linux-stable.git/drivers/net/tun.c, branch linux-3.13.y

tun: remove bogus hardware vlan acceleration flags from vlan_features

2014-03-24T04:43:59+00:00

[ Upstream commit 6671b2240c54585d4afb5286a29f1569fe5e40a8 ]

Even though only the outer vlan tag can be HW accelerated in the transmission
path, in the TUN/TAP driver vlan_features mirrors hw_features, which happens
to have the NETIF_F_HW_VLAN_?TAG_TX flags set. Because of this, during packet
tranmisssion through a stacked vlan device dev_hard_start_xmit, (incorrectly)
assuming that the vlan device supports hardware vlan acceleration, does not
add the vlan header to the skb payload and the inner vlan tags are lost
(vlan_tci contains the outer vlan tag when userspace reads the packet from
the tap device).

Signed-off-by: Fernando Luis Vazquez Cao 
Signed-off-by: Toshiaki Makita 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: core: explicitly select a txq before doing l2 forwarding

2014-01-10T18:23:08+00:00

Currently, the tx queue were selected implicitly in ndo_dfwd_start_xmit(). The
will cause several issues:

- NETIF_F_LLTX were removed for macvlan, so txq lock were done for macvlan
  instead of lower device which misses the necessary txq synchronization for
  lower device such as txq stopping or frozen required by dev watchdog or
  control path.
- dev_hard_start_xmit() was called with NULL txq which bypasses the net device
  watchdog.
- dev_hard_start_xmit() does not check txq everywhere which will lead a crash
  when tso is disabled for lower device.

Fix this by explicitly introducing a new param for .ndo_select_queue() for just
selecting queues in the case of l2 forwarding offload. netdev_pick_tx() was also
extended to accept this parameter and dev_queue_xmit_accel() was used to do l2
forwarding transmission.

With this fixes, NETIF_F_LLTX could be preserved for macvlan and there's no need
to check txq against NULL in dev_hard_start_xmit(). Also there's no need to keep
a dedicated ndo_dfwd_start_xmit() and we can just reuse the code of
dev_queue_xmit() to do the transmission.

In the future, it was also required for macvtap l2 forwarding support since it
provides a necessary synchronization method.

Cc: John Fastabend 
Cc: Neil Horman 
Cc: e1000-devel@lists.sourceforge.net
Signed-off-by: Jason Wang 
Acked-by: Neil Horman 
Acked-by: John Fastabend 
Signed-off-by: David S. Miller

tun: unbreak truncated packet signalling

2013-12-11T20:23:06+00:00

Commit 6680ec68eff47d36f67b4351bc9836fd6cba9532
(tuntap: hardware vlan tx support) breaks the truncated packet signal by nev
return a length greater than iov length in tun_put_user(). This patch fixes
by always return the length of packet plus possible vlan header. Caller can
detect the truncated packet by comparing the return value and the size of io
length.

Cc: Zhi Yong Wu 
Cc: Michael S. Tsirkin 
Signed-off-by: Vlad Yasevich 
Signed-off-by: Jason Wang 
Acked-by: Michael S. Tsirkin 
Signed-off-by: David S. Miller

net: Revert macvtap/tun truncation signalling changes.

2013-12-11T03:10:21+00:00

Jason Wang and Michael S. Tsirkin are still discussing how
to properly fix this.

Signed-off-by: David S. Miller

tun: unbreak truncated packet signalling

2013-12-11T03:06:49+00:00

Commit 6680ec68eff47d36f67b4351bc9836fd6cba9532
(tuntap: hardware vlan tx support) breaks the truncated packet signal by never
return a length greater than iov length in tun_put_user(). This patch fixes this
by always return the length of packet plus possible vlan header. Caller can
detect the truncated packet by comparing the return value and the size of iov
length.

Reported-by: Vlad Yasevich 
Cc: Vlad Yasevich 
Cc: Zhi Yong Wu 
Signed-off-by: Jason Wang 
Signed-off-by: David S. Miller

tun: update file current position

2013-12-06T17:42:14+00:00

Signed-off-by: Zhi Yong Wu 
Signed-off-by: David S. Miller

tuntap: limit head length of skb allocated

2013-11-14T21:05:27+00:00

We currently use hdr_len as a hint of head length which is advertised by
guest. But when guest advertise a very big value, it can lead to an 64K+
allocating of kmalloc() which has a very high possibility of failure when host
memory is fragmented or under heavy stress. The huge hdr_len also reduce the
effect of zerocopy or even disable if a gso skb is linearized in guest.

To solves those issues, this patch introduces an upper limit (PAGE_SIZE) of the
head, which guarantees an order 0 allocation each time.

Cc: Stefan Hajnoczi 
Cc: Michael S. Tsirkin 
Signed-off-by: Jason Wang 
Signed-off-by: David S. Miller

tun: don't look at current when non-blocking

2013-10-08T19:38:35+00:00

We play with a wait queue even if socket is
non blocking. This is an obvious waste.
Besides, it will prevent calling the non blocking
variant when current is not valid.

Signed-off-by: Michael S. Tsirkin 
Acked-by: Jason Wang 
Signed-off-by: David S. Miller

tuntap: correctly handle error in tun_set_iff()

2013-09-12T21:21:42+00:00

Commit c8d68e6be1c3b242f1c598595830890b65cea64a
(tuntap: multiqueue support) only call free_netdev() on error in
tun_set_iff(). This causes several issues:

- memory of tun security were leaked
- use after free since the flow gc timer was not deleted and the tfile
  were not detached

This patch solves the above issues.

Reported-by: Wannes Rombouts 
Cc: Michael S. Tsirkin 
Signed-off-by: Jason Wang 
Acked-by: Michael S. Tsirkin 
Signed-off-by: David S. Miller

tuntap: orphan frags before trying to set tx timestamp

2013-09-05T16:44:31+00:00

sock_tx_timestamp() will clear all zerocopy flags of skb which may lead the
frags never to be orphaned. This will break guest to guest traffic when zerocopy
is enabled. Fix this by orphaning the frags before trying to set tx time stamp.

The issue were introduced by commit eda297729171fe16bf34fe5b0419dfb69060f623
(tun: Support software transmit time stamping).

Cc: Richard Cochran 
Cc: Sergei Shtylyov 
Acked-by: Richard Cochran 
Signed-off-by: Jason Wang 
Signed-off-by: David S. Miller