kernel/linux.git/net/bridge/br.c, branch v6.1.168

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

2025-12-06T21:12:26+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: 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

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2021-08-13T13:41:22+00:00

Conflicts: drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h 9e26680733d5 ("bnxt_en: Update firmware call to retrieve TX PTP timestamp") 9e518f25802c ("bnxt_en: 1PPS functions to configure TSIO pins") 099fdeda659d ("bnxt_en: Event handler for PPS events") kernel/bpf/helpers.c include/linux/bpf-cgroup.h a2baf4e8bb0f ("bpf: Fix potentially incorrect results with bpf_get_local_storage()") c7603cfa04e7 ("bpf: Add ambient BPF runtime context stored in current") drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c 5957cc557dc5 ("net/mlx5: Set all field of mlx5_irq before inserting it to the xarray") 2d0b41a37679 ("net/mlx5: Refcount mlx5_irq with integer") MAINTAINERS 7b637cd52f02 ("MAINTAINERS: fix Microchip CAN BUS Analyzer Tool entry typo") 7d901a1e878a ("net: phy: add Maxlinear GPY115/21x/24x driver") Signed-off-by: Jakub Kicinski

net: bridge: fix flags interpretation for extern learn fdb entries

2021-08-10T18:29:39+00:00

Ignore fdb flags when adding port extern learn entries and always set BR_FDB_LOCAL flag when adding bridge extern learn entries. This is closest to the behaviour we had before and avoids breaking any use cases which were allowed. This patch fixes iproute2 calls which assume NUD_PERMANENT and were allowed before, example: $ bridge fdb add 00:11:22:33:44:55 dev swp1 extern_learn Extern learn entries are allowed to roam, but do not expire, so static or dynamic flags make no sense for them. Also add a comment for future reference. Fixes: eb100e0e24a2 ("net: bridge: allow to add externally learned entries from user-space") Fixes: 0541a6293298 ("net: bridge: validate the NUD_PERMANENT bit when adding an extern_learn FDB entry") Reviewed-by: Ido Schimmel Tested-by: Ido Schimmel Signed-off-by: Nikolay Aleksandrov Reviewed-by: Vladimir Oltean Link: https://lore.kernel.org/r/20210810110010.43859-1-razor@blackwall.org Signed-off-by: Jakub Kicinski

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2021-08-05T22:08:47+00:00

Build failure in drivers/net/wwan/mhi_wwan_mbim.c: add missing parameter (0, assuming we don't want buffer pre-alloc). Conflict in drivers/net/dsa/sja1105/sja1105_main.c between: 589918df9322 ("net: dsa: sja1105: be stateless with FDB entries on SJA1105P/Q/R/S/SJA1110 too") 0fac6aa098ed ("net: dsa: sja1105: delete the best_effort_vlan_filtering mode") Follow the instructions from the commit message of the former commit - removed the if conditions. When looking at commit 589918df9322 ("net: dsa: sja1105: be stateless with FDB entries on SJA1105P/Q/R/S/SJA1110 too") note that the mask_iotag fields get removed by the following patch. Signed-off-by: Jakub Kicinski

net: make switchdev_bridge_port_{,unoffload} loosely coupled with the bridge

2021-08-04T11:35:07+00:00

With the introduction of explicit offloading API in switchdev in commit 2f5dc00f7a3e ("net: bridge: switchdev: let drivers inform which bridge ports are offloaded"), we started having Ethernet switch drivers calling directly into a function exported by net/bridge/br_switchdev.c, which is a function exported by the bridge driver. This means that drivers that did not have an explicit dependency on the bridge before, like cpsw and am65-cpsw, now do - otherwise it is not possible to call a symbol exported by a driver that can be built as module unless you are a module too. There was an attempt to solve the dependency issue in the form of commit b0e81817629a ("net: build all switchdev drivers as modules when the bridge is a module"). Grygorii Strashko, however, says about it: | In my opinion, the problem is a bit bigger here than just fixing the | build :( | | In case, of ^cpsw the switchdev mode is kinda optional and in many | cases (especially for testing purposes, NFS) the multi-mac mode is | still preferable mode. | | There were no such tight dependency between switchdev drivers and | bridge core before and switchdev serviced as independent, notification | based layer between them, so ^cpsw still can be "Y" and bridge can be | "M". Now for mostly every kernel build configuration the CONFIG_BRIDGE | will need to be set as "Y", or we will have to update drivers to | support build with BRIDGE=n and maintain separate builds for | networking vs non-networking testing. But is this enough? Wouldn't | it cause 'chain reaction' required to add more and more "Y" options | (like CONFIG_VLAN_8021Q)? | | PS. Just to be sure we on the same page - ARM builds will be forced | (with this patch) to have CONFIG_TI_CPSW_SWITCHDEV=m and so all our | automation testing will just fail with omap2plus_defconfig. In the light of this, it would be desirable for some configurations to avoid dependencies between switchdev drivers and the bridge, and have the switchdev mode as completely optional within the driver. Arnd Bergmann also tried to write a patch which better expressed the build time dependency for Ethernet switch drivers where the switchdev support is optional, like cpsw/am65-cpsw, and this made the drivers follow the bridge (compile as module if the bridge is a module) only if the optional switchdev support in the driver was enabled in the first place: https://patchwork.kernel.org/project/netdevbpf/patch/20210802144813.1152762-1-arnd@kernel.org/ but this still did not solve the fact that cpsw and am65-cpsw now must be built as modules when the bridge is a module - it just expressed correctly that optional dependency. But the new behavior is an apparent regression from Grygorii's perspective. So to support the use case where the Ethernet driver is built-in, NET_SWITCHDEV (a bool option) is enabled, and the bridge is a module, we need a framework that can handle the possible absence of the bridge from the running system, i.e. runtime bloatware as opposed to build-time bloatware. Luckily we already have this framework, since switchdev has been using it extensively. Events from the bridge side are transmitted to the driver side using notifier chains - this was originally done so that unrelated drivers could snoop for events emitted by the bridge towards ports that are implemented by other drivers (think of a switch driver with LAG offload that listens for switchdev events on a bonding/team interface that it offloads). There are also events which are transmitted from the driver side to the bridge side, which again are modeled using notifiers. SWITCHDEV_FDB_ADD_TO_BRIDGE is an example of this, and deals with notifying the bridge that a MAC address has been dynamically learned. So there is a precedent we can use for modeling the new framework. The difference compared to SWITCHDEV_FDB_ADD_TO_BRIDGE is that the work that the bridge needs to do when a port becomes offloaded is blocking in its nature: replay VLANs, MDBs etc. The calling context is indeed blocking (we are under rtnl_mutex), but the existing switchdev notification chain that the bridge is subscribed to is only the atomic one. So we need to subscribe the bridge to the blocking switchdev notification chain too. This patch: - keeps the driver-side perception of the switchdev_bridge_port_{,un}offload unchanged - moves the implementation of switchdev_bridge_port_{,un}offload from the bridge module into the switchdev module. - makes everybody that is subscribed to the switchdev blocking notifier chain "hear" offload & unoffload events - makes the bridge driver subscribe and handle those events - moves the bridge driver's handling of those events into 2 new functions called br_switchdev_port_{,un}offload. These functions contain in fact the core of the logic that was previously in switchdev_bridge_port_{,un}offload, just that now we go through an extra indirection layer to reach them. Unlike all the other switchdev notification structures, the structure used to carry the bridge port information, struct switchdev_notifier_brport_info, does not contain a "bool handled". This is because in the current usage pattern, we always know that a switchdev bridge port offloading event will be handled by the bridge, because the switchdev_bridge_port_offload() call was initiated by a NETDEV_CHANGEUPPER event in the first place, where info->upper_dev is a bridge. So if the bridge wasn't loaded, then the CHANGEUPPER event couldn't have happened. Signed-off-by: Vladimir Oltean Tested-by: Grygorii Strashko Signed-off-by: David S. Miller

net: bridge: validate the NUD_PERMANENT bit when adding an extern_learn FDB entry

2021-08-02T22:00:48+00:00

Currently it is possible to add broken extern_learn FDB entries to the bridge in two ways: 1. Entries pointing towards the bridge device that are not local/permanent: ip link add br0 type bridge bridge fdb add 00:01:02:03:04:05 dev br0 self extern_learn static 2. Entries pointing towards the bridge device or towards a port that are marked as local/permanent, however the bridge does not process the 'permanent' bit in any way, therefore they are recorded as though they aren't permanent: ip link add br0 type bridge bridge fdb add 00:01:02:03:04:05 dev br0 self extern_learn permanent Since commit 52e4bec15546 ("net: bridge: switchdev: treat local FDBs the same as entries towards the bridge"), these incorrect FDB entries can even trigger NULL pointer dereferences inside the kernel. This is because that commit made the assumption that all FDB entries that are not local/permanent have a valid destination port. For context, local / permanent FDB entries either have fdb->dst == NULL, and these point towards the bridge device and are therefore local and not to be used for forwarding, or have fdb->dst == a net_bridge_port structure (but are to be treated in the same way, i.e. not for forwarding). That assumption _is_ correct as long as things are working correctly in the bridge driver, i.e. we cannot logically have fdb->dst == NULL under any circumstance for FDB entries that are not local. However, the extern_learn code path where FDB entries are managed by a user space controller show that it is possible for the bridge kernel driver to misinterpret the NUD flags of an entry transmitted by user space, and end up having fdb->dst == NULL while not being a local entry. This is invalid and should be rejected. Before, the two commands listed above both crashed the kernel in this check from br_switchdev_fdb_notify: struct net_device *dev = info.is_local ? br->dev : dst->dev; info.is_local == false, dst == NULL. After this patch, the invalid entry added by the first command is rejected: ip link add br0 type bridge && bridge fdb add 00:01:02:03:04:05 dev br0 self extern_learn static; ip link del br0 Error: bridge: FDB entry towards bridge must be permanent. and the valid entry added by the second command is properly treated as a local address and does not crash br_switchdev_fdb_notify anymore: ip link add br0 type bridge && bridge fdb add 00:01:02:03:04:05 dev br0 self extern_learn permanent; ip link del br0 Fixes: eb100e0e24a2 ("net: bridge: allow to add externally learned entries from user-space") Reported-by: syzbot+9ba1174359adba5a5b7c@syzkaller.appspotmail.com Signed-off-by: Vladimir Oltean Acked-by: Nikolay Aleksandrov Link: https://lore.kernel.org/r/20210801231730.7493-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski

net: bridge: move bridge ioctls out of .ndo_do_ioctl

2021-07-27T19:11:45+00:00

Working towards obsoleting the .ndo_do_ioctl operation entirely, stop passing the SIOCBRADDIF/SIOCBRDELIF device ioctl commands into this callback. My first attempt was to add another ndo_siocbr() callback, but as there is only a single driver that takes these commands and there is already a hook mechanism to call directly into this driver, extend this hook instead, and use it for both the deviceless and the device specific ioctl commands. Cc: Roopa Prabhu Cc: Nikolay Aleksandrov Cc: bridge@lists.linux-foundation.org Signed-off-by: Arnd Bergmann Signed-off-by: David S. Miller