xref: /original-bsd/usr.bin/telnet/sys_bsd.c (revision a043e977)
1 /*
2  * Copyright (c) 1988, 1990 Regents of the University of California.
3  * All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  */
7 
8 #ifndef lint
9 static char sccsid[] = "@(#)sys_bsd.c	5.3 (Berkeley) 12/18/92";
10 #endif /* not lint */
11 
12 /*
13  * The following routines try to encapsulate what is system dependent
14  * (at least between 4.x and dos) which is used in telnet.c.
15  */
16 
17 
18 #include <fcntl.h>
19 #include <sys/types.h>
20 #include <sys/time.h>
21 #include <sys/socket.h>
22 #include <signal.h>
23 #include <errno.h>
24 #include <arpa/telnet.h>
25 
26 #include "ring.h"
27 
28 #include "fdset.h"
29 
30 #include "defines.h"
31 #include "externs.h"
32 #include "types.h"
33 
34 #if	defined(CRAY) || (defined(USE_TERMIO) && !defined(SYSV_TERMIO))
35 #define	SIG_FUNC_RET	void
36 #else
37 #define	SIG_FUNC_RET	int
38 #endif
39 
40 int
41 	tout,			/* Output file descriptor */
42 	tin,			/* Input file descriptor */
43 	net;
44 
45 #ifndef	USE_TERMIO
46 struct	tchars otc = { 0 }, ntc = { 0 };
47 struct	ltchars oltc = { 0 }, nltc = { 0 };
48 struct	sgttyb ottyb = { 0 }, nttyb = { 0 };
49 int	olmode = 0;
50 # define cfgetispeed(ptr)	(ptr)->sg_ispeed
51 # define cfgetospeed(ptr)	(ptr)->sg_ospeed
52 # define old_tc ottyb
53 
54 #else	/* USE_TERMIO */
55 struct	termio old_tc = { 0 };
56 extern struct termio new_tc;
57 
58 # ifndef	TCSANOW
59 #  ifdef TCSETS
60 #   define	TCSANOW		TCSETS
61 #   define	TCSADRAIN	TCSETSW
62 #   define	tcgetattr(f, t) ioctl(f, TCGETS, (char *)t)
63 #  else
64 #   ifdef TCSETA
65 #    define	TCSANOW		TCSETA
66 #    define	TCSADRAIN	TCSETAW
67 #    define	tcgetattr(f, t) ioctl(f, TCGETA, (char *)t)
68 #   else
69 #    define	TCSANOW		TIOCSETA
70 #    define	TCSADRAIN	TIOCSETAW
71 #    define	tcgetattr(f, t) ioctl(f, TIOCGETA, (char *)t)
72 #   endif
73 #  endif
74 #  define	tcsetattr(f, a, t) ioctl(f, a, (char *)t)
75 #  define	cfgetospeed(ptr)	((ptr)->c_cflag&CBAUD)
76 #  ifdef CIBAUD
77 #   define	cfgetispeed(ptr)	(((ptr)->c_cflag&CIBAUD) >> IBSHIFT)
78 #  else
79 #   define	cfgetispeed(ptr)	cfgetospeed(ptr)
80 #  endif
81 # endif /* TCSANOW */
82 # ifdef	sysV88
83 # define TIOCFLUSH TC_PX_DRAIN
84 # endif
85 #endif	/* USE_TERMIO */
86 
87 static fd_set ibits, obits, xbits;
88 
89 
90     void
91 init_sys()
92 {
93     tout = fileno(stdout);
94     tin = fileno(stdin);
95     FD_ZERO(&ibits);
96     FD_ZERO(&obits);
97     FD_ZERO(&xbits);
98 
99     errno = 0;
100 }
101 
102 
103     int
104 TerminalWrite(buf, n)
105     char *buf;
106     int  n;
107 {
108     return write(tout, buf, n);
109 }
110 
111     int
112 TerminalRead(buf, n)
113     char *buf;
114     int  n;
115 {
116     return read(tin, buf, n);
117 }
118 
119 /*
120  *
121  */
122 
123     int
124 TerminalAutoFlush()
125 {
126 #if	defined(LNOFLSH)
127     int flush;
128 
129     ioctl(0, TIOCLGET, (char *)&flush);
130     return !(flush&LNOFLSH);	/* if LNOFLSH, no autoflush */
131 #else	/* LNOFLSH */
132     return 1;
133 #endif	/* LNOFLSH */
134 }
135 
136 #ifdef	KLUDGELINEMODE
137 extern int kludgelinemode;
138 #endif
139 /*
140  * TerminalSpecialChars()
141  *
142  * Look at an input character to see if it is a special character
143  * and decide what to do.
144  *
145  * Output:
146  *
147  *	0	Don't add this character.
148  *	1	Do add this character
149  */
150 
151     int
152 TerminalSpecialChars(c)
153     int	c;
154 {
155     void xmitAO(), xmitEL(), xmitEC(), intp(), sendbrk();
156 
157     if (c == termIntChar) {
158 	intp();
159 	return 0;
160     } else if (c == termQuitChar) {
161 #ifdef	KLUDGELINEMODE
162 	if (kludgelinemode)
163 	    sendbrk();
164 	else
165 #endif
166 	    sendabort();
167 	return 0;
168     } else if (c == termEofChar) {
169 	if (my_want_state_is_will(TELOPT_LINEMODE)) {
170 	    sendeof();
171 	    return 0;
172 	}
173 	return 1;
174     } else if (c == termSuspChar) {
175 	sendsusp();
176 	return(0);
177     } else if (c == termFlushChar) {
178 	xmitAO();		/* Transmit Abort Output */
179 	return 0;
180     } else if (!MODE_LOCAL_CHARS(globalmode)) {
181 	if (c == termKillChar) {
182 	    xmitEL();
183 	    return 0;
184 	} else if (c == termEraseChar) {
185 	    xmitEC();		/* Transmit Erase Character */
186 	    return 0;
187 	}
188     }
189     return 1;
190 }
191 
192 
193 /*
194  * Flush output to the terminal
195  */
196 
197     void
198 TerminalFlushOutput()
199 {
200 #ifdef	TIOCFLUSH
201     (void) ioctl(fileno(stdout), TIOCFLUSH, (char *) 0);
202 #else
203     (void) ioctl(fileno(stdout), TCFLSH, (char *) 0);
204 #endif
205 }
206 
207     void
208 TerminalSaveState()
209 {
210 #ifndef	USE_TERMIO
211     ioctl(0, TIOCGETP, (char *)&ottyb);
212     ioctl(0, TIOCGETC, (char *)&otc);
213     ioctl(0, TIOCGLTC, (char *)&oltc);
214     ioctl(0, TIOCLGET, (char *)&olmode);
215 
216     ntc = otc;
217     nltc = oltc;
218     nttyb = ottyb;
219 
220 #else	/* USE_TERMIO */
221     tcgetattr(0, &old_tc);
222 
223     new_tc = old_tc;
224 
225 #ifndef	VDISCARD
226     termFlushChar = CONTROL('O');
227 #endif
228 #ifndef	VWERASE
229     termWerasChar = CONTROL('W');
230 #endif
231 #ifndef	VREPRINT
232     termRprntChar = CONTROL('R');
233 #endif
234 #ifndef	VLNEXT
235     termLiteralNextChar = CONTROL('V');
236 #endif
237 #ifndef	VSTART
238     termStartChar = CONTROL('Q');
239 #endif
240 #ifndef	VSTOP
241     termStopChar = CONTROL('S');
242 #endif
243 #ifndef	VSTATUS
244     termAytChar = CONTROL('T');
245 #endif
246 #endif	/* USE_TERMIO */
247 }
248 
249     cc_t *
250 tcval(func)
251     register int func;
252 {
253     switch(func) {
254     case SLC_IP:	return(&termIntChar);
255     case SLC_ABORT:	return(&termQuitChar);
256     case SLC_EOF:	return(&termEofChar);
257     case SLC_EC:	return(&termEraseChar);
258     case SLC_EL:	return(&termKillChar);
259     case SLC_XON:	return(&termStartChar);
260     case SLC_XOFF:	return(&termStopChar);
261     case SLC_FORW1:	return(&termForw1Char);
262 #ifdef	USE_TERMIO
263     case SLC_FORW2:	return(&termForw2Char);
264 # ifdef	VDISCARD
265     case SLC_AO:	return(&termFlushChar);
266 # endif
267 # ifdef	VSUSP
268     case SLC_SUSP:	return(&termSuspChar);
269 # endif
270 # ifdef	VWERASE
271     case SLC_EW:	return(&termWerasChar);
272 # endif
273 # ifdef	VREPRINT
274     case SLC_RP:	return(&termRprntChar);
275 # endif
276 # ifdef	VLNEXT
277     case SLC_LNEXT:	return(&termLiteralNextChar);
278 # endif
279 # ifdef	VSTATUS
280     case SLC_AYT:	return(&termAytChar);
281 # endif
282 #endif
283 
284     case SLC_SYNCH:
285     case SLC_BRK:
286     case SLC_EOR:
287     default:
288 	return((cc_t *)0);
289     }
290 }
291 
292     void
293 TerminalDefaultChars()
294 {
295 #ifndef	USE_TERMIO
296     ntc = otc;
297     nltc = oltc;
298     nttyb.sg_kill = ottyb.sg_kill;
299     nttyb.sg_erase = ottyb.sg_erase;
300 #else	/* USE_TERMIO */
301     memcpy(new_tc.c_cc, old_tc.c_cc, sizeof(old_tc.c_cc));
302 # ifndef	VDISCARD
303     termFlushChar = CONTROL('O');
304 # endif
305 # ifndef	VWERASE
306     termWerasChar = CONTROL('W');
307 # endif
308 # ifndef	VREPRINT
309     termRprntChar = CONTROL('R');
310 # endif
311 # ifndef	VLNEXT
312     termLiteralNextChar = CONTROL('V');
313 # endif
314 # ifndef	VSTART
315     termStartChar = CONTROL('Q');
316 # endif
317 # ifndef	VSTOP
318     termStopChar = CONTROL('S');
319 # endif
320 # ifndef	VSTATUS
321     termAytChar = CONTROL('T');
322 # endif
323 #endif	/* USE_TERMIO */
324 }
325 
326 #ifdef notdef
327 void
328 TerminalRestoreState()
329 {
330 }
331 #endif
332 
333 /*
334  * TerminalNewMode - set up terminal to a specific mode.
335  *	MODE_ECHO: do local terminal echo
336  *	MODE_FLOW: do local flow control
337  *	MODE_TRAPSIG: do local mapping to TELNET IAC sequences
338  *	MODE_EDIT: do local line editing
339  *
340  *	Command mode:
341  *		MODE_ECHO|MODE_EDIT|MODE_FLOW|MODE_TRAPSIG
342  *		local echo
343  *		local editing
344  *		local xon/xoff
345  *		local signal mapping
346  *
347  *	Linemode:
348  *		local/no editing
349  *	Both Linemode and Single Character mode:
350  *		local/remote echo
351  *		local/no xon/xoff
352  *		local/no signal mapping
353  */
354 
355 
356     void
357 TerminalNewMode(f)
358     register int f;
359 {
360     static int prevmode = 0;
361 #ifndef	USE_TERMIO
362     struct tchars tc;
363     struct ltchars ltc;
364     struct sgttyb sb;
365     int lmode;
366 #else	/* USE_TERMIO */
367     struct termio tmp_tc;
368 #endif	/* USE_TERMIO */
369     int onoff;
370     int old;
371     cc_t esc;
372 
373     globalmode = f&~MODE_FORCE;
374     if (prevmode == f)
375 	return;
376 
377     /*
378      * Write any outstanding data before switching modes
379      * ttyflush() returns 0 only when there is no more data
380      * left to write out, it returns -1 if it couldn't do
381      * anything at all, otherwise it returns 1 + the number
382      * of characters left to write.
383 #ifndef	USE_TERMIO
384      * We would really like ask the kernel to wait for the output
385      * to drain, like we can do with the TCSADRAIN, but we don't have
386      * that option.  The only ioctl that waits for the output to
387      * drain, TIOCSETP, also flushes the input queue, which is NOT
388      * what we want (TIOCSETP is like TCSADFLUSH).
389 #endif
390      */
391     old = ttyflush(SYNCHing|flushout);
392     if (old < 0 || old > 1) {
393 #ifdef	USE_TERMIO
394 	tcgetattr(tin, &tmp_tc);
395 #endif	/* USE_TERMIO */
396 	do {
397 	    /*
398 	     * Wait for data to drain, then flush again.
399 	     */
400 #ifdef	USE_TERMIO
401 	    tcsetattr(tin, TCSADRAIN, &tmp_tc);
402 #endif	/* USE_TERMIO */
403 	    old = ttyflush(SYNCHing|flushout);
404 	} while (old < 0 || old > 1);
405     }
406 
407     old = prevmode;
408     prevmode = f&~MODE_FORCE;
409 #ifndef	USE_TERMIO
410     sb = nttyb;
411     tc = ntc;
412     ltc = nltc;
413     lmode = olmode;
414 #else
415     tmp_tc = new_tc;
416 #endif
417 
418     if (f&MODE_ECHO) {
419 #ifndef	USE_TERMIO
420 	sb.sg_flags |= ECHO;
421 #else
422 	tmp_tc.c_lflag |= ECHO;
423 	tmp_tc.c_oflag |= ONLCR;
424 	if (crlf)
425 		tmp_tc.c_iflag |= ICRNL;
426 #endif
427     } else {
428 #ifndef	USE_TERMIO
429 	sb.sg_flags &= ~ECHO;
430 #else
431 	tmp_tc.c_lflag &= ~ECHO;
432 	tmp_tc.c_oflag &= ~ONLCR;
433 # ifdef notdef
434 	if (crlf)
435 		tmp_tc.c_iflag &= ~ICRNL;
436 # endif
437 #endif
438     }
439 
440     if ((f&MODE_FLOW) == 0) {
441 #ifndef	USE_TERMIO
442 	tc.t_startc = _POSIX_VDISABLE;
443 	tc.t_stopc = _POSIX_VDISABLE;
444 #else
445 	tmp_tc.c_iflag &= ~(IXOFF|IXON);	/* Leave the IXANY bit alone */
446     } else {
447 	if (restartany < 0) {
448 		tmp_tc.c_iflag |= IXOFF|IXON;	/* Leave the IXANY bit alone */
449 	} else if (restartany > 0) {
450 		tmp_tc.c_iflag |= IXOFF|IXON|IXANY;
451 	} else {
452 		tmp_tc.c_iflag |= IXOFF|IXON;
453 		tmp_tc.c_iflag &= ~IXANY;
454 	}
455 #endif
456     }
457 
458     if ((f&MODE_TRAPSIG) == 0) {
459 #ifndef	USE_TERMIO
460 	tc.t_intrc = _POSIX_VDISABLE;
461 	tc.t_quitc = _POSIX_VDISABLE;
462 	tc.t_eofc = _POSIX_VDISABLE;
463 	ltc.t_suspc = _POSIX_VDISABLE;
464 	ltc.t_dsuspc = _POSIX_VDISABLE;
465 #else
466 	tmp_tc.c_lflag &= ~ISIG;
467 #endif
468 	localchars = 0;
469     } else {
470 #ifdef	USE_TERMIO
471 	tmp_tc.c_lflag |= ISIG;
472 #endif
473 	localchars = 1;
474     }
475 
476     if (f&MODE_EDIT) {
477 #ifndef	USE_TERMIO
478 	sb.sg_flags &= ~CBREAK;
479 	sb.sg_flags |= CRMOD;
480 #else
481 	tmp_tc.c_lflag |= ICANON;
482 #endif
483     } else {
484 #ifndef	USE_TERMIO
485 	sb.sg_flags |= CBREAK;
486 	if (f&MODE_ECHO)
487 	    sb.sg_flags |= CRMOD;
488 	else
489 	    sb.sg_flags &= ~CRMOD;
490 #else
491 	tmp_tc.c_lflag &= ~ICANON;
492 	tmp_tc.c_iflag &= ~ICRNL;
493 	tmp_tc.c_cc[VMIN] = 1;
494 	tmp_tc.c_cc[VTIME] = 0;
495 #endif
496     }
497 
498     if ((f&(MODE_EDIT|MODE_TRAPSIG)) == 0) {
499 #ifndef	USE_TERMIO
500 	ltc.t_lnextc = _POSIX_VDISABLE;
501 #else
502 # ifdef VLNEXT
503 	tmp_tc.c_cc[VLNEXT] = (cc_t)(_POSIX_VDISABLE);
504 # endif
505 #endif
506     }
507 
508     if (f&MODE_SOFT_TAB) {
509 #ifndef USE_TERMIO
510 	sb.sg_flags |= XTABS;
511 #else
512 # ifdef	OXTABS
513 	tmp_tc.c_oflag |= OXTABS;
514 # endif
515 # ifdef	TABDLY
516 	tmp_tc.c_oflag &= ~TABDLY;
517 	tmp_tc.c_oflag |= TAB3;
518 # endif
519 #endif
520     } else {
521 #ifndef USE_TERMIO
522 	sb.sg_flags &= ~XTABS;
523 #else
524 # ifdef	OXTABS
525 	tmp_tc.c_oflag &= ~OXTABS;
526 # endif
527 # ifdef	TABDLY
528 	tmp_tc.c_oflag &= ~TABDLY;
529 # endif
530 #endif
531     }
532 
533     if (f&MODE_LIT_ECHO) {
534 #ifndef USE_TERMIO
535 	lmode &= ~LCTLECH;
536 #else
537 # ifdef	ECHOCTL
538 	tmp_tc.c_lflag &= ~ECHOCTL;
539 # endif
540 #endif
541     } else {
542 #ifndef USE_TERMIO
543 	lmode |= LCTLECH;
544 #else
545 # ifdef	ECHOCTL
546 	tmp_tc.c_lflag |= ECHOCTL;
547 # endif
548 #endif
549     }
550 
551     if (f == -1) {
552 	onoff = 0;
553     } else {
554 #ifndef	USE_TERMIO
555 	if (f & MODE_OUTBIN)
556 		lmode |= LLITOUT;
557 	else
558 		lmode &= ~LLITOUT;
559 
560 	if (f & MODE_INBIN)
561 		lmode |= LPASS8;
562 	else
563 		lmode &= ~LPASS8;
564 #else
565 	if (f & MODE_INBIN)
566 		tmp_tc.c_iflag &= ~ISTRIP;
567 	else
568 		tmp_tc.c_iflag |= ISTRIP;
569 	if (f & MODE_OUTBIN) {
570 		tmp_tc.c_cflag &= ~(CSIZE|PARENB);
571 		tmp_tc.c_cflag |= CS8;
572 		tmp_tc.c_oflag &= ~OPOST;
573 	} else {
574 		tmp_tc.c_cflag &= ~(CSIZE|PARENB);
575 		tmp_tc.c_cflag |= old_tc.c_cflag & (CSIZE|PARENB);
576 		tmp_tc.c_oflag |= OPOST;
577 	}
578 #endif
579 	onoff = 1;
580     }
581 
582     if (f != -1) {
583 #ifdef	SIGTSTP
584 	static SIG_FUNC_RET susp();
585 #endif	/* SIGTSTP */
586 #ifdef	SIGINFO
587 	static SIG_FUNC_RET ayt();
588 #endif	SIGINFO
589 
590 #ifdef	SIGTSTP
591 	(void) signal(SIGTSTP, susp);
592 #endif	/* SIGTSTP */
593 #ifdef	SIGINFO
594 	(void) signal(SIGINFO, ayt);
595 #endif	SIGINFO
596 #if	defined(USE_TERMIO) && defined(NOKERNINFO)
597 	tmp_tc.c_lflag |= NOKERNINFO;
598 #endif
599 	/*
600 	 * We don't want to process ^Y here.  It's just another
601 	 * character that we'll pass on to the back end.  It has
602 	 * to process it because it will be processed when the
603 	 * user attempts to read it, not when we send it.
604 	 */
605 #ifndef	USE_TERMIO
606 	ltc.t_dsuspc = _POSIX_VDISABLE;
607 #else
608 # ifdef	VDSUSP
609 	tmp_tc.c_cc[VDSUSP] = (cc_t)(_POSIX_VDISABLE);
610 # endif
611 #endif
612 #ifdef	USE_TERMIO
613 	/*
614 	 * If the VEOL character is already set, then use VEOL2,
615 	 * otherwise use VEOL.
616 	 */
617 	esc = (rlogin != _POSIX_VDISABLE) ? rlogin : escape;
618 	if ((tmp_tc.c_cc[VEOL] != esc)
619 # ifdef	VEOL2
620 	    && (tmp_tc.c_cc[VEOL2] != esc)
621 # endif
622 	    ) {
623 		if (tmp_tc.c_cc[VEOL] == (cc_t)(_POSIX_VDISABLE))
624 		    tmp_tc.c_cc[VEOL] = esc;
625 # ifdef	VEOL2
626 		else if (tmp_tc.c_cc[VEOL2] == (cc_t)(_POSIX_VDISABLE))
627 		    tmp_tc.c_cc[VEOL2] = esc;
628 # endif
629 	}
630 #else
631 	if (tc.t_brkc == (cc_t)(_POSIX_VDISABLE))
632 		tc.t_brkc = esc;
633 #endif
634     } else {
635 #ifdef	SIGINFO
636 	SIG_FUNC_RET ayt_status();
637 
638 	(void) signal(SIGINFO, ayt_status);
639 #endif	SIGINFO
640 #ifdef	SIGTSTP
641 	(void) signal(SIGTSTP, SIG_DFL);
642 	(void) sigsetmask(sigblock(0) & ~(1<<(SIGTSTP-1)));
643 #endif	/* SIGTSTP */
644 #ifndef USE_TERMIO
645 	ltc = oltc;
646 	tc = otc;
647 	sb = ottyb;
648 	lmode = olmode;
649 #else
650 	tmp_tc = old_tc;
651 #endif
652     }
653 #ifndef USE_TERMIO
654     ioctl(tin, TIOCLSET, (char *)&lmode);
655     ioctl(tin, TIOCSLTC, (char *)&ltc);
656     ioctl(tin, TIOCSETC, (char *)&tc);
657     ioctl(tin, TIOCSETN, (char *)&sb);
658 #else
659     if (tcsetattr(tin, TCSADRAIN, &tmp_tc) < 0)
660 	tcsetattr(tin, TCSANOW, &tmp_tc);
661 #endif
662 
663 #if	(!defined(TN3270)) || ((!defined(NOT43)) || defined(PUTCHAR))
664 # if	!defined(sysV88)
665     ioctl(tin, FIONBIO, (char *)&onoff);
666     ioctl(tout, FIONBIO, (char *)&onoff);
667 # endif
668 #endif	/* (!defined(TN3270)) || ((!defined(NOT43)) || defined(PUTCHAR)) */
669 #if	defined(TN3270)
670     if (noasynchtty == 0) {
671 	ioctl(tin, FIOASYNC, (char *)&onoff);
672     }
673 #endif	/* defined(TN3270) */
674 
675 }
676 
677 #ifndef	B19200
678 # define B19200 B9600
679 #endif
680 
681 #ifndef	B38400
682 # define B38400 B19200
683 #endif
684 
685 /*
686  * This code assumes that the values B0, B50, B75...
687  * are in ascending order.  They do not have to be
688  * contiguous.
689  */
690 struct termspeeds {
691 	long speed;
692 	long value;
693 } termspeeds[] = {
694 	{ 0,     B0 },     { 50,    B50 },   { 75,    B75 },
695 	{ 110,   B110 },   { 134,   B134 },  { 150,   B150 },
696 	{ 200,   B200 },   { 300,   B300 },  { 600,   B600 },
697 	{ 1200,  B1200 },  { 1800,  B1800 }, { 2400,  B2400 },
698 	{ 4800,  B4800 },  { 9600,  B9600 }, { 19200, B19200 },
699 	{ 38400, B38400 }, { -1,    B38400 }
700 };
701 
702     void
703 TerminalSpeeds(ispeed, ospeed)
704     long *ispeed;
705     long *ospeed;
706 {
707     register struct termspeeds *tp;
708     register long in, out;
709 
710     out = cfgetospeed(&old_tc);
711     in = cfgetispeed(&old_tc);
712     if (in == 0)
713 	in = out;
714 
715     tp = termspeeds;
716     while ((tp->speed != -1) && (tp->value < in))
717 	tp++;
718     *ispeed = tp->speed;
719 
720     tp = termspeeds;
721     while ((tp->speed != -1) && (tp->value < out))
722 	tp++;
723     *ospeed = tp->speed;
724 }
725 
726     int
727 TerminalWindowSize(rows, cols)
728     long *rows, *cols;
729 {
730 #ifdef	TIOCGWINSZ
731     struct winsize ws;
732 
733     if (ioctl(fileno(stdin), TIOCGWINSZ, (char *)&ws) >= 0) {
734 	*rows = ws.ws_row;
735 	*cols = ws.ws_col;
736 	return 1;
737     }
738 #endif	/* TIOCGWINSZ */
739     return 0;
740 }
741 
742     int
743 NetClose(fd)
744     int	fd;
745 {
746     return close(fd);
747 }
748 
749 
750     void
751 NetNonblockingIO(fd, onoff)
752     int fd;
753     int onoff;
754 {
755     ioctl(fd, FIONBIO, (char *)&onoff);
756 }
757 
758 #if	defined(TN3270)
759     void
760 NetSigIO(fd, onoff)
761     int fd;
762     int onoff;
763 {
764     ioctl(fd, FIOASYNC, (char *)&onoff);	/* hear about input */
765 }
766 
767     void
768 NetSetPgrp(fd)
769     int fd;
770 {
771     int myPid;
772 
773     myPid = getpid();
774     fcntl(fd, F_SETOWN, myPid);
775 }
776 #endif	/*defined(TN3270)*/
777 
778 /*
779  * Various signal handling routines.
780  */
781 
782     /* ARGSUSED */
783     static SIG_FUNC_RET
784 deadpeer(sig)
785     int sig;
786 {
787 	setcommandmode();
788 	longjmp(peerdied, -1);
789 }
790 
791     /* ARGSUSED */
792     static SIG_FUNC_RET
793 intr(sig)
794     int sig;
795 {
796     if (localchars) {
797 	intp();
798 	return;
799     }
800     setcommandmode();
801     longjmp(toplevel, -1);
802 }
803 
804     /* ARGSUSED */
805     static SIG_FUNC_RET
806 intr2(sig)
807     int sig;
808 {
809     if (localchars) {
810 #ifdef	KLUDGELINEMODE
811 	if (kludgelinemode)
812 	    sendbrk();
813 	else
814 #endif
815 	    sendabort();
816 	return;
817     }
818 }
819 
820 #ifdef	SIGTSTP
821     /* ARGSUSED */
822     static SIG_FUNC_RET
823 susp(sig)
824     int sig;
825 {
826     if ((rlogin != _POSIX_VDISABLE) && rlogin_susp())
827 	return;
828     if (localchars)
829 	sendsusp();
830 }
831 #endif
832 
833 #ifdef	SIGWINCH
834     /* ARGSUSED */
835     static SIG_FUNC_RET
836 sendwin(sig)
837     int sig;
838 {
839     if (connected) {
840 	sendnaws();
841     }
842 }
843 #endif
844 
845 #ifdef	SIGINFO
846     /* ARGSUSED */
847     static SIG_FUNC_RET
848 ayt(sig)
849     int sig;
850 {
851     if (connected)
852 	sendayt();
853     else
854 	ayt_status();
855 }
856 #endif
857 
858 
859     void
860 sys_telnet_init()
861 {
862     (void) signal(SIGINT, intr);
863     (void) signal(SIGQUIT, intr2);
864     (void) signal(SIGPIPE, deadpeer);
865 #ifdef	SIGWINCH
866     (void) signal(SIGWINCH, sendwin);
867 #endif
868 #ifdef	SIGTSTP
869     (void) signal(SIGTSTP, susp);
870 #endif
871 #ifdef	SIGINFO
872     (void) signal(SIGINFO, ayt);
873 #endif
874 
875     setconnmode(0);
876 
877     NetNonblockingIO(net, 1);
878 
879 #if	defined(TN3270)
880     if (noasynchnet == 0) {			/* DBX can't handle! */
881 	NetSigIO(net, 1);
882 	NetSetPgrp(net);
883     }
884 #endif	/* defined(TN3270) */
885 
886 #if	defined(SO_OOBINLINE)
887     if (SetSockOpt(net, SOL_SOCKET, SO_OOBINLINE, 1) == -1) {
888 	perror("SetSockOpt");
889     }
890 #endif	/* defined(SO_OOBINLINE) */
891 }
892 
893 /*
894  * Process rings -
895  *
896  *	This routine tries to fill up/empty our various rings.
897  *
898  *	The parameter specifies whether this is a poll operation,
899  *	or a block-until-something-happens operation.
900  *
901  *	The return value is 1 if something happened, 0 if not.
902  */
903 
904     int
905 process_rings(netin, netout, netex, ttyin, ttyout, poll)
906     int poll;		/* If 0, then block until something to do */
907 {
908     register int c;
909 		/* One wants to be a bit careful about setting returnValue
910 		 * to one, since a one implies we did some useful work,
911 		 * and therefore probably won't be called to block next
912 		 * time (TN3270 mode only).
913 		 */
914     int returnValue = 0;
915     static struct timeval TimeValue = { 0 };
916 
917     if (netout) {
918 	FD_SET(net, &obits);
919     }
920     if (ttyout) {
921 	FD_SET(tout, &obits);
922     }
923 #if	defined(TN3270)
924     if (ttyin) {
925 	FD_SET(tin, &ibits);
926     }
927 #else	/* defined(TN3270) */
928     if (ttyin) {
929 	FD_SET(tin, &ibits);
930     }
931 #endif	/* defined(TN3270) */
932 #if	defined(TN3270)
933     if (netin) {
934 	FD_SET(net, &ibits);
935     }
936 #   else /* !defined(TN3270) */
937     if (netin) {
938 	FD_SET(net, &ibits);
939     }
940 #   endif /* !defined(TN3270) */
941     if (netex) {
942 	FD_SET(net, &xbits);
943     }
944     if ((c = select(16, &ibits, &obits, &xbits,
945 			(poll == 0)? (struct timeval *)0 : &TimeValue)) < 0) {
946 	if (c == -1) {
947 		    /*
948 		     * we can get EINTR if we are in line mode,
949 		     * and the user does an escape (TSTP), or
950 		     * some other signal generator.
951 		     */
952 	    if (errno == EINTR) {
953 		return 0;
954 	    }
955 #	    if defined(TN3270)
956 		    /*
957 		     * we can get EBADF if we were in transparent
958 		     * mode, and the transcom process died.
959 		    */
960 	    if (errno == EBADF) {
961 			/*
962 			 * zero the bits (even though kernel does it)
963 			 * to make sure we are selecting on the right
964 			 * ones.
965 			*/
966 		FD_ZERO(&ibits);
967 		FD_ZERO(&obits);
968 		FD_ZERO(&xbits);
969 		return 0;
970 	    }
971 #	    endif /* defined(TN3270) */
972 		    /* I don't like this, does it ever happen? */
973 	    printf("sleep(5) from telnet, after select\r\n");
974 	    sleep(5);
975 	}
976 	return 0;
977     }
978 
979     /*
980      * Any urgent data?
981      */
982     if (FD_ISSET(net, &xbits)) {
983 	FD_CLR(net, &xbits);
984 	SYNCHing = 1;
985 	(void) ttyflush(1);	/* flush already enqueued data */
986     }
987 
988     /*
989      * Something to read from the network...
990      */
991     if (FD_ISSET(net, &ibits)) {
992 	int canread;
993 
994 	FD_CLR(net, &ibits);
995 	canread = ring_empty_consecutive(&netiring);
996 #if	!defined(SO_OOBINLINE)
997 	    /*
998 	     * In 4.2 (and some early 4.3) systems, the
999 	     * OOB indication and data handling in the kernel
1000 	     * is such that if two separate TCP Urgent requests
1001 	     * come in, one byte of TCP data will be overlaid.
1002 	     * This is fatal for Telnet, but we try to live
1003 	     * with it.
1004 	     *
1005 	     * In addition, in 4.2 (and...), a special protocol
1006 	     * is needed to pick up the TCP Urgent data in
1007 	     * the correct sequence.
1008 	     *
1009 	     * What we do is:  if we think we are in urgent
1010 	     * mode, we look to see if we are "at the mark".
1011 	     * If we are, we do an OOB receive.  If we run
1012 	     * this twice, we will do the OOB receive twice,
1013 	     * but the second will fail, since the second
1014 	     * time we were "at the mark", but there wasn't
1015 	     * any data there (the kernel doesn't reset
1016 	     * "at the mark" until we do a normal read).
1017 	     * Once we've read the OOB data, we go ahead
1018 	     * and do normal reads.
1019 	     *
1020 	     * There is also another problem, which is that
1021 	     * since the OOB byte we read doesn't put us
1022 	     * out of OOB state, and since that byte is most
1023 	     * likely the TELNET DM (data mark), we would
1024 	     * stay in the TELNET SYNCH (SYNCHing) state.
1025 	     * So, clocks to the rescue.  If we've "just"
1026 	     * received a DM, then we test for the
1027 	     * presence of OOB data when the receive OOB
1028 	     * fails (and AFTER we did the normal mode read
1029 	     * to clear "at the mark").
1030 	     */
1031 	if (SYNCHing) {
1032 	    int atmark;
1033 	    static int bogus_oob = 0, first = 1;
1034 
1035 	    ioctl(net, SIOCATMARK, (char *)&atmark);
1036 	    if (atmark) {
1037 		c = recv(net, netiring.supply, canread, MSG_OOB);
1038 		if ((c == -1) && (errno == EINVAL)) {
1039 		    c = recv(net, netiring.supply, canread, 0);
1040 		    if (clocks.didnetreceive < clocks.gotDM) {
1041 			SYNCHing = stilloob(net);
1042 		    }
1043 		} else if (first && c > 0) {
1044 		    /*
1045 		     * Bogosity check.  Systems based on 4.2BSD
1046 		     * do not return an error if you do a second
1047 		     * recv(MSG_OOB).  So, we do one.  If it
1048 		     * succeeds and returns exactly the same
1049 		     * data, then assume that we are running
1050 		     * on a broken system and set the bogus_oob
1051 		     * flag.  (If the data was different, then
1052 		     * we probably got some valid new data, so
1053 		     * increment the count...)
1054 		     */
1055 		    int i;
1056 		    i = recv(net, netiring.supply + c, canread - c, MSG_OOB);
1057 		    if (i == c &&
1058 			  bcmp(netiring.supply, netiring.supply + c, i) == 0) {
1059 			bogus_oob = 1;
1060 			first = 0;
1061 		    } else if (i < 0) {
1062 			bogus_oob = 0;
1063 			first = 0;
1064 		    } else
1065 			c += i;
1066 		}
1067 		if (bogus_oob && c > 0) {
1068 		    int i;
1069 		    /*
1070 		     * Bogosity.  We have to do the read
1071 		     * to clear the atmark to get out of
1072 		     * an infinate loop.
1073 		     */
1074 		    i = read(net, netiring.supply + c, canread - c);
1075 		    if (i > 0)
1076 			c += i;
1077 		}
1078 	    } else {
1079 		c = recv(net, netiring.supply, canread, 0);
1080 	    }
1081 	} else {
1082 	    c = recv(net, netiring.supply, canread, 0);
1083 	}
1084 	settimer(didnetreceive);
1085 #else	/* !defined(SO_OOBINLINE) */
1086 	c = recv(net, netiring.supply, canread, 0);
1087 #endif	/* !defined(SO_OOBINLINE) */
1088 	if (c < 0 && errno == EWOULDBLOCK) {
1089 	    c = 0;
1090 	} else if (c <= 0) {
1091 	    return -1;
1092 	}
1093 	if (netdata) {
1094 	    Dump('<', netiring.supply, c);
1095 	}
1096 	if (c)
1097 	    ring_supplied(&netiring, c);
1098 	returnValue = 1;
1099     }
1100 
1101     /*
1102      * Something to read from the tty...
1103      */
1104     if (FD_ISSET(tin, &ibits)) {
1105 	FD_CLR(tin, &ibits);
1106 	c = TerminalRead(ttyiring.supply, ring_empty_consecutive(&ttyiring));
1107 	if (c < 0 && errno == EWOULDBLOCK) {
1108 	    c = 0;
1109 	} else {
1110 	    /* EOF detection for line mode!!!! */
1111 	    if ((c == 0) && MODE_LOCAL_CHARS(globalmode) && isatty(tin)) {
1112 			/* must be an EOF... */
1113 		*ttyiring.supply = termEofChar;
1114 		c = 1;
1115 	    }
1116 	    if (c <= 0) {
1117 		return -1;
1118 	    }
1119 	    if (termdata) {
1120 		Dump('<', ttyiring.supply, c);
1121 	    }
1122 	    ring_supplied(&ttyiring, c);
1123 	}
1124 	returnValue = 1;		/* did something useful */
1125     }
1126 
1127     if (FD_ISSET(net, &obits)) {
1128 	FD_CLR(net, &obits);
1129 	returnValue |= netflush();
1130     }
1131     if (FD_ISSET(tout, &obits)) {
1132 	FD_CLR(tout, &obits);
1133 	returnValue |= (ttyflush(SYNCHing|flushout) > 0);
1134     }
1135 
1136     return returnValue;
1137 }
1138