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 #define SMTP_HELO "HELO "
  47
  48 /* sendmail will syslog a "NOQUEUE" error if session does not attempt
  49  * to do something useful. This can be prevented by giving a command
  50  * even if syntax is illegal (MAIL requires a FROM:<...> argument)
  51  * You can disable sending DUMMYCMD by undefining SMTP_USE_DUMMYCMD.
  52  *
  53  * According to rfc821 you can include a null reversepath in the from command
  54  * - but a log message is generated on the smtp server.
  55  */
  56 #define SMTP_DUMMYCMD  "MAIL FROM:<>\r\n"
  57 #define SMTP_USE_DUMMYCMD 1
  58 #define SMTP_QUIT       "QUIT\r\n"
  59
  60 int process_arguments (int, char **);
  61 int call_getopt (int, char **);
  62 int validate_arguments (void);
  63 int check_disk (int usp, int free_disk);
  64 void print_help (void);
  65 void print_usage (void);
  66
  67 int server_port = SMTP_PORT;
  68 char *server_address = NULL;
  69 char *server_expect = NULL;
  70 int warning_time = 0;
  71 int check_warning_time = FALSE;
  72 int critical_time = 0;
  73 int check_critical_time = FALSE;
  74 int verbose = FALSE;
  75
  76 int
  77 main (int argc, char **argv)
  78 {
  79         int sd;
  80         int result;
  81         char buffer[MAX_INPUT_BUFFER] = "";
  82         char helocmd[255] = SMTP_HELO ;
  83         char myhostname[248];
  84
  85
  86         if (process_arguments (argc, argv) != OK)
  87                 usage ("Invalid command arguments supplied\n");
  88
  89         /* initalize the HELO command with the localhostname */
  90         gethostname(myhostname, sizeof(myhostname));
  91         strcat(helocmd, myhostname);
  92         strcat(helocmd, "\r\n");
  93
  94         /* initialize alarm signal handling */
  95         signal (SIGALRM, socket_timeout_alarm_handler);
  96
  97         /* set socket timeout */
  98         alarm (socket_timeout);
  99
 100         /* try to connect to the host at the given port number */
 101         time (&start_time);
 102         result = my_tcp_connect (server_address, server_port, &sd);
 103
 104         /* we connected, so close connection before exiting */
 105         if (result == STATE_OK) {
 106
 107                 /* watch for the SMTP connection string */
 108                 result = recv (sd, buffer, MAX_INPUT_BUFFER - 1, 0);
 109
 110                 /* strip the buffer of carriage returns */
 111                 strip (buffer);
 112
 113                 /* return a WARNING status if we couldn't read any data */
 114                 if (result == -1) {
 115                         printf ("recv() failed\n");
 116                         result = STATE_WARNING;
 117                 }
 118
 119                 else {
 120
 121                         /* make sure we find the response we are looking for */
 122                         if (!strstr (buffer, server_expect)) {
 123                                 if (server_port == SMTP_PORT)
 124                                         printf ("Invalid SMTP response received from host\n");
 125                                 else
 126                                         printf ("Invalid SMTP response received from host on port %d\n",
 127                                                                         server_port);
 128                                 result = STATE_WARNING;
 129                         }
 130
 131                         else {
 132
 133                                 time (&end_time);
 134
 135                                 result = STATE_OK;
 136
 137                                 if (check_critical_time == TRUE
 138                                                 && (end_time - start_time) > critical_time) result =
 139                                                 STATE_CRITICAL;
 140                                 else if (check_warning_time == TRUE
 141                                                                  && (end_time - start_time) > warning_time) result =
 142                                                 STATE_WARNING;
 143
 144                                 if (verbose == TRUE)
 145                                         printf ("SMTP %s - %d sec. response time, %s\n",
 146                                                                         state_text (result), (int) (end_time - start_time), buffer);
 147                                 else
 148                                         printf ("SMTP %s - %d second response time\n", state_text (result),
 149                                                                         (int) (end_time - start_time));
 150                         }
 151                 }
 152
 153                 /* close the connection */
 154                 /* first send the HELO command */
 155                 send(sd,helocmd,strlen(helocmd),0);
 156                 /* allow for response to helo command to reach us */
 157                 recv(sd,buffer,MAX_INPUT_BUFFER-1,0);
 158
 159 #ifdef SMTP_USE_DUMMYCMD
 160                send(sd,SMTP_DUMMYCMD,strlen(SMTP_DUMMYCMD),0);
 161                /* allow for response to DUMMYCMD to reach us */
 162                recv(sd,buffer,MAX_INPUT_BUFFER-1,0);
 163 #endif /* SMTP_USE_DUMMYCMD */
 164
 165                 /* finally close the connection */
 166                 send (sd, SMTP_QUIT, strlen (SMTP_QUIT), 0);
 167                 close (sd);
 168         }
 169
 170         /* reset the alarm */
 171         alarm (0);
 172
 173         return result;
 174 }
 175
 176
 177
 178
 179
 180
 181 /* process command-line arguments */
 182 int
 183 process_arguments (int argc, char **argv)
 184 {
 185         int c;
 186
 187         if (argc < 2)
 188                 return ERROR;
 189
 190         for (c = 1; c < argc; c++) {
 191                 if (strcmp ("-to", argv[c]) == 0)
 192                         strcpy (argv[c], "-t");
 193                 else if (strcmp ("-wt", argv[c]) == 0)
 194                         strcpy (argv[c], "-w");
 195                 else if (strcmp ("-ct", argv[c]) == 0)
 196                         strcpy (argv[c], "-c");
 197         }
 198
 199
 200
 201         c = 0;
 202         while ((c += (call_getopt (argc - c, &argv[c]))) < argc) {
 203
 204                 if (is_option (argv[c]))
 205                         continue;
 206
 207                 if (server_address == NULL) {
 208                         if (is_host (argv[c])) {
 209                                 server_address = argv[c];
 210                         }
 211                         else {
 212                                 usage ("Invalid host name");
 213                         }
 214                 }
 215         }
 216
 217         if (server_address == NULL)
 218                 server_address = strscpy (NULL, "127.0.0.1");
 219
 220         if (server_expect == NULL)
 221                 server_expect = strscpy (NULL, SMTP_EXPECT);
 222
 223         return validate_arguments ();
 224 }
 225
 226
 227
 228
 229
 230
 231 int
 232 call_getopt (int argc, char **argv)
 233 {
 234         int c, i = 0;
 235
 236 #ifdef HAVE_GETOPT_H
 237         int option_index = 0;
 238         static struct option long_options[] = {
 239                 {"hostname", required_argument, 0, 'H'},
 240                 {"expect", required_argument, 0, 'e'},
 241                 {"critical", required_argument, 0, 'c'},
 242                 {"warning", required_argument, 0, 'w'},
 243                 {"port", required_argument, 0, 'P'},
 244                 {"verbose", no_argument, 0, 'v'},
 245                 {"version", no_argument, 0, 'V'},
 246                 {"help", no_argument, 0, 'h'},
 247                 {0, 0, 0, 0}
 248         };
 249 #endif
 250
 251         while (1) {
 252 #ifdef HAVE_GETOPT_H
 253                 c =
 254                         getopt_long (argc, argv, "+hVvt:p:e:c:w:H:", long_options,
 255                                                                          &option_index);
 256 #else
 257                 c = getopt (argc, argv, "+?hVvt:p:e:c:w:H:");
 258 #endif
 259
 260                 i++;
 261
 262                 if (c == -1 || c == EOF || c == 1)
 263                         break;
 264
 265                 switch (c) {
 266                 case 't':
 267                 case 'p':
 268                 case 'e':
 269                 case 'c':
 270                 case 'w':
 271                 case 'H':
 272                         i++;
 273                 }
 274
 275                 switch (c) {
 276                 case 'H':                                                                       /* hostname */
 277                         if (is_host (optarg)) {
 278                                 server_address = optarg;
 279                         }
 280                         else {
 281                                 usage ("Invalid host name\n");
 282                         }
 283                         break;
 284                 case 'p':                                                                       /* port */
 285                         if (is_intpos (optarg)) {
 286                                 server_port = atoi (optarg);
 287                         }
 288                         else {
 289                                 usage ("Server port must be a positive integer\n");
 290                         }
 291                         break;
 292                 case 'e':                                                                       /* username */
 293                         server_expect = optarg;
 294                         break;
 295                 case 'c':                                                                       /* critical time threshold */
 296                         if (is_intnonneg (optarg)) {
 297                                 critical_time = atoi (optarg);
 298                                 check_critical_time = TRUE;
 299                         }
 300                         else {
 301                                 usage ("Critical time must be a nonnegative integer\n");
 302                         }
 303                         break;
 304                 case 'w':                                                                       /* warning time threshold */
 305                         if (is_intnonneg (optarg)) {
 306                                 warning_time = atoi (optarg);
 307                                 check_warning_time = TRUE;
 308                         }
 309                         else {
 310                                 usage ("Warning time must be a nonnegative integer\n");
 311                         }
 312                         break;
 313                 case 'v':                                                                       /* verbose */
 314                         verbose = TRUE;
 315                         break;
 316                 case 't':                                                                       /* timeout */
 317                         if (is_intnonneg (optarg)) {
 318                                 socket_timeout = atoi (optarg);
 319                         }
 320                         else {
 321                                 usage ("Time interval must be a nonnegative integer\n");
 322                         }
 323                         break;
 324                 case 'V':                                                                       /* version */
 325                         print_revision (PROGNAME, "$Revision$");
 326                         exit (STATE_OK);
 327                 case 'h':                                                                       /* help */
 328                         print_help ();
 329                         exit (STATE_OK);
 330                 case '?':                                                                       /* help */
 331                         usage ("Invalid argument\n");
 332                 }
 333         }
 334         return i;
 335 }
 336
 337
 338
 339
 340
 341 int
 342 validate_arguments (void)
 343 {
 344         return OK;
 345 }
 346
 347
 348
 349
 350
 351 void
 352 print_help (void)
 353 {
 354         print_revision (PROGNAME, "$Revision$");
 355         printf
 356                 ("Copyright (c) 2000 Ethan Galstad/Karl DeBisschop\n\n"
 357                  "This plugin test the SMTP service on the specified host.\n\n");
 358         print_usage ();
 359         printf
 360                 ("\nOptions:\n"
 361                  " -H, --hostname=STRING or IPADDRESS\n"
 362                  "   Check server on the indicated host\n"
 363                  " -p, --port=INTEGER\n"
 364                  "   Make connection on the indicated port (default: %d)\n"
 365                  " -e, --expect=STRING\n"
 366                  "   String to expect in first line of server response (default: %s)\n"
 367                  " -w, --warning=INTEGER\n"
 368                  "   Seconds necessary to result in a warning status\n"
 369                  " -c, --critical=INTEGER\n"
 370                  "   Seconds necessary to result in a critical status\n"
 371                  " -t, --timeout=INTEGER\n"
 372                  "   Seconds before connection attempt times out (default: %d)\n"
 373                  " -v, --verbose\n"
 374                  "   Print extra information (command-line use only)\n"
 375                  " -h, --help\n"
 376                  "   Print detailed help screen\n"
 377                  " -V, --version\n"
 378                  "   Print version information\n\n",
 379                  SMTP_PORT, SMTP_EXPECT, DEFAULT_SOCKET_TIMEOUT);
 380         support ();
 381 }
 382
 383
 384
 385
 386
 387 void
 388 print_usage (void)
 389 {
 390         printf
 391                 ("Usage: %s -H host [-e expect] [-p port] [-w warn] [-c crit] [-t timeout] [-v]\n"
 392                  "       %s --help\n"
 393                  "       %s --version\n", PROGNAME, PROGNAME, PROGNAME);
 394 }