====== PHP RFC: Implement socket_getaddrinfo() ======
  * Version: 0.1
  * Date: 2016-08-08
  * Author: David Walker (dave@mudsite.com)
  * Status: Implemented (PHP 7.2)
  * First Published at: http://wiki.php.net/rfc/socket_getaddrinfo

===== Introduction =====
This RFC targets a reported feature request in [[https://bugs.php.net/bug.php?id=72733|#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 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.

===== Proposal =====
The implementation[[https://wiki.php.net/rfc/socket_getaddrinfo#references|[1]]] I'm proposing implements 4 new functions.  ''socket_addrinfo_lookup()'' will return an array of resources, with each resource corresponding to each returned addrinfo.  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 last, ``socket_addrinfo_explain`` is to convert the resource to an array for examination.
<file php>
socket_addrinfo_lookup(string node[, mixed service, array hints]) : array
socket_addrinfo_connect(resource $addrinfo) : resource
socket_addrinfo_bind(resource $addrinfo) : resource
socket_addrinfo_explain(resource $addrinfo) : array
</file>

IPv4 Example
<file php>
<?php
$addrinfo = socket_addrinfo_lookup('localhost', 2000, array('ai_family' => AF_INET, 'ai_socktype' => SOCK_STREAM));
$sockaddr = reset($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

var_dump(socket_addrinfo_explain($sockaddr));
/* Outputs:
array(5) {
  ["ai_flags"]=>
  int(0)
  ["ai_family"]=>
  int(2)
  ["ai_socktype"]=>
  int(1)
  ["ai_protocol"]=>
  int(6)
  ["ai_addr"]=>
  array(2) {
    ["sin_port"]=>
    int(2000)
    ["sin_addr"]=>
    string(9) "127.0.0.1"
  }
}
*/
</file>

IPv6 Example
<file php>
<?php
$addrinfo = socket_addrinfo_lookup('localhost', 2000, array('ai_family' => AF_INET6, 'ai_socktype' => SOCK_STREAM));
$sockaddr = reset($addrinfo);
if (!$sockaddr) die ("No Valid Socket Types");
$sock = socket_addrinfo_bind($sockaddr);
// ^^ $sock is a socket resource that is bound to [::1]:2000 using TCP/IP ready for reading

var_dump(socket_addrinfo_explain($sockaddr));
/* Outputs:
array(5) {
  ["ai_flags"]=>
  int(0)
  ["ai_family"]=>
  int(10)
  ["ai_socktype"]=>
  int(1)
  ["ai_protocol"]=>
  int(6)
  ["ai_addr"]=>
  array(2) {
    ["sin6_port"]=>
    int(2000)
    ["sin6_addr"]=>
    string(3) "::1"
  }
}
*/
</file>

===== Backward Incompatible Changes =====
New functionality; no BC issues.

===== Proposed PHP Version(s) =====
Next PHP 7.x (currently 7.2)

===== RFC Impact =====
==== To SAPIs ====
None

==== To Existing Extensions ====
Socket acquired new functionality

==== To Opcache ====
None

==== New Constants ====
Exposing the AI_* family of constants.

===== Proposed Voting Choices =====
Vote to implement the new functionality, would require a 2/3 majority.
<doodle title="Implement socket_getaddrinfo family" auth="bp1222" voteType="single" closed="true">
   * Yes
   * No
</doodle>
Vote Start: 2016-08-24 15:23 UTC

Vote End:   2016-08-31 23:59 UTC

===== Implementation =====

  - merged into master (i.e. pre 7.2)
  - https://github.com/php/php-src/commit/d59af68f
  - https://github.com/php/php-src/commit/750f3d3f
  - a link to the PHP manual entry for the feature

===== References =====
  * [1] - [[https://github.com/php/php-src/pull/2078|Proposed Implementation]]