xref: /openssh-portable/loginrec.c (revision ea1f6490)
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 #ifdef HAVE_SYS_TIME_H
154 # include <sys/time.h>
155 #endif
156 
157 #include <netinet/in.h>
158 
159 #include <stdlib.h>
160 #include <errno.h>
161 #include <fcntl.h>
162 #ifdef HAVE_PATHS_H
163 # include <paths.h>
164 #endif
165 #include <pwd.h>
166 #include <stdarg.h>
167 #include <stdio.h>
168 #include <string.h>
169 #include <time.h>
170 #include <unistd.h>
171 
172 #include "xmalloc.h"
173 #include "sshkey.h"
174 #include "hostfile.h"
175 #include "ssh.h"
176 #include "loginrec.h"
177 #include "log.h"
178 #include "atomicio.h"
179 #include "packet.h"
180 #include "canohost.h"
181 #include "auth.h"
182 #include "sshbuf.h"
183 #include "ssherr.h"
184 
185 #ifdef HAVE_UTIL_H
186 # include <util.h>
187 #endif
188 
189 /**
190  ** prototypes for helper functions in this file
191  **/
192 
193 #if HAVE_UTMP_H
194 void set_utmp_time(struct logininfo *li, struct utmp *ut);
195 void construct_utmp(struct logininfo *li, struct utmp *ut);
196 #endif
197 
198 #ifdef HAVE_UTMPX_H
199 void set_utmpx_time(struct logininfo *li, struct utmpx *ut);
200 void construct_utmpx(struct logininfo *li, struct utmpx *ut);
201 #endif
202 
203 int utmp_write_entry(struct logininfo *li);
204 int utmpx_write_entry(struct logininfo *li);
205 int wtmp_write_entry(struct logininfo *li);
206 int wtmpx_write_entry(struct logininfo *li);
207 int lastlog_write_entry(struct logininfo *li);
208 int syslogin_write_entry(struct logininfo *li);
209 
210 int getlast_entry(struct logininfo *li);
211 int lastlog_get_entry(struct logininfo *li);
212 int utmpx_get_entry(struct logininfo *li);
213 int wtmp_get_entry(struct logininfo *li);
214 int wtmpx_get_entry(struct logininfo *li);
215 
216 extern struct sshbuf *loginmsg;
217 
218 /* pick the shortest string */
219 #define MIN_SIZEOF(s1,s2) (sizeof(s1) < sizeof(s2) ? sizeof(s1) : sizeof(s2))
220 
221 /**
222  ** platform-independent login functions
223  **/
224 
225 /*
226  * login_login(struct logininfo *) - Record a login
227  *
228  * Call with a pointer to a struct logininfo initialised with
229  * login_init_entry() or login_alloc_entry()
230  *
231  * Returns:
232  *  >0 if successful
233  *  0  on failure (will use OpenSSH's logging facilities for diagnostics)
234  */
235 int
login_login(struct logininfo * li)236 login_login(struct logininfo *li)
237 {
238 	li->type = LTYPE_LOGIN;
239 	return (login_write(li));
240 }
241 
242 
243 /*
244  * login_logout(struct logininfo *) - Record a logout
245  *
246  * Call as with login_login()
247  *
248  * Returns:
249  *  >0 if successful
250  *  0  on failure (will use OpenSSH's logging facilities for diagnostics)
251  */
252 int
login_logout(struct logininfo * li)253 login_logout(struct logininfo *li)
254 {
255 	li->type = LTYPE_LOGOUT;
256 	return (login_write(li));
257 }
258 
259 /*
260  * login_get_lastlog_time(int) - Retrieve the last login time
261  *
262  * Retrieve the last login time for the given uid. Will try to use the
263  * system lastlog facilities if they are available, but will fall back
264  * to looking in wtmp/wtmpx if necessary
265  *
266  * Returns:
267  *   0 on failure, or if user has never logged in
268  *   Time in seconds from the epoch if successful
269  *
270  * Useful preprocessor symbols:
271  *   DISABLE_LASTLOG: If set, *never* even try to retrieve lastlog
272  *                    info
273  *   USE_LASTLOG: If set, indicates the presence of system lastlog
274  *                facilities. If this and DISABLE_LASTLOG are not set,
275  *                try to retrieve lastlog information from wtmp/wtmpx.
276  */
277 unsigned int
login_get_lastlog_time(const uid_t uid)278 login_get_lastlog_time(const uid_t uid)
279 {
280 	struct logininfo li;
281 
282 	if (login_get_lastlog(&li, uid))
283 		return (li.tv_sec);
284 	else
285 		return (0);
286 }
287 
288 /*
289  * login_get_lastlog(struct logininfo *, int)   - Retrieve a lastlog entry
290  *
291  * Retrieve a logininfo structure populated (only partially) with
292  * information from the system lastlog data, or from wtmp/wtmpx if no
293  * system lastlog information exists.
294  *
295  * Note this routine must be given a pre-allocated logininfo.
296  *
297  * Returns:
298  *  >0: A pointer to your struct logininfo if successful
299  *  0  on failure (will use OpenSSH's logging facilities for diagnostics)
300  */
301 struct logininfo *
login_get_lastlog(struct logininfo * li,const uid_t uid)302 login_get_lastlog(struct logininfo *li, const uid_t uid)
303 {
304 	struct passwd *pw;
305 
306 	memset(li, '\0', sizeof(*li));
307 	li->uid = uid;
308 
309 	/*
310 	 * If we don't have a 'real' lastlog, we need the username to
311 	 * reliably search wtmp(x) for the last login (see
312 	 * wtmp_get_entry().)
313 	 */
314 	pw = getpwuid(uid);
315 	if (pw == NULL)
316 		fatal("%s: Cannot find account for uid %ld", __func__,
317 		    (long)uid);
318 
319 	if (strlcpy(li->username, pw->pw_name, sizeof(li->username)) >=
320 	    sizeof(li->username)) {
321 		error("%s: username too long (%lu > max %lu)", __func__,
322 		    (unsigned long)strlen(pw->pw_name),
323 		    (unsigned long)sizeof(li->username) - 1);
324 		return NULL;
325 	}
326 
327 	if (getlast_entry(li))
328 		return (li);
329 	else
330 		return (NULL);
331 }
332 
333 /*
334  * login_alloc_entry(int, char*, char*, char*)    - Allocate and initialise
335  *                                                  a logininfo structure
336  *
337  * This function creates a new struct logininfo, a data structure
338  * meant to carry the information required to portably record login info.
339  *
340  * Returns a pointer to a newly created struct logininfo. If memory
341  * allocation fails, the program halts.
342  */
343 struct
login_alloc_entry(pid_t pid,const char * username,const char * hostname,const char * line)344 logininfo *login_alloc_entry(pid_t pid, const char *username,
345     const char *hostname, const char *line)
346 {
347 	struct logininfo *newli;
348 
349 	newli = xmalloc(sizeof(*newli));
350 	login_init_entry(newli, pid, username, hostname, line);
351 	return (newli);
352 }
353 
354 
355 /* login_free_entry(struct logininfo *)    - free struct memory */
356 void
login_free_entry(struct logininfo * li)357 login_free_entry(struct logininfo *li)
358 {
359 	free(li);
360 }
361 
362 
363 /* login_init_entry(struct logininfo *, int, char*, char*, char*)
364  *                                        - initialise a struct logininfo
365  *
366  * Populates a new struct logininfo, a data structure meant to carry
367  * the information required to portably record login info.
368  *
369  * Returns: 1
370  */
371 int
login_init_entry(struct logininfo * li,pid_t pid,const char * username,const char * hostname,const char * line)372 login_init_entry(struct logininfo *li, pid_t pid, const char *username,
373     const char *hostname, const char *line)
374 {
375 	struct passwd *pw;
376 
377 	memset(li, 0, sizeof(*li));
378 
379 	li->pid = pid;
380 
381 	/* set the line information */
382 	if (line)
383 		line_fullname(li->line, line, sizeof(li->line));
384 
385 	if (username) {
386 		strlcpy(li->username, username, sizeof(li->username));
387 		pw = getpwnam(li->username);
388 		if (pw == NULL) {
389 			fatal("%s: Cannot find user \"%s\"", __func__,
390 			    li->username);
391 		}
392 		li->uid = pw->pw_uid;
393 	}
394 
395 	if (hostname)
396 		strlcpy(li->hostname, hostname, sizeof(li->hostname));
397 
398 	return (1);
399 }
400 
401 /*
402  * login_set_current_time(struct logininfo *)    - set the current time
403  *
404  * Set the current time in a logininfo structure. This function is
405  * meant to eliminate the need to deal with system dependencies for
406  * time handling.
407  */
408 void
login_set_current_time(struct logininfo * li)409 login_set_current_time(struct logininfo *li)
410 {
411 	struct timeval tv;
412 
413 	gettimeofday(&tv, NULL);
414 
415 	li->tv_sec = tv.tv_sec;
416 	li->tv_usec = tv.tv_usec;
417 }
418 
419 /* copy a sockaddr_* into our logininfo */
420 void
login_set_addr(struct logininfo * li,const struct sockaddr * sa,const unsigned int sa_size)421 login_set_addr(struct logininfo *li, const struct sockaddr *sa,
422     const unsigned int sa_size)
423 {
424 	unsigned int bufsize = sa_size;
425 
426 	/* make sure we don't overrun our union */
427 	if (sizeof(li->hostaddr) < sa_size)
428 		bufsize = sizeof(li->hostaddr);
429 
430 	memcpy(&li->hostaddr.sa, sa, bufsize);
431 }
432 
433 
434 /**
435  ** login_write: Call low-level recording functions based on autoconf
436  ** results
437  **/
438 int
login_write(struct logininfo * li)439 login_write(struct logininfo *li)
440 {
441 #ifndef HAVE_CYGWIN
442 	if (geteuid() != 0) {
443 		logit("Attempt to write login records by non-root user (aborting)");
444 		return (1);
445 	}
446 #endif
447 
448 	/* set the timestamp */
449 	login_set_current_time(li);
450 #ifdef USE_LOGIN
451 	syslogin_write_entry(li);
452 #endif
453 #ifdef USE_LASTLOG
454 	if (li->type == LTYPE_LOGIN)
455 		lastlog_write_entry(li);
456 #endif
457 #ifdef USE_UTMP
458 	utmp_write_entry(li);
459 #endif
460 #ifdef USE_WTMP
461 	wtmp_write_entry(li);
462 #endif
463 #ifdef USE_UTMPX
464 	utmpx_write_entry(li);
465 #endif
466 #ifdef USE_WTMPX
467 	wtmpx_write_entry(li);
468 #endif
469 #ifdef CUSTOM_SYS_AUTH_RECORD_LOGIN
470 	if (li->type == LTYPE_LOGIN &&
471 	    !sys_auth_record_login(li->username,li->hostname,li->line,
472 	    loginmsg))
473 		logit("Writing login record failed for %s", li->username);
474 #endif
475 #ifdef SSH_AUDIT_EVENTS
476 	if (li->type == LTYPE_LOGIN)
477 		audit_session_open(li);
478 	else if (li->type == LTYPE_LOGOUT)
479 		audit_session_close(li);
480 #endif
481 	return (0);
482 }
483 
484 #ifdef LOGIN_NEEDS_UTMPX
485 int
login_utmp_only(struct logininfo * li)486 login_utmp_only(struct logininfo *li)
487 {
488 	li->type = LTYPE_LOGIN;
489 	login_set_current_time(li);
490 # ifdef USE_UTMP
491 	utmp_write_entry(li);
492 # endif
493 # ifdef USE_WTMP
494 	wtmp_write_entry(li);
495 # endif
496 # ifdef USE_UTMPX
497 	utmpx_write_entry(li);
498 # endif
499 # ifdef USE_WTMPX
500 	wtmpx_write_entry(li);
501 # endif
502 	return (0);
503 }
504 #endif
505 
506 /**
507  ** getlast_entry: Call low-level functions to retrieve the last login
508  **                time.
509  **/
510 
511 /* take the uid in li and return the last login time */
512 int
getlast_entry(struct logininfo * li)513 getlast_entry(struct logininfo *li)
514 {
515 #ifdef USE_LASTLOG
516 	return(lastlog_get_entry(li));
517 #else /* !USE_LASTLOG */
518 #if defined(USE_UTMPX) && defined(HAVE_SETUTXDB) && \
519     defined(UTXDB_LASTLOGIN) && defined(HAVE_GETUTXUSER)
520 	return (utmpx_get_entry(li));
521 #endif
522 
523 #if defined(DISABLE_LASTLOG)
524 	/* On some systems we shouldn't even try to obtain last login
525 	 * time, e.g. AIX */
526 	return (0);
527 # elif defined(USE_WTMP) && \
528     (defined(HAVE_TIME_IN_UTMP) || defined(HAVE_TV_IN_UTMP))
529 	/* retrieve last login time from utmp */
530 	return (wtmp_get_entry(li));
531 # elif defined(USE_WTMPX) && \
532     (defined(HAVE_TIME_IN_UTMPX) || defined(HAVE_TV_IN_UTMPX))
533 	/* If wtmp isn't available, try wtmpx */
534 	return (wtmpx_get_entry(li));
535 # else
536 	/* Give up: No means of retrieving last login time */
537 	return (0);
538 # endif /* DISABLE_LASTLOG */
539 #endif /* USE_LASTLOG */
540 }
541 
542 
543 
544 /*
545  * 'line' string utility functions
546  *
547  * These functions process the 'line' string into one of three forms:
548  *
549  * 1. The full filename (including '/dev')
550  * 2. The stripped name (excluding '/dev')
551  * 3. The abbreviated name (e.g. /dev/ttyp00 -> yp00
552  *                               /dev/pts/1  -> ts/1 )
553  *
554  * Form 3 is used on some systems to identify a .tmp.? entry when
555  * attempting to remove it. Typically both addition and removal is
556  * performed by one application - say, sshd - so as long as the choice
557  * uniquely identifies a terminal it's ok.
558  */
559 
560 
561 /*
562  * line_fullname(): add the leading '/dev/' if it doesn't exist make
563  * sure dst has enough space, if not just copy src (ugh)
564  */
565 char *
line_fullname(char * dst,const char * src,u_int dstsize)566 line_fullname(char *dst, const char *src, u_int dstsize)
567 {
568 	memset(dst, '\0', dstsize);
569 	if ((strncmp(src, "/dev/", 5) == 0) || (dstsize < (strlen(src) + 5)))
570 		strlcpy(dst, src, dstsize);
571 	else {
572 		strlcpy(dst, "/dev/", dstsize);
573 		strlcat(dst, src, dstsize);
574 	}
575 	return (dst);
576 }
577 
578 /* line_stripname(): strip the leading '/dev' if it exists, return dst */
579 char *
line_stripname(char * dst,const char * src,int dstsize)580 line_stripname(char *dst, const char *src, int dstsize)
581 {
582 	memset(dst, '\0', dstsize);
583 	if (strncmp(src, "/dev/", 5) == 0)
584 		strlcpy(dst, src + 5, dstsize);
585 	else
586 		strlcpy(dst, src, dstsize);
587 	return (dst);
588 }
589 
590 /*
591  * line_abbrevname(): Return the abbreviated (usually four-character)
592  * form of the line (Just use the last <dstsize> characters of the
593  * full name.)
594  *
595  * NOTE: use strncpy because we do NOT necessarily want zero
596  * termination
597  */
598 char *
line_abbrevname(char * dst,const char * src,int dstsize)599 line_abbrevname(char *dst, const char *src, int dstsize)
600 {
601 	size_t len;
602 
603 	memset(dst, '\0', dstsize);
604 
605 	/* Always skip prefix if present */
606 	if (strncmp(src, "/dev/", 5) == 0)
607 		src += 5;
608 
609 #ifdef WITH_ABBREV_NO_TTY
610 	if (strncmp(src, "tty", 3) == 0)
611 		src += 3;
612 #endif
613 
614 	len = strlen(src);
615 
616 	if (len > 0) {
617 		if (((int)len - dstsize) > 0)
618 			src +=  ((int)len - dstsize);
619 
620 		/* note: _don't_ change this to strlcpy */
621 		strncpy(dst, src, (size_t)dstsize);
622 	}
623 
624 	return (dst);
625 }
626 
627 /**
628  ** utmp utility functions
629  **
630  ** These functions manipulate struct utmp, taking system differences
631  ** into account.
632  **/
633 
634 #if defined(USE_UTMP) || defined (USE_WTMP) || defined (USE_LOGIN)
635 
636 /* build the utmp structure */
637 void
set_utmp_time(struct logininfo * li,struct utmp * ut)638 set_utmp_time(struct logininfo *li, struct utmp *ut)
639 {
640 # if defined(HAVE_TV_IN_UTMP)
641 	ut->ut_tv.tv_sec = li->tv_sec;
642 	ut->ut_tv.tv_usec = li->tv_usec;
643 # elif defined(HAVE_TIME_IN_UTMP)
644 	ut->ut_time = li->tv_sec;
645 # endif
646 }
647 
648 void
construct_utmp(struct logininfo * li,struct utmp * ut)649 construct_utmp(struct logininfo *li,
650 		    struct utmp *ut)
651 {
652 # ifdef HAVE_ADDR_V6_IN_UTMP
653 	struct sockaddr_in6 *sa6;
654 # endif
655 
656 	memset(ut, '\0', sizeof(*ut));
657 
658 	/* First fill out fields used for both logins and logouts */
659 
660 # ifdef HAVE_ID_IN_UTMP
661 	line_abbrevname(ut->ut_id, li->line, sizeof(ut->ut_id));
662 # endif
663 
664 # ifdef HAVE_TYPE_IN_UTMP
665 	/* This is done here to keep utmp constants out of struct logininfo */
666 	switch (li->type) {
667 	case LTYPE_LOGIN:
668 		ut->ut_type = USER_PROCESS;
669 		break;
670 	case LTYPE_LOGOUT:
671 		ut->ut_type = DEAD_PROCESS;
672 		break;
673 	}
674 # endif
675 	set_utmp_time(li, ut);
676 
677 	line_stripname(ut->ut_line, li->line, sizeof(ut->ut_line));
678 
679 # ifdef HAVE_PID_IN_UTMP
680 	ut->ut_pid = li->pid;
681 # endif
682 
683 	/* If we're logging out, leave all other fields blank */
684 	if (li->type == LTYPE_LOGOUT)
685 		return;
686 
687 	/*
688 	 * These fields are only used when logging in, and are blank
689 	 * for logouts.
690 	 */
691 
692 	/* Use strncpy because we don't necessarily want null termination */
693 	strncpy(ut->ut_name, li->username,
694 	    MIN_SIZEOF(ut->ut_name, li->username));
695 # ifdef HAVE_HOST_IN_UTMP
696 	strncpy(ut->ut_host, li->hostname,
697 	    MIN_SIZEOF(ut->ut_host, li->hostname));
698 # endif
699 # ifdef HAVE_ADDR_IN_UTMP
700 	/* this is just a 32-bit IP address */
701 	if (li->hostaddr.sa.sa_family == AF_INET)
702 		ut->ut_addr = li->hostaddr.sa_in.sin_addr.s_addr;
703 # endif
704 # ifdef HAVE_ADDR_V6_IN_UTMP
705 	/* this is just a 128-bit IPv6 address */
706 	if (li->hostaddr.sa.sa_family == AF_INET6) {
707 		sa6 = ((struct sockaddr_in6 *)&li->hostaddr.sa);
708 		memcpy(ut->ut_addr_v6, sa6->sin6_addr.s6_addr, 16);
709 		if (IN6_IS_ADDR_V4MAPPED(&sa6->sin6_addr)) {
710 			ut->ut_addr_v6[0] = ut->ut_addr_v6[3];
711 			ut->ut_addr_v6[1] = 0;
712 			ut->ut_addr_v6[2] = 0;
713 			ut->ut_addr_v6[3] = 0;
714 		}
715 	}
716 # endif
717 }
718 #endif /* USE_UTMP || USE_WTMP || USE_LOGIN */
719 
720 /**
721  ** utmpx utility functions
722  **
723  ** These functions manipulate struct utmpx, accounting for system
724  ** variations.
725  **/
726 
727 #if defined(USE_UTMPX) || defined (USE_WTMPX)
728 /* build the utmpx structure */
729 void
set_utmpx_time(struct logininfo * li,struct utmpx * utx)730 set_utmpx_time(struct logininfo *li, struct utmpx *utx)
731 {
732 # if defined(HAVE_TV_IN_UTMPX)
733 	utx->ut_tv.tv_sec = li->tv_sec;
734 	utx->ut_tv.tv_usec = li->tv_usec;
735 # elif defined(HAVE_TIME_IN_UTMPX)
736 	utx->ut_time = li->tv_sec;
737 # endif
738 }
739 
740 void
construct_utmpx(struct logininfo * li,struct utmpx * utx)741 construct_utmpx(struct logininfo *li, struct utmpx *utx)
742 {
743 # ifdef HAVE_ADDR_V6_IN_UTMP
744 	struct sockaddr_in6 *sa6;
745 #  endif
746 	memset(utx, '\0', sizeof(*utx));
747 
748 # ifdef HAVE_ID_IN_UTMPX
749 	line_abbrevname(utx->ut_id, li->line, sizeof(utx->ut_id));
750 # endif
751 
752 	/* this is done here to keep utmp constants out of loginrec.h */
753 	switch (li->type) {
754 	case LTYPE_LOGIN:
755 		utx->ut_type = USER_PROCESS;
756 		break;
757 	case LTYPE_LOGOUT:
758 		utx->ut_type = DEAD_PROCESS;
759 		break;
760 	}
761 	line_stripname(utx->ut_line, li->line, sizeof(utx->ut_line));
762 	set_utmpx_time(li, utx);
763 	utx->ut_pid = li->pid;
764 
765 	/* strncpy(): Don't necessarily want null termination */
766 	strncpy(utx->ut_user, li->username,
767 	    MIN_SIZEOF(utx->ut_user, li->username));
768 
769 	if (li->type == LTYPE_LOGOUT)
770 		return;
771 
772 	/*
773 	 * These fields are only used when logging in, and are blank
774 	 * for logouts.
775 	 */
776 
777 # ifdef HAVE_HOST_IN_UTMPX
778 	strncpy(utx->ut_host, li->hostname,
779 	    MIN_SIZEOF(utx->ut_host, li->hostname));
780 # endif
781 # ifdef HAVE_SS_IN_UTMPX
782 	utx->ut_ss = li->hostaddr.sa_storage;
783 # endif
784 # ifdef HAVE_ADDR_IN_UTMPX
785 	/* this is just a 32-bit IP address */
786 	if (li->hostaddr.sa.sa_family == AF_INET)
787 		utx->ut_addr = li->hostaddr.sa_in.sin_addr.s_addr;
788 # endif
789 # ifdef HAVE_ADDR_V6_IN_UTMP
790 	/* this is just a 128-bit IPv6 address */
791 	if (li->hostaddr.sa.sa_family == AF_INET6) {
792 		sa6 = ((struct sockaddr_in6 *)&li->hostaddr.sa);
793 		memcpy(utx->ut_addr_v6, sa6->sin6_addr.s6_addr, 16);
794 		if (IN6_IS_ADDR_V4MAPPED(&sa6->sin6_addr)) {
795 			utx->ut_addr_v6[0] = utx->ut_addr_v6[3];
796 			utx->ut_addr_v6[1] = 0;
797 			utx->ut_addr_v6[2] = 0;
798 			utx->ut_addr_v6[3] = 0;
799 		}
800 	}
801 # endif
802 # ifdef HAVE_SYSLEN_IN_UTMPX
803 	/* ut_syslen is the length of the utx_host string */
804 	utx->ut_syslen = MIN(strlen(li->hostname), sizeof(utx->ut_host));
805 # endif
806 }
807 #endif /* USE_UTMPX || USE_WTMPX */
808 
809 /**
810  ** Low-level utmp functions
811  **/
812 
813 /* FIXME: (ATL) utmp_write_direct needs testing */
814 #ifdef USE_UTMP
815 
816 /* if we can, use pututline() etc. */
817 # if !defined(DISABLE_PUTUTLINE) && defined(HAVE_SETUTENT) && \
818 	defined(HAVE_PUTUTLINE)
819 #  define UTMP_USE_LIBRARY
820 # endif
821 
822 
823 /* write a utmp entry with the system's help (pututline() and pals) */
824 # ifdef UTMP_USE_LIBRARY
825 static int
utmp_write_library(struct logininfo * li,struct utmp * ut)826 utmp_write_library(struct logininfo *li, struct utmp *ut)
827 {
828 	setutent();
829 	pututline(ut);
830 #  ifdef HAVE_ENDUTENT
831 	endutent();
832 #  endif
833 	return (1);
834 }
835 # else /* UTMP_USE_LIBRARY */
836 
837 /*
838  * Write a utmp entry direct to the file
839  * This is a slightly modification of code in OpenBSD's login.c
840  */
841 static int
utmp_write_direct(struct logininfo * li,struct utmp * ut)842 utmp_write_direct(struct logininfo *li, struct utmp *ut)
843 {
844 	struct utmp old_ut;
845 	register int fd;
846 	int tty;
847 
848 	/* FIXME: (ATL) ttyslot() needs local implementation */
849 
850 #if defined(HAVE_GETTTYENT)
851 	struct ttyent *ty;
852 
853 	tty=0;
854 	setttyent();
855 	while (NULL != (ty = getttyent())) {
856 		tty++;
857 		if (!strncmp(ty->ty_name, ut->ut_line, sizeof(ut->ut_line)))
858 			break;
859 	}
860 	endttyent();
861 
862 	if (NULL == ty) {
863 		logit("%s: tty not found", __func__);
864 		return (0);
865 	}
866 #else /* FIXME */
867 
868 	tty = ttyslot(); /* seems only to work for /dev/ttyp? style names */
869 
870 #endif /* HAVE_GETTTYENT */
871 
872 	if (tty > 0 && (fd = open(UTMP_FILE, O_RDWR|O_CREAT, 0644)) >= 0) {
873 		off_t pos, ret;
874 
875 		pos = (off_t)tty * sizeof(struct utmp);
876 		if ((ret = lseek(fd, pos, SEEK_SET)) == -1) {
877 			logit("%s: lseek: %s", __func__, strerror(errno));
878 			close(fd);
879 			return (0);
880 		}
881 		if (ret != pos) {
882 			logit("%s: Couldn't seek to tty %d slot in %s",
883 			    __func__, tty, UTMP_FILE);
884 			close(fd);
885 			return (0);
886 		}
887 		/*
888 		 * Prevent luser from zero'ing out ut_host.
889 		 * If the new ut_line is empty but the old one is not
890 		 * and ut_line and ut_name match, preserve the old ut_line.
891 		 */
892 		if (atomicio(read, fd, &old_ut, sizeof(old_ut)) == sizeof(old_ut) &&
893 		    (ut->ut_host[0] == '\0') && (old_ut.ut_host[0] != '\0') &&
894 		    (strncmp(old_ut.ut_line, ut->ut_line, sizeof(ut->ut_line)) == 0) &&
895 		    (strncmp(old_ut.ut_name, ut->ut_name, sizeof(ut->ut_name)) == 0))
896 			memcpy(ut->ut_host, old_ut.ut_host, sizeof(ut->ut_host));
897 
898 		if ((ret = lseek(fd, pos, SEEK_SET)) == -1) {
899 			logit("%s: lseek: %s", __func__, strerror(errno));
900 			close(fd);
901 			return (0);
902 		}
903 		if (ret != pos) {
904 			logit("%s: Couldn't seek to tty %d slot in %s",
905 			    __func__, tty, UTMP_FILE);
906 			close(fd);
907 			return (0);
908 		}
909 		if (atomicio(vwrite, fd, ut, sizeof(*ut)) != sizeof(*ut)) {
910 			logit("%s: error writing %s: %s", __func__,
911 			    UTMP_FILE, strerror(errno));
912 			close(fd);
913 			return (0);
914 		}
915 
916 		close(fd);
917 		return (1);
918 	} else {
919 		return (0);
920 	}
921 }
922 # endif /* UTMP_USE_LIBRARY */
923 
924 static int
utmp_perform_login(struct logininfo * li)925 utmp_perform_login(struct logininfo *li)
926 {
927 	struct utmp ut;
928 
929 	construct_utmp(li, &ut);
930 # ifdef UTMP_USE_LIBRARY
931 	if (!utmp_write_library(li, &ut)) {
932 		logit("%s: utmp_write_library() failed", __func__);
933 		return (0);
934 	}
935 # else
936 	if (!utmp_write_direct(li, &ut)) {
937 		logit("%s: utmp_write_direct() failed", __func__);
938 		return (0);
939 	}
940 # endif
941 	return (1);
942 }
943 
944 
945 static int
utmp_perform_logout(struct logininfo * li)946 utmp_perform_logout(struct logininfo *li)
947 {
948 	struct utmp ut;
949 
950 	construct_utmp(li, &ut);
951 # ifdef UTMP_USE_LIBRARY
952 	if (!utmp_write_library(li, &ut)) {
953 		logit("%s: utmp_write_library() failed", __func__);
954 		return (0);
955 	}
956 # else
957 	if (!utmp_write_direct(li, &ut)) {
958 		logit("%s: utmp_write_direct() failed", __func__);
959 		return (0);
960 	}
961 # endif
962 	return (1);
963 }
964 
965 
966 int
utmp_write_entry(struct logininfo * li)967 utmp_write_entry(struct logininfo *li)
968 {
969 	switch(li->type) {
970 	case LTYPE_LOGIN:
971 		return (utmp_perform_login(li));
972 
973 	case LTYPE_LOGOUT:
974 		return (utmp_perform_logout(li));
975 
976 	default:
977 		logit("%s: invalid type field", __func__);
978 		return (0);
979 	}
980 }
981 #endif /* USE_UTMP */
982 
983 
984 /**
985  ** Low-level utmpx functions
986  **/
987 
988 /* not much point if we don't want utmpx entries */
989 #ifdef USE_UTMPX
990 
991 /* if we have the wherewithall, use pututxline etc. */
992 # if !defined(DISABLE_PUTUTXLINE) && defined(HAVE_SETUTXENT) && \
993 	defined(HAVE_PUTUTXLINE)
994 #  define UTMPX_USE_LIBRARY
995 # endif
996 
997 
998 /* write a utmpx entry with the system's help (pututxline() and pals) */
999 # ifdef UTMPX_USE_LIBRARY
1000 static int
utmpx_write_library(struct logininfo * li,struct utmpx * utx)1001 utmpx_write_library(struct logininfo *li, struct utmpx *utx)
1002 {
1003 	setutxent();
1004 	pututxline(utx);
1005 
1006 #  ifdef HAVE_ENDUTXENT
1007 	endutxent();
1008 #  endif
1009 	return (1);
1010 }
1011 
1012 # else /* UTMPX_USE_LIBRARY */
1013 
1014 /* write a utmp entry direct to the file */
1015 static int
utmpx_write_direct(struct logininfo * li,struct utmpx * utx)1016 utmpx_write_direct(struct logininfo *li, struct utmpx *utx)
1017 {
1018 	logit("%s: not implemented!", __func__);
1019 	return (0);
1020 }
1021 # endif /* UTMPX_USE_LIBRARY */
1022 
1023 static int
utmpx_perform_login(struct logininfo * li)1024 utmpx_perform_login(struct logininfo *li)
1025 {
1026 	struct utmpx utx;
1027 
1028 	construct_utmpx(li, &utx);
1029 # ifdef UTMPX_USE_LIBRARY
1030 	if (!utmpx_write_library(li, &utx)) {
1031 		logit("%s: utmp_write_library() failed", __func__);
1032 		return (0);
1033 	}
1034 # else
1035 	if (!utmpx_write_direct(li, &ut)) {
1036 		logit("%s: utmp_write_direct() failed", __func__);
1037 		return (0);
1038 	}
1039 # endif
1040 	return (1);
1041 }
1042 
1043 
1044 static int
utmpx_perform_logout(struct logininfo * li)1045 utmpx_perform_logout(struct logininfo *li)
1046 {
1047 	struct utmpx utx;
1048 
1049 	construct_utmpx(li, &utx);
1050 # ifdef HAVE_ID_IN_UTMPX
1051 	line_abbrevname(utx.ut_id, li->line, sizeof(utx.ut_id));
1052 # endif
1053 # ifdef HAVE_TYPE_IN_UTMPX
1054 	utx.ut_type = DEAD_PROCESS;
1055 # endif
1056 
1057 # ifdef UTMPX_USE_LIBRARY
1058 	utmpx_write_library(li, &utx);
1059 # else
1060 	utmpx_write_direct(li, &utx);
1061 # endif
1062 	return (1);
1063 }
1064 
1065 int
utmpx_write_entry(struct logininfo * li)1066 utmpx_write_entry(struct logininfo *li)
1067 {
1068 	switch(li->type) {
1069 	case LTYPE_LOGIN:
1070 		return (utmpx_perform_login(li));
1071 	case LTYPE_LOGOUT:
1072 		return (utmpx_perform_logout(li));
1073 	default:
1074 		logit("%s: invalid type field", __func__);
1075 		return (0);
1076 	}
1077 }
1078 #endif /* USE_UTMPX */
1079 
1080 
1081 /**
1082  ** Low-level wtmp functions
1083  **/
1084 
1085 #ifdef USE_WTMP
1086 
1087 /*
1088  * Write a wtmp entry direct to the end of the file
1089  * This is a slight modification of code in OpenBSD's logwtmp.c
1090  */
1091 static int
wtmp_write(struct logininfo * li,struct utmp * ut)1092 wtmp_write(struct logininfo *li, struct utmp *ut)
1093 {
1094 	struct stat buf;
1095 	int fd, ret = 1;
1096 
1097 	if ((fd = open(WTMP_FILE, O_WRONLY|O_APPEND, 0)) < 0) {
1098 		logit("%s: problem writing %s: %s", __func__,
1099 		    WTMP_FILE, strerror(errno));
1100 		return (0);
1101 	}
1102 	if (fstat(fd, &buf) == 0)
1103 		if (atomicio(vwrite, fd, ut, sizeof(*ut)) != sizeof(*ut)) {
1104 			ftruncate(fd, buf.st_size);
1105 			logit("%s: problem writing %s: %s", __func__,
1106 			    WTMP_FILE, strerror(errno));
1107 			ret = 0;
1108 		}
1109 	close(fd);
1110 	return (ret);
1111 }
1112 
1113 static int
wtmp_perform_login(struct logininfo * li)1114 wtmp_perform_login(struct logininfo *li)
1115 {
1116 	struct utmp ut;
1117 
1118 	construct_utmp(li, &ut);
1119 	return (wtmp_write(li, &ut));
1120 }
1121 
1122 
1123 static int
wtmp_perform_logout(struct logininfo * li)1124 wtmp_perform_logout(struct logininfo *li)
1125 {
1126 	struct utmp ut;
1127 
1128 	construct_utmp(li, &ut);
1129 	return (wtmp_write(li, &ut));
1130 }
1131 
1132 
1133 int
wtmp_write_entry(struct logininfo * li)1134 wtmp_write_entry(struct logininfo *li)
1135 {
1136 	switch(li->type) {
1137 	case LTYPE_LOGIN:
1138 		return (wtmp_perform_login(li));
1139 	case LTYPE_LOGOUT:
1140 		return (wtmp_perform_logout(li));
1141 	default:
1142 		logit("%s: invalid type field", __func__);
1143 		return (0);
1144 	}
1145 }
1146 
1147 
1148 /*
1149  * Notes on fetching login data from wtmp/wtmpx
1150  *
1151  * Logouts are usually recorded with (amongst other things) a blank
1152  * username on a given tty line.  However, some systems (HP-UX is one)
1153  * leave all fields set, but change the ut_type field to DEAD_PROCESS.
1154  *
1155  * Since we're only looking for logins here, we know that the username
1156  * must be set correctly. On systems that leave it in, we check for
1157  * ut_type==USER_PROCESS (indicating a login.)
1158  *
1159  * Portability: Some systems may set something other than USER_PROCESS
1160  * to indicate a login process. I don't know of any as I write. Also,
1161  * it's possible that some systems may both leave the username in
1162  * place and not have ut_type.
1163  */
1164 
1165 /* return true if this wtmp entry indicates a login */
1166 static int
wtmp_islogin(struct logininfo * li,struct utmp * ut)1167 wtmp_islogin(struct logininfo *li, struct utmp *ut)
1168 {
1169 	if (strncmp(li->username, ut->ut_name,
1170 	    MIN_SIZEOF(li->username, ut->ut_name)) == 0) {
1171 # ifdef HAVE_TYPE_IN_UTMP
1172 		if (ut->ut_type & USER_PROCESS)
1173 			return (1);
1174 # else
1175 		return (1);
1176 # endif
1177 	}
1178 	return (0);
1179 }
1180 
1181 int
wtmp_get_entry(struct logininfo * li)1182 wtmp_get_entry(struct logininfo *li)
1183 {
1184 	struct stat st;
1185 	struct utmp ut;
1186 	int fd, found = 0;
1187 
1188 	/* Clear the time entries in our logininfo */
1189 	li->tv_sec = li->tv_usec = 0;
1190 
1191 	if ((fd = open(WTMP_FILE, O_RDONLY)) < 0) {
1192 		logit("%s: problem opening %s: %s", __func__,
1193 		    WTMP_FILE, strerror(errno));
1194 		return (0);
1195 	}
1196 	if (fstat(fd, &st) != 0) {
1197 		logit("%s: couldn't stat %s: %s", __func__,
1198 		    WTMP_FILE, strerror(errno));
1199 		close(fd);
1200 		return (0);
1201 	}
1202 
1203 	/* Seek to the start of the last struct utmp */
1204 	if (lseek(fd, -(off_t)sizeof(struct utmp), SEEK_END) == -1) {
1205 		/* Looks like we've got a fresh wtmp file */
1206 		close(fd);
1207 		return (0);
1208 	}
1209 
1210 	while (!found) {
1211 		if (atomicio(read, fd, &ut, sizeof(ut)) != sizeof(ut)) {
1212 			logit("%s: read of %s failed: %s", __func__,
1213 			    WTMP_FILE, strerror(errno));
1214 			close (fd);
1215 			return (0);
1216 		}
1217 		if (wtmp_islogin(li, &ut) ) {
1218 			found = 1;
1219 			/*
1220 			 * We've already checked for a time in struct
1221 			 * utmp, in login_getlast()
1222 			 */
1223 # ifdef HAVE_TIME_IN_UTMP
1224 			li->tv_sec = ut.ut_time;
1225 # else
1226 #  if HAVE_TV_IN_UTMP
1227 			li->tv_sec = ut.ut_tv.tv_sec;
1228 #  endif
1229 # endif
1230 			line_fullname(li->line, ut.ut_line,
1231 			    MIN_SIZEOF(li->line, ut.ut_line));
1232 # ifdef HAVE_HOST_IN_UTMP
1233 			strlcpy(li->hostname, ut.ut_host,
1234 			    MIN_SIZEOF(li->hostname, ut.ut_host));
1235 # endif
1236 			continue;
1237 		}
1238 		/* Seek back 2 x struct utmp */
1239 		if (lseek(fd, -(off_t)(2 * sizeof(struct utmp)), SEEK_CUR) == -1) {
1240 			/* We've found the start of the file, so quit */
1241 			close(fd);
1242 			return (0);
1243 		}
1244 	}
1245 
1246 	/* We found an entry. Tidy up and return */
1247 	close(fd);
1248 	return (1);
1249 }
1250 # endif /* USE_WTMP */
1251 
1252 
1253 /**
1254  ** Low-level wtmpx functions
1255  **/
1256 
1257 #ifdef USE_WTMPX
1258 /*
1259  * Write a wtmpx entry direct to the end of the file
1260  * This is a slight modification of code in OpenBSD's logwtmp.c
1261  */
1262 static int
wtmpx_write(struct logininfo * li,struct utmpx * utx)1263 wtmpx_write(struct logininfo *li, struct utmpx *utx)
1264 {
1265 #ifndef HAVE_UPDWTMPX
1266 	struct stat buf;
1267 	int fd, ret = 1;
1268 
1269 	if ((fd = open(WTMPX_FILE, O_WRONLY|O_APPEND, 0)) < 0) {
1270 		logit("%s: problem opening %s: %s", __func__,
1271 		    WTMPX_FILE, strerror(errno));
1272 		return (0);
1273 	}
1274 
1275 	if (fstat(fd, &buf) == 0)
1276 		if (atomicio(vwrite, fd, utx, sizeof(*utx)) != sizeof(*utx)) {
1277 			ftruncate(fd, buf.st_size);
1278 			logit("%s: problem writing %s: %s", __func__,
1279 			    WTMPX_FILE, strerror(errno));
1280 			ret = 0;
1281 		}
1282 	close(fd);
1283 
1284 	return (ret);
1285 #else
1286 	updwtmpx(WTMPX_FILE, utx);
1287 	return (1);
1288 #endif
1289 }
1290 
1291 
1292 static int
wtmpx_perform_login(struct logininfo * li)1293 wtmpx_perform_login(struct logininfo *li)
1294 {
1295 	struct utmpx utx;
1296 
1297 	construct_utmpx(li, &utx);
1298 	return (wtmpx_write(li, &utx));
1299 }
1300 
1301 
1302 static int
wtmpx_perform_logout(struct logininfo * li)1303 wtmpx_perform_logout(struct logininfo *li)
1304 {
1305 	struct utmpx utx;
1306 
1307 	construct_utmpx(li, &utx);
1308 	return (wtmpx_write(li, &utx));
1309 }
1310 
1311 
1312 int
wtmpx_write_entry(struct logininfo * li)1313 wtmpx_write_entry(struct logininfo *li)
1314 {
1315 	switch(li->type) {
1316 	case LTYPE_LOGIN:
1317 		return (wtmpx_perform_login(li));
1318 	case LTYPE_LOGOUT:
1319 		return (wtmpx_perform_logout(li));
1320 	default:
1321 		logit("%s: invalid type field", __func__);
1322 		return (0);
1323 	}
1324 }
1325 
1326 /* Please see the notes above wtmp_islogin() for information about the
1327    next two functions */
1328 
1329 /* Return true if this wtmpx entry indicates a login */
1330 static int
wtmpx_islogin(struct logininfo * li,struct utmpx * utx)1331 wtmpx_islogin(struct logininfo *li, struct utmpx *utx)
1332 {
1333 	if (strncmp(li->username, utx->ut_user,
1334 	    MIN_SIZEOF(li->username, utx->ut_user)) == 0 ) {
1335 # ifdef HAVE_TYPE_IN_UTMPX
1336 		if (utx->ut_type == USER_PROCESS)
1337 			return (1);
1338 # else
1339 		return (1);
1340 # endif
1341 	}
1342 	return (0);
1343 }
1344 
1345 
1346 int
wtmpx_get_entry(struct logininfo * li)1347 wtmpx_get_entry(struct logininfo *li)
1348 {
1349 	struct stat st;
1350 	struct utmpx utx;
1351 	int fd, found=0;
1352 
1353 	/* Clear the time entries */
1354 	li->tv_sec = li->tv_usec = 0;
1355 
1356 	if ((fd = open(WTMPX_FILE, O_RDONLY)) < 0) {
1357 		logit("%s: problem opening %s: %s", __func__,
1358 		    WTMPX_FILE, strerror(errno));
1359 		return (0);
1360 	}
1361 	if (fstat(fd, &st) != 0) {
1362 		logit("%s: couldn't stat %s: %s", __func__,
1363 		    WTMPX_FILE, strerror(errno));
1364 		close(fd);
1365 		return (0);
1366 	}
1367 
1368 	/* Seek to the start of the last struct utmpx */
1369 	if (lseek(fd, -(off_t)sizeof(struct utmpx), SEEK_END) == -1 ) {
1370 		/* probably a newly rotated wtmpx file */
1371 		close(fd);
1372 		return (0);
1373 	}
1374 
1375 	while (!found) {
1376 		if (atomicio(read, fd, &utx, sizeof(utx)) != sizeof(utx)) {
1377 			logit("%s: read of %s failed: %s", __func__,
1378 			    WTMPX_FILE, strerror(errno));
1379 			close (fd);
1380 			return (0);
1381 		}
1382 		/*
1383 		 * Logouts are recorded as a blank username on a particular
1384 		 * line. So, we just need to find the username in struct utmpx
1385 		 */
1386 		if (wtmpx_islogin(li, &utx)) {
1387 			found = 1;
1388 # if defined(HAVE_TV_IN_UTMPX)
1389 			li->tv_sec = utx.ut_tv.tv_sec;
1390 # elif defined(HAVE_TIME_IN_UTMPX)
1391 			li->tv_sec = utx.ut_time;
1392 # endif
1393 			line_fullname(li->line, utx.ut_line, sizeof(li->line));
1394 # if defined(HAVE_HOST_IN_UTMPX)
1395 			strlcpy(li->hostname, utx.ut_host,
1396 			    MIN_SIZEOF(li->hostname, utx.ut_host));
1397 # endif
1398 			continue;
1399 		}
1400 		if (lseek(fd, -(off_t)(2 * sizeof(struct utmpx)), SEEK_CUR) == -1) {
1401 			close(fd);
1402 			return (0);
1403 		}
1404 	}
1405 
1406 	close(fd);
1407 	return (1);
1408 }
1409 #endif /* USE_WTMPX */
1410 
1411 /**
1412  ** Low-level libutil login() functions
1413  **/
1414 
1415 #ifdef USE_LOGIN
1416 static int
syslogin_perform_login(struct logininfo * li)1417 syslogin_perform_login(struct logininfo *li)
1418 {
1419 	struct utmp *ut;
1420 
1421 	ut = xmalloc(sizeof(*ut));
1422 	construct_utmp(li, ut);
1423 	login(ut);
1424 	free(ut);
1425 
1426 	return (1);
1427 }
1428 
1429 static int
syslogin_perform_logout(struct logininfo * li)1430 syslogin_perform_logout(struct logininfo *li)
1431 {
1432 # ifdef HAVE_LOGOUT
1433 	char line[UT_LINESIZE];
1434 
1435 	(void)line_stripname(line, li->line, sizeof(line));
1436 
1437 	if (!logout(line))
1438 		logit("%s: logout() returned an error", __func__);
1439 #  ifdef HAVE_LOGWTMP
1440 	else
1441 		logwtmp(line, "", "");
1442 #  endif
1443 	/* FIXME: (ATL - if the need arises) What to do if we have
1444 	 * login, but no logout?  what if logout but no logwtmp? All
1445 	 * routines are in libutil so they should all be there,
1446 	 * but... */
1447 # endif
1448 	return (1);
1449 }
1450 
1451 int
syslogin_write_entry(struct logininfo * li)1452 syslogin_write_entry(struct logininfo *li)
1453 {
1454 	switch (li->type) {
1455 	case LTYPE_LOGIN:
1456 		return (syslogin_perform_login(li));
1457 	case LTYPE_LOGOUT:
1458 		return (syslogin_perform_logout(li));
1459 	default:
1460 		logit("%s: Invalid type field", __func__);
1461 		return (0);
1462 	}
1463 }
1464 #endif /* USE_LOGIN */
1465 
1466 /* end of file log-syslogin.c */
1467 
1468 /**
1469  ** Low-level lastlog functions
1470  **/
1471 
1472 #ifdef USE_LASTLOG
1473 
1474 #if !defined(LASTLOG_WRITE_PUTUTXLINE) || !defined(HAVE_GETLASTLOGXBYNAME)
1475 /* open the file (using filemode) and seek to the login entry */
1476 static int
lastlog_openseek(struct logininfo * li,int * fd,int filemode)1477 lastlog_openseek(struct logininfo *li, int *fd, int filemode)
1478 {
1479 	off_t offset;
1480 	char lastlog_file[1024];
1481 	struct stat st;
1482 
1483 	if (stat(LASTLOG_FILE, &st) != 0) {
1484 		logit("%s: Couldn't stat %s: %s", __func__,
1485 		    LASTLOG_FILE, strerror(errno));
1486 		return (0);
1487 	}
1488 	if (S_ISDIR(st.st_mode)) {
1489 		snprintf(lastlog_file, sizeof(lastlog_file), "%s/%s",
1490 		    LASTLOG_FILE, li->username);
1491 	} else if (S_ISREG(st.st_mode)) {
1492 		strlcpy(lastlog_file, LASTLOG_FILE, sizeof(lastlog_file));
1493 	} else {
1494 		logit("%s: %.100s is not a file or directory!", __func__,
1495 		    LASTLOG_FILE);
1496 		return (0);
1497 	}
1498 
1499 	*fd = open(lastlog_file, filemode, 0600);
1500 	if (*fd < 0) {
1501 		debug("%s: Couldn't open %s: %s", __func__,
1502 		    lastlog_file, strerror(errno));
1503 		return (0);
1504 	}
1505 
1506 	if (S_ISREG(st.st_mode)) {
1507 		/* find this uid's offset in the lastlog file */
1508 		offset = (off_t) ((u_long)li->uid * sizeof(struct lastlog));
1509 
1510 		if (lseek(*fd, offset, SEEK_SET) != offset) {
1511 			logit("%s: %s->lseek(): %s", __func__,
1512 			    lastlog_file, strerror(errno));
1513 			close(*fd);
1514 			return (0);
1515 		}
1516 	}
1517 
1518 	return (1);
1519 }
1520 #endif /* !LASTLOG_WRITE_PUTUTXLINE || !HAVE_GETLASTLOGXBYNAME */
1521 
1522 #ifdef LASTLOG_WRITE_PUTUTXLINE
1523 int
lastlog_write_entry(struct logininfo * li)1524 lastlog_write_entry(struct logininfo *li)
1525 {
1526 	switch(li->type) {
1527 	case LTYPE_LOGIN:
1528 		return 1; /* lastlog written by pututxline */
1529 	default:
1530 		logit("lastlog_write_entry: Invalid type field");
1531 		return 0;
1532 	}
1533 }
1534 #else /* LASTLOG_WRITE_PUTUTXLINE */
1535 int
lastlog_write_entry(struct logininfo * li)1536 lastlog_write_entry(struct logininfo *li)
1537 {
1538 	struct lastlog last;
1539 	int fd;
1540 
1541 	switch(li->type) {
1542 	case LTYPE_LOGIN:
1543 		/* create our struct lastlog */
1544 		memset(&last, '\0', sizeof(last));
1545 		line_stripname(last.ll_line, li->line, sizeof(last.ll_line));
1546 		strlcpy(last.ll_host, li->hostname,
1547 		    MIN_SIZEOF(last.ll_host, li->hostname));
1548 		last.ll_time = li->tv_sec;
1549 
1550 		if (!lastlog_openseek(li, &fd, O_RDWR|O_CREAT))
1551 			return (0);
1552 
1553 		/* write the entry */
1554 		if (atomicio(vwrite, fd, &last, sizeof(last)) != sizeof(last)) {
1555 			close(fd);
1556 			logit("%s: Error writing to %s: %s", __func__,
1557 			    LASTLOG_FILE, strerror(errno));
1558 			return (0);
1559 		}
1560 
1561 		close(fd);
1562 		return (1);
1563 	default:
1564 		logit("%s: Invalid type field", __func__);
1565 		return (0);
1566 	}
1567 }
1568 #endif /* LASTLOG_WRITE_PUTUTXLINE */
1569 
1570 #ifdef HAVE_GETLASTLOGXBYNAME
1571 int
lastlog_get_entry(struct logininfo * li)1572 lastlog_get_entry(struct logininfo *li)
1573 {
1574 	struct lastlogx l, *ll;
1575 
1576 	if ((ll = getlastlogxbyname(li->username, &l)) == NULL) {
1577 		memset(&l, '\0', sizeof(l));
1578 		ll = &l;
1579 	}
1580 	line_fullname(li->line, ll->ll_line, sizeof(li->line));
1581 	strlcpy(li->hostname, ll->ll_host,
1582 		MIN_SIZEOF(li->hostname, ll->ll_host));
1583 	li->tv_sec = ll->ll_tv.tv_sec;
1584 	li->tv_usec = ll->ll_tv.tv_usec;
1585 	return (1);
1586 }
1587 #else /* HAVE_GETLASTLOGXBYNAME */
1588 int
lastlog_get_entry(struct logininfo * li)1589 lastlog_get_entry(struct logininfo *li)
1590 {
1591 	struct lastlog last;
1592 	int fd, ret;
1593 
1594 	if (!lastlog_openseek(li, &fd, O_RDONLY))
1595 		return (0);
1596 
1597 	ret = atomicio(read, fd, &last, sizeof(last));
1598 	close(fd);
1599 
1600 	switch (ret) {
1601 	case 0:
1602 		memset(&last, '\0', sizeof(last));
1603 		/* FALLTHRU */
1604 	case sizeof(last):
1605 		line_fullname(li->line, last.ll_line, sizeof(li->line));
1606 		strlcpy(li->hostname, last.ll_host,
1607 		    MIN_SIZEOF(li->hostname, last.ll_host));
1608 		li->tv_sec = last.ll_time;
1609 		return (1);
1610 	case -1:
1611 		error("%s: Error reading from %s: %s", __func__,
1612 		    LASTLOG_FILE, strerror(errno));
1613 		return (0);
1614 	default:
1615 		error("%s: Error reading from %s: Expecting %d, got %d",
1616 		    __func__, LASTLOG_FILE, (int)sizeof(last), ret);
1617 		return (0);
1618 	}
1619 
1620 	/* NOTREACHED */
1621 	return (0);
1622 }
1623 #endif /* HAVE_GETLASTLOGXBYNAME */
1624 #endif /* USE_LASTLOG */
1625 
1626 #if defined(USE_UTMPX) && defined(HAVE_SETUTXDB) && \
1627     defined(UTXDB_LASTLOGIN) && defined(HAVE_GETUTXUSER)
1628 int
utmpx_get_entry(struct logininfo * li)1629 utmpx_get_entry(struct logininfo *li)
1630 {
1631 	struct utmpx *utx;
1632 
1633 	if (setutxdb(UTXDB_LASTLOGIN, NULL) != 0)
1634 		return (0);
1635 	utx = getutxuser(li->username);
1636 	if (utx == NULL) {
1637 		endutxent();
1638 		return (0);
1639 	}
1640 
1641 	line_fullname(li->line, utx->ut_line,
1642 	    MIN_SIZEOF(li->line, utx->ut_line));
1643 	strlcpy(li->hostname, utx->ut_host,
1644 	    MIN_SIZEOF(li->hostname, utx->ut_host));
1645 	li->tv_sec = utx->ut_tv.tv_sec;
1646 	li->tv_usec = utx->ut_tv.tv_usec;
1647 	endutxent();
1648 	return (1);
1649 }
1650 #endif /* USE_UTMPX && HAVE_SETUTXDB && UTXDB_LASTLOGIN && HAVE_GETUTXUSER */
1651 
1652 #ifdef USE_BTMP
1653   /*
1654    * Logs failed login attempts in _PATH_BTMP if that exists.
1655    * The most common login failure is to give password instead of username.
1656    * So the _PATH_BTMP file checked for the correct permission, so that
1657    * only root can read it.
1658    */
1659 
1660 void
record_failed_login(struct ssh * ssh,const char * username,const char * hostname,const char * ttyn)1661 record_failed_login(struct ssh *ssh, const char *username, const char *hostname,
1662     const char *ttyn)
1663 {
1664 	int fd;
1665 	struct utmp ut;
1666 	struct sockaddr_storage from;
1667 	socklen_t fromlen = sizeof(from);
1668 	struct sockaddr_in *a4;
1669 	struct sockaddr_in6 *a6;
1670 	time_t t;
1671 	struct stat fst;
1672 
1673 	if (geteuid() != 0)
1674 		return;
1675 	if ((fd = open(_PATH_BTMP, O_WRONLY | O_APPEND)) < 0) {
1676 		debug("Unable to open the btmp file %s: %s", _PATH_BTMP,
1677 		    strerror(errno));
1678 		return;
1679 	}
1680 	if (fstat(fd, &fst) < 0) {
1681 		logit("%s: fstat of %s failed: %s", __func__, _PATH_BTMP,
1682 		    strerror(errno));
1683 		goto out;
1684 	}
1685 	if((fst.st_mode & (S_IXGRP | S_IRWXO)) || (fst.st_uid != 0)){
1686 		logit("Excess permission or bad ownership on file %s",
1687 		    _PATH_BTMP);
1688 		goto out;
1689 	}
1690 
1691 	memset(&ut, 0, sizeof(ut));
1692 	/* strncpy because we don't necessarily want nul termination */
1693 	strncpy(ut.ut_user, username, sizeof(ut.ut_user));
1694 	strlcpy(ut.ut_line, "ssh:notty", sizeof(ut.ut_line));
1695 
1696 	time(&t);
1697 	ut.ut_time = t;     /* ut_time is not always a time_t */
1698 	ut.ut_type = LOGIN_PROCESS;
1699 	ut.ut_pid = getpid();
1700 
1701 	/* strncpy because we don't necessarily want nul termination */
1702 	strncpy(ut.ut_host, hostname, sizeof(ut.ut_host));
1703 
1704 	if (ssh_packet_connection_is_on_socket(ssh) &&
1705 	    getpeername(ssh_packet_get_connection_in(ssh),
1706 	    (struct sockaddr *)&from, &fromlen) == 0) {
1707 		ipv64_normalise_mapped(&from, &fromlen);
1708 		if (from.ss_family == AF_INET) {
1709 			a4 = (struct sockaddr_in *)&from;
1710 			memcpy(&ut.ut_addr, &(a4->sin_addr),
1711 			    MIN_SIZEOF(ut.ut_addr, a4->sin_addr));
1712 		}
1713 #ifdef HAVE_ADDR_V6_IN_UTMP
1714 		if (from.ss_family == AF_INET6) {
1715 			a6 = (struct sockaddr_in6 *)&from;
1716 			memcpy(&ut.ut_addr_v6, &(a6->sin6_addr),
1717 			    MIN_SIZEOF(ut.ut_addr_v6, a6->sin6_addr));
1718 		}
1719 #endif
1720 	}
1721 
1722 	if (atomicio(vwrite, fd, &ut, sizeof(ut)) != sizeof(ut))
1723 		error("Failed to write to %s: %s", _PATH_BTMP,
1724 		    strerror(errno));
1725 
1726 out:
1727 	close(fd);
1728 }
1729 #endif	/* USE_BTMP */
1730