bridge: mdb: Allow replace of a host-joined group

[ Upstream commit d9e9f6d7b7d0c520bb87f19d2cbc57aeeb2091d5 ]

Attempts to replace an MDB group membership of the host itself are
currently bounced:

 # ip link add name br up type bridge vlan_filtering 1
 # bridge mdb replace dev br port br grp 239.0.0.1 vid 2
 # bridge mdb replace dev br port br grp 239.0.0.1 vid 2
 Error: bridge: Group is already joined by host.

A similar operation done on a member port would succeed. Ignore the check
for replacement of host group memberships as well.

The bit of code that this enables is br_multicast_host_join(), which, for
already-joined groups only refreshes the MC group expiration timer, which
is desirable; and a userspace notification, also desirable.

Change a selftest that exercises this code path from expecting a rejection
to expecting a pass. The rest of MDB selftests pass without modification.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/e5c5188b9787ae806609e7ca3aa2a0a501b9b5c4.1738685648.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Petr Machata
2025-02-04 18:37:15 +01:00
committed by Greg Kroah-Hartman
parent 961ee13210
commit 9ed3c1b11d
2 changed files with 2 additions and 2 deletions

View File

@@ -1030,7 +1030,7 @@ static int br_mdb_add_group(const struct br_mdb_config *cfg,
/* host join */
if (!port) {
if (mp->host_joined) {
if (mp->host_joined && !(cfg->nlflags & NLM_F_REPLACE)) {
NL_SET_ERR_MSG_MOD(extack, "Group is already joined by host");
return -EEXIST;
}

View File

@@ -149,7 +149,7 @@ cfg_test_host_common()
check_err $? "Failed to add $name host entry"
bridge mdb replace dev br0 port br0 grp $grp $state vid 10 &> /dev/null
check_fail $? "Managed to replace $name host entry"
check_err $? "Failed to replace $name host entry"
bridge mdb del dev br0 port br0 grp $grp $state vid 10
bridge mdb get dev br0 grp $grp vid 10 &> /dev/null