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sem_init.3: Mark up SEM_VALUE_MAX.
[dragonfly.git] / libexec / telnetd / state.c
blob2318d3ddea7ed32750e7a8bdcba4efde2e6f2369
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
50 /*
51 * Buffer for sub-options, and macros
52 * for suboptions buffer manipulations
53 */
54 unsigned char subbuffer[512], *subpointer= subbuffer, *subend= subbuffer;
55
56 #define SB_CLEAR() subpointer = subbuffer
57 #define SB_TERM() { subend = subpointer; SB_CLEAR(); }
58 #define SB_ACCUM(c) if (subpointer < (subbuffer+sizeof subbuffer)) { \
59 *subpointer++ = (c); \
60 }
61 #define SB_GET() ((*subpointer++)&0xff)
62 #define SB_EOF() (subpointer >= subend)
63 #define SB_LEN() (subend - subpointer)
64
65 #ifdef ENV_HACK
66 unsigned char *subsave;
67 #define SB_SAVE() subsave = subpointer;
68 #define SB_RESTORE() subpointer = subsave;
69 #endif
70
71
72 /*
73 * State for recv fsm
74 */
75 #define TS_DATA 0 /* base state */
76 #define TS_IAC 1 /* look for double IAC's */
77 #define TS_CR 2 /* CR-LF ->'s CR */
78 #define TS_SB 3 /* throw away begin's... */
79 #define TS_SE 4 /* ...end's (suboption negotiation) */
80 #define TS_WILL 5 /* will option negotiation */
81 #define TS_WONT 6 /* wont " */
82 #define TS_DO 7 /* do " */
83 #define TS_DONT 8 /* dont " */
84
85 static void doclientstat(void);
86
87 void
88 telrcv(void)
89 {
90 int c;
91 static int state = TS_DATA;
92
93 while (ncc > 0) {
94 if ((&ptyobuf[BUFSIZ] - pfrontp) < 2)
95 break;
96 c = *netip++ & 0377, ncc--;
97 #ifdef ENCRYPTION
98 if (decrypt_input)
99 c = (*decrypt_input)(c);
100 #endif /* ENCRYPTION */
101 switch (state) {
102
103 case TS_CR:
104 state = TS_DATA;
105 /* Strip off \n or \0 after a \r */
106 if ((c == 0) || (c == '\n')) {
107 break;
108 }
109 /* FALL THROUGH */
110
111 case TS_DATA:
112 if (c == IAC) {
113 state = TS_IAC;
114 break;
115 }
116 /*
117 * We now map \r\n ==> \r for pragmatic reasons.
118 * Many client implementations send \r\n when
119 * the user hits the CarriageReturn key.
120 *
121 * We USED to map \r\n ==> \n, since \r\n says
122 * that we want to be in column 1 of the next
123 * printable line, and \n is the standard
124 * unix way of saying that (\r is only good
125 * if CRMOD is set, which it normally is).
126 */
127 if ((c == '\r') && his_state_is_wont(TELOPT_BINARY)) {
128 int nc = *netip;
129 #ifdef ENCRYPTION
130 if (decrypt_input)
131 nc = (*decrypt_input)(nc & 0xff);
132 #endif /* ENCRYPTION */
133 #ifdef LINEMODE
134 /*
135 * If we are operating in linemode,
136 * convert to local end-of-line.
137 */
138 if (linemode && (ncc > 0) && (('\n' == nc) ||
139 ((0 == nc) && tty_iscrnl())) ) {
140 netip++; ncc--;
141 c = '\n';
142 } else
143 #endif
144 {
145 #ifdef ENCRYPTION
146 if (decrypt_input)
147 (void)(*decrypt_input)(-1);
148 #endif /* ENCRYPTION */
149 state = TS_CR;
150 }
151 }
152 *pfrontp++ = c;
153 break;
154
155 case TS_IAC:
156 gotiac: switch (c) {
157
158 /*
159 * Send the process on the pty side an
160 * interrupt. Do this with a NULL or
161 * interrupt char; depending on the tty mode.
162 */
163 case IP:
164 DIAG(TD_OPTIONS,
165 printoption("td: recv IAC", c));
166 interrupt();
167 break;
168
169 case BREAK:
170 DIAG(TD_OPTIONS,
171 printoption("td: recv IAC", c));
172 sendbrk();
173 break;
174
175 /*
176 * Are You There?
177 */
178 case AYT:
179 DIAG(TD_OPTIONS,
180 printoption("td: recv IAC", c));
181 recv_ayt();
182 break;
183
184 /*
185 * Abort Output
186 */
187 case AO:
188 {
189 DIAG(TD_OPTIONS,
190 printoption("td: recv IAC", c));
191 ptyflush(); /* half-hearted */
192 init_termbuf();
193
194 if (slctab[SLC_AO].sptr &&
195 *slctab[SLC_AO].sptr != (cc_t)(_POSIX_VDISABLE)) {
196 *pfrontp++ =
197 (unsigned char)*slctab[SLC_AO].sptr;
198 }
199
200 netclear(); /* clear buffer back */
201 output_data("%c%c", IAC, DM);
202 neturg = nfrontp-1; /* off by one XXX */
203 DIAG(TD_OPTIONS,
204 printoption("td: send IAC", DM));
205 break;
206 }
207
208 /*
209 * Erase Character and
210 * Erase Line
211 */
212 case EC:
213 case EL:
214 {
215 cc_t ch;
216
217 DIAG(TD_OPTIONS,
218 printoption("td: recv IAC", c));
219 ptyflush(); /* half-hearted */
220 init_termbuf();
221 if (c == EC)
222 ch = *slctab[SLC_EC].sptr;
223 else
224 ch = *slctab[SLC_EL].sptr;
225 if (ch != (cc_t)(_POSIX_VDISABLE))
226 *pfrontp++ = (unsigned char)ch;
227 break;
228 }
229
230 /*
231 * Check for urgent data...
232 */
233 case DM:
234 DIAG(TD_OPTIONS,
235 printoption("td: recv IAC", c));
236 SYNCHing = stilloob(net);
237 settimer(gotDM);
238 break;
239
240
241 /*
242 * Begin option subnegotiation...
243 */
244 case SB:
245 state = TS_SB;
246 SB_CLEAR();
247 continue;
248
249 case WILL:
250 state = TS_WILL;
251 continue;
252
253 case WONT:
254 state = TS_WONT;
255 continue;
256
257 case DO:
258 state = TS_DO;
259 continue;
260
261 case DONT:
262 state = TS_DONT;
263 continue;
264 case EOR:
265 if (his_state_is_will(TELOPT_EOR))
266 doeof();
267 break;
268
269 /*
270 * Handle RFC 10xx Telnet linemode option additions
271 * to command stream (EOF, SUSP, ABORT).
272 */
273 case xEOF:
274 doeof();
275 break;
276
277 case SUSP:
278 sendsusp();
279 break;
280
281 case ABORT:
282 sendbrk();
283 break;
284
285 case IAC:
286 *pfrontp++ = c;
287 break;
288 }
289 state = TS_DATA;
290 break;
291
292 case TS_SB:
293 if (c == IAC) {
294 state = TS_SE;
295 } else {
296 SB_ACCUM(c);
297 }
298 break;
299
300 case TS_SE:
301 if (c != SE) {
302 if (c != IAC) {
303 /*
304 * bad form of suboption negotiation.
305 * handle it in such a way as to avoid
306 * damage to local state. Parse
307 * suboption buffer found so far,
308 * then treat remaining stream as
309 * another command sequence.
310 */
311
312 /* for DIAGNOSTICS */
313 SB_ACCUM(IAC);
314 SB_ACCUM(c);
315 subpointer -= 2;
316
317 SB_TERM();
318 suboption();
319 state = TS_IAC;
320 goto gotiac;
321 }
322 SB_ACCUM(c);
323 state = TS_SB;
324 } else {
325 /* for DIAGNOSTICS */
326 SB_ACCUM(IAC);
327 SB_ACCUM(SE);
328 subpointer -= 2;
329
330 SB_TERM();
331 suboption(); /* handle sub-option */
332 state = TS_DATA;
333 }
334 break;
335
336 case TS_WILL:
337 willoption(c);
338 state = TS_DATA;
339 continue;
340
341 case TS_WONT:
342 wontoption(c);
343 state = TS_DATA;
344 continue;
345
346 case TS_DO:
347 dooption(c);
348 state = TS_DATA;
349 continue;
350
351 case TS_DONT:
352 dontoption(c);
353 state = TS_DATA;
354 continue;
355
356 default:
357 syslog(LOG_ERR, "panic state=%d", state);
358 printf("telnetd: panic state=%d\n", state);
359 exit(1);
360 }
361 }
362 } /* end of telrcv */
363
364 /*
365 * The will/wont/do/dont state machines are based on Dave Borman's
366 * Telnet option processing state machine.
367 *
368 * These correspond to the following states:
369 * my_state = the last negotiated state
370 * want_state = what I want the state to go to
371 * want_resp = how many requests I have sent
372 * All state defaults are negative, and resp defaults to 0.
373 *
374 * When initiating a request to change state to new_state:
375 *
376 * if ((want_resp == 0 && new_state == my_state) || want_state == new_state) {
377 * do nothing;
378 * } else {
379 * want_state = new_state;
380 * send new_state;
381 * want_resp++;
382 * }
383 *
384 * When receiving new_state:
385 *
386 * if (want_resp) {
387 * want_resp--;
388 * if (want_resp && (new_state == my_state))
389 * want_resp--;
390 * }
391 * if ((want_resp == 0) && (new_state != want_state)) {
392 * if (ok_to_switch_to new_state)
393 * want_state = new_state;
394 * else
395 * want_resp++;
396 * send want_state;
397 * }
398 * my_state = new_state;
399 *
400 * Note that new_state is implied in these functions by the function itself.
401 * will and do imply positive new_state, wont and dont imply negative.
402 *
403 * Finally, there is one catch. If we send a negative response to a
404 * positive request, my_state will be the positive while want_state will
405 * remain negative. my_state will revert to negative when the negative
406 * acknowlegment arrives from the peer. Thus, my_state generally tells
407 * us not only the last negotiated state, but also tells us what the peer
408 * wants to be doing as well. It is important to understand this difference
409 * as we may wish to be processing data streams based on our desired state
410 * (want_state) or based on what the peer thinks the state is (my_state).
411 *
412 * This all works fine because if the peer sends a positive request, the data
413 * that we receive prior to negative acknowlegment will probably be affected
414 * by the positive state, and we can process it as such (if we can; if we
415 * can't then it really doesn't matter). If it is that important, then the
416 * peer probably should be buffering until this option state negotiation
417 * is complete.
418 *
419 */
420 void
421 send_do(int option, int init)
422 {
423 if (init) {
424 if ((do_dont_resp[option] == 0 && his_state_is_will(option)) ||
425 his_want_state_is_will(option))
426 return;
427 /*
428 * Special case for TELOPT_TM: We send a DO, but pretend
429 * that we sent a DONT, so that we can send more DOs if
430 * we want to.
431 */
432 if (option == TELOPT_TM)
433 set_his_want_state_wont(option);
434 else
435 set_his_want_state_will(option);
436 do_dont_resp[option]++;
437 }
438 output_data((const char *)doopt, option);
439
440 DIAG(TD_OPTIONS, printoption("td: send do", option));
441 }
442
443 void
444 willoption(int option)
445 {
446 int changeok = 0;
447 void (*func)(void) = NULL;
448
449 /*
450 * process input from peer.
451 */
452
453 DIAG(TD_OPTIONS, printoption("td: recv will", option));
454
455 if (do_dont_resp[option]) {
456 do_dont_resp[option]--;
457 if (do_dont_resp[option] && his_state_is_will(option))
458 do_dont_resp[option]--;
459 }
460 if (do_dont_resp[option] == 0) {
461 if (his_want_state_is_wont(option)) {
462 switch (option) {
463
464 case TELOPT_BINARY:
465 init_termbuf();
466 tty_binaryin(1);
467 set_termbuf();
468 changeok++;
469 break;
470
471 case TELOPT_ECHO:
472 /*
473 * See comments below for more info.
474 */
475 not42 = 0; /* looks like a 4.2 system */
476 break;
477
478 case TELOPT_TM:
479 #if defined(LINEMODE) && defined(KLUDGELINEMODE)
480 /*
481 * This telnetd implementation does not really
482 * support timing marks, it just uses them to
483 * support the kludge linemode stuff. If we
484 * receive a will or wont TM in response to our
485 * do TM request that may have been sent to
486 * determine kludge linemode support, process
487 * it, otherwise TM should get a negative
488 * response back.
489 */
490 /*
491 * Handle the linemode kludge stuff.
492 * If we are not currently supporting any
493 * linemode at all, then we assume that this
494 * is the client telling us to use kludge
495 * linemode in response to our query. Set the
496 * linemode type that is to be supported, note
497 * that the client wishes to use linemode, and
498 * eat the will TM as though it never arrived.
499 */
500 if (lmodetype < KLUDGE_LINEMODE) {
501 lmodetype = KLUDGE_LINEMODE;
502 clientstat(TELOPT_LINEMODE, WILL, 0);
503 send_wont(TELOPT_SGA, 1);
504 } else if (lmodetype == NO_AUTOKLUDGE) {
505 lmodetype = KLUDGE_OK;
506 }
507 #endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */
508 /*
509 * We never respond to a WILL TM, and
510 * we leave the state WONT.
511 */
512 return;
513
514 case TELOPT_LFLOW:
515 /*
516 * If we are going to support flow control
517 * option, then don't worry peer that we can't
518 * change the flow control characters.
519 */
520 slctab[SLC_XON].defset.flag &= ~SLC_LEVELBITS;
521 slctab[SLC_XON].defset.flag |= SLC_DEFAULT;
522 slctab[SLC_XOFF].defset.flag &= ~SLC_LEVELBITS;
523 slctab[SLC_XOFF].defset.flag |= SLC_DEFAULT;
524 case TELOPT_TTYPE:
525 case TELOPT_SGA:
526 case TELOPT_NAWS:
527 case TELOPT_TSPEED:
528 case TELOPT_XDISPLOC:
529 case TELOPT_NEW_ENVIRON:
530 case TELOPT_OLD_ENVIRON:
531 changeok++;
532 break;
533
534 #ifdef LINEMODE
535 case TELOPT_LINEMODE:
536 # ifdef KLUDGELINEMODE
537 /*
538 * Note client's desire to use linemode.
539 */
540 lmodetype = REAL_LINEMODE;
541 # endif /* KLUDGELINEMODE */
542 func = doclientstat;
543 changeok++;
544 break;
545 #endif /* LINEMODE */
546
547 #ifdef AUTHENTICATION
548 case TELOPT_AUTHENTICATION:
549 func = auth_request;
550 changeok++;
551 break;
552 #endif
553
554 #ifdef ENCRYPTION
555 case TELOPT_ENCRYPT:
556 func = encrypt_send_support;
557 changeok++;
558 break;
559 #endif /* ENCRYPTION */
560
561 default:
562 break;
563 }
564 if (changeok) {
565 set_his_want_state_will(option);
566 send_do(option, 0);
567 } else {
568 do_dont_resp[option]++;
569 send_dont(option, 0);
570 }
571 } else {
572 /*
573 * Option processing that should happen when
574 * we receive conformation of a change in
575 * state that we had requested.
576 */
577 switch (option) {
578 case TELOPT_ECHO:
579 not42 = 0; /* looks like a 4.2 system */
580 /*
581 * Egads, he responded "WILL ECHO". Turn
582 * it off right now!
583 */
584 send_dont(option, 1);
585 /*
586 * "WILL ECHO". Kludge upon kludge!
587 * A 4.2 client is now echoing user input at
588 * the tty. This is probably undesireable and
589 * it should be stopped. The client will
590 * respond WONT TM to the DO TM that we send to
591 * check for kludge linemode. When the WONT TM
592 * arrives, linemode will be turned off and a
593 * change propogated to the pty. This change
594 * will cause us to process the new pty state
595 * in localstat(), which will notice that
596 * linemode is off and send a WILL ECHO
597 * so that we are properly in character mode and
598 * all is well.
599 */
600 break;
601 #ifdef LINEMODE
602 case TELOPT_LINEMODE:
603 # ifdef KLUDGELINEMODE
604 /*
605 * Note client's desire to use linemode.
606 */
607 lmodetype = REAL_LINEMODE;
608 # endif /* KLUDGELINEMODE */
609 func = doclientstat;
610 break;
611 #endif /* LINEMODE */
612
613 #ifdef AUTHENTICATION
614 case TELOPT_AUTHENTICATION:
615 func = auth_request;
616 break;
617 #endif
618
619 #ifdef ENCRYPTION
620 case TELOPT_ENCRYPT:
621 func = encrypt_send_support;
622 break;
623 #endif /* ENCRYPTION */
624 case TELOPT_LFLOW:
625 func = flowstat;
626 break;
627 }
628 }
629 }
630 set_his_state_will(option);
631 if (func)
632 (*func)();
633 } /* end of willoption */
634
635 void
636 send_dont(int option, int init)
637 {
638 if (init) {
639 if ((do_dont_resp[option] == 0 && his_state_is_wont(option)) ||
640 his_want_state_is_wont(option))
641 return;
642 set_his_want_state_wont(option);
643 do_dont_resp[option]++;
644 }
645 output_data((const char *)dont, option);
646
647 DIAG(TD_OPTIONS, printoption("td: send dont", option));
648 }
649
650 void
651 wontoption(int option)
652 {
653 /*
654 * Process client input.
655 */
656
657 DIAG(TD_OPTIONS, printoption("td: recv wont", option));
658
659 if (do_dont_resp[option]) {
660 do_dont_resp[option]--;
661 if (do_dont_resp[option] && his_state_is_wont(option))
662 do_dont_resp[option]--;
663 }
664 if (do_dont_resp[option] == 0) {
665 if (his_want_state_is_will(option)) {
666 /* it is always ok to change to negative state */
667 switch (option) {
668 case TELOPT_ECHO:
669 not42 = 1; /* doesn't seem to be a 4.2 system */
670 break;
671
672 case TELOPT_BINARY:
673 init_termbuf();
674 tty_binaryin(0);
675 set_termbuf();
676 break;
677
678 #ifdef LINEMODE
679 case TELOPT_LINEMODE:
680 # ifdef KLUDGELINEMODE
681 /*
682 * If real linemode is supported, then client is
683 * asking to turn linemode off.
684 */
685 if (lmodetype != REAL_LINEMODE)
686 break;
687 lmodetype = KLUDGE_LINEMODE;
688 # endif /* KLUDGELINEMODE */
689 clientstat(TELOPT_LINEMODE, WONT, 0);
690 break;
691 #endif /* LINEMODE */
692
693 case TELOPT_TM:
694 /*
695 * If we get a WONT TM, and had sent a DO TM,
696 * don't respond with a DONT TM, just leave it
697 * as is. Short circut the state machine to
698 * achive this.
699 */
700 set_his_want_state_wont(TELOPT_TM);
701 return;
702
703 case TELOPT_LFLOW:
704 /*
705 * If we are not going to support flow control
706 * option, then let peer know that we can't
707 * change the flow control characters.
708 */
709 slctab[SLC_XON].defset.flag &= ~SLC_LEVELBITS;
710 slctab[SLC_XON].defset.flag |= SLC_CANTCHANGE;
711 slctab[SLC_XOFF].defset.flag &= ~SLC_LEVELBITS;
712 slctab[SLC_XOFF].defset.flag |= SLC_CANTCHANGE;
713 break;
714
715 #ifdef AUTHENTICATION
716 case TELOPT_AUTHENTICATION:
717 auth_finished(0, AUTH_REJECT);
718 break;
719 #endif
720
721 /*
722 * For options that we might spin waiting for
723 * sub-negotiation, if the client turns off the
724 * option rather than responding to the request,
725 * we have to treat it here as if we got a response
726 * to the sub-negotiation, (by updating the timers)
727 * so that we'll break out of the loop.
728 */
729 case TELOPT_TTYPE:
730 settimer(ttypesubopt);
731 break;
732
733 case TELOPT_TSPEED:
734 settimer(tspeedsubopt);
735 break;
736
737 case TELOPT_XDISPLOC:
738 settimer(xdisplocsubopt);
739 break;
740
741 case TELOPT_OLD_ENVIRON:
742 settimer(oenvironsubopt);
743 break;
744
745 case TELOPT_NEW_ENVIRON:
746 settimer(environsubopt);
747 break;
748
749 default:
750 break;
751 }
752 set_his_want_state_wont(option);
753 if (his_state_is_will(option))
754 send_dont(option, 0);
755 } else {
756 switch (option) {
757 case TELOPT_TM:
758 #if defined(LINEMODE) && defined(KLUDGELINEMODE)
759 if (lmodetype < NO_AUTOKLUDGE) {
760 lmodetype = NO_LINEMODE;
761 clientstat(TELOPT_LINEMODE, WONT, 0);
762 send_will(TELOPT_SGA, 1);
763 send_will(TELOPT_ECHO, 1);
764 }
765 #endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */
766 break;
767
768 #ifdef AUTHENTICATION
769 case TELOPT_AUTHENTICATION:
770 auth_finished(0, AUTH_REJECT);
771 break;
772 #endif
773 default:
774 break;
775 }
776 }
777 }
778 set_his_state_wont(option);
779
780 } /* end of wontoption */
781
782 void
783 send_will(int option, int init)
784 {
785 if (init) {
786 if ((will_wont_resp[option] == 0 && my_state_is_will(option))||
787 my_want_state_is_will(option))
788 return;
789 set_my_want_state_will(option);
790 will_wont_resp[option]++;
791 }
792 output_data((const char *)will, option);
793
794 DIAG(TD_OPTIONS, printoption("td: send will", option));
795 }
796
797 #if !defined(LINEMODE) || !defined(KLUDGELINEMODE)
798 /*
799 * When we get a DONT SGA, we will try once to turn it
800 * back on. If the other side responds DONT SGA, we
801 * leave it at that. This is so that when we talk to
802 * clients that understand KLUDGELINEMODE but not LINEMODE,
803 * we'll keep them in char-at-a-time mode.
804 */
805 int turn_on_sga = 0;
806 #endif
807
808 void
809 dooption(int option)
810 {
811 int changeok = 0;
812
813 /*
814 * Process client input.
815 */
816
817 DIAG(TD_OPTIONS, printoption("td: recv do", option));
818
819 if (will_wont_resp[option]) {
820 will_wont_resp[option]--;
821 if (will_wont_resp[option] && my_state_is_will(option))
822 will_wont_resp[option]--;
823 }
824 if ((will_wont_resp[option] == 0) && (my_want_state_is_wont(option))) {
825 switch (option) {
826 case TELOPT_ECHO:
827 #ifdef LINEMODE
828 # ifdef KLUDGELINEMODE
829 if (lmodetype == NO_LINEMODE)
830 # else
831 if (his_state_is_wont(TELOPT_LINEMODE))
832 # endif
833 #endif
834 {
835 init_termbuf();
836 tty_setecho(1);
837 set_termbuf();
838 }
839 changeok++;
840 break;
841
842 case TELOPT_BINARY:
843 init_termbuf();
844 tty_binaryout(1);
845 set_termbuf();
846 changeok++;
847 break;
848
849 case TELOPT_SGA:
850 #if defined(LINEMODE) && defined(KLUDGELINEMODE)
851 /*
852 * If kludge linemode is in use, then we must
853 * process an incoming do SGA for linemode
854 * purposes.
855 */
856 if (lmodetype == KLUDGE_LINEMODE) {
857 /*
858 * Receipt of "do SGA" in kludge
859 * linemode is the peer asking us to
860 * turn off linemode. Make note of
861 * the request.
862 */
863 clientstat(TELOPT_LINEMODE, WONT, 0);
864 /*
865 * If linemode did not get turned off
866 * then don't tell peer that we did.
867 * Breaking here forces a wont SGA to
868 * be returned.
869 */
870 if (linemode)
871 break;
872 }
873 #else
874 turn_on_sga = 0;
875 #endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */
876 changeok++;
877 break;
878
879 case TELOPT_STATUS:
880 changeok++;
881 break;
882
883 case TELOPT_TM:
884 /*
885 * Special case for TM. We send a WILL, but
886 * pretend we sent a WONT.
887 */
888 send_will(option, 0);
889 set_my_want_state_wont(option);
890 set_my_state_wont(option);
891 return;
892
893 case TELOPT_LOGOUT:
894 /*
895 * When we get a LOGOUT option, respond
896 * with a WILL LOGOUT, make sure that
897 * it gets written out to the network,
898 * and then just go away...
899 */
900 set_my_want_state_will(TELOPT_LOGOUT);
901 send_will(TELOPT_LOGOUT, 0);
902 set_my_state_will(TELOPT_LOGOUT);
903 (void)netflush();
904 cleanup(0);
905 /* NOT REACHED */
906 break;
907
908 #ifdef ENCRYPTION
909 case TELOPT_ENCRYPT:
910 changeok++;
911 break;
912 #endif /* ENCRYPTION */
913 case TELOPT_LINEMODE:
914 case TELOPT_TTYPE:
915 case TELOPT_NAWS:
916 case TELOPT_TSPEED:
917 case TELOPT_LFLOW:
918 case TELOPT_XDISPLOC:
919 #ifdef TELOPT_ENVIRON
920 case TELOPT_NEW_ENVIRON:
921 #endif
922 case TELOPT_OLD_ENVIRON:
923 default:
924 break;
925 }
926 if (changeok) {
927 set_my_want_state_will(option);
928 send_will(option, 0);
929 } else {
930 will_wont_resp[option]++;
931 send_wont(option, 0);
932 }
933 }
934 set_my_state_will(option);
935
936 } /* end of dooption */
937
938 void
939 send_wont(int option, int init)
940 {
941 if (init) {
942 if ((will_wont_resp[option] == 0 && my_state_is_wont(option)) ||
943 my_want_state_is_wont(option))
944 return;
945 set_my_want_state_wont(option);
946 will_wont_resp[option]++;
947 }
948 output_data((const char *)wont, option);
949
950 DIAG(TD_OPTIONS, printoption("td: send wont", option));
951 }
952
953 void
954 dontoption(int option)
955 {
956 /*
957 * Process client input.
958 */
959
960
961 DIAG(TD_OPTIONS, printoption("td: recv dont", option));
962
963 if (will_wont_resp[option]) {
964 will_wont_resp[option]--;
965 if (will_wont_resp[option] && my_state_is_wont(option))
966 will_wont_resp[option]--;
967 }
968 if ((will_wont_resp[option] == 0) && (my_want_state_is_will(option))) {
969 switch (option) {
970 case TELOPT_BINARY:
971 init_termbuf();
972 tty_binaryout(0);
973 set_termbuf();
974 break;
975
976 case TELOPT_ECHO: /* we should stop echoing */
977 #ifdef LINEMODE
978 # ifdef KLUDGELINEMODE
979 if ((lmodetype != REAL_LINEMODE) &&
980 (lmodetype != KLUDGE_LINEMODE))
981 # else
982 if (his_state_is_wont(TELOPT_LINEMODE))
983 # endif
984 #endif
985 {
986 init_termbuf();
987 tty_setecho(0);
988 set_termbuf();
989 }
990 break;
991
992 case TELOPT_SGA:
993 #if defined(LINEMODE) && defined(KLUDGELINEMODE)
994 /*
995 * If kludge linemode is in use, then we
996 * must process an incoming do SGA for
997 * linemode purposes.
998 */
999 if ((lmodetype == KLUDGE_LINEMODE) ||
1000 (lmodetype == KLUDGE_OK)) {
1001 /*
1002 * The client is asking us to turn
1003 * linemode on.
1004 */
1005 lmodetype = KLUDGE_LINEMODE;
1006 clientstat(TELOPT_LINEMODE, WILL, 0);
1007 /*
1008 * If we did not turn line mode on,
1009 * then what do we say? Will SGA?
1010 * This violates design of telnet.
1011 * Gross. Very Gross.
1012 */
1013 }
1014 break;
1015 #else
1016 set_my_want_state_wont(option);
1017 if (my_state_is_will(option))
1018 send_wont(option, 0);
1019 set_my_state_wont(option);
1020 if (turn_on_sga ^= 1)
1021 send_will(option, 1);
1022 return;
1023 #endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */
1024
1025 default:
1026 break;
1027 }
1028
1029 set_my_want_state_wont(option);
1030 if (my_state_is_will(option))
1031 send_wont(option, 0);
1032 }
1033 set_my_state_wont(option);
1034
1035 } /* end of dontoption */
1036
1037 #ifdef ENV_HACK
1038 int env_ovar = -1;
1039 int env_ovalue = -1;
1040 #else /* ENV_HACK */
1041 # define env_ovar OLD_ENV_VAR
1042 # define env_ovalue OLD_ENV_VALUE
1043 #endif /* ENV_HACK */
1044
1045 /* envvarok(char*) */
1046 /* check that variable is safe to pass to login or shell */
1047 static int
1048 envvarok(char *varp)
1049 {
1050
1051 if (strcmp(varp, "TERMCAP") && /* to prevent a security hole */
1052 strcmp(varp, "TERMINFO") && /* with tgetent */
1053 strcmp(varp, "TERMPATH") &&
1054 strcmp(varp, "HOME") && /* to prevent the tegetent bug */
1055 strncmp(varp, "LD_", strlen("LD_")) && /* most systems */
1056 strncmp(varp, "_RLD_", strlen("_RLD_")) && /* IRIX */
1057 strcmp(varp, "LIBPATH") && /* AIX */
1058 strcmp(varp, "ENV") &&
1059 strcmp(varp, "BASH_ENV") &&
1060 strcmp(varp, "IFS") &&
1061 strncmp(varp, "KRB5", strlen("KRB5")) && /* Krb5 */
1062 /*
1063 * The above case is a catch-all for now. Here are some of
1064 * the specific ones we must avoid passing, at least until
1065 * we can prove it can be done safely. Keep this list
1066 * around un case someone wants to remove the catch-all.
1067 */
1068 strcmp(varp, "KRB5_CONFIG") && /* Krb5 */
1069 strcmp(varp, "KRB5CCNAME") && /* Krb5 */
1070 strcmp(varp, "KRB5_KTNAME") && /* Krb5 */
1071 strcmp(varp, "KRBTKFILE") && /* Krb4 */
1072 strcmp(varp, "KRB_CONF") && /* CNS 4 */
1073 strcmp(varp, "KRB_REALMS") && /* CNS 4 */
1074 strcmp(varp, "RESOLV_HOST_CONF")) /* Linux */
1075 return (1);
1076 else {
1077 syslog(LOG_INFO, "Rejected the attempt to modify the "
1078 "environment variable \"%s\"", varp);
1079 return (0);
1080 }
1081 }
1082
1083 /*
1084 * suboption()
1085 *
1086 * Look at the sub-option buffer, and try to be helpful to the other
1087 * side.
1088 *
1089 * Currently we recognize:
1090 *
1091 * Terminal type is
1092 * Linemode
1093 * Window size
1094 * Terminal speed
1095 */
1096 void
1097 suboption(void)
1098 {
1099 int subchar;
1100
1101 DIAG(TD_OPTIONS, {netflush(); printsub('<', subpointer, SB_LEN()+2);});
1102
1103 subchar = SB_GET();
1104 switch (subchar) {
1105 case TELOPT_TSPEED: {
1106 int xspeed, rspeed;
1107
1108 if (his_state_is_wont(TELOPT_TSPEED)) /* Ignore if option disabled */
1109 break;
1110
1111 settimer(tspeedsubopt);
1112
1113 if (SB_EOF() || SB_GET() != TELQUAL_IS)
1114 return;
1115
1116 xspeed = atoi((char *)subpointer);
1117
1118 while (SB_GET() != ',' && !SB_EOF());
1119 if (SB_EOF())
1120 return;
1121
1122 rspeed = atoi((char *)subpointer);
1123 clientstat(TELOPT_TSPEED, xspeed, rspeed);
1124
1125 break;
1126
1127 } /* end of case TELOPT_TSPEED */
1128
1129 case TELOPT_TTYPE: { /* Yaaaay! */
1130 static char terminalname[TERMINAL_TYPE_SIZE];
1131
1132 if (his_state_is_wont(TELOPT_TTYPE)) /* Ignore if option disabled */
1133 break;
1134 settimer(ttypesubopt);
1135
1136 if (SB_EOF() || SB_GET() != TELQUAL_IS) {
1137 return; /* ??? XXX but, this is the most robust */
1138 }
1139
1140 terminaltype = terminalname;
1141
1142 while ((terminaltype < (terminalname + sizeof terminalname-1)) &&
1143 !SB_EOF()) {
1144 int c;
1145
1146 c = SB_GET();
1147 if (isupper(c)) {
1148 c = tolower(c);
1149 }
1150 *terminaltype++ = c; /* accumulate name */
1151 }
1152 *terminaltype = 0;
1153 terminaltype = terminalname;
1154 break;
1155 } /* end of case TELOPT_TTYPE */
1156
1157 case TELOPT_NAWS: {
1158 int xwinsize, ywinsize;
1159
1160 if (his_state_is_wont(TELOPT_NAWS)) /* Ignore if option disabled */
1161 break;
1162
1163 if (SB_EOF())
1164 return;
1165 xwinsize = SB_GET() << 8;
1166 if (SB_EOF())
1167 return;
1168 xwinsize |= SB_GET();
1169 if (SB_EOF())
1170 return;
1171 ywinsize = SB_GET() << 8;
1172 if (SB_EOF())
1173 return;
1174 ywinsize |= SB_GET();
1175 clientstat(TELOPT_NAWS, xwinsize, ywinsize);
1176
1177 break;
1178
1179 } /* end of case TELOPT_NAWS */
1180
1181 #ifdef LINEMODE
1182 case TELOPT_LINEMODE: {
1183 int request;
1184
1185 if (his_state_is_wont(TELOPT_LINEMODE)) /* Ignore if option disabled */
1186 break;
1187 /*
1188 * Process linemode suboptions.
1189 */
1190 if (SB_EOF())
1191 break; /* garbage was sent */
1192 request = SB_GET(); /* get will/wont */
1193
1194 if (SB_EOF())
1195 break; /* another garbage check */
1196
1197 if (request == LM_SLC) { /* SLC is not preceeded by WILL or WONT */
1198 /*
1199 * Process suboption buffer of slc's
1200 */
1201 start_slc(1);
1202 do_opt_slc(subpointer, subend - subpointer);
1203 (void) end_slc(0);
1204 break;
1205 } else if (request == LM_MODE) {
1206 if (SB_EOF())
1207 return;
1208 useeditmode = SB_GET(); /* get mode flag */
1209 clientstat(LM_MODE, 0, 0);
1210 break;
1211 }
1212
1213 if (SB_EOF())
1214 break;
1215 switch (SB_GET()) { /* what suboption? */
1216 case LM_FORWARDMASK:
1217 /*
1218 * According to spec, only server can send request for
1219 * forwardmask, and client can only return a positive response.
1220 * So don't worry about it.
1221 */
1222
1223 default:
1224 break;
1225 }
1226 break;
1227 } /* end of case TELOPT_LINEMODE */
1228 #endif
1229 case TELOPT_STATUS: {
1230 int mode;
1231
1232 if (SB_EOF())
1233 break;
1234 mode = SB_GET();
1235 switch (mode) {
1236 case TELQUAL_SEND:
1237 if (my_state_is_will(TELOPT_STATUS))
1238 send_status();
1239 break;
1240
1241 case TELQUAL_IS:
1242 break;
1243
1244 default:
1245 break;
1246 }
1247 break;
1248 } /* end of case TELOPT_STATUS */
1249
1250 case TELOPT_XDISPLOC: {
1251 if (SB_EOF() || SB_GET() != TELQUAL_IS)
1252 return;
1253 settimer(xdisplocsubopt);
1254 subpointer[SB_LEN()] = '\0';
1255 if (setenv("DISPLAY", (char *)subpointer, 1) == -1)
1256 syslog(LOG_ERR, "setenv: cannot set DISPLAY=%s: %m", (char *)subpointer);
1257 break;
1258 } /* end of case TELOPT_XDISPLOC */
1259
1260 #ifdef TELOPT_NEW_ENVIRON
1261 case TELOPT_NEW_ENVIRON:
1262 #endif
1263 case TELOPT_OLD_ENVIRON: {
1264 int c;
1265 char *cp, *varp, *valp;
1266
1267 if (SB_EOF())
1268 return;
1269 c = SB_GET();
1270 if (c == TELQUAL_IS) {
1271 if (subchar == TELOPT_OLD_ENVIRON)
1272 settimer(oenvironsubopt);
1273 else
1274 settimer(environsubopt);
1275 } else if (c != TELQUAL_INFO) {
1276 return;
1277 }
1278
1279 #ifdef TELOPT_NEW_ENVIRON
1280 if (subchar == TELOPT_NEW_ENVIRON) {
1281 while (!SB_EOF()) {
1282 c = SB_GET();
1283 if ((c == NEW_ENV_VAR) || (c == ENV_USERVAR))
1284 break;
1285 }
1286 } else
1287 #endif
1288 {
1289 #ifdef ENV_HACK
1290 /*
1291 * We only want to do this if we haven't already decided
1292 * whether or not the other side has its VALUE and VAR
1293 * reversed.
1294 */
1295 if (env_ovar < 0) {
1296 int last = -1; /* invalid value */
1297 int empty = 0;
1298 int got_var = 0, got_value = 0, got_uservar = 0;
1299
1300 /*
1301 * The other side might have its VALUE and VAR values
1302 * reversed. To be interoperable, we need to determine
1303 * which way it is. If the first recognized character
1304 * is a VAR or VALUE, then that will tell us what
1305 * type of client it is. If the fist recognized
1306 * character is a USERVAR, then we continue scanning
1307 * the suboption looking for two consecutive
1308 * VAR or VALUE fields. We should not get two
1309 * consecutive VALUE fields, so finding two
1310 * consecutive VALUE or VAR fields will tell us
1311 * what the client is.
1312 */
1313 SB_SAVE();
1314 while (!SB_EOF()) {
1315 c = SB_GET();
1316 switch(c) {
1317 case OLD_ENV_VAR:
1318 if (last < 0 || last == OLD_ENV_VAR
1319 || (empty && (last == OLD_ENV_VALUE)))
1320 goto env_ovar_ok;
1321 got_var++;
1322 last = OLD_ENV_VAR;
1323 break;
1324 case OLD_ENV_VALUE:
1325 if (last < 0 || last == OLD_ENV_VALUE
1326 || (empty && (last == OLD_ENV_VAR)))
1327 goto env_ovar_wrong;
1328 got_value++;
1329 last = OLD_ENV_VALUE;
1330 break;
1331 case ENV_USERVAR:
1332 /* count strings of USERVAR as one */
1333 if (last != ENV_USERVAR)
1334 got_uservar++;
1335 if (empty) {
1336 if (last == OLD_ENV_VALUE)
1337 goto env_ovar_ok;
1338 if (last == OLD_ENV_VAR)
1339 goto env_ovar_wrong;
1340 }
1341 last = ENV_USERVAR;
1342 break;
1343 case ENV_ESC:
1344 if (!SB_EOF())
1345 c = SB_GET();
1346 /* FALL THROUGH */
1347 default:
1348 empty = 0;
1349 continue;
1350 }
1351 empty = 1;
1352 }
1353 if (empty) {
1354 if (last == OLD_ENV_VALUE)
1355 goto env_ovar_ok;
1356 if (last == OLD_ENV_VAR)
1357 goto env_ovar_wrong;
1358 }
1359 /*
1360 * Ok, the first thing was a USERVAR, and there
1361 * are not two consecutive VAR or VALUE commands,
1362 * and none of the VAR or VALUE commands are empty.
1363 * If the client has sent us a well-formed option,
1364 * then the number of VALUEs received should always
1365 * be less than or equal to the number of VARs and
1366 * USERVARs received.
1367 *
1368 * If we got exactly as many VALUEs as VARs and
1369 * USERVARs, the client has the same definitions.
1370 *
1371 * If we got exactly as many VARs as VALUEs and
1372 * USERVARS, the client has reversed definitions.
1373 */
1374 if (got_uservar + got_var == got_value) {
1375 env_ovar_ok:
1376 env_ovar = OLD_ENV_VAR;
1377 env_ovalue = OLD_ENV_VALUE;
1378 } else if (got_uservar + got_value == got_var) {
1379 env_ovar_wrong:
1380 env_ovar = OLD_ENV_VALUE;
1381 env_ovalue = OLD_ENV_VAR;
1382 DIAG(TD_OPTIONS,
1383 output_data("ENVIRON VALUE and VAR are reversed!\r\n"));
1384
1385 }
1386 }
1387 SB_RESTORE();
1388 #endif
1389
1390 while (!SB_EOF()) {
1391 c = SB_GET();
1392 if ((c == env_ovar) || (c == ENV_USERVAR))
1393 break;
1394 }
1395 }
1396
1397 if (SB_EOF())
1398 return;
1399
1400 cp = varp = (char *)subpointer;
1401 valp = NULL;
1402
1403 while (!SB_EOF()) {
1404 c = SB_GET();
1405 if (subchar == TELOPT_OLD_ENVIRON) {
1406 if (c == env_ovar)
1407 c = NEW_ENV_VAR;
1408 else if (c == env_ovalue)
1409 c = NEW_ENV_VALUE;
1410 }
1411 switch (c) {
1412
1413 case NEW_ENV_VALUE:
1414 *cp = '\0';
1415 cp = valp = (char *)subpointer;
1416 break;
1417
1418 case NEW_ENV_VAR:
1419 case ENV_USERVAR:
1420 *cp = '\0';
1421 if (envvarok(varp)) {
1422 if (valp) {
1423 if (setenv(varp, valp, 1) == -1)
1424 syslog(LOG_ERR, "setenv: cannot set %s=%s: %m", varp, valp);
1425 }
1426 else
1427 unsetenv(varp);
1428 }
1429 cp = varp = (char *)subpointer;
1430 valp = NULL;
1431 break;
1432
1433 case ENV_ESC:
1434 if (SB_EOF())
1435 break;
1436 c = SB_GET();
1437 /* FALL THROUGH */
1438 default:
1439 *cp++ = c;
1440 break;
1441 }
1442 }
1443 *cp = '\0';
1444 if (envvarok(varp)) {
1445 if (valp) {
1446 if (setenv(varp, valp, 1) == -1)
1447 syslog(LOG_ERR, "setenv: cannot set %s=%s: %m", varp, valp);
1448 }
1449 else
1450 unsetenv(varp);
1451 }
1452 break;
1453 } /* end of case TELOPT_NEW_ENVIRON */
1454 #ifdef AUTHENTICATION
1455 case TELOPT_AUTHENTICATION:
1456 if (SB_EOF())
1457 break;
1458 switch(SB_GET()) {
1459 case TELQUAL_SEND:
1460 case TELQUAL_REPLY:
1461 /*
1462 * These are sent by us and cannot be sent by
1463 * the client.
1464 */
1465 break;
1466 case TELQUAL_IS:
1467 auth_is(subpointer, SB_LEN());
1468 break;
1469 case TELQUAL_NAME:
1470 auth_name(subpointer, SB_LEN());
1471 break;
1472 }
1473 break;
1474 #endif
1475 #ifdef ENCRYPTION
1476 case TELOPT_ENCRYPT:
1477 if (SB_EOF())
1478 break;
1479 switch(SB_GET()) {
1480 case ENCRYPT_SUPPORT:
1481 encrypt_support(subpointer, SB_LEN());
1482 break;
1483 case ENCRYPT_IS:
1484 encrypt_is(subpointer, SB_LEN());
1485 break;
1486 case ENCRYPT_REPLY:
1487 encrypt_reply(subpointer, SB_LEN());
1488 break;
1489 case ENCRYPT_START:
1490 encrypt_start(subpointer, SB_LEN());
1491 break;
1492 case ENCRYPT_END:
1493 encrypt_end();
1494 break;
1495 case ENCRYPT_REQSTART:
1496 encrypt_request_start(subpointer, SB_LEN());
1497 break;
1498 case ENCRYPT_REQEND:
1499 /*
1500 * We can always send an REQEND so that we cannot
1501 * get stuck encrypting. We should only get this
1502 * if we have been able to get in the correct mode
1503 * anyhow.
1504 */
1505 encrypt_request_end();
1506 break;
1507 case ENCRYPT_ENC_KEYID:
1508 encrypt_enc_keyid(subpointer, SB_LEN());
1509 break;
1510 case ENCRYPT_DEC_KEYID:
1511 encrypt_dec_keyid(subpointer, SB_LEN());
1512 break;
1513 default:
1514 break;
1515 }
1516 break;
1517 #endif /* ENCRYPTION */
1518
1519 default:
1520 break;
1521 } /* end of switch */
1522
1523 } /* end of suboption */
1524
1525 static void
1526 doclientstat(void)
1527 {
1528 clientstat(TELOPT_LINEMODE, WILL, 0);
1529 }
1530
1531 #define ADD(c) *ncp++ = c
1532 #define ADD_DATA(c) { *ncp++ = c; if (c == SE || c == IAC) *ncp++ = c; }
1533 void
1534 send_status(void)
1535 {
1536 unsigned char statusbuf[256];
1537 unsigned char *ncp;
1538 unsigned char i;
1539
1540 ncp = statusbuf;
1541
1542 netflush(); /* get rid of anything waiting to go out */
1543
1544 ADD(IAC);
1545 ADD(SB);
1546 ADD(TELOPT_STATUS);
1547 ADD(TELQUAL_IS);
1548
1549 /*
1550 * We check the want_state rather than the current state,
1551 * because if we received a DO/WILL for an option that we
1552 * don't support, and the other side didn't send a DONT/WONT
1553 * in response to our WONT/DONT, then the "state" will be
1554 * WILL/DO, and the "want_state" will be WONT/DONT. We
1555 * need to go by the latter.
1556 */
1557 for (i = 0; i < (unsigned char)NTELOPTS; i++) {
1558 if (my_want_state_is_will(i)) {
1559 ADD(WILL);
1560 ADD_DATA(i);
1561 if (i == IAC)
1562 ADD(IAC);
1563 }
1564 if (his_want_state_is_will(i)) {
1565 ADD(DO);
1566 ADD_DATA(i);
1567 if (i == IAC)
1568 ADD(IAC);
1569 }
1570 }
1571
1572 if (his_want_state_is_will(TELOPT_LFLOW)) {
1573 ADD(SB);
1574 ADD(TELOPT_LFLOW);
1575 if (flowmode) {
1576 ADD(LFLOW_ON);
1577 } else {
1578 ADD(LFLOW_OFF);
1579 }
1580 ADD(SE);
1581
1582 if (restartany >= 0) {
1583 ADD(SB);
1584 ADD(TELOPT_LFLOW);
1585 if (restartany) {
1586 ADD(LFLOW_RESTART_ANY);
1587 } else {
1588 ADD(LFLOW_RESTART_XON);
1589 }
1590 ADD(SE);
1591 }
1592 }
1593
1594 #ifdef LINEMODE
1595 if (his_want_state_is_will(TELOPT_LINEMODE)) {
1596 unsigned char *cp, *cpe;
1597 int len;
1598
1599 ADD(SB);
1600 ADD(TELOPT_LINEMODE);
1601 ADD(LM_MODE);
1602 ADD_DATA(editmode);
1603 ADD(SE);
1604
1605 ADD(SB);
1606 ADD(TELOPT_LINEMODE);
1607 ADD(LM_SLC);
1608 start_slc(0);
1609 send_slc();
1610 len = end_slc(&cp);
1611 for (cpe = cp + len; cp < cpe; cp++)
1612 ADD_DATA(*cp);
1613 ADD(SE);
1614 }
1615 #endif /* LINEMODE */
1616
1617 ADD(IAC);
1618 ADD(SE);
1619
1620 output_datalen(statusbuf, ncp - statusbuf);
1621 netflush(); /* Send it on its way */
1622
1623 DIAG(TD_OPTIONS,
1624 {printsub('>', statusbuf, ncp - statusbuf); netflush();});
1625 }
1626
1627 /*
1628 * This function appends data to nfrontp and advances nfrontp.
1629 * Returns the number of characters written altogether (the
1630 * buffer may have been flushed in the process).
1631 */
1632
1633 int
1634 output_data(const char *format, ...)
1635 {
1636 va_list args;
1637 int len;
1638 char *buf;
1639
1640 va_start(args, format);
1641 if ((len = vasprintf(&buf, format, args)) == -1) {
1642 va_end(args);
1643 return -1;
1644 }
1645 output_datalen(buf, len);
1646 va_end(args);
1647 free(buf);
1648 return (len);
1649 }
1650
1651 void
1652 output_datalen(const char *buf, int len)
1653 {
1654 int remaining, copied;
1655
1656 remaining = BUFSIZ - (nfrontp - netobuf);
1657 while (len > 0) {
1658 /* Free up enough space if the room is too low*/
1659 if ((len > BUFSIZ ? BUFSIZ : len) > remaining) {
1660 netflush();
1661 remaining = BUFSIZ - (nfrontp - netobuf);
1662 }
1663
1664 /* Copy out as much as will fit */
1665 copied = remaining > len ? len : remaining;
1666 memmove(nfrontp, buf, copied);
1667 nfrontp += copied;
1668 len -= copied;
1669 remaining -= copied;
1670 buf += copied;
1671 }
1672 return;
1673 }
DragonFly BSD