guacamole-spice-protocol/src/libguac/client.c

853 lines
23 KiB
C

/*
* Copyright (C) 2013 Glyptodon LLC
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "config.h"
#include "client.h"
#include "encode-jpeg.h"
#include "encode-png.h"
#include "encode-webp.h"
#include "error.h"
#include "id.h"
#include "layer.h"
#include "pool.h"
#include "plugin.h"
#include "protocol.h"
#include "socket.h"
#include "stream.h"
#include "timestamp.h"
#include "user.h"
#include <dlfcn.h>
#include <pthread.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
guac_layer __GUAC_DEFAULT_LAYER = {
.index = 0
};
const guac_layer* GUAC_DEFAULT_LAYER = &__GUAC_DEFAULT_LAYER;
/**
* Single chunk of data, to be broadcast to all users.
*/
typedef struct __write_chunk {
/**
* The buffer to write.
*/
const void* buffer;
/**
* The number of bytes in the buffer.
*/
size_t length;
} __write_chunk;
guac_layer* guac_client_alloc_layer(guac_client* client) {
/* Init new layer */
guac_layer* allocd_layer = malloc(sizeof(guac_layer));
allocd_layer->index = guac_pool_next_int(client->__layer_pool)+1;
return allocd_layer;
}
guac_layer* guac_client_alloc_buffer(guac_client* client) {
/* Init new layer */
guac_layer* allocd_layer = malloc(sizeof(guac_layer));
allocd_layer->index = -guac_pool_next_int(client->__buffer_pool) - 1;
return allocd_layer;
}
void guac_client_free_buffer(guac_client* client, guac_layer* layer) {
/* Release index to pool */
guac_pool_free_int(client->__buffer_pool, -layer->index - 1);
/* Free layer */
free(layer);
}
void guac_client_free_layer(guac_client* client, guac_layer* layer) {
/* Release index to pool */
guac_pool_free_int(client->__layer_pool, layer->index);
/* Free layer */
free(layer);
}
guac_stream* guac_client_alloc_stream(guac_client* client) {
guac_stream* allocd_stream;
int stream_index;
/* Refuse to allocate beyond maximum */
if (client->__stream_pool->active == GUAC_CLIENT_MAX_STREAMS)
return NULL;
/* Allocate stream */
stream_index = guac_pool_next_int(client->__stream_pool);
/* Initialize stream with odd index (even indices are user-level) */
allocd_stream = &(client->__output_streams[stream_index]);
allocd_stream->index = (stream_index * 2) + 1;
allocd_stream->data = NULL;
allocd_stream->ack_handler = NULL;
allocd_stream->blob_handler = NULL;
allocd_stream->end_handler = NULL;
return allocd_stream;
}
void guac_client_free_stream(guac_client* client, guac_stream* stream) {
/* Release index to pool */
guac_pool_free_int(client->__stream_pool, (stream->index - 1) / 2);
/* Mark stream as closed */
stream->index = GUAC_CLIENT_CLOSED_STREAM_INDEX;
}
/**
* Callback which handles read requests on the broadcast socket. This callback
* always fails, as the broadcast socket is write-only; it cannot be read.
*
* @param socket
* The broadcast socket to read from.
*
* @param buf
* The buffer into which data should be read.
*
* @param count
* The number of bytes to attempt to read.
*
* @return
* The number of bytes read, or -1 if an error occurs. This implementation
* always returns -1, as the broadcast socket is write-only and cannot be
* read.
*/
static ssize_t __guac_socket_broadcast_read_handler(guac_socket* socket,
void* buf, size_t count) {
/* Broadcast socket reads are not allowed */
return -1;
}
/**
* Callback invoked by guac_client_foreach_user() which write a given chunk of
* data to that user's socket. If the write attempt fails, the user is
* signalled to stop with guac_user_stop().
*
* @param user
* The user that the chunk of data should be written to.
*
* @param data
* A pointer to a __write_chunk which describes the data to be written.
*
* @return
* Always NULL.
*/
static void* __write_chunk_callback(guac_user* user, void* data) {
__write_chunk* chunk = (__write_chunk*) data;
/* Attempt write, disconnect on failure */
if (guac_socket_write(user->socket, chunk->buffer, chunk->length))
guac_user_stop(user);
return NULL;
}
/**
* Socket write handler which operates on each of the sockets of all connected
* users. This write handler will always succeed, but any failing user-specific
* writes will invoke guac_user_stop() on the failing user.
*
* @param socket
* The socket to which the given data must be written.
*
* @param buf
* The buffer containing the data to write.
*
* @param count
* The number of bytes to attempt to write from the given buffer.
*
* @return
* The number of bytes written, or -1 if an error occurs. This handler will
* always succeed, and thus will always return the exact number of bytes
* specified by count.
*/
static ssize_t __guac_socket_broadcast_write_handler(guac_socket* socket,
const void* buf, size_t count) {
guac_client* client = (guac_client*) socket->data;
/* Build chunk */
__write_chunk chunk;
chunk.buffer = buf;
chunk.length = count;
/* Broadcast chunk to all users */
guac_client_foreach_user(client, __write_chunk_callback, &chunk);
return count;
}
/**
* Callback which is invoked by guac_client_foreach_user() to flush all
* pending data on the given user's socket. If an error occurs while flushing
* a user's socket, that user is signalled to stop with guac_user_stop().
*
* @param user
* The user whose socket should be flushed.
*
* @param data
* Arbitrary data passed to guac_client_foreach_user(). This is not needed
* by this callback, and should be left as NULL.
*
* @return
* Always NULL.
*/
static void* __flush_callback(guac_user* user, void* data) {
/* Attempt flush, disconnect on failure */
if (guac_socket_flush(user->socket))
guac_user_stop(user);
return NULL;
}
/**
* Socket flush handler which operates on each of the sockets of all connected
* users. This flush handler will always succeed, but any failing user-specific
* flush will invoke guac_user_stop() on the failing user.
*
* @param socket
* The broadcast socket to flush.
*
* @return
* Zero if the flush operation succeeds, non-zero if the operation fails.
* This handler will always succeed, and thus will always return zero.
*/
static ssize_t __guac_socket_broadcast_flush_handler(guac_socket* socket) {
guac_client* client = (guac_client*) socket->data;
/* Flush all users */
guac_client_foreach_user(client, __flush_callback, NULL);
return 0;
}
/**
* Callback which is invoked by guac_client_foreach_user() to lock the given
* user's socket in preparation for the beginning of a Guacamole protocol
* instruction.
*
* @param user
* The user whose socket should be locked.
*
* @param data
* Arbitrary data passed to guac_client_foreach_user(). This is not needed
* by this callback, and should be left as NULL.
*
* @return
* Always NULL.
*/
static void* __lock_callback(guac_user* user, void* data) {
/* Lock socket */
guac_socket_instruction_begin(user->socket);
return NULL;
}
/**
* Socket lock handler which acquires the socket locks of all connected users.
* Socket-level locks are acquired in preparation for the beginning of a new
* Guacamole instruction to ensure that parallel writes are only interleaved at
* instruction boundaries.
*
* @param socket
* The broadcast socket to lock.
*/
static void __guac_socket_broadcast_lock_handler(guac_socket* socket) {
guac_client* client = (guac_client*) socket->data;
/* Lock sockets of all users */
guac_client_foreach_user(client, __lock_callback, NULL);
}
/**
* Callback which is invoked by guac_client_foreach_user() to unlock the given
* user's socket at the end of a Guacamole protocol instruction.
*
* @param user
* The user whose socket should be unlocked.
*
* @param data
* Arbitrary data passed to guac_client_foreach_user(). This is not needed
* by this callback, and should be left as NULL.
*
* @return
* Always NULL.
*/
static void* __unlock_callback(guac_user* user, void* data) {
/* Unlock socket */
guac_socket_instruction_end(user->socket);
return NULL;
}
/**
* Socket unlock handler which releases the socket locks of all connected users.
* Socket-level locks are released after a Guacamole instruction has finished
* being written.
*
* @param socket
* The broadcast socket to unlock.
*/
static void __guac_socket_broadcast_unlock_handler(guac_socket* socket) {
guac_client* client = (guac_client*) socket->data;
/* Unlock sockets of all users */
guac_client_foreach_user(client, __unlock_callback, NULL);
}
/**
* Callback which handles select operations on the broadcast socket, waiting
* for data to become available such that the next read operation will not
* block. This callback always fails, as the broadcast socket is write-only; it
* cannot be read.
*
* @param socket
* The broadcast socket to wait for.
*
* @param usec_timeout
* The maximum amount of time to wait for data, in microseconds, or -1 to
* potentially wait forever.
*
* @return
* A positive value on success, zero if the timeout elapsed and no data is
* available, or a negative value if an error occurs. This implementation
* always returns -1, as the broadcast socket is write-only and cannot be
* read.
*/
static int __guac_socket_broadcast_select_handler(guac_socket* socket,
int usec_timeout) {
/* Selecting the broadcast socket is not possible */
return -1;
}
guac_client* guac_client_alloc() {
int i;
pthread_rwlockattr_t lock_attributes;
/* Allocate new client */
guac_client* client = malloc(sizeof(guac_client));
if (client == NULL) {
guac_error = GUAC_STATUS_NO_MEMORY;
guac_error_message = "Could not allocate memory for client";
return NULL;
}
/* Init new client */
memset(client, 0, sizeof(guac_client));
client->state = GUAC_CLIENT_RUNNING;
client->last_sent_timestamp = guac_timestamp_current();
/* Generate ID */
client->connection_id = guac_generate_id(GUAC_CLIENT_ID_PREFIX);
if (client->connection_id == NULL) {
free(client);
return NULL;
}
/* Allocate buffer and layer pools */
client->__buffer_pool = guac_pool_alloc(GUAC_BUFFER_POOL_INITIAL_SIZE);
client->__layer_pool = guac_pool_alloc(GUAC_BUFFER_POOL_INITIAL_SIZE);
/* Allocate stream pool */
client->__stream_pool = guac_pool_alloc(0);
/* Initialize streams */
client->__output_streams = malloc(sizeof(guac_stream) * GUAC_CLIENT_MAX_STREAMS);
for (i=0; i<GUAC_CLIENT_MAX_STREAMS; i++) {
client->__output_streams[i].index = GUAC_CLIENT_CLOSED_STREAM_INDEX;
}
/* Init locks */
pthread_rwlockattr_init(&lock_attributes);
pthread_rwlockattr_setpshared(&lock_attributes, PTHREAD_PROCESS_SHARED);
pthread_rwlock_init(&(client->__users_lock), &lock_attributes);
/* Set up socket to broadcast to all users */
guac_socket* socket = guac_socket_alloc();
client->socket = socket;
socket->data = client;
socket->read_handler = __guac_socket_broadcast_read_handler;
socket->write_handler = __guac_socket_broadcast_write_handler;
socket->select_handler = __guac_socket_broadcast_select_handler;
socket->flush_handler = __guac_socket_broadcast_flush_handler;
socket->lock_handler = __guac_socket_broadcast_lock_handler;
socket->unlock_handler = __guac_socket_broadcast_unlock_handler;
return client;
}
void guac_client_free(guac_client* client) {
/* Remove all users */
while (client->__users != NULL)
guac_client_remove_user(client, client->__users);
if (client->free_handler) {
/* FIXME: Errors currently ignored... */
client->free_handler(client);
}
/* Free layer pools */
guac_pool_free(client->__buffer_pool);
guac_pool_free(client->__layer_pool);
/* Free streams */
free(client->__output_streams);
/* Free stream pool */
guac_pool_free(client->__stream_pool);
/* Close associated plugin */
if (client->__plugin_handle != NULL) {
if (dlclose(client->__plugin_handle))
guac_client_log(client, GUAC_LOG_ERROR, "Unable to close plugin: %s", dlerror());
}
pthread_rwlock_destroy(&(client->__users_lock));
free(client);
}
void vguac_client_log(guac_client* client, guac_client_log_level level,
const char* format, va_list ap) {
/* Call handler if defined */
if (client->log_handler != NULL)
client->log_handler(client, level, format, ap);
}
void guac_client_log(guac_client* client, guac_client_log_level level,
const char* format, ...) {
va_list args;
va_start(args, format);
vguac_client_log(client, level, format, args);
va_end(args);
}
void guac_client_stop(guac_client* client) {
client->state = GUAC_CLIENT_STOPPING;
}
void vguac_client_abort(guac_client* client, guac_protocol_status status,
const char* format, va_list ap) {
/* Only relevant if client is running */
if (client->state == GUAC_CLIENT_RUNNING) {
/* Log detail of error */
vguac_client_log(client, GUAC_LOG_ERROR, format, ap);
/* Send error immediately, limit information given */
guac_protocol_send_error(client->socket, "Aborted. See logs.", status);
guac_socket_flush(client->socket);
/* Stop client */
guac_client_stop(client);
}
}
void guac_client_abort(guac_client* client, guac_protocol_status status,
const char* format, ...) {
va_list args;
va_start(args, format);
vguac_client_abort(client, status, format, args);
va_end(args);
}
int guac_client_add_user(guac_client* client, guac_user* user, int argc, char** argv) {
int retval = 0;
pthread_rwlock_wrlock(&(client->__users_lock));
/* Call handler, if defined */
if (client->join_handler)
retval = client->join_handler(user, argc, argv);
/* Add to list if join was successful */
if (retval == 0) {
user->__prev = NULL;
user->__next = client->__users;
if (client->__users != NULL)
client->__users->__prev = user;
client->__users = user;
client->connected_users++;
/* Update owner pointer if user is owner */
if (user->owner)
client->__owner = user;
}
pthread_rwlock_unlock(&(client->__users_lock));
return retval;
}
void guac_client_remove_user(guac_client* client, guac_user* user) {
pthread_rwlock_wrlock(&(client->__users_lock));
/* Call handler, if defined */
if (user->leave_handler)
user->leave_handler(user);
else if (client->leave_handler)
client->leave_handler(user);
/* Update prev / head */
if (user->__prev != NULL)
user->__prev->__next = user->__next;
else
client->__users = user->__next;
/* Update next */
if (user->__next != NULL)
user->__next->__prev = user->__prev;
client->connected_users--;
/* Update owner pointer if user was owner */
if (user->owner)
client->__owner = NULL;
pthread_rwlock_unlock(&(client->__users_lock));
}
void guac_client_foreach_user(guac_client* client, guac_user_callback* callback, void* data) {
guac_user* current;
pthread_rwlock_rdlock(&(client->__users_lock));
/* Call function on each user */
current = client->__users;
while (current != NULL) {
callback(current, data);
current = current->__next;
}
pthread_rwlock_unlock(&(client->__users_lock));
}
void* guac_client_for_owner(guac_client* client, guac_user_callback* callback,
void* data) {
void* retval;
pthread_rwlock_rdlock(&(client->__users_lock));
/* Invoke callback with current owner */
retval = callback(client->__owner, data);
pthread_rwlock_unlock(&(client->__users_lock));
/* Return value from callback */
return retval;
}
int guac_client_end_frame(guac_client* client) {
/* Update and send timestamp */
client->last_sent_timestamp = guac_timestamp_current();
return guac_protocol_send_sync(client->socket, client->last_sent_timestamp);
}
/**
* Empty NULL-terminated array of argument names.
*/
const char* __GUAC_CLIENT_NO_ARGS[] = { NULL };
int guac_client_load_plugin(guac_client* client, const char* protocol) {
/* Reference to dlopen()'d plugin */
void* client_plugin_handle;
/* Pluggable client */
char protocol_lib[GUAC_PROTOCOL_LIBRARY_LIMIT] =
GUAC_PROTOCOL_LIBRARY_PREFIX;
/* Type-pun for the sake of dlsym() - cannot typecast a void* to a function
* pointer otherwise */
union {
guac_client_init_handler* client_init;
void* obj;
} alias;
/* Add protocol and .so suffix to protocol_lib */
strncat(protocol_lib, protocol, GUAC_PROTOCOL_NAME_LIMIT-1);
strcat(protocol_lib, GUAC_PROTOCOL_LIBRARY_SUFFIX);
/* Load client plugin */
client_plugin_handle = dlopen(protocol_lib, RTLD_LAZY);
if (!client_plugin_handle) {
guac_error = GUAC_STATUS_NOT_FOUND;
guac_error_message = dlerror();
return -1;
}
dlerror(); /* Clear errors */
/* Get init function */
alias.obj = dlsym(client_plugin_handle, "guac_client_init");
/* Fail if cannot find guac_client_init */
if (dlerror() != NULL) {
guac_error = GUAC_STATUS_INTERNAL_ERROR;
guac_error_message = dlerror();
dlclose(client_plugin_handle);
return -1;
}
/* Init client */
client->args = __GUAC_CLIENT_NO_ARGS;
client->__plugin_handle = client_plugin_handle;
return alias.client_init(client);
}
/**
* Updates the provided approximate processing lag, taking into account the
* processing lag of the given user.
*
* @param user
* The guac_user to use to update the approximate processing lag.
*
* @param data
* Pointer to an int containing the current approximate processing lag.
* The int will be updated according to the processing lag of the given
* user.
*
* @return
* Always NULL.
*/
static void* __calculate_lag(guac_user* user, void* data) {
int* processing_lag = (int*) data;
/* Simply find maximum */
if (user->processing_lag > *processing_lag)
*processing_lag = user->processing_lag;
return NULL;
}
int guac_client_get_processing_lag(guac_client* client) {
int processing_lag = 0;
/* Approximate the processing lag of all users */
guac_client_foreach_user(client, __calculate_lag, &processing_lag);
return processing_lag;
}
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) {
/* Allocate new stream for image */
guac_stream* stream = guac_client_alloc_stream(client);
/* Declare stream as containing image data */
guac_protocol_send_img(socket, stream, mode, layer, "image/png", x, y);
/* Write PNG data */
guac_png_write(socket, stream, surface);
/* Terminate stream */
guac_protocol_send_end(socket, stream);
/* Free allocated stream */
guac_client_free_stream(client, stream);
}
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) {
/* Allocate new stream for image */
guac_stream* stream = guac_client_alloc_stream(client);
/* Declare stream as containing image data */
guac_protocol_send_img(socket, stream, mode, layer, "image/jpeg", x, y);
/* Write JPEG data */
guac_jpeg_write(socket, stream, surface, quality);
/* Terminate stream */
guac_protocol_send_end(socket, stream);
/* Free allocated stream */
guac_client_free_stream(client, stream);
}
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) {
#ifdef ENABLE_WEBP
/* Allocate new stream for image */
guac_stream* stream = guac_client_alloc_stream(client);
/* Declare stream as containing image data */
guac_protocol_send_img(socket, stream, mode, layer, "image/webp", x, y);
/* Write WebP data */
guac_webp_write(socket, stream, surface, quality, lossless);
/* Terminate stream */
guac_protocol_send_end(socket, stream);
/* Free allocated stream */
guac_client_free_stream(client, stream);
#else
/* Do nothing if WebP support is not built in */
#endif
}
#ifdef ENABLE_WEBP
/**
* Callback which is invoked by guac_client_supports_webp() for each user
* associated with the given client, thus updating an overall support flag
* describing the WebP support state for the client as a whole.
*
* @param user
* The user to check for WebP support.
*
* @param data
* Pointer to an int containing the current WebP support status for the
* client associated with the given user. This flag will be 0 if any user
* already checked has lacked WebP support, or 1 otherwise.
*
* @return
* Always NULL.
*/
static void* __webp_support_callback(guac_user* user, void* data) {
int* webp_supported = (int*) data;
/* Check whether current user supports WebP */
if (*webp_supported)
*webp_supported = guac_user_supports_webp(user);
return NULL;
}
#endif
int guac_client_supports_webp(guac_client* client) {
#ifdef ENABLE_WEBP
int webp_supported = 1;
/* WebP is supported for entire client only if each user supports it */
guac_client_foreach_user(client, __webp_support_callback, &webp_supported);
return webp_supported;
#else
/* Support for WebP is completely absent */
return 0;
#endif
}