xref: /original-bsd/libexec/rlogind/rlogind.c (revision 3f799367)
1 /*
2  * Copyright (c) 1983, 1988, 1989 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms are permitted
6  * provided that the above copyright notice and this paragraph are
7  * duplicated in all such forms and that any documentation,
8  * advertising materials, and other materials related to such
9  * distribution and use acknowledge that the software was developed
10  * by the University of California, Berkeley.  The name of the
11  * University may not be used to endorse or promote products derived
12  * from this software without specific prior written permission.
13  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
14  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
15  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
16  */
17 
18 #ifndef lint
19 char copyright[] =
20 "@(#) Copyright (c) 1983, 1988, 1989 The Regents of the University of California.\n\
21  All rights reserved.\n";
22 #endif /* not lint */
23 
24 #ifndef lint
25 static char sccsid[] = "@(#)rlogind.c	5.44 (Berkeley) 06/07/90";
26 #endif /* not lint */
27 
28 #ifdef KERBEROS
29 /* From:
30  *	$Source: /mit/kerberos/ucb/mit/rlogind/RCS/rlogind.c,v $
31  *	$Header: rlogind.c,v 5.0 89/06/26 18:31:01 kfall Locked $
32  */
33 #endif
34 
35 /*
36  * remote login server:
37  *	\0
38  *	remuser\0
39  *	locuser\0
40  *	terminal_type/speed\0
41  *	data
42  */
43 
44 #define	FD_SETSIZE	16		/* don't need many bits for select */
45 #include <sys/param.h>
46 #include <sys/stat.h>
47 #include <sys/socket.h>
48 #include <sys/wait.h>
49 #include <sys/file.h>
50 #include <sys/signal.h>
51 #include <sys/ioctl.h>
52 #include <sys/termios.h>
53 
54 #include <netinet/in.h>
55 
56 #include <errno.h>
57 #include <pwd.h>
58 #include <netdb.h>
59 #include <syslog.h>
60 #include <string.h>
61 #include <stdio.h>
62 #include <unistd.h>
63 #include "pathnames.h"
64 
65 #ifndef TIOCPKT_WINDOW
66 #define TIOCPKT_WINDOW 0x80
67 #endif
68 
69 #ifdef	KERBEROS
70 #include <kerberosIV/des.h>
71 #include <kerberosIV/krb.h>
72 #define	SECURE_MESSAGE "This rlogin session is using DES encryption for all transmissions.\r\n"
73 
74 AUTH_DAT	*kdata;
75 KTEXT		ticket;
76 u_char		auth_buf[sizeof(AUTH_DAT)];
77 u_char		tick_buf[sizeof(KTEXT_ST)];
78 Key_schedule	schedule;
79 int		encrypt = 0, retval, use_kerberos = 0, vacuous = 0;
80 
81 #define		ARGSTR			"alnkvx"
82 #else
83 #define		ARGSTR			"aln"
84 #endif	/* KERBEROS */
85 
86 char	*env[2];
87 #define	NMAX 30
88 char	lusername[NMAX+1], rusername[NMAX+1];
89 static	char term[64] = "TERM=";
90 #define	ENVSIZE	(sizeof("TERM=")-1)	/* skip null for concatenation */
91 int	keepalive = 1;
92 int	check_all = 0;
93 
94 extern	int errno;
95 int	reapchild();
96 struct	passwd *getpwnam(), *pwd;
97 char	*malloc();
98 
99 main(argc, argv)
100 	int argc;
101 	char **argv;
102 {
103 	extern int opterr, optind;
104 	extern int _check_rhosts_file;
105 	int ch;
106 	int on = 1, fromlen;
107 	struct sockaddr_in from;
108 
109 	openlog("rlogind", LOG_PID | LOG_CONS, LOG_AUTH);
110 
111 	opterr = 0;
112 	while ((ch = getopt(argc, argv, ARGSTR)) != EOF)
113 		switch (ch) {
114 		case 'a':
115 			check_all = 1;
116 			break;
117 		case 'l':
118 			_check_rhosts_file = 0;
119 			break;
120 		case 'n':
121 			keepalive = 0;
122 			break;
123 #ifdef KERBEROS
124 		case 'k':
125 			use_kerberos = 1;
126 			break;
127 		case 'v':
128 			vacuous = 1;
129 			break;
130 		case 'x':
131 			encrypt = 1;
132 			break;
133 #endif
134 		case '?':
135 		default:
136 			usage();
137 			break;
138 		}
139 	argc -= optind;
140 	argv += optind;
141 
142 #ifdef	KERBEROS
143 	if (use_kerberos && vacuous) {
144 		usage();
145 		fatal(STDERR_FILENO, "only one of -k and -v allowed", 0);
146 	}
147 #endif
148 	fromlen = sizeof (from);
149 	if (getpeername(0, &from, &fromlen) < 0) {
150 		syslog(LOG_ERR,"Can't get peer name of remote host: %m");
151 		fatal(STDERR_FILENO, "Can't get peer name of remote host", 1);
152 	}
153 	if (keepalive &&
154 	    setsockopt(0, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof (on)) < 0)
155 		syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m");
156 	doit(0, &from);
157 }
158 
159 int	child;
160 int	cleanup();
161 int	netf;
162 char	*line;
163 int	confirmed;
164 extern	char	*inet_ntoa();
165 
166 struct winsize win = { 0, 0, 0, 0 };
167 
168 
169 doit(f, fromp)
170 	int f;
171 	struct sockaddr_in *fromp;
172 {
173 	int i, p, t, pid, on = 1;
174 	int authenticated = 0, hostok = 0;
175 	register struct hostent *hp;
176 	char remotehost[2 * MAXHOSTNAMELEN + 1];
177 	struct hostent hostent;
178 	char c;
179 
180 	alarm(60);
181 	read(f, &c, 1);
182 
183 	if (c != 0)
184 		exit(1);
185 #ifdef	KERBEROS
186 	if (vacuous)
187 		fatal(f, "Remote host requires Kerberos authentication", 0);
188 #endif
189 
190 	alarm(0);
191 	fromp->sin_port = ntohs((u_short)fromp->sin_port);
192 	hp = gethostbyaddr(&fromp->sin_addr, sizeof (struct in_addr),
193 		fromp->sin_family);
194 	if (hp == 0) {
195 		/*
196 		 * Only the name is used below.
197 		 */
198 		hp = &hostent;
199 		hp->h_name = inet_ntoa(fromp->sin_addr);
200 		hostok++;
201 	} else if (check_all || local_domain(hp->h_name)) {
202 		/*
203 		 * If name returned by gethostbyaddr is in our domain,
204 		 * attempt to verify that we haven't been fooled by someone
205 		 * in a remote net; look up the name and check that this
206 		 * address corresponds to the name.
207 		 */
208 		strncpy(remotehost, hp->h_name, sizeof(remotehost) - 1);
209 		remotehost[sizeof(remotehost) - 1] = 0;
210 		hp = gethostbyname(remotehost);
211 		if (hp)
212 		    for (; hp->h_addr_list[0]; hp->h_addr_list++)
213 			if (!bcmp(hp->h_addr_list[0], (caddr_t)&fromp->sin_addr,
214 			    sizeof(fromp->sin_addr))) {
215 				hostok++;
216 				break;
217 			}
218 	} else
219 		hostok++;
220 
221 #ifdef	KERBEROS
222 	if (use_kerberos) {
223 		if (!hostok)
224 			fatal(f, "krlogind: Host address mismatch.", 0);
225 		retval = do_krb_login(hp->h_name, fromp, encrypt);
226 		if (retval == 0)
227 			authenticated++;
228 		else if (retval > 0)
229 			fatal(f, krb_err_txt[retval], 0);
230 		write(f, &c, 1);
231 		confirmed = 1;		/* we sent the null! */
232 	} else
233 #endif
234 	{
235 	    if (fromp->sin_family != AF_INET ||
236 	        fromp->sin_port >= IPPORT_RESERVED ||
237 	        fromp->sin_port < IPPORT_RESERVED/2) {
238 		    syslog(LOG_NOTICE, "Connection from %s on illegal port",
239 			    inet_ntoa(fromp->sin_addr));
240 		    fatal(f, "Permission denied", 0);
241 	    }
242 #ifdef IP_OPTIONS
243 	    {
244 	    u_char optbuf[BUFSIZ/3], *cp;
245 	    char lbuf[BUFSIZ], *lp;
246 	    int optsize = sizeof(optbuf), ipproto;
247 	    struct protoent *ip;
248 
249 	    if ((ip = getprotobyname("ip")) != NULL)
250 		    ipproto = ip->p_proto;
251 	    else
252 		    ipproto = IPPROTO_IP;
253 	    if (getsockopt(0, ipproto, IP_OPTIONS, (char *)optbuf,
254 		&optsize) == 0 && optsize != 0) {
255 		    lp = lbuf;
256 		    for (cp = optbuf; optsize > 0; cp++, optsize--, lp += 3)
257 			    sprintf(lp, " %2.2x", *cp);
258 		    syslog(LOG_NOTICE,
259 			"Connection received using IP options (ignored):%s",
260 			lbuf);
261 		    if (setsockopt(0, ipproto, IP_OPTIONS,
262 			(char *)NULL, &optsize) != 0) {
263 			    syslog(LOG_ERR, "setsockopt IP_OPTIONS NULL: %m");
264 			    exit(1);
265 		    }
266 	        }
267 	    }
268 #endif
269 	    if (do_rlogin(hp->h_name) == 0 && hostok)
270 		    authenticated++;
271 	}
272 
273 	for (c = 'p'; c <= 's'; c++) {
274 		struct stat stb;
275 		line = "/dev/ptyXX";
276 		line[strlen("/dev/pty")] = c;
277 		line[strlen("/dev/ptyp")] = '0';
278 		if (stat(line, &stb) < 0)
279 			break;
280 		for (i = 0; i < 16; i++) {
281 			line[sizeof("/dev/ptyp") - 1] = "0123456789abcdef"[i];
282 			p = open(line, O_RDWR);
283 			if (p > 0)
284 				goto gotpty;
285 		}
286 	}
287 	fatal(f, "Out of ptys", 0);
288 	/*NOTREACHED*/
289 gotpty:
290 	(void) ioctl(p, TIOCSWINSZ, &win);
291 	netf = f;
292 	line[sizeof(_PATH_DEV) - 1] = 't';
293 	t = open(line, O_RDWR);
294 	if (t < 0)
295 		fatal(f, line, 1);
296 	if (fchmod(t, 0))
297 		fatal(f, line, 1);
298 	(void)signal(SIGHUP, SIG_IGN);
299 	vhangup();
300 	(void)signal(SIGHUP, SIG_DFL);
301 	t = open(line, O_RDWR);
302 	if (t < 0)
303 		fatal(f, line, 1);
304 	setup_term(t);
305 	if (confirmed == 0) {
306 		write(f, "", 1);
307 		confirmed = 1;		/* we sent the null! */
308 	}
309 #ifdef	KERBEROS
310 	if (encrypt)
311 		(void) des_write(f, SECURE_MESSAGE, sizeof(SECURE_MESSAGE));
312 
313 	if (use_kerberos == 0)
314 #endif
315 	   if (!authenticated && !hostok)
316 		write(f, "rlogind: Host address mismatch.\r\n",
317 		    sizeof("rlogind: Host address mismatch.\r\n") - 1);
318 
319 	pid = fork();
320 	if (pid < 0)
321 		fatal(f, "", 1);
322 	if (pid == 0) {
323 		if (setsid() < 0)
324 			fatal(f, "setsid", 1);
325 		if (ioctl(t, TIOCSCTTY, 0) < 0)
326 			fatal(f, "ioctl(sctty)", 1);
327 		(void)close(f);
328 		(void)close(p);
329 		dup2(t, STDIN_FILENO);
330 		dup2(t, STDOUT_FILENO);
331 		dup2(t, STDERR_FILENO);
332 		(void)close(t);
333 
334 		if (authenticated)
335 			execl(_PATH_LOGIN, "login", "-p",
336 			    "-h", hp->h_name, "-f", lusername, 0);
337 		else
338 			execl(_PATH_LOGIN, "login", "-p",
339 			    "-h", hp->h_name, lusername, 0);
340 		fatal(STDERR_FILENO, _PATH_LOGIN, 1);
341 		/*NOTREACHED*/
342 	}
343 	close(t);
344 
345 #ifdef	KERBEROS
346 	/*
347 	 * If encrypted, don't turn on NBIO or the des read/write
348 	 * routines will croak.
349 	 */
350 
351 	if (!encrypt)
352 #endif
353 		ioctl(f, FIONBIO, &on);
354 	ioctl(p, FIONBIO, &on);
355 	ioctl(p, TIOCPKT, &on);
356 	signal(SIGCHLD, cleanup);
357 	protocol(f, p);
358 	signal(SIGCHLD, SIG_IGN);
359 	cleanup();
360 }
361 
362 char	magic[2] = { 0377, 0377 };
363 char	oobdata[] = {TIOCPKT_WINDOW};
364 
365 /*
366  * Handle a "control" request (signaled by magic being present)
367  * in the data stream.  For now, we are only willing to handle
368  * window size changes.
369  */
370 control(pty, cp, n)
371 	int pty;
372 	char *cp;
373 	int n;
374 {
375 	struct winsize w;
376 
377 	if (n < 4+sizeof (w) || cp[2] != 's' || cp[3] != 's')
378 		return (0);
379 	oobdata[0] &= ~TIOCPKT_WINDOW;	/* we know he heard */
380 	bcopy(cp+4, (char *)&w, sizeof(w));
381 	w.ws_row = ntohs(w.ws_row);
382 	w.ws_col = ntohs(w.ws_col);
383 	w.ws_xpixel = ntohs(w.ws_xpixel);
384 	w.ws_ypixel = ntohs(w.ws_ypixel);
385 	(void)ioctl(pty, TIOCSWINSZ, &w);
386 	return (4+sizeof (w));
387 }
388 
389 /*
390  * rlogin "protocol" machine.
391  */
392 protocol(f, p)
393 	register int f, p;
394 {
395 	char pibuf[1024+1], fibuf[1024], *pbp, *fbp;
396 	register pcc = 0, fcc = 0;
397 	int cc, nfd, n;
398 	char cntl;
399 
400 	/*
401 	 * Must ignore SIGTTOU, otherwise we'll stop
402 	 * when we try and set slave pty's window shape
403 	 * (our controlling tty is the master pty).
404 	 */
405 	(void) signal(SIGTTOU, SIG_IGN);
406 	send(f, oobdata, 1, MSG_OOB);	/* indicate new rlogin */
407 	if (f > p)
408 		nfd = f + 1;
409 	else
410 		nfd = p + 1;
411 	if (nfd > FD_SETSIZE) {
412 		syslog(LOG_ERR, "select mask too small, increase FD_SETSIZE");
413 		fatal(f, "internal error (select mask too small)", 0);
414 	}
415 	for (;;) {
416 		fd_set ibits, obits, ebits, *omask;
417 
418 		FD_ZERO(&ebits);
419 		FD_ZERO(&ibits);
420 		FD_ZERO(&obits);
421 		omask = (fd_set *)NULL;
422 		if (fcc) {
423 			FD_SET(p, &obits);
424 			omask = &obits;
425 		} else
426 			FD_SET(f, &ibits);
427 		if (pcc >= 0)
428 			if (pcc) {
429 				FD_SET(f, &obits);
430 				omask = &obits;
431 			} else
432 				FD_SET(p, &ibits);
433 		FD_SET(p, &ebits);
434 		if ((n = select(nfd, &ibits, omask, &ebits, 0)) < 0) {
435 			if (errno == EINTR)
436 				continue;
437 			fatal(f, "select", 1);
438 		}
439 		if (n == 0) {
440 			/* shouldn't happen... */
441 			sleep(5);
442 			continue;
443 		}
444 #define	pkcontrol(c)	((c)&(TIOCPKT_FLUSHWRITE|TIOCPKT_NOSTOP|TIOCPKT_DOSTOP))
445 		if (FD_ISSET(p, &ebits)) {
446 			cc = read(p, &cntl, 1);
447 			if (cc == 1 && pkcontrol(cntl)) {
448 				cntl |= oobdata[0];
449 				send(f, &cntl, 1, MSG_OOB);
450 				if (cntl & TIOCPKT_FLUSHWRITE) {
451 					pcc = 0;
452 					FD_CLR(p, &ibits);
453 				}
454 			}
455 		}
456 		if (FD_ISSET(f, &ibits)) {
457 #ifdef KERBEROS
458 			if (encrypt)
459 				fcc = des_read(f, fibuf, sizeof(fibuf));
460 			else
461 #endif
462 				fcc = read(f, fibuf, sizeof(fibuf));
463 			if (fcc < 0 && errno == EWOULDBLOCK)
464 				fcc = 0;
465 			else {
466 				register char *cp;
467 				int left, n;
468 
469 				if (fcc <= 0)
470 					break;
471 				fbp = fibuf;
472 
473 			top:
474 				for (cp = fibuf; cp < fibuf+fcc-1; cp++)
475 					if (cp[0] == magic[0] &&
476 					    cp[1] == magic[1]) {
477 						left = fcc - (cp-fibuf);
478 						n = control(p, cp, left);
479 						if (n) {
480 							left -= n;
481 							if (left > 0)
482 								bcopy(cp+n, cp, left);
483 							fcc -= n;
484 							goto top; /* n^2 */
485 						}
486 					}
487 				FD_SET(p, &obits);		/* try write */
488 			}
489 		}
490 
491 		if (FD_ISSET(p, &obits) && fcc > 0) {
492 			cc = write(p, fbp, fcc);
493 			if (cc > 0) {
494 				fcc -= cc;
495 				fbp += cc;
496 			}
497 		}
498 
499 		if (FD_ISSET(p, &ibits)) {
500 			pcc = read(p, pibuf, sizeof (pibuf));
501 			pbp = pibuf;
502 			if (pcc < 0 && errno == EWOULDBLOCK)
503 				pcc = 0;
504 			else if (pcc <= 0)
505 				break;
506 			else if (pibuf[0] == 0) {
507 				pbp++, pcc--;
508 #ifdef KERBEROS
509 				if (!encrypt)
510 #endif
511 					FD_SET(f, &obits);	/* try write */
512 			} else {
513 				if (pkcontrol(pibuf[0])) {
514 					pibuf[0] |= oobdata[0];
515 					send(f, &pibuf[0], 1, MSG_OOB);
516 				}
517 				pcc = 0;
518 			}
519 		}
520 		if ((FD_ISSET(f, &obits)) && pcc > 0) {
521 #ifdef KERBEROS
522 			if (encrypt)
523 				cc = des_write(f, pbp, pcc);
524 			else
525 #endif
526 				cc = write(f, pbp, pcc);
527 			if (cc < 0 && errno == EWOULDBLOCK) {
528 				/*
529 				 * This happens when we try write after read
530 				 * from p, but some old kernels balk at large
531 				 * writes even when select returns true.
532 				 */
533 				if (!FD_ISSET(p, &ibits))
534 					sleep(5);
535 				continue;
536 			}
537 			if (cc > 0) {
538 				pcc -= cc;
539 				pbp += cc;
540 			}
541 		}
542 	}
543 }
544 
545 cleanup()
546 {
547 	char *p;
548 
549 	p = line + sizeof(_PATH_DEV) - 1;
550 	if (logout(p))
551 		logwtmp(p, "", "");
552 	(void)chmod(line, 0666);
553 	(void)chown(line, 0, 0);
554 	*p = 'p';
555 	(void)chmod(line, 0666);
556 	(void)chown(line, 0, 0);
557 	shutdown(netf, 2);
558 	exit(1);
559 }
560 
561 fatal(f, msg, syserr)
562 	int f, syserr;
563 	char *msg;
564 {
565 	int len;
566 	char buf[BUFSIZ], *bp = buf;
567 
568 	/*
569 	 * Prepend binary one to message if we haven't sent
570 	 * the magic null as confirmation.
571 	 */
572 	if (!confirmed)
573 		*bp++ = '\01';		/* error indicator */
574 	if (syserr)
575 		len = sprintf(bp, "rlogind: %s: %s.\r\n",
576 		    msg, strerror(errno));
577 	else
578 		len = sprintf(bp, "rlogind: %s.\r\n", msg);
579 	(void) write(f, buf, bp + len - buf);
580 	exit(1);
581 }
582 
583 do_rlogin(host)
584 	char *host;
585 {
586 	getstr(rusername, sizeof(rusername), "remuser too long");
587 	getstr(lusername, sizeof(lusername), "locuser too long");
588 	getstr(term+ENVSIZE, sizeof(term)-ENVSIZE, "Terminal type too long");
589 
590 	pwd = getpwnam(lusername);
591 	if (pwd == NULL)
592 		return(-1);
593 	if (pwd->pw_uid == 0)
594 		return(-1);
595 	return(ruserok(host, 0, rusername, lusername));
596 }
597 
598 
599 getstr(buf, cnt, errmsg)
600 	char *buf;
601 	int cnt;
602 	char *errmsg;
603 {
604 	char c;
605 
606 	do {
607 		if (read(0, &c, 1) != 1)
608 			exit(1);
609 		if (--cnt < 0)
610 			fatal(STDOUT_FILENO, errmsg, 0);
611 		*buf++ = c;
612 	} while (c != 0);
613 }
614 
615 extern	char **environ;
616 
617 setup_term(fd)
618 	int fd;
619 {
620 	register char *cp = index(term+ENVSIZE, '/');
621 	char *speed;
622 	struct termios tt;
623 
624 #ifndef notyet
625 	tcgetattr(fd, &tt);
626 	if (cp) {
627 		*cp++ = '\0';
628 		speed = cp;
629 		cp = index(speed, '/');
630 		if (cp)
631 			*cp++ = '\0';
632 		cfsetspeed(&tt, atoi(speed));
633 	}
634 
635 	tt.c_iflag = TTYDEF_IFLAG;
636 	tt.c_oflag = TTYDEF_OFLAG;
637 	tt.c_lflag = TTYDEF_LFLAG;
638 	tcsetattr(fd, TCSADFLUSH, &tt);
639 #else
640 	if (cp) {
641 		*cp++ = '\0';
642 		speed = cp;
643 		cp = index(speed, '/');
644 		if (cp)
645 			*cp++ = '\0';
646 		tcgetattr(fd, &tt);
647 		cfsetspeed(&tt, atoi(speed));
648 		tcsetattr(fd, TCSADFLUSH, &tt);
649 	}
650 #endif
651 
652 	env[0] = term;
653 	env[1] = 0;
654 	environ = env;
655 }
656 
657 #ifdef	KERBEROS
658 #define	VERSION_SIZE	9
659 
660 /*
661  * Do the remote kerberos login to the named host with the
662  * given inet address
663  *
664  * Return 0 on valid authorization
665  * Return -1 on valid authentication, no authorization
666  * Return >0 for error conditions
667  */
668 do_krb_login(host, dest, encrypt)
669 	char *host;
670 	struct sockaddr_in *dest;
671 	int encrypt;
672 {
673 	int rc;
674 	char instance[INST_SZ], version[VERSION_SIZE];
675 	long authopts = 0L;	/* !mutual */
676 	struct sockaddr_in faddr;
677 
678 	kdata = (AUTH_DAT *) auth_buf;
679 	ticket = (KTEXT) tick_buf;
680 
681 	instance[0] = '*';
682 	instance[1] = '\0';
683 
684 	if (encrypt) {
685 		rc = sizeof(faddr);
686 		if (getsockname(0, &faddr, &rc))
687 			return(-1);
688 		authopts = KOPT_DO_MUTUAL;
689 		rc = krb_recvauth(
690 			authopts, 0,
691 			ticket, "rcmd",
692 			instance, dest, &faddr,
693 			kdata, "", schedule, version);
694 		 des_set_key(kdata->session, schedule);
695 
696 	} else {
697 		rc = krb_recvauth(
698 			authopts, 0,
699 			ticket, "rcmd",
700 			instance, dest, (struct sockaddr_in *) 0,
701 			kdata, "", (bit_64 *) 0, version);
702 	}
703 
704 	if (rc != KSUCCESS)
705 		return(rc);
706 
707 	getstr(lusername, sizeof(lusername), "locuser");
708 	/* get the "cmd" in the rcmd protocol */
709 	getstr(term+ENVSIZE, sizeof(term)-ENVSIZE, "Terminal type");
710 
711 	pwd = getpwnam(lusername);
712 	if (pwd == NULL)
713 		return(-1);
714 
715 	/* returns nonzero for no access */
716 	if (kuserok(kdata,lusername) != 0)
717 		return(-1);
718 
719 	return(0);
720 
721 }
722 #endif /* KERBEROS */
723 
724 usage()
725 {
726 #ifdef KERBEROS
727 	syslog(LOG_ERR, "usage: rlogind [-aln] [-k | -v]");
728 #else
729 	syslog(LOG_ERR, "usage: rlogind [-aln]");
730 #endif
731 }
732 
733 /*
734  * Check whether host h is in our local domain,
735  * defined as sharing the last two components of the domain part,
736  * or the entire domain part if the local domain has only one component.
737  * If either name is unqualified (contains no '.'),
738  * assume that the host is local, as it will be
739  * interpreted as such.
740  */
741 local_domain(h)
742 	char *h;
743 {
744 	char localhost[MAXHOSTNAMELEN];
745 	char *p1, *p2, *topdomain();
746 
747 	localhost[0] = 0;
748 	(void) gethostname(localhost, sizeof(localhost));
749 	p1 = topdomain(localhost);
750 	p2 = topdomain(h);
751 	if (p1 == NULL || p2 == NULL || !strcasecmp(p1, p2))
752 		return(1);
753 	return(0);
754 }
755 
756 char *
757 topdomain(h)
758 	char *h;
759 {
760 	register char *p;
761 	char *maybe = NULL;
762 	int dots = 0;
763 
764 	for (p = h + strlen(h); p >= h; p--) {
765 		if (*p == '.') {
766 			if (++dots == 2)
767 				return (p);
768 			maybe = p;
769 		}
770 	}
771 	return (maybe);
772 }
773