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 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25 /* Turn this on to disable all the dangerous
26 rebooting stuff when debugging.
40 #include <sys/fcntl.h>
41 #include <sys/ioctl.h>
42 #include <sys/types.h>
44 #include <sys/reboot.h>
47 #include "init_shared.h"
51 # include <sys/syslog.h>
55 #define INIT_BUFFS_SIZE 256
57 /* From <linux/vt.h> */
59 unsigned short v_active; /* active vt */
60 unsigned short v_signal; /* signal to send */
61 unsigned short v_state; /* vt bitmask */
63 static const int VT_GETSTATE = 0x5603; /* get global vt state info */
65 /* From <linux/serial.h> */
66 struct serial_struct {
75 unsigned short close_delay;
77 char reserved_char[1];
79 unsigned short closing_wait; /* time to wait before closing */
80 unsigned short closing_wait2; /* no longer used... */
81 unsigned char *iomem_base;
82 unsigned short iomem_reg_shift;
83 unsigned int port_high;
84 unsigned long iomap_base; /* cookie passed into ioremap */
90 #define _PATH_STDPATH "/usr/bin:/bin:/usr/sbin:/sbin"
93 #if defined CONFIG_FEATURE_INIT_COREDUMPS
95 * When a file named CORE_ENABLE_FLAG_FILE exists, setrlimit is called
96 * before processes are spawned to set core file size as unlimited.
97 * This is for debugging only. Don't use this is production, unless
98 * you want core dumps lying about....
100 #define CORE_ENABLE_FLAG_FILE "/.init_enable_core"
101 #include <sys/resource.h>
102 #include <sys/time.h>
105 #define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))
107 #define INITTAB "/etc/inittab" /* inittab file location */
109 #define INIT_SCRIPT "/etc/init.d/rcS" /* Default sysinit script. */
112 #define MAXENV 16 /* Number of env. vars */
114 #define CONSOLE_BUFF_SIZE 32
116 /* Allowed init action types */
117 #define SYSINIT 0x001
118 #define RESPAWN 0x002
119 #define ASKFIRST 0x004
122 #define CTRLALTDEL 0x020
123 #define SHUTDOWN 0x040
124 #define RESTART 0x080
126 /* A mapping between "inittab" action name strings and action type codes. */
127 struct init_action_type {
132 static const struct init_action_type actions[] = {
133 {"sysinit", SYSINIT},
134 {"respawn", RESPAWN},
135 {"askfirst", ASKFIRST},
138 {"ctrlaltdel", CTRLALTDEL},
139 {"shutdown", SHUTDOWN},
140 {"restart", RESTART},
144 /* Set up a linked list of init_actions, to be read from inittab */
147 char command[INIT_BUFFS_SIZE];
148 char terminal[CONSOLE_BUFF_SIZE];
149 struct init_action *next;
153 /* Static variables */
154 static struct init_action *init_action_list = NULL;
155 static char console[CONSOLE_BUFF_SIZE] = _PATH_CONSOLE;
157 #ifndef CONFIG_SYSLOGD
158 static char *log_console = VC_5;
160 static sig_atomic_t got_cont = 0;
161 static const int LOG = 0x1;
162 static const int CONSOLE = 0x2;
164 #if defined CONFIG_FEATURE_EXTRA_QUIET
165 static const int MAYBE_CONSOLE = 0x0;
167 #define MAYBE_CONSOLE CONSOLE
169 #ifndef RB_HALT_SYSTEM
170 static const int RB_HALT_SYSTEM = 0xcdef0123;
171 static const int RB_ENABLE_CAD = 0x89abcdef;
172 static const int RB_DISABLE_CAD = 0;
174 #define RB_POWER_OFF 0x4321fedc
175 static const int RB_AUTOBOOT = 0x01234567;
178 static const char * const environment[] = {
180 "PATH=" _PATH_STDPATH,
186 /* Function prototypes */
187 static void delete_init_action(struct init_action *a);
188 static int waitfor(const struct init_action *a);
189 static void halt_signal(int sig);
192 static void loop_forever(void)
198 /* Print a message to the specified device.
199 * Device may be bitwise-or'd from LOG | CONSOLE */
201 static inline void messageD(int device, const char *fmt, ...)
205 #define messageD message
207 static void message(int device, const char *fmt, ...)
208 __attribute__ ((format(printf, 2, 3)));
209 static void message(int device, const char *fmt, ...)
214 #ifndef CONFIG_SYSLOGD
215 static int log_fd = -1;
219 va_start(arguments, fmt);
220 l = vsnprintf(msg + 1, sizeof(msg) - 2, fmt, arguments) + 1;
223 #ifdef CONFIG_SYSLOGD
224 /* Log the message to syslogd */
226 /* don`t out "\r\n" */
227 openlog(bb_applet_name, 0, LOG_DAEMON);
228 syslog(LOG_INFO, "%s", msg);
238 /* Take full control of the log tty, and never close it.
239 * It's mine, all mine! Muhahahaha! */
241 if ((log_fd = device_open(log_console, O_RDWR | O_NONBLOCK | O_NOCTTY)) < 0) {
243 bb_error_msg("Bummer, can't write to log on %s!", log_console);
246 fcntl(log_fd, F_SETFD, FD_CLOEXEC);
249 if ((device & LOG) && (log_fd >= 0)) {
250 bb_full_write(log_fd, msg, l);
254 if (device & CONSOLE) {
255 int fd = device_open(_PATH_CONSOLE,
256 O_WRONLY | O_NOCTTY | O_NONBLOCK);
257 /* Always send console messages to /dev/console so people will see them. */
259 bb_full_write(fd, msg, l);
262 /* all descriptors may be closed */
264 bb_error_msg("Bummer, can't print: ");
265 va_start(arguments, fmt);
266 vfprintf(stderr, fmt, arguments);
273 /* Set terminal settings to reasonable defaults */
274 static void set_term(int fd)
280 /* set control chars */
281 tty.c_cc[VINTR] = 3; /* C-c */
282 tty.c_cc[VQUIT] = 28; /* C-\ */
283 tty.c_cc[VERASE] = 127; /* C-? */
284 tty.c_cc[VKILL] = 21; /* C-u */
285 tty.c_cc[VEOF] = 4; /* C-d */
286 tty.c_cc[VSTART] = 17; /* C-q */
287 tty.c_cc[VSTOP] = 19; /* C-s */
288 tty.c_cc[VSUSP] = 26; /* C-z */
290 /* use line dicipline 0 */
293 /* Make it be sane */
294 tty.c_cflag &= CBAUD | CBAUDEX | CSIZE | CSTOPB | PARENB | PARODD;
295 tty.c_cflag |= CREAD | HUPCL | CLOCAL;
299 tty.c_iflag = ICRNL | IXON | IXOFF;
302 tty.c_oflag = OPOST | ONLCR;
306 ISIG | ICANON | ECHO | ECHOE | ECHOK | ECHOCTL | ECHOKE | IEXTEN;
308 tcsetattr(fd, TCSANOW, &tty);
311 #ifdef CONFIG_FEATURE_INIT_SWAPON
312 /* How much memory does this machine have?
313 Units are kBytes to avoid overflow on 4GB machines */
314 static unsigned int check_free_memory(void)
317 unsigned int result, u, s = 10;
319 if (sysinfo(&info) != 0) {
320 bb_perror_msg("Error checking free memory");
324 /* Kernels 2.0.x and 2.2.x return info.mem_unit==0 with values in bytes.
325 * Kernels 2.4.0 return info.mem_unit in bytes. */
329 while ((u & 1) == 0 && s > 0) {
333 result = (info.totalram >> s) + (info.totalswap >> s);
334 if (((unsigned long long)result * (unsigned long long)u) > UINT_MAX) {
340 #endif /* CONFIG_FEATURE_INIT_SWAPON */
342 static void console_init(void)
347 struct serial_struct sr;
350 if ((s = getenv("CONSOLE")) != NULL || (s = getenv("console")) != NULL) {
351 safe_strncpy(console, s, sizeof(console));
353 /* sparc kernel supports console=tty[ab] parameter which is also
354 * passed to init, so catch it here */
355 /* remap tty[ab] to /dev/ttyS[01] */
356 if (strcmp(s, "ttya") == 0)
357 safe_strncpy(console, SC_0, sizeof(console));
358 else if (strcmp(s, "ttyb") == 0)
359 safe_strncpy(console, SC_1, sizeof(console));
362 /* 2.2 kernels: identify the real console backend and try to use it */
363 if (ioctl(0, TIOCGSERIAL, &sr) == 0) {
364 /* this is a serial console */
365 snprintf(console, sizeof(console) - 1, SC_FORMAT, sr.line);
366 } else if (ioctl(0, VT_GETSTATE, &vt) == 0) {
367 /* this is linux virtual tty */
368 snprintf(console, sizeof(console) - 1, VC_FORMAT, vt.v_active);
370 safe_strncpy(console, _PATH_CONSOLE, sizeof(console));
375 while ((fd = open(console, O_RDONLY | O_NONBLOCK)) < 0 && tried < 2) {
376 /* Can't open selected console -- try
377 logical system console and VT_MASTER */
378 safe_strncpy(console, (tried == 0 ? _PATH_CONSOLE : CURRENT_VC),
383 /* Perhaps we should panic here? */
384 #ifndef CONFIG_SYSLOGD
387 safe_strncpy(console, "/dev/null", sizeof(console));
390 /* check for serial console */
391 if (ioctl(fd, TIOCGSERIAL, &sr) == 0) {
392 /* Force the TERM setting to vt102 for serial console --
393 * if TERM is set to linux (the default) */
394 if (s == NULL || strcmp(s, "linux") == 0)
395 putenv("TERM=vt102");
396 #ifndef CONFIG_SYSLOGD
397 log_console = console;
401 putenv("TERM=linux");
405 messageD(LOG, "console=%s", console);
408 static void fixup_argv(int argc, char **argv, char *new_argv0)
412 /* Fix up argv[0] to be certain we claim to be init */
413 len = strlen(argv[0]);
414 memset(argv[0], 0, len);
415 safe_strncpy(argv[0], new_argv0, len + 1);
417 /* Wipe argv[1]-argv[N] so they don't clutter the ps listing */
420 memset(argv[len], 0, strlen(argv[len]));
425 static pid_t run(const struct init_action *a)
429 pid_t pid, pgrp, tmp_pid;
430 char *s, *tmpCmd, *cmd[INIT_BUFFS_SIZE], *cmdpath;
431 char buf[INIT_BUFFS_SIZE + 6]; /* INIT_BUFFS_SIZE+strlen("exec ")+1 */
432 sigset_t nmask, omask;
433 static const char press_enter[] =
434 #ifdef CUSTOMIZED_BANNER
435 #include CUSTOMIZED_BANNER
437 "\nPlease press Enter to activate this console. ";
439 /* Block sigchild while forking. */
441 sigaddset(&nmask, SIGCHLD);
442 sigprocmask(SIG_BLOCK, &nmask, &omask);
444 if ((pid = fork()) == 0) {
449 sigprocmask(SIG_SETMASK, &omask, NULL);
451 /* Reset signal handlers that were set by the parent process */
452 signal(SIGUSR1, SIG_DFL);
453 signal(SIGUSR2, SIG_DFL);
454 signal(SIGINT, SIG_DFL);
455 signal(SIGTERM, SIG_DFL);
456 signal(SIGHUP, SIG_DFL);
457 signal(SIGQUIT, SIG_DFL);
458 signal(SIGCONT, SIG_DFL);
459 signal(SIGSTOP, SIG_DFL);
460 signal(SIGTSTP, SIG_DFL);
462 /* Create a new session and make ourself the process
466 /* Open the new terminal device */
467 if ((device_open(a->terminal, O_RDWR)) < 0) {
468 if (stat(a->terminal, &sb) != 0) {
469 message(LOG | CONSOLE, "device '%s' does not exist.",
473 message(LOG | CONSOLE, "Bummer, can't open %s", a->terminal);
477 /* Make sure the terminal will act fairly normal for us */
479 /* Setup stdout, stderr for the new process so
480 * they point to the supplied terminal */
484 /* If the init Action requires us to wait, then force the
485 * supplied terminal to be the controlling tty. */
486 if (a->action & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) {
488 /* Now fork off another process to just hang around */
489 if ((pid = fork()) < 0) {
490 message(LOG | CONSOLE, "Can't fork!");
496 /* We are the parent -- wait till the child is done */
497 signal(SIGINT, SIG_IGN);
498 signal(SIGTSTP, SIG_IGN);
499 signal(SIGQUIT, SIG_IGN);
500 signal(SIGCHLD, SIG_DFL);
502 /* Wait for child to exit */
503 while ((tmp_pid = waitpid(pid, &junk, 0)) != pid) {
504 if (tmp_pid == -1 && errno == ECHILD) {
507 /* FIXME handle other errors */
510 /* See if stealing the controlling tty back is necessary */
512 if (pgrp != getpid())
515 /* Use a temporary process to steal the controlling tty. */
516 if ((pid = fork()) < 0) {
517 message(LOG | CONSOLE, "Can't fork!");
522 ioctl(0, TIOCSCTTY, 1);
525 while ((tmp_pid = waitpid(pid, &junk, 0)) != pid) {
526 if (tmp_pid < 0 && errno == ECHILD)
532 /* Now fall though to actually execute things */
535 /* See if any special /bin/sh requiring characters are present */
536 if (strpbrk(a->command, "~`!$^&*()=|\\{}[];\"'<>?") != NULL) {
537 cmd[0] = (char *)DEFAULT_SHELL;
539 cmd[2] = strcat(strcpy(buf, "exec "), a->command);
542 /* Convert command (char*) into cmd (char**, one word per string) */
543 strcpy(buf, a->command);
545 for (tmpCmd = buf, i = 0; (tmpCmd = strsep(&s, " \t")) != NULL;) {
546 if (*tmpCmd != '\0') {
557 Interactive shells want to see a dash in argv[0]. This
558 typically is handled by login, argv will be setup this
559 way if a dash appears at the front of the command path
563 if (*cmdpath == '-') {
565 /* skip over the dash */
568 /* find the last component in the command pathname */
569 s = bb_get_last_path_component(cmdpath);
571 /* make a new argv[0] */
572 if ((cmd[0] = malloc(strlen(s) + 2)) == NULL) {
573 message(LOG | CONSOLE, bb_msg_memory_exhausted);
577 strcpy(cmd[0] + 1, s);
581 #if !defined(__UCLIBC__) || defined(__ARCH_HAS_MMU__)
582 if (a->action & ASKFIRST) {
585 * Save memory by not exec-ing anything large (like a shell)
586 * before the user wants it. This is critical if swap is not
587 * enabled and the system has low memory. Generally this will
588 * be run on the second virtual console, and the first will
589 * be allowed to start a shell or whatever an init script
592 messageD(LOG, "Waiting for enter to start '%s'"
593 "(pid %d, terminal %s)\n",
594 cmdpath, getpid(), a->terminal);
595 bb_full_write(1, press_enter, sizeof(press_enter) - 1);
596 while(read(0, &c, 1) == 1 && c != '\n')
601 /* Log the process name and args */
602 message(LOG, "Starting pid %d, console %s: '%s'",
603 getpid(), a->terminal, cmdpath);
605 #if defined CONFIG_FEATURE_INIT_COREDUMPS
606 if (stat(CORE_ENABLE_FLAG_FILE, &sb) == 0) {
609 limit.rlim_cur = RLIM_INFINITY;
610 limit.rlim_max = RLIM_INFINITY;
611 setrlimit(RLIMIT_CORE, &limit);
615 /* Now run it. The new program will take over this PID,
616 * so nothing further in init.c should be run. */
619 /* We're still here? Some error happened. */
620 message(LOG | CONSOLE, "Bummer, could not run '%s': %m", cmdpath);
623 sigprocmask(SIG_SETMASK, &omask, NULL);
627 static int waitfor(const struct init_action *a)
634 wpid = waitpid(pid,&status,0);
637 if (wpid == -1 && errno == ECHILD) {
638 /* we missed its termination */
641 /* FIXME other errors should maybe trigger an error, but allow
642 * the program to continue */
647 /* Run all commands of a particular type */
648 static void run_actions(int action)
650 struct init_action *a, *tmp;
652 for (a = init_action_list; a; a = tmp) {
654 if (a->action == action) {
655 if (a->action & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) {
657 delete_init_action(a);
658 } else if (a->action & ONCE) {
660 delete_init_action(a);
661 } else if (a->action & (RESPAWN | ASKFIRST)) {
662 /* Only run stuff with pid==0. If they have
663 * a pid, that means it is still running */
673 static void init_reboot(unsigned long magic)
676 /* We have to fork here, since the kernel calls do_exit(0) in
677 * linux/kernel/sys.c, which can cause the machine to panic when
678 * the init process is killed.... */
679 if ((pid = fork()) == 0) {
683 waitpid (pid, NULL, 0);
686 static void shutdown_system(void)
688 sigset_t block_signals;
690 /* run everything to be run at "shutdown". This is done _prior_
691 * to killing everything, in case people wish to use scripts to
692 * shut things down gracefully... */
693 run_actions(SHUTDOWN);
695 /* first disable all our signals */
696 sigemptyset(&block_signals);
697 sigaddset(&block_signals, SIGHUP);
698 sigaddset(&block_signals, SIGQUIT);
699 sigaddset(&block_signals, SIGCHLD);
700 sigaddset(&block_signals, SIGUSR1);
701 sigaddset(&block_signals, SIGUSR2);
702 sigaddset(&block_signals, SIGINT);
703 sigaddset(&block_signals, SIGTERM);
704 sigaddset(&block_signals, SIGCONT);
705 sigaddset(&block_signals, SIGSTOP);
706 sigaddset(&block_signals, SIGTSTP);
707 sigprocmask(SIG_BLOCK, &block_signals, NULL);
709 /* Allow Ctrl-Alt-Del to reboot system. */
710 init_reboot(RB_ENABLE_CAD);
712 message(CONSOLE | LOG, "The system is going down NOW !!");
715 /* Send signals to every process _except_ pid 1 */
716 message(CONSOLE | LOG, "Sending SIGTERM to all processes.");
721 message(CONSOLE | LOG, "Sending SIGKILL to all processes.");
728 static void exec_signal(int sig)
730 struct init_action *a, *tmp;
731 sigset_t unblock_signals;
733 for (a = init_action_list; a; a = tmp) {
735 if (a->action & RESTART) {
740 /* unblock all signals, blocked in shutdown_system() */
741 sigemptyset(&unblock_signals);
742 sigaddset(&unblock_signals, SIGHUP);
743 sigaddset(&unblock_signals, SIGQUIT);
744 sigaddset(&unblock_signals, SIGCHLD);
745 sigaddset(&unblock_signals, SIGUSR1);
746 sigaddset(&unblock_signals, SIGUSR2);
747 sigaddset(&unblock_signals, SIGINT);
748 sigaddset(&unblock_signals, SIGTERM);
749 sigaddset(&unblock_signals, SIGCONT);
750 sigaddset(&unblock_signals, SIGSTOP);
751 sigaddset(&unblock_signals, SIGTSTP);
752 sigprocmask(SIG_UNBLOCK, &unblock_signals, NULL);
754 /* Close whatever files are open. */
759 /* Open the new terminal device */
760 if ((device_open(a->terminal, O_RDWR)) < 0) {
761 if (stat(a->terminal, &sb) != 0) {
762 message(LOG | CONSOLE, "device '%s' does not exist.", a->terminal);
764 message(LOG | CONSOLE, "Bummer, can't open %s", a->terminal);
766 halt_signal(SIGUSR1);
769 /* Make sure the terminal will act fairly normal for us */
771 /* Setup stdout, stderr on the supplied terminal */
775 messageD(CONSOLE | LOG, "Trying to re-exec %s", a->command);
776 execl(a->command, a->command, NULL);
778 message(CONSOLE | LOG, "exec of '%s' failed: %m",
782 init_reboot(RB_HALT_SYSTEM);
788 static void halt_signal(int sig)
791 message(CONSOLE | LOG,
793 /* Seems the s390 console is Wierd(tm). */
794 "The system is halted. You may reboot now."
796 "The system is halted. Press Reset or turn off power"
801 /* allow time for last message to reach serial console */
805 init_reboot(RB_POWER_OFF);
807 init_reboot(RB_HALT_SYSTEM);
812 static void reboot_signal(int sig)
815 message(CONSOLE | LOG, "Please stand by while rebooting the system.");
818 /* allow time for last message to reach serial console */
821 init_reboot(RB_AUTOBOOT);
826 static void ctrlaltdel_signal(int sig)
828 run_actions(CTRLALTDEL);
831 /* The SIGSTOP & SIGTSTP handler */
832 static void stop_handler(int sig)
834 int saved_errno = errno;
843 /* The SIGCONT handler */
844 static void cont_handler(int sig)
849 #endif /* ! DEBUG_INIT */
851 static void new_init_action(int action, const char *command, const char *cons)
853 struct init_action *new_action, *a, *last;
858 /* do not run entries if console device is not available */
859 if (access(cons, R_OK | W_OK))
861 if (strcmp(cons, "/dev/null") == 0 && (action & ASKFIRST))
864 new_action = calloc((size_t) (1), sizeof(struct init_action));
866 message(LOG | CONSOLE, "Memory allocation failure");
870 /* Append to the end of the list */
871 for (a = last = init_action_list; a; a = a->next) {
872 /* don't enter action if it's already in the list,
873 * but do overwrite existing actions */
874 if ((strcmp(a->command, command) == 0) &&
875 (strcmp(a->terminal, cons) ==0)) {
883 last->next = new_action;
885 init_action_list = new_action;
887 strcpy(new_action->command, command);
888 new_action->action = action;
889 strcpy(new_action->terminal, cons);
890 #if 0 /* calloc zeroed always */
893 messageD(LOG|CONSOLE, "command='%s' action='%d' terminal='%s'\n",
894 new_action->command, new_action->action, new_action->terminal);
897 static void delete_init_action(struct init_action *action)
899 struct init_action *a, *b = NULL;
901 for (a = init_action_list; a; b = a, a = a->next) {
904 init_action_list = a->next;
914 #ifdef CONFIG_FEATURE_INIT_SWAPON
915 /* Make sure there is enough memory to do something useful. *
916 * Calls "swapon -a" if needed so be sure /etc/fstab is present... */
917 static void check_memory(void)
921 if (check_free_memory() > 1000)
924 #if !defined(__UCLIBC__) || defined(__ARCH_HAS_MMU__)
925 if (stat("/etc/fstab", &statBuf) == 0) {
926 /* swapon -a requires /proc typically */
927 new_init_action(SYSINIT, "/bin/mount -t proc proc /proc", "");
928 /* Try to turn on swap */
929 new_init_action(SYSINIT, "/sbin/swapon -a", "");
930 run_actions(SYSINIT); /* wait and removing */
931 if (check_free_memory() < 1000)
939 message(CONSOLE, "Sorry, your computer does not have enough memory.");
943 # define check_memory()
944 #endif /* CONFIG_FEATURE_INIT_SWAPON */
946 /* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined,
947 * then parse_inittab() simply adds in some default
948 * actions(i.e., runs INIT_SCRIPT and then starts a pair
949 * of "askfirst" shells). If CONFIG_FEATURE_USE_INITTAB
950 * _is_ defined, but /etc/inittab is missing, this
951 * results in the same set of default behaviors.
953 static void parse_inittab(void)
955 #ifdef CONFIG_FEATURE_USE_INITTAB
957 char buf[INIT_BUFFS_SIZE], lineAsRead[INIT_BUFFS_SIZE];
958 char tmpConsole[CONSOLE_BUFF_SIZE];
959 char *id, *runlev, *action, *command, *eol;
960 const struct init_action_type *a = actions;
963 file = fopen(INITTAB, "r");
965 /* No inittab file -- set up some default behavior */
967 /* Reboot on Ctrl-Alt-Del */
968 new_init_action(CTRLALTDEL, "/sbin/reboot", "");
969 /* Umount all filesystems on halt/reboot */
970 new_init_action(SHUTDOWN, "/bin/umount -a -r", "");
971 #if !defined(__UCLIBC__) || defined(__ARCH_HAS_MMU__)
972 /* Swapoff on halt/reboot */
973 new_init_action(SHUTDOWN, "/sbin/swapoff -a", "");
975 /* Prepare to restart init when a HUP is received */
976 new_init_action(RESTART, "/sbin/init", "");
977 /* Askfirst shell on tty1-4 */
978 new_init_action(ASKFIRST, bb_default_login_shell, "");
979 new_init_action(ASKFIRST, bb_default_login_shell, VC_2);
980 new_init_action(ASKFIRST, bb_default_login_shell, VC_3);
981 new_init_action(ASKFIRST, bb_default_login_shell, VC_4);
983 new_init_action(SYSINIT, INIT_SCRIPT, "");
986 #ifdef CONFIG_FEATURE_USE_INITTAB
989 while (fgets(buf, INIT_BUFFS_SIZE, file) != NULL) {
990 /* Skip leading spaces */
991 for (id = buf; *id == ' ' || *id == '\t'; id++);
993 /* Skip the line if it's a comment */
994 if (*id == '#' || *id == '\n')
997 /* Trim the trailing \n */
998 eol = strrchr(id, '\n');
1002 /* Keep a copy around for posterity's sake (and error msgs) */
1003 strcpy(lineAsRead, buf);
1005 /* Separate the ID field from the runlevels */
1006 runlev = strchr(id, ':');
1007 if (runlev == NULL || *(runlev + 1) == '\0') {
1008 message(LOG | CONSOLE, "Bad inittab entry: %s", lineAsRead);
1015 /* Separate the runlevels from the action */
1016 action = strchr(runlev, ':');
1017 if (action == NULL || *(action + 1) == '\0') {
1018 message(LOG | CONSOLE, "Bad inittab entry: %s", lineAsRead);
1025 /* Separate the action from the command */
1026 command = strchr(action, ':');
1027 if (command == NULL || *(command + 1) == '\0') {
1028 message(LOG | CONSOLE, "Bad inittab entry: %s", lineAsRead);
1035 /* Ok, now process it */
1036 for (a = actions; a->name != 0; a++) {
1037 if (strcmp(a->name, action) == 0) {
1039 if(strncmp(id, "/dev/", 5) == 0)
1041 strcpy(tmpConsole, "/dev/");
1042 safe_strncpy(tmpConsole + 5, id,
1043 CONSOLE_BUFF_SIZE - 5);
1046 new_init_action(a->action, command, id);
1051 /* Choke on an unknown action */
1052 message(LOG | CONSOLE, "Bad inittab entry: %s", lineAsRead);
1057 #endif /* CONFIG_FEATURE_USE_INITTAB */
1060 #ifdef CONFIG_FEATURE_USE_INITTAB
1061 static void reload_signal(int sig)
1063 struct init_action *a, *tmp;
1065 message(LOG, "Reloading /etc/inittab");
1067 /* disable old entrys */
1068 for (a = init_action_list; a; a = a->next ) {
1074 /* remove unused entrys */
1075 for (a = init_action_list; a; a = tmp) {
1077 if (a->action & (ONCE | SYSINIT | WAIT ) &&
1079 delete_init_action(a);
1082 run_actions(RESPAWN);
1085 #endif /* CONFIG_FEATURE_USE_INITTAB */
1087 extern int init_main(int argc, char **argv)
1089 struct init_action *a;
1093 if (argc > 1 && !strcmp(argv[1], "-q")) {
1094 return kill_init(SIGHUP);
1097 /* Expect to be invoked as init with PID=1 or be invoked as linuxrc */
1099 #ifdef CONFIG_FEATURE_INITRD
1100 && strstr(bb_applet_name, "linuxrc") == NULL
1105 /* Set up sig handlers -- be sure to
1106 * clear all of these in run() */
1107 signal(SIGHUP, exec_signal);
1108 signal(SIGQUIT, exec_signal);
1109 signal(SIGUSR1, halt_signal);
1110 signal(SIGUSR2, halt_signal);
1111 signal(SIGINT, ctrlaltdel_signal);
1112 signal(SIGTERM, reboot_signal);
1113 signal(SIGCONT, cont_handler);
1114 signal(SIGSTOP, stop_handler);
1115 signal(SIGTSTP, stop_handler);
1117 /* Turn off rebooting via CTL-ALT-DEL -- we get a
1118 * SIGINT on CAD so we can shut things down gracefully... */
1119 init_reboot(RB_DISABLE_CAD);
1122 /* Figure out where the default console should be */
1125 /* Close whatever files are open, and reset the console. */
1130 if (device_open(console, O_RDWR | O_NOCTTY) == 0) {
1138 const char * const *e;
1139 /* Make sure environs is set to something sane */
1140 for(e = environment; *e; e++)
1141 putenv((char *) *e);
1144 message(MAYBE_CONSOLE | LOG, "init started: %s", bb_msg_full_version);
1146 /* Make sure there is enough memory to do something useful. */
1149 /* Check if we are supposed to be in single user mode */
1150 if (argc > 1 && (!strcmp(argv[1], "single") ||
1151 !strcmp(argv[1], "-s") || !strcmp(argv[1], "1"))) {
1152 /* Start a shell on console */
1153 new_init_action(RESPAWN, bb_default_login_shell, "");
1155 /* Not in single user mode -- see what inittab says */
1157 /* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined,
1158 * then parse_inittab() simply adds in some default
1159 * actions(i.e., runs INIT_SCRIPT and then starts a pair
1160 * of "askfirst" shells */
1164 /* Make the command line just say "init" -- thats all, nothing else */
1165 fixup_argv(argc, argv, "init");
1167 /* Now run everything that needs to be run */
1169 /* First run the sysinit command */
1170 run_actions(SYSINIT);
1172 /* Next run anything that wants to block */
1175 /* Next run anything to be run only once */
1178 #ifdef CONFIG_FEATURE_USE_INITTAB
1179 /* Redefine SIGHUP to reread /etc/inittab */
1180 signal(SIGHUP, reload_signal);
1182 signal(SIGHUP, SIG_IGN);
1183 #endif /* CONFIG_FEATURE_USE_INITTAB */
1186 /* Now run the looping stuff for the rest of forever */
1188 /* run the respawn stuff */
1189 run_actions(RESPAWN);
1191 /* run the askfirst stuff */
1192 run_actions(ASKFIRST);
1194 /* Don't consume all CPU time -- sleep a bit */
1197 /* Wait for a child process to exit */
1198 wpid = wait(&status);
1200 /* Find out who died and clean up their corpse */
1201 for (a = init_action_list; a; a = a->next) {
1202 if (a->pid == wpid) {
1203 /* Set the pid to 0 so that the process gets
1204 * restarted by run_actions() */
1206 message(LOG, "Process '%s' (pid %d) exited. "
1207 "Scheduling it for restart.",
1211 /* see if anyone else is waiting to be reaped */
1212 wpid = waitpid (-1, &status, WNOHANG);
1219 c-file-style: "linux"