ckutio.c

C语言核心协议的C语言源代码,用于早期网络通信

    longjmp(sjbuf,1);
}

 
/* Set up terminal interrupts on console terminal */

#ifdef UXIII
esctrp() {				/* trap console escapes (^\) */
    conesc = 1;
    signal(SIGQUIT,SIG_IGN);		/* ignore until trapped */
}
#endif

#ifdef V7
esctrp() {				/* trap console escapes (^\) */
    conesc = 1;
    signal(SIGQUIT,SIG_IGN);		/* ignore until trapped */
}
#endif

#ifdef C70
esctrp() {				/* trap console escapes (^\) */
    conesc = 1;
    signal(SIGQUIT,SIG_IGN);		/* ignore until trapped */
}
#endif

/*  C O N I N T  --  Console Interrupt setter  */

conint(f) int (*f)(); {			/* Set an interrupt trap. */

    if (!isatty(0)) return(0);		/* only for real ttys */
    if (backgrd) return;		/* must ignore signals in bkgrd */

/*
 Except for special cases below, ignore keyboard quit signal.
 ^\ too easily confused with connect escape, and besides, we don't want
 to leave lock files around.  (Frank Prindle)
*/
    signal(SIGQUIT,SIG_IGN);

#ifdef UXIII
    signal(SIGQUIT,esctrp);		/* console escape in pkt modes */
    if (conesc) {			/* clear out pending escapes */
	conesc = 0;
    }
#endif

#ifdef V7
    signal(SIGQUIT,esctrp);		/* console escape in pkt modes */
    if (conesc) {			/* clear out pending escapes */
	conesc = 0;
    }
#endif

    if (conif) return;			/* Nothing to do if already on. */

/* check if invoked in background -- if so signals set to be ignored */

    if (signal(SIGINT,SIG_IGN) == SIG_IGN) {
	backgrd = 1;			/*   means running in background */
#ifdef UXIII
	signal(SIGQUIT,SIG_IGN);	/*   must leave signals ignored */
#endif
#ifdef V7
	signal(SIGQUIT,SIG_IGN);	/*   must leave signals ignored */
#endif
	return;
    }
    signal(SIGINT,f);			/* Function to trap to on interrupt. */
    signal(SIGHUP,f);			/* Or hangup, so lock file cleared. */
    conif = 1;				/* Flag console interrupts on. */
}


/*  C O N N O I  --  Reset console terminal interrupts */

connoi() {				/* Console-no-interrupts */

    if (!isatty(0)) return(0);		/* only for real ttys */
    if (backgrd) return;		/* Ignore signals in background */

    signal(SIGINT,SIG_DFL);
    signal(SIGHUP,SIG_DFL);
    signal(SIGQUIT,SIG_DFL);
    conif = 0;				/* Flag interrupt trapping off */
}

/*  myread() -- For use by systems that can do nonblocking read() calls  */
/*
 Returns:
  -1  if no characters available,
  -2  upon error (such as disconnect),
  otherwise value of character (0 or greater)
*/
myread() {
    static int inbuf_item;
    static CHAR inbuf[257];
    CHAR readit;
    
    if (ungotn >= 0) {
	readit = ungotn;
    } else {
        if (inbufc > 0) {
	    readit = inbuf[++inbuf_item];
        } else {
	    if ((inbufc = read(ttyfd,inbuf,256)) == 0) {  /* end of file */
			/* means carrier dropped on modem connection */
		errno = 9999;		/* magic number for no carrier */
		return(-2);		/* end of file has no errno */
		}
	    if (inbufc < 0) {		/* Real error */
    	    	return(-2);
    	    }
	    readit = inbuf[inbuf_item = 0];
	}
        inbufc--;	
    }
    ungotn = -1;
    return(readit);
}

myunrd(ch) CHAR ch; {			/* push back up to one character */
    ungotn = ch;
}

/*  I N I T R A W Q  --  Set up to read /DEV/KMEM for character count.  */

#ifdef	V7
/*
 Used in Version 7 to simulate Berkeley's FIONREAD ioctl call.  This
 eliminates blocking on a read, because we can read /dev/kmem to get the
 number of characters available for raw input.  If your system can't
 or you won't let it read /dev/kmem (the world that is) then you must
 figure out a different way to do the counting of characters available,
 or else replace this by a dummy function that always returns 0.
*/
/*
 * Call this routine as: initrawq(tty)
 * where tty is the file descriptor of a terminal.  It will return
 * (as a char *) the kernel-mode memory address of the rawq character
 * count, which may then be read.  It has the side-effect of flushing
 * input on the terminal.
 */
/*
 * John Mackin, Physiology Dept., University of Sydney (Australia)
 * ...!decvax!mulga!physiol.su.oz!john
 *
 * Permission is hereby granted to do anything with this code, as
 * long as this comment is retained unmodified and no commercial
 * advantage is gained.
 */
#include <a.out.h>
#include <sys/proc.h>

char *initrawq(tty) int tty; {
#ifdef UTS24
    return(0);
#else
#ifdef BSD29
    return(0);
#else
    long lseek();
    static struct nlist nl[] = {
	{PROCNAME},
	{NPROCNAME},
	{""}
    };
    static struct proc *pp;
    char *malloc(), *qaddr, *p, c;
    int m, pid, me;
    NPTYPE xproc;			/* Its type is defined in makefile. */
    int catch();

    me = getpid();
    if ((m = open("/dev/kmem", 0)) < 0) err("kmem");
    nlist(BOOTNAME, nl);
    if (nl[0].n_type == 0) err("proc array");
 
    if (nl[1].n_type == 0) err("nproc");

    lseek(m, (long)(nl[1].n_value), 0);
    read (m, &xproc, sizeof(xproc));
    signal(SIGALRM, catch);
    if ((pid = fork()) == 0) {
	while(1)
	    read(tty, &c, 1);
    }
    alarm(2);
 
    if(setjmp(jjbuf) == 0) {
	while(1)
	    read(tty, &c, 1);
    }
    signal(SIGALRM, SIG_DFL);

#ifdef DIRECT
    pp = (struct proc *) nl[0].n_value;
#else 
    if (lseek(m, (long)(nl[0].n_value), 0) < 0L) err("seek");
    if (read(m, &pp, sizeof(pp)) != sizeof(pp))  err("no read of proc ptr");
#endif
    lseek(m, (long)(nl[1].n_value), 0);
    read(m, &xproc, sizeof(xproc));

    if (lseek(m, (long)pp, 0) < 0L) err("Can't seek to proc");
    if ((p = malloc(xproc * sizeof(struct proc))) == NULL) err("malloc");
    if (read(m,p,xproc * sizeof(struct proc)) != xproc*sizeof(struct proc))
    	err("read proc table");
    for (pp = (struct proc *)p; xproc > 0; --xproc, ++pp) {
	if (pp -> p_pid == (short) pid) goto iout;
    }
    err("no such proc");
 
iout:
    close(m);
    qaddr = (char *)(pp -> p_wchan);
    free (p);
    kill(pid, SIGKILL);
    wait((int *)0);		/* Destroy the ZOMBIEs! */
    return (qaddr);
#endif
#endif
}

/*  More V7-support functions...  */

static
err(s) char *s; {
    char buf[200];

    sprintf(buf, "fatal error in initrawq: %s", s);
    perror(buf);
    doexit(1);
}

static
catch() {
    longjmp(jjbuf, -1);
}


/*  G E N B R K  --  Simulate a modem break.  */

#define	BSPEED	B150

genbrk(fn) int fn; {
    struct sgttyb ttbuf;
    int ret, sospeed;

    ret = ioctl(fn, TIOCGETP, &ttbuf);
    sospeed = ttbuf.sg_ospeed;
    ttbuf.sg_ospeed = BSPEED;
    ret = ioctl(fn, TIOCSETP, &ttbuf);
    ret = write(fn, "\0\0\0\0\0\0\0\0\0\0\0\0", 8);
    ttbuf.sg_ospeed = sospeed;
    ret = ioctl(fn, TIOCSETP, &ttbuf);
    ret = write(fn, "@", 1);
    return;
}
#endif	V7

/*  T T C H K  --  Tell how many characters are waiting in tty input buffer  */

ttchk() {
    int x; long n;
#ifdef FIONREAD
    x = ioctl(ttyfd, FIONREAD, &n);	/* Berkeley and maybe some others */
    debug(F101,"ttchk","",n);
    return((x < 0) ? 0 : n);
#else
#ifdef	V7
    lseek(kmem[TTY], (long) qaddr[TTY], 0);
    x = read(kmem[TTY], &n, sizeof(int));
    return((x == sizeof(int))? n: 0);
#else	V7
#ifdef UXIII
    return(inbufc + (ungotn >= 0) );	
#else
#ifdef C70
    return(inbufc + (ungotn >= 0) );
#else
#ifdef PROVX1
    x = ioctl(ttyfd, TIOCQCNT, &ttbuf);
    n = ttbuf.sg_ispeed & 0377;
    return((x < 0) ? 0 : n);
#else
    return(0);
#endif
#endif
#endif
#endif
#endif
}


/*  T T X I N  --  Get n characters from tty input buffer  */

/*  Returns number of characters actually gotten, or -1 on failure  */

/*  Intended for use only when it is known that n characters are actually */
/*  Available in the input buffer.  */

ttxin(n,buf) int n; char *buf; {
    int x;
    CHAR c;

#ifdef MYREAD
    for( x = 0; (x > -1) && (x < n); buf[x++] = myread() );
#else
    debug(F101,"ttxin: n","",n);
    x = read(ttyfd,buf,n);
    debug(F101," x","",x);
#endif
    if (x > 0) buf[x] = '\0';
    if (x < 0) x = -1;
    return(x);
}

/*  T T O L  --  Similar to "ttinl", but for writing.  */

ttol(s,n) int n; char *s; {
    int x;
    if (ttyfd < 0) return(-1);		/* Not open. */
    x = write(ttyfd,s,n);
    debug(F111,"ttol",s,n);
    if (x < 0) debug(F101,"ttol failed","",x);
    return(x);
}


/*  T T O C  --  Output a character to the communication line  */

ttoc(c) char c; {
    if (ttyfd < 0) return(-1);		/* Not open. */
    return(write(ttyfd,&c,1));
}

/*  T T I N L  --  Read a record (up to break character) from comm line.  */
/*
  If no break character encountered within "max", return "max" characters,
  with disposition of any remaining characters undefined.  Otherwise, return
  the characters that were read, including the break character, in "dest" and
  the number of characters read as the value of function, or 0 upon end of
  file, or -1 if an error occurred.  Times out & returns error if not completed
  within "timo" seconds.
*/

ttinl(dest,max,timo,eol) int max,timo; char *dest; char eol; {
    int x, y;
    CHAR c;

    if (ttyfd < 0) return(-1);		/* Not open. */
    if (timo <= 0) {			/* Untimed read... */

#ifdef MYREAD
	for (x = c = 0; (x < max) && (c != eol); x++) {
	     while ((y = myread()) == -1) ;
	     if (y == -2) return(-1);
	     dest[x] = c = y & 0377;
	}
#else
	x = read(ttyfd,dest,max);	/* Try to read. */
#endif
	return(x);			/* Return the count. */
    }

/* Timed read... */

    signal(SIGALRM,timerh);		/* Set up timeout action. */
    alarm(timo);			/* Set the timer. */
    if (setjmp(sjbuf))			/* Do this if timer went off. */
    	x = -1;
    else if (kerld) {			/* Efficient Kermit line discipline */
	x = read(ttyfd,dest,max);	/* for 4.2bsd only... */
    } else {				/* Normal case... */
	for (x = c = y = 0; (x < max) && (c != eol); x++) {
#ifdef MYREAD
    	    while ((y = myread()) == -1) /* Use own buffering if we can */
	    	;
	    if (y == -2) y++;
	    c = y & 0377;
#else
	    while ((y = read(ttyfd,&c,1)) == 0) /* Else call system */
	    	;			/* ...for each character. */
#endif
	    if (y < 0) {
		alarm(0);		/* Error, turn off timer, */
		signal(SIGALRM,SIG_DFL); /* and associated interrupt. */
		return(y);		/* Return the error indication. */
	    }
    	    dest[x] = c;
	}
	x++;
    }
    alarm(0);				/* Success, turn off timer, */
    signal(SIGALRM,SIG_DFL);		/* and associated interrupt. */
    return(x);				/* Return the count. */
}

/*  T T I N C --  Read a character from the communication line  */

ttinc(timo) int timo; {
    int n = 0;
    CHAR ch = 0;

    if (ttyfd < 0) return(-1);		/* Not open. */
    if (timo <= 0) {			/* Untimed. */
#ifdef MYREAD
    	/* comm line failure returns -1 thru myread, so no &= 0377 */
    	while ((n = myread()) == -1) ;	/* Wait for a character... */
	if (n == -2) n++;
	return( n );
#else
	while ((n = read(ttyfd,&ch,1)) == 0) ; /* Wait for a character. */
	return( (n > 0) ? (ch & 0377) : n );
#endif
    }

    signal(SIGALRM,timerh);		/* Timed, set up timer. */
    alarm(timo);
    if (setjmp(sjbuf)) {
	n = -1;
    } else {
#ifdef MYREAD
    	while ((n = myread()) == -1) ;	/* If managing own buffer... */
	if (n == -2) {
	    n++;