<?php
namespace Ratchet\RFC6455\Messaging;
class Frame implements FrameInterface {
const OP_CONTINUE = 0;
const OP_TEXT = 1;
const OP_BINARY = 2;
const OP_CLOSE = 8;
const OP_PING = 9;
const OP_PONG = 10;
const CLOSE_NORMAL = 1000;
const CLOSE_GOING_AWAY = 1001;
const CLOSE_PROTOCOL = 1002;
const CLOSE_BAD_DATA = 1003;
const CLOSE_NO_STATUS = 1005;
const CLOSE_ABNORMAL = 1006;
const CLOSE_BAD_PAYLOAD = 1007;
const CLOSE_POLICY = 1008;
const CLOSE_TOO_BIG = 1009;
const CLOSE_MAND_EXT = 1010;
const CLOSE_SRV_ERR = 1011;
const CLOSE_TLS = 1015;
const MASK_LENGTH = 4;
/**
* The contents of the frame
* @var string
*/
protected $data = '';
/**
* Number of bytes received from the frame
* @var int
*/
public $bytesRecvd = 0;
/**
* Number of bytes in the payload (as per framing protocol)
* @var int
*/
protected $defPayLen = -1;
/**
* If the frame is coalesced this is true
* This is to prevent doing math every time ::isCoalesced is called
* @var boolean
*/
private $isCoalesced = false;
/**
* The unpacked first byte of the frame
* @var int
*/
protected $firstByte = -1;
/**
* The unpacked second byte of the frame
* @var int
*/
protected $secondByte = -1;
/**
* @var callable
* @returns \UnderflowException
*/
private $ufeg;
/**
* @param string|null $payload
* @param bool $final
* @param int $opcode
* @param callable<\UnderflowException> $ufExceptionFactory
*/
public function __construct($payload = null, $final = true, $opcode = 1, callable $ufExceptionFactory = null) {
$this->ufeg = $ufExceptionFactory ?: function($msg = '') {
return new \UnderflowException($msg);
};
if (null === $payload) {
return;
}
$this->defPayLen = strlen($payload);
$this->firstByte = ($final ? 128 : 0) + $opcode;
$this->secondByte = $this->defPayLen;
$this->isCoalesced = true;
$ext = '';
if ($this->defPayLen > 65535) {
$ext = pack('NN', 0, $this->defPayLen);
$this->secondByte = 127;
} elseif ($this->defPayLen > 125) {
$ext = pack('n', $this->defPayLen);
$this->secondByte = 126;
}
$this->data = chr($this->firstByte) . chr($this->secondByte) . $ext . $payload;
$this->bytesRecvd = 2 + strlen($ext) + $this->defPayLen;
}
/**
* {@inheritdoc}
*/
public function isCoalesced() {
if (true === $this->isCoalesced) {
return true;
}
try {
$payload_length = $this->getPayloadLength();
$payload_start = $this->getPayloadStartingByte();
} catch (\UnderflowException $e) {
return false;
}
$this->isCoalesced = $this->bytesRecvd >= $payload_length + $payload_start;
return $this->isCoalesced;
}
/**
* {@inheritdoc}
*/
public function addBuffer($buf) {
$len = strlen($buf);
$this->data .= $buf;
$this->bytesRecvd += $len;
if ($this->firstByte === -1 && $this->bytesRecvd !== 0) {
$this->firstByte = ord($this->data[0]);
}
if ($this->secondByte === -1 && $this->bytesRecvd >= 2) {
$this->secondByte = ord($this->data[1]);
}
}
/**
* {@inheritdoc}
*/
public function isFinal() {
if (-1 === $this->firstByte) {
throw call_user_func($this->ufeg, 'Not enough bytes received to determine if this is the final frame in message');
}
return 128 === ($this->firstByte & 128);
}
/**
* @return boolean
* @throws \UnderflowException
*/
public function getRsv1() {
if (-1 === $this->firstByte) {
throw call_user_func($this->ufeg, 'Not enough bytes received to determine reserved bit');
}
return 64 === ($this->firstByte & 64);
}
/**
* @return boolean
* @throws \UnderflowException
*/
public function getRsv2() {
if (-1 === $this->firstByte) {
throw call_user_func($this->ufeg, 'Not enough bytes received to determine reserved bit');
}
return 32 === ($this->firstByte & 32);
}
/**
* @return boolean
* @throws \UnderflowException
*/
public function getRsv3() {
if (-1 === $this->firstByte) {
throw call_user_func($this->ufeg, 'Not enough bytes received to determine reserved bit');
}
return 16 === ($this->firstByte & 16);
}
/**
* {@inheritdoc}
*/
public function isMasked() {
if (-1 === $this->secondByte) {
throw call_user_func($this->ufeg, "Not enough bytes received ({$this->bytesRecvd}) to determine if mask is set");
}
return 128 === ($this->secondByte & 128);
}
/**
* {@inheritdoc}
*/
public function getMaskingKey() {
if (!$this->isMasked()) {
return '';
}
$start = 1 + $this->getNumPayloadBytes();
if ($this->bytesRecvd < $start + static::MASK_LENGTH) {
throw call_user_func($this->ufeg, 'Not enough data buffered to calculate the masking key');
}
return substr($this->data, $start, static::MASK_LENGTH);
}
/**
* Create a 4 byte masking key
* @return string
*/
public function generateMaskingKey() {
$mask = '';
for ($i = 1; $i <= static::MASK_LENGTH; $i++) {
$mask .= chr(rand(32, 126));
}
return $mask;
}
/**
* Apply a mask to the payload
* @param string|null If NULL is passed a masking key will be generated
* @throws \OutOfBoundsException
* @throws \InvalidArgumentException If there is an issue with the given masking key
* @return Frame
*/
public function maskPayload($maskingKey = null) {
if (null === $maskingKey) {
$maskingKey = $this->generateMaskingKey();
}
if (static::MASK_LENGTH !== strlen($maskingKey)) {
throw new \InvalidArgumentException("Masking key must be " . static::MASK_LENGTH ." characters");
}
if (extension_loaded('mbstring') && true !== mb_check_encoding($maskingKey, 'US-ASCII')) {
throw new \OutOfBoundsException("Masking key MUST be ASCII");
}
$this->unMaskPayload();
$this->secondByte = $this->secondByte | 128;
$this->data[1] = chr($this->secondByte);
$this->data = substr_replace($this->data, $maskingKey, $this->getNumPayloadBytes() + 1, 0);
$this->bytesRecvd += static::MASK_LENGTH;
$this->data = substr_replace($this->data, $this->applyMask($maskingKey), $this->getPayloadStartingByte(), $this->getPayloadLength());
return $this;
}
/**
* Remove a mask from the payload
* @throws \UnderFlowException If the frame is not coalesced
* @return Frame
*/
public function unMaskPayload() {
if (!$this->isCoalesced()) {
throw call_user_func($this->ufeg, 'Frame must be coalesced before applying mask');
}
if (!$this->isMasked()) {
return $this;
}
$maskingKey = $this->getMaskingKey();
$this->secondByte = $this->secondByte & ~128;
$this->data[1] = chr($this->secondByte);
$this->data = substr_replace($this->data, '', $this->getNumPayloadBytes() + 1, static::MASK_LENGTH);
$this->bytesRecvd -= static::MASK_LENGTH;
$this->data = substr_replace($this->data, $this->applyMask($maskingKey), $this->getPayloadStartingByte(), $this->getPayloadLength());
return $this;
}
/**
* Apply a mask to a string or the payload of the instance
* @param string $maskingKey The 4 character masking key to be applied
* @param string|null $payload A string to mask or null to use the payload
* @throws \UnderflowException If using the payload but enough hasn't been buffered
* @return string The masked string
*/
public function applyMask($maskingKey, $payload = null) {
if (null === $payload) {
if (!$this->isCoalesced()) {
throw call_user_func($this->ufeg, 'Frame must be coalesced to apply a mask');
}
$payload = substr($this->data, $this->getPayloadStartingByte(), $this->getPayloadLength());
}
$len = strlen($payload);
if (0 === $len) {
return '';
}
return $payload ^ str_pad('', $len, $maskingKey, STR_PAD_RIGHT);
// TODO: Remove this before publish - keeping methods here to compare performance (above is faster but need control against v0.3.3)
$applied = '';
for ($i = 0, $len = strlen($payload); $i < $len; $i++) {
$applied .= $payload[$i] ^ $maskingKey[$i % static::MASK_LENGTH];
}
return $applied;
}
/**
* {@inheritdoc}
*/
public function getOpcode() {
if (-1 === $this->firstByte) {
throw call_user_func($this->ufeg, 'Not enough bytes received to determine opcode');
}
return ($this->firstByte & ~240);
}
/**
* Gets the decimal value of bits 9 (10th) through 15 inclusive
* @return int
* @throws \UnderflowException If the buffer doesn't have enough data to determine this
*/
protected function getFirstPayloadVal() {
if (-1 === $this->secondByte) {
throw call_user_func($this->ufeg, 'Not enough bytes received');
}
return $this->secondByte & 127;
}
/**
* @return int (7|23|71) Number of bits defined for the payload length in the fame
* @throws \UnderflowException
*/
protected function getNumPayloadBits() {
if (-1 === $this->secondByte) {
throw call_user_func($this->ufeg, 'Not enough bytes received');
}
// By default 7 bits are used to describe the payload length
// These are bits 9 (10th) through 15 inclusive
$bits = 7;
// Get the value of those bits
$check = $this->getFirstPayloadVal();
// If the value is 126 the 7 bits plus the next 16 are used to describe the payload length
if ($check >= 126) {
$bits += 16;
}
// If the value of the initial payload length are is 127 an additional 48 bits are used to describe length
// Note: The documentation specifies the length is to be 63 bits, but I think that's a typo and is 64 (16+48)
if ($check === 127) {
$bits += 48;
}
return $bits;
}
/**
* This just returns the number of bytes used in the frame to describe the payload length (as opposed to # of bits)
* @see getNumPayloadBits
*/
protected function getNumPayloadBytes() {
return (1 + $this->getNumPayloadBits()) / 8;
}
/**
* {@inheritdoc}
*/
public function getPayloadLength() {
if ($this->defPayLen !== -1) {
return $this->defPayLen;
}
$this->defPayLen = $this->getFirstPayloadVal();
if ($this->defPayLen <= 125) {
return $this->getPayloadLength();
}
$byte_length = $this->getNumPayloadBytes();
if ($this->bytesRecvd < 1 + $byte_length) {
$this->defPayLen = -1;
throw call_user_func($this->ufeg, 'Not enough data buffered to determine payload length');
}
$len = 0;
for ($i = 2; $i <= $byte_length; $i++) {
$len <<= 8;
$len += ord($this->data[$i]);
}
$this->defPayLen = $len;
return $this->getPayloadLength();
}
/**
* {@inheritdoc}
*/
public function getPayloadStartingByte() {
return 1 + $this->getNumPayloadBytes() + ($this->isMasked() ? static::MASK_LENGTH : 0);
}
/**
* {@inheritdoc}
* @todo Consider not checking mask, always returning the payload, masked or not
*/
public function getPayload() {
if (!$this->isCoalesced()) {
throw call_user_func($this->ufeg, 'Can not return partial message');
}
return $this->__toString();
}
/**
* Get the raw contents of the frame
* @todo This is untested, make sure the substr is right - trying to return the frame w/o the overflow
*/
public function getContents() {
return substr($this->data, 0, $this->getPayloadStartingByte() + $this->getPayloadLength());
}
public function __toString() {
$payload = (string)substr($this->data, $this->getPayloadStartingByte(), $this->getPayloadLength());
if ($this->isMasked()) {
$payload = $this->applyMask($this->getMaskingKey(), $payload);
}
return $payload;
}
/**
* Sometimes clients will concatenate more than one frame over the wire
* This method will take the extra bytes off the end and return them
* @return string
*/
public function extractOverflow() {
if ($this->isCoalesced()) {
$endPoint = $this->getPayloadLength();
$endPoint += $this->getPayloadStartingByte();
if ($this->bytesRecvd > $endPoint) {
$overflow = substr($this->data, $endPoint);
$this->data = substr($this->data, 0, $endPoint);
return $overflow;
}
}
return '';
}
}