1 # SPDX-License-Identifier: GPL-2.0
2
3 import errno
4 import json
5 import os
6 import random
7 import re
8 import time
9 from .utils import cmd, ip
10
11
12 class NetdevSim:
13 """
14 Class for netdevsim netdevice and its attributes.
15 """
16
17 def __init__(self, nsimdev, port_index, ifname, ns=None):
18 # In case udev renamed the netdev to according to new schema,
19 # check if the name matches the port_index.
20 nsimnamere = re.compile(r"eni\d+np(\d+)")
21 match = nsimnamere.match(ifname)
22 if match and int(match.groups()[0]) != port_index + 1:
23 raise Exception("netdevice name mismatches the expected one")
24
25 self.ifname = ifname
26 self.nsimdev = nsimdev
27 self.port_index = port_index
28 self.ns = ns
29 self.dfs_dir = "%s/ports/%u/" % (nsimdev.dfs_dir, port_index)
30 ret = ip("-j link show dev %s" % ifname, ns=ns)
31 self.dev = json.loads(ret.stdout)[0]
32 self.ifindex = self.dev["ifindex"]
33
34 def dfs_write(self, path, val):
35 self.nsimdev.dfs_write(f'ports/{self.port_index}/' + path, val)
36
37
38 class NetdevSimDev:
39 """
40 Class for netdevsim bus device and its attributes.
41 """
42 @staticmethod
43 def ctrl_write(path, val):
44 fullpath = os.path.join("/sys/bus/netdevsim/", path)
45 with open(fullpath, "w") as f:
46 f.write(val)
47
48 def dfs_write(self, path, val):
49 fullpath = os.path.join(f"/sys/kernel/debug/netdevsim/netdevsim{self.addr}/", path)
50 with open(fullpath, "w") as f:
51 f.write(val)
52
53 def __init__(self, port_count=1, queue_count=1, ns=None):
54 # nsim will spawn in init_net, we'll set to actual ns once we switch it there
55 self.ns = None
56
57 if not os.path.exists("/sys/bus/netdevsim"):
58 cmd("modprobe netdevsim")
59
60 addr = random.randrange(1 << 15)
61 while True:
62 try:
63 self.ctrl_write("new_device", "%u %u %u" % (addr, port_count, queue_count))
64 except OSError as e:
65 if e.errno == errno.ENOSPC:
66 addr = random.randrange(1 << 15)
67 continue
68 raise e
69 break
70 self.addr = addr
71
72 # As probe of netdevsim device might happen from a workqueue,
73 # so wait here until all netdevs appear.
74 self.wait_for_netdevs(port_count)
75
76 if ns:
77 cmd(f"devlink dev reload netdevsim/netdevsim{addr} netns {ns.name}")
78 self.ns = ns
79
80 cmd("udevadm settle", ns=self.ns)
81 ifnames = self.get_ifnames()
82
83 self.dfs_dir = "/sys/kernel/debug/netdevsim/netdevsim%u/" % addr
84
85 self.nsims = []
86 for port_index in range(port_count):
87 self.nsims.append(self._make_port(port_index, ifnames[port_index]))
88
89 self.removed = False
90
91 def __enter__(self):
92 return self
93
94 def __exit__(self, ex_type, ex_value, ex_tb):
95 """
96 __exit__ gets called at the end of a "with" block.
97 """
98 self.remove()
99
100 def _make_port(self, port_index, ifname):
101 return NetdevSim(self, port_index, ifname, self.ns)
102
103 def get_ifnames(self):
104 ifnames = []
105 listdir = cmd(f"ls /sys/bus/netdevsim/devices/netdevsim{self.addr}/net/",
106 ns=self.ns).stdout.split()
107 for ifname in listdir:
108 ifnames.append(ifname)
109 ifnames.sort()
110 return ifnames
111
112 def wait_for_netdevs(self, port_count):
113 timeout = 5
114 timeout_start = time.time()
115
116 while True:
117 try:
118 ifnames = self.get_ifnames()
119 except FileNotFoundError as e:
120 ifnames = []
121 if len(ifnames) == port_count:
122 break
123 if time.time() < timeout_start + timeout:
124 continue
125 raise Exception("netdevices did not appear within timeout")
126
127 def remove(self):
128 if not self.removed:
129 self.ctrl_write("del_device", "%u" % (self.addr, ))
130 self.removed = True
131
132 def remove_nsim(self, nsim):
133 self.nsims.remove(nsim)
134 self.ctrl_write("devices/netdevsim%u/del_port" % (self.addr, ),
135 "%u" % (nsim.port_index, ))
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