From: Petr Machata petrm@nvidia.com

[ 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... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/bridge/br_mdb.c | 2 +- tools/testing/selftests/net/forwarding/bridge_mdb.sh | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/bridge/br_mdb.c b/net/bridge/br_mdb.c index 7305f5f8215ca..96bea0c8408fe 100644 --- a/net/bridge/br_mdb.c +++ b/net/bridge/br_mdb.c @@ -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; } diff --git a/tools/testing/selftests/net/forwarding/bridge_mdb.sh b/tools/testing/selftests/net/forwarding/bridge_mdb.sh index a3678dfe5848a..c151374ddf040 100755 --- a/tools/testing/selftests/net/forwarding/bridge_mdb.sh +++ b/tools/testing/selftests/net/forwarding/bridge_mdb.sh @@ -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