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.
12 /* Turn this on to disable all the dangerous
13 rebooting stuff when debugging.
28 #include <sys/ioctl.h>
29 #include <sys/types.h>
31 #include <sys/reboot.h>
34 #include "init_shared.h"
38 # include <sys/syslog.h>
43 # include <selinux/selinux.h>
44 #endif /* CONFIG_SELINUX */
47 #define INIT_BUFFS_SIZE 256
49 /* From <linux/vt.h> */
51 unsigned short v_active; /* active vt */
52 unsigned short v_signal; /* signal to send */
53 unsigned short v_state; /* vt bitmask */
55 enum { VT_GETSTATE = 0x5603 }; /* get global vt state info */
57 /* From <linux/serial.h> */
58 struct serial_struct {
67 unsigned short close_delay;
69 char reserved_char[1];
71 unsigned short closing_wait; /* time to wait before closing */
72 unsigned short closing_wait2; /* no longer used... */
73 unsigned char *iomem_base;
74 unsigned short iomem_reg_shift;
75 unsigned int port_high;
76 unsigned long iomap_base; /* cookie passed into ioremap */
82 #define _PATH_STDPATH "/usr/bin:/bin:/usr/sbin:/sbin"
85 #if defined CONFIG_FEATURE_INIT_COREDUMPS
87 * When a file named CORE_ENABLE_FLAG_FILE exists, setrlimit is called
88 * before processes are spawned to set core file size as unlimited.
89 * This is for debugging only. Don't use this is production, unless
90 * you want core dumps lying about....
92 #define CORE_ENABLE_FLAG_FILE "/.init_enable_core"
93 #include <sys/resource.h>
96 #define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))
98 #define INITTAB "/etc/inittab" /* inittab file location */
100 #define INIT_SCRIPT "/etc/init.d/rcS" /* Default sysinit script. */
103 #define MAXENV 16 /* Number of env. vars */
105 #define CONSOLE_BUFF_SIZE 32
107 /* Allowed init action types */
108 #define SYSINIT 0x001
109 #define RESPAWN 0x002
110 #define ASKFIRST 0x004
113 #define CTRLALTDEL 0x020
114 #define SHUTDOWN 0x040
115 #define RESTART 0x080
117 /* A mapping between "inittab" action name strings and action type codes. */
118 struct init_action_type {
123 static const struct init_action_type actions[] = {
124 {"sysinit", SYSINIT},
125 {"respawn", RESPAWN},
126 {"askfirst", ASKFIRST},
129 {"ctrlaltdel", CTRLALTDEL},
130 {"shutdown", SHUTDOWN},
131 {"restart", RESTART},
135 /* Set up a linked list of init_actions, to be read from inittab */
138 char command[INIT_BUFFS_SIZE];
139 char terminal[CONSOLE_BUFF_SIZE];
140 struct init_action *next;
144 /* Static variables */
145 static struct init_action *init_action_list = NULL;
146 static char console[CONSOLE_BUFF_SIZE] = _PATH_CONSOLE;
148 #ifndef CONFIG_SYSLOGD
149 static char *log_console = VC_5;
151 static sig_atomic_t got_cont = 0;
157 #if defined CONFIG_FEATURE_EXTRA_QUIET
160 MAYBE_CONSOLE = CONSOLE,
163 #ifndef RB_HALT_SYSTEM
164 RB_HALT_SYSTEM = 0xcdef0123,
165 RB_ENABLE_CAD = 0x89abcdef,
167 RB_POWER_OFF = 0x4321fedc,
168 RB_AUTOBOOT = 0x01234567,
172 static const char * const environment[] = {
174 "PATH=" _PATH_STDPATH,
180 /* Function prototypes */
181 static void delete_init_action(struct init_action *a);
182 static int waitfor(const struct init_action *a);
183 static void halt_signal(int sig);
186 static void loop_forever(void)
192 /* Print a message to the specified device.
193 * Device may be bitwise-or'd from LOG | CONSOLE */
195 static inline void messageD(int ATTRIBUTE_UNUSED device,
196 const char ATTRIBUTE_UNUSED *fmt, ...)
200 #define messageD message
202 static void message(int device, const char *fmt, ...)
203 __attribute__ ((format(printf, 2, 3)));
204 static void message(int device, const char *fmt, ...)
209 #ifndef CONFIG_SYSLOGD
210 static int log_fd = -1;
214 va_start(arguments, fmt);
215 l = vsnprintf(msg + 1, sizeof(msg) - 2, fmt, arguments) + 1;
218 #ifdef CONFIG_SYSLOGD
219 /* Log the message to syslogd */
221 /* don`t out "\r\n" */
222 openlog(bb_applet_name, 0, LOG_DAEMON);
223 syslog(LOG_INFO, "%s", msg + 1);
233 /* Take full control of the log tty, and never close it.
234 * It's mine, all mine! Muhahahaha! */
236 if ((log_fd = device_open(log_console, O_RDWR | O_NONBLOCK | O_NOCTTY)) < 0) {
238 bb_error_msg("Bummer, can't write to log on %s!", log_console);
241 fcntl(log_fd, F_SETFD, FD_CLOEXEC);
244 if ((device & LOG) && (log_fd >= 0)) {
245 bb_full_write(log_fd, msg, l);
249 if (device & CONSOLE) {
250 int fd = device_open(_PATH_CONSOLE,
251 O_WRONLY | O_NOCTTY | O_NONBLOCK);
252 /* Always send console messages to /dev/console so people will see them. */
254 bb_full_write(fd, msg, l);
257 /* all descriptors may be closed */
259 bb_error_msg("Bummer, can't print: ");
260 va_start(arguments, fmt);
261 vfprintf(stderr, fmt, arguments);
268 /* Set terminal settings to reasonable defaults */
269 static void set_term(void)
273 tcgetattr(STDIN_FILENO, &tty);
275 /* set control chars */
276 tty.c_cc[VINTR] = 3; /* C-c */
277 tty.c_cc[VQUIT] = 28; /* C-\ */
278 tty.c_cc[VERASE] = 127; /* C-? */
279 tty.c_cc[VKILL] = 21; /* C-u */
280 tty.c_cc[VEOF] = 4; /* C-d */
281 tty.c_cc[VSTART] = 17; /* C-q */
282 tty.c_cc[VSTOP] = 19; /* C-s */
283 tty.c_cc[VSUSP] = 26; /* C-z */
285 /* use line dicipline 0 */
288 /* Make it be sane */
289 tty.c_cflag &= CBAUD | CBAUDEX | CSIZE | CSTOPB | PARENB | PARODD;
290 tty.c_cflag |= CREAD | HUPCL | CLOCAL;
294 tty.c_iflag = ICRNL | IXON | IXOFF;
297 tty.c_oflag = OPOST | ONLCR;
301 ISIG | ICANON | ECHO | ECHOE | ECHOK | ECHOCTL | ECHOKE | IEXTEN;
303 tcsetattr(STDIN_FILENO, TCSANOW, &tty);
306 static void console_init(void)
311 struct serial_struct sr;
314 if ((s = getenv("CONSOLE")) != NULL || (s = getenv("console")) != NULL) {
315 safe_strncpy(console, s, sizeof(console));
317 /* sparc kernel supports console=tty[ab] parameter which is also
318 * passed to init, so catch it here */
319 /* remap tty[ab] to /dev/ttyS[01] */
320 if (strcmp(s, "ttya") == 0)
321 safe_strncpy(console, SC_0, sizeof(console));
322 else if (strcmp(s, "ttyb") == 0)
323 safe_strncpy(console, SC_1, sizeof(console));
326 /* 2.2 kernels: identify the real console backend and try to use it */
327 if (ioctl(0, TIOCGSERIAL, &sr) == 0) {
328 /* this is a serial console */
329 snprintf(console, sizeof(console) - 1, SC_FORMAT, sr.line);
330 } else if (ioctl(0, VT_GETSTATE, &vt) == 0) {
331 /* this is linux virtual tty */
332 snprintf(console, sizeof(console) - 1, VC_FORMAT, vt.v_active);
334 safe_strncpy(console, _PATH_CONSOLE, sizeof(console));
339 while ((fd = open(console, O_RDONLY | O_NONBLOCK)) < 0 && tried < 2) {
340 /* Can't open selected console -- try
341 logical system console and VT_MASTER */
342 safe_strncpy(console, (tried == 0 ? _PATH_CONSOLE : CURRENT_VC),
347 /* Perhaps we should panic here? */
348 #ifndef CONFIG_SYSLOGD
351 safe_strncpy(console, bb_dev_null, sizeof(console));
354 /* check for serial console */
355 if (ioctl(fd, TIOCGSERIAL, &sr) == 0) {
356 /* Force the TERM setting to vt102 for serial console --
357 * if TERM is set to linux (the default) */
358 if (s == NULL || strcmp(s, "linux") == 0)
359 putenv("TERM=vt102");
360 #ifndef CONFIG_SYSLOGD
361 log_console = console;
365 putenv("TERM=linux");
369 messageD(LOG, "console=%s", console);
372 static void fixup_argv(int argc, char **argv, char *new_argv0)
376 /* Fix up argv[0] to be certain we claim to be init */
377 len = strlen(argv[0]);
378 memset(argv[0], 0, len);
379 safe_strncpy(argv[0], new_argv0, len + 1);
381 /* Wipe argv[1]-argv[N] so they don't clutter the ps listing */
384 memset(argv[len], 0, strlen(argv[len]));
389 /* Open the new terminal device */
390 static void open_new_terminal(const char *device, char fail) {
393 if ((device_open(device, O_RDWR)) < 0) {
394 if (stat(device, &sb) != 0) {
395 message(LOG | CONSOLE, "device '%s' does not exist.", device);
397 message(LOG | CONSOLE, "Bummer, can't open %s", device);
402 halt_signal(SIGUSR1);
406 static pid_t run(const struct init_action *a)
410 char *s, *tmpCmd, *cmd[INIT_BUFFS_SIZE], *cmdpath;
411 char buf[INIT_BUFFS_SIZE + 6]; /* INIT_BUFFS_SIZE+strlen("exec ")+1 */
412 sigset_t nmask, omask;
413 static const char press_enter[] =
414 #ifdef CUSTOMIZED_BANNER
415 #include CUSTOMIZED_BANNER
417 "\nPlease press Enter to activate this console. ";
419 /* Block sigchild while forking. */
421 sigaddset(&nmask, SIGCHLD);
422 sigprocmask(SIG_BLOCK, &nmask, &omask);
424 if ((pid = fork()) == 0) {
430 sigprocmask(SIG_SETMASK, &omask, NULL);
432 /* Reset signal handlers that were set by the parent process */
433 signal(SIGUSR1, SIG_DFL);
434 signal(SIGUSR2, SIG_DFL);
435 signal(SIGINT, SIG_DFL);
436 signal(SIGTERM, SIG_DFL);
437 signal(SIGHUP, SIG_DFL);
438 signal(SIGQUIT, SIG_DFL);
439 signal(SIGCONT, SIG_DFL);
440 signal(SIGSTOP, SIG_DFL);
441 signal(SIGTSTP, SIG_DFL);
443 /* Create a new session and make ourself the process
447 /* Open the new terminal device */
448 open_new_terminal(a->terminal, 1);
450 /* Make sure the terminal will act fairly normal for us */
452 /* Setup stdout, stderr for the new process so
453 * they point to the supplied terminal */
457 /* If the init Action requires us to wait, then force the
458 * supplied terminal to be the controlling tty. */
459 if (a->action & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) {
462 /* Now fork off another process to just hang around */
463 if ((pid = fork()) < 0) {
464 message(LOG | CONSOLE, "Can't fork!");
470 /* We are the parent -- wait till the child is done */
471 signal(SIGINT, SIG_IGN);
472 signal(SIGTSTP, SIG_IGN);
473 signal(SIGQUIT, SIG_IGN);
474 signal(SIGCHLD, SIG_DFL);
476 /* Wait for child to exit */
477 while ((tmp_pid = waitpid(pid, &junk, 0)) != pid) {
478 if (tmp_pid == -1 && errno == ECHILD) {
481 /* FIXME handle other errors */
484 /* See if stealing the controlling tty back is necessary */
486 if (pgrp != getpid())
489 /* Use a temporary process to steal the controlling tty. */
490 if ((pid = fork()) < 0) {
491 message(LOG | CONSOLE, "Can't fork!");
496 ioctl(0, TIOCSCTTY, 1);
499 while ((tmp_pid = waitpid(pid, &junk, 0)) != pid) {
500 if (tmp_pid < 0 && errno == ECHILD)
506 /* Now fall though to actually execute things */
509 /* See if any special /bin/sh requiring characters are present */
510 if (strpbrk(a->command, "~`!$^&*()=|\\{}[];\"'<>?") != NULL) {
511 cmd[0] = (char *)DEFAULT_SHELL;
513 cmd[2] = strcat(strcpy(buf, "exec "), a->command);
516 /* Convert command (char*) into cmd (char**, one word per string) */
517 strcpy(buf, a->command);
519 for (tmpCmd = buf, i = 0; (tmpCmd = strsep(&s, " \t")) != NULL;) {
520 if (*tmpCmd != '\0') {
531 Interactive shells want to see a dash in argv[0]. This
532 typically is handled by login, argv will be setup this
533 way if a dash appears at the front of the command path
537 if (*cmdpath == '-') {
539 /* skip over the dash */
542 /* find the last component in the command pathname */
543 s = bb_get_last_path_component(cmdpath);
545 /* make a new argv[0] */
546 if ((cmd[0] = malloc(strlen(s) + 2)) == NULL) {
547 message(LOG | CONSOLE, bb_msg_memory_exhausted);
551 strcpy(cmd[0] + 1, s);
553 #ifdef CONFIG_FEATURE_INIT_SCTTY
554 /* Establish this process as session leader and
555 * (attempt) to make the tty (if any) a controlling tty.
558 (void) ioctl(0, TIOCSCTTY, 0/*don't steal it*/);
562 #if !defined(__UCLIBC__) || defined(__ARCH_HAS_MMU__)
563 if (a->action & ASKFIRST) {
566 * Save memory by not exec-ing anything large (like a shell)
567 * before the user wants it. This is critical if swap is not
568 * enabled and the system has low memory. Generally this will
569 * be run on the second virtual console, and the first will
570 * be allowed to start a shell or whatever an init script
573 messageD(LOG, "Waiting for enter to start '%s'"
574 "(pid %d, terminal %s)\n",
575 cmdpath, getpid(), a->terminal);
576 bb_full_write(1, press_enter, sizeof(press_enter) - 1);
577 while(read(0, &c, 1) == 1 && c != '\n')
582 /* Log the process name and args */
583 message(LOG, "Starting pid %d, console %s: '%s'",
584 getpid(), a->terminal, cmdpath);
586 #if defined CONFIG_FEATURE_INIT_COREDUMPS
589 if (stat(CORE_ENABLE_FLAG_FILE, &sb) == 0) {
592 limit.rlim_cur = RLIM_INFINITY;
593 limit.rlim_max = RLIM_INFINITY;
594 setrlimit(RLIMIT_CORE, &limit);
599 /* Now run it. The new program will take over this PID,
600 * so nothing further in init.c should be run. */
603 /* We're still here? Some error happened. */
604 message(LOG | CONSOLE, "Bummer, could not run '%s': %m", cmdpath);
607 sigprocmask(SIG_SETMASK, &omask, NULL);
611 static int waitfor(const struct init_action *a)
618 wpid = waitpid(pid,&status,0);
621 if (wpid == -1 && errno == ECHILD) {
622 /* we missed its termination */
625 /* FIXME other errors should maybe trigger an error, but allow
626 * the program to continue */
631 /* Run all commands of a particular type */
632 static void run_actions(int action)
634 struct init_action *a, *tmp;
636 for (a = init_action_list; a; a = tmp) {
638 if (a->action == action) {
639 if (access(a->terminal, R_OK | W_OK)) {
640 delete_init_action(a);
641 } else if (a->action & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) {
643 delete_init_action(a);
644 } else if (a->action & ONCE) {
646 delete_init_action(a);
647 } else if (a->action & (RESPAWN | ASKFIRST)) {
648 /* Only run stuff with pid==0. If they have
649 * a pid, that means it is still running */
659 static void init_reboot(unsigned long magic)
662 /* We have to fork here, since the kernel calls do_exit(0) in
663 * linux/kernel/sys.c, which can cause the machine to panic when
664 * the init process is killed.... */
665 if ((pid = fork()) == 0) {
669 waitpid (pid, NULL, 0);
672 static void shutdown_system(void)
674 sigset_t block_signals;
676 /* run everything to be run at "shutdown". This is done _prior_
677 * to killing everything, in case people wish to use scripts to
678 * shut things down gracefully... */
679 run_actions(SHUTDOWN);
681 /* first disable all our signals */
682 sigemptyset(&block_signals);
683 sigaddset(&block_signals, SIGHUP);
684 sigaddset(&block_signals, SIGQUIT);
685 sigaddset(&block_signals, SIGCHLD);
686 sigaddset(&block_signals, SIGUSR1);
687 sigaddset(&block_signals, SIGUSR2);
688 sigaddset(&block_signals, SIGINT);
689 sigaddset(&block_signals, SIGTERM);
690 sigaddset(&block_signals, SIGCONT);
691 sigaddset(&block_signals, SIGSTOP);
692 sigaddset(&block_signals, SIGTSTP);
693 sigprocmask(SIG_BLOCK, &block_signals, NULL);
695 /* Allow Ctrl-Alt-Del to reboot system. */
696 init_reboot(RB_ENABLE_CAD);
698 message(CONSOLE | LOG, "The system is going down NOW !!");
701 /* Send signals to every process _except_ pid 1 */
702 message(CONSOLE | LOG, "Sending SIGTERM to all processes.");
707 message(CONSOLE | LOG, "Sending SIGKILL to all processes.");
714 static void exec_signal(int sig ATTRIBUTE_UNUSED)
716 struct init_action *a, *tmp;
717 sigset_t unblock_signals;
719 for (a = init_action_list; a; a = tmp) {
721 if (a->action & RESTART) {
724 /* unblock all signals, blocked in shutdown_system() */
725 sigemptyset(&unblock_signals);
726 sigaddset(&unblock_signals, SIGHUP);
727 sigaddset(&unblock_signals, SIGQUIT);
728 sigaddset(&unblock_signals, SIGCHLD);
729 sigaddset(&unblock_signals, SIGUSR1);
730 sigaddset(&unblock_signals, SIGUSR2);
731 sigaddset(&unblock_signals, SIGINT);
732 sigaddset(&unblock_signals, SIGTERM);
733 sigaddset(&unblock_signals, SIGCONT);
734 sigaddset(&unblock_signals, SIGSTOP);
735 sigaddset(&unblock_signals, SIGTSTP);
736 sigprocmask(SIG_UNBLOCK, &unblock_signals, NULL);
738 /* Close whatever files are open. */
743 /* Open the new terminal device */
744 open_new_terminal(a->terminal, 0);
746 /* Make sure the terminal will act fairly normal for us */
748 /* Setup stdout, stderr on the supplied terminal */
752 messageD(CONSOLE | LOG, "Trying to re-exec %s", a->command);
753 execl(a->command, a->command, NULL);
755 message(CONSOLE | LOG, "exec of '%s' failed: %m",
759 init_reboot(RB_HALT_SYSTEM);
765 static void halt_signal(int sig ATTRIBUTE_UNUSED)
768 message(CONSOLE | LOG, "The system is halted.");
771 /* allow time for last message to reach serial console */
775 init_reboot(RB_POWER_OFF);
777 init_reboot(RB_HALT_SYSTEM);
782 static void reboot_signal(int sig ATTRIBUTE_UNUSED)
785 message(CONSOLE | LOG, "Please stand by while rebooting the system.");
788 /* allow time for last message to reach serial console */
791 init_reboot(RB_AUTOBOOT);
796 static void ctrlaltdel_signal(int sig ATTRIBUTE_UNUSED)
798 run_actions(CTRLALTDEL);
801 /* The SIGSTOP & SIGTSTP handler */
802 static void stop_handler(int sig ATTRIBUTE_UNUSED)
804 int saved_errno = errno;
813 /* The SIGCONT handler */
814 static void cont_handler(int sig ATTRIBUTE_UNUSED)
819 #endif /* ! DEBUG_INIT */
821 static void new_init_action(int action, const char *command, const char *cons)
823 struct init_action *new_action, *a, *last;
828 if (strcmp(cons, bb_dev_null) == 0 && (action & ASKFIRST))
831 new_action = calloc((size_t) (1), sizeof(struct init_action));
833 message(LOG | CONSOLE, "Memory allocation failure");
837 /* Append to the end of the list */
838 for (a = last = init_action_list; a; a = a->next) {
839 /* don't enter action if it's already in the list,
840 * but do overwrite existing actions */
841 if ((strcmp(a->command, command) == 0) &&
842 (strcmp(a->terminal, cons) ==0)) {
850 last->next = new_action;
852 init_action_list = new_action;
854 strcpy(new_action->command, command);
855 new_action->action = action;
856 strcpy(new_action->terminal, cons);
857 #if 0 /* calloc zeroed always */
860 messageD(LOG|CONSOLE, "command='%s' action='%d' terminal='%s'\n",
861 new_action->command, new_action->action, new_action->terminal);
864 static void delete_init_action(struct init_action *action)
866 struct init_action *a, *b = NULL;
868 for (a = init_action_list; a; b = a, a = a->next) {
871 init_action_list = a->next;
881 /* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined,
882 * then parse_inittab() simply adds in some default
883 * actions(i.e., runs INIT_SCRIPT and then starts a pair
884 * of "askfirst" shells). If CONFIG_FEATURE_USE_INITTAB
885 * _is_ defined, but /etc/inittab is missing, this
886 * results in the same set of default behaviors.
888 static void parse_inittab(void)
890 #ifdef CONFIG_FEATURE_USE_INITTAB
892 char buf[INIT_BUFFS_SIZE], lineAsRead[INIT_BUFFS_SIZE];
893 char tmpConsole[CONSOLE_BUFF_SIZE];
894 char *id, *runlev, *action, *command, *eol;
895 const struct init_action_type *a = actions;
898 file = fopen(INITTAB, "r");
900 /* No inittab file -- set up some default behavior */
902 /* Reboot on Ctrl-Alt-Del */
903 new_init_action(CTRLALTDEL, "/sbin/reboot", "");
904 /* Umount all filesystems on halt/reboot */
905 new_init_action(SHUTDOWN, "/bin/umount -a -r", "");
906 /* Swapoff on halt/reboot */
907 if(ENABLE_SWAPONOFF) new_init_action(SHUTDOWN, "/sbin/swapoff -a", "");
908 /* Prepare to restart init when a HUP is received */
909 new_init_action(RESTART, "/sbin/init", "");
910 /* Askfirst shell on tty1-4 */
911 new_init_action(ASKFIRST, bb_default_login_shell, "");
912 new_init_action(ASKFIRST, bb_default_login_shell, VC_2);
913 new_init_action(ASKFIRST, bb_default_login_shell, VC_3);
914 new_init_action(ASKFIRST, bb_default_login_shell, VC_4);
916 new_init_action(SYSINIT, INIT_SCRIPT, "");
919 #ifdef CONFIG_FEATURE_USE_INITTAB
922 while (fgets(buf, INIT_BUFFS_SIZE, file) != NULL) {
923 /* Skip leading spaces */
924 for (id = buf; *id == ' ' || *id == '\t'; id++);
926 /* Skip the line if it's a comment */
927 if (*id == '#' || *id == '\n')
930 /* Trim the trailing \n */
931 eol = strrchr(id, '\n');
935 /* Keep a copy around for posterity's sake (and error msgs) */
936 strcpy(lineAsRead, buf);
938 /* Separate the ID field from the runlevels */
939 runlev = strchr(id, ':');
940 if (runlev == NULL || *(runlev + 1) == '\0') {
941 message(LOG | CONSOLE, "Bad inittab entry: %s", lineAsRead);
948 /* Separate the runlevels from the action */
949 action = strchr(runlev, ':');
950 if (action == NULL || *(action + 1) == '\0') {
951 message(LOG | CONSOLE, "Bad inittab entry: %s", lineAsRead);
958 /* Separate the action from the command */
959 command = strchr(action, ':');
960 if (command == NULL || *(command + 1) == '\0') {
961 message(LOG | CONSOLE, "Bad inittab entry: %s", lineAsRead);
968 /* Ok, now process it */
969 for (a = actions; a->name != 0; a++) {
970 if (strcmp(a->name, action) == 0) {
972 if(strncmp(id, "/dev/", 5) == 0)
974 strcpy(tmpConsole, "/dev/");
975 safe_strncpy(tmpConsole + 5, id,
976 CONSOLE_BUFF_SIZE - 5);
979 new_init_action(a->action, command, id);
984 /* Choke on an unknown action */
985 message(LOG | CONSOLE, "Bad inittab entry: %s", lineAsRead);
990 #endif /* CONFIG_FEATURE_USE_INITTAB */
993 #ifdef CONFIG_FEATURE_USE_INITTAB
994 static void reload_signal(int sig ATTRIBUTE_UNUSED)
996 struct init_action *a, *tmp;
998 message(LOG, "Reloading /etc/inittab");
1000 /* disable old entrys */
1001 for (a = init_action_list; a; a = a->next ) {
1007 /* remove unused entrys */
1008 for (a = init_action_list; a; a = tmp) {
1010 if (a->action & (ONCE | SYSINIT | WAIT ) &&
1012 delete_init_action(a);
1015 run_actions(RESPAWN);
1018 #endif /* CONFIG_FEATURE_USE_INITTAB */
1020 int init_main(int argc, char **argv)
1022 struct init_action *a;
1026 if (argc > 1 && !strcmp(argv[1], "-q")) {
1027 return kill(1,SIGHUP);
1030 /* Expect to be invoked as init with PID=1 or be invoked as linuxrc */
1031 if (getpid() != 1 &&
1032 (!ENABLE_FEATURE_INITRD || !strstr(bb_applet_name, "linuxrc")))
1036 /* Set up sig handlers -- be sure to
1037 * clear all of these in run() */
1038 signal(SIGHUP, exec_signal);
1039 signal(SIGQUIT, exec_signal);
1040 signal(SIGUSR1, halt_signal);
1041 signal(SIGUSR2, halt_signal);
1042 signal(SIGINT, ctrlaltdel_signal);
1043 signal(SIGTERM, reboot_signal);
1044 signal(SIGCONT, cont_handler);
1045 signal(SIGSTOP, stop_handler);
1046 signal(SIGTSTP, stop_handler);
1048 /* Turn off rebooting via CTL-ALT-DEL -- we get a
1049 * SIGINT on CAD so we can shut things down gracefully... */
1050 init_reboot(RB_DISABLE_CAD);
1053 /* Figure out where the default console should be */
1056 /* Close whatever files are open, and reset the console. */
1061 if (device_open(console, O_RDWR | O_NOCTTY) == 0) {
1069 const char * const *e;
1070 /* Make sure environs is set to something sane */
1071 for(e = environment; *e; e++)
1072 putenv((char *) *e);
1075 message(MAYBE_CONSOLE | LOG, "init started: %s", bb_msg_full_version);
1077 /* Make sure there is enough memory to do something useful. */
1078 if (ENABLE_SWAPONOFF) {
1079 struct sysinfo info;
1081 if (!sysinfo(&info) &&
1082 (info.mem_unit ? : 1) * (long long)info.totalram < MEGABYTE)
1084 message(CONSOLE,"Low memory: forcing swapon.");
1085 /* swapon -a requires /proc typically */
1086 new_init_action(SYSINIT, "/bin/mount -t proc proc /proc", "");
1087 /* Try to turn on swap */
1088 new_init_action(SYSINIT, "/sbin/swapon -a", "");
1089 run_actions(SYSINIT); /* wait and removing */
1093 /* Check if we are supposed to be in single user mode */
1094 if (argc > 1 && (!strcmp(argv[1], "single") ||
1095 !strcmp(argv[1], "-s") || !strcmp(argv[1], "1"))) {
1096 /* Start a shell on console */
1097 new_init_action(RESPAWN, bb_default_login_shell, "");
1099 /* Not in single user mode -- see what inittab says */
1101 /* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined,
1102 * then parse_inittab() simply adds in some default
1103 * actions(i.e., runs INIT_SCRIPT and then starts a pair
1104 * of "askfirst" shells */
1108 #ifdef CONFIG_SELINUX
1109 if (getenv("SELINUX_INIT") == NULL) {
1112 putenv("SELINUX_INIT=YES");
1113 if (selinux_init_load_policy(&enforce) == 0) {
1114 execv(argv[0], argv);
1115 } else if (enforce > 0) {
1116 /* SELinux in enforcing mode but load_policy failed */
1117 /* At this point, we probably can't open /dev/console, so log() won't work */
1118 message(CONSOLE,"Unable to load SELinux Policy. Machine is in enforcing mode. Halting now.");
1122 #endif /* CONFIG_SELINUX */
1124 /* Make the command line just say "init" -- thats all, nothing else */
1125 fixup_argv(argc, argv, "init");
1127 /* Now run everything that needs to be run */
1129 /* First run the sysinit command */
1130 run_actions(SYSINIT);
1132 /* Next run anything that wants to block */
1135 /* Next run anything to be run only once */
1138 #ifdef CONFIG_FEATURE_USE_INITTAB
1139 /* Redefine SIGHUP to reread /etc/inittab */
1140 signal(SIGHUP, reload_signal);
1142 signal(SIGHUP, SIG_IGN);
1143 #endif /* CONFIG_FEATURE_USE_INITTAB */
1146 /* Now run the looping stuff for the rest of forever */
1148 /* run the respawn stuff */
1149 run_actions(RESPAWN);
1151 /* run the askfirst stuff */
1152 run_actions(ASKFIRST);
1154 /* Don't consume all CPU time -- sleep a bit */
1157 /* Wait for a child process to exit */
1158 wpid = wait(&status);
1160 /* Find out who died and clean up their corpse */
1161 for (a = init_action_list; a; a = a->next) {
1162 if (a->pid == wpid) {
1163 /* Set the pid to 0 so that the process gets
1164 * restarted by run_actions() */
1166 message(LOG, "Process '%s' (pid %d) exited. "
1167 "Scheduling it for restart.",
1171 /* see if anyone else is waiting to be reaped */
1172 wpid = waitpid (-1, &status, WNOHANG);