source: MondoRescue/branches/2.2.5/mindi-busybox/init/init.c@ 3600

Last change on this file since 3600 was 1765, checked in by Bruno Cornec, 16 years ago

Update to busybox 1.7.2
File size: 25.5 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * Mini init implementation for busybox
4 *
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.
8 *
9 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
10 */
11
12#include "libbb.h"
13#include <paths.h>
14//#include <signal.h>
15//#include <sys/ioctl.h>
16//#include <sys/wait.h>
17#include <sys/reboot.h>
18
19#if ENABLE_FEATURE_INIT_SYSLOG
20# include <sys/syslog.h>
21#endif
22
23#define INIT_BUFFS_SIZE 256
24#define CONSOLE_NAME_SIZE 32
25#define MAXENV 16 /* Number of env. vars */
26
27#if ENABLE_FEATURE_INIT_COREDUMPS
28/*
29 * When a file named CORE_ENABLE_FLAG_FILE exists, setrlimit is called
30 * before processes are spawned to set core file size as unlimited.
31 * This is for debugging only. Don't use this is production, unless
32 * you want core dumps lying about....
33 */
34#define CORE_ENABLE_FLAG_FILE "/.init_enable_core"
35#include <sys/resource.h>
36#endif
37
38#define INITTAB "/etc/inittab" /* inittab file location */
39#ifndef INIT_SCRIPT
40#define INIT_SCRIPT "/etc/init.d/rcS" /* Default sysinit script. */
41#endif
42
43/* Allowed init action types */
44#define SYSINIT 0x001
45#define RESPAWN 0x002
46#define ASKFIRST 0x004
47#define WAIT 0x008
48#define ONCE 0x010
49#define CTRLALTDEL 0x020
50#define SHUTDOWN 0x040
51#define RESTART 0x080
52
53/* A mapping between "inittab" action name strings and action type codes. */
54struct init_action_type {
55 const char *name;
56 int action;
57};
58
59static const struct init_action_type actions[] = {
60 {"sysinit", SYSINIT},
61 {"respawn", RESPAWN},
62 {"askfirst", ASKFIRST},
63 {"wait", WAIT},
64 {"once", ONCE},
65 {"ctrlaltdel", CTRLALTDEL},
66 {"shutdown", SHUTDOWN},
67 {"restart", RESTART},
68 {0, 0}
69};
70
71/* Set up a linked list of init_actions, to be read from inittab */
72struct init_action {
73 struct init_action *next;
74 int action;
75 pid_t pid;
76 char command[INIT_BUFFS_SIZE];
77 char terminal[CONSOLE_NAME_SIZE];
78};
79
80/* Static variables */
81static struct init_action *init_action_list = NULL;
82
83#if !ENABLE_FEATURE_INIT_SYSLOG
84static const char *log_console = VC_5;
85#endif
86#if !ENABLE_DEBUG_INIT
87static sig_atomic_t got_cont = 0;
88#endif
89
90enum {
91 L_LOG = 0x1,
92 L_CONSOLE = 0x2,
93
94#if ENABLE_FEATURE_EXTRA_QUIET
95 MAYBE_CONSOLE = 0x0,
96#else
97 MAYBE_CONSOLE = L_CONSOLE,
98#endif
99
100#ifndef RB_HALT_SYSTEM
101 RB_HALT_SYSTEM = 0xcdef0123, /* FIXME: this overflows enum */
102 RB_ENABLE_CAD = 0x89abcdef,
103 RB_DISABLE_CAD = 0,
104 RB_POWER_OFF = 0x4321fedc,
105 RB_AUTOBOOT = 0x01234567,
106#endif
107};
108
109static const char *const environment[] = {
110 "HOME=/",
111 bb_PATH_root_path,
112 "SHELL=/bin/sh",
113 "USER=root",
114 NULL
115};
116
117/* Function prototypes */
118static void delete_init_action(struct init_action *a);
119static int waitfor(const struct init_action *a, pid_t pid);
120#if !ENABLE_DEBUG_INIT
121static void shutdown_signal(int sig);
122#endif
123
124#if !ENABLE_DEBUG_INIT
125static void loop_forever(void)
126{
127 while (1)
128 sleep(1);
129}
130#endif
131
132/* Print a message to the specified device.
133 * Device may be bitwise-or'd from L_LOG | L_CONSOLE */
134#if ENABLE_DEBUG_INIT
135#define messageD message
136#else
137#define messageD(...) do {} while (0)
138#endif
139static void message(int device, const char *fmt, ...)
140 __attribute__ ((format(printf, 2, 3)));
141static void message(int device, const char *fmt, ...)
142{
143#if !ENABLE_FEATURE_INIT_SYSLOG
144 static int log_fd = -1;
145#endif
146
147 va_list arguments;
148 int l;
149 char msg[128];
150
151 msg[0] = '\r';
152 va_start(arguments, fmt);
153 vsnprintf(msg + 1, sizeof(msg) - 2, fmt, arguments);
154 va_end(arguments);
155 msg[sizeof(msg) - 2] = '\0';
156 l = strlen(msg);
157
158#if ENABLE_FEATURE_INIT_SYSLOG
159 /* Log the message to syslogd */
160 if (device & L_LOG) {
161 /* don't out "\r" */
162 openlog(applet_name, 0, LOG_DAEMON);
163 syslog(LOG_INFO, "init: %s", msg + 1);
164 closelog();
165 }
166 msg[l++] = '\n';
167 msg[l] = '\0';
168#else
169 msg[l++] = '\n';
170 msg[l] = '\0';
171 /* Take full control of the log tty, and never close it.
172 * It's mine, all mine! Muhahahaha! */
173 if (log_fd < 0) {
174 if (!log_console) {
175 log_fd = 2;
176 } else {
177 log_fd = device_open(log_console, O_WRONLY | O_NONBLOCK | O_NOCTTY);
178 if (log_fd < 0) {
179 bb_error_msg("can't log to %s", log_console);
180 device = L_CONSOLE;
181 } else {
182 fcntl(log_fd, F_SETFD, FD_CLOEXEC);
183 }
184 }
185 }
186 if (device & L_LOG) {
187 full_write(log_fd, msg, l);
188 if (log_fd == 2)
189 return; /* don't print dup messages */
190 }
191#endif
192
193 if (device & L_CONSOLE) {
194 /* Send console messages to console so people will see them. */
195 full_write(2, msg, l);
196 }
197}
198
199/* Set terminal settings to reasonable defaults */
200static void set_sane_term(void)
201{
202 struct termios tty;
203
204 tcgetattr(STDIN_FILENO, &tty);
205
206 /* set control chars */
207 tty.c_cc[VINTR] = 3; /* C-c */
208 tty.c_cc[VQUIT] = 28; /* C-\ */
209 tty.c_cc[VERASE] = 127; /* C-? */
210 tty.c_cc[VKILL] = 21; /* C-u */
211 tty.c_cc[VEOF] = 4; /* C-d */
212 tty.c_cc[VSTART] = 17; /* C-q */
213 tty.c_cc[VSTOP] = 19; /* C-s */
214 tty.c_cc[VSUSP] = 26; /* C-z */
215
216 /* use line dicipline 0 */
217 tty.c_line = 0;
218
219 /* Make it be sane */
220 tty.c_cflag &= CBAUD | CBAUDEX | CSIZE | CSTOPB | PARENB | PARODD;
221 tty.c_cflag |= CREAD | HUPCL | CLOCAL;
222
223 /* input modes */
224 tty.c_iflag = ICRNL | IXON | IXOFF;
225
226 /* output modes */
227 tty.c_oflag = OPOST | ONLCR;
228
229 /* local modes */
230 tty.c_lflag =
231 ISIG | ICANON | ECHO | ECHOE | ECHOK | ECHOCTL | ECHOKE | IEXTEN;
232
233 tcsetattr(STDIN_FILENO, TCSANOW, &tty);
234}
235
236/* From <linux/serial.h> */
237struct serial_struct {
238 int type;
239 int line;
240 unsigned int port;
241 int irq;
242 int flags;
243 int xmit_fifo_size;
244 int custom_divisor;
245 int baud_base;
246 unsigned short close_delay;
247 char io_type;
248 char reserved_char[1];
249 int hub6;
250 unsigned short closing_wait; /* time to wait before closing */
251 unsigned short closing_wait2; /* no longer used... */
252 unsigned char *iomem_base;
253 unsigned short iomem_reg_shift;
254 unsigned int port_high;
255 unsigned long iomap_base; /* cookie passed into ioremap */
256 int reserved[1];
257 /* Paranoia (imagine 64bit kernel overwriting 32bit userspace stack) */
258 uint32_t bbox_reserved[16];
259};
260static void console_init(void)
261{
262 struct serial_struct sr;
263 char *s;
264
265 s = getenv("CONSOLE");
266 if (!s) s = getenv("console");
267 if (s) {
268 int fd = open(s, O_RDWR | O_NONBLOCK | O_NOCTTY);
269 if (fd >= 0) {
270 dup2(fd, 0);
271 dup2(fd, 1);
272 dup2(fd, 2);
273 while (fd > 2) close(fd--);
274 }
275 messageD(L_LOG, "console='%s'", s);
276 } else {
277 /* Make sure fd 0,1,2 are not closed */
278 bb_sanitize_stdio();
279 }
280
281 s = getenv("TERM");
282 if (ioctl(0, TIOCGSERIAL, &sr) == 0) {
283 /* Force the TERM setting to vt102 for serial console --
284 * if TERM is set to linux (the default) */
285 if (!s || strcmp(s, "linux") == 0)
286 putenv((char*)"TERM=vt102");
287#if !ENABLE_FEATURE_INIT_SYSLOG
288 log_console = NULL;
289#endif
290 } else if (!s)
291 putenv((char*)"TERM=linux");
292}
293
294static void fixup_argv(char **argv)
295{
296 /* Fix up argv[0] to be certain we claim to be init */
297 strncpy(argv[0], "init", strlen(argv[0]));
298
299 /* Wipe argv[1]-argv[N] so they don't clutter the ps listing */
300 while (*++argv)
301 memset(*argv, 0, strlen(*argv));
302}
303
304/* Open the new terminal device */
305static void open_stdio_to_tty(const char* tty_name, int fail)
306{
307 /* empty tty_name means "use init's tty", else... */
308 if (tty_name[0]) {
309 int fd = device_open(tty_name, O_RDWR);
310 if (fd < 0) {
311 message(L_LOG | L_CONSOLE, "Can't open %s: %s",
312 tty_name, strerror(errno));
313 if (fail)
314 _exit(1);
315#if !ENABLE_DEBUG_INIT
316 shutdown_signal(SIGUSR1);
317#else
318 _exit(2);
319#endif
320 } else {
321 dup2(fd, 0);
322 dup2(fd, 1);
323 dup2(fd, 2);
324 if (fd > 2) close(fd);
325 }
326 }
327 set_sane_term();
328}
329
330static pid_t run(const struct init_action *a)
331{
332 int i;
333 pid_t pid;
334 char *s, *tmpCmd, *cmdpath;
335 char *cmd[INIT_BUFFS_SIZE];
336 char buf[INIT_BUFFS_SIZE + 6]; /* INIT_BUFFS_SIZE+strlen("exec ")+1 */
337 sigset_t nmask, omask;
338
339 /* Block sigchild while forking. */
340 sigemptyset(&nmask);
341 sigaddset(&nmask, SIGCHLD);
342 sigprocmask(SIG_BLOCK, &nmask, &omask);
343 pid = fork();
344 sigprocmask(SIG_SETMASK, &omask, NULL);
345
346 if (pid)
347 return pid;
348
349 /* Reset signal handlers that were set by the parent process */
350 signal(SIGUSR1, SIG_DFL);
351 signal(SIGUSR2, SIG_DFL);
352 signal(SIGINT, SIG_DFL);
353 signal(SIGTERM, SIG_DFL);
354 signal(SIGHUP, SIG_DFL);
355 signal(SIGQUIT, SIG_DFL);
356 signal(SIGCONT, SIG_DFL);
357 signal(SIGSTOP, SIG_DFL);
358 signal(SIGTSTP, SIG_DFL);
359
360 /* Create a new session and make ourself the process
361 * group leader */
362 setsid();
363
364 /* Open the new terminal device */
365 open_stdio_to_tty(a->terminal, 1);
366
367 /* If the init Action requires us to wait, then force the
368 * supplied terminal to be the controlling tty. */
369 if (a->action & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) {
370
371 /* Now fork off another process to just hang around */
372 if ((pid = fork()) < 0) {
373 message(L_LOG | L_CONSOLE, "Can't fork");
374 _exit(1);
375 }
376
377 if (pid > 0) {
378
379 /* We are the parent -- wait till the child is done */
380 signal(SIGINT, SIG_IGN);
381 signal(SIGTSTP, SIG_IGN);
382 signal(SIGQUIT, SIG_IGN);
383 signal(SIGCHLD, SIG_DFL);
384
385 waitfor(NULL, pid);
386 /* See if stealing the controlling tty back is necessary */
387 if (tcgetpgrp(0) != getpid())
388 _exit(0);
389
390 /* Use a temporary process to steal the controlling tty. */
391 if ((pid = fork()) < 0) {
392 message(L_LOG | L_CONSOLE, "Can't fork");
393 _exit(1);
394 }
395 if (pid == 0) {
396 setsid();
397 ioctl(0, TIOCSCTTY, 1);
398 _exit(0);
399 }
400 waitfor(NULL, pid);
401 _exit(0);
402 }
403
404 /* Now fall though to actually execute things */
405 }
406
407 /* See if any special /bin/sh requiring characters are present */
408 if (strpbrk(a->command, "~`!$^&*()=|\\{}[];\"'<>?") != NULL) {
409 cmd[0] = (char*)DEFAULT_SHELL;
410 cmd[1] = (char*)"-c";
411 cmd[2] = strcat(strcpy(buf, "exec "), a->command);
412 cmd[3] = NULL;
413 } else {
414 /* Convert command (char*) into cmd (char**, one word per string) */
415 strcpy(buf, a->command);
416 s = buf;
417 for (tmpCmd = buf, i = 0; (tmpCmd = strsep(&s, " \t")) != NULL;) {
418 if (*tmpCmd != '\0') {
419 cmd[i] = tmpCmd;
420 i++;
421 }
422 }
423 cmd[i] = NULL;
424 }
425
426 cmdpath = cmd[0];
427
428 /*
429 * Interactive shells want to see a dash in argv[0]. This
430 * typically is handled by login, argv will be setup this
431 * way if a dash appears at the front of the command path
432 * (like "-/bin/sh").
433 */
434 if (*cmdpath == '-') {
435 /* skip over the dash */
436 ++cmdpath;
437
438 /* find the last component in the command pathname */
439 s = bb_get_last_path_component(cmdpath);
440
441 /* make a new argv[0] */
442 if ((cmd[0] = malloc(strlen(s) + 2)) == NULL) {
443 message(L_LOG | L_CONSOLE, bb_msg_memory_exhausted);
444 cmd[0] = cmdpath;
445 } else {
446 cmd[0][0] = '-';
447 strcpy(cmd[0] + 1, s);
448 }
449#if ENABLE_FEATURE_INIT_SCTTY
450 /* Establish this process as session leader and
451 * (attempt) to make the tty (if any) a controlling tty.
452 */
453 setsid();
454 ioctl(0, TIOCSCTTY, 0 /*don't steal it*/);
455#endif
456 }
457
458#if !defined(__UCLIBC__) || defined(__ARCH_HAS_MMU__)
459 if (a->action & ASKFIRST) {
460 static const char press_enter[] ALIGN1 =
461#ifdef CUSTOMIZED_BANNER
462#include CUSTOMIZED_BANNER
463#endif
464 "\nPlease press Enter to activate this console. ";
465 char c;
466 /*
467 * Save memory by not exec-ing anything large (like a shell)
468 * before the user wants it. This is critical if swap is not
469 * enabled and the system has low memory. Generally this will
470 * be run on the second virtual console, and the first will
471 * be allowed to start a shell or whatever an init script
472 * specifies.
473 */
474 messageD(L_LOG, "waiting for enter to start '%s'"
475 "(pid %d, tty '%s')\n",
476 cmdpath, getpid(), a->terminal);
477 full_write(1, press_enter, sizeof(press_enter) - 1);
478 while (read(0, &c, 1) == 1 && c != '\n')
479 ;
480 }
481#endif
482 /* Log the process name and args */
483 message(L_LOG, "starting pid %d, tty '%s': '%s'",
484 getpid(), a->terminal, cmdpath);
485
486#if ENABLE_FEATURE_INIT_COREDUMPS
487 {
488 struct stat sb;
489 if (stat(CORE_ENABLE_FLAG_FILE, &sb) == 0) {
490 struct rlimit limit;
491
492 limit.rlim_cur = RLIM_INFINITY;
493 limit.rlim_max = RLIM_INFINITY;
494 setrlimit(RLIMIT_CORE, &limit);
495 }
496 }
497#endif
498 /* Now run it. The new program will take over this PID,
499 * so nothing further in init.c should be run. */
500 BB_EXECVP(cmdpath, cmd);
501
502 /* We're still here? Some error happened. */
503 message(L_LOG | L_CONSOLE, "Cannot run '%s': %s",
504 cmdpath, strerror(errno));
505 _exit(-1);
506}
507
508static int waitfor(const struct init_action *a, pid_t pid)
509{
510 int runpid;
511 int status, wpid;
512
513 runpid = (NULL == a)? pid : run(a);
514 while (1) {
515 wpid = waitpid(runpid, &status, 0);
516 if (wpid == runpid)
517 break;
518 if (wpid == -1 && errno == ECHILD) {
519 /* we missed its termination */
520 break;
521 }
522 /* FIXME other errors should maybe trigger an error, but allow
523 * the program to continue */
524 }
525 return wpid;
526}
527
528/* Run all commands of a particular type */
529static void run_actions(int action)
530{
531 struct init_action *a, *tmp;
532
533 for (a = init_action_list; a; a = tmp) {
534 tmp = a->next;
535 if (a->action == action) {
536 /* a->terminal of "" means "init's console" */
537 if (a->terminal[0] && access(a->terminal, R_OK | W_OK)) {
538 delete_init_action(a);
539 } else if (a->action & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) {
540 waitfor(a, 0);
541 delete_init_action(a);
542 } else if (a->action & ONCE) {
543 run(a);
544 delete_init_action(a);
545 } else if (a->action & (RESPAWN | ASKFIRST)) {
546 /* Only run stuff with pid==0. If they have
547 * a pid, that means it is still running */
548 if (a->pid == 0) {
549 a->pid = run(a);
550 }
551 }
552 }
553 }
554}
555
556#if !ENABLE_DEBUG_INIT
557static void init_reboot(unsigned long magic)
558{
559 pid_t pid;
560 /* We have to fork here, since the kernel calls do_exit(0) in
561 * linux/kernel/sys.c, which can cause the machine to panic when
562 * the init process is killed.... */
563 pid = vfork();
564 if (pid == 0) { /* child */
565 reboot(magic);
566 _exit(0);
567 }
568 waitpid(pid, NULL, 0);
569}
570
571static void shutdown_system(void)
572{
573 sigset_t block_signals;
574
575 /* run everything to be run at "shutdown". This is done _prior_
576 * to killing everything, in case people wish to use scripts to
577 * shut things down gracefully... */
578 run_actions(SHUTDOWN);
579
580 /* first disable all our signals */
581 sigemptyset(&block_signals);
582 sigaddset(&block_signals, SIGHUP);
583 sigaddset(&block_signals, SIGQUIT);
584 sigaddset(&block_signals, SIGCHLD);
585 sigaddset(&block_signals, SIGUSR1);
586 sigaddset(&block_signals, SIGUSR2);
587 sigaddset(&block_signals, SIGINT);
588 sigaddset(&block_signals, SIGTERM);
589 sigaddset(&block_signals, SIGCONT);
590 sigaddset(&block_signals, SIGSTOP);
591 sigaddset(&block_signals, SIGTSTP);
592 sigprocmask(SIG_BLOCK, &block_signals, NULL);
593
594 message(L_CONSOLE | L_LOG, "The system is going down NOW!");
595
596 /* Allow Ctrl-Alt-Del to reboot system. */
597 init_reboot(RB_ENABLE_CAD);
598
599 /* Send signals to every process _except_ pid 1 */
600 message(L_CONSOLE | L_LOG, "Sending SIG%s to all processes", "TERM");
601 kill(-1, SIGTERM);
602 sync();
603 sleep(1);
604
605 message(L_CONSOLE | L_LOG, "Sending SIG%s to all processes", "KILL");
606 kill(-1, SIGKILL);
607 sync();
608 sleep(1);
609}
610
611static void exec_signal(int sig ATTRIBUTE_UNUSED)
612{
613 struct init_action *a, *tmp;
614 sigset_t unblock_signals;
615
616 for (a = init_action_list; a; a = tmp) {
617 tmp = a->next;
618 if (a->action & RESTART) {
619 shutdown_system();
620
621 /* unblock all signals, blocked in shutdown_system() */
622 sigemptyset(&unblock_signals);
623 sigaddset(&unblock_signals, SIGHUP);
624 sigaddset(&unblock_signals, SIGQUIT);
625 sigaddset(&unblock_signals, SIGCHLD);
626 sigaddset(&unblock_signals, SIGUSR1);
627 sigaddset(&unblock_signals, SIGUSR2);
628 sigaddset(&unblock_signals, SIGINT);
629 sigaddset(&unblock_signals, SIGTERM);
630 sigaddset(&unblock_signals, SIGCONT);
631 sigaddset(&unblock_signals, SIGSTOP);
632 sigaddset(&unblock_signals, SIGTSTP);
633 sigprocmask(SIG_UNBLOCK, &unblock_signals, NULL);
634
635 /* Open the new terminal device */
636 open_stdio_to_tty(a->terminal, 0);
637
638 messageD(L_CONSOLE | L_LOG, "Trying to re-exec %s", a->command);
639 BB_EXECLP(a->command, a->command, NULL);
640
641 message(L_CONSOLE | L_LOG, "Cannot run '%s': %s",
642 a->command, strerror(errno));
643 sleep(2);
644 init_reboot(RB_HALT_SYSTEM);
645 loop_forever();
646 }
647 }
648}
649
650static void shutdown_signal(int sig)
651{
652 const char *m;
653 int rb;
654
655 shutdown_system();
656
657 m = "halt";
658 rb = RB_HALT_SYSTEM;
659 if (sig == SIGTERM) {
660 m = "reboot";
661 rb = RB_AUTOBOOT;
662 } else if (sig == SIGUSR2) {
663 m = "poweroff";
664 rb = RB_POWER_OFF;
665 }
666 message(L_CONSOLE | L_LOG, "Requesting system %s", m);
667 /* allow time for last message to reach serial console */
668 sleep(2);
669 init_reboot(rb);
670 loop_forever();
671}
672
673static void ctrlaltdel_signal(int sig ATTRIBUTE_UNUSED)
674{
675 run_actions(CTRLALTDEL);
676}
677
678/* The SIGSTOP & SIGTSTP handler */
679static void stop_handler(int sig ATTRIBUTE_UNUSED)
680{
681 int saved_errno = errno;
682
683 got_cont = 0;
684 while (!got_cont)
685 pause();
686 got_cont = 0;
687 errno = saved_errno;
688}
689
690/* The SIGCONT handler */
691static void cont_handler(int sig ATTRIBUTE_UNUSED)
692{
693 got_cont = 1;
694}
695
696#endif /* !ENABLE_DEBUG_INIT */
697
698static void new_init_action(int action, const char *command, const char *cons)
699{
700 struct init_action *new_action, *a, *last;
701
702 if (strcmp(cons, bb_dev_null) == 0 && (action & ASKFIRST))
703 return;
704
705 /* Append to the end of the list */
706 for (a = last = init_action_list; a; a = a->next) {
707 /* don't enter action if it's already in the list,
708 * but do overwrite existing actions */
709 if ((strcmp(a->command, command) == 0)
710 && (strcmp(a->terminal, cons) == 0)
711 ) {
712 a->action = action;
713 return;
714 }
715 last = a;
716 }
717
718 new_action = xzalloc(sizeof(struct init_action));
719 if (last) {
720 last->next = new_action;
721 } else {
722 init_action_list = new_action;
723 }
724 strcpy(new_action->command, command);
725 new_action->action = action;
726 strcpy(new_action->terminal, cons);
727 messageD(L_LOG | L_CONSOLE, "command='%s' action=%d tty='%s'\n",
728 new_action->command, new_action->action, new_action->terminal);
729}
730
731static void delete_init_action(struct init_action *action)
732{
733 struct init_action *a, *b = NULL;
734
735 for (a = init_action_list; a; b = a, a = a->next) {
736 if (a == action) {
737 if (b == NULL) {
738 init_action_list = a->next;
739 } else {
740 b->next = a->next;
741 }
742 free(a);
743 break;
744 }
745 }
746}
747
748/* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined,
749 * then parse_inittab() simply adds in some default
750 * actions(i.e., runs INIT_SCRIPT and then starts a pair
751 * of "askfirst" shells). If CONFIG_FEATURE_USE_INITTAB
752 * _is_ defined, but /etc/inittab is missing, this
753 * results in the same set of default behaviors.
754 */
755static void parse_inittab(void)
756{
757#if ENABLE_FEATURE_USE_INITTAB
758 FILE *file;
759 char buf[INIT_BUFFS_SIZE], lineAsRead[INIT_BUFFS_SIZE];
760 char tmpConsole[CONSOLE_NAME_SIZE];
761 char *id, *runlev, *action, *command, *eol;
762 const struct init_action_type *a = actions;
763
764 file = fopen(INITTAB, "r");
765 if (file == NULL) {
766 /* No inittab file -- set up some default behavior */
767#endif
768 /* Reboot on Ctrl-Alt-Del */
769 new_init_action(CTRLALTDEL, "reboot", "");
770 /* Umount all filesystems on halt/reboot */
771 new_init_action(SHUTDOWN, "umount -a -r", "");
772 /* Swapoff on halt/reboot */
773 if (ENABLE_SWAPONOFF) new_init_action(SHUTDOWN, "swapoff -a", "");
774 /* Prepare to restart init when a HUP is received */
775 new_init_action(RESTART, "init", "");
776 /* Askfirst shell on tty1-4 */
777 new_init_action(ASKFIRST, bb_default_login_shell, "");
778 new_init_action(ASKFIRST, bb_default_login_shell, VC_2);
779 new_init_action(ASKFIRST, bb_default_login_shell, VC_3);
780 new_init_action(ASKFIRST, bb_default_login_shell, VC_4);
781 /* sysinit */
782 new_init_action(SYSINIT, INIT_SCRIPT, "");
783
784 return;
785#if ENABLE_FEATURE_USE_INITTAB
786 }
787
788 while (fgets(buf, INIT_BUFFS_SIZE, file) != NULL) {
789 /* Skip leading spaces */
790 for (id = buf; *id == ' ' || *id == '\t'; id++);
791
792 /* Skip the line if it's a comment */
793 if (*id == '#' || *id == '\n')
794 continue;
795
796 /* Trim the trailing \n */
797 //XXX: chomp() ?
798 eol = strrchr(id, '\n');
799 if (eol != NULL)
800 *eol = '\0';
801
802 /* Keep a copy around for posterity's sake (and error msgs) */
803 strcpy(lineAsRead, buf);
804
805 /* Separate the ID field from the runlevels */
806 runlev = strchr(id, ':');
807 if (runlev == NULL || *(runlev + 1) == '\0') {
808 message(L_LOG | L_CONSOLE, "Bad inittab entry: %s", lineAsRead);
809 continue;
810 } else {
811 *runlev = '\0';
812 ++runlev;
813 }
814
815 /* Separate the runlevels from the action */
816 action = strchr(runlev, ':');
817 if (action == NULL || *(action + 1) == '\0') {
818 message(L_LOG | L_CONSOLE, "Bad inittab entry: %s", lineAsRead);
819 continue;
820 } else {
821 *action = '\0';
822 ++action;
823 }
824
825 /* Separate the action from the command */
826 command = strchr(action, ':');
827 if (command == NULL || *(command + 1) == '\0') {
828 message(L_LOG | L_CONSOLE, "Bad inittab entry: %s", lineAsRead);
829 continue;
830 } else {
831 *command = '\0';
832 ++command;
833 }
834
835 /* Ok, now process it */
836 for (a = actions; a->name != 0; a++) {
837 if (strcmp(a->name, action) == 0) {
838 if (*id != '\0') {
839 if (strncmp(id, "/dev/", 5) == 0)
840 id += 5;
841 strcpy(tmpConsole, "/dev/");
842 safe_strncpy(tmpConsole + 5, id,
843 sizeof(tmpConsole) - 5);
844 id = tmpConsole;
845 }
846 new_init_action(a->action, command, id);
847 break;
848 }
849 }
850 if (a->name == 0) {
851 /* Choke on an unknown action */
852 message(L_LOG | L_CONSOLE, "Bad inittab entry: %s", lineAsRead);
853 }
854 }
855 fclose(file);
856#endif /* FEATURE_USE_INITTAB */
857}
858
859#if ENABLE_FEATURE_USE_INITTAB
860static void reload_signal(int sig ATTRIBUTE_UNUSED)
861{
862 struct init_action *a, *tmp;
863
864 message(L_LOG, "reloading /etc/inittab");
865
866 /* disable old entrys */
867 for (a = init_action_list; a; a = a->next ) {
868 a->action = ONCE;
869 }
870
871 parse_inittab();
872
873 /* remove unused entrys */
874 for (a = init_action_list; a; a = tmp) {
875 tmp = a->next;
876 if ((a->action & (ONCE | SYSINIT | WAIT)) && a->pid == 0) {
877 delete_init_action(a);
878 }
879 }
880 run_actions(RESPAWN);
881}
882#endif /* FEATURE_USE_INITTAB */
883
884int init_main(int argc, char **argv);
885int init_main(int argc, char **argv)
886{
887 struct init_action *a;
888 pid_t wpid;
889
890 die_sleep = 30 * 24*60*60; /* if xmalloc will ever die... */
891
892 if (argc > 1 && !strcmp(argv[1], "-q")) {
893 return kill(1, SIGHUP);
894 }
895#if !ENABLE_DEBUG_INIT
896 /* Expect to be invoked as init with PID=1 or be invoked as linuxrc */
897 if (getpid() != 1
898 && (!ENABLE_FEATURE_INITRD || !strstr(applet_name, "linuxrc"))
899 ) {
900 bb_show_usage();
901 }
902 /* Set up sig handlers -- be sure to
903 * clear all of these in run() */
904 signal(SIGHUP, exec_signal);
905 signal(SIGQUIT, exec_signal);
906 signal(SIGUSR1, shutdown_signal);
907 signal(SIGUSR2, shutdown_signal);
908 signal(SIGINT, ctrlaltdel_signal);
909 signal(SIGTERM, shutdown_signal);
910 signal(SIGCONT, cont_handler);
911 signal(SIGSTOP, stop_handler);
912 signal(SIGTSTP, stop_handler);
913
914 /* Turn off rebooting via CTL-ALT-DEL -- we get a
915 * SIGINT on CAD so we can shut things down gracefully... */
916 init_reboot(RB_DISABLE_CAD);
917#endif
918
919
920 /* Figure out where the default console should be */
921 console_init();
922 set_sane_term();
923 chdir("/");
924 setsid();
925 {
926 const char *const *e;
927 /* Make sure environs is set to something sane */
928 for (e = environment; *e; e++)
929 putenv((char *) *e);
930 }
931
932 if (argc > 1) setenv("RUNLEVEL", argv[1], 1);
933
934 /* Hello world */
935 message(MAYBE_CONSOLE | L_LOG, "init started: %s", bb_banner);
936
937 /* Make sure there is enough memory to do something useful. */
938 if (ENABLE_SWAPONOFF) {
939 struct sysinfo info;
940
941 if (!sysinfo(&info) &&
942 (info.mem_unit ? : 1) * (long long)info.totalram < 1024*1024)
943 {
944 message(L_CONSOLE, "Low memory, forcing swapon");
945 /* swapon -a requires /proc typically */
946 new_init_action(SYSINIT, "mount -t proc proc /proc", "");
947 /* Try to turn on swap */
948 new_init_action(SYSINIT, "swapon -a", "");
949 run_actions(SYSINIT); /* wait and removing */
950 }
951 }
952
953 /* Check if we are supposed to be in single user mode */
954 if (argc > 1
955 && (!strcmp(argv[1], "single") || !strcmp(argv[1], "-s") || LONE_CHAR(argv[1], '1'))
956 ) {
957 /* Start a shell on console */
958 new_init_action(RESPAWN, bb_default_login_shell, "");
959 } else {
960 /* Not in single user mode -- see what inittab says */
961
962 /* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined,
963 * then parse_inittab() simply adds in some default
964 * actions(i.e., runs INIT_SCRIPT and then starts a pair
965 * of "askfirst" shells */
966 parse_inittab();
967 }
968
969#if ENABLE_SELINUX
970 if (getenv("SELINUX_INIT") == NULL) {
971 int enforce = 0;
972
973 putenv((char*)"SELINUX_INIT=YES");
974 if (selinux_init_load_policy(&enforce) == 0) {
975 BB_EXECVP(argv[0], argv);
976 } else if (enforce > 0) {
977 /* SELinux in enforcing mode but load_policy failed */
978 /* At this point, we probably can't open /dev/console, so log() won't work */
979 message(L_CONSOLE, "Cannot load SELinux Policy. "
980 "Machine is in enforcing mode. Halting now.");
981 exit(1);
982 }
983 }
984#endif /* CONFIG_SELINUX */
985
986 /* Make the command line just say "init" -- thats all, nothing else */
987 fixup_argv(argv);
988
989 /* Now run everything that needs to be run */
990
991 /* First run the sysinit command */
992 run_actions(SYSINIT);
993
994 /* Next run anything that wants to block */
995 run_actions(WAIT);
996
997 /* Next run anything to be run only once */
998 run_actions(ONCE);
999
1000#if ENABLE_FEATURE_USE_INITTAB
1001 /* Redefine SIGHUP to reread /etc/inittab */
1002 signal(SIGHUP, reload_signal);
1003#else
1004 signal(SIGHUP, SIG_IGN);
1005#endif /* FEATURE_USE_INITTAB */
1006
1007 /* Now run the looping stuff for the rest of forever */
1008 while (1) {
1009 /* run the respawn stuff */
1010 run_actions(RESPAWN);
1011
1012 /* run the askfirst stuff */
1013 run_actions(ASKFIRST);
1014
1015 /* Don't consume all CPU time -- sleep a bit */
1016 sleep(1);
1017
1018 /* Wait for a child process to exit */
1019 wpid = wait(NULL);
1020 while (wpid > 0) {
1021 /* Find out who died and clean up their corpse */
1022 for (a = init_action_list; a; a = a->next) {
1023 if (a->pid == wpid) {
1024 /* Set the pid to 0 so that the process gets
1025 * restarted by run_actions() */
1026 a->pid = 0;
1027 message(L_LOG, "process '%s' (pid %d) exited. "
1028 "Scheduling it for restart.",
1029 a->command, wpid);
1030 }
1031 }
1032 /* see if anyone else is waiting to be reaped */
1033 wpid = waitpid(-1, NULL, WNOHANG);
1034 }
1035 }
1036}
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