plugins/check_smtp.c

   1 /******************************************************************************
   2 *
   3 * CHECK_SMTP.C
   4 *
   5 * Program: SMTP plugin for Nagios
   6 * License: GPL
   7 * Copyright (c) 1999 Ethan Galstad (nagios@nagios.org)
   8 *
   9 * $Id$
  10 *
  11 * Description:
  12 *
  13 * This plugin will attempt to open an SMTP connection with the host.
  14 * Successul connects return STATE_OK, refusals and timeouts return
  15 * STATE_CRITICAL, other errors return STATE_UNKNOWN.  Successful
  16 * connects, but incorrect reponse messages from the host result in
  17 * STATE_WARNING return values.
  18 *
  19 * License Information:
  20 *
  21 * This program is free software; you can redistribute it and/or modify
  22 * it under the terms of the GNU General Public License as published by
  23 * the Free Software Foundation; either version 2 of the License, or
  24 * (at your option) any later version.
  25 *
  26 * This program is distributed in the hope that it will be useful,
  27 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  28 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  29 * GNU General Public License for more details.
  30 *
  31 * You should have received a copy of the GNU General Public License
  32 * along with this program; if not, write to the Free Software
  33 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  34 *
  35 *****************************************************************************/
  36
  37 #include "config.h"
  38 #include "common.h"
  39 #include "netutils.h"
  40 #include "utils.h"
  41
  42 #define PROGNAME "check_smtp"
  43
  44 #define SMTP_PORT       25
  45 #define SMTP_EXPECT     "220"
  46 /* sendmail will syslog a "NOQUEUE" error if session does not attempt
  47  * to do something useful. This can be prevented by giving a command
  48  * even if syntax is illegal (MAIL requires a FROM:<...> argument)
  49  * You can disable sending DUMMYCMD by undefining SMTP_USE_DUMMYCMD.
  50  */
  51 #define SMTP_DUMMYCMD  "MAIL\r\n"
  52 #define SMTP_USE_DUMMYCMD 1
  53 #define SMTP_QUIT       "QUIT\r\n"
  54
  55 int process_arguments (int, char **);
  56 int call_getopt (int, char **);
  57 int validate_arguments (void);
  58 int check_disk (int usp, int free_disk);
  59 void print_help (void);
  60 void print_usage (void);
  61
  62 int server_port = SMTP_PORT;
  63 char *server_address = NULL;
  64 char *server_expect = NULL;
  65 int warning_time = 0;
  66 int check_warning_time = FALSE;
  67 int critical_time = 0;
  68 int check_critical_time = FALSE;
  69 int verbose = FALSE;
  70
  71 int
  72 main (int argc, char **argv)
  73 {
  74         int sd;
  75         int result;
  76         char buffer[MAX_INPUT_BUFFER] = "";
  77
  78         if (process_arguments (argc, argv) != OK)
  79                 usage ("Invalid command arguments supplied\n");
  80
  81         /* initialize alarm signal handling */
  82         signal (SIGALRM, socket_timeout_alarm_handler);
  83
  84         /* set socket timeout */
  85         alarm (socket_timeout);
  86
  87         /* try to connect to the host at the given port number */
  88         time (&start_time);
  89         result = my_tcp_connect (server_address, server_port, &sd);
  90
  91         /* we connected, so close connection before exiting */
  92         if (result == STATE_OK) {
  93
  94                 /* watch for the SMTP connection string */
  95                 result = recv (sd, buffer, MAX_INPUT_BUFFER - 1, 0);
  96
  97                 /* strip the buffer of carriage returns */
  98                 strip (buffer);
  99
 100                 /* return a WARNING status if we couldn't read any data */
 101                 if (result == -1) {
 102                         printf ("recv() failed\n");
 103                         result = STATE_WARNING;
 104                 }
 105
 106                 else {
 107
 108                         /* make sure we find the response we are looking for */
 109                         if (!strstr (buffer, server_expect)) {
 110                                 if (server_port == SMTP_PORT)
 111                                         printf ("Invalid SMTP response received from host\n");
 112                                 else
 113                                         printf ("Invalid SMTP response received from host on port %d\n",
 114                                                                         server_port);
 115                                 result = STATE_WARNING;
 116                         }
 117
 118                         else {
 119
 120                                 time (&end_time);
 121
 122                                 result = STATE_OK;
 123
 124                                 if (check_critical_time == TRUE
 125                                                 && (end_time - start_time) > critical_time) result =
 126                                                 STATE_CRITICAL;
 127                                 else if (check_warning_time == TRUE
 128                                                                  && (end_time - start_time) > warning_time) result =
 129                                                 STATE_WARNING;
 130
 131                                 if (verbose == TRUE)
 132                                         printf ("SMTP %s - %d sec. response time, %s\n",
 133                                                                         state_text (result), (int) (end_time - start_time), buffer);
 134                                 else
 135                                         printf ("SMTP %s - %d second response time\n", state_text (result),
 136                                                                         (int) (end_time - start_time));
 137                         }
 138                 }
 139
 140                 /* close the connection */
 141 #ifdef SMTP_USE_DUMMYCMD
 142                send(sd,SMTP_DUMMYCMD,strlen(SMTP_DUMMYCMD),0);
 143                /* allow for response to DUMMYCMD to reach us */
 144                recv(sd,buffer,MAX_INPUT_BUFFER-1,0);
 145 #endif /* SMTP_USE_DUMMYCMD */
 146
 147                 send (sd, SMTP_QUIT, strlen (SMTP_QUIT), 0);
 148                 close (sd);
 149         }
 150
 151         /* reset the alarm */
 152         alarm (0);
 153
 154         return result;
 155 }
 156
 157
 158
 159
 160
 161
 162 /* process command-line arguments */
 163 int
 164 process_arguments (int argc, char **argv)
 165 {
 166         int c;
 167
 168         if (argc < 2)
 169                 return ERROR;
 170
 171         for (c = 1; c < argc; c++) {
 172                 if (strcmp ("-to", argv[c]) == 0)
 173                         strcpy (argv[c], "-t");
 174                 else if (strcmp ("-wt", argv[c]) == 0)
 175                         strcpy (argv[c], "-w");
 176                 else if (strcmp ("-ct", argv[c]) == 0)
 177                         strcpy (argv[c], "-c");
 178         }
 179
 180
 181
 182         c = 0;
 183         while ((c += (call_getopt (argc - c, &argv[c]))) < argc) {
 184
 185                 if (is_option (argv[c]))
 186                         continue;
 187
 188                 if (server_address == NULL) {
 189                         if (is_host (argv[c])) {
 190                                 server_address = argv[c];
 191                         }
 192                         else {
 193                                 usage ("Invalid host name");
 194                         }
 195                 }
 196         }
 197
 198         if (server_address == NULL)
 199                 server_address = strscpy (NULL, "127.0.0.1");
 200
 201         if (server_expect == NULL)
 202                 server_expect = strscpy (NULL, SMTP_EXPECT);
 203
 204         return validate_arguments ();
 205 }
 206
 207
 208
 209
 210
 211
 212 int
 213 call_getopt (int argc, char **argv)
 214 {
 215         int c, i = 0;
 216
 217 #ifdef HAVE_GETOPT_H
 218         int option_index = 0;
 219         static struct option long_options[] = {
 220                 {"hostname", required_argument, 0, 'H'},
 221                 {"expect", required_argument, 0, 'e'},
 222                 {"critical", required_argument, 0, 'c'},
 223                 {"warning", required_argument, 0, 'w'},
 224                 {"port", required_argument, 0, 'P'},
 225                 {"verbose", no_argument, 0, 'v'},
 226                 {"version", no_argument, 0, 'V'},
 227                 {"help", no_argument, 0, 'h'},
 228                 {0, 0, 0, 0}
 229         };
 230 #endif
 231
 232         while (1) {
 233 #ifdef HAVE_GETOPT_H
 234                 c =
 235                         getopt_long (argc, argv, "+hVvt:p:e:c:w:H:", long_options,
 236                                                                          &option_index);
 237 #else
 238                 c = getopt (argc, argv, "+?hVvt:p:e:c:w:H:");
 239 #endif
 240
 241                 i++;
 242
 243                 if (c == -1 || c == EOF || c == 1)
 244                         break;
 245
 246                 switch (c) {
 247                 case 't':
 248                 case 'p':
 249                 case 'e':
 250                 case 'c':
 251                 case 'w':
 252                 case 'H':
 253                         i++;
 254                 }
 255
 256                 switch (c) {
 257                 case 'H':                                                                       /* hostname */
 258                         if (is_host (optarg)) {
 259                                 server_address = optarg;
 260                         }
 261                         else {
 262                                 usage ("Invalid host name\n");
 263                         }
 264                         break;
 265                 case 'p':                                                                       /* port */
 266                         if (is_intpos (optarg)) {
 267                                 server_port = atoi (optarg);
 268                         }
 269                         else {
 270                                 usage ("Server port must be a positive integer\n");
 271                         }
 272                         break;
 273                 case 'e':                                                                       /* username */
 274                         server_expect = optarg;
 275                         break;
 276                 case 'c':                                                                       /* critical time threshold */
 277                         if (is_intnonneg (optarg)) {
 278                                 critical_time = atoi (optarg);
 279                                 check_critical_time = TRUE;
 280                         }
 281                         else {
 282                                 usage ("Critical time must be a nonnegative integer\n");
 283                         }
 284                         break;
 285                 case 'w':                                                                       /* warning time threshold */
 286                         if (is_intnonneg (optarg)) {
 287                                 warning_time = atoi (optarg);
 288                                 check_warning_time = TRUE;
 289                         }
 290                         else {
 291                                 usage ("Warning time must be a nonnegative integer\n");
 292                         }
 293                         break;
 294                 case 'v':                                                                       /* verbose */
 295                         verbose = TRUE;
 296                         break;
 297                 case 't':                                                                       /* timeout */
 298                         if (is_intnonneg (optarg)) {
 299                                 socket_timeout = atoi (optarg);
 300                         }
 301                         else {
 302                                 usage ("Time interval must be a nonnegative integer\n");
 303                         }
 304                         break;
 305                 case 'V':                                                                       /* version */
 306                         print_revision (PROGNAME, "$Revision$");
 307                         exit (STATE_OK);
 308                 case 'h':                                                                       /* help */
 309                         print_help ();
 310                         exit (STATE_OK);
 311                 case '?':                                                                       /* help */
 312                         usage ("Invalid argument\n");
 313                 }
 314         }
 315         return i;
 316 }
 317
 318
 319
 320
 321
 322 int
 323 validate_arguments (void)
 324 {
 325         return OK;
 326 }
 327
 328
 329
 330
 331
 332 void
 333 print_help (void)
 334 {
 335         print_revision (PROGNAME, "$Revision$");
 336         printf
 337                 ("Copyright (c) 2000 Ethan Galstad/Karl DeBisschop\n\n"
 338                  "This plugin test the SMTP service on the specified host.\n\n");
 339         print_usage ();
 340         printf
 341                 ("\nOptions:\n"
 342                  " -H, --hostname=STRING or IPADDRESS\n"
 343                  "   Check server on the indicated host\n"
 344                  " -p, --port=INTEGER\n"
 345                  "   Make connection on the indicated port (default: %d)\n"
 346                  " -e, --expect=STRING\n"
 347                  "   String to expect in first line of server response (default: %s)\n"
 348                  " -w, --warning=INTEGER\n"
 349                  "   Seconds necessary to result in a warning status\n"
 350                  " -c, --critical=INTEGER\n"
 351                  "   Seconds necessary to result in a critical status\n"
 352                  " -t, --timeout=INTEGER\n"
 353                  "   Seconds before connection attempt times out (default: %d)\n"
 354                  " -v, --verbose\n"
 355                  "   Print extra information (command-line use only)\n"
 356                  " -h, --help\n"
 357                  "   Print detailed help screen\n"
 358                  " -V, --version\n"
 359                  "   Print version information\n\n",
 360                  SMTP_PORT, SMTP_EXPECT, DEFAULT_SOCKET_TIMEOUT);
 361         support ();
 362 }
 363
 364
 365
 366
 367
 368 void
 369 print_usage (void)
 370 {
 371         printf
 372                 ("Usage: %s -H host [-e expect] [-p port] [-w warn] [-c crit] [-t timeout] [-v]\n"
 373                  "       %s --help\n"
 374                  "       %s --version\n", PROGNAME, PROGNAME, PROGNAME);
 375 }