Functions and structure contents for the Guacamole proxy client. More...

Data Structures
struct	guac_client
	Guacamole proxy client. More...

Functions
guac_client *	guac_client_alloc ()
	Returns a new, barebones guac_client. More...

void	guac_client_free (guac_client *client)
	Free all resources associated with the given client. More...

void	guac_client_log (guac_client client, guac_client_log_level level, const char format,...)
	Writes a message in the log used by the given client. More...

void	vguac_client_log (guac_client client, guac_client_log_level level, const char format, va_list ap)
	Writes a message in the log used by the given client. More...

void	guac_client_stop (guac_client *client)
	Signals the given client to stop gracefully. More...

void	guac_client_abort (guac_client client, guac_protocol_status status, const char format,...)
	Signals the given client to stop gracefully, while also signalling via the Guacamole protocol that an error has occurred. More...

void	vguac_client_abort (guac_client client, guac_protocol_status status, const char format, va_list ap)
	Signals the given client to stop gracefully, while also signalling via the Guacamole protocol that an error has occurred. More...

guac_layer *	guac_client_alloc_buffer (guac_client *client)
	Allocates a new buffer (invisible layer). More...

guac_layer *	guac_client_alloc_layer (guac_client *client)
	Allocates a new layer. More...

void	guac_client_free_buffer (guac_client client, guac_layer layer)
	Returns the given buffer to the pool of available buffers, such that it can be reused by any subsequent call to guac_client_allow_buffer(). More...

void	guac_client_free_layer (guac_client client, guac_layer layer)
	Returns the given layer to the pool of available layers, such that it can be reused by any subsequent call to guac_client_allow_layer(). More...

guac_stream *	guac_client_alloc_stream (guac_client *client)
	Allocates a new stream. More...

void	guac_client_free_stream (guac_client client, guac_stream stream)
	Returns the given stream to the pool of available streams, such that it can be reused by any subsequent call to guac_client_alloc_stream(). More...

int	guac_client_add_user (guac_client client, guac_user user, int argc, char **argv)
	Adds the given user to the internal list of connected users. More...

void	guac_client_remove_user (guac_client client, guac_user user)
	Removes the given user, removing the user from the internally-tracked list of connected users, and calling any appropriate leave handler. More...

void	guac_client_foreach_user (guac_client client, guac_user_callback callback, void *data)
	Calls the given function on all currently-connected users of the given client. More...

void *	guac_client_for_owner (guac_client client, guac_user_callback callback, void *data)
	Calls the given function with the currently-connected user that is marked as the owner. More...

void *	guac_client_for_user (guac_client client, guac_user user, guac_user_callback callback, void data)
	Calls the given function with the given user ONLY if they are currently connected. More...

int	guac_client_end_frame (guac_client *client)
	Marks the end of the current frame by sending a "sync" instruction to all connected users. More...

int	guac_client_load_plugin (guac_client client, const char protocol)
	Initializes the given guac_client using the initialization routine provided by the plugin corresponding to the named protocol. More...

int	guac_client_get_processing_lag (guac_client *client)
	Calculates and returns the approximate processing lag experienced by the pool of users. More...

void	guac_client_stream_png (guac_client client, guac_socket socket, guac_composite_mode mode, const guac_layer layer, int x, int y, cairo_surface_t surface)
	Streams the image data of the given surface over an image stream ("img" instruction) as PNG-encoded data. More...

void	guac_client_stream_jpeg (guac_client client, guac_socket socket, guac_composite_mode mode, const guac_layer layer, int x, int y, cairo_surface_t surface, int quality)
	Streams the image data of the given surface over an image stream ("img" instruction) as JPEG-encoded data at the given quality. More...

void	guac_client_stream_webp (guac_client client, guac_socket socket, guac_composite_mode mode, const guac_layer layer, int x, int y, cairo_surface_t surface, int quality, int lossless)
	Streams the image data of the given surface over an image stream ("img" instruction) as WebP-encoded data at the given quality. More...

int	guac_client_supports_webp (guac_client *client)
	Returns whether all users of the given client support WebP. More...

Variables
const guac_layer *	GUAC_DEFAULT_LAYER
	The default Guacamole client layer, layer 0.

Detailed Description

Functions and structure contents for the Guacamole proxy client.

Function Documentation

void guac_client_abort	(	guac_client *	client,
		guac_protocol_status	status,
		const char *	format,
			...
	)

Signals the given client to stop gracefully, while also signalling via the Guacamole protocol that an error has occurred.

Note that this is a completely cooperative signal, and can be ignored by the client or the hosting daemon. The message given will be logged to the system logs.

Parameters

client	The proxy client to signal to stop.
status	The status to send over the Guacamole protocol.
format	A printf-style format string to log.
...	Arguments to use when filling the format string for printing.

int guac_client_add_user	(	guac_client *	client,
		guac_user *	user,
		int	argc,
		char **	argv
	)

Adds the given user to the internal list of connected users.

Future writes to the broadcast socket stored within guac_client will also write to this user. The join handler of this guac_client will be called.

Parameters

client	The proxy client to add the user to.
user	The user to add.
argc	The number of arguments to pass to the new user.
argv	An array of strings containing the argument values being passed.

Returns: Zero if the user was added successfully, non-zero if the user could not join the connection.

guac_client* guac_client_alloc ( )

Returns a new, barebones guac_client.

This new guac_client has no handlers set, but is otherwise usable.

Returns: A pointer to the new client.

guac_layer* guac_client_alloc_buffer ( guac_client * client )

Allocates a new buffer (invisible layer).

An arbitrary index is automatically assigned if no existing buffer is available for use.

Parameters

client The proxy client to allocate the buffer for.

Returns: The next available buffer, or a newly allocated buffer.

guac_layer* guac_client_alloc_layer ( guac_client * client )

Allocates a new layer.

An arbitrary index is automatically assigned if no existing layer is available for use.

Parameters

client The proxy client to allocate the layer buffer for.

Returns: The next available layer, or a newly allocated layer.

guac_stream* guac_client_alloc_stream ( guac_client * client )

Allocates a new stream.

An arbitrary index is automatically assigned if no previously-allocated stream is available for use.

Parameters

client The client to allocate the stream for.

Returns: The next available stream, or a newly allocated stream.

int guac_client_end_frame ( guac_client * client )

Marks the end of the current frame by sending a "sync" instruction to all connected users.

This instruction will contain the current timestamp. The last_sent_timestamp member of guac_client will be updated accordingly.

If an error occurs sending the instruction, a non-zero value is returned, and guac_error is set appropriately.

Parameters

client The guac_client which has finished a frame.

Returns: Zero on success, non-zero on error.

void* guac_client_for_owner	(	guac_client *	client,
		guac_user_callback *	callback,
		void *	data
	)

Calls the given function with the currently-connected user that is marked as the owner.

The owner of a connection is the user that established the initial connection that created the connection (the first user to connect and join). The function will be given a reference to the guac_user and the specified arbitrary data. If the owner has since left the connection, the function will instead be invoked with NULL as the guac_user. The value returned by the callback will be returned by this function.

This function is reentrant, but the user list MUST NOT be manipulated within the same thread as a callback to this function.

Because this function depends on a consistent list of connected users, this function MUST NOT be invoked within the same thread as a "leave" or "join" handler. Doing so results in undefined behavior, including possible segfaults.

Parameters

client	The client to retrieve the owner from.
callback	The callback to invoke on the user marked as the owner of the connection. NULL will be passed to this callback instead if there is no owner.
data	Arbitrary data to pass to the given callback.

Returns: The value returned by the callback.

void* guac_client_for_user	(	guac_client *	client,
		guac_user *	user,
		guac_user_callback *	callback,
		void *	data
	)

Calls the given function with the given user ONLY if they are currently connected.

The function will be given a reference to the guac_user and the specified arbitrary data. If the provided user doesn't exist or has since left the connection, the function will instead be invoked with NULL as the guac_user. The value returned by the callback will be returned by this function.

This function is reentrant, but the user list MUST NOT be manipulated within the same thread as a callback to this function.

Because this function depends on a consistent list of connected users, this function MUST NOT be invoked within the same thread as a "leave" or "join" handler. Doing so results in undefined behavior, including possible segfaults.

Parameters

client	The client that the given user is expected to be associated with.
user	The user to provide to the given callback if valid. The pointer need not even point to properly allocated memory; the user will only be passed to the callback function if they are valid, and the provided user pointer will not be dereferenced during this process.
callback	The callback to invoke on the given user if they are valid. NULL will be passed to this callback instead if the user is not valid.
data	Arbitrary data to pass to the given callback.

Returns: The value returned by the callback.

void guac_client_foreach_user	(	guac_client *	client,
		guac_user_callback *	callback,
		void *	data
	)

Calls the given function on all currently-connected users of the given client.

The function will be given a reference to a guac_user and the specified arbitrary data. The value returned by the callback will be ignored.

This function is reentrant, but the user list MUST NOT be manipulated within the same thread as a callback to this function. Though the callback MAY invoke guac_client_foreach_user(), doing so should not be necessary, and may indicate poor design choices.

Because this function loops through all connected users, this function MUST NOT be invoked within the same thread as a "leave" or "join" handler. Doing so results in undefined behavior, including possible segfaults.

Parameters

client	The client whose users should be iterated.
callback	The function to call for each user.
data	Arbitrary data to pass to the callback each time it is invoked.

void guac_client_free ( guac_client * client )

Free all resources associated with the given client.

Parameters

client The proxy client to free all reasources of.

void guac_client_free_buffer	(	guac_client *	client,
		guac_layer *	layer
	)

Returns the given buffer to the pool of available buffers, such that it can be reused by any subsequent call to guac_client_allow_buffer().

Parameters

client	The proxy client to return the buffer to.
layer	The buffer to return to the pool of available buffers.

void guac_client_free_layer	(	guac_client *	client,
		guac_layer *	layer
	)

Returns the given layer to the pool of available layers, such that it can be reused by any subsequent call to guac_client_allow_layer().

Parameters

client	The proxy client to return the layer to.
layer	The buffer to return to the pool of available layer.

void guac_client_free_stream	(	guac_client *	client,
		guac_stream *	stream
	)

Returns the given stream to the pool of available streams, such that it can be reused by any subsequent call to guac_client_alloc_stream().

Parameters

client	The client to return the stream to.
stream	The stream to return to the pool of available stream.

int guac_client_get_processing_lag ( guac_client * client )

Calculates and returns the approximate processing lag experienced by the pool of users.

The processing lag is the difference in time between server and client due purely to data processing and excluding network delays.

Parameters

client The guac_client to calculate the processing lag of.

Returns: The approximate processing lag of the pool of users associated with the given guac_client, in milliseconds.

int guac_client_load_plugin	(	guac_client *	client,
		const char *	protocol
	)

Initializes the given guac_client using the initialization routine provided by the plugin corresponding to the named protocol.

This will automatically invoke guac_client_init within the plugin for the given protocol.

Note that the connection will likely not be established until the first user (the "owner") is added to the client.

Parameters

client	The guac_client to initialize.
protocol	The name of the protocol to use.

Returns: Zero if initialization was successful, non-zero otherwise.

void guac_client_log	(	guac_client *	client,
		guac_client_log_level	level,
		const char *	format,
			...
	)

Writes a message in the log used by the given client.

The logger used will normally be defined by guacd (or whichever program loads the proxy client) by setting the logging handlers of the client when it is loaded.

Parameters

client	The proxy client logging this message.
level	The level at which to log this message.
format	A printf-style format string to log.
...	Arguments to use when filling the format string for printing.

void guac_client_remove_user	(	guac_client *	client,
		guac_user *	user
	)

Removes the given user, removing the user from the internally-tracked list of connected users, and calling any appropriate leave handler.

Parameters

client	The proxy client to return the buffer to.
user	The user to remove.

void guac_client_stop ( guac_client * client )

Signals the given client to stop gracefully.

This is a completely cooperative signal, and can be ignored by the client or the hosting daemon.

Parameters

client The proxy client to signal to stop.

void guac_client_stream_jpeg	(	guac_client *	client,
		guac_socket *	socket,
		guac_composite_mode	mode,
		const guac_layer *	layer,
		int	x,
		int	y,
		cairo_surface_t *	surface,
		int	quality
	)

Streams the image data of the given surface over an image stream ("img" instruction) as JPEG-encoded data at the given quality.

The image stream will be automatically allocated and freed.

Parameters

client	The Guacamole client for which the image stream should be allocated.
socket	The socket over which instructions associated with the image stream should be sent.
mode	The composite mode to use when rendering the image over the given layer.
layer	The destination layer.
x	The X coordinate of the upper-left corner of the destination rectangle within the given layer.
y	The Y coordinate of the upper-left corner of the destination rectangle within the given layer.
surface	A Cairo surface containing the image data to be streamed.
quality	The JPEG image quality, which must be an integer value between 0 and 100 inclusive. Larger values indicate improving quality at the expense of larger file size.

void guac_client_stream_png	(	guac_client *	client,
		guac_socket *	socket,
		guac_composite_mode	mode,
		const guac_layer *	layer,
		int	x,
		int	y,
		cairo_surface_t *	surface
	)

Streams the image data of the given surface over an image stream ("img" instruction) as PNG-encoded data.

The image stream will be automatically allocated and freed.

Parameters

client	The Guacamole client for which the image stream should be allocated.
socket	The socket over which instructions associated with the image stream should be sent.
mode	The composite mode to use when rendering the image over the given layer.
layer	The destination layer.
x	The X coordinate of the upper-left corner of the destination rectangle within the given layer.
y	The Y coordinate of the upper-left corner of the destination rectangle within the given layer.
surface	A Cairo surface containing the image data to be streamed.

void guac_client_stream_webp	(	guac_client *	client,
		guac_socket *	socket,
		guac_composite_mode	mode,
		const guac_layer *	layer,
		int	x,
		int	y,
		cairo_surface_t *	surface,
		int	quality,
		int	lossless
	)

Streams the image data of the given surface over an image stream ("img" instruction) as WebP-encoded data at the given quality.

The image stream will be automatically allocated and freed. If the server does not support WebP, this function has no effect, so be sure to check the result of guac_client_supports_webp() prior to calling this function.

Parameters

client	The Guacamole client for whom the image stream should be allocated.
socket	The socket over which instructions associated with the image stream should be sent.
mode	The composite mode to use when rendering the image over the given layer.
layer	The destination layer.
x	The X coordinate of the upper-left corner of the destination rectangle within the given layer.
y	The Y coordinate of the upper-left corner of the destination rectangle within the given layer.
surface	A Cairo surface containing the image data to be streamed.
quality	The WebP image quality, which must be an integer value between 0 and 100 inclusive. For lossy images, larger values indicate improving quality at the expense of larger file size. For lossless images, this dictates the quality of compression, with larger values producing smaller files at the expense of speed.
lossless	Zero to encode a lossy image, non-zero to encode losslessly.

int guac_client_supports_webp ( guac_client * client )

Returns whether all users of the given client support WebP.

If any user does not support WebP, or the server cannot encode WebP images, zero is returned.

Parameters

client The Guacamole client whose users should be checked for WebP support.

Returns: Non-zero if the all users of the given client claim to support WebP and the server has been built with WebP support, zero otherwise.

void vguac_client_abort	(	guac_client *	client,
		guac_protocol_status	status,
		const char *	format,
		va_list	ap
	)

Signals the given client to stop gracefully, while also signalling via the Guacamole protocol that an error has occurred.

Note that this is a completely cooperative signal, and can be ignored by the client or the hosting daemon. The message given will be logged to the system logs.

Parameters

client	The proxy client to signal to stop.
status	The status to send over the Guacamole protocol.
format	A printf-style format string to log.
ap	The va_list containing the arguments to be used when filling the format string for printing.

void vguac_client_log	(	guac_client *	client,
		guac_client_log_level	level,
		const char *	format,
		va_list	ap
	)

Writes a message in the log used by the given client.

The logger used will normally be defined by guacd (or whichever program loads the proxy client) by setting the logging handlers of the client when it is loaded.

Parameters

client	The proxy client logging this message.
level	The level at which to log this message.
format	A printf-style format string to log.
ap	The va_list containing the arguments to be used when filling the format string for printing.

Data Structures

Functions

Variables

Detailed Description

Function Documentation