[TEST] nft_tproxy_udp.sh flaky after Fedora 44 upgrade

Jakub Kicinski
2026-04-08T22:24:33Z

Hi Florian!

When you have a sec -- we upgraded the NIPA systems to Fedora 44
over the weekend, and nft_tproxy_udp.sh has gotten quite flaky:
https://netdev.bots.linux.dev/contest.html?test=nft-tproxy-udp-sh

One thing that we hit immediately is this, in case tproxy test
uses socat:

commit e65d8b6f3092398efd7c74e722cb7a516d9a0d6d
Date: Sat Apr 4 16:01:03 2026 -0700

selftests: drv-net: adjust to socat changes

socat v1.8.1.0 now defaults to shut-null, it sends an extra
0-length UDP packet when sender disconnects. This breaks
our tests which expect the exact packet sequence.

Add shut-none which was the old default where necessary.