Revert "libtelnet/telnetd(8): Fix building with -fno-common."
[dragonfly.git] / libexec / telnetd / telnetd.c
CommitLineData
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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.
dc71b7ab 13 * 3. Neither the name of the University nor the names of its contributors
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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.
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28 *
29 * @(#)telnetd.c 8.4 (Berkeley) 5/30/95
068e7061 30 * $FreeBSD: src/crypto/telnet/telnetd/telnetd.c,v 1.11.2.5 2002/04/13 10:59:09 markm Exp $
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31 */
32
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33#include "telnetd.h"
34#include "pathnames.h"
35
36#include <sys/mman.h>
37#include <err.h>
38#include <libutil.h>
39#include <paths.h>
40#include <termcap.h>
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41
42#include <arpa/inet.h>
43
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44#ifdef AUTHENTICATION
45#include <libtelnet/auth.h>
1c6ee455 46int auth_level = 0;
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47#endif
48#ifdef ENCRYPTION
49#include <libtelnet/encrypt.h>
50#endif
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51#include <libtelnet/misc.h>
52
53char remote_hostname[MAXHOSTNAMELEN];
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54int registerd_host_only = 0;
55
56
57/*
58 * I/O data buffers,
59 * pointers, and counters.
60 */
61char ptyibuf[BUFSIZ], *ptyip = ptyibuf;
62char ptyibuf2[BUFSIZ];
63
64int readstream(int, char *, int);
b9c8dce8 65void doit(struct sockaddr *) __dead2;
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66int terminaltypeok(char *);
67
68int hostinfo = 1; /* do we print login banner? */
69
079881d0 70static int debug = 0;
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71int keepalive = 1;
72const char *altlogin;
73
984263bc 74void startslave(char *, int, char *);
b9c8dce8 75extern void usage(void) __dead2;
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76static void _gettermname(void);
77
78/*
79 * The string to pass to getopt(). We do it this way so
80 * that only the actual options that we support will be
81 * passed off to getopt().
82 */
83char valid_opts[] = {
84 'd', ':', 'h', 'k', 'n', 'p', ':', 'S', ':', 'u', ':', 'U',
85 '4', '6',
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86#ifdef AUTHENTICATION
87 'a', ':', 'X', ':',
88#endif
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89#ifdef BFTPDAEMON
90 'B',
91#endif
92#ifdef DIAGNOSTICS
93 'D', ':',
94#endif
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95#ifdef ENCRYPTION
96 'e', ':',
97#endif
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98#ifdef LINEMODE
99 'l',
100#endif
101 '\0'
102};
103
104int family = AF_INET;
105
106#ifndef MAXHOSTNAMELEN
107#define MAXHOSTNAMELEN 256
108#endif /* MAXHOSTNAMELEN */
109
110char *hostname;
111char host_name[MAXHOSTNAMELEN];
112
b9c8dce8 113extern void telnet(int, int, char *) __dead2;
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114
115int level;
116char user_name[256];
117
118int
119main(int argc, char *argv[])
120{
121 struct sockaddr_storage from;
122 int on = 1, fromlen;
123 int ch;
124#if defined(IPPROTO_IP) && defined(IP_TOS)
125 int tos = -1;
126#endif
127
128 pfrontp = pbackp = ptyobuf;
129 netip = netibuf;
130 nfrontp = nbackp = netobuf;
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131#ifdef ENCRYPTION
132 nclearto = 0;
133#endif /* ENCRYPTION */
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134
135 /*
136 * This initialization causes linemode to default to a configuration
137 * that works on all telnet clients, including the FreeBSD client.
138 * This is not quite the same as the telnet client issuing a "mode
139 * character" command, but has most of the same benefits, and is
140 * preferable since some clients (like usofts) don't have the
141 * mode character command anyway and linemode breaks things.
142 * The most notable symptom of fix is that csh "set filec" operations
143 * like <ESC> (filename completion) and ^D (choices) keys now work
144 * in telnet sessions and can be used more than once on the same line.
145 * CR/LF handling is also corrected in some termio modes. This
146 * change resolves problem reports bin/771 and bin/1037.
147 */
148
149 linemode=1; /*Default to mode that works on bulk of clients*/
150
151 while ((ch = getopt(argc, argv, valid_opts)) != -1) {
152 switch(ch) {
153
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154#ifdef AUTHENTICATION
155 case 'a':
156 /*
157 * Check for required authentication level
158 */
159 if (strcmp(optarg, "debug") == 0) {
160 extern int auth_debug_mode;
161 auth_debug_mode = 1;
162 } else if (strcasecmp(optarg, "none") == 0) {
163 auth_level = 0;
164 } else if (strcasecmp(optarg, "other") == 0) {
165 auth_level = AUTH_OTHER;
166 } else if (strcasecmp(optarg, "user") == 0) {
167 auth_level = AUTH_USER;
168 } else if (strcasecmp(optarg, "valid") == 0) {
169 auth_level = AUTH_VALID;
170 } else if (strcasecmp(optarg, "off") == 0) {
171 /*
172 * This hack turns off authentication
173 */
174 auth_level = -1;
175 } else {
176 warnx("unknown authorization level for -a");
177 }
178 break;
179#endif /* AUTHENTICATION */
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180
181#ifdef BFTPDAEMON
182 case 'B':
183 bftpd++;
184 break;
185#endif /* BFTPDAEMON */
186
187 case 'd':
188 if (strcmp(optarg, "ebug") == 0) {
189 debug++;
190 break;
191 }
192 usage();
193 /* NOTREACHED */
194 break;
195
196#ifdef DIAGNOSTICS
197 case 'D':
198 /*
199 * Check for desired diagnostics capabilities.
200 */
201 if (!strcmp(optarg, "report")) {
202 diagnostic |= TD_REPORT|TD_OPTIONS;
203 } else if (!strcmp(optarg, "exercise")) {
204 diagnostic |= TD_EXERCISE;
205 } else if (!strcmp(optarg, "netdata")) {
206 diagnostic |= TD_NETDATA;
207 } else if (!strcmp(optarg, "ptydata")) {
208 diagnostic |= TD_PTYDATA;
209 } else if (!strcmp(optarg, "options")) {
210 diagnostic |= TD_OPTIONS;
211 } else {
212 usage();
213 /* NOT REACHED */
214 }
215 break;
216#endif /* DIAGNOSTICS */
217
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218#ifdef ENCRYPTION
219 case 'e':
220 if (strcmp(optarg, "debug") == 0) {
221 extern int encrypt_debug_mode;
222 encrypt_debug_mode = 1;
223 break;
224 }
225 usage();
226 /* NOTREACHED */
227 break;
228#endif /* ENCRYPTION */
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229
230 case 'h':
231 hostinfo = 0;
232 break;
233
234#ifdef LINEMODE
235 case 'l':
236 alwayslinemode = 1;
237 break;
238#endif /* LINEMODE */
239
240 case 'k':
241#if defined(LINEMODE) && defined(KLUDGELINEMODE)
242 lmodetype = NO_AUTOKLUDGE;
243#else
244 /* ignore -k option if built without kludge linemode */
245#endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */
246 break;
247
248 case 'n':
249 keepalive = 0;
250 break;
251
252 case 'p':
253 altlogin = optarg;
254 break;
255
256 case 'S':
257#ifdef HAS_GETTOS
258 if ((tos = parsetos(optarg, "tcp")) < 0)
259 warnx("%s%s%s",
260 "bad TOS argument '", optarg,
261 "'; will try to use default TOS");
262#else
263 warnx("TOS option unavailable; -S flag not supported");
264#endif
265 break;
266
267 case 'u':
0ba3ecdc 268 fprintf(stderr, "telnetd: -u option unneeded\n");
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269 break;
270
271 case 'U':
272 registerd_host_only = 1;
273 break;
274
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275#ifdef AUTHENTICATION
276 case 'X':
277 /*
278 * Check for invalid authentication types
279 */
280 auth_disable_name(optarg);
281 break;
282#endif /* AUTHENTICATION */
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283
284 case '4':
285 family = AF_INET;
286 break;
287
288#ifdef INET6
289 case '6':
290 family = AF_INET6;
291 break;
292#endif
293
294 default:
295 warnx("%c: unknown option", ch);
296 /* FALLTHROUGH */
297 case '?':
298 usage();
299 /* NOTREACHED */
300 }
301 }
302
303 argc -= optind;
304 argv += optind;
305
306 if (debug) {
307 int s, ns, foo, error;
308 const char *service = "telnet";
309 struct addrinfo hints, *res;
310
311 if (argc > 1) {
312 usage();
313 /* NOT REACHED */
314 } else if (argc == 1)
315 service = *argv;
316
317 memset(&hints, 0, sizeof(hints));
318 hints.ai_flags = AI_PASSIVE;
319 hints.ai_family = family;
320 hints.ai_socktype = SOCK_STREAM;
321 hints.ai_protocol = 0;
322 error = getaddrinfo(NULL, service, &hints, &res);
323
324 if (error) {
325 errx(1, "tcp/%s: %s\n", service, gai_strerror(error));
326 if (error == EAI_SYSTEM)
327 errx(1, "tcp/%s: %s\n", service, strerror(errno));
328 usage();
329 }
330
331 s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
332 if (s < 0)
333 err(1, "socket");
334 (void) setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
335 (char *)&on, sizeof(on));
336 if (bind(s, res->ai_addr, res->ai_addrlen) < 0)
337 err(1, "bind");
338 if (listen(s, 1) < 0)
339 err(1, "listen");
340 foo = res->ai_addrlen;
341 ns = accept(s, res->ai_addr, &foo);
342 if (ns < 0)
343 err(1, "accept");
344 (void) dup2(ns, 0);
345 (void) close(ns);
346 (void) close(s);
347#ifdef convex
348 } else if (argc == 1) {
349 ; /* VOID*/ /* Just ignore the host/port name */
350#endif
351 } else if (argc > 0) {
352 usage();
353 /* NOT REACHED */
354 }
355
08328df0 356 openlog("telnetd", LOG_PID, LOG_DAEMON);
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357 fromlen = sizeof (from);
358 if (getpeername(0, (struct sockaddr *)&from, &fromlen) < 0) {
359 warn("getpeername");
360 _exit(1);
361 }
362 if (keepalive &&
363 setsockopt(0, SOL_SOCKET, SO_KEEPALIVE,
364 (char *)&on, sizeof (on)) < 0) {
365 syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m");
366 }
367
368#if defined(IPPROTO_IP) && defined(IP_TOS)
369 if (from.ss_family == AF_INET) {
370# if defined(HAS_GETTOS)
371 struct tosent *tp;
372 if (tos < 0 && (tp = gettosbyname("telnet", "tcp")))
373 tos = tp->t_tos;
374# endif
375 if (tos < 0)
376 tos = 020; /* Low Delay bit */
377 if (tos
378 && (setsockopt(0, IPPROTO_IP, IP_TOS,
379 (char *)&tos, sizeof(tos)) < 0)
380 && (errno != ENOPROTOOPT) )
381 syslog(LOG_WARNING, "setsockopt (IP_TOS): %m");
382 }
383#endif /* defined(IPPROTO_IP) && defined(IP_TOS) */
384 net = 0;
385 doit((struct sockaddr *)&from);
386 /* NOTREACHED */
387 return(0);
388} /* end of main */
389
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390void
391usage(void)
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392{
393 fprintf(stderr, "usage: telnetd");
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394#ifdef AUTHENTICATION
395 fprintf(stderr, " [-a (debug|other|user|valid|off|none)]\n\t");
396#endif
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397#ifdef BFTPDAEMON
398 fprintf(stderr, " [-B]");
399#endif
400 fprintf(stderr, " [-debug]");
401#ifdef DIAGNOSTICS
402 fprintf(stderr, " [-D (options|report|exercise|netdata|ptydata)]\n\t");
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403#endif
404#ifdef AUTHENTICATION
405 fprintf(stderr, " [-edebug]");
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406#endif
407 fprintf(stderr, " [-h]");
408#if defined(LINEMODE) && defined(KLUDGELINEMODE)
409 fprintf(stderr, " [-k]");
410#endif
411#ifdef LINEMODE
412 fprintf(stderr, " [-l]");
413#endif
414 fprintf(stderr, " [-n]");
415 fprintf(stderr, "\n\t");
416#ifdef HAS_GETTOS
417 fprintf(stderr, " [-S tos]");
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418#endif
419#ifdef AUTHENTICATION
420 fprintf(stderr, " [-X auth-type]");
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421#endif
422 fprintf(stderr, " [-u utmp_hostname_length] [-U]");
423 fprintf(stderr, " [port]\n");
424 exit(1);
425}
426
427/*
428 * getterminaltype
429 *
430 * Ask the other end to send along its terminal type and speed.
431 * Output is the variable terminaltype filled in.
432 */
433static unsigned char ttytype_sbbuf[] = {
434 IAC, SB, TELOPT_TTYPE, TELQUAL_SEND, IAC, SE
435};
436
437
068e7061 438#ifndef AUTHENTICATION
984263bc 439#define undef2 __unused
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440#else
441#define undef2
442#endif
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443
444static int
445getterminaltype(char *name undef2)
446{
447 int retval = -1;
448
449 settimer(baseline);
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450#ifdef AUTHENTICATION
451 /*
452 * Handle the Authentication option before we do anything else.
453 */
454 send_do(TELOPT_AUTHENTICATION, 1);
455 while (his_will_wont_is_changing(TELOPT_AUTHENTICATION))
456 ttloop();
457 if (his_state_is_will(TELOPT_AUTHENTICATION)) {
458 retval = auth_wait(name);
459 }
460#endif
984263bc 461
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462#ifdef ENCRYPTION
463 send_will(TELOPT_ENCRYPT, 1);
464#endif /* ENCRYPTION */
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465 send_do(TELOPT_TTYPE, 1);
466 send_do(TELOPT_TSPEED, 1);
467 send_do(TELOPT_XDISPLOC, 1);
468 send_do(TELOPT_NEW_ENVIRON, 1);
469 send_do(TELOPT_OLD_ENVIRON, 1);
470 while (
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471#ifdef ENCRYPTION
472 his_do_dont_is_changing(TELOPT_ENCRYPT) ||
473#endif /* ENCRYPTION */
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474 his_will_wont_is_changing(TELOPT_TTYPE) ||
475 his_will_wont_is_changing(TELOPT_TSPEED) ||
476 his_will_wont_is_changing(TELOPT_XDISPLOC) ||
477 his_will_wont_is_changing(TELOPT_NEW_ENVIRON) ||
478 his_will_wont_is_changing(TELOPT_OLD_ENVIRON)) {
479 ttloop();
480 }
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481#ifdef ENCRYPTION
482 /*
483 * Wait for the negotiation of what type of encryption we can
484 * send with. If autoencrypt is not set, this will just return.
485 */
486 if (his_state_is_will(TELOPT_ENCRYPT)) {
487 encrypt_wait();
488 }
489#endif /* ENCRYPTION */
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490 if (his_state_is_will(TELOPT_TSPEED)) {
491 static unsigned char sb[] =
492 { IAC, SB, TELOPT_TSPEED, TELQUAL_SEND, IAC, SE };
493
494 output_datalen(sb, sizeof sb);
495 DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
496 }
497 if (his_state_is_will(TELOPT_XDISPLOC)) {
498 static unsigned char sb[] =
499 { IAC, SB, TELOPT_XDISPLOC, TELQUAL_SEND, IAC, SE };
500
501 output_datalen(sb, sizeof sb);
502 DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
503 }
504 if (his_state_is_will(TELOPT_NEW_ENVIRON)) {
505 static unsigned char sb[] =
506 { IAC, SB, TELOPT_NEW_ENVIRON, TELQUAL_SEND, IAC, SE };
507
508 output_datalen(sb, sizeof sb);
509 DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
510 }
511 else if (his_state_is_will(TELOPT_OLD_ENVIRON)) {
512 static unsigned char sb[] =
513 { IAC, SB, TELOPT_OLD_ENVIRON, TELQUAL_SEND, IAC, SE };
514
515 output_datalen(sb, sizeof sb);
516 DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
517 }
518 if (his_state_is_will(TELOPT_TTYPE)) {
519
520 output_datalen(ttytype_sbbuf, sizeof ttytype_sbbuf);
521 DIAG(TD_OPTIONS, printsub('>', ttytype_sbbuf + 2,
522 sizeof ttytype_sbbuf - 2););
523 }
524 if (his_state_is_will(TELOPT_TSPEED)) {
525 while (sequenceIs(tspeedsubopt, baseline))
526 ttloop();
527 }
528 if (his_state_is_will(TELOPT_XDISPLOC)) {
529 while (sequenceIs(xdisplocsubopt, baseline))
530 ttloop();
531 }
532 if (his_state_is_will(TELOPT_NEW_ENVIRON)) {
533 while (sequenceIs(environsubopt, baseline))
534 ttloop();
535 }
536 if (his_state_is_will(TELOPT_OLD_ENVIRON)) {
537 while (sequenceIs(oenvironsubopt, baseline))
538 ttloop();
539 }
540 if (his_state_is_will(TELOPT_TTYPE)) {
541 char first[256], last[256];
542
543 while (sequenceIs(ttypesubopt, baseline))
544 ttloop();
545
546 /*
547 * If the other side has already disabled the option, then
548 * we have to just go with what we (might) have already gotten.
549 */
550 if (his_state_is_will(TELOPT_TTYPE) && !terminaltypeok(terminaltype)) {
551 (void) strncpy(first, terminaltype, sizeof(first)-1);
552 first[sizeof(first)-1] = '\0';
553 for(;;) {
554 /*
555 * Save the unknown name, and request the next name.
556 */
557 (void) strncpy(last, terminaltype, sizeof(last)-1);
558 last[sizeof(last)-1] = '\0';
559 _gettermname();
560 if (terminaltypeok(terminaltype))
561 break;
562 if ((strncmp(last, terminaltype, sizeof(last)) == 0) ||
563 his_state_is_wont(TELOPT_TTYPE)) {
564 /*
565 * We've hit the end. If this is the same as
566 * the first name, just go with it.
567 */
568 if (strncmp(first, terminaltype, sizeof(first)) == 0)
569 break;
570 /*
571 * Get the terminal name one more time, so that
572 * RFC1091 compliant telnets will cycle back to
573 * the start of the list.
574 */
575 _gettermname();
576 if (strncmp(first, terminaltype, sizeof(first)) != 0) {
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577 (void) strncpy(terminaltype, first, TERMINAL_TYPE_SIZE-1);
578 terminaltype[TERMINAL_TYPE_SIZE-1] = '\0';
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579 }
580 break;
581 }
582 }
583 }
584 }
585 return(retval);
586} /* end of getterminaltype */
587
588static void
589_gettermname(void)
590{
591 /*
592 * If the client turned off the option,
593 * we can't send another request, so we
594 * just return.
595 */
596 if (his_state_is_wont(TELOPT_TTYPE))
597 return;
598 settimer(baseline);
599 output_datalen(ttytype_sbbuf, sizeof ttytype_sbbuf);
600 DIAG(TD_OPTIONS, printsub('>', ttytype_sbbuf + 2,
601 sizeof ttytype_sbbuf - 2););
602 while (sequenceIs(ttypesubopt, baseline))
603 ttloop();
604}
605
606int
607terminaltypeok(char *s)
608{
609 char buf[1024];
610
611 if (terminaltype == NULL)
612 return(1);
613
614 /*
615 * tgetent() will return 1 if the type is known, and
616 * 0 if it is not known. If it returns -1, it couldn't
617 * open the database. But if we can't open the database,
618 * it won't help to say we failed, because we won't be
619 * able to verify anything else. So, we treat -1 like 1.
620 */
621 if (tgetent(buf, s) == 0)
622 return(0);
623 return(1);
624}
625
626/*
627 * Get a pty, scan input lines.
628 */
629void
630doit(struct sockaddr *who)
631{
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632 int ptynum;
633
634 /*
635 * Find an available pty to use.
636 */
637#ifndef convex
638 pty = getpty(&ptynum);
639 if (pty < 0)
ccf9d6e5 640 fatalmsg(net, "All network ports in use");
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641#else
642 for (;;) {
643 char *lp;
644
645 if ((lp = getpty()) == NULL)
ccf9d6e5 646 fatalmsg(net, "Out of ptys");
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647
648 if ((pty = open(lp, 2)) >= 0) {
649 strlcpy(line,lp,sizeof(line));
650 line[5] = 't';
651 break;
652 }
653 }
654#endif
655
656 /* get name of connected client */
657 if (realhostname_sa(remote_hostname, sizeof(remote_hostname) - 1,
658 who, who->sa_len) == HOSTNAME_INVALIDADDR && registerd_host_only)
ccf9d6e5 659 fatalmsg(net, "Couldn't resolve your address into a host name.\r\n\
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660 Please contact your net administrator");
661 remote_hostname[sizeof(remote_hostname) - 1] = '\0';
662
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663 (void) gethostname(host_name, sizeof(host_name) - 1);
664 host_name[sizeof(host_name) - 1] = '\0';
665 hostname = host_name;
666
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667#ifdef AUTHENTICATION
668#ifdef ENCRYPTION
669/* The above #ifdefs should actually be "or"'ed, not "and"'ed.
670 * This is a byproduct of needing "#ifdef" and not "#if defined()"
671 * for unifdef. XXX MarkM
672 */
673 auth_encrypt_init(hostname, remote_hostname, "TELNETD", 1);
674#endif
675#endif
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676
677 init_env();
678 /*
679 * get terminal type.
680 */
681 *user_name = 0;
682 level = getterminaltype(user_name);
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683 if (setenv("TERM", terminaltype ? terminaltype : "network", 1) == -1)
684 syslog(LOG_ERR, "setenv: cannot set TERM=%s: %m", terminaltype ? terminaltype : "network");
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685
686 telnet(net, pty, remote_hostname); /* begin server process */
687
688 /*NOTREACHED*/
689} /* end of doit */
690
691/*
692 * Main loop. Select from pty and network, and
693 * hand data to telnet receiver finite state machine.
694 */
695void
696telnet(int f, int p, char *host)
697{
698 int on = 1;
699#define TABBUFSIZ 512
700 char defent[TABBUFSIZ];
701 char defstrs[TABBUFSIZ];
702#undef TABBUFSIZ
703 char *HE;
704 char *HN;
705 char *IM;
706 int nfd;
707
708 /*
709 * Initialize the slc mapping table.
710 */
711 get_slc_defaults();
712
713 /*
714 * Do some tests where it is desireable to wait for a response.
715 * Rather than doing them slowly, one at a time, do them all
716 * at once.
717 */
718 if (my_state_is_wont(TELOPT_SGA))
719 send_will(TELOPT_SGA, 1);
720 /*
721 * Is the client side a 4.2 (NOT 4.3) system? We need to know this
722 * because 4.2 clients are unable to deal with TCP urgent data.
723 *
724 * To find out, we send out a "DO ECHO". If the remote system
725 * answers "WILL ECHO" it is probably a 4.2 client, and we note
726 * that fact ("WILL ECHO" ==> that the client will echo what
727 * WE, the server, sends it; it does NOT mean that the client will
728 * echo the terminal input).
729 */
730 send_do(TELOPT_ECHO, 1);
731
732#ifdef LINEMODE
733 if (his_state_is_wont(TELOPT_LINEMODE)) {
734 /* Query the peer for linemode support by trying to negotiate
735 * the linemode option.
736 */
737 linemode = 0;
738 editmode = 0;
739 send_do(TELOPT_LINEMODE, 1); /* send do linemode */
740 }
741#endif /* LINEMODE */
742
743 /*
744 * Send along a couple of other options that we wish to negotiate.
745 */
746 send_do(TELOPT_NAWS, 1);
747 send_will(TELOPT_STATUS, 1);
748 flowmode = 1; /* default flow control state */
749 restartany = -1; /* uninitialized... */
750 send_do(TELOPT_LFLOW, 1);
751
752 /*
753 * Spin, waiting for a response from the DO ECHO. However,
754 * some REALLY DUMB telnets out there might not respond
755 * to the DO ECHO. So, we spin looking for NAWS, (most dumb
756 * telnets so far seem to respond with WONT for a DO that
757 * they don't understand...) because by the time we get the
758 * response, it will already have processed the DO ECHO.
759 * Kludge upon kludge.
760 */
761 while (his_will_wont_is_changing(TELOPT_NAWS))
762 ttloop();
763
764 /*
765 * But...
766 * The client might have sent a WILL NAWS as part of its
767 * startup code; if so, we'll be here before we get the
768 * response to the DO ECHO. We'll make the assumption
769 * that any implementation that understands about NAWS
770 * is a modern enough implementation that it will respond
771 * to our DO ECHO request; hence we'll do another spin
772 * waiting for the ECHO option to settle down, which is
773 * what we wanted to do in the first place...
774 */
775 if (his_want_state_is_will(TELOPT_ECHO) &&
776 his_state_is_will(TELOPT_NAWS)) {
777 while (his_will_wont_is_changing(TELOPT_ECHO))
778 ttloop();
779 }
780 /*
781 * On the off chance that the telnet client is broken and does not
782 * respond to the DO ECHO we sent, (after all, we did send the
783 * DO NAWS negotiation after the DO ECHO, and we won't get here
784 * until a response to the DO NAWS comes back) simulate the
785 * receipt of a will echo. This will also send a WONT ECHO
786 * to the client, since we assume that the client failed to
787 * respond because it believes that it is already in DO ECHO
788 * mode, which we do not want.
789 */
790 if (his_want_state_is_will(TELOPT_ECHO)) {
791 DIAG(TD_OPTIONS, output_data("td: simulating recv\r\n"));
792 willoption(TELOPT_ECHO);
793 }
794
795 /*
796 * Finally, to clean things up, we turn on our echo. This
797 * will break stupid 4.2 telnets out of local terminal echo.
798 */
799
800 if (my_state_is_wont(TELOPT_ECHO))
801 send_will(TELOPT_ECHO, 1);
802
803 /*
804 * Turn on packet mode
805 */
806 (void) ioctl(p, TIOCPKT, (char *)&on);
807
808#if defined(LINEMODE) && defined(KLUDGELINEMODE)
809 /*
810 * Continuing line mode support. If client does not support
811 * real linemode, attempt to negotiate kludge linemode by sending
812 * the do timing mark sequence.
813 */
814 if (lmodetype < REAL_LINEMODE)
815 send_do(TELOPT_TM, 1);
816#endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */
817
818 /*
819 * Call telrcv() once to pick up anything received during
820 * terminal type negotiation, 4.2/4.3 determination, and
821 * linemode negotiation.
822 */
823 telrcv();
824
825 (void) ioctl(f, FIONBIO, (char *)&on);
826 (void) ioctl(p, FIONBIO, (char *)&on);
827
828#if defined(SO_OOBINLINE)
829 (void) setsockopt(net, SOL_SOCKET, SO_OOBINLINE,
830 (char *)&on, sizeof on);
831#endif /* defined(SO_OOBINLINE) */
832
833#ifdef SIGTSTP
834 (void) signal(SIGTSTP, SIG_IGN);
835#endif
836#ifdef SIGTTOU
837 /*
838 * Ignoring SIGTTOU keeps the kernel from blocking us
839 * in ttioct() in /sys/tty.c.
840 */
841 (void) signal(SIGTTOU, SIG_IGN);
842#endif
843
844 (void) signal(SIGCHLD, cleanup);
845
846#ifdef TIOCNOTTY
847 {
848 int t;
849 t = open(_PATH_TTY, O_RDWR);
850 if (t >= 0) {
60233e58 851 (void) ioctl(t, TIOCNOTTY, NULL);
984263bc
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852 (void) close(t);
853 }
854 }
855#endif
856
857 /*
858 * Show banner that getty never gave.
859 *
860 * We put the banner in the pty input buffer. This way, it
861 * gets carriage return null processing, etc., just like all
862 * other pty --> client data.
863 */
864
865 if (getent(defent, "default") == 1) {
866 char *cp=defstrs;
867
868 HE = Getstr("he", &cp);
869 HN = Getstr("hn", &cp);
870 IM = Getstr("im", &cp);
871 if (HN && *HN)
872 (void) strlcpy(host_name, HN, sizeof(host_name));
678e8cc6 873 if (IM == NULL)
984263bc
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874 IM = strdup("");
875 } else {
876 IM = strdup(DEFAULT_IM);
678e8cc6 877 HE = NULL;
984263bc
MD
878 }
879 edithost(HE, host_name);
880 if (hostinfo && *IM)
881 putf(IM, ptyibuf2);
882
883 if (pcc)
884 (void) strncat(ptyibuf2, ptyip, pcc+1);
885 ptyip = ptyibuf2;
886 pcc = strlen(ptyip);
887#ifdef LINEMODE
888 /*
889 * Last check to make sure all our states are correct.
890 */
891 init_termbuf();
892 localstat();
893#endif /* LINEMODE */
894
895 DIAG(TD_REPORT, output_data("td: Entering processing loop\r\n"));
896
897 /*
898 * Startup the login process on the slave side of the terminal
899 * now. We delay this until here to insure option negotiation
900 * is complete.
901 */
902 startslave(host, level, user_name);
903
904 nfd = ((f > p) ? f : p) + 1;
905 for (;;) {
906 fd_set ibits, obits, xbits;
907 int c;
908
909 if (ncc < 0 && pcc < 0)
910 break;
911
912 FD_ZERO(&ibits);
913 FD_ZERO(&obits);
914 FD_ZERO(&xbits);
915 /*
916 * Never look for input if there's still
917 * stuff in the corresponding output buffer
918 */
919 if (nfrontp - nbackp || pcc > 0) {
920 FD_SET(f, &obits);
921 } else {
922 FD_SET(p, &ibits);
923 }
924 if (pfrontp - pbackp || ncc > 0) {
925 FD_SET(p, &obits);
926 } else {
927 FD_SET(f, &ibits);
928 }
929 if (!SYNCHing) {
930 FD_SET(f, &xbits);
931 }
60233e58 932 if ((c = select(nfd, &ibits, &obits, &xbits, NULL)) < 1) {
984263bc
MD
933 if (c == -1) {
934 if (errno == EINTR) {
935 continue;
936 }
937 }
938 sleep(5);
939 continue;
940 }
941
942 /*
943 * Any urgent data?
944 */
945 if (FD_ISSET(net, &xbits)) {
946 SYNCHing = 1;
947 }
948
949 /*
950 * Something to read from the network...
951 */
952 if (FD_ISSET(net, &ibits)) {
953#if !defined(SO_OOBINLINE)
954 /*
955 * In 4.2 (and 4.3 beta) systems, the
956 * OOB indication and data handling in the kernel
957 * is such that if two separate TCP Urgent requests
958 * come in, one byte of TCP data will be overlaid.
959 * This is fatal for Telnet, but we try to live
960 * with it.
961 *
962 * In addition, in 4.2 (and...), a special protocol
963 * is needed to pick up the TCP Urgent data in
964 * the correct sequence.
965 *
966 * What we do is: if we think we are in urgent
967 * mode, we look to see if we are "at the mark".
968 * If we are, we do an OOB receive. If we run
969 * this twice, we will do the OOB receive twice,
970 * but the second will fail, since the second
971 * time we were "at the mark", but there wasn't
972 * any data there (the kernel doesn't reset
973 * "at the mark" until we do a normal read).
974 * Once we've read the OOB data, we go ahead
975 * and do normal reads.
976 *
977 * There is also another problem, which is that
978 * since the OOB byte we read doesn't put us
979 * out of OOB state, and since that byte is most
980 * likely the TELNET DM (data mark), we would
981 * stay in the TELNET SYNCH (SYNCHing) state.
982 * So, clocks to the rescue. If we've "just"
983 * received a DM, then we test for the
984 * presence of OOB data when the receive OOB
985 * fails (and AFTER we did the normal mode read
986 * to clear "at the mark").
987 */
988 if (SYNCHing) {
989 int atmark;
990
991 (void) ioctl(net, SIOCATMARK, (char *)&atmark);
992 if (atmark) {
993 ncc = recv(net, netibuf, sizeof (netibuf), MSG_OOB);
994 if ((ncc == -1) && (errno == EINVAL)) {
995 ncc = read(net, netibuf, sizeof (netibuf));
996 if (sequenceIs(didnetreceive, gotDM)) {
997 SYNCHing = stilloob(net);
998 }
999 }
1000 } else {
1001 ncc = read(net, netibuf, sizeof (netibuf));
1002 }
1003 } else {
1004 ncc = read(net, netibuf, sizeof (netibuf));
1005 }
1006 settimer(didnetreceive);
1007#else /* !defined(SO_OOBINLINE)) */
1008 ncc = read(net, netibuf, sizeof (netibuf));
1009#endif /* !defined(SO_OOBINLINE)) */
1010 if (ncc < 0 && errno == EWOULDBLOCK)
1011 ncc = 0;
1012 else {
1013 if (ncc <= 0) {
1014 break;
1015 }
1016 netip = netibuf;
1017 }
1018 DIAG((TD_REPORT | TD_NETDATA),
1019 output_data("td: netread %d chars\r\n", ncc));
1020 DIAG(TD_NETDATA, printdata("nd", netip, ncc));
1021 }
1022
1023 /*
1024 * Something to read from the pty...
1025 */
1026 if (FD_ISSET(p, &ibits)) {
1027 pcc = read(p, ptyibuf, BUFSIZ);
1028 /*
1029 * On some systems, if we try to read something
1030 * off the master side before the slave side is
1031 * opened, we get EIO.
1032 */
1033 if (pcc < 0 && (errno == EWOULDBLOCK ||
1034#ifdef EAGAIN
1035 errno == EAGAIN ||
1036#endif
1037 errno == EIO)) {
1038 pcc = 0;
1039 } else {
1040 if (pcc <= 0)
1041 break;
1042#ifdef LINEMODE
1043 /*
1044 * If ioctl from pty, pass it through net
1045 */
1046 if (ptyibuf[0] & TIOCPKT_IOCTL) {
1047 copy_termbuf(ptyibuf+1, pcc-1);
1048 localstat();
1049 pcc = 1;
1050 }
1051#endif /* LINEMODE */
1052 if (ptyibuf[0] & TIOCPKT_FLUSHWRITE) {
1053 netclear(); /* clear buffer back */
1054#ifndef NO_URGENT
1055 /*
1056 * There are client telnets on some
1057 * operating systems get screwed up
1058 * royally if we send them urgent
1059 * mode data.
1060 */
1061 output_data("%c%c", IAC, DM);
1062 neturg = nfrontp-1; /* off by one XXX */
1063 DIAG(TD_OPTIONS,
1064 printoption("td: send IAC", DM));
1065
1066#endif
1067 }
1068 if (his_state_is_will(TELOPT_LFLOW) &&
1069 (ptyibuf[0] &
1070 (TIOCPKT_NOSTOP|TIOCPKT_DOSTOP))) {
1071 int newflow =
1072 ptyibuf[0] & TIOCPKT_DOSTOP ? 1 : 0;
1073 if (newflow != flowmode) {
1074 flowmode = newflow;
1075 output_data("%c%c%c%c%c%c",
1076 IAC, SB, TELOPT_LFLOW,
1077 flowmode ? LFLOW_ON
1078 : LFLOW_OFF,
1079 IAC, SE);
1080 DIAG(TD_OPTIONS, printsub('>',
1081 (unsigned char *)nfrontp-4,
1082 4););
1083 }
1084 }
1085 pcc--;
1086 ptyip = ptyibuf+1;
1087 }
1088 }
1089
1090 while (pcc > 0) {
1091 if ((&netobuf[BUFSIZ] - nfrontp) < 2)
1092 break;
1093 c = *ptyip++ & 0377, pcc--;
1094 if (c == IAC)
1095 output_data("%c", c);
1096 output_data("%c", c);
1097 if ((c == '\r') && (my_state_is_wont(TELOPT_BINARY))) {
1098 if (pcc > 0 && ((*ptyip & 0377) == '\n')) {
1099 output_data("%c", *ptyip++ & 0377);
1100 pcc--;
1101 } else
1102 output_data("%c", '\0');
1103 }
1104 }
1105
1106 if (FD_ISSET(f, &obits) && (nfrontp - nbackp) > 0)
1107 netflush();
1108 if (ncc > 0)
1109 telrcv();
1110 if (FD_ISSET(p, &obits) && (pfrontp - pbackp) > 0)
1111 ptyflush();
1112 }
1113 cleanup(0);
1114} /* end of telnet */
1115
1116#ifndef TCSIG
1117# ifdef TIOCSIG
1118# define TCSIG TIOCSIG
1119# endif
1120#endif
1121
1122/*
1123 * Send interrupt to process on other side of pty.
1124 * If it is in raw mode, just write NULL;
1125 * otherwise, write intr char.
1126 */
1127void
1128interrupt(void)
1129{
1130 ptyflush(); /* half-hearted */
1131
1132#ifdef TCSIG
1133 (void) ioctl(pty, TCSIG, (char *)SIGINT);
1134#else /* TCSIG */
1135 init_termbuf();
1136 *pfrontp++ = slctab[SLC_IP].sptr ?
1137 (unsigned char)*slctab[SLC_IP].sptr : '\177';
1138#endif /* TCSIG */
1139}
1140
1141/*
1142 * Send quit to process on other side of pty.
1143 * If it is in raw mode, just write NULL;
1144 * otherwise, write quit char.
1145 */
1146void
1147sendbrk(void)
1148{
1149 ptyflush(); /* half-hearted */
1150#ifdef TCSIG
1151 (void) ioctl(pty, TCSIG, (char *)SIGQUIT);
1152#else /* TCSIG */
1153 init_termbuf();
1154 *pfrontp++ = slctab[SLC_ABORT].sptr ?
1155 (unsigned char)*slctab[SLC_ABORT].sptr : '\034';
1156#endif /* TCSIG */
1157}
1158
1159void
1160sendsusp(void)
1161{
1162#ifdef SIGTSTP
1163 ptyflush(); /* half-hearted */
1164# ifdef TCSIG
1165 (void) ioctl(pty, TCSIG, (char *)SIGTSTP);
1166# else /* TCSIG */
1167 *pfrontp++ = slctab[SLC_SUSP].sptr ?
1168 (unsigned char)*slctab[SLC_SUSP].sptr : '\032';
1169# endif /* TCSIG */
1170#endif /* SIGTSTP */
1171}
1172
1173/*
1174 * When we get an AYT, if ^T is enabled, use that. Otherwise,
1175 * just send back "[Yes]".
1176 */
1177void
1178recv_ayt(void)
1179{
1180#if defined(SIGINFO) && defined(TCSIG)
1181 if (slctab[SLC_AYT].sptr && *slctab[SLC_AYT].sptr != _POSIX_VDISABLE) {
1182 (void) ioctl(pty, TCSIG, (char *)SIGINFO);
1183 return;
1184 }
1185#endif
1186 output_data("\r\n[Yes]\r\n");
1187}
1188
1189void
1190doeof(void)
1191{
1192 init_termbuf();
1193
1194#if defined(LINEMODE) && defined(USE_TERMIO) && (VEOF == VMIN)
1195 if (!tty_isediting()) {
1196 extern char oldeofc;
1197 *pfrontp++ = oldeofc;
1198 return;
1199 }
1200#endif
1201 *pfrontp++ = slctab[SLC_EOF].sptr ?
1202 (unsigned char)*slctab[SLC_EOF].sptr : '\004';
1203}