kernel/linux.git/include/uapi/linux/if_tun.h, branch v6.19.11

tun: enable gso over UDP tunnel support.

2025-07-08T16:07:26+00:00

Add new tun features to represent the newly introduced virtio GSO over UDP tunnel offload. Allows detection and selection of such features via the existing TUNSETOFFLOAD ioctl and compute the expected virtio header size and tunnel header offset using the current netdev features, so that we can plug almost seamless the newly introduced virtio helpers to serialize the extended virtio header. Acked-by: Jason Wang Signed-off-by: Paolo Abeni --- v6 -> v7: - rebased v4 -> v5: - encapsulate the guest feature guessing in a tun helper - dropped irrelevant check on xdp buff headroom - do not remove unrelated black line - avoid line len > 80 char v3 -> v4: - virtio tnl-related fields are at fixed offset, cleanup the code accordingly. - use netdev features instead of flags bit to check for the configured offload - drop packet in case of enabled features/configured hdr size mismatch v2 -> v3: - cleaned-up uAPI comments - use explicit struct layout instead of raw buf.

uapi/linux/if_tun.h: Added new offload types for USO4/6.

2022-12-12T09:29:56+00:00

Added 2 additional offlloads for USO(IPv4 & IPv6). Separate offloads are required for Windows VM guests, g.e. Windows may set USO rx only for IPv4. Signed-off-by: Andrew Melnychenko Signed-off-by: David S. Miller

tun: support not enabling carrier in TUNSETIFF

2022-09-23T11:02:03+00:00

This change adds support for not enabling carrier during TUNSETIFF interface creation by specifying the IFF_NO_CARRIER flag. Our tests make heavy use of tun interfaces. In some scenarios, the test process creates the interface but another process brings it up after the interface is discovered via netlink notification. In that case, it is not possible to create a tun/tap interface with carrier off without it racing against the bring up. Immediately setting carrier off via TUNSETCARRIER is still too late. Signed-off-by: Patrick Rohr Cc: Maciej Żenczykowski Cc: Lorenzo Colitti Cc: Jason Wang Cc: Stephen Hemminger Cc: Nicolas Dichtel Reviewed-by: Maciej Żenczykowski Acked-by: Jason Wang Reviewed-by: Nicolas Dichtel Signed-off-by: David S. Miller

treewide: uapi: Replace zero-length arrays with flexible-array members

2022-06-28T19:26:05+00:00

There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. This code was transformed with the help of Coccinelle: (linux-5.19-rc2$ spatch --jobs $(getconf _NPROCESSORS_ONLN) --sp-file script.cocci --include-headers --dir . > output.patch) @@ identifier S, member, array; type T1, T2; @@ struct S { ... T1 member; T2 array[ - 0 ]; }; -fstrict-flex-arrays=3 is coming and we need to land these changes to prevent issues like these in the short future: ../fs/minix/dir.c:337:3: warning: 'strcpy' will always overflow; destination buffer has size 0, but the source string has length 2 (including NUL byte) [-Wfortify-source] strcpy(de3->name, "."); ^ Since these are all [0] to [] changes, the risk to UAPI is nearly zero. If this breaks anything, we can use a union with a new member name. [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays Link: https://github.com/KSPP/linux/issues/78 Build-tested-by: kernel test robot Link: https://lore.kernel.org/lkml/62b675ec.wKX6AOZ6cbE71vtF%25lkp@intel.com/ Acked-by: Dan Williams # For ndctl.h Signed-off-by: Gustavo A. R. Silva

tun: Add ioctl() TUNGETDEVNETNS cmd to allow obtaining real net ns of tun device

2019-03-21T20:19:15+00:00

In commit f2780d6d7475 "tun: Add ioctl() SIOCGSKNS cmd to allow obtaining net ns of tun device" it was missed that tun may change its net ns, while net ns of socket remains the same as it was created initially. SIOCGSKNS returns net ns of socket, so it is not suitable for obtaining net ns of device. We may have two tun devices with the same names in two net ns, and in this case it's not possible to determ, which of them fd refers to (TUNGETIFF will return the same name). This patch adds new ioctl() cmd for obtaining net ns of a device. Reported-by: Harald Albrecht Signed-off-by: Kirill Tkhai Signed-off-by: David S. Miller

tun: implement carrier change

2018-12-01T01:16:38+00:00

The userspace may need to control the carrier state. Signed-off-by: Nicolas Dichtel Signed-off-by: Didier Pallard Signed-off-by: David S. Miller

tun: allow to attach ebpf socket filter

2018-01-17T20:32:10+00:00

This patch allows userspace to attach eBPF filter to tun. This will allow to implement VM dataplane filtering in a more efficient way compared to cBPF filter by allowing either qemu or libvirt to attach eBPF filter to tun. Signed-off-by: Jason Wang Signed-off-by: David S. Miller

tun: add eBPF based queue selection method

2017-12-05T17:01:49+00:00

This patch introduces an eBPF based queue selection method. With this, the policy could be offloaded to userspace completely through a new ioctl TUNSETSTEERINGEBPF. Signed-off-by: Jason Wang Acked-by: Willem de Bruijn Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2017-11-04T00:26:51+00:00

Files removed in 'net-next' had their license header updated in 'net'. We take the remove from 'net-next'. Signed-off-by: David S. Miller

License cleanup: add SPDX license identifier to uapi header files with a license

2017-11-02T10:20:11+00:00

Many user space API headers have licensing information, which is either incomplete, badly formatted or just a shorthand for referring to the license under which the file is supposed to be. This makes it hard for compliance tools to determine the correct license. Update these files with an SPDX license identifier. The identifier was chosen based on the license information in the file. GPL/LGPL licensed headers get the matching GPL/LGPL SPDX license identifier with the added 'WITH Linux-syscall-note' exception, which is the officially assigned exception identifier for the kernel syscall exception: NOTE! This copyright does *not* cover user programs that use kernel services by normal system calls - this is merely considered normal use of the kernel, and does *not* fall under the heading of "derived work". This exception makes it possible to include GPL headers into non GPL code, without confusing license compliance tools. Headers which have either explicit dual licensing or are just licensed under a non GPL license are updated with the corresponding SPDX identifier and the GPLv2 with syscall exception identifier. The format is: ((GPL-2.0 WITH Linux-syscall-note) OR SPDX-ID-OF-OTHER-LICENSE) SPDX license identifiers are a legally binding shorthand, which can be used instead of the full boiler plate text. The update does not remove existing license information as this has to be done on a case by case basis and the copyright holders might have to be consulted. This will happen in a separate step. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. See the previous patch in this series for the methodology of how this patch was researched. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman