kernel/linux.git/net/bridge/br.c, branch v6.12.80

net: bridge: Install FDB for bridge MAC on VLAN 0

2025-11-13T20:34:29+00:00

[ Upstream commit cd9a9562b2559973aa1b68c3af63021a2c5fd022 ] Currently, after the bridge is created, the FDB does not hold an FDB entry for the bridge MAC on VLAN 0: # ip link add name br up type bridge # ip -br link show dev br br UNKNOWN 92:19:8c:4e:01:ed # bridge fdb show | grep 92:19:8c:4e:01:ed 92:19:8c:4e:01:ed dev br vlan 1 master br permanent Later when the bridge MAC is changed, or in fact when the address is given during netdevice creation, the entry appears: # ip link add name br up address 00:11:22:33:44:55 type bridge # bridge fdb show | grep 00:11:22:33:44:55 00:11:22:33:44:55 dev br vlan 1 master br permanent 00:11:22:33:44:55 dev br master br permanent However when the bridge address is set by the user to the current bridge address before the first port is enslaved, none of the address handlers gets invoked, because the address is not actually changed. The address is however marked as NET_ADDR_SET. Then when a port is enslaved, the address is not changed, because it is NET_ADDR_SET. Thus the VLAN 0 entry is not added, and it has not been added previously either: # ip link add name br up type bridge # ip -br link show dev br br UNKNOWN 7e:f0:a8:1a:be:c2 # ip link set dev br addr 7e:f0:a8:1a:be:c2 # ip link add name v up type veth # ip link set dev v master br # ip -br link show dev br br UNKNOWN 7e:f0:a8:1a:be:c2 # bridge fdb | grep 7e:f0:a8:1a:be:c2 7e:f0:a8:1a:be:c2 dev br vlan 1 master br permanent Then when the bridge MAC is used as DMAC, and br_handle_frame_finish() looks up an FDB entry with VLAN=0, it doesn't find any, and floods the traffic instead of passing it up. Fix this by simply adding the VLAN 0 FDB entry for the bridge itself always on netdevice creation. This also makes the behavior consistent with how ports are treated: ports always have an FDB entry for each member VLAN as well as VLAN 0. Signed-off-by: Petr Machata Reviewed-by: Ido Schimmel Acked-by: Nikolay Aleksandrov Link: https://patch.msgid.link/415202b2d1b9b0899479a502bbe2ba188678f192.1758550408.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: bridge: Bounce invalid boolopts

2025-09-19T14:35:48+00:00

[ Upstream commit 8625f5748fea960d2af4f3c3e9891ee8f6f80906 ] The bridge driver currently tolerates options that it does not recognize. Instead, it should bounce them. Fixes: a428afe82f98 ("net: bridge: add support for user-controlled bool options") Signed-off-by: Petr Machata Reviewed-by: Ido Schimmel Acked-by: Nikolay Aleksandrov Link: https://patch.msgid.link/e6fdca3b5a8d54183fbda075daffef38bdd7ddce.1757070067.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

bridge: use exit_batch_rtnl() method

2024-02-08T02:55:12+00:00

exit_batch_rtnl() is called while RTNL is held, and devices to be unregistered can be queued in the dev_kill_list. This saves one rtnl_lock()/rtnl_unlock() pair per netns and one unregister_netdevice_many() call. Signed-off-by: Eric Dumazet Reviewed-by: Antoine Tenart Link: https://lore.kernel.org/r/20240206144313.2050392-16-edumazet@google.com Signed-off-by: Jakub Kicinski

net: bridge: fill in MODULE_DESCRIPTION()

2023-10-27T10:16:44+00:00

Fill in bridge's module description. Suggested-by: Jakub Kicinski Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller

net: switchdev: Add a helper to replay objects on a bridge port

2023-07-21T07:54:03+00:00

When a front panel joins a bridge via another netdevice (typically a LAG), the driver needs to learn about the objects configured on the bridge port. When the bridge port is offloaded by the driver for the first time, this can be achieved by passing a notifier to switchdev_bridge_port_offload(). The notifier is then invoked for the individual objects (such as VLANs) configured on the bridge, and can look for the interesting ones. Calling switchdev_bridge_port_offload() when the second port joins the bridge lower is unnecessary, but the replay is still needed. To that end, add a new function, switchdev_bridge_port_replay(), which does only the replay part of the _offload() function in exactly the same way as that function. Cc: Jiri Pirko Cc: Ivan Vecera Cc: Roopa Prabhu Cc: Nikolay Aleksandrov Cc: bridge@lists.linux-foundation.org Signed-off-by: Petr Machata Reviewed-by: Danielle Ratson Signed-off-by: David S. Miller

bridge: switchdev: Allow device drivers to install locked FDB entries

2022-11-10T03:06:13+00:00

When the bridge is offloaded to hardware, FDB entries are learned and aged-out by the hardware. Some device drivers synchronize the hardware and software FDBs by generating switchdev events towards the bridge. When a port is locked, the hardware must not learn autonomously, as otherwise any host will blindly gain authorization. Instead, the hardware should generate events regarding hosts that are trying to gain authorization and their MAC addresses should be notified by the device driver as locked FDB entries towards the bridge driver. Allow device drivers to notify the bridge driver about such entries by extending the 'switchdev_notifier_fdb_info' structure with the 'locked' bit. The bit can only be set by device drivers and not by the bridge driver. Prevent a locked entry from being installed if MAB is not enabled on the bridge port. If an entry already exists in the bridge driver, reject the locked entry if the current entry does not have the "locked" flag set or if it points to a different port. The same semantics are implemented in the software data path. Signed-off-by: Hans J. Schultz Signed-off-by: Ido Schimmel Reviewed-by: Petr Machata Signed-off-by: Petr Machata Reviewed-by: Vladimir Oltean Acked-by: Nikolay Aleksandrov Signed-off-by: Jakub Kicinski

bridge: switchdev: Let device drivers determine FDB offload indication

2022-11-10T03:06:13+00:00

Currently, FDB entries that are notified to the bridge via 'SWITCHDEV_FDB_ADD_TO_BRIDGE' are always marked as offloaded. With MAB enabled, this will no longer be universally true. Device drivers will report locked FDB entries to the bridge to let it know that the corresponding hosts required authorization, but it does not mean that these entries are necessarily programmed in the underlying hardware. Solve this by determining the offload indication based of the 'offloaded' bit in the FDB notification. Signed-off-by: Ido Schimmel Reviewed-by: Petr Machata Signed-off-by: Petr Machata Reviewed-by: Vladimir Oltean Acked-by: Nikolay Aleksandrov Signed-off-by: Jakub Kicinski

net: bridge: mst: Multiple Spanning Tree (MST) mode

2022-03-17T23:49:57+00:00

Allow the user to switch from the current per-VLAN STP mode to an MST mode. Up to this point, per-VLAN STP states where always isolated from each other. This is in contrast to the MSTP standard (802.1Q-2018, Clause 13.5), where VLANs are grouped into MST instances (MSTIs), and the state is managed on a per-MSTI level, rather that at the per-VLAN level. Perhaps due to the prevalence of the standard, many switching ASICs are built after the same model. Therefore, add a corresponding MST mode to the bridge, which we can later add offloading support for in a straight-forward way. For now, all VLANs are fixed to MSTI 0, also called the Common Spanning Tree (CST). That is, all VLANs will follow the port-global state. Upcoming changes will make this actually useful by allowing VLANs to be mapped to arbitrary MSTIs and allow individual MSTI states to be changed. Signed-off-by: Tobias Waldekranz Acked-by: Nikolay Aleksandrov Signed-off-by: Jakub Kicinski

bridge: switch br_net_exit to batch mode

2022-02-19T16:20:12+00:00

cleanup_net() is competing with other rtnl users. Instead of calling br_net_exit() for each netns, call br_net_exit_batch() once. This gives cleanup_net() ability to group more devices and call unregister_netdevice_many() only once for all bridge devices. Signed-off-by: Eric Dumazet Cc: Roopa Prabhu Cc: Nikolay Aleksandrov Acked-by: Nikolay Aleksandrov Signed-off-by: David S. Miller

net: make use of helper netif_is_bridge_master()

2021-10-16T14:02:56+00:00

Make use of netdev helper functions to improve code readability. Replace 'dev->priv_flags & IFF_EBRIDGE' with netif_is_bridge_master(dev). Signed-off-by: Kyungrok Chung Reviewed-by: Nikolay Aleksandrov Signed-off-by: David S. Miller