driver/rawnetworkinterfacedriver: add interface up/down/wait_state

Add methods to the RawNetworkInterfaceDriver to set interfaces up and
down, as well as getting and waiting for the interface state.

This allows the driver to take more control over the interface,
preconfiguration is not needed anymore. Tests that expect the exporter
interface to be down (such as ethernet selftests, cable tests) are now
possible.

Note that the RawNetworkInterfaceDriver now brings the bound interface
up on activate and down on deactivate.

Signed-off-by: Bastian Krause <[email protected]>

Author: Bastian-Krause

helpers/labgrid-raw-interface

@@ -45,7 +45,7 @@ def main(program, options):
     if options.ifname in denylist:
         raise ValueError(f"Interface name '{options.ifname}' is denied in denylist.")
 
-    programs = ["tcpreplay", "tcpdump"]
+    programs = ["tcpreplay", "tcpdump", "ip"]
     if program not in programs:
         raise ValueError(f"Invalid program {program} called with wrapper, valid programs are: {programs}")
 
@@ -57,7 +57,7 @@ def main(program, options):
         args.append(f"--intf1={options.ifname}")
         args.append("-")
 
-    if program == "tcpdump":
+    elif program == "tcpdump":
         args.append("-n")
         args.append(f"--interface={options.ifname}")
         # Write out each packet as it is received
@@ -79,6 +79,13 @@ def main(program, options):
             args.append("-W")
             args.append("1")
 
+    elif program == "ip":
+        args.append("link")
+        args.append("set")
+        args.append("dev")
+        args.append(options.ifname)
+        args.append(options.action)
+
     try:
         os.execvp(args[0], args)
     except FileNotFoundError as e:
@@ -102,6 +109,11 @@ if __name__ == "__main__":
     tcpreplay_parser = subparsers.add_parser("tcpreplay")
     tcpreplay_parser.add_argument("ifname", type=str, help="interface name")
 
+    # ip
+    ip_parser = subparsers.add_parser("ip")
+    ip_parser.add_argument("ifname", type=str, help="interface name")
+    ip_parser.add_argument("action", type=str, choices=["up", "down"], help="action, one of {%(choices)s}")
+
     args = parser.parse_args()
     try:
         main(args.program, args)

labgrid/driver/rawnetworkinterfacedriver.py

@@ -2,6 +2,7 @@
 import contextlib
 import json
 import subprocess
+import time
 
 import attr
 
@@ -10,6 +11,7 @@
 from ..step import step
 from ..util.helper import processwrapper
 from ..util.managedfile import ManagedFile
+from ..util.timeout import Timeout
 from ..resource.common import NetworkResource
 
 
@@ -25,6 +27,14 @@ def __attrs_post_init__(self):
         self._record_handle = None
         self._replay_handle = None
 
+    def on_activate(self):
+        self._set_interface("up")
+        self._wait_state("up")
+
+    def on_deactivate(self):
+        self._set_interface("down")
+        self._wait_state("down")
+
     def _wrap_command(self, args):
         wrapper = ["sudo", "labgrid-raw-interface"]
 
@@ -35,6 +45,58 @@ def _wrap_command(self, args):
             # keep wrapper and args as-is
             return wrapper + args
 
+    @step(args=["state"])
+    def _set_interface(self, state):
+        """Set interface to given state."""
+        cmd = ["ip", self.iface.ifname, state]
+        cmd = self._wrap_command(cmd)
+        subprocess.check_call(cmd)
+
+    @Driver.check_active
+    def set_interface_up(self):
+        """Set bound interface up."""
+        self._set_interface("up")
+
+    @Driver.check_active
+    def set_interface_down(self):
+        """Set bound interface down."""
+        self._set_interface("down")
+
+    def _get_state(self):
+        """Returns the bound interface's operstate."""
+        if_state = self.iface.extra.get("state")
+        if if_state:
+            return if_state
+
+        cmd = self.iface.command_prefix + ["cat", f"/sys/class/net/{self.iface.ifname}/operstate"]
+        output = processwrapper.check_output(cmd).decode("ascii")
+        if_state = output.strip()
+        return if_state
+
+    @Driver.check_active
+    def get_state(self):
+        """Returns the bound interface's operstate."""
+        return self._get_state()
+
+    @step(title="wait_state", args=["expected_state", "timeout"])
+    def _wait_state(self, expected_state, timeout=60):
+        """Wait until the expected state is reached or the timeout expires."""
+        timeout = Timeout(float(timeout))
+
+        while True:
+            if self._get_state() == expected_state:
+                return
+            if timeout.expired:
+                raise TimeoutError(
+                    f"exported interface {self.iface.ifname} did not go {expected_state} within {timeout.timeout} seconds"
+                )
+            time.sleep(1)
+
+    @Driver.check_active
+    def wait_state(self, expected_state, timeout=60):
+        """Wait until the expected state is reached or the timeout expires."""
+        self._wait_state(expected_state, timeout=timeout)
+
     def _stop(self, proc, *, timeout=None):
         assert proc is not None