Merge branch 'ynl-tests'

Jakub Kicinski says:

====================
selftests: net: groundwork for YNL-based tests

Currently the options for writing networking tests are C, bash or
some mix of the two. YAML/Netlink gives us the ability to easily
interface with Netlink in higher level laguages. In particular,
there is a Python library already available in tree, under tools/net.
Add the scaffolding which allows writing tests using this library.

The "scaffolding" is needed because the library lives under
tools/net and uses YAML files from under Documentation/.
So we need a small amount of glue code to find those things
and add them to TEST_FILES.

This series adds both a basic SW sanity test and driver
test which can be run against netdevsim or a real device.
When I develop core code I usually test with netdevsim,
then a real device, and then a backport to Meta's kernel.
Because of the lack of integration, until now I had
to throw away the (YNL-based) test script and netdevsim code.

Running tests in tree directly:

 $ ./tools/testing/selftests/net/nl_netdev.py
 KTAP version 1
 1..2
 ok 1 nl_netdev.empty_check
 ok 2 nl_netdev.lo_check
 # Totals: pass:2 fail:0 xfail:0 xpass:0 skip:0 error:0

in tree via make:

 $ make -C tools/testing/selftests/ TARGETS=net \
	TEST_PROGS=nl_netdev.py TEST_GEN_PROGS="" run_tests
  [ ... ]

and installed externally, all seem to work:

 $ make -C tools/testing/selftests/ TARGETS=net \
	install INSTALL_PATH=/tmp/ksft-net
 $ /tmp/ksft-net/run_kselftest.sh -t net:nl_netdev.py
  [ ... ]

For driver tests I followed the lead of net/forwarding and
get the device name from env and/or a config file.

v3:
 - fix up netdevsim C
 - various small nits in other patches (see changelog in patches)
v2: https://lore.kernel.org/all/20240403023426.1762996-1-kuba@kernel.org/
 - don't add to TARGETS, create a deperate variable with deps
 - support and use with
 - support and use passing arguments to tests
v1: https://lore.kernel.org/all/20240402010520.1209517-1-kuba@kernel.org/
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 47 insertions, 0 deletions

diff --git a/tools/testing/selftests/net/lib/py/utils.py b/tools/testing/selftests/net/lib/py/utils.py
new file mode 100644
index 000000000000..f0d425731fd4
--- /dev/null
+++ b/tools/testing/selftests/net/lib/py/utils.py
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: GPL-2.0
+
+import json as _json
+import subprocess
+
+class cmd:
+    def __init__(self, comm, shell=True, fail=True, ns=None, background=False):
+        if ns:
+            if isinstance(ns, NetNS):
+                ns = ns.name
+            comm = f'ip netns exec {ns} ' + comm
+
+        self.stdout = None
+        self.stderr = None
+        self.ret = None
+
+        self.comm = comm
+        self.proc = subprocess.Popen(comm, shell=shell, stdout=subprocess.PIPE,
+                                     stderr=subprocess.PIPE)
+        if not background:
+            self.process(terminate=False, fail=fail)
+
+    def process(self, terminate=True, fail=None):
+        if terminate:
+            self.proc.terminate()
+        stdout, stderr = self.proc.communicate()
+        self.stdout = stdout.decode("utf-8")
+        self.stderr = stderr.decode("utf-8")
+        self.proc.stdout.close()
+        self.proc.stderr.close()
+        self.ret = self.proc.returncode
+
+        if self.proc.returncode != 0 and fail:
+            if len(stderr) > 0 and stderr[-1] == "\n":
+                stderr = stderr[:-1]
+            raise Exception("Command failed: %s\n%s" % (self.proc.args, stderr))
+
+
+def ip(args, json=None, ns=None):
+    cmd_str = "ip "
+    if json:
+        cmd_str += '-j '
+    cmd_str += args
+    cmd_obj = cmd(cmd_str, ns=ns)
+    if json:
+        return _json.loads(cmd_obj.stdout)
+    return cmd_obj