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

When a front panel joins a bridge via another netdevice (typically a LAG),
the driver needs to learn about the objects configured on t

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

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 <jiri@resnulli.us>
Cc: Ivan Vecera <ivecera@redhat.com>
Cc: Roopa Prabhu <roopa@nvidia.com>
Cc: Nikolay Aleksandrov <razor@blackwall.org>
Cc: bridge@lists.linux-foundation.org
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Danielle Ratson <danieller@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

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

When the bridge is offloaded to hardware, FDB entries are learned and
aged-out by the hardware. Some device drivers synchronize

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

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 <netdev@kapio-technology.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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bridge: switchdev: Let device drivers determine FDB offload indication

Currently, FDB entries that are notified to the bridge via
'SWITCHDEV_FDB_ADD_TO_BRIDGE' are always marked as offloaded. With M

bridge: switchdev: Let device drivers determine FDB offload indication

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 <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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

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

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

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 <tobias@waldekranz.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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bridge: switch br_net_exit to batch mode

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()

bridge: switch br_net_exit to batch mode

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 <edumazet@google.com>
Cc: Roopa Prabhu <roopa@nvidia.com>
Cc: Nikolay Aleksandrov <razor@blackwall.org>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: make use of helper netif_is_bridge_master()

Make use of netdev helper functions to improve code readability.
Replace 'dev->priv_flags & IFF_EBRIDGE' with netif_is_bridge_master(dev).

Signed-of

net: make use of helper netif_is_bridge_master()

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 <acadx0@gmail.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

Ignore fdb flags when adding port extern learn entries and always set
BR_FDB_LOCAL flag when adding bridge extern learn entries. Th

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

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>

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

With the introduction of explicit offloading API in switchdev in commit
2f5dc00f7a3e ("net: bridge: switchdev: let driver

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

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 <vladimir.oltean@nxp.com>
Tested-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

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

Currently it is possible to add broken extern_learn FDB entries to the
bridge in two ways:

1. Entries pointing towa

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

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net: bridge: move bridge ioctls out of .ndo_do_ioctl

Working towards obsoleting the .ndo_do_ioctl operation entirely,
stop passing the SIOCBRADDIF/SIOCBRDELIF device ioctl commands
into this callbac

net: bridge: move bridge ioctls out of .ndo_do_ioctl

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 <roopa@nvidia.com>
Cc: Nikolay Aleksandrov <nikolay@nvidia.com>
Cc: bridge@lists.linux-foundation.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net: bridge: add vlan mcast snooping knob

Add a global knob that controls if vlan multicast snooping is enabled.
The proper contexts (vlan or bridge-wide) will be chosen based on the knob
when proce

net: bridge: add vlan mcast snooping knob

Add a global knob that controls if vlan multicast snooping is enabled.
The proper contexts (vlan or bridge-wide) will be chosen based on the knob
when processing packets and changing bridge device state. Note that
vlans have their individual mcast snooping enabled by default, but this
knob is needed to turn on bridge vlan snooping. It is disabled by
default. To enable the knob vlan filtering must also be enabled, it
doesn't make sense to have vlan mcast snooping without vlan filtering
since that would lead to inconsistencies. Disabling vlan filtering will
also automatically disable vlan mcast snooping.

Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net: bridge: fix misspellings using codespell tool

Some typos are found out by codespell tool:

$ codespell ./net/bridge/
./net/bridge/br_stp.c:604: permanant ==> permanent
./net/bridge/br_stp.c:60

net: bridge: fix misspellings using codespell tool

Some typos are found out by codespell tool:

$ codespell ./net/bridge/
./net/bridge/br_stp.c:604: permanant ==> permanent
./net/bridge/br_stp.c:605: persistance ==> persistence
./net/bridge/br.c:125: underlaying ==> underlying
./net/bridge/br_input.c:43: modue ==> mode
./net/bridge/br_mrp.c:828: Determin ==> Determine
./net/bridge/br_mrp.c:848: Determin ==> Determine
./net/bridge/br_mrp.c:897: Determin ==> Determine

Fix typos found by codespell.

Signed-off-by: Menglong Dong <dong.menglong@zte.com.cn>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20210108025332.52480-1-dong.menglong@zte.com.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: bridge: Fix a warning when del bridge sysfs

I got a warining report:

br_sysfs_addbr: can't create group bridge4/bridge
------------[ cut here ]------------
sysfs group 'bridge' not found for k

net: bridge: Fix a warning when del bridge sysfs

I got a warining report:

br_sysfs_addbr: can't create group bridge4/bridge
------------[ cut here ]------------
sysfs group 'bridge' not found for kobject 'bridge4'
WARNING: CPU: 2 PID: 9004 at fs/sysfs/group.c:279 sysfs_remove_group fs/sysfs/group.c:279 [inline]
WARNING: CPU: 2 PID: 9004 at fs/sysfs/group.c:279 sysfs_remove_group+0x153/0x1b0 fs/sysfs/group.c:270
Modules linked in: iptable_nat
...
Call Trace:
br_dev_delete+0x112/0x190 net/bridge/br_if.c:384
br_dev_newlink net/bridge/br_netlink.c:1381 [inline]
br_dev_newlink+0xdb/0x100 net/bridge/br_netlink.c:1362
__rtnl_newlink+0xe11/0x13f0 net/core/rtnetlink.c:3441
rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3500
rtnetlink_rcv_msg+0x385/0x980 net/core/rtnetlink.c:5562
netlink_rcv_skb+0x134/0x3d0 net/netlink/af_netlink.c:2494
netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
netlink_unicast+0x4a0/0x6a0 net/netlink/af_netlink.c:1330
netlink_sendmsg+0x793/0xc80 net/netlink/af_netlink.c:1919
sock_sendmsg_nosec net/socket.c:651 [inline]
sock_sendmsg+0x139/0x170 net/socket.c:671
____sys_sendmsg+0x658/0x7d0 net/socket.c:2353
___sys_sendmsg+0xf8/0x170 net/socket.c:2407
__sys_sendmsg+0xd3/0x190 net/socket.c:2440
do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9

In br_device_event(), if the bridge sysfs fails to be added,
br_device_event() should return error. This can prevent warining
when removing bridge sysfs that do not exist.

Fixes: bb900b27a2f4 ("bridge: allow creating bridge devices with netlink")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Tested-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Link: https://lore.kernel.org/r/20201211122921.40386-1-wanghai38@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

show more ...

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

[ Upstream commit 45a687879b31caae4032abd1c2402e289d2b8083 ]

Ignore fdb flags when adding port extern learn entries and always set

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

[ Upstream commit 45a687879b31caae4032abd1c2402e289d2b8083 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

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

[ Upstream commit 0541a6293298fb52789de389dfb27ef54df81f73 ]

Currently it is possible to add broken extern_learn FD

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

[ Upstream commit 0541a6293298fb52789de389dfb27ef54df81f73 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

net: bridge: Fix a warning when del bridge sysfs

[ Upstream commit 989a1db06eb18ff605377eec87e18d795e0ec74b ]

I got a warining report:

br_sysfs_addbr: can't create group bridge4/bridge
-----------

net: bridge: Fix a warning when del bridge sysfs

[ Upstream commit 989a1db06eb18ff605377eec87e18d795e0ec74b ]

I got a warining report:

br_sysfs_addbr: can't create group bridge4/bridge
------------[ cut here ]------------
sysfs group 'bridge' not found for kobject 'bridge4'
WARNING: CPU: 2 PID: 9004 at fs/sysfs/group.c:279 sysfs_remove_group fs/sysfs/group.c:279 [inline]
WARNING: CPU: 2 PID: 9004 at fs/sysfs/group.c:279 sysfs_remove_group+0x153/0x1b0 fs/sysfs/group.c:270
Modules linked in: iptable_nat
...
Call Trace:
br_dev_delete+0x112/0x190 net/bridge/br_if.c:384
br_dev_newlink net/bridge/br_netlink.c:1381 [inline]
br_dev_newlink+0xdb/0x100 net/bridge/br_netlink.c:1362
__rtnl_newlink+0xe11/0x13f0 net/core/rtnetlink.c:3441
rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3500
rtnetlink_rcv_msg+0x385/0x980 net/core/rtnetlink.c:5562
netlink_rcv_skb+0x134/0x3d0 net/netlink/af_netlink.c:2494
netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
netlink_unicast+0x4a0/0x6a0 net/netlink/af_netlink.c:1330
netlink_sendmsg+0x793/0xc80 net/netlink/af_netlink.c:1919
sock_sendmsg_nosec net/socket.c:651 [inline]
sock_sendmsg+0x139/0x170 net/socket.c:671
____sys_sendmsg+0x658/0x7d0 net/socket.c:2353
___sys_sendmsg+0xf8/0x170 net/socket.c:2407
__sys_sendmsg+0xd3/0x190 net/socket.c:2440
do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9

In br_device_event(), if the bridge sysfs fails to be added,
br_device_event() should return error. This can prevent warining
when removing bridge sysfs that do not exist.

Fixes: bb900b27a2f4 ("bridge: allow creating bridge devices with netlink")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Tested-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Link: https://lore.kernel.org/r/20201211122921.40386-1-wanghai38@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

bridge: Add SWITCHDEV_FDB_FLUSH_TO_BRIDGE notifier

so the switchdev can notifiy the bridge to flush non-permanent fdb entries
for this port. This is useful whenever the hardware fdb of the switchdev

bridge: Add SWITCHDEV_FDB_FLUSH_TO_BRIDGE notifier

so the switchdev can notifiy the bridge to flush non-permanent fdb entries
for this port. This is useful whenever the hardware fdb of the switchdev
is reset, but the netdev and the bridgeport are not deleted.

Note that this has the same effect as the IFLA_BRPORT_FLUSH attribute.

CC: Jiri Pirko <jiri@resnulli.us>
CC: Ivan Vecera <ivecera@redhat.com>
CC: Roopa Prabhu <roopa@nvidia.com>
CC: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Acked-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

treewide: Use sizeof_field() macro

Replace all the occurrences of FIELD_SIZEOF() with sizeof_field() except
at places where these are defined. Later patches will remove the unused
definition of FIEL

treewide: Use sizeof_field() macro

Replace all the occurrences of FIELD_SIZEOF() with sizeof_field() except
at places where these are defined. Later patches will remove the unused
definition of FIELD_SIZEOF().

This patch is generated using following script:

EXCLUDE_FILES="include/linux/stddef.h|include/linux/kernel.h"

git grep -l -e "\bFIELD_SIZEOF\b" | while read file;
do

if [[ "$file" =~ $EXCLUDE_FILES ]]; then
continue
fi
sed -i -e 's/\bFIELD_SIZEOF\b/sizeof_field/g' $file;
done

Signed-off-by: Pankaj Bharadiya <pankaj.laxminarayan.bharadiya@intel.com>
Link: https://lore.kernel.org/r/20190924105839.110713-3-pankaj.laxminarayan.bharadiya@intel.com
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: David Miller <davem@davemloft.net> # for net

show more ...

net: bridge: move default pvid init/deinit to NETDEV_REGISTER/UNREGISTER

Most of the bridge device's vlan init bugs come from the fact that its
default pvid is created at the wrong time, way too ear

net: bridge: move default pvid init/deinit to NETDEV_REGISTER/UNREGISTER

Most of the bridge device's vlan init bugs come from the fact that its
default pvid is created at the wrong time, way too early in ndo_init()
before the device is even assigned an ifindex. It introduces a bug when the
bridge's dev_addr is added as fdb during the initial default pvid creation
the notification has ifindex/NDA_MASTER both equal to 0 (see example below)
which really makes no sense for user-space[0] and is wrong.
Usually user-space software would ignore such entries, but they are
actually valid and will eventually have all necessary attributes.
It makes much more sense to send a notification *after* the device has
registered and has a proper ifindex allocated rather than before when
there's a chance that the registration might still fail or to receive
it with ifindex/NDA_MASTER == 0. Note that we can remove the fdb flush
from br_vlan_flush() since that case can no longer happen. At
NETDEV_REGISTER br->default_pvid is always == 1 as it's initialized by
br_vlan_init() before that and at NETDEV_UNREGISTER it can be anything
depending why it was called (if called due to NETDEV_REGISTER error
it'll still be == 1, otherwise it could be any value changed during the
device life time).

For the demonstration below a small change to iproute2 for printing all fdb
notifications is added, because it contained a workaround not to show
entries with ifindex == 0.
Command executed while monitoring: $ ip l add br0 type bridge
Before (both ifindex and master == 0):
$ bridge monitor fdb
36:7e:8a:b3:56:ba dev * vlan 1 master * permanent

After (proper br0 ifindex):
$ bridge monitor fdb
e6:2a:ae:7a:b7:48 dev br0 vlan 1 master br0 permanent

v4: move only the default pvid init/deinit to NETDEV_REGISTER/UNREGISTER
v3: send the correct v2 patch with all changes (stub should return 0)
v2: on error in br_vlan_init set br->vlgrp to NULL and return 0 in
the br_vlan_bridge_event stub when bridge vlans are disabled

[0] https://bugzilla.kernel.org/show_bug.cgi?id=204389

Reported-by: michael-dev <michael-dev@fami-braun.de>
Fixes: 5be5a2df40f0 ("bridge: Add filtering support for default_pvid")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of th

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

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>

show more ...

bridge: Fix possible use-after-free when deleting bridge port

When a bridge port is being deleted, do not dereference it later in
br_vlan_port_event() as it can result in a use-after-free [1] if the

bridge: Fix possible use-after-free when deleting bridge port

When a bridge port is being deleted, do not dereference it later in
br_vlan_port_event() as it can result in a use-after-free [1] if the RCU
callback was executed before invoking the function.

[1]
[ 129.638551] ==================================================================
[ 129.646904] BUG: KASAN: use-after-free in br_vlan_port_event+0x53c/0x5fd
[ 129.654406] Read of size 8 at addr ffff8881e4aa1ae8 by task ip/483
[ 129.663008] CPU: 0 PID: 483 Comm: ip Not tainted 5.1.0-rc5-custom-02265-ga946bd73daac #1383
[ 129.672359] Hardware name: Mellanox Technologies Ltd. MSN2100-CB2FO/SA001017, BIOS 5.6.5 06/07/2016
[ 129.682484] Call Trace:
[ 129.685242] dump_stack+0xa9/0x10e
[ 129.689068] print_address_description.cold.2+0x9/0x25e
[ 129.694930] kasan_report.cold.3+0x78/0x9d
[ 129.704420] br_vlan_port_event+0x53c/0x5fd
[ 129.728300] br_device_event+0x2c7/0x7a0
[ 129.741505] notifier_call_chain+0xb5/0x1c0
[ 129.746202] rollback_registered_many+0x895/0xe90
[ 129.793119] unregister_netdevice_many+0x48/0x210
[ 129.803384] rtnl_delete_link+0xe1/0x140
[ 129.815906] rtnl_dellink+0x2a3/0x820
[ 129.844166] rtnetlink_rcv_msg+0x397/0x910
[ 129.868517] netlink_rcv_skb+0x137/0x3a0
[ 129.882013] netlink_unicast+0x49b/0x660
[ 129.900019] netlink_sendmsg+0x755/0xc90
[ 129.915758] ___sys_sendmsg+0x761/0x8e0
[ 129.966315] __sys_sendmsg+0xf0/0x1c0
[ 129.988918] do_syscall_64+0xa4/0x470
[ 129.993032] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 129.998696] RIP: 0033:0x7ff578104b58
...
[ 130.073811] Allocated by task 479:
[ 130.077633] __kasan_kmalloc.constprop.5+0xc1/0xd0
[ 130.083008] kmem_cache_alloc_trace+0x152/0x320
[ 130.088090] br_add_if+0x39c/0x1580
[ 130.092005] do_set_master+0x1aa/0x210
[ 130.096211] do_setlink+0x985/0x3100
[ 130.100224] __rtnl_newlink+0xc52/0x1380
[ 130.104625] rtnl_newlink+0x6b/0xa0
[ 130.108541] rtnetlink_rcv_msg+0x397/0x910
[ 130.113136] netlink_rcv_skb+0x137/0x3a0
[ 130.117538] netlink_unicast+0x49b/0x660
[ 130.121939] netlink_sendmsg+0x755/0xc90
[ 130.126340] ___sys_sendmsg+0x761/0x8e0
[ 130.130645] __sys_sendmsg+0xf0/0x1c0
[ 130.134753] do_syscall_64+0xa4/0x470
[ 130.138864] entry_SYSCALL_64_after_hwframe+0x49/0xbe

[ 130.146195] Freed by task 0:
[ 130.149421] __kasan_slab_free+0x125/0x170
[ 130.154016] kfree+0xf3/0x310
[ 130.157349] kobject_put+0x1a8/0x4c0
[ 130.161363] rcu_core+0x859/0x19b0
[ 130.165175] __do_softirq+0x250/0xa26
[ 130.170956] The buggy address belongs to the object at ffff8881e4aa1ae8
which belongs to the cache kmalloc-1k of size 1024
[ 130.184972] The buggy address is located 0 bytes inside of
1024-byte region [ffff8881e4aa1ae8, ffff8881e4aa1ee8)

Fixes: 9c0ec2e7182a ("bridge: support binding vlan dev link state to vlan member bridge ports")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Cc: Mike Manning <mmanning@vyatta.att-mail.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Acked-by: Mike Manning <mmanning@vyatta.att-mail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

bridge: support binding vlan dev link state to vlan member bridge ports

In the case of vlan filtering on bridges, the bridge may also have the
corresponding vlan devices as upper devices. A vlan bri

bridge: support binding vlan dev link state to vlan member bridge ports

In the case of vlan filtering on bridges, the bridge may also have the
corresponding vlan devices as upper devices. A vlan bridge binding mode
is added to allow the link state of the vlan device to track only the
state of the subset of bridge ports that are also members of the vlan,
rather than that of all bridge ports. This mode is set with a vlan flag
rather than a bridge sysfs so that the 8021q module is aware that it
should not set the link state for the vlan device.

If bridge vlan is configured, the bridge device event handling results
in the link state for an upper device being set, if it is a vlan device
with the vlan bridge binding mode enabled. This also sets a
vlan_bridge_binding flag so that subsequent UP/DOWN/CHANGE events for
the ports in that bridge result in a link state update of the vlan
device if required.

The link state of the vlan device is up if there is at least one bridge
port that is a vlan member that is admin & oper up, otherwise its oper
state is IF_OPER_LOWERLAYERDOWN.

Signed-off-by: Mike Manning <mmanning@vyatta.att-mail.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: bridge: Handle NETDEV_PRE_CHANGEADDR from ports

When a port device seeks approval of a potential new MAC address, make
sure that should the bridge device end up using this address, all
interest

net: bridge: Handle NETDEV_PRE_CHANGEADDR from ports

When a port device seeks approval of a potential new MAC address, make
sure that should the bridge device end up using this address, all
interested parties would agree with it.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net: bridge: export supported boolopts

Now that we have at least one bool option, we can export all of the
supported bool options via optmask when dumping them.

v2: new patch

Signed-off-by: Nikola

net: bridge: export supported boolopts

Now that we have at least one bool option, we can export all of the
supported bool options via optmask when dumping them.

v2: new patch

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net: bridge: add no_linklocal_learn bool option

Use the new boolopt API to add an option which disables learning from
link-local packets. The default is kept as before and learning is
enabled. This

net: bridge: add no_linklocal_learn bool option

Use the new boolopt API to add an option which disables learning from
link-local packets. The default is kept as before and learning is
enabled. This is a simple map from a boolopt bit to a bridge private
flag that is tested before learning.

v2: pass NULL for extack via sysfs

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...