includes/libs/UDPTransport.php

   1 <?php
   2 /**
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  16  * http://www.gnu.org/copyleft/gpl.html
  17  *
  18  * @file
  19  */
  20
  21 use Wikimedia\IPUtils;
  22
  23 /**
  24  * A generic class to send a message over UDP
  25  *
  26  * If a message prefix is provided to the constructor or via
  27  * UDPTransport::newFromString(), the payload of the UDP datagrams emitted
  28  * will be formatted with the prefix and a single space at the start of each
  29  * line. This is the payload format expected by the udp2log service.
  30  *
  31  * @since 1.25
  32  */
  33 class UDPTransport {
  34         // Limit to 64 KiB
  35         public const MAX_PAYLOAD_SIZE = 65507;
  36         private string $host;
  37         private int $port;
  38         /** @var bool|string */
  39         private $prefix;
  40         private int $domain;
  41
  42         /**
  43          * @param string $host IP address to send to
  44          * @param int $port port number
  45          * @param int $domain AF_INET or AF_INET6 constant
  46          * @param string|bool $prefix Prefix to use, false for no prefix
  47          */
  48         public function __construct( $host, $port, $domain, $prefix = false ) {
  49                 $this->host = $host;
  50                 $this->port = $port;
  51                 $this->domain = $domain;
  52                 $this->prefix = $prefix;
  53         }
  54
  55         /**
  56          * @param string $info In the format of "udp://host:port/prefix"
  57          * @return UDPTransport
  58          */
  59         public static function newFromString( $info ) {
  60                 if ( preg_match( '!^udp:(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $info, $m ) ) {
  61                         // IPv6 bracketed host
  62                         $host = $m[1];
  63                         $port = intval( $m[2] );
  64                         $prefix = $m[3] ?? false;
  65                         $domain = AF_INET6;
  66                 } elseif ( preg_match( '!^udp:(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $info, $m ) ) {
  67                         $host = $m[1];
  68                         if ( !IPUtils::isIPv4( $host ) ) {
  69                                 $host = gethostbyname( $host );
  70                         }
  71                         $port = intval( $m[2] );
  72                         $prefix = $m[3] ?? false;
  73                         $domain = AF_INET;
  74                 } else {
  75                         throw new InvalidArgumentException( __METHOD__ . ': Invalid UDP specification' );
  76                 }
  77
  78                 return new self( $host, $port, $domain, $prefix );
  79         }
  80
  81         /**
  82          * @param string $text
  83          */
  84         public function emit( $text ): void {
  85                 // Clean it up for the multiplexer
  86                 if ( $this->prefix !== false ) {
  87                         $text = preg_replace( '/^/m', $this->prefix . ' ', $text );
  88
  89                         if ( strlen( $text ) > self::MAX_PAYLOAD_SIZE - 1 ) {
  90                                 $text = substr( $text, 0, self::MAX_PAYLOAD_SIZE - 1 );
  91                         }
  92
  93                         if ( substr( $text, -1 ) != "\n" ) {
  94                                 $text .= "\n";
  95                         }
  96                 } elseif ( strlen( $text ) > self::MAX_PAYLOAD_SIZE ) {
  97                         $text = substr( $text, 0, self::MAX_PAYLOAD_SIZE );
  98                 }
  99
 100                 $sock = socket_create( $this->domain, SOCK_DGRAM, SOL_UDP );
 101                 if ( !$sock ) { // @todo should this throw an exception?
 102                         return;
 103                 }
 104
 105                 socket_sendto( $sock, $text, strlen( $text ), 0, $this->host, $this->port );
 106                 socket_close( $sock );
 107         }
 108 }