helpers/labgrid-raw-interface: introduce subparsers per program, pass options

Adding a subparser per program keeps the code cleaner, especially when
introducing ethtool commands in the future. To keep up with various
options, pass the args namespace instead of adding kwargs for each new
setting.

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

Author: Bastian-Krause

helpers/labgrid-raw-interface

@@ -32,18 +32,18 @@ def get_denylist():
     return denylist
 
 
-def main(program, ifname, count):
-    if not ifname:
+def main(program, options):
+    if not options.ifname:
         raise ValueError("Empty interface name.")
-    if any((c == "/" or c.isspace()) for c in ifname):
-        raise ValueError(f"Interface name '{ifname}' contains invalid characters.")
-    if len(ifname) > 16:
-        raise ValueError(f"Interface name '{ifname}' is too long.")
+    if any((c == "/" or c.isspace()) for c in options.ifname):
+        raise ValueError(f"Interface name '{options.ifname}' contains invalid characters.")
+    if len(options.ifname) > 16:
+        raise ValueError(f"Interface name '{options.ifname}' is too long.")
 
     denylist = get_denylist()
 
-    if ifname in denylist:
-        raise ValueError(f"Interface name '{ifname}' is denied in denylist.")
+    if options.ifname in denylist:
+        raise ValueError(f"Interface name '{options.ifname}' is denied in denylist.")
 
     programs = ["tcpreplay", "tcpdump"]
     if program not in programs:
@@ -54,18 +54,18 @@ def main(program, ifname, count):
     ]
 
     if program == "tcpreplay":
-        args.append(f"--intf1={ifname}")
+        args.append(f"--intf1={options.ifname}")
         args.append("-")
 
     if program == "tcpdump":
         args.append("-n")
-        args.append(f"--interface={ifname}")
+        args.append(f"--interface={options.ifname}")
         args.append("-w")
         args.append("-")
 
-        if count:
+        if options.count:
             args.append("-c")
-            args.append(str(count))
+            args.append(str(options.count))
 
     try:
         os.execvp(args[0], args)
@@ -76,12 +76,20 @@ def main(program, ifname, count):
 if __name__ == "__main__":
     parser = argparse.ArgumentParser()
     parser.add_argument("-d", "--debug", action="store_true", default=False, help="enable debug mode")
-    parser.add_argument("program", type=str, help="program to run, either tcpreplay or tcpdump")
-    parser.add_argument("interface", type=str, help="interface name")
-    parser.add_argument("count", nargs="?", type=int, default=None, help="amount of frames to capture while recording")
+    subparsers = parser.add_subparsers(dest="program", help="program to run")
+
+    # tcpdump
+    tcpdump_parser = subparsers.add_parser("tcpdump")
+    tcpdump_parser.add_argument("ifname", type=str, help="interface name")
+    tcpdump_parser.add_argument("count", type=int, default=None, help="amount of frames to capture while recording")
+
+    # tcpreplay
+    tcpreplay_parser = subparsers.add_parser("tcpreplay")
+    tcpreplay_parser.add_argument("ifname", type=str, help="interface name")
+
     args = parser.parse_args()
     try:
-        main(args.program, args.interface, args.count)
+        main(args.program, args)
     except Exception as e:  # pylint: disable=broad-except
         if args.debug:
             import traceback