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<?php |
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namespace SamIT\Proxy; |
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class Header |
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{ |
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const CMD_PROXY = 1; |
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const CMD_LOCAL = 0; |
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const UNSPECIFIED_PROTOCOL = "\x00"; |
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const TCP4 = "\x11"; |
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const UDP4 = "\x12"; |
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const TCP6 = "\x21"; |
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const UDP6 = "\x22"; |
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const USTREAM = "\x31"; |
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const USOCK = "\x32"; |
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// 12 bytes. |
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protected static $signatures = [ |
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2 => "\x0D\x0A\x0D\x0A\x00\x0D\x0A\x51\x55\x49\x54\x0A", |
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1 => "PROXY" |
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]; |
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// 4 bits |
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public $version = 2; |
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// 4 bits |
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public $command = self::CMD_PROXY; |
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// 1 byte |
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public $protocol = self::TCP4; |
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protected static $lengths = [ |
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self::TCP4 => 12, |
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self::UDP4 => 12, |
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self::TCP6 => 36, |
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self::UDP6 => 36, |
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self::USTREAM => 216, |
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self::USOCK => 216, |
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]; |
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/** |
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* @var string The address of the client. |
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*/ |
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public $sourceAddress; |
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/** |
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* @var string The address to which the client connected. |
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*/ |
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public $targetAddress; |
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/** |
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* @var int The port of the client |
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*/ |
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public $sourcePort; |
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/** |
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* @var int The port to which the client connected. |
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*/ |
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public $targetPort; |
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protected function getProtocol() |
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{ |
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if ($this->version == 2) { |
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return $this->protocol; |
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} else { |
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return array_flip((new \ReflectionClass($this))->getConstants())[$this->protocol]; |
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} |
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} |
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protected function getVersionCommand() { |
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if ($this->version == 2) { |
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return chr(($this->version << 4) + $this->command); |
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} |
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} |
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/** |
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* @return uint16_t |
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*/ |
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protected function getAddressLength() |
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{ |
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if ($this->version == 2) { |
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return pack('n', self::$lengths[$this->protocol]); |
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} |
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} |
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1 |
View Code Duplication |
protected function encodeAddress($address, $protocol) { |
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if ($this->version == 1) { |
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return $address; |
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} |
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switch ($protocol) { |
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case self::TCP4: |
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case self::UDP4: |
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case self::TCP6: |
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case self::UDP6: |
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$result = inet_pton($address); |
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break; |
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case self::USTREAM: |
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case self::USOCK: |
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throw new \Exception("Unix socket not (yet) supported."); |
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default: |
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throw new \UnexpectedValueException("Invalid protocol."); |
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} |
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return $result; |
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} |
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View Code Duplication |
protected static function decodeAddress($version, $address, $protocol) |
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{ |
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if ($version == 1) { |
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return $address; |
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} |
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switch ($protocol) { |
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case self::TCP4: |
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case self::UDP4: |
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case self::TCP6: |
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case self::UDP6: |
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$result = inet_ntop($address); |
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break; |
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case self::USTREAM: |
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case self::USOCK: |
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throw new \Exception("Unix socket not (yet) supported."); |
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default: |
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throw new \UnexpectedValueException("Invalid protocol."); |
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} |
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return $result; |
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} |
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/** |
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* @return string |
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* @throws \Exception |
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*/ |
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protected function getAddresses() |
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{ |
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return $this->encodeAddress($this->sourceAddress, $this->protocol) . ($this->version == 1 ? " " : "") .$this->encodeAddress($this->targetAddress, $this->protocol); |
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} |
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View Code Duplication |
protected function encodePort($port, $protocol) { |
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if ($this->version == 1) { |
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return $port; |
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} |
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switch ($protocol) { |
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case self::TCP4: |
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case self::UDP4: |
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case self::TCP6: |
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case self::UDP6: |
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$result = pack('n', $port); |
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break; |
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case self::USTREAM: |
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case self::USOCK: |
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throw new \Exception("Unix socket not (yet) supported."); |
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default: |
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throw new \UnexpectedValueException("Invalid protocol."); |
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} |
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return $result; |
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} |
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/** |
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* @return string |
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* @throws \Exception |
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*/ |
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protected function getPorts() |
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{ |
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return $this->encodePort($this->sourcePort, $this->protocol) . ($this->version == 1 ? " " : "") . $this->encodePort($this->targetPort, $this->protocol); |
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} |
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/** |
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* @return string |
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*/ |
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protected function getSignature() |
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{ |
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return self::$signatures[$this->version]; |
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} |
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/** |
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* Constructs the header by concatenating all relevant fields. |
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* @return string |
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*/ |
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public function constructProxyHeader() { |
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return implode($this->version == 1 ? "\x20" : "", array_filter([ |
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$this->getSignature(), |
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$this->getVersionCommand(), |
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$this->getProtocol(), |
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$this->getAddressLength(), |
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$this->getAddresses(), |
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$this->getPorts(), |
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$this->version == 1 ? "\r\n" : null |
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])); |
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} |
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public function __toString() |
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{ |
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return $this->constructProxyHeader(); |
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} |
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/** |
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* This function creates the forwarding header. This header should be sent over the upstream connection as soon as |
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* it is established. |
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* @param string $sourceAddress |
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* @param int $sourcePort |
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* @param string $targetAddress |
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* @param int $targetPort |
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* @return self |
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* @throws \Exception |
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*/ |
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public static function createForward4($sourceAddress, $sourcePort, $targetAddress, $targetPort, $version = 2) { |
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$result = new static(); |
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$result->version = $version; |
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$result->sourceAddress = $sourceAddress; |
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$result->targetPort = $targetPort; |
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$result->targetAddress = $targetAddress; |
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$result->sourcePort = $sourcePort; |
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return $result; |
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} |
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/** |
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* @param string $data |
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* @return Header|null |
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*/ |
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public static function parseHeader(&$data) |
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{ |
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foreach(self::$signatures as $version => $signature) { |
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// Match. |
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if (strncmp($data, $signature, strlen($signature)) === 0) { |
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if ($version === 1) { |
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$result = self::parseVersion1($data); |
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break; |
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} elseif ($version === 2) { |
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$result = self::parseVersion2($data); |
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break; |
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} |
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} |
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} |
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if (isset($result)) { |
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$constructed = $result->constructProxyHeader(); |
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if (strncmp($constructed, $data, strlen($constructed)) === 0) { |
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$data = substr($data, strlen($constructed)); |
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return $result; |
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} |
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} |
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} |
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protected static function parseVersion1($data) |
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{ |
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$parts = explode("\x20", $data); |
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if (count($parts) === 7 && $parts[6] === "\r\n") { |
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$result = new Header(); |
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$result->version = 1; |
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$result->protocol = $parts[1]; |
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$result->sourceAddress = $parts[2]; |
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$result->targetAddress = $parts[3]; |
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$result->sourcePort = $parts[4]; |
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$result->targetPort = $parts[5]; |
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return $result; |
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} |
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} |
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protected static function parseVersion2($data) |
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{ |
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$version = ord(substr($data, 12, 1)) >> 4; |
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$command = ord(substr($data, 12, 1)) % 16; |
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$protocol = substr($data, 13, 1); |
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261
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1 |
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$pos = 16; |
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$sourceAddress = self::decodeAddress($version, substr($data, $pos, self::$lengths[$protocol] / 2 - 2), $protocol); |
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$pos += self::$lengths[$protocol] / 2 - 2; |
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$targetAddress = self::decodeAddress($version, substr($data, $pos, self::$lengths[$protocol] / 2 - 2), $protocol); |
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$pos += self::$lengths[$protocol] / 2 - 2; |
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$sourcePort = unpack('n', substr($data, $pos, 2))[1]; |
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1 |
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$targetPort = unpack('n', substr($data, $pos + 2, 2))[1]; |
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$result = new Header(); |
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1 |
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$result->version = 2; |
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1 |
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$result->command = $command; |
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1 |
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$result->protocol = $protocol; |
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1 |
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$result->sourceAddress = $sourceAddress; |
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1 |
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$result->targetAddress = $targetAddress; |
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1 |
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$result->sourcePort = $sourcePort; |
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1 |
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$result->targetPort = $targetPort; |
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1 |
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return $result; |
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} |
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} |
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