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>
49 #if (__GNU_LIBRARY__ > 5) || defined(__dietlibc__)
50 #include <sys/reboot.h>
54 #if defined(__UCLIBC__) && !defined(__UCLIBC_HAS_MMU__)
58 #define INIT_BUFFS_SIZE 256
60 /* From <linux/vt.h> */
62 unsigned short v_active; /* active vt */
63 unsigned short v_signal; /* signal to send */
64 unsigned short v_state; /* vt bitmask */
66 static const int VT_GETSTATE = 0x5603; /* get global vt state info */
68 /* From <linux/serial.h> */
69 struct serial_struct {
78 unsigned short close_delay;
79 char reserved_char[2];
81 unsigned short closing_wait; /* time to wait before closing */
82 unsigned short closing_wait2; /* no longer used... */
88 #define _PATH_STDPATH "/usr/bin:/bin:/usr/sbin:/sbin"
91 #if defined CONFIG_FEATURE_INIT_COREDUMPS
93 * When a file named CORE_ENABLE_FLAG_FILE exists, setrlimit is called
94 * before processes are spawned to set core file size as unlimited.
95 * This is for debugging only. Don't use this is production, unless
96 * you want core dumps lying about....
98 #define CORE_ENABLE_FLAG_FILE "/.init_enable_core"
99 #include <sys/resource.h>
100 #include <sys/time.h>
103 #define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))
105 #define SHELL "/bin/sh" /* Default shell */
106 #define LOGIN_SHELL "-" SHELL /* Default login shell */
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 int kernelVersion;
156 static char console[CONSOLE_BUFF_SIZE] = _PATH_CONSOLE;
158 #ifndef CONFIG_SYSLOGD
159 static char *log = VC_5;
161 static sig_atomic_t got_cont = 0;
162 static const int LOG = 0x1;
163 static const int CONSOLE = 0x2;
165 #if defined CONFIG_FEATURE_EXTRA_QUIET
166 static const int MAYBE_CONSOLE = 0x0;
168 #define MAYBE_CONSOLE CONSOLE
170 #ifndef RB_HALT_SYSTEM
171 static const int RB_HALT_SYSTEM = 0xcdef0123;
172 static const int RB_ENABLE_CAD = 0x89abcdef;
173 static const int RB_DISABLE_CAD = 0;
175 #define RB_POWER_OFF 0x4321fedc
176 static const int RB_AUTOBOOT = 0x01234567;
179 static const char * const environment[] = {
181 "PATH=" _PATH_STDPATH,
187 /* Function prototypes */
188 static void delete_init_action(struct init_action *a);
189 static int waitfor(const 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 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 syslog_msg(LOG_DAEMON, LOG_INFO, msg + 1);
236 /* Take full control of the log tty, and never close it.
237 * It's mine, all mine! Muhahahaha! */
239 if ((log_fd = device_open(log, O_RDWR | O_NDELAY | O_NOCTTY)) < 0) {
241 bb_error_msg("Bummer, can't write to log on %s!", log);
244 fcntl(log_fd, F_SETFD, FD_CLOEXEC);
247 if ((device & LOG) && (log_fd >= 0)) {
248 bb_full_write(log_fd, msg, l);
252 if (device & CONSOLE) {
253 int fd = device_open(_PATH_CONSOLE,
254 O_WRONLY | O_NOCTTY | O_NDELAY);
255 /* Always send console messages to /dev/console so people will see them. */
257 bb_full_write(fd, msg, l);
260 /* all descriptors may be closed */
262 bb_error_msg("Bummer, can't print: ");
263 va_start(arguments, fmt);
264 vfprintf(stderr, fmt, arguments);
271 /* Set terminal settings to reasonable defaults */
272 static void set_term(int fd)
278 /* set control chars */
279 tty.c_cc[VINTR] = 3; /* C-c */
280 tty.c_cc[VQUIT] = 28; /* C-\ */
281 tty.c_cc[VERASE] = 127; /* C-? */
282 tty.c_cc[VKILL] = 21; /* C-u */
283 tty.c_cc[VEOF] = 4; /* C-d */
284 tty.c_cc[VSTART] = 17; /* C-q */
285 tty.c_cc[VSTOP] = 19; /* C-s */
286 tty.c_cc[VSUSP] = 26; /* C-z */
288 /* use line dicipline 0 */
291 /* Make it be sane */
292 tty.c_cflag &= CBAUD | CBAUDEX | CSIZE | CSTOPB | PARENB | PARODD;
293 tty.c_cflag |= CREAD | HUPCL | CLOCAL;
297 tty.c_iflag = ICRNL | IXON | IXOFF;
300 tty.c_oflag = OPOST | ONLCR;
304 ISIG | ICANON | ECHO | ECHOE | ECHOK | ECHOCTL | ECHOKE | IEXTEN;
306 tcsetattr(fd, TCSANOW, &tty);
309 /* How much memory does this machine have?
310 Units are kBytes to avoid overflow on 4GB machines */
311 static int check_free_memory(void)
314 unsigned int result, u, s = 10;
316 if (sysinfo(&info) != 0) {
317 bb_perror_msg("Error checking free memory");
321 /* Kernels 2.0.x and 2.2.x return info.mem_unit==0 with values in bytes.
322 * Kernels 2.4.0 return info.mem_unit in bytes. */
326 while ((u & 1) == 0 && s > 0) {
330 result = (info.totalram >> s) + (info.totalswap >> s);
337 static void console_init(void)
342 struct serial_struct sr;
345 if ((s = getenv("CONSOLE")) != NULL || (s = getenv("console")) != NULL) {
346 safe_strncpy(console, s, sizeof(console));
348 /* sparc kernel supports console=tty[ab] parameter which is also
349 * passed to init, so catch it here */
350 /* remap tty[ab] to /dev/ttyS[01] */
351 if (strcmp(s, "ttya") == 0)
352 safe_strncpy(console, SC_0, sizeof(console));
353 else if (strcmp(s, "ttyb") == 0)
354 safe_strncpy(console, SC_1, sizeof(console));
357 /* 2.2 kernels: identify the real console backend and try to use it */
358 if (ioctl(0, TIOCGSERIAL, &sr) == 0) {
359 /* this is a serial console */
360 snprintf(console, sizeof(console) - 1, SC_FORMAT, sr.line);
361 } else if (ioctl(0, VT_GETSTATE, &vt) == 0) {
362 /* this is linux virtual tty */
363 snprintf(console, sizeof(console) - 1, VC_FORMAT, vt.v_active);
365 safe_strncpy(console, _PATH_CONSOLE, sizeof(console));
370 while ((fd = open(console, O_RDONLY | O_NONBLOCK)) < 0 && tried < 2) {
371 /* Can't open selected console -- try
372 logical system console and VT_MASTER */
373 safe_strncpy(console, (tried == 0 ? _PATH_CONSOLE : CURRENT_VC),
378 /* Perhaps we should panic here? */
379 #ifndef CONFIG_SYSLOGD
382 safe_strncpy(console, "/dev/null", sizeof(console));
385 /* check for serial console */
386 if (ioctl(fd, TIOCGSERIAL, &sr) == 0) {
387 /* Force the TERM setting to vt102 for serial console --
388 * if TERM is set to linux (the default) */
389 if (s == NULL || strcmp(s, "linux") == 0)
390 putenv("TERM=vt102");
391 #ifndef CONFIG_SYSLOGD
396 putenv("TERM=linux");
400 messageD(LOG, "console=%s", console);
403 static void fixup_argv(int argc, char **argv, char *new_argv0)
407 /* Fix up argv[0] to be certain we claim to be init */
408 len = strlen(argv[0]);
409 memset(argv[0], 0, len);
410 safe_strncpy(argv[0], new_argv0, len + 1);
412 /* Wipe argv[1]-argv[N] so they don't clutter the ps listing */
415 memset(argv[len], 0, strlen(argv[len]));
420 static pid_t run(const struct init_action *a)
424 pid_t pid, pgrp, tmp_pid;
425 char *s, *tmpCmd, *cmd[INIT_BUFFS_SIZE], *cmdpath;
426 char buf[INIT_BUFFS_SIZE + 6]; /* INIT_BUFFS_SIZE+strlen("exec ")+1 */
427 sigset_t nmask, omask;
428 static const char press_enter[] =
429 #ifdef CUSTOMIZED_BANNER
430 #include CUSTOMIZED_BANNER
432 "\nPlease press Enter to activate this console. ";
434 /* Block sigchild while forking. */
436 sigaddset(&nmask, SIGCHLD);
437 sigprocmask(SIG_BLOCK, &nmask, &omask);
439 if ((pid = fork()) == 0) {
444 sigprocmask(SIG_SETMASK, &omask, NULL);
446 /* Reset signal handlers that were set by the parent process */
447 signal(SIGUSR1, SIG_DFL);
448 signal(SIGUSR2, SIG_DFL);
449 signal(SIGINT, SIG_DFL);
450 signal(SIGTERM, SIG_DFL);
451 signal(SIGHUP, SIG_DFL);
452 signal(SIGCONT, SIG_DFL);
453 signal(SIGSTOP, SIG_DFL);
454 signal(SIGTSTP, SIG_DFL);
456 /* Create a new session and make ourself the process
460 /* Open the new terminal device */
461 if ((device_open(a->terminal, O_RDWR)) < 0) {
462 if (stat(a->terminal, &sb) != 0) {
463 message(LOG | CONSOLE, "device '%s' does not exist.",
467 message(LOG | CONSOLE, "Bummer, can't open %s", a->terminal);
471 /* Make sure the terminal will act fairly normal for us */
473 /* Setup stdout, stderr for the new process so
474 * they point to the supplied terminal */
478 /* If the init Action requires us to wait, then force the
479 * supplied terminal to be the controlling tty. */
480 if (a->action & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) {
482 /* Now fork off another process to just hang around */
483 if ((pid = fork()) < 0) {
484 message(LOG | CONSOLE, "Can't fork!");
490 /* We are the parent -- wait till the child is done */
491 signal(SIGINT, SIG_IGN);
492 signal(SIGTSTP, SIG_IGN);
493 signal(SIGQUIT, SIG_IGN);
494 signal(SIGCHLD, SIG_DFL);
496 /* Wait for child to exit */
497 while ((tmp_pid = waitpid(pid, &junk, 0)) != pid);
499 /* See if stealing the controlling tty back is necessary */
501 if (pgrp != getpid())
504 /* Use a temporary process to steal the controlling tty. */
505 if ((pid = fork()) < 0) {
506 message(LOG | CONSOLE, "Can't fork!");
511 ioctl(0, TIOCSCTTY, 1);
514 while ((tmp_pid = waitpid(pid, &junk, 0)) != pid) {
515 if (tmp_pid < 0 && errno == ECHILD)
521 /* Now fall though to actually execute things */
524 /* See if any special /bin/sh requiring characters are present */
525 if (strpbrk(a->command, "~`!$^&*()=|\\{}[];\"'<>?") != NULL) {
528 cmd[2] = strcat(strcpy(buf, "exec "), a->command);
531 /* Convert command (char*) into cmd (char**, one word per string) */
532 strcpy(buf, a->command);
534 for (tmpCmd = buf, i = 0; (tmpCmd = strsep(&s, " \t")) != NULL;) {
535 if (*tmpCmd != '\0') {
546 Interactive shells want to see a dash in argv[0]. This
547 typically is handled by login, argv will be setup this
548 way if a dash appears at the front of the command path
552 if (*cmdpath == '-') {
554 /* skip over the dash */
557 /* find the last component in the command pathname */
558 s = bb_get_last_path_component(cmdpath);
560 /* make a new argv[0] */
561 if ((cmd[0] = malloc(strlen(s) + 2)) == NULL) {
562 message(LOG | CONSOLE, bb_msg_memory_exhausted);
566 strcpy(cmd[0] + 1, s);
570 if (a->action & ASKFIRST) {
573 * Save memory by not exec-ing anything large (like a shell)
574 * before the user wants it. This is critical if swap is not
575 * enabled and the system has low memory. Generally this will
576 * be run on the second virtual console, and the first will
577 * be allowed to start a shell or whatever an init script
580 messageD(LOG, "Waiting for enter to start '%s'"
581 "(pid %d, terminal %s)\n",
582 cmdpath, getpid(), a->terminal);
583 bb_full_write(1, press_enter, sizeof(press_enter) - 1);
584 while(read(0, &c, 1) == 1 && c != '\n')
588 /* Log the process name and args */
589 message(LOG, "Starting pid %d, console %s: '%s'",
590 getpid(), a->terminal, cmdpath);
592 #if defined CONFIG_FEATURE_INIT_COREDUMPS
593 if (stat(CORE_ENABLE_FLAG_FILE, &sb) == 0) {
596 limit.rlim_cur = RLIM_INFINITY;
597 limit.rlim_max = RLIM_INFINITY;
598 setrlimit(RLIMIT_CORE, &limit);
602 /* Now run it. The new program will take over this PID,
603 * so nothing further in init.c should be run. */
606 /* We're still here? Some error happened. */
607 message(LOG | CONSOLE, "Bummer, could not run '%s': %m", cmdpath);
610 sigprocmask(SIG_SETMASK, &omask, NULL);
614 static int waitfor(const struct init_action *a)
621 wpid = wait(&status);
622 if (wpid > 0 && wpid != pid) {
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 (a->action & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) {
641 delete_init_action(a);
642 } else if (a->action & ONCE) {
644 delete_init_action(a);
645 } else if (a->action & (RESPAWN | ASKFIRST)) {
646 /* Only run stuff with pid==0. If they have
647 * a pid, that means it is still running */
657 static void init_reboot(unsigned long magic)
660 /* We have to fork here, since the kernel calls do_exit(0) in
661 * linux/kernel/sys.c, which can cause the machint to panic when
662 * the init process is killed.... */
663 if ((pid = fork()) == 0) {
664 #if (__GNU_LIBRARY__ > 5) || defined(__dietlibc__)
667 reboot(0xfee1dead, 672274793, magic);
671 waitpid (pid, NULL, 0);
674 static void shutdown_system(void)
676 sigset_t block_signals;
678 /* run everything to be run at "shutdown". This is done _prior_
679 * to killing everything, in case people wish to use scripts to
680 * shut things down gracefully... */
681 run_actions(SHUTDOWN);
683 /* first disable all our signals */
684 sigemptyset(&block_signals);
685 sigaddset(&block_signals, SIGHUP);
686 sigaddset(&block_signals, SIGCHLD);
687 sigaddset(&block_signals, SIGUSR1);
688 sigaddset(&block_signals, SIGUSR2);
689 sigaddset(&block_signals, SIGINT);
690 sigaddset(&block_signals, SIGTERM);
691 sigaddset(&block_signals, SIGCONT);
692 sigaddset(&block_signals, SIGSTOP);
693 sigaddset(&block_signals, SIGTSTP);
694 sigprocmask(SIG_BLOCK, &block_signals, NULL);
696 /* Allow Ctrl-Alt-Del to reboot system. */
697 init_reboot(RB_ENABLE_CAD);
699 message(CONSOLE | LOG, "The system is going down NOW !!");
702 /* Send signals to every process _except_ pid 1 */
703 message(CONSOLE | LOG, "Sending SIGTERM to all processes.");
708 message(CONSOLE | LOG, "Sending SIGKILL to all processes.");
715 static void exec_signal(int sig)
717 struct init_action *a, *tmp;
718 sigset_t unblock_signals;
720 for (a = init_action_list; a; a = tmp) {
722 if (a->action & RESTART) {
725 /* unblock all signals, blocked in shutdown_system() */
726 sigemptyset(&unblock_signals);
727 sigaddset(&unblock_signals, SIGHUP);
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 messageD(CONSOLE | LOG, "Trying to re-exec %s", a->command);
739 execl(a->command, a->command, NULL);
741 message(CONSOLE | LOG, "exec of '%s' failed: %m",
745 init_reboot(RB_HALT_SYSTEM);
751 static void halt_signal(int sig)
754 message(CONSOLE | LOG,
756 /* Seems the s390 console is Wierd(tm). */
757 "The system is halted. You may reboot now."
759 "The system is halted. Press Reset or turn off power"
764 /* allow time for last message to reach serial console */
767 if (sig == SIGUSR2 && kernelVersion >= KERNEL_VERSION(2, 2, 0))
768 init_reboot(RB_POWER_OFF);
770 init_reboot(RB_HALT_SYSTEM);
775 static void reboot_signal(int sig)
778 message(CONSOLE | LOG, "Please stand by while rebooting the system.");
781 /* allow time for last message to reach serial console */
784 init_reboot(RB_AUTOBOOT);
789 static void ctrlaltdel_signal(int sig)
791 run_actions(CTRLALTDEL);
794 /* The SIGSTOP & SIGTSTP handler */
795 static void stop_handler(int sig)
797 int saved_errno = errno;
806 /* The SIGCONT handler */
807 static void cont_handler(int sig)
812 #endif /* ! DEBUG_INIT */
814 static void new_init_action(int action, char *command, const char *cons)
816 struct init_action *new_action, *a;
821 /* do not run entries if console device is not available */
822 if (access(cons, R_OK | W_OK))
824 if (strcmp(cons, "/dev/null") == 0 && (action & ASKFIRST))
827 new_action = calloc((size_t) (1), sizeof(struct init_action));
829 message(LOG | CONSOLE, "Memory allocation failure");
833 /* Append to the end of the list */
834 for (a = init_action_list; a && a->next; a = a->next);
836 a->next = new_action;
838 init_action_list = new_action;
840 strcpy(new_action->command, command);
841 new_action->action = action;
842 strcpy(new_action->terminal, cons);
843 #if 0 /* calloc zeroed always */
846 messageD(LOG|CONSOLE, "command='%s' action='%d' terminal='%s'\n",
847 new_action->command, new_action->action, new_action->terminal);
850 static void delete_init_action(struct init_action *action)
852 struct init_action *a, *b = NULL;
854 for (a = init_action_list; a; b = a, a = a->next) {
857 init_action_list = a->next;
867 /* Make sure there is enough memory to do something useful. *
868 * Calls "swapon -a" if needed so be sure /etc/fstab is present... */
869 static void check_memory(void)
873 if (check_free_memory() > 1000)
876 #if !defined(__UCLIBC__) || defined(__UCLIBC_HAS_MMU__)
877 if (stat("/etc/fstab", &statBuf) == 0) {
878 /* swapon -a requires /proc typically */
879 new_init_action(SYSINIT, "/bin/mount -t proc proc /proc", "");
880 /* Try to turn on swap */
881 new_init_action(SYSINIT, "/sbin/swapon -a", "");
882 run_actions(SYSINIT); /* wait and removing */
883 if (check_free_memory() < 1000)
891 message(CONSOLE, "Sorry, your computer does not have enough memory.");
895 /* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined,
896 * then parse_inittab() simply adds in some default
897 * actions(i.e., runs INIT_SCRIPT and then starts a pair
898 * of "askfirst" shells). If CONFIG_FEATURE_USE_INITTAB
899 * _is_ defined, but /etc/inittab is missing, this
900 * results in the same set of default behaviors.
902 static void parse_inittab(void)
904 #ifdef CONFIG_FEATURE_USE_INITTAB
906 char buf[INIT_BUFFS_SIZE], lineAsRead[INIT_BUFFS_SIZE];
907 char tmpConsole[CONSOLE_BUFF_SIZE];
908 char *id, *runlev, *action, *command, *eol;
909 const struct init_action_type *a = actions;
912 file = fopen(INITTAB, "r");
914 /* No inittab file -- set up some default behavior */
916 /* Reboot on Ctrl-Alt-Del */
917 new_init_action(CTRLALTDEL, "/sbin/reboot", "");
918 /* Umount all filesystems on halt/reboot */
919 new_init_action(SHUTDOWN, "/bin/umount -a -r", "");
920 #if !defined(__UCLIBC__) || defined(__UCLIBC_HAS_MMU__)
921 /* Swapoff on halt/reboot */
922 new_init_action(SHUTDOWN, "/sbin/swapoff -a", "");
924 /* Prepare to restart init when a HUP is received */
925 new_init_action(RESTART, "/sbin/init", "");
926 /* Askfirst shell on tty1-4 */
927 new_init_action(ASKFIRST, LOGIN_SHELL, "");
928 new_init_action(ASKFIRST, LOGIN_SHELL, VC_2);
929 new_init_action(ASKFIRST, LOGIN_SHELL, VC_3);
930 new_init_action(ASKFIRST, LOGIN_SHELL, VC_4);
932 new_init_action(SYSINIT, INIT_SCRIPT, "");
935 #ifdef CONFIG_FEATURE_USE_INITTAB
938 while (fgets(buf, INIT_BUFFS_SIZE, file) != NULL) {
939 /* Skip leading spaces */
940 for (id = buf; *id == ' ' || *id == '\t'; id++);
942 /* Skip the line if it's a comment */
943 if (*id == '#' || *id == '\n')
946 /* Trim the trailing \n */
947 eol = strrchr(id, '\n');
951 /* Keep a copy around for posterity's sake (and error msgs) */
952 strcpy(lineAsRead, buf);
954 /* Separate the ID field from the runlevels */
955 runlev = strchr(id, ':');
956 if (runlev == NULL || *(runlev + 1) == '\0') {
957 message(LOG | CONSOLE, "Bad inittab entry: %s", lineAsRead);
964 /* Separate the runlevels from the action */
965 action = strchr(runlev, ':');
966 if (action == NULL || *(action + 1) == '\0') {
967 message(LOG | CONSOLE, "Bad inittab entry: %s", lineAsRead);
974 /* Separate the action from the command */
975 command = strchr(action, ':');
976 if (command == NULL || *(command + 1) == '\0') {
977 message(LOG | CONSOLE, "Bad inittab entry: %s", lineAsRead);
984 /* Ok, now process it */
985 for (a = actions; a->name != 0; a++) {
986 if (strcmp(a->name, action) == 0) {
988 if(strncmp(id, "/dev/", 5) == 0)
990 strcpy(tmpConsole, "/dev/");
991 safe_strncpy(tmpConsole + 5, id,
992 CONSOLE_BUFF_SIZE - 5);
995 new_init_action(a->action, command, id);
1000 /* Choke on an unknown action */
1001 message(LOG | CONSOLE, "Bad inittab entry: %s", lineAsRead);
1006 #endif /* CONFIG_FEATURE_USE_INITTAB */
1010 extern int init_main(int argc, char **argv)
1012 struct init_action *a;
1016 if (argc > 1 && !strcmp(argv[1], "-q")) {
1017 /* don't assume init's pid == 1 */
1018 long *pid = find_pid_by_name("init");
1020 if (!pid || *pid <= 0) {
1021 pid = find_pid_by_name("linuxrc");
1022 if (!pid || *pid <= 0)
1023 bb_error_msg_and_die("no process killed");
1025 return kill(*pid, SIGHUP);
1028 /* Expect to be invoked as init with PID=1 or be invoked as linuxrc */
1030 #ifdef CONFIG_FEATURE_INITRD
1031 && strstr(bb_applet_name, "linuxrc") == NULL
1036 /* Set up sig handlers -- be sure to
1037 * clear all of these in run() */
1038 signal(SIGHUP, exec_signal);
1039 signal(SIGUSR1, halt_signal);
1040 signal(SIGUSR2, halt_signal);
1041 signal(SIGINT, ctrlaltdel_signal);
1042 signal(SIGTERM, reboot_signal);
1043 signal(SIGCONT, cont_handler);
1044 signal(SIGSTOP, stop_handler);
1045 signal(SIGTSTP, stop_handler);
1047 /* Turn off rebooting via CTL-ALT-DEL -- we get a
1048 * SIGINT on CAD so we can shut things down gracefully... */
1049 init_reboot(RB_DISABLE_CAD);
1052 /* Figure out what kernel this is running */
1053 kernelVersion = get_kernel_revision();
1055 /* Figure out where the default console should be */
1058 /* Close whatever files are open, and reset the console. */
1063 if (device_open(console, O_RDWR | O_NOCTTY) == 0) {
1071 const char * const *e;
1072 /* Make sure environs is set to something sane */
1073 for(e = environment; *e; e++)
1074 putenv((char *) *e);
1077 message(MAYBE_CONSOLE | LOG, "init started: %s", bb_msg_full_version);
1079 /* Make sure there is enough memory to do something useful. */
1082 /* Check if we are supposed to be in single user mode */
1083 if (argc > 1 && (!strcmp(argv[1], "single") ||
1084 !strcmp(argv[1], "-s") || !strcmp(argv[1], "1"))) {
1085 /* Start a shell on console */
1086 new_init_action(RESPAWN, LOGIN_SHELL, "");
1088 /* Not in single user mode -- see what inittab says */
1090 /* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined,
1091 * then parse_inittab() simply adds in some default
1092 * actions(i.e., runs INIT_SCRIPT and then starts a pair
1093 * of "askfirst" shells */
1097 /* Make the command line just say "init" -- thats all, nothing else */
1098 fixup_argv(argc, argv, "init");
1100 /* Now run everything that needs to be run */
1102 /* First run the sysinit command */
1103 run_actions(SYSINIT);
1105 /* Next run anything that wants to block */
1108 /* Next run anything to be run only once */
1111 /* If there is nothing else to do, stop */
1112 if (init_action_list == NULL) {
1113 message(LOG | CONSOLE,
1114 "No more tasks for init -- sleeping forever.");
1118 /* Now run the looping stuff for the rest of forever */
1120 /* run the respawn stuff */
1121 run_actions(RESPAWN);
1123 /* run the askfirst stuff */
1124 run_actions(ASKFIRST);
1126 /* Don't consume all CPU time -- sleep a bit */
1129 /* Wait for a child process to exit */
1130 wpid = wait(&status);
1132 /* Find out who died and clean up their corpse */
1133 for (a = init_action_list; a; a = a->next) {
1134 if (a->pid == wpid) {
1135 /* Set the pid to 0 so that the process gets
1136 * restarted by run_actions() */
1138 message(LOG, "Process '%s' (pid %d) exited. "
1139 "Scheduling it for restart.",
1143 /* see if anyone else is waiting to be reaped */
1144 wpid = waitpid (-1, &status, WNOHANG);
1151 c-file-style: "linux"