$IP ro ls | grep -q 172.16.106.0/24
+	log_test $? 0 "Route in default VRF not removed"
+
+	$IP addr add dev dummy2 172.16.104.12/24
+	$IP route add vrf red 172.16.106.0/24 dev lo src 172.16.104.12
+
+	$IP addr del dev dummy1 172.16.104.12/24
+	$IP ro ls | grep -q 172.16.106.0/24
+	log_test $? 1 "Route removed in default VRF when source address deleted"
+
+	$IP ro ls vrf red | grep -q 172.16.106.0/24
+	log_test $? 0 "Route in VRF is not removed by address delete"
+
+	# removing address from device in default vrf should remove route from
+	# the default vrf even when route was inserted with a table ID of 0.
+	echo "    Table ID 0"
+
+	$IP addr del dev dummy1 172.16.104.13/24
+	$IP ro ls | grep -q 172.16.107.0/24
+	log_test $? 1 "Route removed in default VRF when source address deleted"
+
 	$IP li del dummy1
 	$IP li del dummy2
 	cleanup