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# Copyright 2024 Helmut Grohne <helmut@subdivi.de>
# SPDX-License-Identifier: GPL-3
import functools
import os
import pathlib
import socket
import unittest
import pytest
import linuxnamespaces
def allow_fork_exit(function):
@functools.wraps(function)
def wrapped(*args, **kwargs):
mainpid = os.getpid()
try:
return function(*args, **kwargs)
except SystemExit as sysexit:
if sysexit.code or os.getpid() == mainpid:
raise
# We're supposed to successfully exit from a child process. If we
# were to return or raise here, pytest would record success or
# failure. Instead we hide this process from pytest.
os._exit(0)
return pytest.mark.forked(wrapped)
class IDAllocationTest(unittest.TestCase):
def test_idalloc(self) -> None:
alloc = linuxnamespaces.IDAllocation()
alloc.add_range(1, 2)
alloc.add_range(5, 4)
self.assertIn(alloc.find(3), (5, 6))
self.assertIn(alloc.allocate(3), (5, 6))
self.assertRaises(ValueError, alloc.find, 3)
self.assertRaises(ValueError, alloc.allocate, 3)
self.assertEqual(alloc.find(2), 1)
def test_merge(self) -> None:
alloc = linuxnamespaces.IDAllocation()
alloc.add_range(1, 2)
alloc.add_range(3, 2)
self.assertIn(alloc.allocate(3), (1, 2))
class UnshareTest(unittest.TestCase):
@pytest.mark.forked
def test_unshare_user(self) -> None:
overflowuid = int(pathlib.Path("/proc/sys/fs/overflowuid").read_text())
idmap = linuxnamespaces.IDMapping(0, os.getuid(), 1)
linuxnamespaces.unshare(linuxnamespaces.CloneFlags.NEWUSER)
self.assertEqual(os.getuid(), overflowuid)
linuxnamespaces.newuidmap(-1, [idmap], False)
self.assertEqual(os.getuid(), 0)
# UID 1 is not mapped.
self.assertRaises(OSError, os.setuid, 1)
@allow_fork_exit
def test_mount_proc(self) -> None:
idmap = linuxnamespaces.IDMapping(0, os.getuid(), 1)
linuxnamespaces.unshare(
linuxnamespaces.CloneFlags.NEWUSER
| linuxnamespaces.CloneFlags.NEWNS
| linuxnamespaces.CloneFlags.NEWPID
)
linuxnamespaces.newuidmap(-1, [idmap], False)
@linuxnamespaces.run_in_fork
def setup() -> None:
self.assertEqual(os.getpid(), 1)
linuxnamespaces.mount("proc", "/proc", "proc")
setup()
@pytest.mark.forked
def test_sethostname(self) -> None:
self.assertRaises(socket.error, socket.sethostname, "example")
linuxnamespaces.unshare(
linuxnamespaces.CloneFlags.NEWUSER
| linuxnamespaces.CloneFlags.NEWUTS
)
socket.sethostname("example")
@pytest.mark.forked
def test_populate_dev(self) -> None:
linuxnamespaces.unshare_user_idmap_nohelper(
0,
0,
linuxnamespaces.CloneFlags.NEWUSER
| linuxnamespaces.CloneFlags.NEWNS,
)
linuxnamespaces.mount("tmpfs", "/mnt", "tmpfs", data="mode=0755")
os.mkdir("/mnt/dev")
linuxnamespaces.populate_dev("/", "/mnt", pidns=False)
self.assertTrue(os.access("/mnt/dev/null", os.W_OK))
pathlib.Path("/mnt/dev/null").write_text("")
class UnshareIdmapTest(unittest.TestCase):
def setUp(self) -> None:
super().setUp()
self.uidalloc = linuxnamespaces.IDAllocation.loadsubid("uid")
self.gidalloc = linuxnamespaces.IDAllocation.loadsubid("gid")
try:
self.uidalloc.find(65536)
self.gidalloc.find(65536)
except ValueError:
self.skipTest("insufficient /etc/sub?id allocation")
@allow_fork_exit
def test_unshare_user_idmap(self) -> None:
overflowuid = int(pathlib.Path("/proc/sys/fs/overflowuid").read_text())
uidmap = linuxnamespaces.IDMapping(
0, self.uidalloc.allocate(65536), 65536
)
self.assertNotEqual(os.getuid(), uidmap.outerstart)
gidmap = linuxnamespaces.IDMapping(
0, self.gidalloc.allocate(65536), 65536
)
pid = os.getpid()
@linuxnamespaces.run_in_fork
def setup() -> None:
linuxnamespaces.newgidmap(pid, [gidmap])
linuxnamespaces.newuidmap(pid, [uidmap])
linuxnamespaces.unshare(linuxnamespaces.CloneFlags.NEWUSER)
setup()
self.assertEqual(os.getuid(), overflowuid)
os.setuid(0)
self.assertEqual(os.getuid(), 0)
os.setuid(1)
self.assertEqual(os.getuid(), 1)
@allow_fork_exit
def test_populate_dev(self) -> None:
uidmap = linuxnamespaces.IDMapping(
0, self.uidalloc.allocate(65536), 65536
)
self.assertNotEqual(os.getuid(), uidmap.outerstart)
gidmap = linuxnamespaces.IDMapping(
0, self.gidalloc.allocate(65536), 65536
)
pid = os.getpid()
@linuxnamespaces.run_in_fork
def setup() -> None:
linuxnamespaces.newgidmap(pid, [gidmap])
linuxnamespaces.newuidmap(pid, [uidmap])
linuxnamespaces.unshare(
linuxnamespaces.CloneFlags.NEWUSER
| linuxnamespaces.CloneFlags.NEWNS
| linuxnamespaces.CloneFlags.NEWPID
)
setup()
os.setreuid(0, 0)
os.setregid(0, 0)
linuxnamespaces.mount("tmpfs", "/mnt", "tmpfs")
os.mkdir("/mnt/dev")
@linuxnamespaces.run_in_fork
def test() -> None:
linuxnamespaces.populate_dev("/", "/mnt")
test()
|