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477aedd77f
busybox/init/init.c
Eric Andersen 477aedd77f Commit a patch from Erik Gustavsson <cyrano@algonet.se>, to allow 
environment variables set from the kernel command line to be inherited
bu application programs.  Slightly changed to special case handling of
TERM, so that it has sane defaults when on a serial console.
 -Erik
2001-02-20 18:01:50 +00:00

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/* vi: set sw=4 ts=4: */
/*
* Mini init implementation for busybox
*
*
* Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
* 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"
#define bb_need_full_version
#define BB_DECLARE_EXTERN
#include "messages.c"
#ifdef BB_SYSLOGD
# include <sys/syslog.h>
#endif
/* 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;
int port;
int irq;
int flags;
int xmit_fifo_size;
int custom_divisor;
int baud_base;
unsigned short close_delay;
char reserved_char[2];
int hub6;
unsigned short closing_wait; /* time to wait before closing */
unsigned short closing_wait2; /* no longer used... */
int reserved[4];
};
#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;
#if defined(__GLIBC__) || defined (__UCLIBC__)
#include <sys/reboot.h>
#define init_reboot(magic) reboot(magic)
#else
#define init_reboot(magic) reboot(0xfee1dead, 672274793, magic)
#endif
#endif
#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 defined(__GLIBC__)
#include <sys/kdaemon.h>
#else
#include <sys/syscall.h>
#include <linux/unistd.h>
static _syscall2(int, bdflush, int, func, int, data);
#endif /* __GLIBC__ */
#define VT_PRIMARY "/dev/tty1" /* Primary virtual console */
#define VT_SECONDARY "/dev/tty2" /* Virtual console */
#define VT_THIRD "/dev/tty3" /* Virtual console */
#define VT_FOURTH "/dev/tty4" /* Virtual console */
#define VT_LOG "/dev/tty5" /* Virtual console */
#define SERIAL_CON0 "/dev/ttyS0" /* Primary serial console */
#define SERIAL_CON1 "/dev/ttyS1" /* Serial console */
#define SHELL "-/bin/sh" /* Default shell */
#define INITTAB "/etc/inittab" /* inittab file location */
#ifndef INIT_SCRIPT
#define INIT_SCRIPT "/etc/init.d/rcS" /* Default sysinit script. */
#endif
static const int MAXENV = 16; /* Number of env. vars */
static const int LOG = 0x1;
static const int CONSOLE = 0x2;
/* Allowed init action types */
typedef enum {
SYSINIT = 1,
RESPAWN,
ASKFIRST,
WAIT,
ONCE,
CTRLALTDEL
} initActionEnum;
/* A mapping between "inittab" action name strings and action type codes. */
typedef struct initActionType {
const char *name;
initActionEnum action;
} initActionType;
static const struct initActionType actions[] = {
{"sysinit", SYSINIT},
{"respawn", RESPAWN},
{"askfirst", ASKFIRST},
{"wait", WAIT},
{"once", ONCE},
{"ctrlaltdel", CTRLALTDEL},
{0, 0}
};
/* Set up a linked list of initActions, to be read from inittab */
typedef struct initActionTag initAction;
struct initActionTag {
pid_t pid;
char process[256];
char console[256];
initAction *nextPtr;
initActionEnum action;
};
initAction *initActionList = NULL;
static char *secondConsole = VT_SECONDARY;
static char *thirdConsole = VT_THIRD;
static char *fourthConsole = VT_FOURTH;
static char *log = VT_LOG;
static int kernelVersion = 0;
static char termType[32] = "TERM=linux";
static char console[32] = _PATH_CONSOLE;
static void delete_initAction(initAction * action);
/* Print a message to the specified device.
* Device may be bitwise-or'd from LOG | CONSOLE */
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);
openlog(applet_name, 0, LOG_USER);
syslog(LOG_USER|LOG_INFO, msg);
closelog();
}
#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 == NULL) {
/* don't even try to log, because there is no such console */
log_fd = -2;
/* log to main console instead */
device = CONSOLE;
} else if ((log_fd = device_open(log, O_RDWR|O_NDELAY)) < 0) {
log_fd = -2;
fprintf(stderr, "Bummer, can't write to log on %s!\r\n", log);
log = NULL;
device = CONSOLE;
}
}
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 */
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 |= 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()
{
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()
{
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) {
snprintf(console, sizeof(console) - 1, "%s", s);
}
#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)
snprintf(console, sizeof(console) - 1, "%s", SERIAL_CON0);
else if (strcmp(s, "ttyb") == 0)
snprintf(console, sizeof(console) - 1, "%s", SERIAL_CON1);
}
#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, "/dev/ttyS%d", sr.line);
} else if (ioctl(0, VT_GETSTATE, &vt) == 0) {
/* this is linux virtual tty */
snprintf(console, sizeof(console) - 1, "/dev/tty%d",
vt.v_active);
} else {
snprintf(console, sizeof(console) - 1, "%s", _PATH_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++;
snprintf(console, sizeof(console) - 1, "%s", _PATH_CONSOLE);
continue;
}
/* Can't open selected console -- try vt1 */
if (!tried_vtprimary) {
tried_vtprimary++;
snprintf(console, sizeof(console) - 1, "%s", VT_PRIMARY);
continue;
}
break;
}
if (fd < 0) {
/* Perhaps we should panic here? */
snprintf(console, sizeof(console) - 1, "/dev/null");
} else {
/* check for serial console and disable logging to tty5 & running a
* shell to tty2-4 */
if (ioctl(0, TIOCGSERIAL, &sr) == 0) {
log = NULL;
secondConsole = NULL;
thirdConsole = NULL;
fourthConsole = NULL;
/* Force the TERM setting to vt102 for serial console --
* iff TERM is set to linux (the default) */
if (strcmp( termType, "TERM=linux" ) == 0)
snprintf(termType, sizeof(termType) - 1, "TERM=vt102");
message(LOG | CONSOLE,
"serial console detected. Disabling virtual terminals.\r\n");
}
close(fd);
}
message(LOG, "console=%s\n", console);
}
static pid_t run(char *command, char *terminal, int get_enter)
{
int i=0, j=0;
int fd;
pid_t pid;
char *tmpCmd;
char *cmd[255], *cmdpath;
char buf[255];
static const char press_enter[] =
#ifdef CUSTOMIZED_BANNER
#include CUSTOMIZED_BANNER
#endif
"\nPlease press Enter to activate this console. ";
char *environment[MAXENV+1] = {
"HOME=/",
"PATH=/usr/bin:/bin:/usr/sbin:/sbin",
"SHELL=/bin/sh",
termType,
"USER=root"
};
while (environment[i]) i++;
while ((environ[j]) && (i < MAXENV)) {
if (strncmp(environ[j], "TERM=", 5))
environment[i++] = environ[j];
else {
snprintf(termType, sizeof(termType) - 1, environ[j]);
}
j++;
}
if ((pid = fork()) == 0) {
/* Clean up */
ioctl(0, TIOCNOTTY, 0);
close(0);
close(1);
close(2);
setsid();
/* Reset signal handlers set for parent process */
signal(SIGUSR1, SIG_DFL);
signal(SIGUSR2, SIG_DFL);
signal(SIGINT, SIG_DFL);
signal(SIGTERM, SIG_DFL);
signal(SIGHUP, SIG_DFL);
if ((fd = device_open(terminal, O_RDWR)) < 0) {
message(LOG | CONSOLE, "Bummer, can't open %s\r\n", terminal);
exit(1);
}
dup2(fd, 0);
dup2(fd, 1);
dup2(fd, 2);
ioctl(0, TIOCSCTTY, 1);
tcsetpgrp(0, getpgrp());
set_term(0);
if (get_enter == TRUE) {
/*
* 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.
*/
#ifdef DEBUG_INIT
pid_t shell_pgid = getpid();
message(LOG, "Waiting for enter to start '%s' (pid %d, console %s)\r\n",
command, shell_pgid, terminal);
#endif
write(fileno(stdout), press_enter, sizeof(press_enter) - 1);
getc(stdin);
}
#ifdef DEBUG_INIT
/* Log the process name and args */
message(LOG, "Starting pid %d, console %s: '%s'\r\n",
shell_pgid, terminal, command);
#endif
/* See if any special /bin/sh requiring characters are present */
if (strpbrk(command, "~`!$^&*()=|\\{}[];\"'<>?") != NULL) {
cmd[0] = SHELL;
cmd[1] = "-c";
strcpy(buf, "exec ");
strncat(buf, command, sizeof(buf) - strlen(buf) - 1);
cmd[2] = buf;
cmd[3] = NULL;
} else {
/* Convert command (char*) into cmd (char**, one word per string) */
for (tmpCmd = command, i = 0;
(tmpCmd = strsep(&command, " \t")) != NULL;) {
if (*tmpCmd != '\0') {
cmd[i] = tmpCmd;
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 == '-') {
char *s;
/* 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 defined BB_FEATURE_INIT_COREDUMPS
{
struct stat sb;
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, "Bummer, could not run '%s': %s\n", cmdpath,
strerror(errno));
exit(-1);
}
return pid;
}
static int waitfor(char *command, char *terminal, int get_enter)
{
int status, wpid;
int pid = run(command, terminal, get_enter);
while (1) {
wpid = wait(&status);
if (wpid > 0 && wpid != pid) {
continue;
}
if (wpid == pid)
break;
}
return wpid;
}
/* 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()
{
struct stat statBuf;
if (check_free_memory() > 1000)
return;
if (stat("/etc/fstab", &statBuf) == 0) {
/* swapon -a requires /proc typically */
waitfor("mount proc /proc -t proc", console, FALSE);
/* Try to turn on swap */
waitfor("swapon -a", console, FALSE);
if (check_free_memory() < 1000)
goto goodnight;
} else
goto goodnight;
return;
goodnight:
message(CONSOLE,
"Sorry, your computer does not have enough memory.\r\n");
while (1)
sleep(1);
}
/* Run all commands to be run right before halt/reboot */
static void run_lastAction(void)
{
initAction *a;
for (a = initActionList; a; a = a->nextPtr) {
if (a->action == CTRLALTDEL) {
waitfor(a->process, a->console, FALSE);
delete_initAction(a);
}
}
}
#ifndef DEBUG_INIT
static void shutdown_system(void)
{
/* first disable our SIGHUP signal */
signal(SIGHUP, SIG_DFL);
/* Allow Ctrl-Alt-Del to reboot system. */
init_reboot(RB_ENABLE_CAD);
message(CONSOLE|LOG, "\r\nThe system is going down NOW !!\r\n");
sync();
/* Send signals to every process _except_ pid 1 */
message(CONSOLE|LOG, "Sending SIGTERM to all processes.\r\n");
kill(-1, SIGTERM);
sleep(1);
sync();
message(CONSOLE|LOG, "Sending SIGKILL to all processes.\r\n");
kill(-1, SIGKILL);
sleep(1);
/* run everything to be run at "ctrlaltdel" */
run_lastAction();
sync();
if (kernelVersion > 0 && kernelVersion <= KERNEL_VERSION(2,2,11)) {
/* bdflush, kupdate not needed for kernels >2.2.11 */
bdflush(1, 0);
sync();
}
}
static void halt_signal(int sig)
{
shutdown_system();
message(CONSOLE|LOG,
"The system is halted. Press %s or turn off power\r\n",
(secondConsole == NULL) /* serial console */
? "Reset" : "CTRL-ALT-DEL");
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);
exit(0);
}
static void reboot_signal(int sig)
{
shutdown_system();
message(CONSOLE|LOG, "Please stand by while rebooting the system.\r\n");
sync();
/* allow time for last message to reach serial console */
sleep(2);
init_reboot(RB_AUTOBOOT);
exit(0);
}
#endif /* ! DEBUG_INIT */
void new_initAction(initActionEnum action, char *process, char *cons)
{
initAction *newAction;
if (*cons == '\0')
cons = console;
/* If BusyBox detects that a serial console is in use,
* then entries not refering to the console or null devices will _not_ be run.
* The exception to this rule is the null device.
*/
if (secondConsole == NULL && strcmp(cons, console)
&& strcmp(cons, "/dev/null"))
return;
newAction = calloc((size_t) (1), sizeof(initAction));
if (!newAction) {
message(LOG | CONSOLE, "Memory allocation failure\n");
while (1)
sleep(1);
}
newAction->nextPtr = initActionList;
initActionList = newAction;
strncpy(newAction->process, process, 255);
newAction->action = action;
strncpy(newAction->console, cons, 255);
newAction->pid = 0;
// message(LOG|CONSOLE, "process='%s' action='%d' console='%s'\n",
// newAction->process, newAction->action, newAction->console);
}
static void delete_initAction(initAction * action)
{
initAction *a, *b = NULL;
for (a = initActionList; a; b = a, a = a->nextPtr) {
if (a == action) {
if (b == NULL) {
initActionList = a->nextPtr;
} else {
b->nextPtr = a->nextPtr;
}
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.
* */
void parse_inittab(void)
{
#ifdef BB_FEATURE_USE_INITTAB
FILE *file;
char buf[256], lineAsRead[256], tmpConsole[256];
char *id, *runlev, *action, *process, *eol;
const struct initActionType *a = actions;
int foundIt;
file = fopen(INITTAB, "r");
if (file == NULL) {
/* No inittab file -- set up some default behavior */
#endif
/* Swapoff on halt/reboot */
new_initAction(CTRLALTDEL, "/sbin/swapoff -a", console);
/* Umount all filesystems on halt/reboot */
new_initAction(CTRLALTDEL, "/bin/umount -a -r", console);
/* Askfirst shell on tty1 */
new_initAction(ASKFIRST, SHELL, console);
/* Askfirst shell on tty2 */
if (secondConsole != NULL)
new_initAction(ASKFIRST, SHELL, secondConsole);
/* Askfirst shell on tty3 */
if (thirdConsole != NULL)
new_initAction(ASKFIRST, SHELL, thirdConsole);
/* Askfirst shell on tty4 */
if (fourthConsole != NULL)
new_initAction(ASKFIRST, SHELL, fourthConsole);
/* sysinit */
new_initAction(SYSINIT, INIT_SCRIPT, console);
return;
#ifdef BB_FEATURE_USE_INITTAB
}
while (fgets(buf, 255, 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 */
runlev = strchr(id, ':');
if (runlev == NULL || *(runlev + 1) == '\0') {
message(LOG | CONSOLE, "Bad inittab entry: %s\n", lineAsRead);
continue;
} else {
*runlev = '\0';
++runlev;
}
/* Separate the runlevels from the action */
action = strchr(runlev, ':');
if (action == NULL || *(action + 1) == '\0') {
message(LOG | CONSOLE, "Bad inittab entry: %s\n", lineAsRead);
continue;
} else {
*action = '\0';
++action;
}
/* Separate the action from the process */
process = strchr(action, ':');
if (process == NULL || *(process + 1) == '\0') {
message(LOG | CONSOLE, "Bad inittab entry: %s\n", lineAsRead);
continue;
} else {
*process = '\0';
++process;
}
/* Ok, now process it */
a = actions;
while (a->name != 0) {
if (strcmp(a->name, action) == 0) {
if (*id != '\0') {
struct stat statBuf;
strcpy(tmpConsole, "/dev/");
strncat(tmpConsole, id, 200);
if (stat(tmpConsole, &statBuf) != 0) {
message(LOG | CONSOLE,
"device '%s' does not exist. Did you read the directions?\n",
tmpConsole);
break;
}
id = tmpConsole;
}
new_initAction(a->action, process, id);
foundIt = TRUE;
}
a++;
}
if (foundIt == TRUE)
continue;
else {
/* Choke on an unknown action */
message(LOG | CONSOLE, "Bad inittab entry: %s\n", lineAsRead);
}
}
return;
#endif /* BB_FEATURE_USE_INITTAB */
}
extern int init_main(int argc, char **argv)
{
initAction *a;
pid_t wpid;
int status;
#ifndef DEBUG_INIT
/* Expect to be invoked as init with PID=1 or be invoked as linuxrc */
if (getpid() != 1
#ifdef BB_FEATURE_LINUXRC
&& strstr(applet_name, "linuxrc") == NULL
#endif
)
{
show_usage();
}
/* Set up sig handlers -- be sure to
* clear all of these in run() */
signal(SIGUSR1, halt_signal);
signal(SIGUSR2, halt_signal);
signal(SIGINT, reboot_signal);
signal(SIGTERM, reboot_signal);
/* Turn off rebooting via CTL-ALT-DEL -- we get a
* SIGINT on CAD so we can shut things down gracefully... */
init_reboot(RB_DISABLE_CAD);
#endif
/* Figure out what kernel this is running */
kernelVersion = get_kernel_revision();
/* Figure out where the default console should be */
console_init();
/* Close whatever files are open, and reset the console. */
close(0);
close(1);
close(2);
set_term(0);
chdir("/");
setsid();
/* Make sure PATH is set to something sane */
putenv(_PATH_STDPATH);
/* Hello world */
#ifndef DEBUG_INIT
message(
#if ! defined BB_FEATURE_EXTRA_QUIET
CONSOLE|
#endif
LOG,
"init started: %s\r\n", full_version);
#else
message(
#if ! defined BB_FEATURE_EXTRA_QUIET
CONSOLE|
#endif
LOG,
"init(%d) started: %s\r\n", getpid(), full_version);
#endif
/* Make sure there is enough memory to do something useful. */
check_memory();
/* Check if we are supposed to be in single user mode */
if (argc > 1 && (!strcmp(argv[1], "single") ||
!strcmp(argv[1], "-s") || !strcmp(argv[1], "1"))) {
/* Ask first then start a shell on tty2-4 */
if (secondConsole != NULL)
new_initAction(ASKFIRST, SHELL, secondConsole);
if (thirdConsole != NULL)
new_initAction(ASKFIRST, SHELL, thirdConsole);
if (fourthConsole != NULL)
new_initAction(ASKFIRST, SHELL, fourthConsole);
/* Start a shell on tty1 */
new_initAction(RESPAWN, SHELL, console);
} else {
/* Not in single user mode -- see what inittab says */
/* 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 */
parse_inittab();
}
/* Fix up argv[0] to be certain we claim to be init */
argv[0]="init";
if (argc > 1)
argv[1][0]=0;
/* Now run everything that needs to be run */
/* First run the sysinit command */
for (a = initActionList; a; a = a->nextPtr) {
if (a->action == SYSINIT) {
waitfor(a->process, a->console, FALSE);
/* Now remove the "sysinit" entry from the list */
delete_initAction(a);
}
}
/* Next run anything that wants to block */
for (a = initActionList; a; a = a->nextPtr) {
if (a->action == WAIT) {
waitfor(a->process, a->console, FALSE);
/* Now remove the "wait" entry from the list */
delete_initAction(a);
}
}
/* Next run anything to be run only once */
for (a = initActionList; a; a = a->nextPtr) {
if (a->action == ONCE) {
run(a->process, a->console, FALSE);
/* Now remove the "once" entry from the list */
delete_initAction(a);
}
}
/* If there is nothing else to do, stop */
if (initActionList == NULL) {
message(LOG | CONSOLE,
"No more tasks for init -- sleeping forever.\n");
while (1)
sleep(1);
}
/* Now run the looping stuff for the rest of forever */
while (1) {
for (a = initActionList; a; a = a->nextPtr) {
/* Only run stuff with pid==0. If they have
* a pid, that means they are still running */
if (a->pid == 0) {
switch (a->action) {
case RESPAWN:
/* run the respawn stuff */
a->pid = run(a->process, a->console, FALSE);
break;
case ASKFIRST:
/* run the askfirst stuff */
a->pid = run(a->process, a->console, TRUE);
break;
/* silence the compiler's incessant whining */
default:
break;
}
}
}
/* Wait for a child process to exit */
wpid = wait(&status);
if (wpid > 0) {
/* Find out who died and clean up their corpse */
for (a = initActionList; a; a = a->nextPtr) {
if (a->pid == wpid) {
a->pid = 0;
message(LOG,
"Process '%s' (pid %d) exited. Scheduling it for restart.\n",
a->process, wpid);
}
}
}
sleep(1);
}
}
/*
Local Variables:
c-file-style: "linux"
c-basic-offset: 4
tab-width: 4
End:
*/
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