diff options
Diffstat (limited to 'release/src/router/busybox/init/init.c')
| -rw-r--r-- | release/src/router/busybox/init/init.c | 1190 |
1 files changed, 1190 insertions, 0 deletions
diff --git a/release/src/router/busybox/init/init.c b/release/src/router/busybox/init/init.c new file mode 100644 index 00000000..1ecc43e1 --- /dev/null +++ b/release/src/router/busybox/init/init.c @@ -0,0 +1,1190 @@ +/* vi: set sw=4 ts=4: */ +/* + * Mini init implementation for busybox + * + * Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>. + * Copyright (C) 1999-2003 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 + + +#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) { + 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; +} + +/* Reap any zombie processes that are reparented to init */ +static void child_handler(int sig) +{ + int status; + while ( wait3(&status, WNOHANG, NULL) > 0 ); +} + +#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) { + /* don't enter action if it's already in the list */ + if ((strcmp(a->command, command) == 0) && + (strcmp(a->terminal, cons) ==0)) { + free(new_action); + return; + } + } + 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 */ +} + +static void reload_signal(int sig) +{ + message(LOG, "Reloading /etc/inittab"); + parse_inittab(); + run_actions(RESPAWN); + return; +} + +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); + signal(SIGCHLD, child_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(); + } + + /* Redefine SIGHUP to reread /etc/inittab */ + signal(SIGHUP, reload_signal); + + /* 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: +*/ |