C++ sigprocmask函数代码示例

int
ar_next(void)
{
	static char *arcbuf;
	char buf[PAXPATHLEN+2];
	sigset_t o_mask;

	/*
	 * WE MUST CLOSE THE DEVICE. A lot of devices must see last close, (so
	 * things like writing EOF etc will be done) (Watch out ar_close() can
	 * also be called via a signal handler, so we must prevent a race.
	 */
	if (sigprocmask(SIG_BLOCK, &s_mask, &o_mask) < 0)
		syswarn(0, errno, "Unable to set signal mask");
	ar_close();
	if (sigprocmask(SIG_SETMASK, &o_mask, NULL) < 0)
		syswarn(0, errno, "Unable to restore signal mask");

	if (done || !wr_trail || strcmp(NM_TAR, argv0) == 0)
		return(-1);

	tty_prnt("\nATTENTION! %s archive volume change required.\n", argv0);

	/*
	 * if i/o is on stdin or stdout, we cannot reopen it (we do not know
	 * the name), the user will be forced to type it in.
	 */
	if (strcmp(arcname, stdo) && strcmp(arcname, stdn) && (artyp != ISREG)
	    && (artyp != ISPIPE)) {
		if (artyp == ISTAPE) {
			tty_prnt("%s ready for archive tape volume: %d\n",
				arcname, arvol);
			tty_prnt("Load the NEXT TAPE on the tape drive");
		} else {
			tty_prnt("%s ready for archive volume: %d\n",
				arcname, arvol);
			tty_prnt("Load the NEXT STORAGE MEDIA (if required)");
		}

		if ((act == ARCHIVE) || (act == APPND))
			tty_prnt(" and make sure it is WRITE ENABLED.\n");
		else
			tty_prnt("\n");

		for(;;) {
			tty_prnt("Type \"y\" to continue, \".\" to quit %s,",
				argv0);
			tty_prnt(" or \"s\" to switch to new device.\nIf you");
			tty_prnt(" cannot change storage media, type \"s\"\n");
			tty_prnt("Is the device ready and online? > ");

			if ((tty_read(buf,sizeof(buf))<0) || !strcmp(buf,".")){
				done = 1;
				lstrval = -1;
				tty_prnt("Quitting %s!\n", argv0);
				vfpart = 0;
				return(-1);
			}

			if ((buf[0] == '\0') || (buf[1] != '\0')) {
				tty_prnt("%s unknown command, try again\n",buf);
				continue;
			}

			switch (buf[0]) {
			case 'y':
			case 'Y':
				/*
				 * we are to continue with the same device
				 */
				if (ar_open(arcname) >= 0)
					return(0);
				tty_prnt("Cannot re-open %s, try again\n",
					arcname);
				continue;
			case 's':
			case 'S':
				/*
				 * user wants to open a different device
				 */
				tty_prnt("Switching to a different archive\n");
				break;
			default:
				tty_prnt("%s unknown command, try again\n",buf);
				continue;
			}
			break;
		}
	} else
		tty_prnt("Ready for archive volume: %d\n", arvol);

	/*
	 * have to go to a different archive
	 */
	for (;;) {
		tty_prnt("Input archive name or \".\" to quit %s.\n", argv0);
		tty_prnt("Archive name > ");

		if ((tty_read(buf, sizeof(buf)) < 0) || !strcmp(buf, ".")) {
			done = 1;
//.........这里部分代码省略.........

//.........这里部分代码省略.........
                break;
            case 'v':
                printf("perfalloc " VERSION "\n" );
                exit(EXIT_SUCCESS);
                break;
            default: /* '?' */
                usage(argv[0]);
                exit(EXIT_FAILURE);
        }
    }

    if( optind < argc )
    {
        runmode = RUN_USERCOMMAND;
    }

    if(RUN_AS_DAEMON == runmode)
	{
		if( -1 == daemon(0,0) ) {
			perror("fork");
			exit(EXIT_FAILURE);
		}
	}
    else if (RUN_USERCOMMAND == runmode)
    {
        pid = fork();
        if (pid == -1) 
        {
            perror("fork");
            exit(EXIT_FAILURE);
        }
        if (pid != 0) 
        {     /* Parent - execute the given command. */
            execvp(argv[optind], &argv[optind]);
            perror(argv[optind]);
            exit(EXIT_FAILURE);
        }

        /* Child - make sure that kernel signals when parent dies */
        prctl(PR_SET_PDEATHSIG, SIGHUP);

        if ( -1 == chdir("/") ) {
            perror("chdir");
            /* carry on even if chdir fails ..*/
        }
             
        if ((fd = open("/dev/null", O_RDWR, 0)) != -1) 
        {
            (void) dup2(fd, STDIN_FILENO);
            (void) dup2(fd, STDOUT_FILENO);
            (void) dup2(fd, STDERR_FILENO);
            if (fd > 2)
                close(fd);
        }
    }

	fp = open(lockfile, O_RDONLY);

	if( fp < 0 ) {
		fprintf(stderr, "open %s: %s\n", lockfile, strerror(errno) );
		exit(EXIT_FAILURE);  
	}

	fl.l_type = F_RDLCK;
	fl.l_whence = SEEK_SET;
	fl.l_start = 0;
	fl.l_len = 1;

	res = fcntl(fp, F_SETLK, &fl);

	if( res == -1 )
	{
		perror("fcntl");
		close(fp);
		exit(EXIT_FAILURE);  
	}

	signal (SIGINT, handler);
	signal (SIGHUP, handler);

	sigemptyset (&set);
	sigaddset(&set, SIGINT);
	sigaddset(&set, SIGHUP);

	sigprocmask(SIG_BLOCK, &set, &oldset);

	while(running)
	{
		sigsuspend(&oldset);
	}

	sigprocmask(SIG_UNBLOCK, &set, NULL);

	fl.l_type = F_UNLCK;
	(void) fcntl(fp, F_SETLK, &fl);
	(void) close(fp);
    free_perf_alloc_lockfile();

	return 0;
}

/*
 * handler()
 *
 * 	A signal handler that understands which test case is currently
 * 	being executed and compares the current conditions to the ones it
 * 	expects (based on the test case number).
 */
void handler(int sig, siginfo_t * sip, void *ucp)
{
	struct sigaction oact;
	int err;
	sigset_t nmask, omask;

	/*
	 * Get sigaction setting
	 */
	err = sigaction(SIGUSR1, NULL, &oact);

	if (err == -1) {
		perror("sigaction");
		return;
	}

	/*
	 * Get current signal mask
	 */
	sigemptyset(&nmask);
	sigemptyset(&omask);
	err = sigprocmask(SIG_BLOCK, &nmask, &omask);
	if (err == -1) {
		perror("sigprocmask");
		tst_resm(TWARN, "sigprocmask() failed");
		return;
	}

	switch (testcase_no) {
	case 1:
		/*
		 * SA_RESETHAND and SA_SIGINFO were set. SA_SIGINFO should
		 * be clear in Linux. In Linux kernel, SA_SIGINFO is not
		 * cleared in psig().
		 */
		if (!(oact.sa_flags & SA_SIGINFO)) {
			tst_resm(TFAIL, "SA_RESETHAND should not "
				 "cause SA_SIGINFO to be cleared, but it was.");
			return;
		}
		if (sip == NULL) {
			tst_resm(TFAIL, "siginfo should not be NULL");
			return;
		}
		tst_resm(TPASS, "SA_RESETHAND did not "
			 "cause SA_SIGINFO to be cleared");
		break;

	case 2:
		/*
		 * In Linux, SA_RESETHAND doesn't imply SA_NODEFER; sig
		 * should not be masked.  The testcase should pass if
		 * SA_NODEFER is not masked, ie. if SA_NODEFER is a member
		 * of the signal list
		 */
		if (sigismember(&omask, sig) == 0) {
			tst_resm(TFAIL, "SA_RESETHAND should cause sig to"
				 "be masked when the handler executes.");
			return;
		}
		tst_resm(TPASS, "SA_RESETHAND was masked when handler "
			 "executed");
		break;

	case 3:
		/*
		 * SA_RESETHAND implies SA_NODEFER unless sa_mask already
		 * included sig.
		 */
		if (!sigismember(&omask, sig)) {
			tst_resm(TFAIL, "sig should continue to be masked"
				 "because sa_mask originally contained sig.");
			return;
		}
		tst_resm(TPASS, "sig has been masked "
			 "because sa_mask originally contained sig");
		break;

	case 4:
		/*
		 * A signal generated from a mechanism that does not provide
		 * siginfo should invoke the handler with a non-NULL siginfo
		 * pointer.
		 */
		if (sip == NULL) {
			tst_resm(TFAIL, "siginfo pointer should not be NULL");
			return;
		}
		tst_resm(TPASS, "siginfo pointer non NULL");
		break;

	default:
		tst_resm(TFAIL, "invalid test case number: %d", testcase_no);
//.........这里部分代码省略.........

static void pthread_initialize(void)
{
  struct sigaction sa;
  sigset_t mask;
#ifdef __ARCH_USE_MMU__
  struct rlimit limit;
  rlim_t max_stack;
#endif

  /* If already done (e.g. by a constructor called earlier!), bail out */
  if (__pthread_initial_thread_bos != NULL) return;
#ifdef TEST_FOR_COMPARE_AND_SWAP
  /* Test if compare-and-swap is available */
  __pthread_has_cas = compare_and_swap_is_available();
#endif
  /* For the initial stack, reserve at least STACK_SIZE bytes of stack
     below the current stack address, and align that on a
     STACK_SIZE boundary. */
  __pthread_initial_thread_bos =
    (char *)(((long)CURRENT_STACK_FRAME - 2 * STACK_SIZE) & ~(STACK_SIZE - 1));
  /* Update the descriptor for the initial thread. */
  __pthread_initial_thread.p_pid = getpid();
  /* If we have special thread_self processing, initialize that for the
     main thread now.  */
#ifdef INIT_THREAD_SELF
  INIT_THREAD_SELF(&__pthread_initial_thread, 0);
#endif
  /* The errno/h_errno variable of the main thread are the global ones.  */
  __pthread_initial_thread.p_errnop = &_errno;
  __pthread_initial_thread.p_h_errnop = &_h_errno;

#ifdef __UCLIBC_HAS_XLOCALE__
  /* The locale of the main thread is the current locale in use. */
  __pthread_initial_thread.locale = __curlocale_var;
#endif /* __UCLIBC_HAS_XLOCALE__ */

 {			   /* uClibc-specific stdio initialization for threads. */
	 FILE *fp;

	 _stdio_user_locking = 0;	/* 2 if threading not initialized */
	 for (fp = _stdio_openlist; fp != NULL; fp = fp->__nextopen) {
		 if (fp->__user_locking != 1) {
			 fp->__user_locking = 0;
		 }
	 }
 }

  /* Play with the stack size limit to make sure that no stack ever grows
     beyond STACK_SIZE minus two pages (one page for the thread descriptor
     immediately beyond, and one page to act as a guard page). */

#ifdef __ARCH_USE_MMU__
  /* We cannot allocate a huge chunk of memory to mmap all thread stacks later
   * on a non-MMU system. Thus, we don't need the rlimit either. -StS */
  getrlimit(RLIMIT_STACK, &limit);
  max_stack = STACK_SIZE - 2 * getpagesize();
  if (limit.rlim_cur > max_stack) {
    limit.rlim_cur = max_stack;
    setrlimit(RLIMIT_STACK, &limit);
  }
#else
  /* For non-MMU, the initial thread stack can reside anywhere in memory.
   * We don't have a way of knowing where the kernel started things -- top
   * or bottom (well, that isn't exactly true, but the solution is fairly
   * complex and error prone).  All we can determine here is an address
   * that lies within that stack.  Save that address as a reference so that
   * as other thread stacks are created, we can adjust the estimated bounds
   * of the initial thread's stack appropriately.
   *
   * This checking is handled in NOMMU_INITIAL_THREAD_BOUNDS(), so see that
   * for a few more details.
   */
  __pthread_initial_thread_mid = CURRENT_STACK_FRAME;
  __pthread_initial_thread_tos = (char *) -1;
  __pthread_initial_thread_bos = (char *) 1; /* set it non-zero so we know we have been here */
  PDEBUG("initial thread stack bounds: bos=%p, tos=%p\n",
	 __pthread_initial_thread_bos, __pthread_initial_thread_tos);
#endif /* __ARCH_USE_MMU__ */

  /* Setup signal handlers for the initial thread.
     Since signal handlers are shared between threads, these settings
     will be inherited by all other threads. */
  memset(&sa, 0, sizeof(sa));
  sa.sa_handler = pthread_handle_sigrestart;
  __libc_sigaction(__pthread_sig_restart, &sa, NULL);
  sa.sa_handler = pthread_handle_sigcancel;
  sigaddset(&sa.sa_mask, __pthread_sig_restart);
  __libc_sigaction(__pthread_sig_cancel, &sa, NULL);
  if (__pthread_sig_debug > 0) {
      sa.sa_handler = pthread_handle_sigdebug;
      __sigemptyset(&sa.sa_mask);
      __libc_sigaction(__pthread_sig_debug, &sa, NULL);
  }
  /* Initially, block __pthread_sig_restart. Will be unblocked on demand. */
  __sigemptyset(&mask);
  sigaddset(&mask, __pthread_sig_restart);
  sigprocmask(SIG_BLOCK, &mask, NULL);
  /* And unblock __pthread_sig_cancel if it has been blocked. */
  sigdelset(&mask, __pthread_sig_restart);
  sigaddset(&mask, __pthread_sig_cancel);
//.........这里部分代码省略.........

void Sigprocmask(int method, sigset_t *mask, sigset_t *oldmask) {
    if (sigprocmask(method, mask, oldmask)) {
        unix_error("Sigprocmask error");
    }
}

void
ngx_master_process_cycle(ngx_cycle_t *cycle)
{
    char              *title;
    u_char            *p;
    size_t             size;
    ngx_int_t          i;
    ngx_uint_t         n, sigio;
    sigset_t           set;
    struct itimerval   itv;
    ngx_uint_t         live;
    ngx_msec_t         delay;
    ngx_listening_t   *ls;
    ngx_core_conf_t   *ccf;
    struct rlimit     rlmt;

    sigemptyset(&set);
    sigaddset(&set, SIGCHLD);
    sigaddset(&set, SIGALRM);
    sigaddset(&set, SIGIO);
    sigaddset(&set, SIGINT);
    sigaddset(&set, ngx_signal_value(NGX_RECONFIGURE_SIGNAL));
    sigaddset(&set, ngx_signal_value(NGX_REOPEN_SIGNAL));
    sigaddset(&set, ngx_signal_value(NGX_NOACCEPT_SIGNAL));
    sigaddset(&set, ngx_signal_value(NGX_TERMINATE_SIGNAL));
    sigaddset(&set, ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
    sigaddset(&set, ngx_signal_value(NGX_CHANGEBIN_SIGNAL));

    if (sigprocmask(SIG_BLOCK, &set, NULL) == -1) {
        ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                      "sigprocmask() failed");
    }

    sigemptyset(&set);


    size = sizeof(master_process);

    for (i = 0; i < ngx_argc; i++) {
        size += ngx_strlen(ngx_argv[i]) + 1;
    }

    title = ngx_pnalloc(cycle->pool, size);

    p = ngx_cpymem(title, master_process, sizeof(master_process) - 1);
    for (i = 0; i < ngx_argc; i++) {
        *p++ = ' ';
        p = ngx_cpystrn(p, (u_char *) ngx_argv[i], size);
    }

    ngx_setproctitle(title);


    ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);

    ngx_start_worker_processes(cycle, ccf->worker_processes,
                               NGX_PROCESS_RESPAWN);
    /* The directives such as "user", "rlimit_core", etc. should also be
     * effective on master process. Changed by Zimbra
     */
    if (ccf->rlimit_nofile != NGX_CONF_UNSET) {
        rlmt.rlim_cur = (rlim_t) ccf->rlimit_nofile;
        rlmt.rlim_max = (rlim_t) ccf->rlimit_nofile;

        if (setrlimit(RLIMIT_NOFILE, &rlmt) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "setrlimit(RLIMIT_NOFILE, %i) failed",
                          ccf->rlimit_nofile);
        }
    }

    if (ccf->rlimit_core != NGX_CONF_UNSET) {
        rlmt.rlim_cur = (rlim_t) ccf->rlimit_core;
        rlmt.rlim_max = (rlim_t) ccf->rlimit_core;

        if (setrlimit(RLIMIT_CORE, &rlmt) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "setrlimit(RLIMIT_CORE, %O) failed",
                          ccf->rlimit_core);
        }
    }

#ifdef RLIMIT_SIGPENDING
    if (ccf->rlimit_sigpending != NGX_CONF_UNSET) {
        rlmt.rlim_cur = (rlim_t) ccf->rlimit_sigpending;
        rlmt.rlim_max = (rlim_t) ccf->rlimit_sigpending;

        if (setrlimit(RLIMIT_SIGPENDING, &rlmt) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "setrlimit(RLIMIT_SIGPENDING, %i) failed",
                          ccf->rlimit_sigpending);
        }
    }
#endif

    if (geteuid() == 0) {
        if (setgid(ccf->group) == -1) {
            ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
                          "setgid(%d) failed", ccf->group);
            /* fatal */
//.........这里部分代码省略.........

void do_signal(struct pt_regs *regs)
{
	siginfo_t info;
	int signr;
	struct k_sigaction ka;

	/*
                                             
                                                
                                                   
          
  */
	if (!user_mode(regs))
		return;

	signr = get_signal_to_deliver(&info, &ka, regs, NULL);

	/*                                               
                                                           
                                                             
                                                             
                                                       
                                                          
                                                             
                         
  */
	if (regs->orig_gpr11) {
		int restart = 0;

		switch (regs->gpr[11]) {
		case -ERESTART_RESTARTBLOCK:
		case -ERESTARTNOHAND:
			/*                                       */
			restart = (signr <= 0);
			break;
		case -ERESTARTSYS:
			/*                                      
                             */
			restart = (signr <= 0 || (ka.sa.sa_flags & SA_RESTART));
			break;
		case -ERESTARTNOINTR:
			/*                */
			restart = 1;
			break;
		}

		if (restart) {
			if (regs->gpr[11] == -ERESTART_RESTARTBLOCK)
				regs->gpr[11] = __NR_restart_syscall;
			else
				regs->gpr[11] = regs->orig_gpr11;
			regs->pc -= 4;
		} else {
			regs->gpr[11] = -EINTR;
		}
	}

	if (signr <= 0) {
		/*                                                      
          */
		if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
			clear_thread_flag(TIF_RESTORE_SIGMASK);
			sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
		}

	} else {		/*           */
		sigset_t *oldset;

		if (current_thread_info()->flags & _TIF_RESTORE_SIGMASK)
			oldset = &current->saved_sigmask;
		else
			oldset = &current->blocked;

		/*                                      */
		if (!handle_signal(signr, &info, &ka, oldset, regs)) {
			/*                                               
                                                        
                                                         
                                         */
			clear_thread_flag(TIF_RESTORE_SIGMASK);
		}

		tracehook_signal_handler(signr, &info, &ka, regs,
					 test_thread_flag(TIF_SINGLESTEP));
	}

	return;
}

int armour_proc_recover (armour_proc *proc, void *data)
{
    pid_t pid;
    sigset_t set;
    int i, fd;
    (void)data;

    //pid = vfork ();
    pid = fork ();
    
    switch (pid) {
        case -1:
            DWARN ("fork");
            return -1;
        case 0:
            if (proc->flags & ARPROC_SETSID) {
                pid = fork ();
                switch (pid) {
                    case -1:
                        DWARN ("fork");
                        return -1;
                    case 0:
                        setsid (); // TODO check return value
                        break;
                    default:
                        _exit (0);
                        break;
                }
            } else {
                setpgid (0, 0);
            }
            /*
             * remove signal mask
             */
            sigprocmask (SIG_BLOCK, NULL, &set);
            sigprocmask (SIG_UNBLOCK, &set, NULL);

            /*
             * attach file desc. 0, 1 and 2 to whatever files it used
             */
            for (i = 0; i < 3; i++) {
                fd = open (proc->file[i], O_RDWR);
                dup2 (fd, i);
            }
            /*
             * change working and root directory
             */
            chdir (proc->cwd);
            chroot (proc->root);
            /*
             * set uid and gid
             */
            setgid (proc->gid);
            setuid (proc->uid);

            execve (proc->exe, proc->cmdline, proc->environ);
            DWARN ("execve");
            _exit (127); /* exec error! */

        default:
            break;
    }
    return 0;
}

int
_eval(char *const argv[], char *path, int timeout, int *ppid)
{
	sigset_t set;
	pid_t pid, ret;
	int status;
	int fd;
	int flags;
	int sig, i;

	switch (pid = fork()) {
	case -1:	/* error */
		perror("fork");
		return errno;
	case 0:	 /* child */
		/* Reset signal handlers set for parent process */
		for (sig = 0; sig < (_NSIG-1); sig++)
			signal(sig, SIG_DFL);

		/* Unblock signals if called from signal handler */
		sigemptyset(&set);
		sigprocmask(SIG_SETMASK, &set, NULL);

		/* Clean up */
		for (i=3; i<256; i++)    // close un-needed fd
			close(i);
		ioctl(0, TIOCNOTTY, 0);	// detach from current process
		setsid();
		
		/* Redirect stdout to <path> */
		if (path) {
			flags = O_WRONLY | O_CREAT;
			if (!strncmp(path, ">>", 2)) {
				/* append to <path> */
				flags |= O_APPEND;
				path += 2;
			} else if (!strncmp(path, ">", 1)) {
				/* overwrite <path> */
				flags |= O_TRUNC;
				path += 1;
			}
			if ((fd = open(path, flags, 0644)) < 0)
				perror(path);
			else {
				dup2(fd, STDOUT_FILENO);
				dup2(fd, STDERR_FILENO);
				close(fd);
			}
		}
		
		/* execute command */
		setenv("PATH", SYS_EXEC_PATH, 1);
		alarm(timeout);
		execvp(argv[0], argv);
		perror(argv[0]);
		exit(errno);
	default:	/* parent */
		if (ppid) {
			*ppid = pid;
			return 0;
		} else {
			do
				ret = waitpid(pid, &status, 0);
			while ((ret == -1) && (errno == EINTR));
			
			if (ret != pid) {
				perror("waitpid");
				return errno;
			}
			if (WIFEXITED(status))
				return WEXITSTATUS(status);
			else
				return status;
		}
	}
}

void lxc_fini(const char *name, struct lxc_handler *handler)
{
	int i, rc;
	pid_t self = getpid();
	char *namespaces[LXC_NS_MAX+1];
	size_t namespace_count = 0;

	/* The STOPPING state is there for future cleanup code
	 * which can take awhile
	 */
	lxc_set_state(name, handler, STOPPING);

	for (i = 0; i < LXC_NS_MAX; i++) {
		if (handler->nsfd[i] != -1) {
			rc = asprintf(&namespaces[namespace_count], "%s:/proc/%d/fd/%d",
			              ns_info[i].proc_name, self, handler->nsfd[i]);
			if (rc == -1) {
				SYSERROR("failed to allocate memory");
				break;
			}
			++namespace_count;
		}
	}
	namespaces[namespace_count] = NULL;

	if (handler->conf->reboot && setenv("LXC_TARGET", "reboot", 1)) {
		SYSERROR("failed to set environment variable for stop target");
	}
	if (!handler->conf->reboot && setenv("LXC_TARGET", "stop", 1)) {
		SYSERROR("failed to set environment variable for stop target");
	}

	if (run_lxc_hooks(name, "stop", handler->conf, handler->lxcpath, namespaces))
		ERROR("failed to run stop hooks for container '%s'.", name);

	while (namespace_count--)
		free(namespaces[namespace_count]);
	for (i = 0; i < LXC_NS_MAX; i++) {
		if (handler->nsfd[i] != -1) {
			close(handler->nsfd[i]);
			handler->nsfd[i] = -1;
		}
	}
	lxc_set_state(name, handler, STOPPED);

	if (run_lxc_hooks(name, "post-stop", handler->conf, handler->lxcpath, NULL)) {
		ERROR("failed to run post-stop hooks for container '%s'.", name);
		if (handler->conf->reboot) {
			WARN("Container will be stopped instead of rebooted.");
			handler->conf->reboot = 0;
			setenv("LXC_TARGET", "stop", 1);
		}
	}

	/* reset mask set by setup_signal_fd */
	if (sigprocmask(SIG_SETMASK, &handler->oldmask, NULL))
		WARN("failed to restore sigprocmask");

	lxc_console_delete(&handler->conf->console);
	lxc_delete_tty(&handler->conf->tty_info);
	close(handler->conf->maincmd_fd);
	handler->conf->maincmd_fd = -1;
	free(handler->name);
	if (handler->ttysock[0] != -1) {
		close(handler->ttysock[0]);
		close(handler->ttysock[1]);
	}

	if (handler->conf->ephemeral == 1 && handler->conf->reboot != 1)
		lxc_destroy_container_on_signal(handler, name);

	cgroup_destroy(handler);
	free(handler);
}

//.........这里部分代码省略.........
	/* Here we set SA_RESTART for safety, because SIGUSR1 may not be handled
	 * immediately. -Dan */
	sig_action.sa_flags = SA_RESTART;
	sigaction(SIGTERM, &sig_action, NULL);
	sigaction(SIGINT, &sig_action, NULL);
	sigaction(SIGHUP, &sig_action, NULL);
	sigaction(SIGUSR1, &sig_action, NULL);
	sigaction(SIGUSR2, &sig_action, NULL);

	/* ignore dead pipe */
	/* Because POSIX mandates that only signal with handlers are reset
	 * accross an exec*(), we do not want to propagate ignoring SIGPIPEs
	 * to children. Hence the dummy handler.
	 * Philippe Troin <[email protected]>
	 */
	sig_action.sa_handler = &dummyHandler;
	sig_action.sa_flags = SA_RESTART;
	sigaction(SIGPIPE, &sig_action, NULL);

	/* handle dead children */
	sig_action.sa_handler = buryChild;
	sig_action.sa_flags = SA_NOCLDSTOP | SA_RESTART;
	sigaction(SIGCHLD, &sig_action, NULL);

	/* Now we unblock all signals, that may have been blocked by the parent
	 * who exec()-ed us. This can happen for example if Window Maker crashes
	 * and restarts itself or another window manager from the signal handler.
	 * In this case, the new proccess inherits the blocked signal mask and
	 * will no longer react to that signal, until unblocked.
	 * This is because the signal handler of the proccess who crashed (parent)
	 * didn't return, and the signal remained blocked. -Dan
	 */
	sigfillset(&sig_action.sa_mask);
	sigprocmask(SIG_UNBLOCK, &sig_action.sa_mask, NULL);

	/* handle X shutdowns a such */
	XSetIOErrorHandler(handleXIO);

	/* set hook for out event dispatcher in WINGs event dispatcher */
	WMHookEventHandler(DispatchEvent);

	/* initialize defaults stuff */
	w_global.domain.wmaker = wDefaultsInitDomain("WindowMaker", True);
	if (!w_global.domain.wmaker->dictionary)
		wwarning(_("could not read domain \"%s\" from defaults database"), "WindowMaker");

	/* read defaults that don't change until a restart and are
	 * screen independent */
	wReadStaticDefaults(w_global.domain.wmaker ? w_global.domain.wmaker->dictionary : NULL);

	/* check sanity of some values */
	if (wPreferences.icon_size < 16) {
		wwarning(_("icon size is configured to %i, but it's too small. Using 16 instead"),
			 wPreferences.icon_size);
		wPreferences.icon_size = 16;
	}

	/* init other domains */
	w_global.domain.root_menu = wDefaultsInitDomain("WMRootMenu", False);
	if (!w_global.domain.root_menu->dictionary)
		wwarning(_("could not read domain \"%s\" from defaults database"), "WMRootMenu");

	wDefaultsMergeGlobalMenus(w_global.domain.root_menu);

	w_global.domain.window_attr = wDefaultsInitDomain("WMWindowAttributes", True);
	if (!w_global.domain.window_attr->dictionary)

struct lxc_handler *lxc_init(const char *name, struct lxc_conf *conf, const char *lxcpath)
{
	int i;
	struct lxc_handler *handler;

	handler = malloc(sizeof(*handler));
	if (!handler)
		return NULL;

	memset(handler, 0, sizeof(*handler));

	handler->ttysock[0] = handler->ttysock[1] = -1;
	handler->conf = conf;
	handler->lxcpath = lxcpath;
	handler->pinfd = -1;

	for (i = 0; i < LXC_NS_MAX; i++)
		handler->nsfd[i] = -1;

	lsm_init();

	handler->name = strdup(name);
	if (!handler->name) {
		ERROR("failed to allocate memory");
		goto out_free;
	}

	if (lxc_cmd_init(name, handler, lxcpath))
		goto out_free_name;

	if (lxc_read_seccomp_config(conf) != 0) {
		ERROR("failed loading seccomp policy");
		goto out_close_maincmd_fd;
	}

	/* Begin by setting the state to STARTING */
	if (lxc_set_state(name, handler, STARTING)) {
		ERROR("failed to set state '%s'", lxc_state2str(STARTING));
		goto out_close_maincmd_fd;
	}

	/* Start of environment variable setup for hooks */
	if (name && setenv("LXC_NAME", name, 1)) {
		SYSERROR("failed to set environment variable for container name");
	}
	if (conf->rcfile && setenv("LXC_CONFIG_FILE", conf->rcfile, 1)) {
		SYSERROR("failed to set environment variable for config path");
	}
	if (conf->rootfs.mount && setenv("LXC_ROOTFS_MOUNT", conf->rootfs.mount, 1)) {
		SYSERROR("failed to set environment variable for rootfs mount");
	}
	if (conf->rootfs.path && setenv("LXC_ROOTFS_PATH", conf->rootfs.path, 1)) {
		SYSERROR("failed to set environment variable for rootfs mount");
	}
	if (conf->console.path && setenv("LXC_CONSOLE", conf->console.path, 1)) {
		SYSERROR("failed to set environment variable for console path");
	}
	if (conf->console.log_path && setenv("LXC_CONSOLE_LOGPATH", conf->console.log_path, 1)) {
		SYSERROR("failed to set environment variable for console log");
	}
	if (setenv("LXC_CGNS_AWARE", "1", 1)) {
		SYSERROR("failed to set LXC_CGNS_AWARE environment variable");
	}
	/* End of environment variable setup for hooks */

	if (run_lxc_hooks(name, "pre-start", conf, handler->lxcpath, NULL)) {
		ERROR("failed to run pre-start hooks for container '%s'.", name);
		goto out_aborting;
	}

	/* the signal fd has to be created before forking otherwise
	 * if the child process exits before we setup the signal fd,
	 * the event will be lost and the command will be stuck */
	handler->sigfd = setup_signal_fd(&handler->oldmask);
	if (handler->sigfd < 0) {
		ERROR("failed to set sigchild fd handler");
		goto out_delete_tty;
	}

	/* do this after setting up signals since it might unblock SIGWINCH */
	if (lxc_console_create(conf)) {
		ERROR("failed to create console");
		goto out_restore_sigmask;
	}

	if (ttys_shift_ids(conf) < 0) {
		ERROR("Failed to shift tty into container");
		goto out_restore_sigmask;
	}

	INFO("'%s' is initialized", name);
	return handler;

out_restore_sigmask:
	sigprocmask(SIG_SETMASK, &handler->oldmask, NULL);
out_delete_tty:
	lxc_delete_tty(&conf->tty_info);
out_aborting:
	lxc_set_state(name, handler, ABORTING);
out_close_maincmd_fd:
//.........这里部分代码省略.........

static void restore_sigs(sigset_t *oldset)
{
	sigprocmask(SIG_SETMASK, oldset, NULL);
}

static int recv_fd(int c)
{
    int fd;
    uint8_t msgbuf[CMSG_SPACE(sizeof(fd))];
    struct msghdr msg = {
        .msg_control = msgbuf,
        .msg_controllen = sizeof(msgbuf),
    };
    struct cmsghdr *cmsg;
    struct iovec iov;
    uint8_t req[1];
    ssize_t len;

    cmsg = CMSG_FIRSTHDR(&msg);
    cmsg->cmsg_level = SOL_SOCKET;
    cmsg->cmsg_type = SCM_RIGHTS;
    cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
    msg.msg_controllen = cmsg->cmsg_len;

    iov.iov_base = req;
    iov.iov_len = sizeof(req);

    msg.msg_iov = &iov;
    msg.msg_iovlen = 1;

    len = recvmsg(c, &msg, 0);
    if (len > 0) {
        memcpy(&fd, CMSG_DATA(cmsg), sizeof(fd));
        return fd;
    }

    return len;
}

static int net_bridge_run_helper(const char *helper, const char *bridge)
{
    sigset_t oldmask, mask;
    int pid, status;
    char *args[5];
    char **parg;
    int sv[2];

    sigemptyset(&mask);
    sigaddset(&mask, SIGCHLD);
    sigprocmask(SIG_BLOCK, &mask, &oldmask);

    if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) {
        return -1;
    }

    /* try to launch bridge helper */
    pid = fork();
    if (pid == 0) {
        int open_max = sysconf(_SC_OPEN_MAX), i;
        char fd_buf[6+10];
        char br_buf[6+IFNAMSIZ] = {0};
        char helper_cmd[PATH_MAX + sizeof(fd_buf) + sizeof(br_buf) + 15];

        for (i = 0; i < open_max; i++) {
            if (i != STDIN_FILENO &&
                i != STDOUT_FILENO &&
                i != STDERR_FILENO &&
                i != sv[1]) {
                close(i);
            }
        }

        snprintf(fd_buf, sizeof(fd_buf), "%s%d", "--fd=", sv[1]);

        if (strrchr(helper, ' ') || strrchr(helper, '\t')) {
            /* assume helper is a command */

            if (strstr(helper, "--br=") == NULL) {
                snprintf(br_buf, sizeof(br_buf), "%s%s", "--br=", bridge);
            }

            snprintf(helper_cmd, sizeof(helper_cmd), "%s %s %s %s",
                     helper, "--use-vnet", fd_buf, br_buf);

            parg = args;
            *parg++ = (char *)"sh";
            *parg++ = (char *)"-c";
            *parg++ = helper_cmd;
            *parg++ = NULL;

            execv("/bin/sh", args);
        } else {
            /* assume helper is just the executable path name */

            snprintf(br_buf, sizeof(br_buf), "%s%s", "--br=", bridge);

            parg = args;
            *parg++ = (char *)helper;
            *parg++ = (char *)"--use-vnet";
            *parg++ = fd_buf;
            *parg++ = br_buf;
            *parg++ = NULL;

            execv(helper, args);
        }
//.........这里部分代码省略.........

static RETSIGTYPE
info_signal_proc (int sig)
{
  signal_info *old_signal_handler = NULL;

#if !defined (HAVE_SIGACTION)
  /* best effort: first increment this counter and later block signals */
  if (term_conf_busy)
    return;
  term_conf_busy++;
#if defined (HAVE_SIGPROCMASK) || defined (HAVE_SIGSETMASK)
    {
      sigset_t nvar, ovar;
      sigemptyset (&nvar);
      mask_termsig (&nvar);
      sigprocmask (SIG_BLOCK, &nvar, &ovar);
    }
#endif /* HAVE_SIGPROCMASK || HAVE_SIGSETMASK */
#endif /* !HAVE_SIGACTION */
  switch (sig)
    {
#if defined (SIGTSTP)
    case SIGTSTP:
    case SIGTTOU:
    case SIGTTIN:
#endif
#if defined (SIGQUIT)
    case SIGQUIT:
#endif
#if defined (SIGINT)
    case SIGINT:
#endif
#if defined (SIGTERM)
    case SIGTERM:
#endif
      {
#if defined (SIGTSTP)
        if (sig == SIGTSTP)
          old_signal_handler = &old_TSTP;
        if (sig == SIGTTOU)
          old_signal_handler = &old_TTOU;
        if (sig == SIGTTIN)
          old_signal_handler = &old_TTIN;
#endif /* SIGTSTP */
#if defined (SIGQUIT)
        if (sig == SIGQUIT)
          old_signal_handler = &old_QUIT;
#endif /* SIGQUIT */
#if defined (SIGINT)
        if (sig == SIGINT)
          old_signal_handler = &old_INT;
#endif /* SIGINT */
#if defined (SIGTERM)
        if (sig == SIGTERM)
          old_signal_handler = &old_TERM;
#endif /* SIGTERM */

        /* For stop signals, restore the terminal IO, leave the cursor
           at the bottom of the window, and stop us. */
        terminal_goto_xy (0, screenheight - 1);
        terminal_clear_to_eol ();
        fflush (stdout);
        terminal_unprep_terminal ();
	restore_termsig (sig, old_signal_handler);
	UNBLOCK_SIGNAL (sig);
	kill (getpid (), sig);

        /* The program is returning now.  Restore our signal handler,
           turn on terminal handling, redraw the screen, and place the
           cursor where it belongs. */
        terminal_prep_terminal ();
	set_termsig (sig, old_signal_handler);
	/* window size might be changed while sleeping */
	reset_info_window_sizes ();
      }
      break;

#if defined (SIGWINCH) || defined (SIGUSR1)
#ifdef SIGWINCH
    case SIGWINCH:
#endif
#ifdef SIGUSR1
    case SIGUSR1:
#endif
      {
	/* Turn off terminal IO, tell our parent that the window has changed,
	   then reinitialize the terminal and rebuild our windows. */
#ifdef SIGWINCH
	if (sig == SIGWINCH)
	  old_signal_handler = &old_WINCH;
#endif
#ifdef SIGUSR1
	if (sig == SIGUSR1)
	  old_signal_handler = &old_USR1;
#endif

        /* This seems risky: what if we receive a (real) signal before
           the next line is reached? */
#if 0
	restore_termsig (sig, old_signal_handler);
//.........这里部分代码省略.........