selftests: mlxsw: Test unresolved neigh trap with resilient nexthop groups

The number of nexthop buckets in a resilient nexthop group never
changes, so when the gateway address of a nexthop cannot be resolved,
the nexthop buckets are programmed to trap packets to the CPU in order
to trigger resolution. For example:

 # ip nexthop add id 1 via 198.51.100.1 dev swp3
 # ip nexthop add id 10 group 1 type resilient buckets 32
 # ip nexthop bucket get id 10 index 0
 id 10 index 0 idle_time 1.44 nhid 1 trap

Where 198.51.100.1 is a made-up IP.

Test that in this case packets are indeed trapped to the CPU via the
unresolved neigh trap.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/tools/testing/selftests/drivers/net/mlxsw/devlink_trap_l3_exceptions.sh b/tools/testing/selftests/drivers/net/mlxsw/devlink_trap_l3_exceptions.sh
index 1fedfc9..42d44e2 100755 (executable)
--- a/tools/testing/selftests/drivers/net/mlxsw/devlink_trap_l3_exceptions.sh
+++ b/tools/testing/selftests/drivers/net/mlxsw/devlink_trap_l3_exceptions.sh
@@ -446,6 +446,35 @@ __invalid_nexthop_test()
        log_test "Unresolved neigh: nexthop does not exist: $desc"
 }
 
+__invalid_nexthop_bucket_test()
+{
+       local desc=$1; shift
+       local dip=$1; shift
+       local via_add=$1; shift
+       local trap_name="unresolved_neigh"
+
+       RET=0
+
+       # Check that route to nexthop that does not exist triggers
+       # unresolved_neigh
+       ip nexthop add id 1 via $via_add dev $rp2
+       ip nexthop add id 10 group 1 type resilient buckets 32
+       ip route add $dip nhid 10
+
+       t0_packets=$(devlink_trap_rx_packets_get $trap_name)
+       ping_do $h1 $dip
+       t1_packets=$(devlink_trap_rx_packets_get $trap_name)
+
+       if [[ $t0_packets -eq $t1_packets ]]; then
+               check_err 1 "Trap counter did not increase"
+       fi
+
+       ip route del $dip nhid 10
+       ip nexthop del id 10
+       ip nexthop del id 1
+       log_test "Unresolved neigh: nexthop bucket does not exist: $desc"
+}
+
 unresolved_neigh_test()
 {
        __host_miss_test "IPv4" 198.51.100.1
@@ -453,6 +482,8 @@ unresolved_neigh_test()
        __invalid_nexthop_test "IPv4" 198.51.100.1 198.51.100.3 24 198.51.100.4
        __invalid_nexthop_test "IPv6" 2001:db8:2::1 2001:db8:2::3 64 \
                2001:db8:2::4
+       __invalid_nexthop_bucket_test "IPv4" 198.51.100.1 198.51.100.4
+       __invalid_nexthop_bucket_test "IPv6" 2001:db8:2::1 2001:db8:2::4
 }
 
 vrf_without_routes_create()