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) 1999-2002 by Erik Andersen <andersee@debian.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/mount.h>
43 #include <sys/types.h>
47 # include <sys/syslog.h>
50 #if defined(__UCLIBC__) && !defined(__UCLIBC_HAS_MMU__)
54 #define INIT_BUFFS_SIZE 256
56 /* From <linux/vt.h> */
58 unsigned short v_active; /* active vt */
59 unsigned short v_signal; /* signal to send */
60 unsigned short v_state; /* vt bitmask */
62 static const int VT_GETSTATE = 0x5603; /* get global vt state info */
64 /* From <linux/serial.h> */
65 struct serial_struct {
74 unsigned short close_delay;
75 char reserved_char[2];
77 unsigned short closing_wait; /* time to wait before closing */
78 unsigned short closing_wait2; /* no longer used... */
83 #if (__GNU_LIBRARY__ > 5) || defined(__dietlibc__)
84 #include <sys/reboot.h>
85 #define init_reboot(magic) reboot(magic)
87 #define init_reboot(magic) reboot(0xfee1dead, 672274793, magic)
91 #define _PATH_STDPATH "/usr/bin:/bin:/usr/sbin:/sbin"
94 #if defined CONFIG_FEATURE_INIT_COREDUMPS
96 * When a file named CORE_ENABLE_FLAG_FILE exists, setrlimit is called
97 * before processes are spawned to set core file size as unlimited.
98 * This is for debugging only. Don't use this is production, unless
99 * you want core dumps lying about....
101 #define CORE_ENABLE_FLAG_FILE "/.init_enable_core"
102 #include <sys/resource.h>
103 #include <sys/time.h>
106 #define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))
108 #if __GNU_LIBRARY__ > 5
109 #include <sys/kdaemon.h>
111 extern int bdflush(int func, long int data);
114 #define SHELL "/bin/sh" /* Default shell */
115 #define LOGIN_SHELL "-" SHELL /* Default login shell */
116 #define INITTAB "/etc/inittab" /* inittab file location */
118 #define INIT_SCRIPT "/etc/init.d/rcS" /* Default sysinit script. */
121 #define MAXENV 16 /* Number of env. vars */
123 /* Allowed init action types */
124 #define SYSINIT 0x001
125 #define RESPAWN 0x002
126 #define ASKFIRST 0x004
129 #define CTRLALTDEL 0x020
130 #define SHUTDOWN 0x040
131 #define RESTART 0x080
133 /* A mapping between "inittab" action name strings and action type codes. */
134 struct init_action_type {
139 static const struct init_action_type actions[] = {
140 {"sysinit", SYSINIT},
141 {"respawn", RESPAWN},
142 {"askfirst", ASKFIRST},
145 {"ctrlaltdel", CTRLALTDEL},
146 {"shutdown", SHUTDOWN},
147 {"restart", RESTART},
151 /* Set up a linked list of init_actions, to be read from inittab */
154 char command[INIT_BUFFS_SIZE];
155 char terminal[INIT_BUFFS_SIZE];
156 struct init_action *next;
160 /* Static variables */
161 static struct init_action *init_action_list = NULL;
162 static int kernelVersion = 0;
163 static char termType[32] = "TERM=linux";
164 static char console[32] = _PATH_CONSOLE;
166 #ifndef CONFIG_SYSLOGD
167 static char *log = VC_5;
169 static sig_atomic_t got_cont = 0;
170 static const int LOG = 0x1;
171 static const int CONSOLE = 0x2;
173 #if defined CONFIG_FEATURE_EXTRA_QUIET
174 static const int MAYBE_CONSOLE = 0x0;
176 #define MAYBE_CONSOLE CONSOLE
178 #ifndef RB_HALT_SYSTEM
179 static const int RB_HALT_SYSTEM = 0xcdef0123;
180 static const int RB_ENABLE_CAD = 0x89abcdef;
181 static const int RB_DISABLE_CAD = 0;
183 #define RB_POWER_OFF 0x4321fedc
184 static const int RB_AUTOBOOT = 0x01234567;
187 /* Function prototypes */
188 static void delete_init_action(struct init_action *a);
189 static int waitfor(struct init_action *a);
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 messageND(int device, char *fmt, ...)
205 #define messageND message
207 static void message(int device, char *fmt, ...)
208 __attribute__ ((format(printf, 2, 3)));
209 static void message(int device, char *fmt, ...)
214 #ifdef CONFIG_SYSLOGD
216 /* Log the message to syslogd */
220 va_start(arguments, fmt);
221 vsnprintf(msg, sizeof(msg), fmt, arguments);
223 syslog_msg(LOG_USER, LOG_INFO, msg);
226 static int log_fd = -1;
228 /* Take full control of the log tty, and never close it.
229 * It's mine, all mine! Muhahahaha! */
231 if ((log_fd = device_open(log, O_RDWR | O_NDELAY)) < 0) {
233 fprintf(stderr, "Bummer, can't write to log on %s!\n", log);
237 if ((device & LOG) && (log_fd >= 0)) {
238 va_start(arguments, fmt);
239 vdprintf(log_fd, fmt, arguments);
244 if (device & CONSOLE) {
245 /* Always send console messages to /dev/console so people will see them. */
247 device_open(_PATH_CONSOLE,
248 O_WRONLY | O_NOCTTY | O_NDELAY)) >= 0) {
249 va_start(arguments, fmt);
250 vdprintf(fd, fmt, arguments);
254 fprintf(stderr, "Bummer, can't print: ");
255 va_start(arguments, fmt);
256 vfprintf(stderr, fmt, arguments);
262 /* Set terminal settings to reasonable defaults */
263 static void set_term(int fd)
269 /* set control chars */
270 tty.c_cc[VINTR] = 3; /* C-c */
271 tty.c_cc[VQUIT] = 28; /* C-\ */
272 tty.c_cc[VERASE] = 127; /* C-? */
273 tty.c_cc[VKILL] = 21; /* C-u */
274 tty.c_cc[VEOF] = 4; /* C-d */
275 tty.c_cc[VSTART] = 17; /* C-q */
276 tty.c_cc[VSTOP] = 19; /* C-s */
277 tty.c_cc[VSUSP] = 26; /* C-z */
279 /* use line dicipline 0 */
282 /* Make it be sane */
283 tty.c_cflag &= CBAUD | CBAUDEX | CSIZE | CSTOPB | PARENB | PARODD;
284 tty.c_cflag |= CREAD | HUPCL | CLOCAL;
288 tty.c_iflag = ICRNL | IXON | IXOFF;
291 tty.c_oflag = OPOST | ONLCR;
295 ISIG | ICANON | ECHO | ECHOE | ECHOK | ECHOCTL | ECHOKE | IEXTEN;
297 tcsetattr(fd, TCSANOW, &tty);
300 /* How much memory does this machine have?
301 Units are kBytes to avoid overflow on 4GB machines */
302 static int check_free_memory(void)
305 unsigned int result, u, s = 10;
307 if (sysinfo(&info) != 0) {
308 perror_msg("Error checking free memory");
312 /* Kernels 2.0.x and 2.2.x return info.mem_unit==0 with values in bytes.
313 * Kernels 2.4.0 return info.mem_unit in bytes. */
317 while ((u & 1) == 0 && s > 0) {
321 result = (info.totalram >> s) + (info.totalswap >> s);
328 static void console_init(void)
331 int tried_devcons = 0;
332 int tried_vtprimary = 0;
334 struct serial_struct sr;
337 if ((s = getenv("TERM")) != NULL) {
338 snprintf(termType, sizeof(termType) - 1, "TERM=%s", s);
341 if ((s = getenv("CONSOLE")) != NULL) {
342 safe_strncpy(console, s, sizeof(console));
345 /* sparc kernel supports console=tty[ab] parameter which is also
346 * passed to init, so catch it here */
347 else if ((s = getenv("console")) != NULL) {
348 /* remap tty[ab] to /dev/ttyS[01] */
349 if (strcmp(s, "ttya") == 0)
350 safe_strncpy(console, SC_0, sizeof(console));
351 else if (strcmp(s, "ttyb") == 0)
352 safe_strncpy(console, SC_1, sizeof(console));
356 /* 2.2 kernels: identify the real console backend and try to use it */
357 if (ioctl(0, TIOCGSERIAL, &sr) == 0) {
358 /* this is a serial console */
359 snprintf(console, sizeof(console) - 1, SC_FORMAT, sr.line);
360 } else if (ioctl(0, VT_GETSTATE, &vt) == 0) {
361 /* this is linux virtual tty */
362 snprintf(console, sizeof(console) - 1, VC_FORMAT, vt.v_active);
364 safe_strncpy(console, _PATH_CONSOLE, sizeof(console));
369 while ((fd = open(console, O_RDONLY | O_NONBLOCK)) < 0) {
370 /* Can't open selected console -- try /dev/console */
371 if (!tried_devcons) {
373 safe_strncpy(console, _PATH_CONSOLE, sizeof(console));
376 /* Can't open selected console -- try vt1 */
377 if (!tried_vtprimary) {
379 safe_strncpy(console, VC_1, sizeof(console));
385 /* Perhaps we should panic here? */
386 safe_strncpy(console, "/dev/null", sizeof(console));
388 /* check for serial console */
389 if (ioctl(0, TIOCGSERIAL, &sr) == 0) {
390 /* Force the TERM setting to vt102 for serial console --
391 * if TERM is set to linux (the default) */
392 if (strcmp(termType, "TERM=linux") == 0)
393 safe_strncpy(termType, "TERM=vt102", sizeof(termType));
397 message(LOG, "console=%s\n", console);
400 static void fixup_argv(int argc, char **argv, char *new_argv0)
404 /* Fix up argv[0] to be certain we claim to be init */
405 len = strlen(argv[0]);
406 memset(argv[0], 0, len);
407 safe_strncpy(argv[0], new_argv0, len + 1);
409 /* Wipe argv[1]-argv[N] so they don't clutter the ps listing */
412 memset(argv[len], 0, strlen(argv[len]));
417 /* Make sure there is enough memory to do something useful. *
418 * Calls "swapon -a" if needed so be sure /etc/fstab is present... */
419 static void check_memory(void)
423 if (check_free_memory() > 1000)
426 #if !defined(__UCLIBC__) || defined(__UCLIBC_HAS_MMU__)
427 if (stat("/etc/fstab", &statBuf) == 0) {
428 /* swapon -a requires /proc typically */
429 system("/bin/mount -t proc proc /proc");
430 /* Try to turn on swap */
431 system("/sbin/swapon -a");
432 if (check_free_memory() < 1000)
440 message(CONSOLE, "\rSorry, your computer does not have enough memory.\n");
444 static pid_t run(struct init_action *a)
448 pid_t pid, pgrp, tmp_pid;
449 char *s, *tmpCmd, *cmd[INIT_BUFFS_SIZE], *cmdpath;
450 char buf[INIT_BUFFS_SIZE + 6]; /* INIT_BUFFS_SIZE+strlen("exec ")+1 */
451 sigset_t nmask, omask;
452 char *environment[MAXENV + 1] = {
455 "PATH=" _PATH_STDPATH,
460 static const char press_enter[] =
461 #ifdef CUSTOMIZED_BANNER
462 #include CUSTOMIZED_BANNER
464 "\nPlease press Enter to activate this console. ";
466 /* inherit environment to the child, merging our values -andy */
467 for (i = 0; environ[i]; i++) {
468 for (j = 0; environment[j]; j++) {
469 s = strchr(environment[j], '=');
470 if (!strncmp(environ[i], environment[j], s - environment[j]))
473 if (!environment[j]) {
474 environment[j++] = environ[i];
475 environment[j] = NULL;
479 /* Block sigchild while forking. */
481 sigaddset(&nmask, SIGCHLD);
482 sigprocmask(SIG_BLOCK, &nmask, &omask);
484 if ((pid = fork()) == 0) {
489 sigprocmask(SIG_SETMASK, &omask, NULL);
491 /* Reset signal handlers that were set by the parent process */
492 signal(SIGUSR1, SIG_DFL);
493 signal(SIGUSR2, SIG_DFL);
494 signal(SIGINT, SIG_DFL);
495 signal(SIGTERM, SIG_DFL);
496 signal(SIGHUP, SIG_DFL);
497 signal(SIGCONT, SIG_DFL);
498 signal(SIGSTOP, SIG_DFL);
499 signal(SIGTSTP, SIG_DFL);
501 /* Create a new session and make ourself the process
502 * group leader for non-interactive jobs */
503 if ((a->action & (RESPAWN)) == 0)
506 /* Open the new terminal device */
507 if ((device_open(a->terminal, O_RDWR | O_NOCTTY)) < 0) {
508 if (stat(a->terminal, &sb) != 0) {
509 message(LOG | CONSOLE, "\rdevice '%s' does not exist.\n",
513 message(LOG | CONSOLE, "\rBummer, can't open %s\n", a->terminal);
517 /* Non-interactive jobs should not get a controling tty */
518 if ((a->action & (RESPAWN)) == 0)
519 (void) ioctl(0, TIOCSCTTY, 0);
521 /* Make sure the terminal will act fairly normal for us */
523 /* Setup stdout, stderr for the new process so
524 * they point to the supplied terminal */
528 /* For interactive jobs, create a new session
529 * and become the process group leader */
530 if ((a->action & (RESPAWN)))
533 /* If the init Action requires us to wait, then force the
534 * supplied terminal to be the controlling tty. */
535 if (a->action & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) {
537 /* Now fork off another process to just hang around */
538 if ((pid = fork()) < 0) {
539 message(LOG | CONSOLE, "Can't fork!\n");
545 /* We are the parent -- wait till the child is done */
546 signal(SIGINT, SIG_IGN);
547 signal(SIGTSTP, SIG_IGN);
548 signal(SIGQUIT, SIG_IGN);
549 signal(SIGCHLD, SIG_DFL);
551 /* Wait for child to exit */
552 while ((tmp_pid = waitpid(pid, &junk, 0)) != pid);
554 /* See if stealing the controlling tty back is necessary */
556 if (pgrp != getpid())
559 /* Use a temporary process to steal the controlling tty. */
560 if ((pid = fork()) < 0) {
561 message(LOG | CONSOLE, "\rCan't fork!\n");
566 ioctl(0, TIOCSCTTY, 1);
569 while ((tmp_pid = waitpid(pid, &junk, 0)) != pid) {
570 if (tmp_pid < 0 && errno == ECHILD)
576 /* Now fall though to actually execute things */
579 /* See if any special /bin/sh requiring characters are present */
580 if (strpbrk(a->command, "~`!$^&*()=|\\{}[];\"'<>?") != NULL) {
583 strcat(strcpy(buf, "exec "), a->command);
587 /* Convert command (char*) into cmd (char**, one word per string) */
588 strcpy(buf, a->command);
590 for (tmpCmd = buf, i = 0; (tmpCmd = strsep(&s, " \t")) != NULL;) {
591 if (*tmpCmd != '\0') {
602 Interactive shells want to see a dash in argv[0]. This
603 typically is handled by login, argv will be setup this
604 way if a dash appears at the front of the command path
608 if (*cmdpath == '-') {
610 /* skip over the dash */
613 /* find the last component in the command pathname */
614 s = get_last_path_component(cmdpath);
616 /* make a new argv[0] */
617 if ((cmd[0] = malloc(strlen(s) + 2)) == NULL) {
618 message(LOG | CONSOLE, "malloc failed");
622 strcpy(cmd[0] + 1, s);
626 if (a->action & ASKFIRST) {
628 * Save memory by not exec-ing anything large (like a shell)
629 * before the user wants it. This is critical if swap is not
630 * enabled and the system has low memory. Generally this will
631 * be run on the second virtual console, and the first will
632 * be allowed to start a shell or whatever an init script
636 "Waiting for enter to start '%s' (pid %d, terminal %s)\n",
637 cmdpath, getpid(), a->terminal);
638 write(fileno(stdout), press_enter, sizeof(press_enter) - 1);
642 /* Log the process name and args */
643 messageND(LOG, "Starting pid %d, console %s: '%s'\n",
644 getpid(), a->terminal, cmdpath);
646 #if defined CONFIG_FEATURE_INIT_COREDUMPS
647 if (stat(CORE_ENABLE_FLAG_FILE, &sb) == 0) {
650 limit.rlim_cur = RLIM_INFINITY;
651 limit.rlim_max = RLIM_INFINITY;
652 setrlimit(RLIMIT_CORE, &limit);
656 /* Now run it. The new program will take over this PID,
657 * so nothing further in init.c should be run. */
658 execve(cmdpath, cmd, environment);
660 /* We're still here? Some error happened. */
661 message(LOG | CONSOLE, "\rBummer, could not run '%s': %s\n", cmdpath,
665 sigprocmask(SIG_SETMASK, &omask, NULL);
669 static int waitfor(struct init_action *a)
676 wpid = wait(&status);
677 if (wpid > 0 && wpid != pid) {
686 /* Run all commands of a particular type */
687 static void run_actions(int action)
689 struct init_action *a, *tmp;
691 for (a = init_action_list; a; a = tmp) {
693 if (a->action == action) {
695 action & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) {
697 delete_init_action(a);
698 } else if (a->action & ONCE) {
700 delete_init_action(a);
701 } else if (a->action & (RESPAWN | ASKFIRST)) {
702 /* Only run stuff with pid==0. If they have
703 * a pid, that means it is still running */
714 static void shutdown_system(void)
716 sigset_t block_signals;
718 /* run everything to be run at "shutdown". This is done _prior_
719 * to killing everything, in case people wish to use scripts to
720 * shut things down gracefully... */
721 run_actions(SHUTDOWN);
723 /* first disable all our signals */
724 sigemptyset(&block_signals);
725 sigaddset(&block_signals, SIGHUP);
726 sigaddset(&block_signals, SIGCHLD);
727 sigaddset(&block_signals, SIGUSR1);
728 sigaddset(&block_signals, SIGUSR2);
729 sigaddset(&block_signals, SIGINT);
730 sigaddset(&block_signals, SIGTERM);
731 sigaddset(&block_signals, SIGCONT);
732 sigaddset(&block_signals, SIGSTOP);
733 sigaddset(&block_signals, SIGTSTP);
734 sigprocmask(SIG_BLOCK, &block_signals, NULL);
736 /* Allow Ctrl-Alt-Del to reboot system. */
737 init_reboot(RB_ENABLE_CAD);
739 message(CONSOLE | LOG, "\n\rThe system is going down NOW !!\n");
742 /* Send signals to every process _except_ pid 1 */
743 message(CONSOLE | LOG, "\rSending SIGTERM to all processes.\n");
748 message(CONSOLE | LOG, "\rSending SIGKILL to all processes.\n");
753 if (kernelVersion > 0 && kernelVersion <= KERNEL_VERSION(2, 2, 11)) {
754 /* bdflush, kupdate not needed for kernels >2.2.11 */
760 static void exec_signal(int sig)
762 struct init_action *a, *tmp;
763 sigset_t unblock_signals;
765 for (a = init_action_list; a; a = tmp) {
767 if (a->action & RESTART) {
770 /* unblock all signals, blocked in shutdown_system() */
771 sigemptyset(&unblock_signals);
772 sigaddset(&unblock_signals, SIGHUP);
773 sigaddset(&unblock_signals, SIGCHLD);
774 sigaddset(&unblock_signals, SIGUSR1);
775 sigaddset(&unblock_signals, SIGUSR2);
776 sigaddset(&unblock_signals, SIGINT);
777 sigaddset(&unblock_signals, SIGTERM);
778 sigaddset(&unblock_signals, SIGCONT);
779 sigaddset(&unblock_signals, SIGSTOP);
780 sigaddset(&unblock_signals, SIGTSTP);
781 sigprocmask(SIG_UNBLOCK, &unblock_signals, NULL);
783 message(CONSOLE | LOG, "\rTrying to re-exec %s\n", a->command);
784 execl(a->command, a->command, NULL);
786 message(CONSOLE | LOG, "\rexec of '%s' failed: %s\n",
787 a->command, strerror(errno));
790 init_reboot(RB_HALT_SYSTEM);
796 static void halt_signal(int sig)
799 message(CONSOLE | LOG,
801 /* Seems the s390 console is Wierd(tm). */
802 "\rThe system is halted. You may reboot now.\n"
804 "\rThe system is halted. Press Reset or turn off power\n"
809 /* allow time for last message to reach serial console */
812 if (sig == SIGUSR2 && kernelVersion >= KERNEL_VERSION(2, 2, 0))
813 init_reboot(RB_POWER_OFF);
815 init_reboot(RB_HALT_SYSTEM);
820 static void reboot_signal(int sig)
823 message(CONSOLE | LOG, "\rPlease stand by while rebooting the system.\n");
826 /* allow time for last message to reach serial console */
829 init_reboot(RB_AUTOBOOT);
834 static void ctrlaltdel_signal(int sig)
836 run_actions(CTRLALTDEL);
839 /* The SIGSTOP & SIGTSTP handler */
840 static void stop_handler(int sig)
842 int saved_errno = errno;
851 /* The SIGCONT handler */
852 static void cont_handler(int sig)
857 #endif /* ! DEBUG_INIT */
859 static void new_init_action(int action, char *command, char *cons)
861 struct init_action *new_action, *a;
866 /* do not run entries if console device is not available */
867 if (access(cons, R_OK | W_OK))
869 if (strcmp(cons, "/dev/null") == 0 && (action & ASKFIRST))
872 new_action = calloc((size_t) (1), sizeof(struct init_action));
874 message(LOG | CONSOLE, "\rMemory allocation failure\n");
878 /* Append to the end of the list */
879 for (a = init_action_list; a && a->next; a = a->next);
881 a->next = new_action;
883 init_action_list = new_action;
885 strcpy(new_action->command, command);
886 new_action->action = action;
887 strcpy(new_action->terminal, cons);
889 /* message(LOG|CONSOLE, "command='%s' action='%d' terminal='%s'\n",
890 new_action->command, new_action->action, new_action->terminal); */
893 static void delete_init_action(struct init_action *action)
895 struct init_action *a, *b = NULL;
897 for (a = init_action_list; a; b = a, a = a->next) {
900 init_action_list = a->next;
910 /* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined,
911 * then parse_inittab() simply adds in some default
912 * actions(i.e., runs INIT_SCRIPT and then starts a pair
913 * of "askfirst" shells). If CONFIG_FEATURE_USE_INITTAB
914 * _is_ defined, but /etc/inittab is missing, this
915 * results in the same set of default behaviors.
917 static void parse_inittab(void)
919 #ifdef CONFIG_FEATURE_USE_INITTAB
921 char buf[INIT_BUFFS_SIZE], lineAsRead[INIT_BUFFS_SIZE],
922 tmpConsole[INIT_BUFFS_SIZE];
923 char *id, *runlev, *action, *command, *eol;
924 const struct init_action_type *a = actions;
928 file = fopen(INITTAB, "r");
930 /* No inittab file -- set up some default behavior */
932 /* Reboot on Ctrl-Alt-Del */
933 new_init_action(CTRLALTDEL, "/sbin/reboot", console);
934 /* Umount all filesystems on halt/reboot */
935 new_init_action(SHUTDOWN, "/bin/umount -a -r", console);
936 #if !defined(__UCLIBC__) || defined(__UCLIBC_HAS_MMU__)
937 /* Swapoff on halt/reboot */
938 new_init_action(SHUTDOWN, "/sbin/swapoff -a", console);
940 /* Prepare to restart init when a HUP is received */
941 new_init_action(RESTART, "/sbin/init", console);
942 /* Askfirst shell on tty1-4 */
943 new_init_action(ASKFIRST, LOGIN_SHELL, console);
944 new_init_action(ASKFIRST, LOGIN_SHELL, VC_2);
945 new_init_action(ASKFIRST, LOGIN_SHELL, VC_3);
946 new_init_action(ASKFIRST, LOGIN_SHELL, VC_4);
948 new_init_action(SYSINIT, INIT_SCRIPT, console);
951 #ifdef CONFIG_FEATURE_USE_INITTAB
954 while (fgets(buf, INIT_BUFFS_SIZE, file) != NULL) {
956 /* Skip leading spaces */
957 for (id = buf; *id == ' ' || *id == '\t'; id++);
959 /* Skip the line if it's a comment */
960 if (*id == '#' || *id == '\n')
963 /* Trim the trailing \n */
964 eol = strrchr(id, '\n');
968 /* Keep a copy around for posterity's sake (and error msgs) */
969 strcpy(lineAsRead, buf);
971 /* Separate the ID field from the runlevels */
972 runlev = strchr(id, ':');
973 if (runlev == NULL || *(runlev + 1) == '\0') {
974 message(LOG | CONSOLE, "\rBad inittab entry: %s\n", lineAsRead);
981 /* Separate the runlevels from the action */
982 action = strchr(runlev, ':');
983 if (action == NULL || *(action + 1) == '\0') {
984 message(LOG | CONSOLE, "\rBad inittab entry: %s\n", lineAsRead);
991 /* Separate the action from the command */
992 command = strchr(action, ':');
993 if (command == NULL || *(command + 1) == '\0') {
994 message(LOG | CONSOLE, "\rBad inittab entry: %s\n", lineAsRead);
1001 /* Ok, now process it */
1003 while (a->name != 0) {
1004 if (strcmp(a->name, action) == 0) {
1006 strcpy(tmpConsole, "/dev/");
1007 strncat(tmpConsole, id, INIT_BUFFS_SIZE - 6);
1010 new_init_action(a->action, command, id);
1015 if (foundIt == TRUE)
1018 /* Choke on an unknown action */
1019 message(LOG | CONSOLE, "\rBad inittab entry: %s\n", lineAsRead);
1024 #endif /* CONFIG_FEATURE_USE_INITTAB */
1029 extern int init_main(int argc, char **argv)
1031 struct init_action *a;
1035 if (argc > 1 && !strcmp(argv[1], "-q")) {
1036 /* don't assume init's pid == 1 */
1037 long *pid = find_pid_by_name("init");
1039 if (!pid || *pid <= 0) {
1040 pid = find_pid_by_name("linuxrc");
1041 if (!pid || *pid <= 0)
1042 error_msg_and_die("no process killed");
1048 /* Expect to be invoked as init with PID=1 or be invoked as linuxrc */
1050 #ifdef CONFIG_FEATURE_INITRD
1051 && strstr(applet_name, "linuxrc") == NULL
1056 /* Set up sig handlers -- be sure to
1057 * clear all of these in run() */
1058 signal(SIGHUP, exec_signal);
1059 signal(SIGUSR1, halt_signal);
1060 signal(SIGUSR2, halt_signal);
1061 signal(SIGINT, ctrlaltdel_signal);
1062 signal(SIGTERM, reboot_signal);
1063 signal(SIGCONT, cont_handler);
1064 signal(SIGSTOP, stop_handler);
1065 signal(SIGTSTP, stop_handler);
1066 signal(SIGCHLD, SIG_IGN);
1068 /* Turn off rebooting via CTL-ALT-DEL -- we get a
1069 * SIGINT on CAD so we can shut things down gracefully... */
1070 init_reboot(RB_DISABLE_CAD);
1073 /* Figure out what kernel this is running */
1074 kernelVersion = get_kernel_revision();
1076 /* Figure out where the default console should be */
1079 /* Close whatever files are open, and reset the console. */
1084 if (device_open(console, O_RDWR | O_NOCTTY) == 0) {
1092 /* Make sure PATH is set to something sane */
1093 putenv("PATH=" _PATH_STDPATH);
1096 message(MAYBE_CONSOLE | LOG, "\rinit started: %s\n", full_version);
1098 /* Make sure there is enough memory to do something useful. */
1101 /* Check if we are supposed to be in single user mode */
1102 if (argc > 1 && (!strcmp(argv[1], "single") ||
1103 !strcmp(argv[1], "-s") || !strcmp(argv[1], "1"))) {
1104 /* Ask first then start a shell on tty2-4 */
1105 new_init_action(ASKFIRST, LOGIN_SHELL, VC_2);
1106 new_init_action(ASKFIRST, LOGIN_SHELL, VC_3);
1107 new_init_action(ASKFIRST, LOGIN_SHELL, VC_4);
1108 /* Start a shell on tty1 */
1109 new_init_action(RESPAWN, LOGIN_SHELL, console);
1111 /* Not in single user mode -- see what inittab says */
1113 /* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined,
1114 * then parse_inittab() simply adds in some default
1115 * actions(i.e., runs INIT_SCRIPT and then starts a pair
1116 * of "askfirst" shells */
1120 /* Make the command line just say "init" -- thats all, nothing else */
1121 fixup_argv(argc, argv, "init");
1123 /* Now run everything that needs to be run */
1125 /* First run the sysinit command */
1126 run_actions(SYSINIT);
1128 /* Next run anything that wants to block */
1131 /* Next run anything to be run only once */
1134 /* If there is nothing else to do, stop */
1135 if (init_action_list == NULL) {
1136 message(LOG | CONSOLE,
1137 "\rNo more tasks for init -- sleeping forever.\n");
1141 /* Now run the looping stuff for the rest of forever */
1143 /* run the respawn stuff */
1144 run_actions(RESPAWN);
1146 /* run the askfirst stuff */
1147 run_actions(ASKFIRST);
1149 /* Don't consume all CPU time -- sleep a bit */
1152 /* Wait for a child process to exit */
1153 wpid = wait(&status);
1155 /* Find out who died and clean up their corpse */
1156 for (a = init_action_list; a; a = a->next) {
1157 if (a->pid == wpid) {
1158 /* Set the pid to 0 so that the process gets
1159 * restarted by run_actions() */
1161 message(LOG, "Process '%s' (pid %d) exited. "
1162 "Scheduling it for restart.\n", a->command, wpid);
1171 c-file-style: "linux"