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2021-08-10net: bridge: fix flags interpretation for extern learn fdb entriesNikolay Aleksandrov
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 <idosch@nvidia.com> Tested-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com> Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com> Link: https://lore.kernel.org/r/20210810110010.43859-1-razor@blackwall.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-08-02net: bridge: validate the NUD_PERMANENT bit when adding an extern_learn FDB ↵Vladimir Oltean
entry 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 <vladimir.oltean@nxp.com> Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com> Link: https://lore.kernel.org/r/20210801231730.7493-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-07-20net: bridge: do not replay fdb entries pointing towards the bridge twiceVladimir Oltean
This simple script: ip link add br0 type bridge ip link set swp2 master br0 ip link set br0 address 00:01:02:03:04:05 ip link del br0 produces this result on a DSA switch: [ 421.306399] br0: port 1(swp2) entered blocking state [ 421.311445] br0: port 1(swp2) entered disabled state [ 421.472553] device swp2 entered promiscuous mode [ 421.488986] device swp2 left promiscuous mode [ 421.493508] br0: port 1(swp2) entered disabled state [ 421.886107] sja1105 spi0.1: port 1 failed to delete 00:01:02:03:04:05 vid 1 from fdb: -ENOENT [ 421.894374] sja1105 spi0.1: port 1 failed to delete 00:01:02:03:04:05 vid 0 from fdb: -ENOENT [ 421.943982] br0: port 1(swp2) entered blocking state [ 421.949030] br0: port 1(swp2) entered disabled state [ 422.112504] device swp2 entered promiscuous mode A very simplified view of what happens is: (1) the bridge port is created, and the bridge device inherits its MAC address (2) when joining, the bridge port (DSA) requests a replay of the addition of all FDB entries towards this bridge port and towards the bridge device itself. In fact, DSA calls br_fdb_replay() twice: br_fdb_replay(br, brport_dev); br_fdb_replay(br, br); DSA uses reference counting for the FDB entries. So the MAC address of the bridge is simply kept with refcount 2. When the bridge port leaves under normal circumstances, everything cancels out since the replay of the FDB entry deletion is also done twice per VLAN. (3) when the bridge MAC address changes, switchdev is notified of the deletion of the old address and of the insertion of the new one. But the old address does not really go away, since it had refcount 2, and the new address is added "only" with refcount 1. (4) when the bridge port leaves now, it will replay a deletion of the FDB entries pointing towards the bridge twice. Then DSA will complain that it can't delete something that no longer exists. It is clear that the problem is that the FDB entries towards the bridge are replayed too many times, so let's fix that problem. Fixes: 63c51453c82c ("net: dsa: replay the local bridge FDB entries pointing to the bridge dev too") Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Link: https://lore.kernel.org/r/20210719093916.4099032-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-06-29net: bridge: allow br_fdb_replay to be called for the bridge deviceVladimir Oltean
When a port joins a bridge which already has local FDB entries pointing to the bridge device itself, we would like to offload those, so allow the "dev" argument to be equal to the bridge too. The code already does what we need in that case. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-29net: bridge: switchdev: send FDB notifications for host addressesTobias Waldekranz
Treat addresses added to the bridge itself in the same way as regular ports and send out a notification so that drivers may sync it down to the hardware FDB. Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-29net: bridge: use READ_ONCE() and WRITE_ONCE() compiler barriers for fdb->dstVladimir Oltean
Annotate the writer side of fdb->dst: - fdb_create() - br_fdb_update() - fdb_add_entry() - br_fdb_external_learn_add() with WRITE_ONCE() and the reader side: - br_fdb_test_addr() - br_fdb_update() - fdb_fill_info() - fdb_add_entry() - fdb_delete_by_addr_and_port() - br_fdb_external_learn_add() - br_switchdev_fdb_notify() with compiler barriers such that the readers do not attempt to reload fdb->dst multiple times, leading to potentially different destination ports when the fdb entry is updated concurrently. This is especially important in read-side sections where fdb->dst is used more than once, but let's convert all accesses for the sake of uniformity. Suggested-by: Nikolay Aleksandrov <nikolay@nvidia.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-28net: bridge: allow the switchdev replay functions to be called for deletionVladimir Oltean
When a switchdev port leaves a LAG that is a bridge port, the switchdev objects and port attributes offloaded to that port are not removed: ip link add br0 type bridge ip link add bond0 type bond mode 802.3ad ip link set swp0 master bond0 ip link set bond0 master br0 bridge vlan add dev bond0 vid 100 ip link set swp0 nomaster VLAN 100 will remain installed on swp0 despite it going into standalone mode, because as far as the bridge is concerned, nothing ever happened to its bridge port. Let's extend the bridge vlan, fdb and mdb replay functions to take a 'bool adding' argument, and make DSA and ocelot call the replay functions with 'adding' as false from the switchdev unsync path, for the switch port that leaves the bridge. Note that this patch in itself does not salvage anything, because in the current pull mode of operation, DSA still needs to call the replay helpers with adding=false. This will be done in another patch. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-28net: bridge: constify variables in the replay helpersVladimir Oltean
Some of the arguments and local variables for the newly added switchdev replay helpers can be const, so let's make them so. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-28net: bridge: ignore switchdev events for LAG ports which didn't request replayVladimir Oltean
There is a slight inconvenience in the switchdev replay helpers added recently, and this is when: ip link add br0 type bridge ip link add bond0 type bond ip link set bond0 master br0 bridge vlan add dev bond0 vid 100 ip link set swp0 master bond0 ip link set swp1 master bond0 Since the underlying driver (currently only DSA) asks for a replay of VLANs when swp0 and swp1 join the LAG because it is bridged, what will happen is that DSA will try to react twice on the VLAN event for swp0. This is not really a huge problem right now, because most drivers accept duplicates since the bridge itself does, but it will become a problem when we add support for replaying switchdev object deletions. Let's fix this by adding a blank void *ctx in the replay helpers, which will be passed on by the bridge in the switchdev notifications. If the context is NULL, everything is the same as before. But if the context is populated with a valid pointer, the underlying switchdev driver (currently DSA) can use the pointer to 'see through' the bridge port (which in the example above is bond0) and 'know' that the event is only for a particular physical port offloading that bridge port, and not for all of them. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-28net: bridge: include the is_local bit in br_fdb_replayVladimir Oltean
Since commit 2c4eca3ef716 ("net: bridge: switchdev: include local flag in FDB notifications"), the bridge emits SWITCHDEV_FDB_ADD_TO_DEVICE events with the is_local flag populated (but we ignore it nonetheless). We would like DSA to start treating this bit, but it is still not populated by the replay helper, so add it there too. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-23net: bridge: add helper to replay port and local fdb entriesVladimir Oltean
When a switchdev port starts offloading a LAG that is already in a bridge and has an FDB entry pointing to it: ip link set bond0 master br0 bridge fdb add dev bond0 00:01:02:03:04:05 master static ip link set swp0 master bond0 the switchdev driver will have no idea that this FDB entry is there, because it missed the switchdev event emitted at its creation. Ido Schimmel pointed this out during a discussion about challenges with switchdev offloading of stacked interfaces between the physical port and the bridge, and recommended to just catch that condition and deny the CHANGEUPPER event: https://lore.kernel.org/netdev/20210210105949.GB287766@shredder.lan/ But in fact, we might need to deal with the hard thing anyway, which is to replay all FDB addresses relevant to this port, because it isn't just static FDB entries, but also local addresses (ones that are not forwarded but terminated by the bridge). There, we can't just say 'oh yeah, there was an upper already so I'm not joining that'. So, similar to the logic for replaying MDB entries, add a function that must be called by individual switchdev drivers and replays local FDB entries as well as ones pointing towards a bridge port. This time, we use the atomic switchdev notifier block, since that's what FDB entries expect for some reason. Reported-by: Ido Schimmel <idosch@idosch.org> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-01-07net: bridge: notify switchdev of disappearance of old FDB entry upon migrationVladimir Oltean
Currently the bridge emits atomic switchdev notifications for dynamically learnt FDB entries. Monitoring these notifications works wonders for switchdev drivers that want to keep their hardware FDB in sync with the bridge's FDB. For example station A wants to talk to station B in the diagram below, and we are concerned with the behavior of the bridge on the DUT device: DUT +-------------------------------------+ | br0 | | +------+ +------+ +------+ +------+ | | | | | | | | | | | | | swp0 | | swp1 | | swp2 | | eth0 | | +-------------------------------------+ | | | Station A | | | | +--+------+--+ +--+------+--+ | | | | | | | | | | swp0 | | | | swp0 | | Another | +------+ | | +------+ | Another switch | br0 | | br0 | switch | +------+ | | +------+ | | | | | | | | | | | swp1 | | | | swp1 | | +--+------+--+ +--+------+--+ | Station B Interfaces swp0, swp1, swp2 are handled by a switchdev driver that has the following property: frames injected from its control interface bypass the internal address analyzer logic, and therefore, this hardware does not learn from the source address of packets transmitted by the network stack through it. So, since bridging between eth0 (where Station B is attached) and swp0 (where Station A is attached) is done in software, the switchdev hardware will never learn the source address of Station B. So the traffic towards that destination will be treated as unknown, i.e. flooded. This is where the bridge notifications come in handy. When br0 on the DUT sees frames with Station B's MAC address on eth0, the switchdev driver gets these notifications and can install a rule to send frames towards Station B's address that are incoming from swp0, swp1, swp2, only towards the control interface. This is all switchdev driver private business, which the notification makes possible. All is fine until someone unplugs Station B's cable and moves it to the other switch: DUT +-------------------------------------+ | br0 | | +------+ +------+ +------+ +------+ | | | | | | | | | | | | | swp0 | | swp1 | | swp2 | | eth0 | | +-------------------------------------+ | | | Station A | | | | +--+------+--+ +--+------+--+ | | | | | | | | | | swp0 | | | | swp0 | | Another | +------+ | | +------+ | Another switch | br0 | | br0 | switch | +------+ | | +------+ | | | | | | | | | | | swp1 | | | | swp1 | | +--+------+--+ +--+------+--+ | Station B Luckily for the use cases we care about, Station B is noisy enough that the DUT hears it (on swp1 this time). swp1 receives the frames and delivers them to the bridge, who enters the unlikely path in br_fdb_update of updating an existing entry. It moves the entry in the software bridge to swp1 and emits an addition notification towards that. As far as the switchdev driver is concerned, all that it needs to ensure is that traffic between Station A and Station B is not forever broken. If it does nothing, then the stale rule to send frames for Station B towards the control interface remains in place. But Station B is no longer reachable via the control interface, but via a port that can offload the bridge port learning attribute. It's just that the port is prevented from learning this address, since the rule overrides FDB updates. So the rule needs to go. The question is via what mechanism. It sure would be possible for this switchdev driver to keep track of all addresses which are sent to the control interface, and then also listen for bridge notifier events on its own ports, searching for the ones that have a MAC address which was previously sent to the control interface. But this is cumbersome and inefficient. Instead, with one small change, the bridge could notify of the address deletion from the old port, in a symmetrical manner with how it did for the insertion. Then the switchdev driver would not be required to monitor learn/forget events for its own ports. It could just delete the rule towards the control interface upon bridge entry migration. This would make hardware address learning be possible again. Then it would take a few more packets until the hardware and software FDB would be in sync again. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-09-28net: bridge: fdb: don't flush ext_learn entriesNikolay Aleksandrov
When a user-space software manages fdb entries externally it should set the ext_learn flag which marks the fdb entry as externally managed and avoids expiring it (they're treated as static fdbs). Unfortunately on events where fdb entries are flushed (STP down, netlink fdb flush etc) these fdbs are also deleted automatically by the bridge. That in turn causes trouble for the managing user-space software (e.g. in MLAG setups we lose remote fdb entries on port flaps). These entries are completely externally managed so we should avoid automatically deleting them, the only exception are offloaded entries (i.e. BR_FDB_ADDED_BY_EXT_LEARN + BR_FDB_OFFLOADED). They are flushed as before. Fixes: eb100e0e24a2 ("net: bridge: allow to add externally learned entries from user-space") Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-24net: bridge: add a flag to avoid refreshing fdb when changing/addingNikolay Aleksandrov
When we modify or create a new fdb entry sometimes we want to avoid refreshing its activity in order to track it properly. One example is when a mac is received from EVPN multi-homing peer by FRR, which doesn't want to change local activity accounting. It makes it static and sets a flag to track its activity. Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-24net: bridge: add option to allow activity notifications for any fdb entriesNikolay Aleksandrov
This patch adds the ability to notify about activity of any entries (static, permanent or ext_learn). EVPN multihoming peers need it to properly and efficiently handle mac sync (peer active/locally active). We add a new NFEA_ACTIVITY_NOTIFY attribute which is used to dump the current activity state and to control if static entries should be monitored at all. We use 2 bits - one to activate fdb entry tracking (disabled by default) and the second to denote that an entry is inactive. We need the second bit in order to avoid multiple notifications of inactivity. Obviously this makes no difference for dynamic entries since at the time of inactivity they get deleted, while the tracked non-dynamic entries get the inactive bit set and get a notification. Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-24net: bridge: fdb_add_entry takes ndm as argumentNikolay Aleksandrov
We can just pass ndm as an argument instead of its fields separately. Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-04net: bridge: fdb: eliminate extra port state tests from fast-pathNikolay Aleksandrov
When commit df1c0b8468b3 ("[BRIDGE]: Packets leaking out of disabled/blocked ports.") introduced the port state tests in br_fdb_update() it was to avoid learning/refreshing from STP BPDUs, it was also used to avoid learning/refreshing from user-space with NTF_USE. Those two tests are done for every packet entering the bridge if it's learning, but for the fast-path we already have them checked in br_handle_frame() and is unnecessary to do it again. Thus push the checks to the unlikely cases and drop them from br_fdb_update(), the new nbp_state_should_learn() helper is used to determine if the port state allows br_fdb_update() to be called. The two places which need to do it manually are: - user-space add call with NTF_USE set - link-local packet learning done in __br_handle_local_finish() Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-01net: bridge: fdb: restore unlikely() when taking over externally added entriesNikolay Aleksandrov
Taking over hw-learned entries is not a likely scenario so restore the unlikely() use for the case of SW taking over externally learned entries. Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-01net: bridge: fdb: avoid two atomic bitops in br_fdb_external_learn_add()Nikolay Aleksandrov
If we setup the fdb flags prior to calling fdb_create() we can avoid two atomic bitops when learning a new entry. Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-01net: bridge: fdb: br_fdb_update can take flags directlyNikolay Aleksandrov
If we modify br_fdb_update() to take flags directly we can get rid of one test and one atomic bitop in the learning path. Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-29net: bridge: fdb: set flags directly in fdb_createNikolay Aleksandrov
No need to have separate arguments for each flag, just set the flags to whatever was passed to fdb_create() before the fdb is published. Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-29net: bridge: fdb: convert offloaded to use bitopsNikolay Aleksandrov
Convert the offloaded field to a flag and use bitops. Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-29net: bridge: fdb: convert added_by_external_learn to use bitopsNikolay Aleksandrov
Convert the added_by_external_learn field to a flag and use bitops. Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-29net: bridge: fdb: convert added_by_user to bitopsNikolay Aleksandrov
Straight-forward convert of the added_by_user field to bitops. Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-29net: bridge: fdb: convert is_sticky to bitopsNikolay Aleksandrov
Straight-forward convert of the is_sticky field to bitops. Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-29net: bridge: fdb: convert is_static to bitopsNikolay Aleksandrov
Convert the is_static to bitops, make use of the combined test_and_set/clear_bit to simplify expressions in fdb_add_entry. Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-29net: bridge: fdb: convert is_local to bitopsNikolay Aleksandrov
The patch adds a new fdb flags field in the hole between the two cache lines and uses it to convert is_local to bitops. Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-07rhashtable: use bit_spin_locks to protect hash bucket.NeilBrown
This patch changes rhashtables to use a bit_spin_lock on BIT(1) of the bucket pointer to lock the hash chain for that bucket. The benefits of a bit spin_lock are: - no need to allocate a separate array of locks. - no need to have a configuration option to guide the choice of the size of this array - locking cost is often a single test-and-set in a cache line that will have to be loaded anyway. When inserting at, or removing from, the head of the chain, the unlock is free - writing the new address in the bucket head implicitly clears the lock bit. For __rhashtable_insert_fast() we ensure this always happens when adding a new key. - even when lockings costs 2 updates (lock and unlock), they are in a cacheline that needs to be read anyway. The cost of using a bit spin_lock is a little bit of code complexity, which I think is quite manageable. Bit spin_locks are sometimes inappropriate because they are not fair - if multiple CPUs repeatedly contend of the same lock, one CPU can easily be starved. This is not a credible situation with rhashtable. Multiple CPUs may want to repeatedly add or remove objects, but they will typically do so at different buckets, so they will attempt to acquire different locks. As we have more bit-locks than we previously had spinlocks (by at least a factor of two) we can expect slightly less contention to go with the slightly better cache behavior and reduced memory consumption. To enhance type checking, a new struct is introduced to represent the pointer plus lock-bit that is stored in the bucket-table. This is "struct rhash_lock_head" and is empty. A pointer to this needs to be cast to either an unsigned lock, or a "struct rhash_head *" to be useful. Variables of this type are most often called "bkt". Previously "pprev" would sometimes point to a bucket, and sometimes a ->next pointer in an rhash_head. As these are now different types, pprev is NULL when it would have pointed to the bucket. In that case, 'blk' is used, together with correct locking protocol. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Completely minor snmp doc conflict. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-18net: bridge: Mark FDB entries that were added by user as suchIdo Schimmel
Externally learned entries can be added by a user or by a switch driver that is notifying the bridge driver about entries that were learned in hardware. In the first case, the entries are not marked with the 'added_by_user' flag, which causes switch drivers to ignore them and not offload them. The 'added_by_user' flag can be set on externally learned FDB entries based on the 'swdev_notify' parameter in br_fdb_external_learn_add(), which effectively means if the created / updated FDB entry was added by a user or not. Fixes: 816a3bed9549 ("switchdev: Add fdb.added_by_user to switchdev notifications") Signed-off-by: Ido Schimmel <idosch@mellanox.com> Reported-by: Alexander Petrovskiy <alexpe@mellanox.com> Reviewed-by: Petr Machata <petrm@mellanox.com> Cc: Roopa Prabhu <roopa@cumulusnetworks.com> Cc: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Cc: bridge@lists.linux-foundation.org Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-17net: Add extack argument to ndo_fdb_add()Petr Machata
Drivers may not be able to support certain FDB entries, and an error code is insufficient to give clear hints as to the reasons of rejection. In order to make it possible to communicate the rejection reason, extend ndo_fdb_add() with an extack argument. Adapt the existing implementations of ndo_fdb_add() to take the parameter (and ignore it). Pass the extack parameter when invoking ndo_fdb_add() from rtnl_fdb_add(). Signed-off-by: Petr Machata <petrm@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-16bridge: support for ndo_fdb_getRoopa Prabhu
This patch implements ndo_fdb_get for the bridge fdb. Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Reviewed-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-07bridge: Add br_fdb_clear_offload()Petr Machata
When a driver unoffloads all FDB entries en bloc, it's inefficient to send the switchdev notification one by one. Add a helper that unsets the offload flag on FDB entries on a given bridge port and VLAN. Signed-off-by: Petr Machata <petrm@mellanox.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-17bridge: switchdev: Allow clearing FDB entry offload indicationIdo Schimmel
Currently, an FDB entry only ceases being offloaded when it is deleted. This changes with VxLAN encapsulation. Devices capable of performing VxLAN encapsulation usually have only one FDB table, unlike the software data path which has two - one in the bridge driver and another in the VxLAN driver. Therefore, bridge FDB entries pointing to a VxLAN device are only offloaded if there is a corresponding entry in the VxLAN FDB. Allow clearing the offload indication in case the corresponding entry was deleted from the VxLAN FDB. Signed-off-by: Ido Schimmel <idosch@mellanox.com> Reviewed-by: Petr Machata <petrm@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-28net: bridge: explicitly zero is_sticky in fdb_createNikolay Aleksandrov
We need to explicitly zero is_sticky when creating a new fdb, otherwise we might get a stale value for a new entry. Fixes: 435f2e7cc0b7 ("net: bridge: add support for sticky fdb entries") Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-12net: bridge: add support for sticky fdb entriesNikolay Aleksandrov
Add support for entries which are "sticky", i.e. will not change their port if they show up from a different one. A new ndm flag is introduced for that purpose - NTF_STICKY. We allow to set it only to non-local entries. Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-08net: bridge: Fix locking in br_fdb_find_port()Petr Machata
Callers of br_fdb_find() need to hold the hash lock, which br_fdb_find_port() doesn't do. However, since br_fdb_find_port() is not doing any actual FDB manipulation, the hash lock is not really needed at all. So convert to br_fdb_find_rcu(), surrounded by rcu_read_lock() / _unlock() pair. The device pointer copied from inside the FDB entry is then kept alive by the RTNL lock, which br_fdb_find_port() asserts. Fixes: 4d4fd36126d6 ("net: bridge: Publish bridge accessor functions") Signed-off-by: Petr Machata <petrm@mellanox.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-03net: bridge: Notify about !added_by_user FDB entriesPetr Machata
Do not automatically bail out on sending notifications about activity on non-user-added FDB entries. Instead, notify about this activity except for cases where the activity itself originates in a notification, to avoid sending duplicate notifications. Signed-off-by: Petr Machata <petrm@mellanox.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Acked-by: Ivan Vecera <ivecera@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-30net: bridge: Publish bridge accessor functionsPetr Machata
Add a couple new functions to allow querying FDB and vlan settings of a bridge. Signed-off-by: Petr Machata <petrm@mellanox.com> Signed-off-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-01net: bridge: Fix uninitialized error in br_fdb_sync_static()Geert Uytterhoeven
With gcc-4.1.2.: net/bridge/br_fdb.c: In function ‘br_fdb_sync_static’: net/bridge/br_fdb.c:996: warning: ‘err’ may be used uninitialized in this function Indeed, if the list is empty, err will be uninitialized, and will be propagated up as the function return value. Fix this by preinitializing err to zero. Fixes: eb7935830d00b9e0 ("net: bridge: use rhashtable for fdbs") Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-13net: bridge: use rhashtable for fdbsNikolay Aleksandrov
Before this patch the bridge used a fixed 256 element hash table which was fine for small use cases (in my tests it starts to degrade above 1000 entries), but it wasn't enough for medium or large scale deployments. Modern setups have thousands of participants in a single bridge, even only enabling vlans and adding a few thousand vlan entries will cause a few thousand fdbs to be automatically inserted per participating port. So we need to scale the fdb table considerably to cope with modern workloads, and this patch converts it to use a rhashtable for its operations thus improving the bridge scalability. Tests show the following results (10 runs each), at up to 1000 entries rhashtable is ~3% slower, at 2000 rhashtable is 30% faster, at 3000 it is 2 times faster and at 30000 it is 50 times faster. Obviously this happens because of the properties of the two constructs and is expected, rhashtable keeps pretty much a constant time even with 10000000 entries (tested), while the fixed hash table struggles considerably even above 10000. As a side effect this also reduces the net_bridge struct size from 3248 bytes to 1344 bytes. Also note that the key struct is 8 bytes. Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-31bridge: add tracepoint in br_fdb_updateRoopa Prabhu
This extends bridge fdb table tracepoints to also cover learned fdb entries in the br_fdb_update path. Note that unlike other tracepoints I have moved this to when the fdb is modified because this is in the datapath and can generate a lot of noise in the trace output. br_fdb_update is also called from added_by_user context in the NTF_USE case which is already traced ..hence the !added_by_user check. Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-29bridge: fdb add and delete tracepointsRoopa Prabhu
A few useful tracepoints to trace bridge forwarding database updates. Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-07net: bridge: Remove FDB deletion through switchdev objectArkadi Sharshevsky
At this point no driver supports FDB add/del through switchdev object but rather via notification chain, thus, it is removed. Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com> Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com> Reviewed-by: Ivan Vecera <ivecera@redhat.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-04bridge: allow ext learned entries to change portsNikolay Aleksandrov
current code silently ignores change of port in the request message. This patch makes sure the port is modified and notification is sent to userspace. Fixes: cf6b8e1eedff ("bridge: add API to notify bridge driver of learned FBD on offloaded device") Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08net: bridge: Receive notification about successful FDB offloadArkadi Sharshevsky
When a new static FDB is added to the bridge a notification is sent to the driver for offload. In case of successful offload the driver should notify the bridge back, which in turn should mark the FDB as offloaded. Currently, externally learned is equivalent for being offloaded which is not correct due to the fact that FDBs which are added from user-space are also marked as externally learned. In order to specify if an FDB was successfully offloaded a new flag is introduced. Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08net: bridge: Add support for notifying devices about FDB add/delArkadi Sharshevsky
Currently the bridge doesn't notify the underlying devices about new FDBs learned. The FDB sync is placed on the switchdev notifier chain because devices may potentially learn FDB that are not directly related to their ports, for example: 1. Mixed SW/HW bridge - FDBs that point to the ASICs external devices should be offloaded as CPU traps in order to perform forwarding in slow path. 2. EVPN - Externally learned FDBs for the vtep device. Notification is sent only about static FDB add/del. This is done due to fact that currently this is the only scenario supported by switch drivers. Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Reviewed-by: Ivan Vecera <ivecera@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08net: bridge: Add support for calling FDB external learning under rcuArkadi Sharshevsky
This is done as a preparation to moving the switchdev notifier chain to be atomic. The FDB external learning should be called under rtnl or rcu. Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-30net: bridge: Fix improper taking over HW learned FDBArkadi Sharshevsky
Commit 7e26bf45e4cb ("net: bridge: allow SW learn to take over HW fdb entries") added the ability to "take over an entry which was previously learned via HW when it shows up from a SW port". However, if an entry was learned via HW and then a control packet (e.g., ARP request) was trapped to the CPU, the bridge driver will update the entry and remove the externally learned flag, although the entry is still present in HW. Instead, only clear the externally learned flag in case of roaming. Fixes: 7e26bf45e4cb ("net: bridge: allow SW learn to take over HW fdb entries") Signed-off-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: Arkadi Sharashevsky <arkadis@mellanox.com> Cc: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>