449 lines
11 KiB
C
449 lines
11 KiB
C
/*
|
|
* 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
|
|
*
|
|
*/
|
|
|
|
#include "internal.h"
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <stdarg.h>
|
|
#include <unistd.h>
|
|
#include <errno.h>
|
|
#include <signal.h>
|
|
#include <termios.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 <linux/serial.h> /* for serial_struct */
|
|
#include <sys/vt.h> /* for vt_stat */
|
|
#include <sys/ioctl.h>
|
|
|
|
#define DEBUG_INIT
|
|
|
|
#define CONSOLE "/dev/console" /* Logical system console */
|
|
#define VT_PRIMARY "/dev/tty0" /* Virtual console master */
|
|
#define VT_SECONDARY "/dev/tty1" /* Virtual console master */
|
|
#define VT_LOG "/dev/tty2" /* Virtual console master */
|
|
#define SHELL "/bin/sh" /* Default shell */
|
|
#define INITSCRIPT "/etc/init.d/rcS" /* Initscript. */
|
|
#define PATH_DEFAULT "PATH=/usr/local/sbin:/sbin:/bin:/usr/sbin:/usr/bin"
|
|
|
|
static char *console = CONSOLE;
|
|
//static char *first_terminal = "/dev/tty1";
|
|
static char *second_terminal = "/dev/tty2";
|
|
static char *log = "/dev/tty3";
|
|
|
|
|
|
|
|
/* try to open up the specified device */
|
|
int device_open(char *device, int mode)
|
|
{
|
|
int m, f, fd = -1;
|
|
|
|
mode = m | O_NONBLOCK;
|
|
|
|
/* Retry up to 5 times */
|
|
for (f = 0; f < 5; f++)
|
|
if ((fd = open(device, m)) >= 0)
|
|
break;
|
|
if (fd < 0)
|
|
return fd;
|
|
/* Set original flags. */
|
|
if (m != mode)
|
|
fcntl(fd, F_SETFL, mode);
|
|
return fd;
|
|
}
|
|
|
|
/* print a message to the specified device */
|
|
void message(char *device, char *fmt, ...)
|
|
{
|
|
int fd;
|
|
va_list arguments;
|
|
|
|
if ((fd = device_open(device, 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;
|
|
|
|
tcgetattr(fd, &tty);
|
|
tty.c_cflag &= CBAUD|CBAUDEX|CSIZE|CSTOPB|PARENB|PARODD;
|
|
tty.c_cflag |= HUPCL|CLOCAL;
|
|
|
|
tty.c_cc[VINTR] = 3;
|
|
tty.c_cc[VQUIT] = 28;
|
|
tty.c_cc[VERASE] = 127;
|
|
tty.c_cc[VKILL] = 24;
|
|
tty.c_cc[VEOF] = 4;
|
|
tty.c_cc[VTIME] = 0;
|
|
tty.c_cc[VMIN] = 1;
|
|
tty.c_cc[VSTART] = 17;
|
|
tty.c_cc[VSTOP] = 19;
|
|
tty.c_cc[VSUSP] = 26;
|
|
|
|
tty.c_iflag = IGNPAR|ICRNL|IXON|IXANY;
|
|
tty.c_oflag = OPOST|ONLCR;
|
|
tty.c_lflag = ISIG|ICANON|ECHO|ECHOCTL|ECHOPRT|ECHOKE;
|
|
|
|
tcsetattr(fd, TCSANOW, &tty);
|
|
}
|
|
|
|
static int mem_total()
|
|
{
|
|
char s[80];
|
|
char *p;
|
|
FILE *f;
|
|
const char pattern[] = "MemTotal:";
|
|
|
|
f = fopen("/proc/meminfo", "r");
|
|
while (NULL != fgets(s, 79, f)) {
|
|
p = strstr(s, pattern);
|
|
if (NULL != p) {
|
|
fclose(f);
|
|
return (atoi(p + strlen(pattern)));
|
|
}
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
static void set_free_pages()
|
|
{
|
|
char s[80];
|
|
FILE *f;
|
|
|
|
f = fopen("/proc/sys/vm/freepages", "r");
|
|
fgets(s, 79, f);
|
|
if (atoi(s) < 32) {
|
|
fclose(f);
|
|
f = fopen("/proc/sys/vm/freepages", "w");
|
|
fprintf(f, "30\t40\t50\n");
|
|
printf("\nIncreased /proc/sys/vm/freepages values to 30/40/50\n");
|
|
}
|
|
fclose(f);
|
|
}
|
|
|
|
|
|
static void console_init()
|
|
{
|
|
int fd;
|
|
struct stat statbuf;
|
|
int tried_devcons = 0;
|
|
int tried_vtmaster = 0;
|
|
char *s;
|
|
|
|
fprintf(stderr, "entering console_init()\n");
|
|
if ((s = getenv("CONSOLE")) != NULL)
|
|
console = s;
|
|
else {
|
|
console = CONSOLE;
|
|
tried_devcons++;
|
|
}
|
|
|
|
if ( stat(CONSOLE, &statbuf) && S_ISLNK(statbuf.st_mode)) {
|
|
fprintf(stderr, "Yikes! /dev/console does not exist or is a symlink.\n");
|
|
}
|
|
while ((fd = open(console, O_RDONLY | O_NONBLOCK)) < 0) {
|
|
if (!tried_devcons) {
|
|
tried_devcons++;
|
|
console = CONSOLE;
|
|
continue;
|
|
}
|
|
if (!tried_vtmaster) {
|
|
tried_vtmaster++;
|
|
console = VT_PRIMARY;
|
|
continue;
|
|
}
|
|
break;
|
|
}
|
|
if (fd < 0)
|
|
console = "/dev/null";
|
|
else
|
|
close(fd);
|
|
fprintf(stderr, "console=%s\n", console);
|
|
}
|
|
|
|
static int waitfor(int pid)
|
|
{
|
|
int status, wpid;
|
|
|
|
message(log, "Waiting for process %d.\n", pid);
|
|
while ((wpid = wait(&status)) != pid) {
|
|
if (wpid > 0)
|
|
message(log, "pid %d exited, status=%x.\n", wpid, status);
|
|
}
|
|
return wpid;
|
|
}
|
|
|
|
|
|
static pid_t run(const char * const* command,
|
|
char *terminal, int get_enter)
|
|
{
|
|
int i;
|
|
pid_t pid;
|
|
static const char press_enter[] =
|
|
"\nPlease press Enter to activate this console. ";
|
|
|
|
if ((pid = fork()) == 0) {
|
|
/* Clean up */
|
|
close(0);
|
|
close(1);
|
|
close(2);
|
|
setsid();
|
|
|
|
open(terminal, O_RDWR);
|
|
dup(0);
|
|
dup(0);
|
|
tcsetpgrp(0, getpgrp());
|
|
set_term(0);
|
|
|
|
if (get_enter) {
|
|
/*
|
|
* 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;
|
|
write(0, press_enter, sizeof(press_enter) - 1);
|
|
read(0, &c, 1);
|
|
}
|
|
|
|
/* Log the process name and args */
|
|
|
|
/* Now run it. The new program will take over this PID,
|
|
* so nothing further in init.c should be run. */
|
|
message(log, "Executing '%s', pid(%d)\r\n", *command, getpid());
|
|
execvp(*command, (char**)command+1);
|
|
|
|
message(log, "Hmm. Trying as a script.\r\n");
|
|
/* If shell scripts are not executed, force the issue */
|
|
if (errno == ENOEXEC) {
|
|
char * args[16];
|
|
args[0] = SHELL;
|
|
args[1] = "-c";
|
|
args[2] = "exec";
|
|
for( i=0 ; i<16 && command[i]; i++)
|
|
args[3+i] = (char*)command[i];
|
|
args[i] = NULL;
|
|
execvp(*args, (char**)args+1);
|
|
}
|
|
message(log, "Could not execute '%s'\n", command);
|
|
exit(-1);
|
|
}
|
|
return pid;
|
|
}
|
|
|
|
|
|
#ifndef DEBUG_INIT
|
|
static void shutdown_system(void)
|
|
{
|
|
const char* const swap_off_cmd[] = { "/bin/swapoff", "-a", 0};
|
|
const char* const umount_cmd[] = { "/bin/umount", "-a", "-n", 0};
|
|
|
|
message(console, "The system is going down NOW !!\r\n");
|
|
sync();
|
|
/* Allow Ctrl-Alt-Del to reboot system. */
|
|
reboot(RB_ENABLE_CAD);
|
|
|
|
/* Send signals to every process _except_ pid 1 */
|
|
message(console, "Sending SIGHUP to all processes.\r\n");
|
|
kill(-1, SIGHUP);
|
|
sleep(2);
|
|
sync();
|
|
message(console, "Sending SIGKILL to all processes.\r\n");
|
|
kill(-1, SIGKILL);
|
|
sleep(1);
|
|
waitfor(run( swap_off_cmd, console, 0));
|
|
waitfor(run( umount_cmd, console, 0));
|
|
sync();
|
|
if (get_kernel_revision() <= 2 * 65536 + 2 * 256 + 11) {
|
|
/* Removed bdflush call, kupdate in kernels >2.2.11 */
|
|
bdflush(1, 0);
|
|
sync();
|
|
}
|
|
}
|
|
|
|
static void halt_signal(int sig)
|
|
{
|
|
shutdown_system();
|
|
message(console,
|
|
"The system is halted. Press CTRL-ALT-DEL or turn off power\r\n");
|
|
reboot(RB_POWER_OFF);
|
|
exit(0);
|
|
}
|
|
|
|
static void reboot_signal(int sig)
|
|
{
|
|
shutdown_system();
|
|
message(console, "Please stand by while rebooting the system.\r\n");
|
|
reboot(RB_AUTOBOOT);
|
|
exit(0);
|
|
}
|
|
|
|
#endif
|
|
|
|
extern int init_main(int argc, char **argv)
|
|
{
|
|
int run_rc = TRUE;
|
|
pid_t pid = 0;
|
|
pid_t pid1 = 0;
|
|
pid_t pid2 = 0;
|
|
struct stat statbuf;
|
|
const char* const swap_on_cmd[] = { "/bin/swapon", " -a ", 0};
|
|
const char* const init_commands[] = { SHELL, " -c", " exec ", INITSCRIPT, 0};
|
|
const char* const shell_commands[] = { SHELL, " -", 0};
|
|
const char* const* tty0_commands = init_commands;
|
|
const char* const* tty1_commands = shell_commands;
|
|
char *hello_msg_format =
|
|
"init(%d) started: BusyBox v%s (%s) multi-call binary\r\n";
|
|
const char *no_memory =
|
|
"Sorry, your computer does not have enough memory.\r\n";
|
|
|
|
pid = getpid();
|
|
|
|
#ifndef DEBUG_INIT
|
|
/* Set up sig handlers */
|
|
signal(SIGUSR1, halt_signal);
|
|
signal(SIGSEGV, halt_signal);
|
|
signal(SIGPWR, halt_signal);
|
|
signal(SIGALRM, halt_signal);
|
|
signal(SIGHUP, halt_signal);
|
|
signal(SIGUSR2, reboot_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... */
|
|
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 */
|
|
if (getenv("PATH") == NULL)
|
|
putenv(PATH_DEFAULT);
|
|
|
|
/* Hello world */
|
|
message(log, hello_msg_format, pid, BB_VER, BB_BT);
|
|
fprintf(stderr, hello_msg_format, pid, BB_VER, BB_BT);
|
|
|
|
|
|
/* Mount /proc */
|
|
if (mount("/proc", "/proc", "proc", 0, 0) == 0) {
|
|
fprintf(stderr, "Mounting /proc: done.\n");
|
|
message(log, "Mounting /proc: done.\n");
|
|
} else {
|
|
fprintf(stderr, "Mounting /proc: failed!\n");
|
|
message(log, "Mounting /proc: failed!\n");
|
|
}
|
|
|
|
/* Make sure there is enough memory to do something useful */
|
|
set_free_pages();
|
|
if (mem_total() < 2000) {
|
|
int retval;
|
|
retval = stat("/etc/fstab", &statbuf);
|
|
if (retval) {
|
|
fprintf(stderr, "%s", no_memory);
|
|
while (1) {
|
|
sleep(1);
|
|
}
|
|
} else {
|
|
/* Try to turn on swap */
|
|
waitfor(run(swap_on_cmd, console, 0));
|
|
if (mem_total() < 2000) {
|
|
fprintf(stderr, "%s", no_memory);
|
|
while (1) {
|
|
sleep(1);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* 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"))) {
|
|
run_rc = FALSE;
|
|
tty0_commands = shell_commands;
|
|
tty1_commands = shell_commands;
|
|
}
|
|
|
|
/* Make sure an init script exists before trying to run it */
|
|
if (run_rc == TRUE && stat(INITSCRIPT, &statbuf)) {
|
|
tty0_commands = shell_commands;
|
|
tty1_commands = shell_commands;
|
|
}
|
|
|
|
/* Ok, now launch the rc script and/or prepare to
|
|
* start up some VTs if somebody hits enter...
|
|
*/
|
|
for (;;) {
|
|
pid_t wpid;
|
|
int status;
|
|
|
|
if (pid1 == 0 && tty0_commands) {
|
|
pid1 = run(tty0_commands, console, 1);
|
|
}
|
|
if (pid2 == 0 && tty1_commands) {
|
|
pid2 = run(tty1_commands, second_terminal, 1);
|
|
}
|
|
wpid = wait(&status);
|
|
if (wpid > 0 ) {
|
|
message(log, "pid %d exited, status=%x.\n", wpid, status);
|
|
}
|
|
/* Don't respawn an init script if it exits */
|
|
if (run_rc == FALSE && wpid == pid1) {
|
|
pid1 = 0;
|
|
}
|
|
if (wpid == pid2) {
|
|
pid2 = 0;
|
|
}
|
|
sleep(1);
|
|
}
|
|
}
|