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