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) 1999-2003 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/mount.h>
43 #include <sys/types.h>
45 #include <sys/reboot.h>
48 #include "init_shared.h"
52 # include <sys/syslog.h>
56 #if defined(__UCLIBC__) && !defined(__UCLIBC_HAS_MMU__)
60 #define INIT_BUFFS_SIZE 256
62 /* From <linux/vt.h> */
64 unsigned short v_active; /* active vt */
65 unsigned short v_signal; /* signal to send */
66 unsigned short v_state; /* vt bitmask */
68 static const int VT_GETSTATE = 0x5603; /* get global vt state info */
70 /* From <linux/serial.h> */
71 struct serial_struct {
80 unsigned short close_delay;
81 char reserved_char[2];
83 unsigned short closing_wait; /* time to wait before closing */
84 unsigned short closing_wait2; /* no longer used... */
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 SHELL "/bin/sh" /* Default shell */
108 #define LOGIN_SHELL "-" SHELL /* Default login shell */
109 #define INITTAB "/etc/inittab" /* inittab file location */
111 #define INIT_SCRIPT "/etc/init.d/rcS" /* Default sysinit script. */
114 #define MAXENV 16 /* Number of env. vars */
116 #define CONSOLE_BUFF_SIZE 32
118 /* Allowed init action types */
119 #define SYSINIT 0x001
120 #define RESPAWN 0x002
121 #define ASKFIRST 0x004
124 #define CTRLALTDEL 0x020
125 #define SHUTDOWN 0x040
126 #define RESTART 0x080
128 /* A mapping between "inittab" action name strings and action type codes. */
129 struct init_action_type {
134 static const struct init_action_type actions[] = {
135 {"sysinit", SYSINIT},
136 {"respawn", RESPAWN},
137 {"askfirst", ASKFIRST},
140 {"ctrlaltdel", CTRLALTDEL},
141 {"shutdown", SHUTDOWN},
142 {"restart", RESTART},
146 /* Set up a linked list of init_actions, to be read from inittab */
149 char command[INIT_BUFFS_SIZE];
150 char terminal[CONSOLE_BUFF_SIZE];
151 struct init_action *next;
155 /* Static variables */
156 static struct init_action *init_action_list = NULL;
157 static char console[CONSOLE_BUFF_SIZE] = _PATH_CONSOLE;
159 #ifndef CONFIG_SYSLOGD
160 static char *log = VC_5;
162 static sig_atomic_t got_cont = 0;
163 static const int LOG = 0x1;
164 static const int CONSOLE = 0x2;
166 #if defined CONFIG_FEATURE_EXTRA_QUIET
167 static const int MAYBE_CONSOLE = 0x0;
169 #define MAYBE_CONSOLE CONSOLE
171 #ifndef RB_HALT_SYSTEM
172 static const int RB_HALT_SYSTEM = 0xcdef0123;
173 static const int RB_ENABLE_CAD = 0x89abcdef;
174 static const int RB_DISABLE_CAD = 0;
176 #define RB_POWER_OFF 0x4321fedc
177 static const int RB_AUTOBOOT = 0x01234567;
180 static const char * const environment[] = {
182 "PATH=" _PATH_STDPATH,
188 /* Function prototypes */
189 static void delete_init_action(struct init_action *a);
190 static int waitfor(const struct init_action *a);
191 static void halt_signal(int sig);
194 static void loop_forever(void)
200 /* Print a message to the specified device.
201 * Device may be bitwise-or'd from LOG | CONSOLE */
203 static inline void messageD(int device, const char *fmt, ...)
207 #define messageD message
209 static void message(int device, const char *fmt, ...)
210 __attribute__ ((format(printf, 2, 3)));
211 static void message(int device, const char *fmt, ...)
216 #ifndef CONFIG_SYSLOGD
217 static int log_fd = -1;
221 va_start(arguments, fmt);
222 l = vsnprintf(msg + 1, sizeof(msg) - 2, fmt, arguments) + 1;
225 #ifdef CONFIG_SYSLOGD
226 /* Log the message to syslogd */
228 /* don`t out "\r\n" */
229 syslog_msg(LOG_DAEMON, LOG_INFO, msg + 1);
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, O_RDWR | O_NDELAY | O_NOCTTY)) < 0) {
243 bb_error_msg("Bummer, can't write to log on %s!", log);
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_NDELAY);
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 /* How much memory does this machine have?
312 Units are kBytes to avoid overflow on 4GB machines */
313 static unsigned int check_free_memory(void)
316 unsigned int result, u, s = 10;
318 if (sysinfo(&info) != 0) {
319 bb_perror_msg("Error checking free memory");
323 /* Kernels 2.0.x and 2.2.x return info.mem_unit==0 with values in bytes.
324 * Kernels 2.4.0 return info.mem_unit in bytes. */
328 while ((u & 1) == 0 && s > 0) {
332 result = (info.totalram >> s) + (info.totalswap >> s);
333 if ((unsigned long long) (result * u) > UINT_MAX) {
340 static void console_init(void)
345 struct serial_struct sr;
348 if ((s = getenv("CONSOLE")) != NULL || (s = getenv("console")) != NULL) {
349 safe_strncpy(console, s, sizeof(console));
351 /* sparc kernel supports console=tty[ab] parameter which is also
352 * passed to init, so catch it here */
353 /* remap tty[ab] to /dev/ttyS[01] */
354 if (strcmp(s, "ttya") == 0)
355 safe_strncpy(console, SC_0, sizeof(console));
356 else if (strcmp(s, "ttyb") == 0)
357 safe_strncpy(console, SC_1, sizeof(console));
360 /* 2.2 kernels: identify the real console backend and try to use it */
361 if (ioctl(0, TIOCGSERIAL, &sr) == 0) {
362 /* this is a serial console */
363 snprintf(console, sizeof(console) - 1, SC_FORMAT, sr.line);
364 } else if (ioctl(0, VT_GETSTATE, &vt) == 0) {
365 /* this is linux virtual tty */
366 snprintf(console, sizeof(console) - 1, VC_FORMAT, vt.v_active);
368 safe_strncpy(console, _PATH_CONSOLE, sizeof(console));
373 while ((fd = open(console, O_RDONLY | O_NONBLOCK)) < 0 && tried < 2) {
374 /* Can't open selected console -- try
375 logical system console and VT_MASTER */
376 safe_strncpy(console, (tried == 0 ? _PATH_CONSOLE : CURRENT_VC),
381 /* Perhaps we should panic here? */
382 #ifndef CONFIG_SYSLOGD
385 safe_strncpy(console, "/dev/null", sizeof(console));
388 /* check for serial console */
389 if (ioctl(fd, TIOCGSERIAL, &sr) == 0) {
390 /* Force the TERM setting to vt102 for serial console --
391 * if TERM is set to linux (the default) */
392 if (s == NULL || strcmp(s, "linux") == 0)
393 putenv("TERM=vt102");
394 #ifndef CONFIG_SYSLOGD
399 putenv("TERM=linux");
403 messageD(LOG, "console=%s", console);
406 static void fixup_argv(int argc, char **argv, char *new_argv0)
410 /* Fix up argv[0] to be certain we claim to be init */
411 len = strlen(argv[0]);
412 memset(argv[0], 0, len);
413 safe_strncpy(argv[0], new_argv0, len + 1);
415 /* Wipe argv[1]-argv[N] so they don't clutter the ps listing */
418 memset(argv[len], 0, strlen(argv[len]));
423 static pid_t run(const struct init_action *a)
427 pid_t pid, pgrp, tmp_pid;
428 char *s, *tmpCmd, *cmd[INIT_BUFFS_SIZE], *cmdpath;
429 char buf[INIT_BUFFS_SIZE + 6]; /* INIT_BUFFS_SIZE+strlen("exec ")+1 */
430 sigset_t nmask, omask;
431 static const char press_enter[] =
432 #ifdef CUSTOMIZED_BANNER
433 #include CUSTOMIZED_BANNER
435 "\nPlease press Enter to activate this console. ";
437 /* Block sigchild while forking. */
439 sigaddset(&nmask, SIGCHLD);
440 sigprocmask(SIG_BLOCK, &nmask, &omask);
442 if ((pid = fork()) == 0) {
447 sigprocmask(SIG_SETMASK, &omask, NULL);
449 /* Reset signal handlers that were set by the parent process */
450 signal(SIGUSR1, SIG_DFL);
451 signal(SIGUSR2, SIG_DFL);
452 signal(SIGINT, SIG_DFL);
453 signal(SIGTERM, SIG_DFL);
454 signal(SIGHUP, SIG_DFL);
455 signal(SIGCONT, SIG_DFL);
456 signal(SIGSTOP, SIG_DFL);
457 signal(SIGTSTP, SIG_DFL);
459 /* Create a new session and make ourself the process
463 /* Open the new terminal device */
464 if ((device_open(a->terminal, O_RDWR)) < 0) {
465 if (stat(a->terminal, &sb) != 0) {
466 message(LOG | CONSOLE, "device '%s' does not exist.",
470 message(LOG | CONSOLE, "Bummer, can't open %s", a->terminal);
474 /* Make sure the terminal will act fairly normal for us */
476 /* Setup stdout, stderr for the new process so
477 * they point to the supplied terminal */
481 /* If the init Action requires us to wait, then force the
482 * supplied terminal to be the controlling tty. */
483 if (a->action & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) {
485 /* Now fork off another process to just hang around */
486 if ((pid = fork()) < 0) {
487 message(LOG | CONSOLE, "Can't fork!");
493 /* We are the parent -- wait till the child is done */
494 signal(SIGINT, SIG_IGN);
495 signal(SIGTSTP, SIG_IGN);
496 signal(SIGQUIT, SIG_IGN);
497 signal(SIGCHLD, SIG_DFL);
499 /* Wait for child to exit */
500 while ((tmp_pid = waitpid(pid, &junk, 0)) != pid);
502 /* See if stealing the controlling tty back is necessary */
504 if (pgrp != getpid())
507 /* Use a temporary process to steal the controlling tty. */
508 if ((pid = fork()) < 0) {
509 message(LOG | CONSOLE, "Can't fork!");
514 ioctl(0, TIOCSCTTY, 1);
517 while ((tmp_pid = waitpid(pid, &junk, 0)) != pid) {
518 if (tmp_pid < 0 && errno == ECHILD)
524 /* Now fall though to actually execute things */
527 /* See if any special /bin/sh requiring characters are present */
528 if (strpbrk(a->command, "~`!$^&*()=|\\{}[];\"'<>?") != NULL) {
531 cmd[2] = strcat(strcpy(buf, "exec "), a->command);
534 /* Convert command (char*) into cmd (char**, one word per string) */
535 strcpy(buf, a->command);
537 for (tmpCmd = buf, i = 0; (tmpCmd = strsep(&s, " \t")) != NULL;) {
538 if (*tmpCmd != '\0') {
549 Interactive shells want to see a dash in argv[0]. This
550 typically is handled by login, argv will be setup this
551 way if a dash appears at the front of the command path
555 if (*cmdpath == '-') {
557 /* skip over the dash */
560 /* find the last component in the command pathname */
561 s = bb_get_last_path_component(cmdpath);
563 /* make a new argv[0] */
564 if ((cmd[0] = malloc(strlen(s) + 2)) == NULL) {
565 message(LOG | CONSOLE, bb_msg_memory_exhausted);
569 strcpy(cmd[0] + 1, s);
573 if (a->action & ASKFIRST) {
576 * Save memory by not exec-ing anything large (like a shell)
577 * before the user wants it. This is critical if swap is not
578 * enabled and the system has low memory. Generally this will
579 * be run on the second virtual console, and the first will
580 * be allowed to start a shell or whatever an init script
583 messageD(LOG, "Waiting for enter to start '%s'"
584 "(pid %d, terminal %s)\n",
585 cmdpath, getpid(), a->terminal);
586 bb_full_write(1, press_enter, sizeof(press_enter) - 1);
587 while(read(0, &c, 1) == 1 && c != '\n')
591 /* Log the process name and args */
592 message(LOG, "Starting pid %d, console %s: '%s'",
593 getpid(), a->terminal, cmdpath);
595 #if defined CONFIG_FEATURE_INIT_COREDUMPS
596 if (stat(CORE_ENABLE_FLAG_FILE, &sb) == 0) {
599 limit.rlim_cur = RLIM_INFINITY;
600 limit.rlim_max = RLIM_INFINITY;
601 setrlimit(RLIMIT_CORE, &limit);
605 /* Now run it. The new program will take over this PID,
606 * so nothing further in init.c should be run. */
609 /* We're still here? Some error happened. */
610 message(LOG | CONSOLE, "Bummer, could not run '%s': %m", cmdpath);
613 sigprocmask(SIG_SETMASK, &omask, NULL);
617 static int waitfor(const struct init_action *a)
624 wpid = wait(&status);
625 if (wpid > 0 && wpid != pid) {
634 /* Run all commands of a particular type */
635 static void run_actions(int action)
637 struct init_action *a, *tmp;
639 for (a = init_action_list; a; a = tmp) {
641 if (a->action == action) {
642 if (a->action & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) {
644 delete_init_action(a);
645 } else if (a->action & ONCE) {
647 delete_init_action(a);
648 } else if (a->action & (RESPAWN | ASKFIRST)) {
649 /* Only run stuff with pid==0. If they have
650 * a pid, that means it is still running */
660 static void init_reboot(unsigned long magic)
663 /* We have to fork here, since the kernel calls do_exit(0) in
664 * linux/kernel/sys.c, which can cause the machine to panic when
665 * the init process is killed.... */
666 if ((pid = fork()) == 0) {
670 waitpid (pid, NULL, 0);
673 static void shutdown_system(void)
675 sigset_t block_signals;
677 /* run everything to be run at "shutdown". This is done _prior_
678 * to killing everything, in case people wish to use scripts to
679 * shut things down gracefully... */
680 run_actions(SHUTDOWN);
682 /* first disable all our signals */
683 sigemptyset(&block_signals);
684 sigaddset(&block_signals, SIGHUP);
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)
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) {
726 /* unblock all signals, blocked in shutdown_system() */
727 sigemptyset(&unblock_signals);
728 sigaddset(&unblock_signals, SIGHUP);
729 sigaddset(&unblock_signals, SIGCHLD);
730 sigaddset(&unblock_signals, SIGUSR1);
731 sigaddset(&unblock_signals, SIGUSR2);
732 sigaddset(&unblock_signals, SIGINT);
733 sigaddset(&unblock_signals, SIGTERM);
734 sigaddset(&unblock_signals, SIGCONT);
735 sigaddset(&unblock_signals, SIGSTOP);
736 sigaddset(&unblock_signals, SIGTSTP);
737 sigprocmask(SIG_UNBLOCK, &unblock_signals, NULL);
739 /* Close whatever files are open. */
744 /* Open the new terminal device */
745 if ((device_open(a->terminal, O_RDWR)) < 0) {
746 if (stat(a->terminal, &sb) != 0) {
747 message(LOG | CONSOLE, "device '%s' does not exist.", a->terminal);
749 message(LOG | CONSOLE, "Bummer, can't open %s", a->terminal);
751 halt_signal(SIGUSR1);
754 /* Make sure the terminal will act fairly normal for us */
756 /* Setup stdout, stderr on the supplied terminal */
760 messageD(CONSOLE | LOG, "Trying to re-exec %s", a->command);
761 execl(a->command, a->command, NULL);
763 message(CONSOLE | LOG, "exec of '%s' failed: %m",
767 init_reboot(RB_HALT_SYSTEM);
773 static void halt_signal(int sig)
776 message(CONSOLE | LOG,
778 /* Seems the s390 console is Wierd(tm). */
779 "The system is halted. You may reboot now."
781 "The system is halted. Press Reset or turn off power"
786 /* allow time for last message to reach serial console */
790 init_reboot(RB_POWER_OFF);
792 init_reboot(RB_HALT_SYSTEM);
797 static void reboot_signal(int sig)
800 message(CONSOLE | LOG, "Please stand by while rebooting the system.");
803 /* allow time for last message to reach serial console */
806 init_reboot(RB_AUTOBOOT);
811 static void ctrlaltdel_signal(int sig)
813 run_actions(CTRLALTDEL);
816 /* The SIGSTOP & SIGTSTP handler */
817 static void stop_handler(int sig)
819 int saved_errno = errno;
828 /* The SIGCONT handler */
829 static void cont_handler(int sig)
834 /* Reap any zombie processes that are reparented to init */
835 static void child_handler(int sig)
838 while ( wait3(&status, WNOHANG, NULL) > 0 );
841 #endif /* ! DEBUG_INIT */
843 static void new_init_action(int action, char *command, const char *cons)
845 struct init_action *new_action, *a;
850 /* do not run entries if console device is not available */
851 if (access(cons, R_OK | W_OK))
853 if (strcmp(cons, "/dev/null") == 0 && (action & ASKFIRST))
856 new_action = calloc((size_t) (1), sizeof(struct init_action));
858 message(LOG | CONSOLE, "Memory allocation failure");
862 /* Append to the end of the list */
863 for (a = init_action_list; a && a->next; a = a->next) {
864 /* don't enter action if it's already in the list */
865 if ((strcmp(a->command, command) == 0) &&
866 (strcmp(a->terminal, cons) ==0)) {
872 a->next = new_action;
874 init_action_list = new_action;
876 strcpy(new_action->command, command);
877 new_action->action = action;
878 strcpy(new_action->terminal, cons);
879 #if 0 /* calloc zeroed always */
882 messageD(LOG|CONSOLE, "command='%s' action='%d' terminal='%s'\n",
883 new_action->command, new_action->action, new_action->terminal);
886 static void delete_init_action(struct init_action *action)
888 struct init_action *a, *b = NULL;
890 for (a = init_action_list; a; b = a, a = a->next) {
893 init_action_list = a->next;
903 /* Make sure there is enough memory to do something useful. *
904 * Calls "swapon -a" if needed so be sure /etc/fstab is present... */
905 static void check_memory(void)
909 if (check_free_memory() > 1000)
912 #if !defined(__UCLIBC__) || defined(__UCLIBC_HAS_MMU__)
913 if (stat("/etc/fstab", &statBuf) == 0) {
914 /* swapon -a requires /proc typically */
915 new_init_action(SYSINIT, "/bin/mount -t proc proc /proc", "");
916 /* Try to turn on swap */
917 new_init_action(SYSINIT, "/sbin/swapon -a", "");
918 run_actions(SYSINIT); /* wait and removing */
919 if (check_free_memory() < 1000)
927 message(CONSOLE, "Sorry, your computer does not have enough memory.");
931 /* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined,
932 * then parse_inittab() simply adds in some default
933 * actions(i.e., runs INIT_SCRIPT and then starts a pair
934 * of "askfirst" shells). If CONFIG_FEATURE_USE_INITTAB
935 * _is_ defined, but /etc/inittab is missing, this
936 * results in the same set of default behaviors.
938 static void parse_inittab(void)
940 #ifdef CONFIG_FEATURE_USE_INITTAB
942 char buf[INIT_BUFFS_SIZE], lineAsRead[INIT_BUFFS_SIZE];
943 char tmpConsole[CONSOLE_BUFF_SIZE];
944 char *id, *runlev, *action, *command, *eol;
945 const struct init_action_type *a = actions;
948 file = fopen(INITTAB, "r");
950 /* No inittab file -- set up some default behavior */
952 /* Reboot on Ctrl-Alt-Del */
953 new_init_action(CTRLALTDEL, "/sbin/reboot", "");
954 /* Umount all filesystems on halt/reboot */
955 new_init_action(SHUTDOWN, "/bin/umount -a -r", "");
956 #if !defined(__UCLIBC__) || defined(__UCLIBC_HAS_MMU__)
957 /* Swapoff on halt/reboot */
958 new_init_action(SHUTDOWN, "/sbin/swapoff -a", "");
960 /* Prepare to restart init when a HUP is received */
961 new_init_action(RESTART, "/sbin/init", "");
962 /* Askfirst shell on tty1-4 */
963 new_init_action(ASKFIRST, LOGIN_SHELL, "");
964 new_init_action(ASKFIRST, LOGIN_SHELL, VC_2);
965 new_init_action(ASKFIRST, LOGIN_SHELL, VC_3);
966 new_init_action(ASKFIRST, LOGIN_SHELL, VC_4);
968 new_init_action(SYSINIT, INIT_SCRIPT, "");
971 #ifdef CONFIG_FEATURE_USE_INITTAB
974 while (fgets(buf, INIT_BUFFS_SIZE, file) != NULL) {
975 /* Skip leading spaces */
976 for (id = buf; *id == ' ' || *id == '\t'; id++);
978 /* Skip the line if it's a comment */
979 if (*id == '#' || *id == '\n')
982 /* Trim the trailing \n */
983 eol = strrchr(id, '\n');
987 /* Keep a copy around for posterity's sake (and error msgs) */
988 strcpy(lineAsRead, buf);
990 /* Separate the ID field from the runlevels */
991 runlev = strchr(id, ':');
992 if (runlev == NULL || *(runlev + 1) == '\0') {
993 message(LOG | CONSOLE, "Bad inittab entry: %s", lineAsRead);
1000 /* Separate the runlevels from the action */
1001 action = strchr(runlev, ':');
1002 if (action == NULL || *(action + 1) == '\0') {
1003 message(LOG | CONSOLE, "Bad inittab entry: %s", lineAsRead);
1010 /* Separate the action from the command */
1011 command = strchr(action, ':');
1012 if (command == NULL || *(command + 1) == '\0') {
1013 message(LOG | CONSOLE, "Bad inittab entry: %s", lineAsRead);
1020 /* Ok, now process it */
1021 for (a = actions; a->name != 0; a++) {
1022 if (strcmp(a->name, action) == 0) {
1024 if(strncmp(id, "/dev/", 5) == 0)
1026 strcpy(tmpConsole, "/dev/");
1027 safe_strncpy(tmpConsole + 5, id,
1028 CONSOLE_BUFF_SIZE - 5);
1031 new_init_action(a->action, command, id);
1036 /* Choke on an unknown action */
1037 message(LOG | CONSOLE, "Bad inittab entry: %s", lineAsRead);
1042 #endif /* CONFIG_FEATURE_USE_INITTAB */
1045 static void reload_signal(int sig)
1047 message(LOG, "Reloading /etc/inittab");
1049 run_actions(RESPAWN);
1053 extern int init_main(int argc, char **argv)
1055 struct init_action *a;
1059 if (argc > 1 && !strcmp(argv[1], "-q")) {
1060 return kill_init(SIGHUP);
1063 /* Expect to be invoked as init with PID=1 or be invoked as linuxrc */
1065 #ifdef CONFIG_FEATURE_INITRD
1066 && strstr(bb_applet_name, "linuxrc") == NULL
1071 /* Set up sig handlers -- be sure to
1072 * clear all of these in run() */
1073 signal(SIGHUP, exec_signal);
1074 signal(SIGUSR1, halt_signal);
1075 signal(SIGUSR2, halt_signal);
1076 signal(SIGINT, ctrlaltdel_signal);
1077 signal(SIGTERM, reboot_signal);
1078 signal(SIGCONT, cont_handler);
1079 signal(SIGSTOP, stop_handler);
1080 signal(SIGTSTP, stop_handler);
1081 signal(SIGCHLD, child_handler);
1083 /* Turn off rebooting via CTL-ALT-DEL -- we get a
1084 * SIGINT on CAD so we can shut things down gracefully... */
1085 init_reboot(RB_DISABLE_CAD);
1088 /* Figure out where the default console should be */
1091 /* Close whatever files are open, and reset the console. */
1096 if (device_open(console, O_RDWR | O_NOCTTY) == 0) {
1104 const char * const *e;
1105 /* Make sure environs is set to something sane */
1106 for(e = environment; *e; e++)
1107 putenv((char *) *e);
1110 message(MAYBE_CONSOLE | LOG, "init started: %s", bb_msg_full_version);
1112 /* Make sure there is enough memory to do something useful. */
1115 /* Check if we are supposed to be in single user mode */
1116 if (argc > 1 && (!strcmp(argv[1], "single") ||
1117 !strcmp(argv[1], "-s") || !strcmp(argv[1], "1"))) {
1118 /* Start a shell on console */
1119 new_init_action(RESPAWN, LOGIN_SHELL, "");
1121 /* Not in single user mode -- see what inittab says */
1123 /* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined,
1124 * then parse_inittab() simply adds in some default
1125 * actions(i.e., runs INIT_SCRIPT and then starts a pair
1126 * of "askfirst" shells */
1130 /* Make the command line just say "init" -- thats all, nothing else */
1131 fixup_argv(argc, argv, "init");
1133 /* Now run everything that needs to be run */
1135 /* First run the sysinit command */
1136 run_actions(SYSINIT);
1138 /* Next run anything that wants to block */
1141 /* Next run anything to be run only once */
1144 /* If there is nothing else to do, stop */
1145 if (init_action_list == NULL) {
1146 message(LOG | CONSOLE,
1147 "No more tasks for init -- sleeping forever.");
1151 /* Redefine SIGHUP to reread /etc/inittab */
1152 signal(SIGHUP, reload_signal);
1154 /* Now run the looping stuff for the rest of forever */
1156 /* run the respawn stuff */
1157 run_actions(RESPAWN);
1159 /* run the askfirst stuff */
1160 run_actions(ASKFIRST);
1162 /* Don't consume all CPU time -- sleep a bit */
1165 /* Wait for a child process to exit */
1166 wpid = wait(&status);
1168 /* Find out who died and clean up their corpse */
1169 for (a = init_action_list; a; a = a->next) {
1170 if (a->pid == wpid) {
1171 /* Set the pid to 0 so that the process gets
1172 * restarted by run_actions() */
1174 message(LOG, "Process '%s' (pid %d) exited. "
1175 "Scheduling it for restart.",
1179 /* see if anyone else is waiting to be reaped */
1180 wpid = waitpid (-1, &status, WNOHANG);
1187 c-file-style: "linux"