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, 49 insertions, 0 deletions

diff --git a/tools/testing/selftests/net/lib/py/ynl.py b/tools/testing/selftests/net/lib/py/ynl.py
new file mode 100644
index 000000000000..1ace58370c06
--- /dev/null
+++ b/tools/testing/selftests/net/lib/py/ynl.py
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: GPL-2.0
+
+import sys
+from pathlib import Path
+from .consts import KSRC, KSFT_DIR
+from .ksft import ksft_pr, ktap_result
+
+# Resolve paths
+try:
+    if (KSFT_DIR / "kselftest-list.txt").exists():
+        # Running in "installed" selftests
+        tools_full_path = KSFT_DIR
+        SPEC_PATH = KSFT_DIR / "net/lib/specs"
+
+        sys.path.append(tools_full_path.as_posix())
+        from net.lib.ynl.lib import YnlFamily, NlError
+    else:
+        # Running in tree
+        tools_full_path = KSRC / "tools"
+        SPEC_PATH = KSRC / "Documentation/netlink/specs"
+
+        sys.path.append(tools_full_path.as_posix())
+        from net.ynl.lib import YnlFamily, NlError
+except ModuleNotFoundError as e:
+    ksft_pr("Failed importing `ynl` library from kernel sources")
+    ksft_pr(str(e))
+    ktap_result(True, comment="SKIP")
+    sys.exit(4)
+
+#
+# Wrapper classes, loading the right specs
+# Set schema='' to avoid jsonschema validation, it's slow
+#
+class EthtoolFamily(YnlFamily):
+    def __init__(self):
+        super().__init__((SPEC_PATH / Path('ethtool.yaml')).as_posix(),
+                         schema='')
+
+
+class RtnlFamily(YnlFamily):
+    def __init__(self):
+        super().__init__((SPEC_PATH / Path('rt_link.yaml')).as_posix(),
+                         schema='')
+
+
+class NetdevFamily(YnlFamily):
+    def __init__(self):
+        super().__init__((SPEC_PATH / Path('netdev.yaml')).as_posix(),
+                         schema='')