| /* vi: set sw=4 ts=4: */ |
| /* |
| * Mini init implementation for busybox |
| * |
| * Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>. |
| * Copyright (C) 1999-2002 by Erik Andersen <andersee@debian.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 "busybox.h" |
| |
| #include "init_shared.h" |
| |
| |
| #ifdef CONFIG_SYSLOGD |
| # include <sys/syslog.h> |
| #endif |
| #if (__GNU_LIBRARY__ > 5) || defined(__dietlibc__) |
| #include <sys/reboot.h> |
| #endif |
| |
| |
| #if defined(__UCLIBC__) && !defined(__UCLIBC_HAS_MMU__) |
| #define fork vfork |
| #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; |
| int port; |
| int irq; |
| int flags; |
| int xmit_fifo_size; |
| int custom_divisor; |
| int baud_base; |
| unsigned short close_delay; |
| char reserved_char[2]; |
| int hub6; |
| unsigned short closing_wait; /* time to wait before closing */ |
| unsigned short closing_wait2; /* no longer used... */ |
| int reserved[4]; |
| }; |
| |
| |
| #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 SHELL "/bin/sh" /* Default shell */ |
| #define LOGIN_SHELL "-" SHELL /* Default login shell */ |
| #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=" SHELL, |
| "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" */ |
| syslog_msg(LOG_DAEMON, LOG_INFO, msg + 1); |
| } |
| |
| 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 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); |
| result = result * u; |
| if (result < 0) |
| result = INT_MAX; |
| return result; |
| } |
| |
| 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); |
| |
| /* 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] = 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 (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') |
| ; |
| } |
| |
| /* 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 = wait(&status); |
| if (wpid > 0 && wpid != pid) { |
| continue; |
| } |
| if (wpid == pid) |
| break; |
| } |
| 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) { |
| #if (__GNU_LIBRARY__ > 5) || defined(__dietlibc__) |
| reboot(magic); |
| #else |
| reboot(0xfee1dead, 672274793, magic); |
| #endif |
| _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); |
| |
| /* 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, char *command, const char *cons) |
| { |
| struct init_action *new_action, *a; |
| |
| 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 = init_action_list; a && a->next; a = a->next); |
| if (a) { |
| a->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(__UCLIBC_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(__UCLIBC_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, LOGIN_SHELL, ""); |
| new_init_action(ASKFIRST, LOGIN_SHELL, VC_2); |
| new_init_action(ASKFIRST, LOGIN_SHELL, VC_3); |
| new_init_action(ASKFIRST, 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 */ |
| } |
| |
| |
| 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, 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); |
| |
| /* If there is nothing else to do, stop */ |
| if (init_action_list == NULL) { |
| message(LOG | CONSOLE, |
| "No more tasks for init -- sleeping forever."); |
| loop_forever(); |
| } |
| |
| /* 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: |
| */ |