* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
* Adjusted by so many folks, it's impossible to keep track.
*
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
+//applet:IF_INIT(APPLET(init, BB_DIR_SBIN, BB_SUID_DROP))
+//applet:IF_FEATURE_INITRD(APPLET_ODDNAME(linuxrc, init, BB_DIR_ROOT, BB_SUID_DROP, linuxrc))
+
+//kbuild:lib-$(CONFIG_INIT) += init.o
+
+//config:config INIT
+//config: bool "init"
+//config: default y
+//config: select FEATURE_SYSLOG
+//config: help
+//config: init is the first program run when the system boots.
+//config:
+//config:config FEATURE_USE_INITTAB
+//config: bool "Support reading an inittab file"
+//config: default y
+//config: depends on INIT
+//config: help
+//config: Allow init to read an inittab file when the system boot.
+//config:
+//config:config FEATURE_KILL_REMOVED
+//config: bool "Support killing processes that have been removed from inittab"
+//config: default n
+//config: depends on FEATURE_USE_INITTAB
+//config: help
+//config: When respawn entries are removed from inittab and a SIGHUP is
+//config: sent to init, this option will make init kill the processes
+//config: that have been removed.
+//config:
+//config:config FEATURE_KILL_DELAY
+//config: int "How long to wait between TERM and KILL (0 - send TERM only)" if FEATURE_KILL_REMOVED
+//config: range 0 1024
+//config: default 0
+//config: depends on FEATURE_KILL_REMOVED
+//config: help
+//config: With nonzero setting, init sends TERM, forks, child waits N
+//config: seconds, sends KILL and exits. Setting it too high is unwise
+//config: (child will hang around for too long and could actually kill
+//config: the wrong process!)
+//config:
+//config:config FEATURE_INIT_SCTTY
+//config: bool "Run commands with leading dash with controlling tty"
+//config: default y
+//config: depends on INIT
+//config: help
+//config: If this option is enabled, init will try to give a controlling
+//config: tty to any command which has leading hyphen (often it's "-/bin/sh").
+//config: More precisely, init will do "ioctl(STDIN_FILENO, TIOCSCTTY, 0)".
+//config: If device attached to STDIN_FILENO can be a ctty but is not yet
+//config: a ctty for other session, it will become this process' ctty.
+//config: This is not the traditional init behavour, but is often what you want
+//config: in an embedded system where the console is only accessed during
+//config: development or for maintenance.
+//config: NB: using cttyhack applet may work better.
+//config:
+//config:config FEATURE_INIT_SYSLOG
+//config: bool "Enable init to write to syslog"
+//config: default y
+//config: depends on INIT
+//config:
+//config:config FEATURE_EXTRA_QUIET
+//config: bool "Be _extra_ quiet on boot"
+//config: default y
+//config: depends on INIT
+//config: help
+//config: Prevent init from logging some messages to the console during boot.
+//config:
+//config:config FEATURE_INIT_COREDUMPS
+//config: bool "Support dumping core for child processes (debugging only)"
+//config: default y
+//config: depends on INIT
+//config: help
+//config: If this option is enabled and the file /.init_enable_core
+//config: exists, then init will call setrlimit() to allow unlimited
+//config: core file sizes. If this option is disabled, processes
+//config: will not generate any core files.
+//config:
+//config:config FEATURE_INITRD
+//config: bool "Support running init from within an initrd (not initramfs)"
+//config: default y
+//config: depends on INIT
+//config: help
+//config: Legacy support for running init under the old-style initrd. Allows
+//config: the name linuxrc to act as init, and it doesn't assume init is PID 1.
+//config:
+//config: This does not apply to initramfs, which runs /init as PID 1 and
+//config: requires no special support.
+//config:
+//config:config INIT_TERMINAL_TYPE
+//config: string "Initial terminal type"
+//config: default "linux"
+//config: depends on INIT
+//config: help
+//config: This is the initial value set by init for the TERM environment
+//config: variable. This variable is used by programs which make use of
+//config: extended terminal capabilities.
+//config:
+//config: Note that on Linux, init attempts to detect serial terminal and
+//config: sets TERM to "vt102" if one is found.
+
#include "libbb.h"
#include <syslog.h>
#include <paths.h>
-#include <sys/reboot.h>
#include <sys/resource.h>
#ifdef __linux__
#include <linux/vt.h>
#endif
-#if ENABLE_FEATURE_UTMP
-# include <utmp.h> /* DEAD_PROCESS */
-#endif
+#include "reboot.h" /* reboot() constants */
/* Used only for sanitizing purposes in set_sane_term() below. On systems where
* the baud rate is stored in a separate field, we can safely disable them. */
enum {
L_LOG = 0x1,
L_CONSOLE = 0x2,
-#ifndef RB_HALT_SYSTEM
- RB_HALT_SYSTEM = 0xcdef0123, /* FIXME: this overflows enum */
- RB_ENABLE_CAD = 0x89abcdef,
- RB_DISABLE_CAD = 0,
- RB_POWER_OFF = 0x4321fedc,
- RB_AUTOBOOT = 0x01234567,
-#endif
};
/* Print a message to the specified device.
} else
#endif
if (!s)
- putenv((char*)"TERM=linux");
+ putenv((char*)"TERM=" CONFIG_INIT_TERMINAL_TYPE);
}
/* Set terminal settings to reasonable defaults.
#endif
/* Make it be sane */
- tty.c_cflag &= CBAUD | CBAUDEX | CSIZE | CSTOPB | PARENB | PARODD;
+#ifndef CRTSCTS
+# define CRTSCTS 0
+#endif
+ /* added CRTSCTS to fix Debian bug 528560 */
+ tty.c_cflag &= CBAUD | CBAUDEX | CSIZE | CSTOPB | PARENB | PARODD | CRTSCTS;
tty.c_cflag |= CREAD | HUPCL | CLOCAL;
/* input modes */
tty.c_oflag = OPOST | ONLCR;
/* local modes */
- tty.c_lflag =
- ISIG | ICANON | ECHO | ECHOE | ECHOK | ECHOCTL | ECHOKE | IEXTEN;
+ tty.c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | ECHOCTL | ECHOKE | IEXTEN;
tcsetattr_stdin_TCSANOW(&tty);
}
char buf[COMMAND_SIZE + 6]; /* COMMAND_SIZE+strlen("exec ")+1 */
int dash = (command[0] == '-' /* maybe? && command[1] == '/' */);
+ command += dash;
+
/* See if any special /bin/sh requiring characters are present */
if (strpbrk(command, "~`!$^&*()=|\\{}[];\"'<>?") != NULL) {
- strcpy(buf, "exec ");
- strcpy(buf + 5, command + dash); /* excluding "-" */
+ sprintf(buf, "exec %s", command); /* excluding "-" */
/* NB: LIBBB_DEFAULT_LOGIN_SHELL define has leading dash */
cmd[0] = (char*)(LIBBB_DEFAULT_LOGIN_SHELL + !dash);
cmd[1] = (char*)"-c";
cmd[2] = buf;
cmd[3] = NULL;
+ command = LIBBB_DEFAULT_LOGIN_SHELL + 1;
} else {
/* Convert command (char*) into cmd (char**, one word per string) */
char *word, *next;
int i = 0;
- next = strcpy(buf, command); /* including "-" */
+ next = strcpy(buf, command - dash); /* command including "-" */
while ((word = strsep(&next, " \t")) != NULL) {
if (*word != '\0') { /* not two spaces/tabs together? */
cmd[i] = word;
}
/* If we saw leading "-", it is interactive shell.
* Try harder to give it a controlling tty.
- * And skip "-" in actual exec call. */
- if (dash) {
+ */
+ if (ENABLE_FEATURE_INIT_SCTTY && dash) {
/* _Attempt_ to make stdin a controlling tty. */
- if (ENABLE_FEATURE_INIT_SCTTY)
- ioctl(STDIN_FILENO, TIOCSCTTY, 0 /*only try, don't steal*/);
+ ioctl(STDIN_FILENO, TIOCSCTTY, 0 /*only try, don't steal*/);
}
- BB_EXECVP(cmd[0] + dash, cmd);
- message(L_LOG | L_CONSOLE, "can't run '%s': %s", cmd[0], strerror(errno));
+ /* Here command never contains the dash, cmd[0] might */
+ BB_EXECVP(command, cmd);
+ message(L_LOG | L_CONSOLE, "can't run '%s': %s", command, strerror(errno));
/* returns if execvp fails */
}
return a;
}
}
- update_utmp(pid, DEAD_PROCESS, /*tty_name:*/ NULL, /*username:*/ NULL, /*hostname:*/ NULL);
+ update_utmp(pid, DEAD_PROCESS, /*tty_name:*/ NULL,
+ /*username:*/ NULL,
+ /*hostname:*/ NULL);
}
return NULL;
}
run_shutdown_and_kill_processes();
+#ifdef RB_ENABLE_CAD
/* Allow Ctrl-Alt-Del to reboot the system.
* This is how kernel sets it up for init, we follow suit.
*/
reboot(RB_ENABLE_CAD); /* misnomer */
+#endif
if (open_stdio_to_tty(a->terminal)) {
dbg_message(L_CONSOLE, "Trying to re-exec %s", a->command);
int init_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int init_main(int argc UNUSED_PARAM, char **argv)
{
- die_sleep = 30 * 24*60*60; /* if xmalloc would ever die... */
-
if (argv[1] && strcmp(argv[1], "-q") == 0) {
return kill(1, SIGHUP);
}
if (!DEBUG_INIT) {
/* Expect to be invoked as init with PID=1 or be invoked as linuxrc */
if (getpid() != 1
- && (!ENABLE_FEATURE_INITRD || !strstr(applet_name, "linuxrc"))
+ && (!ENABLE_FEATURE_INITRD || applet_name[0] != 'l') /* not linuxrc? */
) {
- bb_show_usage();
+ bb_error_msg_and_die("must be run as PID 1");
}
+#ifdef RB_DISABLE_CAD
/* Turn off rebooting via CTL-ALT-DEL - we get a
* SIGINT on CAD so we can shut things down gracefully... */
reboot(RB_DISABLE_CAD); /* misnomer */
+#endif
}
+ /* If, say, xmalloc would ever die, we don't want to oops kernel
+ * by exiting.
+ * NB: we set die_sleep *after* PID 1 check and bb_show_usage.
+ * Otherwise, for example, "init u" ("please rexec yourself"
+ * command for sysvinit) will show help text (which isn't too bad),
+ * *and sleep forever* (which is bad!)
+ */
+ die_sleep = 30 * 24*60*60;
+
/* Figure out where the default console should be */
console_init();
set_sane_term();
message(L_CONSOLE | L_LOG, "init started: %s", bb_banner);
#endif
+/* struct sysinfo is linux-specific */
+#ifdef __linux__
/* Make sure there is enough memory to do something useful. */
if (ENABLE_SWAPONOFF) {
struct sysinfo info;
run_actions(SYSINIT); /* wait and removing */
}
}
+#endif
/* Check if we are supposed to be in single user mode */
if (argv[1]
/* SELinux in enforcing mode but load_policy failed */
message(L_CONSOLE, "can't load SELinux Policy. "
"Machine is in enforcing mode. Halting now.");
- exit(EXIT_FAILURE);
+ return EXIT_FAILURE;
}
}
#endif
}
} /* while (1) */
}
+
+//usage:#define linuxrc_trivial_usage NOUSAGE_STR
+//usage:#define linuxrc_full_usage ""
+
+//usage:#define init_trivial_usage
+//usage: ""
+//usage:#define init_full_usage "\n\n"
+//usage: "Init is the parent of all processes"
+//usage:
+//usage:#define init_notes_usage
+//usage: "This version of init is designed to be run only by the kernel.\n"
+//usage: "\n"
+//usage: "BusyBox init doesn't support multiple runlevels. The runlevels field of\n"
+//usage: "the /etc/inittab file is completely ignored by BusyBox init. If you want\n"
+//usage: "runlevels, use sysvinit.\n"
+//usage: "\n"
+//usage: "BusyBox init works just fine without an inittab. If no inittab is found,\n"
+//usage: "it has the following default behavior:\n"
+//usage: "\n"
+//usage: " ::sysinit:/etc/init.d/rcS\n"
+//usage: " ::askfirst:/bin/sh\n"
+//usage: " ::ctrlaltdel:/sbin/reboot\n"
+//usage: " ::shutdown:/sbin/swapoff -a\n"
+//usage: " ::shutdown:/bin/umount -a -r\n"
+//usage: " ::restart:/sbin/init\n"
+//usage: "\n"
+//usage: "if it detects that /dev/console is _not_ a serial console, it will also run:\n"
+//usage: "\n"
+//usage: " tty2::askfirst:/bin/sh\n"
+//usage: " tty3::askfirst:/bin/sh\n"
+//usage: " tty4::askfirst:/bin/sh\n"
+//usage: "\n"
+//usage: "If you choose to use an /etc/inittab file, the inittab entry format is as follows:\n"
+//usage: "\n"
+//usage: " <id>:<runlevels>:<action>:<process>\n"
+//usage: "\n"
+//usage: " <id>:\n"
+//usage: "\n"
+//usage: " WARNING: This field has a non-traditional meaning for BusyBox init!\n"
+//usage: " The id field is used by BusyBox init to specify the controlling tty for\n"
+//usage: " the specified process to run on. The contents of this field are\n"
+//usage: " appended to \"/dev/\" and used as-is. There is no need for this field to\n"
+//usage: " be unique, although if it isn't you may have strange results. If this\n"
+//usage: " field is left blank, the controlling tty is set to the console. Also\n"
+//usage: " note that if BusyBox detects that a serial console is in use, then only\n"
+//usage: " entries whose controlling tty is either the serial console or /dev/null\n"
+//usage: " will be run. BusyBox init does nothing with utmp. We don't need no\n"
+//usage: " stinkin' utmp.\n"
+//usage: "\n"
+//usage: " <runlevels>:\n"
+//usage: "\n"
+//usage: " The runlevels field is completely ignored.\n"
+//usage: "\n"
+//usage: " <action>:\n"
+//usage: "\n"
+//usage: " Valid actions include: sysinit, respawn, askfirst, wait,\n"
+//usage: " once, restart, ctrlaltdel, and shutdown.\n"
+//usage: "\n"
+//usage: " The available actions can be classified into two groups: actions\n"
+//usage: " that are run only once, and actions that are re-run when the specified\n"
+//usage: " process exits.\n"
+//usage: "\n"
+//usage: " Run only-once actions:\n"
+//usage: "\n"
+//usage: " 'sysinit' is the first item run on boot. init waits until all\n"
+//usage: " sysinit actions are completed before continuing. Following the\n"
+//usage: " completion of all sysinit actions, all 'wait' actions are run.\n"
+//usage: " 'wait' actions, like 'sysinit' actions, cause init to wait until\n"
+//usage: " the specified task completes. 'once' actions are asynchronous,\n"
+//usage: " therefore, init does not wait for them to complete. 'restart' is\n"
+//usage: " the action taken to restart the init process. By default this should\n"
+//usage: " simply run /sbin/init, but can be a script which runs pivot_root or it\n"
+//usage: " can do all sorts of other interesting things. The 'ctrlaltdel' init\n"
+//usage: " actions are run when the system detects that someone on the system\n"
+//usage: " console has pressed the CTRL-ALT-DEL key combination. Typically one\n"
+//usage: " wants to run 'reboot' at this point to cause the system to reboot.\n"
+//usage: " Finally the 'shutdown' action specifies the actions to taken when\n"
+//usage: " init is told to reboot. Unmounting filesystems and disabling swap\n"
+//usage: " is a very good here.\n"
+//usage: "\n"
+//usage: " Run repeatedly actions:\n"
+//usage: "\n"
+//usage: " 'respawn' actions are run after the 'once' actions. When a process\n"
+//usage: " started with a 'respawn' action exits, init automatically restarts\n"
+//usage: " it. Unlike sysvinit, BusyBox init does not stop processes from\n"
+//usage: " respawning out of control. The 'askfirst' actions acts just like\n"
+//usage: " respawn, except that before running the specified process it\n"
+//usage: " displays the line \"Please press Enter to activate this console.\"\n"
+//usage: " and then waits for the user to press enter before starting the\n"
+//usage: " specified process.\n"
+//usage: "\n"
+//usage: " Unrecognized actions (like initdefault) will cause init to emit an\n"
+//usage: " error message, and then go along with its business. All actions are\n"
+//usage: " run in the order they appear in /etc/inittab.\n"
+//usage: "\n"
+//usage: " <process>:\n"
+//usage: "\n"
+//usage: " Specifies the process to be executed and its command line.\n"
+//usage: "\n"
+//usage: "Example /etc/inittab file:\n"
+//usage: "\n"
+//usage: " # This is run first except when booting in single-user mode\n"
+//usage: " #\n"
+//usage: " ::sysinit:/etc/init.d/rcS\n"
+//usage: " \n"
+//usage: " # /bin/sh invocations on selected ttys\n"
+//usage: " #\n"
+//usage: " # Start an \"askfirst\" shell on the console (whatever that may be)\n"
+//usage: " ::askfirst:-/bin/sh\n"
+//usage: " # Start an \"askfirst\" shell on /dev/tty2-4\n"
+//usage: " tty2::askfirst:-/bin/sh\n"
+//usage: " tty3::askfirst:-/bin/sh\n"
+//usage: " tty4::askfirst:-/bin/sh\n"
+//usage: " \n"
+//usage: " # /sbin/getty invocations for selected ttys\n"
+//usage: " #\n"
+//usage: " tty4::respawn:/sbin/getty 38400 tty4\n"
+//usage: " tty5::respawn:/sbin/getty 38400 tty5\n"
+//usage: " \n"
+//usage: " \n"
+//usage: " # Example of how to put a getty on a serial line (for a terminal)\n"
+//usage: " #\n"
+//usage: " #::respawn:/sbin/getty -L ttyS0 9600 vt100\n"
+//usage: " #::respawn:/sbin/getty -L ttyS1 9600 vt100\n"
+//usage: " #\n"
+//usage: " # Example how to put a getty on a modem line\n"
+//usage: " #::respawn:/sbin/getty 57600 ttyS2\n"
+//usage: " \n"
+//usage: " # Stuff to do when restarting the init process\n"
+//usage: " ::restart:/sbin/init\n"
+//usage: " \n"
+//usage: " # Stuff to do before rebooting\n"
+//usage: " ::ctrlaltdel:/sbin/reboot\n"
+//usage: " ::shutdown:/bin/umount -a -r\n"
+//usage: " ::shutdown:/sbin/swapoff -a\n"