tools/testing/selftests/net/lib/py/nsim.py

Source file repositories/reference/linux-study-clean/tools/testing/selftests/net/lib/py/nsim.py

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/net/lib/py/nsim.py
Extension
.py
Size
4231 bytes
Lines
136
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: tools
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

# SPDX-License-Identifier: GPL-2.0

import errno
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("-d -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

Annotation

Implementation Notes