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  * Use the -f option to provide a FROM address
  57  */
  58
  59 #define SMTP_DUMMYCMD  "MAIL "
  60 #define SMTP_USE_DUMMYCMD 1
  61 #define SMTP_QUIT       "QUIT\r\n"
  62
  63 int process_arguments (int, char **);
  64 int call_getopt (int, char **);
  65 int validate_arguments (void);
  66 int check_disk (int usp, int free_disk);
  67 void print_help (void);
  68 void print_usage (void);
  69
  70 int server_port = SMTP_PORT;
  71 char *server_address = NULL;
  72 char *server_expect = NULL;
  73 char *from_arg = " ";
  74 int warning_time = 0;
  75 int check_warning_time = FALSE;
  76 int critical_time = 0;
  77 int check_critical_time = FALSE;
  78 int verbose = FALSE;
  79
  80 int
  81 main (int argc, char **argv)
  82 {
  83         int sd;
  84         int result;
  85         char buffer[MAX_INPUT_BUFFER] = "";
  86         char helocmd[255] = SMTP_HELO ;
  87         char from_str[255] = SMTP_DUMMYCMD ;
  88         char myhostname[248];
  89
  90
  91         if (process_arguments (argc, argv) != OK)
  92                 usage ("Invalid command arguments supplied\n");
  93
  94         /* initialize the HELO command with the localhostname */
  95         gethostname(myhostname, sizeof(myhostname));
  96         strcat(helocmd, myhostname);
  97         strcat(helocmd, "\r\n");
  98
  99         /* initialize the MAIL command with optional FROM command  */
 100         if (from_arg) {
 101                 strcat(from_str, "FROM: ");
 102                 strcat(from_str, from_arg);
 103         }
 104         /* terminate line with a CRLF */
 105         strcat(from_str, "\r\n");
 106
 107         if (verbose == TRUE){
 108                 printf ("FROMCMD: %s\n", from_str);
 109         }
 110
 111
 112
 113         /* initialize alarm signal handling */
 114         signal (SIGALRM, socket_timeout_alarm_handler);
 115
 116         /* set socket timeout */
 117         alarm (socket_timeout);
 118
 119         /* try to connect to the host at the given port number */
 120         time (&start_time);
 121         result = my_tcp_connect (server_address, server_port, &sd);
 122
 123         /* we connected, so close connection before exiting */
 124         if (result == STATE_OK) {
 125
 126                 /* watch for the SMTP connection string */
 127                 result = recv (sd, buffer, MAX_INPUT_BUFFER - 1, 0);
 128
 129                 /* strip the buffer of carriage returns */
 130                 strip (buffer);
 131
 132                 /* return a WARNING status if we couldn't read any data */
 133                 if (result == -1) {
 134                         printf ("recv() failed\n");
 135                         result = STATE_WARNING;
 136                 }
 137
 138                 else {
 139
 140                         /* make sure we find the response we are looking for */
 141                         if (!strstr (buffer, server_expect)) {
 142                                 if (server_port == SMTP_PORT)
 143                                         printf ("Invalid SMTP response received from host\n");
 144                                 else
 145                                         printf ("Invalid SMTP response received from host on port %d\n",
 146                                                                         server_port);
 147                                 result = STATE_WARNING;
 148                         }
 149
 150                         else {
 151
 152                                 time (&end_time);
 153
 154                                 result = STATE_OK;
 155
 156                                 if (check_critical_time == TRUE
 157                                                 && (end_time - start_time) > critical_time) result =
 158                                                 STATE_CRITICAL;
 159                                 else if (check_warning_time == TRUE
 160                                                                  && (end_time - start_time) > warning_time) result =
 161                                                 STATE_WARNING;
 162
 163                                 if (verbose == TRUE)
 164                                         printf ("SMTP %s - %d sec. response time, %s\n",
 165                                                                         state_text (result), (int) (end_time - start_time), buffer);
 166                                 else
 167                                         printf ("SMTP %s - %d second response time\n", state_text (result),
 168                                                                         (int) (end_time - start_time));
 169                         }
 170                 }
 171
 172                 /* close the connection */
 173                 /* first send the HELO command */
 174                 send(sd,helocmd,strlen(helocmd),0);
 175                 /* allow for response to helo command to reach us */
 176                 recv(sd,buffer,MAX_INPUT_BUFFER-1,0);
 177
 178 #ifdef SMTP_USE_DUMMYCMD
 179                 send(sd,from_str,strlen(from_str),0);
 180                 /* allow for response to DUMMYCMD to reach us */
 181                 recv(sd,buffer,MAX_INPUT_BUFFER-1,0);
 182                 if (verbose == TRUE)
 183                         printf("DUMMYCMD: %s\n%s\n",from_str,buffer);
 184 #endif /* SMTP_USE_DUMMYCMD */
 185
 186                 /* finally close the connection */
 187                 send (sd, SMTP_QUIT, strlen (SMTP_QUIT), 0);
 188                 close (sd);
 189         }
 190
 191         /* reset the alarm */
 192         alarm (0);
 193
 194         return result;
 195 }
 196
 197
 198
 199
 200
 201
 202 /* process command-line arguments */
 203 int
 204 process_arguments (int argc, char **argv)
 205 {
 206         int c;
 207
 208         if (argc < 2)
 209                 return ERROR;
 210
 211         for (c = 1; c < argc; c++) {
 212                 if (strcmp ("-to", argv[c]) == 0)
 213                         strcpy (argv[c], "-t");
 214                 else if (strcmp ("-wt", argv[c]) == 0)
 215                         strcpy (argv[c], "-w");
 216                 else if (strcmp ("-ct", argv[c]) == 0)
 217                         strcpy (argv[c], "-c");
 218         }
 219
 220
 221
 222         c = 0;
 223         while ((c += (call_getopt (argc - c, &argv[c]))) < argc) {
 224
 225                 if (is_option (argv[c]))
 226                         continue;
 227
 228                 if (server_address == NULL) {
 229                         if (is_host (argv[c])) {
 230                                 server_address = argv[c];
 231                         }
 232                         else {
 233                                 usage ("Invalid host name");
 234                         }
 235                 }
 236         }
 237
 238         if (server_address == NULL)
 239                 server_address = strscpy (NULL, "127.0.0.1");
 240
 241         if (server_expect == NULL)
 242                 server_expect = strscpy (NULL, SMTP_EXPECT);
 243
 244         return validate_arguments ();
 245 }
 246
 247
 248
 249
 250
 251
 252 int
 253 call_getopt (int argc, char **argv)
 254 {
 255         int c, i = 0;
 256
 257 #ifdef HAVE_GETOPT_H
 258         int option_index = 0;
 259         static struct option long_options[] = {
 260                 {"hostname", required_argument, 0, 'H'},
 261                 {"expect", required_argument, 0, 'e'},
 262                 {"critical", required_argument, 0, 'c'},
 263                 {"warning", required_argument, 0, 'w'},
 264                 {"port", required_argument, 0, 'p'},
 265                 {"from", required_argument, 0, 'f'},
 266                 {"verbose", no_argument, 0, 'v'},
 267                 {"version", no_argument, 0, 'V'},
 268                 {"help", no_argument, 0, 'h'},
 269                 {0, 0, 0, 0}
 270         };
 271 #endif
 272
 273         while (1) {
 274 #ifdef HAVE_GETOPT_H
 275                 c =
 276                         getopt_long (argc, argv, "+hVvt:p:f:e:c:w:H:", long_options,
 277                                                                          &option_index);
 278 #else
 279                 c = getopt (argc, argv, "+?hVvt:p:f:e:c:w:H:");
 280 #endif
 281
 282                 i++;
 283
 284                 if (c == -1 || c == EOF || c == 1)
 285                         break;
 286
 287                 switch (c) {
 288                 case 't':
 289                 case 'p':
 290                 case 'e':
 291                 case 'f':
 292                 case 'c':
 293                 case 'w':
 294                 case 'H':
 295                         i++;
 296                 }
 297
 298                 switch (c) {
 299                 case 'H':                                                                       /* hostname */
 300                         if (is_host (optarg)) {
 301                                 server_address = optarg;
 302                         }
 303                         else {
 304                                 usage ("Invalid host name\n");
 305                         }
 306                         break;
 307                 case 'p':                                                                       /* port */
 308                         if (is_intpos (optarg)) {
 309                                 server_port = atoi (optarg);
 310                         }
 311                         else {
 312                                 usage ("Server port must be a positive integer\n");
 313                         }
 314                         break;
 315                 case 'f':                                                                       /* from argument */
 316                         from_arg = optarg;
 317                         break;
 318                 case 'e':                                                                       /* server expect string on 220  */
 319                         server_expect = optarg;
 320                         break;
 321                 case 'c':                                                                       /* critical time threshold */
 322                         if (is_intnonneg (optarg)) {
 323                                 critical_time = atoi (optarg);
 324                                 check_critical_time = TRUE;
 325                         }
 326                         else {
 327                                 usage ("Critical time must be a nonnegative integer\n");
 328                         }
 329                         break;
 330                 case 'w':                                                                       /* warning time threshold */
 331                         if (is_intnonneg (optarg)) {
 332                                 warning_time = atoi (optarg);
 333                                 check_warning_time = TRUE;
 334                         }
 335                         else {
 336                                 usage ("Warning time must be a nonnegative integer\n");
 337                         }
 338                         break;
 339                 case 'v':                                                                       /* verbose */
 340                         verbose = TRUE;
 341                         break;
 342                 case 't':                                                                       /* timeout */
 343                         if (is_intnonneg (optarg)) {
 344                                 socket_timeout = atoi (optarg);
 345                         }
 346                         else {
 347                                 usage ("Time interval must be a nonnegative integer\n");
 348                         }
 349                         break;
 350                 case 'V':                                                                       /* version */
 351                         print_revision (PROGNAME, "$Revision$");
 352                         exit (STATE_OK);
 353                 case 'h':                                                                       /* help */
 354                         print_help ();
 355                         exit (STATE_OK);
 356                 case '?':                                                                       /* help */
 357                         usage ("Invalid argument\n");
 358                 }
 359         }
 360         return i;
 361 }
 362
 363
 364
 365
 366
 367 int
 368 validate_arguments (void)
 369 {
 370         return OK;
 371 }
 372
 373
 374
 375
 376
 377 void
 378 print_help (void)
 379 {
 380         print_revision (PROGNAME, "$Revision$");
 381         printf
 382                 ("Copyright (c) 2000 Ethan Galstad/Karl DeBisschop\n\n"
 383                  "This plugin test the SMTP service on the specified host.\n\n");
 384         print_usage ();
 385         printf
 386                 ("\nOptions:\n"
 387                  " -H, --hostname=STRING or IPADDRESS\n"
 388                  "   Check server on the indicated host\n"
 389                  " -p, --port=INTEGER\n"
 390                  "   Make connection on the indicated port (default: %d)\n"
 391                  " -e, --expect=STRING\n"
 392                  "   String to expect in first line of server response (default: %s)\n"
 393                  " -f, --from=STRING\n"
 394                  "   from address to include in MAIL command (default NULL, Exchange2000 requires one)\n"
 395                  " -w, --warning=INTEGER\n"
 396                  "   Seconds necessary to result in a warning status\n"
 397                  " -c, --critical=INTEGER\n"
 398                  "   Seconds necessary to result in a critical status\n"
 399                  " -t, --timeout=INTEGER\n"
 400                  "   Seconds before connection attempt times out (default: %d)\n"
 401                  " -v, --verbose\n"
 402                  "   Print extra information (command-line use only)\n"
 403                  " -h, --help\n"
 404                  "   Print detailed help screen\n"
 405                  " -V, --version\n"
 406                  "   Print version information\n\n",
 407                  SMTP_PORT, SMTP_EXPECT, DEFAULT_SOCKET_TIMEOUT);
 408         support ();
 409 }
 410
 411
 412
 413
 414
 415 void
 416 print_usage (void)
 417 {
 418         printf
 419                 ("Usage: %s -H host [-e expect] [-p port] [-f from addr] [-w warn] [-c crit] [-t timeout] [-v]\n"
 420                  "       %s --help\n"
 421                  "       %s --version\n", PROGNAME, PROGNAME, PROGNAME);
 422 }