diff options
Diffstat (limited to 'init/init.c')
-rw-r--r-- | init/init.c | 942 |
1 files changed, 942 insertions, 0 deletions
diff --git a/init/init.c b/init/init.c new file mode 100644 index 0000000..5536504 --- /dev/null +++ b/init/init.c @@ -0,0 +1,942 @@ +/* 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 = 1 + vsnprintf(msg + 1, sizeof(msg) - 2, fmt, arguments); + if (l > sizeof(msg) - 1) + l = sizeof(msg) - 1; + msg[l] = '\0'; + va_end(arguments); + + if (ENABLE_FEATURE_INIT_SYSLOG) { + if (where & L_LOG) { + /* Log the message to syslogd */ + openlog("init", 0, LOG_DAEMON); + /* don't print "\r" */ + syslog(LOG_INFO, "%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(); +// Users report problems +// /* 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) +{ +#if ENABLE_FEATURE_USE_INITTAB + char *token[4]; + parser_t *parser = config_open2("/etc/inittab", fopen_for_read); + + if (parser == NULL) +#endif + { + /* No inittab file -- set up some default behavior */ + /* 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; + } + +#if ENABLE_FEATURE_USE_INITTAB + /* 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))) { + /* 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"; + 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); +#endif +} + +#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); + } + } +} |