1
0
Fork 0
mirror of synced 2025-03-06 20:59:54 +01:00
linux/tools/testing/selftests/net/lib/py/utils.py
Jakub Kicinski 31611cea8f selftests: drv-net: add a TCP ping test case (and useful helpers)
More complex tests often have to spawn a background process,
like a server which will respond to requests or tcpdump.

Add support for creating such processes using the with keyword:

  with bkg("my-daemon", ..):
     # my-daemon is alive in this block

My initial thought was to add this support to cmd() directly
but it runs the command in the constructor, so by the time
we __enter__ it's too late to make sure we used "background=True".

Second useful helper transplanted from net_helper.sh is
wait_port_listen().

The test itself uses socat, which insists on v6 addresses
being wrapped in [], it's not the only command which requires
this format, so add the wrapped address to env. The hope
is to save test code from checking if address is v6.

Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20240420025237.3309296-7-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-23 10:13:56 -07:00

92 lines
2.7 KiB
Python

# SPDX-License-Identifier: GPL-2.0
import json as _json
import random
import re
import subprocess
import time
class cmd:
def __init__(self, comm, shell=True, fail=True, ns=None, background=False, host=None):
if ns:
comm = f'ip netns exec {ns} ' + comm
self.stdout = None
self.stderr = None
self.ret = None
self.comm = comm
if host:
self.proc = host.cmd(comm)
else:
self.proc = subprocess.Popen(comm, shell=shell, stdout=subprocess.PIPE,
stderr=subprocess.PIPE)
if not background:
self.process(terminate=False, fail=fail)
def process(self, terminate=True, fail=None):
if terminate:
self.proc.terminate()
stdout, stderr = self.proc.communicate(timeout=5)
self.stdout = stdout.decode("utf-8")
self.stderr = stderr.decode("utf-8")
self.proc.stdout.close()
self.proc.stderr.close()
self.ret = self.proc.returncode
if self.proc.returncode != 0 and fail:
if len(stderr) > 0 and stderr[-1] == "\n":
stderr = stderr[:-1]
raise Exception("Command failed: %s\nSTDOUT: %s\nSTDERR: %s" %
(self.proc.args, stdout, stderr))
class bkg(cmd):
def __init__(self, comm, shell=True, fail=True, ns=None, host=None,
exit_wait=False):
super().__init__(comm, background=True,
shell=shell, fail=fail, ns=ns, host=host)
self.terminate = not exit_wait
def __enter__(self):
return self
def __exit__(self, ex_type, ex_value, ex_tb):
return self.process(terminate=self.terminate)
def ip(args, json=None, ns=None, host=None):
cmd_str = "ip "
if json:
cmd_str += '-j '
cmd_str += args
cmd_obj = cmd(cmd_str, ns=ns, host=host)
if json:
return _json.loads(cmd_obj.stdout)
return cmd_obj
def rand_port():
"""
Get unprivileged port, for now just random, one day we may decide to check if used.
"""
return random.randint(1024, 65535)
def wait_port_listen(port, proto="tcp", ns=None, host=None, sleep=0.005, deadline=5):
end = time.monotonic() + deadline
pattern = f":{port:04X} .* "
if proto == "tcp": # for tcp protocol additionally check the socket state
pattern += "0A"
pattern = re.compile(pattern)
while True:
data = cmd(f'cat /proc/net/{proto}*', ns=ns, host=host, shell=True).stdout
for row in data.split("\n"):
if pattern.search(row):
return
if time.monotonic() > end:
raise Exception("Waiting for port listen timed out")
time.sleep(sleep)