PHP RFC: Implement socket_getaddrinfo()

• Version: 0.1
• Date: 2016-08-08
• Author: David Walker (dave@mudsite.com)
• Status: Draft
• First Published at: http://wiki.php.net/rfc/socket_getaddrinfo

This RFC targets a reported feature request in #72733. The request is that PHP expose the C level function getaddrinfo(). This is a missing nice piece to the current socket library. When dealing with IP variable networks it would be beneficial to allow libc to tell us what methods of connecting/listening would be most appropriate given a set of hints.

The implementation[1] I'm proposing implements 4 new socket_* functions. socket_getaddrinfo() will return an array of resources, with each resource corresponding to each returned addrinfo sockaddr. The next two implemented methods socket_addrinfo_bind(), and socket_addrinfo_connect(), would be used to bind, or connect, to a given resource rather than make the user go through the process of creating the socket and connect/binding themselves. The fourth function is a free'r if you'd want to free the resources before end of script.

array    socket_getaddrinfo(string node[, mixed service, array hints])
resource socket_addrinfo_connect(sockaddrresource sockaddr)
resource socket_addrinfo_bind(sockaddrresource sockaddr)
null     socket_addrinfo_close(sockaddrresource sockaddr)

<?php
$addrinfo = socket_getaddrinfo('127.0.0.1', 2000, array('ai_family' => AI_INET, 'ai_socktype' => SOCK_STREAM));
$sockaddr = array_shift($addrinfo);
if (!$sockaddr) die ("No Valid Socket Types");
$sock = socket_addrinfo_bind($sockaddr);
// ^^ $sock is a socket resource that is bound to 127.0.0.1:2000 using TCP/IP ready for reading
foreach ($addrinfo as $sockaddr) {
    socket_addrinfo_close($sockaddr);
}

New functionality; no BC problems here.

Next PHP 7.x (currently 7.2)

None

Socket acquired new functionality

None

Exposing the AI_* family of constants.

Vote to implement the new functions, would require a 2/3 majority.

[1] - Proposed RFC Implementation