selftests: forwarding: bridge_mdb_max: Add a test for rejected MDB entries

Add a test that checks that MDB entries that are rejected because the
port reached its maximum number of MDB entries (mcast_max_groups) do not
count towards the maximum number of MDB entries in the bridge
(mcast_hash_max).

The test lowers mcast_hash_max so that only three more entries can be
added. It then configures the port's maximum so that new (*, G) entries
are rejected and tries to add four of them. Next, it raises the maximum
by one so that a new (*, G) entry is accepted, but its (S, G) entry is
rejected, and tries this with four groups. Finally, it checks that
multicast snooping was not disabled because the bridge ran out of MDB
entries.

Like the other tests, the test is run for entries added both by the
control path (IGMP / MLD reports) and by the configuration path
(RTM_NEWMDB), and for both the port and port-VLAN maximums.

Without "bridge: mcast: Delete empty MDB entry when port group creation
fails", the new tests fail (other tests omitted):

 # ./bridge_mdb_max.sh
 INFO: 802.1d tests
 TEST: cfg4: port maxgroups: rejected entries do not exhaust MDB     [FAIL]
         Multicast snooping disabled by rejected MDB entries
 TEST: ctl4: port maxgroups: rejected entries do not exhaust MDB     [FAIL]
         Multicast snooping disabled by rejected MDB entries
 TEST: cfg6: port maxgroups: rejected entries do not exhaust MDB     [FAIL]
         Multicast snooping disabled by rejected MDB entries
 TEST: ctl6: port maxgroups: rejected entries do not exhaust MDB     [FAIL]
         Multicast snooping disabled by rejected MDB entries
 INFO: 802.1q tests
 TEST: cfg4: port maxgroups: rejected entries do not exhaust MDB     [FAIL]
         Multicast snooping disabled by rejected MDB entries
 TEST: ctl4: port maxgroups: rejected entries do not exhaust MDB     [FAIL]
         Multicast snooping disabled by rejected MDB entries
 TEST: cfg6: port maxgroups: rejected entries do not exhaust MDB     [FAIL]
         Multicast snooping disabled by rejected MDB entries
 TEST: ctl6: port maxgroups: rejected entries do not exhaust MDB     [FAIL]
         Multicast snooping disabled by rejected MDB entries
 INFO: 802.1q mcast_vlan_snooping 1 tests
 TEST: cfg4: port_vlan maxgroups: rejected entries do not exhaust MDB   [FAIL]
         Multicast snooping disabled by rejected MDB entries
 TEST: ctl4: port_vlan maxgroups: rejected entries do not exhaust MDB   [FAIL]
         Multicast snooping disabled by rejected MDB entries
 TEST: cfg6: port_vlan maxgroups: rejected entries do not exhaust MDB   [FAIL]
         Multicast snooping disabled by rejected MDB entries
 TEST: ctl6: port_vlan maxgroups: rejected entries do not exhaust MDB   [FAIL]
         Multicast snooping disabled by rejected MDB entries

Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Gabriel Goller <g.goller@proxmox.com>
Reviewed-by: Gabriel Goller <g.goller@proxmox.com>
Link: https://patch.msgid.link/20261016101407.2030133-3-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

0 files changed, 0 insertions, 0 deletions