Add missing ETH_P_ALL identifier to socket

[bytemarx]

It seems #10247/#11219 missed a couple identifiers in the socket stub (the _socket stub seems good, though). This PR adds socket.ETH_P_ALL (https://docs.python.org/3/library/socket.html#socket.ETH_P_ALL).

There's also AF_DIVERT and PF_DIVERT missing from the socket stub, as well, but I've omitted those from this PR for a couple reasons. These are only available on FreeBSD systems, which was correctly noted in the comment above their type annotations in _socket, but the condition to check for this availability is (or at least seems to be) logically incorrect:

if sys.version_info >= (3, 12) and sys.platform != "linux" and sys.platform != "win32" and sys.platform != "darwin":
    # Availability: FreeBSD >= 14.0
    AF_DIVERT: int
    PF_DIVERT: int

The sys.platform documentation shows the correct (or at least a more correct) conditional statement:

if sys.platform.startswith('freebsd'):
    # Availability: FreeBSD >= 14.0
    AF_DIVERT: int
    PF_DIVERT: int

And similarly for the socket stub:

if sys.platform.startswith('freebsd'):
    from _socket import (
        AF_DIVERT as AF_DIVERT,
        PF_DIVERT as PF_DIVERT,
    )

All this essentially to ask if the current check (sys.platform != "linux" and sys.platform != "win32" and sys.platform != "darwin") is just how typeshed has decided to check for FreeBSD systems, or if it would be preferable to use the sys.platform.startswith('freebsd') check. And, if this would be preferred, should parsing and checking the version be included, as well?

I also don't have a FreeBSD system to personally test with, so wasn't sure if I should let someone on an actual FreeBSD 14 system handle this (although, I suppose it wouldn't be too much trouble to spin up a FreeBSD VM if necessary).

[srittau]

All this essentially to ask if the current check (sys.platform != "linux" and sys.platform != "win32" and sys.platform != "darwin") is just how typeshed has decided to check for FreeBSD systems, or if it would be preferable to use the sys.platform.startswith('freebsd') check. And, if this would be preferred, should parsing and checking the version be included, as well?

Unfortunately, only simple platform checks using == and != are allowed at the moment, which is why we use the awkward workaround.

[srittau]

For reference, https://typing.readthedocs.io/en/latest/source/stubs.html#version-and-platform-checks documents the currently supported formats. I've also opened python/typing#1732, suggesting to add startswith() checks, but for now the chained together != checks are the best we've got.

[bytemarx]

Understood. For now, I'll just add in those missing FreeBSD identifiers using the current platform check syntax with a comment identifying them as FreeBSD constants.

[bytemarx]

If preferred, can also do this as

if sys.version_info >= (3, 12):
    if sys.platform == "win32":
        AF_HYPERV = 34
    if sys.platform != "linux" and sys.platform != "win32" and sys.platform != "darwin":
        # FreeBSD >= 14.0
        AF_DIVERT = 44

[github-actions]

According to mypy_primer, this change has no effect on the checked open source code. 🤖🎉

[srittau]

Thanks!