inet_pton() rejects valid IPv6 addresses

[nahime0]

Summary

Elephc's native inet_pton() implementation accepts IPv4 but returns false for valid IPv6 addresses. PHP supports both address families and returns a 16-byte packed string for IPv6.

This came up while validating proxy-provided client IP addresses in NativeBin.

Reproducer

<?php

$ipv4 = inet_pton('127.0.0.1');
$ipv6 = inet_pton('2001:4860:4860::8888');

echo is_string($ipv4) ? strlen($ipv4) : -1;
echo "\n";
echo is_string($ipv6) ? strlen($ipv6) : -1;
echo "\n";

Actual behavior

Elephc output:

4
-1

PHP output:

4
16

Expected behavior

Valid IPv6 input should return its 16-byte packed binary representation. Invalid IPv4 or IPv6 input should return false.

Implementation note

The AOT runtime helper is currently documented and implemented as a dotted-quad IPv4 parser in src/codegen_support/runtime/strings/inet_pton.rs, even though the PHP builtin covers IPv4 and IPv6.

Environment

Reproduced on Elephc e47a8e9dab44d3ed08415f115c0f4233adeca0ab. The current remote main only adds a repository-statistics commit after this code revision.

Workaround

NativeBin uses a dedicated IPv6 validator instead of relying on inet_pton() for IPv6 addresses.