Commit Graph

2370 Commits

Author SHA1 Message Date
Tobias Waldekranz
f54fd0e163 net: bridge: mst: Add helper to query a port's MST state
This is useful for switchdev drivers who are offloading MST states
into hardware. As an example, a driver may wish to flush the FDB for a
port when it transitions from forwarding to blocking - which means
that the previous state must be discoverable.

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-17 16:49:58 -07:00
Tobias Waldekranz
48d57b2e5f net: bridge: mst: Add helper to check if MST is enabled
This is useful for switchdev drivers that might want to refuse to join
a bridge where MST is enabled, if the hardware can't support it.

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-17 16:49:58 -07:00
Tobias Waldekranz
cceac97afa net: bridge: mst: Add helper to map an MSTI to a VID set
br_mst_get_info answers the question: "On this bridge, which VIDs are
mapped to the given MSTI?"

This is useful in switchdev drivers, which might have to fan-out
operations, relating to an MSTI, per VLAN.

An example: When a port's MST state changes from forwarding to
blocking, a driver may choose to flush the dynamic FDB entries on that
port to get faster reconvergence of the network, but this should only
be done in the VLANs that are managed by the MSTI in question.

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-17 16:49:58 -07:00
Tobias Waldekranz
7ae9147f43 net: bridge: mst: Notify switchdev drivers of MST state changes
Generate a switchdev notification whenever an MST state changes. This
notification is keyed by the VLANs MSTI rather than the VID, since
multiple VLANs may share the same MST instance.

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-17 16:49:58 -07:00
Tobias Waldekranz
6284c723d9 net: bridge: mst: Notify switchdev drivers of VLAN MSTI migrations
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 <tobias@waldekranz.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-17 16:49:58 -07:00
Tobias Waldekranz
87c167bb94 net: bridge: mst: Notify switchdev drivers of MST mode changes
Trigger a switchdev event whenever the bridge's MST mode is
enabled/disabled. This allows constituent ports to either perform any
required hardware config, or refuse the change if it not supported.

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-17 16:49:57 -07:00
Tobias Waldekranz
122c29486e net: bridge: mst: Support setting and reporting MST port states
Make it possible to change the port state in a given MSTI by extending
the bridge port netlink interface (RTM_SETLINK on PF_BRIDGE).The
proposed iproute2 interface would be:

    bridge mst set dev <PORT> msti <MSTI> state <STATE>

Current states in all applicable MSTIs can also be dumped via a
corresponding RTM_GETLINK. The proposed iproute interface looks like
this:

$ bridge mst
port              msti
vb1               0
		    state forwarding
		  100
		    state disabled
vb2               0
		    state forwarding
		  100
		    state forwarding

The preexisting per-VLAN states are still valid in the MST
mode (although they are read-only), and can be queried as usual if one
is interested in knowing a particular VLAN's state without having to
care about the VID to MSTI mapping (in this example VLAN 20 and 30 are
bound to MSTI 100):

$ bridge -d vlan
port              vlan-id
vb1               10
		    state forwarding mcast_router 1
		  20
		    state disabled mcast_router 1
		  30
		    state disabled mcast_router 1
		  40
		    state forwarding mcast_router 1
vb2               10
		    state forwarding mcast_router 1
		  20
		    state forwarding mcast_router 1
		  30
		    state forwarding mcast_router 1
		  40
		    state forwarding mcast_router 1

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-17 16:49:57 -07:00
Tobias Waldekranz
8c678d6056 net: bridge: mst: Allow changing a VLAN's MSTI
Allow a VLAN to move out of the CST (MSTI 0), to an independent tree.

The user manages the VID to MSTI mappings via a global VLAN
setting. The proposed iproute2 interface would be:

    bridge vlan global set dev br0 vid <VID> msti <MSTI>

Changing the state in non-zero MSTIs is still not supported, but will
be addressed in upcoming changes.

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-17 16:49:57 -07:00
Tobias Waldekranz
ec7328b591 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>
2022-03-17 16:49:57 -07:00
Jakub Kicinski
abe2fec8ee Merge git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next
Pablo Neira Ayuso says:

====================
Netfilter updates for net-next

1) Revert CHECKSUM_UNNECESSARY for UDP packet from conntrack.

2) Reject unsupported families when creating tables, from Phil Sutter.

3) GRE support for the flowtable, from Toshiaki Makita.

4) Add GRE offload support for act_ct, also from Toshiaki.

5) Update mlx5 driver to support for GRE flowtable offload,
   from Toshiaki Makita.

6) Oneliner to clean up incorrect indentation in nf_conntrack_bridge,
   from Jiapeng Chong.

* git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next:
  netfilter: bridge: clean up some inconsistent indenting
  net/mlx5: Support GRE conntrack offload
  act_ct: Support GRE offload
  netfilter: flowtable: Support GRE
  netfilter: nf_tables: Reject tables of unsupported family
  Revert "netfilter: conntrack: mark UDP zero checksum as CHECKSUM_UNNECESSARY"
====================

Link: https://lore.kernel.org/r/20220315091513.66544-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-15 11:52:25 -07:00
Jiapeng Chong
334ff12284 netfilter: bridge: clean up some inconsistent indenting
Eliminate the follow smatch warning:

net/bridge/netfilter/nf_conntrack_bridge.c:385 nf_ct_bridge_confirm()
warn: inconsistent indenting.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
2022-03-07 12:42:37 +01:00
Sebastian Andrzej Siewior
2e83bdd5d6 net: bridge: Use netif_rx().
Since commit
   baebdf48c3 ("net: dev: Makes sure netif_rx() can be invoked in any context.")

the function netif_rx() can be used in preemptible/thread context as
well as in interrupt context.

Use netif_rx().

Cc: Roopa Prabhu <roopa@nvidia.com>
Cc: Nikolay Aleksandrov <razor@blackwall.org>
Cc: bridge@lists.linux-foundation.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-04 12:02:19 +00:00
Martin KaFai Lau
de79910151 net: Add skb_clear_tstamp() to keep the mono delivery_time
Right now, skb->tstamp is reset to 0 whenever the skb is forwarded.

If skb->tstamp has the mono delivery_time, clearing it can hurt
the performance when it finally transmits out to fq@phy-dev.

The earlier patch added a skb->mono_delivery_time bit to
flag the skb->tstamp carrying the mono delivery_time.

This patch adds skb_clear_tstamp() helper which keeps
the mono delivery_time and clears everything else.

The delivery_time clearing will be postponed until the stack knows the
skb will be delivered locally.  It will be done in a latter patch.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-03 14:38:48 +00:00
Martin KaFai Lau
a1ac9c8ace net: Add skb->mono_delivery_time to distinguish mono delivery_time from (rcv) timestamp
skb->tstamp was first used as the (rcv) timestamp.
The major usage is to report it to the user (e.g. SO_TIMESTAMP).

Later, skb->tstamp is also set as the (future) delivery_time (e.g. EDT in TCP)
during egress and used by the qdisc (e.g. sch_fq) to make decision on when
the skb can be passed to the dev.

Currently, there is no way to tell skb->tstamp having the (rcv) timestamp
or the delivery_time, so it is always reset to 0 whenever forwarded
between egress and ingress.

While it makes sense to always clear the (rcv) timestamp in skb->tstamp
to avoid confusing sch_fq that expects the delivery_time, it is a
performance issue [0] to clear the delivery_time if the skb finally
egress to a fq@phy-dev.  For example, when forwarding from egress to
ingress and then finally back to egress:

            tcp-sender => veth@netns => veth@hostns => fq@eth0@hostns
                                     ^              ^
                                     reset          rest

This patch adds one bit skb->mono_delivery_time to flag the skb->tstamp
is storing the mono delivery_time (EDT) instead of the (rcv) timestamp.

The current use case is to keep the TCP mono delivery_time (EDT) and
to be used with sch_fq.  A latter patch will also allow tc-bpf@ingress
to read and change the mono delivery_time.

In the future, another bit (e.g. skb->user_delivery_time) can be added
for the SCM_TXTIME where the clock base is tracked by sk->sk_clockid.

[ This patch is a prep work.  The following patches will
  get the other parts of the stack ready first.  Then another patch
  after that will finally set the skb->mono_delivery_time. ]

skb_set_delivery_time() function is added.  It is used by the tcp_output.c
and during ip[6] fragmentation to assign the delivery_time to
the skb->tstamp and also set the skb->mono_delivery_time.

A note on the change in ip_send_unicast_reply() in ip_output.c.
It is only used by TCP to send reset/ack out of a ctl_sk.
Like the new skb_set_delivery_time(), this patch sets
the skb->mono_delivery_time to 0 for now as a place
holder.  It will be enabled in a latter patch.
A similar case in tcp_ipv6 can be done with
skb_set_delivery_time() in tcp_v6_send_response().

[0] (slide 22): https://linuxplumbersconf.org/event/11/contributions/953/attachments/867/1658/LPC_2021_BPF_Datapath_Extensions.pdf

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-03 14:38:48 +00:00
Hans Schultz
fa1c833429 net: bridge: Add support for offloading of locked port flag
Various switchcores support setting ports in locked mode, so that
clients behind locked ports cannot send traffic through the port
unless a fdb entry is added with the clients MAC address.

Signed-off-by: Hans Schultz <schultz.hans+netdev@gmail.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-23 12:52:34 +00:00
Hans Schultz
a21d9a670d net: bridge: Add support for bridge port in locked mode
In a 802.1X scenario, clients connected to a bridge port shall not
be allowed to have traffic forwarded until fully authenticated.
A static fdb entry of the clients MAC address for the bridge port
unlocks the client and allows bidirectional communication.

This scenario is facilitated with setting the bridge port in locked
mode, which is also supported by various switchcore chipsets.

Signed-off-by: Hans Schultz <schultz.hans+netdev@gmail.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-23 12:52:34 +00:00
Eric Dumazet
36a29fb6b2 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>
2022-02-19 16:20:12 +00:00
Jakub Kicinski
6b5567b1b2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
No conflicts.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-17 11:44:20 -08:00
Oleksandr Mazur
c832962ac9 net: bridge: multicast: notify switchdev driver whenever MC processing gets disabled
Whenever bridge driver hits the max capacity of MDBs, it disables
the MC processing (by setting corresponding bridge option), but never
notifies switchdev about such change (the notifiers are called only upon
explicit setting of this option, through the registered netlink interface).

This could lead to situation when Software MDB processing gets disabled,
but this event never gets offloaded to the underlying Hardware.

Fix this by adding a notify message in such case.

Fixes: 147c1e9b90 ("switchdev: bridge: Offload multicast disabled")
Signed-off-by: Oleksandr Mazur <oleksandr.mazur@plvision.eu>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Link: https://lore.kernel.org/r/20220215165303.31908-1-oleksandr.mazur@plvision.eu
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-16 20:35:00 -08:00
Vladimir Oltean
b28d580e29 net: bridge: switchdev: replay all VLAN groups
The major user of replayed switchdev objects is DSA, and so far it
hasn't needed information about anything other than bridge port VLANs,
so this is all that br_switchdev_vlan_replay() knows to handle.

DSA has managed to get by through replicating every VLAN addition on a
user port such that the same VLAN is also added on all DSA and CPU
ports, but there is a corner case where this does not work.

The mv88e6xxx DSA driver currently prints this error message as soon as
the first port of a switch joins a bridge:

mv88e6085 0x0000000008b96000:00: port 0 failed to add a6:ef:77:c8:5f:3d vid 1 to fdb: -95

where a6:ef:77:c8:5f:3d vid 1 is a local FDB entry corresponding to the
bridge MAC address in the default_pvid.

The -EOPNOTSUPP is returned by mv88e6xxx_port_db_load_purge() because it
tries to map VID 1 to a FID (the ATU is indexed by FID not VID), but
fails to do so. This is because ->port_fdb_add() is called before
->port_vlan_add() for VID 1.

The abridged timeline of the calls is:

br_add_if
-> netdev_master_upper_dev_link
   -> dsa_port_bridge_join
      -> switchdev_bridge_port_offload
         -> br_switchdev_vlan_replay (*)
         -> br_switchdev_fdb_replay
            -> mv88e6xxx_port_fdb_add
-> nbp_vlan_init
   -> nbp_vlan_add
      -> mv88e6xxx_port_vlan_add

and the issue is that at the time of (*), the bridge port isn't in VID 1
(nbp_vlan_init hasn't been called), therefore br_switchdev_vlan_replay()
won't have anything to replay, therefore VID 1 won't be in the VTU by
the time mv88e6xxx_port_fdb_add() is called.

This happens only when the first port of a switch joins. For further
ports, the initial mv88e6xxx_port_vlan_add() is sufficient for VID 1 to
be loaded in the VTU (which is switch-wide, not per port).

The problem is somewhat unique to mv88e6xxx by chance, because most
other drivers offload an FDB entry by VID, so FDBs and VLANs can be
added asynchronously with respect to each other, but addressing the
issue at the bridge layer makes sense, since what mv88e6xxx requires
isn't absurd.

To fix this problem, we need to recognize that it isn't the VLAN group
of the port that we're interested in, but the VLAN group of the bridge
itself (so it isn't a timing issue, but rather insufficient information
being passed from switchdev to drivers).

As mentioned, currently nbp_switchdev_sync_objs() only calls
br_switchdev_vlan_replay() for VLANs corresponding to the port, but the
VLANs corresponding to the bridge itself, for local termination, also
need to be replayed. In this case, VID 1 is not (yet) present in the
port's VLAN group but is present in the bridge's VLAN group.

So to fix this bug, DSA is now obligated to explicitly handle VLANs
pointing towards the bridge in order to "close this race" (which isn't
really a race). As Tobias Waldekranz notices, this also implies that it
must explicitly handle port VLANs on foreign interfaces, something that
worked implicitly before:
https://patchwork.kernel.org/project/netdevbpf/patch/20220209213044.2353153-6-vladimir.oltean@nxp.com/#24735260

So in the end, br_switchdev_vlan_replay() must replay all VLANs from all
VLAN groups: all the ports, and the bridge itself.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-16 11:21:04 +00:00
Vladimir Oltean
263029ae31 net: bridge: make nbp_switchdev_unsync_objs() follow reverse order of sync()
There may be switchdev drivers that can add/remove a FDB or MDB entry
only as long as the VLAN it's in has been notified and offloaded first.
The nbp_switchdev_sync_objs() method satisfies this requirement on
addition, but nbp_switchdev_unsync_objs() first deletes VLANs, then
deletes MDBs and FDBs. Reverse the order of the function calls to cater
to this requirement.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-16 11:21:04 +00:00
Vladimir Oltean
8d23a54f5b net: bridge: switchdev: differentiate new VLANs from changed ones
br_switchdev_port_vlan_add() currently emits a SWITCHDEV_PORT_OBJ_ADD
event with a SWITCHDEV_OBJ_ID_PORT_VLAN for 2 distinct cases:

- a struct net_bridge_vlan got created
- an existing struct net_bridge_vlan was modified

This makes it impossible for switchdev drivers to properly balance
PORT_OBJ_ADD with PORT_OBJ_DEL events, so if we want to allow that to
happen, we must provide a way for drivers to distinguish between a
VLAN with changed flags and a new one.

Annotate struct switchdev_obj_port_vlan with a "bool changed" that
distinguishes the 2 cases above.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-16 11:21:04 +00:00
Vladimir Oltean
27c5f74c7b net: bridge: vlan: notify switchdev only when something changed
Currently, when a VLAN entry is added multiple times in a row to a
bridge port, nbp_vlan_add() calls br_switchdev_port_vlan_add() each
time, even if the VLAN already exists and nothing about it has changed:

bridge vlan add dev lan12 vid 100 master static

Similarly, when a VLAN is added multiple times in a row to a bridge,
br_vlan_add_existing() doesn't filter at all the calls to
br_switchdev_port_vlan_add():

bridge vlan add dev br0 vid 100 self

This behavior makes driver-level accounting of VLANs impossible, since
it is enough for a single deletion event to remove a VLAN, but the
addition event can be emitted an unlimited number of times.

The cause for this can be identified as follows: we rely on
__vlan_add_flags() to retroactively tell us whether it has changed
anything about the VLAN flags or VLAN group pvid. So we'd first have to
call __vlan_add_flags() before calling br_switchdev_port_vlan_add(), in
order to have access to the "bool *changed" information. But we don't
want to change the event ordering, because we'd have to revert the
struct net_bridge_vlan changes we've made if switchdev returns an error.

So to solve this, we need another function that tells us whether any
change is going to occur in the VLAN or VLAN group, _prior_ to calling
__vlan_add_flags().

Split __vlan_add_flags() into a precommit and a commit stage, and rename
it to __vlan_flags_update(). The precommit stage,
__vlan_flags_would_change(), will determine whether there is any reason
to notify switchdev due to a change of flags (note: the BRENTRY flag
transition from false to true is treated separately: as a new switchdev
entry, because we skipped notifying the master VLAN when it wasn't a
brentry yet, and therefore not as a change of flags).

With this lookahead/precommit function in place, we can avoid notifying
switchdev if nothing changed for the VLAN and VLAN group.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-16 11:21:04 +00:00
Vladimir Oltean
cab2cd7700 net: bridge: vlan: make __vlan_add_flags react only to PVID and UNTAGGED
Currently there is a very subtle aspect to the behavior of
__vlan_add_flags(): it changes the struct net_bridge_vlan flags and
pvid, yet it returns true ("changed") even if none of those changed,
just a transition of br_vlan_is_brentry(v) took place from false to
true.

This can be seen in br_vlan_add_existing(), however we do not actually
rely on this subtle behavior, since the "if" condition that checks that
the vlan wasn't a brentry before had a useless (until now) assignment:

	*changed = true;

Make things more obvious by actually making __vlan_add_flags() do what's
written on the box, and be more specific about what is actually written
on the box. This is needed because further transformations will be done
to __vlan_add_flags().

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>
2022-02-16 11:21:04 +00:00
Vladimir Oltean
3116ad0696 net: bridge: vlan: don't notify to switchdev master VLANs without BRENTRY flag
When a VLAN is added to a bridge port and it doesn't exist on the bridge
device yet, it gets created for the multicast context, but it is
'hidden', since it doesn't have the BRENTRY flag yet:

ip link add br0 type bridge && ip link set swp0 master br0
bridge vlan add dev swp0 vid 100 # the master VLAN 100 gets created
bridge vlan add dev br0 vid 100 self # that VLAN becomes brentry just now

All switchdev drivers ignore switchdev notifiers for VLAN entries which
have the BRENTRY unset, and for good reason: these are merely private
data structures used by the bridge driver. So we might just as well not
notify those at all.

Cleanup in the switchdev drivers that check for the BRENTRY flag is now
possible, and will be handled separately, since those checks just became
dead code.

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>
2022-02-16 11:21:04 +00:00
Vladimir Oltean
b2bc58d41f net: bridge: vlan: check early for lack of BRENTRY flag in br_vlan_add_existing
When a VLAN is added to a bridge port, a master VLAN gets created on the
bridge for context, but it doesn't have the BRENTRY flag.

Then, when the same VLAN is added to the bridge itself, that enters
through the br_vlan_add_existing() code path and gains the BRENTRY flag,
thus it becomes "existing".

It seems natural to check for this condition early, because the current
code flow is to notify switchdev of the addition of a VLAN that isn't a
brentry, just to delete it immediately afterwards.

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>
2022-02-16 11:21:04 +00:00
Vladimir Oltean
5454f5c28e net: bridge: vlan: check for errors from __vlan_del in __vlan_flush
If the following call path returns an error from switchdev:

nbp_vlan_flush
-> __vlan_del
   -> __vlan_vid_del
      -> br_switchdev_port_vlan_del
-> __vlan_group_free
   -> WARN_ON(!list_empty(&vg->vlan_list));

then the deletion of the net_bridge_vlan is silently halted, which will
trigger the WARN_ON from __vlan_group_free().

The WARN_ON is rather unhelpful, because nothing about the source of the
error is printed. Add a print to catch errors from __vlan_del.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-15 14:37:28 +00:00
Jakub Kicinski
33d12dc91b Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf
Pablo Neira Ayuso says:

====================
Netfilter fixes for net

1) Remove leftovers from flowtable modules, from Geert Uytterhoeven.

2) Missing refcount increment of conntrack template in nft_ct,
   from Florian Westphal.

3) Reduce nft_zone selftest time, also from Florian.

4) Add selftest to cover stateless NAT on fragments, from Florian Westphal.

5) Do not set net_device when for reject packets from the bridge path,
   from Phil Sutter.

6) Cancel register tracking info on nft_byteorder operations.

7) Extend nft_concat_range selftest to cover set reload with no elements,
   from Florian Westphal.

8) Remove useless update of pointer in chain blob builder, reported
   by kbuild test robot.

* git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf:
  netfilter: nf_tables: remove assignment with no effect in chain blob builder
  selftests: nft_concat_range: add test for reload with no element add/del
  netfilter: nft_byteorder: track register operations
  netfilter: nft_reject_bridge: Fix for missing reply from prerouting
  selftests: netfilter: check stateless nat udp checksum fixup
  selftests: netfilter: reduce zone stress test running time
  netfilter: nft_ct: fix use after free when attaching zone template
  netfilter: Remove flowtable relics
====================

Link: https://lore.kernel.org/r/20220127235235.656931-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-01-27 18:53:02 -08:00
Tim Yi
fd20d97383 net: bridge: vlan: fix memory leak in __allowed_ingress
When using per-vlan state, if vlan snooping and stats are disabled,
untagged or priority-tagged ingress frame will go to check pvid state.
If the port state is forwarding and the pvid state is not
learning/forwarding, untagged or priority-tagged frame will be dropped
but skb memory is not freed.
Should free skb when __allowed_ingress returns false.

Fixes: a580c76d53 ("net: bridge: vlan: add per-vlan state")
Signed-off-by: Tim Yi <tim.yi@pica8.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Link: https://lore.kernel.org/r/20220127074953.12632-1-tim.yi@pica8.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-01-27 09:01:25 -08:00
Nikolay Aleksandrov
dcb2c5c6ca net: bridge: vlan: fix single net device option dumping
When dumping vlan options for a single net device we send the same
entries infinitely because user-space expects a 0 return at the end but
we keep returning skb->len and restarting the dump on retry. Fix it by
returning the value from br_vlan_dump_dev() if it completed or there was
an error. The only case that must return skb->len is when the dump was
incomplete and needs to continue (-EMSGSIZE).

Reported-by: Benjamin Poirier <bpoirier@nvidia.com>
Fixes: 8dcea18708 ("net: bridge: vlan: add rtm definitions and dump support")
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-27 13:48:17 +00:00
Phil Sutter
aeac4554eb netfilter: nft_reject_bridge: Fix for missing reply from prerouting
Prior to commit fa538f7cf0 ("netfilter: nf_reject: add reject skbuff
creation helpers"), nft_reject_bridge did not assign to nskb->dev before
passing nskb on to br_forward(). The shared skbuff creation helpers
introduced in above commit do which seems to confuse br_forward() as
reject statements in prerouting hook won't emit a packet anymore.

Fix this by simply passing NULL instead of 'dev' to the helpers - they
use the pointer for just that assignment, nothing else.

Fixes: fa538f7cf0 ("netfilter: nf_reject: add reject skbuff creation helpers")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-01-27 00:06:52 +01:00
Eric Dumazet
fcfb894d59 net: bridge: fix net device refcount tracking issue in error path
I left one dev_put() in br_add_if() error path and sure enough
syzbot found its way.

As the tracker is allocated in new_nbp(), we must make sure
to properly free it.

We have to call dev_put_track(dev, &p->dev_tracker) before
@p object is freed, of course. This is not an issue because
br_add_if() owns a reference on @dev.

Fixes: b2dcdc7f73 ("net: bridge: add net device refcount tracker")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-12 14:44:18 +00:00
Jakub Kicinski
77bbcb60f7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next
Pablo Neira Ayuso says:

====================
Netfilter updates for net-next

The following patchset contains Netfilter updates for net-next. This
includes one patch to update ovs and act_ct to use nf_ct_put() instead
of nf_conntrack_put().

1) Add netns_tracker to nfnetlink_log and masquerade, from Eric Dumazet.

2) Remove redundant rcu read-size lock in nf_tables packet path.

3) Replace BUG() by WARN_ON_ONCE() in nft_payload.

4) Consolidate rule verdict tracing.

5) Replace WARN_ON() by WARN_ON_ONCE() in nf_tables core.

6) Make counter support built-in in nf_tables.

7) Add new field to conntrack object to identify locally generated
   traffic, from Florian Westphal.

8) Prevent NAT from shadowing well-known ports, from Florian Westphal.

9) Merge nf_flow_table_{ipv4,ipv6} into nf_flow_table_inet, also from
   Florian.

10) Remove redundant pointer in nft_pipapo AVX2 support, from Colin Ian King.

11) Replace opencoded max() in conntrack, from Jiapeng Chong.

12) Update conntrack to use refcount_t API, from Florian Westphal.

13) Move ip_ct_attach indirection into the nf_ct_hook structure.

14) Constify several pointer object in the netfilter codebase,
    from Florian Westphal.

15) Tree-wide replacement of nf_conntrack_put() by nf_ct_put(), also
    from Florian.

16) Fix egress splat due to incorrect rcu notation, from Florian.

17) Move stateful fields of connlimit, last, quota, numgen and limit
    out of the expression data area.

18) Build a blob to represent the ruleset in nf_tables, this is a
    requirement of the new register tracking infrastructure.

19) Add NFT_REG32_NUM to define the maximum number of 32-bit registers.

20) Add register tracking infrastructure to skip redundant
    store-to-register operations, this includes support for payload,
    meta and bitwise expresssions.

* git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next: (32 commits)
  netfilter: nft_meta: cancel register tracking after meta update
  netfilter: nft_payload: cancel register tracking after payload update
  netfilter: nft_bitwise: track register operations
  netfilter: nft_meta: track register operations
  netfilter: nft_payload: track register operations
  netfilter: nf_tables: add register tracking infrastructure
  netfilter: nf_tables: add NFT_REG32_NUM
  netfilter: nf_tables: add rule blob layout
  netfilter: nft_limit: move stateful fields out of expression data
  netfilter: nft_limit: rename stateful structure
  netfilter: nft_numgen: move stateful fields out of expression data
  netfilter: nft_quota: move stateful fields out of expression data
  netfilter: nft_last: move stateful fields out of expression data
  netfilter: nft_connlimit: move stateful fields out of expression data
  netfilter: egress: avoid a lockdep splat
  net: prefer nf_ct_put instead of nf_conntrack_put
  netfilter: conntrack: avoid useless indirection during conntrack destruction
  netfilter: make function op structures const
  netfilter: core: move ip_ct_attach indirection to struct nf_ct_hook
  netfilter: conntrack: convert to refcount_t api
  ...
====================

Link: https://lore.kernel.org/r/20220109231640.104123-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-01-09 15:59:23 -08:00
Pablo Neira Ayuso
4a80e02698 netfilter: nft_meta: cancel register tracking after meta update
The meta expression might mangle the packet metadata, cancel register
tracking since any metadata in the registers is stale.

Finer grain register tracking cancellation by inspecting the meta type
on the register is also possible.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-01-09 23:35:17 +01:00
David S. Miller
e63a023489 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
pull-request: bpf-next 2021-12-30

The following pull-request contains BPF updates for your *net-next* tree.

We've added 72 non-merge commits during the last 20 day(s) which contain
a total of 223 files changed, 3510 insertions(+), 1591 deletions(-).

The main changes are:

1) Automatic setrlimit in libbpf when bpf is memcg's in the kernel, from Andrii.

2) Beautify and de-verbose verifier logs, from Christy.

3) Composable verifier types, from Hao.

4) bpf_strncmp helper, from Hou.

5) bpf.h header dependency cleanup, from Jakub.

6) get_func_[arg|ret|arg_cnt] helpers, from Jiri.

7) Sleepable local storage, from KP.

8) Extend kfunc with PTR_TO_CTX, PTR_TO_MEM argument support, from Kumar.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-31 14:35:40 +00:00
Jakub Kicinski
aec53e60e0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
  commit 077cdda764 ("net/mlx5e: TC, Fix memory leak with rules with internal port")
  commit 31108d142f ("net/mlx5: Fix some error handling paths in 'mlx5e_tc_add_fdb_flow()'")
  commit 4390c6edc0 ("net/mlx5: Fix some error handling paths in 'mlx5e_tc_add_fdb_flow()'")
  https://lore.kernel.org/all/20211229065352.30178-1-saeed@kernel.org/

net/smc/smc_wr.c
  commit 49dc9013e3 ("net/smc: Use the bitmap API when applicable")
  commit 349d43127d ("net/smc: fix kernel panic caused by race of smc_sock")
  bitmap_zero()/memset() is removed by the fix

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-30 12:12:12 -08:00
Nikolay Aleksandrov
168fed986b net: bridge: mcast: fix br_multicast_ctx_vlan_global_disabled helper
We need to first check if the context is a vlan one, then we need to
check the global bridge multicast vlan snooping flag, and finally the
vlan's multicast flag, otherwise we will unnecessarily enable vlan mcast
processing (e.g. querier timers).

Fixes: 7b54aaaf53 ("net: bridge: multicast: add vlan state initialization and control")
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Link: https://lore.kernel.org/r/20211228153142.536969-1-nikolay@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-29 17:49:45 -08:00
Nikolay Aleksandrov
f83a112bd9 net: bridge: mcast: add and enforce startup query interval minimum
As reported[1] if startup query interval is set too low in combination with
large number of startup queries and we have multiple bridges or even a
single bridge with multiple querier vlans configured we can crash the
machine. Add a 1 second minimum which must be enforced by overwriting the
value if set lower (i.e. without returning an error) to avoid breaking
user-space. If that happens a log message is emitted to let the admin know
that the startup interval has been set to the minimum. It doesn't make
sense to make the startup interval lower than the normal query interval
so use the same value of 1 second. The issue has been present since these
intervals could be user-controlled.

[1] https://lore.kernel.org/netdev/e8b9ce41-57b9-b6e2-a46a-ff9c791cf0ba@gmail.com/

Fixes: d902eee43f ("bridge: Add multicast count/interval sysfs entries")
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-29 12:59:38 -08:00
Nikolay Aleksandrov
99b4061095 net: bridge: mcast: add and enforce query interval minimum
As reported[1] if query interval is set too low and we have multiple
bridges or even a single bridge with multiple querier vlans configured
we can crash the machine. Add a 1 second minimum which must be enforced
by overwriting the value if set lower (i.e. without returning an error) to
avoid breaking user-space. If that happens a log message is emitted to let
the administrator know that the interval has been set to the minimum.
The issue has been present since these intervals could be user-controlled.

[1] https://lore.kernel.org/netdev/e8b9ce41-57b9-b6e2-a46a-ff9c791cf0ba@gmail.com/

Fixes: d902eee43f ("bridge: Add multicast count/interval sysfs entries")
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-29 12:59:37 -08:00
Jakub Kicinski
b6459415b3 net: Don't include filter.h from net/sock.h
sock.h is pretty heavily used (5k objects rebuilt on x86 after
it's touched). We can drop the include of filter.h from it and
add a forward declaration of struct sk_filter instead.
This decreases the number of rebuilt objects when bpf.h
is touched from ~5k to ~1k.

There's a lot of missing includes this was masking. Primarily
in networking tho, this time.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Acked-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/bpf/20211229004913.513372-1-kuba@kernel.org
2021-12-29 08:48:14 -08:00
Remi Pommarel
fd3a459000 net: bridge: Get SIOCGIFBR/SIOCSIFBR ioctl working in compat mode
In compat mode SIOC{G,S}IFBR ioctls were only supporting
BRCTL_GET_VERSION returning an artificially version to spur userland
tool to use SIOCDEVPRIVATE instead. But some userland tools ignore that
and use SIOC{G,S}IFBR unconditionally as seen with busybox's brctl.

Example of non working 32-bit brctl with CONFIG_COMPAT=y:
$ brctl show
brctl: SIOCGIFBR: Invalid argument

Example of fixed 32-bit brctl with CONFIG_COMPAT=y:
$ brctl show
bridge name     bridge id               STP enabled     interfaces
br0

Signed-off-by: Remi Pommarel <repk@triplefau.lt>
Co-developed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-27 12:31:57 +00:00
Jakub Kicinski
8b3f913322 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
include/net/sock.h
  commit 8f905c0e73 ("inet: fully convert sk->sk_rx_dst to RCU rules")
  commit 43f51df417 ("net: move early demux fields close to sk_refcnt")
  https://lore.kernel.org/all/20211222141641.0caa0ab3@canb.auug.org.au/

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-23 16:09:58 -08:00
Remi Pommarel
d95a56207c net: bridge: fix ioctl old_deviceless bridge argument
Commit 561d835281 ("bridge: use ndo_siocdevprivate") changed the
source and destination arguments of copy_{to,from}_user in bridge's
old_deviceless() from args[1] to uarg breaking SIOC{G,S}IFBR ioctls.

Commit cbd7ad29a5 ("net: bridge: fix ioctl old_deviceless bridge
argument") fixed only BRCTL_{ADD,DEL}_BRIDGES commands leaving
BRCTL_GET_BRIDGES one untouched.

The fixes BRCTL_GET_BRIDGES as well and has been tested with busybox's
brctl.

Example of broken brctl:
$ brctl show
bridge name     bridge id               STP enabled     interfaces
brctl: can't get bridge name for index 0: No such device or address

Example of fixed brctl:
$ brctl show
bridge name     bridge id               STP enabled     interfaces
br0             8000.000000000000       no

Fixes: 561d835281 ("bridge: use ndo_siocdevprivate")
Signed-off-by: Remi Pommarel <repk@triplefau.lt>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Link: https://lore.kernel.org/all/20211223153139.7661-2-repk@triplefau.lt/
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-23 09:53:50 -08:00
Jakub Kicinski
bd1d97d861 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next
Pablo Neira Ayuso says:

====================
Netfilter updates for net-next

The following patchset contains Netfilter updates for net-next, mostly
rather small housekeeping patches:

1) Remove unused variable in IPVS, from GuoYong Zheng.

2) Use memset_after in conntrack, from Kees Cook.

3) Remove leftover function in nfnetlink_queue, from Florian Westphal.

4) Remove redundant test on bool in conntrack, from Bernard Zhao.

5) egress support for nft_fwd, from Lukas Wunner.

6) Make pppoe work for br_netfilter, from Florian Westphal.

7) Remove unused variable in conntrack resize routine, from luo penghao.

* git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next:
  netfilter: conntrack: Remove useless assignment statements
  netfilter: bridge: add support for pppoe filtering
  netfilter: nft_fwd_netdev: Support egress hook
  netfilter: ctnetlink: remove useless type conversion to bool
  netfilter: nf_queue: remove leftover synchronize_rcu
  netfilter: conntrack: Use memset_startat() to zero struct nf_conn
  ipvs: remove unused variable for ip_vs_new_dest
====================

Link: https://lore.kernel.org/r/20211215234911.170741-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-15 17:29:28 -08:00
Eric Dumazet
b2dcdc7f73 net: bridge: add net device refcount tracker
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-07 20:44:58 -08:00
Florian Westphal
28b78ecffe netfilter: bridge: add support for pppoe filtering
This makes 'bridge-nf-filter-pppoe-tagged' sysctl work for
bridged traffic.

Looking at the original commit it doesn't appear this ever worked:

 static unsigned int br_nf_post_routing(unsigned int hook, struct sk_buff **pskb,
[..]
        if (skb->protocol == htons(ETH_P_8021Q)) {
                skb_pull(skb, VLAN_HLEN);
                skb->network_header += VLAN_HLEN;
+       } else if (skb->protocol == htons(ETH_P_PPP_SES)) {
+               skb_pull(skb, PPPOE_SES_HLEN);
+               skb->network_header += PPPOE_SES_HLEN;
        }
 [..]
	NF_HOOK(... POST_ROUTING, ...)

... but the adjusted offsets are never restored.

The alternative would be to rip this code out for good,
but otoh we'd have to keep this anyway for the vlan handling
(which works because vlan tag info is in the skb, not the packet
 payload).

Reported-and-tested-by: Amish Chana <amish@3g.co.za>
Fixes: 516299d2f5 ("[NETFILTER]: bridge-nf: filter bridged IPv4/IPv6 encapsulated in pppoe traffic")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-11-30 23:37:55 +01:00
Xin Long
442b03c32c bridge: use __set_bit in __br_vlan_set_default_pvid
The same optimization as the one in commit cc0be1ad68 ("net:
bridge: Slightly optimize 'find_portno()'") is needed for the
'changed' bitmap in __br_vlan_set_default_pvid().

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Link: https://lore.kernel.org/r/4e35f415226765e79c2a11d2c96fbf3061c486e2.1637782773.git.lucien.xin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-11-26 16:47:56 -08:00
Ido Schimmel
5a45ab3f24 net: bridge: Allow base 16 inputs in sysfs
Cited commit converted simple_strtoul() to kstrtoul() as suggested by
the former's documentation. However, it also forced all the inputs to be
decimal resulting in user space breakage.

Fix by setting the base to '0' so that the base is automatically
detected.

Before:

 # ip link add name br0 type bridge vlan_filtering 1
 # echo "0x88a8" > /sys/class/net/br0/bridge/vlan_protocol
 bash: echo: write error: Invalid argument

After:

 # ip link add name br0 type bridge vlan_filtering 1
 # echo "0x88a8" > /sys/class/net/br0/bridge/vlan_protocol
 # echo $?
 0

Fixes: 520fbdf7fb ("net/bridge: replace simple_strtoul to kstrtol")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Link: https://lore.kernel.org/r/20211124101122.3321496-1-idosch@idosch.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-11-24 17:23:52 -08:00
Eric Dumazet
6d872df3e3 net: annotate accesses to dev->gso_max_segs
dev->gso_max_segs is written under RTNL protection, or when the device is
not yet visible, but is read locklessly.

Add netif_set_gso_max_segs() helper.

Add the READ_ONCE()/WRITE_ONCE() pairs, and use netif_set_gso_max_segs()
where we can to better document what is going on.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-11-22 12:49:42 +00:00
Eric Dumazet
4b66d2161b net: annotate accesses to dev->gso_max_size
dev->gso_max_size is written under RTNL protection, or when the device is
not yet visible, but is read locklessly.

Add the READ_ONCE()/WRITE_ONCE() pairs, and use netif_set_gso_max_size()
where we can to better document what is going on.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-11-22 12:49:42 +00:00