[Python-checkins] Revert "bpo-32107 - Better merge of #4494 (#4576)" (#4593)
Victor Stinner
webhook-mailer at python.org
Mon Nov 27 18:30:24 EST 2017
https://github.com/python/cpython/commit/c9409f7c4533f75b11a4c44e839d95a1403f8a0a
commit: c9409f7c4533f75b11a4c44e839d95a1403f8a0a
branch: master
author: Victor Stinner <victor.stinner at gmail.com>
committer: GitHub <noreply at github.com>
date: 2017-11-28T00:30:21+01:00
summary:
Revert "bpo-32107 - Better merge of #4494 (#4576)" (#4593)
This reverts commit 9522a218f7dff95c490ff359cc60e8c2af35f5c8.
files:
D Misc/NEWS.d/next/Library/2017-11-26-18-48-17.bpo-32107.h2ph2K.rst
M Lib/test/test_uuid.py
M Lib/uuid.py
diff --git a/Lib/test/test_uuid.py b/Lib/test/test_uuid.py
index 54d73f7391e..083c2aa8aab 100644
--- a/Lib/test/test_uuid.py
+++ b/Lib/test/test_uuid.py
@@ -512,69 +512,60 @@ def test_find_mac(self):
self.assertEqual(mac, 0x1234567890ab)
- def check_node(self, node, requires=None, *, check_bit=True):
+ def check_node(self, node, requires=None, network=False):
if requires and node is None:
self.skipTest('requires ' + requires)
hex = '%012x' % node
if support.verbose >= 2:
print(hex, end=' ')
- # The MAC address will be universally administered (i.e. the second
- # least significant bit of the first octet must be unset) for any
- # physical interface, such as an ethernet port or wireless adapter.
- # There are some cases where this won't be the case. Randomly
- # generated MACs may not be universally administered, but they must
- # have their multicast bit set, though this is tested in the
- # `test_random_getnode()` method specifically. Another case is the
- # Travis-CI case, which apparently only has locally administered MAC
- # addresses.
- if check_bit and not os.getenv('TRAVIS'):
- self.assertFalse(node & (1 << 41), '%012x' % node)
+ if network:
+ # 47 bit will never be set in IEEE 802 addresses obtained
+ # from network cards.
+ self.assertFalse(node & 0x010000000000, hex)
self.assertTrue(0 < node < (1 << 48),
"%s is not an RFC 4122 node ID" % hex)
@unittest.skipUnless(os.name == 'posix', 'requires Posix')
def test_ifconfig_getnode(self):
node = self.uuid._ifconfig_getnode()
- self.check_node(node, 'ifconfig')
+ self.check_node(node, 'ifconfig', True)
@unittest.skipUnless(os.name == 'posix', 'requires Posix')
def test_ip_getnode(self):
node = self.uuid._ip_getnode()
- self.check_node(node, 'ip')
+ self.check_node(node, 'ip', True)
@unittest.skipUnless(os.name == 'posix', 'requires Posix')
def test_arp_getnode(self):
node = self.uuid._arp_getnode()
- self.check_node(node, 'arp')
+ self.check_node(node, 'arp', True)
@unittest.skipUnless(os.name == 'posix', 'requires Posix')
def test_lanscan_getnode(self):
node = self.uuid._lanscan_getnode()
- self.check_node(node, 'lanscan')
+ self.check_node(node, 'lanscan', True)
@unittest.skipUnless(os.name == 'posix', 'requires Posix')
def test_netstat_getnode(self):
node = self.uuid._netstat_getnode()
- self.check_node(node, 'netstat')
+ self.check_node(node, 'netstat', True)
@unittest.skipUnless(os.name == 'nt', 'requires Windows')
def test_ipconfig_getnode(self):
node = self.uuid._ipconfig_getnode()
- self.check_node(node, 'ipconfig')
+ self.check_node(node, 'ipconfig', True)
@unittest.skipUnless(importable('win32wnet'), 'requires win32wnet')
@unittest.skipUnless(importable('netbios'), 'requires netbios')
def test_netbios_getnode(self):
node = self.uuid._netbios_getnode()
- self.check_node(node)
+ self.check_node(node, network=True)
def test_random_getnode(self):
node = self.uuid._random_getnode()
- # The multicast bit, i.e. the least significant bit of first octet,
- # must be set for randomly generated MAC addresses. See RFC 4122,
- # $4.1.6.
- self.assertTrue(node & (1 << 40), '%012x' % node)
- self.check_node(node, check_bit=False)
+ # Least significant bit of first octet must be set.
+ self.assertTrue(node & 0x010000000000, '%012x' % node)
+ self.check_node(node)
@unittest.skipUnless(os.name == 'posix', 'requires Posix')
def test_unix_getnode(self):
@@ -584,17 +575,13 @@ def test_unix_getnode(self):
node = self.uuid._unix_getnode()
except TypeError:
self.skipTest('requires uuid_generate_time')
- # Since we don't know the provenance of the MAC address, don't check
- # whether it is locally or universally administered.
- self.check_node(node, 'unix', check_bit=False)
+ self.check_node(node, 'unix')
@unittest.skipUnless(os.name == 'nt', 'requires Windows')
@unittest.skipUnless(importable('ctypes'), 'requires ctypes')
def test_windll_getnode(self):
node = self.uuid._windll_getnode()
- # Since we don't know the provenance of the MAC address, don't check
- # whether it is locally or universally administered.
- self.check_node(node, check_bit=False)
+ self.check_node(node)
class TestInternalsWithoutExtModule(BaseTestInternals, unittest.TestCase):
diff --git a/Lib/uuid.py b/Lib/uuid.py
index 9e7c672f7a0..020c6e73c86 100644
--- a/Lib/uuid.py
+++ b/Lib/uuid.py
@@ -342,29 +342,11 @@ def _popen(command, *args):
env=env)
return proc
-# For MAC (a.k.a. IEEE 802, or EUI-48) addresses, the second least significant
-# bit of the first octet signifies whether the MAC address is universally (0)
-# or locally (1) administered. Network cards from hardware manufacturers will
-# always be universally administered to guarantee global uniqueness of the MAC
-# address, but any particular machine may have other interfaces which are
-# locally administered. An example of the latter is the bridge interface to
-# the Touch Bar on MacBook Pros.
-#
-# This bit works out to be the 42nd bit counting from 1 being the least
-# significant, or 1<<41. We'll skip over any locally administered MAC
-# addresses, as it makes no sense to use those in UUID calculation.
-#
-# See https://en.wikipedia.org/wiki/MAC_address#Universal_vs._local
-
-def _is_universal(mac):
- return not (mac & (1 << 41))
-
def _find_mac(command, args, hw_identifiers, get_index):
- first_local_mac = None
try:
proc = _popen(command, *args.split())
if not proc:
- return None
+ return
with proc:
for line in proc.stdout:
words = line.lower().rstrip().split()
@@ -373,9 +355,8 @@ def _find_mac(command, args, hw_identifiers, get_index):
try:
word = words[get_index(i)]
mac = int(word.replace(b':', b''), 16)
- if _is_universal(mac):
+ if mac:
return mac
- first_local_mac = first_local_mac or mac
except (ValueError, IndexError):
# Virtual interfaces, such as those provided by
# VPNs, do not have a colon-delimited MAC address
@@ -385,7 +366,6 @@ def _find_mac(command, args, hw_identifiers, get_index):
pass
except OSError:
pass
- return first_local_mac or None
def _ifconfig_getnode():
"""Get the hardware address on Unix by running ifconfig."""
@@ -395,7 +375,6 @@ def _ifconfig_getnode():
mac = _find_mac('ifconfig', args, keywords, lambda i: i+1)
if mac:
return mac
- return None
def _ip_getnode():
"""Get the hardware address on Unix by running ip."""
@@ -403,7 +382,6 @@ def _ip_getnode():
mac = _find_mac('ip', 'link list', [b'link/ether'], lambda i: i+1)
if mac:
return mac
- return None
def _arp_getnode():
"""Get the hardware address on Unix by running arp."""
@@ -426,10 +404,8 @@ def _arp_getnode():
# This works on Linux, FreeBSD and NetBSD
mac = _find_mac('arp', '-an', [os.fsencode('(%s)' % ip_addr)],
lambda i: i+2)
- # Return None instead of 0.
if mac:
return mac
- return None
def _lanscan_getnode():
"""Get the hardware address on Unix by running lanscan."""
@@ -439,36 +415,32 @@ def _lanscan_getnode():
def _netstat_getnode():
"""Get the hardware address on Unix by running netstat."""
# This might work on AIX, Tru64 UNIX.
- first_local_mac = None
try:
proc = _popen('netstat', '-ia')
if not proc:
- return None
+ return
with proc:
words = proc.stdout.readline().rstrip().split()
try:
i = words.index(b'Address')
except ValueError:
- return None
+ return
for line in proc.stdout:
try:
words = line.rstrip().split()
word = words[i]
if len(word) == 17 and word.count(b':') == 5:
mac = int(word.replace(b':', b''), 16)
- if _is_universal(mac):
+ if mac:
return mac
- first_local_mac = first_local_mac or mac
except (ValueError, IndexError):
pass
except OSError:
pass
- return first_local_mac or None
def _ipconfig_getnode():
"""Get the hardware address on Windows by running ipconfig.exe."""
import os, re
- first_local_mac = None
dirs = ['', r'c:\windows\system32', r'c:\winnt\system32']
try:
import ctypes
@@ -486,23 +458,18 @@ def _ipconfig_getnode():
for line in pipe:
value = line.split(':')[-1].strip().lower()
if re.match('([0-9a-f][0-9a-f]-){5}[0-9a-f][0-9a-f]', value):
- mac = int(value.replace('-', ''), 16)
- if _is_universal(mac):
- return mac
- first_local_mac = first_local_mac or mac
- return first_local_mac or None
+ return int(value.replace('-', ''), 16)
def _netbios_getnode():
"""Get the hardware address on Windows using NetBIOS calls.
See http://support.microsoft.com/kb/118623 for details."""
import win32wnet, netbios
- first_local_mac = None
ncb = netbios.NCB()
ncb.Command = netbios.NCBENUM
ncb.Buffer = adapters = netbios.LANA_ENUM()
adapters._pack()
if win32wnet.Netbios(ncb) != 0:
- return None
+ return
adapters._unpack()
for i in range(adapters.length):
ncb.Reset()
@@ -521,11 +488,7 @@ def _netbios_getnode():
bytes = status.adapter_address[:6]
if len(bytes) != 6:
continue
- mac = int.from_bytes(bytes, 'big')
- if _is_universal(mac):
- return mac
- first_local_mac = first_local_mac or mac
- return first_local_mac or None
+ return int.from_bytes(bytes, 'big')
_generate_time_safe = _UuidCreate = None
@@ -638,19 +601,9 @@ def _windll_getnode():
return UUID(bytes=bytes_(_buffer.raw)).node
def _random_getnode():
- """Get a random node ID."""
- # RFC 4122, $4.1.6 says "For systems with no IEEE address, a randomly or
- # pseudo-randomly generated value may be used; see Section 4.5. The
- # multicast bit must be set in such addresses, in order that they will
- # never conflict with addresses obtained from network cards."
- #
- # The "multicast bit" of a MAC address is defined to be "the least
- # significant bit of the first octet". This works out to be the 41st bit
- # counting from 1 being the least significant bit, or 1<<40.
- #
- # See https://en.wikipedia.org/wiki/MAC_address#Unicast_vs._multicast
+ """Get a random node ID, with eighth bit set as suggested by RFC 4122."""
import random
- return random.getrandbits(48) | (1 << 40)
+ return random.getrandbits(48) | 0x010000000000
_node = None
@@ -673,14 +626,13 @@ def getnode():
getters = [_unix_getnode, _ifconfig_getnode, _ip_getnode,
_arp_getnode, _lanscan_getnode, _netstat_getnode]
- for getter in getters:
+ for getter in getters + [_random_getnode]:
try:
_node = getter()
except:
continue
if _node is not None:
return _node
- return _random_getnode()
_last_timestamp = None
diff --git a/Misc/NEWS.d/next/Library/2017-11-26-18-48-17.bpo-32107.h2ph2K.rst b/Misc/NEWS.d/next/Library/2017-11-26-18-48-17.bpo-32107.h2ph2K.rst
deleted file mode 100644
index fc4f5fe9f19..00000000000
--- a/Misc/NEWS.d/next/Library/2017-11-26-18-48-17.bpo-32107.h2ph2K.rst
+++ /dev/null
@@ -1,4 +0,0 @@
-Improve the private ``*_getnode()`` methods for UUID1 such that universally
-administered MAC addresses are preferred over locally administered MAC
-addresses. If only the latter is available, the first such one is returned.
-Improve the related tests and fix some bugs there as well.
More information about the Python-checkins
mailing list