Commit Graph

126 Commits

Author SHA1 Message Date
Joe Perches
6b8a66ee91 tun: Convert logging messages to pr_<level> and tun_debug
Use the current logging forms with pr_fmt.
Convert DBG macro to tun_debug, use netdev_printk as well.
Add printf verification when TUN_DEBUG not defined.
Miscellaneous comment typo fix.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-03 12:21:14 -08:00
Michał Mirosław
04ed3e741d net: change netdev->features to u32
Quoting Ben Hutchings: we presumably won't be defining features that
can only be enabled on 64-bit architectures.

Occurences found by `grep -r` on net/, drivers/net, include/

[ Move features and vlan_features next to each other in
  struct netdev, as per Eric Dumazet's suggestion -DaveM ]

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-24 15:32:47 -08:00
Linus Torvalds
008d23e485 Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (43 commits)
  Documentation/trace/events.txt: Remove obsolete sched_signal_send.
  writeback: fix global_dirty_limits comment runtime -> real-time
  ppc: fix comment typo singal -> signal
  drivers: fix comment typo diable -> disable.
  m68k: fix comment typo diable -> disable.
  wireless: comment typo fix diable -> disable.
  media: comment typo fix diable -> disable.
  remove doc for obsolete dynamic-printk kernel-parameter
  remove extraneous 'is' from Documentation/iostats.txt
  Fix spelling milisec -> ms in snd_ps3 module parameter description
  Fix spelling mistakes in comments
  Revert conflicting V4L changes
  i7core_edac: fix typos in comments
  mm/rmap.c: fix comment
  sound, ca0106: Fix assignment to 'channel'.
  hrtimer: fix a typo in comment
  init/Kconfig: fix typo
  anon_inodes: fix wrong function name in comment
  fix comment typos concerning "consistent"
  poll: fix a typo in comment
  ...

Fix up trivial conflicts in:
 - drivers/net/wireless/iwlwifi/iwl-core.c (moved to iwl-legacy.c)
 - fs/ext4/ext4.h

Also fix missed 'diabled' typo in drivers/net/bnx2x/bnx2x.h while at it.
2011-01-13 10:05:56 -08:00
Michał Mirosław
55508d601d net: Use skb_checksum_start_offset()
Replace skb->csum_start - skb_headroom(skb) with skb_checksum_start_offset().

Note for usb/smsc95xx: skb->data - skb->head == skb_headroom(skb).

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-16 14:43:14 -08:00
Uwe Kleine-König
b595076a18 tree-wide: fix comment/printk typos
"gadget", "through", "command", "maintain", "maintain", "controller", "address",
"between", "initiali[zs]e", "instead", "function", "select", "already",
"equal", "access", "management", "hierarchy", "registration", "interest",
"relative", "memory", "offset", "already",

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-11-01 15:38:34 -04:00
Nolan Leake
bee31369ce tun: keep link (carrier) state up to date
Currently, only ethtool can get accurate link state of a tap device.
With this patch, IFF_RUNNING and IF_OPER_UP/DOWN are kept up to date as
well.

Signed-off-by: Nolan Leake <nolan@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-30 22:06:41 -07:00
Michael S. Tsirkin
ef3db4a595 tun: avoid BUG, dump packet on GSO errors
There are still some LRO cards that cause GSO errors in tun,
and BUG on this is an unfriendly way to tell the admin
to disable LRO.

Further, experience shows we might have more GSO bugs lurking.
See https://bugzilla.kernel.org/show_bug.cgi?id=16413
as a recent example.
dumping a packet will make it easier to figure it out.

Replace BUG with warning+dump+drop the packet to make
GSO errors in tun less critical and easier to debug.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Alex Unigovsky <unik@compot.ru>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-24 20:47:20 -07:00
Linus Torvalds
b1cdc4670b Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (63 commits)
  drivers/net/usb/asix.c: Fix pointer cast.
  be2net: Bug fix to avoid disabling bottom half during firmware upgrade.
  proc_dointvec: write a single value
  hso: add support for new products
  Phonet: fix potential use-after-free in pep_sock_close()
  ath9k: remove VEOL support for ad-hoc
  ath9k: change beacon allocation to prefer the first beacon slot
  sock.h: fix kernel-doc warning
  cls_cgroup: Fix build error when built-in
  macvlan: do proper cleanup in macvlan_common_newlink() V2
  be2net: Bug fix in init code in probe
  net/dccp: expansion of error code size
  ath9k: Fix rx of mcast/bcast frames in PS mode with auto sleep
  wireless: fix sta_info.h kernel-doc warnings
  wireless: fix mac80211.h kernel-doc warnings
  iwlwifi: testing the wrong variable in iwl_add_bssid_station()
  ath9k_htc: rare leak in ath9k_hif_usb_alloc_tx_urbs()
  ath9k_htc: dereferencing before check in hif_usb_tx_cb()
  rt2x00: Fix rt2800usb TX descriptor writing.
  rt2x00: Fix failed SLEEP->AWAKE and AWAKE->SLEEP transitions.
  ...
2010-05-25 16:59:51 -07:00
Kay Sievers
578454ff7e driver core: add devname module aliases to allow module on-demand auto-loading
This adds:
  alias: devname:<name>
to some common kernel modules, which will allow the on-demand loading
of the kernel module when the device node is accessed.

Ideally all these modules would be compiled-in, but distros seems too
much in love with their modularization that we need to cover the common
cases with this new facility. It will allow us to remove a bunch of pretty
useless init scripts and modprobes from init scripts.

The static device node aliases will be carried in the module itself. The
program depmod will extract this information to a file in the module directory:
  $ cat /lib/modules/2.6.34-00650-g537b60d-dirty/modules.devname
  # Device nodes to trigger on-demand module loading.
  microcode cpu/microcode c10:184
  fuse fuse c10:229
  ppp_generic ppp c108:0
  tun net/tun c10:200
  dm_mod mapper/control c10:235

Udev will pick up the depmod created file on startup and create all the
static device nodes which the kernel modules specify, so that these modules
get automatically loaded when the device node is accessed:
  $ /sbin/udevd --debug
  ...
  static_dev_create_from_modules: mknod '/dev/cpu/microcode' c10:184
  static_dev_create_from_modules: mknod '/dev/fuse' c10:229
  static_dev_create_from_modules: mknod '/dev/ppp' c108:0
  static_dev_create_from_modules: mknod '/dev/net/tun' c10:200
  static_dev_create_from_modules: mknod '/dev/mapper/control' c10:235
  udev_rules_apply_static_dev_perms: chmod '/dev/net/tun' 0666
  udev_rules_apply_static_dev_perms: chmod '/dev/fuse' 0666

A few device nodes are switched to statically allocated numbers, to allow
the static nodes to work. This might also useful for systems which still run
a plain static /dev, which is completely unsafe to use with any dynamic minor
numbers.

Note:
The devname aliases must be limited to the *common* and *single*instance*
device nodes, like the misc devices, and never be used for conceptually limited
systems like the loop devices, which should rather get fixed properly and get a
control node for losetup to talk to, instead of creating a random number of
device nodes in advance, regardless if they are ever used.

This facility is to hide the mess distros are creating with too modualized
kernels, and just to hide that these modules are not compiled-in, and not to
paper-over broken concepts. Thanks! :)

Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: David S. Miller <davem@davemloft.net>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Alasdair G Kergon <agk@redhat.com>
Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
Cc: Ian Kent <raven@themaw.net>
Signed-Off-By: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-25 15:08:26 -07:00
Herbert Xu
8286274284 tun: Update classid on packet injection
This patch makes tun update its socket classid every time we
inject a packet into the network stack.  This is so that any
updates made by the admin to the process writing packets to
tun is effected.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-24 00:14:10 -07:00
Joe Perches
ee289b6440 drivers/net: remove useless semicolons
switch and while statements don't need semicolons at end of statement

[ Fixup minor conflicts with recent wimax merge... -DaveM ]

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-17 22:47:34 -07:00
Joe Perches
a4b770972b drivers/net: Remove unnecessary returns from void function()s
This patch removes from drivers/net/ all the unnecessary
return; statements that precede the last closing brace of
void functions.

It does not remove the returns that are immediately
preceded by a label as gcc doesn't like that.

It also does not remove null void functions with return.

Done via:
$ grep -rP --include=*.[ch] -l "return;\n}" net/ | \
  xargs perl -i -e 'local $/ ; while (<>) { s/\n[ \t\n]+return;\n}/\n}/g; print; }'

with some cleanups by hand.

Compile tested x86 allmodconfig only.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-14 00:19:28 -07:00
Eric Dumazet
1ae5dc342a net: trans_start cleanups
Now that core network takes care of trans_start updates, dont do it
in drivers themselves, if possible. Drivers can avoid one cache miss
(on dev->trans_start) in their start_xmit() handler.

Exceptions are NETIF_F_LLTX drivers

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-10 05:01:31 -07:00
Michael S. Tsirkin
d9d52b5178 tun: add ioctl to modify vnet header size
virtio added mergeable buffers mode where 2 bytes of extra info is put
after vnet header but before actual data (tun does not need this data).
In hindsight, it would have been better to add the new info *before* the
packet: as it is, users need a lot of tricky code to skip the extra 2
bytes in the middle of the iovec, and in fact applications seem to get
it wrong, and only work with specific iovec layout.  The fact we might
need to split iovec also means we might in theory overflow iovec max
size.

This patch adds a simpler way for applications to handle this,
and future proofs the interface against further extensions,
by making the size of the virtio net header configurable
from userspace. As a result, tun driver will simply
skip the extra 2 bytes on both input and output.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: David S. Miller <davem@davemloft.net>
2010-05-03 12:33:13 +03:00
Eric Dumazet
4381548237 net: sock_def_readable() and friends RCU conversion
sk_callback_lock rwlock actually protects sk->sk_sleep pointer, so we
need two atomic operations (and associated dirtying) per incoming
packet.

RCU conversion is pretty much needed :

1) Add a new structure, called "struct socket_wq" to hold all fields
that will need rcu_read_lock() protection (currently: a
wait_queue_head_t and a struct fasync_struct pointer).

[Future patch will add a list anchor for wakeup coalescing]

2) Attach one of such structure to each "struct socket" created in
sock_alloc_inode().

3) Respect RCU grace period when freeing a "struct socket_wq"

4) Change sk_sleep pointer in "struct sock" by sk_wq, pointer to "struct
socket_wq"

5) Change sk_sleep() function to use new sk->sk_wq instead of
sk->sk_sleep

6) Change sk_has_sleeper() to wq_has_sleeper() that must be used inside
a rcu_read_lock() section.

7) Change all sk_has_sleeper() callers to :
  - Use rcu_read_lock() instead of read_lock(&sk->sk_callback_lock)
  - Use wq_has_sleeper() to eventually wakeup tasks.
  - Use rcu_read_unlock() instead of read_unlock(&sk->sk_callback_lock)

8) sock_wake_async() is modified to use rcu protection as well.

9) Exceptions :
  macvtap, drivers/net/tun.c, af_unix use integrated "struct socket_wq"
instead of dynamically allocated ones. They dont need rcu freeing.

Some cleanups or followups are probably needed, (possible
sk_callback_lock conversion to a spinlock for example...).

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-01 15:00:15 -07:00
Eric Dumazet
aa39514516 net: sk_sleep() helper
Define a new function to return the waitqueue of a "struct sock".

static inline wait_queue_head_t *sk_sleep(struct sock *sk)
{
	return sk->sk_sleep;
}

Change all read occurrences of sk_sleep by a call to this function.

Needed for a future RCU conversion. sk_sleep wont be a field directly
available.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-20 16:37:13 -07:00
Michael S. Tsirkin
0110d6f22f tun: orphan an skb on tx
The following situation was observed in the field:
tap1 sends packets, tap2 does not consume them, as a result
tap1 can not be closed. This happens because
tun/tap devices can hang on to skbs undefinitely.

As noted by Herbert, possible solutions include a timeout followed by a
copy/change of ownership of the skb, or always copying/changing
ownership if we're going into a hostile device.

This patch implements the second approach.

Note: one issue still remaining is that since skbs
keep reference to tun socket and tun socket has a
reference to tun device, we won't flush backlog,
instead simply waiting for all skbs to get transmitted.
At least this is not user-triggerable, and
this was not reported in practice, my assumption is
other devices besides tap complete an skb
within finite time after it has been queued.

A possible solution for the second issue
would not to have socket reference the device,
instead, implement dev->destructor for tun, and
wait for all skbs to complete there, but this
needs some thought, probably too risky for 2.6.34.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Yan Vugenfirer <yvugenfi@redhat.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-14 04:52:03 -07:00
Jiri Kosina
318ae2edc3 Merge branch 'for-next' into for-linus
Conflicts:
	Documentation/filesystems/proc.txt
	arch/arm/mach-u300/include/mach/debug-macro.S
	drivers/net/qlge/qlge_ethtool.c
	drivers/net/qlge/qlge_main.c
	drivers/net/typhoon.c
2010-03-08 16:55:37 +01:00
Michael S. Tsirkin
9940516259 tun: socket filter support
This patch adds Linux Socket Filter support to
tun driver.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-17 16:35:17 -08:00
Daniel Mack
3ad2f3fbb9 tree-wide: Assorted spelling fixes
In particular, several occurances of funny versions of 'success',
'unknown', 'therefore', 'acknowledge', 'argument', 'achieve', 'address',
'beginning', 'desirable', 'separate' and 'necessary' are fixed.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Joe Perches <joe@perches.com>
Cc: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-02-09 11:13:56 +01:00
Michael S. Tsirkin
05c2828c72 tun: export underlying socket
Tun device looks similar to a packet socket
in that both pass complete frames from/to userspace.

This patch fills in enough fields in the socket underlying tun driver
to support sendmsg/recvmsg operations, and message flags
MSG_TRUNC and MSG_DONTWAIT, and exports access to this socket
to modules.  Regular read/write behaviour is unchanged.

This way, code using raw sockets to inject packets
into a physical device, can support injecting
packets into host network stack almost without modification.

First user of this interface will be vhost virtualization
accelerator.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-01-15 01:43:28 -08:00
Vitaliy Gusev
80924e5f7d tun: use tun_sk instead container_of
Using macro tun_sk is more clear and shorter. However tun.c has tun_sk,
but doesn't use it.

Signed-off-by: Vitaliy Gusev <vgusev@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-26 20:24:44 -08:00
Arnd Bergmann
50857e2a59 net/tun: handle compat_ioctl directly
The tun driver is the only code in the kernel that operates
on a character device with struct ifreq. Change the driver
to handle the conversion itself so we can contain the
remaining ifreq handling in the socket layer.

This also fixes a bug in the handling of invalid ioctl
numbers on an unbound tun device. The driver treats this
as a TUNSETIFF in native mode, but there is no way for
the generic compat_ioctl() function to emulate this
behaviour. Possibly the driver was only doing this
accidentally anyway, but if any code relies on this
misfeature, it now also works in compat mode.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-06 22:52:32 -08:00
Thomas Gleixner
deed49fbb6 net: Remove BKL from tun
The lock_kernel/unlock_kernel() in cycle_kernel_lock() which is called
in tun_chr_open() is not serializing against anything and safe to
remove.

tun_chr_fasync() is serialized by get/put_tun() and fasync_helper()
has no dependency on BKL. The modification of tun->flags is racy with
and without the BKL so removing it does not make it worse.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-14 01:19:46 -07:00
David S. Miller
8b3f6af863 Merge branch 'master' of /home/davem/src/GIT/linux-2.6/
Conflicts:
	drivers/staging/Kconfig
	drivers/staging/Makefile
	drivers/staging/cpc-usb/TODO
	drivers/staging/cpc-usb/cpc-usb_drv.c
	drivers/staging/cpc-usb/cpc.h
	drivers/staging/cpc-usb/cpc_int.h
	drivers/staging/cpc-usb/cpcusb.h
2009-09-24 15:13:11 -07:00
Kusanagi Kouichi
36989b9087 tun: Return -EINVAL if neither IFF_TUN nor IFF_TAP is set.
After commit 2b980dbd77
("lsm: Add hooks to the TUN driver") tun_set_iff doesn't
return -EINVAL though neither IFF_TUN nor IFF_TAP is set.

Signed-off-by: Kusanagi Kouichi <slash@ma.neweb.ne.jp>
Reviewed-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-22 14:00:16 -07:00
Kay Sievers
e454cea20b Driver-Core: extend devnode callbacks to provide permissions
This allows subsytems to provide devtmpfs with non-default permissions
for the device node. Instead of the default mode of 0600, null, zero,
random, urandom, full, tty, ptmx now have a mode of 0666, which allows
non-privileged processes to access standard device nodes in case no
other userspace process applies the expected permissions.

This also fixes a wrong assignment in pktcdvd and a checkpatch.pl complain.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 12:50:38 -07:00
Linus Torvalds
d7e9660ad9 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1623 commits)
  netxen: update copyright
  netxen: fix tx timeout recovery
  netxen: fix file firmware leak
  netxen: improve pci memory access
  netxen: change firmware write size
  tg3: Fix return ring size breakage
  netxen: build fix for INET=n
  cdc-phonet: autoconfigure Phonet address
  Phonet: back-end for autoconfigured addresses
  Phonet: fix netlink address dump error handling
  ipv6: Add IFA_F_DADFAILED flag
  net: Add DEVTYPE support for Ethernet based devices
  mv643xx_eth.c: remove unused txq_set_wrr()
  ucc_geth: Fix hangs after switching from full to half duplex
  ucc_geth: Rearrange some code to avoid forward declarations
  phy/marvell: Make non-aneg speed/duplex forcing work for 88E1111 PHYs
  drivers/net/phy: introduce missing kfree
  drivers/net/wan: introduce missing kfree
  net: force bridge module(s) to be GPL
  Subject: [PATCH] appletalk: Fix skb leak when ipddp interface is not loaded
  ...

Fixed up trivial conflicts:

 - arch/x86/include/asm/socket.h

   converted to <asm-generic/socket.h> in the x86 tree.  The generic
   header has the same new #define's, so that works out fine.

 - drivers/net/tun.c

   fix conflict between 89f56d1e9 ("tun: reuse struct sock fields") that
   switched over to using 'tun->socket.sk' instead of the redundantly
   available (and thus removed) 'tun->sk', and 2b980dbd ("lsm: Add hooks
   to the TUN driver") which added a new 'tun->sk' use.

   Noted in 'next' by Stephen Rothwell.
2009-09-14 10:37:28 -07:00
Michael S. Tsirkin
89f56d1e91 tun: reuse struct sock fields
As tun always has an embeedded struct sock,
use sk and sk_receive_queue fields instead of
duplicating them in tun_struct.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-01 17:40:33 -07:00
Stephen Hemminger
424efe9caf netdev: convert pseudo drivers to netdev_tx_t
These are all drivers that don't touch real hardware.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-01 01:13:40 -07:00
Paul Moore
2b980dbd77 lsm: Add hooks to the TUN driver
The TUN driver lacks any LSM hooks which makes it difficult for LSM modules,
such as SELinux, to enforce access controls on network traffic generated by
TUN users; this is particularly problematic for virtualization apps such as
QEMU and KVM.  This patch adds three new LSM hooks designed to control the
creation and attachment of TUN devices, the hooks are:

 * security_tun_dev_create()
   Provides access control for the creation of new TUN devices

 * security_tun_dev_post_create()
   Provides the ability to create the necessary socket LSM state for newly
   created TUN devices

 * security_tun_dev_attach()
   Provides access control for attaching to existing, persistent TUN devices
   and the ability to update the TUN device's socket LSM state as necessary

Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: Eric Paris <eparis@parisplace.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: James Morris <jmorris@namei.org>
2009-09-01 08:29:48 +10:00
David S. Miller
aa11d958d1 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	arch/microblaze/include/asm/socket.h
2009-08-12 17:44:53 -07:00
Herbert Xu
876bfd4d0f tun: Extend RTNL lock coverage over whole ioctl
As it is, parts of the ioctl runs under the RTNL and parts of
it do not.  The unlocked section is still protected by the BKL,
but there can be subtle races.  For example, Eric Biederman and
Paul Moore observed that if two threads tried to create two tun
devices on the same file descriptor, then unexpected results
may occur.

As there isn't anything in the ioctl that is expected to sleep
indefinitely, we can prevent this from occurring by extending
the RTNL lock coverage.

This also allows to get rid of the BKL.

Finally, I changed tun_get_iff to take a tun device in order to
avoid calling tun_put which would dead-lock as it also tries to
take the RTNL lock.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-08-09 21:45:35 -07:00
Sridhar Samudrala
e36aa25a53 tun: Allow tap device to send/receive UFO packets.
- Allow setting UFO on tap device and handle UFO packets.

Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>

---------------------------------------------------------
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-17 10:11:00 -07:00
David S. Miller
e5a8a896f5 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2009-07-09 20:18:24 -07:00
Paul Moore
460deefae6 tun: Remove a dead line of code
Remove an unnecessary assignment.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-07 19:22:11 -07:00
Mariusz Kozlowski
3c8a9c63d5 tun/tap: Fix crashes if open() /dev/net/tun and then poll() it.
Fix NULL pointer dereference in tun_chr_pool() introduced by commit
33dccbb050 ("tun: Limit amount of queued
packets per device") and triggered by this code:

	int fd;
	struct pollfd pfd;
	fd = open("/dev/net/tun", O_RDWR);
	pfd.fd = fd;
	pfd.events = POLLIN | POLLOUT;
	poll(&pfd, 1, 0);

Reported-by: Eugene Kapun <abacabadabacaba@gmail.com>
Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-06 12:47:07 -07:00
Patrick McHardy
6ed106549d net: use NETDEV_TX_OK instead of 0 in ndo_start_xmit() functions
This patch is the result of an automatic spatch transformation to convert
all ndo_start_xmit() return values of 0 to NETDEV_TX_OK.

Some occurences are missed by the automatic conversion, those will be
handled in a seperate patch.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-05 19:16:04 -07:00
Herbert Xu
d23e43658a tun: Fix device unregister race
It is currently possible for an asynchronous device unregister
to cause the same tun device to be unregistered twice.  This
is because the unregister in tun_chr_close only checks whether
__tun_get(tfile) != NULL.  This however has nothing to do with
whether the device has already been unregistered.  All it tells
you is whether __tun_detach has been called.

This patch fixes this by using the most obvious thing to test
whether the device has been unregistered.

It also moves __tun_detach outside of rtnl_unlock since nothing
that it does requires that lock.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-05 18:03:18 -07:00
Kay Sievers
d405640539 Driver Core: misc: add nodename support for misc devices.
This adds support for misc devices to report their requested nodename to
userspace.  It also updates a number of misc drivers to provide the
needed subdirectory and device name to be used for them.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-15 21:30:25 -07:00
Eric W. Biederman
f0a4d0e5b5 tun: Fix unregister race
It is possible for tun_chr_close to race with dellink on the
a tun device.  In which case if __tun_get runs before dellink
but dellink runs before tun_chr_close calls unregister_netdevice
we will attempt to unregister the netdevice after it is already
gone.  

The two cases are already serialized on the rtnl_lock, so I have
gone for the cheap simple fix of moving rtnl_lock to cover __tun_get
in tun_chr_close.  Eliminating the possibility of the tun device
being unregistered between __tun_get and unregister_netdevice in
tun_chr_close.

Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Tested-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-08 00:44:31 -07:00
Sridhar Samudrala
6f536f4039 tun: Fix copy/paste error in tun_get_user
Use the right structure while incrementing the offset in tun_get_user.

Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-08 00:27:28 -07:00
Herbert Xu
4909122fb8 tun: Optimise handling of bogus gso->hdr_len
As all current versions of virtio_net generate a value for the
header length that's too small, we should optimise this so that
we don't copy it twice.  This can be done by ensuring that it is
at least as large as the place where we'll write the checksum.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-08 00:20:01 -07:00
Herbert Xu
c722c625db tun: Only wake up writers
When I added socket accounting to tun I inadvertently introduced
spurious wake-up events that kills qemu performance.  The problem
occurs when qemu polls on the tun fd for read, and then transmits
packets.  For each packet transmitted, we will wake up qemu even
if it only cares about read events.

Now this affects all sockets, but it is only a new problem for
tun.  So this patch tries to fix it for tun first and we can then
look at the problem in general.
 
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-03 21:45:55 -07:00
David Woodhouse
980c9e8cee tun: add tun_flags, owner, group attributes in sysfs
This patch adds three attribute files in /sys/class/net/$dev/ for tun
devices; allowing userspace to obtain the information which TUNGETIFF
offers, and more, but without having to attach to the device in question
(which may not be possible if it's in use).

It also fixes a bug which has been present in the TUNGETIFF ioctl since
its inception, where it would never set IFF_TUN or IFF_TAP according to
the device type. (Look carefully at the code which I remove from
tun_get_iff() and how the new tun_flags() helper is subtly different).

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-05-09 22:54:21 -07:00
David Woodhouse
f85ba78068 tun: add IFF_TUN_EXCL flag to avoid opening a persistent device.
When creating a certain types of VPN, NetworkManager will first attempt
to find an available tun device by iterating through 'vpn%d' until it
finds one that isn't already busy. Then it'll set that to be persistent
and owned by the otherwise unprivileged user that the VPN dæmon itself
runs as.

There's a race condition here -- during the period where the vpn%d
device is created and we're waiting for the VPN dæmon to actually
connect and use it, if we try to create _another_ device we could end up
re-using the same one -- because trying to open it again doesn't get
-EBUSY as it would while it's _actually_ busy.

So solve this, we add an IFF_TUN_EXCL flag which causes tun_set_iff() to
fail if it would be opening an existing persistent tundevice -- so that
we can make sure we're getting an entirely _new_ device.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-27 03:23:54 -07:00
Michael S. Tsirkin
6f26c9a755 tun: fix tun_chr_aio_write so that aio works
aio_write gets const struct iovec * but tun_chr_aio_write casts this to struct
iovec * and modifies the iovec. As a result, attempts to use io_submit
to send packets to a tun device fail with weird errors such as EINVAL.

Since tun is the only user of skb_copy_datagram_from_iovec, we can
fix this simply by changing the later so that it does not
touch the iovec passed to it.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-21 05:42:46 -07:00
Michael S. Tsirkin
43b39dcdbd tun: fix tun_chr_aio_read so that aio works
aio_read gets const struct iovec * but tun_chr_aio_read casts this to struct
iovec * and modifies the iovec. As a result, attempts to use io_submit
to get packets from a tun device fail with weird errors such as EINVAL.

Fix by using the new skb_copy_datagram_const_iovec.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-21 05:42:45 -07:00
Herbert Xu
c40af84a67 tun: Fix sk_sleep races when attaching/detaching
As the sk_sleep wait queue actually lives in tfile, which may be
detached from the tun device, bad things will happen when we use
sk_sleep after detaching.

Since the tun device is the persistent data structure here (when
requested by the user), it makes much more sense to have the wait
queue live there.  There is no reason to have it in tfile at all
since the only time we can wait is if we have a tun attached.
In fact we already have a wait queue in tun_struct, so we might
as well use it.

Reported-by: Eric W. Biederman <ebiederm@xmission.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Tested-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-20 03:01:48 -07:00
Herbert Xu
9c3fea6ab0 tun: Only free a netdev when all tun descriptors are closed
The commit c70f182940 ("tun: Fix
races between tun_net_close and free_netdev") fixed a race where
an asynchronous deletion of a tun device can hose a poll(2) on
a tun fd attached to that device.

However, this came at the cost of moving the tun wait queue into
the tun file data structure.  The problem with this is that it
imposes restrictions on when and where the tun device can access
the wait queue since the tun file may change at any time due to
detaching and reattaching.

In particular, now that we need to use the wait queue on the
receive path it becomes difficult to properly synchronise this
with the detachment of the tun device.

This patch solves the original race in a different way.  Since
the race is only because the underlying memory gets freed, we
can prevent it simply by ensuring that we don't do that until
all tun descriptors ever attached to the device (even if they
have since be detached because they may still be sitting in poll)
have been closed.

This is done by using reference counting the attached tun file
descriptors.  The refcount in tun->sk has been reappropriated
for this purpose since it was already being used for that, albeit
from the opposite angle.

Note that we no longer zero tfile->tun since tun_get will return
NULL anyway after the refcount on tfile hits zero.  Instead it
represents whether this device has ever been attached to a device.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-20 03:01:47 -07:00