FrameReader::validate() - Code Metrics - Inspection of "websockets :: refactored, implemented stream readi..." - hfw/socket - Measure and Improve Code Quality continuously with Scrutinizer

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created 2021-01-31 10:47 UTC

FrameReader::validate() A

↳ Parent: Project

Complexity

Conditions	6
Paths	6

Size

Total Lines

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
dl	0
loc	18
rs	9.0444
c	0
b	0
f	0
cc	6
nc	6
nop	0

<?php

namespace Helix\Socket\WebSocket;

use Generator;

/**
 * Reads frames from the peer.
 *
 * https://tools.ietf.org/html/rfc6455#section-5
 *
 * TODO: Support unmasked frames.
 */
class FrameReader {

    /**
     * https://tools.ietf.org/html/rfc6455#section-5.2
     */
    protected const REGEXP =
        //op((char     )|(short     )|(bigint      ))(mask       )
        '/^.([\x80-\xfd]|\xfe(?<n>..)|\xff(?<J>.{8}))(?<mask>.{4})/s';

    /**
     * Peer read buffer.
     *
     * @var string
     */
    protected $buffer = '';

    /**
     * @var WebSocketClient
     */
    protected $client;

    /**
     * Frame header buffer.
     *
     * @var null|array
     */
    protected $header;

    /**
     * Maximum inbound per-frame payload length (fragment).
     *
     * Must be greater than or equal to `125`
     *
     * Defaults to 128 KiB.
     *
     * https://tools.ietf.org/html/rfc6455#section-5.2
     *
     * @var int
     */
    protected $maxLength = 128 * 1024;

    /**
     * RSV bit mask claimed by extensions.
     *
     * @var int
     */
    protected $rsv = 0;

    /**
     * @param WebSocketClient $client
     */
    public function __construct (WebSocketClient $client) {
        $this->client = $client;
    }

    /**
     * Reads and returns a single pending frame from the buffer, or nothing.
     *
     * @return null|Frame
     * @throws WebSocketError
     */
    protected function getFrame (): ?Frame {
        // wait for the header
        if (!$this->header ??= $this->getFrame_header()) {

            return null;
        }

        // wait for the whole frame
        $length = $this->header['length'];
        if (strlen($this->buffer) < $length) {
            return null;
        }

        // extract the payload
        $payload = substr($this->buffer, 0, $length);

        // chop the buffer
        $this->buffer = substr($this->buffer, $length);

        // unmask the payload
        $mask = $this->header['mask'];
        for ($i = 0; $i < $length; $i++) {
            $payload[$i] = chr(ord($payload[$i]) ^ $mask[$i % 4]);
        }

        // construct the frame instance
        $frame = $this->newFrame($payload);

        // destroy the header buffer
        $this->header = null;

        // return the frame
        return $frame;
    }

    /**
     * https://tools.ietf.org/html/rfc6455#section-5.2
     * @return null|array
     */
    protected function getFrame_header (): ?array {
        if (!preg_match(self::REGEXP, $this->buffer, $match)) {
            if (strlen($this->buffer) >= 14) { // max head room
                throw new WebSocketError(Frame::CLOSE_PROTOCOL_ERROR, 'Bad frame.');
            }
            return null;
        }

        // unpack the first two bytes
        [, $b0, $b1] = unpack('C2', $match[0]); // 1-based indices

        // convert the second byte into an unpack() format, or the actual length (sans the MASK bit).
        // the unpack() format is also used as the length's named-group in the regexp match.
        $len = [0xfe => 'n', 0xff => 'J'][$b1] ?? ($b1 & Frame::LEN);

        // fill the header buffer
        $header = [
            'final' => $final = $b0 & Frame::FIN,
            'rsv' => $rsv = $b0 & Frame::RSV123,
            'opCode' => $opCode = $b0 & Frame::OP,
            'length' => $length = is_int($len) ? $len : unpack($len, $match[$len])[1],
            'mask' => array_values(unpack('C*', $match['mask'])),
        ];

        // chop the peer buffer
        $this->buffer = substr($this->buffer, strlen($match[0]));

        // validate
        if ($badRsv = $rsv & ~$this->rsv) {
            $badRsv = str_pad(base_convert($badRsv >> 4, 10, 2), 3, '0', STR_PAD_LEFT);
            throw new WebSocketError(Frame::CLOSE_PROTOCOL_ERROR, "Received unknown RSV bits: 0b{$badRsv}");
        }
        elseif ($opCode >= Frame::OP_CLOSE) {
            if ($opCode > Frame::OP_PONG) {
                throw new WebSocketError(Frame::CLOSE_PROTOCOL_ERROR, "Received unsupported control frame ({$opCode})");
            }
            elseif (!$final) {
                throw new WebSocketError(Frame::CLOSE_PROTOCOL_ERROR, "Received fragmented control frame ({$opCode})");
            }
        }
        elseif ($opCode > Frame::OP_BINARY) {
            throw new WebSocketError(Frame::CLOSE_PROTOCOL_ERROR, "Received unsupported data frame ({$opCode})");
        }
        elseif ($length > $this->maxLength) {
            throw new WebSocketError(Frame::CLOSE_TOO_LARGE, "Payload would exceed {$this->maxLength} bytes");
        }

        // return the header
        return $header;
    }

    /**
     * Yields all available frames from the peer.
     *
     * @return Generator|Frame[]
     */
    public function getFrames () {
        // read into the buffer
        $this->buffer .= $bytes = $this->client->recvAll();

        // check for peer disconnection
        if (!strlen($bytes)) {
            $this->client->close();
        }

        // yield frames
        while ($frame = $this->getFrame()) {
            yield $frame;
        }
    }

    /**
     * @return int
     */
    public function getMaxLength (): int {
        return $this->maxLength;
    }

    /**
     * @return int
     */
    public function getRsv (): int {
        return $this->rsv;
    }

    /**
     * {@link Frame} factory.
     *
     * @param string $payload
     * @return Frame
     */
    protected function newFrame (string $payload): Frame {
        return new Frame($this->header['final'], $this->header['rsv'], $this->header['opCode'], $payload);
    }

    /**
     * @param int $bytes
     * @return $this
     */
    public function setMaxLength (int $bytes) {
        $this->maxLength = min(max(125, $bytes), 2 ** 63 - 1);
        return $this;
    }

    /**
     * @param int $rsv
     * @return $this
     */
    public function setRsv (int $rsv) {
        $this->rsv = $rsv;
        return $this;
    }
}

1			<?php
2
3			namespace Helix\Socket\WebSocket;
4
5			use Generator;
6
7			/**
8			* Reads frames from the peer.
9			*
10			* https://tools.ietf.org/html/rfc6455#section-5
11			*
12			* TODO: Support unmasked frames.
13			*/
14			class FrameReader {
15
16			/**
17			* https://tools.ietf.org/html/rfc6455#section-5.2
18			*/
19			protected const REGEXP =
20			//op((char )\|(short )\|(bigint ))(mask )
21			'/^.([\x80-\xfd]\|\xfe(?<n>..)\|\xff(?<J>.{8}))(?<mask>.{4})/s';
22
23			/**
24			* Peer read buffer.
25			*
26			* @var string
27			*/
28			protected $buffer = '';
29
30			/**
31			* @var WebSocketClient
32			*/
33			protected $client;
34
35			/**
36			* Frame header buffer.
37			*
38			* @var null\|array
39			*/
40			protected $header;
41
42			/**
43			* Maximum inbound per-frame payload length (fragment).
44			*
45			* Must be greater than or equal to `125`
46			*
47			* Defaults to 128 KiB.
48			*
49			* https://tools.ietf.org/html/rfc6455#section-5.2
50			*
51			* @var int
52			*/
53			protected $maxLength = 128 * 1024;
54
55			/**
56			* RSV bit mask claimed by extensions.
57			*
58			* @var int
59			*/
60			protected $rsv = 0;
61
62			/**
63			* @param WebSocketClient $client
64			*/
65			public function __construct (WebSocketClient $client) {
66			$this->client = $client;
67			}
68
69			/**
70			* Reads and returns a single pending frame from the buffer, or nothing.
71			*
72			* @return null\|Frame
73			* @throws WebSocketError
74			*/
75			protected function getFrame (): ?Frame {
76			// wait for the header
77			if (!$this->header ??= $this->getFrame_header()) {
			0 ignored issues – show Bug introduced 2021-01-31 10:49 UTC by Report Bug Copy Issue Report This code did not parse for me. Apparently, there is an error somewhere around this line: Syntax error, unexpected '=' Loading history...
78			return null;
79			}
80
81			// wait for the whole frame
82			$length = $this->header['length'];
83			if (strlen($this->buffer) < $length) {
84			return null;
85			}
86
87			// extract the payload
88			$payload = substr($this->buffer, 0, $length);
89
90			// chop the buffer
91			$this->buffer = substr($this->buffer, $length);
92
93			// unmask the payload
94			$mask = $this->header['mask'];
95			for ($i = 0; $i < $length; $i++) {
96			$payload[$i] = chr(ord($payload[$i]) ^ $mask[$i % 4]);
97			}
98
99			// construct the frame instance
100			$frame = $this->newFrame($payload);
101
102			// destroy the header buffer
103			$this->header = null;
104
105			// return the frame
106			return $frame;
107			}
108
109			/**
110			* https://tools.ietf.org/html/rfc6455#section-5.2
111			* @return null\|array
112			*/
113			protected function getFrame_header (): ?array {
114			if (!preg_match(self::REGEXP, $this->buffer, $match)) {
115			if (strlen($this->buffer) >= 14) { // max head room
116			throw new WebSocketError(Frame::CLOSE_PROTOCOL_ERROR, 'Bad frame.');
117			}
118			return null;
119			}
120
121			// unpack the first two bytes
122			[, $b0, $b1] = unpack('C2', $match[0]); // 1-based indices
123
124			// convert the second byte into an unpack() format, or the actual length (sans the MASK bit).
125			// the unpack() format is also used as the length's named-group in the regexp match.
126			$len = [0xfe => 'n', 0xff => 'J'][$b1] ?? ($b1 & Frame::LEN);
127
128			// fill the header buffer
129			$header = [
130			'final' => $final = $b0 & Frame::FIN,
131			'rsv' => $rsv = $b0 & Frame::RSV123,
132			'opCode' => $opCode = $b0 & Frame::OP,
133			'length' => $length = is_int($len) ? $len : unpack($len, $match[$len])[1],
134			'mask' => array_values(unpack('C*', $match['mask'])),
135			];
136
137			// chop the peer buffer
138			$this->buffer = substr($this->buffer, strlen($match[0]));
139
140			// validate
141			if ($badRsv = $rsv & ~$this->rsv) {
142			$badRsv = str_pad(base_convert($badRsv >> 4, 10, 2), 3, '0', STR_PAD_LEFT);
143			throw new WebSocketError(Frame::CLOSE_PROTOCOL_ERROR, "Received unknown RSV bits: 0b{$badRsv}");
144			}
145			elseif ($opCode >= Frame::OP_CLOSE) {
146			if ($opCode > Frame::OP_PONG) {
147			throw new WebSocketError(Frame::CLOSE_PROTOCOL_ERROR, "Received unsupported control frame ({$opCode})");
148			}
149			elseif (!$final) {
150			throw new WebSocketError(Frame::CLOSE_PROTOCOL_ERROR, "Received fragmented control frame ({$opCode})");
151			}
152			}
153			elseif ($opCode > Frame::OP_BINARY) {
154			throw new WebSocketError(Frame::CLOSE_PROTOCOL_ERROR, "Received unsupported data frame ({$opCode})");
155			}
156			elseif ($length > $this->maxLength) {
157			throw new WebSocketError(Frame::CLOSE_TOO_LARGE, "Payload would exceed {$this->maxLength} bytes");
158			}
159
160			// return the header
161			return $header;
162			}
163
164			/**
165			* Yields all available frames from the peer.
166			*
167			* @return Generator\|Frame[]
168			*/
169			public function getFrames () {
170			// read into the buffer
171			$this->buffer .= $bytes = $this->client->recvAll();
172
173			// check for peer disconnection
174			if (!strlen($bytes)) {
175			$this->client->close();
176			}
177
178			// yield frames
179			while ($frame = $this->getFrame()) {
180			yield $frame;
181			}
182			}
183
184			/**
185			* @return int
186			*/
187			public function getMaxLength (): int {
188			return $this->maxLength;
189			}
190
191			/**
192			* @return int
193			*/
194			public function getRsv (): int {
195			return $this->rsv;
196			}
197
198			/**
199			* {@link Frame} factory.
200			*
201			* @param string $payload
202			* @return Frame
203			*/
204			protected function newFrame (string $payload): Frame {
205			return new Frame($this->header['final'], $this->header['rsv'], $this->header['opCode'], $payload);
206			}
207
208			/**
209			* @param int $bytes
210			* @return $this
211			*/
212			public function setMaxLength (int $bytes) {
213			$this->maxLength = min(max(125, $bytes), 2 ** 63 - 1);
214			return $this;
215			}
216
217			/**
218			* @param int $rsv
219			* @return $this
220			*/
221			public function setRsv (int $rsv) {
222			$this->rsv = $rsv;
223			return $this;
224			}
225			}

hfw / socket

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FrameReader::validate() A

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