Exemple #1
0
void* guac_rdp_client_thread(void* data) {

    guac_client* client = (guac_client*) data;
    guac_rdp_client* rdp_client = (guac_rdp_client*) client->data;
    guac_rdp_settings* settings = rdp_client->settings;

    /* If audio enabled, choose an encoder */
    if (settings->audio_enabled) {

        rdp_client->audio = guac_audio_stream_alloc(client, NULL,
                GUAC_RDP_AUDIO_RATE,
                GUAC_RDP_AUDIO_CHANNELS,
                GUAC_RDP_AUDIO_BPS);

        /* Warn if no audio encoding is available */
        if (rdp_client->audio == NULL)
            guac_client_log(client, GUAC_LOG_INFO,
                    "No available audio encoding. Sound disabled.");

    } /* end if audio enabled */

    /* Load filesystem if drive enabled */
    if (settings->drive_enabled) {

        /* Allocate actual emulated filesystem */
        rdp_client->filesystem =
            guac_rdp_fs_alloc(client, settings->drive_path,
                    settings->create_drive_path);

        /* Expose filesystem to owner */
        guac_client_for_owner(client, guac_rdp_fs_expose,
                rdp_client->filesystem);

    }

#ifdef ENABLE_COMMON_SSH
    /* Connect via SSH if SFTP is enabled */
    if (settings->enable_sftp) {

        /* Abort if username is missing */
        if (settings->sftp_username == NULL) {
            guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR,
                    "A username or SFTP-specific username is required if "
                    "SFTP is enabled.");
            return NULL;
        }

        guac_client_log(client, GUAC_LOG_DEBUG,
                "Connecting via SSH for SFTP filesystem access.");

        rdp_client->sftp_user =
            guac_common_ssh_create_user(settings->sftp_username);

        /* Import private key, if given */
        if (settings->sftp_private_key != NULL) {

            guac_client_log(client, GUAC_LOG_DEBUG,
                    "Authenticating with private key.");

            /* Abort if private key cannot be read */
            if (guac_common_ssh_user_import_key(rdp_client->sftp_user,
                        settings->sftp_private_key,
                        settings->sftp_passphrase)) {
                guac_common_ssh_destroy_user(rdp_client->sftp_user);
                guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR,
                        "Private key unreadable.");
                return NULL;
            }

        }

        /* Otherwise, use specified password */
        else {

            guac_client_log(client, GUAC_LOG_DEBUG,
                    "Authenticating with password.");

            guac_common_ssh_user_set_password(rdp_client->sftp_user,
                    settings->sftp_password);

        }

        /* Attempt SSH connection */
        rdp_client->sftp_session =
            guac_common_ssh_create_session(client, settings->sftp_hostname,
                    settings->sftp_port, rdp_client->sftp_user);

        /* Fail if SSH connection does not succeed */
        if (rdp_client->sftp_session == NULL) {
            /* Already aborted within guac_common_ssh_create_session() */
            guac_common_ssh_destroy_user(rdp_client->sftp_user);
            return NULL;
        }

        /* Load and expose filesystem */
        rdp_client->sftp_filesystem =
            guac_common_ssh_create_sftp_filesystem(
                    rdp_client->sftp_session, "/");

        /* Expose filesystem to connection owner */
        guac_client_for_owner(client,
                guac_common_ssh_expose_sftp_filesystem,
                rdp_client->sftp_filesystem);

        /* Abort if SFTP connection fails */
        if (rdp_client->sftp_filesystem == NULL) {
            guac_common_ssh_destroy_session(rdp_client->sftp_session);
            guac_common_ssh_destroy_user(rdp_client->sftp_user);
            guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR,
                    "SFTP connection failed.");
            return NULL;
        }

        guac_client_log(client, GUAC_LOG_DEBUG,
                "SFTP connection succeeded.");

    }
#endif

    /* Continue handling connections until error or client disconnect */
    while (client->state == GUAC_CLIENT_RUNNING) {
        if (guac_rdp_handle_connection(client))
            break;
    }

    return NULL;

}
void* ssh_client_thread(void* data) {

    guac_client* client = (guac_client*) data;
    ssh_guac_client_data* client_data = (ssh_guac_client_data*) client->data;

    guac_socket* socket = client->socket;
    char buffer[8192];

    pthread_t input_thread;

    /* Init SSH base libraries */
    if (guac_common_ssh_init(client))
        return NULL;

    /* Get user and credentials */
    client_data->user = guac_ssh_get_user(client);

    /* Send new name */
    char name[1024];
    snprintf(name, sizeof(name)-1, "%s@%s",
            client_data->username, client_data->hostname);
    guac_protocol_send_name(socket, name);

    /* Open SSH session */
    client_data->session = guac_common_ssh_create_session(client,
            client_data->hostname, client_data->port, client_data->user);
    if (client_data->session == NULL) {
        /* Already aborted within guac_common_ssh_create_session() */
        return NULL;
    }

    pthread_mutex_init(&client_data->term_channel_lock, NULL);

    /* Open channel for terminal */
    client_data->term_channel =
        libssh2_channel_open_session(client_data->session->session);
    if (client_data->term_channel == NULL) {
        guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR,
                "Unable to open terminal channel.");
        return NULL;
    }

#ifdef ENABLE_SSH_AGENT
    /* Start SSH agent forwarding, if enabled */
    if (client_data->enable_agent) {
        libssh2_session_callback_set(client_data->session,
                LIBSSH2_CALLBACK_AUTH_AGENT, (void*) ssh_auth_agent_callback);

        /* Request agent forwarding */
        if (libssh2_channel_request_auth_agent(client_data->term_channel))
            guac_client_log(client, GUAC_LOG_ERROR, "Agent forwarding request failed");
        else
            guac_client_log(client, GUAC_LOG_INFO, "Agent forwarding enabled.");
    }

    client_data->auth_agent = NULL;
#endif

    /* Start SFTP session as well, if enabled */
    if (client_data->enable_sftp) {

        /* Create SSH session specific for SFTP */
        guac_client_log(client, GUAC_LOG_DEBUG, "Reconnecting for SFTP...");
        client_data->sftp_session =
            guac_common_ssh_create_session(client, client_data->hostname,
                    client_data->port, client_data->user);
        if (client_data->sftp_session == NULL) {
            /* Already aborted within guac_common_ssh_create_session() */
            return NULL;
        }

        /* Request SFTP */
        client_data->sftp_filesystem =
            guac_common_ssh_create_sftp_filesystem(
                    client_data->sftp_session, "/");

        /* Set generic (non-filesystem) file upload handler */
        client->file_handler = guac_sftp_file_handler;

        /* Init handlers for Guacamole-specific console codes */
        client_data->term->upload_path_handler = guac_sftp_set_upload_path;
        client_data->term->file_download_handler = guac_sftp_download_file;

        guac_client_log(client, GUAC_LOG_DEBUG, "SFTP session initialized");

    }

    /* Request PTY */
    if (libssh2_channel_request_pty_ex(client_data->term_channel, "linux", sizeof("linux")-1, NULL, 0,
            client_data->term->term_width, client_data->term->term_height, 0, 0)) {
        guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR, "Unable to allocate PTY.");
        return NULL;
    }

    /* Request shell */
    if (libssh2_channel_shell(client_data->term_channel)) {
        guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR, "Unable to associate shell with PTY.");
        return NULL;
    }

    /* Logged in */
    guac_client_log(client, GUAC_LOG_INFO, "SSH connection successful.");

    /* Start input thread */
    if (pthread_create(&(input_thread), NULL, ssh_input_thread, (void*) client)) {
        guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR, "Unable to start input thread");
        return NULL;
    }

    /* Set non-blocking */
    libssh2_session_set_blocking(client_data->session->session, 0);

    /* While data available, write to terminal */
    int bytes_read = 0;
    for (;;) {

        /* Track total amount of data read */
        int total_read = 0;

        pthread_mutex_lock(&(client_data->term_channel_lock));

        /* Stop reading at EOF */
        if (libssh2_channel_eof(client_data->term_channel)) {
            pthread_mutex_unlock(&(client_data->term_channel_lock));
            break;
        }

        /* Read terminal data */
        bytes_read = libssh2_channel_read(client_data->term_channel,
                buffer, sizeof(buffer));

        pthread_mutex_unlock(&(client_data->term_channel_lock));

        /* Attempt to write data received. Exit on failure. */
        if (bytes_read > 0) {
            int written = guac_terminal_write_stdout(client_data->term, buffer, bytes_read);
            if (written < 0)
                break;

            total_read += bytes_read;
        }

        else if (bytes_read < 0 && bytes_read != LIBSSH2_ERROR_EAGAIN)
            break;

#ifdef ENABLE_SSH_AGENT
        /* If agent open, handle any agent packets */
        if (client_data->auth_agent != NULL) {
            bytes_read = ssh_auth_agent_read(client_data->auth_agent);
            if (bytes_read > 0)
                total_read += bytes_read;
            else if (bytes_read < 0 && bytes_read != LIBSSH2_ERROR_EAGAIN)
                client_data->auth_agent = NULL;
        }
#endif

        /* Wait for more data if reads turn up empty */
        if (total_read == 0) {
            fd_set fds;
            struct timeval timeout;

            FD_ZERO(&fds);
            FD_SET(client_data->session->fd, &fds);

            /* Wait for one second */
            timeout.tv_sec = 1;
            timeout.tv_usec = 0;

            if (select(client_data->session->fd + 1, &fds,
                        NULL, NULL, &timeout) < 0)
                break;
        }

    }

    /* Kill client and Wait for input thread to die */
    guac_client_stop(client);
    pthread_join(input_thread, NULL);

    pthread_mutex_destroy(&client_data->term_channel_lock);

    guac_client_log(client, GUAC_LOG_INFO, "SSH connection ended.");
    return NULL;

}
Exemple #3
0
int guac_client_init(guac_client* client, int argc, char** argv) {

    rdp_guac_client_data* guac_client_data;
    guac_rdp_settings* settings;

    freerdp* rdp_inst;

    /* Validate number of arguments received */
    if (argc != RDP_ARGS_COUNT) {
        guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR, "Wrong argument count received.");
        return 1;
    }

    /* Allocate client data */
    guac_client_data = malloc(sizeof(rdp_guac_client_data));

    /* Init random number generator */
    srandom(time(NULL));

    /* Init client */
#ifdef HAVE_FREERDP_CHANNELS_GLOBAL_INIT
    freerdp_channels_global_init();
#endif
    rdp_inst = freerdp_new();
    rdp_inst->PreConnect = rdp_freerdp_pre_connect;
    rdp_inst->PostConnect = rdp_freerdp_post_connect;
    rdp_inst->Authenticate = rdp_freerdp_authenticate;
    rdp_inst->VerifyCertificate = rdp_freerdp_verify_certificate;
    rdp_inst->ReceiveChannelData = __guac_receive_channel_data;

    /* Allocate FreeRDP context */
#ifdef LEGACY_FREERDP
    rdp_inst->context_size = sizeof(rdp_freerdp_context);
#else
    rdp_inst->ContextSize = sizeof(rdp_freerdp_context);
#endif
    rdp_inst->ContextNew  = (pContextNew) rdp_freerdp_context_new;
    rdp_inst->ContextFree = (pContextFree) rdp_freerdp_context_free;
    freerdp_context_new(rdp_inst);

    /* Set settings */
    settings = &(guac_client_data->settings);

    /* Console */
    settings->console         = (strcmp(argv[IDX_CONSOLE], "true") == 0);
    settings->console_audio   = (strcmp(argv[IDX_CONSOLE_AUDIO], "true") == 0);

    /* Certificate and auth */
    settings->ignore_certificate = (strcmp(argv[IDX_IGNORE_CERT], "true") == 0);
    settings->disable_authentication = (strcmp(argv[IDX_DISABLE_AUTH], "true") == 0);

    /* NLA security */
    if (strcmp(argv[IDX_SECURITY], "nla") == 0) {
        guac_client_log(client, GUAC_LOG_INFO, "Security mode: NLA");
        settings->security_mode = GUAC_SECURITY_NLA;
    }

    /* TLS security */
    else if (strcmp(argv[IDX_SECURITY], "tls") == 0) {
        guac_client_log(client, GUAC_LOG_INFO, "Security mode: TLS");
        settings->security_mode = GUAC_SECURITY_TLS;
    }

    /* RDP security */
    else if (strcmp(argv[IDX_SECURITY], "rdp") == 0) {
        guac_client_log(client, GUAC_LOG_INFO, "Security mode: RDP");
        settings->security_mode = GUAC_SECURITY_RDP;
    }

    /* ANY security (allow server to choose) */
    else if (strcmp(argv[IDX_SECURITY], "any") == 0) {
        guac_client_log(client, GUAC_LOG_INFO, "Security mode: ANY");
        settings->security_mode = GUAC_SECURITY_ANY;
    }

    /* If nothing given, default to RDP */
    else {
        guac_client_log(client, GUAC_LOG_INFO, "No security mode specified. Defaulting to RDP.");
        settings->security_mode = GUAC_SECURITY_RDP;
    }

    /* Set hostname */
    settings->hostname = strdup(argv[IDX_HOSTNAME]);

    /* If port specified, use it */
    settings->port = RDP_DEFAULT_PORT;
    if (argv[IDX_PORT][0] != '\0')
        settings->port = atoi(argv[IDX_PORT]);

    guac_client_log(client, GUAC_LOG_DEBUG,
            "Client resolution is %ix%i at %i DPI",
            client->info.optimal_width,
            client->info.optimal_height,
            client->info.optimal_resolution);

    /* Use suggested resolution unless overridden */
    settings->resolution = guac_rdp_suggest_resolution(client);
    if (argv[IDX_DPI][0] != '\0')
        settings->resolution = atoi(argv[IDX_DPI]);

    /* Use optimal width unless overridden */
    settings->width = client->info.optimal_width
                    * settings->resolution
                    / client->info.optimal_resolution;

    if (argv[IDX_WIDTH][0] != '\0')
        settings->width = atoi(argv[IDX_WIDTH]);

    /* Use default width if given width is invalid. */
    if (settings->width <= 0) {
        settings->width = RDP_DEFAULT_WIDTH;
        guac_client_log(client, GUAC_LOG_ERROR,
                "Invalid width: \"%s\". Using default of %i.",
                argv[IDX_WIDTH], settings->width);
    }

    /* Round width down to nearest multiple of 4 */
    settings->width = settings->width & ~0x3;

    /* Use optimal height unless overridden */
    settings->height = client->info.optimal_height
                     * settings->resolution
                     / client->info.optimal_resolution;

    if (argv[IDX_HEIGHT][0] != '\0')
        settings->height = atoi(argv[IDX_HEIGHT]);

    /* Use default height if given height is invalid. */
    if (settings->height <= 0) {
        settings->height = RDP_DEFAULT_HEIGHT;
        guac_client_log(client, GUAC_LOG_ERROR,
                "Invalid height: \"%s\". Using default of %i.",
                argv[IDX_WIDTH], settings->height);
    }

    guac_client_log(client, GUAC_LOG_DEBUG,
            "Using resolution of %ix%i at %i DPI",
            settings->width,
            settings->height,
            settings->resolution);

    /* Domain */
    settings->domain = NULL;
    if (argv[IDX_DOMAIN][0] != '\0')
        settings->domain = strdup(argv[IDX_DOMAIN]);

    /* Username */
    settings->username = NULL;
    if (argv[IDX_USERNAME][0] != '\0')
        settings->username = strdup(argv[IDX_USERNAME]);

    /* Password */
    settings->password = NULL;
    if (argv[IDX_PASSWORD][0] != '\0')
        settings->password = strdup(argv[IDX_PASSWORD]);

    /* Client name */
    settings->client_name = NULL;
    if (argv[IDX_CLIENT_NAME][0] != '\0')
        settings->client_name = strdup(argv[IDX_CLIENT_NAME]);

    /* Initial program */
    settings->initial_program = NULL;
    if (argv[IDX_INITIAL_PROGRAM][0] != '\0')
        settings->initial_program = strdup(argv[IDX_INITIAL_PROGRAM]);

    /* RemoteApp program */
    settings->remote_app = NULL;
    if (argv[IDX_REMOTE_APP][0] != '\0')
        settings->remote_app = strdup(argv[IDX_REMOTE_APP]);

    /* RemoteApp working directory */
    settings->remote_app_dir = NULL;
    if (argv[IDX_REMOTE_APP_DIR][0] != '\0')
        settings->remote_app_dir = strdup(argv[IDX_REMOTE_APP_DIR]);

    /* RemoteApp arguments */
    settings->remote_app_args = NULL;
    if (argv[IDX_REMOTE_APP_ARGS][0] != '\0')
        settings->remote_app_args = strdup(argv[IDX_REMOTE_APP_ARGS]);

    /* Static virtual channels */
    settings->svc_names = NULL;
    if (argv[IDX_STATIC_CHANNELS][0] != '\0')
        settings->svc_names = guac_split(argv[IDX_STATIC_CHANNELS], ',');

    /* Performance flags */
    settings->wallpaper_enabled           = (strcmp(argv[IDX_ENABLE_WALLPAPER],           "true") == 0);
    settings->theming_enabled             = (strcmp(argv[IDX_ENABLE_THEMING],             "true") == 0);
    settings->font_smoothing_enabled      = (strcmp(argv[IDX_ENABLE_FONT_SMOOTHING],      "true") == 0);
    settings->full_window_drag_enabled    = (strcmp(argv[IDX_ENABLE_FULL_WINDOW_DRAG],    "true") == 0);
    settings->desktop_composition_enabled = (strcmp(argv[IDX_ENABLE_DESKTOP_COMPOSITION], "true") == 0);
    settings->menu_animations_enabled     = (strcmp(argv[IDX_ENABLE_MENU_ANIMATIONS],     "true") == 0);

    /* Session color depth */
    settings->color_depth = RDP_DEFAULT_DEPTH;
    if (argv[IDX_COLOR_DEPTH][0] != '\0')
        settings->color_depth = atoi(argv[IDX_COLOR_DEPTH]);

    /* Use default depth if given depth is invalid. */
    if (settings->color_depth == 0) {
        settings->color_depth = RDP_DEFAULT_DEPTH;
        guac_client_log(client, GUAC_LOG_ERROR,
                "Invalid color-depth: \"%s\". Using default of %i.",
                argv[IDX_WIDTH], settings->color_depth);
    }

    /* Audio enable/disable */
    guac_client_data->settings.audio_enabled =
        (strcmp(argv[IDX_DISABLE_AUDIO], "true") != 0);

    /* Printing enable/disable */
    guac_client_data->settings.printing_enabled =
        (strcmp(argv[IDX_ENABLE_PRINTING], "true") == 0);

    /* Drive enable/disable */
    guac_client_data->settings.drive_enabled =
        (strcmp(argv[IDX_ENABLE_DRIVE], "true") == 0);

    guac_client_data->settings.drive_path = strdup(argv[IDX_DRIVE_PATH]);

    guac_client_data->settings.create_drive_path =
        (strcmp(argv[IDX_CREATE_DRIVE_PATH], "true") == 0);

    /* Store client data */
    guac_client_data->rdp_inst = rdp_inst;
    guac_client_data->mouse_button_mask = 0;
    guac_client_data->clipboard = guac_common_clipboard_alloc(GUAC_RDP_CLIPBOARD_MAX_LENGTH);
    guac_client_data->requested_clipboard_format = CB_FORMAT_TEXT;
    guac_client_data->audio = NULL;
    guac_client_data->filesystem = NULL;
    guac_client_data->available_svc = guac_common_list_alloc();

    /* Main socket needs to be threadsafe */
    guac_socket_require_threadsafe(client->socket);

    /* Recursive attribute for locks */
    pthread_mutexattr_init(&(guac_client_data->attributes));
    pthread_mutexattr_settype(&(guac_client_data->attributes),
            PTHREAD_MUTEX_RECURSIVE);

    /* Init RDP lock */
    pthread_mutex_init(&(guac_client_data->rdp_lock),
           &(guac_client_data->attributes));

    /* Clear keysym state mapping and keymap */
    memset(guac_client_data->keysym_state, 0,
            sizeof(guac_rdp_keysym_state_map));

    memset(guac_client_data->keymap, 0,
            sizeof(guac_rdp_static_keymap));

    client->data = guac_client_data;
    ((rdp_freerdp_context*) rdp_inst->context)->client = client;

    /* Pick keymap based on argument */
    settings->server_layout = NULL;
    if (argv[IDX_SERVER_LAYOUT][0] != '\0')
        settings->server_layout =
            guac_rdp_keymap_find(argv[IDX_SERVER_LAYOUT]);

    /* If no keymap requested, use default */
    if (settings->server_layout == NULL)
        settings->server_layout = guac_rdp_keymap_find(GUAC_DEFAULT_KEYMAP);

    /* Load keymap into client */
    __guac_rdp_client_load_keymap(client, settings->server_layout);

#ifdef ENABLE_COMMON_SSH
    guac_common_ssh_init(client);

    /* Connect via SSH if SFTP is enabled */
    if (strcmp(argv[IDX_ENABLE_SFTP], "true") == 0) {

        guac_client_log(client, GUAC_LOG_DEBUG,
                "Connecting via SSH for SFTP filesystem access.");

        /* Parse username - use RDP username by default */
        const char* sftp_username = argv[IDX_SFTP_USERNAME];
        if (sftp_username[0] == '\0' && settings->username != NULL)
            sftp_username = settings->username;

        guac_client_data->sftp_user =
            guac_common_ssh_create_user(sftp_username);

        /* Import private key, if given */
        if (argv[IDX_SFTP_PRIVATE_KEY][0] != '\0') {

            guac_client_log(client, GUAC_LOG_DEBUG,
                    "Authenticating with private key.");

            /* Abort if private key cannot be read */
            if (guac_common_ssh_user_import_key(guac_client_data->sftp_user,
                        argv[IDX_SFTP_PRIVATE_KEY],
                        argv[IDX_SFTP_PASSPHRASE])) {
                guac_common_ssh_destroy_user(guac_client_data->sftp_user);
                return 1;
            }

        }

        /* Otherwise, use specified password */
        else {

            guac_client_log(client, GUAC_LOG_DEBUG,
                    "Authenticating with password.");

            /* Parse password - use RDP password by default */
            const char* sftp_password = argv[IDX_SFTP_PASSWORD];
            if (sftp_password[0] == '\0' && settings->password != NULL)
                sftp_password = settings->password;

            guac_common_ssh_user_set_password(guac_client_data->sftp_user,
                    sftp_password);

        }

        /* Parse hostname - use RDP hostname by default */
        const char* sftp_hostname = argv[IDX_SFTP_HOSTNAME];
        if (sftp_hostname[0] == '\0')
            sftp_hostname = settings->hostname;

        /* Parse port, defaulting to standard SSH port */
        const char* sftp_port = argv[IDX_SFTP_PORT];
        if (sftp_port[0] == '\0')
            sftp_port = "22";

        /* Attempt SSH connection */
        guac_client_data->sftp_session =
            guac_common_ssh_create_session(client, sftp_hostname, sftp_port,
                    guac_client_data->sftp_user);

        /* Fail if SSH connection does not succeed */
        if (guac_client_data->sftp_session == NULL) {
            /* Already aborted within guac_common_ssh_create_session() */
            guac_common_ssh_destroy_user(guac_client_data->sftp_user);
            return 1;
        }

        /* Load and expose filesystem */
        guac_client_data->sftp_filesystem =
            guac_common_ssh_create_sftp_filesystem(
                    guac_client_data->sftp_session, "/");

        /* Abort if SFTP connection fails */
        if (guac_client_data->sftp_filesystem == NULL) {
            guac_common_ssh_destroy_session(guac_client_data->sftp_session);
            guac_common_ssh_destroy_user(guac_client_data->sftp_user);
            return 1;
        }

        /* Configure destination for basic uploads, if specified */
        if (argv[IDX_SFTP_DIRECTORY][0] != '\0') {
            client->file_handler = guac_rdp_sftp_file_handler;
            guac_common_ssh_sftp_set_upload_path(
                    guac_client_data->sftp_filesystem,
                    argv[IDX_SFTP_DIRECTORY]);
        }

        /* Otherwise, use SFTP for basic uploads only if drive not enabled */
        else if (!settings->drive_enabled)
            client->file_handler = guac_rdp_sftp_file_handler;

        guac_client_log(client, GUAC_LOG_DEBUG,
                "SFTP connection succeeded.");

    }
#endif

    /* Create default surface */
    guac_client_data->default_surface = guac_common_surface_alloc(client->socket, GUAC_DEFAULT_LAYER,
                                                                  settings->width, settings->height);
    guac_client_data->current_surface = guac_client_data->default_surface;

    /* Send connection name */
    guac_protocol_send_name(client->socket, settings->hostname);

    /* Set default pointer */
    guac_common_set_pointer_cursor(client);

    /* Push desired settings to FreeRDP */
    guac_rdp_push_settings(settings, rdp_inst);

    /* Connect to RDP server */
    if (!freerdp_connect(rdp_inst)) {
        guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR, "Error connecting to RDP server");
        return 1;
    }

    /* Success */
    return 0;

}
void* guac_vnc_client_thread(void* data) {

    guac_client* client = (guac_client*) data;
    guac_vnc_client* vnc_client = (guac_vnc_client*) client->data;
    guac_vnc_settings* settings = vnc_client->settings;

    /* Configure clipboard encoding */
    if (guac_vnc_set_clipboard_encoding(client, settings->clipboard_encoding)) {
        guac_client_log(client, GUAC_LOG_INFO, "Using non-standard VNC "
                "clipboard encoding: '%s'.", settings->clipboard_encoding);
    }

    /* Ensure connection is kept alive during lengthy connects */
    guac_socket_require_keep_alive(client->socket);

    /* Set up libvncclient logging */
    rfbClientLog = guac_vnc_client_log_info;
    rfbClientErr = guac_vnc_client_log_error;

    /* Attempt connection */
    rfbClient* rfb_client = guac_vnc_get_client(client);
    int retries_remaining = settings->retries;

    /* If unsuccessful, retry as many times as specified */
    while (!rfb_client && retries_remaining > 0) {

        guac_client_log(client, GUAC_LOG_INFO,
                "Connect failed. Waiting %ims before retrying...",
                GUAC_VNC_CONNECT_INTERVAL);

        /* Wait for given interval then retry */
        guac_timestamp_msleep(GUAC_VNC_CONNECT_INTERVAL);
        rfb_client = guac_vnc_get_client(client);
        retries_remaining--;

    }

    /* If the final connect attempt fails, return error */
    if (!rfb_client) {
        guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_NOT_FOUND,
                "Unable to connect to VNC server.");
        return NULL;
    }

#ifdef ENABLE_PULSE
    /* If audio is enabled, start streaming via PulseAudio */
    if (settings->audio_enabled)
        vnc_client->audio = guac_pa_stream_alloc(client, 
                settings->pa_servername);
#endif

#ifdef ENABLE_COMMON_SSH
    guac_common_ssh_init(client);

    /* Connect via SSH if SFTP is enabled */
    if (settings->enable_sftp) {

        /* Abort if username is missing */
        if (settings->sftp_username == NULL) {
            guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR,
                    "SFTP username is required if SFTP is enabled.");
            return NULL;
        }

        guac_client_log(client, GUAC_LOG_DEBUG,
                "Connecting via SSH for SFTP filesystem access.");

        vnc_client->sftp_user =
            guac_common_ssh_create_user(settings->sftp_username);

        /* Import private key, if given */
        if (settings->sftp_private_key != NULL) {

            guac_client_log(client, GUAC_LOG_DEBUG,
                    "Authenticating with private key.");

            /* Abort if private key cannot be read */
            if (guac_common_ssh_user_import_key(vnc_client->sftp_user,
                        settings->sftp_private_key,
                        settings->sftp_passphrase)) {
                guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR,
                        "Private key unreadable.");
                return NULL;
            }

        }

        /* Otherwise, use specified password */
        else {
            guac_client_log(client, GUAC_LOG_DEBUG,
                    "Authenticating with password.");
            guac_common_ssh_user_set_password(vnc_client->sftp_user,
                    settings->sftp_password);
        }

        /* Attempt SSH connection */
        vnc_client->sftp_session =
            guac_common_ssh_create_session(client, settings->sftp_hostname,
                    settings->sftp_port, vnc_client->sftp_user, settings->sftp_server_alive_interval);

        /* Fail if SSH connection does not succeed */
        if (vnc_client->sftp_session == NULL) {
            /* Already aborted within guac_common_ssh_create_session() */
            return NULL;
        }

        /* Load filesystem */
        vnc_client->sftp_filesystem =
            guac_common_ssh_create_sftp_filesystem(vnc_client->sftp_session,
                    settings->sftp_root_directory, NULL);

        /* Expose filesystem to connection owner */
        guac_client_for_owner(client,
                guac_common_ssh_expose_sftp_filesystem,
                vnc_client->sftp_filesystem);

        /* Abort if SFTP connection fails */
        if (vnc_client->sftp_filesystem == NULL) {
            guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR,
                    "SFTP connection failed.");
            return NULL;
        }

        /* Configure destination for basic uploads, if specified */
        if (settings->sftp_directory != NULL)
            guac_common_ssh_sftp_set_upload_path(
                    vnc_client->sftp_filesystem,
                    settings->sftp_directory);

        guac_client_log(client, GUAC_LOG_DEBUG,
                "SFTP connection succeeded.");

    }
#endif

    /* Set remaining client data */
    vnc_client->rfb_client = rfb_client;

    /* Set up screen recording, if requested */
    if (settings->recording_path != NULL) {
        guac_common_recording_create(client,
                settings->recording_path,
                settings->recording_name,
                settings->create_recording_path);
    }

    /* Send name */
    guac_protocol_send_name(client->socket, rfb_client->desktopName);

    /* Create display */
    vnc_client->display = guac_common_display_alloc(client,
            rfb_client->width, rfb_client->height);

    /* If not read-only, set an appropriate cursor */
    if (settings->read_only == 0) {
        if (settings->remote_cursor)
            guac_common_cursor_set_dot(vnc_client->display->cursor);
        else
            guac_common_cursor_set_pointer(vnc_client->display->cursor);

    }

    guac_socket_flush(client->socket);

    guac_timestamp last_frame_end = guac_timestamp_current();

    /* Handle messages from VNC server while client is running */
    while (client->state == GUAC_CLIENT_RUNNING) {

        /* Wait for start of frame */
        int wait_result = guac_vnc_wait_for_messages(rfb_client,
                GUAC_VNC_FRAME_START_TIMEOUT);
        if (wait_result > 0) {

            int processing_lag = guac_client_get_processing_lag(client);
            guac_timestamp frame_start = guac_timestamp_current();

            /* Read server messages until frame is built */
            do {

                guac_timestamp frame_end;
                int frame_remaining;

                /* Handle any message received */
                if (!HandleRFBServerMessage(rfb_client)) {
                    guac_client_abort(client,
                            GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR,
                            "Error handling message from VNC server.");
                    break;
                }

                /* Calculate time remaining in frame */
                frame_end = guac_timestamp_current();
                frame_remaining = frame_start + GUAC_VNC_FRAME_DURATION
                                - frame_end;

                /* Calculate time that client needs to catch up */
                int time_elapsed = frame_end - last_frame_end;
                int required_wait = processing_lag - time_elapsed;

                /* Increase the duration of this frame if client is lagging */
                if (required_wait > GUAC_VNC_FRAME_TIMEOUT)
                    wait_result = guac_vnc_wait_for_messages(rfb_client,
                            required_wait*1000);

                /* Wait again if frame remaining */
                else if (frame_remaining > 0)
                    wait_result = guac_vnc_wait_for_messages(rfb_client,
                            GUAC_VNC_FRAME_TIMEOUT*1000);
                else
                    break;

            } while (wait_result > 0);

            /* Record end of frame, excluding server-side rendering time (we
             * assume server-side rendering time will be consistent between any
             * two subsequent frames, and that this time should thus be
             * excluded from the required wait period of the next frame). */
            last_frame_end = frame_start;

        }

        /* If an error occurs, log it and fail */
        if (wait_result < 0)
            guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR, "Connection closed.");

        /* Flush frame */
        guac_common_surface_flush(vnc_client->display->default_surface);
        guac_client_end_frame(client);
        guac_socket_flush(client->socket);

    }

    /* Kill client and finish connection */
    guac_client_stop(client);
    guac_client_log(client, GUAC_LOG_INFO, "Internal VNC client disconnected");
    return NULL;

}
Exemple #5
0
int guac_client_init(guac_client* client, int argc, char** argv) {

    rfbClient* rfb_client;

    vnc_guac_client_data* guac_client_data;

    int retries_remaining;

    /* Set up libvncclient logging */
    rfbClientLog = guac_vnc_client_log_info;
    rfbClientErr = guac_vnc_client_log_error;

    /*** PARSE ARGUMENTS ***/

    if (argc != VNC_ARGS_COUNT) {
        guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR, "Wrong argument count received.");
        return 1;
    }

    /* Alloc client data */
    guac_client_data = malloc(sizeof(vnc_guac_client_data));
    client->data = guac_client_data;

    guac_client_data->hostname = strdup(argv[IDX_HOSTNAME]);
    guac_client_data->port = atoi(argv[IDX_PORT]);
    guac_client_data->password = strdup(argv[IDX_PASSWORD]); /* NOTE: freed by libvncclient */
    guac_client_data->default_surface = NULL;

    /* Set flags */
    guac_client_data->remote_cursor = (strcmp(argv[IDX_CURSOR], "remote") == 0);
    guac_client_data->swap_red_blue = (strcmp(argv[IDX_SWAP_RED_BLUE], "true") == 0);
    guac_client_data->read_only     = (strcmp(argv[IDX_READ_ONLY], "true") == 0);

    /* Parse color depth */
    guac_client_data->color_depth = atoi(argv[IDX_COLOR_DEPTH]);

#ifdef ENABLE_VNC_REPEATER
    /* Set repeater parameters if specified */
    if (argv[IDX_DEST_HOST][0] != '\0')
        guac_client_data->dest_host = strdup(argv[IDX_DEST_HOST]);
    else
        guac_client_data->dest_host = NULL;

    if (argv[IDX_DEST_PORT][0] != '\0')
        guac_client_data->dest_port = atoi(argv[IDX_DEST_PORT]);
#endif

    /* Set encodings if specified */
    if (argv[IDX_ENCODINGS][0] != '\0')
        guac_client_data->encodings = strdup(argv[IDX_ENCODINGS]);
    else
        guac_client_data->encodings = NULL;

    /* Parse autoretry */
    if (argv[IDX_AUTORETRY][0] != '\0')
        retries_remaining = atoi(argv[IDX_AUTORETRY]);
    else
        retries_remaining = 0; 

#ifdef ENABLE_VNC_LISTEN
    /* Set reverse-connection flag */
    guac_client_data->reverse_connect =
        (strcmp(argv[IDX_REVERSE_CONNECT], "true") == 0);

    /* Parse listen timeout */
    if (argv[IDX_LISTEN_TIMEOUT][0] != '\0')
        guac_client_data->listen_timeout = atoi(argv[IDX_LISTEN_TIMEOUT]);
    else
        guac_client_data->listen_timeout = 5000;
#endif

    /* Init clipboard */
    guac_client_data->clipboard = guac_common_clipboard_alloc(GUAC_VNC_CLIPBOARD_MAX_LENGTH);

    /* Configure clipboard encoding */
    if (guac_vnc_set_clipboard_encoding(client, argv[IDX_CLIPBOARD_ENCODING]))
        guac_client_log(client, GUAC_LOG_INFO,
                "Using non-standard VNC clipboard encoding: '%s'.",
                argv[IDX_CLIPBOARD_ENCODING]);

    /* Ensure connection is kept alive during lengthy connects */
    guac_socket_require_keep_alive(client->socket);

    /* Attempt connection */
    rfb_client = __guac_vnc_get_client(client);

    /* If unsuccessful, retry as many times as specified */
    while (!rfb_client && retries_remaining > 0) {

        struct timespec guac_vnc_connect_interval = {
            .tv_sec  =  GUAC_VNC_CONNECT_INTERVAL/1000,
            .tv_nsec = (GUAC_VNC_CONNECT_INTERVAL%1000)*1000000
        };

        guac_client_log(client, GUAC_LOG_INFO,
                "Connect failed. Waiting %ims before retrying...",
                GUAC_VNC_CONNECT_INTERVAL);

        /* Wait for given interval then retry */
        nanosleep(&guac_vnc_connect_interval, NULL);
        rfb_client = __guac_vnc_get_client(client);
        retries_remaining--;

    }

    /* If the final connect attempt fails, return error */
    if (!rfb_client) {
        guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR, "Unable to connect to VNC server.");
        return 1;
    }

#ifdef ENABLE_PULSE
    guac_client_data->audio_enabled =
        (strcmp(argv[IDX_ENABLE_AUDIO], "true") == 0);

    /* If an encoding is available, load an audio stream */
    if (guac_client_data->audio_enabled) {    

        guac_client_data->audio = guac_audio_stream_alloc(client, NULL);

        /* Load servername if specified */
        if (argv[IDX_AUDIO_SERVERNAME][0] != '\0')
            guac_client_data->pa_servername =
                strdup(argv[IDX_AUDIO_SERVERNAME]);
        else
            guac_client_data->pa_servername = NULL;

        /* If successful, init audio system */
        if (guac_client_data->audio != NULL) {
            
            guac_client_log(client, GUAC_LOG_INFO,
                    "Audio will be encoded as %s",
                    guac_client_data->audio->encoder->mimetype);

            /* Require threadsafe sockets if audio enabled */
            guac_socket_require_threadsafe(client->socket);

            /* Start audio stream */
            guac_pa_start_stream(client);
            
        }

        /* Otherwise, audio loading failed */
        else
            guac_client_log(client, GUAC_LOG_INFO,
                    "No available audio encoding. Sound disabled.");

    } /* end if audio enabled */
#endif

#ifdef ENABLE_COMMON_SSH
    guac_common_ssh_init(client);

    /* Connect via SSH if SFTP is enabled */
    if (strcmp(argv[IDX_ENABLE_SFTP], "true") == 0) {

        guac_client_log(client, GUAC_LOG_DEBUG,
                "Connecting via SSH for SFTP filesystem access.");

        guac_client_data->sftp_user =
            guac_common_ssh_create_user(argv[IDX_SFTP_USERNAME]);

        /* Import private key, if given */
        if (argv[IDX_SFTP_PRIVATE_KEY][0] != '\0') {

            guac_client_log(client, GUAC_LOG_DEBUG,
                    "Authenticating with private key.");

            /* Abort if private key cannot be read */
            if (guac_common_ssh_user_import_key(guac_client_data->sftp_user,
                        argv[IDX_SFTP_PRIVATE_KEY],
                        argv[IDX_SFTP_PASSPHRASE])) {
                guac_common_ssh_destroy_user(guac_client_data->sftp_user);
                return 1;
            }

        }

        /* Otherwise, use specified password */
        else {
            guac_client_log(client, GUAC_LOG_DEBUG,
                    "Authenticating with password.");
            guac_common_ssh_user_set_password(guac_client_data->sftp_user,
                    argv[IDX_SFTP_PASSWORD]);
        }

        /* Parse hostname - use VNC hostname by default */
        const char* sftp_hostname = argv[IDX_SFTP_HOSTNAME];
        if (sftp_hostname[0] == '\0')
            sftp_hostname = guac_client_data->hostname;

        /* Parse port, defaulting to standard SSH port */
        const char* sftp_port = argv[IDX_SFTP_PORT];
        if (sftp_port[0] == '\0')
            sftp_port = "22";

        /* Attempt SSH connection */
        guac_client_data->sftp_session =
            guac_common_ssh_create_session(client, sftp_hostname, sftp_port,
                    guac_client_data->sftp_user);

        /* Fail if SSH connection does not succeed */
        if (guac_client_data->sftp_session == NULL) {
            /* Already aborted within guac_common_ssh_create_session() */
            guac_common_ssh_destroy_user(guac_client_data->sftp_user);
            return 1;
        }

        /* Load and expose filesystem */
        guac_client_data->sftp_filesystem =
            guac_common_ssh_create_sftp_filesystem(
                    guac_client_data->sftp_session, "/");

        /* Abort if SFTP connection fails */
        if (guac_client_data->sftp_filesystem == NULL) {
            guac_common_ssh_destroy_session(guac_client_data->sftp_session);
            guac_common_ssh_destroy_user(guac_client_data->sftp_user);
            return 1;
        }

        /* Configure destination for basic uploads, if specified */
        if (argv[IDX_SFTP_DIRECTORY][0] != '\0')
            guac_common_ssh_sftp_set_upload_path(
                    guac_client_data->sftp_filesystem,
                    argv[IDX_SFTP_DIRECTORY]);

        /* Set file handler for basic uploads */
        client->file_handler = guac_vnc_sftp_file_handler;

        guac_client_log(client, GUAC_LOG_DEBUG,
                "SFTP connection succeeded.");

    }
#endif

    /* Set remaining client data */
    guac_client_data->rfb_client = rfb_client;
    guac_client_data->copy_rect_used = 0;
    guac_client_data->cursor = guac_client_alloc_buffer(client);

    /* Set handlers */
    client->handle_messages = vnc_guac_client_handle_messages;
    client->free_handler = vnc_guac_client_free_handler;

    /* If not read-only, set input handlers and pointer */
    if (guac_client_data->read_only == 0) {

        /* Only handle mouse/keyboard/clipboard if not read-only */
        client->mouse_handler = vnc_guac_client_mouse_handler;
        client->key_handler = vnc_guac_client_key_handler;
        client->clipboard_handler = guac_vnc_clipboard_handler;

        /* If not read-only but cursor is remote, set a dot cursor */
        if (guac_client_data->remote_cursor)
            guac_common_set_dot_cursor(client);

        /* Otherwise, set pointer until explicitly requested otherwise */
        else
            guac_common_set_pointer_cursor(client);

    }

    /* Send name */
    guac_protocol_send_name(client->socket, rfb_client->desktopName);

    /* Create default surface */
    guac_client_data->default_surface = guac_common_surface_alloc(client->socket, GUAC_DEFAULT_LAYER,
                                                                  rfb_client->width, rfb_client->height);
    return 0;

}
void* ssh_client_thread(void* data) {

    guac_client* client = (guac_client*) data;
    guac_ssh_client* ssh_client = (guac_ssh_client*) client->data;
    guac_ssh_settings* settings = ssh_client->settings;

    char buffer[8192];

    pthread_t input_thread;

    /* Init SSH base libraries */
    if (guac_common_ssh_init(client)) {
        guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR,
                "SSH library initialization failed");
        return NULL;
    }

    /* Set up screen recording, if requested */
    if (settings->recording_path != NULL) {
        guac_common_recording_create(client,
                settings->recording_path,
                settings->recording_name,
                settings->create_recording_path);
    }

    /* Create terminal */
    ssh_client->term = guac_terminal_create(client,
            settings->font_name, settings->font_size,
            settings->resolution, settings->width, settings->height,
            settings->color_scheme);

    /* Fail if terminal init failed */
    if (ssh_client->term == NULL) {
        guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR,
                "Terminal initialization failed");
        return NULL;
    }

    /* Set up typescript, if requested */
    if (settings->typescript_path != NULL) {
        guac_terminal_create_typescript(ssh_client->term,
                settings->typescript_path,
                settings->typescript_name,
                settings->create_typescript_path);
    }

    /* Get user and credentials */
    ssh_client->user = guac_ssh_get_user(client);

    /* Open SSH session */
    ssh_client->session = guac_common_ssh_create_session(client,
            settings->hostname, settings->port, ssh_client->user);
    if (ssh_client->session == NULL) {
        /* Already aborted within guac_common_ssh_create_session() */
        return NULL;
    }

    pthread_mutex_init(&ssh_client->term_channel_lock, NULL);

    /* Open channel for terminal */
    ssh_client->term_channel =
        libssh2_channel_open_session(ssh_client->session->session);
    if (ssh_client->term_channel == NULL) {
        guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR,
                "Unable to open terminal channel.");
        return NULL;
    }

#ifdef ENABLE_SSH_AGENT
    /* Start SSH agent forwarding, if enabled */
    if (ssh_client->enable_agent) {
        libssh2_session_callback_set(ssh_client->session,
                LIBSSH2_CALLBACK_AUTH_AGENT, (void*) ssh_auth_agent_callback);

        /* Request agent forwarding */
        if (libssh2_channel_request_auth_agent(ssh_client->term_channel))
            guac_client_log(client, GUAC_LOG_ERROR, "Agent forwarding request failed");
        else
            guac_client_log(client, GUAC_LOG_INFO, "Agent forwarding enabled.");
    }

    ssh_client->auth_agent = NULL;
#endif

    /* Start SFTP session as well, if enabled */
    if (settings->enable_sftp) {

        /* Create SSH session specific for SFTP */
        guac_client_log(client, GUAC_LOG_DEBUG, "Reconnecting for SFTP...");
        ssh_client->sftp_session =
            guac_common_ssh_create_session(client, settings->hostname,
                    settings->port, ssh_client->user);
        if (ssh_client->sftp_session == NULL) {
            /* Already aborted within guac_common_ssh_create_session() */
            return NULL;
        }

        /* Request SFTP */
        ssh_client->sftp_filesystem = guac_common_ssh_create_sftp_filesystem(
                    ssh_client->sftp_session, "/");

        /* Expose filesystem to connection owner */
        guac_client_for_owner(client,
                guac_common_ssh_expose_sftp_filesystem,
                ssh_client->sftp_filesystem);

        /* Init handlers for Guacamole-specific console codes */
        ssh_client->term->upload_path_handler = guac_sftp_set_upload_path;
        ssh_client->term->file_download_handler = guac_sftp_download_file;

        guac_client_log(client, GUAC_LOG_DEBUG, "SFTP session initialized");

    }

    /* Request PTY */
    if (libssh2_channel_request_pty_ex(ssh_client->term_channel, "linux", sizeof("linux")-1, NULL, 0,
            ssh_client->term->term_width, ssh_client->term->term_height, 0, 0)) {
        guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR, "Unable to allocate PTY.");
        return NULL;
    }

    /* If a command is specified, run that instead of a shell */
    if (settings->command != NULL) {
        if (libssh2_channel_exec(ssh_client->term_channel, settings->command)) {
            guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR,
                    "Unable to execute command.");
            return NULL;
        }
    }

    /* Otherwise, request a shell */
    else if (libssh2_channel_shell(ssh_client->term_channel)) {
        guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR,
                "Unable to associate shell with PTY.");
        return NULL;
    }

    /* Logged in */
    guac_client_log(client, GUAC_LOG_INFO, "SSH connection successful.");

    /* Start input thread */
    if (pthread_create(&(input_thread), NULL, ssh_input_thread, (void*) client)) {
        guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR, "Unable to start input thread");
        return NULL;
    }

    /* Set non-blocking */
    libssh2_session_set_blocking(ssh_client->session->session, 0);

    /* While data available, write to terminal */
    int bytes_read = 0;
    for (;;) {

        /* Track total amount of data read */
        int total_read = 0;

        pthread_mutex_lock(&(ssh_client->term_channel_lock));

        /* Stop reading at EOF */
        if (libssh2_channel_eof(ssh_client->term_channel)) {
            pthread_mutex_unlock(&(ssh_client->term_channel_lock));
            break;
        }

        /* Read terminal data */
        bytes_read = libssh2_channel_read(ssh_client->term_channel,
                buffer, sizeof(buffer));

        pthread_mutex_unlock(&(ssh_client->term_channel_lock));

        /* Attempt to write data received. Exit on failure. */
        if (bytes_read > 0) {
            int written = guac_terminal_write_stdout(ssh_client->term, buffer, bytes_read);
            if (written < 0)
                break;

            total_read += bytes_read;
        }

        else if (bytes_read < 0 && bytes_read != LIBSSH2_ERROR_EAGAIN)
            break;

#ifdef ENABLE_SSH_AGENT
        /* If agent open, handle any agent packets */
        if (ssh_client->auth_agent != NULL) {
            bytes_read = ssh_auth_agent_read(ssh_client->auth_agent);
            if (bytes_read > 0)
                total_read += bytes_read;
            else if (bytes_read < 0 && bytes_read != LIBSSH2_ERROR_EAGAIN)
                ssh_client->auth_agent = NULL;
        }
#endif

        /* Wait for more data if reads turn up empty */
        if (total_read == 0) {
            fd_set fds;
            struct timeval timeout;

            FD_ZERO(&fds);
            FD_SET(ssh_client->session->fd, &fds);

            /* Wait for one second */
            timeout.tv_sec = 1;
            timeout.tv_usec = 0;

            if (select(ssh_client->session->fd + 1, &fds,
                        NULL, NULL, &timeout) < 0)
                break;
        }

    }

    /* Kill client and Wait for input thread to die */
    guac_client_stop(client);
    pthread_join(input_thread, NULL);

    pthread_mutex_destroy(&ssh_client->term_channel_lock);

    guac_client_log(client, GUAC_LOG_INFO, "SSH connection ended.");
    return NULL;

}