static void guacd_exec_proc()

in src/guacd/proc.c [325:417]

• 56 lines of code
• 8 McCabe index (conditional complexity)

static void guacd_exec_proc(guacd_proc* proc, const char* protocol) {

    int result = 1;
   
    /* Set process group ID to match PID */ 
    if (setpgid(0, 0)) {
        guacd_log(GUAC_LOG_ERROR, "Cannot set PGID for connection process: %s",
                strerror(errno));
        goto cleanup_process;
    }

    /* Init client for selected protocol */
    guac_client* client = proc->client;
    if (guac_client_load_plugin(client, protocol)) {

        /* Log error */
        if (guac_error == GUAC_STATUS_NOT_FOUND)
            guacd_log(GUAC_LOG_WARNING,
                    "Support for protocol \"%s\" is not installed", protocol);
        else
            guacd_log_guac_error(GUAC_LOG_ERROR,
                    "Unable to load client plugin");

        goto cleanup_client;
    }

    /* The first file descriptor is the owner */
    int owner = 1;

    /* Enable keep alive on the broadcast socket */
    guac_socket_require_keep_alive(client->socket);

    guacd_proc_self = proc;

    /* Clean up and exit if SIGINT or SIGTERM signals are caught */
    struct sigaction signal_stop_action = { .sa_handler = signal_stop_handler };
    sigaction(SIGINT, &signal_stop_action, NULL);
    sigaction(SIGTERM, &signal_stop_action, NULL);

    /* Add each received file descriptor as a new user */
    int received_fd;
    while ((received_fd = guacd_recv_fd(proc->fd_socket)) != -1) {

        guacd_proc_add_user(proc, received_fd, owner);

        /* Future file descriptors are not owners */
        owner = 0;

    }
    
cleanup_client:

    /* Request client to stop/disconnect */
    guac_client_stop(client);

    /* Attempt to free client cleanly */
    guacd_log(GUAC_LOG_DEBUG, "Requesting termination of client...");
    result = guacd_timed_client_free(client, GUACD_CLIENT_FREE_TIMEOUT);

    /* If client was unable to be freed, warn and forcibly kill */
    if (result) {
        guacd_log(GUAC_LOG_WARNING, "Client did not terminate in a timely "
                "manner. Forcibly terminating client and any child "
                "processes.");
        guacd_kill_current_proc_group();
    }
    else
        guacd_log(GUAC_LOG_DEBUG, "Client terminated successfully.");

    /* Verify whether children were all properly reaped */
    pid_t child_pid;
    while ((child_pid = waitpid(0, NULL, WNOHANG)) > 0) {
        guacd_log(GUAC_LOG_DEBUG, "Automatically reaped unreaped "
                "(zombie) child process with PID %i.", child_pid);
    }

    /* If running children remain, warn and forcibly kill */
    if (child_pid == 0) {
        guacd_log(GUAC_LOG_WARNING, "Client reported successful termination, "
                "but child processes remain. Forcibly terminating client and "
                "child processes.");
        guacd_kill_current_proc_group();
    }

cleanup_process:

    /* Free up all internal resources outside the client */
    close(proc->fd_socket);
    guac_mem_free(proc);

    exit(result);

}