wiki.techinc.nl/includes/IP.php

260 lines
7.2 KiB
PHP

<?php
/*
* Collection of public static functions to play with IP address
* and IP blocks.
*
* @Author "Ashar Voultoiz" <hashar@altern.org>
* @License GPL v2 or later
*/
// Some regex definition to "play" with IP address and IP address blocks
// An IP is made of 4 bytes from x00 to xFF which is d0 to d255
define( 'RE_IP_BYTE', '(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)');
define( 'RE_IP_ADD' , RE_IP_BYTE . '\.' . RE_IP_BYTE . '\.' . RE_IP_BYTE . '\.' . RE_IP_BYTE );
// An IP block is an IP address and a prefix (d1 to d32)
define( 'RE_IP_PREFIX', '(3[0-2]|[12]?\d)');
define( 'RE_IP_BLOCK', RE_IP_ADD . '\/' . RE_IP_PREFIX);
// For IPv6 canonicalization (NOT for strict validation; these are quite lax!)
define( 'RE_IPV6_WORD', '([0-9A-Fa-f]{1,4})' );
define( 'RE_IPV6_GAP', ':(?:0+:)*(?::(?:0+:)*)?' );
define( 'RE_IPV6_V4_PREFIX', '0*' . RE_IPV6_GAP . '(?:ffff:)?' );
class IP {
/**
* Validate an IP address.
* @return boolean True if it is valid.
*/
public static function isValid( $ip ) {
return preg_match( '/^' . RE_IP_ADD . '$/', $ip) ;
}
/**
* Validate an IP Block.
* @return boolean True if it is valid.
*/
public static function isValidBlock( $ipblock ) {
return ( count(self::toArray($ipblock)) == 1 + 5 );
}
/**
* Determine if an IP address really is an IP address, and if it is public,
* i.e. not RFC 1918 or similar
* Comes from ProxyTools.php
*/
public static function isPublic( $ip ) {
$n = IP::toUnsigned( $ip );
if ( !$n ) {
return false;
}
// ip2long accepts incomplete addresses, as well as some addresses
// followed by garbage characters. Check that it's really valid.
if( $ip != long2ip( $n ) ) {
return false;
}
static $privateRanges = false;
if ( !$privateRanges ) {
$privateRanges = array(
array( '10.0.0.0', '10.255.255.255' ), # RFC 1918 (private)
array( '172.16.0.0', '172.31.255.255' ), # "
array( '192.168.0.0', '192.168.255.255' ), # "
array( '0.0.0.0', '0.255.255.255' ), # this network
array( '127.0.0.0', '127.255.255.255' ), # loopback
);
}
foreach ( $privateRanges as $r ) {
$start = IP::toUnsigned( $r[0] );
$end = IP::toUnsigned( $r[1] );
if ( $n >= $start && $n <= $end ) {
return false;
}
}
return true;
}
/**
* Split out an IP block as an array of 4 bytes and a mask,
* return false if it cant be determined
*
* @parameter $ip string A quad dotted IP address
* @return array
*/
public static function toArray( $ipblock ) {
$matches = array();
if(! preg_match( '/^' . RE_IP_ADD . '(?:\/(?:'.RE_IP_PREFIX.'))?' . '$/', $ipblock, $matches ) ) {
return false;
} else {
return $matches;
}
}
/**
* Return a zero-padded hexadecimal representation of an IP address.
*
* Hexadecimal addresses are used because they can easily be extended to
* IPv6 support. To separate the ranges, the return value from this
* function for an IPv6 address will be prefixed with "v6-", a non-
* hexadecimal string which sorts after the IPv4 addresses.
*
* @param $ip Quad dotted IP address.
*/
public static function toHex( $ip ) {
$n = self::toUnsigned( $ip );
if ( $n !== false ) {
$n = sprintf( '%08X', $n );
}
return $n;
}
/**
* Given an IP address in dotted-quad notation, returns an unsigned integer.
* Like ip2long() except that it actually works and has a consistent error return value.
* Comes from ProxyTools.php
* @param $ip Quad dotted IP address.
*/
public static function toUnsigned( $ip ) {
if ( $ip == '255.255.255.255' ) {
$n = -1;
} else {
$n = ip2long( $ip );
if ( $n == -1 || $n === false ) { # Return value on error depends on PHP version
$n = false;
}
}
if ( $n < 0 ) {
$n += pow( 2, 32 );
}
return $n;
}
/**
* Convert a dotted-quad IP to a signed integer
* Returns false on failure
*/
public static function toSigned( $ip ) {
if ( $ip == '255.255.255.255' ) {
$n = -1;
} else {
$n = ip2long( $ip );
if ( $n == -1 ) {
$n = false;
}
}
return $n;
}
/**
* Convert a network specification in CIDR notation to an integer network and a number of bits
*/
public static function parseCIDR( $range ) {
$parts = explode( '/', $range, 2 );
if ( count( $parts ) != 2 ) {
return array( false, false );
}
$network = IP::toSigned( $parts[0] );
if ( $network !== false && is_numeric( $parts[1] ) && $parts[1] >= 0 && $parts[1] <= 32 ) {
$bits = $parts[1];
if ( $bits == 0 ) {
$network = 0;
} else {
$network &= ~((1 << (32 - $bits)) - 1);
}
# Convert to unsigned
if ( $network < 0 ) {
$network += pow( 2, 32 );
}
} else {
$network = false;
$bits = false;
}
return array( $network, $bits );
}
/**
* Given a string range in a number of formats, return the start and end of
* the range in hexadecimal.
*
* Formats are:
* 1.2.3.4/24 CIDR
* 1.2.3.4 - 1.2.3.5 Explicit range
* 1.2.3.4 Single IP
*/
public static function parseRange( $range ) {
if ( strpos( $range, '/' ) !== false ) {
# CIDR
list( $network, $bits ) = IP::parseCIDR( $range );
if ( $network === false ) {
$start = $end = false;
} else {
$start = sprintf( '%08X', $network );
$end = sprintf( '%08X', $network + pow( 2, (32 - $bits) ) - 1 );
}
} elseif ( strpos( $range, '-' ) !== false ) {
# Explicit range
list( $start, $end ) = array_map( 'trim', explode( '-', $range, 2 ) );
if ( $start > $end ) {
$start = $end = false;
} else {
$start = IP::toHex( $start );
$end = IP::toHex( $end );
}
} else {
# Single IP
$start = $end = IP::toHex( $range );
}
if ( $start === false || $end === false ) {
return array( false, false );
} else {
return array( $start, $end );
}
}
/**
* Determine if a given integer IPv4 address is in a given CIDR network
* @param $addr The address to check against the given range.
* @param $range The range to check the given address against.
* @return bool Whether or not the given address is in the given range.
*/
public static function isInRange( $addr, $range ) {
$unsignedIP = IP::toUnsigned($addr);
list( $start, $end ) = IP::parseRange($range);
$start = hexdec($start);
$end = hexdec($end);
return (($unsignedIP >= $start) && ($unsignedIP <= $end));
}
/**
* Convert some unusual representations of IPv4 addresses to their
* canonical dotted quad representation.
*
* This currently only checks a few IPV4-to-IPv6 related cases. More
* unusual representations may be added later.
*
* @param $addr something that might be an IP address
* @return valid dotted quad IPv4 address or null
*/
public static function canonicalize( $addr ) {
if ( IP::isValid( $addr ) )
return $addr;
// IPv6 loopback address
if ( preg_match( '/^0*' . RE_IPV6_GAP . '1$/', $addr, $m ) )
return '127.0.0.1';
// IPv4-mapped and IPv4-compatible IPv6 addresses
if ( preg_match( '/^' . RE_IPV6_V4_PREFIX . '(' . RE_IP_ADD . ')$/i', $addr, $m ) )
return $m[1];
if ( preg_match( '/^' . RE_IPV6_V4_PREFIX . RE_IPV6_WORD . ':' . RE_IPV6_WORD . '$/i', $addr, $m ) )
return long2ip( ( hexdec( $m[1] ) << 16 ) + hexdec( $m[2] ) );
return null; // give up
}
}
?>