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gh-132710: only use stable _uuid.generate_time_safe() to deduce MAC address #132901

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gh-132710: only use stable _uuid.generate_time_safe() to deduce MAC address #132901

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@picnixz picnixz commented Apr 25, 2025 •
edited by bedevere-app bot
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picnixz commented Apr 25, 2025

cc @zanieb

@picnixz picnixz force-pushed the fix/uuid/mac-address-libuuid-132710 branch 2 times, most recently from 2d398c9 to 99bdd52 Compare April 25, 2025 08:02
@picnixz picnixz force-pushed the fix/uuid/mac-address-libuuid-132710 branch from 99bdd52 to ee71d62 Compare April 25, 2025 08:03
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picnixz commented Apr 25, 2025
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picnixz commented Apr 25, 2025 •
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@zanieb Does it actually solve your issue? because my system also appears to be unable to get the MAC address... but I was offline (I work offline during the week in general) and I didn't check when I'm online.

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zanieb commented Apr 25, 2025

It's kind of hard to test because I haven't added support for the latest 3.14 in python-build-standalone and the patch doesn't apply cleanly to 3.13.

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zanieb commented Apr 25, 2025 •
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Okay, the patch does apply cleanly to the previous 3.14 alpha so I can test this. On macOS, it does resolve the problem. I did not test Linux.

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zanieb commented Apr 25, 2025

I tested a Linux build at astral-sh/python-build-standalone#595 (comment) and it didn't seem to work.

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picnixz commented Apr 25, 2025

Hum. It's very strange. Did I mess the configure script? what's the value of HAVE_UUID_GENERATE_TIME_SAFE_STABLE_MAC?

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zanieb commented Apr 25, 2025

Looking at the logs... "HAVE_UUID_GENERATE_TIME_SAFE_STABLE_MAC": "0",

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picnixz commented Apr 25, 2025

... so it's not _unix_node() that is being called?

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zanieb commented Apr 25, 2025 •
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The builds are attached there if you want to hop into a debugger.

Briefly... yeah it looks like it's called and we try each getter until we reach the random one:

(Pdb) getter
<function _unix_getnode at 0xffffb77b74d0>
(Pdb) s
--Call--
> /python/install/lib/python3.14/uuid.py(634)_unix_getnode()
-> def _unix_getnode():
(Pdb) n
> /python/install/lib/python3.14/uuid.py(636)_unix_getnode()
-> if _generate_time_safe and _has_stable_extractable_node:
(Pdb) n
--Return--
> /python/install/lib/python3.14/uuid.py(636)_unix_getnode()->None
-> if _generate_time_safe and _has_stable_extractable_node:
(Pdb) n
> /python/install/lib/python3.14/uuid.py(706)getnode()
-> if (_node is not None) and (0 <= _node < (1 << 48)):
(Pdb) l
701  	   for getter in _GETTERS + [_random_getnode]:
702  	       try:
703  	           _node = getter()
704  	       except:
705  	           continue
706  ->	       if (_node is not None) and (0 <= _node < (1 << 48)):
707  	           return _node
708  	   assert False, '_random_getnode() returned invalid value: {}'.format(_node)
709  	
710  	
711  	_last_timestamp = None
(Pdb) n
> /python/install/lib/python3.14/uuid.py(701)getnode()
-> for getter in _GETTERS + [_random_getnode]:
(Pdb) n
> /python/install/lib/python3.14/uuid.py(702)getnode()
-> try:
(Pdb) getter
<function _ip_getnode at 0xffffb77b71d0>
(Pdb) n
> /python/install/lib/python3.14/uuid.py(703)getnode()
-> _node = getter()
(Pdb) n
> /python/install/lib/python3.14/uuid.py(706)getnode()
-> if (_node is not None) and (0 <= _node < (1 << 48)):
(Pdb) _node
(Pdb) n
> /python/install/lib/python3.14/uuid.py(701)getnode()
-> for getter in _GETTERS + [_random_getnode]:
(Pdb) n
> /python/install/lib/python3.14/uuid.py(702)getnode()
-> try:
(Pdb) getter
<function _ifconfig_getnode at 0xffffb77b7110>
(Pdb) n
> /python/install/lib/python3.14/uuid.py(703)getnode()
-> _node = getter()
(Pdb) n
> /python/install/lib/python3.14/uuid.py(706)getnode()
-> if (_node is not None) and (0 <= _node < (1 << 48)):
(Pdb) _node
(Pdb) n
> /python/install/lib/python3.14/uuid.py(701)getnode()
-> for getter in _GETTERS + [_random_getnode]:
(Pdb) n
> /python/install/lib/python3.14/uuid.py(702)getnode()
-> try:
(Pdb) getter
<function _random_getnode at 0xffffb77b7650>
(Pdb) n
> /python/install/lib/python3.14/uuid.py(703)getnode()
-> _node = getter()
(Pdb) n
> /python/install/lib/python3.14/uuid.py(706)getnode()
-> if (_node is not None) and (0 <= _node < (1 << 48)):
(Pdb) _node
23292345252342

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zanieb commented Apr 25, 2025

So, the patch worked but it turns out generate_time_safe is necessary for MAC address retrieval on (at least) ubuntu:latest?

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picnixz commented Apr 25, 2025

Maybe we should add all possible getnode fallbacks based on ifconfig, ip, arp, netstat, lanscan?

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zanieb commented Apr 25, 2025

We did try _ip_getnode and _ifconfig_getnode as expected there. I didn't look into why those might fail. It does feel like a bit of a separate concern than this patch.

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picnixz commented Apr 25, 2025

I suggest adding a print in the except: continue as well just in case and also print the output of the invoked command to see whether we need to upgrade how the output is being parsed.

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zanieb commented Apr 26, 2025

Those commands are just not installed by default in the ubuntu image. If you apt-get install net-tools, the getnode result is static.

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picnixz commented Apr 26, 2025 •
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Ha! so that's why. Let's also fix this by adding them as a dependency then

@picnixz picnixz added the 🔨 test-with-buildbots Test PR w/ buildbots; report in status section label Apr 26, 2025
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🤖 New build scheduled with the buildbot fleet by @picnixz for commit 16200ae 🤖

Results will be shown at:

https://buildbot.python.org/all/#/grid?branch=refs%2Fpull%2F132901%2Fmerge

If you want to schedule another build, you need to add the 🔨 test-with-buildbots label again.

@bedevere-bot bedevere-bot removed the 🔨 test-with-buildbots Test PR w/ buildbots; report in status section label Apr 26, 2025
@picnixz picnixz added the needs backport to 3.13 bugs and security fixes label Apr 26, 2025
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picnixz commented Apr 26, 2025

Ok the refleaks were fixed in #132989.

@picnixz picnixz requested a review from hugovk April 28, 2025 11:07
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