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  1. Mar 14, 2022
    • Vladimir Oltean's avatar
      net: dsa: report and change port default priority using dcbnl · d538eca8
      Vladimir Oltean authored 
      The port-based default QoS class is assigned to packets that lack a
VLAN PCP (or the port is configured to not trust the VLAN PCP),
an IP DSCP (or the port is configured to not trust IP DSCP), and packets
on which no tc-skbedit action has matched.

Similar to other drivers, this can be exposed to user space using the
DCB Application Priority Table. IEEE 802.1Q-2018 specifies in Table
D-8 - Sel field values that when the Selector is 1, the Protocol ID
value of 0 denotes the "Default application priority. For use when
application priority is not otherwise specified."

The way in which the dcbnl integration in DSA has been designed has to
do with its requirements. Andrew Lunn explains that SOHO switches are
expected to come with some sort of pre-configured QoS profile, and that
it is desirable for this to come pre-loaded into the DSA slave interfaces'
DCB application priority table.

In the dcbnl design, this is possible because calls to dcb_ieee_setapp()
can be initiated by anyone including being self-initiated by this device
driver.

However, what makes this challenging to implement in DSA is that the DSA
core manages the net_devices (effectively hiding them from drivers),
while drivers manage the hardware. The DSA core has no knowledge of what
individual drivers' QoS policies are. DSA could export to drivers a
wrapper over dcb_ieee_setapp() and these could call that function to
pre-populate the app priority table, however drivers don't have a good
moment in time to do this. The dsa_switch_ops :: setup() method gets
called before the net_devices are created (dsa_slave_create), and so is
dsa_switch_ops :: port_setup(). What remains is dsa_switch_ops ::
port_enable(), but this gets called upon each ndo_open. If we add app
table entries on every open, we'd need to remove them on close, to avoid
duplicate entry errors. But if we delete app priority entries on close,
what we delete may not be the initial, driver pre-populated entries, but
rather user-added entries.

So it is clear that letting drivers choose the timing of the
dcb_ieee_setapp() call is inappropriate. The alternative which was
chosen is to introduce hardware-specific ops in dsa_switch_ops, and
effectively hide dcbnl details from drivers as well. For pre-populating
the application table, dsa_slave_dcbnl_init() will call
ds->ops->port_get_default_prio() which is supposed to read from
hardware. If the operation succeeds, DSA creates a default-prio app
table entry. The method is called as soon as the slave_dev is
registered, but before we release the rtnl_mutex. This is done such that
user space sees the app table entries as soon as it sees the interface
being registered.

The fact that we populate slave_dev->dcbnl_ops with a non-NULL pointer
changes behavior in dcb_doit() from net/dcb/dcbnl.c, which used to
return -EOPNOTSUPP for any dcbnl operation where netdev->dcbnl_ops is
NULL. Because there are still dcbnl-unaware DSA drivers even if they
have dcbnl_ops populated, the way to restore the behavior is to make all
dcbnl_ops return -EOPNOTSUPP on absence of the hardware-specific
dsa_switch_ops method.

The dcbnl framework absurdly allows there to be more than one app table
entry for the same selector and protocol (in other words, more than one
port-based default priority). In the iproute2 dcb program, there is a
"replace" syntactical sugar command which performs an "add" and a "del"
to hide this away. But we choose the largest configured priority when we
call ds->ops->port_set_default_prio(), using __fls(). When there is no
default-prio app table entry left, the port-default priority is restored
to 0.

Link: https://patchwork.kernel.org/project/netdevbpf/patch/20210113154139.1803705-2-olteanv@gmail.com/


Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      d538eca8
    • Victor Nogueira's avatar
      selftests: tc-testing: Increase timeout in tdc config file · 102e4a8e
      Victor Nogueira authored 
      

Some tests, such as Test d052: Add 1M filters with the same action, may
not work with a small timeout value.

Increase timeout to 24 seconds.

Signed-off-by: default avatarVictor Nogueira <victor@mojatatu.com>
Acked-by: default avatarDavide Caratti <dcaratti@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      102e4a8e
    • Sebastian Andrzej Siewior's avatar
      net: Add lockdep asserts to ____napi_schedule(). · fbd9a2ce
      Sebastian Andrzej Siewior authored 
      

____napi_schedule() needs to be invoked with disabled interrupts due to
__raise_softirq_irqoff (in order not to corrupt the per-CPU list).
____napi_schedule() needs also to be invoked from an interrupt context
so that the raised-softirq is processed while the interrupt context is
left.

Add lockdep asserts for both conditions.
While this is the second time the irq/softirq check is needed, provide a
generic lockdep_assert_softirq_will_run() which is used by both caller.

Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      fbd9a2ce
    • David S. Miller's avatar
      Merge branch 'macvlan-uaf' · d96657dc
      David S. Miller authored 
      

Ziyang Xuan says:

====================
net: macvlan: fix potential UAF problem for lowerdev

Add the reference operation to lowerdev of macvlan to avoid
the potential UAF problem under the following known scenario:

Someone module puts the NETDEV_UNREGISTER event handler to a
work, and lowerdev is accessed in the work handler. But when
the work is excuted, lowerdev has been destroyed because upper
macvlan did not get reference to lowerdev correctly.

In addition, add net device refcount tracker to macvlan.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      d96657dc
    • Ziyang Xuan's avatar
      net: macvlan: add net device refcount tracker · 1f4a5983
      Ziyang Xuan authored 
      

Add net device refcount tracker to macvlan.

Signed-off-by: default avatarZiyang Xuan <william.xuanziyang@huawei.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      1f4a5983
    • Ziyang Xuan's avatar
      net: macvlan: fix potential UAF problem for lowerdev · 291ac684
      Ziyang Xuan authored 
      Add the reference operation to lowerdev of macvlan to avoid
the potential UAF problem under the following known scenario:

Someone module puts the NETDEV_UNREGISTER event handler to a
work, and lowerdev is accessed in the work handler. But when
the work is excuted, lowerdev has been destroyed because upper
macvlan did not get reference to lowerdev correctly.

That likes as the scenario occurred by
commit 563bcbae

 ("net: vlan: fix a UAF in vlan_dev_real_dev()").

Signed-off-by: default avatarZiyang Xuan <william.xuanziyang@huawei.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      291ac684
  3. Mar 13, 2022
  5. Mar 12, 2022