1/*
2 * Copyright (c) 1983, 1990, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 * Copyright (c) 2002 Networks Associates Technology, Inc.
5 * All rights reserved.
6 *
7 * Portions of this software were developed for the FreeBSD Project by
8 * ThinkSec AS and NAI Labs, the Security Research Division of Network
9 * Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
10 * ("CBOSS"), as part of the DARPA CHATS research program.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 *    notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 *    notice, this list of conditions and the following disclaimer in the
19 *    documentation and/or other materials provided with the distribution.
20 * 3. All advertising materials mentioning features or use of this software
21 *    must display the following acknowledgement:
22 *	This product includes software developed by the University of
23 *	California, Berkeley and its contributors.
24 * 4. Neither the name of the University nor the names of its contributors
25 *    may be used to endorse or promote products derived from this software
26 *    without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * SUCH DAMAGE.
39 */
40
41#ifndef lint
42__attribute__((__used__))
43static const char copyright[] =
44"@(#) Copyright (c) 1983, 1990, 1993\n\
45	The Regents of the University of California.  All rights reserved.\n";
46#endif /* not lint */
47
48#if 0
49#ifndef lint
50static const char sccsid[] = "@(#)rlogin.c	8.1 (Berkeley) 6/6/93";
51#endif /* not lint */
52#endif
53
54#include <sys/cdefs.h>
55__FBSDID("$FreeBSD: src/usr.bin/rlogin/rlogin.c,v 1.40 2005/11/13 21:03:56 dwmalone Exp $");
56
57/*
58 * rlogin - remote login
59 */
60
61#include <sys/param.h>
62#include <sys/ioctl.h>
63#include <sys/socket.h>
64#include <sys/time.h>
65#include <sys/resource.h>
66#include <sys/wait.h>
67
68#include <netinet/in.h>
69#include <netinet/in_systm.h>
70#include <netinet/ip.h>
71#include <netinet/tcp.h>
72
73#include <err.h>
74#include <errno.h>
75#include <fcntl.h>
76#ifndef __APPLE__
77#include <libutil.h>
78#endif
79#include <netdb.h>
80#include <paths.h>
81#include <pwd.h>
82#include <setjmp.h>
83#include <termios.h>
84#include <signal.h>
85#include <stdio.h>
86#include <stdlib.h>
87#include <string.h>
88#include <unistd.h>
89
90#include <stdarg.h>
91
92#if defined(KERBEROS)
93#include <kerberosIV/des.h>
94#include <kerberosIV/krb.h>
95
96#include "krb.h"
97
98CREDENTIALS cred;
99Key_schedule schedule;
100int use_kerberos = 1, doencrypt;
101char dst_realm_buf[REALM_SZ], *dest_realm = NULL;
102#endif /* KERBEROS */
103
104#ifndef TIOCPKT_WINDOW
105#define	TIOCPKT_WINDOW	0x80
106#endif
107
108/* concession to Sun */
109#ifndef SIGUSR1
110#define	SIGUSR1	30
111#endif
112
113int eight, rem;
114struct termios deftty;
115
116int family = PF_UNSPEC;
117
118int noescape;
119u_char escapechar = '~';
120
121#define	get_window_size(fd, wp)	ioctl(fd, TIOCGWINSZ, wp)
122struct	winsize winsize;
123
124void		catch_child(int);
125void		copytochild(int);
126#ifdef __APPLE__
127void		doit(sigset_t *) __dead2;
128#else
129void		doit(long) __dead2;
130#endif
131void		done(int) __dead2;
132void		echo(char);
133u_int		getescape(const char *);
134void		lostpeer(int);
135void		mode(int);
136void		msg(const char *);
137void		oob(int);
138#ifdef __APPLE__
139int		reader(sigset_t *);
140#else
141int		reader(int);
142#endif
143void		sendwindow(void);
144void		setsignal(int);
145void		sigwinch(int);
146void		stop(char);
147void		usage(void) __dead2;
148void		writer(void);
149void		writeroob(int);
150
151#if defined(KERBEROS)
152void		warning(const char *, ...);
153#endif
154
155int
156main(int argc, char *argv[])
157{
158	struct passwd *pw;
159	struct servent *sp;
160	struct termios tty;
161#ifndef __APPLE__
162	long omask;
163#else
164	sigset_t smask;
165	struct sigaction sa;
166#endif
167	int argoff, ch, dflag, Dflag, one;
168	uid_t uid;
169	char *host, *localname, *p, *user, term[1024];
170	speed_t ospeed;
171	struct sockaddr_storage ss;
172	socklen_t sslen;
173	size_t len, len2;
174	int i;
175
176	argoff = dflag = Dflag = 0;
177	one = 1;
178	host = localname = user = NULL;
179
180#ifdef __APPLE__
181	if (argv[0] == NULL)
182		usage();
183#endif
184	if ((p = rindex(argv[0], '/')))
185		++p;
186	else
187		p = argv[0];
188
189	if (strcmp(p, "rlogin"))
190		host = p;
191
192	/* handle "rlogin host flags" */
193	if (!host && argc > 2 && argv[1][0] != '-') {
194		host = argv[1];
195		argoff = 1;
196	}
197
198#if defined(KERBEROS)
199#define	OPTIONS	"468EKLde:k:l:x"
200#else
201#define	OPTIONS	"468DEde:i:l:"
202#endif
203	while ((ch = getopt(argc - argoff, argv + argoff, OPTIONS)) != -1)
204		switch(ch) {
205		case '4':
206			family = PF_INET;
207			break;
208
209		case '6':
210			family = PF_INET6;
211			break;
212
213		case '8':
214			eight = 1;
215			break;
216		case 'D':
217			Dflag = 1;
218			break;
219		case 'E':
220			noescape = 1;
221			break;
222#if defined(KERBEROS)
223		case 'K':
224			use_kerberos = 0;
225			break;
226		case 'L':
227			litout = 1;
228			break;
229#endif
230		case 'd':
231			dflag = 1;
232			break;
233		case 'e':
234			noescape = 0;
235			escapechar = getescape(optarg);
236			break;
237		case 'i':
238			if (getuid() != 0)
239				errx(1, "-i user: permission denied");
240			localname = optarg;
241#if defined(KERBEROS)
242		case 'k':
243			dest_realm = dst_realm_buf;
244			(void)strncpy(dest_realm, optarg, REALM_SZ);
245			break;
246#endif
247		case 'l':
248			user = optarg;
249			break;
250#if defined(KERBEROS) && defined(CRYPT)
251		case 'x':
252			doencrypt = 1;
253			des_set_key(cred.session, schedule);
254			break;
255#endif
256		case '?':
257		default:
258			usage();
259		}
260	optind += argoff;
261
262	/* if haven't gotten a host yet, do so */
263	if (!host && !(host = argv[optind++]))
264		usage();
265
266	if (argv[optind])
267		usage();
268
269	if (!(pw = getpwuid(uid = getuid())))
270		errx(1, "unknown user id");
271#ifdef __APPLE__
272	/* Accept user1@host format, though "-l user2" overrides user1 */
273	p = strchr(host, '@');
274	if (p) {
275		*p = '\0';
276		if (!user && p > host)
277			user = host;
278		host = p + 1;
279		if (*host == '\0')
280			usage();
281	}
282#endif
283	if (!user)
284		user = pw->pw_name;
285	if (!localname)
286		localname = pw->pw_name;
287
288	sp = NULL;
289#if defined(KERBEROS)
290	if (use_kerberos) {
291		sp = getservbyname((doencrypt ? "eklogin" : "klogin"), "tcp");
292		if (sp == NULL) {
293			use_kerberos = 0;
294			warning("can't get entry for %s/tcp service",
295			    doencrypt ? "eklogin" : "klogin");
296		}
297	}
298	if (sp == NULL)
299#endif
300	sp = getservbyname("login", "tcp");
301	if (sp == NULL)
302		errx(1, "login/tcp: unknown service");
303
304	if ((p = getenv("TERM")) != NULL)
305		(void)strlcpy(term, p, sizeof(term));
306#if __APPLE__
307	else
308		(void)strcpy(term, "network");
309#endif
310	len = strlen(term);
311	if (len < (sizeof(term) - 1) && tcgetattr(0, &tty) == 0) {
312		/* start at 2 to include the / */
313		for (ospeed = i = cfgetospeed(&tty), len2 = 2; i > 9; len2++)
314			i /= 10;
315		if (len + len2 < sizeof(term))
316			(void)snprintf(term + len, len2 + 1, "/%ld", ospeed);
317	}
318
319	(void)get_window_size(0, &winsize);
320
321#ifdef __APPLE__
322	sigemptyset(&sa.sa_mask);
323	sa.sa_flags = SA_RESTART;
324	sa.sa_handler = lostpeer;
325	(void)sigaction(SIGPIPE, &sa, (struct sigaction *) 0);
326#else
327	(void)signal(SIGPIPE, lostpeer);
328#endif
329	/* will use SIGUSR1 for window size hack, so hold it off */
330#ifdef __APPLE__
331	sigemptyset(&smask);
332	sigaddset(&smask, SIGURG);
333	sigaddset(&smask, SIGUSR1);
334	(void)sigprocmask(SIG_SETMASK, &smask, &smask);
335#else
336	omask = sigblock(sigmask(SIGURG) | sigmask(SIGUSR1));
337#endif
338	/*
339	 * We set SIGURG and SIGUSR1 below so that an
340	 * incoming signal will be held pending rather than being
341	 * discarded. Note that these routines will be ready to get
342	 * a signal by the time that they are unblocked below.
343	 */
344#ifdef __APPLE__
345	sa.sa_handler = copytochild;
346	(void)sigaction(SIGURG, &sa, (struct sigaction *) 0);
347	sa.sa_handler = writeroob;
348	(void)sigaction(SIGUSR1, &sa, (struct sigaction *) 0);
349#else
350	(void)signal(SIGURG, copytochild);
351	(void)signal(SIGUSR1, writeroob);
352#endif
353
354#if defined(KERBEROS)
355try_connect:
356	if (use_kerberos) {
357		struct hostent *hp;
358
359		/* Fully qualify hostname (needed for krb_realmofhost). */
360		hp = gethostbyname(host);
361		if (hp != NULL && !(host = strdup(hp->h_name)))
362			errx(1, "%s", strerror(ENOMEM));
363
364		rem = KSUCCESS;
365		errno = 0;
366		if (dest_realm == NULL)
367			dest_realm = krb_realmofhost(host);
368
369#if defined(CRYPT)
370		if (doencrypt)
371			rem = krcmd_mutual(&host, sp->s_port, user, term, 0,
372			    dest_realm, &cred, schedule);
373		else
374#endif /* CRYPT */
375			rem = krcmd(&host, sp->s_port, user, term, 0,
376			    dest_realm);
377		if (rem < 0) {
378			use_kerberos = 0;
379			sp = getservbyname("login", "tcp");
380			if (sp == NULL)
381				errx(1, "unknown service login/tcp");
382			if (errno == ECONNREFUSED)
383				warning("remote host doesn't support Kerberos");
384			if (errno == ENOENT)
385				warning("can't provide Kerberos auth data");
386			goto try_connect;
387		}
388	} else {
389#if defined(CRYPT)
390		if (doencrypt)
391			errx(1, "the -x flag requires Kerberos authentication");
392#endif /* CRYPT */
393		rem = rcmd(&host, sp->s_port, pw->pw_name, user, term, 0);
394	}
395#else /* KERBEROS */
396	rem = rcmd_af(&host, sp->s_port, localname, user, term, 0, family);
397//	rem = rcmd(&host, sp->s_port, pw->pw_name, user, term, 0);
398#endif /* KERBEROS */
399
400	if (rem < 0)
401		exit(1);
402
403	if (dflag &&
404	    setsockopt(rem, SOL_SOCKET, SO_DEBUG, &one, sizeof(one)) < 0)
405		warn("setsockopt");
406	if (Dflag &&
407	    setsockopt(rem, IPPROTO_TCP, TCP_NODELAY, &one, sizeof(one)) < 0)
408		warn("setsockopt NODELAY (ignored)");
409
410	sslen = sizeof(ss);
411	one = IPTOS_LOWDELAY;
412	if (getsockname(rem, (struct sockaddr *)&ss, &sslen) == 0 &&
413	    ss.ss_family == AF_INET) {
414		if (setsockopt(rem, IPPROTO_IP, IP_TOS, (char *)&one,
415			       sizeof(int)) < 0)
416			warn("setsockopt TOS (ignored)");
417	} else
418		if (ss.ss_family == AF_INET)
419			warn("setsockopt getsockname failed");
420
421	(void)setuid(uid);
422#ifdef __APPLE__
423	doit(&smask);
424#else
425	doit(omask);
426#endif
427	/*NOTREACHED*/
428}
429
430int child;
431
432void
433#ifdef __APPLE__
434doit(sigset_t *omask)
435#else
436doit(long omask)
437#endif
438{
439
440//	int i;
441//	for (i = 0; i < NCCS; i++)
442//		nott.c_cc[i] = _POSIX_VDISABLE;
443//	tcgetattr(0, &deftt);
444//	nott.c_cc[VSTART] = deftt.c_cc[VSTART];
445//	nott.c_cc[VSTOP] = deftt.c_cc[VSTOP];
446#ifdef __APPLE__
447	struct sigaction sa;
448
449	sigemptyset(&sa.sa_mask);
450	sa.sa_flags = SA_RESTART;
451	sa.sa_handler = SIG_IGN;
452	(void)sigaction(SIGINT, &sa, (struct sigaction *) 0);
453#else
454	(void)signal(SIGINT, SIG_IGN);
455#endif
456	setsignal(SIGHUP);
457	setsignal(SIGQUIT);
458	mode(1);
459	child = fork();
460	if (child == -1) {
461		warn("fork");
462		done(1);
463	}
464	if (child == 0) {
465		if (reader(omask) == 0) {
466			msg("connection closed");
467			exit(0);
468		}
469		sleep(1);
470		msg("\007connection closed");
471		exit(1);
472	}
473
474	/*
475	 * We may still own the socket, and may have a pending SIGURG (or might
476	 * receive one soon) that we really want to send to the reader.  When
477	 * one of these comes in, the trap copytochild simply copies such
478	 * signals to the child. We can now unblock SIGURG and SIGUSR1
479	 * that were set above.
480	 */
481#ifdef __APPLE__
482	(void)sigprocmask(SIG_SETMASK, omask, (sigset_t *) 0);
483	sa.sa_handler = catch_child;
484	(void)sigaction(SIGCHLD, &sa, (struct sigaction *) 0);
485#else
486	(void)sigsetmask(omask);
487	(void)signal(SIGCHLD, catch_child);
488#endif
489	writer();
490	msg("closed connection");
491	done(0);
492}
493
494/* trap a signal, unless it is being ignored. */
495void
496setsignal(int sig)
497{
498#ifdef __APPLE__
499	struct sigaction sa;
500	sigset_t sigs;
501
502	sigemptyset(&sigs);
503	sigaddset(&sigs, sig);
504	sigprocmask(SIG_BLOCK, &sigs, &sigs);
505
506	sigemptyset(&sa.sa_mask);
507	sa.sa_handler = exit;
508	sa.sa_flags = SA_RESTART;
509	(void)sigaction(sig, &sa, &sa);
510	if (sa.sa_handler == SIG_IGN)
511		(void)sigaction(sig, &sa, (struct sigaction *) 0);
512
513	(void)sigprocmask(SIG_SETMASK, &sigs, (sigset_t *) 0);
514#else
515	int omask = sigblock(sigmask(sig));
516
517	if (signal(sig, exit) == SIG_IGN)
518		(void)signal(sig, SIG_IGN);
519	(void)sigsetmask(omask);
520#endif
521}
522
523void
524done(int status)
525{
526	int w, wstatus;
527
528	mode(0);
529	if (child > 0) {
530		/* make sure catch_child does not snap it up */
531#if __APPLE__
532		struct sigaction sa;
533		sigemptyset(&sa.sa_mask);
534		sa.sa_handler = SIG_DFL;
535		sa.sa_flags = 0;
536		(void)sigaction(SIGCHLD, &sa, (struct sigaction *) 0);
537#else
538		(void)signal(SIGCHLD, SIG_DFL);
539#endif
540		if (kill(child, SIGKILL) >= 0)
541			while ((w = wait(&wstatus)) > 0 && w != child);
542	}
543	exit(status);
544}
545
546int dosigwinch;
547
548/*
549 * This is called when the reader process gets the out-of-band (urgent)
550 * request to turn on the window-changing protocol.
551 */
552/* ARGSUSED */
553void
554writeroob(int signo __unused)
555{
556	if (dosigwinch == 0) {
557		sendwindow();
558#ifdef __APPLE__
559		struct sigaction sa;
560		sigemptyset(&sa.sa_mask);
561		sa.sa_handler = sigwinch;
562		sa.sa_flags = SA_RESTART;
563		(void)sigaction(SIGWINCH, &sa, (struct sigaction *) 0);
564#else
565		(void)signal(SIGWINCH, sigwinch);
566#endif
567	}
568	dosigwinch = 1;
569}
570
571/* ARGSUSED */
572void
573catch_child(int signo __unused)
574{
575	pid_t pid;
576	int status;
577
578	for (;;) {
579		pid = wait3(&status, WNOHANG|WUNTRACED, NULL);
580		if (pid == 0)
581			return;
582		/* if the child (reader) dies, just quit */
583		if (pid < 0 || (pid == child && !WIFSTOPPED(status)))
584			done(WTERMSIG(status) | WEXITSTATUS(status));
585	}
586	/* NOTREACHED */
587}
588
589/*
590 * writer: write to remote: 0 -> line.
591 * ~.				terminate
592 * ~^Z				suspend rlogin process.
593 * ~<delayed-suspend char>	suspend rlogin process, but leave reader alone.
594 */
595void
596writer(void)
597{
598	int bol, local, n;
599	char c;
600
601	bol = 1;			/* beginning of line */
602	local = 0;
603	for (;;) {
604		n = read(STDIN_FILENO, &c, 1);
605		if (n <= 0) {
606			if (n < 0 && errno == EINTR)
607				continue;
608			break;
609		}
610		/*
611		 * If we're at the beginning of the line and recognize a
612		 * command character, then we echo locally.  Otherwise,
613		 * characters are echo'd remotely.  If the command character
614		 * is doubled, this acts as a force and local echo is
615		 * suppressed.
616		 */
617		if (bol) {
618			bol = 0;
619			if (!noescape && c == escapechar) {
620				local = 1;
621				continue;
622			}
623		} else if (local) {
624			local = 0;
625			if (c == '.' || CCEQ(deftty.c_cc[VEOF], c)) {
626				echo(c);
627				break;
628			}
629			if (CCEQ(deftty.c_cc[VSUSP], c) ||
630			    CCEQ(deftty.c_cc[VDSUSP], c)) {
631				bol = 1;
632				echo(c);
633				stop(c);
634				continue;
635			}
636			if (c != escapechar)
637#if defined(KERBEROS) && defined(CRYPT)
638				if (doencrypt)
639					(void)des_write(rem,
640					    (char *)&escapechar, 1);
641				else
642#endif
643				(void)write(rem, &escapechar, 1);
644		}
645
646#if defined(KERBEROS) && defined(CRYPT)
647		if (doencrypt) {
648			if (des_write(rem, &c, 1) == 0) {
649				msg("line gone");
650				break;
651			}
652		} else
653#endif
654		if (write(rem, &c, 1) == 0) {
655			msg("line gone");
656			break;
657		}
658		bol = CCEQ(deftty.c_cc[VKILL], c) ||
659		    CCEQ(deftty.c_cc[VEOF], c) ||
660		    CCEQ(deftty.c_cc[VINTR], c) ||
661		    CCEQ(deftty.c_cc[VSUSP], c) ||
662		    c == '\r' || c == '\n';
663	}
664}
665
666void
667echo(char c)
668{
669	char *p;
670	char buf[8];
671
672	p = buf;
673	c &= 0177;
674	*p++ = escapechar;
675	if (c < ' ') {
676		*p++ = '^';
677		*p++ = c + '@';
678	} else if (c == 0177) {
679		*p++ = '^';
680		*p++ = '?';
681	} else
682		*p++ = c;
683	*p++ = '\r';
684	*p++ = '\n';
685	(void)write(STDOUT_FILENO, buf, p - buf);
686}
687
688void
689stop(char cmdc)
690{
691	mode(0);
692#ifdef __APPLE__
693	struct sigaction sa;
694
695	sigemptyset(&sa.sa_mask);
696	sa.sa_handler = SIG_IGN;
697	sa.sa_flags = SA_RESTART;
698	(void)sigaction(SIGCHLD, &sa, (struct sigaction *) 0);
699#else
700	(void)signal(SIGCHLD, SIG_IGN);
701#endif
702	(void)kill(CCEQ(deftty.c_cc[VSUSP], cmdc) ? 0 : getpid(), SIGTSTP);
703#ifdef __APPLE__
704	sa.sa_handler = catch_child;
705	(void)sigaction(SIGCHLD, &sa, (struct sigaction *) 0);
706#else
707	(void)signal(SIGCHLD, catch_child);
708#endif
709	mode(1);
710	sigwinch(0);			/* check for size changes */
711}
712
713/* ARGSUSED */
714void
715sigwinch(int signo __unused)
716{
717	struct winsize ws;
718
719	if (dosigwinch && get_window_size(0, &ws) == 0 &&
720	    bcmp(&ws, &winsize, sizeof(ws))) {
721		winsize = ws;
722		sendwindow();
723	}
724}
725
726/*
727 * Send the window size to the server via the magic escape
728 */
729void
730sendwindow(void)
731{
732	struct winsize *wp;
733	char obuf[4 + sizeof (struct winsize)];
734
735	wp = (struct winsize *)(obuf+4);
736	obuf[0] = 0377;
737	obuf[1] = 0377;
738	obuf[2] = 's';
739	obuf[3] = 's';
740	wp->ws_row = htons(winsize.ws_row);
741	wp->ws_col = htons(winsize.ws_col);
742	wp->ws_xpixel = htons(winsize.ws_xpixel);
743	wp->ws_ypixel = htons(winsize.ws_ypixel);
744
745#if defined(KERBEROS) && defined(CRYPT)
746	if(doencrypt)
747		(void)des_write(rem, obuf, sizeof(obuf));
748	else
749#endif
750	(void)write(rem, obuf, sizeof(obuf));
751}
752
753/*
754 * reader: read from remote: line -> 1
755 */
756#define	READING	1
757#define	WRITING	2
758
759jmp_buf rcvtop;
760int rcvcnt, rcvstate;
761pid_t ppid;
762char rcvbuf[8 * 1024];
763
764/* ARGSUSED */
765void
766oob(int signo __unused)
767{
768	struct termios tty;
769	int atmark, n, rcvd;
770	char waste[BUFSIZ], mark;
771
772	rcvd = 0;
773	while (recv(rem, &mark, 1, MSG_OOB) < 0) {
774		switch (errno) {
775		case EWOULDBLOCK:
776			/*
777			 * Urgent data not here yet.  It may not be possible
778			 * to send it yet if we are blocked for output and
779			 * our input buffer is full.
780			 */
781			if (rcvcnt < (int)sizeof(rcvbuf)) {
782				n = read(rem, rcvbuf + rcvcnt,
783				    sizeof(rcvbuf) - rcvcnt);
784				if (n <= 0)
785					return;
786				rcvd += n;
787			} else {
788				n = read(rem, waste, sizeof(waste));
789				if (n <= 0)
790					return;
791			}
792			continue;
793		default:
794			return;
795		}
796	}
797	if (mark & TIOCPKT_WINDOW) {
798		/* Let server know about window size changes */
799		(void)kill(ppid, SIGUSR1);
800	}
801	if (!eight && (mark & TIOCPKT_NOSTOP)) {
802		(void)tcgetattr(0, &tty);
803		tty.c_iflag &= ~IXON;
804		(void)tcsetattr(0, TCSANOW, &tty);
805//		tt.c_iflag &= ~(IXON | IXOFF);
806//		tt.c_cc[VSTOP] = _POSIX_VDISABLE;
807//		tt.c_cc[VSTART] = _POSIX_VDISABLE;
808	}
809	if (!eight && (mark & TIOCPKT_DOSTOP)) {
810		(void)tcgetattr(0, &tty);
811		tty.c_iflag |= (deftty.c_iflag & IXON);
812		(void)tcsetattr(0, TCSANOW, &tty);
813//		tt.c_iflag |= (IXON|IXOFF);
814//		tt.c_cc[VSTOP] = deftt.c_cc[VSTOP];
815//		tt.c_cc[VSTART] = deftt.c_cc[VSTART];
816	}
817	if (mark & TIOCPKT_FLUSHWRITE) {
818		(void)tcflush(1, TCIOFLUSH);
819		for (;;) {
820			if (ioctl(rem, SIOCATMARK, &atmark) < 0) {
821				warn("ioctl");
822				break;
823			}
824			if (atmark)
825				break;
826			n = read(rem, waste, sizeof (waste));
827			if (n <= 0)
828				break;
829		}
830		/*
831		 * Don't want any pending data to be output, so clear the recv
832		 * buffer.  If we were hanging on a write when interrupted,
833		 * don't want it to restart.  If we were reading, restart
834		 * anyway.
835		 */
836		rcvcnt = 0;
837		longjmp(rcvtop, 1);
838	}
839
840	/* oob does not do FLUSHREAD (alas!) */
841
842	/*
843	 * If we filled the receive buffer while a read was pending, longjmp
844	 * to the top to restart appropriately.  Don't abort a pending write,
845	 * however, or we won't know how much was written.
846	 */
847	if (rcvd && rcvstate == READING)
848		longjmp(rcvtop, 1);
849}
850
851/* reader: read from remote: line -> 1 */
852int
853#if __APPLE__
854reader(sigset_t *smask)
855#else
856reader(int omask)
857#endif
858{
859	int n, remaining;
860	char *bufp;
861	pid_t pid;
862
863	pid = getpid();
864#if __APPLE__
865	struct sigaction sa;
866
867	sigemptyset(&sa.sa_mask);
868	sa.sa_flags = SA_RESTART;
869	sa.sa_handler = SIG_IGN;
870	(void)sigaction(SIGTTOU, &sa, (struct sigaction *) 0);
871	sa.sa_handler = oob;
872	(void)sigaction(SIGURG, &sa, (struct sigaction *) 0);
873	(void)sigaction(SIGUSR1, &sa, (struct sigaction *) 0);
874#else
875	(void)signal(SIGTTOU, SIG_IGN);
876	(void)signal(SIGURG, oob);
877	(void)signal(SIGUSR1, oob); /* When propogating SIGURG from parent */
878#endif
879	ppid = getppid();
880	(void)fcntl(rem, F_SETOWN, pid);
881	(void)setjmp(rcvtop);
882#if __APPLE__
883	(void)sigprocmask(SIG_SETMASK, smask, (sigset_t *) 0);
884#else
885	(void)sigsetmask(omask);
886#endif
887	bufp = rcvbuf;
888	for (;;) {
889		while ((remaining = rcvcnt - (bufp - rcvbuf)) > 0) {
890			rcvstate = WRITING;
891			n = write(STDOUT_FILENO, bufp, remaining);
892			if (n < 0) {
893				if (errno != EINTR)
894					return (-1);
895				continue;
896			}
897			bufp += n;
898		}
899		bufp = rcvbuf;
900		rcvcnt = 0;
901		rcvstate = READING;
902
903#if defined(KERBEROS) && defined(CRYPT)
904		if (doencrypt)
905			rcvcnt = des_read(rem, rcvbuf, sizeof(rcvbuf));
906		else
907#endif
908		rcvcnt = read(rem, rcvbuf, sizeof (rcvbuf));
909		if (rcvcnt == 0)
910			return (0);
911		if (rcvcnt < 0) {
912			if (errno == EINTR)
913				continue;
914			warn("read");
915			return (-1);
916		}
917	}
918}
919
920void
921mode(int f)
922{
923	struct termios tty;
924
925	switch (f) {
926	case 0:
927		(void)tcsetattr(0, TCSANOW, &deftty);
928//		(void)tcsetattr(0, TCSADRAIN, &deftty);
929		break;
930	case 1:
931		(void)tcgetattr(0, &deftty);
932		tty = deftty;
933		/* This is loosely derived from sys/kern/tty_compat.c. */
934		tty.c_lflag &= ~(ECHO|ICANON|ISIG|IEXTEN);
935		tty.c_iflag &= ~ICRNL;
936		tty.c_oflag &= ~OPOST;
937		tty.c_cc[VMIN] = 1;
938		tty.c_cc[VTIME] = 0;
939		if (eight) {
940			tty.c_iflag &= IXOFF;
941			tty.c_cflag &= ~(CSIZE|PARENB);
942			tty.c_cflag |= CS8;
943//			tt.c_iflag &= ~(IXON | IXOFF | ISTRIP);
944//			tt.c_cc[VSTOP] = _POSIX_VDISABLE;
945//			tt.c_cc[VSTART] = _POSIX_VDISABLE;
946		}
947		(void)tcsetattr(0, TCSANOW, &tty);
948//		tcsetattr(0, TCSADRAIN, &tt);
949		break;
950	default:
951		return;
952	}
953}
954
955/* ARGSUSED */
956void
957lostpeer(int signo __unused)
958{
959#ifdef __APPLE__
960	struct sigaction sa;
961
962	sigemptyset(&sa.sa_mask);
963	sa.sa_flags = SA_RESTART;
964	sa.sa_handler = SIG_IGN;
965	(void)sigaction(SIGPIPE, &sa, (struct sigaction *) 0);
966#else
967	(void)signal(SIGPIPE, SIG_IGN);
968#endif
969	msg("\007connection closed");
970	done(1);
971}
972
973/* copy SIGURGs to the child process via SIGUSR1. */
974/* ARGSUSED */
975void
976copytochild(int signo __unused)
977{
978	(void)kill(child, SIGUSR1);
979}
980
981void
982msg(const char *str)
983{
984	(void)fprintf(stderr, "rlogin: %s\r\n", str);
985}
986
987#if defined(KERBEROS)
988/* VARARGS */
989void
990warning(const char *fmt, ...)
991{
992	va_list ap;
993
994	(void)fprintf(stderr, "rlogin: warning, using standard rlogin: ");
995	va_start(ap, fmt);
996	vfprintf(stderr, fmt, ap);
997	va_end(ap);
998	(void)fprintf(stderr, ".\n");
999}
1000#endif
1001
1002void
1003usage(void)
1004{
1005	(void)fprintf(stderr,
1006#ifdef __APPLE__
1007	"usage: rlogin [-46%s]%s[-e char] [-i localname] [-l username] [username@]host\n",
1008#else
1009	"usage: rlogin [-46%s]%s[-e char] [-i localname] [-l username] host\n",
1010#endif
1011#if defined(KERBEROS) && defined(CRYPT)
1012	    "8EKLx", " [-k realm] ");
1013#elif defined(KERBEROS)
1014	    "8EKL", " [-k realm] ");
1015#else
1016	    "8DEd", " ");
1017#endif
1018	exit(1);
1019}
1020
1021u_int
1022getescape(const char *p)
1023{
1024	long val;
1025	size_t len;
1026
1027	if ((len = strlen(p)) == 1)	/* use any single char, including '\' */
1028		return ((u_int)*p);
1029					/* otherwise, \nnn */
1030	if (*p == '\\' && len >= 2 && len <= 4) {
1031		val = strtol(++p, NULL, 8);
1032		for (;;) {
1033			if (!*++p)
1034				return ((u_int)val);
1035			if (*p < '0' || *p > '8')
1036				break;
1037		}
1038	}
1039	msg("illegal option value -- e");
1040	usage();
1041	/* NOTREACHED */
1042}
1043