shadow/src/lastlog.c

/*
 * Copyright (c) 1989 - 1994, Julianne Frances Haugh
 * Copyright (c) 1996 - 2000, Marek Michałkiewicz
 * Copyright (c) 2000 - 2006, Tomasz Kłoczko
 * Copyright (c) 2007 - 2008, Nicolas François
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the copyright holders or contributors may not be used to
 *    endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <config.h>

#ident "$Id$"

#include <getopt.h>
#include <lastlog.h>
#include <pwd.h>
#include <stdio.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <time.h>
#include "defines.h"
#include "prototypes.h"

/*
 * Needed for MkLinux DR1/2/2.1 - J.
 */
#ifndef LASTLOG_FILE
#define LASTLOG_FILE "/var/log/lastlog"
#endif

/*
 * Global variables
 */
static FILE *lastlogfile;	/* lastlog file stream */
static long umin;		/* if uflg, only display users with uid >= umin */
static long umax;		/* if uflg, only display users with uid <= umax */
static int days;		/* number of days to consider for print command */
static time_t seconds;		/* that number of days in seconds */
static int inverse_days;	/* number of days to consider for print command */
static time_t inverse_seconds;	/* that number of days in seconds */


static bool uflg = false;	/* print only an user of range of users */
static bool tflg = false;	/* print is restricted to most recent days */
static bool bflg = false;	/* print excludes most recent days */
static struct lastlog lastlog;	/* scratch structure to play with ... */
static struct passwd *pwent;

#define	NOW	(time ((time_t *) 0))

static void usage (void)
{
	fputs (_("Usage: lastlog [options]\n"
	         "\n"
	         "Options:\n"
	         "  -b, --before DAYS             print only lastlog records older than DAYS\n"
	         "  -h, --help                    display this help message and exit\n"
	         "  -t, --time DAYS               print only lastlog records more recent than DAYS\n"
	         "  -u, --user LOGIN              print lastlog record of the specified LOGIN\n"
	         "\n"), stderr);
	exit (1);
}

static void print_one (const struct passwd *pw)
{
	static bool once = false;
	char *cp;
	struct tm *tm;
	time_t ll_time;

#ifdef HAVE_STRFTIME
	char ptime[80];
#endif

	if (NULL == pw) {
		return;
	}

	if (!once) {
#ifdef HAVE_LL_HOST
		puts (_("Username         Port     From             Latest"));
#else
		puts (_("Username                Port     Latest"));
#endif
		once = true;
	}
	ll_time = lastlog.ll_time;
	tm = localtime (&ll_time);
#ifdef HAVE_STRFTIME
	strftime (ptime, sizeof (ptime), "%a %b %e %H:%M:%S %z %Y", tm);
	cp = ptime;
#else
	cp = asctime (tm);
	cp[24] = '\0';
#endif

	if (lastlog.ll_time == (time_t) 0) {
		cp = _("**Never logged in**\0");
	}

#ifdef HAVE_LL_HOST
	printf ("%-16s %-8.8s %-16.16s %s\n", pw->pw_name,
		lastlog.ll_line, lastlog.ll_host, cp);
#else
	printf ("%-16s\t%-8.8s %s\n", pw->pw_name, lastlog.ll_line, cp);
#endif
}

static void print (void)
{
	off_t offset;
	uid_t user;

	setpwent ();
	while ( (pwent = getpwent ()) != NULL ) {
		user = pwent->pw_uid;
		if (   uflg
		    && (   (umin != -1 && user < (uid_t)umin)
		        || (umax != -1 && user > (uid_t)umax))) {
			continue;
		}
		offset = user * sizeof lastlog;

		fseeko (lastlogfile, offset, SEEK_SET);
		if (fread ((char *) &lastlog, sizeof lastlog, 1,
			   lastlogfile) != 1) {
			continue;
		}

		if (tflg && ((NOW - lastlog.ll_time) > seconds)) {
			continue;
		}

		if (bflg && ((NOW - lastlog.ll_time) < inverse_seconds)) {
			continue;
		}

		print_one (pwent);
	}
	endpwent ();
}

int main (int argc, char **argv)
{
	(void) setlocale (LC_ALL, "");
	(void) bindtextdomain (PACKAGE, LOCALEDIR);
	(void) textdomain (PACKAGE);

	{
		int c;
		static struct option const longopts[] = {
			{"help", no_argument, NULL, 'h'},
			{"time", required_argument, NULL, 't'},
			{"before", required_argument, NULL, 'b'},
			{"user", required_argument, NULL, 'u'},
			{NULL, 0, NULL, '\0'}
		};

		while ((c =
			getopt_long (argc, argv, "ht:b:u:", longopts,
				     NULL)) != -1) {
			switch (c) {
			case 'h':
				usage ();
				break;
			case 't':
				days = atoi (optarg);
				seconds = days * DAY;
				tflg = true;
				break;
			case 'b':
				inverse_days = atoi (optarg);
				inverse_seconds = inverse_days * DAY;
				bflg = true;
				break;
			case 'u':
				/*
				 * The user can be:
				 *  - a login name
				 *  - numerical
				 *  - a numerical login ID
				 *  - a range (-x, x-, x-y)
				 */
				uflg = true;
				pwent = xgetpwnam (optarg);
				if (NULL != pwent) {
					umin = pwent->pw_uid;
					umax = umin;
				} else {
					char *endptr = NULL;
					long int user;
					user = strtol(optarg, &endptr, 10);
					if (*optarg != '\0' && *endptr == '\0') {
						if (user < 0) {
							/* -<userid> */
							umin = -1;
							umax = -user;
						} else {
							/* <userid> */
							umin = user;
							umax = user;
						}
					} else if (endptr[0] == '-' && endptr[1] == '\0') {
						/* <userid>- */
						umin = user;
						umax = -1;
					} else if (*endptr == '-') {
						/* <userid>-<userid> */
						umin = user;
						umax = atol(endptr+1);
					} else {
						fprintf (stderr,
							 _("Unknown user or range: %s\n"),
							 optarg);
						exit (1);
					}
				}
				break;
			default:
				usage ();
				break;
			}
		}
		if (argc > optind) {
			fprintf (stderr,
			         _("lastlog: unexpected argument: %s\n"),
			         argv[optind]);
			usage();
		}
	}

	if ((lastlogfile = fopen (LASTLOG_FILE, "r")) == (FILE *) 0) {
		perror (LASTLOG_FILE);
		exit (1);
	}

	print ();
	fclose (lastlogfile);
	exit (0);
}