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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 <errno.h>
    160 #include <fcntl.h>
    161 #ifdef HAVE_PATHS_H
    162 # include <paths.h>
    163 #endif
    164 #include <pwd.h>
    165 #include <stdarg.h>
    166 #include <string.h>
    167 #include <time.h>
    168 #include <unistd.h>
    169 
    170 #include "xmalloc.h"
    171 #include "key.h"
    172 #include "hostfile.h"
    173 #include "ssh.h"
    174 #include "loginrec.h"
    175 #include "log.h"
    176 #include "atomicio.h"
    177 #include "packet.h"
    178 #include "canohost.h"
    179 #include "auth.h"
    180 #include "buffer.h"
    181 
    182 #ifdef HAVE_UTIL_H
    183 # include <util.h>
    184 #endif
    185 
    186 /**
    187  ** prototypes for helper functions in this file
    188  **/
    189 
    190 #if HAVE_UTMP_H
    191 void set_utmp_time(struct logininfo *li, struct utmp *ut);
    192 void construct_utmp(struct logininfo *li, struct utmp *ut);
    193 #endif
    194 
    195 #ifdef HAVE_UTMPX_H
    196 void set_utmpx_time(struct logininfo *li, struct utmpx *ut);
    197 void construct_utmpx(struct logininfo *li, struct utmpx *ut);
    198 #endif
    199 
    200 int utmp_write_entry(struct logininfo *li);
    201 int utmpx_write_entry(struct logininfo *li);
    202 int wtmp_write_entry(struct logininfo *li);
    203 int wtmpx_write_entry(struct logininfo *li);
    204 int lastlog_write_entry(struct logininfo *li);
    205 int syslogin_write_entry(struct logininfo *li);
    206 
    207 int getlast_entry(struct logininfo *li);
    208 int lastlog_get_entry(struct logininfo *li);
    209 int utmpx_get_entry(struct logininfo *li);
    210 int wtmp_get_entry(struct logininfo *li);
    211 int wtmpx_get_entry(struct logininfo *li);
    212 
    213 extern Buffer loginmsg;
    214 
    215 /* pick the shortest string */
    216 #define MIN_SIZEOF(s1,s2) (sizeof(s1) < sizeof(s2) ? sizeof(s1) : sizeof(s2))
    217 
    218 /**
    219  ** platform-independent login functions
    220  **/
    221 
    222 /*
    223  * login_login(struct logininfo *) - Record a login
    224  *
    225  * Call with a pointer to a struct logininfo initialised with
    226  * login_init_entry() or login_alloc_entry()
    227  *
    228  * Returns:
    229  *  >0 if successful
    230  *  0  on failure (will use OpenSSH's logging facilities for diagnostics)
    231  */
    232 int
    233 login_login(struct logininfo *li)
    234 {
    235 	li->type = LTYPE_LOGIN;
    236 	return (login_write(li));
    237 }
    238 
    239 
    240 /*
    241  * login_logout(struct logininfo *) - Record a logout
    242  *
    243  * Call as with login_login()
    244  *
    245  * Returns:
    246  *  >0 if successful
    247  *  0  on failure (will use OpenSSH's logging facilities for diagnostics)
    248  */
    249 int
    250 login_logout(struct logininfo *li)
    251 {
    252 	li->type = LTYPE_LOGOUT;
    253 	return (login_write(li));
    254 }
    255 
    256 /*
    257  * login_get_lastlog_time(int) - Retrieve the last login time
    258  *
    259  * Retrieve the last login time for the given uid. Will try to use the
    260  * system lastlog facilities if they are available, but will fall back
    261  * to looking in wtmp/wtmpx if necessary
    262  *
    263  * Returns:
    264  *   0 on failure, or if user has never logged in
    265  *   Time in seconds from the epoch if successful
    266  *
    267  * Useful preprocessor symbols:
    268  *   DISABLE_LASTLOG: If set, *never* even try to retrieve lastlog
    269  *                    info
    270  *   USE_LASTLOG: If set, indicates the presence of system lastlog
    271  *                facilities. If this and DISABLE_LASTLOG are not set,
    272  *                try to retrieve lastlog information from wtmp/wtmpx.
    273  */
    274 unsigned int
    275 login_get_lastlog_time(const uid_t uid)
    276 {
    277 	struct logininfo li;
    278 
    279 	if (login_get_lastlog(&li, uid))
    280 		return (li.tv_sec);
    281 	else
    282 		return (0);
    283 }
    284 
    285 /*
    286  * login_get_lastlog(struct logininfo *, int)   - Retrieve a lastlog entry
    287  *
    288  * Retrieve a logininfo structure populated (only partially) with
    289  * information from the system lastlog data, or from wtmp/wtmpx if no
    290  * system lastlog information exists.
    291  *
    292  * Note this routine must be given a pre-allocated logininfo.
    293  *
    294  * Returns:
    295  *  >0: A pointer to your struct logininfo if successful
    296  *  0  on failure (will use OpenSSH's logging facilities for diagnostics)
    297  */
    298 struct logininfo *
    299 login_get_lastlog(struct logininfo *li, const uid_t uid)
    300 {
    301 	struct passwd *pw;
    302 
    303 	memset(li, '\0', sizeof(*li));
    304 	li->uid = uid;
    305 
    306 	/*
    307 	 * If we don't have a 'real' lastlog, we need the username to
    308 	 * reliably search wtmp(x) for the last login (see
    309 	 * wtmp_get_entry().)
    310 	 */
    311 	pw = getpwuid(uid);
    312 	if (pw == NULL)
    313 		fatal("%s: Cannot find account for uid %ld", __func__,
    314 		    (long)uid);
    315 
    316 	if (strlcpy(li->username, pw->pw_name, sizeof(li->username)) >=
    317 	    sizeof(li->username)) {
    318 		error("%s: username too long (%lu > max %lu)", __func__,
    319 		    (unsigned long)strlen(pw->pw_name),
    320 		    (unsigned long)sizeof(li->username) - 1);
    321 		return NULL;
    322 	}
    323 
    324 	if (getlast_entry(li))
    325 		return (li);
    326 	else
    327 		return (NULL);
    328 }
    329 
    330 /*
    331  * login_alloc_entry(int, char*, char*, char*)    - Allocate and initialise
    332  *                                                  a logininfo structure
    333  *
    334  * This function creates a new struct logininfo, a data structure
    335  * meant to carry the information required to portably record login info.
    336  *
    337  * Returns a pointer to a newly created struct logininfo. If memory
    338  * allocation fails, the program halts.
    339  */
    340 struct
    341 logininfo *login_alloc_entry(pid_t pid, const char *username,
    342     const char *hostname, const char *line)
    343 {
    344 	struct logininfo *newli;
    345 
    346 	newli = xmalloc(sizeof(*newli));
    347 	login_init_entry(newli, pid, username, hostname, line);
    348 	return (newli);
    349 }
    350 
    351 
    352 /* login_free_entry(struct logininfo *)    - free struct memory */
    353 void
    354 login_free_entry(struct logininfo *li)
    355 {
    356 	free(li);
    357 }
    358 
    359 
    360 /* login_init_entry(struct logininfo *, int, char*, char*, char*)
    361  *                                        - initialise a struct logininfo
    362  *
    363  * Populates a new struct logininfo, a data structure meant to carry
    364  * the information required to portably record login info.
    365  *
    366  * Returns: 1
    367  */
    368 int
    369 login_init_entry(struct logininfo *li, pid_t pid, const char *username,
    370     const char *hostname, const char *line)
    371 {
    372 	struct passwd *pw;
    373 
    374 	memset(li, 0, sizeof(*li));
    375 
    376 	li->pid = pid;
    377 
    378 	/* set the line information */
    379 	if (line)
    380 		line_fullname(li->line, line, sizeof(li->line));
    381 
    382 	if (username) {
    383 		strlcpy(li->username, username, sizeof(li->username));
    384 		pw = getpwnam(li->username);
    385 		if (pw == NULL) {
    386 			fatal("%s: Cannot find user \"%s\"", __func__,
    387 			    li->username);
    388 		}
    389 		li->uid = pw->pw_uid;
    390 	}
    391 
    392 	if (hostname)
    393 		strlcpy(li->hostname, hostname, sizeof(li->hostname));
    394 
    395 	return (1);
    396 }
    397 
    398 /*
    399  * login_set_current_time(struct logininfo *)    - set the current time
    400  *
    401  * Set the current time in a logininfo structure. This function is
    402  * meant to eliminate the need to deal with system dependencies for
    403  * time handling.
    404  */
    405 void
    406 login_set_current_time(struct logininfo *li)
    407 {
    408 	struct timeval tv;
    409 
    410 	gettimeofday(&tv, NULL);
    411 
    412 	li->tv_sec = tv.tv_sec;
    413 	li->tv_usec = tv.tv_usec;
    414 }
    415 
    416 /* copy a sockaddr_* into our logininfo */
    417 void
    418 login_set_addr(struct logininfo *li, const struct sockaddr *sa,
    419     const unsigned int sa_size)
    420 {
    421 	unsigned int bufsize = sa_size;
    422 
    423 	/* make sure we don't overrun our union */
    424 	if (sizeof(li->hostaddr) < sa_size)
    425 		bufsize = sizeof(li->hostaddr);
    426 
    427 	memcpy(&li->hostaddr.sa, sa, bufsize);
    428 }
    429 
    430 
    431 /**
    432  ** login_write: Call low-level recording functions based on autoconf
    433  ** results
    434  **/
    435 int
    436 login_write(struct logininfo *li)
    437 {
    438 #ifndef HAVE_CYGWIN
    439 	if (geteuid() != 0) {
    440 		logit("Attempt to write login records by non-root user (aborting)");
    441 		return (1);
    442 	}
    443 #endif
    444 
    445 	/* set the timestamp */
    446 	login_set_current_time(li);
    447 #ifdef USE_LOGIN
    448 	syslogin_write_entry(li);
    449 #endif
    450 #ifdef USE_LASTLOG
    451 	if (li->type == LTYPE_LOGIN)
    452 		lastlog_write_entry(li);
    453 #endif
    454 #ifdef USE_UTMP
    455 	utmp_write_entry(li);
    456 #endif
    457 #ifdef USE_WTMP
    458 	wtmp_write_entry(li);
    459 #endif
    460 #ifdef USE_UTMPX
    461 	utmpx_write_entry(li);
    462 #endif
    463 #ifdef USE_WTMPX
    464 	wtmpx_write_entry(li);
    465 #endif
    466 #ifdef CUSTOM_SYS_AUTH_RECORD_LOGIN
    467 	if (li->type == LTYPE_LOGIN &&
    468 	    !sys_auth_record_login(li->username,li->hostname,li->line,
    469 	    &loginmsg))
    470 		logit("Writing login record failed for %s", li->username);
    471 #endif
    472 #ifdef SSH_AUDIT_EVENTS
    473 	if (li->type == LTYPE_LOGIN)
    474 		audit_session_open(li);
    475 	else if (li->type == LTYPE_LOGOUT)
    476 		audit_session_close(li);
    477 #endif
    478 	return (0);
    479 }
    480 
    481 #ifdef LOGIN_NEEDS_UTMPX
    482 int
    483 login_utmp_only(struct logininfo *li)
    484 {
    485 	li->type = LTYPE_LOGIN;
    486 	login_set_current_time(li);
    487 # ifdef USE_UTMP
    488 	utmp_write_entry(li);
    489 # endif
    490 # ifdef USE_WTMP
    491 	wtmp_write_entry(li);
    492 # endif
    493 # ifdef USE_UTMPX
    494 	utmpx_write_entry(li);
    495 # endif
    496 # ifdef USE_WTMPX
    497 	wtmpx_write_entry(li);
    498 # endif
    499 	return (0);
    500 }
    501 #endif
    502 
    503 /**
    504  ** getlast_entry: Call low-level functions to retrieve the last login
    505  **                time.
    506  **/
    507 
    508 /* take the uid in li and return the last login time */
    509 int
    510 getlast_entry(struct logininfo *li)
    511 {
    512 #ifdef USE_LASTLOG
    513 	return(lastlog_get_entry(li));
    514 #else /* !USE_LASTLOG */
    515 #if defined(USE_UTMPX) && defined(HAVE_SETUTXDB) && \
    516     defined(UTXDB_LASTLOGIN) && defined(HAVE_GETUTXUSER)
    517 	return (utmpx_get_entry(li));
    518 #endif
    519 
    520 #if defined(DISABLE_LASTLOG)
    521 	/* On some systems we shouldn't even try to obtain last login
    522 	 * time, e.g. AIX */
    523 	return (0);
    524 # elif defined(USE_WTMP) && \
    525     (defined(HAVE_TIME_IN_UTMP) || defined(HAVE_TV_IN_UTMP))
    526 	/* retrieve last login time from utmp */
    527 	return (wtmp_get_entry(li));
    528 # elif defined(USE_WTMPX) && \
    529     (defined(HAVE_TIME_IN_UTMPX) || defined(HAVE_TV_IN_UTMPX))
    530 	/* If wtmp isn't available, try wtmpx */
    531 	return (wtmpx_get_entry(li));
    532 # else
    533 	/* Give up: No means of retrieving last login time */
    534 	return (0);
    535 # endif /* DISABLE_LASTLOG */
    536 #endif /* USE_LASTLOG */
    537 }
    538 
    539 
    540 
    541 /*
    542  * 'line' string utility functions
    543  *
    544  * These functions process the 'line' string into one of three forms:
    545  *
    546  * 1. The full filename (including '/dev')
    547  * 2. The stripped name (excluding '/dev')
    548  * 3. The abbreviated name (e.g. /dev/ttyp00 -> yp00
    549  *                               /dev/pts/1  -> ts/1 )
    550  *
    551  * Form 3 is used on some systems to identify a .tmp.? entry when
    552  * attempting to remove it. Typically both addition and removal is
    553  * performed by one application - say, sshd - so as long as the choice
    554  * uniquely identifies a terminal it's ok.
    555  */
    556 
    557 
    558 /*
    559  * line_fullname(): add the leading '/dev/' if it doesn't exist make
    560  * sure dst has enough space, if not just copy src (ugh)
    561  */
    562 char *
    563 line_fullname(char *dst, const char *src, u_int dstsize)
    564 {
    565 	memset(dst, '\0', dstsize);
    566 	if ((strncmp(src, "/dev/", 5) == 0) || (dstsize < (strlen(src) + 5)))
    567 		strlcpy(dst, src, dstsize);
    568 	else {
    569 		strlcpy(dst, "/dev/", dstsize);
    570 		strlcat(dst, src, dstsize);
    571 	}
    572 	return (dst);
    573 }
    574 
    575 /* line_stripname(): strip the leading '/dev' if it exists, return dst */
    576 char *
    577 line_stripname(char *dst, const char *src, int dstsize)
    578 {
    579 	memset(dst, '\0', dstsize);
    580 	if (strncmp(src, "/dev/", 5) == 0)
    581 		strlcpy(dst, src + 5, dstsize);
    582 	else
    583 		strlcpy(dst, src, dstsize);
    584 	return (dst);
    585 }
    586 
    587 /*
    588  * line_abbrevname(): Return the abbreviated (usually four-character)
    589  * form of the line (Just use the last <dstsize> characters of the
    590  * full name.)
    591  *
    592  * NOTE: use strncpy because we do NOT necessarily want zero
    593  * termination
    594  */
    595 char *
    596 line_abbrevname(char *dst, const char *src, int dstsize)
    597 {
    598 	size_t len;
    599 
    600 	memset(dst, '\0', dstsize);
    601 
    602 	/* Always skip prefix if present */
    603 	if (strncmp(src, "/dev/", 5) == 0)
    604 		src += 5;
    605 
    606 #ifdef WITH_ABBREV_NO_TTY
    607 	if (strncmp(src, "tty", 3) == 0)
    608 		src += 3;
    609 #endif
    610 
    611 	len = strlen(src);
    612 
    613 	if (len > 0) {
    614 		if (((int)len - dstsize) > 0)
    615 			src +=  ((int)len - dstsize);
    616 
    617 		/* note: _don't_ change this to strlcpy */
    618 		strncpy(dst, src, (size_t)dstsize);
    619 	}
    620 
    621 	return (dst);
    622 }
    623 
    624 /**
    625  ** utmp utility functions
    626  **
    627  ** These functions manipulate struct utmp, taking system differences
    628  ** into account.
    629  **/
    630 
    631 #if defined(USE_UTMP) || defined (USE_WTMP) || defined (USE_LOGIN)
    632 
    633 /* build the utmp structure */
    634 void
    635 set_utmp_time(struct logininfo *li, struct utmp *ut)
    636 {
    637 # if defined(HAVE_TV_IN_UTMP)
    638 	ut->ut_tv.tv_sec = li->tv_sec;
    639 	ut->ut_tv.tv_usec = li->tv_usec;
    640 # elif defined(HAVE_TIME_IN_UTMP)
    641 	ut->ut_time = li->tv_sec;
    642 # endif
    643 }
    644 
    645 void
    646 construct_utmp(struct logininfo *li,
    647 		    struct utmp *ut)
    648 {
    649 # ifdef HAVE_ADDR_V6_IN_UTMP
    650 	struct sockaddr_in6 *sa6;
    651 # endif
    652 
    653 	memset(ut, '\0', sizeof(*ut));
    654 
    655 	/* First fill out fields used for both logins and logouts */
    656 
    657 # ifdef HAVE_ID_IN_UTMP
    658 	line_abbrevname(ut->ut_id, li->line, sizeof(ut->ut_id));
    659 # endif
    660 
    661 # ifdef HAVE_TYPE_IN_UTMP
    662 	/* This is done here to keep utmp constants out of struct logininfo */
    663 	switch (li->type) {
    664 	case LTYPE_LOGIN:
    665 		ut->ut_type = USER_PROCESS;
    666 #ifdef _UNICOS
    667 		cray_set_tmpdir(ut);
    668 #endif
    669 		break;
    670 	case LTYPE_LOGOUT:
    671 		ut->ut_type = DEAD_PROCESS;
    672 #ifdef _UNICOS
    673 		cray_retain_utmp(ut, li->pid);
    674 #endif
    675 		break;
    676 	}
    677 # endif
    678 	set_utmp_time(li, ut);
    679 
    680 	line_stripname(ut->ut_line, li->line, sizeof(ut->ut_line));
    681 
    682 # ifdef HAVE_PID_IN_UTMP
    683 	ut->ut_pid = li->pid;
    684 # endif
    685 
    686 	/* If we're logging out, leave all other fields blank */
    687 	if (li->type == LTYPE_LOGOUT)
    688 		return;
    689 
    690 	/*
    691 	 * These fields are only used when logging in, and are blank
    692 	 * for logouts.
    693 	 */
    694 
    695 	/* Use strncpy because we don't necessarily want null termination */
    696 	strncpy(ut->ut_name, li->username,
    697 	    MIN_SIZEOF(ut->ut_name, li->username));
    698 # ifdef HAVE_HOST_IN_UTMP
    699 	strncpy(ut->ut_host, li->hostname,
    700 	    MIN_SIZEOF(ut->ut_host, li->hostname));
    701 # endif
    702 # ifdef HAVE_ADDR_IN_UTMP
    703 	/* this is just a 32-bit IP address */
    704 	if (li->hostaddr.sa.sa_family == AF_INET)
    705 		ut->ut_addr = li->hostaddr.sa_in.sin_addr.s_addr;
    706 # endif
    707 # ifdef HAVE_ADDR_V6_IN_UTMP
    708 	/* this is just a 128-bit IPv6 address */
    709 	if (li->hostaddr.sa.sa_family == AF_INET6) {
    710 		sa6 = ((struct sockaddr_in6 *)&li->hostaddr.sa);
    711 		memcpy(ut->ut_addr_v6, sa6->sin6_addr.s6_addr, 16);
    712 		if (IN6_IS_ADDR_V4MAPPED(&sa6->sin6_addr)) {
    713 			ut->ut_addr_v6[0] = ut->ut_addr_v6[3];
    714 			ut->ut_addr_v6[1] = 0;
    715 			ut->ut_addr_v6[2] = 0;
    716 			ut->ut_addr_v6[3] = 0;
    717 		}
    718 	}
    719 # endif
    720 }
    721 #endif /* USE_UTMP || USE_WTMP || USE_LOGIN */
    722 
    723 /**
    724  ** utmpx utility functions
    725  **
    726  ** These functions manipulate struct utmpx, accounting for system
    727  ** variations.
    728  **/
    729 
    730 #if defined(USE_UTMPX) || defined (USE_WTMPX)
    731 /* build the utmpx structure */
    732 void
    733 set_utmpx_time(struct logininfo *li, struct utmpx *utx)
    734 {
    735 # if defined(HAVE_TV_IN_UTMPX)
    736 	utx->ut_tv.tv_sec = li->tv_sec;
    737 	utx->ut_tv.tv_usec = li->tv_usec;
    738 # elif defined(HAVE_TIME_IN_UTMPX)
    739 	utx->ut_time = li->tv_sec;
    740 # endif
    741 }
    742 
    743 void
    744 construct_utmpx(struct logininfo *li, struct utmpx *utx)
    745 {
    746 # ifdef HAVE_ADDR_V6_IN_UTMP
    747 	struct sockaddr_in6 *sa6;
    748 #  endif
    749 	memset(utx, '\0', sizeof(*utx));
    750 
    751 # ifdef HAVE_ID_IN_UTMPX
    752 	line_abbrevname(utx->ut_id, li->line, sizeof(utx->ut_id));
    753 # endif
    754 
    755 	/* this is done here to keep utmp constants out of loginrec.h */
    756 	switch (li->type) {
    757 	case LTYPE_LOGIN:
    758 		utx->ut_type = USER_PROCESS;
    759 		break;
    760 	case LTYPE_LOGOUT:
    761 		utx->ut_type = DEAD_PROCESS;
    762 		break;
    763 	}
    764 	line_stripname(utx->ut_line, li->line, sizeof(utx->ut_line));
    765 	set_utmpx_time(li, utx);
    766 	utx->ut_pid = li->pid;
    767 
    768 	/* strncpy(): Don't necessarily want null termination */
    769 	strncpy(utx->ut_user, li->username,
    770 	    MIN_SIZEOF(utx->ut_user, li->username));
    771 
    772 	if (li->type == LTYPE_LOGOUT)
    773 		return;
    774 
    775 	/*
    776 	 * These fields are only used when logging in, and are blank
    777 	 * for logouts.
    778 	 */
    779 
    780 # ifdef HAVE_HOST_IN_UTMPX
    781 	strncpy(utx->ut_host, li->hostname,
    782 	    MIN_SIZEOF(utx->ut_host, li->hostname));
    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
    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
    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
    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
    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
    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
   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
   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
   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
   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
   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
   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
   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
   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
   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
   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
   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
   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
   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
   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
   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
   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
   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
   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
   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
   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
   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
   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
   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
   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
   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
   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
   1661 record_failed_login(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 (packet_connection_is_on_socket() &&
   1705 	    getpeername(packet_get_connection_in(),
   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