linux/net/bridge/br_switchdev.c, branch v6.7

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

2023-07-21T07:54:03Z

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

net: bridge: br_switchdev: Tolerate -EOPNOTSUPP when replaying MDB

2023-07-21T07:54:03Z

There are two kinds of MDB entries to be replayed: port MDB entries, and host MDB entries. They are both replayed by br_switchdev_mdb_replay(). If the driver supports one kind, but lacks the other, the first -EOPNOTSUPP returned terminates the whole replay, including any further still-supported objects in the list. For this to cause issues, there must be MDB entries for both the host and the port being replayed. In that case, if the driver bails out from handling the host entry, the port entries are never replayed. However, the replay is currently only done when a switchdev port joins a bridge. There would be no port memberships at that point. Thus despite being erroneous, the code does not cause observable bugs. This is not an issue with other object kinds either, because there, each function replays one object kind. If a driver does not support that kind, it makes sense to bail out early. -EOPNOTSUPP is then ignored in nbp_switchdev_sync_objs(). For MDB, suppress the -EOPNOTSUPP error code in br_switchdev_mdb_replay() already, so that the whole list gets replayed. The reason we need this patch is that a future patch will introduce a replay that should be used when a front-panel port netdevice is enslaved to a bridge lower, in particular a LAG. The LAG netdevice can already have both host and port MDB entries. The port entries need to be replayed so that they are offloaded on the port that joins the LAG. 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

net: bridge: switchdev: don't notify FDB entries with "master dynamic"

2023-04-20T07:20:14Z

There is a structural problem in switchdev, where the flag bits in struct switchdev_notifier_fdb_info (added_by_user, is_local etc) only represent a simplified / denatured view of what's in struct net_bridge_fdb_entry :: flags (BR_FDB_ADDED_BY_USER, BR_FDB_LOCAL etc). Each time we want to pass more information about struct net_bridge_fdb_entry :: flags to struct switchdev_notifier_fdb_info (here, BR_FDB_STATIC), we find that FDB entries were already notified to switchdev with no regard to this flag, and thus, switchdev drivers had no indication whether the notified entries were static or not. For example, this command: ip link add br0 type bridge && ip link set swp0 master br0 bridge fdb add dev swp0 00:01:02:03:04:05 master dynamic has never worked as intended with switchdev. It causes a struct net_bridge_fdb_entry to be passed to br_switchdev_fdb_notify() which has a single flag set: BR_FDB_ADDED_BY_USER. This is further passed to the switchdev notifier chain, where interested drivers have no choice but to assume this is a static (does not age) and sticky (does not migrate) FDB entry. So currently, all drivers offload it to hardware as such, as can be seen below ("offload" is set). bridge fdb get 00:01:02:03:04:05 dev swp0 master 00:01:02:03:04:05 dev swp0 offload master br0 The software FDB entry expires $ageing_time centiseconds after the kernel last sees a packet with this MAC SA, and the bridge notifies its deletion as well, so it eventually disappears from hardware too. This is a problem, because it is actually desirable to start offloading "master dynamic" FDB entries correctly - they should expire $ageing_time centiseconds after the *hardware* port last sees a packet with this MAC SA - and this is how the current incorrect behavior was discovered. With an offloaded data plane, it can be expected that software only sees exception path packets, so an otherwise active dynamic FDB entry would be aged out by software sooner than it should. With the change in place, these FDB entries are no longer offloaded: bridge fdb get 00:01:02:03:04:05 dev swp0 master 00:01:02:03:04:05 dev swp0 master br0 and this also constitutes a better way (assuming a backport to stable kernels) for user space to determine whether the kernel has the capability of doing something sane with these or not. As opposed to "master dynamic" FDB entries, on the current behavior of which no one currently depends on (which can be deduced from the lack of kselftests), Ido Schimmel explains that entries with the "extern_learn" flag (BR_FDB_ADDED_BY_EXT_LEARN) should still be notified to switchdev, since the spectrum driver listens to them (and this is kind of okay, because although they are treated identically to "static", they are expected to not age, and to roam). Fixes: 6b26b51b1d13 ("net: bridge: Add support for notifying devices about FDB add/del") Link: https://lore.kernel.org/netdev/20230327115206.jk5q5l753aoelwus@skbuf/ Signed-off-by: Vladimir Oltean Reviewed-by: Jesse Brandeburg Reviewed-by: Ido Schimmel Tested-by: Ido Schimmel Link: https://lore.kernel.org/r/20230418155902.898627-1-vladimir.oltean@nxp.com Signed-off-by: Paolo Abeni

netlink: provide an ability to set default extack message

2023-02-02T05:04:09Z

In netdev common pattern, extack pointer is forwarded to the drivers to be filled with error message. However, the caller can easily overwrite the filled message. Instead of adding multiple "if (!extack->_msg)" checks before any NL_SET_ERR_MSG() call, which appears after call to the driver, let's add new macro to common code. [1] https://lore.kernel.org/all/Y9Irgrgf3uxOjwUm@unreal Reviewed-by: Simon Horman Reviewed-by: Nikolay Aleksandrov Signed-off-by: Leon Romanovsky Link: https://lore.kernel.org/r/6993fac557a40a1973dfa0095107c3d03d40bec1.1675171790.git.leon@kernel.org Signed-off-by: Jakub Kicinski

bridge: switchdev: Reflect MAB bridge port flag to device drivers

2022-11-10T03:06:14Z

Reflect the 'BR_PORT_MAB' flag to device drivers so that: * Drivers that support MAB could act upon the flag being toggled. * Drivers that do not support MAB will prevent MAB from being enabled. 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: Allow device drivers to install locked FDB entries

2022-11-10T03:06:13Z

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

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

2022-04-28T20:02:01Z

include/linux/netdevice.h net/core/dev.c 6510ea973d8d ("net: Use this_cpu_inc() to increment net->core_stats") 794c24e9921f ("net-core: rx_otherhost_dropped to core_stats") https://lore.kernel.org/all/20220428111903.5f4304e0@canb.auug.org.au/ drivers/net/wan/cosa.c d48fea8401cf ("net: cosa: fix error check return value of register_chrdev()") 89fbca3307d4 ("net: wan: remove support for COSA and SRP synchronous serial boards") https://lore.kernel.org/all/20220428112130.1f689e5e@canb.auug.org.au/ Signed-off-by: Jakub Kicinski

net: bridge: switchdev: check br_vlan_group() return value

2022-04-22T22:12:18Z

br_vlan_group() can return NULL and thus return value must be checked to avoid dereferencing a NULL pointer. Fixes: 6284c723d9b9 ("net: bridge: mst: Notify switchdev drivers of VLAN MSTI migrations") Signed-off-by: Clément Léger Acked-by: Nikolay Aleksandrov Link: https://lore.kernel.org/r/20220421101247.121896-1-clement.leger@bootlin.com Signed-off-by: Jakub Kicinski

net: bridge: offload BR_HAIRPIN_MODE, BR_ISOLATED, BR_MULTICAST_TO_UNICAST

2022-04-12T03:52:38Z

Add BR_HAIRPIN_MODE, BR_ISOLATED and BR_MULTICAST_TO_UNICAST port flags to BR_PORT_FLAGS_HW_OFFLOAD so that switchdev drivers which have an offloaded data plane have a chance to reject these bridge port flags if they don't support them yet. It makes the code path go through the SWITCHDEV_ATTR_ID_PORT_PRE_BRIDGE_FLAGS driver handlers, which return -EINVAL for everything they don't recognize. For drivers that don't catch SWITCHDEV_ATTR_ID_PORT_PRE_BRIDGE_FLAGS at all, switchdev will return -EOPNOTSUPP for those which is then ignored, but those are in the minority. Signed-off-by: Arınç ÜNAL Reviewed-by: Ido Schimmel Reviewed-by: Vladimir Oltean Link: https://lore.kernel.org/r/20220410134227.18810-1-arinc.unal@arinc9.com Signed-off-by: Jakub Kicinski

net: bridge: mst: Notify switchdev drivers of VLAN MSTI migrations

2022-03-17T23:49:58Z

Whenever a VLAN moves to a new MSTI, send a switchdev notification so that switchdevs can track a bridge's VID to MSTI mappings. Signed-off-by: Tobias Waldekranz Acked-by: Nikolay Aleksandrov Signed-off-by: Jakub Kicinski