1 /* vi: set sw=4 ts=4: */
3 * Mini init implementation for busybox
5 * Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
6 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
7 * Adjusted by so many folks, it's impossible to keep track.
9 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
16 #include <sys/ioctl.h>
18 #include <sys/reboot.h>
20 #include "init_shared.h"
23 # include <sys/syslog.h>
26 #define INIT_BUFFS_SIZE 256
28 /* From <linux/vt.h> */
30 unsigned short v_active; /* active vt */
31 unsigned short v_signal; /* signal to send */
32 unsigned short v_state; /* vt bitmask */
34 enum { VT_GETSTATE = 0x5603 }; /* get global vt state info */
36 /* From <linux/serial.h> */
37 struct serial_struct {
46 unsigned short close_delay;
48 char reserved_char[1];
50 unsigned short closing_wait; /* time to wait before closing */
51 unsigned short closing_wait2; /* no longer used... */
52 unsigned char *iomem_base;
53 unsigned short iomem_reg_shift;
54 unsigned int port_high;
55 unsigned long iomap_base; /* cookie passed into ioremap */
60 #define _PATH_STDPATH "/usr/bin:/bin:/usr/sbin:/sbin"
63 #if ENABLE_FEATURE_INIT_COREDUMPS
65 * When a file named CORE_ENABLE_FLAG_FILE exists, setrlimit is called
66 * before processes are spawned to set core file size as unlimited.
67 * This is for debugging only. Don't use this is production, unless
68 * you want core dumps lying about....
70 #define CORE_ENABLE_FLAG_FILE "/.init_enable_core"
71 #include <sys/resource.h>
74 #define INITTAB "/etc/inittab" /* inittab file location */
76 #define INIT_SCRIPT "/etc/init.d/rcS" /* Default sysinit script. */
79 #define MAXENV 16 /* Number of env. vars */
81 #define CONSOLE_BUFF_SIZE 32
83 /* Allowed init action types */
86 #define ASKFIRST 0x004
89 #define CTRLALTDEL 0x020
90 #define SHUTDOWN 0x040
93 /* A mapping between "inittab" action name strings and action type codes. */
94 struct init_action_type {
99 static const struct init_action_type actions[] = {
100 {"sysinit", SYSINIT},
101 {"respawn", RESPAWN},
102 {"askfirst", ASKFIRST},
105 {"ctrlaltdel", CTRLALTDEL},
106 {"shutdown", SHUTDOWN},
107 {"restart", RESTART},
111 /* Set up a linked list of init_actions, to be read from inittab */
114 char command[INIT_BUFFS_SIZE];
115 char terminal[CONSOLE_BUFF_SIZE];
116 struct init_action *next;
120 /* Static variables */
121 static struct init_action *init_action_list = NULL;
122 static char console[CONSOLE_BUFF_SIZE] = CONSOLE_DEV;
125 static char *log_console = VC_5;
127 #if !ENABLE_DEBUG_INIT
128 static sig_atomic_t got_cont = 0;
135 #if ENABLE_FEATURE_EXTRA_QUIET
138 MAYBE_CONSOLE = CONSOLE,
141 #ifndef RB_HALT_SYSTEM
142 RB_HALT_SYSTEM = 0xcdef0123, /* FIXME: this overflows enum */
143 RB_ENABLE_CAD = 0x89abcdef,
145 RB_POWER_OFF = 0x4321fedc,
146 RB_AUTOBOOT = 0x01234567,
150 static const char * const environment[] = {
152 "PATH=" _PATH_STDPATH,
158 /* Function prototypes */
159 static void delete_init_action(struct init_action *a);
160 static int waitfor(const struct init_action *a, pid_t pid);
161 #if !ENABLE_DEBUG_INIT
162 static void shutdown_signal(int sig);
165 #if !ENABLE_DEBUG_INIT
166 static void loop_forever(void)
173 /* Print a message to the specified device.
174 * Device may be bitwise-or'd from LOG | CONSOLE */
175 #if ENABLE_DEBUG_INIT
176 #define messageD message
178 #define messageD(...) do {} while (0)
180 static void message(int device, const char *fmt, ...)
181 __attribute__ ((format(printf, 2, 3)));
182 static void message(int device, const char *fmt, ...)
186 RESERVE_CONFIG_BUFFER(msg, 1024);
188 static int log_fd = -1;
192 va_start(arguments, fmt);
193 l = vsnprintf(msg + 1, 1024 - 2, fmt, arguments) + 1;
197 /* Log the message to syslogd */
199 /* don`t out "\r\n" */
200 openlog(applet_name, 0, LOG_DAEMON);
201 syslog(LOG_INFO, "%s", msg + 1);
211 /* Take full control of the log tty, and never close it.
212 * It's mine, all mine! Muhahahaha! */
214 if ((log_fd = device_open(log_console, O_RDWR | O_NONBLOCK | O_NOCTTY)) < 0) {
216 bb_error_msg("bummer, can't write to log on %s!", log_console);
219 fcntl(log_fd, F_SETFD, FD_CLOEXEC);
222 if ((device & LOG) && (log_fd >= 0)) {
223 full_write(log_fd, msg, l);
227 if (device & CONSOLE) {
228 int fd = device_open(CONSOLE_DEV,
229 O_WRONLY | O_NOCTTY | O_NONBLOCK);
230 /* Always send console messages to /dev/console so people will see them. */
232 full_write(fd, msg, l);
234 #if ENABLE_DEBUG_INIT
235 /* all descriptors may be closed */
237 bb_error_msg("bummer, can't print: ");
238 va_start(arguments, fmt);
239 vfprintf(stderr, fmt, arguments);
244 RELEASE_CONFIG_BUFFER(msg);
247 /* Set terminal settings to reasonable defaults */
248 static void set_term(void)
252 tcgetattr(STDIN_FILENO, &tty);
254 /* set control chars */
255 tty.c_cc[VINTR] = 3; /* C-c */
256 tty.c_cc[VQUIT] = 28; /* C-\ */
257 tty.c_cc[VERASE] = 127; /* C-? */
258 tty.c_cc[VKILL] = 21; /* C-u */
259 tty.c_cc[VEOF] = 4; /* C-d */
260 tty.c_cc[VSTART] = 17; /* C-q */
261 tty.c_cc[VSTOP] = 19; /* C-s */
262 tty.c_cc[VSUSP] = 26; /* C-z */
264 /* use line dicipline 0 */
267 /* Make it be sane */
268 tty.c_cflag &= CBAUD | CBAUDEX | CSIZE | CSTOPB | PARENB | PARODD;
269 tty.c_cflag |= CREAD | HUPCL | CLOCAL;
273 tty.c_iflag = ICRNL | IXON | IXOFF;
276 tty.c_oflag = OPOST | ONLCR;
280 ISIG | ICANON | ECHO | ECHOE | ECHOK | ECHOCTL | ECHOKE | IEXTEN;
282 tcsetattr(STDIN_FILENO, TCSANOW, &tty);
285 static void console_init(void)
290 struct serial_struct sr;
293 if ((s = getenv("CONSOLE")) != NULL || (s = getenv("console")) != NULL) {
294 safe_strncpy(console, s, sizeof(console));
296 /* 2.2 kernels: identify the real console backend and try to use it */
297 if (ioctl(0, TIOCGSERIAL, &sr) == 0) {
298 /* this is a serial console */
299 snprintf(console, sizeof(console) - 1, SC_FORMAT, sr.line);
300 } else if (ioctl(0, VT_GETSTATE, &vt) == 0) {
301 /* this is linux virtual tty */
302 snprintf(console, sizeof(console) - 1, VC_FORMAT, vt.v_active);
304 safe_strncpy(console, CONSOLE_DEV, sizeof(console));
309 while ((fd = open(console, O_RDONLY | O_NONBLOCK)) < 0 && tried < 2) {
310 /* Can't open selected console -- try
311 logical system console and VT_MASTER */
312 safe_strncpy(console, (tried == 0 ? CONSOLE_DEV : CURRENT_VC),
317 /* Perhaps we should panic here? */
321 safe_strncpy(console, bb_dev_null, sizeof(console));
324 /* check for serial console */
325 if (ioctl(fd, TIOCGSERIAL, &sr) == 0) {
326 /* Force the TERM setting to vt102 for serial console --
327 * if TERM is set to linux (the default) */
328 if (s == NULL || strcmp(s, "linux") == 0)
329 putenv((char*)"TERM=vt102");
331 log_console = console;
335 putenv((char*)"TERM=linux");
339 messageD(LOG, "console=%s", console);
342 static void fixup_argv(int argc, char **argv, const char *new_argv0)
346 /* Fix up argv[0] to be certain we claim to be init */
347 len = strlen(argv[0]);
348 strncpy(argv[0], new_argv0, len);
350 /* Wipe argv[1]-argv[N] so they don't clutter the ps listing */
353 memset(argv[len], 0, strlen(argv[len]));
358 /* Open the new terminal device */
359 static void open_new_terminal(const char * const device, const int fail) {
362 if ((device_open(device, O_RDWR)) < 0) {
363 if (stat(device, &sb) != 0) {
364 message(LOG | CONSOLE, "device '%s' does not exist.", device);
366 message(LOG | CONSOLE, "Bummer, can't open %s", device);
371 #if !ENABLE_DEBUG_INIT
372 shutdown_signal(SIGUSR1);
379 static pid_t run(const struct init_action *a)
383 char *s, *tmpCmd, *cmdpath;
384 char *cmd[INIT_BUFFS_SIZE];
385 char buf[INIT_BUFFS_SIZE + 6]; /* INIT_BUFFS_SIZE+strlen("exec ")+1 */
386 sigset_t nmask, omask;
387 static const char press_enter[] =
388 #ifdef CUSTOMIZED_BANNER
389 #include CUSTOMIZED_BANNER
391 "\nPlease press Enter to activate this console. ";
394 /* Block sigchild while forking. */
396 sigaddset(&nmask, SIGCHLD);
397 sigprocmask(SIG_BLOCK, &nmask, &omask);
399 if ((pid = fork()) == 0) {
405 sigprocmask(SIG_SETMASK, &omask, NULL);
407 /* Reset signal handlers that were set by the parent process */
408 signal(SIGUSR1, SIG_DFL);
409 signal(SIGUSR2, SIG_DFL);
410 signal(SIGINT, SIG_DFL);
411 signal(SIGTERM, SIG_DFL);
412 signal(SIGHUP, SIG_DFL);
413 signal(SIGQUIT, SIG_DFL);
414 signal(SIGCONT, SIG_DFL);
415 signal(SIGSTOP, SIG_DFL);
416 signal(SIGTSTP, SIG_DFL);
418 /* Create a new session and make ourself the process
422 /* Open the new terminal device */
423 open_new_terminal(a->terminal, 1);
425 /* Make sure the terminal will act fairly normal for us */
427 /* Setup stdout, stderr for the new process so
428 * they point to the supplied terminal */
432 /* If the init Action requires us to wait, then force the
433 * supplied terminal to be the controlling tty. */
434 if (a->action & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) {
436 /* Now fork off another process to just hang around */
437 if ((pid = fork()) < 0) {
438 message(LOG | CONSOLE, "Can't fork!");
444 /* We are the parent -- wait till the child is done */
445 signal(SIGINT, SIG_IGN);
446 signal(SIGTSTP, SIG_IGN);
447 signal(SIGQUIT, SIG_IGN);
448 signal(SIGCHLD, SIG_DFL);
451 /* See if stealing the controlling tty back is necessary */
452 if (tcgetpgrp(0) != getpid())
455 /* Use a temporary process to steal the controlling tty. */
456 if ((pid = fork()) < 0) {
457 message(LOG | CONSOLE, "Can't fork!");
462 ioctl(0, TIOCSCTTY, 1);
469 /* Now fall though to actually execute things */
472 /* See if any special /bin/sh requiring characters are present */
473 if (strpbrk(a->command, "~`!$^&*()=|\\{}[];\"'<>?") != NULL) {
474 cmd[0] = (char *)DEFAULT_SHELL;
475 cmd[1] = (char*)"-c";
476 cmd[2] = strcat(strcpy(buf, "exec "), a->command);
479 /* Convert command (char*) into cmd (char**, one word per string) */
480 strcpy(buf, a->command);
482 for (tmpCmd = buf, i = 0; (tmpCmd = strsep(&s, " \t")) != NULL;) {
483 if (*tmpCmd != '\0') {
494 Interactive shells want to see a dash in argv[0]. This
495 typically is handled by login, argv will be setup this
496 way if a dash appears at the front of the command path
500 if (*cmdpath == '-') {
502 /* skip over the dash */
505 /* find the last component in the command pathname */
506 s = bb_get_last_path_component(cmdpath);
508 /* make a new argv[0] */
509 if ((cmd[0] = malloc(strlen(s) + 2)) == NULL) {
510 message(LOG | CONSOLE, bb_msg_memory_exhausted);
514 strcpy(cmd[0] + 1, s);
516 #if ENABLE_FEATURE_INIT_SCTTY
517 /* Establish this process as session leader and
518 * (attempt) to make the tty (if any) a controlling tty.
521 (void) ioctl(0, TIOCSCTTY, 0/*don't steal it*/);
525 #if !defined(__UCLIBC__) || defined(__ARCH_HAS_MMU__)
526 if (a->action & ASKFIRST) {
529 * Save memory by not exec-ing anything large (like a shell)
530 * before the user wants it. This is critical if swap is not
531 * enabled and the system has low memory. Generally this will
532 * be run on the second virtual console, and the first will
533 * be allowed to start a shell or whatever an init script
536 messageD(LOG, "Waiting for enter to start '%s'"
537 "(pid %d, terminal %s)\n",
538 cmdpath, getpid(), a->terminal);
539 full_write(1, press_enter, sizeof(press_enter) - 1);
540 while (read(0, &c, 1) == 1 && c != '\n')
545 /* Log the process name and args */
546 message(LOG, "Starting pid %d, console %s: '%s'",
547 getpid(), a->terminal, cmdpath);
549 #if ENABLE_FEATURE_INIT_COREDUMPS
552 if (stat(CORE_ENABLE_FLAG_FILE, &sb) == 0) {
555 limit.rlim_cur = RLIM_INFINITY;
556 limit.rlim_max = RLIM_INFINITY;
557 setrlimit(RLIMIT_CORE, &limit);
562 /* Now run it. The new program will take over this PID,
563 * so nothing further in init.c should be run. */
565 if (ENABLE_FEATURE_EXEC_PREFER_APPLETS && find_applet_by_name(prog))
566 prog = CONFIG_BUSYBOX_EXEC_PATH;
569 /* We're still here? Some error happened. */
570 message(LOG | CONSOLE, "Bummer, cannot run '%s': %m", cmdpath);
573 sigprocmask(SIG_SETMASK, &omask, NULL);
577 static int waitfor(const struct init_action *a, pid_t pid)
582 runpid = (NULL == a)? pid : run(a);
584 wpid = waitpid(runpid,&status,0);
587 if (wpid == -1 && errno == ECHILD) {
588 /* we missed its termination */
591 /* FIXME other errors should maybe trigger an error, but allow
592 * the program to continue */
597 /* Run all commands of a particular type */
598 static void run_actions(int action)
600 struct init_action *a, *tmp;
602 for (a = init_action_list; a; a = tmp) {
604 if (a->action == action) {
605 if (access(a->terminal, R_OK | W_OK)) {
606 delete_init_action(a);
607 } else if (a->action & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) {
609 delete_init_action(a);
610 } else if (a->action & ONCE) {
612 delete_init_action(a);
613 } else if (a->action & (RESPAWN | ASKFIRST)) {
614 /* Only run stuff with pid==0. If they have
615 * a pid, that means it is still running */
624 #if !ENABLE_DEBUG_INIT
625 static void init_reboot(unsigned long magic)
628 /* We have to fork here, since the kernel calls do_exit(0) in
629 * linux/kernel/sys.c, which can cause the machine to panic when
630 * the init process is killed.... */
632 if (pid == 0) { /* child */
636 waitpid(pid, NULL, 0);
639 static void shutdown_system(void)
641 sigset_t block_signals;
643 /* run everything to be run at "shutdown". This is done _prior_
644 * to killing everything, in case people wish to use scripts to
645 * shut things down gracefully... */
646 run_actions(SHUTDOWN);
648 /* first disable all our signals */
649 sigemptyset(&block_signals);
650 sigaddset(&block_signals, SIGHUP);
651 sigaddset(&block_signals, SIGQUIT);
652 sigaddset(&block_signals, SIGCHLD);
653 sigaddset(&block_signals, SIGUSR1);
654 sigaddset(&block_signals, SIGUSR2);
655 sigaddset(&block_signals, SIGINT);
656 sigaddset(&block_signals, SIGTERM);
657 sigaddset(&block_signals, SIGCONT);
658 sigaddset(&block_signals, SIGSTOP);
659 sigaddset(&block_signals, SIGTSTP);
660 sigprocmask(SIG_BLOCK, &block_signals, NULL);
662 /* Allow Ctrl-Alt-Del to reboot system. */
663 init_reboot(RB_ENABLE_CAD);
665 message(CONSOLE | LOG, "The system is going down NOW !!");
668 /* Send signals to every process _except_ pid 1 */
669 message(CONSOLE | LOG, init_sending_format, "TERM");
674 message(CONSOLE | LOG, init_sending_format, "KILL");
681 static void exec_signal(int sig ATTRIBUTE_UNUSED)
683 struct init_action *a, *tmp;
684 sigset_t unblock_signals;
687 for (a = init_action_list; a; a = tmp) {
689 if (a->action & RESTART) {
692 /* unblock all signals, blocked in shutdown_system() */
693 sigemptyset(&unblock_signals);
694 sigaddset(&unblock_signals, SIGHUP);
695 sigaddset(&unblock_signals, SIGQUIT);
696 sigaddset(&unblock_signals, SIGCHLD);
697 sigaddset(&unblock_signals, SIGUSR1);
698 sigaddset(&unblock_signals, SIGUSR2);
699 sigaddset(&unblock_signals, SIGINT);
700 sigaddset(&unblock_signals, SIGTERM);
701 sigaddset(&unblock_signals, SIGCONT);
702 sigaddset(&unblock_signals, SIGSTOP);
703 sigaddset(&unblock_signals, SIGTSTP);
704 sigprocmask(SIG_UNBLOCK, &unblock_signals, NULL);
706 /* Close whatever files are open. */
711 /* Open the new terminal device */
712 open_new_terminal(a->terminal, 0);
714 /* Make sure the terminal will act fairly normal for us */
716 /* Setup stdout, stderr on the supplied terminal */
720 messageD(CONSOLE | LOG, "Trying to re-exec %s", a->command);
722 if (ENABLE_FEATURE_EXEC_PREFER_APPLETS && find_applet_by_name(prog))
723 prog = CONFIG_BUSYBOX_EXEC_PATH;
724 execlp(prog, a->command, NULL);
726 message(CONSOLE | LOG, "exec of '%s' failed: %m",
730 init_reboot(RB_HALT_SYSTEM);
736 static void shutdown_signal(int sig)
743 if (sig == SIGTERM) {
746 } else if (sig == SIGUSR2) {
753 message(CONSOLE | LOG, "Requesting system %s.", m);
756 /* allow time for last message to reach serial console */
763 static void ctrlaltdel_signal(int sig ATTRIBUTE_UNUSED)
765 run_actions(CTRLALTDEL);
768 /* The SIGSTOP & SIGTSTP handler */
769 static void stop_handler(int sig ATTRIBUTE_UNUSED)
771 int saved_errno = errno;
780 /* The SIGCONT handler */
781 static void cont_handler(int sig ATTRIBUTE_UNUSED)
786 #endif /* ! ENABLE_DEBUG_INIT */
788 static void new_init_action(int action, const char *command, const char *cons)
790 struct init_action *new_action, *a, *last;
795 if (strcmp(cons, bb_dev_null) == 0 && (action & ASKFIRST))
798 new_action = xzalloc(sizeof(struct init_action));
800 /* Append to the end of the list */
801 for (a = last = init_action_list; a; a = a->next) {
802 /* don't enter action if it's already in the list,
803 * but do overwrite existing actions */
804 if ((strcmp(a->command, command) == 0) &&
805 (strcmp(a->terminal, cons) ==0)) {
813 last->next = new_action;
815 init_action_list = new_action;
817 strcpy(new_action->command, command);
818 new_action->action = action;
819 strcpy(new_action->terminal, cons);
820 messageD(LOG|CONSOLE, "command='%s' action='%d' terminal='%s'\n",
821 new_action->command, new_action->action, new_action->terminal);
824 static void delete_init_action(struct init_action *action)
826 struct init_action *a, *b = NULL;
828 for (a = init_action_list; a; b = a, a = a->next) {
831 init_action_list = a->next;
841 /* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined,
842 * then parse_inittab() simply adds in some default
843 * actions(i.e., runs INIT_SCRIPT and then starts a pair
844 * of "askfirst" shells). If CONFIG_FEATURE_USE_INITTAB
845 * _is_ defined, but /etc/inittab is missing, this
846 * results in the same set of default behaviors.
848 static void parse_inittab(void)
850 #if ENABLE_FEATURE_USE_INITTAB
852 char buf[INIT_BUFFS_SIZE], lineAsRead[INIT_BUFFS_SIZE];
853 char tmpConsole[CONSOLE_BUFF_SIZE];
854 char *id, *runlev, *action, *command, *eol;
855 const struct init_action_type *a = actions;
858 file = fopen(INITTAB, "r");
860 /* No inittab file -- set up some default behavior */
862 /* Reboot on Ctrl-Alt-Del */
863 new_init_action(CTRLALTDEL, "reboot", "");
864 /* Umount all filesystems on halt/reboot */
865 new_init_action(SHUTDOWN, "umount -a -r", "");
866 /* Swapoff on halt/reboot */
867 if(ENABLE_SWAPONOFF) new_init_action(SHUTDOWN, "swapoff -a", "");
868 /* Prepare to restart init when a HUP is received */
869 new_init_action(RESTART, "init", "");
870 /* Askfirst shell on tty1-4 */
871 new_init_action(ASKFIRST, bb_default_login_shell, "");
872 new_init_action(ASKFIRST, bb_default_login_shell, VC_2);
873 new_init_action(ASKFIRST, bb_default_login_shell, VC_3);
874 new_init_action(ASKFIRST, bb_default_login_shell, VC_4);
876 new_init_action(SYSINIT, INIT_SCRIPT, "");
879 #if ENABLE_FEATURE_USE_INITTAB
882 while (fgets(buf, INIT_BUFFS_SIZE, file) != NULL) {
883 /* Skip leading spaces */
884 for (id = buf; *id == ' ' || *id == '\t'; id++);
886 /* Skip the line if it's a comment */
887 if (*id == '#' || *id == '\n')
890 /* Trim the trailing \n */
891 eol = strrchr(id, '\n');
895 /* Keep a copy around for posterity's sake (and error msgs) */
896 strcpy(lineAsRead, buf);
898 /* Separate the ID field from the runlevels */
899 runlev = strchr(id, ':');
900 if (runlev == NULL || *(runlev + 1) == '\0') {
901 message(LOG | CONSOLE, "Bad inittab entry: %s", lineAsRead);
908 /* Separate the runlevels from the action */
909 action = strchr(runlev, ':');
910 if (action == NULL || *(action + 1) == '\0') {
911 message(LOG | CONSOLE, "Bad inittab entry: %s", lineAsRead);
918 /* Separate the action from the command */
919 command = strchr(action, ':');
920 if (command == NULL || *(command + 1) == '\0') {
921 message(LOG | CONSOLE, "Bad inittab entry: %s", lineAsRead);
928 /* Ok, now process it */
929 for (a = actions; a->name != 0; a++) {
930 if (strcmp(a->name, action) == 0) {
932 if(strncmp(id, "/dev/", 5) == 0)
934 strcpy(tmpConsole, "/dev/");
935 safe_strncpy(tmpConsole + 5, id,
936 CONSOLE_BUFF_SIZE - 5);
939 new_init_action(a->action, command, id);
944 /* Choke on an unknown action */
945 message(LOG | CONSOLE, "Bad inittab entry: %s", lineAsRead);
950 #endif /* FEATURE_USE_INITTAB */
953 #if ENABLE_FEATURE_USE_INITTAB
954 static void reload_signal(int sig ATTRIBUTE_UNUSED)
956 struct init_action *a, *tmp;
958 message(LOG, "Reloading /etc/inittab");
960 /* disable old entrys */
961 for (a = init_action_list; a; a = a->next ) {
967 /* remove unused entrys */
968 for (a = init_action_list; a; a = tmp) {
970 if (a->action & (ONCE | SYSINIT | WAIT ) &&
972 delete_init_action(a);
975 run_actions(RESPAWN);
978 #endif /* FEATURE_USE_INITTAB */
980 int init_main(int argc, char **argv)
982 struct init_action *a;
985 die_sleep = 30 * 24*60*60; /* if xmalloc will ever die... */
987 if (argc > 1 && !strcmp(argv[1], "-q")) {
988 return kill(1,SIGHUP);
990 #if !ENABLE_DEBUG_INIT
991 /* Expect to be invoked as init with PID=1 or be invoked as linuxrc */
993 (!ENABLE_FEATURE_INITRD || !strstr(applet_name, "linuxrc")))
997 /* Set up sig handlers -- be sure to
998 * clear all of these in run() */
999 signal(SIGHUP, exec_signal);
1000 signal(SIGQUIT, exec_signal);
1001 signal(SIGUSR1, shutdown_signal);
1002 signal(SIGUSR2, shutdown_signal);
1003 signal(SIGINT, ctrlaltdel_signal);
1004 signal(SIGTERM, shutdown_signal);
1005 signal(SIGCONT, cont_handler);
1006 signal(SIGSTOP, stop_handler);
1007 signal(SIGTSTP, stop_handler);
1009 /* Turn off rebooting via CTL-ALT-DEL -- we get a
1010 * SIGINT on CAD so we can shut things down gracefully... */
1011 init_reboot(RB_DISABLE_CAD);
1014 /* Figure out where the default console should be */
1017 /* Close whatever files are open, and reset the console. */
1022 if (device_open(console, O_RDWR | O_NOCTTY) == 0) {
1030 const char * const *e;
1031 /* Make sure environs is set to something sane */
1032 for (e = environment; *e; e++)
1033 putenv((char *) *e);
1036 if (argc > 1) setenv("RUNLEVEL", argv[1], 1);
1039 message(MAYBE_CONSOLE | LOG, "init started: %s", bb_msg_full_version);
1041 /* Make sure there is enough memory to do something useful. */
1042 if (ENABLE_SWAPONOFF) {
1043 struct sysinfo info;
1045 if (!sysinfo(&info) &&
1046 (info.mem_unit ? : 1) * (long long)info.totalram < 1024*1024)
1048 message(CONSOLE,"Low memory: forcing swapon.");
1049 /* swapon -a requires /proc typically */
1050 new_init_action(SYSINIT, "mount -t proc proc /proc", "");
1051 /* Try to turn on swap */
1052 new_init_action(SYSINIT, "swapon -a", "");
1053 run_actions(SYSINIT); /* wait and removing */
1057 /* Check if we are supposed to be in single user mode */
1059 && (!strcmp(argv[1], "single") || !strcmp(argv[1], "-s") || LONE_CHAR(argv[1], '1'))
1061 /* Start a shell on console */
1062 new_init_action(RESPAWN, bb_default_login_shell, "");
1064 /* Not in single user mode -- see what inittab says */
1066 /* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined,
1067 * then parse_inittab() simply adds in some default
1068 * actions(i.e., runs INIT_SCRIPT and then starts a pair
1069 * of "askfirst" shells */
1074 if (getenv("SELINUX_INIT") == NULL) {
1077 putenv("SELINUX_INIT=YES");
1078 if (selinux_init_load_policy(&enforce) == 0) {
1079 char *prog = argv[0];
1080 if (ENABLE_FEATURE_EXEC_PREFER_APPLETS && find_applet_by_name(prog))
1081 prog = CONFIG_BUSYBOX_EXEC_PATH;
1083 } else if (enforce > 0) {
1084 /* SELinux in enforcing mode but load_policy failed */
1085 /* At this point, we probably can't open /dev/console, so log() won't work */
1086 message(CONSOLE,"Unable to load SELinux Policy. Machine is in enforcing mode. Halting now.");
1090 #endif /* CONFIG_SELINUX */
1092 /* Make the command line just say "init" -- thats all, nothing else */
1093 fixup_argv(argc, argv, "init");
1095 /* Now run everything that needs to be run */
1097 /* First run the sysinit command */
1098 run_actions(SYSINIT);
1100 /* Next run anything that wants to block */
1103 /* Next run anything to be run only once */
1106 #if ENABLE_FEATURE_USE_INITTAB
1107 /* Redefine SIGHUP to reread /etc/inittab */
1108 signal(SIGHUP, reload_signal);
1110 signal(SIGHUP, SIG_IGN);
1111 #endif /* FEATURE_USE_INITTAB */
1114 /* Now run the looping stuff for the rest of forever */
1116 /* run the respawn stuff */
1117 run_actions(RESPAWN);
1119 /* run the askfirst stuff */
1120 run_actions(ASKFIRST);
1122 /* Don't consume all CPU time -- sleep a bit */
1125 /* Wait for a child process to exit */
1128 /* Find out who died and clean up their corpse */
1129 for (a = init_action_list; a; a = a->next) {
1130 if (a->pid == wpid) {
1131 /* Set the pid to 0 so that the process gets
1132 * restarted by run_actions() */
1134 message(LOG, "Process '%s' (pid %d) exited. "
1135 "Scheduling it for restart.",
1139 /* see if anyone else is waiting to be reaped */
1140 wpid = waitpid(-1, NULL, WNOHANG);