usr.sbin/lastlogin/lastlogin.c

   1 /*
   2  * Copyright (c) 1996 John M. Vinopal
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed for the NetBSD Project
  16  *      by John M. Vinopal.
  17  * 4. The name of the author may not be used to endorse or promote products
  18  *    derived from this software without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  23  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  25  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  26  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  27  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  28  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  * $NetBSD: lastlogin.c,v 1.4 1998/02/03 04:45:35 perry Exp $
  33  * $FreeBSD: src/usr.sbin/lastlogin/lastlogin.c,v 1.2.2.2 2001/07/19 05:02:46 kris Exp $
  34  * $DragonFly: src/usr.sbin/lastlogin/lastlogin.c,v 1.5 2004/11/13 16:14:33 liamfoy Exp $
  35  */
  36
  37 #include <sys/cdefs.h>
  38 #include <sys/user.h>
  39
  40 #include <err.h>
  41 #include <pwd.h>
  42 #include <stdio.h>
  43 #include <stdlib.h>
  44 #include <time.h>
  45 #include <utmp.h>
  46 #include <utmpx.h>
  47 #include <unistd.h>
  48
  49 static  void    output(struct passwd *, struct lastlog *);
  50 static  void    outputx(struct passwd *, struct lastlogx *);
  51 static  void    usage(void);
  52
  53 int
  54 main(int argc, char **argv)
  55 {
  56         int     ch, i;
  57         long offset;
  58         FILE    *fp;
  59         struct passwd   *passwd;
  60         struct lastlog  last;
  61         struct lastlogx lastx;
  62
  63         while ((ch = getopt(argc, argv, "")) != -1) {
  64                 usage();
  65         }
  66
  67         if ((fp = fopen(_PATH_LASTLOG, "r")) == NULL)
  68                 err(1, "%s", _PATH_LASTLOG);
  69
  70         setpassent(1);  /* Keep passwd file pointers open */
  71
  72         /* Process usernames given on the command line. */
  73         if (argc > 1) {
  74                 for (i = 1; i < argc; ++i) {
  75                         if ((passwd = getpwnam(argv[i])) == NULL) {
  76                                 warnx("user '%s' not found", argv[i]);
  77                                 continue;
  78                         }
  79                         if ((getlastlogx(_PATH_LASTLOGX, passwd->pw_uid,
  80                             &lastx)) != NULL) {
  81                                 outputx(passwd, &lastx);
  82                                 goto done;
  83                         }
  84                         /* Calculate the offset into the lastlog file. */
  85                         offset = (long)(passwd->pw_uid * sizeof(last));
  86                         if (fseek(fp, offset, SEEK_SET)) {
  87                                 warn("fseek error");
  88                                 continue;
  89                         }
  90                         if (fread(&last, sizeof(last), 1, fp) != 1) {
  91                                 warnx("fread error on '%s'", passwd->pw_name);
  92                                 clearerr(fp);
  93                                 continue;
  94                         }
  95                         output(passwd, &last);
  96                 }
  97         }
  98         /* Read all lastlog entries, looking for active ones */
  99         else {
 100                 while ((passwd = getpwent()) != NULL) {
 101                         if ((getlastlogx(_PATH_LASTLOGX, passwd->pw_uid,
 102                             &lastx)) != NULL) {
 103                                 if (lastx.ll_tv.tv_sec == 0)
 104                                         continue;
 105                                 outputx(passwd, &lastx);
 106                         } else {
 107                                 offset = (long)(passwd->pw_uid * sizeof(last));
 108
 109                                 if (fseek(fp, offset, SEEK_SET)) {
 110                                         continue;
 111                                 }
 112                                 if (fread(&last, sizeof(last), 1, fp) != 1) {
 113                                         continue;
 114                                 }
 115                                 if (last.ll_time == 0)
 116                                         continue;
 117                                 output(passwd, &last);
 118                         }
 119                 }
 120 #if 0
 121                 for (i = 0; fread(&last, sizeof(last), 1, fp) == 1; i++) {
 122                         if (last.ll_time == 0)
 123                                 continue;
 124                         if ((passwd = getpwuid((uid_t)i)) != NULL)
 125                                 output(passwd, &last);
 126                 }
 127                 if (ferror(fp))
 128                         warnx("fread error");
 129 #endif
 130         }
 131
 132 done:
 133         setpassent(0);  /* Close passwd file pointers */
 134
 135         fclose(fp);
 136         exit(0);
 137 }
 138
 139 /* Duplicate the output of last(1) */
 140 static void
 141 output(struct passwd *p, struct lastlog *l)
 142 {
 143         printf("%-*.*s  %-*.*s %-*.*s   %s",
 144                 UT_NAMESIZE, UT_NAMESIZE, p->pw_name,
 145                 UT_LINESIZE+4, UT_LINESIZE+4, l->ll_line,
 146                 UT_HOSTSIZE, UT_HOSTSIZE, l->ll_host,
 147                 (l->ll_time) ? ctime(&(l->ll_time)) : "Never logged in\n");
 148 }
 149
 150 static void
 151 outputx(struct passwd *p, struct lastlogx *l)
 152 {
 153         printf("%-*.*s  %-*.*s %-*.*s   %s",
 154                 UT_NAMESIZE, UT_NAMESIZE, p->pw_name,
 155                 UT_LINESIZE+4, UT_LINESIZE+4, l->ll_line,
 156                 UT_HOSTSIZE, UT_HOSTSIZE, l->ll_host,
 157                 (l->ll_tv.tv_sec) ? ctime((&l->ll_tv.tv_sec)) : "Never logged in\n");
 158 }
 159
 160 static void
 161 usage(void)
 162 {
 163         fprintf(stderr, "usage: lastlogin [user ...]\n");
 164         exit(1);
 165 }