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mirror of https://github.com/python/cpython.git synced 2024-11-24 08:52:25 +01:00
cpython/Misc
Barry Warsaw 9522a218f7
bpo-32107 - Better merge of #4494 (#4576)
Improve UUID1 MAC address calculation and related tests.

There are two bits in the MAC address that are relevant to UUID1.  The first is the locally administered vs. universally administered bit (second least significant of the first octet).   Physical network interfaces such as ethernet ports and wireless adapters will always be universally administered, but some interfaces --such as the interface that MacBook Pros communicate with their Touch Bars-- are locally administered.  The former are guaranteed to be globally unique, while the latter are demonstrably *not* globally unique and are in fact the same on every MBP with a Touch Bar.  With this bit is set, the MAC is locally administered; with it unset it is universally administered.

The other bit is the multicast bit (least significant bit of the first octet).  When no other MAC address can be found, RFC 4122 mandates that a random 48-bit number be generated.  This randomly generated number *must* have the multicast bit set.

The improvements in uuid.py include:

* Preferentially return a universally administered MAC address, falling back to a locally administered address if none of the former can be found.
* Improve several coding style issues, such as adding explicit returns of None, using a more readable bitmask pattern, and assuming that the ultimate fallback, random MAC generation will not fail (and propagating any exception there instead of swallowing them).

Improvements in test_uuid.py include:

* Always testing the calculated MAC for universal administration, unless explicitly disabled (i.e. for the random case), or implicitly disabled due to running in the Travis environment.  Travis test machines have *no* universally administered MAC address at the time of this writing.
2017-11-27 14:40:10 -05:00
..
NEWS.d bpo-32107 - Better merge of #4494 (#4576) 2017-11-27 14:40:10 -05:00
ACKS bpo-23033: Improve SSL Certificate handling (GH-937) 2017-11-26 14:31:27 -08:00
coverity_model.c
gdbinit
HISTORY
indent.pro
Porting
python-config.in
python-config.sh.in
python-wing3.wpr
python-wing4.wpr
python-wing5.wpr
python.man bpo-32124: Document C functions safe before init (#4540) 2017-11-24 22:30:27 +01:00
python.pc.in
README
README.AIX Replace KB unit with KiB (#4293) 2017-11-08 14:44:44 -08:00
README.coverity
README.valgrind
SpecialBuilds.txt
svnmap.txt
valgrind-python.supp
vgrindefs

Python Misc subdirectory
========================

This directory contains files that wouldn't fit in elsewhere.  Some
documents are only of historic importance.

Files found here
----------------

ACKS                    Acknowledgements
gdbinit                 Handy stuff to put in your .gdbinit file, if you use gdb
HISTORY                 News from previous releases -- oldest last
indent.pro              GNU indent profile approximating my C style
NEWS                    News for this release (for some meaning of "this")
Porting                 Mini-FAQ on porting to new platforms
python-config.in        Python script template for python-config
python.man              UNIX man page for the python interpreter
python.pc.in            Package configuration info template for pkg-config
python-wing*.wpr        Wing IDE project file
README                  The file you're reading now
README.AIX              Information about using Python on AIX
README.coverity         Information about running Coverity's Prevent on Python
README.valgrind         Information for Valgrind users, see valgrind-python.supp
SpecialBuilds.txt       Describes extra symbols you can set for debug builds
svnmap.txt              Map of old SVN revs and branches to hg changeset ids
valgrind-python.supp    Valgrind suppression file, see README.valgrind
vgrindefs               Python configuration for vgrind (a generic pretty printer)