# 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]
self.ifindex = self.dev["ifindex"]
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, queue_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 %u" % (addr, port_count, queue_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, ))