login.c revision 33332 
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	"$Id: login.c,v 1.31 1998/02/05 18:37:02 guido Exp $";
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/time.h>
58#include <sys/resource.h>
59#include <sys/file.h>
60#include <netinet/in.h>
61#include <arpa/inet.h>
62
63#include <err.h>
64#include <errno.h>
65#include <grp.h>
66#include <netdb.h>
67#include <pwd.h>
68#include <setjmp.h>
69#include <signal.h>
70#include <stdio.h>
71#include <stdlib.h>
72#include <string.h>
73#include <syslog.h>
74#include <ttyent.h>
75#include <unistd.h>
76#include <utmp.h>
77
78#ifdef LOGIN_CAP
79#include <login_cap.h>
80#else /* Undef AUTH as well */
81#undef LOGIN_CAP_AUTH
82#endif
83
84/*
85 * If LOGIN_CAP_AUTH is activated:
86 * kerberose & skey logins are runtime selected via login
87 * login_getstyle() and authentication types for login classes
88 * The actual login itself is handled via /usr/libexec/login_<style>
89 * Valid styles are determined by the auth-type=style,style entries
90 * in the login class.
91 */
92#ifdef LOGIN_CAP_AUTH
93#undef KERBEROS
94#undef SKEY
95#endif /* LOGIN_CAP_AUTH */
96
97#ifdef	SKEY
98#include <skey.h>
99#endif /* SKEY */
100
101#include "pathnames.h"
102
103void	 badlogin __P((char *));
104void	 checknologin __P((void));
105void	 dolastlog __P((int));
106void	 getloginname __P((void));
107void	 motd __P((char *));
108int	 rootterm __P((char *));
109void	 sigint __P((int));
110void	 sleepexit __P((int));
111void	 refused __P((char *,char *,int));
112char	*stypeof __P((char *));
113void	 timedout __P((int));
114int	 login_access __P((char *, char *));
115void     login_fbtab __P((char *, uid_t, gid_t));
116#ifdef KERBEROS
117int	 klogin __P((struct passwd *, char *, char *, char *));
118#endif
119
120extern void login __P((struct utmp *));
121static void usage __P((void));
122
123#define	TTYGRPNAME	"tty"		/* name of group to own ttys */
124#define	DEFAULT_BACKOFF	3
125#define	DEFAULT_RETRIES	10
126
127/*
128 * This bounds the time given to login.  Not a define so it can
129 * be patched on machines where it's too small.
130 */
131u_int	timeout = 300;
132
133#ifdef KERBEROS
134int	notickets = 1;
135int	noticketsdontcomplain = 1;
136char	*instance;
137char	*krbtkfile_env;
138int	authok;
139#endif
140
141struct	passwd *pwd;
142int	failures;
143char	*term, *envinit[1], *hostname, *username, *tty;
144char    full_hostname[MAXHOSTNAMELEN];
145
146int
147main(argc, argv)
148	int argc;
149	char *argv[];
150{
151	extern char **environ;
152	struct group *gr;
153	struct stat st;
154	struct timeval tp;
155	struct utmp utmp;
156	int rootok, retries, backoff;
157	int ask, ch, cnt, fflag, hflag, pflag, quietlog, rootlogin, rval;
158	int changepass;
159	time_t warntime;
160	uid_t uid;
161	char *domain, *p, *ep, *salt, *ttyn;
162	char tbuf[MAXPATHLEN + 2], tname[sizeof(_PATH_TTY) + 10];
163	char localhost[MAXHOSTNAMELEN];
164	char *shell = NULL;
165#ifdef LOGIN_CAP
166	login_cap_t *lc = NULL;
167#ifdef LOGIN_CAP_AUTH
168	char *style, *authtype;
169	char *auth_method = NULL;
170	char *instance = NULL;
171	int authok;
172#endif /* LOGIN_CAP_AUTH */
173#endif /* LOGIN_CAP */
174#ifdef SKEY
175	int permit_passwd = 0;
176#endif /* SKEY */
177
178	(void)signal(SIGALRM, timedout);
179	(void)alarm(timeout);
180	(void)signal(SIGQUIT, SIG_IGN);
181	(void)signal(SIGINT, SIG_IGN);
182	(void)setpriority(PRIO_PROCESS, 0, 0);
183
184	openlog("login", LOG_ODELAY, LOG_AUTH);
185
186	/*
187	 * -p is used by getty to tell login not to destroy the environment
188	 * -f is used to skip a second login authentication
189	 * -h is used by other servers to pass the name of the remote
190	 *    host to login so that it may be placed in utmp and wtmp
191	 */
192	*full_hostname = '\0';
193	domain = NULL;
194	term = NULL;
195	if (gethostname(localhost, sizeof(localhost)) < 0)
196		syslog(LOG_ERR, "couldn't get local hostname: %m");
197	else
198		domain = strchr(localhost, '.');
199
200	fflag = hflag = pflag = 0;
201	uid = getuid();
202	while ((ch = getopt(argc, argv, "fh:p")) != -1)
203		switch (ch) {
204		case 'f':
205			fflag = 1;
206			break;
207		case 'h':
208			if (uid)
209				errx(1, "-h option: %s", strerror(EPERM));
210			hflag = 1;
211			strncpy(full_hostname, optarg, sizeof(full_hostname)-1);
212			if (domain && (p = strchr(optarg, '.')) &&
213			    strcasecmp(p, domain) == 0)
214				*p = 0;
215			if (strlen(optarg) > UT_HOSTSIZE) {
216				struct hostent *hp = gethostbyname(optarg);
217
218				if (hp != NULL) {
219					struct in_addr in;
220
221					memmove(&in, hp->h_addr, sizeof(in));
222					optarg = strdup(inet_ntoa(in));
223				} else
224					optarg = "invalid hostname";
225			}
226			hostname = optarg;
227			break;
228		case 'p':
229			pflag = 1;
230			break;
231		case '?':
232		default:
233			if (!uid)
234				syslog(LOG_ERR, "invalid flag %c", ch);
235			usage();
236		}
237	argc -= optind;
238	argv += optind;
239
240	if (*argv) {
241		username = *argv;
242		ask = 0;
243	} else
244		ask = 1;
245
246	for (cnt = getdtablesize(); cnt > 2; cnt--)
247		(void)close(cnt);
248
249	ttyn = ttyname(STDIN_FILENO);
250	if (ttyn == NULL || *ttyn == '\0') {
251		(void)snprintf(tname, sizeof(tname), "%s??", _PATH_TTY);
252		ttyn = tname;
253	}
254	if ((tty = strrchr(ttyn, '/')) != NULL)
255		++tty;
256	else
257		tty = ttyn;
258
259#ifdef LOGIN_CAP_AUTH
260	authtype = hostname ? "rlogin" : "login";
261#endif
262#ifdef LOGIN_CAP
263	/*
264	 * Get "login-retries" & "login-backoff" from default class
265	 */
266	lc = login_getclass(NULL);
267	retries = login_getcapnum(lc, "login-retries", DEFAULT_RETRIES, DEFAULT_RETRIES);
268	backoff = login_getcapnum(lc, "login-backoff", DEFAULT_BACKOFF, DEFAULT_BACKOFF);
269	login_close(lc);
270	lc = NULL;
271#else
272	retries = DEFAULT_RETRIES;
273	backoff = DEFAULT_BACKOFF;
274#endif
275
276	for (cnt = 0;; ask = 1) {
277		if (ask) {
278			fflag = 0;
279			getloginname();
280		}
281		rootlogin = 0;
282		rootok = rootterm(tty); /* Default (auth may change) */
283#ifdef LOGIN_CAP_AUTH
284		authok = 0;
285		if (auth_method = strchr(username, ':')) {
286			*auth_method = '\0';
287			auth_method++;
288			if (*auth_method == '\0')
289				auth_method = NULL;
290		}
291		/*
292		 * We need to do this regardless of whether
293		 * kerberos is available.
294		 */
295		if ((instance = strchr(username, '.')) != NULL) {
296			if (strncmp(instance, ".root", 5) == 0)
297				rootlogin = 1;
298			*instance++ = '\0';
299		} else
300			instance = "";
301#else /* !LOGIN_CAP_AUTH */
302#ifdef KERBEROS
303		if ((instance = strchr(username, '.')) != NULL) {
304			if (strncmp(instance, ".root", 5) == 0)
305				rootlogin = 1;
306			*instance++ = '\0';
307		} else
308			instance = "";
309#endif /* KERBEROS */
310#endif /* LOGIN_CAP_AUTH */
311
312		if (strlen(username) > UT_NAMESIZE)
313			username[UT_NAMESIZE] = '\0';
314
315		/*
316		 * Note if trying multiple user names; log failures for
317		 * previous user name, but don't bother logging one failure
318		 * for nonexistent name (mistyped username).
319		 */
320		if (failures && strcmp(tbuf, username)) {
321			if (failures > (pwd ? 0 : 1))
322				badlogin(tbuf);
323			failures = 0;
324		}
325		(void)strncpy(tbuf, username, sizeof tbuf-1);
326		tbuf[sizeof tbuf-1] = '\0';
327
328		if ((pwd = getpwnam(username)) != NULL)
329			salt = pwd->pw_passwd;
330		else
331			salt = "xx";
332
333#ifdef LOGIN_CAP
334		/*
335		 * Establish the class now, before we might goto
336		 * within the next block. pwd can be NULL since it
337		 * falls back to the "default" class if it is.
338		 */
339		lc = login_getpwclass(pwd);
340#endif /* LOGIN_CAP */
341
342		/*
343		 * if we have a valid account name, and it doesn't have a
344		 * password, or the -f option was specified and the caller
345		 * is root or the caller isn't changing their uid, don't
346		 * authenticate.
347		 */
348		rval = 1;
349		if (pwd != NULL) {
350			if (pwd->pw_uid == 0)
351				rootlogin = 1;
352
353			if (fflag && (uid == (uid_t)0 ||
354				      uid == (uid_t)pwd->pw_uid)) {
355				/* already authenticated */
356				break;
357			} else if (pwd->pw_passwd[0] == '\0') {
358				if (!rootlogin || rootok) {
359					/* pretend password okay */
360					rval = 0;
361					goto ttycheck;
362				}
363			}
364		}
365
366		fflag = 0;
367
368		(void)setpriority(PRIO_PROCESS, 0, -4);
369
370#ifdef LOGIN_CAP_AUTH
371		/*
372		 * This hands off authorization to an authorization program,
373		 * depending on the styles available for the "auth-login",
374		 * auth-rlogin (or default) authorization styles.
375		 * We do this regardless of whether an account exists so that
376		 * the remote user cannot tell a "real" from an invented
377		 * account name. If we don't have an account we just fall
378		 * back to the first method for the "default" class.
379		 */
380		if (!(style = login_getstyle(lc, auth_method, authtype))) {
381
382			/*
383			 * No available authorization method
384			 */
385			rval = 1;
386			(void)printf("No auth method available for %s.\n",
387				     authtype);
388		} else {
389
390			/*
391			 * Put back the kerberos instance, if any was given.
392			 * Don't worry about the non-kerberos case here, since
393			 * if kerberos is not available or not selected and an
394			 * instance is given at the login prompt, su or rlogin -l,
395			 * then anything else should fail as well.
396			 */
397			if (*instance)
398				*(instance - 1) = '.';
399
400			rval = authenticate(username,
401					    lc ? lc->lc_class : "default",
402					    style, authtype);
403			/* Junk it again */
404			if (*instance)
405				*(instance - 1) = '\0';
406		}
407
408		if (!rval) {
409			char * approvp;
410
411			/*
412			 * If authentication succeeds, run any approval
413			 * program, if applicable for this class.
414			 */
415			approvep = login_getcapstr(lc, "approve", NULL, NULL);
416			rval = 1; /* Assume bad login again */
417
418			if (approvep==NULL ||
419			    auth_script(approvep, approvep, username,
420					lc->lc_class, 0) == 0) {
421				int     r;
422
423				r = auth_scan(AUTH_OKAY);
424				/*
425				 * See what the authorize program says
426				 */
427				if (r != AUTH_NONE) {
428					rval = 0;
429
430					if (!rootok && (r & AUTH_ROOTOKAY))
431						rootok = 1; /* root approved */
432					else
433						rootlogin = 0;
434
435					if (!authok && (r & AUTH_SECURE))
436						authok = 1; /* secure */
437				}
438			}
439		}
440#else /* !LOGIN_CAP_AUTH */
441		(void)signal(SIGINT, SIG_DFL);
442		(void)signal(SIGQUIT, SIG_DFL);
443#ifdef SKEY
444		permit_passwd = skeyaccess(username, tty,
445					   hostname ? full_hostname : NULL,
446					   NULL);
447		p = skey_getpass("Password:", pwd, permit_passwd);
448		ep = skey_crypt(p, salt, pwd, permit_passwd);
449#else /* !SKEY */
450		p = getpass("Password:");
451		ep = crypt(p, salt);
452#endif/* SKEY */
453		(void)signal(SIGINT, SIG_IGN);
454		(void)signal(SIGQUIT, SIG_IGN);
455
456		if (pwd) {
457			if (!p[0] && pwd->pw_passwd[0])
458				ep = ":";
459#ifdef KERBEROS
460#ifdef SKEY
461			/*
462			 * Do not allow user to type in kerberos password
463			 * over the net (actually, this is ok for encrypted
464			 * links, but we have no way of determining if the
465			 * link is encrypted.
466			 */
467			if (!permit_passwd) {
468				rval = 1;		/* failed */
469			} else
470#endif /* SKEY */
471			rval = klogin(pwd, instance, localhost, p);
472			if (rval != 0 && rootlogin && pwd->pw_uid != 0)
473				rootlogin = 0;
474			if (rval == 0)
475				authok = 1; /* kerberos authenticated ok */
476			else if (rval == 1) /* fallback to unix passwd */
477				rval = strcmp(ep, pwd->pw_passwd);
478#else /* !KERBEROS */
479			rval = strcmp(ep, pwd->pw_passwd);
480#endif /* KERBEROS */
481		}
482
483		/* clear entered password */
484		memset(p, 0, strlen(p));
485#endif /* LOGIN_CAP_AUTH */
486
487		(void)setpriority(PRIO_PROCESS, 0, 0);
488
489#ifdef LOGIN_CAP_AUTH
490		if (rval)
491			auth_rmfiles();
492#endif
493	ttycheck:
494		/*
495		 * If trying to log in as root without Kerberos,
496		 * but with insecure terminal, refuse the login attempt.
497		 */
498		if (pwd && !rval) {
499#if defined(KERBEROS) || defined(LOGIN_CAP_AUTH)
500			if (authok == 0 && rootlogin && !rootok)
501#else
502			if (rootlogin && !rootok)
503#endif
504				refused(NULL, "NOROOT", 0);
505			else	/* valid password & authenticated */
506				break;
507		}
508
509		(void)printf("Login incorrect\n");
510		failures++;
511
512		/*
513		 * we allow up to 'retry' (10) tries,
514		 * but after 'backoff' (3) we start backing off
515		 */
516		if (++cnt > backoff) {
517			if (cnt >= retries) {
518				badlogin(username);
519				sleepexit(1);
520			}
521			sleep((u_int)((cnt - 3) * 5));
522		}
523	}
524
525	/* committed to login -- turn off timeout */
526	(void)alarm((u_int)0);
527
528	endpwent();
529
530	/* if user not super-user, check for disabled logins */
531#ifdef LOGIN_CAP
532	if (!rootlogin)
533		auth_checknologin(lc);
534#else
535	if (!rootlogin)
536		checknologin();
537#endif
538
539#ifdef LOGIN_CAP
540	quietlog = login_getcapbool(lc, "hushlogin", 0);
541#else
542	quietlog = 0;
543#endif
544	if (!*pwd->pw_dir || chdir(pwd->pw_dir) < 0) {
545#ifdef LOGIN_CAP
546		if (login_getcapbool(lc, "requirehome", 0))
547			refused("Home directory not available", "HOMEDIR", 1);
548#endif
549		if (chdir("/") < 0)
550			refused("Cannot find root directory", "ROOTDIR", 1);
551		pwd->pw_dir = "/";
552		if (!quietlog || *pwd->pw_dir)
553			printf("No home directory.\nLogging in with home = \"/\".\n");
554	}
555	if (!quietlog)
556		quietlog = access(_PATH_HUSHLOGIN, F_OK) == 0;
557
558	if (pwd->pw_change || pwd->pw_expire)
559		(void)gettimeofday(&tp, (struct timezone *)NULL);
560
561#define DEFAULT_WARN  (2L * 7L * 86400L)  /* Two weeks */
562
563#ifdef LOGIN_CAP
564	warntime = login_getcaptime(lc, "warnpassword",
565				    DEFAULT_WARN, DEFAULT_WARN);
566#else
567	warntime = DEFAULT_WARN;
568#endif
569
570	changepass=0;
571	if (pwd->pw_change) {
572		if (tp.tv_sec >= pwd->pw_change) {
573			(void)printf("Sorry -- your password has expired.\n");
574			changepass=1;
575			syslog(LOG_INFO,
576			       "%s Password expired - forcing change",
577			       pwd->pw_name);
578		} else if (pwd->pw_change - tp.tv_sec < warntime && !quietlog)
579		    (void)printf("Warning: your password expires on %s",
580				 ctime(&pwd->pw_change));
581	}
582
583#ifdef LOGIN_CAP
584	warntime = login_getcaptime(lc, "warnexpire",
585				    DEFAULT_WARN, DEFAULT_WARN);
586#else
587	warntime = DEFAULT_WARN;
588#endif
589
590	if (pwd->pw_expire) {
591		if (tp.tv_sec >= pwd->pw_expire) {
592			refused("Sorry -- your account has expired",
593				"EXPIRED", 1);
594		} else if (pwd->pw_expire - tp.tv_sec < warntime && !quietlog)
595		    (void)printf("Warning: your account expires on %s",
596				 ctime(&pwd->pw_expire));
597	}
598
599#ifdef LOGIN_CAP
600	if (lc != NULL) {
601		if (hostname) {
602			struct hostent *hp = gethostbyname(full_hostname);
603
604			if (hp == NULL)
605				optarg = NULL;
606			else {
607				struct in_addr in;
608				memmove(&in, hp->h_addr, sizeof(in));
609				optarg = strdup(inet_ntoa(in));
610			}
611			if (!auth_hostok(lc, full_hostname, optarg))
612				refused("Permission denied", "HOST", 1);
613		}
614
615		if (!auth_ttyok(lc, tty))
616			refused("Permission denied", "TTY", 1);
617
618		if (!auth_timeok(lc, time(NULL)))
619			refused("Logins not available right now", "TIME", 1);
620	}
621        shell=login_getcapstr(lc, "shell", pwd->pw_shell, pwd->pw_shell);
622#else /* !LOGIN_CAP */
623       shell=pwd->pw_shell;
624#endif /* LOGIN_CAP */
625	if (*pwd->pw_shell == '\0')
626		pwd->pw_shell = _PATH_BSHELL;
627	if (*shell == '\0')   /* Not overridden */
628		shell = pwd->pw_shell;
629	if ((shell = strdup(shell)) == NULL) {
630		syslog(LOG_NOTICE, "memory allocation error");
631		sleepexit(1);
632	}
633
634#ifdef LOGIN_ACCESS
635	if (login_access(pwd->pw_name, hostname ? full_hostname : tty) == 0)
636		refused("Permission denied", "ACCESS", 1);
637#endif /* LOGIN_ACCESS */
638
639	/* Nothing else left to fail -- really log in. */
640	memset((void *)&utmp, 0, sizeof(utmp));
641	(void)time(&utmp.ut_time);
642	(void)strncpy(utmp.ut_name, username, sizeof(utmp.ut_name));
643	if (hostname)
644		(void)strncpy(utmp.ut_host, hostname, sizeof(utmp.ut_host));
645	(void)strncpy(utmp.ut_line, tty, sizeof(utmp.ut_line));
646	login(&utmp);
647
648	dolastlog(quietlog);
649
650	/*
651	 * Set device protections, depending on what terminal the
652	 * user is logged in. This feature is used on Suns to give
653	 * console users better privacy.
654	 */
655	login_fbtab(tty, pwd->pw_uid, pwd->pw_gid);
656
657	(void)chown(ttyn, pwd->pw_uid,
658		    (gr = getgrnam(TTYGRPNAME)) ? gr->gr_gid : pwd->pw_gid);
659
660	/*
661	 * Preserve TERM if it happens to be already set.
662	 */
663	if ((term = getenv("TERM")) != NULL)
664		term = strdup(term);
665
666	/*
667	 * Exclude cons/vt/ptys only, assume dialup otherwise
668	 * TODO: Make dialup tty determination a library call
669	 * for consistency (finger etc.)
670	 */
671	if (hostname==NULL && isdialuptty(tty))
672		syslog(LOG_INFO, "DIALUP %s, %s", tty, pwd->pw_name);
673
674#ifdef KERBEROS
675	if (!quietlog && notickets == 1 && !noticketsdontcomplain)
676		(void)printf("Warning: no Kerberos tickets issued.\n");
677#endif
678
679#ifdef LOGALL
680	/*
681	 * Syslog each successful login, so we don't have to watch hundreds
682	 * of wtmp or lastlogin files.
683	 */
684	if (hostname)
685		syslog(LOG_INFO, "login from %s on %s as %s",
686		       full_hostname, tty, pwd->pw_name);
687	else
688		syslog(LOG_INFO, "login on %s as %s",
689		       tty, pwd->pw_name);
690#endif
691
692	/*
693	 * If fflag is on, assume caller/authenticator has logged root login.
694	 */
695	if (rootlogin && fflag == 0)
696	{
697		if (hostname)
698			syslog(LOG_NOTICE, "ROOT LOGIN (%s) ON %s FROM %s",
699			       username, tty, full_hostname);
700		else
701			syslog(LOG_NOTICE, "ROOT LOGIN (%s) ON %s",
702			       username, tty);
703	}
704
705	/*
706	 * Destroy environment unless user has requested its preservation.
707	 * We need to do this before setusercontext() because that may
708	 * set or reset some environment variables.
709	 */
710	if (!pflag)
711		environ = envinit;
712
713	/*
714	 * We don't need to be root anymore, so
715	 * set the user and session context
716	 */
717#ifdef LOGIN_CAP
718	if (setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETALL) != 0) {
719                syslog(LOG_ERR, "setusercontext() failed - exiting");
720		exit(1);
721	}
722#else
723     	if (setlogin(pwd->pw_name) < 0)
724                syslog(LOG_ERR, "setlogin() failure: %m");
725
726	(void)setgid(pwd->pw_gid);
727	initgroups(username, pwd->pw_gid);
728	(void)setuid(rootlogin ? 0 : pwd->pw_uid);
729#endif
730
731	(void)setenv("SHELL", pwd->pw_shell, 1);
732	(void)setenv("HOME", pwd->pw_dir, 1);
733	if (term != NULL && *term != '\0')
734		(void)setenv("TERM", term, 1);	/* Preset overrides */
735	else {
736		(void)setenv("TERM", stypeof(tty), 0);	/* Fallback doesn't */
737	}
738	(void)setenv("LOGNAME", pwd->pw_name, 1);
739	(void)setenv("USER", pwd->pw_name, 1);
740	(void)setenv("PATH", rootlogin ? _PATH_STDPATH : _PATH_DEFPATH, 0);
741#ifdef KERBEROS
742	if (krbtkfile_env)
743		(void)setenv("KRBTKFILE", krbtkfile_env, 1);
744#endif
745#if LOGIN_CAP_AUTH
746	auth_env();
747#endif
748
749#ifdef LOGIN_CAP
750	if (!quietlog) {
751		char	*cw;
752
753		cw = login_getcapstr(lc, "copyright", NULL, NULL);
754		if (cw != NULL && access(cw, F_OK) == 0)
755			motd(cw);
756		else
757		    (void)printf("%s\n\t%s %s\n",
758	"Copyright (c) 1980, 1983, 1986, 1988, 1990, 1991, 1993, 1994",
759	"The Regents of the University of California. ",
760	"All rights reserved.");
761
762		(void)printf("\n");
763
764		cw = login_getcapstr(lc, "welcome", NULL, NULL);
765		if (cw == NULL || access(cw, F_OK) != 0)
766			cw = _PATH_MOTDFILE;
767		motd(cw);
768
769		cw = getenv("MAIL");	/* $MAIL may have been set by class */
770		if (cw != NULL) {
771			strncpy(tbuf, cw, sizeof(tbuf));
772			tbuf[sizeof(tbuf)-1] = '\0';
773		} else
774			snprintf(tbuf, sizeof(tbuf), "%s/%s",
775				 _PATH_MAILDIR, pwd->pw_name);
776#else
777	if (!quietlog) {
778		    (void)printf("%s\n\t%s %s\n",
779	"Copyright (c) 1980, 1983, 1986, 1988, 1990, 1991, 1993, 1994",
780	"The Regents of the University of California. ",
781	"All rights reserved.");
782		motd(_PATH_MOTDFILE);
783		snprintf(tbuf, sizeof(tbuf), "%s/%s",
784			 _PATH_MAILDIR, pwd->pw_name);
785#endif
786		if (stat(tbuf, &st) == 0 && st.st_size != 0)
787			(void)printf("You have %smail.\n",
788				     (st.st_mtime > st.st_atime) ? "new " : "");
789	}
790
791#ifdef LOGIN_CAP
792	login_close(lc);
793#endif
794
795	(void)signal(SIGALRM, SIG_DFL);
796	(void)signal(SIGQUIT, SIG_DFL);
797	(void)signal(SIGINT, SIG_DFL);
798	(void)signal(SIGTSTP, SIG_IGN);
799
800	if (changepass) {
801		if (system(_PATH_CHPASS) != 0)
802			sleepexit(1);
803	}
804
805	/*
806	 * Login shells have a leading '-' in front of argv[0]
807	 */
808	tbuf[0] = '-';
809	(void)strcpy(tbuf + 1, (p = strrchr(pwd->pw_shell, '/')) ? p + 1 : pwd->pw_shell);
810
811	execlp(shell, tbuf, 0);
812	err(1, "%s", shell);
813}
814
815static void
816usage()
817{
818	(void)fprintf(stderr, "usage: login [-fp] [-h hostname] [username]\n");
819	exit(1);
820}
821
822/*
823 * Allow for authentication style and/or kerberos instance
824 * */
825
826#define	NBUFSIZ		UT_NAMESIZE + 64
827
828void
829getloginname()
830{
831	int ch;
832	char *p;
833	static char nbuf[NBUFSIZ];
834
835	for (;;) {
836		(void)printf("login: ");
837		for (p = nbuf; (ch = getchar()) != '\n'; ) {
838			if (ch == EOF) {
839				badlogin(username);
840				exit(0);
841			}
842			if (p < nbuf + (NBUFSIZ - 1))
843				*p++ = ch;
844		}
845		if (p > nbuf)
846			if (nbuf[0] == '-')
847				(void)fprintf(stderr,
848				    "login names may not start with '-'.\n");
849			else {
850				*p = '\0';
851				username = nbuf;
852				break;
853			}
854	}
855}
856
857int
858rootterm(ttyn)
859	char *ttyn;
860{
861	struct ttyent *t;
862
863	return ((t = getttynam(ttyn)) && t->ty_status & TTY_SECURE);
864}
865
866volatile int motdinterrupt;
867
868/* ARGSUSED */
869void
870sigint(signo)
871	int signo;
872{
873	motdinterrupt = 1;
874}
875
876void
877motd(motdfile)
878	char *motdfile;
879{
880	int fd, nchars;
881	sig_t oldint;
882	char tbuf[256];
883
884	if ((fd = open(motdfile, O_RDONLY, 0)) < 0)
885		return;
886	motdinterrupt = 0;
887	oldint = signal(SIGINT, sigint);
888	while ((nchars = read(fd, tbuf, sizeof(tbuf))) > 0 && !motdinterrupt)
889		(void)write(fileno(stdout), tbuf, nchars);
890	(void)signal(SIGINT, oldint);
891	(void)close(fd);
892}
893
894/* ARGSUSED */
895void
896timedout(signo)
897	int signo;
898{
899	(void)fprintf(stderr, "Login timed out after %d seconds\n", timeout);
900	exit(0);
901}
902
903#ifndef LOGIN_CAP
904void
905checknologin()
906{
907	int fd, nchars;
908	char tbuf[8192];
909
910	if ((fd = open(_PATH_NOLOGIN, O_RDONLY, 0)) >= 0) {
911		while ((nchars = read(fd, tbuf, sizeof(tbuf))) > 0)
912			(void)write(fileno(stdout), tbuf, nchars);
913		sleepexit(0);
914	}
915}
916#endif
917
918void
919dolastlog(quiet)
920	int quiet;
921{
922	struct lastlog ll;
923	int fd;
924
925	if ((fd = open(_PATH_LASTLOG, O_RDWR, 0)) >= 0) {
926		(void)lseek(fd, (off_t)pwd->pw_uid * sizeof(ll), L_SET);
927		if (!quiet) {
928			if (read(fd, (char *)&ll, sizeof(ll)) == sizeof(ll) &&
929			    ll.ll_time != 0) {
930				(void)printf("Last login: %.*s ",
931				    24-5, (char *)ctime(&ll.ll_time));
932				if (*ll.ll_host != '\0')
933					(void)printf("from %.*s\n",
934					    (int)sizeof(ll.ll_host),
935					    ll.ll_host);
936				else
937					(void)printf("on %.*s\n",
938					    (int)sizeof(ll.ll_line),
939					    ll.ll_line);
940			}
941			(void)lseek(fd, (off_t)pwd->pw_uid * sizeof(ll), L_SET);
942		}
943		memset((void *)&ll, 0, sizeof(ll));
944		(void)time(&ll.ll_time);
945		(void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line));
946		if (hostname)
947			(void)strncpy(ll.ll_host, hostname, sizeof(ll.ll_host));
948		(void)write(fd, (char *)&ll, sizeof(ll));
949		(void)close(fd);
950	}
951}
952
953void
954badlogin(name)
955	char *name;
956{
957
958	if (failures == 0)
959		return;
960	if (hostname) {
961		syslog(LOG_NOTICE, "%d LOGIN FAILURE%s FROM %s",
962		    failures, failures > 1 ? "S" : "", full_hostname);
963		syslog(LOG_AUTHPRIV|LOG_NOTICE,
964		    "%d LOGIN FAILURE%s FROM %s, %s",
965		    failures, failures > 1 ? "S" : "", full_hostname, name);
966	} else {
967		syslog(LOG_NOTICE, "%d LOGIN FAILURE%s ON %s",
968		    failures, failures > 1 ? "S" : "", tty);
969		syslog(LOG_AUTHPRIV|LOG_NOTICE,
970		    "%d LOGIN FAILURE%s ON %s, %s",
971		    failures, failures > 1 ? "S" : "", tty, name);
972	}
973}
974
975#undef	UNKNOWN
976#define	UNKNOWN	"su"
977
978char *
979stypeof(ttyid)
980	char *ttyid;
981{
982
983	struct ttyent *t;
984
985	return (ttyid && (t = getttynam(ttyid)) ? t->ty_type : UNKNOWN);
986}
987
988void
989refused(msg, rtype, lout)
990	char *msg;
991	char *rtype;
992	int lout;
993{
994
995	if (msg != NULL)
996	    printf("%s.\n", msg);
997	if (hostname)
998		syslog(LOG_NOTICE, "LOGIN %s REFUSED (%s) FROM %s ON TTY %s",
999		       pwd->pw_name, rtype, full_hostname, tty);
1000	else
1001		syslog(LOG_NOTICE, "LOGIN %s REFUSED (%s) ON TTY %s",
1002		       pwd->pw_name, rtype, tty);
1003	if (lout)
1004		sleepexit(1);
1005}
1006
1007void
1008sleepexit(eval)
1009	int eval;
1010{
1011
1012	(void)sleep(5);
1013	exit(eval);
1014}
1015