| /* vi: set sw=4 ts=4: */ |
| /* |
| * Mini init implementation for busybox |
| * |
| * Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>. |
| * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org> |
| * Adjusted by so many folks, it's impossible to keep track. |
| * |
| * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. |
| */ |
| |
| #include "libbb.h" |
| #include <syslog.h> |
| #include <paths.h> |
| #include <sys/reboot.h> |
| |
| /* Was a CONFIG_xxx option. A lot of people were building |
| * not fully functional init by switching it on! */ |
| #define DEBUG_INIT 0 |
| |
| #define COMMAND_SIZE 256 |
| #define CONSOLE_NAME_SIZE 32 |
| #define MAXENV 16 /* Number of env. vars */ |
| |
| /* |
| * 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> |
| |
| #define INITTAB "/etc/inittab" /* inittab file location */ |
| #ifndef INIT_SCRIPT |
| #define INIT_SCRIPT "/etc/init.d/rcS" /* Default sysinit script. */ |
| #endif |
| |
| /* Allowed init action types */ |
| #define SYSINIT 0x01 |
| #define RESPAWN 0x02 |
| /* like respawn, but wait for <Enter> to be pressed on tty: */ |
| #define ASKFIRST 0x04 |
| #define WAIT 0x08 |
| #define ONCE 0x10 |
| #define CTRLALTDEL 0x20 |
| #define SHUTDOWN 0x40 |
| #define RESTART 0x80 |
| |
| /* Set up a linked list of init_actions, to be read from inittab */ |
| struct init_action { |
| struct init_action *next; |
| pid_t pid; |
| uint8_t action_type; |
| char terminal[CONSOLE_NAME_SIZE]; |
| char command[COMMAND_SIZE]; |
| }; |
| |
| /* Static variables */ |
| static struct init_action *init_action_list = NULL; |
| |
| static const char *log_console = VC_5; |
| |
| enum { |
| L_LOG = 0x1, |
| L_CONSOLE = 0x2, |
| |
| #if ENABLE_FEATURE_EXTRA_QUIET |
| MAYBE_CONSOLE = 0x0, |
| #else |
| MAYBE_CONSOLE = L_CONSOLE, |
| #endif |
| |
| #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 |
| }; |
| |
| /* Function prototypes */ |
| static void halt_reboot_pwoff(int sig) NORETURN; |
| |
| static void waitfor(pid_t pid) |
| { |
| /* waitfor(run(x)): protect against failed fork inside run() */ |
| if (pid <= 0) |
| return; |
| |
| /* Wait for any child (prevent zombies from exiting orphaned processes) |
| * but exit the loop only when specified one has exited. */ |
| while (wait(NULL) != pid) |
| continue; |
| } |
| |
| static void loop_forever(void) NORETURN; |
| static void loop_forever(void) |
| { |
| while (1) |
| sleep(1); |
| } |
| |
| /* Print a message to the specified device. |
| * "where" may be bitwise-or'd from L_LOG | L_CONSOLE |
| * NB: careful, we can be called after vfork! |
| */ |
| #define messageD(...) do { if (DEBUG_INIT) message(__VA_ARGS__); } while (0) |
| static void message(int where, const char *fmt, ...) |
| __attribute__ ((format(printf, 2, 3))); |
| static void message(int where, const char *fmt, ...) |
| { |
| static int log_fd = -1; |
| va_list arguments; |
| unsigned l; |
| char msg[128]; |
| |
| msg[0] = '\r'; |
| va_start(arguments, fmt); |
| l = vsnprintf(msg + 1, sizeof(msg) - 2, fmt, arguments); |
| if (l > sizeof(msg) - 2) |
| l = sizeof(msg) - 2; |
| msg[l] = '\0'; |
| va_end(arguments); |
| |
| if (ENABLE_FEATURE_INIT_SYSLOG) { |
| /* Log the message to syslogd */ |
| if (where & L_LOG) { |
| /* don't print out "\r" */ |
| openlog(applet_name, 0, LOG_DAEMON); |
| syslog(LOG_INFO, "init: %s", msg + 1); |
| closelog(); |
| } |
| msg[l++] = '\n'; |
| msg[l] = '\0'; |
| } else { |
| msg[l++] = '\n'; |
| msg[l] = '\0'; |
| /* Take full control of the log tty, and never close it. |
| * It's mine, all mine! Muhahahaha! */ |
| if (log_fd < 0) { |
| if (!log_console) { |
| log_fd = STDERR_FILENO; |
| } else { |
| log_fd = device_open(log_console, O_WRONLY | O_NONBLOCK | O_NOCTTY); |
| if (log_fd < 0) { |
| bb_error_msg("can't log to %s", log_console); |
| where = L_CONSOLE; |
| } else { |
| close_on_exec_on(log_fd); |
| } |
| } |
| } |
| if (where & L_LOG) { |
| full_write(log_fd, msg, l); |
| if (log_fd == STDERR_FILENO) |
| return; /* don't print dup messages */ |
| } |
| } |
| |
| if (where & L_CONSOLE) { |
| /* Send console messages to console so people will see them. */ |
| full_write(STDERR_FILENO, msg, l); |
| } |
| } |
| |
| /* From <linux/serial.h> */ |
| struct serial_struct { |
| int type; |
| int line; |
| unsigned int port; |
| int irq; |
| int flags; |
| int xmit_fifo_size; |
| int custom_divisor; |
| int baud_base; |
| unsigned short close_delay; |
| char io_type; |
| char reserved_char[1]; |
| int hub6; |
| unsigned short closing_wait; /* time to wait before closing */ |
| unsigned short closing_wait2; /* no longer used... */ |
| unsigned char *iomem_base; |
| unsigned short iomem_reg_shift; |
| unsigned int port_high; |
| unsigned long iomap_base; /* cookie passed into ioremap */ |
| int reserved[1]; |
| /* Paranoia (imagine 64bit kernel overwriting 32bit userspace stack) */ |
| uint32_t bbox_reserved[16]; |
| }; |
| static void console_init(void) |
| { |
| struct serial_struct sr; |
| char *s; |
| |
| s = getenv("CONSOLE"); |
| if (!s) |
| s = getenv("console"); |
| if (s) { |
| int fd = open(s, O_RDWR | O_NONBLOCK | O_NOCTTY); |
| if (fd >= 0) { |
| dup2(fd, STDIN_FILENO); |
| dup2(fd, STDOUT_FILENO); |
| xmove_fd(fd, STDERR_FILENO); |
| } |
| messageD(L_LOG, "console='%s'", s); |
| } else { |
| /* Make sure fd 0,1,2 are not closed |
| * (so that they won't be used by future opens) */ |
| bb_sanitize_stdio(); |
| /* Make sure init can't be blocked by writing to stderr */ |
| fcntl(STDERR_FILENO, F_SETFL, fcntl(STDERR_FILENO, F_GETFL) | O_NONBLOCK); |
| } |
| |
| s = getenv("TERM"); |
| if (ioctl(STDIN_FILENO, TIOCGSERIAL, &sr) == 0) { |
| /* Force the TERM setting to vt102 for serial console |
| * if TERM is set to linux (the default) */ |
| if (!s || strcmp(s, "linux") == 0) |
| putenv((char*)"TERM=vt102"); |
| if (!ENABLE_FEATURE_INIT_SYSLOG) |
| log_console = NULL; |
| } else if (!s) |
| putenv((char*)"TERM=linux"); |
| } |
| |
| /* Set terminal settings to reasonable defaults. |
| * NB: careful, we can be called after vfork! */ |
| static void set_sane_term(void) |
| { |
| struct termios tty; |
| |
| tcgetattr(STDIN_FILENO, &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 discipline 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_stdin_TCSANOW(&tty); |
| } |
| |
| /* Open the new terminal device. |
| * NB: careful, we can be called after vfork! */ |
| static void open_stdio_to_tty(const char* tty_name, int exit_on_failure) |
| { |
| /* empty tty_name means "use init's tty", else... */ |
| if (tty_name[0]) { |
| int fd; |
| close(STDIN_FILENO); |
| /* fd can be only < 0 or 0: */ |
| fd = device_open(tty_name, O_RDWR); |
| if (fd) { |
| message(L_LOG | L_CONSOLE, "can't open %s: %s", |
| tty_name, strerror(errno)); |
| if (exit_on_failure) |
| _exit(EXIT_FAILURE); |
| if (DEBUG_INIT) |
| _exit(2); |
| /* NB: we don't reach this if we were called after vfork. |
| * Thus halt_reboot_pwoff() itself need not be vfork-safe. */ |
| halt_reboot_pwoff(SIGUSR1); /* halt the system */ |
| } |
| dup2(STDIN_FILENO, STDOUT_FILENO); |
| dup2(STDIN_FILENO, STDERR_FILENO); |
| } |
| set_sane_term(); |
| } |
| |
| /* Wrapper around exec: |
| * Takes string (max COMMAND_SIZE chars). |
| * If chars like '>' detected, execs '[-]/bin/sh -c "exec ......."'. |
| * Otherwise splits words on whitespace, deals with leading dash, |
| * and uses plain exec(). |
| * NB: careful, we can be called after vfork! |
| */ |
| static void init_exec(const char *command) |
| { |
| char *cmd[COMMAND_SIZE / 2]; |
| char buf[COMMAND_SIZE + 6]; /* COMMAND_SIZE+strlen("exec ")+1 */ |
| int dash = (command[0] == '-' /* maybe? && command[1] == '/' */); |
| |
| /* See if any special /bin/sh requiring characters are present */ |
| if (strpbrk(command, "~`!$^&*()=|\\{}[];\"'<>?") != NULL) { |
| strcpy(buf, "exec "); |
| strcpy(buf + 5, command + dash); /* 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; |
| } else { |
| /* Convert command (char*) into cmd (char**, one word per string) */ |
| char *word, *next; |
| int i = 0; |
| next = strcpy(buf, command); /* including "-" */ |
| while ((word = strsep(&next, " \t")) != NULL) { |
| if (*word != '\0') { /* not two spaces/tabs together? */ |
| cmd[i] = word; |
| i++; |
| } |
| } |
| cmd[i] = NULL; |
| } |
| /* If we saw leading "-", it is interactive shell. |
| * Try harder to give it a controlling tty. |
| * And skip "-" in actual exec call. */ |
| if (dash) { |
| /* _Attempt_ to make stdin a controlling tty. */ |
| if (ENABLE_FEATURE_INIT_SCTTY) |
| ioctl(STDIN_FILENO, TIOCSCTTY, 0 /*only try, don't steal*/); |
| } |
| BB_EXECVP(cmd[0] + dash, cmd); |
| message(L_LOG | L_CONSOLE, "cannot run '%s': %s", cmd[0], strerror(errno)); |
| /* returns if execvp fails */ |
| } |
| |
| /* Used only by run_actions */ |
| static pid_t run(const struct init_action *a) |
| { |
| pid_t pid; |
| sigset_t nmask, omask; |
| |
| /* Block sigchild while forking (why?) */ |
| sigemptyset(&nmask); |
| sigaddset(&nmask, SIGCHLD); |
| sigprocmask(SIG_BLOCK, &nmask, &omask); |
| if (BB_MMU && (a->action_type & ASKFIRST)) |
| pid = fork(); |
| else |
| pid = vfork(); |
| sigprocmask(SIG_SETMASK, &omask, NULL); |
| |
| if (pid < 0) |
| message(L_LOG | L_CONSOLE, "can't fork"); |
| if (pid) |
| return pid; |
| |
| /* Child */ |
| |
| /* Reset signal handlers that were set by the parent process */ |
| bb_signals(0 |
| + (1 << SIGUSR1) |
| + (1 << SIGUSR2) |
| + (1 << SIGINT) |
| + (1 << SIGTERM) |
| + (1 << SIGHUP) |
| + (1 << SIGQUIT) |
| + (1 << SIGCONT) |
| + (1 << SIGSTOP) |
| + (1 << SIGTSTP) |
| , SIG_DFL); |
| |
| /* Create a new session and make ourself the process |
| * group leader */ |
| setsid(); |
| |
| /* Open the new terminal device */ |
| open_stdio_to_tty(a->terminal, 1 /* - exit if open fails */); |
| |
| // NB: do not enable unless you change vfork to fork above |
| #ifdef BUT_RUN_ACTIONS_ALREADY_DOES_WAITING |
| /* If the init Action requires us to wait, then force the |
| * supplied terminal to be the controlling tty. */ |
| if (a->action_type & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) { |
| /* Now fork off another process to just hang around */ |
| pid = fork(); |
| if (pid < 0) { |
| message(L_LOG | L_CONSOLE, "can't fork"); |
| _exit(EXIT_FAILURE); |
| } |
| |
| if (pid > 0) { |
| /* Parent - wait till the child is done */ |
| bb_signals(0 |
| + (1 << SIGINT) |
| + (1 << SIGTSTP) |
| + (1 << SIGQUIT) |
| , SIG_IGN); |
| signal(SIGCHLD, SIG_DFL); |
| |
| waitfor(pid); |
| /* See if stealing the controlling tty back is necessary */ |
| if (tcgetpgrp(0) != getpid()) |
| _exit(EXIT_SUCCESS); |
| |
| /* Use a temporary process to steal the controlling tty. */ |
| pid = fork(); |
| if (pid < 0) { |
| message(L_LOG | L_CONSOLE, "can't fork"); |
| _exit(EXIT_FAILURE); |
| } |
| if (pid == 0) { |
| setsid(); |
| ioctl(0, TIOCSCTTY, 1); |
| _exit(EXIT_SUCCESS); |
| } |
| waitfor(pid); |
| _exit(EXIT_SUCCESS); |
| } |
| /* Child - fall though to actually execute things */ |
| } |
| #endif |
| |
| /* NB: on NOMMU we can't wait for input in child, so |
| * "askfirst" will work the same as "respawn". */ |
| if (BB_MMU && (a->action_type & ASKFIRST)) { |
| static const char press_enter[] ALIGN1 = |
| #ifdef CUSTOMIZED_BANNER |
| #include CUSTOMIZED_BANNER |
| #endif |
| "\nPlease press Enter to activate this console. "; |
| 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(L_LOG, "waiting for enter to start '%s'" |
| "(pid %d, tty '%s')\n", |
| a->command, getpid(), a->terminal); |
| full_write(STDOUT_FILENO, press_enter, sizeof(press_enter) - 1); |
| while (safe_read(STDIN_FILENO, &c, 1) == 1 && c != '\n') |
| continue; |
| } |
| |
| if (ENABLE_FEATURE_INIT_COREDUMPS) { |
| struct stat sb; |
| 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); |
| } |
| } |
| |
| /* Log the process name and args */ |
| message(L_LOG, "starting pid %d, tty '%s': '%s'", |
| getpid(), a->terminal, a->command); |
| |
| /* Now run it. The new program will take over this PID, |
| * so nothing further in init.c should be run. */ |
| init_exec(a->command); |
| /* We're still here? Some error happened. */ |
| _exit(-1); |
| } |
| |
| 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; |
| } |
| } |
| } |
| |
| /* Run all commands of a particular type */ |
| static void run_actions(int action_type) |
| { |
| struct init_action *a, *tmp; |
| |
| for (a = init_action_list; a; a = tmp) { |
| tmp = a->next; |
| if (a->action_type & action_type) { |
| // Pointless: run() will error out if open of device fails. |
| ///* a->terminal of "" means "init's console" */ |
| //if (a->terminal[0] && access(a->terminal, R_OK | W_OK)) { |
| // //message(L_LOG | L_CONSOLE, "Device %s cannot be opened in RW mode", a->terminal /*, strerror(errno)*/); |
| // delete_init_action(a); |
| //} else |
| if (a->action_type & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) { |
| waitfor(run(a)); |
| delete_init_action(a); |
| } else if (a->action_type & ONCE) { |
| run(a); |
| delete_init_action(a); |
| } else if (a->action_type & (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); |
| } |
| } |
| } |
| } |
| } |
| |
| static void init_reboot(unsigned long magic) |
| { |
| pid_t pid; |
| /* We have to fork here, since the kernel calls do_exit(EXIT_SUCCESS) in |
| * linux/kernel/sys.c, which can cause the machine to panic when |
| * the init process is killed.... */ |
| pid = vfork(); |
| if (pid == 0) { /* child */ |
| reboot(magic); |
| _exit(EXIT_SUCCESS); |
| } |
| waitfor(pid); |
| } |
| |
| static void kill_all_processes(void) |
| { |
| /* 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 */ |
| sigprocmask_allsigs(SIG_BLOCK); |
| |
| message(L_CONSOLE | L_LOG, "The system is going down NOW!"); |
| |
| /* Allow Ctrl-Alt-Del to reboot system. */ |
| init_reboot(RB_ENABLE_CAD); |
| |
| /* Send signals to every process _except_ pid 1 */ |
| message(L_CONSOLE | L_LOG, "Sending SIG%s to all processes", "TERM"); |
| kill(-1, SIGTERM); |
| sync(); |
| sleep(1); |
| |
| message(L_CONSOLE | L_LOG, "Sending SIG%s to all processes", "KILL"); |
| kill(-1, SIGKILL); |
| sync(); |
| sleep(1); |
| } |
| |
| static void halt_reboot_pwoff(int sig) |
| { |
| const char *m = "halt"; |
| int rb; |
| |
| kill_all_processes(); |
| |
| rb = RB_HALT_SYSTEM; |
| if (sig == SIGTERM) { |
| m = "reboot"; |
| rb = RB_AUTOBOOT; |
| } else if (sig == SIGUSR2) { |
| m = "poweroff"; |
| rb = RB_POWER_OFF; |
| } |
| message(L_CONSOLE | L_LOG, "Requesting system %s", m); |
| /* allow time for last message to reach serial console */ |
| sleep(2); |
| init_reboot(rb); |
| loop_forever(); |
| } |
| |
| /* Handler for QUIT - exec "restart" action, |
| * else (no such action defined) do nothing */ |
| static void exec_restart_action(int sig UNUSED_PARAM) |
| { |
| struct init_action *a; |
| |
| for (a = init_action_list; a; a = a->next) { |
| if (a->action_type & RESTART) { |
| kill_all_processes(); |
| |
| /* unblock all signals (blocked in kill_all_processes()) */ |
| sigprocmask_allsigs(SIG_UNBLOCK); |
| |
| /* Open the new terminal device */ |
| open_stdio_to_tty(a->terminal, 0 /* - halt if open fails */); |
| |
| messageD(L_CONSOLE | L_LOG, "Trying to re-exec %s", a->command); |
| init_exec(a->command); |
| sleep(2); |
| init_reboot(RB_HALT_SYSTEM); |
| loop_forever(); |
| } |
| } |
| } |
| |
| static void ctrlaltdel_signal(int sig UNUSED_PARAM) |
| { |
| run_actions(CTRLALTDEL); |
| } |
| |
| /* The SIGCONT handler is set to record_signo(). |
| * It just sets bb_got_signal = SIGCONT. */ |
| |
| /* The SIGSTOP & SIGTSTP handler */ |
| static void stop_handler(int sig UNUSED_PARAM) |
| { |
| int saved_errno = errno; |
| |
| bb_got_signal = 0; |
| while (bb_got_signal == 0) |
| pause(); |
| |
| errno = saved_errno; |
| } |
| |
| static void new_init_action(uint8_t action_type, const char *command, const char *cons) |
| { |
| struct init_action *a, *last; |
| |
| // Why? |
| // if (strcmp(cons, bb_dev_null) == 0 && (action & ASKFIRST)) |
| // return; |
| |
| /* Append to the end of the list */ |
| for (a = last = init_action_list; a; a = a->next) { |
| /* don't enter action if it's already in the list, |
| * but do overwrite existing actions */ |
| if ((strcmp(a->command, command) == 0) |
| && (strcmp(a->terminal, cons) == 0) |
| ) { |
| a->action_type = action_type; |
| return; |
| } |
| last = a; |
| } |
| |
| a = xzalloc(sizeof(*a)); |
| if (last) { |
| last->next = a; |
| } else { |
| init_action_list = a; |
| } |
| a->action_type = action_type; |
| safe_strncpy(a->command, command, sizeof(a->command)); |
| safe_strncpy(a->terminal, cons, sizeof(a->terminal)); |
| messageD(L_LOG | L_CONSOLE, "command='%s' action=%d tty='%s'\n", |
| a->command, a->action_type, a->terminal); |
| } |
| |
| /* 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) |
| { |
| char *token[4]; |
| /* order must correspond to SYSINIT..RESTART constants */ |
| static const char actions[] ALIGN1 = |
| "sysinit\0""respawn\0""askfirst\0""wait\0""once\0" |
| "ctrlaltdel\0""shutdown\0""restart\0"; |
| |
| parser_t *parser = config_open2(INITTAB, fopen_for_read); |
| /* No inittab file -- set up some default behavior */ |
| if (parser == NULL) { |
| /* Reboot on Ctrl-Alt-Del */ |
| new_init_action(CTRLALTDEL, "reboot", ""); |
| /* Umount all filesystems on halt/reboot */ |
| new_init_action(SHUTDOWN, "umount -a -r", ""); |
| /* Swapoff on halt/reboot */ |
| if (ENABLE_SWAPONOFF) |
| new_init_action(SHUTDOWN, "swapoff -a", ""); |
| /* Prepare to restart init when a QUIT is received */ |
| new_init_action(RESTART, "init", ""); |
| /* Askfirst shell on tty1-4 */ |
| new_init_action(ASKFIRST, bb_default_login_shell, ""); |
| //TODO: VC_1 instead of ""? "" is console -> ctty problems -> angry users |
| 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; |
| } |
| /* optional_tty:ignored_runlevel:action:command |
| * Delims are not to be collapsed and need exactly 4 tokens |
| */ |
| while (config_read(parser, token, 4, 0, "#:", |
| PARSE_NORMAL & ~(PARSE_TRIM | PARSE_COLLAPSE))) { |
| int action; |
| char *tty = token[0]; |
| |
| if (!token[3]) /* less than 4 tokens */ |
| goto bad_entry; |
| action = index_in_strings(actions, token[2]); |
| if (action < 0 || !token[3][0]) /* token[3]: command */ |
| goto bad_entry; |
| /* turn .*TTY -> /dev/TTY */ |
| if (tty[0]) { |
| if (strncmp(tty, "/dev/", 5) == 0) |
| tty += 5; |
| tty = concat_path_file("/dev/", tty); |
| } |
| new_init_action(1 << action, token[3], tty); |
| if (tty[0]) |
| free(tty); |
| continue; |
| bad_entry: |
| message(L_LOG | L_CONSOLE, "Bad inittab entry at line %d", |
| parser->lineno); |
| } |
| config_close(parser); |
| } |
| |
| #if ENABLE_FEATURE_USE_INITTAB |
| static void reload_signal(int sig UNUSED_PARAM) |
| { |
| struct init_action *a, *tmp; |
| |
| message(L_LOG, "reloading /etc/inittab"); |
| |
| /* disable old entrys */ |
| for (a = init_action_list; a; a = a->next) { |
| a->action_type = ONCE; |
| } |
| |
| parse_inittab(); |
| |
| if (ENABLE_FEATURE_KILL_REMOVED) { |
| /* Be nice and send SIGTERM first */ |
| for (a = init_action_list; a; a = a->next) { |
| pid_t pid = a->pid; |
| if ((a->action_type & ONCE) && pid != 0) { |
| kill(pid, SIGTERM); |
| } |
| } |
| #if CONFIG_FEATURE_KILL_DELAY |
| /* NB: parent will wait in NOMMU case */ |
| if ((BB_MMU ? fork() : vfork()) == 0) { /* child */ |
| sleep(CONFIG_FEATURE_KILL_DELAY); |
| for (a = init_action_list; a; a = a->next) { |
| pid_t pid = a->pid; |
| if ((a->action_type & ONCE) && pid != 0) { |
| kill(pid, SIGKILL); |
| } |
| } |
| _exit(EXIT_SUCCESS); |
| } |
| #endif |
| } |
| |
| /* remove unused entrys */ |
| for (a = init_action_list; a; a = tmp) { |
| tmp = a->next; |
| if ((a->action_type & (ONCE | SYSINIT | WAIT)) && a->pid == 0) { |
| delete_init_action(a); |
| } |
| } |
| run_actions(RESPAWN | ASKFIRST); |
| } |
| #endif |
| |
| int init_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| int init_main(int argc UNUSED_PARAM, char **argv) |
| { |
| struct init_action *a; |
| pid_t wpid; |
| |
| die_sleep = 30 * 24*60*60; /* if xmalloc will ever die... */ |
| |
| if (argv[1] && !strcmp(argv[1], "-q")) { |
| 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")) |
| ) { |
| bb_show_usage(); |
| } |
| /* Set up sig handlers -- be sure to |
| * clear all of these in run() */ |
| signal(SIGQUIT, exec_restart_action); |
| bb_signals(0 |
| + (1 << SIGUSR1) /* halt */ |
| + (1 << SIGUSR2) /* poweroff */ |
| + (1 << SIGTERM) /* reboot */ |
| , halt_reboot_pwoff); |
| signal(SIGINT, ctrlaltdel_signal); |
| signal(SIGCONT, record_signo); |
| bb_signals(0 |
| + (1 << SIGSTOP) |
| + (1 << 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); |
| } |
| |
| /* Figure out where the default console should be */ |
| console_init(); |
| set_sane_term(); |
| xchdir("/"); |
| setsid(); |
| |
| /* Make sure environs is set to something sane */ |
| putenv((char *) "HOME=/"); |
| putenv((char *) bb_PATH_root_path); |
| putenv((char *) "SHELL=/bin/sh"); |
| putenv((char *) "USER=root"); /* needed? why? */ |
| |
| if (argv[1]) |
| xsetenv("RUNLEVEL", argv[1]); |
| |
| /* Hello world */ |
| message(MAYBE_CONSOLE | L_LOG, "init started: %s", bb_banner); |
| |
| /* Make sure there is enough memory to do something useful. */ |
| if (ENABLE_SWAPONOFF) { |
| struct sysinfo info; |
| |
| if (!sysinfo(&info) && |
| (info.mem_unit ? : 1) * (long long)info.totalram < 1024*1024) |
| { |
| message(L_CONSOLE, "Low memory, forcing swapon"); |
| /* swapon -a requires /proc typically */ |
| new_init_action(SYSINIT, "mount -t proc proc /proc", ""); |
| /* Try to turn on swap */ |
| new_init_action(SYSINIT, "swapon -a", ""); |
| run_actions(SYSINIT); /* wait and removing */ |
| } |
| } |
| |
| /* Check if we are supposed to be in single user mode */ |
| if (argv[1] |
| && (!strcmp(argv[1], "single") || !strcmp(argv[1], "-s") || LONE_CHAR(argv[1], '1')) |
| ) { |
| /* ??? shouldn't we set RUNLEVEL="b" here? */ |
| /* 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(); |
| } |
| |
| #if ENABLE_SELINUX |
| if (getenv("SELINUX_INIT") == NULL) { |
| int enforce = 0; |
| |
| putenv((char*)"SELINUX_INIT=YES"); |
| if (selinux_init_load_policy(&enforce) == 0) { |
| BB_EXECVP(argv[0], argv); |
| } else if (enforce > 0) { |
| /* SELinux in enforcing mode but load_policy failed */ |
| message(L_CONSOLE, "cannot load SELinux Policy. " |
| "Machine is in enforcing mode. Halting now."); |
| exit(EXIT_FAILURE); |
| } |
| } |
| #endif /* CONFIG_SELINUX */ |
| |
| /* Make the command line just say "init" - thats all, nothing else */ |
| strncpy(argv[0], "init", strlen(argv[0])); |
| /* Wipe argv[1]-argv[N] so they don't clutter the ps listing */ |
| while (*++argv) |
| memset(*argv, 0, strlen(*argv)); |
| |
| /* 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); |
| |
| /* Redefine SIGHUP to reread /etc/inittab */ |
| #if ENABLE_FEATURE_USE_INITTAB |
| signal(SIGHUP, reload_signal); |
| #else |
| signal(SIGHUP, SIG_IGN); |
| #endif |
| |
| /* Now run the looping stuff for the rest of forever */ |
| while (1) { |
| /* run the respawn/askfirst stuff */ |
| run_actions(RESPAWN | ASKFIRST); |
| |
| /* Don't consume all CPU time -- sleep a bit */ |
| sleep(1); |
| |
| /* Wait for any child process to exit */ |
| wpid = wait(NULL); |
| 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(L_LOG, "process '%s' (pid %d) exited. " |
| "Scheduling for restart.", |
| a->command, wpid); |
| } |
| } |
| /* see if anyone else is waiting to be reaped */ |
| wpid = wait_any_nohang(NULL); |
| } |
| } |
| } |