linux-stable.git/drivers/net/tun.c, branch linux-3.12.y

tun: read vnet_hdr_sz once

2017-03-01T08:59:48+00:00

[ Upstream commit e1edab87faf6ca30cd137e0795bc73aa9a9a22ec ]

When IFF_VNET_HDR is enabled, a virtio_net header must precede data.
Data length is verified to be greater than or equal to expected header
length tun->vnet_hdr_sz before copying.

Read this value once and cache locally, as it can be updated between
the test and use (TOCTOU).

[js] we have TUN_VNET_HDR in 3.12

Signed-off-by: Willem de Bruijn 
Reported-by: Dmitry Vyukov 
CC: Eric Dumazet 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Jiri Slaby

tun: Fix TUN_PKT_STRIP setting

2017-03-01T08:39:08+00:00

commit 2eb783c43e7cf807a45899c10ed556b6dc116625 upstream.

We set the flag TUN_PKT_STRIP if the user buffer provided is too
small to contain the entire packet plus meta-data.  However, this
has been broken ever since we added GSO meta-data.  VLAN acceleration
also has the same problem.

This patch fixes this by taking both into account when setting the
TUN_PKT_STRIP flag.

The fact that this has been broken for six years without anyone
realising means that nobody actually uses this flag.

Fixes: f43798c27684 ("tun: Allow GSO using virtio_net_hdr")
Signed-off-by: Herbert Xu 
Signed-off-by: David S. Miller 
Signed-off-by: Jiri Slaby

Revert "drivers/net: Disable UFO through virtio"

2016-12-01T09:02:44+00:00

commit e3e3c423f82a415195a7bbbfa619bfa7b20d2db6 upstream.

This reverts commit 3d0ad09412ffe00c9afa201d01effdb6023d09b4.

Now that GSO functionality can correctly track if the fragment
id has been selected and select a fragment id if necessary,
we can re-enable UFO on tap/macvap and virtio devices.

Signed-off-by: Vladislav Yasevich 
Signed-off-by: David S. Miller 
Cc: Ben Hutchings 
Signed-off-by: Jiri Slaby

drivers/net: Disable UFO through virtio

2016-11-28T21:22:48+00:00

commit 3d0ad09412ffe00c9afa201d01effdb6023d09b4 upstream.

IPv6 does not allow fragmentation by routers, so there is no
fragmentation ID in the fixed header.  UFO for IPv6 requires the ID to
be passed separately, but there is no provision for this in the virtio
net protocol.

Until recently our software implementation of UFO/IPv6 generated a new
ID, but this was a bug.  Now we will use ID=0 for any UFO/IPv6 packet
passed through a tap, which is even worse.

Unfortunately there is no distinction between UFO/IPv4 and v6
features, so disable UFO on taps and virtio_net completely until we
have a proper solution.

We cannot depend on VM managers respecting the tap feature flags, so
keep accepting UFO packets but log a warning the first time we do
this.

Signed-off-by: Ben Hutchings 
Fixes: 916e4cf46d02 ("ipv6: reuse ip6_frag_id from ip6_ufo_append_data")
Signed-off-by: David S. Miller 
Signed-off-by: Jiri Slaby

tun: fix transmit timestamp support

2016-09-29T09:14:10+00:00

[ Upstream commit 7b996243fab46092fb3a29c773c54be8152366e4 ]

Instead of using sock_tx_timestamp, use skb_tx_timestamp to record
software transmit timestamp of a packet.

sock_tx_timestamp resets and overrides the tx_flags of the skb.
The function is intended to be called from within the protocol
layer when creating the skb, not from a device driver. This is
inconsistent with other drivers and will cause issues for TCP.

In TCP, we intend to sample the timestamps for the last byte
for each sendmsg/sendpage. For that reason, tcp_sendmsg calls
tcp_tx_timestamp only with the last skb that it generates.
For example, if a 128KB message is split into two 64KB packets
we want to sample the SND timestamp of the last packet. The current
code in the tun driver, however, will result in sampling the SND
timestamp for both packets.

Also, when the last packet is split into smaller packets for
retranmission (see tcp_fragment), the tun driver will record
timestamps for all of the retransmitted packets and not only the
last packet.

Fixes: eda297729171 (tun: Support software transmit time stamping.)
Signed-off-by: Soheil Hassas Yeganeh 
Signed-off-by: Francis Yan 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Jiri Slaby

tun: Fix csum_start with VLAN acceleration

2014-11-19T17:38:15+00:00

commit a8f9bfdf982e2b1fb9f094e4de9ab08c57f3d2fd upstream.

When VLAN acceleration is in use on the xmit path, we end up
setting csum_start to the wrong place.  The result is that the
whoever ends up doing the checksum setting will corrupt the packet
instead of writing the checksum to the expected location, usually
this means writing the checksum with an offset of -4.

This patch fixes this by adjusting csum_start when VLAN acceleration
is detected.

Fixes: 6680ec68eff4 ("tuntap: hardware vlan tx support")
Signed-off-by: Herbert Xu 
Signed-off-by: David S. Miller 
Signed-off-by: Jiri Slaby

drivers/net, ipv6: Select IPv6 fragment idents for virtio UFO packets

2014-11-13T18:01:51+00:00

[ Upstream commit 5188cd44c55db3e92cd9e77a40b5baa7ed4340f7 ]

UFO is now disabled on all drivers that work with virtio net headers,
but userland may try to send UFO/IPv6 packets anyway.  Instead of
sending with ID=0, we should select identifiers on their behalf (as we
used to).

Signed-off-by: Ben Hutchings 
Fixes: 916e4cf46d02 ("ipv6: reuse ip6_frag_id from ip6_ufo_append_data")
Signed-off-by: David S. Miller

tun: remove bogus hardware vlan acceleration flags from vlan_features

2014-03-13T22:19:38+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: Jiri Slaby

tun: unbreak truncated packet signalling

2014-01-15T23:31:33+00:00

[ Upstream commit e6fd07c899cd719bb5517bc7f32ce03a62220351 ]

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 
Signed-off-by: Greg Kroah-Hartman

tun: update file current position

2014-01-15T23:31:33+00:00

[ Upstream commit d0b7da8afa079ffe018ab3e92879b7138977fc8f ]

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