kernel/linux.git/tools/testing/selftests/net/forwarding, branch v6.18.22

selftests: tc_actions: don't dump 2MB of \0 to stdout

2026-02-26T22:59:40+00:00

[ Upstream commit 32b70e62034aa72f8414ad4e9122cce7ad418c48 ] Since we started running selftests in NIPA we have been seeing tc_actions.sh generate a soft lockup warning on ~20% of the runs. On the pre-netdev foundation setup it was actually a missed irq splat from the console. Now it's either that or a lockup. I initially suspected a socket locking issue since the test is exercising local loopback with act_mirred. After hours of staring at this I noticed in strace that ncat when -o $file is specified _both_ saves the output to the file and still prints it to stdout. Because the file being sent is constructed with: dd conv=sparse status=none if=/dev/zero bs=1M count=2 of=$mirred ^^^^^^^^^ the data printed is all \0. Most terminals don't display nul characters (and neither does vng output capture save them). But QEMU's serial console still has to poke them thru which is very slow and causes the lockup (if the file is >600kB). Replace the '-o $file' with '> $file'. This speeds the test up from 2m20s to 18s on debug kernels, and prevents the warnings. Fixes: ca22da2fbd69 ("act_mirred: use the backlog for nested calls to mirred ingress") Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260214035159.2119699-1-kuba@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

selftests: forwarding: vxlan_bridge_1d_ipv6: fix test failure with br_netfilter enabled

2026-02-26T22:59:39+00:00

[ Upstream commit ce9f6aec0fb780dafc1dfc5f47c688422aff464a ] The test generates VXLAN traffic using mausezahn, where the encapsulated inner IPv6 packet has an incorrect payload length set in the IPv6 header. After VXLAN decapsulation, such packets do not pass sanity checks in br_netfilter and are dropped, which causes the test to fail. Fix this by setting the correct IPv6 payload length for the encapsulated packet generated by mausezahn, so that the packet is accepted by br_netfilter. tools/testing/selftests/net/forwarding/vxlan_bridge_1d_ipv6.sh lines 698-706 )"00:03:"$( : Payload length )"3a:"$( : Next header )"04:"$( : Hop limit )"$saddr:"$( : IP saddr )"$daddr:"$( : IP daddr )"80:"$( : ICMPv6.type )"00:"$( : ICMPv6.code )"00:"$( : ICMPv6.checksum ) Data after IPv6 header: • 80: — 1 byte (ICMPv6 type) • 00: — 1 byte (ICMPv6 code) • 00: — 1 byte (ICMPv6 checksum, truncated) Total: 3 bytes → 00:03 is correct. The old value 00:08 did not match the actual payload size. Fixes: b07e9957f220 ("selftests: forwarding: Add VxLAN tests with a VLAN-unaware bridge for IPv6") Signed-off-by: Aleksei Oladko Reviewed-by: Ido Schimmel Link: https://patch.msgid.link/20260213131907.43351-3-aleksey.oladko@virtuozzo.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

selftests: forwarding: vxlan_bridge_1d: fix test failure with br_netfilter enabled

2026-02-26T22:59:39+00:00

[ Upstream commit 02cb2e6bacbb08ebf6acb61be816efd11e1f4a21 ] The test generates VXLAN traffic using mausezahn, where the encapsulated inner IPv4 packet contains a zero IP header checksum. After VXLAN decapsulation, such packets do not pass sanity checks in br_netfilter and are dropped, which causes the test to fail. Fix this by calculating and setting a valid IPv4 header checksum for the encapsulated packet generated by mausezahn, so that the packet is accepted by br_netfilter. Fixed by using the payload_template_calc_checksum() / payload_template_expand_checksum() helpers that are only available in v6.3 and newer kernels. Fixes: a0b61f3d8ebf ("selftests: forwarding: vxlan_bridge_1d: Add an ECN decap test") Signed-off-by: Aleksei Oladko Reviewed-by: Ido Schimmel Link: https://patch.msgid.link/20260213131907.43351-2-aleksey.oladko@virtuozzo.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

selftests: net: lib: Do not overwrite error messages

2025-11-18T03:32:12+00:00

ret_set_ksft_status() calls ksft_status_merge() with the current return status and the last one. It treats a non-zero return code from ksft_status_merge() as an indication that the return status was overwritten by the last one and therefore overwrites the return message with the last one. Currently, ksft_status_merge() returns a non-zero return code even if the current return status and the last one are equal. This results in return messages being overwritten which is counter-productive since we are more interested in the first failure message and not the last one. Fix by changing ksft_status_merge() to only return a non-zero return code if the current return status was actually changed. Add a test case which checks that the first error message is not overwritten. Before: # ./lib_sh_test.sh [...] TEST: RET tfail2 tfail -> fail [FAIL] retmsg=tfail expected tfail2 [...] # echo $? 1 After: # ./lib_sh_test.sh [...] TEST: RET tfail2 tfail -> fail [ OK ] [...] # echo $? 0 Fixes: 596c8819cb78 ("selftests: forwarding: Have RET track kselftest framework constants") Reviewed-by: Petr Machata Signed-off-by: Ido Schimmel Link: https://patch.msgid.link/20251116081029.69112-1-idosch@nvidia.com Signed-off-by: Jakub Kicinski

selftests: net: local_termination: Wait for interfaces to come up

2025-11-08T02:46:36+00:00

It seems that most of the tests prepare the interfaces once before the test run (setup_prepare()), rely on setup_wait() to wait for link and only then run the test(s). local_termination brings the physical interfaces down and up during test run but never wait for them to come up. If the auto-negotiation takes some seconds, first test packets are being lost, which leads to false-negative test results. Use setup_wait() in run_test() to make sure auto-negotiation has been completed after all simple_if_init() calls on physical interfaces and test packets will not be lost because of the race against link establishment. Fixes: 90b9566aa5cd3f ("selftests: forwarding: add a test for local_termination.sh") Reviewed-by: Vladimir Oltean Signed-off-by: Alexander Sverdlin Link: https://patch.msgid.link/20251106161213.459501-1-alexander.sverdlin@siemens.com Signed-off-by: Jakub Kicinski

selftests: net: unify the Makefile formats

2025-10-06T20:14:06+00:00

We get a significant number of conflicts between net and net-next because of selftests Makefile changes. People tend to append new test cases at the end of the Makefile when there's no clear sort order. Sort all networking selftests Makefiles, use the following format: VAR_NAME := \ entry1 \ entry2 \ entry3 \ # end of VAR_NAME Some Makefiles are already pretty close to this. Acked-by: Antonio Quartulli Acked-by: Matthieu Baerts (NGI0) Acked-by: Allison Henderson Reviewed-by: Petr Machata Link: https://patch.msgid.link/20251003210127.1021918-1-kuba@kernel.org Signed-off-by: Jakub Kicinski

selftests: net: sort configs

2025-10-06T20:12:59+00:00

Sort config files for networking selftests. This should help us avoid merge conflicts between net and net-next. patchwork check will be added to prevent new issues. Acked-by: Phil Sutter Acked-by: Matthieu Baerts (NGI0) Acked-by: Florian Westphal Acked-by: Antonio Quartulli Link: https://patch.msgid.link/20251003205736.1019673-1-kuba@kernel.org Signed-off-by: Jakub Kicinski

selftests: forwarding: README: Mention defer, adf_

2025-09-27T00:48:41+00:00

Mention how it would be nice if new code used defer. Also if it does that in dirtying helpers, how it would be nice if these were named adf_*. Signed-off-by: Petr Machata Reviewed-by: Simon Horman Link: https://patch.msgid.link/0764bdb9266cd516da23ddeec110e01118cf981e.1758821127.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski

selftests: forwarding: lib: Add an autodefer variant of forwarding_enable()

2025-09-27T00:48:40+00:00

Most forwarding tests invoke forwarding_enable() to enable the router and forwarding_restore() to restore the original configuration. Add a helper, adf_forwarding_enable(), which is like forwarding_enable(), but takes care of scheduling the cleanup automatically. Convert the tests that currently use defer to schedule the cleanup. Signed-off-by: Petr Machata Reviewed-by: Simon Horman Link: https://patch.msgid.link/78b752c40069cde21c44dcf4c7b966a76a0eef2c.1758821127.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski

selftests: forwarding: lib: Add an autodefer variant of simple_if_init()

2025-09-27T00:48:40+00:00

Most forwarding tests invoke simple_if_init() to set up a VRF-based "host" and simple_if_fini() to tear it down again. Add a helper, adf_simple_if_init(), which is like simple_if_fini(), but takes care of scheduling the cleanup automatically. Convert the tests that currently use defer to schedule the cleanup. Signed-off-by: Petr Machata Reviewed-by: Simon Horman Link: https://patch.msgid.link/6b9ee1a7946a36fd32a47fdb1aa9325198ffc695.1758821127.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski