busybox/init/init.c
Eric Andersen 82baf63de5 Hiroshi Ito writes:
Hello, all.

Busybox init does not handle removed inittab entry correctly.

# I'm sorry about my poor english, but you can find
# what I would like to say from patch, isn't it?

even if you apply this path,
when yoy try to change a command line option in inittab,
you have to do following steps.
1. remove old line from initrd
2. send HUP signal to init
3. kill old proces which is invoked from init.
4. append new line to inittab
5. send HUP signal to init, again

patch is against current CVS + last patch witch I send it last.
2004-10-08 08:21:54 +00:00

1215 lines
30 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Mini init implementation for busybox
*
* Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
* 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 <sys/reboot.h>
#include "busybox.h"
#include "init_shared.h"
#ifdef CONFIG_SYSLOGD
# include <sys/syslog.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 CONFIG_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))
#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 */
#define CONSOLE_BUFF_SIZE 32
/* 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[CONSOLE_BUFF_SIZE];
struct init_action *next;
int action;
};
/* Static variables */
static struct init_action *init_action_list = NULL;
static char console[CONSOLE_BUFF_SIZE] = _PATH_CONSOLE;
#ifndef CONFIG_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 CONFIG_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
static const char * const environment[] = {
"HOME=/",
"PATH=" _PATH_STDPATH,
"SHELL=/bin/sh",
"USER=root",
NULL
};
/* Function prototypes */
static void delete_init_action(struct init_action *a);
static int waitfor(const 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 */
#ifndef DEBUG_INIT
static inline void messageD(int device, const char *fmt, ...)
{
}
#else
#define messageD message
#endif
static void message(int device, const char *fmt, ...)
__attribute__ ((format(printf, 2, 3)));
static void message(int device, const char *fmt, ...)
{
va_list arguments;
int l;
char msg[1024];
#ifndef CONFIG_SYSLOGD
static int log_fd = -1;
#endif
msg[0] = '\r';
va_start(arguments, fmt);
l = vsnprintf(msg + 1, sizeof(msg) - 2, fmt, arguments) + 1;
va_end(arguments);
#ifdef CONFIG_SYSLOGD
/* Log the message to syslogd */
if (device & LOG) {
/* don`t out "\r\n" */
openlog(bb_applet_name, 0, LOG_DAEMON);
syslog(LOG_INFO, "%s", msg);
closelog();
}
msg[l++] = '\n';
msg[l] = 0;
#else
msg[l++] = '\n';
msg[l] = 0;
/* 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 | O_NOCTTY)) < 0) {
log_fd = -2;
bb_error_msg("Bummer, can't write to log on %s!", log);
device = CONSOLE;
} else {
fcntl(log_fd, F_SETFD, FD_CLOEXEC);
}
}
if ((device & LOG) && (log_fd >= 0)) {
bb_full_write(log_fd, msg, l);
}
#endif
if (device & CONSOLE) {
int fd = device_open(_PATH_CONSOLE,
O_WRONLY | O_NOCTTY | O_NDELAY);
/* Always send console messages to /dev/console so people will see them. */
if (fd >= 0) {
bb_full_write(fd, msg, l);
close(fd);
#ifdef DEBUG_INIT
/* all descriptors may be closed */
} else {
bb_error_msg("Bummer, can't print: ");
va_start(arguments, fmt);
vfprintf(stderr, fmt, arguments);
va_end(arguments);
#endif
}
}
}
/* 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 unsigned int check_free_memory(void)
{
struct sysinfo info;
unsigned int result, u, s = 10;
if (sysinfo(&info) != 0) {
bb_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);
if (((unsigned long long)result * (unsigned long long)u) > UINT_MAX) {
return(UINT_MAX);
} else {
return(result * u);
}
}
static void console_init(void)
{
int fd;
int tried = 0;
struct vt_stat vt;
struct serial_struct sr;
char *s;
if ((s = getenv("CONSOLE")) != NULL || (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 */
/* 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++;
}
}
while ((fd = open(console, O_RDONLY | O_NONBLOCK)) < 0 && tried < 2) {
/* Can't open selected console -- try
logical system console and VT_MASTER */
safe_strncpy(console, (tried == 0 ? _PATH_CONSOLE : CURRENT_VC),
sizeof(console));
tried++;
}
if (fd < 0) {
/* Perhaps we should panic here? */
#ifndef CONFIG_SYSLOGD
log =
#endif
safe_strncpy(console, "/dev/null", sizeof(console));
} else {
s = getenv("TERM");
/* check for serial console */
if (ioctl(fd, TIOCGSERIAL, &sr) == 0) {
/* Force the TERM setting to vt102 for serial console --
* if TERM is set to linux (the default) */
if (s == NULL || strcmp(s, "linux") == 0)
putenv("TERM=vt102");
#ifndef CONFIG_SYSLOGD
log = console;
#endif
} else {
if (s == NULL)
putenv("TERM=linux");
}
close(fd);
}
messageD(LOG, "console=%s", 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++;
}
}
static pid_t run(const struct init_action *a)
{
struct stat sb;
int i, 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;
static const char press_enter[] =
#ifdef CUSTOMIZED_BANNER
#include CUSTOMIZED_BANNER
#endif
"\nPlease press Enter to activate this console. ";
/* 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, "device '%s' does not exist.",
a->terminal);
_exit(1);
}
message(LOG | CONSOLE, "Bummer, can't open %s", 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!");
_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) {
if (tmp_pid == -1 && errno == ECHILD) {
break;
}
/* FIXME handle other errors */
}
/* 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, "Can't fork!");
_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] = (char *)DEFAULT_SHELL;
cmd[1] = "-c";
cmd[2] = strcat(strcpy(buf, "exec "), a->command);
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 = bb_get_last_path_component(cmdpath);
/* make a new argv[0] */
if ((cmd[0] = malloc(strlen(s) + 2)) == NULL) {
message(LOG | CONSOLE, bb_msg_memory_exhausted);
cmd[0] = cmdpath;
} else {
cmd[0][0] = '-';
strcpy(cmd[0] + 1, s);
}
}
#if !defined(__UCLIBC__) || defined(__ARCH_HAS_MMU__)
if (a->action & ASKFIRST) {
char c;
/*
* 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.
*/
messageD(LOG, "Waiting for enter to start '%s'"
"(pid %d, terminal %s)\n",
cmdpath, getpid(), a->terminal);
bb_full_write(1, press_enter, sizeof(press_enter) - 1);
while(read(0, &c, 1) == 1 && c != '\n')
;
}
#endif
/* Log the process name and args */
message(LOG, "Starting pid %d, console %s: '%s'",
getpid(), a->terminal, cmdpath);
#if defined CONFIG_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. */
execv(cmdpath, cmd);
/* We're still here? Some error happened. */
message(LOG | CONSOLE, "Bummer, could not run '%s': %m", cmdpath);
_exit(-1);
}
sigprocmask(SIG_SETMASK, &omask, NULL);
return pid;
}
static int waitfor(const struct init_action *a)
{
int pid;
int status, wpid;
pid = run(a);
while (1) {
wpid = waitpid(pid,&status,0);
if (wpid == pid)
break;
if (wpid == -1 && errno == ECHILD) {
/* we missed its termination */
break;
}
/* FIXME other errors should maybe trigger an error, but allow
* the program to continue */
}
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) {
reboot(magic);
_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, "The system is going down NOW !!");
sync();
/* Send signals to every process _except_ pid 1 */
message(CONSOLE | LOG, "Sending SIGTERM to all processes.");
kill(-1, SIGTERM);
sleep(1);
sync();
message(CONSOLE | LOG, "Sending SIGKILL to all processes.");
kill(-1, SIGKILL);
sleep(1);
sync();
}
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);
/* Close whatever files are open. */
close(0);
close(1);
close(2);
/* 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);
messageD(CONSOLE | LOG, "Trying to re-exec %s", a->command);
execl(a->command, a->command, NULL);
message(CONSOLE | LOG, "exec of '%s' failed: %m",
a->command);
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). */
"The system is halted. You may reboot now."
#else
"The system is halted. Press Reset or turn off power"
#endif
);
sync();
/* allow time for last message to reach serial console */
sleep(2);
if (sig == SIGUSR2)
init_reboot(RB_POWER_OFF);
else
init_reboot(RB_HALT_SYSTEM);
loop_forever();
}
static void reboot_signal(int sig)
{
shutdown_system();
message(CONSOLE | LOG, "Please stand by while rebooting the system.");
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;
}
#endif /* ! DEBUG_INIT */
static void new_init_action(int action, const char *command, const char *cons)
{
struct init_action *new_action, *a, *last;
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, "Memory allocation failure");
loop_forever();
}
/* Append to the end of the list */
for (a = last = init_action_list; a; a = a->next) {
/* don't enter action if it's already in the list,
* but do overwrite existing actions */
if ((strcmp(a->command, command) == 0) &&
(strcmp(a->terminal, cons) ==0)) {
a->action = action;
free(new_action);
return;
}
last = a;
}
if (last) {
last->next = new_action;
} else {
init_action_list = new_action;
}
strcpy(new_action->command, command);
new_action->action = action;
strcpy(new_action->terminal, cons);
#if 0 /* calloc zeroed always */
new_action->pid = 0;
#endif
messageD(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;
}
}
}
/* 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)
{
struct stat statBuf;
if (check_free_memory() > 1000)
return;
#if !defined(__UCLIBC__) || defined(__ARCH_HAS_MMU__)
if (stat("/etc/fstab", &statBuf) == 0) {
/* swapon -a requires /proc typically */
new_init_action(SYSINIT, "/bin/mount -t proc proc /proc", "");
/* Try to turn on swap */
new_init_action(SYSINIT, "/sbin/swapon -a", "");
run_actions(SYSINIT); /* wait and removing */
if (check_free_memory() < 1000)
goto goodnight;
} else
goto goodnight;
return;
#endif
goodnight:
message(CONSOLE, "Sorry, your computer does not have enough memory.");
loop_forever();
}
/* NOTE that if CONFIG_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 CONFIG_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 CONFIG_FEATURE_USE_INITTAB
FILE *file;
char buf[INIT_BUFFS_SIZE], lineAsRead[INIT_BUFFS_SIZE];
char tmpConsole[CONSOLE_BUFF_SIZE];
char *id, *runlev, *action, *command, *eol;
const struct init_action_type *a = actions;
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", "");
/* Umount all filesystems on halt/reboot */
new_init_action(SHUTDOWN, "/bin/umount -a -r", "");
#if !defined(__UCLIBC__) || defined(__ARCH_HAS_MMU__)
/* Swapoff on halt/reboot */
new_init_action(SHUTDOWN, "/sbin/swapoff -a", "");
#endif
/* Prepare to restart init when a HUP is received */
new_init_action(RESTART, "/sbin/init", "");
/* Askfirst shell on tty1-4 */
new_init_action(ASKFIRST, bb_default_login_shell, "");
new_init_action(ASKFIRST, bb_default_login_shell, VC_2);
new_init_action(ASKFIRST, bb_default_login_shell, VC_3);
new_init_action(ASKFIRST, bb_default_login_shell, VC_4);
/* sysinit */
new_init_action(SYSINIT, INIT_SCRIPT, "");
return;
#ifdef CONFIG_FEATURE_USE_INITTAB
}
while (fgets(buf, INIT_BUFFS_SIZE, file) != NULL) {
/* 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", 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", lineAsRead);
continue;
} else {
*action = '\0';
++action;
}
/* Separate the action from the command */
command = strchr(action, ':');
if (command == NULL || *(command + 1) == '\0') {
message(LOG | CONSOLE, "Bad inittab entry: %s", lineAsRead);
continue;
} else {
*command = '\0';
++command;
}
/* Ok, now process it */
for (a = actions; a->name != 0; a++) {
if (strcmp(a->name, action) == 0) {
if (*id != '\0') {
if(strncmp(id, "/dev/", 5) == 0)
id += 5;
strcpy(tmpConsole, "/dev/");
safe_strncpy(tmpConsole + 5, id,
CONSOLE_BUFF_SIZE - 5);
id = tmpConsole;
}
new_init_action(a->action, command, id);
break;
}
}
if (a->name == 0) {
/* Choke on an unknown action */
message(LOG | CONSOLE, "Bad inittab entry: %s", lineAsRead);
}
}
fclose(file);
return;
#endif /* CONFIG_FEATURE_USE_INITTAB */
}
#ifdef CONFIG_FEATURE_USE_INITTAB
static void reload_signal(int sig)
{
struct init_action *a, *tmp;
message(LOG, "Reloading /etc/inittab");
/* disable old entrys */
for (a = init_action_list; a; a = a->next ) {
a->action = ONCE;
}
parse_inittab();
/* remove unused entrys */
for (a = init_action_list; a; a = tmp) {
tmp = a->next;
if (a->action & (ONCE | SYSINIT | WAIT ) &&
a->pid == 0 ) {
delete_init_action(a);
}
}
run_actions(RESPAWN);
return;
}
#endif /* CONFIG_FEATURE_USE_INITTAB */
extern int init_main(int argc, char **argv)
{
struct init_action *a;
pid_t wpid;
int status;
if (argc > 1 && !strcmp(argv[1], "-q")) {
return kill_init(SIGHUP);
}
#ifndef DEBUG_INIT
/* Expect to be invoked as init with PID=1 or be invoked as linuxrc */
if (getpid() != 1
#ifdef CONFIG_FEATURE_INITRD
&& strstr(bb_applet_name, "linuxrc") == NULL
#endif
) {
bb_show_usage();
}
/* Set up sig handlers -- be sure to
* clear all of these in run() */
signal(SIGHUP, exec_signal);
signal(SIGUSR1, halt_signal);
signal(SIGUSR2, halt_signal);
signal(SIGINT, ctrlaltdel_signal);
signal(SIGTERM, reboot_signal);
signal(SIGCONT, cont_handler);
signal(SIGSTOP, stop_handler);
signal(SIGTSTP, stop_handler);
/* 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 where the default console should be */
console_init();
/* Close whatever files are open, and reset the console. */
close(0);
close(1);
close(2);
if (device_open(console, O_RDWR | O_NOCTTY) == 0) {
set_term(0);
close(0);
}
chdir("/");
setsid();
{
const char * const *e;
/* Make sure environs is set to something sane */
for(e = environment; *e; e++)
putenv((char *) *e);
}
/* Hello world */
message(MAYBE_CONSOLE | LOG, "init started: %s", bb_msg_full_version);
/* 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"))) {
/* Start a shell on console */
new_init_action(RESPAWN, bb_default_login_shell, "");
} else {
/* Not in single user mode -- see what inittab says */
/* NOTE that if CONFIG_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();
}
/* Make the command line just say "init" -- thats all, nothing else */
fixup_argv(argc, argv, "init");
/* Now run everything that needs to be run */
/* First run the sysinit command */
run_actions(SYSINIT);
/* Next run anything that wants to block */
run_actions(WAIT);
/* Next run anything to be run only once */
run_actions(ONCE);
#ifdef CONFIG_FEATURE_USE_INITTAB
/* Redefine SIGHUP to reread /etc/inittab */
signal(SIGHUP, reload_signal);
#else
signal(SIGHUP, SIG_IGN);
#endif /* CONFIG_FEATURE_USE_INITTAB */
/* Now run the looping stuff for the rest of forever */
while (1) {
/* run the respawn stuff */
run_actions(RESPAWN);
/* run the askfirst stuff */
run_actions(ASKFIRST);
/* Don't consume all CPU time -- sleep a bit */
sleep(1);
/* Wait for a child process to exit */
wpid = wait(&status);
while (wpid > 0) {
/* Find out who died and clean up their corpse */
for (a = init_action_list; a; a = a->next) {
if (a->pid == wpid) {
/* Set the pid to 0 so that the process gets
* restarted by run_actions() */
a->pid = 0;
message(LOG, "Process '%s' (pid %d) exited. "
"Scheduling it for restart.",
a->command, wpid);
}
}
/* see if anyone else is waiting to be reaped */
wpid = waitpid (-1, &status, WNOHANG);
}
}
}
/*
Local Variables:
c-file-style: "linux"
c-basic-offset: 4
tab-width: 4
End:
*/