Data structures and utility functions for manipulating WebSocket frames. More...

Namespaces
	limits
	Constants related to frame and payload limits.

	opcode
	Constants and utility functions related to WebSocket opcodes.

Classes
struct	basic_header
	The constant size component of a WebSocket frame header. More...

struct	extended_header
	The variable size component of a WebSocket frame header. More...

union	uint16_converter
	Two byte conversion union. More...

union	uint32_converter
	Four byte conversion union. More...

union	uint64_converter
	Eight byte conversion union. More...

Typedefs
typedef uint32_converter	masking_key_type

Functions
bool	get_fin (basic_header const &h)
	Check whether the frame's FIN bit is set. More...

void	set_fin (basic_header &h, bool value)
	Set the frame's FIN bit. More...

bool	get_rsv1 (const basic_header &h)
	check whether the frame's RSV1 bit is set More...

void	set_rsv1 (basic_header &h, bool value)
	Set the frame's RSV1 bit. More...

bool	get_rsv2 (const basic_header &h)
	check whether the frame's RSV2 bit is set More...

void	set_rsv2 (basic_header &h, bool value)
	Set the frame's RSV2 bit. More...

bool	get_rsv3 (const basic_header &h)
	check whether the frame's RSV3 bit is set More...

void	set_rsv3 (basic_header &h, bool value)
	Set the frame's RSV3 bit. More...

opcode::value	get_opcode (const basic_header &h)
	Extract opcode from basic header. More...

bool	get_masked (basic_header const &h)
	check whether the frame is masked More...

void	set_masked (basic_header &h, bool value)
	Set the frame's MASK bit. More...

uint8_t	get_basic_size (const basic_header &h)
	Extracts the raw payload length specified in the basic header. More...

size_t	get_header_len (basic_header const &h)
	Calculates the full length of the header based on the first bytes. More...

unsigned int	get_masking_key_offset (const basic_header &h)
	Calculate the offset location of the masking key within the extended header. More...

std::string	write_header (basic_header const &, extended_header const &)

masking_key_type	get_masking_key (const basic_header &h, const extended_header &e)
	Extract the masking key from a frame header. More...

uint16_t	get_extended_size (const extended_header &e)
	Extract the extended size field from an extended header. More...

uint64_t	get_jumbo_size (const extended_header &e)
	Extract the jumbo size field from an extended header. More...

uint64_t	get_payload_size (const basic_header &h, const extended_header &e)
	Extract the full payload size field from a WebSocket header. More...

size_t	prepare_masking_key (const masking_key_type &key)
	Extract a masking key into a value the size of a machine word. More...

size_t	circshift_prepared_key (size_t prepared_key, size_t offset)
	circularly shifts the supplied prepared masking key by offset bytes More...

template<typename input_iter , typename output_iter >
void	byte_mask (input_iter first, input_iter last, output_iter result, masking_key_type const &key, size_t key_offset)
	Byte by byte mask/unmask. More...

template<typename iter_type >
void	byte_mask (iter_type b, iter_type e, masking_key_type const &key, size_t key_offset)
	Byte by byte mask/unmask (in place) More...

void	word_mask_exact (uint8_t input, uint8_t output, size_t length, const masking_key_type &key)
	Exact word aligned mask/unmask. More...

void	word_mask_exact (uint8_t *data, size_t length, const masking_key_type &key)
	Exact word aligned mask/unmask (in place) More...

size_t	word_mask_circ (uint8_t input, uint8_t output, size_t length, size_t prepared_key)
	Circular word aligned mask/unmask. More...

size_t	word_mask_circ (uint8_t *data, size_t length, size_t prepared_key)
	Circular word aligned mask/unmask (in place) More...

std::string	prepare_header (const basic_header &h, const extended_header &e)
	Generate a properly sized contiguous string that encodes a full frame header. More...

size_t	byte_mask_circ (uint8_t input, uint8_t output, size_t length, size_t prepared_key)
	Circular byte aligned mask/unmask. More...

size_t	byte_mask_circ (uint8_t *data, size_t length, size_t prepared_key)
	Circular byte aligned mask/unmask (in place) More...

Variables
static unsigned int const	BASIC_HEADER_LENGTH = 2
	Minimum length of a WebSocket frame header. More...

static unsigned int const	MAX_HEADER_LENGTH = 14
	Maximum length of a WebSocket header. More...

static unsigned int const	MAX_EXTENDED_HEADER_LENGTH = 12
	Maximum length of the variable portion of the WebSocket header. More...

static uint8_t const	BHB0_OPCODE = 0x0F

static uint8_t const	BHB0_RSV3 = 0x10

static uint8_t const	BHB0_RSV2 = 0x20

static uint8_t const	BHB0_RSV1 = 0x40

static uint8_t const	BHB0_FIN = 0x80

static uint8_t const	BHB1_PAYLOAD = 0x7F

static uint8_t const	BHB1_MASK = 0x80

static uint8_t const	payload_size_code_16bit = 0x7E

static uint8_t const	payload_size_code_64bit = 0x7F

Detailed Description

Data structures and utility functions for manipulating WebSocket frames.

namespace frame provides a number of data structures and utility functions for reading, writing, and manipulating binary encoded WebSocket frames.

Typedef Documentation

typedef uint32_converter websocketpp::frame::masking_key_type

Definition at line 186 of file frame.hpp.

Function Documentation

bool websocketpp::frame::get_fin ( basic_header const & h )

inline

Check whether the frame's FIN bit is set.

Parameters

[in] h The basic header to extract from.

Returns: True if the header's fin bit is set.

Definition at line 321 of file frame.hpp.

References websocketpp::frame::basic_header::b0.

Referenced by BOOST_AUTO_TEST_CASE(), websocketpp::processor::hybi13< stub_config >::consume(), and websocketpp::processor::hybi13< stub_config >::validate_incoming_basic_header().

void websocketpp::frame::set_fin	(	basic_header &	h,
		bool	value
	)

inline

Set the frame's FIN bit.

Parameters

[out]	h	Header to set.
[in]	value	Value to set it to.

Definition at line 330 of file frame.hpp.

References websocketpp::frame::basic_header::b0.

Referenced by BOOST_AUTO_TEST_CASE().

bool websocketpp::frame::get_rsv1 ( const basic_header & h )

inline

check whether the frame's RSV1 bit is set

Parameters

[in] h The basic header to extract from.

Returns: True if the header's RSV1 bit is set.

Definition at line 339 of file frame.hpp.

References websocketpp::frame::basic_header::b0.

Referenced by BOOST_AUTO_TEST_CASE(), websocketpp::processor::hybi13< stub_config >::consume(), and websocketpp::processor::hybi13< stub_config >::validate_incoming_basic_header().

void websocketpp::frame::set_rsv1	(	basic_header &	h,
		bool	value
	)

inline

Set the frame's RSV1 bit.

Parameters

[out]	h	Header to set.
[in]	value	Value to set it to.

Definition at line 348 of file frame.hpp.

References websocketpp::frame::basic_header::b0.

Referenced by BOOST_AUTO_TEST_CASE().

bool websocketpp::frame::get_rsv2 ( const basic_header & h )

inline

check whether the frame's RSV2 bit is set

Parameters

[in] h The basic header to extract from.

Returns: True if the header's RSV2 bit is set.

Definition at line 357 of file frame.hpp.

References websocketpp::frame::basic_header::b0.

Referenced by BOOST_AUTO_TEST_CASE(), and websocketpp::processor::hybi13< stub_config >::validate_incoming_basic_header().

void websocketpp::frame::set_rsv2	(	basic_header &	h,
		bool	value
	)

inline

Set the frame's RSV2 bit.

Parameters

[out]	h	Header to set.
[in]	value	Value to set it to.

Definition at line 366 of file frame.hpp.

References websocketpp::frame::basic_header::b0.

Referenced by BOOST_AUTO_TEST_CASE().

bool websocketpp::frame::get_rsv3 ( const basic_header & h )

inline

check whether the frame's RSV3 bit is set

Parameters

[in] h The basic header to extract from.

Returns: True if the header's RSV3 bit is set.

Definition at line 375 of file frame.hpp.

References websocketpp::frame::basic_header::b0.

Referenced by BOOST_AUTO_TEST_CASE(), and websocketpp::processor::hybi13< stub_config >::validate_incoming_basic_header().

void websocketpp::frame::set_rsv3	(	basic_header &	h,
		bool	value
	)

inline

Set the frame's RSV3 bit.

Parameters

[out]	h	Header to set.
[in]	value	Value to set it to.

Definition at line 384 of file frame.hpp.

References websocketpp::frame::basic_header::b0.

Referenced by BOOST_AUTO_TEST_CASE().

opcode::value websocketpp::frame::get_opcode ( const basic_header & h )

inline

Extract opcode from basic header.

Parameters

[in] h The basic header to extract from.

Returns: The opcode value of the header.

Definition at line 393 of file frame.hpp.

References websocketpp::frame::basic_header::b0.

Referenced by BOOST_AUTO_TEST_CASE(), websocketpp::processor::hybi13< stub_config >::consume(), websocketpp::processor::hybi13< stub_config >::finalize_message(), and websocketpp::processor::hybi13< stub_config >::validate_incoming_basic_header().

bool websocketpp::frame::get_masked ( basic_header const & h )

inline

check whether the frame is masked

Parameters

[in] h The basic header to extract from.

Returns: True if the header mask bit is set.

Definition at line 402 of file frame.hpp.

References websocketpp::frame::basic_header::b1.

Referenced by BOOST_AUTO_TEST_CASE(), get_header_len(), get_masking_key(), websocketpp::processor::hybi13< stub_config >::process_payload_bytes(), and websocketpp::processor::hybi13< stub_config >::validate_incoming_basic_header().

void websocketpp::frame::set_masked	(	basic_header &	h,
		bool	value
	)

inline

Set the frame's MASK bit.

Parameters

[out]	h	Header to set.
	value	Value to set it to.

Definition at line 411 of file frame.hpp.

References websocketpp::frame::basic_header::b1.

Referenced by BOOST_AUTO_TEST_CASE().

uint8_t websocketpp::frame::get_basic_size ( const basic_header & h )

inline

Extracts the raw payload length specified in the basic header.

A basic WebSocket frame header contains a 7 bit value that represents the payload size. There are two reserved values that are used to indicate that the actual payload size will not fit in 7 bits and that the full payload size is included in a separate field. The values are as follows:

PAYLOAD_SIZE_CODE_16BIT (0x7E) indicates that the actual payload is less than 16 bit

PAYLOAD_SIZE_CODE_64BIT (0x7F) indicates that the actual payload is less than 63 bit

Parameters

[in] h Basic header to read value from.

Returns: The exact size encoded in h.

Definition at line 431 of file frame.hpp.

References websocketpp::frame::basic_header::b1, and BHB1_PAYLOAD.

Referenced by BOOST_AUTO_TEST_CASE(), get_masking_key_offset(), get_payload_size(), websocketpp::processor::hybi13< stub_config >::validate_incoming_basic_header(), and websocketpp::processor::hybi13< stub_config >::validate_incoming_extended_header().

size_t websocketpp::frame::get_header_len ( basic_header const & h )

inline

Calculates the full length of the header based on the first bytes.

A WebSocket frame header always has at least two bytes. Encoded within the first two bytes is all the information necessary to calculate the full (variable) header length. get_header_len() calculates the full header length for the given two byte basic header.

Parameters

h	Basic frame header to extract size from.

Returns: Full length of the extended header.

Definition at line 445 of file frame.hpp.

References get_masked(), and get_masking_key_offset().

Referenced by BOOST_AUTO_TEST_CASE(), and websocketpp::processor::hybi13< stub_config >::consume().

unsigned int websocketpp::frame::get_masking_key_offset ( const basic_header & h )

inline

Calculate the offset location of the masking key within the extended header.

Calculate the offset location of the masking key within the extended header using information from its corresponding basic header

Parameters

h	Corresponding basic header to calculate from.

Returns: byte offset of the first byte of the masking key

Definition at line 469 of file frame.hpp.

References get_basic_size().

Referenced by BOOST_AUTO_TEST_CASE(), get_header_len(), and get_masking_key().

std::string websocketpp::frame::write_header	(	basic_header const &	,
		extended_header const &
	)

masking_key_type websocketpp::frame::get_masking_key	(	const basic_header &	h,
		const extended_header &	e
	)

inline

Extract the masking key from a frame header.

Note that while read and written as an integer at times, this value is not an integer and should never be interpreted as one. Big and little endian machines will generate and store masking keys differently without issue as long as the integer values remain irrelivant.

Parameters

h	The basic header to extract from
e	The extended header to extract from

Returns: The masking key as an integer.

Definition at line 516 of file frame.hpp.

References websocketpp::frame::extended_header::bytes, websocketpp::frame::uint32_converter::c, get_masked(), get_masking_key_offset(), and websocketpp::frame::uint32_converter::i.

Referenced by BOOST_AUTO_TEST_CASE(), and websocketpp::processor::hybi13< stub_config >::consume().

uint16_t websocketpp::frame::get_extended_size ( const extended_header & e )

inline

Extract the extended size field from an extended header.

It is the responsibility of the caller to verify that e is a valid extended header. This function assumes that e contains an extended payload size.

Parameters

e	The extended header to extract from

Returns: The size encoded in the extended header in host byte order

Definition at line 540 of file frame.hpp.

References websocketpp::frame::extended_header::bytes, websocketpp::frame::uint16_converter::c, and websocketpp::frame::uint16_converter::i.

Referenced by BOOST_AUTO_TEST_CASE(), and get_payload_size().

uint64_t websocketpp::frame::get_jumbo_size ( const extended_header & e )

inline

Extract the jumbo size field from an extended header.

It is the responsibility of the caller to verify that e is a valid extended header. This function assumes that e contains a jumbo payload size.

Parameters

e	The extended header to extract from

Returns: The size encoded in the extended header in host byte order

Definition at line 555 of file frame.hpp.

References websocketpp::lib::net::_ntohll(), websocketpp::frame::extended_header::bytes, websocketpp::frame::uint64_converter::c, and websocketpp::frame::uint64_converter::i.

Referenced by BOOST_AUTO_TEST_CASE(), and get_payload_size().

uint64_t websocketpp::frame::get_payload_size	(	const basic_header &	h,
		const extended_header &	e
	)

inline

Extract the full payload size field from a WebSocket header.

It is the responsibility of the caller to verify that h and e together represent a valid WebSocket frame header. This function assumes only that h and e are valid. It uses information in the basic header to determine where to look for the payload_size

Parameters

h	The basic header to extract from
e	The extended header to extract from

Returns: The size encoded in the combined header in host byte order.

Definition at line 573 of file frame.hpp.

References get_basic_size(), get_extended_size(), get_jumbo_size(), and websocketpp::frame::limits::payload_size_basic.

Referenced by BOOST_AUTO_TEST_CASE(), websocketpp::processor::hybi13< stub_config >::consume(), and websocketpp::processor::hybi13< stub_config >::validate_incoming_extended_header().

size_t websocketpp::frame::prepare_masking_key ( const masking_key_type & key )

inline

Extract a masking key into a value the size of a machine word.

Machine word size must be 4 or 8.

Parameters

key	Masking key to extract from

Returns: prepared key as a machine word

Definition at line 595 of file frame.hpp.

References websocketpp::frame::uint32_converter::i.

Referenced by BOOST_AUTO_TEST_CASE(), websocketpp::processor::hybi13< stub_config >::consume(), and word_mask_exact().

size_t websocketpp::frame::circshift_prepared_key	(	size_t	prepared_key,
		size_t	offset
	)

inline

circularly shifts the supplied prepared masking key by offset bytes

Prepared_key must be the output of prepare_masking_key with the associated restrictions on the machine word size. offset must be greater than or equal to zero and less than sizeof(size_t).

Definition at line 612 of file frame.hpp.

References websocketpp::lib::net::is_little_endian().

Referenced by BOOST_AUTO_TEST_CASE(), byte_mask_circ(), and word_mask_circ().

template<typename input_iter , typename output_iter >

void websocketpp::frame::byte_mask	(	input_iter	first,
		input_iter	last,
		output_iter	result,
		masking_key_type const &	key,
		size_t	key_offset
	)

Byte by byte mask/unmask.

Iterator based byte by byte masking and unmasking for WebSocket payloads. Performs masking in place using the supplied key offset by the supplied offset number of bytes.

This function is simple and can be done in place on input with arbitrary lengths and does not vary based on machine word size. It is slow.

Parameters

b	Beginning iterator to start masking
e	Ending iterator to end masking
o	Beginning iterator to store masked results
key	32 bit key to mask with.
key_offset	offset value to start masking at.

Definition at line 642 of file frame.hpp.

References websocketpp::frame::uint32_converter::c.

Referenced by BOOST_AUTO_TEST_CASE(), byte_mask(), main(), and websocketpp::processor::hybi13< stub_config >::masked_copy().

template<typename iter_type >

void websocketpp::frame::byte_mask	(	iter_type	b,
		iter_type	e,
		masking_key_type const &	key,
		size_t	key_offset
	)

Byte by byte mask/unmask (in place)

Iterator based byte by byte masking and unmasking for WebSocket payloads. Performs masking in place using the supplied key offset by the supplied offset number of bytes.

This function is simple and can be done in place on input with arbitrary lengths and does not vary based on machine word size. It is slow.

Parameters

b	Beginning iterator to start masking
e	Ending iterator to end masking
key	32 bit key to mask with.
key_offset	offset value to start masking at.

Definition at line 672 of file frame.hpp.

References byte_mask().

void websocketpp::frame::word_mask_exact	(	uint8_t *	input,
		uint8_t *	output,
		size_t	length,
		const masking_key_type &	key
	)

inline

Exact word aligned mask/unmask.

Balanced combination of byte by byte and circular word by word masking. Best used to mask complete messages at once. Has much higher setup costs than word_mask_circ but works with exact sized buffers.

Buffer based word by word masking and unmasking for WebSocket payloads. Masking is done in word by word chunks with the remainder not divisible by the word size done byte by byte.

input and output must both be at least length bytes. Exactly length bytes will be written.

Parameters

input	buffer to mask or unmask
output	buffer to store the output. May be the same as input.
length	length of data buffer
key	Masking key to use

Definition at line 699 of file frame.hpp.

References websocketpp::frame::uint32_converter::c, websocketpp::frame::uint16_converter::i, and prepare_masking_key().

Referenced by BOOST_AUTO_TEST_CASE(), main(), and word_mask_exact().

void websocketpp::frame::word_mask_exact	(	uint8_t *	data,
		size_t	length,
		const masking_key_type &	key
	)

inline

Exact word aligned mask/unmask (in place)

In place version of word_mask_exact

See also: word_mask_exact

Parameters

data	buffer to read and write from
length	length of data buffer
key	Masking key to use

Definition at line 728 of file frame.hpp.

References word_mask_exact().

size_t websocketpp::frame::word_mask_circ	(	uint8_t *	input,
		uint8_t *	output,
		size_t	length,
		size_t	prepared_key
	)

inline

Circular word aligned mask/unmask.

Performs a circular mask/unmask in word sized chunks using pre-prepared keys that store state between calls. Best for providing streaming masking or unmasking of small chunks at a time of a larger message. Requires that the underlying allocated size of the data buffer be a multiple of the word size. Data in the buffer after length will be overwritten only with the same values that were originally present.

Buffer based word by word masking and unmasking for WebSocket payloads. Performs masking in place using the supplied key. Casts the data buffer to an array of size_t's and performs masking word by word. The underlying buffer size must be a muliple of the word size.

word_mask returns a copy of prepared_key circularly shifted based on the length value. The returned value may be fed back into word_mask when more data is available.

input and output must both have length at least: ceil(length/sizeof(size_t))*sizeof(size_t) Exactly that many bytes will be written, although only exactly length bytes will be changed (trailing bytes will be replaced without masking)

Parameters

data	Character buffer to mask
length	Length of data
prepared_key	Prepared key to use.

Returns: the prepared_key shifted to account for the input length

Definition at line 765 of file frame.hpp.

References circshift_prepared_key(), and websocketpp::frame::uint16_converter::i.

Referenced by BOOST_AUTO_TEST_CASE(), and word_mask_circ().

size_t websocketpp::frame::word_mask_circ	(	uint8_t *	data,
		size_t	length,
		size_t	prepared_key
	)

inline

Circular word aligned mask/unmask (in place)

In place version of word_mask_circ

See also: word_mask_circ

Parameters

data	Character buffer to read from and write to
length	Length of data
prepared_key	Prepared key to use.

Returns: the prepared_key shifted to account for the input length

Definition at line 802 of file frame.hpp.

References word_mask_circ().

std::string websocketpp::frame::prepare_header	(	const basic_header &	h,
		const extended_header &	e
	)

inline

Generate a properly sized contiguous string that encodes a full frame header.

Copy the basic header h and extended header e into a properly sized contiguous frame header string for the purposes of writing out to the wire.

Parameters

h	The basic header to include
e	The extended header to include

Returns: A contiguous string containing h and e

Definition at line 489 of file frame.hpp.

References websocketpp::frame::basic_header::b0, websocketpp::frame::basic_header::b1, and websocketpp::frame::extended_header::bytes.

Referenced by BOOST_AUTO_TEST_CASE(), websocketpp::processor::hybi13< stub_config >::prepare_control(), and websocketpp::processor::hybi13< stub_config >::prepare_data_frame().

size_t websocketpp::frame::byte_mask_circ	(	uint8_t *	input,
		uint8_t *	output,
		size_t	length,
		size_t	prepared_key
	)

inline

Circular byte aligned mask/unmask.

Performs a circular mask/unmask in byte sized chunks using pre-prepared keys that store state between calls. Best for providing streaming masking or unmasking of small chunks at a time of a larger message. Requires that the underlying allocated size of the data buffer be a multiple of the word size. Data in the buffer after length will be overwritten only with the same values that were originally present.

word_mask returns a copy of prepared_key circularly shifted based on the length value. The returned value may be fed back into byte_mask when more data is available.

Parameters