linux-stable.git/drivers/net/veth.c, branch linux-3.16.y

veth: don’t modify ip_summed; doing so treats packets with bad checksums as good.

2016-01-28T10:10:59+00:00

commit ce8c839b74e3017996fad4e1b7ba2e2625ede82f upstream.

Packets that arrive from real hardware devices have ip_summed ==
CHECKSUM_UNNECESSARY if the hardware verified the checksums, or
CHECKSUM_NONE if the packet is bad or it was unable to verify it. The
current version of veth will replace CHECKSUM_NONE with
CHECKSUM_UNNECESSARY, which causes corrupt packets routed from hardware to
a veth device to be delivered to the application. This caused applications
at Twitter to receive corrupt data when network hardware was corrupting
packets.

We believe this was added as an optimization to skip computing and
verifying checksums for communication between containers. However, locally
generated packets have ip_summed == CHECKSUM_PARTIAL, so the code as
written does nothing for them. As far as we can tell, after removing this
code, these packets are transmitted from one stack to another unmodified
(tcpdump shows invalid checksums on both sides, as expected), and they are
delivered correctly to applications. We didn’t test every possible network
configuration, but we tried a few common ones such as bridging containers,
using NAT between the host and a container, and routing from hardware
devices to containers. We have effectively deployed this in production at
Twitter (by disabling RX checksum offloading on veth devices).

This code dates back to the first version of the driver, commit
 ("[NET]: Virtual ethernet device driver"), so I
suspect this bug occurred mostly because the driver API has evolved
significantly since then. Commit <0b7967503dc97864f283a> ("net/veth: Fix
packet checksumming") (in December 2010) fixed this for packets that get
created locally and sent to hardware devices, by not changing
CHECKSUM_PARTIAL. However, the same issue still occurs for packets coming
in from hardware devices.

Co-authored-by: Evan Jones 
Signed-off-by: Evan Jones 
Cc: Nicolas Dichtel 
Cc: Phil Sutter 
Cc: Toshiaki Makita 
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Vijay Pandurangan 
Acked-by: Cong Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Luis Henriques

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

2014-03-29T22:48:54+00:00

Conflicts:
	drivers/net/ethernet/marvell/mvneta.c

The mvneta.c conflict is a case of overlapping changes,
a conversion to devm_ioremap_resource() vs. a conversion
to netdev_alloc_pcpu_stats.

Signed-off-by: David S. Miller

veth: Turn off vlan rx acceleration in vlan_features

2014-03-28T21:16:51+00:00

For completeness, turn off vlan rx acceleration in vlan_features so
that it doesn't show up on q-in-q setups.

Signed-off-by: Vlad Yasevich 
Signed-off-by: David S. Miller

net: Replace u64_stats_fetch_begin_bh to u64_stats_fetch_begin_irq

2014-03-15T02:41:36+00:00

Replace the bh safe variant with the hard irq safe variant.

We need a hard irq safe variant to deal with netpoll transmitting
packets from hard irq context, and we need it in most if not all of
the places using the bh safe variant.

Except on 32bit uni-processor the code is exactly the same so don't
bother with a bh variant, just have a hard irq safe variant that
everyone can use.

Signed-off-by: "Eric W. Biederman" 
Signed-off-by: David S. Miller

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

2014-03-06T01:32:02+00:00

Conflicts:
	drivers/net/wireless/ath/ath9k/recv.c
	drivers/net/wireless/mwifiex/pcie.c
	net/ipv6/sit.c

The SIT driver conflict consists of a bug fix being done by hand
in 'net' (missing u64_stats_init()) whilst in 'net-next' a helper
was created (netdev_alloc_pcpu_stats()) which takes care of this.

The two wireless conflicts were overlapping changes.

Signed-off-by: David S. Miller

veth: Fix vlan_features so as to be able to use stacked vlan interfaces

2014-02-20T07:15:38+00:00

Even if we create a stacked vlan interface such as veth0.10.20, it sends
single tagged frames (tagged with only vid 10).
Because vlan_features of a veth interface has the
NETIF_F_HW_VLAN_[CTAG/STAG]_TX bits, veth0.10 also has that feature, so
dev_hard_start_xmit(veth0.10) doesn't call __vlan_put_tag() and
vlan_dev_hard_start_xmit(veth0.10) overwrites vlan_tci.
This prevents us from using a combination of 802.1ad and 802.1Q
in containers, etc.

Signed-off-by: Toshiaki Makita 
Acked-by: Flavio Leitner 
Signed-off-by: David S. Miller

rtnl: make ifla_policy static

2014-02-18T23:15:42+00:00

The only place this is used outside rtnetlink.c is veth. So provide
wrapper function for this usage.

Signed-off-by: Jiri Pirko 
Signed-off-by: David S. Miller

net: introduce netdev_alloc_pcpu_stats() for drivers

2014-02-14T20:49:55+00:00

There are many drivers calling alloc_percpu() to allocate pcpu stats
and then initializing ->syncp. So just introduce a helper function for them.

Cc: David S. Miller 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller

Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2013-11-14T07:30:30+00:00

Pull core locking changes from Ingo Molnar:
 "The biggest changes:

   - add lockdep support for seqcount/seqlocks structures, this
     unearthed both bugs and required extra annotation.

   - move the various kernel locking primitives to the new
     kernel/locking/ directory"

* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
  block: Use u64_stats_init() to initialize seqcounts
  locking/lockdep: Mark __lockdep_count_forward_deps() as static
  lockdep/proc: Fix lock-time avg computation
  locking/doc: Update references to kernel/mutex.c
  ipv6: Fix possible ipv6 seqlock deadlock
  cpuset: Fix potential deadlock w/ set_mems_allowed
  seqcount: Add lockdep functionality to seqcount/seqlock structures
  net: Explicitly initialize u64_stats_sync structures for lockdep
  locking: Move the percpu-rwsem code to kernel/locking/
  locking: Move the lglocks code to kernel/locking/
  locking: Move the rwsem code to kernel/locking/
  locking: Move the rtmutex code to kernel/locking/
  locking: Move the semaphore core to kernel/locking/
  locking: Move the spinlock code to kernel/locking/
  locking: Move the lockdep code to kernel/locking/
  locking: Move the mutex code to kernel/locking/
  hung_task debugging: Add tracepoint to report the hang
  x86/locking/kconfig: Update paravirt spinlock Kconfig description
  lockstat: Report avg wait and hold times
  lockdep, x86/alternatives: Drop ancient lockdep fixup message
  ...

net: Explicitly initialize u64_stats_sync structures for lockdep

2013-11-06T11:40:25+00:00

In order to enable lockdep on seqcount/seqlock structures, we
must explicitly initialize any locks.

The u64_stats_sync structure, uses a seqcount, and thus we need
to introduce a u64_stats_init() function and use it to initialize
the structure.

This unfortunately adds a lot of fairly trivial initialization code
to a number of drivers. But the benefit of ensuring correctness makes
this worth while.

Because these changes are required for lockdep to be enabled, and the
changes are quite trivial, I've not yet split this patch out into 30-some
separate patches, as I figured it would be better to get the various
maintainers thoughts on how to best merge this change along with
the seqcount lockdep enablement.

Feedback would be appreciated!

Signed-off-by: John Stultz 
Acked-by: Julian Anastasov 
Signed-off-by: Peter Zijlstra 
Cc: Alexey Kuznetsov 
Cc: "David S. Miller" 
Cc: Eric Dumazet 
Cc: Hideaki YOSHIFUJI 
Cc: James Morris 
Cc: Jesse Gross 
Cc: Mathieu Desnoyers 
Cc: "Michael S. Tsirkin" 
Cc: Mirko Lindner 
Cc: Patrick McHardy 
Cc: Roger Luethi 
Cc: Rusty Russell 
Cc: Simon Horman 
Cc: Stephen Hemminger 
Cc: Steven Rostedt 
Cc: Thomas Petazzoni 
Cc: Wensong Zhang 
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/1381186321-4906-2-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar