login.c revision 59198 
1/*-
2 * Copyright (c) 1980, 1987, 1988, 1991, 1993, 1994
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#if 0
35static char copyright[] =
36"@(#) Copyright (c) 1980, 1987, 1988, 1991, 1993, 1994\n\
37	The Regents of the University of California.  All rights reserved.\n";
38#endif
39
40#ifndef lint
41#if 0
42static char sccsid[] = "@(#)login.c	8.4 (Berkeley) 4/2/94";
43#endif
44static const char rcsid[] =
45  "$FreeBSD: head/usr.bin/login/login.c 59198 2000-04-13 09:39:29Z sheldonh $";
46#endif /* not lint */
47
48/*
49 * login [ name ]
50 * login -h hostname	(for telnetd, etc.)
51 * login -f name	(for pre-authenticated login: datakit, xterm, etc.)
52 */
53
54#include <sys/copyright.h>
55#include <sys/param.h>
56#include <sys/stat.h>
57#include <sys/socket.h>
58#include <sys/time.h>
59#include <sys/resource.h>
60#include <sys/file.h>
61#include <netinet/in.h>
62#include <arpa/inet.h>
63
64#include <err.h>
65#include <errno.h>
66#include <grp.h>
67#include <libutil.h>
68#include <login_cap.h>
69#include <netdb.h>
70#include <pwd.h>
71#include <setjmp.h>
72#include <signal.h>
73#include <stdio.h>
74#include <stdlib.h>
75#include <string.h>
76#include <syslog.h>
77#include <ttyent.h>
78#include <unistd.h>
79#include <utmp.h>
80
81#ifndef NO_PAM
82#include <security/pam_appl.h>
83#include <security/pam_misc.h>
84#endif
85
86#include "pathnames.h"
87
88/* wrapper for KAME-special getnameinfo() */
89#ifndef NI_WITHSCOPEID
90#define	NI_WITHSCOPEID	0
91#endif
92
93void	 badlogin __P((char *));
94void	 checknologin __P((void));
95void	 dolastlog __P((int));
96void	 getloginname __P((void));
97void	 motd __P((char *));
98int	 rootterm __P((char *));
99void	 sigint __P((int));
100void	 sleepexit __P((int));
101void	 refused __P((char *,char *,int));
102char	*stypeof __P((char *));
103void	 timedout __P((int));
104int	 login_access __P((char *, char *));
105void     login_fbtab __P((char *, uid_t, gid_t));
106
107#ifndef NO_PAM
108static int auth_pam __P((void));
109#endif
110static int auth_traditional __P((void));
111extern void login __P((struct utmp *));
112static void usage __P((void));
113
114#define	TTYGRPNAME	"tty"		/* name of group to own ttys */
115#define	DEFAULT_BACKOFF	3
116#define	DEFAULT_RETRIES	10
117
118/*
119 * This bounds the time given to login.  Not a define so it can
120 * be patched on machines where it's too small.
121 */
122u_int	timeout = 300;
123
124/* Buffer for signal handling of timeout */
125jmp_buf timeout_buf;
126
127struct	passwd *pwd;
128int	failures;
129char	*term, *envinit[1], *hostname, *username, *tty;
130char    full_hostname[MAXHOSTNAMELEN];
131
132int
133main(argc, argv)
134	int argc;
135	char *argv[];
136{
137	extern char **environ;
138	struct group *gr;
139	struct stat st;
140	struct timeval tp;
141	struct utmp utmp;
142	int rootok, retries, backoff;
143	int ask, ch, cnt, fflag, hflag, pflag, quietlog, rootlogin, rval;
144	int changepass;
145	time_t warntime;
146	uid_t uid, euid;
147	gid_t egid;
148	char *p, *ttyn;
149	char tbuf[MAXPATHLEN + 2];
150	char tname[sizeof(_PATH_TTY) + 10];
151	char *shell = NULL;
152	login_cap_t *lc = NULL;
153
154	(void)signal(SIGQUIT, SIG_IGN);
155	(void)signal(SIGINT, SIG_IGN);
156	if (setjmp(timeout_buf)) {
157		if (failures)
158			badlogin(tbuf);
159		(void)fprintf(stderr,
160			      "Login timed out after %d seconds\n", timeout);
161		exit(0);
162	}
163	(void)signal(SIGALRM, timedout);
164	(void)alarm(timeout);
165	(void)setpriority(PRIO_PROCESS, 0, 0);
166
167	openlog("login", LOG_ODELAY, LOG_AUTH);
168
169	/*
170	 * -p is used by getty to tell login not to destroy the environment
171	 * -f is used to skip a second login authentication
172	 * -h is used by other servers to pass the name of the remote
173	 *    host to login so that it may be placed in utmp and wtmp
174	 */
175	*full_hostname = '\0';
176	term = NULL;
177
178	fflag = hflag = pflag = 0;
179	uid = getuid();
180	euid = geteuid();
181	egid = getegid();
182	while ((ch = getopt(argc, argv, "fh:p")) != -1)
183		switch (ch) {
184		case 'f':
185			fflag = 1;
186			break;
187		case 'h':
188			if (uid)
189				errx(1, "-h option: %s", strerror(EPERM));
190			hflag = 1;
191			strncpy(full_hostname, optarg, sizeof(full_hostname)-1);
192
193			trimdomain(optarg, UT_HOSTSIZE);
194
195			if (strlen(optarg) > UT_HOSTSIZE) {
196				struct addrinfo hints, *res;
197				int ga_err;
198
199				memset(&hints, 0, sizeof(hints));
200				hints.ai_family = AF_UNSPEC;
201				ga_err = getaddrinfo(optarg, NULL, &hints,
202						    &res);
203				if (ga_err == 0) {
204					char hostbuf[MAXHOSTNAMELEN];
205
206					getnameinfo(res->ai_addr,
207						    res->ai_addrlen,
208						    hostbuf,
209						    sizeof(hostbuf), NULL, 0,
210						    NI_NUMERICHOST|
211						    NI_WITHSCOPEID);
212					optarg = strdup(hostbuf);
213				} else
214					optarg = "invalid hostname";
215				if (res != NULL)
216					freeaddrinfo(res);
217			}
218			hostname = optarg;
219			break;
220		case 'p':
221			pflag = 1;
222			break;
223		case '?':
224		default:
225			if (!uid)
226				syslog(LOG_ERR, "invalid flag %c", ch);
227			usage();
228		}
229	argc -= optind;
230	argv += optind;
231
232	if (*argv) {
233		username = *argv;
234		ask = 0;
235	} else
236		ask = 1;
237
238	for (cnt = getdtablesize(); cnt > 2; cnt--)
239		(void)close(cnt);
240
241	ttyn = ttyname(STDIN_FILENO);
242	if (ttyn == NULL || *ttyn == '\0') {
243		(void)snprintf(tname, sizeof(tname), "%s??", _PATH_TTY);
244		ttyn = tname;
245	}
246	if ((tty = strrchr(ttyn, '/')) != NULL)
247		++tty;
248	else
249		tty = ttyn;
250
251	/*
252	 * Get "login-retries" & "login-backoff" from default class
253	 */
254	lc = login_getclass(NULL);
255	retries = login_getcapnum(lc, "login-retries", DEFAULT_RETRIES, DEFAULT_RETRIES);
256	backoff = login_getcapnum(lc, "login-backoff", DEFAULT_BACKOFF, DEFAULT_BACKOFF);
257	login_close(lc);
258	lc = NULL;
259
260	for (cnt = 0;; ask = 1) {
261		if (ask) {
262			fflag = 0;
263			getloginname();
264		}
265		rootlogin = 0;
266		rootok = rootterm(tty); /* Default (auth may change) */
267
268		if (strlen(username) > UT_NAMESIZE)
269			username[UT_NAMESIZE] = '\0';
270
271		/*
272		 * Note if trying multiple user names; log failures for
273		 * previous user name, but don't bother logging one failure
274		 * for nonexistent name (mistyped username).
275		 */
276		if (failures && strcmp(tbuf, username)) {
277			if (failures > (pwd ? 0 : 1))
278				badlogin(tbuf);
279		}
280		(void)strncpy(tbuf, username, sizeof tbuf-1);
281		tbuf[sizeof tbuf-1] = '\0';
282
283		pwd = getpwnam(username);
284
285		/*
286		 * if we have a valid account name, and it doesn't have a
287		 * password, or the -f option was specified and the caller
288		 * is root or the caller isn't changing their uid, don't
289		 * authenticate.
290		 */
291		if (pwd != NULL) {
292			if (pwd->pw_uid == 0)
293				rootlogin = 1;
294
295			if (fflag && (uid == (uid_t)0 ||
296				      uid == (uid_t)pwd->pw_uid)) {
297				/* already authenticated */
298				break;
299			} else if (pwd->pw_passwd[0] == '\0') {
300				if (!rootlogin || rootok) {
301					/* pretend password okay */
302					rval = 0;
303					goto ttycheck;
304				}
305			}
306		}
307
308		fflag = 0;
309
310		(void)setpriority(PRIO_PROCESS, 0, -4);
311
312#ifndef NO_PAM
313		/*
314		 * Try to authenticate using PAM.  If a PAM system error
315		 * occurs, perhaps because of a botched configuration,
316		 * then fall back to using traditional Unix authentication.
317		 */
318		if ((rval = auth_pam()) == -1)
319#endif /* NO_PAM */
320			rval = auth_traditional();
321
322		(void)setpriority(PRIO_PROCESS, 0, 0);
323
324#ifndef NO_PAM
325		/*
326		 * PAM authentication may have changed "pwd" to the
327		 * entry for the template user.  Check again to see if
328		 * this is a root login after all.
329		 */
330		if (pwd != NULL && pwd->pw_uid == 0)
331			rootlogin = 1;
332#endif /* NO_PAM */
333
334	ttycheck:
335		/*
336		 * If trying to log in as root without Kerberos,
337		 * but with insecure terminal, refuse the login attempt.
338		 */
339		if (pwd && !rval) {
340			if (rootlogin && !rootok)
341				refused(NULL, "NOROOT", 0);
342			else	/* valid password & authenticated */
343				break;
344		}
345
346		(void)printf("Login incorrect\n");
347		failures++;
348
349		/*
350		 * we allow up to 'retry' (10) tries,
351		 * but after 'backoff' (3) we start backing off
352		 */
353		if (++cnt > backoff) {
354			if (cnt >= retries) {
355				badlogin(username);
356				sleepexit(1);
357			}
358			sleep((u_int)((cnt - backoff) * 5));
359		}
360	}
361
362	/* committed to login -- turn off timeout */
363	(void)alarm((u_int)0);
364
365	endpwent();
366
367	/*
368	 * Establish the login class.
369	 */
370	lc = login_getpwclass(pwd);
371
372	/* if user not super-user, check for disabled logins */
373	if (!rootlogin)
374		auth_checknologin(lc);
375
376	quietlog = login_getcapbool(lc, "hushlogin", 0);
377	/* Switching needed for NFS with root access disabled */
378	(void)setegid(pwd->pw_gid);
379	(void)seteuid(rootlogin ? 0 : pwd->pw_uid);
380	if (!*pwd->pw_dir || chdir(pwd->pw_dir) < 0) {
381		if (login_getcapbool(lc, "requirehome", 0))
382			refused("Home directory not available", "HOMEDIR", 1);
383		if (chdir("/") < 0)
384			refused("Cannot find root directory", "ROOTDIR", 1);
385		if (!quietlog || *pwd->pw_dir)
386			printf("No home directory.\nLogging in with home = \"/\".\n");
387		pwd->pw_dir = "/";
388	}
389	(void)seteuid(euid);
390	(void)setegid(egid);
391	if (!quietlog)
392		quietlog = access(_PATH_HUSHLOGIN, F_OK) == 0;
393
394	if (pwd->pw_change || pwd->pw_expire)
395		(void)gettimeofday(&tp, (struct timezone *)NULL);
396
397#define DEFAULT_WARN  (2L * 7L * 86400L)  /* Two weeks */
398
399	warntime = login_getcaptime(lc, "warnpassword",
400				    DEFAULT_WARN, DEFAULT_WARN);
401
402	changepass=0;
403	if (pwd->pw_change) {
404		if (tp.tv_sec >= pwd->pw_change) {
405			(void)printf("Sorry -- your password has expired.\n");
406			changepass=1;
407			syslog(LOG_INFO,
408			       "%s Password expired - forcing change",
409			       pwd->pw_name);
410		} else if (pwd->pw_change - tp.tv_sec < warntime && !quietlog)
411		    (void)printf("Warning: your password expires on %s",
412				 ctime(&pwd->pw_change));
413	}
414
415	warntime = login_getcaptime(lc, "warnexpire",
416				    DEFAULT_WARN, DEFAULT_WARN);
417
418	if (pwd->pw_expire) {
419		if (tp.tv_sec >= pwd->pw_expire) {
420			refused("Sorry -- your account has expired",
421				"EXPIRED", 1);
422		} else if (pwd->pw_expire - tp.tv_sec < warntime && !quietlog)
423		    (void)printf("Warning: your account expires on %s",
424				 ctime(&pwd->pw_expire));
425	}
426
427	if (lc != NULL) {
428		if (hostname) {
429			struct addrinfo hints, *res;
430			int ga_err;
431
432			memset(&hints, 0, sizeof(hints));
433			hints.ai_family = AF_UNSPEC;
434			ga_err = getaddrinfo(full_hostname, NULL, &hints,
435					     &res);
436			if (ga_err == 0) {
437				char hostbuf[MAXHOSTNAMELEN];
438
439				getnameinfo(res->ai_addr, res->ai_addrlen,
440					    hostbuf, sizeof(hostbuf), NULL, 0,
441					    NI_NUMERICHOST|NI_WITHSCOPEID);
442				optarg = strdup(hostbuf);
443			} else
444				optarg = NULL;
445			if (res != NULL)
446				freeaddrinfo(res);
447			if (!auth_hostok(lc, full_hostname, optarg))
448				refused("Permission denied", "HOST", 1);
449		}
450
451		if (!auth_ttyok(lc, tty))
452			refused("Permission denied", "TTY", 1);
453
454		if (!auth_timeok(lc, time(NULL)))
455			refused("Logins not available right now", "TIME", 1);
456	}
457        shell=login_getcapstr(lc, "shell", pwd->pw_shell, pwd->pw_shell);
458	if (*pwd->pw_shell == '\0')
459		pwd->pw_shell = _PATH_BSHELL;
460	if (*shell == '\0')   /* Not overridden */
461		shell = pwd->pw_shell;
462	if ((shell = strdup(shell)) == NULL) {
463		syslog(LOG_NOTICE, "memory allocation error");
464		sleepexit(1);
465	}
466
467#ifdef LOGIN_ACCESS
468	if (login_access(pwd->pw_name, hostname ? full_hostname : tty) == 0)
469		refused("Permission denied", "ACCESS", 1);
470#endif /* LOGIN_ACCESS */
471
472	/* Nothing else left to fail -- really log in. */
473	memset((void *)&utmp, 0, sizeof(utmp));
474	(void)time(&utmp.ut_time);
475	(void)strncpy(utmp.ut_name, username, sizeof(utmp.ut_name));
476	if (hostname)
477		(void)strncpy(utmp.ut_host, hostname, sizeof(utmp.ut_host));
478	(void)strncpy(utmp.ut_line, tty, sizeof(utmp.ut_line));
479	login(&utmp);
480
481	dolastlog(quietlog);
482
483	/*
484	 * Set device protections, depending on what terminal the
485	 * user is logged in. This feature is used on Suns to give
486	 * console users better privacy.
487	 */
488	login_fbtab(tty, pwd->pw_uid, pwd->pw_gid);
489
490	/*
491	 * Clear flags of the tty.  None should be set, and when the
492	 * user sets them otherwise, this can cause the chown to fail.
493	 * Since it isn't clear that flags are useful on character
494	 * devices, we just clear them.
495	 */
496	if (chflags(ttyn, 0) && (errno != EOPNOTSUPP))
497		syslog(LOG_ERR, "chmod(%s): %m", ttyn);
498	if (chown(ttyn, pwd->pw_uid,
499	    (gr = getgrnam(TTYGRPNAME)) ? gr->gr_gid : pwd->pw_gid))
500		syslog(LOG_ERR, "chmod(%s): %m", ttyn);
501
502
503	/*
504	 * Preserve TERM if it happens to be already set.
505	 */
506	if ((term = getenv("TERM")) != NULL)
507		term = strdup(term);
508
509	/*
510	 * Exclude cons/vt/ptys only, assume dialup otherwise
511	 * TODO: Make dialup tty determination a library call
512	 * for consistency (finger etc.)
513	 */
514	if (hostname==NULL && isdialuptty(tty))
515		syslog(LOG_INFO, "DIALUP %s, %s", tty, pwd->pw_name);
516
517#ifdef LOGALL
518	/*
519	 * Syslog each successful login, so we don't have to watch hundreds
520	 * of wtmp or lastlogin files.
521	 */
522	if (hostname)
523		syslog(LOG_INFO, "login from %s on %s as %s",
524		       full_hostname, tty, pwd->pw_name);
525	else
526		syslog(LOG_INFO, "login on %s as %s",
527		       tty, pwd->pw_name);
528#endif
529
530	/*
531	 * If fflag is on, assume caller/authenticator has logged root login.
532	 */
533	if (rootlogin && fflag == 0)
534	{
535		if (hostname)
536			syslog(LOG_NOTICE, "ROOT LOGIN (%s) ON %s FROM %s",
537			       username, tty, full_hostname);
538		else
539			syslog(LOG_NOTICE, "ROOT LOGIN (%s) ON %s",
540			       username, tty);
541	}
542
543	/*
544	 * Destroy environment unless user has requested its preservation.
545	 * We need to do this before setusercontext() because that may
546	 * set or reset some environment variables.
547	 */
548	if (!pflag)
549		environ = envinit;
550
551	/*
552	 * We don't need to be root anymore, so
553	 * set the user and session context
554	 */
555	if (setlogin(username) != 0) {
556                syslog(LOG_ERR, "setlogin(%s): %m - exiting", username);
557		exit(1);
558	}
559	if (setusercontext(lc, pwd, pwd->pw_uid,
560	    LOGIN_SETALL & ~LOGIN_SETLOGIN) != 0) {
561                syslog(LOG_ERR, "setusercontext() failed - exiting");
562		exit(1);
563	}
564
565	(void)setenv("SHELL", pwd->pw_shell, 1);
566	(void)setenv("HOME", pwd->pw_dir, 1);
567	if (term != NULL && *term != '\0')
568		(void)setenv("TERM", term, 1);	/* Preset overrides */
569	else {
570		(void)setenv("TERM", stypeof(tty), 0);	/* Fallback doesn't */
571	}
572	(void)setenv("LOGNAME", username, 1);
573	(void)setenv("USER", username, 1);
574	(void)setenv("PATH", rootlogin ? _PATH_STDPATH : _PATH_DEFPATH, 0);
575
576	if (!quietlog) {
577		char	*cw;
578
579		cw = login_getcapstr(lc, "copyright", NULL, NULL);
580		if (cw != NULL && access(cw, F_OK) == 0)
581			motd(cw);
582		else
583		    (void)printf("%s\n\t%s %s\n",
584	"Copyright (c) 1980, 1983, 1986, 1988, 1990, 1991, 1993, 1994",
585	"The Regents of the University of California. ",
586	"All rights reserved.");
587
588		(void)printf("\n");
589
590		cw = login_getcapstr(lc, "welcome", NULL, NULL);
591		if (cw == NULL || access(cw, F_OK) != 0)
592			cw = _PATH_MOTDFILE;
593		motd(cw);
594
595		cw = getenv("MAIL");	/* $MAIL may have been set by class */
596		if (cw != NULL) {
597			strncpy(tbuf, cw, sizeof(tbuf));
598			tbuf[sizeof(tbuf)-1] = '\0';
599		} else
600			snprintf(tbuf, sizeof(tbuf), "%s/%s",
601				 _PATH_MAILDIR, pwd->pw_name);
602		if (stat(tbuf, &st) == 0 && st.st_size != 0)
603			(void)printf("You have %smail.\n",
604				     (st.st_mtime > st.st_atime) ? "new " : "");
605	}
606
607	login_close(lc);
608
609	(void)signal(SIGALRM, SIG_DFL);
610	(void)signal(SIGQUIT, SIG_DFL);
611	(void)signal(SIGINT, SIG_DFL);
612	(void)signal(SIGTSTP, SIG_IGN);
613
614	if (changepass) {
615		if (system(_PATH_CHPASS) != 0)
616			sleepexit(1);
617	}
618
619	/*
620	 * Login shells have a leading '-' in front of argv[0]
621	 */
622	tbuf[0] = '-';
623	(void)strcpy(tbuf + 1, (p = strrchr(pwd->pw_shell, '/')) ? p + 1 : pwd->pw_shell);
624
625	execlp(shell, tbuf, 0);
626	err(1, "%s", shell);
627}
628
629static int
630auth_traditional()
631{
632	int rval;
633	char *p;
634	char *ep;
635	char *salt;
636
637	rval = 1;
638	salt = pwd != NULL ? pwd->pw_passwd : "xx";
639
640	p = getpass("Password:");
641	ep = crypt(p, salt);
642
643	if (pwd) {
644		if (!p[0] && pwd->pw_passwd[0])
645			ep = ":";
646		if (strcmp(ep, pwd->pw_passwd) == 0)
647			rval = 0;
648	}
649
650	/* clear entered password */
651	memset(p, 0, strlen(p));
652	return rval;
653}
654
655#ifndef NO_PAM
656/*
657 * Attempt to authenticate the user using PAM.  Returns 0 if the user is
658 * authenticated, or 1 if not authenticated.  If some sort of PAM system
659 * error occurs (e.g., the "/etc/pam.conf" file is missing) then this
660 * function returns -1.  This can be used as an indication that we should
661 * fall back to a different authentication mechanism.
662 */
663static int
664auth_pam()
665{
666	pam_handle_t *pamh = NULL;
667	const char *tmpl_user;
668	const void *item;
669	int rval;
670	int e;
671	static struct pam_conv conv = { misc_conv, NULL };
672
673	if ((e = pam_start("login", username, &conv, &pamh)) != PAM_SUCCESS) {
674		syslog(LOG_ERR, "pam_start: %s", pam_strerror(pamh, e));
675		return -1;
676	}
677	if ((e = pam_set_item(pamh, PAM_TTY, tty)) != PAM_SUCCESS) {
678		syslog(LOG_ERR, "pam_set_item(PAM_TTY): %s",
679		    pam_strerror(pamh, e));
680		return -1;
681	}
682	if (hostname != NULL &&
683	    (e = pam_set_item(pamh, PAM_RHOST, full_hostname)) != PAM_SUCCESS) {
684		syslog(LOG_ERR, "pam_set_item(PAM_RHOST): %s",
685		    pam_strerror(pamh, e));
686		return -1;
687	}
688	e = pam_authenticate(pamh, 0);
689	switch (e) {
690
691	case PAM_SUCCESS:
692		/*
693		 * With PAM we support the concept of a "template"
694		 * user.  The user enters a login name which is
695		 * authenticated by PAM, usually via a remote service
696		 * such as RADIUS or TACACS+.  If authentication
697		 * succeeds, a different but related "template" name
698		 * is used for setting the credentials, shell, and
699		 * home directory.  The name the user enters need only
700		 * exist on the remote authentication server, but the
701		 * template name must be present in the local password
702		 * database.
703		 *
704		 * This is supported by two various mechanisms in the
705		 * individual modules.  However, from the application's
706		 * point of view, the template user is always passed
707		 * back as a changed value of the PAM_USER item.
708		 */
709		if ((e = pam_get_item(pamh, PAM_USER, &item)) ==
710		    PAM_SUCCESS) {
711			tmpl_user = (const char *) item;
712			if (strcmp(username, tmpl_user) != 0)
713				pwd = getpwnam(tmpl_user);
714		} else
715			syslog(LOG_ERR, "Couldn't get PAM_USER: %s",
716			    pam_strerror(pamh, e));
717		rval = 0;
718		break;
719
720	case PAM_AUTH_ERR:
721	case PAM_USER_UNKNOWN:
722	case PAM_MAXTRIES:
723		rval = 1;
724		break;
725
726	default:
727		syslog(LOG_ERR, "auth_pam: %s", pam_strerror(pamh, e));
728		rval = -1;
729		break;
730	}
731	if ((e = pam_end(pamh, e)) != PAM_SUCCESS) {
732		syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e));
733		rval = -1;
734	}
735	return rval;
736}
737#endif /* NO_PAM */
738
739static void
740usage()
741{
742	(void)fprintf(stderr, "usage: login [-fp] [-h hostname] [username]\n");
743	exit(1);
744}
745
746/*
747 * Allow for authentication style and/or kerberos instance
748 * */
749
750#define	NBUFSIZ		UT_NAMESIZE + 64
751
752void
753getloginname()
754{
755	int ch;
756	char *p;
757	static char nbuf[NBUFSIZ];
758
759	for (;;) {
760		(void)printf("login: ");
761		for (p = nbuf; (ch = getchar()) != '\n'; ) {
762			if (ch == EOF) {
763				badlogin(username);
764				exit(0);
765			}
766			if (p < nbuf + (NBUFSIZ - 1))
767				*p++ = ch;
768		}
769		if (p > nbuf)
770			if (nbuf[0] == '-')
771				(void)fprintf(stderr,
772				    "login names may not start with '-'.\n");
773			else {
774				*p = '\0';
775				username = nbuf;
776				break;
777			}
778	}
779}
780
781int
782rootterm(ttyn)
783	char *ttyn;
784{
785	struct ttyent *t;
786
787	return ((t = getttynam(ttyn)) && t->ty_status & TTY_SECURE);
788}
789
790volatile int motdinterrupt;
791
792/* ARGSUSED */
793void
794sigint(signo)
795	int signo;
796{
797	motdinterrupt = 1;
798}
799
800void
801motd(motdfile)
802	char *motdfile;
803{
804	int fd, nchars;
805	sig_t oldint;
806	char tbuf[256];
807
808	if ((fd = open(motdfile, O_RDONLY, 0)) < 0)
809		return;
810	motdinterrupt = 0;
811	oldint = signal(SIGINT, sigint);
812	while ((nchars = read(fd, tbuf, sizeof(tbuf))) > 0 && !motdinterrupt)
813		(void)write(fileno(stdout), tbuf, nchars);
814	(void)signal(SIGINT, oldint);
815	(void)close(fd);
816}
817
818/* ARGSUSED */
819void
820timedout(signo)
821	int signo;
822{
823	longjmp(timeout_buf, signo);
824}
825
826
827void
828dolastlog(quiet)
829	int quiet;
830{
831	struct lastlog ll;
832	int fd;
833
834	if ((fd = open(_PATH_LASTLOG, O_RDWR, 0)) >= 0) {
835		(void)lseek(fd, (off_t)pwd->pw_uid * sizeof(ll), L_SET);
836		if (!quiet) {
837			if (read(fd, (char *)&ll, sizeof(ll)) == sizeof(ll) &&
838			    ll.ll_time != 0) {
839				(void)printf("Last login: %.*s ",
840				    24-5, (char *)ctime(&ll.ll_time));
841				if (*ll.ll_host != '\0')
842					(void)printf("from %.*s\n",
843					    (int)sizeof(ll.ll_host),
844					    ll.ll_host);
845				else
846					(void)printf("on %.*s\n",
847					    (int)sizeof(ll.ll_line),
848					    ll.ll_line);
849			}
850			(void)lseek(fd, (off_t)pwd->pw_uid * sizeof(ll), L_SET);
851		}
852		memset((void *)&ll, 0, sizeof(ll));
853		(void)time(&ll.ll_time);
854		(void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line));
855		if (hostname)
856			(void)strncpy(ll.ll_host, hostname, sizeof(ll.ll_host));
857		(void)write(fd, (char *)&ll, sizeof(ll));
858		(void)close(fd);
859	}
860}
861
862void
863badlogin(name)
864	char *name;
865{
866
867	if (failures == 0)
868		return;
869	if (hostname) {
870		syslog(LOG_NOTICE, "%d LOGIN FAILURE%s FROM %s",
871		    failures, failures > 1 ? "S" : "", full_hostname);
872		syslog(LOG_AUTHPRIV|LOG_NOTICE,
873		    "%d LOGIN FAILURE%s FROM %s, %s",
874		    failures, failures > 1 ? "S" : "", full_hostname, name);
875	} else {
876		syslog(LOG_NOTICE, "%d LOGIN FAILURE%s ON %s",
877		    failures, failures > 1 ? "S" : "", tty);
878		syslog(LOG_AUTHPRIV|LOG_NOTICE,
879		    "%d LOGIN FAILURE%s ON %s, %s",
880		    failures, failures > 1 ? "S" : "", tty, name);
881	}
882	failures = 0;
883}
884
885#undef	UNKNOWN
886#define	UNKNOWN	"su"
887
888char *
889stypeof(ttyid)
890	char *ttyid;
891{
892
893	struct ttyent *t;
894
895	return (ttyid && (t = getttynam(ttyid)) ? t->ty_type : UNKNOWN);
896}
897
898void
899refused(msg, rtype, lout)
900	char *msg;
901	char *rtype;
902	int lout;
903{
904
905	if (msg != NULL)
906	    printf("%s.\n", msg);
907	if (hostname)
908		syslog(LOG_NOTICE, "LOGIN %s REFUSED (%s) FROM %s ON TTY %s",
909		       pwd->pw_name, rtype, full_hostname, tty);
910	else
911		syslog(LOG_NOTICE, "LOGIN %s REFUSED (%s) ON TTY %s",
912		       pwd->pw_name, rtype, tty);
913	if (lout)
914		sleepexit(1);
915}
916
917void
918sleepexit(eval)
919	int eval;
920{
921
922	(void)sleep(5);
923	exit(eval);
924}
925