shadow/src/lastlog.c

/*
 * Copyright 1989 - 1994, Julianne Frances Haugh
 * 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. Neither the name of Julianne F. Haugh nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY JULIE HAUGH 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 JULIE HAUGH 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>

#include "rcsid.h"
RCSID (PKG_VER "$Id: lastlog.c,v 1.13 2003/12/17 12:52:25 kloczek Exp $")
#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <pwd.h>
#include <time.h>
#include "prototypes.h"
#include "defines.h"
#if HAVE_LASTLOG_H
#include <lastlog.h>
#else
#include "lastlog_.h"
#endif
/*
 * Needed for MkLinux DR1/2/2.1 - J.
 */
#ifndef LASTLOG_FILE
#define LASTLOG_FILE "/var/log/lastlog"
#endif
static FILE *lastlogfile;	/* lastlog file stream */
static off_t user;		/* one single user, specified on command line */
static int days;		/* number of days to consider for print command */
static time_t seconds;		/* that number of days in seconds */

static int uflg = 0;		/* set if user is a valid user id */
static int tflg = 0;		/* print is restricted to most recent days */
static struct lastlog lastlog;	/* scratch structure to play with ... */
static struct stat statbuf;	/* fstat buffer for file size */
static struct passwd *pwent;

#include <getopt.h>
static struct option const longopts[] = {
	{"user", required_argument, 0, 'u'},
	{"time", required_argument, 0, 't'},
	{"help", no_argument, 0, 'h'},
	{0, 0, 0, 0}
};

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

/* local function prototypes */
static void print (void);
static void print_one (const struct passwd *);

int main (int argc, char **argv)
{
	int c;

	setlocale (LC_ALL, "");
	bindtextdomain (PACKAGE, LOCALEDIR);
	textdomain (PACKAGE);

	if ((lastlogfile = fopen (LASTLOG_FILE, "r")) == (FILE *) 0) {
		perror (LASTLOG_FILE);
		exit (1);
	}
	while ((c =
		getopt_long (argc, argv, "u:t:h", longopts, NULL)) != -1) {
		switch (c) {
		case 'u':
			pwent = getpwnam (optarg);
			if (!pwent) {
				fprintf (stderr,
					 _("Unknown User: %s\n"), optarg);
				exit (1);
			}
			uflg++;
			user = pwent->pw_uid;
			break;
		case 't':
			days = atoi (optarg);
			seconds = days * DAY;
			tflg++;
			break;
		case 'h':
			fprintf (stdout,
				 _
				 ("Usage: %s [{-u|--login} login] [{-t|--time} days] [{-h|--help}]\n"),
				 argv[0]);
			exit (0);
		default:
			fprintf (stdout,
				 _
				 ("Usage: %s [{-u|--login} login] [{-t|--time} days] [{-h|--help}]\n"),
				 argv[0]);
			exit (1);
		}
	}
	print ();
	fclose (lastlogfile);
	exit (0);
 /*NOTREACHED*/}

static void print (void)
{
	off_t offset;

	if (uflg) {
		offset = (unsigned long) user *sizeof lastlog;

		if (fstat (fileno (lastlogfile), &statbuf)) {
			perror (LASTLOG_FILE);
			return;
		}
		if (offset >= statbuf.st_size)
			return;

		fseek (lastlogfile, offset, SEEK_SET);
		if (fread ((char *) &lastlog, sizeof lastlog, 1,
			   lastlogfile) == 1)
			print_one (pwent);
		else
			perror (LASTLOG_FILE);
	} else {
		setpwent ();
		while ((pwent = getpwent ())) {
			user = pwent->pw_uid;
			offset = (unsigned long) user *sizeof lastlog;

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

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

			print_one (pwent);
		}
	}
}

static void print_one (const struct passwd *pw)
{
	static int once;
	char *cp;
	struct tm *tm;
	time_t ll_time;
#ifdef HAVE_STRFTIME
	char ptime[80];
#endif

	if (!pw)
		return;

	if (!once) {
#ifdef HAVE_LL_HOST
		printf (_
			("Username         Port     From             Latest\n"));
#else
		printf (_("Username                Port     Latest\n"));
#endif
		once++;
	}
	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
}