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init.c
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/* vi: set sw=4 ts=4: */
/*
* Mini init implementation for busybox
*
*
* Copyright (C) 1995, 1996 by Bruce Perens <[email protected]>.
* Copyright (C) 1999-2002 Erik Andersen <[email protected]>
* Adjusted by so many folks, it's impossible to keep track.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
/* Turn this on to disable all the dangerous
rebooting stuff when debugging.
#define DEBUG_INIT
*/
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <paths.h>
#include <signal.h>
#include <stdarg.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>
#include <limits.h>
#include <sys/fcntl.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/types.h>
#include <sys/wait.h>
#include "busybox.h"
#ifdef BB_SYSLOGD
# include <sys/syslog.h>
#endif
#if (__GNU_LIBRARY__ > 5) || defined(__dietlibc__)
#include <sys/reboot.h>
#endif
#define INIT_BUFFS_SIZE 256
/* From <linux/vt.h> */
struct vt_stat {
unsigned short v_active; /* active vt */
unsigned short v_signal; /* signal to send */
unsigned short v_state; /* vt bitmask */
};
static const int VT_GETSTATE = 0x5603; /* get global vt state info */
/* From <linux/serial.h> */
struct serial_struct {
int type;
int line;
unsigned int port;
int irq;
int flags;
int xmit_fifo_size;
int custom_divisor;
int baud_base;
unsigned short close_delay;
char io_type;
char reserved_char[1];
int hub6;
unsigned short closing_wait; /* time to wait before closing */
unsigned short closing_wait2; /* no longer used... */
unsigned char *iomem_base;
unsigned short iomem_reg_shift;
unsigned int port_high;
unsigned long iomap_base; /* cookie passed into ioremap */
int reserved[1];
};
#ifndef _PATH_STDPATH
#define _PATH_STDPATH "/usr/bin:/bin:/usr/sbin:/sbin"
#endif
#if defined BB_FEATURE_INIT_COREDUMPS
/*
* When a file named CORE_ENABLE_FLAG_FILE exists, setrlimit is called
* before processes are spawned to set core file size as unlimited.
* This is for debugging only. Don't use this is production, unless
* you want core dumps lying about....
*/
#define CORE_ENABLE_FLAG_FILE "/.init_enable_core"
#include <sys/resource.h>
#include <sys/time.h>
#endif
#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))
#if __GNU_LIBRARY__ > 5
#include <sys/kdaemon.h>
#else
extern int bdflush (int func, long int data);
#endif
#define SHELL "/bin/sh" /* Default shell */
#define LOGIN_SHELL "-" SHELL /* Default login shell */
#define INITTAB "/etc/inittab" /* inittab file location */
#ifndef INIT_SCRIPT
#define INIT_SCRIPT "/etc/init.d/rcS" /* Default sysinit script. */
#endif
#define MAXENV 16 /* Number of env. vars */
/* Allowed init action types */
#define SYSINIT 0x001
#define RESPAWN 0x002
#define ASKFIRST 0x004
#define WAIT 0x008
#define ONCE 0x010
#define CTRLALTDEL 0x020
#define SHUTDOWN 0x040
#define RESTART 0x080
/* A mapping between "inittab" action name strings and action type codes. */
struct init_action_type {
const char *name;
int action;
};
static const struct init_action_type actions[] = {
{"sysinit", SYSINIT},
{"respawn", RESPAWN},
{"askfirst", ASKFIRST},
{"wait", WAIT},
{"once", ONCE},
{"ctrlaltdel", CTRLALTDEL},
{"shutdown", SHUTDOWN},
{"restart", RESTART},
{0, 0}
};
/* Set up a linked list of init_actions, to be read from inittab */
struct init_action {
pid_t pid;
char command[INIT_BUFFS_SIZE];
char terminal[INIT_BUFFS_SIZE];
struct init_action *next;
int action;
};
/* Static variables */
static struct init_action *init_action_list = NULL;
static int kernelVersion = 0;
static char termType[32] = "TERM=linux";
static char console[32] = _PATH_CONSOLE;
#ifndef BB_SYSLOGD
static char *log = VC_5;
#endif
static sig_atomic_t got_cont = 0;
static const int LOG = 0x1;
static const int CONSOLE = 0x2;
#if defined BB_FEATURE_EXTRA_QUIET
static const int MAYBE_CONSOLE = 0x0;
#else
#define MAYBE_CONSOLE CONSOLE
#endif
#ifndef RB_HALT_SYSTEM
static const int RB_HALT_SYSTEM = 0xcdef0123;
static const int RB_ENABLE_CAD = 0x89abcdef;
static const int RB_DISABLE_CAD = 0;
#define RB_POWER_OFF 0x4321fedc
static const int RB_AUTOBOOT = 0x01234567;
#endif
/* Function prototypes */
static void delete_init_action(struct init_action *a);
static int waitfor(struct init_action *a);
static void halt_signal(int sig);
static void loop_forever(void)
{
while (1)
sleep (1);
}
/* Print a message to the specified device.
* Device may be bitwise-or'd from LOG | CONSOLE */
#ifdef DEBUG_INIT
static inline messageND(int device, char *fmt, ...) { }
#else
#define messageND message
#endif
static void message(int device, char *fmt, ...) __attribute__ ((format (printf, 2, 3)));
static void message(int device, char *fmt, ...)
{
va_list arguments;
int fd;
#ifdef BB_SYSLOGD
/* Log the message to syslogd */
if (device & LOG) {
char msg[1024];
va_start(arguments, fmt);
vsnprintf(msg, sizeof(msg), fmt, arguments);
va_end(arguments);
syslog_msg(LOG_USER, LOG_INFO, msg);
}
#else
static int log_fd = -1;
/* Take full control of the log tty, and never close it.
* It's mine, all mine! Muhahahaha! */
if (log_fd < 0) {
if ((log_fd = device_open(log, O_RDWR|O_NDELAY)) < 0) {
log_fd = -2;
fprintf(stderr, "Bummer, can't write to log on %s!\n", log);
device = CONSOLE;
} else {
fcntl(log_fd, F_SETFD, FD_CLOEXEC);
}
}
if ((device & LOG) && (log_fd >= 0)) {
va_start(arguments, fmt);
vdprintf(log_fd, fmt, arguments);
va_end(arguments);
}
#endif
if (device & CONSOLE) {
/* Always send console messages to /dev/console so people will see them. */
if (
(fd =
device_open(_PATH_CONSOLE, O_WRONLY | O_NOCTTY | O_NDELAY)) >= 0) {
va_start(arguments, fmt);
vdprintf(fd, fmt, arguments);
va_end(arguments);
close(fd);
} else {
fprintf(stderr, "Bummer, can't print: ");
va_start(arguments, fmt);
vfprintf(stderr, fmt, arguments);
va_end(arguments);
}
}
}
/* Set terminal settings to reasonable defaults */
static void set_term(int fd)
{
struct termios tty;
tcgetattr(fd, &tty);
/* set control chars */
tty.c_cc[VINTR] = 3; /* C-c */
tty.c_cc[VQUIT] = 28; /* C-\ */
tty.c_cc[VERASE] = 127; /* C-? */
tty.c_cc[VKILL] = 21; /* C-u */
tty.c_cc[VEOF] = 4; /* C-d */
tty.c_cc[VSTART] = 17; /* C-q */
tty.c_cc[VSTOP] = 19; /* C-s */
tty.c_cc[VSUSP] = 26; /* C-z */
/* use line dicipline 0 */
tty.c_line = 0;
/* Make it be sane */
tty.c_cflag &= CBAUD|CBAUDEX|CSIZE|CSTOPB|PARENB|PARODD;
tty.c_cflag |= CREAD|HUPCL|CLOCAL;
/* input modes */
tty.c_iflag = ICRNL | IXON | IXOFF;
/* output modes */
tty.c_oflag = OPOST | ONLCR;
/* local modes */
tty.c_lflag =
ISIG | ICANON | ECHO | ECHOE | ECHOK | ECHOCTL | ECHOKE | IEXTEN;
tcsetattr(fd, TCSANOW, &tty);
}
/* How much memory does this machine have?
Units are kBytes to avoid overflow on 4GB machines */
static int check_free_memory(void)
{
struct sysinfo info;
unsigned int result, u, s=10;
if (sysinfo(&info) != 0) {
perror_msg("Error checking free memory");
return -1;
}
/* Kernels 2.0.x and 2.2.x return info.mem_unit==0 with values in bytes.
* Kernels 2.4.0 return info.mem_unit in bytes. */
u = info.mem_unit;
if (u==0) u=1;
while ( (u&1) == 0 && s > 0 ) { u>>=1; s--; }
result = (info.totalram>>s) + (info.totalswap>>s);
result = result*u;
if (result < 0) result = INT_MAX;
return result;
}
static void console_init(void)
{
int fd;
int tried_devcons = 0;
int tried_vtprimary = 0;
struct vt_stat vt;
struct serial_struct sr;
char *s;
if ((s = getenv("TERM")) != NULL) {
snprintf(termType, sizeof(termType) - 1, "TERM=%s", s);
}
if ((s = getenv("CONSOLE")) != NULL) {
safe_strncpy(console, s, sizeof(console));
}
#if #cpu(sparc)
/* sparc kernel supports console=tty[ab] parameter which is also
* passed to init, so catch it here */
else if ((s = getenv("console")) != NULL) {
/* remap tty[ab] to /dev/ttyS[01] */
if (strcmp(s, "ttya") == 0)
safe_strncpy(console, SC_0, sizeof(console));
else if (strcmp(s, "ttyb") == 0)
safe_strncpy(console, SC_1, sizeof(console));
}
#endif
else {
/* 2.2 kernels: identify the real console backend and try to use it */
if (ioctl(0, TIOCGSERIAL, &sr) == 0) {
/* this is a serial console */
snprintf(console, sizeof(console) - 1, SC_FORMAT, sr.line);
} else if (ioctl(0, VT_GETSTATE, &vt) == 0) {
/* this is linux virtual tty */
snprintf(console, sizeof(console) - 1, VC_FORMAT, vt.v_active);
} else {
safe_strncpy(console, _PATH_CONSOLE, sizeof(console));
tried_devcons++;
}
}
while ((fd = open(console, O_RDONLY | O_NONBLOCK)) < 0) {
/* Can't open selected console -- try /dev/console */
if (!tried_devcons) {
tried_devcons++;
safe_strncpy(console, _PATH_CONSOLE, sizeof(console));
continue;
}
/* Can't open selected console -- try vt1 */
if (!tried_vtprimary) {
tried_vtprimary++;
safe_strncpy(console, VC_1, sizeof(console));
continue;
}
break;
}
if (fd < 0) {
/* Perhaps we should panic here? */
safe_strncpy(console, "/dev/null", sizeof(console));
} else {
/* check for serial console */
if (ioctl(0, TIOCGSERIAL, &sr) == 0) {
/* Force the TERM setting to vt102 for serial console --
* if TERM is set to linux (the default) */
if (strcmp( termType, "TERM=linux" ) == 0)
safe_strncpy(termType, "TERM=vt102", sizeof(termType));
}
close(fd);
}
message(LOG, "console=%s\n", console);
}
static void fixup_argv(int argc, char **argv, char *new_argv0)
{
int len;
/* Fix up argv[0] to be certain we claim to be init */
len = strlen(argv[0]);
memset(argv[0], 0, len);
safe_strncpy(argv[0], new_argv0, len + 1);
/* Wipe argv[1]-argv[N] so they don't clutter the ps listing */
len = 1;
while (argc > len) {
memset(argv[len], 0, strlen(argv[len]));
len++;
}
}
/* Make sure there is enough memory to do something useful. *
* Calls "swapon -a" if needed so be sure /etc/fstab is present... */
static void check_memory(void)
{
#if !defined(__UCLIBC__) || defined(__UCLIBC_HAS_MMU__)
struct stat statBuf;
#endif
if (check_free_memory() > 1000)
return;
#if !defined(__UCLIBC__) || defined(__UCLIBC_HAS_MMU__)
if (stat("/etc/fstab", &statBuf) == 0) {
/* swapon -a requires /proc typically */
system("/bin/mount -t proc proc /proc");
/* Try to turn on swap */
system("/sbin/swapon -a");
if (check_free_memory() < 1000)
goto goodnight;
} else
goto goodnight;
return;
goodnight:
#endif
message(CONSOLE,
"\rSorry, your computer does not have enough memory.\n");
loop_forever();
}
static pid_t run(struct init_action *a)
{
struct stat sb;
int i, j, junk;
pid_t pid, pgrp, tmp_pid;
char *s, *tmpCmd, *cmd[INIT_BUFFS_SIZE], *cmdpath;
char buf[INIT_BUFFS_SIZE+6]; /* INIT_BUFFS_SIZE+strlen("exec ")+1 */
sigset_t nmask, omask;
char *environment[MAXENV+1] = {
termType,
"HOME=/",
"PATH=" _PATH_STDPATH,
"SHELL=" SHELL,
"USER=root",
NULL
};
static const char press_enter[] =
#ifdef CUSTOMIZED_BANNER
#include CUSTOMIZED_BANNER
#endif
"\nPlease press Enter to activate this console. ";
#if __GNUC__
/* Avoid longjmp clobbering */
(void) &tmp_pid;
#endif
/* inherit environment to the child, merging our values -andy */
for (i=0; environ[i]; i++) {
for (j=0; environment[j]; j++) {
s = strchr(environment[j], '=');
if (!strncmp(environ[i], environment[j], s - environment[j]))
break;
}
if (!environment[j]) {
environment[j++] = environ[i];
environment[j] = NULL;
}
}
/* Block sigchild while forking. */
sigemptyset(&nmask);
sigaddset(&nmask, SIGCHLD);
sigprocmask(SIG_BLOCK, &nmask, &omask);
if ((pid = fork()) == 0)
{
/* Clean up */
close(0);
close(1);
close(2);
sigprocmask(SIG_SETMASK, &omask, NULL);
/* Reset signal handlers that were set by the parent process */
signal(SIGUSR1, SIG_DFL);
signal(SIGUSR2, SIG_DFL);
signal(SIGINT, SIG_DFL);
signal(SIGTERM, SIG_DFL);
signal(SIGHUP, SIG_DFL);
signal(SIGCONT, SIG_DFL);
signal(SIGSTOP, SIG_DFL);
signal(SIGTSTP, SIG_DFL);
/* Create a new session and make ourself the process
* group leader */
setsid();
/* Open the new terminal device */
if ((device_open(a->terminal, O_RDWR)) < 0) {
if (stat(a->terminal, &sb) != 0) {
message(LOG | CONSOLE, "\rdevice '%s' does not exist.\n",
a->terminal);
_exit(1);
}
message(LOG | CONSOLE, "\rBummer, can't open %s\n", a->terminal);
_exit(1);
}
/* Make sure the terminal will act fairly normal for us */
set_term(0);
/* Setup stdout, stderr for the new process so
* they point to the supplied terminal */
dup(0);
dup(0);
/* If the init Action requires us to wait, then force the
* supplied terminal to be the controlling tty. */
if (a->action & (SYSINIT|WAIT|CTRLALTDEL|SHUTDOWN|RESTART)) {
/* Now fork off another process to just hang around */
if ((pid = fork()) < 0) {
message(LOG | CONSOLE, "Can't fork!\n");
_exit(1);
}
if (pid > 0) {
/* We are the parent -- wait till the child is done */
signal(SIGINT, SIG_IGN);
signal(SIGTSTP, SIG_IGN);
signal(SIGQUIT, SIG_IGN);
signal(SIGCHLD, SIG_DFL);
/* Wait for child to exit */
while ((tmp_pid = waitpid(pid, &junk, 0)) != pid)
;
/* See if stealing the controlling tty back is necessary */
pgrp = tcgetpgrp(0);
if (pgrp != getpid())
_exit(0);
/* Use a temporary process to steal the controlling tty. */
if ((pid = fork()) < 0) {
message(LOG | CONSOLE, "\rCan't fork!\n");
_exit(1);
}
if (pid == 0) {
setsid();
ioctl(0, TIOCSCTTY, 1);
_exit(0);
}
while((tmp_pid = waitpid(pid, &junk, 0)) != pid) {
if (tmp_pid < 0 && errno == ECHILD)
break;
}
_exit(0);
}
/* Now fall though to actually execute things */
}
/* See if any special /bin/sh requiring characters are present */
if (strpbrk(a->command, "~`!$^&*()=|\\{}[];\"'<>?") != NULL) {
cmd[0] = SHELL;
cmd[1] = "-c";
strcat(strcpy(buf, "exec "), a->command);
cmd[2] = buf;
cmd[3] = NULL;
} else {
/* Convert command (char*) into cmd (char**, one word per string) */
strcpy(buf, a->command);
s = buf;
for (tmpCmd = buf, i = 0;
(tmpCmd = strsep(&s, " \t")) != NULL;) {
if (*tmpCmd != '\0') {
cmd[i] = tmpCmd;
i++;
}
}
cmd[i] = NULL;
}
cmdpath = cmd[0];
/*
Interactive shells want to see a dash in argv[0]. This
typically is handled by login, argv will be setup this
way if a dash appears at the front of the command path
(like "-/bin/sh").
*/
if (*cmdpath == '-') {
/* skip over the dash */
++cmdpath;
/* find the last component in the command pathname */
s = get_last_path_component(cmdpath);
/* make a new argv[0] */
if ((cmd[0] = malloc(strlen(s)+2)) == NULL) {
message(LOG | CONSOLE, "malloc failed");
cmd[0] = cmdpath;
} else {
cmd[0][0] = '-';
strcpy(cmd[0]+1, s);
}
}
if (a->action & ASKFIRST) {
/*
* Save memory by not exec-ing anything large (like a shell)
* before the user wants it. This is critical if swap is not
* enabled and the system has low memory. Generally this will
* be run on the second virtual console, and the first will
* be allowed to start a shell or whatever an init script
* specifies.
*/
messageND(LOG, "Waiting for enter to start '%s' (pid %d, terminal %s)\n",
cmdpath, getpid(), a->terminal);
fflush(stdout);
write(fileno(stdout), press_enter, sizeof(press_enter) - 1);
getc(stdin);
}
/* Log the process name and args */
messageND(LOG, "Starting pid %d, console %s: '%s'\n",
getpid(), a->terminal, cmdpath);
#if defined BB_FEATURE_INIT_COREDUMPS
if (stat (CORE_ENABLE_FLAG_FILE, &sb) == 0) {
struct rlimit limit;
limit.rlim_cur = RLIM_INFINITY;
limit.rlim_max = RLIM_INFINITY;
setrlimit(RLIMIT_CORE, &limit);
}
#endif
/* Now run it. The new program will take over this PID,
* so nothing further in init.c should be run. */
execve(cmdpath, cmd, environment);
/* We're still here? Some error happened. */
message(LOG | CONSOLE, "\rBummer, could not run '%s': %s\n", cmdpath,
strerror(errno));
_exit(-1);
}
sigprocmask(SIG_SETMASK, &omask, NULL);
return pid;
}
static int waitfor(struct init_action *a)
{
int pid;
int status, wpid;
pid = run(a);
while (1) {
wpid = wait(&status);
if (wpid > 0 && wpid != pid) {
continue;
}
if (wpid == pid)
break;
}
return wpid;
}
/* Run all commands of a particular type */
static void run_actions(int action)
{
struct init_action *a, *tmp;
for (a = init_action_list; a; a = tmp) {
tmp = a->next;
if (a->action == action) {
if (a->action & (SYSINIT|WAIT|CTRLALTDEL|SHUTDOWN|RESTART)) {
waitfor(a);
delete_init_action(a);
} else if (a->action & ONCE) {
run(a);
delete_init_action(a);
} else if (a->action & (RESPAWN|ASKFIRST)) {
/* Only run stuff with pid==0. If they have
* a pid, that means it is still running */
if (a->pid == 0) {
a->pid = run(a);
}
}
}
}
}
#ifndef DEBUG_INIT
static void init_reboot(unsigned long magic)
{
pid_t pid;
/* We have to fork here, since the kernel calls do_exit(0) in
* linux/kernel/sys.c, which can cause the machine to panic when
* the init process is killed.... */
if ((pid = fork()) == 0) {
#if (__GNU_LIBRARY__ > 5) || defined(__dietlibc__)
reboot(magic);
#else
reboot(0xfee1dead, 672274793, magic);
#endif
_exit(0);
}
waitpid (pid, NULL, 0);
}
static void shutdown_system(void)
{
sigset_t block_signals;
/* run everything to be run at "shutdown". This is done _prior_
* to killing everything, in case people wish to use scripts to
* shut things down gracefully... */
run_actions(SHUTDOWN);
/* first disable all our signals */
sigemptyset(&block_signals);
sigaddset(&block_signals, SIGHUP);
sigaddset(&block_signals, SIGCHLD);
sigaddset(&block_signals, SIGUSR1);
sigaddset(&block_signals, SIGUSR2);
sigaddset(&block_signals, SIGINT);
sigaddset(&block_signals, SIGTERM);
sigaddset(&block_signals, SIGCONT);
sigaddset(&block_signals, SIGSTOP);
sigaddset(&block_signals, SIGTSTP);
sigprocmask(SIG_BLOCK, &block_signals, NULL);
/* Allow Ctrl-Alt-Del to reboot system. */
init_reboot(RB_ENABLE_CAD);
message(CONSOLE|LOG, "\n\rThe system is going down NOW !!\n");
sync();
/* Send signals to every process _except_ pid 1 */
message(CONSOLE|LOG, "\rSending SIGTERM to all processes.\n");
kill(-1, SIGTERM);
sleep(1);
sync();
message(CONSOLE|LOG, "\rSending SIGKILL to all processes.\n");
kill(-1, SIGKILL);
sleep(1);
sync();
#if 0
if (kernelVersion > 0 && kernelVersion <= KERNEL_VERSION(2,2,11)) {
/* bdflush, kupdate not needed for kernels >2.2.11 */
bdflush(1, 0);
sync();
}
#endif
}
static void exec_signal(int sig)
{
struct init_action *a, *tmp;
sigset_t unblock_signals;
for (a = init_action_list; a; a = tmp) {
tmp = a->next;
if (a->action & RESTART) {
struct stat sb;
shutdown_system();
/* unblock all signals, blocked in shutdown_system() */
sigemptyset(&unblock_signals);
sigaddset(&unblock_signals, SIGHUP);
sigaddset(&unblock_signals, SIGCHLD);
sigaddset(&unblock_signals, SIGUSR1);
sigaddset(&unblock_signals, SIGUSR2);
sigaddset(&unblock_signals, SIGINT);
sigaddset(&unblock_signals, SIGTERM);
sigaddset(&unblock_signals, SIGCONT);
sigaddset(&unblock_signals, SIGSTOP);
sigaddset(&unblock_signals, SIGTSTP);
sigprocmask(SIG_UNBLOCK, &unblock_signals, NULL);
/* Open the new terminal device */
if ((device_open(a->terminal, O_RDWR)) < 0) {
if (stat(a->terminal, &sb) != 0) {
message(LOG | CONSOLE, "device '%s' does not exist.", a->terminal);
} else {
message(LOG | CONSOLE, "Bummer, can't open %s", a->terminal);
}
halt_signal(SIGUSR1);
}
/* Make sure the terminal will act fairly normal for us */
set_term(0);
/* Setup stdout, stderr on the supplied terminal */
dup(0);
dup(0);
message(CONSOLE|LOG, "\rTrying to re-exec %s\n", a->command);
execl(a->command, a->command, NULL);
message(CONSOLE|LOG, "\rexec of '%s' failed: %s\n",
a->command, strerror(errno));
sync();
sleep(2);
init_reboot(RB_HALT_SYSTEM);
loop_forever();
}
}
}
static void halt_signal(int sig)
{
shutdown_system();
message(CONSOLE|LOG,
#if #cpu(s390)
/* Seems the s390 console is Wierd(tm). */
"\rThe system is halted. You may reboot now.\n"
#else
"\rThe system is halted. Press Reset or turn off power\n"
#endif
);
sync();
/* allow time for last message to reach serial console */
sleep(2);
if (sig == SIGUSR2 && kernelVersion >= KERNEL_VERSION(2,2,0))
init_reboot(RB_POWER_OFF);
else
init_reboot(RB_HALT_SYSTEM);
loop_forever();
}
static void reboot_signal(int sig)
{
shutdown_system();
message(CONSOLE|LOG, "\rPlease stand by while rebooting the system.\n");
sync();
/* allow time for last message to reach serial console */
sleep(2);
init_reboot(RB_AUTOBOOT);
loop_forever();
}
static void ctrlaltdel_signal(int sig)
{
run_actions(CTRLALTDEL);
}
/* The SIGSTOP & SIGTSTP handler */
static void stop_handler(int sig)
{
int saved_errno = errno;
got_cont = 0;
while(!got_cont) pause();
got_cont = 0;
errno = saved_errno;
}
/* The SIGCONT handler */
static void cont_handler(int sig)
{
got_cont = 1;
}
/* Reap any zombie processes that are reparented to init */
static void child_handler(int sig)
{
int status;
while ( wait3(&status, WNOHANG, NULL) > 0 );
}
#endif /* ! DEBUG_INIT */
static void new_init_action(int action, char *command, char *cons)
{
struct init_action *new_action, *a;
if (*cons == '\0')
cons = console;
/* do not run entries if console device is not available */
if (access(cons, R_OK|W_OK))
return;
if (strcmp(cons, "/dev/null") == 0 && (action & ASKFIRST))
return;
new_action = calloc((size_t) (1), sizeof(struct init_action));
if (!new_action) {
message(LOG | CONSOLE, "\rMemory allocation failure\n");
loop_forever();
}
/* Append to the end of the list */
for (a = init_action_list; a && a->next; a = a->next) ;
if (a) {
a->next = new_action;
} else {
init_action_list = new_action;
}
strcpy(new_action->command, command);
new_action->action = action;
strcpy(new_action->terminal, cons);
new_action->pid = 0;
// message(LOG|CONSOLE, "command='%s' action='%d' terminal='%s'\n",
// new_action->command, new_action->action, new_action->terminal);
}
static void delete_init_action(struct init_action * action)
{
struct init_action *a, *b = NULL;
for (a = init_action_list; a; b = a, a = a->next) {
if (a == action) {
if (b == NULL) {
init_action_list = a->next;
} else {
b->next = a->next;
}
free(a);
break;
}
}
}
/* NOTE that if BB_FEATURE_USE_INITTAB is NOT defined,
* then parse_inittab() simply adds in some default
* actions(i.e., runs INIT_SCRIPT and then starts a pair
* of "askfirst" shells). If BB_FEATURE_USE_INITTAB
* _is_ defined, but /etc/inittab is missing, this
* results in the same set of default behaviors.
* */
static void parse_inittab(void)
{
#ifdef BB_FEATURE_USE_INITTAB
FILE *file;
char buf[INIT_BUFFS_SIZE], lineAsRead[INIT_BUFFS_SIZE], tmpConsole[INIT_BUFFS_SIZE];
char *id, *runlev, *action, *command, *eol;
const struct init_action_type *a = actions;
int foundIt;
file = fopen(INITTAB, "r");
if (file == NULL) {
/* No inittab file -- set up some default behavior */
#endif
/* Reboot on Ctrl-Alt-Del */
new_init_action(CTRLALTDEL, "/sbin/reboot", console);
/* Umount all filesystems on halt/reboot */
new_init_action(SHUTDOWN, "/bin/umount -a -r", console);
#if !defined(__UCLIBC__) || defined(__UCLIBC_HAS_MMU__)
/* Swapoff on halt/reboot */
new_init_action(SHUTDOWN, "/sbin/swapoff -a", console);
#endif
/* Prepare to restart init when a HUP is received */
new_init_action(RESTART, "/sbin/init", console);
/* Askfirst shell on tty1-4 */
new_init_action(ASKFIRST, LOGIN_SHELL, console);
new_init_action(ASKFIRST, LOGIN_SHELL, VC_2);
new_init_action(ASKFIRST, LOGIN_SHELL, VC_3);
new_init_action(ASKFIRST, LOGIN_SHELL, VC_4);
/* sysinit */
new_init_action(SYSINIT, INIT_SCRIPT, console);
return;
#ifdef BB_FEATURE_USE_INITTAB
}
while (fgets(buf, INIT_BUFFS_SIZE, file) != NULL) {
foundIt = FALSE;
/* Skip leading spaces */
for (id = buf; *id == ' ' || *id == '\t'; id++);
/* Skip the line if it's a comment */
if (*id == '#' || *id == '\n')
continue;
/* Trim the trailing \n */
eol = strrchr(id, '\n');
if (eol != NULL)
*eol = '\0';
/* Keep a copy around for posterity's sake (and error msgs) */
strcpy(lineAsRead, buf);
/* Separate the ID field from the runlevels */