linux.git/net/core/dev.c, branch v2.6.26-rc7

net: Fix test for VLAN TX checksum offload capability

2008-06-17T00:02:28+00:00

Selected device feature bits can be propagated to VLAN devices, so we
can make use of TX checksum offload and TSO on VLAN-tagged packets.
However, if the physical device does not do VLAN tag insertion or
generic checksum offload then the test for TX checksum offload in
dev_queue_xmit() will see a protocol of htons(ETH_P_8021Q) and yield
false.

This splits the checksum offload test into two functions:

- can_checksum_protocol() tests a given protocol against a feature bitmask

- dev_can_checksum() first tests the skb protocol against the device
  features; if that fails and the protocol is htons(ETH_P_8021Q) then
  it tests the encapsulated protocol against the effective device
  features for VLANs

Signed-off-by: Ben Hutchings 
Acked-by: Patrick McHardy 
Signed-off-by: David S. Miller

net: Fix call to ->change_rx_flags(dev, IFF_MULTICAST) in dev_change_flags()

2008-05-20T21:36:14+00:00

Am I just being particularly dim today, or can the call to
dev->change_rx_flags(dev, IFF_MULTICAST) in dev_change_flags() never
happen?

We've just set dev->flags = flags & IFF_MULTICAST, effectively. So the
condition '(dev->flags ^ flags) & IFF_MULTICAST' is _never_ going to be
true.

Signed-off-by: David Woodhouse 
Signed-off-by: David S. Miller

net: handle errors from device_rename

2008-05-15T05:33:38+00:00

device_rename can fail with -EEXIST or -ENOMEM, so handle any
problems.

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller

net: Added ASSERT_RTNL() to dev_open() and dev_close().

2008-05-08T09:53:17+00:00

dev_open() and dev_close() must be called holding the RTNL, since they
call device functions and netdevice notifiers that are promised the RTNL.

Signed-off-by: Ben Hutchings 
Signed-off-by: David S. Miller

netns: Fix arbitrary net_device-s corruptions on net_ns stop.

2008-05-08T08:24:25+00:00

When a net namespace is destroyed, some devices (those, not killed
on ns stop explicitly) are moved back to init_net.

The problem, is that this net_ns change has one point of failure -
the __dev_alloc_name() may be called if a name collision occurs (and
this is easy to trigger). This allocator performs a likely-to-fail
GFP_ATOMIC allocation to find a suitable number. Other possible 
conditions that may cause error (for device being ns local or not
registered) are always false in this case.

So, when this call fails, the device is unregistered. But this is
*not* the right thing to do, since after this the device may be
released (and kfree-ed) improperly. E. g. bridges require more
actions (sysfs update, timer disarming, etc.), some other devices 
want to remove their private areas from lists, etc.

I. e. arbitrary use-after-free cases may occur.

The proposed fix is the following: since the only reason for the
dev_change_net_namespace to fail is the name generation, we may
give it a unique fall-back name w/o %d-s in it - the dev
one, since ifindexes are still unique.

So make this change, raise the failure-case printk loglevel to 
EMERG and replace the unregister_netdevice call with BUG().

[ Use snprintf() -DaveM ]

Signed-off-by: Pavel Emelyanov 
Signed-off-by: David S. Miller

netns: Fix device renaming for sysfs

2008-05-03T00:00:58+00:00

When a netdev is moved across namespaces with the
'dev_change_net_namespace' function, the 'device_rename' function is
used to fixup kobject and refresh the sysfs tree. The device_rename
function will call kobject_rename and this one will check if there is
an object with the same name and this is the case because we are
renaming the object with the same name.

The use of 'device_rename' seems for me wrong because we usually don't
rename it but just move it across namespaces. As we just want to do a
mini "netdev_[un]register", IMO the functions
'netdev_[un]register_kobject' should be used instead, like an usual
network device [un]registering.

This patch replace device_rename by netdev_unregister_kobject,
followed by netdev_register_kobject.

The netdev_register_kobject will call device_initialize and will raise
a warning indicating the device was already initialized. In order to
fix that, I split the device initialization into a separate function
and use it together with 'netdev_register_kobject' into
register_netdevice. So we can safely call 'netdev_register_kobject' in
'dev_change_net_namespace'.

This fix will allow to properly use the sysfs per namespace which is
coming from -mm tree.

Signed-off-by: Daniel Lezcano 
Acked-by: Benjamin Thery 
Signed-off-by: David S. Miller

net: remove NR_CPUS arrays in net/core/dev.c

2008-05-02T23:43:08+00:00

Remove the fixed size channels[NR_CPUS] array in net/core/dev.c and
dynamically allocate array based on nr_cpu_ids.

Signed-off-by: Mike Travis 
Signed-off-by: Andrew Morton 
Signed-off-by: David S. Miller

Remove duplicated unlikely() in IS_ERR()

2008-04-29T15:06:25+00:00

Some drivers have duplicated unlikely() macros.  IS_ERR() already has
unlikely() in itself.

This patch cleans up such pointless code.

Signed-off-by: Hirofumi Nakagawa 
Acked-by: David S. Miller 
Acked-by: Jeff Garzik 
Cc: Paul Clements 
Cc: Richard Purdie 
Cc: Alessandro Zummo 
Cc: David Brownell 
Cc: James Bottomley 
Cc: Michael Halcrow 
Cc: Anton Altaparmakov 
Cc: Al Viro 
Cc: Carsten Otte 
Cc: Patrick McHardy 
Cc: Paul Mundt 
Cc: Jaroslav Kysela 
Cc: Takashi Iwai 
Acked-by: Mike Frysinger 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[NET]: Fix and allocate less memory for ->priv'less netdevices

2008-04-18T22:43:32+00:00

This patch effectively reverts commit d0498d9ae1a5cebac363e38907266d5cd2eedf89
aka "[NET]: Do not allocate unneeded memory for dev->priv alignment."
It was found to be buggy because of final unconditional += NETDEV_ALIGN_CONST
removal.

For example, for sizeof(struct net_device) being 2048 bytes, "alloc_size"
was also 2048 bytes, but allocator with debugging options turned on started
giving out !32-byte aligned memory resulting in redzones overwrites.

Patch does small optimization in ->priv'less case: bumping size to next
32-byte boundary was always done to ensure ->priv will also be aligned.
But, no ->priv, no need to do that.

Signed-off-by: Alexey Dobriyan 
Signed-off-by: David S. Miller

[NET]: Do not allocate unneeded memory for dev->priv alignment.

2008-04-16T09:17:42+00:00

The alloc_netdev_mq() tries to produce 32-bytes alignment for both
the net_device itself and its private data. The second alignment is
achieved by adding the NETDEV_ALIGN_CONST to the whole size of
the memory to be allocated.

However, for those devices that do not need the private area, this
addition just makes the net_device weight 1024 + 32 = 1068 bytes,
i.e. consume twice as much memory.

Since loopback device is such (sizeof_priv == 0 for it), and each
net namespace creates one, this can save a noticeable amount of
memory for kernel with net namespaces turned on.

After this set the lo device is actually allocated from a size-1024
kmem cache on i386 box even with NETPOLL and WIRELESS_EXT turned on.

Signed-off-by: Pavel Emelyanov 
Signed-off-by: David S. Miller