/* * 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 #include #include /** * 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_INFO, "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)); } /** * Copies the given array of mimetypes (strings) into a newly-allocated NULL- * terminated array of strings. Both the array and the strings within the array * are newly-allocated and must be later freed via guac_free_mimetypes(). * * @param mimetypes * The array of mimetypes to copy. * * @param count * The number of mimetypes in the given array. * * @return * A newly-allocated, NULL-terminated array containing newly-allocated * copies of each of the mimetypes provided in the original mimetypes * array. */ static char** guac_copy_mimetypes(char** mimetypes, int count) { int i; /* Allocate sufficient space for NULL-terminated array of mimetypes */ char** mimetypes_copy = malloc(sizeof(char*) * (count+1)); /* Copy each provided mimetype */ for (i = 0; i < count; i++) mimetypes_copy[i] = strdup(mimetypes[i]); /* Terminate with NULL */ mimetypes_copy[count] = NULL; return mimetypes_copy; } /** * Frees the given array of mimetypes, including the space allocated to each * mimetype string within the array. The provided array of mimetypes MUST have * been allocated with guac_copy_mimetypes(). * * @param mimetypes * The NULL-terminated array of mimetypes to free. This array MUST have * been previously allocated with guac_copy_mimetypes(). */ static void guac_free_mimetypes(char** mimetypes) { char** current_mimetype = mimetypes; /* Free all strings within NULL-terminated mimetype array */ while (*current_mimetype != NULL) { free(*current_mimetype); current_mimetype++; } /* Free the array itself, now that its contents have been freed */ free(mimetypes); } /** * 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_handle_instruction(user, parser->opcode, parser->argc, parser->argv) < 0) { /* 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; } int guac_user_handle_connection(guac_user* user, int usec_timeout) { guac_socket* socket = user->socket; guac_client* client = user->client; /* 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(); /* Get optimal screen size */ if (guac_parser_expect(parser, socket, usec_timeout, "size")) { /* Log error */ guac_user_log_handshake_failure(user); guac_user_log_guac_error(user, GUAC_LOG_DEBUG, "Error reading \"size\""); guac_parser_free(parser); return 1; } /* Validate content of size instruction */ if (parser->argc < 2) { guac_user_log(user, GUAC_LOG_ERROR, "Received \"size\" " "instruction lacked required arguments."); guac_parser_free(parser); return 1; } /* Parse optimal screen dimensions from size instruction */ user->info.optimal_width = atoi(parser->argv[0]); user->info.optimal_height = atoi(parser->argv[1]); /* If DPI given, set the user resolution */ if (parser->argc >= 3) user->info.optimal_resolution = atoi(parser->argv[2]); /* Otherwise, use a safe default for rough backwards compatibility */ else user->info.optimal_resolution = 96; /* Get supported audio formats */ if (guac_parser_expect(parser, socket, usec_timeout, "audio")) { /* Log error */ guac_user_log_handshake_failure(user); guac_user_log_guac_error(user, GUAC_LOG_DEBUG, "Error reading \"audio\""); guac_parser_free(parser); return 1; } /* Store audio mimetypes */ char** audio_mimetypes = guac_copy_mimetypes(parser->argv, parser->argc); user->info.audio_mimetypes = (const char**) audio_mimetypes; /* Get supported video formats */ if (guac_parser_expect(parser, socket, usec_timeout, "video")) { /* Log error */ guac_user_log_handshake_failure(user); guac_user_log_guac_error(user, GUAC_LOG_DEBUG, "Error reading \"video\""); guac_parser_free(parser); return 1; } /* Store video mimetypes */ char** video_mimetypes = guac_copy_mimetypes(parser->argv, parser->argc); user->info.video_mimetypes = (const char**) video_mimetypes; /* Get supported image formats */ if (guac_parser_expect(parser, socket, usec_timeout, "image")) { /* Log error */ guac_user_log_handshake_failure(user); guac_user_log_guac_error(user, GUAC_LOG_DEBUG, "Error reading \"image\""); guac_parser_free(parser); return 1; } /* Store image mimetypes */ char** image_mimetypes = guac_copy_mimetypes(parser->argv, parser->argc); user->info.image_mimetypes = (const char**) image_mimetypes; /* Get args from connect instruction */ if (guac_parser_expect(parser, socket, usec_timeout, "connect")) { /* Log error */ guac_user_log_handshake_failure(user); guac_user_log_guac_error(user, GUAC_LOG_DEBUG, "Error reading \"connect\""); guac_parser_free(parser); return 1; } /* Acknowledge connection availability */ guac_protocol_send_ready(socket, client->connection_id); guac_socket_flush(socket); /* Attempt join */ if (guac_client_add_user(client, user, parser->argc, parser->argv)) 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); /* 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 lists */ guac_free_mimetypes(audio_mimetypes); guac_free_mimetypes(video_mimetypes); guac_free_mimetypes(image_mimetypes); guac_parser_free(parser); /* Successful disconnect */ return 0; }