/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
#include "config.h"
#include "guacamole/client.h"
#include "guacamole/error.h"
#include "guacamole/parser.h"
#include "guacamole/protocol.h"
#include "guacamole/socket.h"
#include "guacamole/user.h"
#include "user-handlers.h"
#include <pthread.h>
#include <stdlib.h>
#include <string.h>
/**
* Parameters required by the user input thread.
*/
typedef struct guac_user_input_thread_params {
/**
* The parser which will be used throughout the user's session.
*/
guac_parser* parser;
/**
* A reference to the connected user.
*/
guac_user* user;
/**
* The number of microseconds to wait for instructions from a connected
* user before closing the connection with an error.
*/
int usec_timeout;
} guac_user_input_thread_params;
/**
* Prints an error message using the logging facilities of the given user,
* automatically including any information present in guac_error.
*
* @param user
* The guac_user associated with the error that occurred.
*
* @param level
* The level at which to log this message.
*
* @param message
* The message to log.
*/
static void guac_user_log_guac_error(guac_user* user,
guac_client_log_level level, const char* message) {
if (guac_error != GUAC_STATUS_SUCCESS) {
/* If error message provided, include in log */
if (guac_error_message != NULL)
guac_user_log(user, level, "%s: %s", message,
guac_error_message);
/* Otherwise just log with standard status string */
else
guac_user_log(user, level, "%s: %s", message,
guac_status_string(guac_error));
}
/* Just log message if no status code */
else
guac_user_log(user, level, "%s", message);
}
/**
* Logs a reasonable explanatory message regarding handshake failure based on
* the current value of guac_error.
*
* @param user
* The guac_user associated with the failed Guacamole protocol handshake.
*/
static void guac_user_log_handshake_failure(guac_user* user) {
if (guac_error == GUAC_STATUS_CLOSED)
guac_user_log(user, GUAC_LOG_DEBUG,
"Guacamole connection closed during handshake");
else if (guac_error == GUAC_STATUS_PROTOCOL_ERROR)
guac_user_log(user, GUAC_LOG_ERROR,
"Guacamole protocol violation. Perhaps the version of "
"guacamole-client is incompatible with this version of "
"libguac?");
else
guac_user_log(user, GUAC_LOG_WARNING,
"Guacamole handshake failed: %s",
guac_status_string(guac_error));
}
/**
* The thread which handles all user input, calling event handlers for received
* instructions.
*
* @param data
* A pointer to a guac_user_input_thread_params structure describing the
* user whose input is being handled and the guac_parser with which to
* handle it.
*
* @return
* Always NULL.
*/
static void* guac_user_input_thread(void* data) {
guac_user_input_thread_params* params =
(guac_user_input_thread_params*) data;
int usec_timeout = params->usec_timeout;
guac_user* user = params->user;
guac_parser* parser = params->parser;
guac_client* client = user->client;
guac_socket* socket = user->socket;
/* Guacamole user input loop */
while (client->state == GUAC_CLIENT_RUNNING && user->active) {
/* Read instruction, stop on error */
if (guac_parser_read(parser, socket, usec_timeout)) {
if (guac_error == GUAC_STATUS_TIMEOUT)
guac_user_abort(user, GUAC_PROTOCOL_STATUS_CLIENT_TIMEOUT, "User is not responding.");
else {
if (guac_error != GUAC_STATUS_CLOSED)
guac_user_log_guac_error(user, GUAC_LOG_WARNING,
"Guacamole connection failure");
guac_user_stop(user);
}
return NULL;
}
/* Reset guac_error and guac_error_message (user/client handlers are not
* guaranteed to set these) */
guac_error = GUAC_STATUS_SUCCESS;
guac_error_message = NULL;
/* Call handler, stop on error */
if (__guac_user_call_opcode_handler(__guac_instruction_handler_map,
user, parser->opcode, parser->argc, parser->argv)) {
/* Log error */
guac_user_log_guac_error(user, GUAC_LOG_WARNING,
"User connection aborted");
/* Log handler details */
guac_user_log(user, GUAC_LOG_DEBUG, "Failing instruction handler in user was \"%s\"", parser->opcode);
guac_user_stop(user);
return NULL;
}
}
return NULL;
}
/**
* Starts the input/output threads of a new user. This function will block
* until the user disconnects. If an error prevents the input/output threads
* from starting, guac_user_stop() will be invoked on the given user.
*
* @param parser
* The guac_parser to use to handle all input from the given user.
*
* @param user
* The user whose associated I/O transfer threads should be started.
*
* @param usec_timeout
* The number of microseconds to wait for instructions from the given
* user before closing the connection with an error.
*
* @return
* Zero if the I/O threads started successfully and user has disconnected,
* or non-zero if the I/O threads could not be started.
*/
static int guac_user_start(guac_parser* parser, guac_user* user,
int usec_timeout) {
guac_user_input_thread_params params = {
.parser = parser,
.user = user,
.usec_timeout = usec_timeout
};
pthread_t input_thread;
if (pthread_create(&input_thread, NULL, guac_user_input_thread, (void*) ¶ms)) {
guac_user_log(user, GUAC_LOG_ERROR, "Unable to start input thread");
guac_user_stop(user);
return -1;
}
/* Wait for I/O threads */
pthread_join(input_thread, NULL);
/* Explicitly signal disconnect */
guac_protocol_send_disconnect(user->socket);
guac_socket_flush(user->socket);
/* Done */
return 0;
}
/**
* This function loops through the received instructions during the handshake
* with the client attempting to join the connection, and runs the handlers
* for each of the opcodes, ending when the connect instruction is received.
* Returns zero if the handshake completes successfully with the connect opcode,
* or a non-zero value if an error occurs.
*
* @param user
* The guac_user attempting to join the connection.
*
* @param parser
* The parser used to examine the received data.
*
* @param usec_timeout
* The timeout, in microseconds, for reading the instructions.
*
* @return
* Zero if the handshake completes successfully with the connect opcode,
* or non-zero if an error occurs.
*/
static int __guac_user_handshake(guac_user* user, guac_parser* parser,
int usec_timeout) {
guac_socket* socket = user->socket;
/* Handle each of the opcodes. */
while (guac_parser_read(parser, socket, usec_timeout) == 0) {
/* If we receive the connect opcode, we're done. */
if (strcmp(parser->opcode, "connect") == 0)
return 0;
guac_user_log(user, GUAC_LOG_DEBUG, "Processing instruction: %s",
parser->opcode);
/* Run instruction handler for opcode with arguments. */
if (__guac_user_call_opcode_handler(__guac_handshake_handler_map, user,
parser->opcode, parser->argc, parser->argv)) {
guac_user_log_handshake_failure(user);
guac_user_log_guac_error(user, GUAC_LOG_DEBUG,
"Error handling instruction during handshake.");
guac_user_log(user, GUAC_LOG_DEBUG, "Failed opcode: %s",
parser->opcode);
guac_parser_free(parser);
return 1;
}
}
/* If we get here it's because we never got the connect instruction. */
guac_user_log(user, GUAC_LOG_ERROR,
"Handshake failed, \"connect\" instruction was not received.");
return 1;
}
int guac_user_handle_connection(guac_user* user, int usec_timeout) {
guac_socket* socket = user->socket;
guac_client* client = user->client;
user->info.audio_mimetypes = NULL;
user->info.image_mimetypes = NULL;
user->info.video_mimetypes = NULL;
user->info.timezone = NULL;
/* Count number of arguments. */
int num_args;
for (num_args = 0; client->args[num_args] != NULL; num_args++);
/* Send args */
if (guac_protocol_send_args(socket, client->args)
|| guac_socket_flush(socket)) {
/* Log error */
guac_user_log_handshake_failure(user);
guac_user_log_guac_error(user, GUAC_LOG_DEBUG,
"Error sending \"args\" to new user");
return 1;
}
guac_parser* parser = guac_parser_alloc();
/* Perform the handshake with the client. */
if (__guac_user_handshake(user, parser, usec_timeout)) {
guac_parser_free(parser);
return 1;
}
/* Acknowledge connection availability */
guac_protocol_send_ready(socket, client->connection_id);
guac_socket_flush(socket);
/* Verify argument count. */
if (parser->argc != (num_args + 1)) {
guac_client_log(client, GUAC_LOG_ERROR, "Client did not return the "
"expected number of arguments.");
return 1;
}
/* Attempt to join user to connection. */
if (guac_client_add_user(client, user, (parser->argc - 1), parser->argv + 1))
guac_client_log(client, GUAC_LOG_ERROR, "User \"%s\" could NOT "
"join connection \"%s\"", user->user_id, client->connection_id);
/* Begin user connection if join successful */
else {
guac_client_log(client, GUAC_LOG_INFO, "User \"%s\" joined connection "
"\"%s\" (%i users now present)", user->user_id,
client->connection_id, client->connected_users);
if (strcmp(parser->argv[0],"") != 0) {
guac_client_log(client, GUAC_LOG_DEBUG, "Client is using protocol "
"version \"%s\"", parser->argv[0]);
user->info.protocol_version = guac_protocol_string_to_version(parser->argv[0]);
}
else {
guac_client_log(client, GUAC_LOG_DEBUG, "Client has not defined "
"its protocol version.");
user->info.protocol_version = GUAC_PROTOCOL_VERSION_1_0_0;
}
/* Handle user I/O, wait for connection to terminate */
guac_user_start(parser, user, usec_timeout);
/* Remove/free user */
guac_client_remove_user(client, user);
guac_client_log(client, GUAC_LOG_INFO, "User \"%s\" disconnected (%i "
"users remain)", user->user_id, client->connected_users);
}
/* Free mimetype character arrays. */
guac_free_mimetypes((char **) user->info.audio_mimetypes);
guac_free_mimetypes((char **) user->info.image_mimetypes);
guac_free_mimetypes((char **) user->info.video_mimetypes);
/* Free timezone info. */
free((char *) user->info.timezone);
guac_parser_free(parser);
/* Successful disconnect */
return 0;
}