Annotation of /trunk/mkinitrd-magellan/busybox/init/init.c
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Revision 816 -
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Fri Apr 24 18:33:46 2009 UTC (15 years ago) by niro
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Fri Apr 24 18:33:46 2009 UTC (15 years ago) by niro
File MIME type: text/plain
File size: 25272 byte(s)
-updated to busybox-1.13.4
1 | niro | 532 | /* 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 | niro | 816 | #include "libbb.h" |
13 | #include <syslog.h> | ||
14 | niro | 532 | #include <paths.h> |
15 | #include <sys/reboot.h> | ||
16 | |||
17 | niro | 816 | /* Was a CONFIG_xxx option. A lot of people were building |
18 | * not fully functional init by switching it on! */ | ||
19 | #define DEBUG_INIT 0 | ||
20 | niro | 532 | |
21 | niro | 816 | #define COMMAND_SIZE 256 |
22 | #define CONSOLE_NAME_SIZE 32 | ||
23 | #define MAXENV 16 /* Number of env. vars */ | ||
24 | niro | 532 | |
25 | /* | ||
26 | * When a file named CORE_ENABLE_FLAG_FILE exists, setrlimit is called | ||
27 | * before processes are spawned to set core file size as unlimited. | ||
28 | * This is for debugging only. Don't use this is production, unless | ||
29 | * you want core dumps lying about.... | ||
30 | */ | ||
31 | #define CORE_ENABLE_FLAG_FILE "/.init_enable_core" | ||
32 | #include <sys/resource.h> | ||
33 | |||
34 | #define INITTAB "/etc/inittab" /* inittab file location */ | ||
35 | #ifndef INIT_SCRIPT | ||
36 | #define INIT_SCRIPT "/etc/init.d/rcS" /* Default sysinit script. */ | ||
37 | #endif | ||
38 | |||
39 | /* Allowed init action types */ | ||
40 | niro | 816 | #define SYSINIT 0x01 |
41 | #define RESPAWN 0x02 | ||
42 | /* like respawn, but wait for <Enter> to be pressed on tty: */ | ||
43 | #define ASKFIRST 0x04 | ||
44 | #define WAIT 0x08 | ||
45 | #define ONCE 0x10 | ||
46 | #define CTRLALTDEL 0x20 | ||
47 | #define SHUTDOWN 0x40 | ||
48 | #define RESTART 0x80 | ||
49 | niro | 532 | |
50 | /* Set up a linked list of init_actions, to be read from inittab */ | ||
51 | struct init_action { | ||
52 | niro | 816 | struct init_action *next; |
53 | niro | 532 | pid_t pid; |
54 | niro | 816 | uint8_t action_type; |
55 | char terminal[CONSOLE_NAME_SIZE]; | ||
56 | char command[COMMAND_SIZE]; | ||
57 | niro | 532 | }; |
58 | |||
59 | /* Static variables */ | ||
60 | static struct init_action *init_action_list = NULL; | ||
61 | |||
62 | niro | 816 | static const char *log_console = VC_5; |
63 | niro | 532 | |
64 | enum { | ||
65 | niro | 816 | L_LOG = 0x1, |
66 | L_CONSOLE = 0x2, | ||
67 | niro | 532 | |
68 | #if ENABLE_FEATURE_EXTRA_QUIET | ||
69 | MAYBE_CONSOLE = 0x0, | ||
70 | #else | ||
71 | niro | 816 | MAYBE_CONSOLE = L_CONSOLE, |
72 | niro | 532 | #endif |
73 | |||
74 | #ifndef RB_HALT_SYSTEM | ||
75 | RB_HALT_SYSTEM = 0xcdef0123, /* FIXME: this overflows enum */ | ||
76 | RB_ENABLE_CAD = 0x89abcdef, | ||
77 | RB_DISABLE_CAD = 0, | ||
78 | RB_POWER_OFF = 0x4321fedc, | ||
79 | RB_AUTOBOOT = 0x01234567, | ||
80 | #endif | ||
81 | }; | ||
82 | |||
83 | /* Function prototypes */ | ||
84 | niro | 816 | static void halt_reboot_pwoff(int sig) NORETURN; |
85 | niro | 532 | |
86 | niro | 816 | static void waitfor(pid_t pid) |
87 | { | ||
88 | /* waitfor(run(x)): protect against failed fork inside run() */ | ||
89 | if (pid <= 0) | ||
90 | return; | ||
91 | |||
92 | /* Wait for any child (prevent zombies from exiting orphaned processes) | ||
93 | * but exit the loop only when specified one has exited. */ | ||
94 | while (wait(NULL) != pid) | ||
95 | continue; | ||
96 | } | ||
97 | |||
98 | static void loop_forever(void) NORETURN; | ||
99 | niro | 532 | static void loop_forever(void) |
100 | { | ||
101 | while (1) | ||
102 | sleep(1); | ||
103 | } | ||
104 | |||
105 | /* Print a message to the specified device. | ||
106 | niro | 816 | * "where" may be bitwise-or'd from L_LOG | L_CONSOLE |
107 | * NB: careful, we can be called after vfork! | ||
108 | */ | ||
109 | #define messageD(...) do { if (DEBUG_INIT) message(__VA_ARGS__); } while (0) | ||
110 | static void message(int where, const char *fmt, ...) | ||
111 | niro | 532 | __attribute__ ((format(printf, 2, 3))); |
112 | niro | 816 | static void message(int where, const char *fmt, ...) |
113 | niro | 532 | { |
114 | niro | 816 | static int log_fd = -1; |
115 | niro | 532 | va_list arguments; |
116 | niro | 816 | unsigned l; |
117 | char msg[128]; | ||
118 | niro | 532 | |
119 | msg[0] = '\r'; | ||
120 | niro | 816 | va_start(arguments, fmt); |
121 | l = 1 + vsnprintf(msg + 1, sizeof(msg) - 2, fmt, arguments); | ||
122 | if (l > sizeof(msg) - 1) | ||
123 | l = sizeof(msg) - 1; | ||
124 | msg[l] = '\0'; | ||
125 | va_end(arguments); | ||
126 | niro | 532 | |
127 | niro | 816 | if (ENABLE_FEATURE_INIT_SYSLOG) { |
128 | if (where & L_LOG) { | ||
129 | /* Log the message to syslogd */ | ||
130 | openlog("init", 0, LOG_DAEMON); | ||
131 | /* don't print "\r" */ | ||
132 | syslog(LOG_INFO, "%s", msg + 1); | ||
133 | closelog(); | ||
134 | } | ||
135 | msg[l++] = '\n'; | ||
136 | msg[l] = '\0'; | ||
137 | } else { | ||
138 | msg[l++] = '\n'; | ||
139 | msg[l] = '\0'; | ||
140 | /* Take full control of the log tty, and never close it. | ||
141 | * It's mine, all mine! Muhahahaha! */ | ||
142 | if (log_fd < 0) { | ||
143 | if (!log_console) { | ||
144 | log_fd = STDERR_FILENO; | ||
145 | } else { | ||
146 | log_fd = device_open(log_console, O_WRONLY | O_NONBLOCK | O_NOCTTY); | ||
147 | if (log_fd < 0) { | ||
148 | bb_error_msg("can't log to %s", log_console); | ||
149 | where = L_CONSOLE; | ||
150 | } else { | ||
151 | close_on_exec_on(log_fd); | ||
152 | } | ||
153 | } | ||
154 | } | ||
155 | if (where & L_LOG) { | ||
156 | full_write(log_fd, msg, l); | ||
157 | if (log_fd == STDERR_FILENO) | ||
158 | return; /* don't print dup messages */ | ||
159 | } | ||
160 | niro | 532 | } |
161 | |||
162 | niro | 816 | if (where & L_CONSOLE) { |
163 | /* Send console messages to console so people will see them. */ | ||
164 | full_write(STDERR_FILENO, msg, l); | ||
165 | niro | 532 | } |
166 | niro | 816 | } |
167 | niro | 532 | |
168 | niro | 816 | /* From <linux/serial.h> */ |
169 | struct serial_struct { | ||
170 | int type; | ||
171 | int line; | ||
172 | unsigned int port; | ||
173 | int irq; | ||
174 | int flags; | ||
175 | int xmit_fifo_size; | ||
176 | int custom_divisor; | ||
177 | int baud_base; | ||
178 | unsigned short close_delay; | ||
179 | char io_type; | ||
180 | char reserved_char[1]; | ||
181 | int hub6; | ||
182 | unsigned short closing_wait; /* time to wait before closing */ | ||
183 | unsigned short closing_wait2; /* no longer used... */ | ||
184 | unsigned char *iomem_base; | ||
185 | unsigned short iomem_reg_shift; | ||
186 | unsigned int port_high; | ||
187 | unsigned long iomap_base; /* cookie passed into ioremap */ | ||
188 | int reserved[1]; | ||
189 | /* Paranoia (imagine 64bit kernel overwriting 32bit userspace stack) */ | ||
190 | uint32_t bbox_reserved[16]; | ||
191 | }; | ||
192 | static void console_init(void) | ||
193 | { | ||
194 | struct serial_struct sr; | ||
195 | char *s; | ||
196 | |||
197 | s = getenv("CONSOLE"); | ||
198 | if (!s) | ||
199 | s = getenv("console"); | ||
200 | if (s) { | ||
201 | int fd = open(s, O_RDWR | O_NONBLOCK | O_NOCTTY); | ||
202 | niro | 532 | if (fd >= 0) { |
203 | niro | 816 | dup2(fd, STDIN_FILENO); |
204 | dup2(fd, STDOUT_FILENO); | ||
205 | xmove_fd(fd, STDERR_FILENO); | ||
206 | niro | 532 | } |
207 | niro | 816 | messageD(L_LOG, "console='%s'", s); |
208 | } else { | ||
209 | /* Make sure fd 0,1,2 are not closed | ||
210 | * (so that they won't be used by future opens) */ | ||
211 | bb_sanitize_stdio(); | ||
212 | // Users report problems | ||
213 | // /* Make sure init can't be blocked by writing to stderr */ | ||
214 | // fcntl(STDERR_FILENO, F_SETFL, fcntl(STDERR_FILENO, F_GETFL) | O_NONBLOCK); | ||
215 | niro | 532 | } |
216 | niro | 816 | |
217 | s = getenv("TERM"); | ||
218 | if (ioctl(STDIN_FILENO, TIOCGSERIAL, &sr) == 0) { | ||
219 | /* Force the TERM setting to vt102 for serial console | ||
220 | * if TERM is set to linux (the default) */ | ||
221 | if (!s || strcmp(s, "linux") == 0) | ||
222 | putenv((char*)"TERM=vt102"); | ||
223 | if (!ENABLE_FEATURE_INIT_SYSLOG) | ||
224 | log_console = NULL; | ||
225 | } else if (!s) | ||
226 | putenv((char*)"TERM=linux"); | ||
227 | niro | 532 | } |
228 | |||
229 | niro | 816 | /* Set terminal settings to reasonable defaults. |
230 | * NB: careful, we can be called after vfork! */ | ||
231 | static void set_sane_term(void) | ||
232 | niro | 532 | { |
233 | struct termios tty; | ||
234 | |||
235 | tcgetattr(STDIN_FILENO, &tty); | ||
236 | |||
237 | /* set control chars */ | ||
238 | tty.c_cc[VINTR] = 3; /* C-c */ | ||
239 | tty.c_cc[VQUIT] = 28; /* C-\ */ | ||
240 | tty.c_cc[VERASE] = 127; /* C-? */ | ||
241 | tty.c_cc[VKILL] = 21; /* C-u */ | ||
242 | tty.c_cc[VEOF] = 4; /* C-d */ | ||
243 | tty.c_cc[VSTART] = 17; /* C-q */ | ||
244 | tty.c_cc[VSTOP] = 19; /* C-s */ | ||
245 | tty.c_cc[VSUSP] = 26; /* C-z */ | ||
246 | |||
247 | niro | 816 | /* use line discipline 0 */ |
248 | niro | 532 | tty.c_line = 0; |
249 | |||
250 | /* Make it be sane */ | ||
251 | tty.c_cflag &= CBAUD | CBAUDEX | CSIZE | CSTOPB | PARENB | PARODD; | ||
252 | tty.c_cflag |= CREAD | HUPCL | CLOCAL; | ||
253 | |||
254 | /* input modes */ | ||
255 | tty.c_iflag = ICRNL | IXON | IXOFF; | ||
256 | |||
257 | /* output modes */ | ||
258 | tty.c_oflag = OPOST | ONLCR; | ||
259 | |||
260 | /* local modes */ | ||
261 | tty.c_lflag = | ||
262 | ISIG | ICANON | ECHO | ECHOE | ECHOK | ECHOCTL | ECHOKE | IEXTEN; | ||
263 | |||
264 | niro | 816 | tcsetattr_stdin_TCSANOW(&tty); |
265 | niro | 532 | } |
266 | |||
267 | niro | 816 | /* Open the new terminal device. |
268 | * NB: careful, we can be called after vfork! */ | ||
269 | static void open_stdio_to_tty(const char* tty_name, int exit_on_failure) | ||
270 | niro | 532 | { |
271 | niro | 816 | /* empty tty_name means "use init's tty", else... */ |
272 | if (tty_name[0]) { | ||
273 | int fd; | ||
274 | close(STDIN_FILENO); | ||
275 | /* fd can be only < 0 or 0: */ | ||
276 | fd = device_open(tty_name, O_RDWR); | ||
277 | if (fd) { | ||
278 | message(L_LOG | L_CONSOLE, "can't open %s: %s", | ||
279 | tty_name, strerror(errno)); | ||
280 | if (exit_on_failure) | ||
281 | _exit(EXIT_FAILURE); | ||
282 | if (DEBUG_INIT) | ||
283 | _exit(2); | ||
284 | /* NB: we don't reach this if we were called after vfork. | ||
285 | * Thus halt_reboot_pwoff() itself need not be vfork-safe. */ | ||
286 | halt_reboot_pwoff(SIGUSR1); /* halt the system */ | ||
287 | niro | 532 | } |
288 | niro | 816 | dup2(STDIN_FILENO, STDOUT_FILENO); |
289 | dup2(STDIN_FILENO, STDERR_FILENO); | ||
290 | niro | 532 | } |
291 | niro | 816 | set_sane_term(); |
292 | niro | 532 | } |
293 | |||
294 | niro | 816 | /* Wrapper around exec: |
295 | * Takes string (max COMMAND_SIZE chars). | ||
296 | * If chars like '>' detected, execs '[-]/bin/sh -c "exec ......."'. | ||
297 | * Otherwise splits words on whitespace, deals with leading dash, | ||
298 | * and uses plain exec(). | ||
299 | * NB: careful, we can be called after vfork! | ||
300 | */ | ||
301 | static void init_exec(const char *command) | ||
302 | niro | 532 | { |
303 | niro | 816 | char *cmd[COMMAND_SIZE / 2]; |
304 | char buf[COMMAND_SIZE + 6]; /* COMMAND_SIZE+strlen("exec ")+1 */ | ||
305 | int dash = (command[0] == '-' /* maybe? && command[1] == '/' */); | ||
306 | niro | 532 | |
307 | niro | 816 | /* See if any special /bin/sh requiring characters are present */ |
308 | if (strpbrk(command, "~`!$^&*()=|\\{}[];\"'<>?") != NULL) { | ||
309 | strcpy(buf, "exec "); | ||
310 | strcpy(buf + 5, command + dash); /* excluding "-" */ | ||
311 | /* NB: LIBBB_DEFAULT_LOGIN_SHELL define has leading dash */ | ||
312 | cmd[0] = (char*)(LIBBB_DEFAULT_LOGIN_SHELL + !dash); | ||
313 | cmd[1] = (char*)"-c"; | ||
314 | cmd[2] = buf; | ||
315 | cmd[3] = NULL; | ||
316 | } else { | ||
317 | /* Convert command (char*) into cmd (char**, one word per string) */ | ||
318 | char *word, *next; | ||
319 | int i = 0; | ||
320 | next = strcpy(buf, command); /* including "-" */ | ||
321 | while ((word = strsep(&next, " \t")) != NULL) { | ||
322 | if (*word != '\0') { /* not two spaces/tabs together? */ | ||
323 | cmd[i] = word; | ||
324 | i++; | ||
325 | } | ||
326 | niro | 532 | } |
327 | niro | 816 | cmd[i] = NULL; |
328 | niro | 532 | } |
329 | niro | 816 | /* If we saw leading "-", it is interactive shell. |
330 | * Try harder to give it a controlling tty. | ||
331 | * And skip "-" in actual exec call. */ | ||
332 | if (dash) { | ||
333 | /* _Attempt_ to make stdin a controlling tty. */ | ||
334 | if (ENABLE_FEATURE_INIT_SCTTY) | ||
335 | ioctl(STDIN_FILENO, TIOCSCTTY, 0 /*only try, don't steal*/); | ||
336 | } | ||
337 | BB_EXECVP(cmd[0] + dash, cmd); | ||
338 | message(L_LOG | L_CONSOLE, "cannot run '%s': %s", cmd[0], strerror(errno)); | ||
339 | /* returns if execvp fails */ | ||
340 | niro | 532 | } |
341 | |||
342 | niro | 816 | /* Used only by run_actions */ |
343 | niro | 532 | static pid_t run(const struct init_action *a) |
344 | { | ||
345 | pid_t pid; | ||
346 | sigset_t nmask, omask; | ||
347 | |||
348 | niro | 816 | /* Block sigchild while forking (why?) */ |
349 | niro | 532 | sigemptyset(&nmask); |
350 | sigaddset(&nmask, SIGCHLD); | ||
351 | sigprocmask(SIG_BLOCK, &nmask, &omask); | ||
352 | niro | 816 | if (BB_MMU && (a->action_type & ASKFIRST)) |
353 | pid = fork(); | ||
354 | else | ||
355 | pid = vfork(); | ||
356 | sigprocmask(SIG_SETMASK, &omask, NULL); | ||
357 | niro | 532 | |
358 | niro | 816 | if (pid < 0) |
359 | message(L_LOG | L_CONSOLE, "can't fork"); | ||
360 | if (pid) | ||
361 | return pid; | ||
362 | niro | 532 | |
363 | niro | 816 | /* Child */ |
364 | niro | 532 | |
365 | niro | 816 | /* Reset signal handlers that were set by the parent process */ |
366 | bb_signals(0 | ||
367 | + (1 << SIGUSR1) | ||
368 | + (1 << SIGUSR2) | ||
369 | + (1 << SIGINT) | ||
370 | + (1 << SIGTERM) | ||
371 | + (1 << SIGHUP) | ||
372 | + (1 << SIGQUIT) | ||
373 | + (1 << SIGCONT) | ||
374 | + (1 << SIGSTOP) | ||
375 | + (1 << SIGTSTP) | ||
376 | , SIG_DFL); | ||
377 | niro | 532 | |
378 | niro | 816 | /* Create a new session and make ourself the process |
379 | * group leader */ | ||
380 | setsid(); | ||
381 | niro | 532 | |
382 | niro | 816 | /* Open the new terminal device */ |
383 | open_stdio_to_tty(a->terminal, 1 /* - exit if open fails */); | ||
384 | niro | 532 | |
385 | niro | 816 | // NB: do not enable unless you change vfork to fork above |
386 | #ifdef BUT_RUN_ACTIONS_ALREADY_DOES_WAITING | ||
387 | /* If the init Action requires us to wait, then force the | ||
388 | * supplied terminal to be the controlling tty. */ | ||
389 | if (a->action_type & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) { | ||
390 | /* Now fork off another process to just hang around */ | ||
391 | pid = fork(); | ||
392 | if (pid < 0) { | ||
393 | message(L_LOG | L_CONSOLE, "can't fork"); | ||
394 | _exit(EXIT_FAILURE); | ||
395 | } | ||
396 | niro | 532 | |
397 | niro | 816 | if (pid > 0) { |
398 | /* Parent - wait till the child is done */ | ||
399 | bb_signals(0 | ||
400 | + (1 << SIGINT) | ||
401 | + (1 << SIGTSTP) | ||
402 | + (1 << SIGQUIT) | ||
403 | , SIG_IGN); | ||
404 | signal(SIGCHLD, SIG_DFL); | ||
405 | niro | 532 | |
406 | niro | 816 | waitfor(pid); |
407 | /* See if stealing the controlling tty back is necessary */ | ||
408 | if (tcgetpgrp(0) != getpid()) | ||
409 | _exit(EXIT_SUCCESS); | ||
410 | niro | 532 | |
411 | niro | 816 | /* Use a temporary process to steal the controlling tty. */ |
412 | pid = fork(); | ||
413 | if (pid < 0) { | ||
414 | message(L_LOG | L_CONSOLE, "can't fork"); | ||
415 | _exit(EXIT_FAILURE); | ||
416 | niro | 532 | } |
417 | niro | 816 | if (pid == 0) { |
418 | setsid(); | ||
419 | ioctl(0, TIOCSCTTY, 1); | ||
420 | _exit(EXIT_SUCCESS); | ||
421 | niro | 532 | } |
422 | niro | 816 | waitfor(pid); |
423 | _exit(EXIT_SUCCESS); | ||
424 | niro | 532 | } |
425 | niro | 816 | /* Child - fall though to actually execute things */ |
426 | } | ||
427 | #endif | ||
428 | niro | 532 | |
429 | niro | 816 | /* NB: on NOMMU we can't wait for input in child, so |
430 | * "askfirst" will work the same as "respawn". */ | ||
431 | if (BB_MMU && (a->action_type & ASKFIRST)) { | ||
432 | static const char press_enter[] ALIGN1 = | ||
433 | #ifdef CUSTOMIZED_BANNER | ||
434 | #include CUSTOMIZED_BANNER | ||
435 | #endif | ||
436 | "\nPlease press Enter to activate this console. "; | ||
437 | char c; | ||
438 | niro | 532 | /* |
439 | niro | 816 | * Save memory by not exec-ing anything large (like a shell) |
440 | * before the user wants it. This is critical if swap is not | ||
441 | * enabled and the system has low memory. Generally this will | ||
442 | * be run on the second virtual console, and the first will | ||
443 | * be allowed to start a shell or whatever an init script | ||
444 | * specifies. | ||
445 | niro | 532 | */ |
446 | niro | 816 | messageD(L_LOG, "waiting for enter to start '%s'" |
447 | "(pid %d, tty '%s')\n", | ||
448 | a->command, getpid(), a->terminal); | ||
449 | full_write(STDOUT_FILENO, press_enter, sizeof(press_enter) - 1); | ||
450 | while (safe_read(STDIN_FILENO, &c, 1) == 1 && c != '\n') | ||
451 | continue; | ||
452 | } | ||
453 | niro | 532 | |
454 | niro | 816 | if (ENABLE_FEATURE_INIT_COREDUMPS) { |
455 | struct stat sb; | ||
456 | if (stat(CORE_ENABLE_FLAG_FILE, &sb) == 0) { | ||
457 | struct rlimit limit; | ||
458 | limit.rlim_cur = RLIM_INFINITY; | ||
459 | limit.rlim_max = RLIM_INFINITY; | ||
460 | setrlimit(RLIMIT_CORE, &limit); | ||
461 | niro | 532 | } |
462 | niro | 816 | } |
463 | niro | 532 | |
464 | niro | 816 | /* Log the process name and args */ |
465 | message(L_LOG, "starting pid %d, tty '%s': '%s'", | ||
466 | getpid(), a->terminal, a->command); | ||
467 | niro | 532 | |
468 | niro | 816 | /* Now run it. The new program will take over this PID, |
469 | * so nothing further in init.c should be run. */ | ||
470 | init_exec(a->command); | ||
471 | /* We're still here? Some error happened. */ | ||
472 | _exit(-1); | ||
473 | niro | 532 | } |
474 | |||
475 | niro | 816 | static void delete_init_action(struct init_action *action) |
476 | niro | 532 | { |
477 | niro | 816 | struct init_action *a, *b = NULL; |
478 | niro | 532 | |
479 | niro | 816 | for (a = init_action_list; a; b = a, a = a->next) { |
480 | if (a == action) { | ||
481 | if (b == NULL) { | ||
482 | init_action_list = a->next; | ||
483 | } else { | ||
484 | b->next = a->next; | ||
485 | } | ||
486 | free(a); | ||
487 | niro | 532 | break; |
488 | } | ||
489 | } | ||
490 | } | ||
491 | |||
492 | /* Run all commands of a particular type */ | ||
493 | niro | 816 | static void run_actions(int action_type) |
494 | niro | 532 | { |
495 | struct init_action *a, *tmp; | ||
496 | |||
497 | for (a = init_action_list; a; a = tmp) { | ||
498 | tmp = a->next; | ||
499 | niro | 816 | if (a->action_type & action_type) { |
500 | // Pointless: run() will error out if open of device fails. | ||
501 | ///* a->terminal of "" means "init's console" */ | ||
502 | //if (a->terminal[0] && access(a->terminal, R_OK | W_OK)) { | ||
503 | // //message(L_LOG | L_CONSOLE, "Device %s cannot be opened in RW mode", a->terminal /*, strerror(errno)*/); | ||
504 | // delete_init_action(a); | ||
505 | //} else | ||
506 | if (a->action_type & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) { | ||
507 | waitfor(run(a)); | ||
508 | niro | 532 | delete_init_action(a); |
509 | niro | 816 | } else if (a->action_type & ONCE) { |
510 | niro | 532 | run(a); |
511 | delete_init_action(a); | ||
512 | niro | 816 | } else if (a->action_type & (RESPAWN | ASKFIRST)) { |
513 | niro | 532 | /* Only run stuff with pid==0. If they have |
514 | * a pid, that means it is still running */ | ||
515 | if (a->pid == 0) { | ||
516 | a->pid = run(a); | ||
517 | } | ||
518 | } | ||
519 | } | ||
520 | } | ||
521 | } | ||
522 | |||
523 | static void init_reboot(unsigned long magic) | ||
524 | { | ||
525 | pid_t pid; | ||
526 | niro | 816 | /* We have to fork here, since the kernel calls do_exit(EXIT_SUCCESS) in |
527 | niro | 532 | * linux/kernel/sys.c, which can cause the machine to panic when |
528 | * the init process is killed.... */ | ||
529 | pid = vfork(); | ||
530 | if (pid == 0) { /* child */ | ||
531 | reboot(magic); | ||
532 | niro | 816 | _exit(EXIT_SUCCESS); |
533 | niro | 532 | } |
534 | niro | 816 | waitfor(pid); |
535 | niro | 532 | } |
536 | |||
537 | niro | 816 | static void kill_all_processes(void) |
538 | niro | 532 | { |
539 | /* run everything to be run at "shutdown". This is done _prior_ | ||
540 | * to killing everything, in case people wish to use scripts to | ||
541 | * shut things down gracefully... */ | ||
542 | run_actions(SHUTDOWN); | ||
543 | |||
544 | /* first disable all our signals */ | ||
545 | niro | 816 | sigprocmask_allsigs(SIG_BLOCK); |
546 | niro | 532 | |
547 | niro | 816 | message(L_CONSOLE | L_LOG, "The system is going down NOW!"); |
548 | |||
549 | niro | 532 | /* Allow Ctrl-Alt-Del to reboot system. */ |
550 | init_reboot(RB_ENABLE_CAD); | ||
551 | |||
552 | /* Send signals to every process _except_ pid 1 */ | ||
553 | niro | 816 | message(L_CONSOLE | L_LOG, "Sending SIG%s to all processes", "TERM"); |
554 | niro | 532 | kill(-1, SIGTERM); |
555 | niro | 816 | sync(); |
556 | niro | 532 | sleep(1); |
557 | |||
558 | niro | 816 | message(L_CONSOLE | L_LOG, "Sending SIG%s to all processes", "KILL"); |
559 | niro | 532 | kill(-1, SIGKILL); |
560 | niro | 816 | sync(); |
561 | niro | 532 | sleep(1); |
562 | } | ||
563 | |||
564 | niro | 816 | static void halt_reboot_pwoff(int sig) |
565 | niro | 532 | { |
566 | niro | 816 | const char *m = "halt"; |
567 | niro | 532 | int rb; |
568 | |||
569 | niro | 816 | kill_all_processes(); |
570 | niro | 532 | |
571 | niro | 816 | rb = RB_HALT_SYSTEM; |
572 | niro | 532 | if (sig == SIGTERM) { |
573 | m = "reboot"; | ||
574 | rb = RB_AUTOBOOT; | ||
575 | } else if (sig == SIGUSR2) { | ||
576 | m = "poweroff"; | ||
577 | rb = RB_POWER_OFF; | ||
578 | } | ||
579 | niro | 816 | message(L_CONSOLE | L_LOG, "Requesting system %s", m); |
580 | niro | 532 | /* allow time for last message to reach serial console */ |
581 | sleep(2); | ||
582 | init_reboot(rb); | ||
583 | loop_forever(); | ||
584 | } | ||
585 | |||
586 | niro | 816 | /* Handler for QUIT - exec "restart" action, |
587 | * else (no such action defined) do nothing */ | ||
588 | static void exec_restart_action(int sig UNUSED_PARAM) | ||
589 | niro | 532 | { |
590 | niro | 816 | struct init_action *a; |
591 | |||
592 | for (a = init_action_list; a; a = a->next) { | ||
593 | if (a->action_type & RESTART) { | ||
594 | kill_all_processes(); | ||
595 | |||
596 | /* unblock all signals (blocked in kill_all_processes()) */ | ||
597 | sigprocmask_allsigs(SIG_UNBLOCK); | ||
598 | |||
599 | /* Open the new terminal device */ | ||
600 | open_stdio_to_tty(a->terminal, 0 /* - halt if open fails */); | ||
601 | |||
602 | messageD(L_CONSOLE | L_LOG, "Trying to re-exec %s", a->command); | ||
603 | init_exec(a->command); | ||
604 | sleep(2); | ||
605 | init_reboot(RB_HALT_SYSTEM); | ||
606 | loop_forever(); | ||
607 | } | ||
608 | } | ||
609 | } | ||
610 | |||
611 | static void ctrlaltdel_signal(int sig UNUSED_PARAM) | ||
612 | { | ||
613 | niro | 532 | run_actions(CTRLALTDEL); |
614 | } | ||
615 | |||
616 | niro | 816 | /* The SIGCONT handler is set to record_signo(). |
617 | * It just sets bb_got_signal = SIGCONT. */ | ||
618 | |||
619 | niro | 532 | /* The SIGSTOP & SIGTSTP handler */ |
620 | niro | 816 | static void stop_handler(int sig UNUSED_PARAM) |
621 | niro | 532 | { |
622 | int saved_errno = errno; | ||
623 | |||
624 | niro | 816 | bb_got_signal = 0; |
625 | while (bb_got_signal == 0) | ||
626 | niro | 532 | pause(); |
627 | niro | 816 | |
628 | niro | 532 | errno = saved_errno; |
629 | } | ||
630 | |||
631 | niro | 816 | static void new_init_action(uint8_t action_type, const char *command, const char *cons) |
632 | niro | 532 | { |
633 | niro | 816 | struct init_action *a, *last; |
634 | niro | 532 | |
635 | niro | 816 | // Why? |
636 | // if (strcmp(cons, bb_dev_null) == 0 && (action & ASKFIRST)) | ||
637 | // return; | ||
638 | niro | 532 | |
639 | /* Append to the end of the list */ | ||
640 | for (a = last = init_action_list; a; a = a->next) { | ||
641 | /* don't enter action if it's already in the list, | ||
642 | * but do overwrite existing actions */ | ||
643 | niro | 816 | if ((strcmp(a->command, command) == 0) |
644 | && (strcmp(a->terminal, cons) == 0) | ||
645 | ) { | ||
646 | a->action_type = action_type; | ||
647 | niro | 532 | return; |
648 | } | ||
649 | last = a; | ||
650 | } | ||
651 | niro | 816 | |
652 | a = xzalloc(sizeof(*a)); | ||
653 | niro | 532 | if (last) { |
654 | niro | 816 | last->next = a; |
655 | niro | 532 | } else { |
656 | niro | 816 | init_action_list = a; |
657 | niro | 532 | } |
658 | niro | 816 | a->action_type = action_type; |
659 | safe_strncpy(a->command, command, sizeof(a->command)); | ||
660 | safe_strncpy(a->terminal, cons, sizeof(a->terminal)); | ||
661 | messageD(L_LOG | L_CONSOLE, "command='%s' action=%d tty='%s'\n", | ||
662 | a->command, a->action_type, a->terminal); | ||
663 | niro | 532 | } |
664 | |||
665 | /* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined, | ||
666 | * then parse_inittab() simply adds in some default | ||
667 | * actions(i.e., runs INIT_SCRIPT and then starts a pair | ||
668 | * of "askfirst" shells). If CONFIG_FEATURE_USE_INITTAB | ||
669 | * _is_ defined, but /etc/inittab is missing, this | ||
670 | * results in the same set of default behaviors. | ||
671 | */ | ||
672 | static void parse_inittab(void) | ||
673 | { | ||
674 | #if ENABLE_FEATURE_USE_INITTAB | ||
675 | niro | 816 | char *token[4]; |
676 | parser_t *parser = config_open2("/etc/inittab", fopen_for_read); | ||
677 | niro | 532 | |
678 | niro | 816 | if (parser == NULL) |
679 | #endif | ||
680 | { | ||
681 | niro | 532 | /* No inittab file -- set up some default behavior */ |
682 | /* Reboot on Ctrl-Alt-Del */ | ||
683 | niro | 816 | new_init_action(CTRLALTDEL, "reboot", ""); |
684 | niro | 532 | /* Umount all filesystems on halt/reboot */ |
685 | niro | 816 | new_init_action(SHUTDOWN, "umount -a -r", ""); |
686 | niro | 532 | /* Swapoff on halt/reboot */ |
687 | niro | 816 | if (ENABLE_SWAPONOFF) |
688 | new_init_action(SHUTDOWN, "swapoff -a", ""); | ||
689 | /* Prepare to restart init when a QUIT is received */ | ||
690 | new_init_action(RESTART, "init", ""); | ||
691 | niro | 532 | /* Askfirst shell on tty1-4 */ |
692 | new_init_action(ASKFIRST, bb_default_login_shell, ""); | ||
693 | niro | 816 | //TODO: VC_1 instead of ""? "" is console -> ctty problems -> angry users |
694 | niro | 532 | new_init_action(ASKFIRST, bb_default_login_shell, VC_2); |
695 | new_init_action(ASKFIRST, bb_default_login_shell, VC_3); | ||
696 | new_init_action(ASKFIRST, bb_default_login_shell, VC_4); | ||
697 | /* sysinit */ | ||
698 | new_init_action(SYSINIT, INIT_SCRIPT, ""); | ||
699 | return; | ||
700 | } | ||
701 | |||
702 | niro | 816 | #if ENABLE_FEATURE_USE_INITTAB |
703 | /* optional_tty:ignored_runlevel:action:command | ||
704 | * Delims are not to be collapsed and need exactly 4 tokens | ||
705 | */ | ||
706 | while (config_read(parser, token, 4, 0, "#:", | ||
707 | PARSE_NORMAL & ~(PARSE_TRIM | PARSE_COLLAPSE))) { | ||
708 | /* order must correspond to SYSINIT..RESTART constants */ | ||
709 | static const char actions[] ALIGN1 = | ||
710 | "sysinit\0""respawn\0""askfirst\0""wait\0""once\0" | ||
711 | "ctrlaltdel\0""shutdown\0""restart\0"; | ||
712 | int action; | ||
713 | char *tty = token[0]; | ||
714 | niro | 532 | |
715 | niro | 816 | if (!token[3]) /* less than 4 tokens */ |
716 | goto bad_entry; | ||
717 | action = index_in_strings(actions, token[2]); | ||
718 | if (action < 0 || !token[3][0]) /* token[3]: command */ | ||
719 | goto bad_entry; | ||
720 | /* turn .*TTY -> /dev/TTY */ | ||
721 | if (tty[0]) { | ||
722 | if (strncmp(tty, "/dev/", 5) == 0) | ||
723 | tty += 5; | ||
724 | tty = concat_path_file("/dev/", tty); | ||
725 | niro | 532 | } |
726 | niro | 816 | new_init_action(1 << action, token[3], tty); |
727 | if (tty[0]) | ||
728 | free(tty); | ||
729 | continue; | ||
730 | bad_entry: | ||
731 | message(L_LOG | L_CONSOLE, "Bad inittab entry at line %d", | ||
732 | parser->lineno); | ||
733 | niro | 532 | } |
734 | niro | 816 | config_close(parser); |
735 | #endif | ||
736 | niro | 532 | } |
737 | |||
738 | #if ENABLE_FEATURE_USE_INITTAB | ||
739 | niro | 816 | static void reload_signal(int sig UNUSED_PARAM) |
740 | niro | 532 | { |
741 | struct init_action *a, *tmp; | ||
742 | |||
743 | niro | 816 | message(L_LOG, "reloading /etc/inittab"); |
744 | niro | 532 | |
745 | /* disable old entrys */ | ||
746 | niro | 816 | for (a = init_action_list; a; a = a->next) { |
747 | a->action_type = ONCE; | ||
748 | niro | 532 | } |
749 | |||
750 | parse_inittab(); | ||
751 | |||
752 | niro | 816 | if (ENABLE_FEATURE_KILL_REMOVED) { |
753 | /* Be nice and send SIGTERM first */ | ||
754 | for (a = init_action_list; a; a = a->next) { | ||
755 | pid_t pid = a->pid; | ||
756 | if ((a->action_type & ONCE) && pid != 0) { | ||
757 | kill(pid, SIGTERM); | ||
758 | } | ||
759 | } | ||
760 | #if CONFIG_FEATURE_KILL_DELAY | ||
761 | /* NB: parent will wait in NOMMU case */ | ||
762 | if ((BB_MMU ? fork() : vfork()) == 0) { /* child */ | ||
763 | sleep(CONFIG_FEATURE_KILL_DELAY); | ||
764 | for (a = init_action_list; a; a = a->next) { | ||
765 | pid_t pid = a->pid; | ||
766 | if ((a->action_type & ONCE) && pid != 0) { | ||
767 | kill(pid, SIGKILL); | ||
768 | } | ||
769 | } | ||
770 | _exit(EXIT_SUCCESS); | ||
771 | } | ||
772 | #endif | ||
773 | } | ||
774 | |||
775 | niro | 532 | /* remove unused entrys */ |
776 | for (a = init_action_list; a; a = tmp) { | ||
777 | tmp = a->next; | ||
778 | niro | 816 | if ((a->action_type & (ONCE | SYSINIT | WAIT)) && a->pid == 0) { |
779 | niro | 532 | delete_init_action(a); |
780 | } | ||
781 | } | ||
782 | niro | 816 | run_actions(RESPAWN | ASKFIRST); |
783 | niro | 532 | } |
784 | niro | 816 | #endif |
785 | niro | 532 | |
786 | niro | 816 | int init_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
787 | int init_main(int argc UNUSED_PARAM, char **argv) | ||
788 | niro | 532 | { |
789 | struct init_action *a; | ||
790 | pid_t wpid; | ||
791 | |||
792 | die_sleep = 30 * 24*60*60; /* if xmalloc will ever die... */ | ||
793 | |||
794 | niro | 816 | if (argv[1] && !strcmp(argv[1], "-q")) { |
795 | return kill(1, SIGHUP); | ||
796 | niro | 532 | } |
797 | niro | 816 | |
798 | if (!DEBUG_INIT) { | ||
799 | /* Expect to be invoked as init with PID=1 or be invoked as linuxrc */ | ||
800 | if (getpid() != 1 | ||
801 | && (!ENABLE_FEATURE_INITRD || !strstr(applet_name, "linuxrc")) | ||
802 | ) { | ||
803 | bb_show_usage(); | ||
804 | } | ||
805 | /* Set up sig handlers -- be sure to | ||
806 | * clear all of these in run() */ | ||
807 | signal(SIGQUIT, exec_restart_action); | ||
808 | bb_signals(0 | ||
809 | + (1 << SIGUSR1) /* halt */ | ||
810 | + (1 << SIGUSR2) /* poweroff */ | ||
811 | + (1 << SIGTERM) /* reboot */ | ||
812 | , halt_reboot_pwoff); | ||
813 | signal(SIGINT, ctrlaltdel_signal); | ||
814 | signal(SIGCONT, record_signo); | ||
815 | bb_signals(0 | ||
816 | + (1 << SIGSTOP) | ||
817 | + (1 << SIGTSTP) | ||
818 | , stop_handler); | ||
819 | |||
820 | /* Turn off rebooting via CTL-ALT-DEL -- we get a | ||
821 | * SIGINT on CAD so we can shut things down gracefully... */ | ||
822 | init_reboot(RB_DISABLE_CAD); | ||
823 | niro | 532 | } |
824 | |||
825 | /* Figure out where the default console should be */ | ||
826 | console_init(); | ||
827 | niro | 816 | set_sane_term(); |
828 | xchdir("/"); | ||
829 | setsid(); | ||
830 | niro | 532 | |
831 | niro | 816 | /* Make sure environs is set to something sane */ |
832 | putenv((char *) "HOME=/"); | ||
833 | putenv((char *) bb_PATH_root_path); | ||
834 | putenv((char *) "SHELL=/bin/sh"); | ||
835 | putenv((char *) "USER=root"); /* needed? why? */ | ||
836 | niro | 532 | |
837 | niro | 816 | if (argv[1]) |
838 | xsetenv("RUNLEVEL", argv[1]); | ||
839 | niro | 532 | |
840 | /* Hello world */ | ||
841 | niro | 816 | message(MAYBE_CONSOLE | L_LOG, "init started: %s", bb_banner); |
842 | niro | 532 | |
843 | /* Make sure there is enough memory to do something useful. */ | ||
844 | if (ENABLE_SWAPONOFF) { | ||
845 | struct sysinfo info; | ||
846 | |||
847 | if (!sysinfo(&info) && | ||
848 | (info.mem_unit ? : 1) * (long long)info.totalram < 1024*1024) | ||
849 | { | ||
850 | niro | 816 | message(L_CONSOLE, "Low memory, forcing swapon"); |
851 | niro | 532 | /* swapon -a requires /proc typically */ |
852 | niro | 816 | new_init_action(SYSINIT, "mount -t proc proc /proc", ""); |
853 | niro | 532 | /* Try to turn on swap */ |
854 | niro | 816 | new_init_action(SYSINIT, "swapon -a", ""); |
855 | niro | 532 | run_actions(SYSINIT); /* wait and removing */ |
856 | } | ||
857 | } | ||
858 | |||
859 | /* Check if we are supposed to be in single user mode */ | ||
860 | niro | 816 | if (argv[1] |
861 | niro | 532 | && (!strcmp(argv[1], "single") || !strcmp(argv[1], "-s") || LONE_CHAR(argv[1], '1')) |
862 | ) { | ||
863 | niro | 816 | /* ??? shouldn't we set RUNLEVEL="b" here? */ |
864 | niro | 532 | /* Start a shell on console */ |
865 | new_init_action(RESPAWN, bb_default_login_shell, ""); | ||
866 | } else { | ||
867 | /* Not in single user mode -- see what inittab says */ | ||
868 | |||
869 | /* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined, | ||
870 | * then parse_inittab() simply adds in some default | ||
871 | * actions(i.e., runs INIT_SCRIPT and then starts a pair | ||
872 | * of "askfirst" shells */ | ||
873 | parse_inittab(); | ||
874 | } | ||
875 | |||
876 | #if ENABLE_SELINUX | ||
877 | if (getenv("SELINUX_INIT") == NULL) { | ||
878 | int enforce = 0; | ||
879 | |||
880 | niro | 816 | putenv((char*)"SELINUX_INIT=YES"); |
881 | niro | 532 | if (selinux_init_load_policy(&enforce) == 0) { |
882 | niro | 816 | BB_EXECVP(argv[0], argv); |
883 | niro | 532 | } else if (enforce > 0) { |
884 | /* SELinux in enforcing mode but load_policy failed */ | ||
885 | niro | 816 | message(L_CONSOLE, "cannot load SELinux Policy. " |
886 | "Machine is in enforcing mode. Halting now."); | ||
887 | exit(EXIT_FAILURE); | ||
888 | niro | 532 | } |
889 | } | ||
890 | #endif /* CONFIG_SELINUX */ | ||
891 | |||
892 | niro | 816 | /* Make the command line just say "init" - thats all, nothing else */ |
893 | strncpy(argv[0], "init", strlen(argv[0])); | ||
894 | /* Wipe argv[1]-argv[N] so they don't clutter the ps listing */ | ||
895 | while (*++argv) | ||
896 | memset(*argv, 0, strlen(*argv)); | ||
897 | niro | 532 | |
898 | /* Now run everything that needs to be run */ | ||
899 | |||
900 | /* First run the sysinit command */ | ||
901 | run_actions(SYSINIT); | ||
902 | |||
903 | /* Next run anything that wants to block */ | ||
904 | run_actions(WAIT); | ||
905 | |||
906 | /* Next run anything to be run only once */ | ||
907 | run_actions(ONCE); | ||
908 | |||
909 | niro | 816 | /* Redefine SIGHUP to reread /etc/inittab */ |
910 | niro | 532 | #if ENABLE_FEATURE_USE_INITTAB |
911 | signal(SIGHUP, reload_signal); | ||
912 | #else | ||
913 | signal(SIGHUP, SIG_IGN); | ||
914 | niro | 816 | #endif |
915 | niro | 532 | |
916 | /* Now run the looping stuff for the rest of forever */ | ||
917 | while (1) { | ||
918 | niro | 816 | /* run the respawn/askfirst stuff */ |
919 | run_actions(RESPAWN | ASKFIRST); | ||
920 | niro | 532 | |
921 | /* Don't consume all CPU time -- sleep a bit */ | ||
922 | sleep(1); | ||
923 | |||
924 | niro | 816 | /* Wait for any child process to exit */ |
925 | niro | 532 | wpid = wait(NULL); |
926 | while (wpid > 0) { | ||
927 | /* Find out who died and clean up their corpse */ | ||
928 | for (a = init_action_list; a; a = a->next) { | ||
929 | if (a->pid == wpid) { | ||
930 | /* Set the pid to 0 so that the process gets | ||
931 | * restarted by run_actions() */ | ||
932 | a->pid = 0; | ||
933 | niro | 816 | message(L_LOG, "process '%s' (pid %d) exited. " |
934 | "Scheduling for restart.", | ||
935 | niro | 532 | a->command, wpid); |
936 | } | ||
937 | } | ||
938 | /* see if anyone else is waiting to be reaped */ | ||
939 | niro | 816 | wpid = wait_any_nohang(NULL); |
940 | niro | 532 | } |
941 | } | ||
942 | } |