Commit d9e9f6d7 authored by Petr Machata's avatar Petr Machata Committed by Jakub Kicinski
Browse files

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



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: default avatarPetr Machata <petrm@nvidia.com>
Reviewed-by: default avatarIdo Schimmel <idosch@nvidia.com>
Acked-by: default avatarNikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/e5c5188b9787ae806609e7ca3aa2a0a501b9b5c4.1738685648.git.petrm@nvidia.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent cbecd06a

net/bridge/br_mdb.c

+1 −1
Original line number Diff line number Diff line
@@ -1040,7 +1040,7 @@ 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;

		}

tools/testing/selftests/net/forwarding/bridge_mdb.sh

+1 −1
Original line number Diff line number Diff line
@@ -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