diff options
author | Pierre Schmitz <pierre@archlinux.de> | 2015-12-17 09:15:42 +0100 |
---|---|---|
committer | Pierre Schmitz <pierre@archlinux.de> | 2015-12-17 09:44:51 +0100 |
commit | a1789ddde42033f1b05cc4929491214ee6e79383 (patch) | |
tree | 63615735c4ddffaaabf2428946bb26f90899f7bf /vendor/wikimedia/ip-set/src/IPSet.php | |
parent | 9e06a62f265e3a2aaabecc598d4bc617e06fa32d (diff) |
Update to MediaWiki 1.26.0
Diffstat (limited to 'vendor/wikimedia/ip-set/src/IPSet.php')
-rw-r--r-- | vendor/wikimedia/ip-set/src/IPSet.php | 284 |
1 files changed, 284 insertions, 0 deletions
diff --git a/vendor/wikimedia/ip-set/src/IPSet.php b/vendor/wikimedia/ip-set/src/IPSet.php new file mode 100644 index 00000000..1c79f067 --- /dev/null +++ b/vendor/wikimedia/ip-set/src/IPSet.php @@ -0,0 +1,284 @@ +<?php +/** + * Copyright 2014, 2015 Brandon Black <blblack@gmail.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * http://www.gnu.org/copyleft/gpl.html + * + * @file + * @author Brandon Black <blblack@gmail.com> + */ +namespace IPSet; + +/** + * Matches IP addresses against a set of CIDR specifications + * + * Usage: + * + * // At startup, calculate the optimized data structure for the set: + * $ipset = new IPSet( array( + * '208.80.154.0/26', + * '2620:0:861:1::/64', + * '10.64.0.0/22', + * ) ); + * + * // Runtime check against cached set (returns bool): + * $allowme = $ipset->match( $ip ); + * + * In rough benchmarking, this takes about 80% more time than + * in_array() checks on a short (a couple hundred at most) array + * of addresses. It's fast either way at those levels, though, + * and IPSet would scale better than in_array if the array were + * much larger. + * + * For mixed-family CIDR sets, however, this code gives well over + * 100x speedup vs iterating IP::isInRange() over an array + * of CIDR specs. + * + * The basic implementation is two separate binary trees + * (IPv4 and IPv6) as nested php arrays with keys named 0 and 1. + * The values false and true are terminal match-fail and match-success, + * otherwise the value is a deeper node in the tree. + * + * A simple depth-compression scheme is also implemented: whole-byte + * tree compression at whole-byte boundaries only, where no branching + * occurs during that whole byte of depth. A compressed node has + * keys 'comp' (the byte to compare) and 'next' (the next node to + * recurse into if 'comp' matched successfully). + * + * For example, given these inputs: + * + * 25.0.0.0/9 + * 25.192.0.0/10 + * + * The v4 tree would look like: + * + * root4 => array( + * 'comp' => 25, + * 'next' => array( + * 0 => true, + * 1 => array( + * 0 => false, + * 1 => true, + * ), + * ), + * ); + * + * (multi-byte compression nodes were attempted as well, but were + * a net loss in my test scenarios due to additional match complexity) + */ +class IPSet { + /** @var array $root4 The root of the IPv4 matching tree */ + private $root4 = array( false, false ); + + /** @var array $root6 The root of the IPv6 matching tree */ + private $root6 = array( false, false ); + + /** + * Instantiate the object from an array of CIDR specs + * + * Invalid input network/mask values in $cfg will result in issuing + * E_WARNING and/or E_USER_WARNING and the bad values being ignored. + * + * @param array $cfg Array of IPv[46] CIDR specs as strings + */ + public function __construct( array $cfg ) { + foreach ( $cfg as $cidr ) { + $this->addCidr( $cidr ); + } + + self::recOptimize( $this->root4 ); + self::recCompress( $this->root4, 0, 24 ); + self::recOptimize( $this->root6 ); + self::recCompress( $this->root6, 0, 120 ); + } + + /** + * Add a single CIDR spec to the internal matching trees + * + * @param string $cidr String CIDR spec, IPv[46], optional /mask (def all-1's) + */ + private function addCidr( $cidr ) { + // v4 or v6 check + if ( strpos( $cidr, ':' ) === false ) { + $node =& $this->root4; + $defMask = '32'; + } else { + $node =& $this->root6; + $defMask = '128'; + } + + // Default to all-1's mask if no netmask in the input + if ( strpos( $cidr, '/' ) === false ) { + $net = $cidr; + $mask = $defMask; + } else { + list( $net, $mask ) = explode( '/', $cidr, 2 ); + if ( !ctype_digit( $mask ) || intval( $mask ) > $defMask ) { + trigger_error( "IPSet: Bad mask '$mask' from '$cidr', ignored", E_USER_WARNING ); + return; + } + } + $mask = intval( $mask ); // explicit integer convert, checked above + + // convert $net to an array of integer bytes, length 4 or 16: + $raw = inet_pton( $net ); + if ( $raw === false ) { + return; // inet_pton() sends an E_WARNING for us + } + $rawOrd = array_map( 'ord', str_split( $raw ) ); + + // special-case: zero mask overwrites the whole tree with a pair of terminal successes + if ( $mask == 0 ) { + $node = array( true, true ); + return; + } + + // iterate the bits of the address while walking the tree structure for inserts + $curBit = 0; + while ( 1 ) { + $maskShift = 7 - ( $curBit & 7 ); + $node =& $node[( $rawOrd[$curBit >> 3] & ( 1 << $maskShift ) ) >> $maskShift]; + ++$curBit; + if ( $node === true ) { + // already added a larger supernet, no need to go deeper + return; + } elseif ( $curBit == $mask ) { + // this may wipe out deeper subnets from earlier + $node = true; + return; + } elseif ( $node === false ) { + // create new subarray to go deeper + $node = array( false, false ); + } + } + } + + /** + * Match an IP address against the set + * + * If $ip is unparseable, inet_pton may issue an E_WARNING to that effect + * + * @param string $ip string IPv[46] address + * @return bool True is match success, false is match failure + */ + public function match( $ip ) { + $raw = inet_pton( $ip ); + if ( $raw === false ) { + return false; // inet_pton() sends an E_WARNING for us + } + + $rawOrd = array_map( 'ord', str_split( $raw ) ); + if ( count( $rawOrd ) == 4 ) { + $node =& $this->root4; + } else { + $node =& $this->root6; + } + + $curBit = 0; + while ( 1 ) { + if ( isset( $node['comp'] ) ) { + // compressed node, matches 1 whole byte on a byte boundary + if ( $rawOrd[$curBit >> 3] != $node['comp'] ) { + return false; + } + $curBit += 8; + $node =& $node['next']; + } else { + // uncompressed node, walk in the correct direction for the current bit-value + $maskShift = 7 - ( $curBit & 7 ); + $node =& $node[( $rawOrd[$curBit >> 3] & ( 1 << $maskShift ) ) >> $maskShift]; + ++$curBit; + } + + if ( $node === true || $node === false ) { + return $node; + } + } + } + + /** + * Recursively merges adjacent nets into larger supernets + * + * @param array &$node Tree node to optimize, by-reference + * + * e.g.: 8.0.0.0/8 + 9.0.0.0/8 -> 8.0.0.0/7 + */ + private static function recOptimize( &$node ) { + if ( $node[0] !== false && $node[0] !== true && self::recOptimize( $node[0] ) ) { + $node[0] = true; + } + if ( $node[1] !== false && $node[1] !== true && self::recOptimize( $node[1] ) ) { + $node[1] = true; + } + if ( $node[0] === true && $node[1] === true ) { + return true; + } + return false; + } + + /** + * Recursively compresses a tree + * + * @param array &$node Tree node to compress, by-reference + * @param integer $curBit current depth in the tree + * @param integer $maxCompStart maximum depth at which compression can start, family-specific + * + * This is a very simplistic compression scheme: if we go through a whole + * byte of address starting at a byte boundary with no real branching + * other than immediate false-vs-(node|true), compress that subtree down to a single + * byte-matching node. + * The $maxCompStart check elides recursing the final 7 levels of depth (family-dependent) + */ + private static function recCompress( &$node, $curBit, $maxCompStart ) { + if ( !( $curBit & 7 ) ) { // byte boundary, check for depth-8 single path(s) + $byte = 0; + $cnode =& $node; + $i = 8; + while ( $i-- ) { + if ( $cnode[0] === false ) { + $byte |= 1 << $i; + $cnode =& $cnode[1]; + } elseif ( $cnode[1] === false ) { + $cnode =& $cnode[0]; + } else { + // partial-byte branching, give up + break; + } + } + if ( $i == -1 ) { // means we did not exit the while() via break + $node = array( + 'comp' => $byte, + 'next' => &$cnode, + ); + $curBit += 8; + if ( $cnode !== true ) { + self::recCompress( $cnode, $curBit, $maxCompStart ); + } + return; + } + } + + ++$curBit; + if ( $curBit <= $maxCompStart ) { + if ( $node[0] !== false && $node[0] !== true ) { + self::recCompress( $node[0], $curBit, $maxCompStart ); + } + if ( $node[1] !== false && $node[1] !== true ) { + self::recCompress( $node[1], $curBit, $maxCompStart ); + } + } + } +} |