This helper could be useful to more than just forwarding tests.
Move it upstairs and port over to log_test_skip().

Split the function into two parts: the bit that actually checks and
reports skip, which is in a new function check_command(). And a bit
that exits the test script if the check fails. This allows users
consistent checking behavior while giving an option to bail out from
a single test without bailing out of the whole script.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Running "make kselftest TARGETS=net/forwarding" results in
multiple ccurrences of the same error:
- ./lib.sh: line 787: teamd: command not found

This patch adds the variable $REQUIRE_TEAMD in every test that uses the
command teamd and checks the $REQUIRE_TEAMD variable in the file "lib.sh"
to skip the test if the command is not installed.

Signed-off-by: Alessandro Zanni <alessandro.zanni87@gmail.com>
Link: https://patch.msgid.link/20250114003323.97207-1-alessandro.zanni87@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Add ip_link_set_addr(), ip_link_set_up(), ip_addr_add() and ip_route_add()
to the suite of helpers that automatically schedule a corresponding
cleanup.

When setting a new MAC, one needs to remember the old address first. Move
mac_get() from forwarding/ to that end.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/add6bcbe30828fd01363266df20c338cf13aaf25.1733412063.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

A number of selftests run processes in the background and need to kill them
afterwards. Instead for everyone to open-code the kill / wait / redirect
mantra, add a helper in net/lib.sh. Convert existing open-code sites.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Reviewed-by: Amit Cohen <amcohen@nvidia.com>
Link: https://patch.msgid.link/a9db102067d741c118f0bd93b10c75e2a34665ea.1731589511.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

For logging to be useful, something has to set RET and retmsg by calling
ret_set_ksft_status(). There is a suite of functions to that end in
forwarding/lib: check_err, check_fail et.al. Move them to net/lib.sh so
that every net test can use them.

Existing lib.sh users might be using these same names for their functions.
However lib.sh is always sourced near the top of the file (checked), and
whatever new definitions will simply override the ones provided by lib.sh.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Amit Cohen <amcohen@nvidia.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://patch.msgid.link/f488a00dc85b8e0c1f3c71476b32b21b5189a847.1731589511.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

It would be good to use the same mechanism for scheduling and dispatching
general net tests as the many forwarding tests already use. To that end,
move the logging helpers to net/lib.sh so that every net test can use them.

Existing lib.sh users might be using the name themselves. However lib.sh is
always sourced near the top of the file (checked), and whatever new
definition will simply override the one provided by lib.sh.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Amit Cohen <amcohen@nvidia.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://patch.msgid.link/a6fc083486493425b2c61185c327845b6ce3233a.1731589511.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Many net selftests invent their own logging helpers. These really should be
in a library sourced by these tests. Currently forwarding/lib.sh has a
suite of perfectly fine logging helpers, but sourcing a forwarding/ library
from a higher-level directory smells of layering violation. In this patch,
move the logging helpers to net/lib.sh so that every net test can use them.

Together with the logging helpers, it's also necessary to move
pause_on_fail(), and EXIT_STATUS and RET.

Existing lib.sh users might be using these same names for their functions
or variables. However lib.sh is always sourced near the top of the
file (checked), and whatever new definitions will simply override the ones
provided by lib.sh.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Amit Cohen <amcohen@nvidia.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://patch.msgid.link/edd3785a3bd72ffbe1409300989e993ee50ae98b.1731589511.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Now that it is possible to schedule a deferral of stop_traffic() right
after the traffic is started, we do not have to rely on the %% magic to
kill the background process that was started last. Instead we can just give
the PID explicitly. This makes it possible to start other background
processes after the traffic is started without confusing the cleanup.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Consistent use of defers obviates the need for a separate test-specific
cleanup function -- everything is just taken care of in defers. So in this
patch, introduce a cleanup() helper in the forwarding lib.sh, which calls
just pre_cleanup() and defer_scopes_cleanup(). Selftests are obviously
still free to override the function.

Since pre_cleanup() is too entangled with forwarding-specific minutia, the
function cannot currently be in net/lib.sh.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

In commit 8510801a9dbd ("selftests: drv-net: add ability to schedule
cleanup with defer()"), a defer helper was added to Python selftests.
The idea is to keep cleanup commands close to their dirtying counterparts,
thereby making it more transparent what is cleaning up what, making it
harder to miss a cleanup, and make the whole cleanup business exception
safe. All these benefits are applicable to bash as well, exception safety
can be interpreted in terms of safety vs. a SIGINT.

This patch therefore introduces a framework of several helpers that serve
to schedule cleanups in bash selftests:

- defer_scope_push(), defer_scope_pop(): Deferred statements can be batched
  together in scopes. When a scope is popped, the deferred commands
  scheduled in that scope are executed in the order opposite to order of
  their scheduling.

- defer(): Schedules a defer to the most recently pushed scope (or the
  default scope if none was pushed.)

- defer_prio(): Schedules a defer on the priority track. The priority defer
  queue is run before the default defer queue when scope is popped.

  The issue that this is addressing is specifically the one of restoring
  devlink shared buffer threshold type. When setting up static thresholds,
  one has to first change the threshold type to static, then override the
  individual thresholds. When cleaning up, it would be natural to reset the
  threshold values first, then change the threshold type. But the values
  that are valid for dynamic thresholds are generally invalid for static
  thresholds and vice versa. Attempts to restore the values first would be
  bounced. Thus one has to first reset the threshold type, then adjust the
  thresholds.

  (You could argue that the shared buffer threshold type API is broken and
  you would be right, but here we are.)

  This cannot be solved by pure defers easily. I considered making it
  possible to disable an existing defer, so that one could then schedule a
  new defer and disable the original. But this forward-shifting of the
  defer job would have to take place after every threshold-adjusting
  command, which would make it very awkward to schedule these jobs.

- defer_scopes_cleanup(): Pops any unpopped scopes, including the default
  one. The selftests that use defer should run this in their exit trap.
  This is important to get cleanups of interrupted scripts.

- in_defer_scope(): Sometimes a function would like to introduce a new
  defer scope, then run whatever it is that it wants to run, and then pop
  the scope to run the deferred cleanups. The helper in_defer_scope() can
  be used to run another command within such environment, such that any
  scheduled defers run after the command finishes.

The framework is added as a separate file lib/sh/defer.sh so that it can be
used by all bash selftests, including those that do not currently use
lib.sh. lib.sh however includes the file by default, because ideally all
tests would use these helpers instead of hand-rolling their cleanups.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>