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sysvinit/src/init.c
Werner Fink 13de2e9e05 Add the comment from Andrea Arcangeli about the correct 
place of setting the default childhandler within spawn().
Make sure that newline is printed out for last(1) even
if an utmp record entry is truncated.
Check if utmp not only exists but is writable and delay
writing out of the utmp runlevel record if utmp is not writable.
Be able to find libcrypt also on 64 bit based architectures.
2009-11-24 10:03:19 +00:00

2762 lines
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/*
* Init A System-V Init Clone.
*
* Usage: /sbin/init
* init [0123456SsQqAaBbCc]
* telinit [0123456SsQqAaBbCc]
*
* Version: @(#)init.c 2.86 30-Jul-2004 miquels@cistron.nl
*/
#define VERSION "2.88"
#define DATE "31-Jul-2004"
/*
* This file is part of the sysvinit suite,
* Copyright (C) 1991-2004 Miquel van Smoorenburg.
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/wait.h>
#ifdef __linux__
#include <sys/kd.h>
#endif
#include <sys/resource.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <time.h>
#include <fcntl.h>
#include <string.h>
#include <signal.h>
#include <termios.h>
#include <utmp.h>
#include <ctype.h>
#include <stdarg.h>
#include <sys/syslog.h>
#include <sys/time.h>
#ifdef WITH_SELINUX
#include <selinux/selinux.h>
#endif
#ifdef __i386__
# if (__GLIBC__ >= 2)
/* GNU libc 2.x */
# define STACK_DEBUG 1
# if (__GLIBC__ == 2 && __GLIBC_MINOR__ == 0)
/* Only glibc 2.0 needs this */
# include <sigcontext.h>
# endif
# endif
#endif
#include "init.h"
#include "initreq.h"
#include "paths.h"
#include "reboot.h"
#include "set.h"
#ifndef SIGPWR
# define SIGPWR SIGUSR2
#endif
#ifndef CBAUD
# define CBAUD 0
#endif
#ifndef CBAUDEX
# define CBAUDEX 0
#endif
/* Set a signal handler. */
#define SETSIG(sa, sig, fun, flags) \
do { \
sa.sa_handler = fun; \
sa.sa_flags = flags; \
sigemptyset(&sa.sa_mask); \
sigaction(sig, &sa, NULL); \
} while(0)
/* Version information */
char *Version = "@(#) init " VERSION " " DATE " miquels@cistron.nl";
char *bootmsg = "version " VERSION " %s";
#define E_VERSION "INIT_VERSION=sysvinit-" VERSION
CHILD *family = NULL; /* The linked list of all entries */
CHILD *newFamily = NULL; /* The list after inittab re-read */
CHILD ch_emerg = { /* Emergency shell */
WAITING, 0, 0, 0, 0,
"~~",
"S",
3,
"/sbin/sulogin",
NULL,
NULL
};
char runlevel = 'S'; /* The current run level */
char thislevel = 'S'; /* The current runlevel */
char prevlevel = 'N'; /* Previous runlevel */
int dfl_level = 0; /* Default runlevel */
sig_atomic_t got_cont = 0; /* Set if we received the SIGCONT signal */
sig_atomic_t got_signals; /* Set if we received a signal. */
int emerg_shell = 0; /* Start emergency shell? */
int wrote_wtmp_reboot = 1; /* Set when we wrote the reboot record */
int wrote_utmp_reboot = 1; /* Set when we wrote the reboot record */
int wrote_wtmp_rlevel = 1; /* Set when we wrote the runlevel record */
int wrote_utmp_rlevel = 1; /* Set when we wrote the runlevel record */
int sltime = 5; /* Sleep time between TERM and KILL */
char *argv0; /* First arguments; show up in ps listing */
int maxproclen; /* Maximal length of argv[0] with \0 */
struct utmp utproto; /* Only used for sizeof(utproto.ut_id) */
char *console_dev; /* Console device. */
int pipe_fd = -1; /* /dev/initctl */
int did_boot = 0; /* Did we already do BOOT* stuff? */
int main(int, char **);
/* Used by re-exec part */
int reload = 0; /* Should we do initialization stuff? */
char *myname="/sbin/init"; /* What should we exec */
int oops_error; /* Used by some of the re-exec code. */
const char *Signature = "12567362"; /* Signature for re-exec fd */
/* Macro to see if this is a special action */
#define ISPOWER(i) ((i) == POWERWAIT || (i) == POWERFAIL || \
(i) == POWEROKWAIT || (i) == POWERFAILNOW || \
(i) == CTRLALTDEL)
/* ascii values for the `action' field. */
struct actions {
char *name;
int act;
} actions[] = {
{ "respawn", RESPAWN },
{ "wait", WAIT },
{ "once", ONCE },
{ "boot", BOOT },
{ "bootwait", BOOTWAIT },
{ "powerfail", POWERFAIL },
{ "powerfailnow",POWERFAILNOW },
{ "powerwait", POWERWAIT },
{ "powerokwait", POWEROKWAIT },
{ "ctrlaltdel", CTRLALTDEL },
{ "off", OFF },
{ "ondemand", ONDEMAND },
{ "initdefault", INITDEFAULT },
{ "sysinit", SYSINIT },
{ "kbrequest", KBREQUEST },
{ NULL, 0 },
};
/*
* State parser token table (see receive_state)
*/
struct {
char name[4];
int cmd;
} cmds[] = {
{ "VER", C_VER },
{ "END", C_END },
{ "REC", C_REC },
{ "EOR", C_EOR },
{ "LEV", C_LEV },
{ "FL ", C_FLAG },
{ "AC ", C_ACTION },
{ "CMD", C_PROCESS },
{ "PID", C_PID },
{ "EXS", C_EXS },
{ "-RL", D_RUNLEVEL },
{ "-TL", D_THISLEVEL },
{ "-PL", D_PREVLEVEL },
{ "-SI", D_GOTSIGN },
{ "-WR", D_WROTE_WTMP_REBOOT},
{ "-WU", D_WROTE_UTMP_REBOOT},
{ "-ST", D_SLTIME },
{ "-DB", D_DIDBOOT },
{ "-LW", D_WROTE_WTMP_RLEVEL},
{ "-LU", D_WROTE_UTMP_RLEVEL},
{ "", 0 }
};
struct {
char *name;
int mask;
} flags[]={
{"RU",RUNNING},
{"DE",DEMAND},
{"XD",XECUTED},
{"WT",WAITING},
{NULL,0}
};
#define NR_EXTRA_ENV 16
char *extra_env[NR_EXTRA_ENV];
/*
* Sleep a number of seconds.
*
* This only works correctly because the linux select updates
* the elapsed time in the struct timeval passed to select!
*/
void do_sleep(int sec)
{
struct timeval tv;
tv.tv_sec = sec;
tv.tv_usec = 0;
while(select(0, NULL, NULL, NULL, &tv) < 0 && errno == EINTR)
;
}
/*
* Non-failing allocation routines (init cannot fail).
*/
void *imalloc(size_t size)
{
void *m;
while ((m = malloc(size)) == NULL) {
initlog(L_VB, "out of memory");
do_sleep(5);
}
memset(m, 0, size);
return m;
}
char *istrdup(char *s)
{
char *m;
int l;
l = strlen(s) + 1;
m = imalloc(l);
memcpy(m, s, l);
return m;
}
/*
* Send the state info of the previous running init to
* the new one, in a version-independant way.
*/
void send_state(int fd)
{
FILE *fp;
CHILD *p;
int i,val;
fp = fdopen(fd,"w");
fprintf(fp, "VER%s\n", Version);
fprintf(fp, "-RL%c\n", runlevel);
fprintf(fp, "-TL%c\n", thislevel);
fprintf(fp, "-PL%c\n", prevlevel);
fprintf(fp, "-SI%u\n", got_signals);
fprintf(fp, "-WR%d\n", wrote_wtmp_reboot);
fprintf(fp, "-WU%d\n", wrote_utmp_reboot);
fprintf(fp, "-ST%d\n", sltime);
fprintf(fp, "-DB%d\n", did_boot);
for (p = family; p; p = p->next) {
fprintf(fp, "REC%s\n", p->id);
fprintf(fp, "LEV%s\n", p->rlevel);
for (i = 0, val = p->flags; flags[i].mask; i++)
if (val & flags[i].mask) {
val &= ~flags[i].mask;
fprintf(fp, "FL %s\n",flags[i].name);
}
fprintf(fp, "PID%d\n",p->pid);
fprintf(fp, "EXS%u\n",p->exstat);
for(i = 0; actions[i].act; i++)
if (actions[i].act == p->action) {
fprintf(fp, "AC %s\n", actions[i].name);
break;
}
fprintf(fp, "CMD%s\n", p->process);
fprintf(fp, "EOR\n");
}
fprintf(fp, "END\n");
fclose(fp);
}
/*
* Read a string from a file descriptor.
* FIXME: why not use fgets() ?
*/
static int get_string(char *p, int size, FILE *f)
{
int c;
while ((c = getc(f)) != EOF && c != '\n') {
if (--size > 0)
*p++ = c;
}
*p = '\0';
return (c != EOF) && (size > 0);
}
/*
* Read trailing data from the state pipe until we see a newline.
*/
static int get_void(FILE *f)
{
int c;
while ((c = getc(f)) != EOF && c != '\n')
;
return (c != EOF);
}
/*
* Read the next "command" from the state pipe.
*/
static int get_cmd(FILE *f)
{
char cmd[4] = " ";
int i;
if (fread(cmd, 1, sizeof(cmd) - 1, f) != sizeof(cmd) - 1)
return C_EOF;
for(i = 0; cmds[i].cmd && strcmp(cmds[i].name, cmd) != 0; i++)
;
return cmds[i].cmd;
}
/*
* Read a CHILD * from the state pipe.
*/
static CHILD *get_record(FILE *f)
{
int cmd;
char s[32];
int i;
CHILD *p;
do {
switch (cmd = get_cmd(f)) {
case C_END:
get_void(f);
return NULL;
case 0:
get_void(f);
break;
case C_REC:
break;
case D_RUNLEVEL:
fscanf(f, "%c\n", &runlevel);
break;
case D_THISLEVEL:
fscanf(f, "%c\n", &thislevel);
break;
case D_PREVLEVEL:
fscanf(f, "%c\n", &prevlevel);
break;
case D_GOTSIGN:
fscanf(f, "%u\n", &got_signals);
break;
case D_WROTE_WTMP_REBOOT:
fscanf(f, "%d\n", &wrote_wtmp_reboot);
break;
case D_WROTE_UTMP_REBOOT:
fscanf(f, "%d\n", &wrote_utmp_reboot);
break;
case D_SLTIME:
fscanf(f, "%d\n", &sltime);
break;
case D_DIDBOOT:
fscanf(f, "%d\n", &did_boot);
break;
case D_WROTE_WTMP_RLEVEL:
fscanf(f, "%d\n", &wrote_wtmp_rlevel);
break;
case D_WROTE_UTMP_RLEVEL:
fscanf(f, "%d\n", &wrote_utmp_rlevel);
break;
default:
if (cmd > 0 || cmd == C_EOF) {
oops_error = -1;
return NULL;
}
}
} while (cmd != C_REC);
p = imalloc(sizeof(CHILD));
get_string(p->id, sizeof(p->id), f);
do switch(cmd = get_cmd(f)) {
case 0:
case C_EOR:
get_void(f);
break;
case C_PID:
fscanf(f, "%d\n", &(p->pid));
break;
case C_EXS:
fscanf(f, "%u\n", &(p->exstat));
break;
case C_LEV:
get_string(p->rlevel, sizeof(p->rlevel), f);
break;
case C_PROCESS:
get_string(p->process, sizeof(p->process), f);
break;
case C_FLAG:
get_string(s, sizeof(s), f);
for(i = 0; flags[i].name; i++) {
if (strcmp(flags[i].name,s) == 0)
break;
}
p->flags |= flags[i].mask;
break;
case C_ACTION:
get_string(s, sizeof(s), f);
for(i = 0; actions[i].name; i++) {
if (strcmp(actions[i].name, s) == 0)
break;
}
p->action = actions[i].act ? actions[i].act : OFF;
break;
default:
free(p);
oops_error = -1;
return NULL;
} while( cmd != C_EOR);
return p;
}
/*
* Read the complete state info from the state pipe.
* Returns 0 on success
*/
int receive_state(int fd)
{
FILE *f;
char old_version[256];
CHILD **pp;
f = fdopen(fd, "r");
if (get_cmd(f) != C_VER)
return -1;
get_string(old_version, sizeof(old_version), f);
oops_error = 0;
for (pp = &family; (*pp = get_record(f)) != NULL; pp = &((*pp)->next))
;
fclose(f);
return oops_error;
}
/*
* Set the process title.
*/
#ifdef __GNUC__
__attribute__ ((format (printf, 1, 2)))
#endif
static int setproctitle(char *fmt, ...)
{
va_list ap;
int len;
char buf[256];
buf[0] = 0;
va_start(ap, fmt);
len = vsnprintf(buf, sizeof(buf), fmt, ap);
va_end(ap);
if (maxproclen > 1) {
memset(argv0, 0, maxproclen);
strncpy(argv0, buf, maxproclen - 1);
}
return len;
}
/*
* Set console_dev to a working console.
*/
void console_init(void)
{
int fd;
int tried_devcons = 0;
int tried_vtmaster = 0;
char *s;
if ((s = getenv("CONSOLE")) != NULL)
console_dev = s;
else {
console_dev = CONSOLE;
tried_devcons++;
}
while ((fd = open(console_dev, O_RDONLY|O_NONBLOCK)) < 0) {
if (!tried_devcons) {
tried_devcons++;
console_dev = CONSOLE;
continue;
}
if (!tried_vtmaster) {
tried_vtmaster++;
console_dev = VT_MASTER;
continue;
}
break;
}
if (fd < 0)
console_dev = "/dev/null";
else
close(fd);
}
/*
* Open the console with retries.
*/
int console_open(int mode)
{
int f, fd = -1;
int m;
/*
* Open device in nonblocking mode.
*/
m = mode | O_NONBLOCK;
/*
* Retry the open five times.
*/
for(f = 0; f < 5; f++) {
if ((fd = open(console_dev, m)) >= 0) break;
usleep(100);
}
if (fd < 0) return fd;
/*
* Set original flags.
*/
if (m != mode)
fcntl(fd, F_SETFL, mode);
return fd;
}
/*
* We got a signal (HUP PWR WINCH ALRM INT)
*/
void signal_handler(int sig)
{
ADDSET(got_signals, sig);
}
/*
* SIGCHLD: one of our children has died.
*/
void chld_handler()
{
CHILD *ch;
int pid, st;
int saved_errno = errno;
/*
* Find out which process(es) this was (were)
*/
while((pid = waitpid(-1, &st, WNOHANG)) != 0) {
if (errno == ECHILD) break;
for( ch = family; ch; ch = ch->next )
if ( ch->pid == pid && (ch->flags & RUNNING) ) {
INITDBG(L_VB,
"chld_handler: marked %d as zombie",
ch->pid);
ADDSET(got_signals, SIGCHLD);
ch->exstat = st;
ch->flags |= ZOMBIE;
if (ch->new) {
ch->new->exstat = st;
ch->new->flags |= ZOMBIE;
}
break;
}
if (ch == NULL) {
INITDBG(L_VB, "chld_handler: unknown child %d exited.",
pid);
}
}
errno = saved_errno;
}
/*
* Linux ignores all signals sent to init when the
* SIG_DFL handler is installed. Therefore we must catch SIGTSTP
* and SIGCONT, or else they won't work....
*
* The SIGCONT handler
*/
void cont_handler()
{
got_cont = 1;
}
/*
* Fork and dump core in /.
*/
void coredump(void)
{
static int dumped = 0;
struct rlimit rlim;
sigset_t mask;
if (dumped) return;
dumped = 1;
if (fork() != 0) return;
sigfillset(&mask);
sigprocmask(SIG_SETMASK, &mask, NULL);
rlim.rlim_cur = RLIM_INFINITY;
rlim.rlim_max = RLIM_INFINITY;
setrlimit(RLIMIT_CORE, &rlim);
chdir("/");
signal(SIGSEGV, SIG_DFL);
raise(SIGSEGV);
sigdelset(&mask, SIGSEGV);
sigprocmask(SIG_SETMASK, &mask, NULL);
do_sleep(5);
exit(0);
}
/*
* OOPS: segmentation violation!
* If we have the info, print where it occured.
* Then sleep 30 seconds and try to continue.
*/
#if defined(STACK_DEBUG) && defined(__linux__)
void segv_handler(int sig, struct sigcontext ctx)
{
char *p = "";
int saved_errno = errno;
if ((void *)ctx.eip >= (void *)do_sleep &&
(void *)ctx.eip < (void *)main)
p = " (code)";
initlog(L_VB, "PANIC: segmentation violation at %p%s! "
"sleeping for 30 seconds.", (void *)ctx.eip, p);
coredump();
do_sleep(30);
errno = saved_errno;
}
#else
void segv_handler()
{
int saved_errno = errno;
initlog(L_VB,
"PANIC: segmentation violation! sleeping for 30 seconds.");
coredump();
do_sleep(30);
errno = saved_errno;
}
#endif
/*
* The SIGSTOP & SIGTSTP handler
*/
void stop_handler()
{
int saved_errno = errno;
got_cont = 0;
while(!got_cont) pause();
got_cont = 0;
errno = saved_errno;
}
/*
* Set terminal settings to reasonable defaults
*/
void console_stty(void)
{
struct termios tty;
int fd;
if ((fd = console_open(O_RDWR|O_NOCTTY)) < 0) {
initlog(L_VB, "can't open %s", console_dev);
return;
}
(void) tcgetattr(fd, &tty);
tty.c_cflag &= CBAUD|CBAUDEX|CSIZE|CSTOPB|PARENB|PARODD;
tty.c_cflag |= HUPCL|CLOCAL|CREAD;
tty.c_cc[VINTR] = 3; /* ctrl('c') */
tty.c_cc[VQUIT] = 28; /* ctrl('\\') */
tty.c_cc[VERASE] = 127;
tty.c_cc[VKILL] = 24; /* ctrl('x') */
tty.c_cc[VEOF] = 4; /* ctrl('d') */
tty.c_cc[VTIME] = 0;
tty.c_cc[VMIN] = 1;
tty.c_cc[VSTART] = 17; /* ctrl('q') */
tty.c_cc[VSTOP] = 19; /* ctrl('s') */
tty.c_cc[VSUSP] = 26; /* ctrl('z') */
/*
* Set pre and post processing
*/
tty.c_iflag = IGNPAR|ICRNL|IXON|IXANY
#ifdef IUTF8 /* Not defined on FreeBSD */
| (tty.c_iflag & IUTF8)
#endif /* IUTF8 */
;
tty.c_oflag = OPOST|ONLCR;
tty.c_lflag = ISIG|ICANON|ECHO|ECHOCTL|ECHOPRT|ECHOKE;
/*
* Now set the terminal line.
* We don't care about non-transmitted output data
* and non-read input data.
*/
(void) tcsetattr(fd, TCSANOW, &tty);
(void) tcflush(fd, TCIOFLUSH);
(void) close(fd);
}
/*
* Print to the system console
*/
void print(char *s)
{
int fd;
if ((fd = console_open(O_WRONLY|O_NOCTTY|O_NDELAY)) >= 0) {
write(fd, s, strlen(s));
close(fd);
}
}
/*
* Log something to a logfile and the console.
*/
#ifdef __GNUC__
__attribute__ ((format (printf, 2, 3)))
#endif
void initlog(int loglevel, char *s, ...)
{
va_list va_alist;
char buf[256];
sigset_t nmask, omask;
va_start(va_alist, s);
vsnprintf(buf, sizeof(buf), s, va_alist);
va_end(va_alist);
if (loglevel & L_SY) {
/*
* Re-establish connection with syslogd every time.
* Block signals while talking to syslog.
*/
sigfillset(&nmask);
sigprocmask(SIG_BLOCK, &nmask, &omask);
openlog("init", 0, LOG_DAEMON);
syslog(LOG_INFO, "%s", buf);
closelog();
sigprocmask(SIG_SETMASK, &omask, NULL);
}
/*
* And log to the console.
*/
if (loglevel & L_CO) {
print("\rINIT: ");
print(buf);
print("\r\n");
}
}
/*
* Build a new environment for execve().
*/
char **init_buildenv(int child)
{
char i_lvl[] = "RUNLEVEL=x";
char i_prev[] = "PREVLEVEL=x";
char i_cons[32];
char **e;
int n, i;
for (n = 0; environ[n]; n++)
;
n += NR_EXTRA_ENV + 8;
e = calloc(n, sizeof(char *));
for (n = 0; environ[n]; n++)
e[n] = istrdup(environ[n]);
for (i = 0; i < NR_EXTRA_ENV; i++)
if (extra_env[i])
e[n++] = istrdup(extra_env[i]);
if (child) {
snprintf(i_cons, sizeof(i_cons), "CONSOLE=%s", console_dev);
i_lvl[9] = thislevel;
i_prev[10] = prevlevel;
e[n++] = istrdup(i_lvl);
e[n++] = istrdup(i_prev);
e[n++] = istrdup(i_cons);
e[n++] = istrdup(E_VERSION);
}
e[n++] = NULL;
return e;
}
void init_freeenv(char **e)
{
int n;
for (n = 0; e[n]; n++)
free(e[n]);
free(e);
}
/*
* Fork and execute.
*
* This function is too long and indents too deep.
*
*/
int spawn(CHILD *ch, int *res)
{
char *args[16]; /* Argv array */
char buf[136]; /* Line buffer */
int f, st, rc; /* Scratch variables */
char *ptr; /* Ditto */
time_t t; /* System time */
int oldAlarm; /* Previous alarm value */
char *proc = ch->process; /* Command line */
pid_t pid, pgrp; /* child, console process group. */
sigset_t nmask, omask; /* For blocking SIGCHLD */
struct sigaction sa;
*res = -1;
buf[sizeof(buf) - 1] = 0;
/* Skip '+' if it's there */
if (proc[0] == '+') proc++;
ch->flags |= XECUTED;
if (ch->action == RESPAWN || ch->action == ONDEMAND) {
/* Is the date stamp from less than 2 minutes ago? */
time(&t);
if (ch->tm + TESTTIME > t) {
ch->count++;
} else {
ch->count = 0;
ch->tm = t;
}
/* Do we try to respawn too fast? */
if (ch->count >= MAXSPAWN) {
initlog(L_VB,
"Id \"%s\" respawning too fast: disabled for %d minutes",
ch->id, SLEEPTIME / 60);
ch->flags &= ~RUNNING;
ch->flags |= FAILING;
/* Remember the time we stopped */
ch->tm = t;
/* Try again in 5 minutes */
oldAlarm = alarm(0);
if (oldAlarm > SLEEPTIME || oldAlarm <= 0) oldAlarm = SLEEPTIME;
alarm(oldAlarm);
return(-1);
}
}
/* See if there is an "initscript" (except in single user mode). */
if (access(INITSCRIPT, R_OK) == 0 && runlevel != 'S') {
/* Build command line using "initscript" */
args[1] = SHELL;
args[2] = INITSCRIPT;
args[3] = ch->id;
args[4] = ch->rlevel;
args[5] = "unknown";
for(f = 0; actions[f].name; f++) {
if (ch->action == actions[f].act) {
args[5] = actions[f].name;
break;
}
}
args[6] = proc;
args[7] = NULL;
} else if (strpbrk(proc, "~`!$^&*()=|\\{}[];\"'<>?")) {
/* See if we need to fire off a shell for this command */
/* Give command line to shell */
args[1] = SHELL;
args[2] = "-c";
strcpy(buf, "exec ");
strncat(buf, proc, sizeof(buf) - strlen(buf) - 1);
args[3] = buf;
args[4] = NULL;
} else {
/* Split up command line arguments */
buf[0] = 0;
strncat(buf, proc, sizeof(buf) - 1);
ptr = buf;
for(f = 1; f < 15; f++) {
/* Skip white space */
while(*ptr == ' ' || *ptr == '\t') ptr++;
args[f] = ptr;
/* May be trailing space.. */
if (*ptr == 0) break;
/* Skip this `word' */
while(*ptr && *ptr != ' ' && *ptr != '\t' && *ptr != '#')
ptr++;
/* If end-of-line, break */
if (*ptr == '#' || *ptr == 0) {
f++;
*ptr = 0;
break;
}
/* End word with \0 and continue */
*ptr++ = 0;
}
args[f] = NULL;
}
args[0] = args[1];
while(1) {
/*
* Block sigchild while forking.
*/
sigemptyset(&nmask);
sigaddset(&nmask, SIGCHLD);
sigprocmask(SIG_BLOCK, &nmask, &omask);
if ((pid = fork()) == 0) {
close(0);
close(1);
close(2);
if (pipe_fd >= 0) close(pipe_fd);
sigprocmask(SIG_SETMASK, &omask, NULL);
/*
* Update utmp/wtmp file prior to starting
* any child. This MUST be done right here in
* the child process in order to prevent a race
* condition that occurs when the child
* process' time slice executes before the
* parent (can and does happen in a uniprocessor
* environment). If the child is a getty and
* the race condition happens, then init's utmp
* update will happen AFTER the getty runs
* and expects utmp to be updated already!
*
* Do NOT log if process field starts with '+'
* FIXME: that's for compatibility with *very*
* old getties - probably it can be taken out.
*/
if (ch->action == RESPAWN && ch->process[0] != '+')
write_utmp_wtmp("", ch->id, getpid(), INIT_PROCESS, "");
/*
* In sysinit, boot, bootwait or single user mode:
* for any wait-type subprocess we _force_ the console
* to be its controlling tty.
*/
if (strchr("*#sS", runlevel) && ch->flags & WAITING) {
/*
* We fork once extra. This is so that we can
* wait and change the process group and session
* of the console after exit of the leader.
*/
setsid();
if ((f = console_open(O_RDWR|O_NOCTTY)) >= 0) {
/* Take over controlling tty by force */
(void)ioctl(f, TIOCSCTTY, 1);
dup(f);
dup(f);
}
/*
* 4 Sep 2001, Andrea Arcangeli:
* Fix a race in spawn() that is used to deadlock init in a
* waitpid() loop: must set the childhandler as default before forking
* off the child or the chld_handler could run before the waitpid loop
* has a chance to find its zombie-child.
*/
SETSIG(sa, SIGCHLD, SIG_DFL, SA_RESTART);
if ((pid = fork()) < 0) {
initlog(L_VB, "cannot fork: %s",
strerror(errno));
exit(1);
}
if (pid > 0) {
/*
* Ignore keyboard signals etc.
* Then wait for child to exit.
*/
SETSIG(sa, SIGINT, SIG_IGN, SA_RESTART);
SETSIG(sa, SIGTSTP, SIG_IGN, SA_RESTART);
SETSIG(sa, SIGQUIT, SIG_IGN, SA_RESTART);
while ((rc = waitpid(pid, &st, 0)) != pid)
if (rc < 0 && errno == ECHILD)
break;
/*
* Small optimization. See if stealing
* controlling tty back is needed.
*/
pgrp = tcgetpgrp(f);
if (pgrp != getpid())
exit(0);
/*
* Steal controlling tty away. We do
* this with a temporary process.
*/
if ((pid = fork()) < 0) {
initlog(L_VB, "cannot fork: %s",
strerror(errno));
exit(1);
}
if (pid == 0) {
setsid();
(void)ioctl(f, TIOCSCTTY, 1);
exit(0);
}
while((rc = waitpid(pid, &st, 0)) != pid)
if (rc < 0 && errno == ECHILD)
break;
exit(0);
}
/* Set ioctl settings to default ones */
console_stty();
} else {
setsid();
if ((f = console_open(O_RDWR|O_NOCTTY)) < 0) {
initlog(L_VB, "open(%s): %s", console_dev,
strerror(errno));
f = open("/dev/null", O_RDWR);
}
dup(f);
dup(f);
}
/* Reset all the signals, set up environment */
for(f = 1; f < NSIG; f++) SETSIG(sa, f, SIG_DFL, SA_RESTART);
environ = init_buildenv(1);
/*
* Execute prog. In case of ENOEXEC try again
* as a shell script.
*/
execvp(args[1], args + 1);
if (errno == ENOEXEC) {
args[1] = SHELL;
args[2] = "-c";
strcpy(buf, "exec ");
strncat(buf, proc, sizeof(buf) - strlen(buf) - 1);
args[3] = buf;
args[4] = NULL;
execvp(args[1], args + 1);
}
initlog(L_VB, "cannot execute \"%s\"", args[1]);
exit(1);
}
*res = pid;
sigprocmask(SIG_SETMASK, &omask, NULL);
INITDBG(L_VB, "Started id %s (pid %d)", ch->id, pid);
if (pid == -1) {
initlog(L_VB, "cannot fork, retry..");
do_sleep(5);
continue;
}
return(pid);
}
}
/*
* Start a child running!
*/
void startup(CHILD *ch)
{
/*
* See if it's disabled
*/
if (ch->flags & FAILING) return;
switch(ch->action) {
case SYSINIT:
case BOOTWAIT:
case WAIT:
case POWERWAIT:
case POWERFAILNOW:
case POWEROKWAIT:
case CTRLALTDEL:
if (!(ch->flags & XECUTED)) ch->flags |= WAITING;
case KBREQUEST:
case BOOT:
case POWERFAIL:
case ONCE:
if (ch->flags & XECUTED) break;
case ONDEMAND:
case RESPAWN:
ch->flags |= RUNNING;
(void)spawn(ch, &(ch->pid));
break;
}
}
/*
* Read the inittab file.
*/
void read_inittab(void)
{
FILE *fp; /* The INITTAB file */
CHILD *ch, *old, *i; /* Pointers to CHILD structure */
CHILD *head = NULL; /* Head of linked list */
#ifdef INITLVL
struct stat st; /* To stat INITLVL */
#endif
sigset_t nmask, omask; /* For blocking SIGCHLD. */
char buf[256]; /* Line buffer */
char err[64]; /* Error message. */
char *id, *rlevel,
*action, *process; /* Fields of a line */
char *p;
int lineNo = 0; /* Line number in INITTAB file */
int actionNo; /* Decoded action field */
int f; /* Counter */
int round; /* round 0 for SIGTERM, 1 for SIGKILL */
int foundOne = 0; /* No killing no sleep */
int talk; /* Talk to the user */
int done = 0; /* Ready yet? */
#if DEBUG
if (newFamily != NULL) {
INITDBG(L_VB, "PANIC newFamily != NULL");
exit(1);
}
INITDBG(L_VB, "Reading inittab");
#endif
/*
* Open INITTAB and real line by line.
*/
if ((fp = fopen(INITTAB, "r")) == NULL)
initlog(L_VB, "No inittab file found");
while(!done) {
/*
* Add single user shell entry at the end.
*/
if (fp == NULL || fgets(buf, sizeof(buf), fp) == NULL) {
done = 1;
/*
* See if we have a single user entry.
*/
for(old = newFamily; old; old = old->next)
if (strpbrk(old->rlevel, "S")) break;
if (old == NULL)
snprintf(buf, sizeof(buf), "~~:S:wait:%s\n", SULOGIN);
else
continue;
}
lineNo++;
/*
* Skip comments and empty lines
*/
for(p = buf; *p == ' ' || *p == '\t'; p++)
;
if (*p == '#' || *p == '\n') continue;
/*
* Decode the fields
*/
id = strsep(&p, ":");
rlevel = strsep(&p, ":");
action = strsep(&p, ":");
process = strsep(&p, "\n");
/*
* Check if syntax is OK. Be very verbose here, to
* avoid newbie postings on comp.os.linux.setup :)
*/
err[0] = 0;
if (!id || !*id) strcpy(err, "missing id field");
if (!rlevel) strcpy(err, "missing runlevel field");
if (!process) strcpy(err, "missing process field");
if (!action || !*action)
strcpy(err, "missing action field");
if (id && strlen(id) > sizeof(utproto.ut_id))
sprintf(err, "id field too long (max %d characters)",
(int)sizeof(utproto.ut_id));
if (rlevel && strlen(rlevel) > 11)
strcpy(err, "rlevel field too long (max 11 characters)");
if (process && strlen(process) > 127)
strcpy(err, "process field too long");
if (action && strlen(action) > 32)
strcpy(err, "action field too long");
if (err[0] != 0) {
initlog(L_VB, "%s[%d]: %s", INITTAB, lineNo, err);
INITDBG(L_VB, "%s:%s:%s:%s", id, rlevel, action, process);
continue;
}
/*
* Decode the "action" field
*/
actionNo = -1;
for(f = 0; actions[f].name; f++)
if (strcasecmp(action, actions[f].name) == 0) {
actionNo = actions[f].act;
break;
}
if (actionNo == -1) {
initlog(L_VB, "%s[%d]: %s: unknown action field",
INITTAB, lineNo, action);
continue;
}
/*
* See if the id field is unique
*/
for(old = newFamily; old; old = old->next) {
if(strcmp(old->id, id) == 0 && strcmp(id, "~~")) {
initlog(L_VB, "%s[%d]: duplicate ID field \"%s\"",
INITTAB, lineNo, id);
break;
}
}
if (old) continue;
/*
* Allocate a CHILD structure
*/
ch = imalloc(sizeof(CHILD));
/*
* And fill it in.
*/
ch->action = actionNo;
strncpy(ch->id, id, sizeof(utproto.ut_id) + 1); /* Hack for different libs. */
strncpy(ch->process, process, sizeof(ch->process) - 1);
if (rlevel[0]) {
for(f = 0; f < (int)sizeof(rlevel) - 1 && rlevel[f]; f++) {
ch->rlevel[f] = rlevel[f];
if (ch->rlevel[f] == 's') ch->rlevel[f] = 'S';
}
strncpy(ch->rlevel, rlevel, sizeof(ch->rlevel) - 1);
} else {
strcpy(ch->rlevel, "0123456789");
if (ISPOWER(ch->action))
strcpy(ch->rlevel, "S0123456789");
}
/*
* We have the fake runlevel '#' for SYSINIT and
* '*' for BOOT and BOOTWAIT.
*/
if (ch->action == SYSINIT) strcpy(ch->rlevel, "#");
if (ch->action == BOOT || ch->action == BOOTWAIT)
strcpy(ch->rlevel, "*");
/*
* Now add it to the linked list. Special for powerfail.
*/
if (ISPOWER(ch->action)) {
/*
* Disable by default
*/
ch->flags |= XECUTED;
/*
* Tricky: insert at the front of the list..
*/
old = NULL;
for(i = newFamily; i; i = i->next) {
if (!ISPOWER(i->action)) break;
old = i;
}
/*
* Now add after entry "old"
*/
if (old) {
ch->next = i;
old->next = ch;
if (i == NULL) head = ch;
} else {
ch->next = newFamily;
newFamily = ch;
if (ch->next == NULL) head = ch;
}
} else {
/*
* Just add at end of the list
*/
if (ch->action == KBREQUEST) ch->flags |= XECUTED;
ch->next = NULL;
if (head)
head->next = ch;
else
newFamily = ch;
head = ch;
}
/*
* Walk through the old list comparing id fields
*/
for(old = family; old; old = old->next)
if (strcmp(old->id, ch->id) == 0) {
old->new = ch;
break;
}
}
/*
* We're done.
*/
if (fp) fclose(fp);
/*
* Loop through the list of children, and see if they need to
* be killed.
*/
INITDBG(L_VB, "Checking for children to kill");
for(round = 0; round < 2; round++) {
talk = 1;
for(ch = family; ch; ch = ch->next) {
ch->flags &= ~KILLME;
/*
* Is this line deleted?
*/
if (ch->new == NULL) ch->flags |= KILLME;
/*
* If the entry has changed, kill it anyway. Note that
* we do not check ch->process, only the "action" field.
* This way, you can turn an entry "off" immediately, but
* changes in the command line will only become effective
* after the running version has exited.
*/
if (ch->new && ch->action != ch->new->action) ch->flags |= KILLME;
/*
* Only BOOT processes may live in all levels
*/
if (ch->action != BOOT &&
strchr(ch->rlevel, runlevel) == NULL) {
/*
* Ondemand procedures live always,
* except in single user
*/
if (runlevel == 'S' || !(ch->flags & DEMAND))
ch->flags |= KILLME;
}
/*
* Now, if this process may live note so in the new list
*/
if ((ch->flags & KILLME) == 0) {
ch->new->flags = ch->flags;
ch->new->pid = ch->pid;
ch->new->exstat = ch->exstat;
continue;
}
/*
* Is this process still around?
*/
if ((ch->flags & RUNNING) == 0) {
ch->flags &= ~KILLME;
continue;
}
INITDBG(L_VB, "Killing \"%s\"", ch->process);
switch(round) {
case 0: /* Send TERM signal */
if (talk)
initlog(L_CO,
"Sending processes the TERM signal");
kill(-(ch->pid), SIGTERM);
foundOne = 1;
break;
case 1: /* Send KILL signal and collect status */
if (talk)
initlog(L_CO,
"Sending processes the KILL signal");
kill(-(ch->pid), SIGKILL);
break;
}
talk = 0;
}
/*
* See if we have to wait 5 seconds
*/
if (foundOne && round == 0) {
/*
* Yup, but check every second if we still have children.
*/
for(f = 0; f < sltime; f++) {
for(ch = family; ch; ch = ch->next) {
if (!(ch->flags & KILLME)) continue;
if ((ch->flags & RUNNING) && !(ch->flags & ZOMBIE))
break;
}
if (ch == NULL) {
/*
* No running children, skip SIGKILL
*/
round = 1;
foundOne = 0; /* Skip the sleep below. */
break;
}
do_sleep(1);
}
}
}
/*
* Now give all processes the chance to die and collect exit statuses.
*/
if (foundOne) do_sleep(1);
for(ch = family; ch; ch = ch->next)
if (ch->flags & KILLME) {
if (!(ch->flags & ZOMBIE))
initlog(L_CO, "Pid %d [id %s] seems to hang", ch->pid,
ch->id);
else {
INITDBG(L_VB, "Updating utmp for pid %d [id %s]",
ch->pid, ch->id);
ch->flags &= ~RUNNING;
if (ch->process[0] != '+')
write_utmp_wtmp("", ch->id, ch->pid, DEAD_PROCESS, NULL);
}
}
/*
* Both rounds done; clean up the list.
*/
sigemptyset(&nmask);
sigaddset(&nmask, SIGCHLD);
sigprocmask(SIG_BLOCK, &nmask, &omask);
for(ch = family; ch; ch = old) {
old = ch->next;
free(ch);
}
family = newFamily;
for(ch = family; ch; ch = ch->next) ch->new = NULL;
newFamily = NULL;
sigprocmask(SIG_SETMASK, &omask, NULL);
#ifdef INITLVL
/*
* Dispose of INITLVL file.
*/
if (lstat(INITLVL, &st) >= 0 && S_ISLNK(st.st_mode)) {
/*
* INITLVL is a symbolic link, so just truncate the file.
*/
close(open(INITLVL, O_WRONLY|O_TRUNC));
} else {
/*
* Delete INITLVL file.
*/
unlink(INITLVL);
}
#endif
#ifdef INITLVL2
/*
* Dispose of INITLVL2 file.
*/
if (lstat(INITLVL2, &st) >= 0 && S_ISLNK(st.st_mode)) {
/*
* INITLVL2 is a symbolic link, so just truncate the file.
*/
close(open(INITLVL2, O_WRONLY|O_TRUNC));
} else {
/*
* Delete INITLVL2 file.
*/
unlink(INITLVL2);
}
#endif
}
/*
* Walk through the family list and start up children.
* The entries that do not belong here at all are removed
* from the list.
*/
void start_if_needed(void)
{
CHILD *ch; /* Pointer to child */
int delete; /* Delete this entry from list? */
INITDBG(L_VB, "Checking for children to start");
for(ch = family; ch; ch = ch->next) {
#if DEBUG
if (ch->rlevel[0] == 'C') {
INITDBG(L_VB, "%s: flags %d", ch->process, ch->flags);
}
#endif
/* Are we waiting for this process? Then quit here. */
if (ch->flags & WAITING) break;
/* Already running? OK, don't touch it */
if (ch->flags & RUNNING) continue;
/* See if we have to start it up */
delete = 1;
if (strchr(ch->rlevel, runlevel) ||
((ch->flags & DEMAND) && !strchr("#*Ss", runlevel))) {
startup(ch);
delete = 0;
}
if (delete) {
/* FIXME: is this OK? */
ch->flags &= ~(RUNNING|WAITING);
if (!ISPOWER(ch->action) && ch->action != KBREQUEST)
ch->flags &= ~XECUTED;
ch->pid = 0;
} else
/* Do we have to wait for this process? */
if (ch->flags & WAITING) break;
}
/* Done. */
}
/*
* Ask the user on the console for a runlevel
*/
int ask_runlevel(void)
{
const char prompt[] = "\nEnter runlevel: ";
char buf[8];
int lvl = -1;
int fd;
console_stty();
fd = console_open(O_RDWR|O_NOCTTY);
if (fd < 0) return('S');
while(!strchr("0123456789S", lvl)) {
write(fd, prompt, sizeof(prompt) - 1);
buf[0] = 0;
read(fd, buf, sizeof(buf));
if (buf[0] != 0 && (buf[1] == '\r' || buf[1] == '\n'))
lvl = buf[0];
if (islower(lvl)) lvl = toupper(lvl);
}
close(fd);
return lvl;
}
/*
* Search the INITTAB file for the 'initdefault' field, with the default
* runlevel. If this fails, ask the user to supply a runlevel.
*/
int get_init_default(void)
{
CHILD *ch;
int lvl = -1;
char *p;
/*
* Look for initdefault.
*/
for(ch = family; ch; ch = ch->next)
if (ch->action == INITDEFAULT) {
p = ch->rlevel;
while(*p) {
if (*p > lvl) lvl = *p;
p++;
}
break;
}
/*
* See if level is valid
*/
if (lvl > 0) {
if (islower(lvl)) lvl = toupper(lvl);
if (strchr("0123456789S", lvl) == NULL) {
initlog(L_VB,
"Initdefault level '%c' is invalid", lvl);
lvl = 0;
}
}
/*
* Ask for runlevel on console if needed.
*/
if (lvl <= 0) lvl = ask_runlevel();
/*
* Log the fact that we have a runlevel now.
*/
return lvl;
}
/*
* We got signaled.
*
* Do actions for the new level. If we are compatible with
* the "old" INITLVL and arg == 0, try to read the new
* runlevel from that file first.
*/
int read_level(int arg)
{
CHILD *ch; /* Walk through list */
unsigned char foo = 'X'; /* Contents of INITLVL */
int ok = 1;
#ifdef INITLVL
FILE *fp;
struct stat stt;
int st;
#endif
if (arg) foo = arg;
#ifdef INITLVL
ok = 0;
if (arg == 0) {
fp = NULL;
if (stat(INITLVL, &stt) != 0 || stt.st_size != 0L)
fp = fopen(INITLVL, "r");
#ifdef INITLVL2
if (fp == NULL &&
(stat(INITLVL2, &stt) != 0 || stt.st_size != 0L))
fp = fopen(INITLVL2, "r");
#endif
if (fp == NULL) {
/* INITLVL file empty or not there - act as 'init q' */
initlog(L_SY, "Re-reading inittab");
return(runlevel);
}
ok = fscanf(fp, "%c %d", &foo, &st);
fclose(fp);
} else {
/* We go to the new runlevel passed as an argument. */
foo = arg;
ok = 1;
}
if (ok == 2) sltime = st;
#endif /* INITLVL */
if (islower(foo)) foo = toupper(foo);
if (ok < 1 || ok > 2 || strchr("QS0123456789ABCU", foo) == NULL) {
initlog(L_VB, "bad runlevel: %c", foo);
return runlevel;
}
/* Log this action */
switch(foo) {
case 'S':
initlog(L_VB, "Going single user");
break;
case 'Q':
initlog(L_SY, "Re-reading inittab");
break;
case 'A':
case 'B':
case 'C':
initlog(L_SY,
"Activating demand-procedures for '%c'", foo);
break;
case 'U':
initlog(L_SY, "Trying to re-exec init");
return 'U';
default:
initlog(L_VB, "Switching to runlevel: %c", foo);
}
if (foo == 'Q') return runlevel;
/* Check if this is a runlevel a, b or c */
if (strchr("ABC", foo)) {
if (runlevel == 'S') return(runlevel);
/* Read inittab again first! */
read_inittab();
/* Mark those special tasks */
for(ch = family; ch; ch = ch->next)
if (strchr(ch->rlevel, foo) != NULL ||
strchr(ch->rlevel, tolower(foo)) != NULL) {
ch->flags |= DEMAND;
ch->flags &= ~XECUTED;
INITDBG(L_VB,
"Marking (%s) as ondemand, flags %d",
ch->id, ch->flags);
}
return runlevel;
}
/* Store both the old and the new runlevel. */
wrote_utmp_rlevel = 0;
wrote_wtmp_rlevel = 0;
write_utmp_wtmp("runlevel", "~~", foo + 256*runlevel, RUN_LVL, "~");
thislevel = foo;
prevlevel = runlevel;
return foo;
}
/*
* This procedure is called after every signal (SIGHUP, SIGALRM..)
*
* Only clear the 'failing' flag if the process is sleeping
* longer than 5 minutes, or inittab was read again due
* to user interaction.
*/
void fail_check(void)
{
CHILD *ch; /* Pointer to child structure */
time_t t; /* System time */
time_t next_alarm = 0; /* When to set next alarm */
time(&t);
for(ch = family; ch; ch = ch->next) {
if (ch->flags & FAILING) {
/* Can we free this sucker? */
if (ch->tm + SLEEPTIME < t) {
ch->flags &= ~FAILING;
ch->count = 0;
ch->tm = 0;
} else {
/* No, we'll look again later */
if (next_alarm == 0 ||
ch->tm + SLEEPTIME > next_alarm)
next_alarm = ch->tm + SLEEPTIME;
}
}
}
if (next_alarm) {
next_alarm -= t;
if (next_alarm < 1) next_alarm = 1;
alarm(next_alarm);
}
}
/* Set all 'Fail' timers to 0 */
void fail_cancel(void)
{
CHILD *ch;
for(ch = family; ch; ch = ch->next) {
ch->count = 0;
ch->tm = 0;
ch->flags &= ~FAILING;
}
}
/*
* Start up powerfail entries.
*/
void do_power_fail(int pwrstat)
{
CHILD *ch;
/*
* Tell powerwait & powerfail entries to start up
*/
for (ch = family; ch; ch = ch->next) {
if (pwrstat == 'O') {
/*
* The power is OK again.
*/
if (ch->action == POWEROKWAIT)
ch->flags &= ~XECUTED;
} else if (pwrstat == 'L') {
/*
* Low battery, shut down now.
*/
if (ch->action == POWERFAILNOW)
ch->flags &= ~XECUTED;
} else {
/*
* Power is failing, shutdown imminent
*/
if (ch->action == POWERFAIL || ch->action == POWERWAIT)
ch->flags &= ~XECUTED;
}
}
}
/*
* Check for state-pipe presence
*/
int check_pipe(int fd)
{
struct timeval t;
fd_set s;
char signature[8];
FD_ZERO(&s);
FD_SET(fd, &s);
t.tv_sec = t.tv_usec = 0;
if (select(fd+1, &s, NULL, NULL, &t) != 1)
return 0;
if (read(fd, signature, 8) != 8)
return 0;
return strncmp(Signature, signature, 8) == 0;
}
/*
* Make a state-pipe.
*/
int make_pipe(int fd)
{
int fds[2];
pipe(fds);
dup2(fds[0], fd);
close(fds[0]);
fcntl(fds[1], F_SETFD, 1);
fcntl(fd, F_SETFD, 0);
write(fds[1], Signature, 8);
return fds[1];
}
/*
* Attempt to re-exec.
*/
void re_exec(void)
{
CHILD *ch;
sigset_t mask, oldset;
pid_t pid;
char **env;
int fd;
if (strchr("S0123456",runlevel) == NULL)
return;
/*
* Reset the alarm, and block all signals.
*/
alarm(0);
sigfillset(&mask);
sigprocmask(SIG_BLOCK, &mask, &oldset);
/*
* construct a pipe fd --> STATE_PIPE and write a signature
*/
fd = make_pipe(STATE_PIPE);
/*
* It's a backup day today, so I'm pissed off. Being a BOFH, however,
* does have it's advantages...
*/
fail_cancel();
close(pipe_fd);
pipe_fd = -1;
DELSET(got_signals, SIGCHLD);
DELSET(got_signals, SIGHUP);
DELSET(got_signals, SIGUSR1);
/*
* That should be cleaned.
*/
for(ch = family; ch; ch = ch->next)
if (ch->flags & ZOMBIE) {
INITDBG(L_VB, "Child died, PID= %d", ch->pid);
ch->flags &= ~(RUNNING|ZOMBIE|WAITING);
if (ch->process[0] != '+')
write_utmp_wtmp("", ch->id, ch->pid, DEAD_PROCESS, NULL);
}
if ((pid = fork()) == 0) {
/*
* Child sends state information to the parent.
*/
send_state(fd);
exit(0);
}
/*
* The existing init process execs a new init binary.
*/
env = init_buildenv(0);
execle(myname, myname, "--init", NULL, env);
/*
* We shouldn't be here, something failed.
* Bitch, close the state pipe, unblock signals and return.
*/
close(fd);
close(STATE_PIPE);
sigprocmask(SIG_SETMASK, &oldset, NULL);
init_freeenv(env);
initlog(L_CO, "Attempt to re-exec failed");
}
/*
* Redo utmp/wtmp entries if required or requested
* Check for written records and size of utmp
*/
static
void redo_utmp_wtmp(void)
{
struct stat ustat;
const int ret = stat(UTMP_FILE, &ustat);
if ((ret < 0) || (ustat.st_size == 0))
wrote_utmp_rlevel = wrote_utmp_reboot = 0;
if ((wrote_wtmp_reboot == 0) || (wrote_utmp_reboot == 0))
write_utmp_wtmp("reboot", "~~", 0, BOOT_TIME, "~");
if ((wrote_wtmp_rlevel == 0) || (wrote_wtmp_rlevel == 0))
write_utmp_wtmp("runlevel", "~~", thislevel + 256 * prevlevel, RUN_LVL, "~");
}
/*
* We got a change runlevel request through the
* init.fifo. Process it.
*/
void fifo_new_level(int level)
{
#if CHANGE_WAIT
CHILD *ch;
#endif
int oldlevel;
if (level == runlevel) return;
#if CHANGE_WAIT
/* Are we waiting for a child? */
for(ch = family; ch; ch = ch->next)
if (ch->flags & WAITING) break;
if (ch == NULL)
#endif
{
/* We need to go into a new runlevel */
oldlevel = runlevel;
runlevel = read_level(level);
if (runlevel == 'U') {
runlevel = oldlevel;
re_exec();
} else {
if (oldlevel != 'S' && runlevel == 'S') console_stty();
if (runlevel == '6' || runlevel == '0' ||
runlevel == '1') console_stty();
if (runlevel > '1' && runlevel < '6') redo_utmp_wtmp();
read_inittab();
fail_cancel();
setproctitle("init [%c]", runlevel);
}
}
}
/*
* Set/unset environment variables. The variables are
* encoded as KEY=VAL\0KEY=VAL\0\0. With "=VAL" it means
* setenv, without it means unsetenv.
*/
void initcmd_setenv(char *data, int size)
{
char *env, *p, *e, *eq;
int i, sz;
e = data + size;
while (*data && data < e) {
eq = NULL;
for (p = data; *p && p < e; p++)
if (*p == '=') eq = p;
if (*p) break;
env = data;
data = ++p;
sz = eq ? (eq - env) : (p - env);
/*initlog(L_SY, "init_setenv: %s, %s, %d", env, eq, sz);*/
/*
* We only allow INIT_* to be set.
*/
if (strncmp(env, "INIT_", 5) != 0)
continue;
/* Free existing vars. */
for (i = 0; i < NR_EXTRA_ENV; i++) {
if (extra_env[i] == NULL) continue;
if (!strncmp(extra_env[i], env, sz) &&
extra_env[i][sz] == '=') {
free(extra_env[i]);
extra_env[i] = NULL;
}
}
/* Set new vars if needed. */
if (eq == NULL) continue;
for (i = 0; i < NR_EXTRA_ENV; i++) {
if (extra_env[i] == NULL) {
extra_env[i] = istrdup(env);
break;
}
}
}
}
/*
* Read from the init FIFO. Processes like telnetd and rlogind can
* ask us to create login processes on their behalf.
*
* FIXME: this needs to be finished. NOT that it is buggy, but we need
* to add the telnetd/rlogind stuff so people can start using it.
* Maybe move to using an AF_UNIX socket so we can use
* the 2.2 kernel credential stuff to see who we're talking to.
*
*/
void check_init_fifo(void)
{
struct init_request request;
struct timeval tv;
struct stat st, st2;
fd_set fds;
int n;
int quit = 0;
/*
* First, try to create /dev/initctl if not present.
*/
if (stat(INIT_FIFO, &st2) < 0 && errno == ENOENT)
(void)mkfifo(INIT_FIFO, 0600);
/*
* If /dev/initctl is open, stat the file to see if it
* is still the _same_ inode.
*/
if (pipe_fd >= 0) {
fstat(pipe_fd, &st);
if (stat(INIT_FIFO, &st2) < 0 ||
st.st_dev != st2.st_dev ||
st.st_ino != st2.st_ino) {
close(pipe_fd);
pipe_fd = -1;
}
}
/*
* Now finally try to open /dev/initctl
*/
if (pipe_fd < 0) {
if ((pipe_fd = open(INIT_FIFO, O_RDWR|O_NONBLOCK)) >= 0) {
fstat(pipe_fd, &st);
if (!S_ISFIFO(st.st_mode)) {
initlog(L_VB, "%s is not a fifo", INIT_FIFO);
close(pipe_fd);
pipe_fd = -1;
}
}
if (pipe_fd >= 0) {
/*
* Don't use fd's 0, 1 or 2.
*/
(void) dup2(pipe_fd, PIPE_FD);
close(pipe_fd);
pipe_fd = PIPE_FD;
/*
* Return to caller - we'll be back later.
*/
}
}
/* Wait for data to appear, _if_ the pipe was opened. */
if (pipe_fd >= 0) while(!quit) {
/* Do select, return on EINTR. */
FD_ZERO(&fds);
FD_SET(pipe_fd, &fds);
tv.tv_sec = 5;
tv.tv_usec = 0;
n = select(pipe_fd + 1, &fds, NULL, NULL, &tv);
if (n <= 0) {
if (n == 0 || errno == EINTR) return;
continue;
}
/* Read the data, return on EINTR. */
n = read(pipe_fd, &request, sizeof(request));
if (n == 0) {
/*
* End of file. This can't happen under Linux (because
* the pipe is opened O_RDWR - see select() in the
* kernel) but you never know...
*/
close(pipe_fd);
pipe_fd = -1;
return;
}
if (n <= 0) {
if (errno == EINTR) return;
initlog(L_VB, "error reading initrequest");
continue;
}
/*
* This is a convenient point to also try to
* find the console device or check if it changed.
*/
console_init();
/*
* Process request.
*/
if (request.magic != INIT_MAGIC || n != sizeof(request)) {
initlog(L_VB, "got bogus initrequest");
continue;
}
switch(request.cmd) {
case INIT_CMD_RUNLVL:
sltime = request.sleeptime;
fifo_new_level(request.runlevel);
quit = 1;
break;
case INIT_CMD_POWERFAIL:
sltime = request.sleeptime;
do_power_fail('F');
quit = 1;
break;
case INIT_CMD_POWERFAILNOW:
sltime = request.sleeptime;
do_power_fail('L');
quit = 1;
break;
case INIT_CMD_POWEROK:
sltime = request.sleeptime;
do_power_fail('O');
quit = 1;
break;
case INIT_CMD_SETENV:
initcmd_setenv(request.i.data, sizeof(request.i.data));
break;
default:
initlog(L_VB, "got unimplemented initrequest.");
break;
}
}
/*
* We come here if the pipe couldn't be opened.
*/
if (pipe_fd < 0) pause();
}
/*
* This function is used in the transition
* sysinit (-> single user) boot -> multi-user.
*/
void boot_transitions()
{
CHILD *ch;
static int newlevel = 0;
static int warn = 1;
int loglevel;
int oldlevel;
/* Check if there is something to wait for! */
for( ch = family; ch; ch = ch->next )
if ((ch->flags & RUNNING) && ch->action != BOOT) break;
if (ch == NULL) {
/* No processes left in this level, proceed to next level. */
loglevel = -1;
oldlevel = 'N';
switch(runlevel) {
case '#': /* SYSINIT -> BOOT */
INITDBG(L_VB, "SYSINIT -> BOOT");
/* Write a boot record. */
wrote_utmp_reboot = 0;
wrote_wtmp_reboot = 0;
write_utmp_wtmp("reboot", "~~", 0, BOOT_TIME, "~");
/* Get our run level */
newlevel = dfl_level ? dfl_level : get_init_default();
if (newlevel == 'S') {
runlevel = newlevel;
/* Not really 'S' but show anyway. */
setproctitle("init [S]");
} else
runlevel = '*';
break;
case '*': /* BOOT -> NORMAL */
INITDBG(L_VB, "BOOT -> NORMAL");
if (runlevel != newlevel)
loglevel = newlevel;
runlevel = newlevel;
did_boot = 1;
warn = 1;
break;
case 'S': /* Ended SU mode */
case 's':
INITDBG(L_VB, "END SU MODE");
newlevel = get_init_default();
if (!did_boot && newlevel != 'S')
runlevel = '*';
else {
if (runlevel != newlevel)
loglevel = newlevel;
runlevel = newlevel;
oldlevel = 'S';
}
warn = 1;
for(ch = family; ch; ch = ch->next)
if (strcmp(ch->rlevel, "S") == 0)
ch->flags &= ~(FAILING|WAITING|XECUTED);
break;
default:
if (warn)
initlog(L_VB,
"no more processes left in this runlevel");
warn = 0;
loglevel = -1;
if (got_signals == 0)
check_init_fifo();
break;
}
if (loglevel > 0) {
initlog(L_VB, "Entering runlevel: %c", runlevel);
wrote_utmp_rlevel = 0;
wrote_wtmp_rlevel = 0;
write_utmp_wtmp("runlevel", "~~", runlevel + 256 * oldlevel, RUN_LVL, "~");
thislevel = runlevel;
prevlevel = oldlevel;
setproctitle("init [%c]", runlevel);
}
}
}
/*
* Init got hit by a signal. See which signal it is,
* and act accordingly.
*/
void process_signals()
{
CHILD *ch;
int pwrstat;
int oldlevel;
int fd;
char c;
if (ISMEMBER(got_signals, SIGPWR)) {
INITDBG(L_VB, "got SIGPWR");
/* See _what_ kind of SIGPWR this is. */
pwrstat = 0;
if ((fd = open(PWRSTAT, O_RDONLY)) >= 0) {
c = 0;
read(fd, &c, 1);
pwrstat = c;
close(fd);
unlink(PWRSTAT);
}
do_power_fail(pwrstat);
DELSET(got_signals, SIGPWR);
}
if (ISMEMBER(got_signals, SIGINT)) {
INITDBG(L_VB, "got SIGINT");
/* Tell ctrlaltdel entry to start up */
for(ch = family; ch; ch = ch->next)
if (ch->action == CTRLALTDEL)
ch->flags &= ~XECUTED;
DELSET(got_signals, SIGINT);
}
if (ISMEMBER(got_signals, SIGWINCH)) {
INITDBG(L_VB, "got SIGWINCH");
/* Tell kbrequest entry to start up */
for(ch = family; ch; ch = ch->next)
if (ch->action == KBREQUEST)
ch->flags &= ~XECUTED;
DELSET(got_signals, SIGWINCH);
}
if (ISMEMBER(got_signals, SIGALRM)) {
INITDBG(L_VB, "got SIGALRM");
/* The timer went off: check it out */
DELSET(got_signals, SIGALRM);
}
if (ISMEMBER(got_signals, SIGCHLD)) {
INITDBG(L_VB, "got SIGCHLD");
/* First set flag to 0 */
DELSET(got_signals, SIGCHLD);
/* See which child this was */
for(ch = family; ch; ch = ch->next)
if (ch->flags & ZOMBIE) {
INITDBG(L_VB, "Child died, PID= %d", ch->pid);
ch->flags &= ~(RUNNING|ZOMBIE|WAITING);
if (ch->process[0] != '+')
write_utmp_wtmp("", ch->id, ch->pid, DEAD_PROCESS, NULL);
}
}
if (ISMEMBER(got_signals, SIGHUP)) {
INITDBG(L_VB, "got SIGHUP");
#if CHANGE_WAIT
/* Are we waiting for a child? */
for(ch = family; ch; ch = ch->next)
if (ch->flags & WAITING) break;
if (ch == NULL)
#endif
{
/* We need to go into a new runlevel */
oldlevel = runlevel;
#ifdef INITLVL
runlevel = read_level(0);
#endif
if (runlevel == 'U') {
runlevel = oldlevel;
re_exec();
} else {
if (oldlevel != 'S' && runlevel == 'S') console_stty();
if (runlevel == '6' || runlevel == '0' ||
runlevel == '1') console_stty();
read_inittab();
fail_cancel();
setproctitle("init [%c]", runlevel);
DELSET(got_signals, SIGHUP);
}
}
}
if (ISMEMBER(got_signals, SIGUSR1)) {
/*
* SIGUSR1 means close and reopen /dev/initctl
*/
INITDBG(L_VB, "got SIGUSR1");
close(pipe_fd);
pipe_fd = -1;
DELSET(got_signals, SIGUSR1);
}
}
/*
* The main loop
*/
int init_main()
{
CHILD *ch;
struct sigaction sa;
sigset_t sgt;
pid_t rc;
int f, st;
if (!reload) {
#if INITDEBUG
/*
* Fork so we can debug the init process.
*/
if ((f = fork()) > 0) {
static const char killmsg[] = "PRNT: init killed.\r\n";
pid_t rc;
while((rc = wait(&st)) != f)
if (rc < 0 && errno == ECHILD)
break;
write(1, killmsg, sizeof(killmsg) - 1);
while(1) pause();
}
#endif
#ifdef __linux__
/*
* Tell the kernel to send us SIGINT when CTRL-ALT-DEL
* is pressed, and that we want to handle keyboard signals.
*/
init_reboot(BMAGIC_SOFT);
if ((f = open(VT_MASTER, O_RDWR | O_NOCTTY)) >= 0) {
(void) ioctl(f, KDSIGACCEPT, SIGWINCH);
close(f);
} else
(void) ioctl(0, KDSIGACCEPT, SIGWINCH);
#endif
/*
* Ignore all signals.
*/
for(f = 1; f <= NSIG; f++)
SETSIG(sa, f, SIG_IGN, SA_RESTART);
}
SETSIG(sa, SIGALRM, signal_handler, 0);
SETSIG(sa, SIGHUP, signal_handler, 0);
SETSIG(sa, SIGINT, signal_handler, 0);
SETSIG(sa, SIGCHLD, chld_handler, SA_RESTART);
SETSIG(sa, SIGPWR, signal_handler, 0);
SETSIG(sa, SIGWINCH, signal_handler, 0);
SETSIG(sa, SIGUSR1, signal_handler, 0);
SETSIG(sa, SIGSTOP, stop_handler, SA_RESTART);
SETSIG(sa, SIGTSTP, stop_handler, SA_RESTART);
SETSIG(sa, SIGCONT, cont_handler, SA_RESTART);
SETSIG(sa, SIGSEGV, (void (*)(int))segv_handler, SA_RESTART);
console_init();
if (!reload) {
int fd;
/* Close whatever files are open, and reset the console. */
close(0);
close(1);
close(2);
console_stty();
setsid();
/*
* Set default PATH variable.
*/
setenv("PATH", PATH_DEFAULT, 1 /* Overwrite */);
/*
* Initialize /var/run/utmp (only works if /var is on
* root and mounted rw)
*/
if ((fd = open(UTMP_FILE, O_WRONLY|O_CREAT|O_TRUNC, 0644)) >= 0)
close(fd);
/*
* Say hello to the world
*/
initlog(L_CO, bootmsg, "booting");
/*
* See if we have to start an emergency shell.
*/
if (emerg_shell) {
SETSIG(sa, SIGCHLD, SIG_DFL, SA_RESTART);
if (spawn(&ch_emerg, &f) > 0) {
while((rc = wait(&st)) != f)
if (rc < 0 && errno == ECHILD)
break;
}
SETSIG(sa, SIGCHLD, chld_handler, SA_RESTART);
}
/*
* Start normal boot procedure.
*/
runlevel = '#';
read_inittab();
} else {
/*
* Restart: unblock signals and let the show go on
*/
initlog(L_CO, bootmsg, "reloading");
sigfillset(&sgt);
sigprocmask(SIG_UNBLOCK, &sgt, NULL);
/*
* Set default PATH variable.
*/
setenv("PATH", PATH_DEFAULT, 0 /* Don't overwrite */);
}
start_if_needed();
while(1) {
/* See if we need to make the boot transitions. */
boot_transitions();
INITDBG(L_VB, "init_main: waiting..");
/* Check if there are processes to be waited on. */
for(ch = family; ch; ch = ch->next)
if ((ch->flags & RUNNING) && ch->action != BOOT) break;
#if CHANGE_WAIT
/* Wait until we get hit by some signal. */
while (ch != NULL && got_signals == 0) {
if (ISMEMBER(got_signals, SIGHUP)) {
/* See if there are processes to be waited on. */
for(ch = family; ch; ch = ch->next)
if (ch->flags & WAITING) break;
}
if (ch != NULL) check_init_fifo();
}
#else /* CHANGE_WAIT */
if (ch != NULL && got_signals == 0) check_init_fifo();
#endif /* CHANGE_WAIT */
/* Check the 'failing' flags */
fail_check();
/* Process any signals. */
process_signals();
/* See what we need to start up (again) */
start_if_needed();
}
/*NOTREACHED*/
}
/*
* Tell the user about the syntax we expect.
*/
void usage(char *s)
{
fprintf(stderr, "Usage: %s {-e VAR[=VAL] | [-t SECONDS] {0|1|2|3|4|5|6|S|s|Q|q|A|a|B|b|C|c|U|u}}\n", s);
exit(1);
}
int telinit(char *progname, int argc, char **argv)
{
#ifdef TELINIT_USES_INITLVL
FILE *fp;
#endif
struct init_request request;
struct sigaction sa;
int f, fd, l;
char *env = NULL;
memset(&request, 0, sizeof(request));
request.magic = INIT_MAGIC;
while ((f = getopt(argc, argv, "t:e:")) != EOF) switch(f) {
case 't':
sltime = atoi(optarg);
break;
case 'e':
if (env == NULL)
env = request.i.data;
l = strlen(optarg);
if (env + l + 2 > request.i.data + sizeof(request.i.data)) {
fprintf(stderr, "%s: -e option data "
"too large\n", progname);
exit(1);
}
memcpy(env, optarg, l);
env += l;
*env++ = 0;
break;
default:
usage(progname);
break;
}
if (env) *env++ = 0;
if (env) {
if (argc != optind)
usage(progname);
request.cmd = INIT_CMD_SETENV;
} else {
if (argc - optind != 1 || strlen(argv[optind]) != 1)
usage(progname);
if (!strchr("0123456789SsQqAaBbCcUu", argv[optind][0]))
usage(progname);
request.cmd = INIT_CMD_RUNLVL;
request.runlevel = env ? 0 : argv[optind][0];
request.sleeptime = sltime;
}
/* Open the fifo and write a command. */
/* Make sure we don't hang on opening /dev/initctl */
SETSIG(sa, SIGALRM, signal_handler, 0);
alarm(3);
if ((fd = open(INIT_FIFO, O_WRONLY)) >= 0 &&
write(fd, &request, sizeof(request)) == sizeof(request)) {
close(fd);
alarm(0);
return 0;
}
#ifdef TELINIT_USES_INITLVL
if (request.cmd == INIT_CMD_RUNLVL) {
/* Fallthrough to the old method. */
/* Now write the new runlevel. */
if ((fp = fopen(INITLVL, "w")) == NULL) {
fprintf(stderr, "%s: cannot create %s\n",
progname, INITLVL);
exit(1);
}
fprintf(fp, "%s %d", argv[optind], sltime);
fclose(fp);
/* And tell init about the pending runlevel change. */
if (kill(INITPID, SIGHUP) < 0) perror(progname);
return 0;
}
#endif
fprintf(stderr, "%s: ", progname);
if (ISMEMBER(got_signals, SIGALRM)) {
fprintf(stderr, "timeout opening/writing control channel %s\n",
INIT_FIFO);
} else {
perror(INIT_FIFO);
}
return 1;
}
/*
* Main entry for init and telinit.
*/
int main(int argc, char **argv)
{
char *p;
int f;
int isinit;
#ifdef WITH_SELINUX
int enforce = 0;
#endif
/* Get my own name */
if ((p = strrchr(argv[0], '/')) != NULL)
p++;
else
p = argv[0];
umask(022);
/* Quick check */
if (geteuid() != 0) {
fprintf(stderr, "%s: must be superuser.\n", p);
exit(1);
}
/*
* Is this telinit or init ?
*/
isinit = (getpid() == 1);
for (f = 1; f < argc; f++) {
if (!strcmp(argv[f], "-i") || !strcmp(argv[f], "--init")) {
isinit = 1;
break;
}
}
if (!isinit) exit(telinit(p, argc, argv));
/*
* Check for re-exec
*/
if (check_pipe(STATE_PIPE)) {
receive_state(STATE_PIPE);
myname = istrdup(argv[0]);
argv0 = argv[0];
maxproclen = 0;
for (f = 0; f < argc; f++)
maxproclen += strlen(argv[f]) + 1;
reload = 1;
setproctitle("init [%c]",runlevel);
init_main();
}
/* Check command line arguments */
maxproclen = strlen(argv[0]) + 1;
for(f = 1; f < argc; f++) {
if (!strcmp(argv[f], "single") || !strcmp(argv[f], "-s"))
dfl_level = 'S';
else if (!strcmp(argv[f], "-a") || !strcmp(argv[f], "auto"))
putenv("AUTOBOOT=YES");
else if (!strcmp(argv[f], "-b") || !strcmp(argv[f],"emergency"))
emerg_shell = 1;
else if (!strcmp(argv[f], "-z")) {
/* Ignore -z xxx */
if (argv[f + 1]) f++;
} else if (strchr("0123456789sS", argv[f][0])
&& strlen(argv[f]) == 1)
dfl_level = argv[f][0];
/* "init u" in the very beginning makes no sense */
if (dfl_level == 's') dfl_level = 'S';
maxproclen += strlen(argv[f]) + 1;
}
#ifdef WITH_SELINUX
if (getenv("SELINUX_INIT") == NULL && !is_selinux_enabled()) {
putenv("SELINUX_INIT=YES");
if (selinux_init_load_policy(&enforce) == 0 ) {
execv(myname, argv);
} else {
if (enforce > 0) {
/* SELinux in enforcing mode but load_policy failed */
/* At this point, we probably can't open /dev/console, so log() won't work */
fprintf(stderr,"Unable to load SELinux Policy. Machine is in enforcing mode. Halting now.\n");
exit(1);
}
}
}
#endif
/* Start booting. */
argv0 = argv[0];
argv[1] = NULL;
setproctitle("init boot");
init_main(dfl_level);
/*NOTREACHED*/
return 0;
}
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