Merge branch 'selftests-drv-net-round-some-sharp-edges'

Jakub Kicinski says:

====================
selftests: drv-net: round some sharp edges

I had to explain how to run the driver tests twice already.
Improve the README so we can just point to it.
Improve the config validation.

v1: https://lore.kernel.org/r/20240424221444.4194069-1-kuba@kernel.org/
====================

Link: https://lore.kernel.org/r/20240425222341.309778-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

tools/testing/selftests/drivers/net/README.rst

@@ -1,18 +1,42 @@
-Running tests
-=============
+.. SPDX-License-Identifier: GPL-2.0
 
-Tests are executed within kselftest framework like any other tests.
-By default tests execute against software drivers such as netdevsim.
-All tests must support running against a real device (SW-only tests
-should instead be placed in net/ or drivers/net/netdevsim, HW-only
-tests in drivers/net/hw).
+Running driver tests
+====================
 
-Set appropriate variables to point the tests at a real device.
+Networking driver tests are executed within kselftest framework like any
+other tests. They support testing both real device drivers and emulated /
+software drivers (latter mostly to test the core parts of the stack).
+
+SW mode
+~~~~~~~
+
+By default, when no extra parameters are set or exported, tests execute
+against software drivers such as netdevsim. No extra preparation is required
+the software devices are created and destroyed as part of the test.
+In this mode the tests are indistinguishable from other selftests and
+(for example) can be run under ``virtme-ng`` like the core networking selftests.
+
+HW mode
+~~~~~~~
+
+Executing tests against a real device requires external preparation.
+The netdevice against which tests will be run must exist, be running
+(in UP state) and be configured with an IP address.
+
+Refer to list of :ref:`Variables` later in this file to set up running
+the tests against a real device.
+
+Both modes required
+~~~~~~~~~~~~~~~~~~~
+
+All tests in drivers/net must support running both against a software device
+and a real device. SW-only tests should instead be placed in net/ or
+drivers/net/netdevsim, HW-only tests in drivers/net/hw.
 
 Variables
 =========
 
-Variables can be set in the environment or by creating a net.config
+The variables can be set in the environment or by creating a net.config
 file in the same directory as this README file. Example::
 
   $ NETIF=eth0 ./some_test.sh
@@ -23,9 +47,9 @@ or::
   # Variable set in a file
   NETIF=eth0
 
-Please note that the config parser is very simple, if there are
-any non-alphanumeric characters in the value it needs to be in
-double quotes.
+Local test (which don't require endpoint for sending / receiving traffic)
+need only the ``NETIF`` variable. Remaining variables define the endpoint
+and communication method.
 
 NETIF
 ~~~~~
@@ -61,3 +85,52 @@ Communication channel dependent::
 
   for netns - name of the "remote" namespace
   for ssh - name/address of the remote host
+
+Example
+=======
+
+Build the selftests::
+
+  # make -C tools/testing/selftests/ TARGETS="drivers/net drivers/net/hw"
+
+"Install" the tests and copy them over to the target machine::
+
+  # make -C tools/testing/selftests/ TARGETS="drivers/net drivers/net/hw" \
+     install INSTALL_PATH=/tmp/ksft-net-drv
+
+  # rsync -ra --delete /tmp/ksft-net-drv root@192.168.1.1:/root/
+
+On the target machine, running the tests will use netdevsim by default::
+
+  [/root] # ./ksft-net-drv/run_kselftest.sh -t drivers/net:ping.py
+  TAP version 13
+  1..1
+  # timeout set to 45
+  # selftests: drivers/net: ping.py
+  # KTAP version 1
+  # 1..3
+  # ok 1 ping.test_v4
+  # ok 2 ping.test_v6
+  # ok 3 ping.test_tcp
+  # # Totals: pass:3 fail:0 xfail:0 xpass:0 skip:0 error:0
+  ok 1 selftests: drivers/net: ping.py
+
+Create a config with remote info::
+
+  [/root] # cat > ./ksft-net-drv/drivers/net/net.config <<EOF
+  NETIF=eth0
+  LOCAL_V4=192.168.1.1
+  REMOTE_V4=192.168.1.2
+  REMOTE_TYPE=ssh
+  REMOTE_ARGS=root@192.168.1.2
+  EOF
+
+Run the test::
+
+  [/root] # ./ksft-net-drv/drivers/net/ping.py
+  KTAP version 1
+  1..3
+  ok 1 ping.test_v4
+  ok 2 ping.test_v6 # SKIP Test requires IPv6 connectivity
+  ok 3 ping.test_tcp
+  # Totals: pass:2 fail:0 xfail:0 xpass:0 skip:1 error:0

tools/testing/selftests/drivers/net/lib/py/env.py

@@ -1,7 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 
 import os
-import shlex
 from pathlib import Path
 from lib.py import KsftSkipEx
 from lib.py import cmd, ip
@@ -16,17 +15,20 @@ def _load_env_file(src_path):
     if not (src_dir / "net.config").exists():
         return env
 
-    lexer = shlex.shlex(open((src_dir / "net.config").as_posix(), 'r').read())
-    k = None
-    for token in lexer:
-        if k is None:
-            k = token
-            env[k] = ""
-        elif token == "=":
-            pass
-        else:
-            env[k] = token
-            k = None
+    with open((src_dir / "net.config").as_posix(), 'r') as fp:
+        for line in fp.readlines():
+            full_file = line
+            # Strip comments
+            pos = line.find("#")
+            if pos >= 0:
+                line = line[:pos]
+            line = line.strip()
+            if not line:
+                continue
+            pair = line.split('=', maxsplit=1)
+            if len(pair) != 2:
+                raise Exception("Can't parse configuration line:", full_file)
+            env[pair[0]] = pair[1]
     return env
 
 
@@ -86,6 +88,7 @@ class NetDrvEpEnv:
         self._ns_peer = None
 
         if "NETIF" in self.env:
+            self._check_env()
             self.dev = ip("link show dev " + self.env['NETIF'], json=True)[0]
 
             self.v4 = self.env.get("LOCAL_V4")
@@ -141,6 +144,30 @@ class NetDrvEpEnv:
         ip(f"-6 addr add dev {self._ns_peer.nsims[0].ifname} {self.nsim_v6_pfx}2/64 nodad", ns=self._netns)
         ip(f"   link set dev {self._ns_peer.nsims[0].ifname} up", ns=self._netns)
 
+    def _check_env(self):
+        vars_needed = [
+            ["LOCAL_V4", "LOCAL_V6"],
+            ["REMOTE_V4", "REMOTE_V6"],
+            ["REMOTE_TYPE"],
+            ["REMOTE_ARGS"]
+        ]
+        missing = []
+
+        for choice in vars_needed:
+            for entry in choice:
+                if entry in self.env:
+                    break
+            else:
+                missing.append(choice)
+        # Make sure v4 / v6 configs are symmetric
+        if ("LOCAL_V6" in self.env) != ("REMOTE_V6" in self.env):
+            missing.append(["LOCAL_V6", "REMOTE_V6"])
+        if ("LOCAL_V4" in self.env) != ("REMOTE_V4" in self.env):
+            missing.append(["LOCAL_V4", "REMOTE_V4"])
+        if missing:
+            raise Exception("Invalid environment, missing configuration:", missing,
+                            "Please see tools/testing/selftests/drivers/net/README.rst")
+
     def __enter__(self):
         return self