BSD 4_1_snap release

[unix-history] / usr / src / cmd / init.c

static  char *sccsid = "@(#)init.c      4.5 (Berkeley) 4/26/81";
#include <signal.h>
#include <sys/types.h>
#include <utmp.h>
#include <setjmp.h>
#include <sys/reboot.h>
#include <errno.h>

#define LINSIZ  sizeof(wtmp.ut_line)
#define TABSIZ  100
#define ALL     p = &itab[0]; p < &itab[TABSIZ]; p++
#define EVER    ;;
#define SCPYN(a, b)     strncpy(a, b, sizeof(a))
#define SCMPN(a, b)     strncmp(a, b, sizeof(a))

char    shell[] = "/bin/sh";
char    getty[]  = "/etc/getty";
char    minus[] = "-";
char    runc[]  = "/etc/rc";
char    ifile[] = "/etc/ttys";
char    utmp[]  = "/etc/utmp";
char    wtmpf[] = "/usr/adm/wtmp";
char    ctty[]  = "/dev/console";
char    dev[]   = "/dev/";

struct utmp wtmp;
struct
{
       char    line[LINSIZ];
       char    comn;
       char    flag;
} line;
struct  tab
{
       char    line[LINSIZ];
       char    comn;
       char    xflag;
       int     pid;
} itab[TABSIZ];

int     fi;
int     mergflag;
char    tty[20];
jmp_buf sjbuf, shutpass;
time_t  time0;

int     reset();
int     idle();
char    *strcpy(), *strcat();
long    lseek();

main()
{
       register int r11;               /* passed thru from boot */
       int howto, oldhowto;

       time0 = time(0);
       howto = r11;
       setjmp(sjbuf);
       signal(SIGTERM, reset);
       signal(SIGTSTP, idle);
       signal(SIGSTOP, SIG_IGN);
       signal(SIGTTIN, SIG_IGN);
       signal(SIGTTOU, SIG_IGN);
       for(EVER) {
               oldhowto = howto;
               howto = RB_SINGLE;
               if (setjmp(shutpass) == 0)
                       shutdown();
               if (oldhowto & RB_SINGLE)
                       single();
               if (runcom(oldhowto) == 0) 
                       continue;
               merge();
               multiple();
       }
}

int     shutreset();

shutdown()
{
       register i;
       register struct tab *p;

       close(creat(utmp, 0644));
       signal(SIGHUP, SIG_IGN);
       for(ALL) {
               term(p);
               p->line[0] = 0;
       }
       signal(SIGALRM, shutreset);
       alarm(30);
       for(i=0; i<5; i++)
               kill(-1, SIGKILL);
       while(wait((int *)0) != -1)
               ;
       alarm(0);
       shutend();
}

char shutfailm[] = "WARNING: Something is hung (wont die); ps axl advised\n";

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, f;

       acct(0);
       signal(SIGALRM, SIG_DFL);
       for(i=0; i<10; i++)
               close(i);
       f = open(wtmpf, 1);
       if (f >= 0) {
               lseek(f, 0L, 2);
               SCPYN(wtmp.ut_line, "~");
               SCPYN(wtmp.ut_name, "shutdown");
               time(&wtmp.ut_time);
               write(f, (char *)&wtmp, sizeof(wtmp));
               close(f);
       }
       return(1);
}

single()
{
       register pid;
       register xpid;
       extern  errno;

  do {
       pid = fork();
       if(pid == 0) {
/*
               alarm(300);
*/
               signal(SIGTERM, SIG_DFL);
               signal(SIGHUP, SIG_DFL);
               signal(SIGALRM, SIG_DFL);
               open(ctty, 2);
               dup(0);
               dup(0);
               write(1,"System single user\n", 20);
               execl(shell, minus, (char *)0);
               exit(0);
       }
       while((xpid = wait((int *)0)) != pid)
               if (xpid == -1 && errno == ECHILD)
                       break;
  } while (xpid == -1);
}

runcom(oldhowto)
       int oldhowto;
{
       register pid, f;
       int status;

       pid = fork();
       if(pid == 0) {
               open("/", 0);
               dup(0);
               dup(0);
               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);
       f = open(wtmpf, 1);
       if (f >= 0) {
               lseek(f, 0L, 2);
               SCPYN(wtmp.ut_line, "~");
               SCPYN(wtmp.ut_name, "reboot");
               if (time0) {
                       wtmp.ut_time = time0;
                       time0 = 0;
               } else
                       time(&wtmp.ut_time);
               write(f, (char *)&wtmp, sizeof(wtmp));
               close(f);
       }
       return(1);
}

setmerge()
{

       signal(SIGHUP, setmerge);
       mergflag = 1;
}

multiple()
{
       register struct tab *p;
       register pid;

loop:
       mergflag = 0;
       signal(SIGHUP, setmerge);
       for(EVER) {
               pid = wait((int *)0);
               if(mergflag) {
                       merge();
                       goto loop;
               }
               if(pid == -1)
                       return;
               for(ALL)
                       if(p->pid == pid || p->pid == -1) {
                               rmut(p);
                               dfork(p);
                       }
       }
}

term(p)
register struct tab *p;
{

       if(p->pid != 0) {
               rmut(p);
               kill(p->pid, SIGKILL);
       }
       p->pid = 0;
}

rline()
{
       register c, i;

loop:
       c = get();
       if(c < 0)
               return(0);
       if(c == 0)
               goto loop;
       line.flag = c;
       c = get();
       if(c <= 0)
               goto loop;
       line.comn = c;
       SCPYN(line.line, "");
       for (i=0; i<LINSIZ; i++) {
               c = get();
               if(c <= 0)
                       break;
               line.line[i] = c;
       }
       while(c > 0)
               c = get();
       if(line.line[0] == 0)
               goto loop;
       if(line.flag == '0')
               goto loop;
       strcpy(tty, dev);
       strncat(tty, line.line, LINSIZ);
       if(access(tty, 06) < 0)
               goto loop;
       return(1);
}

get()
{
       char b;

       if(read(fi, &b, 1) != 1)
               return(-1);
       if(b == '\n')
               return(0);
       return(b);
}

#define FOUND   1
#define CHANGE  2

merge()
{
       register struct tab *p;

       fi = open(ifile, 0);
       if(fi < 0)
               return;
       for(ALL)
               p->xflag = 0;
       while(rline()) {
               for(ALL) {
                       if (SCMPN(p->line, line.line))
                               continue;
                       p->xflag |= FOUND;
                       if(line.comn != p->comn) {
                               p->xflag |= CHANGE;
                               p->comn = line.comn;
                       }
                       goto contin1;
               }
               for(ALL) {
                       if(p->line[0] != 0)
                               continue;
                       SCPYN(p->line, line.line);
                       p->xflag |= FOUND|CHANGE;
                       p->comn = line.comn;
                       goto contin1;
               }
       contin1:
               ;
       }
       close(fi);
       for(ALL) {
               if((p->xflag&FOUND) == 0) {
                       term(p);
                       p->line[0] = 0;
               }
               if((p->xflag&CHANGE) != 0) {
                       term(p);
                       dfork(p);
               }
       }
}

dfork(p)
struct tab *p;
{
       register pid;

       pid = fork();
       if(pid == 0) {
               signal(SIGTERM, SIG_DFL);
               signal(SIGHUP, SIG_IGN);
               strcpy(tty, dev);
               strncat(tty, p->line, LINSIZ);
               chown(tty, 0, 0);
               chmod(tty, 0622);
               if (open(tty, 2) < 0) {
                       int repcnt = 0;
                       do {
                               if (repcnt % 10 == 0) {
                                       int f = open("/dev/console", 1);
                                       write(f, "init: ", 6);
                                       write(f, tty, strlen(tty));
                                       write(f, ": cannot open\n\r", 15);
                                       close(f);
                               }
                               repcnt++;
                               sleep(60);
                       } while (open(tty, 2) < 0);
                       exit(0);        /* have wrong control tty, start over */
               }
               vhangup();
               signal(SIGHUP, SIG_DFL);
               open(tty, 2);
               close(0);
               dup(1);
               dup(0);
               tty[0] = p->comn;
               tty[1] = 0;
               execl(getty, minus, tty, (char *)0);
               exit(0);
       }
       p->pid = pid;
}

rmut(p)
register struct tab *p;
{
       register f;
       int found = 0;

       f = open(utmp, 2);
       if(f >= 0) {
               while(read(f, (char *)&wtmp, sizeof(wtmp)) == sizeof(wtmp)) {
                       if (SCMPN(wtmp.ut_line, p->line) || wtmp.ut_name[0]==0)
                               continue;
                       lseek(f, -(long)sizeof(wtmp), 1);
                       SCPYN(wtmp.ut_name, "");
                       time(&wtmp.ut_time);
                       write(f, (char *)&wtmp, sizeof(wtmp));
                       found++;
               }
               close(f);
       }
       if (found) {
               f = open(wtmpf, 1);
               if (f >= 0) {
                       SCPYN(wtmp.ut_line, p->line);
                       SCPYN(wtmp.ut_name, "");
                       time(&wtmp.ut_time);
                       lseek(f, (long)0, 2);
                       write(f, (char *)&wtmp, sizeof(wtmp));
                       close(f);
               }
       }
}

reset()
{
       longjmp(sjbuf, 1);
}

idle()
{
       register struct tab *p;
       register pid;

       signal(SIGTSTP, idle);
       for (;;) {
               pid = wait((int *) 0);
               if (mergflag)
                       return;
               if (pid == -1)
                       pause();
               else {
                       for (ALL)
                               if (p->pid == pid) {
                                       rmut(p);
                                       p->pid = -1;
                               }
               }
       }
}