The primary goal is to add test validation for GSO when operating over
UDP tunnels, a scenario which is not currently covered.

The design strategy is to extend the existing tun/tap testing infrastructure
to support this new use-case, rather than introducing a new or parallel framework.
This allows for better integration and re-use of existing test logic.

---
v2 -> v3:
 - Re-send the patch series becasue Patchwork don't update them

v2: https://lore.kernel.org/all/cover.1767074545.git.xudu@redhat.com/
 - Addresse sporadic failures due to too early send.
 - Refactor environment address assign helper function.
 - Fix incorrect argument passing in build packet functions.

v1: https://lore.kernel.org/netdev/cover.1763345426.git.xudu@redhat.com/

Xu Du (8):
  selftest: tun: Format tun.c existing code
  selftest: tun: Introduce tuntap_helpers.h header for TUN/TAP testing
  selftest: tun: Refactor tun_delete to use tuntap_helpers
  selftest: tap: Refactor tap test to use tuntap_helpers
  selftest: tun: Add helpers for GSO over UDP tunnel
  selftest: tun: Add test for sending gso packet into tun
  selftest: tun: Add test for receiving gso packet from tun
  selftest: tun: Add test data for success and failure paths

 tools/testing/selftests/net/tap.c            | 287 +-----
 tools/testing/selftests/net/tun.c            | 917 ++++++++++++++++++-
 tools/testing/selftests/net/tuntap_helpers.h | 608 ++++++++++++
 3 files changed, 1530 insertions(+), 282 deletions(-)
 create mode 100644 tools/testing/selftests/net/tuntap_helpers.h


base-commit: 7b8e9264f55a9c320f398e337d215e68cca50131
-- 
2.49.0

On Mon,  5 Jan 2026 11:44:35 +0800 Xu Du wrote:
> v2 -> v3:
>  - Re-send the patch series becasue Patchwork don't update them

Not sure what this means, but:
 1 - please do not repost patches sooner than 24h after previous
     posting, per
     https://www.kernel.org/doc/html/next/process/maintainer-netdev.html

 2 - the patches do not apply to net-next:

Applying: selftest: tun: Format tun.c existing code
Applying: selftest: tun: Introduce tuntap_helpers.h header for TUN/TAP testing
Applying: selftest: tun: Refactor tun_delete to use tuntap_helpers
Applying: selftest: tap: Refactor tap test to use tuntap_helpers
Using index info to reconstruct a base tree...
M	tools/testing/selftests/net/tap.c
Falling back to patching base and 3-way merge...
Auto-merging tools/testing/selftests/net/tap.c
CONFLICT (content): Merge conflict in tools/testing/selftests/net/tap.c
Recorded preimage for 'tools/testing/selftests/net/tap.c'
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
hint: When you have resolved this problem, run "git am --continue".
hint: If you prefer to skip this patch, run "git am --skip" instead.
hint: To restore the original branch and stop patching, run "git am --abort".
hint: Disable this message with "git config set advice.mergeConflict false"
Patch failed at 0004 selftest: tap: Refactor tap test to use tuntap_helpers