rlogin.c revision 47549
1/*
2 * Copyright (c) 1983, 1990, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#ifndef lint
35static const char copyright[] =
36"@(#) Copyright (c) 1983, 1990, 1993\n\
37	The Regents of the University of California.  All rights reserved.\n";
38#endif /* not lint */
39
40#ifndef lint
41static const char sccsid[] = "@(#)rlogin.c	8.1 (Berkeley) 6/6/93";
42static const char rcsid[] =
43	"$Id: rlogin.c,v 1.19 1999/05/25 11:14:33 peter Exp $";
44#endif /* not lint */
45
46/*
47 * rlogin - remote login
48 */
49#include <sys/param.h>
50#include <sys/socket.h>
51#include <sys/time.h>
52#include <sys/resource.h>
53#include <sys/wait.h>
54
55#include <netinet/in.h>
56#include <netinet/in_systm.h>
57#include <netinet/ip.h>
58#include <netinet/tcp.h>
59
60#include <err.h>
61#include <errno.h>
62#include <fcntl.h>
63#include <libutil.h>
64#include <netdb.h>
65#include <pwd.h>
66#include <setjmp.h>
67#include <sgtty.h>
68#include <signal.h>
69#include <stdio.h>
70#include <stdlib.h>
71#include <string.h>
72#include <unistd.h>
73#include <err.h>
74
75#ifdef KERBEROS
76#include <des.h>
77#include <krb.h>
78
79#include "../../bin/rcp/pathnames.h"
80#include "krb.h"
81
82CREDENTIALS cred;
83Key_schedule schedule;
84int use_kerberos = 1, doencrypt;
85char dst_realm_buf[REALM_SZ], *dest_realm = NULL;
86#endif
87
88#ifndef TIOCPKT_WINDOW
89#define	TIOCPKT_WINDOW	0x80
90#endif
91
92/* concession to Sun */
93#ifndef SIGUSR1
94#define	SIGUSR1	30
95#endif
96
97int eight, litout, rem;
98
99int noescape;
100u_char escapechar = '~';
101
102char *speeds[] = {
103	"0", "50", "75", "110", "134", "150", "200", "300", "600", "1200",
104	"1800", "2400", "4800", "9600", "19200", "38400", "57600", "115200"
105#define	MAX_SPEED_LENGTH	(sizeof("115200") - 1)
106};
107
108#ifdef OLDSUN
109struct winsize {
110	unsigned short ws_row, ws_col;
111	unsigned short ws_xpixel, ws_ypixel;
112};
113#else
114#define	get_window_size(fd, wp)	ioctl(fd, TIOCGWINSZ, wp)
115#endif
116struct	winsize winsize;
117
118void		catch_child __P((int));
119void		copytochild __P((int));
120void		doit __P((long)) __dead2;
121void		done __P((int)) __dead2;
122void		echo __P((char));
123u_int		getescape __P((char *));
124void		lostpeer __P((int));
125void		mode __P((int));
126void		msg __P((char *));
127void		oob __P((int));
128int		reader __P((int));
129void		sendwindow __P((void));
130void		setsignal __P((int));
131void		sigwinch __P((int));
132void		stop __P((char));
133void		usage __P((void)) __dead2;
134void		writer __P((void));
135void		writeroob __P((int));
136
137#ifdef OLDSUN
138int		get_window_size __P((int, struct winsize *));
139#endif
140
141int
142main(argc, argv)
143	int argc;
144	char *argv[];
145{
146	extern char *optarg;
147	extern int optind;
148	struct passwd *pw;
149	struct servent *sp;
150	struct sgttyb ttyb;
151	long omask;
152	int argoff, ch, dflag, Dflag, one, uid;
153	char *host, *localname, *p, *user, term[1024];
154#ifdef KERBEROS
155	char *k;
156#endif
157
158	argoff = dflag = Dflag = 0;
159	one = 1;
160	host = localname = user = NULL;
161
162	if ((p = rindex(argv[0], '/')))
163		++p;
164	else
165		p = argv[0];
166
167	if (strcmp(p, "rlogin"))
168		host = p;
169
170	/* handle "rlogin host flags" */
171	if (!host && argc > 2 && argv[1][0] != '-') {
172		host = argv[1];
173		argoff = 1;
174	}
175
176#ifdef KERBEROS
177#define	OPTIONS	"8DEKLde:i:k:l:x"
178#else
179#define	OPTIONS	"8DEKLde:i:l:"
180#endif
181	while ((ch = getopt(argc - argoff, argv + argoff, OPTIONS)) != -1)
182		switch(ch) {
183		case '8':
184			eight = 1;
185			break;
186		case 'D':
187			Dflag = 1;
188			break;
189		case 'E':
190			noescape = 1;
191			break;
192		case 'K':
193#ifdef KERBEROS
194			use_kerberos = 0;
195#endif
196			break;
197		case 'L':
198			litout = 1;
199			break;
200		case 'd':
201			dflag = 1;
202			break;
203		case 'e':
204			noescape = 0;
205			escapechar = getescape(optarg);
206			break;
207		case 'i':
208			if (getuid() != 0)
209				errx(1, "-i user: permission denied");
210			localname = optarg;
211			break;
212#ifdef KERBEROS
213		case 'k':
214			dest_realm = dst_realm_buf;
215			(void)strncpy(dest_realm, optarg, REALM_SZ);
216			break;
217#endif
218		case 'l':
219			user = optarg;
220			break;
221#ifdef CRYPT
222#ifdef KERBEROS
223		case 'x':
224			doencrypt = 1;
225			break;
226#endif
227#endif
228		case '?':
229		default:
230			usage();
231		}
232	optind += argoff;
233
234	/* if haven't gotten a host yet, do so */
235	if (!host && !(host = argv[optind++]))
236		usage();
237
238	if (argv[optind])
239		usage();
240
241	if (!(pw = getpwuid(uid = getuid())))
242		errx(1, "unknown user id");
243	if (!user)
244		user = pw->pw_name;
245	if (!localname)
246		localname = pw->pw_name;
247
248	sp = NULL;
249#ifdef KERBEROS
250	k = auth_getval("auth_list");
251	if (k && !strstr(k, "kerberos"))
252	    use_kerberos = 0;
253	if (use_kerberos) {
254		sp = getservbyname((doencrypt ? "eklogin" : "klogin"), "tcp");
255		if (sp == NULL) {
256			use_kerberos = 0;
257			warn("can't get entry for %s/tcp service",
258			    doencrypt ? "eklogin" : "klogin");
259		}
260	}
261#endif
262	if (sp == NULL)
263		sp = getservbyname("login", "tcp");
264	if (sp == NULL)
265		errx(1, "login/tcp: unknown service");
266
267#define	MAX_TERM_LENGTH	(sizeof(term) - 1 - MAX_SPEED_LENGTH - 1)
268
269	(void)strncpy(term, (p = getenv("TERM")) ? p : "network",
270		      MAX_TERM_LENGTH);
271	term[MAX_TERM_LENGTH] = '\0';
272	if (ioctl(0, TIOCGETP, &ttyb) == 0) {
273		(void)strcat(term, "/");
274		(void)strcat(term, speeds[(int)ttyb.sg_ospeed]);
275	}
276
277	(void)get_window_size(0, &winsize);
278
279	(void)signal(SIGPIPE, lostpeer);
280	/* will use SIGUSR1 for window size hack, so hold it off */
281	omask = sigblock(sigmask(SIGURG) | sigmask(SIGUSR1));
282	/*
283	 * We set SIGURG and SIGUSR1 below so that an
284	 * incoming signal will be held pending rather than being
285	 * discarded. Note that these routines will be ready to get
286	 * a signal by the time that they are unblocked below.
287	 */
288	(void)signal(SIGURG, copytochild);
289	(void)signal(SIGUSR1, writeroob);
290
291#ifdef KERBEROS
292	if (use_kerberos) {
293		setuid(getuid());
294		rem = KSUCCESS;
295		errno = 0;
296		if (dest_realm == NULL)
297			dest_realm = krb_realmofhost(host);
298
299#ifdef CRYPT
300		if (doencrypt) {
301			rem = krcmd_mutual(&host, sp->s_port, user, term, 0,
302			    dest_realm, &cred, schedule);
303			des_set_key(&cred.session, schedule);
304		} else
305#endif /* CRYPT */
306			rem = krcmd(&host, sp->s_port, user, term, 0,
307			    dest_realm);
308		if (rem < 0) {
309			int i;
310			char **newargv;
311
312			sp = getservbyname("login", "tcp");
313			if (sp == NULL)
314				errx(1, "unknown service login/tcp");
315			if (errno == ECONNREFUSED)
316				warn("remote host doesn't support Kerberos");
317			if (errno == ENOENT)
318				warn("can't provide Kerberos auth data");
319			newargv = malloc((argc + 2) * sizeof(*newargv));
320			if (newargv == NULL)
321				err(1, "malloc");
322			newargv[0] = argv[0];
323			newargv[1] = "-K";
324			for(i = 1; i < argc; ++i)
325			newargv[i + 1] = argv[i];
326			newargv[argc + 1] = NULL;
327			execv(_PATH_RLOGIN, newargv);
328		}
329	} else {
330#ifdef CRYPT
331		if (doencrypt)
332			errx(1, "the -x flag requires Kerberos authentication");
333#endif /* CRYPT */
334		rem = rcmd(&host, sp->s_port, localname, user, term, 0);
335	}
336#else
337	rem = rcmd(&host, sp->s_port, localname, user, term, 0);
338#endif /* KERBEROS */
339
340	if (rem < 0)
341		exit(1);
342
343	if (dflag &&
344	    setsockopt(rem, SOL_SOCKET, SO_DEBUG, &one, sizeof(one)) < 0)
345		warn("setsockopt");
346	if (Dflag &&
347	    setsockopt(rem, IPPROTO_TCP, TCP_NODELAY, &one, sizeof(one)) < 0)
348		warn("setsockopt NODELAY (ignored)");
349
350	one = IPTOS_LOWDELAY;
351	if (setsockopt(rem, IPPROTO_IP, IP_TOS, (char *)&one, sizeof(int)) < 0)
352		warn("setsockopt TOS (ignored)");
353
354	(void)setuid(uid);
355	doit(omask);
356	/*NOTREACHED*/
357}
358
359int child, defflags, deflflags, tabflag;
360char deferase, defkill;
361struct tchars deftc;
362struct ltchars defltc;
363struct tchars notc = { -1, -1, -1, -1, -1, -1 };
364struct ltchars noltc = { -1, -1, -1, -1, -1, -1 };
365
366void
367doit(omask)
368	long omask;
369{
370	struct sgttyb sb;
371
372	(void)ioctl(0, TIOCGETP, (char *)&sb);
373	defflags = sb.sg_flags;
374	tabflag = defflags & TBDELAY;
375	defflags &= ECHO | CRMOD;
376	deferase = sb.sg_erase;
377	defkill = sb.sg_kill;
378	(void)ioctl(0, TIOCLGET, &deflflags);
379	(void)ioctl(0, TIOCGETC, &deftc);
380	notc.t_startc = deftc.t_startc;
381	notc.t_stopc = deftc.t_stopc;
382	(void)ioctl(0, TIOCGLTC, &defltc);
383	(void)signal(SIGINT, SIG_IGN);
384	setsignal(SIGHUP);
385	setsignal(SIGQUIT);
386	child = fork();
387	if (child == -1) {
388		warn("fork");
389		done(1);
390	}
391	if (child == 0) {
392		mode(1);
393		if (reader(omask) == 0) {
394			msg("connection closed.");
395			exit(0);
396		}
397		sleep(1);
398		msg("\007connection closed.");
399		exit(1);
400	}
401
402	/*
403	 * We may still own the socket, and may have a pending SIGURG (or might
404	 * receive one soon) that we really want to send to the reader.  When
405	 * one of these comes in, the trap copytochild simply copies such
406	 * signals to the child. We can now unblock SIGURG and SIGUSR1
407	 * that were set above.
408	 */
409	(void)sigsetmask(omask);
410	(void)signal(SIGCHLD, catch_child);
411	writer();
412	msg("closed connection.");
413	done(0);
414}
415
416/* trap a signal, unless it is being ignored. */
417void
418setsignal(sig)
419	int sig;
420{
421	int omask = sigblock(sigmask(sig));
422
423	if (signal(sig, exit) == SIG_IGN)
424		(void)signal(sig, SIG_IGN);
425	(void)sigsetmask(omask);
426}
427
428void
429done(status)
430	int status;
431{
432	int w, wstatus;
433
434	mode(0);
435	if (child > 0) {
436		/* make sure catch_child does not snap it up */
437		(void)signal(SIGCHLD, SIG_DFL);
438		if (kill(child, SIGKILL) >= 0)
439			while ((w = wait(&wstatus)) > 0 && w != child);
440	}
441	exit(status);
442}
443
444int dosigwinch;
445
446/*
447 * This is called when the reader process gets the out-of-band (urgent)
448 * request to turn on the window-changing protocol.
449 */
450void
451writeroob(signo)
452	int signo;
453{
454	if (dosigwinch == 0) {
455		sendwindow();
456		(void)signal(SIGWINCH, sigwinch);
457	}
458	dosigwinch = 1;
459}
460
461void
462catch_child(signo)
463	int signo;
464{
465	union wait status;
466	int pid;
467
468	for (;;) {
469		pid = wait3((int *)&status, WNOHANG|WUNTRACED, NULL);
470		if (pid == 0)
471			return;
472		/* if the child (reader) dies, just quit */
473		if (pid < 0 || (pid == child && !WIFSTOPPED(status)))
474			done((int)(status.w_termsig | status.w_retcode));
475	}
476	/* NOTREACHED */
477}
478
479/*
480 * writer: write to remote: 0 -> line.
481 * ~.				terminate
482 * ~^Z				suspend rlogin process.
483 * ~<delayed-suspend char>	suspend rlogin process, but leave reader alone.
484 */
485void
486writer()
487{
488	register int bol, local, n;
489	char c;
490
491	bol = 1;			/* beginning of line */
492	local = 0;
493	for (;;) {
494		n = read(STDIN_FILENO, &c, 1);
495		if (n <= 0) {
496			if (n < 0 && errno == EINTR)
497				continue;
498			break;
499		}
500		/*
501		 * If we're at the beginning of the line and recognize a
502		 * command character, then we echo locally.  Otherwise,
503		 * characters are echo'd remotely.  If the command character
504		 * is doubled, this acts as a force and local echo is
505		 * suppressed.
506		 */
507		if (bol) {
508			bol = 0;
509			if (!noescape && c == escapechar) {
510				local = 1;
511				continue;
512			}
513		} else if (local) {
514			local = 0;
515			if (c == '.' || c == deftc.t_eofc) {
516				echo(c);
517				break;
518			}
519			if (c == defltc.t_suspc || c == defltc.t_dsuspc) {
520				bol = 1;
521				echo(c);
522				stop(c);
523				continue;
524			}
525			if (c != escapechar)
526#ifdef CRYPT
527#ifdef KERBEROS
528				if (doencrypt)
529					(void)des_enc_write(rem,
530					    (char *)&escapechar, 1,
531						schedule, &cred.session);
532				else
533#endif
534#endif
535					(void)write(rem, &escapechar, 1);
536		}
537
538#ifdef CRYPT
539#ifdef KERBEROS
540		if (doencrypt) {
541			if (des_enc_write(rem, &c, 1, schedule, &cred.session) == 0) {
542				msg("line gone");
543				break;
544			}
545		} else
546#endif
547#endif
548			if (write(rem, &c, 1) == 0) {
549				msg("line gone");
550				break;
551			}
552		bol = c == defkill || c == deftc.t_eofc ||
553		    c == deftc.t_intrc || c == defltc.t_suspc ||
554		    c == '\r' || c == '\n';
555	}
556}
557
558void
559#if __STDC__
560echo(register char c)
561#else
562echo(c)
563	register char c;
564#endif
565{
566	register char *p;
567	char buf[8];
568
569	p = buf;
570	c &= 0177;
571	*p++ = escapechar;
572	if (c < ' ') {
573		*p++ = '^';
574		*p++ = c + '@';
575	} else if (c == 0177) {
576		*p++ = '^';
577		*p++ = '?';
578	} else
579		*p++ = c;
580	*p++ = '\r';
581	*p++ = '\n';
582	(void)write(STDOUT_FILENO, buf, p - buf);
583}
584
585void
586#if __STDC__
587stop(char cmdc)
588#else
589stop(cmdc)
590	char cmdc;
591#endif
592{
593	mode(0);
594	(void)signal(SIGCHLD, SIG_IGN);
595	(void)kill(cmdc == defltc.t_suspc ? 0 : getpid(), SIGTSTP);
596	(void)signal(SIGCHLD, catch_child);
597	mode(1);
598	sigwinch(0);			/* check for size changes */
599}
600
601void
602sigwinch(signo)
603	int signo;
604{
605	struct winsize ws;
606
607	if (dosigwinch && get_window_size(0, &ws) == 0 &&
608	    bcmp(&ws, &winsize, sizeof(ws))) {
609		winsize = ws;
610		sendwindow();
611	}
612}
613
614/*
615 * Send the window size to the server via the magic escape
616 */
617void
618sendwindow()
619{
620	struct winsize *wp;
621	char obuf[4 + sizeof (struct winsize)];
622
623	wp = (struct winsize *)(obuf+4);
624	obuf[0] = 0377;
625	obuf[1] = 0377;
626	obuf[2] = 's';
627	obuf[3] = 's';
628	wp->ws_row = htons(winsize.ws_row);
629	wp->ws_col = htons(winsize.ws_col);
630	wp->ws_xpixel = htons(winsize.ws_xpixel);
631	wp->ws_ypixel = htons(winsize.ws_ypixel);
632
633#ifdef CRYPT
634#ifdef KERBEROS
635	if(doencrypt)
636		(void)des_enc_write(rem, obuf, sizeof(obuf),
637			schedule, &cred.session);
638	else
639#endif
640#endif
641		(void)write(rem, obuf, sizeof(obuf));
642}
643
644/*
645 * reader: read from remote: line -> 1
646 */
647#define	READING	1
648#define	WRITING	2
649
650jmp_buf rcvtop;
651int ppid, rcvcnt, rcvstate;
652char rcvbuf[8 * 1024];
653
654void
655oob(signo)
656	int signo;
657{
658	struct sgttyb sb;
659	int atmark, n, out, rcvd;
660	char waste[BUFSIZ], mark;
661
662	out = O_RDWR;
663	rcvd = 0;
664	while (recv(rem, &mark, 1, MSG_OOB) < 0) {
665		switch (errno) {
666		case EWOULDBLOCK:
667			/*
668			 * Urgent data not here yet.  It may not be possible
669			 * to send it yet if we are blocked for output and
670			 * our input buffer is full.
671			 */
672			if (rcvcnt < sizeof(rcvbuf)) {
673				n = read(rem, rcvbuf + rcvcnt,
674				    sizeof(rcvbuf) - rcvcnt);
675				if (n <= 0)
676					return;
677				rcvd += n;
678			} else {
679				n = read(rem, waste, sizeof(waste));
680				if (n <= 0)
681					return;
682			}
683			continue;
684		default:
685			return;
686		}
687	}
688	if (mark & TIOCPKT_WINDOW) {
689		/* Let server know about window size changes */
690		(void)kill(ppid, SIGUSR1);
691	}
692	if (!eight && (mark & TIOCPKT_NOSTOP)) {
693		(void)ioctl(0, TIOCGETP, (char *)&sb);
694		sb.sg_flags &= ~CBREAK;
695		sb.sg_flags |= RAW;
696		(void)ioctl(0, TIOCSETN, (char *)&sb);
697		notc.t_stopc = -1;
698		notc.t_startc = -1;
699		(void)ioctl(0, TIOCSETC, (char *)&notc);
700	}
701	if (!eight && (mark & TIOCPKT_DOSTOP)) {
702		(void)ioctl(0, TIOCGETP, (char *)&sb);
703		sb.sg_flags &= ~RAW;
704		sb.sg_flags |= CBREAK;
705		(void)ioctl(0, TIOCSETN, (char *)&sb);
706		notc.t_stopc = deftc.t_stopc;
707		notc.t_startc = deftc.t_startc;
708		(void)ioctl(0, TIOCSETC, (char *)&notc);
709	}
710	if (mark & TIOCPKT_FLUSHWRITE) {
711		(void)ioctl(1, TIOCFLUSH, (char *)&out);
712		for (;;) {
713			if (ioctl(rem, SIOCATMARK, &atmark) < 0) {
714				warn("ioctl");
715				break;
716			}
717			if (atmark)
718				break;
719			n = read(rem, waste, sizeof (waste));
720			if (n <= 0)
721				break;
722		}
723		/*
724		 * Don't want any pending data to be output, so clear the recv
725		 * buffer.  If we were hanging on a write when interrupted,
726		 * don't want it to restart.  If we were reading, restart
727		 * anyway.
728		 */
729		rcvcnt = 0;
730		longjmp(rcvtop, 1);
731	}
732
733	/* oob does not do FLUSHREAD (alas!) */
734
735	/*
736	 * If we filled the receive buffer while a read was pending, longjmp
737	 * to the top to restart appropriately.  Don't abort a pending write,
738	 * however, or we won't know how much was written.
739	 */
740	if (rcvd && rcvstate == READING)
741		longjmp(rcvtop, 1);
742}
743
744/* reader: read from remote: line -> 1 */
745int
746reader(omask)
747	int omask;
748{
749	int pid, n, remaining;
750	char *bufp;
751
752#if BSD >= 43 || defined(SUNOS4)
753	pid = getpid();		/* modern systems use positives for pid */
754#else
755	pid = -getpid();	/* old broken systems use negatives */
756#endif
757	(void)signal(SIGTTOU, SIG_IGN);
758	(void)signal(SIGURG, oob);
759	ppid = getppid();
760	(void)fcntl(rem, F_SETOWN, pid);
761	(void)setjmp(rcvtop);
762	(void)sigsetmask(omask);
763	bufp = rcvbuf;
764	for (;;) {
765		while ((remaining = rcvcnt - (bufp - rcvbuf)) > 0) {
766			rcvstate = WRITING;
767			n = write(STDOUT_FILENO, bufp, remaining);
768			if (n < 0) {
769				if (errno != EINTR)
770					return (-1);
771				continue;
772			}
773			bufp += n;
774		}
775		bufp = rcvbuf;
776		rcvcnt = 0;
777		rcvstate = READING;
778
779#ifdef CRYPT
780#ifdef KERBEROS
781		if (doencrypt)
782			rcvcnt = des_enc_read(rem, rcvbuf, sizeof(rcvbuf),
783				schedule, &cred.session);
784		else
785#endif
786#endif
787			rcvcnt = read(rem, rcvbuf, sizeof (rcvbuf));
788		if (rcvcnt == 0)
789			return (0);
790		if (rcvcnt < 0) {
791			if (errno == EINTR)
792				continue;
793			warn("read");
794			return (-1);
795		}
796	}
797}
798
799void
800mode(f)
801	int f;
802{
803	struct ltchars *ltc;
804	struct sgttyb sb;
805	struct tchars *tc;
806	int lflags;
807
808	(void)ioctl(0, TIOCGETP, (char *)&sb);
809	(void)ioctl(0, TIOCLGET, (char *)&lflags);
810	switch(f) {
811	case 0:
812		sb.sg_flags &= ~(CBREAK|RAW|TBDELAY);
813		sb.sg_flags |= defflags|tabflag;
814		tc = &deftc;
815		ltc = &defltc;
816		sb.sg_kill = defkill;
817		sb.sg_erase = deferase;
818		lflags = deflflags;
819		break;
820	case 1:
821		sb.sg_flags |= (eight ? RAW : CBREAK);
822		sb.sg_flags &= ~defflags;
823		/* preserve tab delays, but turn off XTABS */
824		if ((sb.sg_flags & TBDELAY) == XTABS)
825			sb.sg_flags &= ~TBDELAY;
826		tc = &notc;
827		ltc = &noltc;
828		sb.sg_kill = sb.sg_erase = -1;
829		if (litout)
830			lflags |= LLITOUT;
831		break;
832	default:
833		return;
834	}
835	(void)ioctl(0, TIOCSLTC, (char *)ltc);
836	(void)ioctl(0, TIOCSETC, (char *)tc);
837	(void)ioctl(0, TIOCSETN, (char *)&sb);
838	(void)ioctl(0, TIOCLSET, (char *)&lflags);
839}
840
841void
842lostpeer(signo)
843	int signo;
844{
845	(void)signal(SIGPIPE, SIG_IGN);
846	msg("\007connection closed.");
847	done(1);
848}
849
850/* copy SIGURGs to the child process. */
851void
852copytochild(signo)
853	int signo;
854{
855	(void)kill(child, SIGURG);
856}
857
858void
859msg(str)
860	char *str;
861{
862	(void)fprintf(stderr, "rlogin: %s\r\n", str);
863}
864
865void
866usage()
867{
868	(void)fprintf(stderr,
869	"usage: rlogin [-%s]%s[-e char] [-i localname] [-l username] host\n",
870#ifdef KERBEROS
871#ifdef CRYPT
872	    "8DEKLdx", " [-k realm] ");
873#else
874	    "8DEKLd", " [-k realm] ");
875#endif
876#else
877	    "8DELd", " ");
878#endif
879	exit(1);
880}
881
882/*
883 * The following routine provides compatibility (such as it is) between older
884 * Suns and others.  Suns have only a `ttysize', so we convert it to a winsize.
885 */
886#ifdef OLDSUN
887int
888get_window_size(fd, wp)
889	int fd;
890	struct winsize *wp;
891{
892	struct ttysize ts;
893	int error;
894
895	if ((error = ioctl(0, TIOCGSIZE, &ts)) != 0)
896		return (error);
897	wp->ws_row = ts.ts_lines;
898	wp->ws_col = ts.ts_cols;
899	wp->ws_xpixel = 0;
900	wp->ws_ypixel = 0;
901	return (0);
902}
903#endif
904
905u_int
906getescape(p)
907	register char *p;
908{
909	long val;
910	int len;
911
912	if ((len = strlen(p)) == 1)	/* use any single char, including '\' */
913		return ((u_int)*p);
914					/* otherwise, \nnn */
915	if (*p == '\\' && len >= 2 && len <= 4) {
916		val = strtol(++p, NULL, 8);
917		for (;;) {
918			if (!*++p)
919				return ((u_int)val);
920			if (*p < '0' || *p > '8')
921				break;
922		}
923	}
924	msg("illegal option value -- e");
925	usage();
926	/* NOTREACHED */
927}
928