kernel/git/stable/linux.git/drivers/net/tun.c, branch linux-2.6.31.y

tun: Return -EINVAL if neither IFF_TUN nor IFF_TAP is set.

2009-10-12T19:40:26+00:00

[ Upstream commit 36989b90879c785f95b877bdcf65a2527dadd893 ] After commit 2b980dbd77d229eb60588802162c9659726b11f4 ("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 Reviewed-by: Paul Moore Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tun: Extend RTNL lock coverage over whole ioctl

2009-08-10T04:45:35+00:00

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 Signed-off-by: David S. Miller

tun/tap: Fix crashes if open() /dev/net/tun and then poll() it.

2009-07-06T19:47:07+00:00

Fix NULL pointer dereference in tun_chr_pool() introduced by commit 33dccbb050bbe35b88ca8cf1228dcf3e4d4b3554 ("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 Signed-off-by: Mariusz Kozlowski Signed-off-by: David S. Miller

tun: Fix device unregister race

2009-07-06T01:03:18+00:00

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 Signed-off-by: David S. Miller

Driver Core: misc: add nodename support for misc devices.

2009-06-16T04:30:25+00:00

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 Signed-off-by: Jan Blunck Signed-off-by: Greg Kroah-Hartman

tun: Fix unregister race

2009-06-08T07:44:31+00:00

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

tun: Fix copy/paste error in tun_get_user

2009-06-08T07:27:28+00:00

Use the right structure while incrementing the offset in tun_get_user. Signed-off-by: Sridhar Samudrala Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller

tun: Optimise handling of bogus gso->hdr_len

2009-06-08T07:20:01+00:00

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 Signed-off-by: David S. Miller

tun: Only wake up writers

2009-06-04T04:45:55+00:00

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 Signed-off-by: David S. Miller

tun: add tun_flags, owner, group attributes in sysfs

2009-05-10T05:54:21+00:00

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 Signed-off-by: David S. Miller