IP.php

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<?php
// Some regex definition to "play" with IP address and IP address blocks

// An IPv4 address is made of 4 bytes from x00 to xFF which is d0 to d255
define( 'RE_IP_BYTE', '(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|0?[0-9]?[0-9])' );
define( 'RE_IP_ADD', RE_IP_BYTE . '\.' . RE_IP_BYTE . '\.' . RE_IP_BYTE . '\.' . RE_IP_BYTE );
// An IPv4 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 );

// An IPv6 address is made up of 8 words (each x0000 to xFFFF).
// However, the "::" abbreviation can be used on consecutive x0000 words.
define( 'RE_IPV6_WORD', '([0-9A-Fa-f]{1,4})' );
define( 'RE_IPV6_PREFIX', '(12[0-8]|1[01][0-9]|[1-9]?\d)');
define( 'RE_IPV6_ADD',
        '(?:' . // starts with "::" (including "::")
                ':(?::|(?::' . RE_IPV6_WORD . '){1,7})' .
        '|' . // ends with "::" (except "::")
                RE_IPV6_WORD . '(?::' . RE_IPV6_WORD . '){0,6}::' .
        '|' . // contains one "::" in the middle, ending in "::WORD"
                RE_IPV6_WORD . '(?::' . RE_IPV6_WORD . '){0,5}' . '::' . RE_IPV6_WORD .
        '|' . // contains one "::" in the middle, not ending in "::WORD" (regex for PCRE 4.0+)
                RE_IPV6_WORD . '(?::(?P<abn>:(?P<iabn>))?' . RE_IPV6_WORD . '(?!:(?P=abn))){1,5}' .
                        ':' . RE_IPV6_WORD . '(?P=iabn)' .
                // NOTE: (?!(?P=abn)) fails iff "::" used twice; (?P=iabn) passes iff a "::" was found.
        '|' . // contains no "::"
                RE_IPV6_WORD . '(?::' . RE_IPV6_WORD . '){7}' .
        ')'
        // NOTE: With PCRE 7.2+, we can combine the two '"::" in the middle' cases into:
        //              RE_IPV6_WORD . '(?::((?(-1)|:))?' . RE_IPV6_WORD . '){1,6}(?(-2)|^)'
        // This also improves regex concatenation by using relative references.
);
// An IPv6 block is an IP address and a prefix (d1 to d128)
define( 'RE_IPV6_BLOCK', RE_IPV6_ADD . '\/' . RE_IPV6_PREFIX );
// For IPv6 canonicalization (NOT for strict validation; these are quite lax!)
define( 'RE_IPV6_GAP', ':(?:0+:)*(?::(?:0+:)*)?' );
define( 'RE_IPV6_V4_PREFIX', '0*' . RE_IPV6_GAP . '(?:ffff:)?' );

// This might be useful for regexps used elsewhere, matches any IPv6 or IPv6 address or network
define( 'IP_ADDRESS_STRING',
        '(?:' .
                RE_IP_ADD . '(?:\/' . RE_IP_PREFIX . ')?' . // IPv4
        '|' .
                RE_IPV6_ADD . '(?:\/' . RE_IPV6_PREFIX . ')?' . // IPv6
        ')'
);

class IP {
        public static function isIPAddress( $ip ) {
                return (bool)preg_match( '/^' . IP_ADDRESS_STRING . '$/', $ip );
        }

        public static function isIPv6( $ip ) {
                return (bool)preg_match( '/^' . RE_IPV6_ADD . '(?:\/' . RE_IPV6_PREFIX . ')?$/', $ip );
        }

        public static function isIPv4( $ip ) {
                return (bool)preg_match( '/^' . RE_IP_ADD . '(?:\/' . RE_IP_PREFIX . ')?$/', $ip );
        }

        public static function isValid( $ip ) {
                return ( preg_match( '/^' . RE_IP_ADD . '$/', $ip )
                        || preg_match( '/^' . RE_IPV6_ADD . '$/', $ip ) );
        }

        public static function isValidBlock( $ipblock ) {
                return ( preg_match( '/^' . RE_IPV6_BLOCK . '$/', $ipblock )
                        || preg_match( '/^' . RE_IP_BLOCK . '$/', $ipblock ) );
        }

        public static function sanitizeIP( $ip ) {
                $ip = trim( $ip );
                if ( $ip === '' ) {
                        return null;
                }
                if ( self::isIPv4( $ip ) || !self::isIPv6( $ip ) ) {
                        return $ip; // nothing else to do for IPv4 addresses or invalid ones
                }
                // Remove any whitespaces, convert to upper case
                $ip = strtoupper( $ip );
                // Expand zero abbreviations
                $abbrevPos = strpos( $ip, '::' );
                if ( $abbrevPos !== false ) {
                        // We know this is valid IPv6. Find the last index of the
                        // address before any CIDR number (e.g. "a:b:c::/24").
                        $CIDRStart = strpos( $ip, "/" );
                        $addressEnd = ( $CIDRStart !== false )
                                ? $CIDRStart - 1
                                : strlen( $ip ) - 1;
                        // If the '::' is at the beginning...
                        if ( $abbrevPos == 0 ) {
                                $repeat = '0:';
                                $extra = ( $ip == '::' ) ? '0' : ''; // for the address '::'
                                $pad = 9; // 7+2 (due to '::')
                        // If the '::' is at the end...
                        } elseif ( $abbrevPos == ( $addressEnd - 1 ) ) {
                                $repeat = ':0';
                                $extra = '';
                                $pad = 9; // 7+2 (due to '::')
                        // If the '::' is in the middle...
                        } else {
                                $repeat = ':0';
                                $extra = ':';
                                $pad = 8; // 6+2 (due to '::')
                        }
                        $ip = str_replace( '::',
                                str_repeat( $repeat, $pad - substr_count( $ip, ':' ) ) . $extra,
                                $ip
                        );
                }
                // Remove leading zereos from each bloc as needed
                $ip = preg_replace( '/(^|:)0+(' . RE_IPV6_WORD . ')/', '$1$2', $ip );
                return $ip;
        }

        public static function splitHostAndPort( $both ) {
                if ( substr( $both, 0, 1 ) === '[' ) {
                        if ( preg_match( '/^\[(' . RE_IPV6_ADD . ')\](?::(?P<port>\d+))?$/', $both, $m ) ) {
                                if ( isset( $m['port'] ) ) {
                                        return array( $m[1], intval( $m['port'] ) );
                                } else {
                                        return array( $m[1], false );
                                }
                        } else {
                                // Square bracket found but no IPv6
                                return false;
                        }
                }
                $numColons = substr_count( $both, ':' );
                if ( $numColons >= 2 ) {
                        // Is it a bare IPv6 address?
                        if ( preg_match( '/^' . RE_IPV6_ADD . '$/', $both ) ) {
                                return array( $both, false );
                        } else {
                                // Not valid IPv6, but too many colons for anything else
                                return false;
                        }
                }
                if ( $numColons >= 1 ) {
                        // Host:port?
                        $bits = explode( ':', $both );
                        if ( preg_match( '/^\d+/', $bits[1] ) ) {
                                return array( $bits[0], intval( $bits[1] ) );
                        } else {
                                // Not a valid port
                                return false;
                        }
                }
                // Plain hostname
                return array( $both, false );
        }

        public static function combineHostAndPort( $host, $port, $defaultPort = false ) {
                if ( strpos( $host, ':' ) !== false ) {
                        $host = "[$host]";
                }
                if ( $defaultPort !== false && $port == $defaultPort ) {
                        return $host;
                } else {
                        return "$host:$port";
                }
        }

        public static function toOctet( $ip_int ) {
                return self::hexToOctet( wfBaseConvert( $ip_int, 10, 16, 32, false ) );
        }

        public static function formatHex( $hex ) {
                if ( substr( $hex, 0, 3 ) == 'v6-' ) { // IPv6
                        return self::hexToOctet( substr( $hex, 3 ) );
                } else { // IPv4
                        return self::hexToQuad( $hex );
                }
        }

        public static function hexToOctet( $ip_hex ) {
                // Pad hex to 32 chars (128 bits)
                $ip_hex = str_pad( strtoupper( $ip_hex ), 32, '0', STR_PAD_LEFT );
                // Separate into 8 words
                $ip_oct = substr( $ip_hex, 0, 4 );
                for ( $n = 1; $n < 8; $n++ ) {
                        $ip_oct .= ':' . substr( $ip_hex, 4 * $n, 4 );
                }
                // NO leading zeroes
                $ip_oct = preg_replace( '/(^|:)0+(' . RE_IPV6_WORD . ')/', '$1$2', $ip_oct );
                return $ip_oct;
        }

        public static function hexToQuad( $ip_hex ) {
                // Pad hex to 8 chars (32 bits)
                $ip_hex = str_pad( strtoupper( $ip_hex ), 8, '0', STR_PAD_LEFT );
                // Separate into four quads
                $s = '';
                for ( $i = 0; $i < 4; $i++ ) {
                        if ( $s !== '' ) {
                                $s .= '.';
                        }
                        $s .= base_convert( substr( $ip_hex, $i * 2, 2 ), 16, 10 );
                }
                return $s;
        }

        public static function isPublic( $ip ) {
                if ( self::isIPv6( $ip ) ) {
                        return self::isPublic6( $ip );
                }
                $n = self::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 = self::toUnsigned( $r[0] );
                        $end = self::toUnsigned( $r[1] );
                        if ( $n >= $start && $n <= $end ) {
                                return false;
                        }
                }
                return true;
        }

        private static function isPublic6( $ip ) {
                static $privateRanges = false;
                if ( !$privateRanges ) {
                        $privateRanges = array(
                                array( 'fc00::', 'fdff:ffff:ffff:ffff:ffff:ffff:ffff:ffff' ), # RFC 4193 (local)
                                array( '0:0:0:0:0:0:0:1', '0:0:0:0:0:0:0:1' ), # loopback
                        );
                }
                $n = self::toHex( $ip );
                foreach ( $privateRanges as $r ) {
                        $start = self::toHex( $r[0] );
                        $end = self::toHex( $r[1] );
                        if ( $n >= $start && $n <= $end ) {
                                return false;
                        }
                }
                return true;
        }

        public static function toHex( $ip ) {
                if ( self::isIPv6( $ip ) ) {
                        $n = 'v6-' . self::IPv6ToRawHex( $ip );
                } else {
                        $n = self::toUnsigned( $ip );
                        if ( $n !== false ) {
                                $n = wfBaseConvert( $n, 10, 16, 8, false );
                        }
                }
                return $n;
        }

        private static function IPv6ToRawHex( $ip ) {
                $ip = self::sanitizeIP( $ip );
                if ( !$ip ) {
                        return null;
                }
                $r_ip = '';
                foreach ( explode( ':', $ip ) as $v ) {
                        $r_ip .= str_pad( $v, 4, 0, STR_PAD_LEFT );
                }
                return $r_ip;
        }

        public static function toUnsigned( $ip ) {
                if ( self::isIPv6( $ip ) ) {
                        $n = self::toUnsigned6( $ip );
                } else {
                        $n = ip2long( $ip );
                        if ( $n < 0 ) {
                                $n += pow( 2, 32 );
                        }
                }
                return $n;
        }

        private static function toUnsigned6( $ip ) {
                return wfBaseConvert( self::IPv6ToRawHex( $ip ), 16, 10 );
        }

        public static function parseCIDR( $range ) {
                if ( self::isIPv6( $range ) ) {
                        return self::parseCIDR6( $range );
                }
                $parts = explode( '/', $range, 2 );
                if ( count( $parts ) != 2 ) {
                        return array( false, false );
                }
                list( $network, $bits ) = $parts;
                $network = ip2long( $network );
                if ( $network !== false && is_numeric( $bits ) && $bits >= 0 && $bits <= 32 ) {
                        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 );
        }

        public static function parseRange( $range ) {
                // CIDR notation
                if ( strpos( $range, '/' ) !== false ) {
                        if ( self::isIPv6( $range ) ) {
                                return self::parseRange6( $range );
                        }
                        list( $network, $bits ) = self::parseCIDR( $range );
                        if ( $network === false ) {
                                $start = $end = false;
                        } else {
                                $start = sprintf( '%08X', $network );
                                $end = sprintf( '%08X', $network + pow( 2, ( 32 - $bits ) ) - 1 );
                        }
                // Explicit range
                } elseif ( strpos( $range, '-' ) !== false ) {
                        list( $start, $end ) = array_map( 'trim', explode( '-', $range, 2 ) );
                        if ( self::isIPv6( $start ) && self::isIPv6( $end ) ) {
                                return self::parseRange6( $range );
                        }
                        if ( self::isIPv4( $start ) && self::isIPv4( $end ) ) {
                                $start = self::toUnsigned( $start );
                                $end = self::toUnsigned( $end );
                                if ( $start > $end ) {
                                        $start = $end = false;
                                } else {
                                        $start = sprintf( '%08X', $start );
                                        $end = sprintf( '%08X', $end );
                                }
                        } else {
                                $start = $end = false;
                        }
                } else {
                        # Single IP
                        $start = $end = self::toHex( $range );
                }
                if ( $start === false || $end === false ) {
                        return array( false, false );
                } else {
                        return array( $start, $end );
                }
        }

        private static function parseCIDR6( $range ) {
                # Explode into <expanded IP,range>
                $parts = explode( '/', IP::sanitizeIP( $range ), 2 );
                if ( count( $parts ) != 2 ) {
                        return array( false, false );
                }
                list( $network, $bits ) = $parts;
                $network = self::IPv6ToRawHex( $network );
                if ( $network !== false && is_numeric( $bits ) && $bits >= 0 && $bits <= 128 ) {
                        if ( $bits == 0 ) {
                                $network = "0";
                        } else {
                                # Native 32 bit functions WONT work here!!!
                                # Convert to a padded binary number
                                $network = wfBaseConvert( $network, 16, 2, 128 );
                                # Truncate the last (128-$bits) bits and replace them with zeros
                                $network = str_pad( substr( $network, 0, $bits ), 128, 0, STR_PAD_RIGHT );
                                # Convert back to an integer
                                $network = wfBaseConvert( $network, 2, 10 );
                        }
                } else {
                        $network = false;
                        $bits = false;
                }
                return array( $network, (int)$bits );
        }

        private static function parseRange6( $range ) {
                # Expand any IPv6 IP
                $range = IP::sanitizeIP( $range );
                // CIDR notation...
                if ( strpos( $range, '/' ) !== false ) {
                        list( $network, $bits ) = self::parseCIDR6( $range );
                        if ( $network === false ) {
                                $start = $end = false;
                        } else {
                                $start = wfBaseConvert( $network, 10, 16, 32, false );
                                # Turn network to binary (again)
                                $end = wfBaseConvert( $network, 10, 2, 128 );
                                # Truncate the last (128-$bits) bits and replace them with ones
                                $end = str_pad( substr( $end, 0, $bits ), 128, 1, STR_PAD_RIGHT );
                                # Convert to hex
                                $end = wfBaseConvert( $end, 2, 16, 32, false );
                                # see toHex() comment
                                $start = "v6-$start";
                                $end = "v6-$end";
                        }
                // Explicit range notation...
                } elseif ( strpos( $range, '-' ) !== false ) {
                        list( $start, $end ) = array_map( 'trim', explode( '-', $range, 2 ) );
                        $start = self::toUnsigned6( $start );
                        $end = self::toUnsigned6( $end );
                        if ( $start > $end ) {
                                $start = $end = false;
                        } else {
                                $start = wfBaseConvert( $start, 10, 16, 32, false );
                                $end = wfBaseConvert( $end, 10, 16, 32, false );
                        }
                        # see toHex() comment
                        $start = "v6-$start";
                        $end = "v6-$end";
                } else {
                        # Single IP
                        $start = $end = self::toHex( $range );
                }
                if ( $start === false || $end === false ) {
                        return array( false, false );
                } else {
                        return array( $start, $end );
                }
        }

        public static function isInRange( $addr, $range ) {
                $hexIP = self::toHex( $addr );
                list( $start, $end ) = self::parseRange( $range );
                return ( strcmp( $hexIP, $start ) >= 0 &&
                        strcmp( $hexIP, $end ) <= 0 );
        }

        public static function canonicalize( $addr ) {
                if ( self::isValid( $addr ) ) {
                        return $addr;
                }
                // Turn mapped addresses from ::ce:ffff:1.2.3.4 to 1.2.3.4
                if ( strpos( $addr, ':' ) !== false && strpos( $addr, '.' ) !== false ) {
                        $addr = substr( $addr, strrpos( $addr, ':' ) + 1 );
                        if ( self::isIPv4( $addr ) ) {
                                return $addr;
                        }
                }
                // IPv6 loopback address
                $m = array();
                if ( preg_match( '/^0*' . RE_IPV6_GAP . '1$/', $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
        }

        public static function sanitizeRange( $range ) {
                list( /*...*/, $bits ) = self::parseCIDR( $range );
                list( $start, /*...*/ ) = self::parseRange( $range );
                $start = self::formatHex( $start );
                if ( $bits === false ) {
                        return $start; // wasn't actually a range
                }
                return "$start/$bits";
        }
}