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Fix UTIME_OMIT handling
[dragonfly.git] / libexec / telnetd / state.c
blob3a596b3e633f0111458b5735009c6d2a9f45796b
1 /*
2 * Copyright (c) 1989, 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. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * @(#)state.c 8.5 (Berkeley) 5/30/95
30 * $FreeBSD: src/crypto/telnet/telnetd/state.c,v 1.4.2.3 2002/04/13 10:59:08 markm Exp $
31 */
32
33 #include <stdarg.h>
34 #include "telnetd.h"
35 #ifdef AUTHENTICATION
36 #include <libtelnet/auth.h>
37 #endif
38 #ifdef ENCRYPTION
39 #include <libtelnet/encrypt.h>
40 #endif
41
42 static int envvarok(char *);
43
44 unsigned char doopt[] = { IAC, DO, '%', 'c', 0 };
45 unsigned char dont[] = { IAC, DONT, '%', 'c', 0 };
46 unsigned char will[] = { IAC, WILL, '%', 'c', 0 };
47 unsigned char wont[] = { IAC, WONT, '%', 'c', 0 };
48 int not42 = 1;
49 char *terminaltype;
50
51 /*
52 * Buffer for sub-options, and macros
53 * for suboptions buffer manipulations
54 */
55 unsigned char subbuffer[512], *subpointer= subbuffer, *subend= subbuffer;
56
57 #define SB_CLEAR() subpointer = subbuffer
58 #define SB_TERM() { subend = subpointer; SB_CLEAR(); }
59 #define SB_ACCUM(c) if (subpointer < (subbuffer+sizeof subbuffer)) { \
60 *subpointer++ = (c); \
61 }
62 #define SB_GET() ((*subpointer++)&0xff)
63 #define SB_EOF() (subpointer >= subend)
64 #define SB_LEN() (subend - subpointer)
65
66 #ifdef ENV_HACK
67 unsigned char *subsave;
68 #define SB_SAVE() subsave = subpointer;
69 #define SB_RESTORE() subpointer = subsave;
70 #endif
71
72
73 /*
74 * State for recv fsm
75 */
76 #define TS_DATA 0 /* base state */
77 #define TS_IAC 1 /* look for double IAC's */
78 #define TS_CR 2 /* CR-LF ->'s CR */
79 #define TS_SB 3 /* throw away begin's... */
80 #define TS_SE 4 /* ...end's (suboption negotiation) */
81 #define TS_WILL 5 /* will option negotiation */
82 #define TS_WONT 6 /* wont " */
83 #define TS_DO 7 /* do " */
84 #define TS_DONT 8 /* dont " */
85
86 static void doclientstat(void);
87
88 void
89 telrcv(void)
90 {
91 int c;
92 static int state = TS_DATA;
93
94 while (ncc > 0) {
95 if ((&ptyobuf[BUFSIZ] - pfrontp) < 2)
96 break;
97 c = *netip++ & 0377, ncc--;
98 #ifdef ENCRYPTION
99 if (decrypt_input)
100 c = (*decrypt_input)(c);
101 #endif /* ENCRYPTION */
102 switch (state) {
103
104 case TS_CR:
105 state = TS_DATA;
106 /* Strip off \n or \0 after a \r */
107 if ((c == 0) || (c == '\n')) {
108 break;
109 }
110 /* FALL THROUGH */
111
112 case TS_DATA:
113 if (c == IAC) {
114 state = TS_IAC;
115 break;
116 }
117 /*
118 * We now map \r\n ==> \r for pragmatic reasons.
119 * Many client implementations send \r\n when
120 * the user hits the CarriageReturn key.
121 *
122 * We USED to map \r\n ==> \n, since \r\n says
123 * that we want to be in column 1 of the next
124 * printable line, and \n is the standard
125 * unix way of saying that (\r is only good
126 * if CRMOD is set, which it normally is).
127 */
128 if ((c == '\r') && his_state_is_wont(TELOPT_BINARY)) {
129 int nc = *netip;
130 #ifdef ENCRYPTION
131 if (decrypt_input)
132 nc = (*decrypt_input)(nc & 0xff);
133 #endif /* ENCRYPTION */
134 #ifdef LINEMODE
135 /*
136 * If we are operating in linemode,
137 * convert to local end-of-line.
138 */
139 if (linemode && (ncc > 0) && (('\n' == nc) ||
140 ((0 == nc) && tty_iscrnl())) ) {
141 netip++; ncc--;
142 c = '\n';
143 } else
144 #endif
145 {
146 #ifdef ENCRYPTION
147 if (decrypt_input)
148 (void)(*decrypt_input)(-1);
149 #endif /* ENCRYPTION */
150 state = TS_CR;
151 }
152 }
153 *pfrontp++ = c;
154 break;
155
156 case TS_IAC:
157 gotiac: switch (c) {
158
159 /*
160 * Send the process on the pty side an
161 * interrupt. Do this with a NULL or
162 * interrupt char; depending on the tty mode.
163 */
164 case IP:
165 DIAG(TD_OPTIONS,
166 printoption("td: recv IAC", c));
167 interrupt();
168 break;
169
170 case BREAK:
171 DIAG(TD_OPTIONS,
172 printoption("td: recv IAC", c));
173 sendbrk();
174 break;
175
176 /*
177 * Are You There?
178 */
179 case AYT:
180 DIAG(TD_OPTIONS,
181 printoption("td: recv IAC", c));
182 recv_ayt();
183 break;
184
185 /*
186 * Abort Output
187 */
188 case AO:
189 {
190 DIAG(TD_OPTIONS,
191 printoption("td: recv IAC", c));
192 ptyflush(); /* half-hearted */
193 init_termbuf();
194
195 if (slctab[SLC_AO].sptr &&
196 *slctab[SLC_AO].sptr != (cc_t)(_POSIX_VDISABLE)) {
197 *pfrontp++ =
198 (unsigned char)*slctab[SLC_AO].sptr;
199 }
200
201 netclear(); /* clear buffer back */
202 output_data("%c%c", IAC, DM);
203 neturg = nfrontp-1; /* off by one XXX */
204 DIAG(TD_OPTIONS,
205 printoption("td: send IAC", DM));
206 break;
207 }
208
209 /*
210 * Erase Character and
211 * Erase Line
212 */
213 case EC:
214 case EL:
215 {
216 cc_t ch;
217
218 DIAG(TD_OPTIONS,
219 printoption("td: recv IAC", c));
220 ptyflush(); /* half-hearted */
221 init_termbuf();
222 if (c == EC)
223 ch = *slctab[SLC_EC].sptr;
224 else
225 ch = *slctab[SLC_EL].sptr;
226 if (ch != (cc_t)(_POSIX_VDISABLE))
227 *pfrontp++ = (unsigned char)ch;
228 break;
229 }
230
231 /*
232 * Check for urgent data...
233 */
234 case DM:
235 DIAG(TD_OPTIONS,
236 printoption("td: recv IAC", c));
237 SYNCHing = stilloob(net);
238 settimer(gotDM);
239 break;
240
241
242 /*
243 * Begin option subnegotiation...
244 */
245 case SB:
246 state = TS_SB;
247 SB_CLEAR();
248 continue;
249
250 case WILL:
251 state = TS_WILL;
252 continue;
253
254 case WONT:
255 state = TS_WONT;
256 continue;
257
258 case DO:
259 state = TS_DO;
260 continue;
261
262 case DONT:
263 state = TS_DONT;
264 continue;
265 case EOR:
266 if (his_state_is_will(TELOPT_EOR))
267 doeof();
268 break;
269
270 /*
271 * Handle RFC 10xx Telnet linemode option additions
272 * to command stream (EOF, SUSP, ABORT).
273 */
274 case xEOF:
275 doeof();
276 break;
277
278 case SUSP:
279 sendsusp();
280 break;
281
282 case ABORT:
283 sendbrk();
284 break;
285
286 case IAC:
287 *pfrontp++ = c;
288 break;
289 }
290 state = TS_DATA;
291 break;
292
293 case TS_SB:
294 if (c == IAC) {
295 state = TS_SE;
296 } else {
297 SB_ACCUM(c);
298 }
299 break;
300
301 case TS_SE:
302 if (c != SE) {
303 if (c != IAC) {
304 /*
305 * bad form of suboption negotiation.
306 * handle it in such a way as to avoid
307 * damage to local state. Parse
308 * suboption buffer found so far,
309 * then treat remaining stream as
310 * another command sequence.
311 */
312
313 /* for DIAGNOSTICS */
314 SB_ACCUM(IAC);
315 SB_ACCUM(c);
316 subpointer -= 2;
317
318 SB_TERM();
319 suboption();
320 state = TS_IAC;
321 goto gotiac;
322 }
323 SB_ACCUM(c);
324 state = TS_SB;
325 } else {
326 /* for DIAGNOSTICS */
327 SB_ACCUM(IAC);
328 SB_ACCUM(SE);
329 subpointer -= 2;
330
331 SB_TERM();
332 suboption(); /* handle sub-option */
333 state = TS_DATA;
334 }
335 break;
336
337 case TS_WILL:
338 willoption(c);
339 state = TS_DATA;
340 continue;
341
342 case TS_WONT:
343 wontoption(c);
344 state = TS_DATA;
345 continue;
346
347 case TS_DO:
348 dooption(c);
349 state = TS_DATA;
350 continue;
351
352 case TS_DONT:
353 dontoption(c);
354 state = TS_DATA;
355 continue;
356
357 default:
358 syslog(LOG_ERR, "panic state=%d", state);
359 printf("telnetd: panic state=%d\n", state);
360 exit(1);
361 }
362 }
363 } /* end of telrcv */
364
365 /*
366 * The will/wont/do/dont state machines are based on Dave Borman's
367 * Telnet option processing state machine.
368 *
369 * These correspond to the following states:
370 * my_state = the last negotiated state
371 * want_state = what I want the state to go to
372 * want_resp = how many requests I have sent
373 * All state defaults are negative, and resp defaults to 0.
374 *
375 * When initiating a request to change state to new_state:
376 *
377 * if ((want_resp == 0 && new_state == my_state) || want_state == new_state) {
378 * do nothing;
379 * } else {
380 * want_state = new_state;
381 * send new_state;
382 * want_resp++;
383 * }
384 *
385 * When receiving new_state:
386 *
387 * if (want_resp) {
388 * want_resp--;
389 * if (want_resp && (new_state == my_state))
390 * want_resp--;
391 * }
392 * if ((want_resp == 0) && (new_state != want_state)) {
393 * if (ok_to_switch_to new_state)
394 * want_state = new_state;
395 * else
396 * want_resp++;
397 * send want_state;
398 * }
399 * my_state = new_state;
400 *
401 * Note that new_state is implied in these functions by the function itself.
402 * will and do imply positive new_state, wont and dont imply negative.
403 *
404 * Finally, there is one catch. If we send a negative response to a
405 * positive request, my_state will be the positive while want_state will
406 * remain negative. my_state will revert to negative when the negative
407 * acknowlegment arrives from the peer. Thus, my_state generally tells
408 * us not only the last negotiated state, but also tells us what the peer
409 * wants to be doing as well. It is important to understand this difference
410 * as we may wish to be processing data streams based on our desired state
411 * (want_state) or based on what the peer thinks the state is (my_state).
412 *
413 * This all works fine because if the peer sends a positive request, the data
414 * that we receive prior to negative acknowlegment will probably be affected
415 * by the positive state, and we can process it as such (if we can; if we
416 * can't then it really doesn't matter). If it is that important, then the
417 * peer probably should be buffering until this option state negotiation
418 * is complete.
419 *
420 */
421 void
422 send_do(int option, int init)
423 {
424 if (init) {
425 if ((do_dont_resp[option] == 0 && his_state_is_will(option)) ||
426 his_want_state_is_will(option))
427 return;
428 /*
429 * Special case for TELOPT_TM: We send a DO, but pretend
430 * that we sent a DONT, so that we can send more DOs if
431 * we want to.
432 */
433 if (option == TELOPT_TM)
434 set_his_want_state_wont(option);
435 else
436 set_his_want_state_will(option);
437 do_dont_resp[option]++;
438 }
439 output_data((const char *)doopt, option);
440
441 DIAG(TD_OPTIONS, printoption("td: send do", option));
442 }
443
444 void
445 willoption(int option)
446 {
447 int changeok = 0;
448 void (*func)(void) = NULL;
449
450 /*
451 * process input from peer.
452 */
453
454 DIAG(TD_OPTIONS, printoption("td: recv will", option));
455
456 if (do_dont_resp[option]) {
457 do_dont_resp[option]--;
458 if (do_dont_resp[option] && his_state_is_will(option))
459 do_dont_resp[option]--;
460 }
461 if (do_dont_resp[option] == 0) {
462 if (his_want_state_is_wont(option)) {
463 switch (option) {
464
465 case TELOPT_BINARY:
466 init_termbuf();
467 tty_binaryin(1);
468 set_termbuf();
469 changeok++;
470 break;
471
472 case TELOPT_ECHO:
473 /*
474 * See comments below for more info.
475 */
476 not42 = 0; /* looks like a 4.2 system */
477 break;
478
479 case TELOPT_TM:
480 #if defined(LINEMODE) && defined(KLUDGELINEMODE)
481 /*
482 * This telnetd implementation does not really
483 * support timing marks, it just uses them to
484 * support the kludge linemode stuff. If we
485 * receive a will or wont TM in response to our
486 * do TM request that may have been sent to
487 * determine kludge linemode support, process
488 * it, otherwise TM should get a negative
489 * response back.
490 */
491 /*
492 * Handle the linemode kludge stuff.
493 * If we are not currently supporting any
494 * linemode at all, then we assume that this
495 * is the client telling us to use kludge
496 * linemode in response to our query. Set the
497 * linemode type that is to be supported, note
498 * that the client wishes to use linemode, and
499 * eat the will TM as though it never arrived.
500 */
501 if (lmodetype < KLUDGE_LINEMODE) {
502 lmodetype = KLUDGE_LINEMODE;
503 clientstat(TELOPT_LINEMODE, WILL, 0);
504 send_wont(TELOPT_SGA, 1);
505 } else if (lmodetype == NO_AUTOKLUDGE) {
506 lmodetype = KLUDGE_OK;
507 }
508 #endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */
509 /*
510 * We never respond to a WILL TM, and
511 * we leave the state WONT.
512 */
513 return;
514
515 case TELOPT_LFLOW:
516 /*
517 * If we are going to support flow control
518 * option, then don't worry peer that we can't
519 * change the flow control characters.
520 */
521 slctab[SLC_XON].defset.flag &= ~SLC_LEVELBITS;
522 slctab[SLC_XON].defset.flag |= SLC_DEFAULT;
523 slctab[SLC_XOFF].defset.flag &= ~SLC_LEVELBITS;
524 slctab[SLC_XOFF].defset.flag |= SLC_DEFAULT;
525 /* FALLTHROUGH */
526 case TELOPT_TTYPE:
527 case TELOPT_SGA:
528 case TELOPT_NAWS:
529 case TELOPT_TSPEED:
530 case TELOPT_XDISPLOC:
531 case TELOPT_NEW_ENVIRON:
532 case TELOPT_OLD_ENVIRON:
533 changeok++;
534 break;
535
536 #ifdef LINEMODE
537 case TELOPT_LINEMODE:
538 # ifdef KLUDGELINEMODE
539 /*
540 * Note client's desire to use linemode.
541 */
542 lmodetype = REAL_LINEMODE;
543 # endif /* KLUDGELINEMODE */
544 func = doclientstat;
545 changeok++;
546 break;
547 #endif /* LINEMODE */
548
549 #ifdef AUTHENTICATION
550 case TELOPT_AUTHENTICATION:
551 func = auth_request;
552 changeok++;
553 break;
554 #endif
555
556 #ifdef ENCRYPTION
557 case TELOPT_ENCRYPT:
558 func = encrypt_send_support;
559 changeok++;
560 break;
561 #endif /* ENCRYPTION */
562
563 default:
564 break;
565 }
566 if (changeok) {
567 set_his_want_state_will(option);
568 send_do(option, 0);
569 } else {
570 do_dont_resp[option]++;
571 send_dont(option, 0);
572 }
573 } else {
574 /*
575 * Option processing that should happen when
576 * we receive conformation of a change in
577 * state that we had requested.
578 */
579 switch (option) {
580 case TELOPT_ECHO:
581 not42 = 0; /* looks like a 4.2 system */
582 /*
583 * Egads, he responded "WILL ECHO". Turn
584 * it off right now!
585 */
586 send_dont(option, 1);
587 /*
588 * "WILL ECHO". Kludge upon kludge!
589 * A 4.2 client is now echoing user input at
590 * the tty. This is probably undesireable and
591 * it should be stopped. The client will
592 * respond WONT TM to the DO TM that we send to
593 * check for kludge linemode. When the WONT TM
594 * arrives, linemode will be turned off and a
595 * change propogated to the pty. This change
596 * will cause us to process the new pty state
597 * in localstat(), which will notice that
598 * linemode is off and send a WILL ECHO
599 * so that we are properly in character mode and
600 * all is well.
601 */
602 break;
603 #ifdef LINEMODE
604 case TELOPT_LINEMODE:
605 # ifdef KLUDGELINEMODE
606 /*
607 * Note client's desire to use linemode.
608 */
609 lmodetype = REAL_LINEMODE;
610 # endif /* KLUDGELINEMODE */
611 func = doclientstat;
612 break;
613 #endif /* LINEMODE */
614
615 #ifdef AUTHENTICATION
616 case TELOPT_AUTHENTICATION:
617 func = auth_request;
618 break;
619 #endif
620
621 #ifdef ENCRYPTION
622 case TELOPT_ENCRYPT:
623 func = encrypt_send_support;
624 break;
625 #endif /* ENCRYPTION */
626 case TELOPT_LFLOW:
627 func = flowstat;
628 break;
629 }
630 }
631 }
632 set_his_state_will(option);
633 if (func)
634 (*func)();
635 } /* end of willoption */
636
637 void
638 send_dont(int option, int init)
639 {
640 if (init) {
641 if ((do_dont_resp[option] == 0 && his_state_is_wont(option)) ||
642 his_want_state_is_wont(option))
643 return;
644 set_his_want_state_wont(option);
645 do_dont_resp[option]++;
646 }
647 output_data((const char *)dont, option);
648
649 DIAG(TD_OPTIONS, printoption("td: send dont", option));
650 }
651
652 void
653 wontoption(int option)
654 {
655 /*
656 * Process client input.
657 */
658
659 DIAG(TD_OPTIONS, printoption("td: recv wont", option));
660
661 if (do_dont_resp[option]) {
662 do_dont_resp[option]--;
663 if (do_dont_resp[option] && his_state_is_wont(option))
664 do_dont_resp[option]--;
665 }
666 if (do_dont_resp[option] == 0) {
667 if (his_want_state_is_will(option)) {
668 /* it is always ok to change to negative state */
669 switch (option) {
670 case TELOPT_ECHO:
671 not42 = 1; /* doesn't seem to be a 4.2 system */
672 break;
673
674 case TELOPT_BINARY:
675 init_termbuf();
676 tty_binaryin(0);
677 set_termbuf();
678 break;
679
680 #ifdef LINEMODE
681 case TELOPT_LINEMODE:
682 # ifdef KLUDGELINEMODE
683 /*
684 * If real linemode is supported, then client is
685 * asking to turn linemode off.
686 */
687 if (lmodetype != REAL_LINEMODE)
688 break;
689 lmodetype = KLUDGE_LINEMODE;
690 # endif /* KLUDGELINEMODE */
691 clientstat(TELOPT_LINEMODE, WONT, 0);
692 break;
693 #endif /* LINEMODE */
694
695 case TELOPT_TM:
696 /*
697 * If we get a WONT TM, and had sent a DO TM,
698 * don't respond with a DONT TM, just leave it
699 * as is. Short circut the state machine to
700 * achive this.
701 */
702 set_his_want_state_wont(TELOPT_TM);
703 return;
704
705 case TELOPT_LFLOW:
706 /*
707 * If we are not going to support flow control
708 * option, then let peer know that we can't
709 * change the flow control characters.
710 */
711 slctab[SLC_XON].defset.flag &= ~SLC_LEVELBITS;
712 slctab[SLC_XON].defset.flag |= SLC_CANTCHANGE;
713 slctab[SLC_XOFF].defset.flag &= ~SLC_LEVELBITS;
714 slctab[SLC_XOFF].defset.flag |= SLC_CANTCHANGE;
715 break;
716
717 #ifdef AUTHENTICATION
718 case TELOPT_AUTHENTICATION:
719 auth_finished(0, AUTH_REJECT);
720 break;
721 #endif
722
723 /*
724 * For options that we might spin waiting for
725 * sub-negotiation, if the client turns off the
726 * option rather than responding to the request,
727 * we have to treat it here as if we got a response
728 * to the sub-negotiation, (by updating the timers)
729 * so that we'll break out of the loop.
730 */
731 case TELOPT_TTYPE:
732 settimer(ttypesubopt);
733 break;
734
735 case TELOPT_TSPEED:
736 settimer(tspeedsubopt);
737 break;
738
739 case TELOPT_XDISPLOC:
740 settimer(xdisplocsubopt);
741 break;
742
743 case TELOPT_OLD_ENVIRON:
744 settimer(oenvironsubopt);
745 break;
746
747 case TELOPT_NEW_ENVIRON:
748 settimer(environsubopt);
749 break;
750
751 default:
752 break;
753 }
754 set_his_want_state_wont(option);
755 if (his_state_is_will(option))
756 send_dont(option, 0);
757 } else {
758 switch (option) {
759 case TELOPT_TM:
760 #if defined(LINEMODE) && defined(KLUDGELINEMODE)
761 if (lmodetype < NO_AUTOKLUDGE) {
762 lmodetype = NO_LINEMODE;
763 clientstat(TELOPT_LINEMODE, WONT, 0);
764 send_will(TELOPT_SGA, 1);
765 send_will(TELOPT_ECHO, 1);
766 }
767 #endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */
768 break;
769
770 #ifdef AUTHENTICATION
771 case TELOPT_AUTHENTICATION:
772 auth_finished(0, AUTH_REJECT);
773 break;
774 #endif
775 default:
776 break;
777 }
778 }
779 }
780 set_his_state_wont(option);
781
782 } /* end of wontoption */
783
784 void
785 send_will(int option, int init)
786 {
787 if (init) {
788 if ((will_wont_resp[option] == 0 && my_state_is_will(option))||
789 my_want_state_is_will(option))
790 return;
791 set_my_want_state_will(option);
792 will_wont_resp[option]++;
793 }
794 output_data((const char *)will, option);
795
796 DIAG(TD_OPTIONS, printoption("td: send will", option));
797 }
798
799 #if !defined(LINEMODE) || !defined(KLUDGELINEMODE)
800 /*
801 * When we get a DONT SGA, we will try once to turn it
802 * back on. If the other side responds DONT SGA, we
803 * leave it at that. This is so that when we talk to
804 * clients that understand KLUDGELINEMODE but not LINEMODE,
805 * we'll keep them in char-at-a-time mode.
806 */
807 int turn_on_sga = 0;
808 #endif
809
810 void
811 dooption(int option)
812 {
813 int changeok = 0;
814
815 /*
816 * Process client input.
817 */
818
819 DIAG(TD_OPTIONS, printoption("td: recv do", option));
820
821 if (will_wont_resp[option]) {
822 will_wont_resp[option]--;
823 if (will_wont_resp[option] && my_state_is_will(option))
824 will_wont_resp[option]--;
825 }
826 if ((will_wont_resp[option] == 0) && (my_want_state_is_wont(option))) {
827 switch (option) {
828 case TELOPT_ECHO:
829 #ifdef LINEMODE
830 # ifdef KLUDGELINEMODE
831 if (lmodetype == NO_LINEMODE)
832 # else
833 if (his_state_is_wont(TELOPT_LINEMODE))
834 # endif
835 #endif
836 {
837 init_termbuf();
838 tty_setecho(1);
839 set_termbuf();
840 }
841 changeok++;
842 break;
843
844 case TELOPT_BINARY:
845 init_termbuf();
846 tty_binaryout(1);
847 set_termbuf();
848 changeok++;
849 break;
850
851 case TELOPT_SGA:
852 #if defined(LINEMODE) && defined(KLUDGELINEMODE)
853 /*
854 * If kludge linemode is in use, then we must
855 * process an incoming do SGA for linemode
856 * purposes.
857 */
858 if (lmodetype == KLUDGE_LINEMODE) {
859 /*
860 * Receipt of "do SGA" in kludge
861 * linemode is the peer asking us to
862 * turn off linemode. Make note of
863 * the request.
864 */
865 clientstat(TELOPT_LINEMODE, WONT, 0);
866 /*
867 * If linemode did not get turned off
868 * then don't tell peer that we did.
869 * Breaking here forces a wont SGA to
870 * be returned.
871 */
872 if (linemode)
873 break;
874 }
875 #else
876 turn_on_sga = 0;
877 #endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */
878 changeok++;
879 break;
880
881 case TELOPT_STATUS:
882 changeok++;
883 break;
884
885 case TELOPT_TM:
886 /*
887 * Special case for TM. We send a WILL, but
888 * pretend we sent a WONT.
889 */
890 send_will(option, 0);
891 set_my_want_state_wont(option);
892 set_my_state_wont(option);
893 return;
894
895 case TELOPT_LOGOUT:
896 /*
897 * When we get a LOGOUT option, respond
898 * with a WILL LOGOUT, make sure that
899 * it gets written out to the network,
900 * and then just go away...
901 */
902 set_my_want_state_will(TELOPT_LOGOUT);
903 send_will(TELOPT_LOGOUT, 0);
904 set_my_state_will(TELOPT_LOGOUT);
905 (void)netflush();
906 cleanup(0);
907 /* NOT REACHED */
908 break;
909
910 #ifdef ENCRYPTION
911 case TELOPT_ENCRYPT:
912 changeok++;
913 break;
914 #endif /* ENCRYPTION */
915 case TELOPT_LINEMODE:
916 case TELOPT_TTYPE:
917 case TELOPT_NAWS:
918 case TELOPT_TSPEED:
919 case TELOPT_LFLOW:
920 case TELOPT_XDISPLOC:
921 #ifdef TELOPT_ENVIRON
922 case TELOPT_NEW_ENVIRON:
923 #endif
924 case TELOPT_OLD_ENVIRON:
925 default:
926 break;
927 }
928 if (changeok) {
929 set_my_want_state_will(option);
930 send_will(option, 0);
931 } else {
932 will_wont_resp[option]++;
933 send_wont(option, 0);
934 }
935 }
936 set_my_state_will(option);
937
938 } /* end of dooption */
939
940 void
941 send_wont(int option, int init)
942 {
943 if (init) {
944 if ((will_wont_resp[option] == 0 && my_state_is_wont(option)) ||
945 my_want_state_is_wont(option))
946 return;
947 set_my_want_state_wont(option);
948 will_wont_resp[option]++;
949 }
950 output_data((const char *)wont, option);
951
952 DIAG(TD_OPTIONS, printoption("td: send wont", option));
953 }
954
955 void
956 dontoption(int option)
957 {
958 /*
959 * Process client input.
960 */
961
962
963 DIAG(TD_OPTIONS, printoption("td: recv dont", option));
964
965 if (will_wont_resp[option]) {
966 will_wont_resp[option]--;
967 if (will_wont_resp[option] && my_state_is_wont(option))
968 will_wont_resp[option]--;
969 }
970 if ((will_wont_resp[option] == 0) && (my_want_state_is_will(option))) {
971 switch (option) {
972 case TELOPT_BINARY:
973 init_termbuf();
974 tty_binaryout(0);
975 set_termbuf();
976 break;
977
978 case TELOPT_ECHO: /* we should stop echoing */
979 #ifdef LINEMODE
980 # ifdef KLUDGELINEMODE
981 if ((lmodetype != REAL_LINEMODE) &&
982 (lmodetype != KLUDGE_LINEMODE))
983 # else
984 if (his_state_is_wont(TELOPT_LINEMODE))
985 # endif
986 #endif
987 {
988 init_termbuf();
989 tty_setecho(0);
990 set_termbuf();
991 }
992 break;
993
994 case TELOPT_SGA:
995 #if defined(LINEMODE) && defined(KLUDGELINEMODE)
996 /*
997 * If kludge linemode is in use, then we
998 * must process an incoming do SGA for
999 * linemode purposes.
1000 */
1001 if ((lmodetype == KLUDGE_LINEMODE) ||
1002 (lmodetype == KLUDGE_OK)) {
1003 /*
1004 * The client is asking us to turn
1005 * linemode on.
1006 */
1007 lmodetype = KLUDGE_LINEMODE;
1008 clientstat(TELOPT_LINEMODE, WILL, 0);
1009 /*
1010 * If we did not turn line mode on,
1011 * then what do we say? Will SGA?
1012 * This violates design of telnet.
1013 * Gross. Very Gross.
1014 */
1015 }
1016 break;
1017 #else
1018 set_my_want_state_wont(option);
1019 if (my_state_is_will(option))
1020 send_wont(option, 0);
1021 set_my_state_wont(option);
1022 if (turn_on_sga ^= 1)
1023 send_will(option, 1);
1024 return;
1025 #endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */
1026
1027 default:
1028 break;
1029 }
1030
1031 set_my_want_state_wont(option);
1032 if (my_state_is_will(option))
1033 send_wont(option, 0);
1034 }
1035 set_my_state_wont(option);
1036
1037 } /* end of dontoption */
1038
1039 #ifdef ENV_HACK
1040 int env_ovar = -1;
1041 int env_ovalue = -1;
1042 #else /* ENV_HACK */
1043 # define env_ovar OLD_ENV_VAR
1044 # define env_ovalue OLD_ENV_VALUE
1045 #endif /* ENV_HACK */
1046
1047 /* envvarok(char*) */
1048 /* check that variable is safe to pass to login or shell */
1049 static int
1050 envvarok(char *varp)
1051 {
1052
1053 if (strcmp(varp, "TERMCAP") && /* to prevent a security hole */
1054 strcmp(varp, "TERMINFO") && /* with tgetent */
1055 strcmp(varp, "TERMPATH") &&
1056 strcmp(varp, "HOME") && /* to prevent the tegetent bug */
1057 strncmp(varp, "LD_", strlen("LD_")) && /* most systems */
1058 strncmp(varp, "_RLD_", strlen("_RLD_")) && /* IRIX */
1059 strcmp(varp, "LIBPATH") && /* AIX */
1060 strcmp(varp, "ENV") &&
1061 strcmp(varp, "BASH_ENV") &&
1062 strcmp(varp, "IFS") &&
1063 strncmp(varp, "KRB5", strlen("KRB5")) && /* Krb5 */
1064 /*
1065 * The above case is a catch-all for now. Here are some of
1066 * the specific ones we must avoid passing, at least until
1067 * we can prove it can be done safely. Keep this list
1068 * around un case someone wants to remove the catch-all.
1069 */
1070 strcmp(varp, "KRB5_CONFIG") && /* Krb5 */
1071 strcmp(varp, "KRB5CCNAME") && /* Krb5 */
1072 strcmp(varp, "KRB5_KTNAME") && /* Krb5 */
1073 strcmp(varp, "KRBTKFILE") && /* Krb4 */
1074 strcmp(varp, "KRB_CONF") && /* CNS 4 */
1075 strcmp(varp, "KRB_REALMS") && /* CNS 4 */
1076 strcmp(varp, "RESOLV_HOST_CONF")) /* Linux */
1077 return (1);
1078 else {
1079 syslog(LOG_INFO, "Rejected the attempt to modify the "
1080 "environment variable \"%s\"", varp);
1081 return (0);
1082 }
1083 }
1084
1085 /*
1086 * suboption()
1087 *
1088 * Look at the sub-option buffer, and try to be helpful to the other
1089 * side.
1090 *
1091 * Currently we recognize:
1092 *
1093 * Terminal type is
1094 * Linemode
1095 * Window size
1096 * Terminal speed
1097 */
1098 void
1099 suboption(void)
1100 {
1101 int subchar;
1102
1103 DIAG(TD_OPTIONS, {netflush(); printsub('<', subpointer, SB_LEN()+2);});
1104
1105 subchar = SB_GET();
1106 switch (subchar) {
1107 case TELOPT_TSPEED: {
1108 int xspeed, rspeed;
1109
1110 if (his_state_is_wont(TELOPT_TSPEED)) /* Ignore if option disabled */
1111 break;
1112
1113 settimer(tspeedsubopt);
1114
1115 if (SB_EOF() || SB_GET() != TELQUAL_IS)
1116 return;
1117
1118 xspeed = atoi((char *)subpointer);
1119
1120 while (SB_GET() != ',' && !SB_EOF());
1121 if (SB_EOF())
1122 return;
1123
1124 rspeed = atoi((char *)subpointer);
1125 clientstat(TELOPT_TSPEED, xspeed, rspeed);
1126
1127 break;
1128
1129 } /* end of case TELOPT_TSPEED */
1130
1131 case TELOPT_TTYPE: { /* Yaaaay! */
1132 static char terminalname[TERMINAL_TYPE_SIZE];
1133
1134 if (his_state_is_wont(TELOPT_TTYPE)) /* Ignore if option disabled */
1135 break;
1136 settimer(ttypesubopt);
1137
1138 if (SB_EOF() || SB_GET() != TELQUAL_IS) {
1139 return; /* ??? XXX but, this is the most robust */
1140 }
1141
1142 terminaltype = terminalname;
1143
1144 while ((terminaltype < (terminalname + sizeof terminalname-1)) &&
1145 !SB_EOF()) {
1146 int c;
1147
1148 c = SB_GET();
1149 if (isupper(c)) {
1150 c = tolower(c);
1151 }
1152 *terminaltype++ = c; /* accumulate name */
1153 }
1154 *terminaltype = 0;
1155 terminaltype = terminalname;
1156 break;
1157 } /* end of case TELOPT_TTYPE */
1158
1159 case TELOPT_NAWS: {
1160 int xwinsize, ywinsize;
1161
1162 if (his_state_is_wont(TELOPT_NAWS)) /* Ignore if option disabled */
1163 break;
1164
1165 if (SB_EOF())
1166 return;
1167 xwinsize = SB_GET() << 8;
1168 if (SB_EOF())
1169 return;
1170 xwinsize |= SB_GET();
1171 if (SB_EOF())
1172 return;
1173 ywinsize = SB_GET() << 8;
1174 if (SB_EOF())
1175 return;
1176 ywinsize |= SB_GET();
1177 clientstat(TELOPT_NAWS, xwinsize, ywinsize);
1178
1179 break;
1180
1181 } /* end of case TELOPT_NAWS */
1182
1183 #ifdef LINEMODE
1184 case TELOPT_LINEMODE: {
1185 int request;
1186
1187 if (his_state_is_wont(TELOPT_LINEMODE)) /* Ignore if option disabled */
1188 break;
1189 /*
1190 * Process linemode suboptions.
1191 */
1192 if (SB_EOF())
1193 break; /* garbage was sent */
1194 request = SB_GET(); /* get will/wont */
1195
1196 if (SB_EOF())
1197 break; /* another garbage check */
1198
1199 if (request == LM_SLC) { /* SLC is not preceeded by WILL or WONT */
1200 /*
1201 * Process suboption buffer of slc's
1202 */
1203 start_slc(1);
1204 do_opt_slc(subpointer, subend - subpointer);
1205 (void) end_slc(0);
1206 break;
1207 } else if (request == LM_MODE) {
1208 if (SB_EOF())
1209 return;
1210 useeditmode = SB_GET(); /* get mode flag */
1211 clientstat(LM_MODE, 0, 0);
1212 break;
1213 }
1214
1215 if (SB_EOF())
1216 break;
1217 switch (SB_GET()) { /* what suboption? */
1218 case LM_FORWARDMASK:
1219 /*
1220 * According to spec, only server can send request for
1221 * forwardmask, and client can only return a positive response.
1222 * So don't worry about it.
1223 */
1224
1225 default:
1226 break;
1227 }
1228 break;
1229 } /* end of case TELOPT_LINEMODE */
1230 #endif
1231 case TELOPT_STATUS: {
1232 int mode;
1233
1234 if (SB_EOF())
1235 break;
1236 mode = SB_GET();
1237 switch (mode) {
1238 case TELQUAL_SEND:
1239 if (my_state_is_will(TELOPT_STATUS))
1240 send_status();
1241 break;
1242
1243 case TELQUAL_IS:
1244 break;
1245
1246 default:
1247 break;
1248 }
1249 break;
1250 } /* end of case TELOPT_STATUS */
1251
1252 case TELOPT_XDISPLOC: {
1253 if (SB_EOF() || SB_GET() != TELQUAL_IS)
1254 return;
1255 settimer(xdisplocsubopt);
1256 subpointer[SB_LEN()] = '\0';
1257 if (setenv("DISPLAY", (char *)subpointer, 1) == -1)
1258 syslog(LOG_ERR, "setenv: cannot set DISPLAY=%s: %m", (char *)subpointer);
1259 break;
1260 } /* end of case TELOPT_XDISPLOC */
1261
1262 #ifdef TELOPT_NEW_ENVIRON
1263 case TELOPT_NEW_ENVIRON:
1264 #endif
1265 case TELOPT_OLD_ENVIRON: {
1266 int c;
1267 char *cp, *varp, *valp;
1268
1269 if (SB_EOF())
1270 return;
1271 c = SB_GET();
1272 if (c == TELQUAL_IS) {
1273 if (subchar == TELOPT_OLD_ENVIRON)
1274 settimer(oenvironsubopt);
1275 else
1276 settimer(environsubopt);
1277 } else if (c != TELQUAL_INFO) {
1278 return;
1279 }
1280
1281 #ifdef TELOPT_NEW_ENVIRON
1282 if (subchar == TELOPT_NEW_ENVIRON) {
1283 while (!SB_EOF()) {
1284 c = SB_GET();
1285 if ((c == NEW_ENV_VAR) || (c == ENV_USERVAR))
1286 break;
1287 }
1288 } else
1289 #endif
1290 {
1291 #ifdef ENV_HACK
1292 /*
1293 * We only want to do this if we haven't already decided
1294 * whether or not the other side has its VALUE and VAR
1295 * reversed.
1296 */
1297 if (env_ovar < 0) {
1298 int last = -1; /* invalid value */
1299 int empty = 0;
1300 int got_var = 0, got_value = 0, got_uservar = 0;
1301
1302 /*
1303 * The other side might have its VALUE and VAR values
1304 * reversed. To be interoperable, we need to determine
1305 * which way it is. If the first recognized character
1306 * is a VAR or VALUE, then that will tell us what
1307 * type of client it is. If the fist recognized
1308 * character is a USERVAR, then we continue scanning
1309 * the suboption looking for two consecutive
1310 * VAR or VALUE fields. We should not get two
1311 * consecutive VALUE fields, so finding two
1312 * consecutive VALUE or VAR fields will tell us
1313 * what the client is.
1314 */
1315 SB_SAVE();
1316 while (!SB_EOF()) {
1317 c = SB_GET();
1318 switch(c) {
1319 case OLD_ENV_VAR:
1320 if (last < 0 || last == OLD_ENV_VAR
1321 || (empty && (last == OLD_ENV_VALUE)))
1322 goto env_ovar_ok;
1323 got_var++;
1324 last = OLD_ENV_VAR;
1325 break;
1326 case OLD_ENV_VALUE:
1327 if (last < 0 || last == OLD_ENV_VALUE
1328 || (empty && (last == OLD_ENV_VAR)))
1329 goto env_ovar_wrong;
1330 got_value++;
1331 last = OLD_ENV_VALUE;
1332 break;
1333 case ENV_USERVAR:
1334 /* count strings of USERVAR as one */
1335 if (last != ENV_USERVAR)
1336 got_uservar++;
1337 if (empty) {
1338 if (last == OLD_ENV_VALUE)
1339 goto env_ovar_ok;
1340 if (last == OLD_ENV_VAR)
1341 goto env_ovar_wrong;
1342 }
1343 last = ENV_USERVAR;
1344 break;
1345 case ENV_ESC:
1346 if (!SB_EOF())
1347 c = SB_GET();
1348 /* FALL THROUGH */
1349 default:
1350 empty = 0;
1351 continue;
1352 }
1353 empty = 1;
1354 }
1355 if (empty) {
1356 if (last == OLD_ENV_VALUE)
1357 goto env_ovar_ok;
1358 if (last == OLD_ENV_VAR)
1359 goto env_ovar_wrong;
1360 }
1361 /*
1362 * Ok, the first thing was a USERVAR, and there
1363 * are not two consecutive VAR or VALUE commands,
1364 * and none of the VAR or VALUE commands are empty.
1365 * If the client has sent us a well-formed option,
1366 * then the number of VALUEs received should always
1367 * be less than or equal to the number of VARs and
1368 * USERVARs received.
1369 *
1370 * If we got exactly as many VALUEs as VARs and
1371 * USERVARs, the client has the same definitions.
1372 *
1373 * If we got exactly as many VARs as VALUEs and
1374 * USERVARS, the client has reversed definitions.
1375 */
1376 if (got_uservar + got_var == got_value) {
1377 env_ovar_ok:
1378 env_ovar = OLD_ENV_VAR;
1379 env_ovalue = OLD_ENV_VALUE;
1380 } else if (got_uservar + got_value == got_var) {
1381 env_ovar_wrong:
1382 env_ovar = OLD_ENV_VALUE;
1383 env_ovalue = OLD_ENV_VAR;
1384 DIAG(TD_OPTIONS,
1385 output_data("ENVIRON VALUE and VAR are reversed!\r\n"));
1386
1387 }
1388 }
1389 SB_RESTORE();
1390 #endif
1391
1392 while (!SB_EOF()) {
1393 c = SB_GET();
1394 if ((c == env_ovar) || (c == ENV_USERVAR))
1395 break;
1396 }
1397 }
1398
1399 if (SB_EOF())
1400 return;
1401
1402 cp = varp = (char *)subpointer;
1403 valp = NULL;
1404
1405 while (!SB_EOF()) {
1406 c = SB_GET();
1407 if (subchar == TELOPT_OLD_ENVIRON) {
1408 if (c == env_ovar)
1409 c = NEW_ENV_VAR;
1410 else if (c == env_ovalue)
1411 c = NEW_ENV_VALUE;
1412 }
1413 switch (c) {
1414
1415 case NEW_ENV_VALUE:
1416 *cp = '\0';
1417 cp = valp = (char *)subpointer;
1418 break;
1419
1420 case NEW_ENV_VAR:
1421 case ENV_USERVAR:
1422 *cp = '\0';
1423 if (envvarok(varp)) {
1424 if (valp) {
1425 if (setenv(varp, valp, 1) == -1)
1426 syslog(LOG_ERR, "setenv: cannot set %s=%s: %m", varp, valp);
1427 }
1428 else
1429 unsetenv(varp);
1430 }
1431 cp = varp = (char *)subpointer;
1432 valp = NULL;
1433 break;
1434
1435 case ENV_ESC:
1436 if (SB_EOF())
1437 break;
1438 c = SB_GET();
1439 /* FALL THROUGH */
1440 default:
1441 *cp++ = c;
1442 break;
1443 }
1444 }
1445 *cp = '\0';
1446 if (envvarok(varp)) {
1447 if (valp) {
1448 if (setenv(varp, valp, 1) == -1)
1449 syslog(LOG_ERR, "setenv: cannot set %s=%s: %m", varp, valp);
1450 }
1451 else
1452 unsetenv(varp);
1453 }
1454 break;
1455 } /* end of case TELOPT_NEW_ENVIRON */
1456 #ifdef AUTHENTICATION
1457 case TELOPT_AUTHENTICATION:
1458 if (SB_EOF())
1459 break;
1460 switch(SB_GET()) {
1461 case TELQUAL_SEND:
1462 case TELQUAL_REPLY:
1463 /*
1464 * These are sent by us and cannot be sent by
1465 * the client.
1466 */
1467 break;
1468 case TELQUAL_IS:
1469 auth_is(subpointer, SB_LEN());
1470 break;
1471 case TELQUAL_NAME:
1472 auth_name(subpointer, SB_LEN());
1473 break;
1474 }
1475 break;
1476 #endif
1477 #ifdef ENCRYPTION
1478 case TELOPT_ENCRYPT:
1479 if (SB_EOF())
1480 break;
1481 switch(SB_GET()) {
1482 case ENCRYPT_SUPPORT:
1483 encrypt_support(subpointer, SB_LEN());
1484 break;
1485 case ENCRYPT_IS:
1486 encrypt_is(subpointer, SB_LEN());
1487 break;
1488 case ENCRYPT_REPLY:
1489 encrypt_reply(subpointer, SB_LEN());
1490 break;
1491 case ENCRYPT_START:
1492 encrypt_start(subpointer, SB_LEN());
1493 break;
1494 case ENCRYPT_END:
1495 encrypt_end();
1496 break;
1497 case ENCRYPT_REQSTART:
1498 encrypt_request_start(subpointer, SB_LEN());
1499 break;
1500 case ENCRYPT_REQEND:
1501 /*
1502 * We can always send an REQEND so that we cannot
1503 * get stuck encrypting. We should only get this
1504 * if we have been able to get in the correct mode
1505 * anyhow.
1506 */
1507 encrypt_request_end();
1508 break;
1509 case ENCRYPT_ENC_KEYID:
1510 encrypt_enc_keyid(subpointer, SB_LEN());
1511 break;
1512 case ENCRYPT_DEC_KEYID:
1513 encrypt_dec_keyid(subpointer, SB_LEN());
1514 break;
1515 default:
1516 break;
1517 }
1518 break;
1519 #endif /* ENCRYPTION */
1520
1521 default:
1522 break;
1523 } /* end of switch */
1524
1525 } /* end of suboption */
1526
1527 static void
1528 doclientstat(void)
1529 {
1530 clientstat(TELOPT_LINEMODE, WILL, 0);
1531 }
1532
1533 #define ADD(c) *ncp++ = c
1534 #define ADD_DATA(c) { *ncp++ = c; if (c == SE || c == IAC) *ncp++ = c; }
1535 void
1536 send_status(void)
1537 {
1538 unsigned char statusbuf[256];
1539 unsigned char *ncp;
1540 unsigned char i;
1541
1542 ncp = statusbuf;
1543
1544 netflush(); /* get rid of anything waiting to go out */
1545
1546 ADD(IAC);
1547 ADD(SB);
1548 ADD(TELOPT_STATUS);
1549 ADD(TELQUAL_IS);
1550
1551 /*
1552 * We check the want_state rather than the current state,
1553 * because if we received a DO/WILL for an option that we
1554 * don't support, and the other side didn't send a DONT/WONT
1555 * in response to our WONT/DONT, then the "state" will be
1556 * WILL/DO, and the "want_state" will be WONT/DONT. We
1557 * need to go by the latter.
1558 */
1559 for (i = 0; i < (unsigned char)NTELOPTS; i++) {
1560 if (my_want_state_is_will(i)) {
1561 ADD(WILL);
1562 ADD_DATA(i);
1563 if (i == IAC)
1564 ADD(IAC);
1565 }
1566 if (his_want_state_is_will(i)) {
1567 ADD(DO);
1568 ADD_DATA(i);
1569 if (i == IAC)
1570 ADD(IAC);
1571 }
1572 }
1573
1574 if (his_want_state_is_will(TELOPT_LFLOW)) {
1575 ADD(SB);
1576 ADD(TELOPT_LFLOW);
1577 if (flowmode) {
1578 ADD(LFLOW_ON);
1579 } else {
1580 ADD(LFLOW_OFF);
1581 }
1582 ADD(SE);
1583
1584 if (restartany >= 0) {
1585 ADD(SB);
1586 ADD(TELOPT_LFLOW);
1587 if (restartany) {
1588 ADD(LFLOW_RESTART_ANY);
1589 } else {
1590 ADD(LFLOW_RESTART_XON);
1591 }
1592 ADD(SE);
1593 }
1594 }
1595
1596 #ifdef LINEMODE
1597 if (his_want_state_is_will(TELOPT_LINEMODE)) {
1598 unsigned char *cp, *cpe;
1599 int len;
1600
1601 ADD(SB);
1602 ADD(TELOPT_LINEMODE);
1603 ADD(LM_MODE);
1604 ADD_DATA(editmode);
1605 ADD(SE);
1606
1607 ADD(SB);
1608 ADD(TELOPT_LINEMODE);
1609 ADD(LM_SLC);
1610 start_slc(0);
1611 send_slc();
1612 len = end_slc(&cp);
1613 for (cpe = cp + len; cp < cpe; cp++)
1614 ADD_DATA(*cp);
1615 ADD(SE);
1616 }
1617 #endif /* LINEMODE */
1618
1619 ADD(IAC);
1620 ADD(SE);
1621
1622 output_datalen(statusbuf, ncp - statusbuf);
1623 netflush(); /* Send it on its way */
1624
1625 DIAG(TD_OPTIONS,
1626 {printsub('>', statusbuf, ncp - statusbuf); netflush();});
1627 }
1628
1629 /*
1630 * This function appends data to nfrontp and advances nfrontp.
1631 * Returns the number of characters written altogether (the
1632 * buffer may have been flushed in the process).
1633 */
1634
1635 int
1636 output_data(const char *format, ...)
1637 {
1638 va_list args;
1639 int len;
1640 char *buf;
1641
1642 va_start(args, format);
1643 if ((len = vasprintf(&buf, format, args)) == -1) {
1644 va_end(args);
1645 return -1;
1646 }
1647 output_datalen(buf, len);
1648 va_end(args);
1649 free(buf);
1650 return (len);
1651 }
1652
1653 void
1654 output_datalen(const char *buf, int len)
1655 {
1656 int remaining, copied;
1657
1658 remaining = BUFSIZ - (nfrontp - netobuf);
1659 while (len > 0) {
1660 /* Free up enough space if the room is too low*/
1661 if ((len > BUFSIZ ? BUFSIZ : len) > remaining) {
1662 netflush();
1663 remaining = BUFSIZ - (nfrontp - netobuf);
1664 }
1665
1666 /* Copy out as much as will fit */
1667 copied = remaining > len ? len : remaining;
1668 memmove(nfrontp, buf, copied);
1669 nfrontp += copied;
1670 len -= copied;
1671 remaining -= copied;
1672 buf += copied;
1673 }
1674 return;
1675 }
DragonFly BSD