busybox/init.c
Eric Andersen cb6e25655f More stuff
1999-10-16 15:48:40 +00:00

430 lines
8.8 KiB
C

#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/swap.h>
#include <sys/sysmacros.h>
const char init_usage[] = "Used internally by the system.";
char console[16] = "";
const char * default_console = "/dev/tty1";
char * first_terminal = NULL;
const char * second_terminal = "/dev/tty2";
const char log[] = "/dev/tty3";
char * term_ptr = NULL;
static void
message(const char * terminal, const char * pattern, ...)
{
int fd;
FILE * con = 0;
va_list arguments;
/*
* Open the console device each time a message is printed. If the user
* has switched consoles, the open will get the new console. If we kept
* the console open, we'd always print to the same one.
*/
if ( ((fd = open(terminal, O_WRONLY|O_NOCTTY)) < 0)
|| ((con = fdopen(fd, "w")) == NULL) )
return;
va_start(arguments, pattern);
vfprintf(con, pattern, arguments);
va_end(arguments);
fclose(con);
}
static int
waitfor(int pid)
{
int status;
int 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 int
run(const char* program, const char* const* arguments,
const char* terminal, int get_enter)
{
static const char control_characters[] = {
'\003',
'\034',
'\177',
'\025',
'\004',
'\0',
'\1',
'\0',
'\021',
'\023',
'\032',
'\0',
'\022',
'\017',
'\027',
'\026',
'\0'
};
static char * environment[] = {
"HOME=/",
"PATH=/bin:/sbin:/usr/bin:/usr/sbin",
"SHELL=/bin/sh",
0,
"USER=root",
0
};
static const char press_enter[] =
"\nPlease press Enter to activate this console. ";
int pid;
environment[3]=term_ptr;
pid = fork();
if ( pid == 0 ) {
struct termios t;
const char * const * arg;
close(0);
close(1);
close(2);
setsid();
open(terminal, O_RDWR);
dup(0);
dup(0);
tcsetpgrp(0, getpgrp());
tcgetattr(0, &t);
memcpy(t.c_cc, control_characters, sizeof(control_characters));
t.c_line = 0;
t.c_iflag = ICRNL|IXON|IXOFF;
t.c_oflag = OPOST|ONLCR;
t.c_lflag = ISIG|ICANON|ECHO|ECHOE|ECHOK|ECHOCTL|ECHOKE|IEXTEN;
tcsetattr(0, TCSANOW, &t);
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(1, press_enter, sizeof(press_enter) - 1);
read(0, &c, 1);
}
message(log, "Executing ");
arg = arguments;
while ( *arg != 0 )
message(log, "%s ", *arg++);
message(log, "\n");
execve(program, (char * *)arguments, (char * *)environment);
message(log, "%s: could not execute: %s.\r\n", program, strerror(errno));
exit(-1);
}
return pid;
}
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
shutdown_system(int do_reboot)
{
static const char * const umount_args[] = {"/bin/umount", "-a", "-n", 0};
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("/bin/umount", umount_args, console, 0));
sync();
bdflush(1, 0);
sync();
reboot(do_reboot ?RB_AUTOBOOT : RB_HALT_SYSTEM);
exit(0);
}
static void
halt_signal(int sig)
{
shutdown_system(0);
}
static void
reboot_signal(int sig)
{
shutdown_system(1);
}
static void
exit_signal(int sig)
{
/* initrd doesn't work anyway */
shutdown_system(1);
/* This is used on the initial ramdisk */
/* message(log, "Init exiting.");
exit(0);
*/
}
void
configure_terminals( int serial_cons )
{
//struct stat statbuf;
char *tty;
switch (serial_cons) {
case 1:
strcpy( console, "/dev/ttyS0" );
break;
case 2:
strcpy( console, "/dev/ttyS1" );
break;
default:
tty = ttyname(0);
if (tty) {
strcpy( console, tty );
if (!strncmp( tty, "/dev/ttyS", 9 ))
serial_cons=1;
}
else
/* falls back to /dev/tty1 if an error occurs */
strcpy( console, default_console );
}
if (!first_terminal)
first_terminal = console;
if (serial_cons && !strncmp(term_ptr,"TERM=linux",10))
term_ptr = "TERM=vt100";
}
extern int
init_main(int argc, char * * argv)
{
static const char* const rc = "etc/rc";
const char * arguments[100];
int run_rc = 1;
int j;
int pid1 = 0;
int pid2 = 0;
int create_swap= -1;
struct stat statbuf;
const char * tty_commands[2] = { "bin/sh", "bin/sh"};
char swap[20];
int serial_console = 0;
/*
* If I am started as /linuxrc instead of /sbin/init, I don't have the
* environment that init expects. I can't fix the signal behavior. Try
* to divorce from the controlling terminal with setsid(). This won't work
* if I am the process group leader.
*/
setsid();
signal(SIGUSR1, halt_signal);
signal(SIGUSR2, reboot_signal);
signal(SIGINT, reboot_signal);
signal(SIGTERM, exit_signal);
reboot(RB_DISABLE_CAD);
message(log, "%s: started. ", argv[0]);
for ( j = 1; j < argc; j++ ) {
if ( strcmp(argv[j], "single") == 0 ) {
run_rc = 0;
tty_commands[0] = "bin/sh";
tty_commands[1] = 0;
}
}
for ( j = 0; __environ[j] != 0; j++ ) {
if ( strncmp(__environ[j], "tty", 3) == 0
&& __environ[j][3] >= '1'
&& __environ[j][3] <= '2'
&& __environ[j][4] == '=' ) {
const char * s = &__environ[j][5];
if ( *s == 0 || strcmp(s, "off") == 0 )
s = 0;
tty_commands[__environ[j][3] - '1'] = s;
}
/* Should catch the syntax of Sparc kernel console setting. */
/* The kernel does not recognize a serial console when getting*/
/* console=/dev/ttySX !! */
else if ( strcmp(__environ[j], "console=ttya") == 0 ) {
serial_console=1;
}
else if ( strcmp(__environ[j], "console=ttyb") == 0 ) {
serial_console=2;
}
/* standard console settings */
else if ( strncmp(__environ[j], "console=", 8) == 0 ) {
first_terminal=&(__environ[j][8]);
}
else if ( strncmp(__environ[j], "TERM=", 5) == 0) {
term_ptr=__environ[j];
}
}
configure_terminals( serial_console );
printf("mounting /proc ...\n");
if (mount("/proc","/proc","proc",0,0)) {
perror("mounting /proc failed\n");
}
printf("\tdone.\n");
set_free_pages();
/* not enough memory to do anything useful*/
if (mem_total() < 2000) {
int retval;
retval= stat("/etc/swappartition",&statbuf);
if (retval) {
printf("You do not have enough RAM, sorry.\n");
while (1) { sleep(1);}
} else { /* everything OK */
FILE *f;
f=fopen("/etc/swappartition","r");
fgets(swap,19,f);
fclose(f);
*(strstr(swap,"\n"))='\0';
if (swapon(swap,0)) {
perror("swapon failed\n");
} else {
f=fopen("/etc/swaps","w");
fprintf(f,"%s none swap rw 0 0",swap);
fclose(f);
create_swap = 0;
}
}
}
/*
* Don't modify **argv directly, it would show up in the "ps" display.
* I don't want "init" to look like "rc".
*/
arguments[0] = rc;
for ( j = 1; j < argc; j++ ) {
arguments[j] = argv[j];
}
arguments[j] = 0;
if ( run_rc ) {
run(rc, arguments, console, 0);
//waitfor(run(rc, arguments, console, 0));
}
if ( 0 == create_swap) {
if (unlink("/etc/swappartition")) {
perror("unlinking /etc/swappartition");
}
}
arguments[0] = "-sh";
arguments[1] = 0;
for ( ; ; ) {
int wpid;
int status;
if ( pid1 == 0 && tty_commands[0] ) {
/* Ask before starting a shell */
/*
arguments[0] = tty_commands[0];
*/
pid1 = run(tty_commands[0], arguments, first_terminal, 1);
}
if ( pid2 == 0 && tty_commands[1] ) {
pid2 = run(tty_commands[1], arguments, second_terminal, 1);
}
wpid = wait(&status);
if ( wpid > 0 ) {
/* DEBUGGING */
message(log, "pid %d exited, status=%x.\n", wpid, status);
}
if ( wpid == pid1 ) {
pid1 = 0;
}
if ( wpid == pid2 )
pid2 = 0;
}
}