plugins/check_users.c

   1 /*****************************************************************************
   2 *
   3 * Nagios check_users plugin
   4 *
   5 * License: GPL
   6 * Copyright (c) 2000-2007 Nagios Plugins Development Team
   7 *
   8 * Last Modified: $Date$
   9 *
  10 * Description:
  11 *
  12 * This file contains the check_users plugin
  13 *
  14 * This plugin checks the number of users currently logged in on the local
  15 * system and generates an error if the number exceeds the thresholds
  16 * specified.
  17 *
  18 *
  19 * This program is free software: you can redistribute it and/or modify
  20 * it under the terms of the GNU General Public License as published by
  21 * the Free Software Foundation, either version 3 of the License, or
  22 * (at your option) any later version.
  23 *
  24 * This program is distributed in the hope that it will be useful,
  25 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  26 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  27 * GNU General Public License for more details.
  28 *
  29 * You should have received a copy of the GNU General Public License
  30 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  31 *
  32 * $Id$
  33 *
  34 *****************************************************************************/
  35
  36 const char *progname = "check_users";
  37 const char *revision = "$Revision$";
  38 const char *copyright = "2000-2007";
  39 const char *email = "nagiosplug-devel@lists.sourceforge.net";
  40
  41 #include "common.h"
  42 #include "popen.h"
  43 #include "utils.h"
  44
  45 #define possibly_set(a,b) ((a) == 0 ? (b) : 0)
  46
  47 int process_arguments (int, char **);
  48 void print_help (void);
  49 void print_usage (void);
  50
  51 int wusers = -1;
  52 int cusers = -1;
  53
  54 int
  55 main (int argc, char **argv)
  56 {
  57         int users = -1;
  58         int result = STATE_UNKNOWN;
  59         char input_buffer[MAX_INPUT_BUFFER];
  60         char *perf;
  61
  62         setlocale (LC_ALL, "");
  63         bindtextdomain (PACKAGE, LOCALEDIR);
  64         textdomain (PACKAGE);
  65
  66         perf = strdup("");
  67
  68         /* Parse extra opts if any */
  69         argv=np_extra_opts (&argc, argv, progname);
  70
  71         if (process_arguments (argc, argv) == ERROR)
  72                 usage4 (_("Could not parse arguments"));
  73
  74         /* run the command */
  75         child_process = spopen (WHO_COMMAND);
  76         if (child_process == NULL) {
  77                 printf (_("Could not open pipe: %s\n"), WHO_COMMAND);
  78                 return STATE_UNKNOWN;
  79         }
  80
  81         child_stderr = fdopen (child_stderr_array[fileno (child_process)], "r");
  82         if (child_stderr == NULL)
  83                 printf (_("Could not open stderr for %s\n"), WHO_COMMAND);
  84
  85         users = 0;
  86
  87         while (fgets (input_buffer, MAX_INPUT_BUFFER - 1, child_process)) {
  88
  89                 /* increment 'users' on all lines except total user count */
  90                 if (input_buffer[0] != '#') {
  91                         users++;
  92                         continue;
  93                 }
  94
  95                 /* get total logged in users */
  96                 if (sscanf (input_buffer, _("# users=%d"), &users) == 1)
  97                         break;
  98
  99         }
 100
 101         /* check STDERR */
 102         if (fgets (input_buffer, MAX_INPUT_BUFFER - 1, child_stderr))
 103                 result = possibly_set (result, STATE_UNKNOWN);
 104         (void) fclose (child_stderr);
 105
 106         /* close the pipe */
 107         if (spclose (child_process))
 108                 result = possibly_set (result, STATE_UNKNOWN);
 109
 110         /* else check the user count against warning and critical thresholds */
 111         if (users >= cusers)
 112                 result = STATE_CRITICAL;
 113         else if (users >= wusers)
 114                 result = STATE_WARNING;
 115         else if (users >= 0)
 116                 result = STATE_OK;
 117
 118         if (result == STATE_UNKNOWN)
 119                 printf ("%s\n", _("Unable to read output"));
 120         else {
 121                 asprintf(&perf, "%s", perfdata ("users", users, "",
 122                   TRUE, wusers,
 123                   TRUE, cusers,
 124                   TRUE, 0,
 125                   FALSE, 0));
 126                 printf (_("USERS %s - %d users currently logged in |%s\n"), state_text (result),
 127                   users, perf);
 128         }
 129
 130         return result;
 131 }
 132
 133
 134
 135 /* process command-line arguments */
 136 int
 137 process_arguments (int argc, char **argv)
 138 {
 139         int c;
 140
 141         int option = 0;
 142         static struct option longopts[] = {
 143                 {"critical", required_argument, 0, 'c'},
 144                 {"warning", required_argument, 0, 'w'},
 145                 {"version", no_argument, 0, 'V'},
 146                 {"help", no_argument, 0, 'h'},
 147                 {0, 0, 0, 0}
 148         };
 149
 150         if (argc < 2)
 151                 usage ("\n");
 152
 153         while (1) {
 154                 c = getopt_long (argc, argv, "+hVvc:w:", longopts, &option);
 155
 156                 if (c == -1 || c == EOF || c == 1)
 157                         break;
 158
 159                 switch (c) {
 160                 case '?':                                                                       /* print short usage statement if args not parsable */
 161                         usage5 ();
 162                 case 'h':                                                                       /* help */
 163                         print_help ();
 164                         exit (STATE_OK);
 165                 case 'V':                                                                       /* version */
 166                         print_revision (progname, revision);
 167                         exit (STATE_OK);
 168                 case 'c':                                                                       /* critical */
 169                         if (!is_intnonneg (optarg))
 170                                 usage4 (_("Critical threshold must be a positive integer"));
 171                         else
 172                                 cusers = atoi (optarg);
 173                         break;
 174                 case 'w':                                                                       /* warning */
 175                         if (!is_intnonneg (optarg))
 176                                 usage4 (_("Warning threshold must be a positive integer"));
 177                         else
 178                                 wusers = atoi (optarg);
 179                         break;
 180                 }
 181         }
 182
 183         c = optind;
 184         if (wusers == -1 && argc > c) {
 185                 if (is_intnonneg (argv[c]) == FALSE)
 186                         usage4 (_("Warning threshold must be a positive integer"));
 187                 else
 188                         wusers = atoi (argv[c++]);
 189         }
 190
 191         if (cusers == -1 && argc > c) {
 192                 if (is_intnonneg (argv[c]) == FALSE)
 193                         usage4 (_("Warning threshold must be a positive integer"));
 194                 else
 195                         cusers = atoi (argv[c]);
 196         }
 197
 198         return OK;
 199 }
 200
 201
 202
 203 void
 204 print_help (void)
 205 {
 206         print_revision (progname, revision);
 207
 208         printf ("Copyright (c) 1999 Ethan Galstad\n");
 209         printf (COPYRIGHT, copyright, email);
 210
 211         printf ("%s\n", _("This plugin checks the number of users currently logged in on the local"));
 212   printf ("%s\n", _("system and generates an error if the number exceeds the thresholds specified."));
 213
 214   printf ("\n\n");
 215
 216         print_usage ();
 217
 218         printf (_(UT_HELP_VRSN));
 219         printf (_(UT_EXTRA_OPTS));
 220
 221         printf (" %s\n", "-w, --warning=INTEGER");
 222   printf ("    %s\n", _("Set WARNING status if more than INTEGER users are logged in"));
 223   printf (" %s\n", "-c, --critical=INTEGER");
 224   printf ("    %s\n", _("Set CRITICAL status if more than INTEGER users are logged in"));
 225
 226 #ifdef NP_EXTRA_OPTS
 227   printf ("\n");
 228   printf ("%s\n", _("Notes:"));
 229   printf (_(UT_EXTRA_OPTS_NOTES));
 230 #endif
 231
 232         printf (_(UT_SUPPORT));
 233 }
 234
 235
 236 void
 237 print_usage (void)
 238 {
 239   printf (_("Usage:"));
 240         printf ("%s -w <users> -c <users>\n", progname);
 241 }