driver/rawnetworkinterfacedriver: ethtool get/change pause settings

Add interface pause configuration (`ethtool --pause`) support to the
RawNetworkInterfaceDriver. This allows configuring the pause parameters
autoneg, rx and tx on the bound interface.

Also add a `get_pause_settings()` method to query those settings.

Signed-off-by: Bastian Krause <bst@pengutronix.de>

helpers/labgrid-raw-interface

@@ -108,6 +108,15 @@ def main(program, options):
             args.append(options.ifname)
             args.extend(options.ethtool_set_eee_args)
 
+        elif options.subcommand == "pause":
+            for arg in options.ethtool_pause_args:
+                if arg.startswith("-") or not allowed_chars.issuperset(arg):
+                    raise ValueError(f"ethtool --pause arg '{arg}' contains invalid characters")
+
+            args.append("--pause")
+            args.append(options.ifname)
+            args.extend(options.ethtool_pause_args)
+
     try:
         os.execvp(args[0], args)
     except FileNotFoundError as e:
@@ -154,6 +163,13 @@ if __name__ == "__main__":
         "ethtool_set_eee_args", metavar="ARG", nargs=argparse.REMAINDER, help="ethtool --set-eee args"
     )
 
+    # ethtool: pause
+    ethtool_change_parser = ethtool_subparsers.add_parser("pause")
+    ethtool_change_parser.add_argument("ifname", type=str, help="interface name")
+    ethtool_change_parser.add_argument(
+        "ethtool_pause_args", metavar="ARG", nargs=argparse.REMAINDER, help="ethtool --pause args"
+    )
+
     args = parser.parse_args()
     try:
         main(args.program, args)

labgrid/driver/rawnetworkinterfacedriver.py

@@ -140,6 +140,28 @@ def ethtool_configure_eee(self, **settings):
         cmd = self._wrap_command(cmd)
         subprocess.check_call(cmd)
 
+    @Driver.check_active
+    def get_ethtool_pause_settings(self):
+        """
+        Returns pause parameters via ethtool of the bound network interface resource.
+        """
+        cmd = self.iface.command_prefix + ["ethtool", "--json", "--show-pause", self.iface.ifname]
+        output = subprocess.check_output(cmd, encoding="utf-8")
+        return json.loads(output)[0]
+
+    @Driver.check_active
+    @step(args=["settings"])
+    def ethtool_configure_pause(self, **settings):
+        """
+        Change pause parameters via ethtool of the bound network interface resource.
+
+        Supported settings are described in ethtool(8) --pause
+        """
+        cmd = ["ethtool", "pause", self.iface.ifname]
+        cmd += [item for pair in settings.items() for item in pair]
+        cmd = self._wrap_command(cmd)
+        subprocess.check_call(cmd)
+
     def _stop(self, proc, *, timeout=None):
         assert proc is not None