Re: [PATCH net-next v4 09/14] net: bridge: mcast: track active state, VLAN snooping
From: Ido Schimmel <idosch@nvidia.com>
Date: 2026-03-08 20:13:03
Also in:
bridge, linux-kselftest, lkml
On Sat, Mar 07, 2026 at 05:45:43AM +0100, Linus Lüssing wrote:
quoted hunk ↗ jump to hunk
If VLAN aware multicast snooping is enabled then we need to perform a few extra checks to figure out if multicast snooping is actually enabled for a specific VLAN, as there is then an additional per VLAN multicast snooping toggle. Signed-off-by: Linus Lüssing <redacted> --- net/bridge/br_multicast.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-)diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index cdc921b97243..1059984d8147 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c@@ -1142,9 +1142,31 @@ static void br_multicast_update_active(struct net_bridge_mcast *brmctx) lockdep_assert_held_once(&brmctx->br->multicast_lock); - if (!br_opt_get(brmctx->br, BROPT_MULTICAST_ENABLED)) + if (!br_opt_get(brmctx->br, BROPT_MULTICAST_ENABLED)) { force_inactive = true; + goto update; + } + if (br_opt_get(brmctx->br, BROPT_MCAST_VLAN_SNOOPING_ENABLED)) { + /* with per-vlan snooping enabled there is an extra per-vlan + * toggle to enable/disable snooping which we must check + */ + if (br_multicast_ctx_vlan_global_disabled(brmctx)) + force_inactive = true; + /* with per-vlan snooping enabled the non-vlan multicast + * snooping context is inactive + */ + else if (!br_multicast_ctx_is_vlan(brmctx)) + force_inactive = true; + } else { + /* with per-vlan snooping disabled a vlan multicast + * snooping context is inactive + */ + if (br_multicast_ctx_is_vlan(brmctx)) + force_inactive = true; + } + +update: br_ip4_multicast_update_active(brmctx, force_inactive); br_ip6_multicast_update_active(brmctx, force_inactive);@@ -4505,6 +4527,7 @@ void br_multicast_toggle_one_vlan(struct net_bridge_vlan *vlan, bool on) spin_lock_bh(&br->multicast_lock); vlan->priv_flags ^= BR_VLFLAG_MCAST_ENABLED; + br_multicast_update_active(&vlan->br_mcast_ctx); if (on) __br_multicast_open(&vlan->br_mcast_ctx);
I believe the active state is not disabled when snooping is disabled on a specific VLAN. AFAICT that's because br_multicast_update_active() is only called when the VLAN is actually used by the bridge (i.e., "brentry"). Can be reproduced with [1]. Please add it as a test case in patch #2. Will continue tomorrow. [1] #!/bin/bash for ns in ns0 ns1; do ip netns del $ns &> /dev/null ip netns add $ns ip -n $ns link set dev lo up done ip -n ns0 link add name veth0 type veth peer name veth1 netns ns1 ip -n ns0 link add name br0 up type bridge vlan_filtering 1 mcast_snooping 1 mcast_vlan_snooping 1 ip -n ns1 link add name br1 up type bridge vlan_filtering 1 mcast_snooping 1 mcast_vlan_snooping 1 ip -n ns0 link set dev veth0 up master br0 ip -n ns1 link set dev veth1 up master br1 bridge -n ns0 vlan add vid 10 dev veth0 master bridge -n ns1 vlan add vid 10 dev veth1 master sleep 1 bridge -n ns0 vlan global set vid 10 dev br0 mcast_snooping 1 mcast_query_response_interval 100 mcast_querier 1 bridge -n ns1 vlan global set vid 10 dev br1 mcast_snooping 1 mcast_query_response_interval 100 mcast_querier 0 sleep 1 bridge -n ns1 -j -p vlan global show dev br1 vid 10 | jq '.[]["vlans"][]["mcast_active_v4"]' bridge -n ns1 vlan global set vid 10 dev br1 mcast_snooping 0 sleep 1 bridge -n ns1 -j -p vlan global show dev br1 vid 10 | jq '.[]["vlans"][]["mcast_active_v4"]'