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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_ADDR_IN_UTMPX
782 	/* this is just a 32-bit IP address */
783 	if (li->hostaddr.sa.sa_family == AF_INET)
784 		utx->ut_addr = li->hostaddr.sa_in.sin_addr.s_addr;
785 # endif
786 # ifdef HAVE_ADDR_V6_IN_UTMP
787 	/* this is just a 128-bit IPv6 address */
788 	if (li->hostaddr.sa.sa_family == AF_INET6) {
789 		sa6 = ((struct sockaddr_in6 *)&li->hostaddr.sa);
790 		memcpy(utx->ut_addr_v6, sa6->sin6_addr.s6_addr, 16);
791 		if (IN6_IS_ADDR_V4MAPPED(&sa6->sin6_addr)) {
792 			utx->ut_addr_v6[0] = utx->ut_addr_v6[3];
793 			utx->ut_addr_v6[1] = 0;
794 			utx->ut_addr_v6[2] = 0;
795 			utx->ut_addr_v6[3] = 0;
796 		}
797 	}
798 # endif
799 # ifdef HAVE_SYSLEN_IN_UTMPX
800 	/* ut_syslen is the length of the utx_host string */
801 	utx->ut_syslen = MIN(strlen(li->hostname), sizeof(utx->ut_host));
802 # endif
803 }
804 #endif /* USE_UTMPX || USE_WTMPX */
805 
806 /**
807  ** Low-level utmp functions
808  **/
809 
810 /* FIXME: (ATL) utmp_write_direct needs testing */
811 #ifdef USE_UTMP
812 
813 /* if we can, use pututline() etc. */
814 # if !defined(DISABLE_PUTUTLINE) && defined(HAVE_SETUTENT) && \
815 	defined(HAVE_PUTUTLINE)
816 #  define UTMP_USE_LIBRARY
817 # endif
818 
819 
820 /* write a utmp entry with the system's help (pututline() and pals) */
821 # ifdef UTMP_USE_LIBRARY
822 static int
utmp_write_library(struct logininfo * li,struct utmp * ut)823 utmp_write_library(struct logininfo *li, struct utmp *ut)
824 {
825 	setutent();
826 	pututline(ut);
827 #  ifdef HAVE_ENDUTENT
828 	endutent();
829 #  endif
830 	return (1);
831 }
832 # else /* UTMP_USE_LIBRARY */
833 
834 /*
835  * Write a utmp entry direct to the file
836  * This is a slightly modification of code in OpenBSD's login.c
837  */
838 static int
utmp_write_direct(struct logininfo * li,struct utmp * ut)839 utmp_write_direct(struct logininfo *li, struct utmp *ut)
840 {
841 	struct utmp old_ut;
842 	register int fd;
843 	int tty;
844 
845 	/* FIXME: (ATL) ttyslot() needs local implementation */
846 
847 #if defined(HAVE_GETTTYENT)
848 	struct ttyent *ty;
849 
850 	tty=0;
851 	setttyent();
852 	while (NULL != (ty = getttyent())) {
853 		tty++;
854 		if (!strncmp(ty->ty_name, ut->ut_line, sizeof(ut->ut_line)))
855 			break;
856 	}
857 	endttyent();
858 
859 	if (NULL == ty) {
860 		logit("%s: tty not found", __func__);
861 		return (0);
862 	}
863 #else /* FIXME */
864 
865 	tty = ttyslot(); /* seems only to work for /dev/ttyp? style names */
866 
867 #endif /* HAVE_GETTTYENT */
868 
869 	if (tty > 0 && (fd = open(UTMP_FILE, O_RDWR|O_CREAT, 0644)) >= 0) {
870 		off_t pos, ret;
871 
872 		pos = (off_t)tty * sizeof(struct utmp);
873 		if ((ret = lseek(fd, pos, SEEK_SET)) == -1) {
874 			logit("%s: lseek: %s", __func__, strerror(errno));
875 			close(fd);
876 			return (0);
877 		}
878 		if (ret != pos) {
879 			logit("%s: Couldn't seek to tty %d slot in %s",
880 			    __func__, tty, UTMP_FILE);
881 			close(fd);
882 			return (0);
883 		}
884 		/*
885 		 * Prevent luser from zero'ing out ut_host.
886 		 * If the new ut_line is empty but the old one is not
887 		 * and ut_line and ut_name match, preserve the old ut_line.
888 		 */
889 		if (atomicio(read, fd, &old_ut, sizeof(old_ut)) == sizeof(old_ut) &&
890 		    (ut->ut_host[0] == '\0') && (old_ut.ut_host[0] != '\0') &&
891 		    (strncmp(old_ut.ut_line, ut->ut_line, sizeof(ut->ut_line)) == 0) &&
892 		    (strncmp(old_ut.ut_name, ut->ut_name, sizeof(ut->ut_name)) == 0))
893 			memcpy(ut->ut_host, old_ut.ut_host, sizeof(ut->ut_host));
894 
895 		if ((ret = lseek(fd, pos, SEEK_SET)) == -1) {
896 			logit("%s: lseek: %s", __func__, strerror(errno));
897 			close(fd);
898 			return (0);
899 		}
900 		if (ret != pos) {
901 			logit("%s: Couldn't seek to tty %d slot in %s",
902 			    __func__, tty, UTMP_FILE);
903 			close(fd);
904 			return (0);
905 		}
906 		if (atomicio(vwrite, fd, ut, sizeof(*ut)) != sizeof(*ut)) {
907 			logit("%s: error writing %s: %s", __func__,
908 			    UTMP_FILE, strerror(errno));
909 			close(fd);
910 			return (0);
911 		}
912 
913 		close(fd);
914 		return (1);
915 	} else {
916 		return (0);
917 	}
918 }
919 # endif /* UTMP_USE_LIBRARY */
920 
921 static int
utmp_perform_login(struct logininfo * li)922 utmp_perform_login(struct logininfo *li)
923 {
924 	struct utmp ut;
925 
926 	construct_utmp(li, &ut);
927 # ifdef UTMP_USE_LIBRARY
928 	if (!utmp_write_library(li, &ut)) {
929 		logit("%s: utmp_write_library() failed", __func__);
930 		return (0);
931 	}
932 # else
933 	if (!utmp_write_direct(li, &ut)) {
934 		logit("%s: utmp_write_direct() failed", __func__);
935 		return (0);
936 	}
937 # endif
938 	return (1);
939 }
940 
941 
942 static int
utmp_perform_logout(struct logininfo * li)943 utmp_perform_logout(struct logininfo *li)
944 {
945 	struct utmp ut;
946 
947 	construct_utmp(li, &ut);
948 # ifdef UTMP_USE_LIBRARY
949 	if (!utmp_write_library(li, &ut)) {
950 		logit("%s: utmp_write_library() failed", __func__);
951 		return (0);
952 	}
953 # else
954 	if (!utmp_write_direct(li, &ut)) {
955 		logit("%s: utmp_write_direct() failed", __func__);
956 		return (0);
957 	}
958 # endif
959 	return (1);
960 }
961 
962 
963 int
utmp_write_entry(struct logininfo * li)964 utmp_write_entry(struct logininfo *li)
965 {
966 	switch(li->type) {
967 	case LTYPE_LOGIN:
968 		return (utmp_perform_login(li));
969 
970 	case LTYPE_LOGOUT:
971 		return (utmp_perform_logout(li));
972 
973 	default:
974 		logit("%s: invalid type field", __func__);
975 		return (0);
976 	}
977 }
978 #endif /* USE_UTMP */
979 
980 
981 /**
982  ** Low-level utmpx functions
983  **/
984 
985 /* not much point if we don't want utmpx entries */
986 #ifdef USE_UTMPX
987 
988 /* if we have the wherewithall, use pututxline etc. */
989 # if !defined(DISABLE_PUTUTXLINE) && defined(HAVE_SETUTXENT) && \
990 	defined(HAVE_PUTUTXLINE)
991 #  define UTMPX_USE_LIBRARY
992 # endif
993 
994 
995 /* write a utmpx entry with the system's help (pututxline() and pals) */
996 # ifdef UTMPX_USE_LIBRARY
997 static int
utmpx_write_library(struct logininfo * li,struct utmpx * utx)998 utmpx_write_library(struct logininfo *li, struct utmpx *utx)
999 {
1000 	setutxent();
1001 	pututxline(utx);
1002 
1003 #  ifdef HAVE_ENDUTXENT
1004 	endutxent();
1005 #  endif
1006 	return (1);
1007 }
1008 
1009 # else /* UTMPX_USE_LIBRARY */
1010 
1011 /* write a utmp entry direct to the file */
1012 static int
utmpx_write_direct(struct logininfo * li,struct utmpx * utx)1013 utmpx_write_direct(struct logininfo *li, struct utmpx *utx)
1014 {
1015 	logit("%s: not implemented!", __func__);
1016 	return (0);
1017 }
1018 # endif /* UTMPX_USE_LIBRARY */
1019 
1020 static int
utmpx_perform_login(struct logininfo * li)1021 utmpx_perform_login(struct logininfo *li)
1022 {
1023 	struct utmpx utx;
1024 
1025 	construct_utmpx(li, &utx);
1026 # ifdef UTMPX_USE_LIBRARY
1027 	if (!utmpx_write_library(li, &utx)) {
1028 		logit("%s: utmp_write_library() failed", __func__);
1029 		return (0);
1030 	}
1031 # else
1032 	if (!utmpx_write_direct(li, &ut)) {
1033 		logit("%s: utmp_write_direct() failed", __func__);
1034 		return (0);
1035 	}
1036 # endif
1037 	return (1);
1038 }
1039 
1040 
1041 static int
utmpx_perform_logout(struct logininfo * li)1042 utmpx_perform_logout(struct logininfo *li)
1043 {
1044 	struct utmpx utx;
1045 
1046 	construct_utmpx(li, &utx);
1047 # ifdef HAVE_ID_IN_UTMPX
1048 	line_abbrevname(utx.ut_id, li->line, sizeof(utx.ut_id));
1049 # endif
1050 # ifdef HAVE_TYPE_IN_UTMPX
1051 	utx.ut_type = DEAD_PROCESS;
1052 # endif
1053 
1054 # ifdef UTMPX_USE_LIBRARY
1055 	utmpx_write_library(li, &utx);
1056 # else
1057 	utmpx_write_direct(li, &utx);
1058 # endif
1059 	return (1);
1060 }
1061 
1062 int
utmpx_write_entry(struct logininfo * li)1063 utmpx_write_entry(struct logininfo *li)
1064 {
1065 	switch(li->type) {
1066 	case LTYPE_LOGIN:
1067 		return (utmpx_perform_login(li));
1068 	case LTYPE_LOGOUT:
1069 		return (utmpx_perform_logout(li));
1070 	default:
1071 		logit("%s: invalid type field", __func__);
1072 		return (0);
1073 	}
1074 }
1075 #endif /* USE_UTMPX */
1076 
1077 
1078 /**
1079  ** Low-level wtmp functions
1080  **/
1081 
1082 #ifdef USE_WTMP
1083 
1084 /*
1085  * Write a wtmp entry direct to the end of the file
1086  * This is a slight modification of code in OpenBSD's logwtmp.c
1087  */
1088 static int
wtmp_write(struct logininfo * li,struct utmp * ut)1089 wtmp_write(struct logininfo *li, struct utmp *ut)
1090 {
1091 	struct stat buf;
1092 	int fd, ret = 1;
1093 
1094 	if ((fd = open(WTMP_FILE, O_WRONLY|O_APPEND, 0)) < 0) {
1095 		logit("%s: problem writing %s: %s", __func__,
1096 		    WTMP_FILE, strerror(errno));
1097 		return (0);
1098 	}
1099 	if (fstat(fd, &buf) == 0)
1100 		if (atomicio(vwrite, fd, ut, sizeof(*ut)) != sizeof(*ut)) {
1101 			ftruncate(fd, buf.st_size);
1102 			logit("%s: problem writing %s: %s", __func__,
1103 			    WTMP_FILE, strerror(errno));
1104 			ret = 0;
1105 		}
1106 	close(fd);
1107 	return (ret);
1108 }
1109 
1110 static int
wtmp_perform_login(struct logininfo * li)1111 wtmp_perform_login(struct logininfo *li)
1112 {
1113 	struct utmp ut;
1114 
1115 	construct_utmp(li, &ut);
1116 	return (wtmp_write(li, &ut));
1117 }
1118 
1119 
1120 static int
wtmp_perform_logout(struct logininfo * li)1121 wtmp_perform_logout(struct logininfo *li)
1122 {
1123 	struct utmp ut;
1124 
1125 	construct_utmp(li, &ut);
1126 	return (wtmp_write(li, &ut));
1127 }
1128 
1129 
1130 int
wtmp_write_entry(struct logininfo * li)1131 wtmp_write_entry(struct logininfo *li)
1132 {
1133 	switch(li->type) {
1134 	case LTYPE_LOGIN:
1135 		return (wtmp_perform_login(li));
1136 	case LTYPE_LOGOUT:
1137 		return (wtmp_perform_logout(li));
1138 	default:
1139 		logit("%s: invalid type field", __func__);
1140 		return (0);
1141 	}
1142 }
1143 
1144 
1145 /*
1146  * Notes on fetching login data from wtmp/wtmpx
1147  *
1148  * Logouts are usually recorded with (amongst other things) a blank
1149  * username on a given tty line.  However, some systems (HP-UX is one)
1150  * leave all fields set, but change the ut_type field to DEAD_PROCESS.
1151  *
1152  * Since we're only looking for logins here, we know that the username
1153  * must be set correctly. On systems that leave it in, we check for
1154  * ut_type==USER_PROCESS (indicating a login.)
1155  *
1156  * Portability: Some systems may set something other than USER_PROCESS
1157  * to indicate a login process. I don't know of any as I write. Also,
1158  * it's possible that some systems may both leave the username in
1159  * place and not have ut_type.
1160  */
1161 
1162 /* return true if this wtmp entry indicates a login */
1163 static int
wtmp_islogin(struct logininfo * li,struct utmp * ut)1164 wtmp_islogin(struct logininfo *li, struct utmp *ut)
1165 {
1166 	if (strncmp(li->username, ut->ut_name,
1167 	    MIN_SIZEOF(li->username, ut->ut_name)) == 0) {
1168 # ifdef HAVE_TYPE_IN_UTMP
1169 		if (ut->ut_type & USER_PROCESS)
1170 			return (1);
1171 # else
1172 		return (1);
1173 # endif
1174 	}
1175 	return (0);
1176 }
1177 
1178 int
wtmp_get_entry(struct logininfo * li)1179 wtmp_get_entry(struct logininfo *li)
1180 {
1181 	struct stat st;
1182 	struct utmp ut;
1183 	int fd, found = 0;
1184 
1185 	/* Clear the time entries in our logininfo */
1186 	li->tv_sec = li->tv_usec = 0;
1187 
1188 	if ((fd = open(WTMP_FILE, O_RDONLY)) < 0) {
1189 		logit("%s: problem opening %s: %s", __func__,
1190 		    WTMP_FILE, strerror(errno));
1191 		return (0);
1192 	}
1193 	if (fstat(fd, &st) != 0) {
1194 		logit("%s: couldn't stat %s: %s", __func__,
1195 		    WTMP_FILE, strerror(errno));
1196 		close(fd);
1197 		return (0);
1198 	}
1199 
1200 	/* Seek to the start of the last struct utmp */
1201 	if (lseek(fd, -(off_t)sizeof(struct utmp), SEEK_END) == -1) {
1202 		/* Looks like we've got a fresh wtmp file */
1203 		close(fd);
1204 		return (0);
1205 	}
1206 
1207 	while (!found) {
1208 		if (atomicio(read, fd, &ut, sizeof(ut)) != sizeof(ut)) {
1209 			logit("%s: read of %s failed: %s", __func__,
1210 			    WTMP_FILE, strerror(errno));
1211 			close (fd);
1212 			return (0);
1213 		}
1214 		if (wtmp_islogin(li, &ut) ) {
1215 			found = 1;
1216 			/*
1217 			 * We've already checked for a time in struct
1218 			 * utmp, in login_getlast()
1219 			 */
1220 # ifdef HAVE_TIME_IN_UTMP
1221 			li->tv_sec = ut.ut_time;
1222 # else
1223 #  if HAVE_TV_IN_UTMP
1224 			li->tv_sec = ut.ut_tv.tv_sec;
1225 #  endif
1226 # endif
1227 			line_fullname(li->line, ut.ut_line,
1228 			    MIN_SIZEOF(li->line, ut.ut_line));
1229 # ifdef HAVE_HOST_IN_UTMP
1230 			strlcpy(li->hostname, ut.ut_host,
1231 			    MIN_SIZEOF(li->hostname, ut.ut_host));
1232 # endif
1233 			continue;
1234 		}
1235 		/* Seek back 2 x struct utmp */
1236 		if (lseek(fd, -(off_t)(2 * sizeof(struct utmp)), SEEK_CUR) == -1) {
1237 			/* We've found the start of the file, so quit */
1238 			close(fd);
1239 			return (0);
1240 		}
1241 	}
1242 
1243 	/* We found an entry. Tidy up and return */
1244 	close(fd);
1245 	return (1);
1246 }
1247 # endif /* USE_WTMP */
1248 
1249 
1250 /**
1251  ** Low-level wtmpx functions
1252  **/
1253 
1254 #ifdef USE_WTMPX
1255 /*
1256  * Write a wtmpx entry direct to the end of the file
1257  * This is a slight modification of code in OpenBSD's logwtmp.c
1258  */
1259 static int
wtmpx_write(struct logininfo * li,struct utmpx * utx)1260 wtmpx_write(struct logininfo *li, struct utmpx *utx)
1261 {
1262 #ifndef HAVE_UPDWTMPX
1263 	struct stat buf;
1264 	int fd, ret = 1;
1265 
1266 	if ((fd = open(WTMPX_FILE, O_WRONLY|O_APPEND, 0)) < 0) {
1267 		logit("%s: problem opening %s: %s", __func__,
1268 		    WTMPX_FILE, strerror(errno));
1269 		return (0);
1270 	}
1271 
1272 	if (fstat(fd, &buf) == 0)
1273 		if (atomicio(vwrite, fd, utx, sizeof(*utx)) != sizeof(*utx)) {
1274 			ftruncate(fd, buf.st_size);
1275 			logit("%s: problem writing %s: %s", __func__,
1276 			    WTMPX_FILE, strerror(errno));
1277 			ret = 0;
1278 		}
1279 	close(fd);
1280 
1281 	return (ret);
1282 #else
1283 	updwtmpx(WTMPX_FILE, utx);
1284 	return (1);
1285 #endif
1286 }
1287 
1288 
1289 static int
wtmpx_perform_login(struct logininfo * li)1290 wtmpx_perform_login(struct logininfo *li)
1291 {
1292 	struct utmpx utx;
1293 
1294 	construct_utmpx(li, &utx);
1295 	return (wtmpx_write(li, &utx));
1296 }
1297 
1298 
1299 static int
wtmpx_perform_logout(struct logininfo * li)1300 wtmpx_perform_logout(struct logininfo *li)
1301 {
1302 	struct utmpx utx;
1303 
1304 	construct_utmpx(li, &utx);
1305 	return (wtmpx_write(li, &utx));
1306 }
1307 
1308 
1309 int
wtmpx_write_entry(struct logininfo * li)1310 wtmpx_write_entry(struct logininfo *li)
1311 {
1312 	switch(li->type) {
1313 	case LTYPE_LOGIN:
1314 		return (wtmpx_perform_login(li));
1315 	case LTYPE_LOGOUT:
1316 		return (wtmpx_perform_logout(li));
1317 	default:
1318 		logit("%s: invalid type field", __func__);
1319 		return (0);
1320 	}
1321 }
1322 
1323 /* Please see the notes above wtmp_islogin() for information about the
1324    next two functions */
1325 
1326 /* Return true if this wtmpx entry indicates a login */
1327 static int
wtmpx_islogin(struct logininfo * li,struct utmpx * utx)1328 wtmpx_islogin(struct logininfo *li, struct utmpx *utx)
1329 {
1330 	if (strncmp(li->username, utx->ut_user,
1331 	    MIN_SIZEOF(li->username, utx->ut_user)) == 0 ) {
1332 # ifdef HAVE_TYPE_IN_UTMPX
1333 		if (utx->ut_type == USER_PROCESS)
1334 			return (1);
1335 # else
1336 		return (1);
1337 # endif
1338 	}
1339 	return (0);
1340 }
1341 
1342 
1343 int
wtmpx_get_entry(struct logininfo * li)1344 wtmpx_get_entry(struct logininfo *li)
1345 {
1346 	struct stat st;
1347 	struct utmpx utx;
1348 	int fd, found=0;
1349 
1350 	/* Clear the time entries */
1351 	li->tv_sec = li->tv_usec = 0;
1352 
1353 	if ((fd = open(WTMPX_FILE, O_RDONLY)) < 0) {
1354 		logit("%s: problem opening %s: %s", __func__,
1355 		    WTMPX_FILE, strerror(errno));
1356 		return (0);
1357 	}
1358 	if (fstat(fd, &st) != 0) {
1359 		logit("%s: couldn't stat %s: %s", __func__,
1360 		    WTMPX_FILE, strerror(errno));
1361 		close(fd);
1362 		return (0);
1363 	}
1364 
1365 	/* Seek to the start of the last struct utmpx */
1366 	if (lseek(fd, -(off_t)sizeof(struct utmpx), SEEK_END) == -1 ) {
1367 		/* probably a newly rotated wtmpx file */
1368 		close(fd);
1369 		return (0);
1370 	}
1371 
1372 	while (!found) {
1373 		if (atomicio(read, fd, &utx, sizeof(utx)) != sizeof(utx)) {
1374 			logit("%s: read of %s failed: %s", __func__,
1375 			    WTMPX_FILE, strerror(errno));
1376 			close (fd);
1377 			return (0);
1378 		}
1379 		/*
1380 		 * Logouts are recorded as a blank username on a particular
1381 		 * line. So, we just need to find the username in struct utmpx
1382 		 */
1383 		if (wtmpx_islogin(li, &utx)) {
1384 			found = 1;
1385 # if defined(HAVE_TV_IN_UTMPX)
1386 			li->tv_sec = utx.ut_tv.tv_sec;
1387 # elif defined(HAVE_TIME_IN_UTMPX)
1388 			li->tv_sec = utx.ut_time;
1389 # endif
1390 			line_fullname(li->line, utx.ut_line, sizeof(li->line));
1391 # if defined(HAVE_HOST_IN_UTMPX)
1392 			strlcpy(li->hostname, utx.ut_host,
1393 			    MIN_SIZEOF(li->hostname, utx.ut_host));
1394 # endif
1395 			continue;
1396 		}
1397 		if (lseek(fd, -(off_t)(2 * sizeof(struct utmpx)), SEEK_CUR) == -1) {
1398 			close(fd);
1399 			return (0);
1400 		}
1401 	}
1402 
1403 	close(fd);
1404 	return (1);
1405 }
1406 #endif /* USE_WTMPX */
1407 
1408 /**
1409  ** Low-level libutil login() functions
1410  **/
1411 
1412 #ifdef USE_LOGIN
1413 static int
syslogin_perform_login(struct logininfo * li)1414 syslogin_perform_login(struct logininfo *li)
1415 {
1416 	struct utmp *ut;
1417 
1418 	ut = xmalloc(sizeof(*ut));
1419 	construct_utmp(li, ut);
1420 	login(ut);
1421 	free(ut);
1422 
1423 	return (1);
1424 }
1425 
1426 static int
syslogin_perform_logout(struct logininfo * li)1427 syslogin_perform_logout(struct logininfo *li)
1428 {
1429 # ifdef HAVE_LOGOUT
1430 	char line[UT_LINESIZE];
1431 
1432 	(void)line_stripname(line, li->line, sizeof(line));
1433 
1434 	if (!logout(line))
1435 		logit("%s: logout() returned an error", __func__);
1436 #  ifdef HAVE_LOGWTMP
1437 	else
1438 		logwtmp(line, "", "");
1439 #  endif
1440 	/* FIXME: (ATL - if the need arises) What to do if we have
1441 	 * login, but no logout?  what if logout but no logwtmp? All
1442 	 * routines are in libutil so they should all be there,
1443 	 * but... */
1444 # endif
1445 	return (1);
1446 }
1447 
1448 int
syslogin_write_entry(struct logininfo * li)1449 syslogin_write_entry(struct logininfo *li)
1450 {
1451 	switch (li->type) {
1452 	case LTYPE_LOGIN:
1453 		return (syslogin_perform_login(li));
1454 	case LTYPE_LOGOUT:
1455 		return (syslogin_perform_logout(li));
1456 	default:
1457 		logit("%s: Invalid type field", __func__);
1458 		return (0);
1459 	}
1460 }
1461 #endif /* USE_LOGIN */
1462 
1463 /* end of file log-syslogin.c */
1464 
1465 /**
1466  ** Low-level lastlog functions
1467  **/
1468 
1469 #ifdef USE_LASTLOG
1470 
1471 #if !defined(LASTLOG_WRITE_PUTUTXLINE) || !defined(HAVE_GETLASTLOGXBYNAME)
1472 /* open the file (using filemode) and seek to the login entry */
1473 static int
lastlog_openseek(struct logininfo * li,int * fd,int filemode)1474 lastlog_openseek(struct logininfo *li, int *fd, int filemode)
1475 {
1476 	off_t offset;
1477 	char lastlog_file[1024];
1478 	struct stat st;
1479 
1480 	if (stat(LASTLOG_FILE, &st) != 0) {
1481 		logit("%s: Couldn't stat %s: %s", __func__,
1482 		    LASTLOG_FILE, strerror(errno));
1483 		return (0);
1484 	}
1485 	if (S_ISDIR(st.st_mode)) {
1486 		snprintf(lastlog_file, sizeof(lastlog_file), "%s/%s",
1487 		    LASTLOG_FILE, li->username);
1488 	} else if (S_ISREG(st.st_mode)) {
1489 		strlcpy(lastlog_file, LASTLOG_FILE, sizeof(lastlog_file));
1490 	} else {
1491 		logit("%s: %.100s is not a file or directory!", __func__,
1492 		    LASTLOG_FILE);
1493 		return (0);
1494 	}
1495 
1496 	*fd = open(lastlog_file, filemode, 0600);
1497 	if (*fd < 0) {
1498 		debug("%s: Couldn't open %s: %s", __func__,
1499 		    lastlog_file, strerror(errno));
1500 		return (0);
1501 	}
1502 
1503 	if (S_ISREG(st.st_mode)) {
1504 		/* find this uid's offset in the lastlog file */
1505 		offset = (off_t) ((u_long)li->uid * sizeof(struct lastlog));
1506 
1507 		if (lseek(*fd, offset, SEEK_SET) != offset) {
1508 			logit("%s: %s->lseek(): %s", __func__,
1509 			    lastlog_file, strerror(errno));
1510 			close(*fd);
1511 			return (0);
1512 		}
1513 	}
1514 
1515 	return (1);
1516 }
1517 #endif /* !LASTLOG_WRITE_PUTUTXLINE || !HAVE_GETLASTLOGXBYNAME */
1518 
1519 #ifdef LASTLOG_WRITE_PUTUTXLINE
1520 int
lastlog_write_entry(struct logininfo * li)1521 lastlog_write_entry(struct logininfo *li)
1522 {
1523 	switch(li->type) {
1524 	case LTYPE_LOGIN:
1525 		return 1; /* lastlog written by pututxline */
1526 	default:
1527 		logit("lastlog_write_entry: Invalid type field");
1528 		return 0;
1529 	}
1530 }
1531 #else /* LASTLOG_WRITE_PUTUTXLINE */
1532 int
lastlog_write_entry(struct logininfo * li)1533 lastlog_write_entry(struct logininfo *li)
1534 {
1535 	struct lastlog last;
1536 	int fd;
1537 
1538 	switch(li->type) {
1539 	case LTYPE_LOGIN:
1540 		/* create our struct lastlog */
1541 		memset(&last, '\0', sizeof(last));
1542 		line_stripname(last.ll_line, li->line, sizeof(last.ll_line));
1543 		strlcpy(last.ll_host, li->hostname,
1544 		    MIN_SIZEOF(last.ll_host, li->hostname));
1545 		last.ll_time = li->tv_sec;
1546 
1547 		if (!lastlog_openseek(li, &fd, O_RDWR|O_CREAT))
1548 			return (0);
1549 
1550 		/* write the entry */
1551 		if (atomicio(vwrite, fd, &last, sizeof(last)) != sizeof(last)) {
1552 			close(fd);
1553 			logit("%s: Error writing to %s: %s", __func__,
1554 			    LASTLOG_FILE, strerror(errno));
1555 			return (0);
1556 		}
1557 
1558 		close(fd);
1559 		return (1);
1560 	default:
1561 		logit("%s: Invalid type field", __func__);
1562 		return (0);
1563 	}
1564 }
1565 #endif /* LASTLOG_WRITE_PUTUTXLINE */
1566 
1567 #ifdef HAVE_GETLASTLOGXBYNAME
1568 int
lastlog_get_entry(struct logininfo * li)1569 lastlog_get_entry(struct logininfo *li)
1570 {
1571 	struct lastlogx l, *ll;
1572 
1573 	if ((ll = getlastlogxbyname(li->username, &l)) == NULL) {
1574 		memset(&l, '\0', sizeof(l));
1575 		ll = &l;
1576 	}
1577 	line_fullname(li->line, ll->ll_line, sizeof(li->line));
1578 	strlcpy(li->hostname, ll->ll_host,
1579 		MIN_SIZEOF(li->hostname, ll->ll_host));
1580 	li->tv_sec = ll->ll_tv.tv_sec;
1581 	li->tv_usec = ll->ll_tv.tv_usec;
1582 	return (1);
1583 }
1584 #else /* HAVE_GETLASTLOGXBYNAME */
1585 int
lastlog_get_entry(struct logininfo * li)1586 lastlog_get_entry(struct logininfo *li)
1587 {
1588 	struct lastlog last;
1589 	int fd, ret;
1590 
1591 	if (!lastlog_openseek(li, &fd, O_RDONLY))
1592 		return (0);
1593 
1594 	ret = atomicio(read, fd, &last, sizeof(last));
1595 	close(fd);
1596 
1597 	switch (ret) {
1598 	case 0:
1599 		memset(&last, '\0', sizeof(last));
1600 		/* FALLTHRU */
1601 	case sizeof(last):
1602 		line_fullname(li->line, last.ll_line, sizeof(li->line));
1603 		strlcpy(li->hostname, last.ll_host,
1604 		    MIN_SIZEOF(li->hostname, last.ll_host));
1605 		li->tv_sec = last.ll_time;
1606 		return (1);
1607 	case -1:
1608 		error("%s: Error reading from %s: %s", __func__,
1609 		    LASTLOG_FILE, strerror(errno));
1610 		return (0);
1611 	default:
1612 		error("%s: Error reading from %s: Expecting %d, got %d",
1613 		    __func__, LASTLOG_FILE, (int)sizeof(last), ret);
1614 		return (0);
1615 	}
1616 
1617 	/* NOTREACHED */
1618 	return (0);
1619 }
1620 #endif /* HAVE_GETLASTLOGXBYNAME */
1621 #endif /* USE_LASTLOG */
1622 
1623 #if defined(USE_UTMPX) && defined(HAVE_SETUTXDB) && \
1624     defined(UTXDB_LASTLOGIN) && defined(HAVE_GETUTXUSER)
1625 int
utmpx_get_entry(struct logininfo * li)1626 utmpx_get_entry(struct logininfo *li)
1627 {
1628 	struct utmpx *utx;
1629 
1630 	if (setutxdb(UTXDB_LASTLOGIN, NULL) != 0)
1631 		return (0);
1632 	utx = getutxuser(li->username);
1633 	if (utx == NULL) {
1634 		endutxent();
1635 		return (0);
1636 	}
1637 
1638 	line_fullname(li->line, utx->ut_line,
1639 	    MIN_SIZEOF(li->line, utx->ut_line));
1640 	strlcpy(li->hostname, utx->ut_host,
1641 	    MIN_SIZEOF(li->hostname, utx->ut_host));
1642 	li->tv_sec = utx->ut_tv.tv_sec;
1643 	li->tv_usec = utx->ut_tv.tv_usec;
1644 	endutxent();
1645 	return (1);
1646 }
1647 #endif /* USE_UTMPX && HAVE_SETUTXDB && UTXDB_LASTLOGIN && HAVE_GETUTXUSER */
1648 
1649 #ifdef USE_BTMP
1650   /*
1651    * Logs failed login attempts in _PATH_BTMP if that exists.
1652    * The most common login failure is to give password instead of username.
1653    * So the _PATH_BTMP file checked for the correct permission, so that
1654    * only root can read it.
1655    */
1656 
1657 void
record_failed_login(struct ssh * ssh,const char * username,const char * hostname,const char * ttyn)1658 record_failed_login(struct ssh *ssh, const char *username, const char *hostname,
1659     const char *ttyn)
1660 {
1661 	int fd;
1662 	struct utmp ut;
1663 	struct sockaddr_storage from;
1664 	socklen_t fromlen = sizeof(from);
1665 	struct sockaddr_in *a4;
1666 	struct sockaddr_in6 *a6;
1667 	time_t t;
1668 	struct stat fst;
1669 
1670 	if (geteuid() != 0)
1671 		return;
1672 	if ((fd = open(_PATH_BTMP, O_WRONLY | O_APPEND)) < 0) {
1673 		debug("Unable to open the btmp file %s: %s", _PATH_BTMP,
1674 		    strerror(errno));
1675 		return;
1676 	}
1677 	if (fstat(fd, &fst) < 0) {
1678 		logit("%s: fstat of %s failed: %s", __func__, _PATH_BTMP,
1679 		    strerror(errno));
1680 		goto out;
1681 	}
1682 	if((fst.st_mode & (S_IXGRP | S_IRWXO)) || (fst.st_uid != 0)){
1683 		logit("Excess permission or bad ownership on file %s",
1684 		    _PATH_BTMP);
1685 		goto out;
1686 	}
1687 
1688 	memset(&ut, 0, sizeof(ut));
1689 	/* strncpy because we don't necessarily want nul termination */
1690 	strncpy(ut.ut_user, username, sizeof(ut.ut_user));
1691 	strlcpy(ut.ut_line, "ssh:notty", sizeof(ut.ut_line));
1692 
1693 	time(&t);
1694 	ut.ut_time = t;     /* ut_time is not always a time_t */
1695 	ut.ut_type = LOGIN_PROCESS;
1696 	ut.ut_pid = getpid();
1697 
1698 	/* strncpy because we don't necessarily want nul termination */
1699 	strncpy(ut.ut_host, hostname, sizeof(ut.ut_host));
1700 
1701 	if (ssh_packet_connection_is_on_socket(ssh) &&
1702 	    getpeername(ssh_packet_get_connection_in(ssh),
1703 	    (struct sockaddr *)&from, &fromlen) == 0) {
1704 		ipv64_normalise_mapped(&from, &fromlen);
1705 		if (from.ss_family == AF_INET) {
1706 			a4 = (struct sockaddr_in *)&from;
1707 			memcpy(&ut.ut_addr, &(a4->sin_addr),
1708 			    MIN_SIZEOF(ut.ut_addr, a4->sin_addr));
1709 		}
1710 #ifdef HAVE_ADDR_V6_IN_UTMP
1711 		if (from.ss_family == AF_INET6) {
1712 			a6 = (struct sockaddr_in6 *)&from;
1713 			memcpy(&ut.ut_addr_v6, &(a6->sin6_addr),
1714 			    MIN_SIZEOF(ut.ut_addr_v6, a6->sin6_addr));
1715 		}
1716 #endif
1717 	}
1718 
1719 	if (atomicio(vwrite, fd, &ut, sizeof(ut)) != sizeof(ut))
1720 		error("Failed to write to %s: %s", _PATH_BTMP,
1721 		    strerror(errno));
1722 
1723 out:
1724 	close(fd);
1725 }
1726 #endif	/* USE_BTMP */
1727