xref: /linux/tools/testing/selftests/net/lib/py/nsim.py (revision 6ce2b689932ba8288ceef9a82c1caf029b0b23f9)
1# SPDX-License-Identifier: GPL-2.0
2
3import json
4import os
5import random
6import re
7import time
8from .utils import cmd, ip
9
10
11class NetdevSim:
12    """
13    Class for netdevsim netdevice and its attributes.
14    """
15
16    def __init__(self, nsimdev, port_index, ifname, ns=None):
17        # In case udev renamed the netdev to according to new schema,
18        # check if the name matches the port_index.
19        nsimnamere = re.compile(r"eni\d+np(\d+)")
20        match = nsimnamere.match(ifname)
21        if match and int(match.groups()[0]) != port_index + 1:
22            raise Exception("netdevice name mismatches the expected one")
23
24        self.ifname = ifname
25        self.nsimdev = nsimdev
26        self.port_index = port_index
27        self.ns = ns
28        self.dfs_dir = "%s/ports/%u/" % (nsimdev.dfs_dir, port_index)
29        ret = ip("-j link show dev %s" % ifname, ns=ns)
30        self.dev = json.loads(ret.stdout)[0]
31
32    def dfs_write(self, path, val):
33        self.nsimdev.dfs_write(f'ports/{self.port_index}/' + path, val)
34
35
36class NetdevSimDev:
37    """
38    Class for netdevsim bus device and its attributes.
39    """
40    @staticmethod
41    def ctrl_write(path, val):
42        fullpath = os.path.join("/sys/bus/netdevsim/", path)
43        with open(fullpath, "w") as f:
44            f.write(val)
45
46    def dfs_write(self, path, val):
47        fullpath = os.path.join(f"/sys/kernel/debug/netdevsim/netdevsim{self.addr}/", path)
48        with open(fullpath, "w") as f:
49            f.write(val)
50
51    def __init__(self, port_count=1, ns=None):
52        # nsim will spawn in init_net, we'll set to actual ns once we switch it there
53        self.ns = None
54
55        if not os.path.exists("/sys/bus/netdevsim"):
56            cmd("modprobe netdevsim")
57
58        addr = random.randrange(1 << 15)
59        while True:
60            try:
61                self.ctrl_write("new_device", "%u %u" % (addr, port_count))
62            except OSError as e:
63                if e.errno == errno.ENOSPC:
64                    addr = random.randrange(1 << 15)
65                    continue
66                raise e
67            break
68        self.addr = addr
69
70        # As probe of netdevsim device might happen from a workqueue,
71        # so wait here until all netdevs appear.
72        self.wait_for_netdevs(port_count)
73
74        if ns:
75            cmd(f"devlink dev reload netdevsim/netdevsim{addr} netns {ns.name}")
76            self.ns = ns
77
78        cmd("udevadm settle", ns=self.ns)
79        ifnames = self.get_ifnames()
80
81        self.dfs_dir = "/sys/kernel/debug/netdevsim/netdevsim%u/" % addr
82
83        self.nsims = []
84        for port_index in range(port_count):
85            self.nsims.append(self._make_port(port_index, ifnames[port_index]))
86
87    def _make_port(self, port_index, ifname):
88        return NetdevSim(self, port_index, ifname, self.ns)
89
90    def get_ifnames(self):
91        ifnames = []
92        listdir = cmd(f"ls /sys/bus/netdevsim/devices/netdevsim{self.addr}/net/",
93                      ns=self.ns).stdout.split()
94        for ifname in listdir:
95            ifnames.append(ifname)
96        ifnames.sort()
97        return ifnames
98
99    def wait_for_netdevs(self, port_count):
100        timeout = 5
101        timeout_start = time.time()
102
103        while True:
104            try:
105                ifnames = self.get_ifnames()
106            except FileNotFoundError as e:
107                ifnames = []
108            if len(ifnames) == port_count:
109                break
110            if time.time() < timeout_start + timeout:
111                continue
112            raise Exception("netdevices did not appear within timeout")
113
114    def remove(self):
115        self.ctrl_write("del_device", "%u" % (self.addr, ))
116
117    def remove_nsim(self, nsim):
118        self.nsims.remove(nsim)
119        self.ctrl_write("devices/netdevsim%u/del_port" % (self.addr, ),
120                        "%u" % (nsim.port_index, ))
121