socketpool: let ports raise gaierror with the real error code

[mikeysklar]

What

common_hal_socketpool_socketpool_raise_gaierror_noname() was the only way for a port to raise gaierror, so every getaddrinfo() failure surfaced as EAI_NONAME regardless of what actually went wrong. A lookup that failed because the resolver was unreachable looked identical to one for a name that does not exist.

How

Add common_hal_socketpool_socketpool_raise_gaierror(int err), which puts the real code in args[0] where callers can act on it, and express the existing _noname() helper in terms of it.

MP_WEAK MP_NORETURN
void common_hal_socketpool_socketpool_raise_gaierror_noname(void) {
    common_hal_socketpool_socketpool_raise_gaierror(SOCKETPOOL_EAI_NONAME);
}

Existing callers are unchanged and still raise EAI_NONAME with the same message.

No new translatable strings. The message stays "Name or service not known", with the numeric code appended only when it is not NONAME.

zephyr-cp is the first user. Its getaddrinfo path already had the resolver's error in hand and discarded it.

Testing

Built adafruit_metro_esp32s3 on the espressif port, which exercises the shared-bindings change against an existing consumer. Clean build.

No runtime behavior change for existing callers, so there is nothing to observe on hardware for them: _noname() raises the same exception type, code and message as before. The zephyr-cp boards are covered by the port matrix in CI.

Scope

Adds one function and refactors one. Does not change any existing error path.

AI assistance

Written with Claude Code.

[dhalbert]

Thanks - makes sense. I suggest a broader error message for non-NONAME.

[dhalbert]

I think "Name or service not known" can be misleading for error codes other than EAI_NONAME. There are other possibilities, like bad family, etc.

You could use the generic "%q failure: %d", which already exists, and pass MP_QSTR_getaddrinfo for the %q.

[mikeysklar]

Done, with one adjustment: mp_printf takes const char *, so MP_ERROR_TEXT cannot be the format. Used mp_cprintf, which takes mp_rom_error_text_t.

Tested on a SiWx917 DK2605A. A bogus hostname there returns -4 rather than EAI_NONAME, so it lands on the new path:

>>> import wifi, socketpool
>>> pool = socketpool.SocketPool(wifi.radio)
>>> pool.getaddrinfo("no-such-host-xyz.invalid", 80)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
gaierror: (-4, 'getaddrinfo failure: -4')
>>>

Before this change the same lookup reported gaierror(-2, 'Name or service not known'), which was both the wrong code and the wrong reason.