xref: /linux/tools/testing/selftests/net/lib/py/netns.py (revision 1a9239bb4253f9076b5b4b2a1a4e8d7defd77a95) 
1# SPDX-License-Identifier: GPL-2.0
2
3from .utils import ip
4import ctypes
5import random
6import string
7
8libc = ctypes.cdll.LoadLibrary('libc.so.6')
9
10
11class NetNS:
12    def __init__(self, name=None):
13        if name:
14            self.name = name
15        else:
16            self.name = ''.join(random.choice(string.ascii_lowercase) for _ in range(8))
17        ip('netns add ' + self.name)
18
19    def __del__(self):
20        if self.name:
21            ip('netns del ' + self.name)
22            self.name = None
23
24    def __enter__(self):
25        return self
26
27    def __exit__(self, ex_type, ex_value, ex_tb):
28        self.__del__()
29
30    def __str__(self):
31        return self.name
32
33    def __repr__(self):
34        return f"NetNS({self.name})"
35
36
37class NetNSEnter:
38    def __init__(self, ns_name):
39        self.ns_path = f"/run/netns/{ns_name}"
40
41    def __enter__(self):
42        self.saved = open("/proc/thread-self/ns/net")
43        with open(self.ns_path) as ns_file:
44            libc.setns(ns_file.fileno(), 0)
45        return self
46
47    def __exit__(self, exc_type, exc_value, traceback):
48        libc.setns(self.saved.fileno(), 0)
49        self.saved.close()
50