hush/init.c
Erik Andersen d07ee46919 Removed proc dependancies for init and free (which maintaining exactly
the same functionality).  /proc takes up 90k of kernel space, so it is
nice to avoid using it at all costs.  The only places where it is depended
on is for cetain optional mount/umount features, and for ps and lsmod.
 -Erik
2000-02-21 21:26:32 +00:00

948 lines
23 KiB
C

/* 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 "internal.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdarg.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>
#include <termios.h>
#include <paths.h>
#include <sys/types.h>
#include <sys/fcntl.h>
#include <sys/wait.h>
#include <string.h>
#include <sys/mount.h>
#include <sys/reboot.h>
#include <sys/kdaemon.h>
#include <sys/sysmacros.h>
#include <asm/types.h>
#include <linux/serial.h> /* for serial_struct */
#include <sys/vt.h> /* for vt_stat */
#include <sys/ioctl.h>
#include <sys/sysinfo.h> /* For check_free_memory() */
#include <linux/version.h>
#ifdef BB_SYSLOGD
#include <sys/syslog.h>
#endif
#ifndef KERNEL_VERSION
#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))
#endif
#define VT_PRIMARY "/dev/tty1" /* Primary virtual console */
#define VT_SECONDARY "/dev/tty2" /* Virtual console */
#define VT_LOG "/dev/tty3" /* 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
#define LOG 0x1
#define CONSOLE 0x2
/* Allowed init action types */
typedef enum {
SYSINIT = 1,
RESPAWN,
ASKFIRST,
WAIT,
ONCE,
CTRLALTDEL
} initActionEnum;
/* And now a list of the actions we support in the version of init */
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}
};
/* 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 *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 */
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("init", 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);
fflush(stderr);
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);
fflush(stderr);
va_end(arguments);
}
}
}
/* Set terminal settings to reasonable defaults */
void set_term(int fd)
{
struct termios tty;
static const char control_characters[] = {
'\003', '\034', '\177', '\025', '\004', '\0',
'\1', '\0', '\021', '\023', '\032', '\0', '\022',
'\017', '\027', '\026', '\0'
};
tcgetattr(fd, &tty);
/* set control chars */
memcpy(tty.c_cc, control_characters, sizeof(control_characters));
/* 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? */
static int check_free_memory()
{
struct sysinfo info;
sysinfo(&info);
if (sysinfo(&info) != 0) {
message(LOG, "Error checking free memory: %s\n", strerror(errno));
return -1;
}
return(info.freeram/1024);
}
static void console_init()
{
int fd;
int tried_devcons = 0;
int tried_vtprimary = 0;
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 {
struct vt_stat vt;
/* 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 tty3 & running a
* shell to tty2 */
if (ioctl(0, TIOCGSERIAL, &sr) == 0) {
log = NULL;
secondConsole = 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, fd;
pid_t pid;
char *tmpCmd;
char *cmd[255];
char buf[255];
static const char press_enter[] =
"\nPlease press Enter to activate this console. ";
char *environment[] = {
"HOME=/",
"PATH=/usr/bin:/bin:/usr/sbin:/sbin",
"SHELL=/bin/sh",
termType,
"USER=root",
0
};
if ((pid = fork()) == 0) {
#ifdef DEBUG_INIT
pid_t shell_pgid = getpid();
#endif
/* Clean up */
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);
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.
*/
char c;
#ifdef DEBUG_INIT
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);
read(fileno(stdin), &c, 1);
}
#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;
}
/* Now run it. The new program will take over this PID,
* so nothing further in init.c should be run. */
execve(cmd[0], cmd, environment);
/* We're still here? Some error happened. */
message(LOG | CONSOLE, "Bummer, could not run '%s': %s\n", cmd[0],
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) {
/* Try to turn on swap */
system("/sbin/swapon -a");
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. */
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 <= 2 * 65536 + 2 * 256 + 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 LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,0)
if (sig == SIGUSR2)
reboot(RB_POWER_OFF);
else
#endif
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);
reboot(RB_AUTOBOOT);
exit(0);
}
#if defined BB_FEATURE_INIT_CHROOT
#if ! defined BB_FEATURE_USE_PROCFS
#error Sorry, I depend on the /proc filesystem right now.
#endif
static void check_chroot(int sig)
{
char *argv_init[2] = { "init", NULL, };
char *envp_init[3] = { "HOME=/", "TERM=linux", NULL, };
char rootpath[256], *tc;
int fd;
if ((fd = open("/proc/sys/kernel/init-chroot", O_RDONLY)) == -1) {
message(CONSOLE,
"SIGHUP recived, but could not open proc file\r\n");
sleep(2);
return;
}
if (read(fd, rootpath, sizeof(rootpath)) == -1) {
message(CONSOLE,
"SIGHUP recived, but could not read proc file\r\n");
sleep(2);
return;
}
close(fd);
if (rootpath[0] == '\0') {
message(CONSOLE,
"SIGHUP recived, but new root is not valid: %s\r\n",
rootpath);
sleep(2);
return;
}
tc = strrchr(rootpath, '\n');
*tc = '\0';
/* Ok, making it this far means we commit */
message(CONSOLE, "Please stand by, changing root to `%s'.\r\n",
rootpath);
/* kill all other programs first */
message(CONSOLE, "Sending SIGTERM to all processes.\r\n");
kill(-1, SIGTERM);
sleep(2);
sync();
message(CONSOLE, "Sending SIGKILL to all processes.\r\n");
kill(-1, SIGKILL);
sleep(2);
sync();
/* ok, we don't need /proc anymore. we also assume that the signaling
* process left the rest of the filesystems alone for us */
umount("/proc");
/* Ok, now we chroot. Hopefully we only have two things mounted, the
* new chroot'd mount point, and the old "/" mount. s,
* we go ahead and unmount the old "/". This should trigger the kernel
* to set things up the Right Way(tm). */
if (!chroot(rootpath))
umount("/dev/root");
/* If the chroot fails, we are already too far to turn back, so we
* continue and hope that executing init below will revive the system */
/* close all of our descriptors and open new ones */
close(0);
close(1);
close(2);
open("/dev/console", O_RDWR, 0);
dup(0);
dup(0);
message(CONSOLE, "Executing real init...\r\n");
/* execute init in the (hopefully) new root */
execve("/sbin/init", argv_init, envp_init);
message(CONSOLE,
"ERROR: Could not exec new init. Press %s to reboot.\r\n",
(secondConsole == NULL) /* serial console */
? "Reset" : "CTRL-ALT-DEL");
return;
}
#endif /* BB_FEATURE_INIT_CHROOT */
#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 *p, *q, *r, *s;
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 > /dev/null 2>&1", console);
/* Umount all filesystems on halt/reboot */
new_initAction(CTRLALTDEL, "/bin/umount -a -r > /dev/null 2>&1", console);
/* Askfirst shell on tty1 */
new_initAction(ASKFIRST, SHELL, console);
/* Askfirst shell on tty2 */
if (secondConsole != NULL)
new_initAction(ASKFIRST, SHELL, secondConsole);
/* sysinit */
new_initAction(SYSINIT, INIT_SCRIPT, console);
return;
#ifdef BB_FEATURE_USE_INITTAB
}
while (fgets(buf, 255, file) != NULL) {
foundIt = FALSE;
for (p = buf; *p == ' ' || *p == '\t'; p++);
if (*p == '#' || *p == '\n')
continue;
/* Trim the trailing \n */
q = strrchr(p, '\n');
if (q != NULL)
*q = '\0';
/* Keep a copy around for posterity's sake (and error msgs) */
strcpy(lineAsRead, buf);
/* Grab the ID field */
s = p;
p = strchr(p, ':');
if (p != NULL || *(p + 1) != '\0') {
*p = '\0';
++p;
}
/* Now peal off the process field from the end
* of the string */
q = strrchr(p, ':');
if (q == NULL || *(q + 1) == '\0') {
message(LOG | CONSOLE, "Bad inittab entry: %s\n", lineAsRead);
continue;
} else {
*q = '\0';
++q;
}
/* Now peal off the action field */
r = strrchr(p, ':');
if (r == NULL || *(r + 1) == '\0') {
message(LOG | CONSOLE, "Bad inittab entry: %s\n", lineAsRead);
continue;
} else {
++r;
}
/* Ok, now process it */
a = actions;
while (a->name != 0) {
if (strcmp(a->name, r) == 0) {
if (*s != '\0') {
struct stat statBuf;
strcpy(tmpConsole, "/dev/");
strncat(tmpConsole, s, 200);
if (stat(tmpConsole, &statBuf) != 0) {
message(LOG | CONSOLE,
"device '%s' does not exist. Did you read the directions?\n",
tmpConsole);
break;
}
s = tmpConsole;
}
new_initAction(a->action, q, s);
foundIt = TRUE;
}
a++;
}
if (foundIt == TRUE)
continue;
else {
/* Choke on an unknown action */
message(LOG | CONSOLE, "Bad inittab entry: %s\n", lineAsRead);
}
}
return;
#endif
}
extern int init_main(int argc, char **argv)
{
initAction *a;
pid_t wpid;
int status;
#ifndef DEBUG_INIT
/* Expect to be PID 1 if we are run as init (not linuxrc) */
if (getpid() != 1 && strstr(argv[0], "init") != NULL) {
usage("init\n\nInit is the parent of all processes.\n\n"
"This version of init is designed to be run only by the kernel\n");
}
/* Set up sig handlers -- be sure to
* clear all of these in run() */
signal(SIGUSR1, halt_signal);
signal(SIGUSR2, reboot_signal);
signal(SIGINT, reboot_signal);
signal(SIGTERM, reboot_signal);
#if defined BB_FEATURE_INIT_CHROOT
signal(SIGHUP, check_chroot);
#endif
/* Turn off rebooting via CTL-ALT-DEL -- we get a
* SIGINT on CAD so we can shut things down gracefully... */
reboot(RB_DISABLE_CAD);
#endif
/* 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);
setsid();
/* Make sure PATH is set to something sane */
putenv(_PATH_STDPATH);
/* Hello world */
#ifndef DEBUG_INIT
message(LOG,
"init started: BusyBox v%s (%s) multi-call binary\r\n",
BB_VER, BB_BT);
#else
message(LOG,
"init(%d) started: BusyBox v%s (%s) multi-call binary\r\n",
getpid(), BB_VER, BB_BT);
#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 */
if (secondConsole != NULL)
new_initAction(ASKFIRST, SHELL, secondConsole);
/* 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 */
strncpy(argv[0], "init", strlen(argv[0])+1);
if (argc > 1)
strncpy(argv[1], "\0", strlen(argv[1])+1);
/* 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);
}
}