/* vi: set sw=4 ts=4: */ /* * Mini init implementation for busybox * * Copyright (C) 1995, 1996 by Bruce Perens . * Copyright (C) 1999-2003 by Erik Andersen * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "busybox.h" #include "init_shared.h" #ifdef CONFIG_SYSLOGD # include #endif #if defined(__UCLIBC__) && !defined(__UCLIBC_HAS_MMU__) #define fork vfork #endif #define INIT_BUFFS_SIZE 256 /* From */ 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 */ 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 #include #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" */ 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[VERASE] = 8; /* C-H */ 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 * 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); /* 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 (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; } #endif /* ! DEBUG_INIT */ static void new_init_action(int action, const 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, 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 */ } 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); /* 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); /* 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: */