3/28/2020, 10:36HEADmaster

1 files changed, 309 insertions, 0 deletions

diff --git a/includes/vendor/maxmind-db/reader/src/MaxMind/Db/Reader.php b/includes/vendor/maxmind-db/reader/src/MaxMind/Db/Reader.php
new file mode 100644
index 0000000..745f7bb
--- /dev/null
+++ b/includes/vendor/maxmind-db/reader/src/MaxMind/Db/Reader.php
@@ -0,0 +1,309 @@
+<?php
+
+namespace MaxMind\Db;
+
+use MaxMind\Db\Reader\Decoder;
+use MaxMind\Db\Reader\InvalidDatabaseException;
+use MaxMind\Db\Reader\Metadata;
+use MaxMind\Db\Reader\Util;
+
+/**
+ * Instances of this class provide a reader for the MaxMind DB format. IP
+ * addresses can be looked up using the <code>get</code> method.
+ */
+class Reader
+{
+    private static $DATA_SECTION_SEPARATOR_SIZE = 16;
+    private static $METADATA_START_MARKER = "\xAB\xCD\xEFMaxMind.com";
+    private static $METADATA_START_MARKER_LENGTH = 14;
+    private static $METADATA_MAX_SIZE = 131072; // 128 * 1024 = 128KB
+
+    private $decoder;
+    private $fileHandle;
+    private $fileSize;
+    private $ipV4Start;
+    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 $database
+     *                         the MaxMind DB file to use
+     *
+     * @throws \InvalidArgumentException                   for invalid database path or unknown arguments
+     * @throws \MaxMind\Db\Reader\InvalidDatabaseException
+     *                                                     if the database is invalid or there is an error reading
+     *                                                     from it
+     */
+    public function __construct($database)
+    {
+        if (\func_num_args() !== 1) {
+            throw new \InvalidArgumentException(
+                'The constructor takes exactly one argument.'
+            );
+        }
+
+        if (!is_readable($database)) {
+            throw new \InvalidArgumentException(
+                "The file \"$database\" does not exist or is not readable."
+            );
+        }
+        $this->fileHandle = @fopen($database, 'rb');
+        if ($this->fileHandle === false) {
+            throw new \InvalidArgumentException(
+                "Error opening \"$database\"."
+            );
+        }
+        $this->fileSize = @filesize($database);
+        if ($this->fileSize === false) {
+            throw new \UnexpectedValueException(
+                "Error determining the size of \"$database\"."
+            );
+        }
+
+        $start = $this->findMetadataStart($database);
+        $metadataDecoder = new Decoder($this->fileHandle, $start);
+        list($metadataArray) = $metadataDecoder->decode($start);
+        $this->metadata = new Metadata($metadataArray);
+        $this->decoder = new Decoder(
+            $this->fileHandle,
+            $this->metadata->searchTreeSize + self::$DATA_SECTION_SEPARATOR_SIZE
+        );
+    }
+
+    /**
+     * Looks up the <code>address</code> in the MaxMind DB.
+     *
+     * @param string $ipAddress
+     *                          the IP address to look up
+     *
+     * @throws \BadMethodCallException   if this method is called on a closed database
+     * @throws \InvalidArgumentException if something other than a single IP address is passed to the method
+     * @throws InvalidDatabaseException
+     *                                   if the database is invalid or there is an error reading
+     *                                   from it
+     *
+     * @return array the record for the IP address
+     */
+    public function get($ipAddress)
+    {
+        if (\func_num_args() !== 1) {
+            throw new \InvalidArgumentException(
+                'Method takes exactly one argument.'
+            );
+        }
+
+        if (!\is_resource($this->fileHandle)) {
+            throw new \BadMethodCallException(
+                'Attempt to read from a closed MaxMind DB.'
+            );
+        }
+
+        if (!filter_var($ipAddress, FILTER_VALIDATE_IP)) {
+            throw new \InvalidArgumentException(
+                "The value \"$ipAddress\" is not a valid IP address."
+            );
+        }
+
+        if ($this->metadata->ipVersion === 4 && strrpos($ipAddress, ':')) {
+            throw new \InvalidArgumentException(
+                "Error looking up $ipAddress. You attempted to look up an"
+                . ' IPv6 address in an IPv4-only database.'
+            );
+        }
+        $pointer = $this->findAddressInTree($ipAddress);
+        if ($pointer === 0) {
+            return null;
+        }
+
+        return $this->resolveDataPointer($pointer);
+    }
+
+    private function findAddressInTree($ipAddress)
+    {
+        // XXX - could simplify. Done as a byte array to ease porting
+        $rawAddress = array_merge(unpack('C*', inet_pton($ipAddress)));
+
+        $bitCount = \count($rawAddress) * 8;
+
+        // The first node of the tree is always node 0, at the beginning of the
+        // value
+        $node = $this->startNode($bitCount);
+
+        for ($i = 0; $i < $bitCount; ++$i) {
+            if ($node >= $this->metadata->nodeCount) {
+                break;
+            }
+            $tempBit = 0xFF & $rawAddress[$i >> 3];
+            $bit = 1 & ($tempBit >> 7 - ($i % 8));
+
+            $node = $this->readNode($node, $bit);
+        }
+        if ($node === $this->metadata->nodeCount) {
+            // Record is empty
+            return 0;
+        } elseif ($node > $this->metadata->nodeCount) {
+            // Record is a data pointer
+            return $node;
+        }
+        throw new InvalidDatabaseException('Something bad happened');
+    }
+
+    private function startNode($length)
+    {
+        // 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 ($this->metadata->ipVersion === 6 && $length === 32) {
+            return $this->ipV4StartNode();
+        }
+        // The first node of the tree is always node 0, at the beginning of the
+        // value
+        return 0;
+    }
+
+    private function ipV4StartNode()
+    {
+        // This is a defensive check. There is no reason to call this when you
+        // have an IPv4 tree.
+        if ($this->metadata->ipVersion === 4) {
+            return 0;
+        }
+
+        if ($this->ipV4Start) {
+            return $this->ipV4Start;
+        }
+        $node = 0;
+
+        for ($i = 0; $i < 96 && $node < $this->metadata->nodeCount; ++$i) {
+            $node = $this->readNode($node, 0);
+        }
+        $this->ipV4Start = $node;
+
+        return $node;
+    }
+
+    private function readNode($nodeNumber, $index)
+    {
+        $baseOffset = $nodeNumber * $this->metadata->nodeByteSize;
+
+        // XXX - probably could condense this.
+        switch ($this->metadata->recordSize) {
+            case 24:
+                $bytes = Util::read($this->fileHandle, $baseOffset + $index * 3, 3);
+                list(, $node) = unpack('N', "\x00" . $bytes);
+
+                return $node;
+            case 28:
+                $middleByte = Util::read($this->fileHandle, $baseOffset + 3, 1);
+                list(, $middle) = unpack('C', $middleByte);
+                if ($index === 0) {
+                    $middle = (0xF0 & $middle) >> 4;
+                } else {
+                    $middle = 0x0F & $middle;
+                }
+                $bytes = Util::read($this->fileHandle, $baseOffset + $index * 4, 3);
+                list(, $node) = unpack('N', \chr($middle) . $bytes);
+
+                return $node;
+            case 32:
+                $bytes = Util::read($this->fileHandle, $baseOffset + $index * 4, 4);
+                list(, $node) = unpack('N', $bytes);
+
+                return $node;
+            default:
+                throw new InvalidDatabaseException(
+                    'Unknown record size: '
+                    . $this->metadata->recordSize
+                );
+        }
+    }
+
+    private function resolveDataPointer($pointer)
+    {
+        $resolved = $pointer - $this->metadata->nodeCount
+            + $this->metadata->searchTreeSize;
+        if ($resolved > $this->fileSize) {
+            throw new InvalidDatabaseException(
+                "The MaxMind DB file's search tree is corrupt"
+            );
+        }
+
+        list($data) = $this->decoder->decode($resolved);
+
+        return $data;
+    }
+
+    /*
+     * This is an extremely naive but reasonably readable implementation. There
+     * are much faster algorithms (e.g., Boyer-Moore) for this if speed is ever
+     * an issue, but I suspect it won't be.
+     */
+    private function findMetadataStart($filename)
+    {
+        $handle = $this->fileHandle;
+        $fstat = fstat($handle);
+        $fileSize = $fstat['size'];
+        $marker = self::$METADATA_START_MARKER;
+        $markerLength = self::$METADATA_START_MARKER_LENGTH;
+        $metadataMaxLengthExcludingMarker
+            = min(self::$METADATA_MAX_SIZE, $fileSize) - $markerLength;
+
+        for ($i = 0; $i <= $metadataMaxLengthExcludingMarker; ++$i) {
+            for ($j = 0; $j < $markerLength; ++$j) {
+                fseek($handle, $fileSize - $i - $j - 1);
+                $matchBit = fgetc($handle);
+                if ($matchBit !== $marker[$markerLength - $j - 1]) {
+                    continue 2;
+                }
+            }
+
+            return $fileSize - $i;
+        }
+        throw new InvalidDatabaseException(
+            "Error opening database file ($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()
+    {
+        if (\func_num_args()) {
+            throw new \InvalidArgumentException(
+                'Method takes no arguments.'
+            );
+        }
+
+        // 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 $this->metadata;
+    }
+
+    /**
+     * Closes the MaxMind DB and returns resources to the system.
+     *
+     * @throws \Exception
+     *                    if an I/O error occurs
+     */
+    public function close()
+    {
+        if (!\is_resource($this->fileHandle)) {
+            throw new \BadMethodCallException(
+                'Attempt to close a closed MaxMind DB.'
+            );
+        }
+        fclose($this->fileHandle);
+    }
+}