1 /*
2 * Copyright (c) 1988, 1990, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #include "telnet_locl.h"
35
36 RCSID("$Id$");
37
38 /*
39 * The following routines try to encapsulate what is system dependent
40 * (at least between 4.x and dos) which is used in telnet.c.
41 */
42
43 int
44 tout, /* Output file descriptor */
45 tin, /* Input file descriptor */
46 net;
47
48 struct termios old_tc = { 0 };
49 extern struct termios new_tc;
50
51 # ifndef TCSANOW
52 # ifdef TCSETS
53 # define TCSANOW TCSETS
54 # define TCSADRAIN TCSETSW
55 # define tcgetattr(f, t) ioctl(f, TCGETS, (char *)t)
56 # else
57 # ifdef TCSETA
58 # define TCSANOW TCSETA
59 # define TCSADRAIN TCSETAW
60 # define tcgetattr(f, t) ioctl(f, TCGETA, (char *)t)
61 # else
62 # define TCSANOW TIOCSETA
63 # define TCSADRAIN TIOCSETAW
64 # define tcgetattr(f, t) ioctl(f, TIOCGETA, (char *)t)
65 # endif
66 # endif
67 # define tcsetattr(f, a, t) ioctl(f, a, (char *)t)
68 # define cfgetospeed(ptr) ((ptr)->c_cflag&CBAUD)
69 # ifdef CIBAUD
70 # define cfgetispeed(ptr) (((ptr)->c_cflag&CIBAUD) >> IBSHIFT)
71 # else
72 # define cfgetispeed(ptr) cfgetospeed(ptr)
73 # endif
74 # endif /* TCSANOW */
75
76 static fd_set ibits, obits, xbits;
77
78
79 void
init_sys(void)80 init_sys(void)
81 {
82 tout = fileno(stdout);
83 tin = fileno(stdin);
84 FD_ZERO(&ibits);
85 FD_ZERO(&obits);
86 FD_ZERO(&xbits);
87
88 errno = 0;
89 }
90
91
92 int
TerminalWrite(char * buf,int n)93 TerminalWrite(char *buf, int n)
94 {
95 return write(tout, buf, n);
96 }
97
98 int
TerminalRead(unsigned char * buf,int n)99 TerminalRead(unsigned char *buf, int n)
100 {
101 return read(tin, buf, n);
102 }
103
104 /*
105 *
106 */
107
108 int
TerminalAutoFlush(void)109 TerminalAutoFlush(void)
110 {
111 #if defined(LNOFLSH)
112 int flush;
113
114 ioctl(0, TIOCLGET, (char *)&flush);
115 return !(flush&LNOFLSH); /* if LNOFLSH, no autoflush */
116 #else /* LNOFLSH */
117 return 1;
118 #endif /* LNOFLSH */
119 }
120
121 /*
122 * TerminalSpecialChars()
123 *
124 * Look at an input character to see if it is a special character
125 * and decide what to do.
126 *
127 * Output:
128 *
129 * 0 Don't add this character.
130 * 1 Do add this character
131 */
132
133 int
TerminalSpecialChars(int c)134 TerminalSpecialChars(int c)
135 {
136 if (c == termIntChar) {
137 intp();
138 return 0;
139 } else if (c == termQuitChar) {
140 #ifdef KLUDGELINEMODE
141 if (kludgelinemode)
142 sendbrk();
143 else
144 #endif
145 sendabort();
146 return 0;
147 } else if (c == termEofChar) {
148 if (my_want_state_is_will(TELOPT_LINEMODE)) {
149 sendeof();
150 return 0;
151 }
152 return 1;
153 } else if (c == termSuspChar) {
154 sendsusp();
155 return(0);
156 } else if (c == termFlushChar) {
157 xmitAO(); /* Transmit Abort Output */
158 return 0;
159 } else if (!MODE_LOCAL_CHARS(globalmode)) {
160 if (c == termKillChar) {
161 xmitEL();
162 return 0;
163 } else if (c == termEraseChar) {
164 xmitEC(); /* Transmit Erase Character */
165 return 0;
166 }
167 }
168 return 1;
169 }
170
171
172 /*
173 * Flush output to the terminal
174 */
175
176 void
TerminalFlushOutput(void)177 TerminalFlushOutput(void)
178 {
179 #ifdef TIOCFLUSH
180 ioctl(fileno(stdout), TIOCFLUSH, (char *) 0);
181 #else
182 ioctl(fileno(stdout), TCFLSH, (char *) 0);
183 #endif
184 }
185
186 void
TerminalSaveState(void)187 TerminalSaveState(void)
188 {
189 tcgetattr(0, &old_tc);
190
191 new_tc = old_tc;
192
193 #ifndef VDISCARD
194 termFlushChar = CONTROL('O');
195 #endif
196 #ifndef VWERASE
197 termWerasChar = CONTROL('W');
198 #endif
199 #ifndef VREPRINT
200 termRprntChar = CONTROL('R');
201 #endif
202 #ifndef VLNEXT
203 termLiteralNextChar = CONTROL('V');
204 #endif
205 #ifndef VSTART
206 termStartChar = CONTROL('Q');
207 #endif
208 #ifndef VSTOP
209 termStopChar = CONTROL('S');
210 #endif
211 #ifndef VSTATUS
212 termAytChar = CONTROL('T');
213 #endif
214 }
215
216 cc_t*
tcval(int func)217 tcval(int func)
218 {
219 switch(func) {
220 case SLC_IP: return(&termIntChar);
221 case SLC_ABORT: return(&termQuitChar);
222 case SLC_EOF: return(&termEofChar);
223 case SLC_EC: return(&termEraseChar);
224 case SLC_EL: return(&termKillChar);
225 case SLC_XON: return(&termStartChar);
226 case SLC_XOFF: return(&termStopChar);
227 case SLC_FORW1: return(&termForw1Char);
228 case SLC_FORW2: return(&termForw2Char);
229 # ifdef VDISCARD
230 case SLC_AO: return(&termFlushChar);
231 # endif
232 # ifdef VSUSP
233 case SLC_SUSP: return(&termSuspChar);
234 # endif
235 # ifdef VWERASE
236 case SLC_EW: return(&termWerasChar);
237 # endif
238 # ifdef VREPRINT
239 case SLC_RP: return(&termRprntChar);
240 # endif
241 # ifdef VLNEXT
242 case SLC_LNEXT: return(&termLiteralNextChar);
243 # endif
244 # ifdef VSTATUS
245 case SLC_AYT: return(&termAytChar);
246 # endif
247
248 case SLC_SYNCH:
249 case SLC_BRK:
250 case SLC_EOR:
251 default:
252 return((cc_t *)0);
253 }
254 }
255
256 void
TerminalDefaultChars(void)257 TerminalDefaultChars(void)
258 {
259 memmove(new_tc.c_cc, old_tc.c_cc, sizeof(old_tc.c_cc));
260 # ifndef VDISCARD
261 termFlushChar = CONTROL('O');
262 # endif
263 # ifndef VWERASE
264 termWerasChar = CONTROL('W');
265 # endif
266 # ifndef VREPRINT
267 termRprntChar = CONTROL('R');
268 # endif
269 # ifndef VLNEXT
270 termLiteralNextChar = CONTROL('V');
271 # endif
272 # ifndef VSTART
273 termStartChar = CONTROL('Q');
274 # endif
275 # ifndef VSTOP
276 termStopChar = CONTROL('S');
277 # endif
278 # ifndef VSTATUS
279 termAytChar = CONTROL('T');
280 # endif
281 }
282
283 #ifdef notdef
284 void
TerminalRestoreState()285 TerminalRestoreState()
286 {
287 }
288 #endif
289
290 /*
291 * TerminalNewMode - set up terminal to a specific mode.
292 * MODE_ECHO: do local terminal echo
293 * MODE_FLOW: do local flow control
294 * MODE_TRAPSIG: do local mapping to TELNET IAC sequences
295 * MODE_EDIT: do local line editing
296 *
297 * Command mode:
298 * MODE_ECHO|MODE_EDIT|MODE_FLOW|MODE_TRAPSIG
299 * local echo
300 * local editing
301 * local xon/xoff
302 * local signal mapping
303 *
304 * Linemode:
305 * local/no editing
306 * Both Linemode and Single Character mode:
307 * local/remote echo
308 * local/no xon/xoff
309 * local/no signal mapping
310 */
311
312
313 #ifdef SIGTSTP
314 static RETSIGTYPE susp(int);
315 #endif /* SIGTSTP */
316 #ifdef SIGINFO
317 static RETSIGTYPE ayt(int);
318 #endif
319
320 void
TerminalNewMode(int f)321 TerminalNewMode(int f)
322 {
323 static int prevmode = 0;
324 struct termios tmp_tc;
325 int onoff;
326 int old;
327 cc_t esc;
328
329 globalmode = f&~MODE_FORCE;
330 if (prevmode == f)
331 return;
332
333 /*
334 * Write any outstanding data before switching modes
335 * ttyflush() returns 0 only when there is no more data
336 * left to write out, it returns -1 if it couldn't do
337 * anything at all, otherwise it returns 1 + the number
338 * of characters left to write.
339 */
340 old = ttyflush(SYNCHing|flushout);
341 if (old < 0 || old > 1) {
342 tcgetattr(tin, &tmp_tc);
343 do {
344 /*
345 * Wait for data to drain, then flush again.
346 */
347 tcsetattr(tin, TCSADRAIN, &tmp_tc);
348 old = ttyflush(SYNCHing|flushout);
349 } while (old < 0 || old > 1);
350 }
351
352 old = prevmode;
353 prevmode = f&~MODE_FORCE;
354 tmp_tc = new_tc;
355
356 if (f&MODE_ECHO) {
357 tmp_tc.c_lflag |= ECHO;
358 tmp_tc.c_oflag |= ONLCR;
359 if (crlf)
360 tmp_tc.c_iflag |= ICRNL;
361 } else {
362 tmp_tc.c_lflag &= ~ECHO;
363 tmp_tc.c_oflag &= ~ONLCR;
364 # ifdef notdef
365 if (crlf)
366 tmp_tc.c_iflag &= ~ICRNL;
367 # endif
368 }
369
370 if ((f&MODE_FLOW) == 0) {
371 tmp_tc.c_iflag &= ~(IXOFF|IXON); /* Leave the IXANY bit alone */
372 } else {
373 if (restartany < 0) {
374 tmp_tc.c_iflag |= IXOFF|IXON; /* Leave the IXANY bit alone */
375 } else if (restartany > 0) {
376 tmp_tc.c_iflag |= IXOFF|IXON|IXANY;
377 } else {
378 tmp_tc.c_iflag |= IXOFF|IXON;
379 tmp_tc.c_iflag &= ~IXANY;
380 }
381 }
382
383 if ((f&MODE_TRAPSIG) == 0) {
384 tmp_tc.c_lflag &= ~ISIG;
385 localchars = 0;
386 } else {
387 tmp_tc.c_lflag |= ISIG;
388 localchars = 1;
389 }
390
391 if (f&MODE_EDIT) {
392 tmp_tc.c_lflag |= ICANON;
393 } else {
394 tmp_tc.c_lflag &= ~ICANON;
395 tmp_tc.c_iflag &= ~ICRNL;
396 tmp_tc.c_cc[VMIN] = 1;
397 tmp_tc.c_cc[VTIME] = 0;
398 }
399
400 if ((f&(MODE_EDIT|MODE_TRAPSIG)) == 0) {
401 # ifdef VLNEXT
402 tmp_tc.c_cc[VLNEXT] = (cc_t)(_POSIX_VDISABLE);
403 # endif
404 }
405
406 if (f&MODE_SOFT_TAB) {
407 # ifdef OXTABS
408 tmp_tc.c_oflag |= OXTABS;
409 # endif
410 # ifdef TABDLY
411 tmp_tc.c_oflag &= ~TABDLY;
412 tmp_tc.c_oflag |= TAB3;
413 # endif
414 } else {
415 # ifdef OXTABS
416 tmp_tc.c_oflag &= ~OXTABS;
417 # endif
418 # ifdef TABDLY
419 tmp_tc.c_oflag &= ~TABDLY;
420 # endif
421 }
422
423 if (f&MODE_LIT_ECHO) {
424 # ifdef ECHOCTL
425 tmp_tc.c_lflag &= ~ECHOCTL;
426 # endif
427 } else {
428 # ifdef ECHOCTL
429 tmp_tc.c_lflag |= ECHOCTL;
430 # endif
431 }
432
433 if (f == -1) {
434 onoff = 0;
435 } else {
436 if (f & MODE_INBIN)
437 tmp_tc.c_iflag &= ~ISTRIP;
438 else
439 tmp_tc.c_iflag |= ISTRIP;
440 if ((f & MODE_OUTBIN) || (f & MODE_OUT8)) {
441 tmp_tc.c_cflag &= ~(CSIZE|PARENB);
442 tmp_tc.c_cflag |= CS8;
443 if(f & MODE_OUTBIN)
444 tmp_tc.c_oflag &= ~OPOST;
445 else
446 tmp_tc.c_oflag |= OPOST;
447 } else {
448 tmp_tc.c_cflag &= ~(CSIZE|PARENB);
449 tmp_tc.c_cflag |= old_tc.c_cflag & (CSIZE|PARENB);
450 tmp_tc.c_oflag |= OPOST;
451 }
452 onoff = 1;
453 }
454
455 if (f != -1) {
456
457 #ifdef SIGTSTP
458 signal(SIGTSTP, susp);
459 #endif /* SIGTSTP */
460 #ifdef SIGINFO
461 signal(SIGINFO, ayt);
462 #endif
463 #ifdef NOKERNINFO
464 tmp_tc.c_lflag |= NOKERNINFO;
465 #endif
466 /*
467 * We don't want to process ^Y here. It's just another
468 * character that we'll pass on to the back end. It has
469 * to process it because it will be processed when the
470 * user attempts to read it, not when we send it.
471 */
472 # ifdef VDSUSP
473 tmp_tc.c_cc[VDSUSP] = (cc_t)(_POSIX_VDISABLE);
474 # endif
475 /*
476 * If the VEOL character is already set, then use VEOL2,
477 * otherwise use VEOL.
478 */
479 esc = (rlogin != _POSIX_VDISABLE) ? rlogin : escape;
480 if ((tmp_tc.c_cc[VEOL] != esc)
481 # ifdef VEOL2
482 && (tmp_tc.c_cc[VEOL2] != esc)
483 # endif
484 ) {
485 if (tmp_tc.c_cc[VEOL] == (cc_t)(_POSIX_VDISABLE))
486 tmp_tc.c_cc[VEOL] = esc;
487 # ifdef VEOL2
488 else if (tmp_tc.c_cc[VEOL2] == (cc_t)(_POSIX_VDISABLE))
489 tmp_tc.c_cc[VEOL2] = esc;
490 # endif
491 }
492 } else {
493 sigset_t sm;
494
495 #ifdef SIGINFO
496 signal(SIGINFO, ayt_status);
497 #endif
498 #ifdef SIGTSTP
499 signal(SIGTSTP, SIG_DFL);
500 sigemptyset(&sm);
501 sigaddset(&sm, SIGTSTP);
502 sigprocmask(SIG_UNBLOCK, &sm, NULL);
503 #endif /* SIGTSTP */
504 tmp_tc = old_tc;
505 }
506 if (tcsetattr(tin, TCSADRAIN, &tmp_tc) < 0)
507 tcsetattr(tin, TCSANOW, &tmp_tc);
508
509 ioctl(tin, FIONBIO, (char *)&onoff);
510 ioctl(tout, FIONBIO, (char *)&onoff);
511
512 }
513
514 /*
515 * Try to guess whether speeds are "encoded" (4.2BSD) or just numeric (4.4BSD).
516 */
517 #if B4800 != 4800
518 #define DECODE_BAUD
519 #endif
520
521 #ifdef DECODE_BAUD
522 #ifndef B7200
523 #define B7200 B4800
524 #endif
525
526 #ifndef B14400
527 #define B14400 B9600
528 #endif
529
530 #ifndef B19200
531 # define B19200 B14400
532 #endif
533
534 #ifndef B28800
535 #define B28800 B19200
536 #endif
537
538 #ifndef B38400
539 # define B38400 B28800
540 #endif
541
542 #ifndef B57600
543 #define B57600 B38400
544 #endif
545
546 #ifndef B76800
547 #define B76800 B57600
548 #endif
549
550 #ifndef B115200
551 #define B115200 B76800
552 #endif
553
554 #ifndef B230400
555 #define B230400 B115200
556 #endif
557
558
559 /*
560 * This code assumes that the values B0, B50, B75...
561 * are in ascending order. They do not have to be
562 * contiguous.
563 */
564 struct termspeeds {
565 long speed;
566 long value;
567 } termspeeds[] = {
568 { 0, B0 }, { 50, B50 }, { 75, B75 },
569 { 110, B110 }, { 134, B134 }, { 150, B150 },
570 { 200, B200 }, { 300, B300 }, { 600, B600 },
571 { 1200, B1200 }, { 1800, B1800 }, { 2400, B2400 },
572 { 4800, B4800 }, { 7200, B7200 }, { 9600, B9600 },
573 { 14400, B14400 }, { 19200, B19200 }, { 28800, B28800 },
574 { 38400, B38400 }, { 57600, B57600 }, { 115200, B115200 },
575 { 230400, B230400 }, { -1, B230400 }
576 };
577 #endif /* DECODE_BAUD */
578
579 void
TerminalSpeeds(long * input_speed,long * output_speed)580 TerminalSpeeds(long *input_speed, long *output_speed)
581 {
582 #ifdef DECODE_BAUD
583 struct termspeeds *tp;
584 #endif /* DECODE_BAUD */
585 long in, out;
586
587 out = cfgetospeed(&old_tc);
588 in = cfgetispeed(&old_tc);
589 if (in == 0)
590 in = out;
591
592 #ifdef DECODE_BAUD
593 tp = termspeeds;
594 while ((tp->speed != -1) && (tp->value < in))
595 tp++;
596 *input_speed = tp->speed;
597
598 tp = termspeeds;
599 while ((tp->speed != -1) && (tp->value < out))
600 tp++;
601 *output_speed = tp->speed;
602 #else /* DECODE_BAUD */
603 *input_speed = in;
604 *output_speed = out;
605 #endif /* DECODE_BAUD */
606 }
607
608 int
TerminalWindowSize(long * rows,long * cols)609 TerminalWindowSize(long *rows, long *cols)
610 {
611 int irows, icols;
612
613 if (get_window_size(STDIN_FILENO, &irows, &icols) == 0) {
614 *rows = irows;
615 *cols = icols;
616 return 1;
617 } else
618 return 0;
619 }
620
621 int
NetClose(int fd)622 NetClose(int fd)
623 {
624 return close(fd);
625 }
626
627
628 void
NetNonblockingIO(int fd,int onoff)629 NetNonblockingIO(int fd, int onoff)
630 {
631 ioctl(fd, FIONBIO, (char *)&onoff);
632 }
633
634
635 /*
636 * Various signal handling routines.
637 */
638
639 static RETSIGTYPE deadpeer(int),
640 intr(int), intr2(int), susp(int), sendwin(int);
641 #ifdef SIGINFO
642 static RETSIGTYPE ayt(int);
643 #endif
644
645
646 /* ARGSUSED */
647 static RETSIGTYPE
deadpeer(int sig)648 deadpeer(int sig)
649 {
650 setcommandmode();
651 longjmp(peerdied, -1);
652 }
653
654 int intr_happened = 0;
655 int intr_waiting = 0;
656
657 /* ARGSUSED */
658 static RETSIGTYPE
intr(int sig)659 intr(int sig)
660 {
661 if (intr_waiting) {
662 intr_happened = 1;
663 return;
664 }
665 if (localchars) {
666 intp();
667 return;
668 }
669 setcommandmode();
670 longjmp(toplevel, -1);
671 }
672
673 /* ARGSUSED */
674 static RETSIGTYPE
intr2(int sig)675 intr2(int sig)
676 {
677 if (localchars) {
678 #ifdef KLUDGELINEMODE
679 if (kludgelinemode)
680 sendbrk();
681 else
682 #endif
683 sendabort();
684 return;
685 }
686 }
687
688 #ifdef SIGTSTP
689 /* ARGSUSED */
690 static RETSIGTYPE
susp(int sig)691 susp(int sig)
692 {
693 if ((rlogin != _POSIX_VDISABLE) && rlogin_susp())
694 return;
695 if (localchars)
696 sendsusp();
697 }
698 #endif
699
700 #ifdef SIGWINCH
701 /* ARGSUSED */
702 static RETSIGTYPE
sendwin(int sig)703 sendwin(int sig)
704 {
705 if (connected) {
706 sendnaws();
707 }
708 }
709 #endif
710
711 #ifdef SIGINFO
712 /* ARGSUSED */
713 static RETSIGTYPE
ayt(int sig)714 ayt(int sig)
715 {
716 if (connected)
717 sendayt();
718 else
719 ayt_status(sig);
720 }
721 #endif
722
723
724 void
sys_telnet_init(void)725 sys_telnet_init(void)
726 {
727 signal(SIGINT, intr);
728 signal(SIGQUIT, intr2);
729 signal(SIGPIPE, deadpeer);
730 #ifdef SIGWINCH
731 signal(SIGWINCH, sendwin);
732 #endif
733 #ifdef SIGTSTP
734 signal(SIGTSTP, susp);
735 #endif
736 #ifdef SIGINFO
737 signal(SIGINFO, ayt);
738 #endif
739
740 setconnmode(0);
741
742 NetNonblockingIO(net, 1);
743
744
745 #if defined(SO_OOBINLINE)
746 if (SetSockOpt(net, SOL_SOCKET, SO_OOBINLINE, 1) == -1)
747 perror("setsockopt (SO_OOBINLINE) (ignored)");
748 #endif /* defined(SO_OOBINLINE) */
749 }
750
751 /*
752 * Process rings -
753 *
754 * This routine tries to fill up/empty our various rings.
755 *
756 * The parameter specifies whether this is a poll operation,
757 * or a block-until-something-happens operation.
758 *
759 * The return value is 1 if something happened, 0 if not.
760 */
761
762 int
process_rings(int netin,int netout,int netex,int ttyin,int ttyout,int poll)763 process_rings(int netin,
764 int netout,
765 int netex,
766 int ttyin,
767 int ttyout,
768 int poll) /* If 0, then block until something to do */
769 {
770 int c;
771 /* One wants to be a bit careful about setting returnValue
772 * to one, since a one implies we did some useful work,
773 * and therefore probably won't be called to block next
774 * time (TN3270 mode only).
775 */
776 int returnValue = 0;
777 static struct timeval TimeValue = { 0 };
778
779 if (net >= FD_SETSIZE
780 || tout >= FD_SETSIZE
781 || tin >= FD_SETSIZE)
782 errx (1, "fd too large");
783
784 if (netout) {
785 FD_SET(net, &obits);
786 }
787 if (ttyout) {
788 FD_SET(tout, &obits);
789 }
790 if (ttyin) {
791 FD_SET(tin, &ibits);
792 }
793 if (netin) {
794 FD_SET(net, &ibits);
795 }
796 #if !defined(SO_OOBINLINE)
797 if (netex) {
798 FD_SET(net, &xbits);
799 }
800 #endif
801 if ((c = select(FD_SETSIZE, &ibits, &obits, &xbits,
802 (poll == 0)? (struct timeval *)0 : &TimeValue)) < 0) {
803 if (c == -1) {
804 /*
805 * we can get EINTR if we are in line mode,
806 * and the user does an escape (TSTP), or
807 * some other signal generator.
808 */
809 if (errno == EINTR) {
810 return 0;
811 }
812 /* I don't like this, does it ever happen? */
813 printf("sleep(5) from telnet, after select\r\n");
814 sleep(5);
815 }
816 return 0;
817 }
818
819 /*
820 * Any urgent data?
821 */
822 if (FD_ISSET(net, &xbits)) {
823 FD_CLR(net, &xbits);
824 SYNCHing = 1;
825 ttyflush(1); /* flush already enqueued data */
826 }
827
828 /*
829 * Something to read from the network...
830 */
831 if (FD_ISSET(net, &ibits)) {
832 int canread;
833
834 FD_CLR(net, &ibits);
835 canread = ring_empty_consecutive(&netiring);
836 #if !defined(SO_OOBINLINE)
837 /*
838 * In 4.2 (and some early 4.3) systems, the
839 * OOB indication and data handling in the kernel
840 * is such that if two separate TCP Urgent requests
841 * come in, one byte of TCP data will be overlaid.
842 * This is fatal for Telnet, but we try to live
843 * with it.
844 *
845 * In addition, in 4.2 (and...), a special protocol
846 * is needed to pick up the TCP Urgent data in
847 * the correct sequence.
848 *
849 * What we do is: if we think we are in urgent
850 * mode, we look to see if we are "at the mark".
851 * If we are, we do an OOB receive. If we run
852 * this twice, we will do the OOB receive twice,
853 * but the second will fail, since the second
854 * time we were "at the mark", but there wasn't
855 * any data there (the kernel doesn't reset
856 * "at the mark" until we do a normal read).
857 * Once we've read the OOB data, we go ahead
858 * and do normal reads.
859 *
860 * There is also another problem, which is that
861 * since the OOB byte we read doesn't put us
862 * out of OOB state, and since that byte is most
863 * likely the TELNET DM (data mark), we would
864 * stay in the TELNET SYNCH (SYNCHing) state.
865 * So, clocks to the rescue. If we've "just"
866 * received a DM, then we test for the
867 * presence of OOB data when the receive OOB
868 * fails (and AFTER we did the normal mode read
869 * to clear "at the mark").
870 */
871 if (SYNCHing) {
872 int atmark;
873 static int bogus_oob = 0, first = 1;
874
875 ioctl(net, SIOCATMARK, (char *)&atmark);
876 if (atmark) {
877 c = recv(net, netiring.supply, canread, MSG_OOB);
878 if ((c == -1) && (errno == EINVAL)) {
879 c = recv(net, netiring.supply, canread, 0);
880 if (clocks.didnetreceive < clocks.gotDM) {
881 SYNCHing = stilloob();
882 }
883 } else if (first && c > 0) {
884 /*
885 * Bogosity check. Systems based on 4.2BSD
886 * do not return an error if you do a second
887 * recv(MSG_OOB). So, we do one. If it
888 * succeeds and returns exactly the same
889 * data, then assume that we are running
890 * on a broken system and set the bogus_oob
891 * flag. (If the data was different, then
892 * we probably got some valid new data, so
893 * increment the count...)
894 */
895 int i;
896 i = recv(net, netiring.supply + c, canread - c, MSG_OOB);
897 if (i == c &&
898 memcmp(netiring.supply, netiring.supply + c, i) == 0) {
899 bogus_oob = 1;
900 first = 0;
901 } else if (i < 0) {
902 bogus_oob = 0;
903 first = 0;
904 } else
905 c += i;
906 }
907 if (bogus_oob && c > 0) {
908 int i;
909 /*
910 * Bogosity. We have to do the read
911 * to clear the atmark to get out of
912 * an infinate loop.
913 */
914 i = read(net, netiring.supply + c, canread - c);
915 if (i > 0)
916 c += i;
917 }
918 } else {
919 c = recv(net, netiring.supply, canread, 0);
920 }
921 } else {
922 c = recv(net, netiring.supply, canread, 0);
923 }
924 settimer(didnetreceive);
925 #else /* !defined(SO_OOBINLINE) */
926 c = recv(net, (char *)netiring.supply, canread, 0);
927 #endif /* !defined(SO_OOBINLINE) */
928 if (c < 0 && errno == EWOULDBLOCK) {
929 c = 0;
930 } else if (c <= 0) {
931 return -1;
932 }
933 if (netdata) {
934 Dump('<', netiring.supply, c);
935 }
936 if (c)
937 ring_supplied(&netiring, c);
938 returnValue = 1;
939 }
940
941 /*
942 * Something to read from the tty...
943 */
944 if (FD_ISSET(tin, &ibits)) {
945 FD_CLR(tin, &ibits);
946 c = TerminalRead(ttyiring.supply, ring_empty_consecutive(&ttyiring));
947 if (c < 0 && errno == EIO)
948 c = 0;
949 if (c < 0 && errno == EWOULDBLOCK) {
950 c = 0;
951 } else {
952 /* EOF detection for line mode!!!! */
953 if ((c == 0) && MODE_LOCAL_CHARS(globalmode) && isatty(tin)) {
954 /* must be an EOF... */
955 *ttyiring.supply = termEofChar;
956 c = 1;
957 }
958 if (c <= 0) {
959 return -1;
960 }
961 if (termdata) {
962 Dump('<', ttyiring.supply, c);
963 }
964 ring_supplied(&ttyiring, c);
965 }
966 returnValue = 1; /* did something useful */
967 }
968
969 if (FD_ISSET(net, &obits)) {
970 FD_CLR(net, &obits);
971 returnValue |= netflush();
972 }
973 if (FD_ISSET(tout, &obits)) {
974 FD_CLR(tout, &obits);
975 returnValue |= (ttyflush(SYNCHing|flushout) > 0);
976 }
977
978 return returnValue;
979 }
980