1/*
2 * Copyright (c) 2000 Andre Lucas.  All rights reserved.
3 * Portions copyright (c) 1998 Todd C. Miller
4 * Portions copyright (c) 1996 Jason Downs
5 * Portions copyright (c) 1996 Theo de Raadt
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28/*
29 * The btmp logging code is derived from login.c from util-linux and is under
30 * the the following license:
31 *
32 * Copyright (c) 1980, 1987, 1988 The Regents of the University of California.
33 * All rights reserved.
34 *
35 * Redistribution and use in source and binary forms are permitted
36 * provided that the above copyright notice and this paragraph are
37 * duplicated in all such forms and that any documentation,
38 * advertising materials, and other materials related to such
39 * distribution and use acknowledge that the software was developed
40 * by the University of California, Berkeley.  The name of the
41 * University may not be used to endorse or promote products derived
42 * from this software without specific prior written permission.
43 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
44 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
45 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
46 */
47
48
49/**
50 ** loginrec.c:  platform-independent login recording and lastlog retrieval
51 **/
52
53/*
54 *  The new login code explained
55 *  ============================
56 *
57 *  This code attempts to provide a common interface to login recording
58 *  (utmp and friends) and last login time retrieval.
59 *
60 *  Its primary means of achieving this is to use 'struct logininfo', a
61 *  union of all the useful fields in the various different types of
62 *  system login record structures one finds on UNIX variants.
63 *
64 *  We depend on autoconf to define which recording methods are to be
65 *  used, and which fields are contained in the relevant data structures
66 *  on the local system. Many C preprocessor symbols affect which code
67 *  gets compiled here.
68 *
69 *  The code is designed to make it easy to modify a particular
70 *  recording method, without affecting other methods nor requiring so
71 *  many nested conditional compilation blocks as were commonplace in
72 *  the old code.
73 *
74 *  For login recording, we try to use the local system's libraries as
75 *  these are clearly most likely to work correctly. For utmp systems
76 *  this usually means login() and logout() or setutent() etc., probably
77 *  in libutil, along with logwtmp() etc. On these systems, we fall back
78 *  to writing the files directly if we have to, though this method
79 *  requires very thorough testing so we do not corrupt local auditing
80 *  information. These files and their access methods are very system
81 *  specific indeed.
82 *
83 *  For utmpx systems, the corresponding library functions are
84 *  setutxent() etc. To the author's knowledge, all utmpx systems have
85 *  these library functions and so no direct write is attempted. If such
86 *  a system exists and needs support, direct analogues of the [uw]tmp
87 *  code should suffice.
88 *
89 *  Retrieving the time of last login ('lastlog') is in some ways even
90 *  more problemmatic than login recording. Some systems provide a
91 *  simple table of all users which we seek based on uid and retrieve a
92 *  relatively standard structure. Others record the same information in
93 *  a directory with a separate file, and others don't record the
94 *  information separately at all. For systems in the latter category,
95 *  we look backwards in the wtmp or wtmpx file for the last login entry
96 *  for our user. Naturally this is slower and on busy systems could
97 *  incur a significant performance penalty.
98 *
99 *  Calling the new code
100 *  --------------------
101 *
102 *  In OpenSSH all login recording and retrieval is performed in
103 *  login.c. Here you'll find working examples. Also, in the logintest.c
104 *  program there are more examples.
105 *
106 *  Internal handler calling method
107 *  -------------------------------
108 *
109 *  When a call is made to login_login() or login_logout(), both
110 *  routines set a struct logininfo flag defining which action (log in,
111 *  or log out) is to be taken. They both then call login_write(), which
112 *  calls whichever of the many structure-specific handlers autoconf
113 *  selects for the local system.
114 *
115 *  The handlers themselves handle system data structure specifics. Both
116 *  struct utmp and struct utmpx have utility functions (see
117 *  construct_utmp*()) to try to make it simpler to add extra systems
118 *  that introduce new features to either structure.
119 *
120 *  While it may seem terribly wasteful to replicate so much similar
121 *  code for each method, experience has shown that maintaining code to
122 *  write both struct utmp and utmpx in one function, whilst maintaining
123 *  support for all systems whether they have library support or not, is
124 *  a difficult and time-consuming task.
125 *
126 *  Lastlog support proceeds similarly. Functions login_get_lastlog()
127 *  (and its OpenSSH-tuned friend login_get_lastlog_time()) call
128 *  getlast_entry(), which tries one of three methods to find the last
129 *  login time. It uses local system lastlog support if it can,
130 *  otherwise it tries wtmp or wtmpx before giving up and returning 0,
131 *  meaning "tilt".
132 *
133 *  Maintenance
134 *  -----------
135 *
136 *  In many cases it's possible to tweak autoconf to select the correct
137 *  methods for a particular platform, either by improving the detection
138 *  code (best), or by presetting DISABLE_<method> or CONF_<method>_FILE
139 *  symbols for the platform.
140 *
141 *  Use logintest to check which symbols are defined before modifying
142 *  configure.ac and loginrec.c. (You have to build logintest yourself
143 *  with 'make logintest' as it's not built by default.)
144 *
145 *  Otherwise, patches to the specific method(s) are very helpful!
146 */
147
148#include "includes.h"
149
150#include <sys/types.h>
151#include <sys/stat.h>
152#include <sys/socket.h>
153
154#include <netinet/in.h>
155
156#include <errno.h>
157#include <fcntl.h>
158#ifdef HAVE_PATHS_H
159# include <paths.h>
160#endif
161#include <pwd.h>
162#include <stdarg.h>
163#include <string.h>
164#include <time.h>
165#include <unistd.h>
166
167#include "xmalloc.h"
168#include "key.h"
169#include "hostfile.h"
170#include "ssh.h"
171#include "loginrec.h"
172#include "log.h"
173#include "atomicio.h"
174#include "packet.h"
175#include "canohost.h"
176#include "auth.h"
177#include "buffer.h"
178
179#ifdef HAVE_UTIL_H
180# include <util.h>
181#endif
182
183#ifdef HAVE_LIBUTIL_H
184# include <libutil.h>
185#endif
186
187/**
188 ** prototypes for helper functions in this file
189 **/
190
191#if HAVE_UTMP_H
192void set_utmp_time(struct logininfo *li, struct utmp *ut);
193void construct_utmp(struct logininfo *li, struct utmp *ut);
194#endif
195
196#ifdef HAVE_UTMPX_H
197void set_utmpx_time(struct logininfo *li, struct utmpx *ut);
198void construct_utmpx(struct logininfo *li, struct utmpx *ut);
199#endif
200
201int utmp_write_entry(struct logininfo *li);
202int utmpx_write_entry(struct logininfo *li);
203int wtmp_write_entry(struct logininfo *li);
204int wtmpx_write_entry(struct logininfo *li);
205int lastlog_write_entry(struct logininfo *li);
206int syslogin_write_entry(struct logininfo *li);
207
208int getlast_entry(struct logininfo *li);
209int lastlog_get_entry(struct logininfo *li);
210int utmpx_get_entry(struct logininfo *li);
211int wtmp_get_entry(struct logininfo *li);
212int wtmpx_get_entry(struct logininfo *li);
213
214extern Buffer loginmsg;
215
216/* pick the shortest string */
217#define MIN_SIZEOF(s1,s2) (sizeof(s1) < sizeof(s2) ? sizeof(s1) : sizeof(s2))
218
219/**
220 ** platform-independent login functions
221 **/
222
223/*
224 * login_login(struct logininfo *) - Record a login
225 *
226 * Call with a pointer to a struct logininfo initialised with
227 * login_init_entry() or login_alloc_entry()
228 *
229 * Returns:
230 *  >0 if successful
231 *  0  on failure (will use OpenSSH's logging facilities for diagnostics)
232 */
233int
234login_login(struct logininfo *li)
235{
236	li->type = LTYPE_LOGIN;
237	return (login_write(li));
238}
239
240
241/*
242 * login_logout(struct logininfo *) - Record a logout
243 *
244 * Call as with login_login()
245 *
246 * Returns:
247 *  >0 if successful
248 *  0  on failure (will use OpenSSH's logging facilities for diagnostics)
249 */
250int
251login_logout(struct logininfo *li)
252{
253	li->type = LTYPE_LOGOUT;
254	return (login_write(li));
255}
256
257/*
258 * login_get_lastlog_time(int) - Retrieve the last login time
259 *
260 * Retrieve the last login time for the given uid. Will try to use the
261 * system lastlog facilities if they are available, but will fall back
262 * to looking in wtmp/wtmpx if necessary
263 *
264 * Returns:
265 *   0 on failure, or if user has never logged in
266 *   Time in seconds from the epoch if successful
267 *
268 * Useful preprocessor symbols:
269 *   DISABLE_LASTLOG: If set, *never* even try to retrieve lastlog
270 *                    info
271 *   USE_LASTLOG: If set, indicates the presence of system lastlog
272 *                facilities. If this and DISABLE_LASTLOG are not set,
273 *                try to retrieve lastlog information from wtmp/wtmpx.
274 */
275unsigned int
276login_get_lastlog_time(const uid_t uid)
277{
278	struct logininfo li;
279
280	if (login_get_lastlog(&li, uid))
281		return (li.tv_sec);
282	else
283		return (0);
284}
285
286/*
287 * login_get_lastlog(struct logininfo *, int)   - Retrieve a lastlog entry
288 *
289 * Retrieve a logininfo structure populated (only partially) with
290 * information from the system lastlog data, or from wtmp/wtmpx if no
291 * system lastlog information exists.
292 *
293 * Note this routine must be given a pre-allocated logininfo.
294 *
295 * Returns:
296 *  >0: A pointer to your struct logininfo if successful
297 *  0  on failure (will use OpenSSH's logging facilities for diagnostics)
298 */
299struct logininfo *
300login_get_lastlog(struct logininfo *li, const uid_t uid)
301{
302	struct passwd *pw;
303
304	memset(li, '\0', sizeof(*li));
305	li->uid = uid;
306
307	/*
308	 * If we don't have a 'real' lastlog, we need the username to
309	 * reliably search wtmp(x) for the last login (see
310	 * wtmp_get_entry().)
311	 */
312	pw = getpwuid(uid);
313	if (pw == NULL)
314		fatal("%s: Cannot find account for uid %ld", __func__,
315		    (long)uid);
316
317	/* No MIN_SIZEOF here - we absolutely *must not* truncate the
318	 * username (XXX - so check for trunc!) */
319	strlcpy(li->username, pw->pw_name, sizeof(li->username));
320
321	if (getlast_entry(li))
322		return (li);
323	else
324		return (NULL);
325}
326
327
328/*
329 * login_alloc_entry(int, char*, char*, char*)    - Allocate and initialise
330 *                                                  a logininfo structure
331 *
332 * This function creates a new struct logininfo, a data structure
333 * meant to carry the information required to portably record login info.
334 *
335 * Returns a pointer to a newly created struct logininfo. If memory
336 * allocation fails, the program halts.
337 */
338struct
339logininfo *login_alloc_entry(pid_t pid, const char *username,
340    const char *hostname, const char *line)
341{
342	struct logininfo *newli;
343
344	newli = xmalloc(sizeof(*newli));
345	login_init_entry(newli, pid, username, hostname, line);
346	return (newli);
347}
348
349
350/* login_free_entry(struct logininfo *)    - free struct memory */
351void
352login_free_entry(struct logininfo *li)
353{
354	xfree(li);
355}
356
357
358/* login_init_entry(struct logininfo *, int, char*, char*, char*)
359 *                                        - initialise a struct logininfo
360 *
361 * Populates a new struct logininfo, a data structure meant to carry
362 * the information required to portably record login info.
363 *
364 * Returns: 1
365 */
366int
367login_init_entry(struct logininfo *li, pid_t pid, const char *username,
368    const char *hostname, const char *line)
369{
370	struct passwd *pw;
371
372	memset(li, 0, sizeof(*li));
373
374	li->pid = pid;
375
376	/* set the line information */
377	if (line)
378		line_fullname(li->line, line, sizeof(li->line));
379
380	if (username) {
381		strlcpy(li->username, username, sizeof(li->username));
382		pw = getpwnam(li->username);
383		if (pw == NULL) {
384			fatal("%s: Cannot find user \"%s\"", __func__,
385			    li->username);
386		}
387		li->uid = pw->pw_uid;
388	}
389
390	if (hostname)
391		strlcpy(li->hostname, hostname, sizeof(li->hostname));
392
393	return (1);
394}
395
396/*
397 * login_set_current_time(struct logininfo *)    - set the current time
398 *
399 * Set the current time in a logininfo structure. This function is
400 * meant to eliminate the need to deal with system dependencies for
401 * time handling.
402 */
403void
404login_set_current_time(struct logininfo *li)
405{
406	struct timeval tv;
407
408	gettimeofday(&tv, NULL);
409
410	li->tv_sec = tv.tv_sec;
411	li->tv_usec = tv.tv_usec;
412}
413
414/* copy a sockaddr_* into our logininfo */
415void
416login_set_addr(struct logininfo *li, const struct sockaddr *sa,
417    const unsigned int sa_size)
418{
419	unsigned int bufsize = sa_size;
420
421	/* make sure we don't overrun our union */
422	if (sizeof(li->hostaddr) < sa_size)
423		bufsize = sizeof(li->hostaddr);
424
425	memcpy(&li->hostaddr.sa, sa, bufsize);
426}
427
428
429/**
430 ** login_write: Call low-level recording functions based on autoconf
431 ** results
432 **/
433int
434login_write(struct logininfo *li)
435{
436#ifndef HAVE_CYGWIN
437	if (geteuid() != 0) {
438		logit("Attempt to write login records by non-root user (aborting)");
439		return (1);
440	}
441#endif
442
443	/* set the timestamp */
444	login_set_current_time(li);
445#ifdef USE_LOGIN
446	syslogin_write_entry(li);
447#endif
448#ifdef USE_LASTLOG
449	if (li->type == LTYPE_LOGIN)
450		lastlog_write_entry(li);
451#endif
452#ifdef USE_UTMP
453	utmp_write_entry(li);
454#endif
455#ifdef USE_WTMP
456	wtmp_write_entry(li);
457#endif
458#ifdef USE_UTMPX
459	utmpx_write_entry(li);
460#endif
461#ifdef USE_WTMPX
462	wtmpx_write_entry(li);
463#endif
464#ifdef CUSTOM_SYS_AUTH_RECORD_LOGIN
465	if (li->type == LTYPE_LOGIN &&
466	    !sys_auth_record_login(li->username,li->hostname,li->line,
467	    &loginmsg))
468		logit("Writing login record failed for %s", li->username);
469#endif
470#ifdef SSH_AUDIT_EVENTS
471	if (li->type == LTYPE_LOGIN)
472		audit_session_open(li);
473	else if (li->type == LTYPE_LOGOUT)
474		audit_session_close(li);
475#endif
476	return (0);
477}
478
479#ifdef LOGIN_NEEDS_UTMPX
480int
481login_utmp_only(struct logininfo *li)
482{
483	li->type = LTYPE_LOGIN;
484	login_set_current_time(li);
485# ifdef USE_UTMP
486	utmp_write_entry(li);
487# endif
488# ifdef USE_WTMP
489	wtmp_write_entry(li);
490# endif
491# ifdef USE_UTMPX
492	utmpx_write_entry(li);
493# endif
494# ifdef USE_WTMPX
495	wtmpx_write_entry(li);
496# endif
497	return (0);
498}
499#endif
500
501/**
502 ** getlast_entry: Call low-level functions to retrieve the last login
503 **                time.
504 **/
505
506/* take the uid in li and return the last login time */
507int
508getlast_entry(struct logininfo *li)
509{
510#ifdef USE_LASTLOG
511	return(lastlog_get_entry(li));
512#else /* !USE_LASTLOG */
513#if defined(USE_UTMPX) && defined(HAVE_SETUTXDB) && \
514    defined(UTXDB_LASTLOGIN) && defined(HAVE_GETUTXUSER)
515	return (utmpx_get_entry(li));
516#endif
517
518#if defined(DISABLE_LASTLOG)
519	/* On some systems we shouldn't even try to obtain last login
520	 * time, e.g. AIX */
521	return (0);
522# elif defined(USE_WTMP) && \
523    (defined(HAVE_TIME_IN_UTMP) || defined(HAVE_TV_IN_UTMP))
524	/* retrieve last login time from utmp */
525	return (wtmp_get_entry(li));
526# elif defined(USE_WTMPX) && \
527    (defined(HAVE_TIME_IN_UTMPX) || defined(HAVE_TV_IN_UTMPX))
528	/* If wtmp isn't available, try wtmpx */
529	return (wtmpx_get_entry(li));
530# else
531	/* Give up: No means of retrieving last login time */
532	return (0);
533# endif /* DISABLE_LASTLOG */
534#endif /* USE_LASTLOG */
535}
536
537
538
539/*
540 * 'line' string utility functions
541 *
542 * These functions process the 'line' string into one of three forms:
543 *
544 * 1. The full filename (including '/dev')
545 * 2. The stripped name (excluding '/dev')
546 * 3. The abbreviated name (e.g. /dev/ttyp00 -> yp00
547 *                               /dev/pts/1  -> ts/1 )
548 *
549 * Form 3 is used on some systems to identify a .tmp.? entry when
550 * attempting to remove it. Typically both addition and removal is
551 * performed by one application - say, sshd - so as long as the choice
552 * uniquely identifies a terminal it's ok.
553 */
554
555
556/*
557 * line_fullname(): add the leading '/dev/' if it doesn't exist make
558 * sure dst has enough space, if not just copy src (ugh)
559 */
560char *
561line_fullname(char *dst, const char *src, u_int dstsize)
562{
563	memset(dst, '\0', dstsize);
564	if ((strncmp(src, "/dev/", 5) == 0) || (dstsize < (strlen(src) + 5)))
565		strlcpy(dst, src, dstsize);
566	else {
567		strlcpy(dst, "/dev/", dstsize);
568		strlcat(dst, src, dstsize);
569	}
570	return (dst);
571}
572
573/* line_stripname(): strip the leading '/dev' if it exists, return dst */
574char *
575line_stripname(char *dst, const char *src, int dstsize)
576{
577	memset(dst, '\0', dstsize);
578	if (strncmp(src, "/dev/", 5) == 0)
579		strlcpy(dst, src + 5, dstsize);
580	else
581		strlcpy(dst, src, dstsize);
582	return (dst);
583}
584
585/*
586 * line_abbrevname(): Return the abbreviated (usually four-character)
587 * form of the line (Just use the last <dstsize> characters of the
588 * full name.)
589 *
590 * NOTE: use strncpy because we do NOT necessarily want zero
591 * termination
592 */
593char *
594line_abbrevname(char *dst, const char *src, int dstsize)
595{
596	size_t len;
597
598	memset(dst, '\0', dstsize);
599
600	/* Always skip prefix if present */
601	if (strncmp(src, "/dev/", 5) == 0)
602		src += 5;
603
604#ifdef WITH_ABBREV_NO_TTY
605	if (strncmp(src, "tty", 3) == 0)
606		src += 3;
607#endif
608
609	len = strlen(src);
610
611	if (len > 0) {
612		if (((int)len - dstsize) > 0)
613			src +=  ((int)len - dstsize);
614
615		/* note: _don't_ change this to strlcpy */
616		strncpy(dst, src, (size_t)dstsize);
617	}
618
619	return (dst);
620}
621
622/**
623 ** utmp utility functions
624 **
625 ** These functions manipulate struct utmp, taking system differences
626 ** into account.
627 **/
628
629#if defined(USE_UTMP) || defined (USE_WTMP) || defined (USE_LOGIN)
630
631/* build the utmp structure */
632void
633set_utmp_time(struct logininfo *li, struct utmp *ut)
634{
635# if defined(HAVE_TV_IN_UTMP)
636	ut->ut_tv.tv_sec = li->tv_sec;
637	ut->ut_tv.tv_usec = li->tv_usec;
638# elif defined(HAVE_TIME_IN_UTMP)
639	ut->ut_time = li->tv_sec;
640# endif
641}
642
643void
644construct_utmp(struct logininfo *li,
645		    struct utmp *ut)
646{
647# ifdef HAVE_ADDR_V6_IN_UTMP
648	struct sockaddr_in6 *sa6;
649# endif
650
651	memset(ut, '\0', sizeof(*ut));
652
653	/* First fill out fields used for both logins and logouts */
654
655# ifdef HAVE_ID_IN_UTMP
656	line_abbrevname(ut->ut_id, li->line, sizeof(ut->ut_id));
657# endif
658
659# ifdef HAVE_TYPE_IN_UTMP
660	/* This is done here to keep utmp constants out of struct logininfo */
661	switch (li->type) {
662	case LTYPE_LOGIN:
663		ut->ut_type = USER_PROCESS;
664#ifdef _UNICOS
665		cray_set_tmpdir(ut);
666#endif
667		break;
668	case LTYPE_LOGOUT:
669		ut->ut_type = DEAD_PROCESS;
670#ifdef _UNICOS
671		cray_retain_utmp(ut, li->pid);
672#endif
673		break;
674	}
675# endif
676	set_utmp_time(li, ut);
677
678	line_stripname(ut->ut_line, li->line, sizeof(ut->ut_line));
679
680# ifdef HAVE_PID_IN_UTMP
681	ut->ut_pid = li->pid;
682# endif
683
684	/* If we're logging out, leave all other fields blank */
685	if (li->type == LTYPE_LOGOUT)
686		return;
687
688	/*
689	 * These fields are only used when logging in, and are blank
690	 * for logouts.
691	 */
692
693	/* Use strncpy because we don't necessarily want null termination */
694	strncpy(ut->ut_name, li->username,
695	    MIN_SIZEOF(ut->ut_name, li->username));
696# ifdef HAVE_HOST_IN_UTMP
697	strncpy(ut->ut_host, li->hostname,
698	    MIN_SIZEOF(ut->ut_host, li->hostname));
699# endif
700# ifdef HAVE_ADDR_IN_UTMP
701	/* this is just a 32-bit IP address */
702	if (li->hostaddr.sa.sa_family == AF_INET)
703		ut->ut_addr = li->hostaddr.sa_in.sin_addr.s_addr;
704# endif
705# ifdef HAVE_ADDR_V6_IN_UTMP
706	/* this is just a 128-bit IPv6 address */
707	if (li->hostaddr.sa.sa_family == AF_INET6) {
708		sa6 = ((struct sockaddr_in6 *)&li->hostaddr.sa);
709		memcpy(ut->ut_addr_v6, sa6->sin6_addr.s6_addr, 16);
710		if (IN6_IS_ADDR_V4MAPPED(&sa6->sin6_addr)) {
711			ut->ut_addr_v6[0] = ut->ut_addr_v6[3];
712			ut->ut_addr_v6[1] = 0;
713			ut->ut_addr_v6[2] = 0;
714			ut->ut_addr_v6[3] = 0;
715		}
716	}
717# endif
718}
719#endif /* USE_UTMP || USE_WTMP || USE_LOGIN */
720
721/**
722 ** utmpx utility functions
723 **
724 ** These functions manipulate struct utmpx, accounting for system
725 ** variations.
726 **/
727
728#if defined(USE_UTMPX) || defined (USE_WTMPX)
729/* build the utmpx structure */
730void
731set_utmpx_time(struct logininfo *li, struct utmpx *utx)
732{
733# if defined(HAVE_TV_IN_UTMPX)
734	utx->ut_tv.tv_sec = li->tv_sec;
735	utx->ut_tv.tv_usec = li->tv_usec;
736# elif defined(HAVE_TIME_IN_UTMPX)
737	utx->ut_time = li->tv_sec;
738# endif
739}
740
741void
742construct_utmpx(struct logininfo *li, struct utmpx *utx)
743{
744# ifdef HAVE_ADDR_V6_IN_UTMP
745	struct sockaddr_in6 *sa6;
746#  endif
747	memset(utx, '\0', sizeof(*utx));
748
749# ifdef HAVE_ID_IN_UTMPX
750	line_abbrevname(utx->ut_id, li->line, sizeof(utx->ut_id));
751# endif
752
753	/* this is done here to keep utmp constants out of loginrec.h */
754	switch (li->type) {
755	case LTYPE_LOGIN:
756		utx->ut_type = USER_PROCESS;
757		break;
758	case LTYPE_LOGOUT:
759		utx->ut_type = DEAD_PROCESS;
760		break;
761	}
762	line_stripname(utx->ut_line, li->line, sizeof(utx->ut_line));
763	set_utmpx_time(li, utx);
764	utx->ut_pid = li->pid;
765
766	/* strncpy(): Don't necessarily want null termination */
767	strncpy(utx->ut_user, li->username,
768	    MIN_SIZEOF(utx->ut_user, li->username));
769
770	if (li->type == LTYPE_LOGOUT)
771		return;
772
773	/*
774	 * These fields are only used when logging in, and are blank
775	 * for logouts.
776	 */
777
778# ifdef HAVE_HOST_IN_UTMPX
779	strncpy(utx->ut_host, li->hostname,
780	    MIN_SIZEOF(utx->ut_host, li->hostname));
781# endif
782# ifdef HAVE_ADDR_IN_UTMPX
783	/* this is just a 32-bit IP address */
784	if (li->hostaddr.sa.sa_family == AF_INET)
785		utx->ut_addr = li->hostaddr.sa_in.sin_addr.s_addr;
786# endif
787# ifdef HAVE_ADDR_V6_IN_UTMP
788	/* this is just a 128-bit IPv6 address */
789	if (li->hostaddr.sa.sa_family == AF_INET6) {
790		sa6 = ((struct sockaddr_in6 *)&li->hostaddr.sa);
791		memcpy(ut->ut_addr_v6, sa6->sin6_addr.s6_addr, 16);
792		if (IN6_IS_ADDR_V4MAPPED(&sa6->sin6_addr)) {
793			ut->ut_addr_v6[0] = ut->ut_addr_v6[3];
794			ut->ut_addr_v6[1] = 0;
795			ut->ut_addr_v6[2] = 0;
796			ut->ut_addr_v6[3] = 0;
797		}
798	}
799# endif
800# ifdef HAVE_SYSLEN_IN_UTMPX
801	/* ut_syslen is the length of the utx_host string */
802	utx->ut_syslen = MIN(strlen(li->hostname), sizeof(utx->ut_host));
803# endif
804}
805#endif /* USE_UTMPX || USE_WTMPX */
806
807/**
808 ** Low-level utmp functions
809 **/
810
811/* FIXME: (ATL) utmp_write_direct needs testing */
812#ifdef USE_UTMP
813
814/* if we can, use pututline() etc. */
815# if !defined(DISABLE_PUTUTLINE) && defined(HAVE_SETUTENT) && \
816	defined(HAVE_PUTUTLINE)
817#  define UTMP_USE_LIBRARY
818# endif
819
820
821/* write a utmp entry with the system's help (pututline() and pals) */
822# ifdef UTMP_USE_LIBRARY
823static int
824utmp_write_library(struct logininfo *li, struct utmp *ut)
825{
826	setutent();
827	pututline(ut);
828#  ifdef HAVE_ENDUTENT
829	endutent();
830#  endif
831	return (1);
832}
833# else /* UTMP_USE_LIBRARY */
834
835/*
836 * Write a utmp entry direct to the file
837 * This is a slightly modification of code in OpenBSD's login.c
838 */
839static int
840utmp_write_direct(struct logininfo *li, struct utmp *ut)
841{
842	struct utmp old_ut;
843	register int fd;
844	int tty;
845
846	/* FIXME: (ATL) ttyslot() needs local implementation */
847
848#if defined(HAVE_GETTTYENT)
849	struct ttyent *ty;
850
851	tty=0;
852	setttyent();
853	while (NULL != (ty = getttyent())) {
854		tty++;
855		if (!strncmp(ty->ty_name, ut->ut_line, sizeof(ut->ut_line)))
856			break;
857	}
858	endttyent();
859
860	if (NULL == ty) {
861		logit("%s: tty not found", __func__);
862		return (0);
863	}
864#else /* FIXME */
865
866	tty = ttyslot(); /* seems only to work for /dev/ttyp? style names */
867
868#endif /* HAVE_GETTTYENT */
869
870	if (tty > 0 && (fd = open(UTMP_FILE, O_RDWR|O_CREAT, 0644)) >= 0) {
871		off_t pos, ret;
872
873		pos = (off_t)tty * sizeof(struct utmp);
874		if ((ret = lseek(fd, pos, SEEK_SET)) == -1) {
875			logit("%s: lseek: %s", __func__, strerror(errno));
876			close(fd);
877			return (0);
878		}
879		if (ret != pos) {
880			logit("%s: Couldn't seek to tty %d slot in %s",
881			    __func__, tty, UTMP_FILE);
882			close(fd);
883			return (0);
884		}
885		/*
886		 * Prevent luser from zero'ing out ut_host.
887		 * If the new ut_line is empty but the old one is not
888		 * and ut_line and ut_name match, preserve the old ut_line.
889		 */
890		if (atomicio(read, fd, &old_ut, sizeof(old_ut)) == sizeof(old_ut) &&
891		    (ut->ut_host[0] == '\0') && (old_ut.ut_host[0] != '\0') &&
892		    (strncmp(old_ut.ut_line, ut->ut_line, sizeof(ut->ut_line)) == 0) &&
893		    (strncmp(old_ut.ut_name, ut->ut_name, sizeof(ut->ut_name)) == 0))
894			memcpy(ut->ut_host, old_ut.ut_host, sizeof(ut->ut_host));
895
896		if ((ret = lseek(fd, pos, SEEK_SET)) == -1) {
897			logit("%s: lseek: %s", __func__, strerror(errno));
898			close(fd);
899			return (0);
900		}
901		if (ret != pos) {
902			logit("%s: Couldn't seek to tty %d slot in %s",
903			    __func__, tty, UTMP_FILE);
904			close(fd);
905			return (0);
906		}
907		if (atomicio(vwrite, fd, ut, sizeof(*ut)) != sizeof(*ut)) {
908			logit("%s: error writing %s: %s", __func__,
909			    UTMP_FILE, strerror(errno));
910			close(fd);
911			return (0);
912		}
913
914		close(fd);
915		return (1);
916	} else {
917		return (0);
918	}
919}
920# endif /* UTMP_USE_LIBRARY */
921
922static int
923utmp_perform_login(struct logininfo *li)
924{
925	struct utmp ut;
926
927	construct_utmp(li, &ut);
928# ifdef UTMP_USE_LIBRARY
929	if (!utmp_write_library(li, &ut)) {
930		logit("%s: utmp_write_library() failed", __func__);
931		return (0);
932	}
933# else
934	if (!utmp_write_direct(li, &ut)) {
935		logit("%s: utmp_write_direct() failed", __func__);
936		return (0);
937	}
938# endif
939	return (1);
940}
941
942
943static int
944utmp_perform_logout(struct logininfo *li)
945{
946	struct utmp ut;
947
948	construct_utmp(li, &ut);
949# ifdef UTMP_USE_LIBRARY
950	if (!utmp_write_library(li, &ut)) {
951		logit("%s: utmp_write_library() failed", __func__);
952		return (0);
953	}
954# else
955	if (!utmp_write_direct(li, &ut)) {
956		logit("%s: utmp_write_direct() failed", __func__);
957		return (0);
958	}
959# endif
960	return (1);
961}
962
963
964int
965utmp_write_entry(struct logininfo *li)
966{
967	switch(li->type) {
968	case LTYPE_LOGIN:
969		return (utmp_perform_login(li));
970
971	case LTYPE_LOGOUT:
972		return (utmp_perform_logout(li));
973
974	default:
975		logit("%s: invalid type field", __func__);
976		return (0);
977	}
978}
979#endif /* USE_UTMP */
980
981
982/**
983 ** Low-level utmpx functions
984 **/
985
986/* not much point if we don't want utmpx entries */
987#ifdef USE_UTMPX
988
989/* if we have the wherewithall, use pututxline etc. */
990# if !defined(DISABLE_PUTUTXLINE) && defined(HAVE_SETUTXENT) && \
991	defined(HAVE_PUTUTXLINE)
992#  define UTMPX_USE_LIBRARY
993# endif
994
995
996/* write a utmpx entry with the system's help (pututxline() and pals) */
997# ifdef UTMPX_USE_LIBRARY
998static int
999utmpx_write_library(struct logininfo *li, struct utmpx *utx)
1000{
1001	setutxent();
1002	pututxline(utx);
1003
1004#  ifdef HAVE_ENDUTXENT
1005	endutxent();
1006#  endif
1007	return (1);
1008}
1009
1010# else /* UTMPX_USE_LIBRARY */
1011
1012/* write a utmp entry direct to the file */
1013static int
1014utmpx_write_direct(struct logininfo *li, struct utmpx *utx)
1015{
1016	logit("%s: not implemented!", __func__);
1017	return (0);
1018}
1019# endif /* UTMPX_USE_LIBRARY */
1020
1021static int
1022utmpx_perform_login(struct logininfo *li)
1023{
1024	struct utmpx utx;
1025
1026	construct_utmpx(li, &utx);
1027# ifdef UTMPX_USE_LIBRARY
1028	if (!utmpx_write_library(li, &utx)) {
1029		logit("%s: utmp_write_library() failed", __func__);
1030		return (0);
1031	}
1032# else
1033	if (!utmpx_write_direct(li, &ut)) {
1034		logit("%s: utmp_write_direct() failed", __func__);
1035		return (0);
1036	}
1037# endif
1038	return (1);
1039}
1040
1041
1042static int
1043utmpx_perform_logout(struct logininfo *li)
1044{
1045	struct utmpx utx;
1046
1047	construct_utmpx(li, &utx);
1048# ifdef HAVE_ID_IN_UTMPX
1049	line_abbrevname(utx.ut_id, li->line, sizeof(utx.ut_id));
1050# endif
1051# ifdef HAVE_TYPE_IN_UTMPX
1052	utx.ut_type = DEAD_PROCESS;
1053# endif
1054
1055# ifdef UTMPX_USE_LIBRARY
1056	utmpx_write_library(li, &utx);
1057# else
1058	utmpx_write_direct(li, &utx);
1059# endif
1060	return (1);
1061}
1062
1063int
1064utmpx_write_entry(struct logininfo *li)
1065{
1066	switch(li->type) {
1067	case LTYPE_LOGIN:
1068		return (utmpx_perform_login(li));
1069	case LTYPE_LOGOUT:
1070		return (utmpx_perform_logout(li));
1071	default:
1072		logit("%s: invalid type field", __func__);
1073		return (0);
1074	}
1075}
1076#endif /* USE_UTMPX */
1077
1078
1079/**
1080 ** Low-level wtmp functions
1081 **/
1082
1083#ifdef USE_WTMP
1084
1085/*
1086 * Write a wtmp entry direct to the end of the file
1087 * This is a slight modification of code in OpenBSD's logwtmp.c
1088 */
1089static int
1090wtmp_write(struct logininfo *li, struct utmp *ut)
1091{
1092	struct stat buf;
1093	int fd, ret = 1;
1094
1095	if ((fd = open(WTMP_FILE, O_WRONLY|O_APPEND, 0)) < 0) {
1096		logit("%s: problem writing %s: %s", __func__,
1097		    WTMP_FILE, strerror(errno));
1098		return (0);
1099	}
1100	if (fstat(fd, &buf) == 0)
1101		if (atomicio(vwrite, fd, ut, sizeof(*ut)) != sizeof(*ut)) {
1102			ftruncate(fd, buf.st_size);
1103			logit("%s: problem writing %s: %s", __func__,
1104			    WTMP_FILE, strerror(errno));
1105			ret = 0;
1106		}
1107	close(fd);
1108	return (ret);
1109}
1110
1111static int
1112wtmp_perform_login(struct logininfo *li)
1113{
1114	struct utmp ut;
1115
1116	construct_utmp(li, &ut);
1117	return (wtmp_write(li, &ut));
1118}
1119
1120
1121static int
1122wtmp_perform_logout(struct logininfo *li)
1123{
1124	struct utmp ut;
1125
1126	construct_utmp(li, &ut);
1127	return (wtmp_write(li, &ut));
1128}
1129
1130
1131int
1132wtmp_write_entry(struct logininfo *li)
1133{
1134	switch(li->type) {
1135	case LTYPE_LOGIN:
1136		return (wtmp_perform_login(li));
1137	case LTYPE_LOGOUT:
1138		return (wtmp_perform_logout(li));
1139	default:
1140		logit("%s: invalid type field", __func__);
1141		return (0);
1142	}
1143}
1144
1145
1146/*
1147 * Notes on fetching login data from wtmp/wtmpx
1148 *
1149 * Logouts are usually recorded with (amongst other things) a blank
1150 * username on a given tty line.  However, some systems (HP-UX is one)
1151 * leave all fields set, but change the ut_type field to DEAD_PROCESS.
1152 *
1153 * Since we're only looking for logins here, we know that the username
1154 * must be set correctly. On systems that leave it in, we check for
1155 * ut_type==USER_PROCESS (indicating a login.)
1156 *
1157 * Portability: Some systems may set something other than USER_PROCESS
1158 * to indicate a login process. I don't know of any as I write. Also,
1159 * it's possible that some systems may both leave the username in
1160 * place and not have ut_type.
1161 */
1162
1163/* return true if this wtmp entry indicates a login */
1164static int
1165wtmp_islogin(struct logininfo *li, struct utmp *ut)
1166{
1167	if (strncmp(li->username, ut->ut_name,
1168	    MIN_SIZEOF(li->username, ut->ut_name)) == 0) {
1169# ifdef HAVE_TYPE_IN_UTMP
1170		if (ut->ut_type & USER_PROCESS)
1171			return (1);
1172# else
1173		return (1);
1174# endif
1175	}
1176	return (0);
1177}
1178
1179int
1180wtmp_get_entry(struct logininfo *li)
1181{
1182	struct stat st;
1183	struct utmp ut;
1184	int fd, found = 0;
1185
1186	/* Clear the time entries in our logininfo */
1187	li->tv_sec = li->tv_usec = 0;
1188
1189	if ((fd = open(WTMP_FILE, O_RDONLY)) < 0) {
1190		logit("%s: problem opening %s: %s", __func__,
1191		    WTMP_FILE, strerror(errno));
1192		return (0);
1193	}
1194	if (fstat(fd, &st) != 0) {
1195		logit("%s: couldn't stat %s: %s", __func__,
1196		    WTMP_FILE, strerror(errno));
1197		close(fd);
1198		return (0);
1199	}
1200
1201	/* Seek to the start of the last struct utmp */
1202	if (lseek(fd, -(off_t)sizeof(struct utmp), SEEK_END) == -1) {
1203		/* Looks like we've got a fresh wtmp file */
1204		close(fd);
1205		return (0);
1206	}
1207
1208	while (!found) {
1209		if (atomicio(read, fd, &ut, sizeof(ut)) != sizeof(ut)) {
1210			logit("%s: read of %s failed: %s", __func__,
1211			    WTMP_FILE, strerror(errno));
1212			close (fd);
1213			return (0);
1214		}
1215		if (wtmp_islogin(li, &ut) ) {
1216			found = 1;
1217			/*
1218			 * We've already checked for a time in struct
1219			 * utmp, in login_getlast()
1220			 */
1221# ifdef HAVE_TIME_IN_UTMP
1222			li->tv_sec = ut.ut_time;
1223# else
1224#  if HAVE_TV_IN_UTMP
1225			li->tv_sec = ut.ut_tv.tv_sec;
1226#  endif
1227# endif
1228			line_fullname(li->line, ut.ut_line,
1229			    MIN_SIZEOF(li->line, ut.ut_line));
1230# ifdef HAVE_HOST_IN_UTMP
1231			strlcpy(li->hostname, ut.ut_host,
1232			    MIN_SIZEOF(li->hostname, ut.ut_host));
1233# endif
1234			continue;
1235		}
1236		/* Seek back 2 x struct utmp */
1237		if (lseek(fd, -(off_t)(2 * sizeof(struct utmp)), SEEK_CUR) == -1) {
1238			/* We've found the start of the file, so quit */
1239			close(fd);
1240			return (0);
1241		}
1242	}
1243
1244	/* We found an entry. Tidy up and return */
1245	close(fd);
1246	return (1);
1247}
1248# endif /* USE_WTMP */
1249
1250
1251/**
1252 ** Low-level wtmpx functions
1253 **/
1254
1255#ifdef USE_WTMPX
1256/*
1257 * Write a wtmpx entry direct to the end of the file
1258 * This is a slight modification of code in OpenBSD's logwtmp.c
1259 */
1260static int
1261wtmpx_write(struct logininfo *li, struct utmpx *utx)
1262{
1263#ifndef HAVE_UPDWTMPX
1264	struct stat buf;
1265	int fd, ret = 1;
1266
1267	if ((fd = open(WTMPX_FILE, O_WRONLY|O_APPEND, 0)) < 0) {
1268		logit("%s: problem opening %s: %s", __func__,
1269		    WTMPX_FILE, strerror(errno));
1270		return (0);
1271	}
1272
1273	if (fstat(fd, &buf) == 0)
1274		if (atomicio(vwrite, fd, utx, sizeof(*utx)) != sizeof(*utx)) {
1275			ftruncate(fd, buf.st_size);
1276			logit("%s: problem writing %s: %s", __func__,
1277			    WTMPX_FILE, strerror(errno));
1278			ret = 0;
1279		}
1280	close(fd);
1281
1282	return (ret);
1283#else
1284	updwtmpx(WTMPX_FILE, utx);
1285	return (1);
1286#endif
1287}
1288
1289
1290static int
1291wtmpx_perform_login(struct logininfo *li)
1292{
1293	struct utmpx utx;
1294
1295	construct_utmpx(li, &utx);
1296	return (wtmpx_write(li, &utx));
1297}
1298
1299
1300static int
1301wtmpx_perform_logout(struct logininfo *li)
1302{
1303	struct utmpx utx;
1304
1305	construct_utmpx(li, &utx);
1306	return (wtmpx_write(li, &utx));
1307}
1308
1309
1310int
1311wtmpx_write_entry(struct logininfo *li)
1312{
1313	switch(li->type) {
1314	case LTYPE_LOGIN:
1315		return (wtmpx_perform_login(li));
1316	case LTYPE_LOGOUT:
1317		return (wtmpx_perform_logout(li));
1318	default:
1319		logit("%s: invalid type field", __func__);
1320		return (0);
1321	}
1322}
1323
1324/* Please see the notes above wtmp_islogin() for information about the
1325   next two functions */
1326
1327/* Return true if this wtmpx entry indicates a login */
1328static int
1329wtmpx_islogin(struct logininfo *li, struct utmpx *utx)
1330{
1331	if (strncmp(li->username, utx->ut_user,
1332	    MIN_SIZEOF(li->username, utx->ut_user)) == 0 ) {
1333# ifdef HAVE_TYPE_IN_UTMPX
1334		if (utx->ut_type == USER_PROCESS)
1335			return (1);
1336# else
1337		return (1);
1338# endif
1339	}
1340	return (0);
1341}
1342
1343
1344int
1345wtmpx_get_entry(struct logininfo *li)
1346{
1347	struct stat st;
1348	struct utmpx utx;
1349	int fd, found=0;
1350
1351	/* Clear the time entries */
1352	li->tv_sec = li->tv_usec = 0;
1353
1354	if ((fd = open(WTMPX_FILE, O_RDONLY)) < 0) {
1355		logit("%s: problem opening %s: %s", __func__,
1356		    WTMPX_FILE, strerror(errno));
1357		return (0);
1358	}
1359	if (fstat(fd, &st) != 0) {
1360		logit("%s: couldn't stat %s: %s", __func__,
1361		    WTMPX_FILE, strerror(errno));
1362		close(fd);
1363		return (0);
1364	}
1365
1366	/* Seek to the start of the last struct utmpx */
1367	if (lseek(fd, -(off_t)sizeof(struct utmpx), SEEK_END) == -1 ) {
1368		/* probably a newly rotated wtmpx file */
1369		close(fd);
1370		return (0);
1371	}
1372
1373	while (!found) {
1374		if (atomicio(read, fd, &utx, sizeof(utx)) != sizeof(utx)) {
1375			logit("%s: read of %s failed: %s", __func__,
1376			    WTMPX_FILE, strerror(errno));
1377			close (fd);
1378			return (0);
1379		}
1380		/*
1381		 * Logouts are recorded as a blank username on a particular
1382		 * line. So, we just need to find the username in struct utmpx
1383		 */
1384		if (wtmpx_islogin(li, &utx)) {
1385			found = 1;
1386# if defined(HAVE_TV_IN_UTMPX)
1387			li->tv_sec = utx.ut_tv.tv_sec;
1388# elif defined(HAVE_TIME_IN_UTMPX)
1389			li->tv_sec = utx.ut_time;
1390# endif
1391			line_fullname(li->line, utx.ut_line, sizeof(li->line));
1392# if defined(HAVE_HOST_IN_UTMPX)
1393			strlcpy(li->hostname, utx.ut_host,
1394			    MIN_SIZEOF(li->hostname, utx.ut_host));
1395# endif
1396			continue;
1397		}
1398		if (lseek(fd, -(off_t)(2 * sizeof(struct utmpx)), SEEK_CUR) == -1) {
1399			close(fd);
1400			return (0);
1401		}
1402	}
1403
1404	close(fd);
1405	return (1);
1406}
1407#endif /* USE_WTMPX */
1408
1409/**
1410 ** Low-level libutil login() functions
1411 **/
1412
1413#ifdef USE_LOGIN
1414static int
1415syslogin_perform_login(struct logininfo *li)
1416{
1417	struct utmp *ut;
1418
1419	ut = xmalloc(sizeof(*ut));
1420	construct_utmp(li, ut);
1421	login(ut);
1422	free(ut);
1423
1424	return (1);
1425}
1426
1427static int
1428syslogin_perform_logout(struct logininfo *li)
1429{
1430# ifdef HAVE_LOGOUT
1431	char line[UT_LINESIZE];
1432
1433	(void)line_stripname(line, li->line, sizeof(line));
1434
1435	if (!logout(line))
1436		logit("%s: logout() returned an error", __func__);
1437#  ifdef HAVE_LOGWTMP
1438	else
1439		logwtmp(line, "", "");
1440#  endif
1441	/* FIXME: (ATL - if the need arises) What to do if we have
1442	 * login, but no logout?  what if logout but no logwtmp? All
1443	 * routines are in libutil so they should all be there,
1444	 * but... */
1445# endif
1446	return (1);
1447}
1448
1449int
1450syslogin_write_entry(struct logininfo *li)
1451{
1452	switch (li->type) {
1453	case LTYPE_LOGIN:
1454		return (syslogin_perform_login(li));
1455	case LTYPE_LOGOUT:
1456		return (syslogin_perform_logout(li));
1457	default:
1458		logit("%s: Invalid type field", __func__);
1459		return (0);
1460	}
1461}
1462#endif /* USE_LOGIN */
1463
1464/* end of file log-syslogin.c */
1465
1466/**
1467 ** Low-level lastlog functions
1468 **/
1469
1470#ifdef USE_LASTLOG
1471
1472#if !defined(LASTLOG_WRITE_PUTUTXLINE) || !defined(HAVE_GETLASTLOGXBYNAME)
1473/* open the file (using filemode) and seek to the login entry */
1474static int
1475lastlog_openseek(struct logininfo *li, int *fd, int filemode)
1476{
1477	off_t offset;
1478	char lastlog_file[1024];
1479	struct stat st;
1480
1481	if (stat(LASTLOG_FILE, &st) != 0) {
1482		logit("%s: Couldn't stat %s: %s", __func__,
1483		    LASTLOG_FILE, strerror(errno));
1484		return (0);
1485	}
1486	if (S_ISDIR(st.st_mode)) {
1487		snprintf(lastlog_file, sizeof(lastlog_file), "%s/%s",
1488		    LASTLOG_FILE, li->username);
1489	} else if (S_ISREG(st.st_mode)) {
1490		strlcpy(lastlog_file, LASTLOG_FILE, sizeof(lastlog_file));
1491	} else {
1492		logit("%s: %.100s is not a file or directory!", __func__,
1493		    LASTLOG_FILE);
1494		return (0);
1495	}
1496
1497	*fd = open(lastlog_file, filemode, 0600);
1498	if (*fd < 0) {
1499		debug("%s: Couldn't open %s: %s", __func__,
1500		    lastlog_file, strerror(errno));
1501		return (0);
1502	}
1503
1504	if (S_ISREG(st.st_mode)) {
1505		/* find this uid's offset in the lastlog file */
1506		offset = (off_t) ((u_long)li->uid * sizeof(struct lastlog));
1507
1508		if (lseek(*fd, offset, SEEK_SET) != offset) {
1509			logit("%s: %s->lseek(): %s", __func__,
1510			    lastlog_file, strerror(errno));
1511			close(*fd);
1512			return (0);
1513		}
1514	}
1515
1516	return (1);
1517}
1518#endif /* !LASTLOG_WRITE_PUTUTXLINE || !HAVE_GETLASTLOGXBYNAME */
1519
1520#ifdef LASTLOG_WRITE_PUTUTXLINE
1521int
1522lastlog_write_entry(struct logininfo *li)
1523{
1524	switch(li->type) {
1525	case LTYPE_LOGIN:
1526		return 1; /* lastlog written by pututxline */
1527	default:
1528		logit("lastlog_write_entry: Invalid type field");
1529		return 0;
1530	}
1531}
1532#else /* LASTLOG_WRITE_PUTUTXLINE */
1533int
1534lastlog_write_entry(struct logininfo *li)
1535{
1536	struct lastlog last;
1537	int fd;
1538
1539	switch(li->type) {
1540	case LTYPE_LOGIN:
1541		/* create our struct lastlog */
1542		memset(&last, '\0', sizeof(last));
1543		line_stripname(last.ll_line, li->line, sizeof(last.ll_line));
1544		strlcpy(last.ll_host, li->hostname,
1545		    MIN_SIZEOF(last.ll_host, li->hostname));
1546		last.ll_time = li->tv_sec;
1547
1548		if (!lastlog_openseek(li, &fd, O_RDWR|O_CREAT))
1549			return (0);
1550
1551		/* write the entry */
1552		if (atomicio(vwrite, fd, &last, sizeof(last)) != sizeof(last)) {
1553			close(fd);
1554			logit("%s: Error writing to %s: %s", __func__,
1555			    LASTLOG_FILE, strerror(errno));
1556			return (0);
1557		}
1558
1559		close(fd);
1560		return (1);
1561	default:
1562		logit("%s: Invalid type field", __func__);
1563		return (0);
1564	}
1565}
1566#endif /* LASTLOG_WRITE_PUTUTXLINE */
1567
1568#ifdef HAVE_GETLASTLOGXBYNAME
1569int
1570lastlog_get_entry(struct logininfo *li)
1571{
1572	struct lastlogx l, *ll;
1573
1574	if ((ll = getlastlogxbyname(li->username, &l)) == NULL) {
1575		memset(&l, '\0', sizeof(l));
1576		ll = &l;
1577	}
1578	line_fullname(li->line, ll->ll_line, sizeof(li->line));
1579	strlcpy(li->hostname, ll->ll_host,
1580		MIN_SIZEOF(li->hostname, ll->ll_host));
1581	li->tv_sec = ll->ll_tv.tv_sec;
1582	li->tv_usec = ll->ll_tv.tv_usec;
1583	return (1);
1584}
1585#else /* HAVE_GETLASTLOGXBYNAME */
1586int
1587lastlog_get_entry(struct logininfo *li)
1588{
1589	struct lastlog last;
1590	int fd, ret;
1591
1592	if (!lastlog_openseek(li, &fd, O_RDONLY))
1593		return (0);
1594
1595	ret = atomicio(read, fd, &last, sizeof(last));
1596	close(fd);
1597
1598	switch (ret) {
1599	case 0:
1600		memset(&last, '\0', sizeof(last));
1601		/* FALLTHRU */
1602	case sizeof(last):
1603		line_fullname(li->line, last.ll_line, sizeof(li->line));
1604		strlcpy(li->hostname, last.ll_host,
1605		    MIN_SIZEOF(li->hostname, last.ll_host));
1606		li->tv_sec = last.ll_time;
1607		return (1);
1608	case -1:
1609		error("%s: Error reading from %s: %s", __func__,
1610		    LASTLOG_FILE, strerror(errno));
1611		return (0);
1612	default:
1613		error("%s: Error reading from %s: Expecting %d, got %d",
1614		    __func__, LASTLOG_FILE, (int)sizeof(last), ret);
1615		return (0);
1616	}
1617
1618	/* NOTREACHED */
1619	return (0);
1620}
1621#endif /* HAVE_GETLASTLOGXBYNAME */
1622#endif /* USE_LASTLOG */
1623
1624#if defined(USE_UTMPX) && defined(HAVE_SETUTXDB) && \
1625    defined(UTXDB_LASTLOGIN) && defined(HAVE_GETUTXUSER)
1626int
1627utmpx_get_entry(struct logininfo *li)
1628{
1629	struct utmpx *utx;
1630
1631	if (setutxdb(UTXDB_LASTLOGIN, NULL) != 0)
1632		return (0);
1633	utx = getutxuser(li->username);
1634	if (utx == NULL) {
1635		endutxent();
1636		return (0);
1637	}
1638
1639	line_fullname(li->line, utx->ut_line,
1640	    MIN_SIZEOF(li->line, utx->ut_line));
1641	strlcpy(li->hostname, utx->ut_host,
1642	    MIN_SIZEOF(li->hostname, utx->ut_host));
1643	li->tv_sec = utx->ut_tv.tv_sec;
1644	li->tv_usec = utx->ut_tv.tv_usec;
1645	endutxent();
1646	return (1);
1647}
1648#endif /* USE_UTMPX && HAVE_SETUTXDB && UTXDB_LASTLOGIN && HAVE_GETUTXUSER */
1649
1650#ifdef USE_BTMP
1651  /*
1652   * Logs failed login attempts in _PATH_BTMP if that exists.
1653   * The most common login failure is to give password instead of username.
1654   * So the _PATH_BTMP file checked for the correct permission, so that
1655   * only root can read it.
1656   */
1657
1658void
1659record_failed_login(const char *username, const char *hostname,
1660    const char *ttyn)
1661{
1662	int fd;
1663	struct utmp ut;
1664	struct sockaddr_storage from;
1665	socklen_t fromlen = sizeof(from);
1666	struct sockaddr_in *a4;
1667	struct sockaddr_in6 *a6;
1668	time_t t;
1669	struct stat fst;
1670
1671	if (geteuid() != 0)
1672		return;
1673	if ((fd = open(_PATH_BTMP, O_WRONLY | O_APPEND)) < 0) {
1674		debug("Unable to open the btmp file %s: %s", _PATH_BTMP,
1675		    strerror(errno));
1676		return;
1677	}
1678	if (fstat(fd, &fst) < 0) {
1679		logit("%s: fstat of %s failed: %s", __func__, _PATH_BTMP,
1680		    strerror(errno));
1681		goto out;
1682	}
1683	if((fst.st_mode & (S_IXGRP | S_IRWXO)) || (fst.st_uid != 0)){
1684		logit("Excess permission or bad ownership on file %s",
1685		    _PATH_BTMP);
1686		goto out;
1687	}
1688
1689	memset(&ut, 0, sizeof(ut));
1690	/* strncpy because we don't necessarily want nul termination */
1691	strncpy(ut.ut_user, username, sizeof(ut.ut_user));
1692	strlcpy(ut.ut_line, "ssh:notty", sizeof(ut.ut_line));
1693
1694	time(&t);
1695	ut.ut_time = t;     /* ut_time is not always a time_t */
1696	ut.ut_type = LOGIN_PROCESS;
1697	ut.ut_pid = getpid();
1698
1699	/* strncpy because we don't necessarily want nul termination */
1700	strncpy(ut.ut_host, hostname, sizeof(ut.ut_host));
1701
1702	if (packet_connection_is_on_socket() &&
1703	    getpeername(packet_get_connection_in(),
1704	    (struct sockaddr *)&from, &fromlen) == 0) {
1705		ipv64_normalise_mapped(&from, &fromlen);
1706		if (from.ss_family == AF_INET) {
1707			a4 = (struct sockaddr_in *)&from;
1708			memcpy(&ut.ut_addr, &(a4->sin_addr),
1709			    MIN_SIZEOF(ut.ut_addr, a4->sin_addr));
1710		}
1711#ifdef HAVE_ADDR_V6_IN_UTMP
1712		if (from.ss_family == AF_INET6) {
1713			a6 = (struct sockaddr_in6 *)&from;
1714			memcpy(&ut.ut_addr_v6, &(a6->sin6_addr),
1715			    MIN_SIZEOF(ut.ut_addr_v6, a6->sin6_addr));
1716		}
1717#endif
1718	}
1719
1720	if (atomicio(vwrite, fd, &ut, sizeof(ut)) != sizeof(ut))
1721		error("Failed to write to %s: %s", _PATH_BTMP,
1722		    strerror(errno));
1723
1724out:
1725	close(fd);
1726}
1727#endif	/* USE_BTMP */
1728