selftests: net: add scaffolding for Netlink tests in Python

Add glue code for accessing the YNL library which lives under
tools/net and YAML spec files from under Documentation/.
Automatically figure out if tests are run in tree or not.
Since we'll want to use this library both from net and
drivers/net test targets make the library a target as well,
and automatically include it when net or drivers/net are
included. Making net/lib a target ensures that we end up
with only one copy of it, and saves us some path guessing.

Add a tiny bit of formatting support to be able to output KTAP
from the start.

Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 96 insertions, 0 deletions

diff --git a/tools/testing/selftests/net/lib/py/ksft.py b/tools/testing/selftests/net/lib/py/ksft.py
new file mode 100644
index 000000000000..c7210525981c
--- /dev/null
+++ b/tools/testing/selftests/net/lib/py/ksft.py
@@ -0,0 +1,96 @@
+# SPDX-License-Identifier: GPL-2.0
+
+import builtins
+from .consts import KSFT_MAIN_NAME
+
+KSFT_RESULT = None
+
+
+class KsftSkipEx(Exception):
+    pass
+
+
+class KsftXfailEx(Exception):
+    pass
+
+
+def ksft_pr(*objs, **kwargs):
+    print("#", *objs, **kwargs)
+
+
+def ksft_eq(a, b, comment=""):
+    global KSFT_RESULT
+    if a != b:
+        KSFT_RESULT = False
+        ksft_pr("Check failed", a, "!=", b, comment)
+
+
+def ksft_true(a, comment=""):
+    global KSFT_RESULT
+    if not a:
+        KSFT_RESULT = False
+        ksft_pr("Check failed", a, "does not eval to True", comment)
+
+
+def ksft_in(a, b, comment=""):
+    global KSFT_RESULT
+    if a not in b:
+        KSFT_RESULT = False
+        ksft_pr("Check failed", a, "not in", b, comment)
+
+
+def ksft_ge(a, b, comment=""):
+    global KSFT_RESULT
+    if a < b:
+        KSFT_RESULT = False
+        ksft_pr("Check failed", a, "<", b, comment)
+
+
+def ktap_result(ok, cnt=1, case="", comment=""):
+    res = ""
+    if not ok:
+        res += "not "
+    res += "ok "
+    res += str(cnt) + " "
+    res += KSFT_MAIN_NAME
+    if case:
+        res += "." + str(case.__name__)
+    if comment:
+        res += " # " + comment
+    print(res)
+
+
+def ksft_run(cases, args=()):
+    totals = {"pass": 0, "fail": 0, "skip": 0, "xfail": 0}
+
+    print("KTAP version 1")
+    print("1.." + str(len(cases)))
+
+    global KSFT_RESULT
+    cnt = 0
+    for case in cases:
+        KSFT_RESULT = True
+        cnt += 1
+        try:
+            case(*args)
+        except KsftSkipEx as e:
+            ktap_result(True, cnt, case, comment="SKIP " + str(e))
+            totals['skip'] += 1
+            continue
+        except KsftXfailEx as e:
+            ktap_result(True, cnt, case, comment="XFAIL " + str(e))
+            totals['xfail'] += 1
+            continue
+        except Exception as e:
+            for line in str(e).split('\n'):
+                ksft_pr("Exception|", line)
+            ktap_result(False, cnt, case)
+            totals['fail'] += 1
+            continue
+
+        ktap_result(KSFT_RESULT, cnt, case)
+        totals['pass'] += 1
+
+    print(
+        f"# Totals: pass:{totals['pass']} fail:{totals['fail']} xfail:{totals['xfail']} xpass:0 skip:{totals['skip']} error:0"
+    )