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f6a290932e
Within a dual VM test-setup a strange behaviour was observed. The two VMs are connected via one vde_switch instance (instancevirtualisation.vlans = [ 1 ]; IMO a bad attribute name for switch instances, has nothing to do with VLANs in sense of 802.1Q). A ping on the base interface (eth1) works, but not on VLAN subinterfaces (vlan1@eth1). A tcpdump of eth1 includes the ARP requests tagged with the subinterfaces VLAN ID, but responses seems not to pass the vde_switch. This works fine if performed on the base interface. Putting the vde_switch in hub mode results in flooding traffic to all vde_switch ports. This results in a expected behaviour and a ping on a VLAN subinterface works as expected. Signed-off-by: Philippe Schaaf <philippe.schaaf@secunet.com>
58 lines
1.7 KiB
Python
58 lines
1.7 KiB
Python
from pathlib import Path
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import io
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import os
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import pty
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import subprocess
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from test_driver.logger import rootlog
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class VLan:
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"""This class handles a VLAN that the run-vm scripts identify via its
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number handles. The network's lifetime equals the object's lifetime.
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"""
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nr: int
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socket_dir: Path
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process: subprocess.Popen
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pid: int
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fd: io.TextIOBase
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def __repr__(self) -> str:
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return f"<Vlan Nr. {self.nr}>"
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def __init__(self, nr: int, tmp_dir: Path):
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self.nr = nr
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self.socket_dir = tmp_dir / f"vde{self.nr}.ctl"
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# TODO: don't side-effect environment here
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os.environ[f"QEMU_VDE_SOCKET_{self.nr}"] = str(self.socket_dir)
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rootlog.info("start vlan")
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pty_master, pty_slave = pty.openpty()
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self.process = subprocess.Popen(
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["vde_switch", "-s", self.socket_dir, "--dirmode", "0700", "--hub"],
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stdin=pty_slave,
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stdout=subprocess.PIPE,
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stderr=subprocess.PIPE,
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shell=False,
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)
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self.pid = self.process.pid
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self.fd = os.fdopen(pty_master, "w")
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self.fd.write("version\n")
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# TODO: perl version checks if this can be read from
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# an if not, dies. we could hang here forever. Fix it.
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assert self.process.stdout is not None
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self.process.stdout.readline()
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if not (self.socket_dir / "ctl").exists():
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rootlog.error("cannot start vde_switch")
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rootlog.info(f"running vlan (pid {self.pid}; ctl {self.socket_dir})")
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def __del__(self) -> None:
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rootlog.info(f"kill vlan (pid {self.pid})")
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self.fd.close()
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self.process.terminate()
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