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linux/tools/testing/selftests/net/lib/py/nsim.py
Jakub Kicinski 8554d6e39b selftests: net: support use of NetdevSimDev under "with" in python
Using "with" on an entire driver test env is supported already,
but it's also useful to use "with" on an individual nsim.

Reviewed-by: Petr Machata <petrm@nvidia.com>
Link: https://lore.kernel.org/r/20240412141436.828666-6-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-15 11:21:12 -07:00

133 lines
4 KiB
Python

# SPDX-License-Identifier: GPL-2.0
import json
import os
import random
import re
import time
from .utils import cmd, ip
class NetdevSim:
"""
Class for netdevsim netdevice and its attributes.
"""
def __init__(self, nsimdev, port_index, ifname, ns=None):
# In case udev renamed the netdev to according to new schema,
# check if the name matches the port_index.
nsimnamere = re.compile(r"eni\d+np(\d+)")
match = nsimnamere.match(ifname)
if match and int(match.groups()[0]) != port_index + 1:
raise Exception("netdevice name mismatches the expected one")
self.ifname = ifname
self.nsimdev = nsimdev
self.port_index = port_index
self.ns = ns
self.dfs_dir = "%s/ports/%u/" % (nsimdev.dfs_dir, port_index)
ret = ip("-j link show dev %s" % ifname, ns=ns)
self.dev = json.loads(ret.stdout)[0]
def dfs_write(self, path, val):
self.nsimdev.dfs_write(f'ports/{self.port_index}/' + path, val)
class NetdevSimDev:
"""
Class for netdevsim bus device and its attributes.
"""
@staticmethod
def ctrl_write(path, val):
fullpath = os.path.join("/sys/bus/netdevsim/", path)
with open(fullpath, "w") as f:
f.write(val)
def dfs_write(self, path, val):
fullpath = os.path.join(f"/sys/kernel/debug/netdevsim/netdevsim{self.addr}/", path)
with open(fullpath, "w") as f:
f.write(val)
def __init__(self, port_count=1, ns=None):
# nsim will spawn in init_net, we'll set to actual ns once we switch it there
self.ns = None
if not os.path.exists("/sys/bus/netdevsim"):
cmd("modprobe netdevsim")
addr = random.randrange(1 << 15)
while True:
try:
self.ctrl_write("new_device", "%u %u" % (addr, port_count))
except OSError as e:
if e.errno == errno.ENOSPC:
addr = random.randrange(1 << 15)
continue
raise e
break
self.addr = addr
# As probe of netdevsim device might happen from a workqueue,
# so wait here until all netdevs appear.
self.wait_for_netdevs(port_count)
if ns:
cmd(f"devlink dev reload netdevsim/netdevsim{addr} netns {ns.name}")
self.ns = ns
cmd("udevadm settle", ns=self.ns)
ifnames = self.get_ifnames()
self.dfs_dir = "/sys/kernel/debug/netdevsim/netdevsim%u/" % addr
self.nsims = []
for port_index in range(port_count):
self.nsims.append(self._make_port(port_index, ifnames[port_index]))
self.removed = False
def __enter__(self):
return self
def __exit__(self, ex_type, ex_value, ex_tb):
"""
__exit__ gets called at the end of a "with" block.
"""
self.remove()
def _make_port(self, port_index, ifname):
return NetdevSim(self, port_index, ifname, self.ns)
def get_ifnames(self):
ifnames = []
listdir = cmd(f"ls /sys/bus/netdevsim/devices/netdevsim{self.addr}/net/",
ns=self.ns).stdout.split()
for ifname in listdir:
ifnames.append(ifname)
ifnames.sort()
return ifnames
def wait_for_netdevs(self, port_count):
timeout = 5
timeout_start = time.time()
while True:
try:
ifnames = self.get_ifnames()
except FileNotFoundError as e:
ifnames = []
if len(ifnames) == port_count:
break
if time.time() < timeout_start + timeout:
continue
raise Exception("netdevices did not appear within timeout")
def remove(self):
if not self.removed:
self.ctrl_write("del_device", "%u" % (self.addr, ))
self.removed = True
def remove_nsim(self, nsim):
self.nsims.remove(nsim)
self.ctrl_write("devices/netdevsim%u/del_port" % (self.addr, ),
"%u" % (nsim.port_index, ))