If a neighbor solictation or neighbor advertisement isn't from the
[dragonfly.git] / libexec / telnetd / telnetd.c
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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.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
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32 *
33 * @(#)telnetd.c 8.4 (Berkeley) 5/30/95
34 * $FreeBSD: src/libexec/telnetd/telnetd.c,v 1.22.2.8 2002/04/13 11:07:12 markm Exp $
6fb88001 35 * $DragonFly: src/libexec/telnetd/telnetd.c,v 1.3 2006/01/12 13:43:10 corecode Exp $
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36 */
37
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38#include "telnetd.h"
39#include "pathnames.h"
40
41#include <sys/mman.h>
42#include <err.h>
43#include <libutil.h>
44#include <paths.h>
45#include <termcap.h>
46#include <utmp.h>
47
48#include <arpa/inet.h>
49
50#include <libtelnet/misc.h>
51
52char remote_hostname[MAXHOSTNAMELEN];
53size_t utmp_len = sizeof(remote_hostname) - 1;
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);
65void doit(struct sockaddr *);
66int terminaltypeok(char *);
67
68int hostinfo = 1; /* do we print login banner? */
69
70int debug = 0;
71int keepalive = 1;
72const char *altlogin;
73
74void doit(struct sockaddr *);
75int terminaltypeok(char *);
76void startslave(char *, int, char *);
77extern void usage(void);
78static void _gettermname(void);
79
80/*
81 * The string to pass to getopt(). We do it this way so
82 * that only the actual options that we support will be
83 * passed off to getopt().
84 */
85char valid_opts[] = {
86 'd', ':', 'h', 'k', 'n', 'p', ':', 'S', ':', 'u', ':', 'U',
87 '4', '6',
88#ifdef BFTPDAEMON
89 'B',
90#endif
91#ifdef DIAGNOSTICS
92 'D', ':',
93#endif
94#ifdef LINEMODE
95 'l',
96#endif
97 '\0'
98};
99
100int family = AF_INET;
101
102#ifndef MAXHOSTNAMELEN
103#define MAXHOSTNAMELEN 256
104#endif /* MAXHOSTNAMELEN */
105
106char *hostname;
107char host_name[MAXHOSTNAMELEN];
108
109extern void telnet(int, int, char *);
110
111int level;
112char user_name[256];
113
114int
115main(int argc, char *argv[])
116{
117 struct sockaddr_storage from;
118 int on = 1, fromlen;
119 int ch;
120#if defined(IPPROTO_IP) && defined(IP_TOS)
121 int tos = -1;
122#endif
123
124 pfrontp = pbackp = ptyobuf;
125 netip = netibuf;
126 nfrontp = nbackp = netobuf;
127
128 /*
129 * This initialization causes linemode to default to a configuration
130 * that works on all telnet clients, including the FreeBSD client.
131 * This is not quite the same as the telnet client issuing a "mode
132 * character" command, but has most of the same benefits, and is
133 * preferable since some clients (like usofts) don't have the
134 * mode character command anyway and linemode breaks things.
135 * The most notable symptom of fix is that csh "set filec" operations
136 * like <ESC> (filename completion) and ^D (choices) keys now work
137 * in telnet sessions and can be used more than once on the same line.
138 * CR/LF handling is also corrected in some termio modes. This
139 * change resolves problem reports bin/771 and bin/1037.
140 */
141
142 linemode=1; /*Default to mode that works on bulk of clients*/
143
144 while ((ch = getopt(argc, argv, valid_opts)) != -1) {
145 switch(ch) {
146
147
148#ifdef BFTPDAEMON
149 case 'B':
150 bftpd++;
151 break;
152#endif /* BFTPDAEMON */
153
154 case 'd':
155 if (strcmp(optarg, "ebug") == 0) {
156 debug++;
157 break;
158 }
159 usage();
160 /* NOTREACHED */
161 break;
162
163#ifdef DIAGNOSTICS
164 case 'D':
165 /*
166 * Check for desired diagnostics capabilities.
167 */
168 if (!strcmp(optarg, "report")) {
169 diagnostic |= TD_REPORT|TD_OPTIONS;
170 } else if (!strcmp(optarg, "exercise")) {
171 diagnostic |= TD_EXERCISE;
172 } else if (!strcmp(optarg, "netdata")) {
173 diagnostic |= TD_NETDATA;
174 } else if (!strcmp(optarg, "ptydata")) {
175 diagnostic |= TD_PTYDATA;
176 } else if (!strcmp(optarg, "options")) {
177 diagnostic |= TD_OPTIONS;
178 } else {
179 usage();
180 /* NOT REACHED */
181 }
182 break;
183#endif /* DIAGNOSTICS */
184
185
186 case 'h':
187 hostinfo = 0;
188 break;
189
190#ifdef LINEMODE
191 case 'l':
192 alwayslinemode = 1;
193 break;
194#endif /* LINEMODE */
195
196 case 'k':
197#if defined(LINEMODE) && defined(KLUDGELINEMODE)
198 lmodetype = NO_AUTOKLUDGE;
199#else
200 /* ignore -k option if built without kludge linemode */
201#endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */
202 break;
203
204 case 'n':
205 keepalive = 0;
206 break;
207
208 case 'p':
209 altlogin = optarg;
210 break;
211
212 case 'S':
213#ifdef HAS_GETTOS
214 if ((tos = parsetos(optarg, "tcp")) < 0)
215 warnx("%s%s%s",
216 "bad TOS argument '", optarg,
217 "'; will try to use default TOS");
218#else
219 warnx("TOS option unavailable; -S flag not supported");
220#endif
221 break;
222
223 case 'u':
224 utmp_len = (size_t)atoi(optarg);
225 if (utmp_len >= sizeof(remote_hostname))
226 utmp_len = sizeof(remote_hostname) - 1;
227 break;
228
229 case 'U':
230 registerd_host_only = 1;
231 break;
232
233
234 case '4':
235 family = AF_INET;
236 break;
237
238#ifdef INET6
239 case '6':
240 family = AF_INET6;
241 break;
242#endif
243
244 default:
245 warnx("%c: unknown option", ch);
246 /* FALLTHROUGH */
247 case '?':
248 usage();
249 /* NOTREACHED */
250 }
251 }
252
253 argc -= optind;
254 argv += optind;
255
256 if (debug) {
257 int s, ns, foo, error;
258 const char *service = "telnet";
259 struct addrinfo hints, *res;
260
261 if (argc > 1) {
262 usage();
263 /* NOT REACHED */
264 } else if (argc == 1)
265 service = *argv;
266
267 memset(&hints, 0, sizeof(hints));
268 hints.ai_flags = AI_PASSIVE;
269 hints.ai_family = family;
270 hints.ai_socktype = SOCK_STREAM;
271 hints.ai_protocol = 0;
272 error = getaddrinfo(NULL, service, &hints, &res);
273
274 if (error) {
275 errx(1, "tcp/%s: %s\n", service, gai_strerror(error));
276 if (error == EAI_SYSTEM)
277 errx(1, "tcp/%s: %s\n", service, strerror(errno));
278 usage();
279 }
280
281 s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
282 if (s < 0)
283 err(1, "socket");
284 (void) setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
285 (char *)&on, sizeof(on));
286 if (bind(s, res->ai_addr, res->ai_addrlen) < 0)
287 err(1, "bind");
288 if (listen(s, 1) < 0)
289 err(1, "listen");
290 foo = res->ai_addrlen;
291 ns = accept(s, res->ai_addr, &foo);
292 if (ns < 0)
293 err(1, "accept");
294 (void) dup2(ns, 0);
295 (void) close(ns);
296 (void) close(s);
297#ifdef convex
298 } else if (argc == 1) {
299 ; /* VOID*/ /* Just ignore the host/port name */
300#endif
301 } else if (argc > 0) {
302 usage();
303 /* NOT REACHED */
304 }
305
306 openlog("telnetd", LOG_PID | LOG_ODELAY, LOG_DAEMON);
307 fromlen = sizeof (from);
308 if (getpeername(0, (struct sockaddr *)&from, &fromlen) < 0) {
309 warn("getpeername");
310 _exit(1);
311 }
312 if (keepalive &&
313 setsockopt(0, SOL_SOCKET, SO_KEEPALIVE,
314 (char *)&on, sizeof (on)) < 0) {
315 syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m");
316 }
317
318#if defined(IPPROTO_IP) && defined(IP_TOS)
319 if (from.ss_family == AF_INET) {
320# if defined(HAS_GETTOS)
321 struct tosent *tp;
322 if (tos < 0 && (tp = gettosbyname("telnet", "tcp")))
323 tos = tp->t_tos;
324# endif
325 if (tos < 0)
326 tos = 020; /* Low Delay bit */
327 if (tos
328 && (setsockopt(0, IPPROTO_IP, IP_TOS,
329 (char *)&tos, sizeof(tos)) < 0)
330 && (errno != ENOPROTOOPT) )
331 syslog(LOG_WARNING, "setsockopt (IP_TOS): %m");
332 }
333#endif /* defined(IPPROTO_IP) && defined(IP_TOS) */
334 net = 0;
335 doit((struct sockaddr *)&from);
336 /* NOTREACHED */
337 return(0);
338} /* end of main */
339
340 void
341usage()
342{
343 fprintf(stderr, "usage: telnetd");
344#ifdef BFTPDAEMON
345 fprintf(stderr, " [-B]");
346#endif
347 fprintf(stderr, " [-debug]");
348#ifdef DIAGNOSTICS
349 fprintf(stderr, " [-D (options|report|exercise|netdata|ptydata)]\n\t");
350#endif
351 fprintf(stderr, " [-h]");
352#if defined(LINEMODE) && defined(KLUDGELINEMODE)
353 fprintf(stderr, " [-k]");
354#endif
355#ifdef LINEMODE
356 fprintf(stderr, " [-l]");
357#endif
358 fprintf(stderr, " [-n]");
359 fprintf(stderr, "\n\t");
360#ifdef HAS_GETTOS
361 fprintf(stderr, " [-S tos]");
362#endif
363 fprintf(stderr, " [-u utmp_hostname_length] [-U]");
364 fprintf(stderr, " [port]\n");
365 exit(1);
366}
367
368/*
369 * getterminaltype
370 *
371 * Ask the other end to send along its terminal type and speed.
372 * Output is the variable terminaltype filled in.
373 */
374static unsigned char ttytype_sbbuf[] = {
375 IAC, SB, TELOPT_TTYPE, TELQUAL_SEND, IAC, SE
376};
377
378
379#define undef2 __unused
380
381static int
382getterminaltype(char *name undef2)
383{
384 int retval = -1;
385
386 settimer(baseline);
387
388 send_do(TELOPT_TTYPE, 1);
389 send_do(TELOPT_TSPEED, 1);
390 send_do(TELOPT_XDISPLOC, 1);
391 send_do(TELOPT_NEW_ENVIRON, 1);
392 send_do(TELOPT_OLD_ENVIRON, 1);
393 while (
394 his_will_wont_is_changing(TELOPT_TTYPE) ||
395 his_will_wont_is_changing(TELOPT_TSPEED) ||
396 his_will_wont_is_changing(TELOPT_XDISPLOC) ||
397 his_will_wont_is_changing(TELOPT_NEW_ENVIRON) ||
398 his_will_wont_is_changing(TELOPT_OLD_ENVIRON)) {
399 ttloop();
400 }
401 if (his_state_is_will(TELOPT_TSPEED)) {
402 static unsigned char sb[] =
403 { IAC, SB, TELOPT_TSPEED, TELQUAL_SEND, IAC, SE };
404
405 output_datalen(sb, sizeof sb);
406 DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
407 }
408 if (his_state_is_will(TELOPT_XDISPLOC)) {
409 static unsigned char sb[] =
410 { IAC, SB, TELOPT_XDISPLOC, TELQUAL_SEND, IAC, SE };
411
412 output_datalen(sb, sizeof sb);
413 DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
414 }
415 if (his_state_is_will(TELOPT_NEW_ENVIRON)) {
416 static unsigned char sb[] =
417 { IAC, SB, TELOPT_NEW_ENVIRON, TELQUAL_SEND, IAC, SE };
418
419 output_datalen(sb, sizeof sb);
420 DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
421 }
422 else if (his_state_is_will(TELOPT_OLD_ENVIRON)) {
423 static unsigned char sb[] =
424 { IAC, SB, TELOPT_OLD_ENVIRON, TELQUAL_SEND, IAC, SE };
425
426 output_datalen(sb, sizeof sb);
427 DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
428 }
429 if (his_state_is_will(TELOPT_TTYPE)) {
430
431 output_datalen(ttytype_sbbuf, sizeof ttytype_sbbuf);
432 DIAG(TD_OPTIONS, printsub('>', ttytype_sbbuf + 2,
433 sizeof ttytype_sbbuf - 2););
434 }
435 if (his_state_is_will(TELOPT_TSPEED)) {
436 while (sequenceIs(tspeedsubopt, baseline))
437 ttloop();
438 }
439 if (his_state_is_will(TELOPT_XDISPLOC)) {
440 while (sequenceIs(xdisplocsubopt, baseline))
441 ttloop();
442 }
443 if (his_state_is_will(TELOPT_NEW_ENVIRON)) {
444 while (sequenceIs(environsubopt, baseline))
445 ttloop();
446 }
447 if (his_state_is_will(TELOPT_OLD_ENVIRON)) {
448 while (sequenceIs(oenvironsubopt, baseline))
449 ttloop();
450 }
451 if (his_state_is_will(TELOPT_TTYPE)) {
452 char first[256], last[256];
453
454 while (sequenceIs(ttypesubopt, baseline))
455 ttloop();
456
457 /*
458 * If the other side has already disabled the option, then
459 * we have to just go with what we (might) have already gotten.
460 */
461 if (his_state_is_will(TELOPT_TTYPE) && !terminaltypeok(terminaltype)) {
462 (void) strncpy(first, terminaltype, sizeof(first)-1);
463 first[sizeof(first)-1] = '\0';
464 for(;;) {
465 /*
466 * Save the unknown name, and request the next name.
467 */
468 (void) strncpy(last, terminaltype, sizeof(last)-1);
469 last[sizeof(last)-1] = '\0';
470 _gettermname();
471 if (terminaltypeok(terminaltype))
472 break;
473 if ((strncmp(last, terminaltype, sizeof(last)) == 0) ||
474 his_state_is_wont(TELOPT_TTYPE)) {
475 /*
476 * We've hit the end. If this is the same as
477 * the first name, just go with it.
478 */
479 if (strncmp(first, terminaltype, sizeof(first)) == 0)
480 break;
481 /*
482 * Get the terminal name one more time, so that
483 * RFC1091 compliant telnets will cycle back to
484 * the start of the list.
485 */
486 _gettermname();
487 if (strncmp(first, terminaltype, sizeof(first)) != 0) {
488 (void) strncpy(terminaltype, first, sizeof(terminaltype)-1);
489 terminaltype[sizeof(terminaltype)-1] = '\0';
490 }
491 break;
492 }
493 }
494 }
495 }
496 return(retval);
497} /* end of getterminaltype */
498
499static void
500_gettermname(void)
501{
502 /*
503 * If the client turned off the option,
504 * we can't send another request, so we
505 * just return.
506 */
507 if (his_state_is_wont(TELOPT_TTYPE))
508 return;
509 settimer(baseline);
510 output_datalen(ttytype_sbbuf, sizeof ttytype_sbbuf);
511 DIAG(TD_OPTIONS, printsub('>', ttytype_sbbuf + 2,
512 sizeof ttytype_sbbuf - 2););
513 while (sequenceIs(ttypesubopt, baseline))
514 ttloop();
515}
516
517int
518terminaltypeok(char *s)
519{
520 char buf[1024];
521
522 if (terminaltype == NULL)
523 return(1);
524
525 /*
526 * tgetent() will return 1 if the type is known, and
527 * 0 if it is not known. If it returns -1, it couldn't
528 * open the database. But if we can't open the database,
529 * it won't help to say we failed, because we won't be
530 * able to verify anything else. So, we treat -1 like 1.
531 */
532 if (tgetent(buf, s) == 0)
533 return(0);
534 return(1);
535}
536
537/*
538 * Get a pty, scan input lines.
539 */
540void
541doit(struct sockaddr *who)
542{
543 int err_; /* XXX */
544 int ptynum;
545
546 /*
547 * Find an available pty to use.
548 */
549#ifndef convex
550 pty = getpty(&ptynum);
551 if (pty < 0)
552 fatal(net, "All network ports in use");
553#else
554 for (;;) {
555 char *lp;
556
557 if ((lp = getpty()) == NULL)
558 fatal(net, "Out of ptys");
559
560 if ((pty = open(lp, 2)) >= 0) {
561 strlcpy(line,lp,sizeof(line));
562 line[5] = 't';
563 break;
564 }
565 }
566#endif
567
568 /* get name of connected client */
569 if (realhostname_sa(remote_hostname, sizeof(remote_hostname) - 1,
570 who, who->sa_len) == HOSTNAME_INVALIDADDR && registerd_host_only)
571 fatal(net, "Couldn't resolve your address into a host name.\r\n\
572 Please contact your net administrator");
573 remote_hostname[sizeof(remote_hostname) - 1] = '\0';
574
575 trimdomain(remote_hostname, UT_HOSTSIZE);
576 if (!isdigit(remote_hostname[0]) && strlen(remote_hostname) > utmp_len)
577 err_ = getnameinfo(who, who->sa_len, remote_hostname,
578 sizeof(remote_hostname), NULL, 0,
579 NI_NUMERICHOST|NI_WITHSCOPEID);
580 /* XXX: do 'err_' check */
581
582 (void) gethostname(host_name, sizeof(host_name) - 1);
583 host_name[sizeof(host_name) - 1] = '\0';
584 hostname = host_name;
585
586
587 init_env();
588 /*
589 * get terminal type.
590 */
591 *user_name = 0;
592 level = getterminaltype(user_name);
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593 if (setenv("TERM", terminaltype ? terminaltype : "network", 1) == -1)
594 syslog(LOG_ERR, "setenv: cannot set TERM=%s: %m", terminaltype ? terminaltype : "network");
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595
596 telnet(net, pty, remote_hostname); /* begin server process */
597
598 /*NOTREACHED*/
599} /* end of doit */
600
601/*
602 * Main loop. Select from pty and network, and
603 * hand data to telnet receiver finite state machine.
604 */
605void
606telnet(int f, int p, char *host)
607{
608 int on = 1;
609#define TABBUFSIZ 512
610 char defent[TABBUFSIZ];
611 char defstrs[TABBUFSIZ];
612#undef TABBUFSIZ
613 char *HE;
614 char *HN;
615 char *IM;
616 int nfd;
617
618 /*
619 * Initialize the slc mapping table.
620 */
621 get_slc_defaults();
622
623 /*
624 * Do some tests where it is desireable to wait for a response.
625 * Rather than doing them slowly, one at a time, do them all
626 * at once.
627 */
628 if (my_state_is_wont(TELOPT_SGA))
629 send_will(TELOPT_SGA, 1);
630 /*
631 * Is the client side a 4.2 (NOT 4.3) system? We need to know this
632 * because 4.2 clients are unable to deal with TCP urgent data.
633 *
634 * To find out, we send out a "DO ECHO". If the remote system
635 * answers "WILL ECHO" it is probably a 4.2 client, and we note
636 * that fact ("WILL ECHO" ==> that the client will echo what
637 * WE, the server, sends it; it does NOT mean that the client will
638 * echo the terminal input).
639 */
640 send_do(TELOPT_ECHO, 1);
641
642#ifdef LINEMODE
643 if (his_state_is_wont(TELOPT_LINEMODE)) {
644 /* Query the peer for linemode support by trying to negotiate
645 * the linemode option.
646 */
647 linemode = 0;
648 editmode = 0;
649 send_do(TELOPT_LINEMODE, 1); /* send do linemode */
650 }
651#endif /* LINEMODE */
652
653 /*
654 * Send along a couple of other options that we wish to negotiate.
655 */
656 send_do(TELOPT_NAWS, 1);
657 send_will(TELOPT_STATUS, 1);
658 flowmode = 1; /* default flow control state */
659 restartany = -1; /* uninitialized... */
660 send_do(TELOPT_LFLOW, 1);
661
662 /*
663 * Spin, waiting for a response from the DO ECHO. However,
664 * some REALLY DUMB telnets out there might not respond
665 * to the DO ECHO. So, we spin looking for NAWS, (most dumb
666 * telnets so far seem to respond with WONT for a DO that
667 * they don't understand...) because by the time we get the
668 * response, it will already have processed the DO ECHO.
669 * Kludge upon kludge.
670 */
671 while (his_will_wont_is_changing(TELOPT_NAWS))
672 ttloop();
673
674 /*
675 * But...
676 * The client might have sent a WILL NAWS as part of its
677 * startup code; if so, we'll be here before we get the
678 * response to the DO ECHO. We'll make the assumption
679 * that any implementation that understands about NAWS
680 * is a modern enough implementation that it will respond
681 * to our DO ECHO request; hence we'll do another spin
682 * waiting for the ECHO option to settle down, which is
683 * what we wanted to do in the first place...
684 */
685 if (his_want_state_is_will(TELOPT_ECHO) &&
686 his_state_is_will(TELOPT_NAWS)) {
687 while (his_will_wont_is_changing(TELOPT_ECHO))
688 ttloop();
689 }
690 /*
691 * On the off chance that the telnet client is broken and does not
692 * respond to the DO ECHO we sent, (after all, we did send the
693 * DO NAWS negotiation after the DO ECHO, and we won't get here
694 * until a response to the DO NAWS comes back) simulate the
695 * receipt of a will echo. This will also send a WONT ECHO
696 * to the client, since we assume that the client failed to
697 * respond because it believes that it is already in DO ECHO
698 * mode, which we do not want.
699 */
700 if (his_want_state_is_will(TELOPT_ECHO)) {
701 DIAG(TD_OPTIONS, output_data("td: simulating recv\r\n"));
702 willoption(TELOPT_ECHO);
703 }
704
705 /*
706 * Finally, to clean things up, we turn on our echo. This
707 * will break stupid 4.2 telnets out of local terminal echo.
708 */
709
710 if (my_state_is_wont(TELOPT_ECHO))
711 send_will(TELOPT_ECHO, 1);
712
713 /*
714 * Turn on packet mode
715 */
716 (void) ioctl(p, TIOCPKT, (char *)&on);
717
718#if defined(LINEMODE) && defined(KLUDGELINEMODE)
719 /*
720 * Continuing line mode support. If client does not support
721 * real linemode, attempt to negotiate kludge linemode by sending
722 * the do timing mark sequence.
723 */
724 if (lmodetype < REAL_LINEMODE)
725 send_do(TELOPT_TM, 1);
726#endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */
727
728 /*
729 * Call telrcv() once to pick up anything received during
730 * terminal type negotiation, 4.2/4.3 determination, and
731 * linemode negotiation.
732 */
733 telrcv();
734
735 (void) ioctl(f, FIONBIO, (char *)&on);
736 (void) ioctl(p, FIONBIO, (char *)&on);
737
738#if defined(SO_OOBINLINE)
739 (void) setsockopt(net, SOL_SOCKET, SO_OOBINLINE,
740 (char *)&on, sizeof on);
741#endif /* defined(SO_OOBINLINE) */
742
743#ifdef SIGTSTP
744 (void) signal(SIGTSTP, SIG_IGN);
745#endif
746#ifdef SIGTTOU
747 /*
748 * Ignoring SIGTTOU keeps the kernel from blocking us
749 * in ttioct() in /sys/tty.c.
750 */
751 (void) signal(SIGTTOU, SIG_IGN);
752#endif
753
754 (void) signal(SIGCHLD, cleanup);
755
756#ifdef TIOCNOTTY
757 {
758 int t;
759 t = open(_PATH_TTY, O_RDWR);
760 if (t >= 0) {
761 (void) ioctl(t, TIOCNOTTY, (char *)0);
762 (void) close(t);
763 }
764 }
765#endif
766
767 /*
768 * Show banner that getty never gave.
769 *
770 * We put the banner in the pty input buffer. This way, it
771 * gets carriage return null processing, etc., just like all
772 * other pty --> client data.
773 */
774
775 if (getent(defent, "default") == 1) {
776 char *cp=defstrs;
777
778 HE = Getstr("he", &cp);
779 HN = Getstr("hn", &cp);
780 IM = Getstr("im", &cp);
781 if (HN && *HN)
782 (void) strlcpy(host_name, HN, sizeof(host_name));
783 if (IM == 0)
784 IM = strdup("");
785 } else {
786 IM = strdup(DEFAULT_IM);
787 HE = 0;
788 }
789 edithost(HE, host_name);
790 if (hostinfo && *IM)
791 putf(IM, ptyibuf2);
792
793 if (pcc)
794 (void) strncat(ptyibuf2, ptyip, pcc+1);
795 ptyip = ptyibuf2;
796 pcc = strlen(ptyip);
797#ifdef LINEMODE
798 /*
799 * Last check to make sure all our states are correct.
800 */
801 init_termbuf();
802 localstat();
803#endif /* LINEMODE */
804
805 DIAG(TD_REPORT, output_data("td: Entering processing loop\r\n"));
806
807 /*
808 * Startup the login process on the slave side of the terminal
809 * now. We delay this until here to insure option negotiation
810 * is complete.
811 */
812 startslave(host, level, user_name);
813
814 nfd = ((f > p) ? f : p) + 1;
815 for (;;) {
816 fd_set ibits, obits, xbits;
817 int c;
818
819 if (ncc < 0 && pcc < 0)
820 break;
821
822 FD_ZERO(&ibits);
823 FD_ZERO(&obits);
824 FD_ZERO(&xbits);
825 /*
826 * Never look for input if there's still
827 * stuff in the corresponding output buffer
828 */
829 if (nfrontp - nbackp || pcc > 0) {
830 FD_SET(f, &obits);
831 } else {
832 FD_SET(p, &ibits);
833 }
834 if (pfrontp - pbackp || ncc > 0) {
835 FD_SET(p, &obits);
836 } else {
837 FD_SET(f, &ibits);
838 }
839 if (!SYNCHing) {
840 FD_SET(f, &xbits);
841 }
842 if ((c = select(nfd, &ibits, &obits, &xbits,
843 (struct timeval *)0)) < 1) {
844 if (c == -1) {
845 if (errno == EINTR) {
846 continue;
847 }
848 }
849 sleep(5);
850 continue;
851 }
852
853 /*
854 * Any urgent data?
855 */
856 if (FD_ISSET(net, &xbits)) {
857 SYNCHing = 1;
858 }
859
860 /*
861 * Something to read from the network...
862 */
863 if (FD_ISSET(net, &ibits)) {
864#if !defined(SO_OOBINLINE)
865 /*
866 * In 4.2 (and 4.3 beta) systems, the
867 * OOB indication and data handling in the kernel
868 * is such that if two separate TCP Urgent requests
869 * come in, one byte of TCP data will be overlaid.
870 * This is fatal for Telnet, but we try to live
871 * with it.
872 *
873 * In addition, in 4.2 (and...), a special protocol
874 * is needed to pick up the TCP Urgent data in
875 * the correct sequence.
876 *
877 * What we do is: if we think we are in urgent
878 * mode, we look to see if we are "at the mark".
879 * If we are, we do an OOB receive. If we run
880 * this twice, we will do the OOB receive twice,
881 * but the second will fail, since the second
882 * time we were "at the mark", but there wasn't
883 * any data there (the kernel doesn't reset
884 * "at the mark" until we do a normal read).
885 * Once we've read the OOB data, we go ahead
886 * and do normal reads.
887 *
888 * There is also another problem, which is that
889 * since the OOB byte we read doesn't put us
890 * out of OOB state, and since that byte is most
891 * likely the TELNET DM (data mark), we would
892 * stay in the TELNET SYNCH (SYNCHing) state.
893 * So, clocks to the rescue. If we've "just"
894 * received a DM, then we test for the
895 * presence of OOB data when the receive OOB
896 * fails (and AFTER we did the normal mode read
897 * to clear "at the mark").
898 */
899 if (SYNCHing) {
900 int atmark;
901
902 (void) ioctl(net, SIOCATMARK, (char *)&atmark);
903 if (atmark) {
904 ncc = recv(net, netibuf, sizeof (netibuf), MSG_OOB);
905 if ((ncc == -1) && (errno == EINVAL)) {
906 ncc = read(net, netibuf, sizeof (netibuf));
907 if (sequenceIs(didnetreceive, gotDM)) {
908 SYNCHing = stilloob(net);
909 }
910 }
911 } else {
912 ncc = read(net, netibuf, sizeof (netibuf));
913 }
914 } else {
915 ncc = read(net, netibuf, sizeof (netibuf));
916 }
917 settimer(didnetreceive);
918#else /* !defined(SO_OOBINLINE)) */
919 ncc = read(net, netibuf, sizeof (netibuf));
920#endif /* !defined(SO_OOBINLINE)) */
921 if (ncc < 0 && errno == EWOULDBLOCK)
922 ncc = 0;
923 else {
924 if (ncc <= 0) {
925 break;
926 }
927 netip = netibuf;
928 }
929 DIAG((TD_REPORT | TD_NETDATA),
930 output_data("td: netread %d chars\r\n", ncc));
931 DIAG(TD_NETDATA, printdata("nd", netip, ncc));
932 }
933
934 /*
935 * Something to read from the pty...
936 */
937 if (FD_ISSET(p, &ibits)) {
938 pcc = read(p, ptyibuf, BUFSIZ);
939 /*
940 * On some systems, if we try to read something
941 * off the master side before the slave side is
942 * opened, we get EIO.
943 */
944 if (pcc < 0 && (errno == EWOULDBLOCK ||
945#ifdef EAGAIN
946 errno == EAGAIN ||
947#endif
948 errno == EIO)) {
949 pcc = 0;
950 } else {
951 if (pcc <= 0)
952 break;
953#ifdef LINEMODE
954 /*
955 * If ioctl from pty, pass it through net
956 */
957 if (ptyibuf[0] & TIOCPKT_IOCTL) {
958 copy_termbuf(ptyibuf+1, pcc-1);
959 localstat();
960 pcc = 1;
961 }
962#endif /* LINEMODE */
963 if (ptyibuf[0] & TIOCPKT_FLUSHWRITE) {
964 netclear(); /* clear buffer back */
965#ifndef NO_URGENT
966 /*
967 * There are client telnets on some
968 * operating systems get screwed up
969 * royally if we send them urgent
970 * mode data.
971 */
972 output_data("%c%c", IAC, DM);
973 neturg = nfrontp-1; /* off by one XXX */
974 DIAG(TD_OPTIONS,
975 printoption("td: send IAC", DM));
976
977#endif
978 }
979 if (his_state_is_will(TELOPT_LFLOW) &&
980 (ptyibuf[0] &
981 (TIOCPKT_NOSTOP|TIOCPKT_DOSTOP))) {
982 int newflow =
983 ptyibuf[0] & TIOCPKT_DOSTOP ? 1 : 0;
984 if (newflow != flowmode) {
985 flowmode = newflow;
986 output_data("%c%c%c%c%c%c",
987 IAC, SB, TELOPT_LFLOW,
988 flowmode ? LFLOW_ON
989 : LFLOW_OFF,
990 IAC, SE);
991 DIAG(TD_OPTIONS, printsub('>',
992 (unsigned char *)nfrontp-4,
993 4););
994 }
995 }
996 pcc--;
997 ptyip = ptyibuf+1;
998 }
999 }
1000
1001 while (pcc > 0) {
1002 if ((&netobuf[BUFSIZ] - nfrontp) < 2)
1003 break;
1004 c = *ptyip++ & 0377, pcc--;
1005 if (c == IAC)
1006 output_data("%c", c);
1007 output_data("%c", c);
1008 if ((c == '\r') && (my_state_is_wont(TELOPT_BINARY))) {
1009 if (pcc > 0 && ((*ptyip & 0377) == '\n')) {
1010 output_data("%c", *ptyip++ & 0377);
1011 pcc--;
1012 } else
1013 output_data("%c", '\0');
1014 }
1015 }
1016
1017 if (FD_ISSET(f, &obits) && (nfrontp - nbackp) > 0)
1018 netflush();
1019 if (ncc > 0)
1020 telrcv();
1021 if (FD_ISSET(p, &obits) && (pfrontp - pbackp) > 0)
1022 ptyflush();
1023 }
1024 cleanup(0);
1025} /* end of telnet */
1026
1027#ifndef TCSIG
1028# ifdef TIOCSIG
1029# define TCSIG TIOCSIG
1030# endif
1031#endif
1032
1033/*
1034 * Send interrupt to process on other side of pty.
1035 * If it is in raw mode, just write NULL;
1036 * otherwise, write intr char.
1037 */
1038void
1039interrupt(void)
1040{
1041 ptyflush(); /* half-hearted */
1042
1043#ifdef TCSIG
1044 (void) ioctl(pty, TCSIG, (char *)SIGINT);
1045#else /* TCSIG */
1046 init_termbuf();
1047 *pfrontp++ = slctab[SLC_IP].sptr ?
1048 (unsigned char)*slctab[SLC_IP].sptr : '\177';
1049#endif /* TCSIG */
1050}
1051
1052/*
1053 * Send quit to process on other side of pty.
1054 * If it is in raw mode, just write NULL;
1055 * otherwise, write quit char.
1056 */
1057void
1058sendbrk(void)
1059{
1060 ptyflush(); /* half-hearted */
1061#ifdef TCSIG
1062 (void) ioctl(pty, TCSIG, (char *)SIGQUIT);
1063#else /* TCSIG */
1064 init_termbuf();
1065 *pfrontp++ = slctab[SLC_ABORT].sptr ?
1066 (unsigned char)*slctab[SLC_ABORT].sptr : '\034';
1067#endif /* TCSIG */
1068}
1069
1070void
1071sendsusp(void)
1072{
1073#ifdef SIGTSTP
1074 ptyflush(); /* half-hearted */
1075# ifdef TCSIG
1076 (void) ioctl(pty, TCSIG, (char *)SIGTSTP);
1077# else /* TCSIG */
1078 *pfrontp++ = slctab[SLC_SUSP].sptr ?
1079 (unsigned char)*slctab[SLC_SUSP].sptr : '\032';
1080# endif /* TCSIG */
1081#endif /* SIGTSTP */
1082}
1083
1084/*
1085 * When we get an AYT, if ^T is enabled, use that. Otherwise,
1086 * just send back "[Yes]".
1087 */
1088void
1089recv_ayt(void)
1090{
1091#if defined(SIGINFO) && defined(TCSIG)
1092 if (slctab[SLC_AYT].sptr && *slctab[SLC_AYT].sptr != _POSIX_VDISABLE) {
1093 (void) ioctl(pty, TCSIG, (char *)SIGINFO);
1094 return;
1095 }
1096#endif
1097 output_data("\r\n[Yes]\r\n");
1098}
1099
1100void
1101doeof(void)
1102{
1103 init_termbuf();
1104
1105#if defined(LINEMODE) && defined(USE_TERMIO) && (VEOF == VMIN)
1106 if (!tty_isediting()) {
1107 extern char oldeofc;
1108 *pfrontp++ = oldeofc;
1109 return;
1110 }
1111#endif
1112 *pfrontp++ = slctab[SLC_EOF].sptr ?
1113 (unsigned char)*slctab[SLC_EOF].sptr : '\004';
1114}