4.4BSD/usr/src/old/init/init.c
/*
* Copyright (c) 1980,1986 Regents of the University of California.
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*/
#ifndef lint
static char sccsid[] = "@(#)init.c 5.19 (Berkeley) 3/25/91";
#endif not lint
#include <sys/types.h>
#include <sys/file.h>
#include <sys/signal.h>
#include <sys/reboot.h>
#include <sys/syslog.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <setjmp.h>
#include <utmp.h>
#include <errno.h>
#include <ttyent.h>
#include "pathnames.h"
#define CMDSIZ 200 /* max string length for getty or window command*/
#define ALL p = itab; p ; p = p->next
#define EVER ;;
#define SCPYN(a, b) strncpy(a, b, sizeof(a))
#define SCMPN(a, b) strncmp(a, b, sizeof(a))
char shell[] = _PATH_BSHELL;
char minus[] = "-";
char runc[] = _PATH_RC;
char ctty[] = _PATH_CONSOLE;
struct tab
{
char line[UT_LINESIZE];
char comn[CMDSIZ];
char xflag;
int pid;
int wpid; /* window system pid for SIGHUP */
char wcmd[CMDSIZ]; /* command to start window system process */
time_t gettytime;
int gettycnt;
time_t windtime;
int windcnt;
struct tab *next;
} *itab;
int fi;
int mergflag;
char tty[20];
jmp_buf sjbuf, shutpass;
char *strcpy(), *strcat();
long lseek();
void idle(), merge(), reset();
struct sigvec rvec = { reset, sigmask(SIGHUP), 0 };
main(argc, argv)
char **argv;
{
/* insure proper semantics for setjmp/longjmp */
static int howto, oldhowto, started = 0;
#if defined(tahoe)
register int r12; /* make sure r11 gets bootflags */
#endif
#if defined(vax) || defined(tahoe) || defined(hp300)
/* howto passed in high-order register XXX */
register int r11; /* passed thru from boot */
#ifdef __GNUC__
#ifdef hp300
asm("movl d7,%0" : "=rm" (howto));
#else
asm("movl r11,%0" : "=rm" (howto));
#endif
#else
howto = r11;
#endif /* __GNUC__ */
#else /* vax || tahoe || hp300 */
/* howto passed as argument */
howto = 0;
#endif /* ! (vax || tahoe || hp300) */
/*
* We expect a single options argument from the kernel.
* If it is present, we ignore anything in registers from above.
*/
if (argc > 1 && argv[1][0] == '-') {
char *cp;
howto = 0;
cp = &argv[1][1];
while (*cp) switch (*cp++) {
#ifdef notyet
case 'f':
howto |= RB_FASTBOOT;
break;
#endif
case 's':
howto |= RB_SINGLE;
break;
}
}
if (getuid() != 0)
exit(1);
openlog("init", LOG_CONS|LOG_ODELAY, LOG_AUTH);
if (setsid() < 0)
syslog(LOG_ERR, "setsid failed (initial) %m");
sigvec(SIGTERM, &rvec, (struct sigvec *)0);
signal(SIGTSTP, idle);
signal(SIGTTIN, SIG_IGN);
signal(SIGTTOU, SIG_IGN);
(void) setjmp(sjbuf);
for (; ; ) {
oldhowto = howto;
howto = RB_SINGLE;
if (started && setjmp(shutpass) == 0)
shutdown();
started = 1;
if (oldhowto & RB_SINGLE)
single();
if (runcom(oldhowto) == 0)
continue;
merge();
multiple();
}
}
void shutreset();
shutdown()
{
register i;
register struct tab *p, *p1;
signal(SIGHUP, SIG_IGN);
for (p = itab; p ; ) {
term(p);
p1 = p->next;
free(p);
p = p1;
}
itab = (struct tab *)0;
signal(SIGALRM, shutreset);
(void) kill(-1, SIGTERM); /* one chance to catch it */
sleep(5);
alarm(30);
for (i = 0; i < 5; i++)
kill(-1, SIGKILL);
while (wait((int *)0) != -1)
;
alarm(0);
shutend();
}
char shutfailm[] = "init: WARNING: something is hung (won't die); ps axl advised\n";
void
shutreset()
{
int status;
if (fork() == 0) {
int ct = open(ctty, 1);
write(ct, shutfailm, sizeof (shutfailm));
sleep(5);
exit(1);
}
sleep(5);
shutend();
longjmp(shutpass, 1);
}
shutend()
{
register i;
acct(0);
signal(SIGALRM, SIG_DFL);
for (i = 0; i < 10; i++)
close(i);
logwtmp("~", "shutdown", "");
}
single()
{
register pid;
register xpid;
int fd;
extern int errno;
do {
pid = fork();
if (pid == 0) {
signal(SIGTERM, SIG_DFL);
signal(SIGHUP, SIG_DFL);
signal(SIGALRM, SIG_DFL);
signal(SIGTSTP, SIG_IGN);
if (setsid() < 0)
syslog(LOG_ERR, "setsid failed (single): %m");
(void) revoke(ctty);
if ((fd = open(ctty, O_RDWR)) < 0) {
syslog(LOG_ERR, "open %s: %m", ctty);
exit(1);
}
if (ioctl(fd, TIOCSCTTY, 0) < 0)
syslog(LOG_ERR, "TIOCSCTTY failed: %m");
dup2(fd, 0);
dup2(fd, 1);
dup2(fd, 2);
if (fd > 2)
close(fd);
execl(shell, minus, (char *)0);
perror(shell);
exit(0);
}
while ((xpid = wait((int *)0)) != pid)
if (xpid == -1 && errno == ECHILD)
break;
} while (xpid == -1);
}
runcom(oldhowto)
int oldhowto;
{
register pid;
int fd, status;
pid = fork();
if (pid == 0) {
signal(SIGTSTP, SIG_IGN);
signal(SIGHUP, SIG_IGN);
if ((fd = open(ctty, O_RDWR)) < 0)
syslog(LOG_ERR, "open %s: %m", ctty);
else {
dup2(fd, 0);
dup2(fd, 1);
dup2(fd, 2);
if (fd > 2)
close(fd);
}
if (setsid() < 0)
syslog(LOG_ERR, "setsid failed (runcom) %m");
if (ioctl(0, TIOCSCTTY, 0) < 0)
syslog(LOG_ERR, "TIOCSCTTY failed (runcom) %m");
if (oldhowto & RB_SINGLE)
execl(shell, shell, runc, (char *)0);
else
execl(shell, shell, runc, "autoboot", (char *)0);
exit(1);
}
while (wait(&status) != pid)
;
if (status)
return (0);
logwtmp("~", "reboot", "");
return (1);
}
struct sigvec mvec = { merge, sigmask(SIGTERM), 0 };
/*
* Multi-user. Listen for users leaving, SIGHUP's
* which indicate ttys has changed, and SIGTERM's which
* are used to shutdown the system.
*/
multiple()
{
extern int errno;
register struct tab *p;
register pid;
int omask;
sigvec(SIGHUP, &mvec, (struct sigvec *)0);
for (EVER) {
pid = wait((int *)0);
/* SHOULD FIX THIS IN THE KERNEL */
if (pid == -1 && errno != EINTR)
return;
omask = sigblock(sigmask(SIGHUP));
for (ALL) {
/* must restart window system BEFORE emulator */
if (p->wpid == pid || p->wpid == -1)
wstart(p);
if (p->pid == pid || p->pid == -1) {
/* disown the window system */
if (p->wpid)
kill(p->wpid, SIGHUP);
cleanutmp(p);
dfork(p);
}
}
sigsetmask(omask);
}
}
/*
* Merge current contents of ttys file
* into in-core table of configured tty lines.
* Entered as signal handler for SIGHUP.
*/
#define FOUND 1
#define CHANGE 2
#define WCHANGE 4
void
merge()
{
register struct tab *p;
register struct ttyent *t;
register struct tab *p1;
for (ALL)
p->xflag = 0;
setttyent();
while (t = getttyent()) {
if ((t->ty_status & TTY_ON) == 0)
continue;
for (ALL) {
if (SCMPN(p->line, t->ty_name))
continue;
p->xflag |= FOUND;
if (SCMPN(p->comn, t->ty_getty)) {
p->xflag |= CHANGE;
SCPYN(p->comn, t->ty_getty);
}
if (SCMPN(p->wcmd, t->ty_window ? t->ty_window : "")) {
p->xflag |= WCHANGE|CHANGE;
SCPYN(p->wcmd, t->ty_window);
}
goto contin1;
}
/*
* Make space for a new one
*/
p1 = (struct tab *)calloc(1, sizeof(*p1));
if (!p1) {
syslog(LOG_ERR, "no space for '%s' !?!", t->ty_name);
goto contin1;
}
/*
* Put new terminal at the end of the linked list.
*/
if (itab) {
for (p = itab; p->next ; p = p->next)
;
p->next = p1;
} else
itab = p1;
p = p1;
SCPYN(p->line, t->ty_name);
p->xflag |= FOUND|CHANGE;
SCPYN(p->comn, t->ty_getty);
if (t->ty_window && strcmp(t->ty_window, "") != 0) {
p->xflag |= WCHANGE;
SCPYN(p->wcmd, t->ty_window);
}
contin1:
;
}
endttyent();
p1 = (struct tab *)0;
for (ALL) {
if ((p->xflag&FOUND) == 0) {
term(p);
wterm(p);
if (p1)
p1->next = p->next;
else
itab = p->next;
free(p);
p = p1 ? p1 : itab;
} else {
/* window system should be started first */
if (p->xflag&WCHANGE) {
wterm(p);
wstart(p);
}
if (p->xflag&CHANGE) {
term(p);
dfork(p);
}
}
p1 = p;
}
}
term(p)
register struct tab *p;
{
if (p->pid != 0) {
cleanutmp(p);
kill(p->pid, SIGKILL);
}
p->pid = 0;
/* send SIGHUP to get rid of connections */
if (p->wpid > 0)
kill(p->wpid, SIGHUP);
}
dfork(p)
struct tab *p;
{
register pid;
time_t t;
int dowait = 0;
time(&t);
p->gettycnt++;
if ((t - p->gettytime) >= 60) {
p->gettytime = t;
p->gettycnt = 1;
} else if (p->gettycnt >= 5) {
dowait = 1;
p->gettytime = t;
p->gettycnt = 1;
}
pid = fork();
if (pid == 0) {
signal(SIGTERM, SIG_DFL);
signal(SIGHUP, SIG_IGN);
sigsetmask(0); /* since can be called from masked code */
if (dowait) {
syslog(LOG_ERR, "'%s %s' failing, sleeping", p->comn, p->line);
closelog();
sleep(30);
}
if (setsid() < 0)
syslog(LOG_ERR, "setsid failed(dfork) %m");
execit(p->comn, p->line);
exit(0);
}
p->pid = pid;
}
cleanutmp(p)
register struct tab *p;
{
if (logout(p->line)) {
logwtmp(p->line, "", "");
/*
* After a proper login force reset
* of error detection code in dfork.
*/
p->gettytime = 0;
p->windtime = 0;
}
}
void
reset()
{
longjmp(sjbuf, 1);
}
jmp_buf idlebuf;
void
idlehup()
{
longjmp(idlebuf, 1);
}
void
idle()
{
register struct tab *p;
register pid;
signal(SIGHUP, idlehup);
for (EVER) {
if (setjmp(idlebuf))
return;
pid = wait((int *) 0);
if (pid == -1) {
sigpause(0);
continue;
}
for (ALL) {
/* if window system dies, mark it for restart */
if (p->wpid == pid)
p->wpid = -1;
if (p->pid == pid) {
cleanutmp(p);
p->pid = -1;
}
}
}
}
wterm(p)
register struct tab *p;
{
if (p->wpid != 0) {
kill(p->wpid, SIGKILL);
}
p->wpid = 0;
}
wstart(p)
register struct tab *p;
{
register pid;
time_t t;
int dowait = 0;
time(&t);
p->windcnt++;
if ((t - p->windtime) >= 60) {
p->windtime = t;
p->windcnt = 1;
} else if (p->windcnt >= 5) {
dowait = 1;
p->windtime = t;
p->windcnt = 1;
}
pid = fork();
if (pid == 0) {
signal(SIGTERM, SIG_DFL);
signal(SIGHUP, SIG_IGN);
sigsetmask(0); /* since can be called from masked code */
if (dowait) {
syslog(LOG_ERR, "'%s %s' failing, sleeping", p->wcmd, p->line);
closelog();
sleep(30);
}
if (setsid() < 0)
syslog(LOG_ERR, "setsid failed (window) %m");
execit(p->wcmd, p->line);
exit(0);
}
p->wpid = pid;
}
#define NARGS 20 /* must be at least 4 */
#define ARGLEN 512 /* total size for all the argument strings */
execit(s, arg)
char *s;
char *arg; /* last argument on line */
{
char *argv[NARGS], args[ARGLEN], *envp[1];
register char *sp = s;
register char *ap = args;
register char c;
register int i;
/*
* First we have to set up the argument vector.
* "prog arg1 arg2" maps to exec("prog", "-", "arg1", "arg2").
*/
for (i = 1; i < NARGS - 2; i++) {
argv[i] = ap;
for (EVER) {
if ((c = *sp++) == '\0' || ap >= &args[ARGLEN-1]) {
*ap = '\0';
goto done;
}
if (c == ' ') {
*ap++ = '\0';
while (*sp == ' ')
sp++;
if (*sp == '\0')
goto done;
break;
}
*ap++ = c;
}
}
done:
argv[0] = argv[1];
argv[1] = "-";
argv[i+1] = arg;
argv[i+2] = 0;
envp[0] = 0;
execve(argv[0], &argv[1], envp);
/* report failure of exec */
syslog(LOG_ERR, "%s: %m", argv[0]);
closelog();
sleep(10); /* prevent failures from eating machine */
}