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path: root/include/uapi/linux/if_tun.h
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2013-08-21tun: Get skfilter layoutPavel Emelyanov
The only thing we may have from tun device is the fprog, whic contains the number of filter elements and a pointer to (user-space) memory where the elements are. The program itself may not be available if the device is persistent and detached. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-21tun: Allow to skip filter on attachPavel Emelyanov
There's a small problem with sk-filters on tun devices. Consider an application doing this sequence of steps: fd = open("/dev/net/tun"); ioctl(fd, TUNSETIFF, { .ifr_name = "tun0" }); ioctl(fd, TUNATTACHFILTER, &my_filter); ioctl(fd, TUNSETPERSIST, 1); close(fd); At that point the tun0 will remain in the system and will keep in mind that there should be a socket filter at address '&my_filter'. If after that we do fd = open("/dev/net/tun"); ioctl(fd, TUNSETIFF, { .ifr_name = "tun0" }); we most likely receive the -EFAULT error, since tun_attach() would try to connect the filter back. But (!) if we provide a filter at address &my_filter, then tun0 will be created and the "new" filter would be attached, but application may not know about that. This may create certain problems to anyone using tun-s, but it's critical problem for c/r -- if we meet a persistent tun device with a filter in mind, we will not be able to attach to it to dump its state (flags, owner, address, vnethdr size, etc.). The proposal is to allow to attach to tun device (with TUNSETIFF) w/o attaching the filter to the tun-file's socket. After this attach app may e.g clean the device by dropping the filter, it doesn't want to have one, or (in case of c/r) get information about the device with tun ioctls. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-21tun: Add ability to create tun device with given indexPavel Emelyanov
Tun devices cannot be created with ifidex user wants, but it's required by checkpoint-restore project. Long time ago such ability was implemented for rtnl_ops-based interface for creating links (9c7dafbf net: Allow to create links with given ifindex), but the only API for creating and managing tuntap devices is ioctl-based and is evolving with adding new ones (cde8b15f tuntap: add ioctl to attach or detach a file form tuntap device). Following that trend, here's how a new ioctl that sets the ifindex for device, that _will_ be created by TUNSETIFF ioctl looks like. So those who want a tuntap device with the ifindex N, should open the tun device, call ioctl(fd, TUNSETIFINDEX, &N), then call TUNSETIFF. If the index N is busy, then the register_netdev will find this out and the ioctl would be failed with -EBUSY. If setifindex is not called, then it will be generated as before. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-07-22tun: Support software transmit time stamping.Richard Cochran
This patch adds transmit time stamping to the tun/tap driver. Similar support already exists for UDP, can, and raw packets. Signed-off-by: Richard Cochran <richardcochran@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-12tun: Report "persist" flag to userspacePavel Emelyanov
The TUN_PERSIST flag is not reported at all -- both TUNGETIFF, and sysfs "flags" attribute skip one. Knowing whether a device is persistent or not is critical for checkpoint-restore, thus I propose to add the read-only IFF_PERSIST one for this. Setting this new IFF_PERSIST is hardly possible, as TUNSETIFF doesn't check for unknown flags being zero and thus there can be trash. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-03tun: only queue packets on deviceMichael S. Tsirkin
Historically tun supported two modes of operation: - in default mode, a small number of packets would get queued at the device, the rest would be queued in qdisc - in one queue mode, all packets would get queued at the device This might have made sense up to a point where we made the queue depth for both modes the same and set it to a huge value (500) so unless the consumer is stuck the chance of losing packets is small. Thus in practice both modes behave the same, but the default mode has some problems: - if packets are never consumed, fragments are never orphaned which cases a DOS for sender using zero copy transmit - overrun errors are hard to diagnose: fifo error is incremented only once so you can not distinguish between userspace that is stuck and a transient failure, tcpdump on the device does not show any traffic Userspace solves this simply by enabling IFF_ONE_QUEUE but there seems to be little point in not doing the right thing for everyone, by default. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-01tuntap: add ioctl to attach or detach a file form tuntap deviceJason Wang
Sometimes usespace may need to active/deactive a queue, this could be done by detaching and attaching a file from tuntap device. This patch introduces a new ioctls - TUNSETQUEUE which could be used to do this. Flag IFF_ATTACH_QUEUE were introduced to do attaching while IFF_DETACH_QUEUE were introduced to do the detaching. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-01tuntap: introduce multiqueue flagsJason Wang
Add flags to be used by creating multiqueue tuntap device. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-13UAPI: (Scripted) Disintegrate include/linuxDavid Howells
Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Dave Jones <davej@redhat.com>