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/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(__ARCH_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;
82 char reserved_char[1];
84 unsigned short closing_wait; /* time to wait before closing */
85 unsigned short closing_wait2; /* no longer used... */
86 unsigned char *iomem_base;
87 unsigned short iomem_reg_shift;
88 unsigned int port_high;
89 unsigned long iomap_base; /* cookie passed into ioremap */
95 #define _PATH_STDPATH "/usr/bin:/bin:/usr/sbin:/sbin"
98 #if defined CONFIG_FEATURE_INIT_COREDUMPS
100 * When a file named CORE_ENABLE_FLAG_FILE exists, setrlimit is called
101 * before processes are spawned to set core file size as unlimited.
102 * This is for debugging only. Don't use this is production, unless
103 * you want core dumps lying about....
105 #define CORE_ENABLE_FLAG_FILE "/.init_enable_core"
106 #include <sys/resource.h>
107 #include <sys/time.h>
110 #define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))
112 #define INITTAB "/etc/inittab" /* inittab file location */
114 #define INIT_SCRIPT "/etc/init.d/rcS" /* Default sysinit script. */
117 #define MAXENV 16 /* Number of env. vars */
119 #define CONSOLE_BUFF_SIZE 32
121 /* Allowed init action types */
122 #define SYSINIT 0x001
123 #define RESPAWN 0x002
124 #define ASKFIRST 0x004
127 #define CTRLALTDEL 0x020
128 #define SHUTDOWN 0x040
129 #define RESTART 0x080
131 /* A mapping between "inittab" action name strings and action type codes. */
132 struct init_action_type {
137 static const struct init_action_type actions[] = {
138 {"sysinit", SYSINIT},
139 {"respawn", RESPAWN},
140 {"askfirst", ASKFIRST},
143 {"ctrlaltdel", CTRLALTDEL},
144 {"shutdown", SHUTDOWN},
145 {"restart", RESTART},
149 /* Set up a linked list of init_actions, to be read from inittab */
152 char command[INIT_BUFFS_SIZE];
153 char terminal[CONSOLE_BUFF_SIZE];
154 struct init_action *next;
158 /* Static variables */
159 static struct init_action *init_action_list = NULL;
160 static char console[CONSOLE_BUFF_SIZE] = _PATH_CONSOLE;
162 #ifndef CONFIG_SYSLOGD
163 static char *log = VC_5;
165 static sig_atomic_t got_cont = 0;
166 static const int LOG = 0x1;
167 static const int CONSOLE = 0x2;
169 #if defined CONFIG_FEATURE_EXTRA_QUIET
170 static const int MAYBE_CONSOLE = 0x0;
172 #define MAYBE_CONSOLE CONSOLE
174 #ifndef RB_HALT_SYSTEM
175 static const int RB_HALT_SYSTEM = 0xcdef0123;
176 static const int RB_ENABLE_CAD = 0x89abcdef;
177 static const int RB_DISABLE_CAD = 0;
179 #define RB_POWER_OFF 0x4321fedc
180 static const int RB_AUTOBOOT = 0x01234567;
183 static const char * const environment[] = {
185 "PATH=" _PATH_STDPATH,
191 /* Function prototypes */
192 static void delete_init_action(struct init_action *a);
193 static int waitfor(const struct init_action *a);
194 static void halt_signal(int sig);
197 static void loop_forever(void)
203 /* Print a message to the specified device.
204 * Device may be bitwise-or'd from LOG | CONSOLE */
206 static inline void messageD(int device, const char *fmt, ...)
210 #define messageD message
212 static void message(int device, const char *fmt, ...)
213 __attribute__ ((format(printf, 2, 3)));
214 static void message(int device, const char *fmt, ...)
219 #ifndef CONFIG_SYSLOGD
220 static int log_fd = -1;
224 va_start(arguments, fmt);
225 l = vsnprintf(msg + 1, sizeof(msg) - 2, fmt, arguments) + 1;
228 #ifdef CONFIG_SYSLOGD
229 /* Log the message to syslogd */
231 /* don`t out "\r\n" */
232 openlog(bb_applet_name, 0, LOG_DAEMON);
233 syslog(LOG_INFO, "%s", msg);
243 /* Take full control of the log tty, and never close it.
244 * It's mine, all mine! Muhahahaha! */
246 if ((log_fd = device_open(log, O_RDWR | O_NDELAY | O_NOCTTY)) < 0) {
248 bb_error_msg("Bummer, can't write to log on %s!", log);
251 fcntl(log_fd, F_SETFD, FD_CLOEXEC);
254 if ((device & LOG) && (log_fd >= 0)) {
255 bb_full_write(log_fd, msg, l);
259 if (device & CONSOLE) {
260 int fd = device_open(_PATH_CONSOLE,
261 O_WRONLY | O_NOCTTY | O_NDELAY);
262 /* Always send console messages to /dev/console so people will see them. */
264 bb_full_write(fd, msg, l);
267 /* all descriptors may be closed */
269 bb_error_msg("Bummer, can't print: ");
270 va_start(arguments, fmt);
271 vfprintf(stderr, fmt, arguments);
278 /* Set terminal settings to reasonable defaults */
279 static void set_term(int fd)
285 /* set control chars */
286 tty.c_cc[VINTR] = 3; /* C-c */
287 tty.c_cc[VQUIT] = 28; /* C-\ */
288 tty.c_cc[VERASE] = 127; /* C-? */
289 tty.c_cc[VKILL] = 21; /* C-u */
290 tty.c_cc[VEOF] = 4; /* C-d */
291 tty.c_cc[VSTART] = 17; /* C-q */
292 tty.c_cc[VSTOP] = 19; /* C-s */
293 tty.c_cc[VSUSP] = 26; /* C-z */
295 /* use line dicipline 0 */
298 /* Make it be sane */
299 tty.c_cflag &= CBAUD | CBAUDEX | CSIZE | CSTOPB | PARENB | PARODD;
300 tty.c_cflag |= CREAD | HUPCL | CLOCAL;
304 tty.c_iflag = ICRNL | IXON | IXOFF;
307 tty.c_oflag = OPOST | ONLCR;
311 ISIG | ICANON | ECHO | ECHOE | ECHOK | ECHOCTL | ECHOKE | IEXTEN;
313 tcsetattr(fd, TCSANOW, &tty);
316 /* How much memory does this machine have?
317 Units are kBytes to avoid overflow on 4GB machines */
318 static unsigned int check_free_memory(void)
321 unsigned int result, u, s = 10;
323 if (sysinfo(&info) != 0) {
324 bb_perror_msg("Error checking free memory");
328 /* Kernels 2.0.x and 2.2.x return info.mem_unit==0 with values in bytes.
329 * Kernels 2.4.0 return info.mem_unit in bytes. */
333 while ((u & 1) == 0 && s > 0) {
337 result = (info.totalram >> s) + (info.totalswap >> s);
338 if (((unsigned long long)result * (unsigned long long)u) > UINT_MAX) {
345 static void console_init(void)
350 struct serial_struct sr;
353 if ((s = getenv("CONSOLE")) != NULL || (s = getenv("console")) != NULL) {
354 safe_strncpy(console, s, sizeof(console));
356 /* sparc kernel supports console=tty[ab] parameter which is also
357 * passed to init, so catch it here */
358 /* remap tty[ab] to /dev/ttyS[01] */
359 if (strcmp(s, "ttya") == 0)
360 safe_strncpy(console, SC_0, sizeof(console));
361 else if (strcmp(s, "ttyb") == 0)
362 safe_strncpy(console, SC_1, sizeof(console));
365 /* 2.2 kernels: identify the real console backend and try to use it */
366 if (ioctl(0, TIOCGSERIAL, &sr) == 0) {
367 /* this is a serial console */
368 snprintf(console, sizeof(console) - 1, SC_FORMAT, sr.line);
369 } else if (ioctl(0, VT_GETSTATE, &vt) == 0) {
370 /* this is linux virtual tty */
371 snprintf(console, sizeof(console) - 1, VC_FORMAT, vt.v_active);
373 safe_strncpy(console, _PATH_CONSOLE, sizeof(console));
378 while ((fd = open(console, O_RDONLY | O_NONBLOCK)) < 0 && tried < 2) {
379 /* Can't open selected console -- try
380 logical system console and VT_MASTER */
381 safe_strncpy(console, (tried == 0 ? _PATH_CONSOLE : CURRENT_VC),
386 /* Perhaps we should panic here? */
387 #ifndef CONFIG_SYSLOGD
390 safe_strncpy(console, "/dev/null", sizeof(console));
393 /* check for serial console */
394 if (ioctl(fd, TIOCGSERIAL, &sr) == 0) {
395 /* Force the TERM setting to vt102 for serial console --
396 * if TERM is set to linux (the default) */
397 if (s == NULL || strcmp(s, "linux") == 0)
398 putenv("TERM=vt102");
399 #ifndef CONFIG_SYSLOGD
404 putenv("TERM=linux");
408 messageD(LOG, "console=%s", console);
411 static void fixup_argv(int argc, char **argv, char *new_argv0)
415 /* Fix up argv[0] to be certain we claim to be init */
416 len = strlen(argv[0]);
417 memset(argv[0], 0, len);
418 safe_strncpy(argv[0], new_argv0, len + 1);
420 /* Wipe argv[1]-argv[N] so they don't clutter the ps listing */
423 memset(argv[len], 0, strlen(argv[len]));
428 static pid_t run(const struct init_action *a)
432 pid_t pid, pgrp, tmp_pid;
433 char *s, *tmpCmd, *cmd[INIT_BUFFS_SIZE], *cmdpath;
434 char buf[INIT_BUFFS_SIZE + 6]; /* INIT_BUFFS_SIZE+strlen("exec ")+1 */
435 sigset_t nmask, omask;
436 static const char press_enter[] =
437 #ifdef CUSTOMIZED_BANNER
438 #include CUSTOMIZED_BANNER
440 "\nPlease press Enter to activate this console. ";
442 /* Block sigchild while forking. */
444 sigaddset(&nmask, SIGCHLD);
445 sigprocmask(SIG_BLOCK, &nmask, &omask);
447 if ((pid = fork()) == 0) {
452 sigprocmask(SIG_SETMASK, &omask, NULL);
454 /* Reset signal handlers that were set by the parent process */
455 signal(SIGUSR1, SIG_DFL);
456 signal(SIGUSR2, SIG_DFL);
457 signal(SIGINT, SIG_DFL);
458 signal(SIGTERM, SIG_DFL);
459 signal(SIGHUP, SIG_DFL);
460 signal(SIGCONT, SIG_DFL);
461 signal(SIGSTOP, SIG_DFL);
462 signal(SIGTSTP, SIG_DFL);
464 /* Create a new session and make ourself the process
468 /* Open the new terminal device */
469 if ((device_open(a->terminal, O_RDWR)) < 0) {
470 if (stat(a->terminal, &sb) != 0) {
471 message(LOG | CONSOLE, "device '%s' does not exist.",
475 message(LOG | CONSOLE, "Bummer, can't open %s", a->terminal);
479 /* Make sure the terminal will act fairly normal for us */
481 /* Setup stdout, stderr for the new process so
482 * they point to the supplied terminal */
486 /* If the init Action requires us to wait, then force the
487 * supplied terminal to be the controlling tty. */
488 if (a->action & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) {
490 /* Now fork off another process to just hang around */
491 if ((pid = fork()) < 0) {
492 message(LOG | CONSOLE, "Can't fork!");
498 /* We are the parent -- wait till the child is done */
499 signal(SIGINT, SIG_IGN);
500 signal(SIGTSTP, SIG_IGN);
501 signal(SIGQUIT, SIG_IGN);
502 signal(SIGCHLD, SIG_DFL);
504 /* Wait for child to exit */
505 while ((tmp_pid = waitpid(pid, &junk, 0)) != pid) {
506 if (tmp_pid == -1 && errno == ECHILD) {
509 /* FIXME handle other errors */
512 /* See if stealing the controlling tty back is necessary */
514 if (pgrp != getpid())
517 /* Use a temporary process to steal the controlling tty. */
518 if ((pid = fork()) < 0) {
519 message(LOG | CONSOLE, "Can't fork!");
524 ioctl(0, TIOCSCTTY, 1);
527 while ((tmp_pid = waitpid(pid, &junk, 0)) != pid) {
528 if (tmp_pid < 0 && errno == ECHILD)
534 /* Now fall though to actually execute things */
537 /* See if any special /bin/sh requiring characters are present */
538 if (strpbrk(a->command, "~`!$^&*()=|\\{}[];\"'<>?") != NULL) {
539 cmd[0] = (char *)DEFAULT_SHELL;
541 cmd[2] = strcat(strcpy(buf, "exec "), a->command);
544 /* Convert command (char*) into cmd (char**, one word per string) */
545 strcpy(buf, a->command);
547 for (tmpCmd = buf, i = 0; (tmpCmd = strsep(&s, " \t")) != NULL;) {
548 if (*tmpCmd != '\0') {
559 Interactive shells want to see a dash in argv[0]. This
560 typically is handled by login, argv will be setup this
561 way if a dash appears at the front of the command path
565 if (*cmdpath == '-') {
567 /* skip over the dash */
570 /* find the last component in the command pathname */
571 s = bb_get_last_path_component(cmdpath);
573 /* make a new argv[0] */
574 if ((cmd[0] = malloc(strlen(s) + 2)) == NULL) {
575 message(LOG | CONSOLE, bb_msg_memory_exhausted);
579 strcpy(cmd[0] + 1, s);
583 if (a->action & ASKFIRST) {
586 * Save memory by not exec-ing anything large (like a shell)
587 * before the user wants it. This is critical if swap is not
588 * enabled and the system has low memory. Generally this will
589 * be run on the second virtual console, and the first will
590 * be allowed to start a shell or whatever an init script
593 messageD(LOG, "Waiting for enter to start '%s'"
594 "(pid %d, terminal %s)\n",
595 cmdpath, getpid(), a->terminal);
596 bb_full_write(1, press_enter, sizeof(press_enter) - 1);
597 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, SIGCHLD);
699 sigaddset(&block_signals, SIGUSR1);
700 sigaddset(&block_signals, SIGUSR2);
701 sigaddset(&block_signals, SIGINT);
702 sigaddset(&block_signals, SIGTERM);
703 sigaddset(&block_signals, SIGCONT);
704 sigaddset(&block_signals, SIGSTOP);
705 sigaddset(&block_signals, SIGTSTP);
706 sigprocmask(SIG_BLOCK, &block_signals, NULL);
708 /* Allow Ctrl-Alt-Del to reboot system. */
709 init_reboot(RB_ENABLE_CAD);
711 message(CONSOLE | LOG, "The system is going down NOW !!");
714 /* Send signals to every process _except_ pid 1 */
715 message(CONSOLE | LOG, "Sending SIGTERM to all processes.");
720 message(CONSOLE | LOG, "Sending SIGKILL to all processes.");
727 static void exec_signal(int sig)
729 struct init_action *a, *tmp;
730 sigset_t unblock_signals;
732 for (a = init_action_list; a; a = tmp) {
734 if (a->action & RESTART) {
739 /* unblock all signals, blocked in shutdown_system() */
740 sigemptyset(&unblock_signals);
741 sigaddset(&unblock_signals, SIGHUP);
742 sigaddset(&unblock_signals, SIGCHLD);
743 sigaddset(&unblock_signals, SIGUSR1);
744 sigaddset(&unblock_signals, SIGUSR2);
745 sigaddset(&unblock_signals, SIGINT);
746 sigaddset(&unblock_signals, SIGTERM);
747 sigaddset(&unblock_signals, SIGCONT);
748 sigaddset(&unblock_signals, SIGSTOP);
749 sigaddset(&unblock_signals, SIGTSTP);
750 sigprocmask(SIG_UNBLOCK, &unblock_signals, NULL);
752 /* Close whatever files are open. */
757 /* Open the new terminal device */
758 if ((device_open(a->terminal, O_RDWR)) < 0) {
759 if (stat(a->terminal, &sb) != 0) {
760 message(LOG | CONSOLE, "device '%s' does not exist.", a->terminal);
762 message(LOG | CONSOLE, "Bummer, can't open %s", a->terminal);
764 halt_signal(SIGUSR1);
767 /* Make sure the terminal will act fairly normal for us */
769 /* Setup stdout, stderr on the supplied terminal */
773 messageD(CONSOLE | LOG, "Trying to re-exec %s", a->command);
774 execl(a->command, a->command, NULL);
776 message(CONSOLE | LOG, "exec of '%s' failed: %m",
780 init_reboot(RB_HALT_SYSTEM);
786 static void halt_signal(int sig)
789 message(CONSOLE | LOG,
791 /* Seems the s390 console is Wierd(tm). */
792 "The system is halted. You may reboot now."
794 "The system is halted. Press Reset or turn off power"
799 /* allow time for last message to reach serial console */
803 init_reboot(RB_POWER_OFF);
805 init_reboot(RB_HALT_SYSTEM);
810 static void reboot_signal(int sig)
813 message(CONSOLE | LOG, "Please stand by while rebooting the system.");
816 /* allow time for last message to reach serial console */
819 init_reboot(RB_AUTOBOOT);
824 static void ctrlaltdel_signal(int sig)
826 run_actions(CTRLALTDEL);
829 /* The SIGSTOP & SIGTSTP handler */
830 static void stop_handler(int sig)
832 int saved_errno = errno;
841 /* The SIGCONT handler */
842 static void cont_handler(int sig)
847 #endif /* ! DEBUG_INIT */
849 static void new_init_action(int action, const char *command, const char *cons)
851 struct init_action *new_action, *a;
856 /* do not run entries if console device is not available */
857 if (access(cons, R_OK | W_OK))
859 if (strcmp(cons, "/dev/null") == 0 && (action & ASKFIRST))
862 new_action = calloc((size_t) (1), sizeof(struct init_action));
864 message(LOG | CONSOLE, "Memory allocation failure");
868 /* Append to the end of the list */
869 for (a = init_action_list; a && a->next; a = a->next) {
870 /* don't enter action if it's already in the list */
871 if ((strcmp(a->command, command) == 0) &&
872 (strcmp(a->terminal, cons) ==0)) {
878 a->next = new_action;
880 init_action_list = new_action;
882 strcpy(new_action->command, command);
883 new_action->action = action;
884 strcpy(new_action->terminal, cons);
885 #if 0 /* calloc zeroed always */
888 messageD(LOG|CONSOLE, "command='%s' action='%d' terminal='%s'\n",
889 new_action->command, new_action->action, new_action->terminal);
892 static void delete_init_action(struct init_action *action)
894 struct init_action *a, *b = NULL;
896 for (a = init_action_list; a; b = a, a = a->next) {
899 init_action_list = a->next;
909 /* Make sure there is enough memory to do something useful. *
910 * Calls "swapon -a" if needed so be sure /etc/fstab is present... */
911 static void check_memory(void)
915 if (check_free_memory() > 1000)
918 #if !defined(__UCLIBC__) || defined(__ARCH_HAS_MMU__)
919 if (stat("/etc/fstab", &statBuf) == 0) {
920 /* swapon -a requires /proc typically */
921 new_init_action(SYSINIT, "/bin/mount -t proc proc /proc", "");
922 /* Try to turn on swap */
923 new_init_action(SYSINIT, "/sbin/swapon -a", "");
924 run_actions(SYSINIT); /* wait and removing */
925 if (check_free_memory() < 1000)
933 message(CONSOLE, "Sorry, your computer does not have enough memory.");
937 /* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined,
938 * then parse_inittab() simply adds in some default
939 * actions(i.e., runs INIT_SCRIPT and then starts a pair
940 * of "askfirst" shells). If CONFIG_FEATURE_USE_INITTAB
941 * _is_ defined, but /etc/inittab is missing, this
942 * results in the same set of default behaviors.
944 static void parse_inittab(void)
946 #ifdef CONFIG_FEATURE_USE_INITTAB
948 char buf[INIT_BUFFS_SIZE], lineAsRead[INIT_BUFFS_SIZE];
949 char tmpConsole[CONSOLE_BUFF_SIZE];
950 char *id, *runlev, *action, *command, *eol;
951 const struct init_action_type *a = actions;
954 file = fopen(INITTAB, "r");
956 /* No inittab file -- set up some default behavior */
958 /* Reboot on Ctrl-Alt-Del */
959 new_init_action(CTRLALTDEL, "/sbin/reboot", "");
960 /* Umount all filesystems on halt/reboot */
961 new_init_action(SHUTDOWN, "/bin/umount -a -r", "");
962 #if !defined(__UCLIBC__) || defined(__ARCH_HAS_MMU__)
963 /* Swapoff on halt/reboot */
964 new_init_action(SHUTDOWN, "/sbin/swapoff -a", "");
966 /* Prepare to restart init when a HUP is received */
967 new_init_action(RESTART, "/sbin/init", "");
968 /* Askfirst shell on tty1-4 */
969 new_init_action(ASKFIRST, bb_default_login_shell, "");
970 new_init_action(ASKFIRST, bb_default_login_shell, VC_2);
971 new_init_action(ASKFIRST, bb_default_login_shell, VC_3);
972 new_init_action(ASKFIRST, bb_default_login_shell, VC_4);
974 new_init_action(SYSINIT, INIT_SCRIPT, "");
977 #ifdef CONFIG_FEATURE_USE_INITTAB
980 while (fgets(buf, INIT_BUFFS_SIZE, file) != NULL) {
981 /* Skip leading spaces */
982 for (id = buf; *id == ' ' || *id == '\t'; id++);
984 /* Skip the line if it's a comment */
985 if (*id == '#' || *id == '\n')
988 /* Trim the trailing \n */
989 eol = strrchr(id, '\n');
993 /* Keep a copy around for posterity's sake (and error msgs) */
994 strcpy(lineAsRead, buf);
996 /* Separate the ID field from the runlevels */
997 runlev = strchr(id, ':');
998 if (runlev == NULL || *(runlev + 1) == '\0') {
999 message(LOG | CONSOLE, "Bad inittab entry: %s", lineAsRead);
1006 /* Separate the runlevels from the action */
1007 action = strchr(runlev, ':');
1008 if (action == NULL || *(action + 1) == '\0') {
1009 message(LOG | CONSOLE, "Bad inittab entry: %s", lineAsRead);
1016 /* Separate the action from the command */
1017 command = strchr(action, ':');
1018 if (command == NULL || *(command + 1) == '\0') {
1019 message(LOG | CONSOLE, "Bad inittab entry: %s", lineAsRead);
1026 /* Ok, now process it */
1027 for (a = actions; a->name != 0; a++) {
1028 if (strcmp(a->name, action) == 0) {
1030 if(strncmp(id, "/dev/", 5) == 0)
1032 strcpy(tmpConsole, "/dev/");
1033 safe_strncpy(tmpConsole + 5, id,
1034 CONSOLE_BUFF_SIZE - 5);
1037 new_init_action(a->action, command, id);
1042 /* Choke on an unknown action */
1043 message(LOG | CONSOLE, "Bad inittab entry: %s", lineAsRead);
1048 #endif /* CONFIG_FEATURE_USE_INITTAB */
1051 static void reload_signal(int sig)
1053 message(LOG, "Reloading /etc/inittab");
1055 run_actions(RESPAWN);
1059 extern int init_main(int argc, char **argv)
1061 struct init_action *a;
1065 if (argc > 1 && !strcmp(argv[1], "-q")) {
1066 return kill_init(SIGHUP);
1069 /* Expect to be invoked as init with PID=1 or be invoked as linuxrc */
1071 #ifdef CONFIG_FEATURE_INITRD
1072 && strstr(bb_applet_name, "linuxrc") == NULL
1077 /* Set up sig handlers -- be sure to
1078 * clear all of these in run() */
1079 signal(SIGHUP, exec_signal);
1080 signal(SIGUSR1, halt_signal);
1081 signal(SIGUSR2, halt_signal);
1082 signal(SIGINT, ctrlaltdel_signal);
1083 signal(SIGTERM, reboot_signal);
1084 signal(SIGCONT, cont_handler);
1085 signal(SIGSTOP, stop_handler);
1086 signal(SIGTSTP, stop_handler);
1088 /* Turn off rebooting via CTL-ALT-DEL -- we get a
1089 * SIGINT on CAD so we can shut things down gracefully... */
1090 init_reboot(RB_DISABLE_CAD);
1093 /* Figure out where the default console should be */
1096 /* Close whatever files are open, and reset the console. */
1101 if (device_open(console, O_RDWR | O_NOCTTY) == 0) {
1109 const char * const *e;
1110 /* Make sure environs is set to something sane */
1111 for(e = environment; *e; e++)
1112 putenv((char *) *e);
1115 message(MAYBE_CONSOLE | LOG, "init started: %s", bb_msg_full_version);
1117 /* Make sure there is enough memory to do something useful. */
1120 /* Check if we are supposed to be in single user mode */
1121 if (argc > 1 && (!strcmp(argv[1], "single") ||
1122 !strcmp(argv[1], "-s") || !strcmp(argv[1], "1"))) {
1123 /* Start a shell on console */
1124 new_init_action(RESPAWN, bb_default_login_shell, "");
1126 /* Not in single user mode -- see what inittab says */
1128 /* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined,
1129 * then parse_inittab() simply adds in some default
1130 * actions(i.e., runs INIT_SCRIPT and then starts a pair
1131 * of "askfirst" shells */
1135 /* Make the command line just say "init" -- thats all, nothing else */
1136 fixup_argv(argc, argv, "init");
1138 /* Now run everything that needs to be run */
1140 /* First run the sysinit command */
1141 run_actions(SYSINIT);
1143 /* Next run anything that wants to block */
1146 /* Next run anything to be run only once */
1149 /* Redefine SIGHUP to reread /etc/inittab */
1150 signal(SIGHUP, reload_signal);
1152 /* Now run the looping stuff for the rest of forever */
1154 /* run the respawn stuff */
1155 run_actions(RESPAWN);
1157 /* run the askfirst stuff */
1158 run_actions(ASKFIRST);
1160 /* Don't consume all CPU time -- sleep a bit */
1163 /* Wait for a child process to exit */
1164 wpid = wait(&status);
1166 /* Find out who died and clean up their corpse */
1167 for (a = init_action_list; a; a = a->next) {
1168 if (a->pid == wpid) {
1169 /* Set the pid to 0 so that the process gets
1170 * restarted by run_actions() */
1172 message(LOG, "Process '%s' (pid %d) exited. "
1173 "Scheduling it for restart.",
1177 /* see if anyone else is waiting to be reaped */
1178 wpid = waitpid (-1, &status, WNOHANG);
1185 c-file-style: "linux"