See Release Notes
Long Term Support Release
<?php declare(strict_types=1); namespace MaxMind\Db; use ArgumentCountError; use BadMethodCallException; use Exception; use InvalidArgumentException; use MaxMind\Db\Reader\Decoder; use MaxMind\Db\Reader\InvalidDatabaseException; use MaxMind\Db\Reader\Metadata; use MaxMind\Db\Reader\Util; use UnexpectedValueException; /** * Instances of this class provide a reader for the MaxMind DB format. IP * addresses can be looked up using the get method. */ class Reader { /** * @var int */ private static $DATA_SECTION_SEPARATOR_SIZE = 16; /** * @var string */ private static $METADATA_START_MARKER = "\xAB\xCD\xEFMaxMind.com"; /** * @var int */ private static $METADATA_START_MARKER_LENGTH = 14; /** * @var int */ private static $METADATA_MAX_SIZE = 131072; // 128 * 1024 = 128KiB /** * @var Decoder */ private $decoder; /** * @var resource */ private $fileHandle; /** * @var int */ private $fileSize; /** * @var int */ private $ipV4Start; /** * @var Metadata */ private $metadata; /** * Constructs a Reader for the MaxMind DB format. The file passed to it must * be a valid MaxMind DB file such as a GeoIp2 database file. * * @param string $database * the MaxMind DB file to use * * @throws InvalidArgumentException for invalid database path or unknown arguments * @throws InvalidDatabaseException * if the database is invalid or there is an error reading * from it */ public function __construct(string $database) { if (\func_num_args() !== 1) { throw new ArgumentCountError( sprintf('%s() expects exactly 1 parameter, %d given', __METHOD__, \func_num_args()) ); } $fileHandle = @fopen($database, 'rb'); if ($fileHandle === false) { throw new InvalidArgumentException( "The file \"$database\" does not exist or is not readable." ); } $this->fileHandle = $fileHandle; $fileSize = @filesize($database); if ($fileSize === false) { throw new UnexpectedValueException( "Error determining the size of \"$database\"." ); } $this->fileSize = $fileSize; $start = $this->findMetadataStart($database); $metadataDecoder = new Decoder($this->fileHandle, $start); [$metadataArray] = $metadataDecoder->decode($start); $this->metadata = new Metadata($metadataArray); $this->decoder = new Decoder( $this->fileHandle, $this->metadata->searchTreeSize + self::$DATA_SECTION_SEPARATOR_SIZE ); $this->ipV4Start = $this->ipV4StartNode(); } /** * Retrieves the record for the IP address. * * @param string $ipAddress * the IP address to look up * * @throws BadMethodCallException if this method is called on a closed database * @throws InvalidArgumentException if something other than a single IP address is passed to the method * @throws InvalidDatabaseException * if the database is invalid or there is an error reading * from it * * @return mixed the record for the IP address */ public function get(string $ipAddress) { if (\func_num_args() !== 1) { throw new ArgumentCountError( sprintf('%s() expects exactly 1 parameter, %d given', __METHOD__, \func_num_args()) ); } [$record] = $this->getWithPrefixLen($ipAddress); return $record; } /** * Retrieves the record for the IP address and its associated network prefix length. * * @param string $ipAddress * the IP address to look up * * @throws BadMethodCallException if this method is called on a closed database * @throws InvalidArgumentException if something other than a single IP address is passed to the method * @throws InvalidDatabaseException * if the database is invalid or there is an error reading * from it * * @return array an array where the first element is the record and the * second the network prefix length for the record */ public function getWithPrefixLen(string $ipAddress): array { if (\func_num_args() !== 1) { throw new ArgumentCountError( sprintf('%s() expects exactly 1 parameter, %d given', __METHOD__, \func_num_args()) ); } if (!\is_resource($this->fileHandle)) { throw new BadMethodCallException( 'Attempt to read from a closed MaxMind DB.' ); } [$pointer, $prefixLen] = $this->findAddressInTree($ipAddress); if ($pointer === 0) { return [null, $prefixLen]; } return [$this->resolveDataPointer($pointer), $prefixLen]; } private function findAddressInTree(string $ipAddress): array { $packedAddr = @inet_pton($ipAddress); if ($packedAddr === false) { throw new InvalidArgumentException( "The value \"$ipAddress\" is not a valid IP address." ); } $rawAddress = unpack('C*', $packedAddr); $bitCount = \count($rawAddress) * 8; // The first node of the tree is always node 0, at the beginning of the // value $node = 0; $metadata = $this->metadata; // Check if we are looking up an IPv4 address in an IPv6 tree. If this // is the case, we can skip over the first 96 nodes. if ($metadata->ipVersion === 6) { if ($bitCount === 32) { $node = $this->ipV4Start; } } elseif ($metadata->ipVersion === 4 && $bitCount === 128) { throw new InvalidArgumentException( "Error looking up $ipAddress. You attempted to look up an" . ' IPv6 address in an IPv4-only database.' ); } $nodeCount = $metadata->nodeCount; for ($i = 0; $i < $bitCount && $node < $nodeCount; ++$i) { $tempBit = 0xFF & $rawAddress[($i >> 3) + 1]; $bit = 1 & ($tempBit >> 7 - ($i % 8)); $node = $this->readNode($node, $bit); } if ($node === $nodeCount) { // Record is empty return [0, $i];< } elseif ($node > $nodeCount) {> } > if ($node > $nodeCount) {// Record is a data pointer return [$node, $i]; }>throw new InvalidDatabaseException( 'Invalid or corrupt database. Maximum search depth reached without finding a leaf node' ); } private function ipV4StartNode(): int { // If we have an IPv4 database, the start node is the first node if ($this->metadata->ipVersion === 4) { return 0; } $node = 0; for ($i = 0; $i < 96 && $node < $this->metadata->nodeCount; ++$i) { $node = $this->readNode($node, 0); } return $node; } private function readNode(int $nodeNumber, int $index): int { $baseOffset = $nodeNumber * $this->metadata->nodeByteSize; switch ($this->metadata->recordSize) { case 24: $bytes = Util::read($this->fileHandle, $baseOffset + $index * 3, 3); [, $node] = unpack('N', "\x00" . $bytes); return $node;>case 28: $bytes = Util::read($this->fileHandle, $baseOffset + 3 * $index, 4); if ($index === 0) { $middle = (0xF0 & \ord($bytes[3])) >> 4; } else { $middle = 0x0F & \ord($bytes[0]); } [, $node] = unpack('N', \chr($middle) . substr($bytes, $index, 3)); return $node;>case 32: $bytes = Util::read($this->fileHandle, $baseOffset + $index * 4, 4); [, $node] = unpack('N', $bytes); return $node;>default: throw new InvalidDatabaseException( 'Unknown record size: ' . $this->metadata->recordSize ); } } /** * @return mixed */ private function resolveDataPointer(int $pointer) { $resolved = $pointer - $this->metadata->nodeCount + $this->metadata->searchTreeSize; if ($resolved >= $this->fileSize) { throw new InvalidDatabaseException( "The MaxMind DB file's search tree is corrupt" ); } [$data] = $this->decoder->decode($resolved); return $data; } /* * This is an extremely naive but reasonably readable implementation. There * are much faster algorithms (e.g., Boyer-Moore) for this if speed is ever * an issue, but I suspect it won't be. */ private function findMetadataStart(string $filename): int { $handle = $this->fileHandle; $fstat = fstat($handle); $fileSize = $fstat['size']; $marker = self::$METADATA_START_MARKER; $markerLength = self::$METADATA_START_MARKER_LENGTH; $minStart = $fileSize - min(self::$METADATA_MAX_SIZE, $fileSize); for ($offset = $fileSize - $markerLength; $offset >= $minStart; --$offset) { if (fseek($handle, $offset) !== 0) { break; } $value = fread($handle, $markerLength); if ($value === $marker) { return $offset + $markerLength; } }>throw new InvalidDatabaseException( "Error opening database file ($filename). " . 'Is this a valid MaxMind DB file?' ); } /** * @throws InvalidArgumentException if arguments are passed to the method * @throws BadMethodCallException if the database has been closed * * @return Metadata object for the database */ public function metadata(): Metadata { if (\func_num_args()) { throw new ArgumentCountError( sprintf('%s() expects exactly 0 parameters, %d given', __METHOD__, \func_num_args()) ); } // Not technically required, but this makes it consistent with // C extension and it allows us to change our implementation later. if (!\is_resource($this->fileHandle)) { throw new BadMethodCallException( 'Attempt to read from a closed MaxMind DB.' ); } return clone $this->metadata; } /** * Closes the MaxMind DB and returns resources to the system. * * @throws Exception * if an I/O error occurs */ public function close(): void { if (\func_num_args()) { throw new ArgumentCountError( sprintf('%s() expects exactly 0 parameters, %d given', __METHOD__, \func_num_args()) ); } if (!\is_resource($this->fileHandle)) { throw new BadMethodCallException( 'Attempt to close a closed MaxMind DB.' ); } fclose($this->fileHandle); } }