plugins/check_smtp.c

   1 /******************************************************************************
   2 *
   3 * Nagios check_smtp plugin
   4 *
   5 * License: GPL
   6 * Copyright (c) 1999-2006 nagios-plugins team
   7 *
   8 * Last Modified: $Date$
   9 *
  10 * Description:
  11 *
  12 * This file contains the check_smtp plugin
  13 *
  14 *  This plugin will attempt to open an SMTP connection with the host.
  15 *
  16 *
  17 * License Information:
  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 2 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, write to the Free Software
  31 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  32 *
  33 *
  34 * $Id$
  35 *
  36 ******************************************************************************/
  37
  38 const char *progname = "check_smtp";
  39 const char *revision = "$Revision$";
  40 const char *copyright = "2000-2006";
  41 const char *email = "nagiosplug-devel@lists.sourceforge.net";
  42
  43 #include <ctype.h>
  44
  45 #include "common.h"
  46 #include "netutils.h"
  47 #include "utils.h"
  48
  49 #ifdef HAVE_SSL
  50 int check_cert = FALSE;
  51 int days_till_exp;
  52 #  define my_recv(buf, len) ((use_ssl && ssl_established) ? np_net_ssl_read(buf, len) : read(sd, buf, len))
  53 #  define my_send(buf, len) ((use_ssl && ssl_established) ? np_net_ssl_write(buf, len) : send(sd, buf, len, 0))
  54 #else /* ifndef HAVE_SSL */
  55 #  define my_recv(buf, len) read(sd, buf, len)
  56 #  define my_send(buf, len) send(sd, buf, len, 0)
  57 #endif
  58
  59 enum {
  60         SMTP_PORT       = 25
  61 };
  62 #define SMTP_EXPECT "220"
  63 #define SMTP_HELO "HELO "
  64 #define SMTP_EHLO "EHLO "
  65 #define SMTP_QUIT "QUIT\r\n"
  66 #define SMTP_STARTTLS "STARTTLS\r\n"
  67 #define SMTP_AUTH_LOGIN "AUTH LOGIN\r\n"
  68
  69 #ifndef HOST_MAX_BYTES
  70 #define HOST_MAX_BYTES 255
  71 #endif
  72
  73 #define EHLO_SUPPORTS_STARTTLS 1
  74
  75 int process_arguments (int, char **);
  76 int validate_arguments (void);
  77 void print_help (void);
  78 void print_usage (void);
  79 void smtp_quit(void);
  80 int recvline(char *, size_t);
  81 int recvlines(char *, size_t);
  82 int my_close(void);
  83
  84 #include "regex.h"
  85 char regex_expect[MAX_INPUT_BUFFER] = "";
  86 regex_t preg;
  87 regmatch_t pmatch[10];
  88 char timestamp[20] = "";
  89 char errbuf[MAX_INPUT_BUFFER];
  90 int cflags = REG_EXTENDED | REG_NOSUB | REG_NEWLINE;
  91 int eflags = 0;
  92 int errcode, excode;
  93
  94 int server_port = SMTP_PORT;
  95 char *server_address = NULL;
  96 char *server_expect = NULL;
  97 int smtp_use_dummycmd = 0;
  98 char *mail_command = NULL;
  99 char *from_arg = NULL;
 100 int ncommands=0;
 101 int command_size=0;
 102 int nresponses=0;
 103 int response_size=0;
 104 char **commands = NULL;
 105 char **responses = NULL;
 106 char *authtype = NULL;
 107 char *authuser = NULL;
 108 char *authpass = NULL;
 109 int warning_time = 0;
 110 int check_warning_time = FALSE;
 111 int critical_time = 0;
 112 int check_critical_time = FALSE;
 113 int verbose = 0;
 114 int use_ssl = FALSE;
 115 short use_ehlo = FALSE;
 116 short ssl_established = 0;
 117 char *localhostname = NULL;
 118 int sd;
 119 char buffer[MAX_INPUT_BUFFER];
 120 enum {
 121   TCP_PROTOCOL = 1,
 122   UDP_PROTOCOL = 2,
 123 };
 124
 125 /* written by lauri alanko */
 126 static char *
 127 base64 (const char *bin, size_t len)
 128 {
 129
 130         char *buf = (char *) malloc ((len + 2) / 3 * 4 + 1);
 131         size_t i = 0, j = 0;
 132
 133         char BASE64_END = '=';
 134         char base64_table[64];
 135         strncpy (base64_table, "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/", 64);
 136
 137         while (j < len - 2) {
 138                 buf[i++] = base64_table[bin[j] >> 2];
 139                 buf[i++] = base64_table[((bin[j] & 3) << 4) | (bin[j + 1] >> 4)];
 140                 buf[i++] = base64_table[((bin[j + 1] & 15) << 2) | (bin[j + 2] >> 6)];
 141                 buf[i++] = base64_table[bin[j + 2] & 63];
 142                 j += 3;
 143         }
 144
 145         switch (len - j) {
 146         case 1:
 147                 buf[i++] = base64_table[bin[j] >> 2];
 148                 buf[i++] = base64_table[(bin[j] & 3) << 4];
 149                 buf[i++] = BASE64_END;
 150                 buf[i++] = BASE64_END;
 151                 break;
 152         case 2:
 153                 buf[i++] = base64_table[bin[j] >> 2];
 154                 buf[i++] = base64_table[((bin[j] & 3) << 4) | (bin[j + 1] >> 4)];
 155                 buf[i++] = base64_table[(bin[j + 1] & 15) << 2];
 156                 buf[i++] = BASE64_END;
 157                 break;
 158         case 0:
 159                 break;
 160         }
 161
 162         buf[i] = '\0';
 163         return buf;
 164 }
 165
 166 int
 167 main (int argc, char **argv)
 168 {
 169         short supports_tls=FALSE;
 170         int n = 0;
 171         double elapsed_time;
 172         long microsec;
 173         int result = STATE_UNKNOWN;
 174         char *cmd_str = NULL;
 175         char *helocmd = NULL;
 176         char *error_msg = "";
 177         struct timeval tv;
 178
 179         setlocale (LC_ALL, "");
 180         bindtextdomain (PACKAGE, LOCALEDIR);
 181         textdomain (PACKAGE);
 182
 183         if (process_arguments (argc, argv) == ERROR)
 184                 usage4 (_("Could not parse arguments"));
 185
 186         /* If localhostname not set on command line, use gethostname to set */
 187         if(! localhostname){
 188                 localhostname = malloc (HOST_MAX_BYTES);
 189                 if(!localhostname){
 190                         printf(_("malloc() failed!\n"));
 191                         return STATE_CRITICAL;
 192                 }
 193                 if(gethostname(localhostname, HOST_MAX_BYTES)){
 194                         printf(_("gethostname() failed!\n"));
 195                         return STATE_CRITICAL;
 196                 }
 197         }
 198         if(use_ehlo)
 199                 asprintf (&helocmd, "%s%s%s", SMTP_EHLO, localhostname, "\r\n");
 200         else
 201                 asprintf (&helocmd, "%s%s%s", SMTP_HELO, localhostname, "\r\n");
 202
 203         if (verbose)
 204                 printf("HELOCMD: %s", helocmd);
 205
 206         /* initialize the MAIL command with optional FROM command  */
 207         asprintf (&cmd_str, "%sFROM: %s%s", mail_command, from_arg, "\r\n");
 208
 209         if (verbose && smtp_use_dummycmd)
 210                 printf ("FROM CMD: %s", cmd_str);
 211
 212         /* initialize alarm signal handling */
 213         (void) signal (SIGALRM, socket_timeout_alarm_handler);
 214
 215         /* set socket timeout */
 216         (void) alarm (socket_timeout);
 217
 218         /* start timer */
 219         gettimeofday (&tv, NULL);
 220
 221         /* try to connect to the host at the given port number */
 222         result = my_tcp_connect (server_address, server_port, &sd);
 223
 224         if (result == STATE_OK) { /* we connected */
 225
 226                 /* watch for the SMTP connection string and */
 227                 /* return a WARNING status if we couldn't read any data */
 228                 if (recvlines(buffer, MAX_INPUT_BUFFER) <= 0) {
 229                         printf (_("recv() failed\n"));
 230                         result = STATE_WARNING;
 231                 }
 232                 else {
 233                         if (verbose)
 234                                 printf ("%s", buffer);
 235                         /* strip the buffer of carriage returns */
 236                         strip (buffer);
 237                         /* make sure we find the response we are looking for */
 238                         if (!strstr (buffer, server_expect)) {
 239                                 if (server_port == SMTP_PORT)
 240                                         printf (_("Invalid SMTP response received from host\n"));
 241                                 else
 242                                         printf (_("Invalid SMTP response received from host on port %d\n"),
 243                                                                         server_port);
 244                                 result = STATE_WARNING;
 245                         }
 246                 }
 247
 248                 /* send the HELO/EHLO command */
 249                 send(sd, helocmd, strlen(helocmd), 0);
 250
 251                 /* allow for response to helo command to reach us */
 252                 if (recvlines(buffer, MAX_INPUT_BUFFER) <= 0) {
 253                         printf (_("recv() failed\n"));
 254                         return STATE_WARNING;
 255                 } else if(use_ehlo){
 256                         if(strstr(buffer, "250 STARTTLS") != NULL ||
 257                            strstr(buffer, "250-STARTTLS") != NULL){
 258                                 supports_tls=TRUE;
 259                         }
 260                 }
 261
 262                 if(use_ssl && ! supports_tls){
 263                         printf(_("WARNING - TLS not supported by server\n"));
 264                         smtp_quit();
 265                         return STATE_WARNING;
 266                 }
 267
 268 #ifdef HAVE_SSL
 269                 if(use_ssl) {
 270                   /* send the STARTTLS command */
 271                   send(sd, SMTP_STARTTLS, strlen(SMTP_STARTTLS), 0);
 272
 273                   recvlines(buffer, MAX_INPUT_BUFFER); /* wait for it */
 274                   if (!strstr (buffer, server_expect)) {
 275                     printf (_("Server does not support STARTTLS\n"));
 276                     smtp_quit();
 277                     return STATE_UNKNOWN;
 278                   }
 279                   result = np_net_ssl_init(sd);
 280                   if(result != STATE_OK) {
 281                     printf (_("CRITICAL - Cannot create SSL context.\n"));
 282                     np_net_ssl_cleanup();
 283                     close(sd);
 284                     return STATE_CRITICAL;
 285                   } else {
 286                         ssl_established = 1;
 287                   }
 288
 289                 /*
 290                  * Resend the EHLO command.
 291                  *
 292                  * RFC 3207 (4.2) says: ``The client MUST discard any knowledge
 293                  * obtained from the server, such as the list of SMTP service
 294                  * extensions, which was not obtained from the TLS negotiation
 295                  * itself.  The client SHOULD send an EHLO command as the first
 296                  * command after a successful TLS negotiation.''  For this
 297                  * reason, some MTAs will not allow an AUTH LOGIN command before
 298                  * we resent EHLO via TLS.
 299                  */
 300                 if (my_send(helocmd, strlen(helocmd)) <= 0) {
 301                         printf("%s\n", _("SMTP UNKNOWN - Cannot send EHLO command via TLS."));
 302                         my_close();
 303                         return STATE_UNKNOWN;
 304                 }
 305                 if (verbose)
 306                         printf(_("sent %s"), helocmd);
 307                 if ((n = recvlines(buffer, MAX_INPUT_BUFFER)) <= 0) {
 308                         printf("%s\n", _("SMTP UNKNOWN - Cannot read EHLO response via TLS."));
 309                         my_close();
 310                         return STATE_UNKNOWN;
 311                 }
 312                 if (verbose) {
 313                         printf("%s", buffer);
 314                 }
 315
 316 #  ifdef USE_OPENSSL
 317                   if ( check_cert ) {
 318                     result = np_net_ssl_check_cert(days_till_exp);
 319                     if(result != STATE_OK){
 320                       printf ("%s\n", _("CRITICAL - Cannot retrieve server certificate."));
 321                     }
 322                     my_close();
 323                     return result;
 324                   }
 325 #  endif /* USE_OPENSSL */
 326                 }
 327 #endif
 328
 329                 /* sendmail will syslog a "NOQUEUE" error if session does not attempt
 330                  * to do something useful. This can be prevented by giving a command
 331                  * even if syntax is illegal (MAIL requires a FROM:<...> argument)
 332                  *
 333                  * According to rfc821 you can include a null reversepath in the from command
 334                  * - but a log message is generated on the smtp server.
 335                  *
 336                  * You can disable sending mail_command with '--nocommand'
 337                  * Use the -f option to provide a FROM address
 338                  */
 339                 if (smtp_use_dummycmd) {
 340                   my_send(cmd_str, strlen(cmd_str));
 341                   if (recvlines(buffer, MAX_INPUT_BUFFER) >= 1 && verbose)
 342                     printf("%s", buffer);
 343                 }
 344
 345                 while (n < ncommands) {
 346                         asprintf (&cmd_str, "%s%s", commands[n], "\r\n");
 347                         my_send(cmd_str, strlen(cmd_str));
 348                         if (recvlines(buffer, MAX_INPUT_BUFFER) >= 1 && verbose)
 349                                 printf("%s", buffer);
 350                         strip (buffer);
 351                         if (n < nresponses) {
 352                                 cflags |= REG_EXTENDED | REG_NOSUB | REG_NEWLINE;
 353                                 errcode = regcomp (&preg, responses[n], cflags);
 354                                 if (errcode != 0) {
 355                                         regerror (errcode, &preg, errbuf, MAX_INPUT_BUFFER);
 356                                         printf (_("Could Not Compile Regular Expression"));
 357                                         return ERROR;
 358                                 }
 359                                 excode = regexec (&preg, buffer, 10, pmatch, eflags);
 360                                 if (excode == 0) {
 361                                         result = STATE_OK;
 362                                 }
 363                                 else if (excode == REG_NOMATCH) {
 364                                         result = STATE_WARNING;
 365                                         printf (_("SMTP %s - Invalid response '%s' to command '%s'\n"), state_text (result), buffer, commands[n]);
 366                                 }
 367                                 else {
 368                                         regerror (excode, &preg, errbuf, MAX_INPUT_BUFFER);
 369                                         printf (_("Execute Error: %s\n"), errbuf);
 370                                         result = STATE_UNKNOWN;
 371                                 }
 372                         }
 373                         n++;
 374                 }
 375
 376                 if (authtype != NULL) {
 377                         if (strcmp (authtype, "LOGIN") == 0) {
 378                                 char *abuf;
 379                                 int ret;
 380                                 do {
 381                                         if (authuser == NULL) {
 382                                                 result = STATE_CRITICAL;
 383                                                 asprintf(&error_msg, _("no authuser specified, "));
 384                                                 break;
 385                                         }
 386                                         if (authpass == NULL) {
 387                                                 result = STATE_CRITICAL;
 388                                                 asprintf(&error_msg, _("no authpass specified, "));
 389                                                 break;
 390                                         }
 391
 392                                         /* send AUTH LOGIN */
 393                                         my_send(SMTP_AUTH_LOGIN, strlen(SMTP_AUTH_LOGIN));
 394                                         if (verbose)
 395                                                 printf (_("sent %s\n"), "AUTH LOGIN");
 396
 397                                         if ((ret = recvlines(buffer, MAX_INPUT_BUFFER)) <= 0) {
 398                                                 asprintf(&error_msg, _("recv() failed after AUTH LOGIN, "));
 399                                                 result = STATE_WARNING;
 400                                                 break;
 401                                         }
 402                                         if (verbose)
 403                                                 printf (_("received %s\n"), buffer);
 404
 405                                         if (strncmp (buffer, "334", 3) != 0) {
 406                                                 result = STATE_CRITICAL;
 407                                                 asprintf(&error_msg, _("invalid response received after AUTH LOGIN, "));
 408                                                 break;
 409                                         }
 410
 411                                         /* encode authuser with base64 */
 412                                         abuf = base64 (authuser, strlen(authuser));
 413                                         strcat (abuf, "\r\n");
 414                                         my_send(abuf, strlen(abuf));
 415                                         if (verbose)
 416                                                 printf (_("sent %s\n"), abuf);
 417
 418                                         if ((ret = recvlines(buffer, MAX_INPUT_BUFFER)) <= 0) {
 419                                                 result = STATE_CRITICAL;
 420                                                 asprintf(&error_msg, _("recv() failed after sending authuser, "));
 421                                                 break;
 422                                         }
 423                                         if (verbose) {
 424                                                 printf (_("received %s\n"), buffer);
 425                                         }
 426                                         if (strncmp (buffer, "334", 3) != 0) {
 427                                                 result = STATE_CRITICAL;
 428                                                 asprintf(&error_msg, _("invalid response received after authuser, "));
 429                                                 break;
 430                                         }
 431                                         /* encode authpass with base64 */
 432                                         abuf = base64 (authpass, strlen(authpass));
 433                                         strcat (abuf, "\r\n");
 434                                         my_send(abuf, strlen(abuf));
 435                                         if (verbose) {
 436                                                 printf (_("sent %s\n"), abuf);
 437                                         }
 438                                         if ((ret = recvlines(buffer, MAX_INPUT_BUFFER)) <= 0) {
 439                                                 result = STATE_CRITICAL;
 440                                                 asprintf(&error_msg, _("recv() failed after sending authpass, "));
 441                                                 break;
 442                                         }
 443                                         if (verbose) {
 444                                                 printf (_("received %s\n"), buffer);
 445                                         }
 446                                         if (strncmp (buffer, "235", 3) != 0) {
 447                                                 result = STATE_CRITICAL;
 448                                                 asprintf(&error_msg, _("invalid response received after authpass, "));
 449                                                 break;
 450                                         }
 451                                         break;
 452                                 } while (0);
 453                         } else {
 454                                 result = STATE_CRITICAL;
 455                                 asprintf(&error_msg, _("only authtype LOGIN is supported, "));
 456                         }
 457                 }
 458
 459                 /* tell the server we're done */
 460                 smtp_quit();
 461
 462                 /* finally close the connection */
 463                 close (sd);
 464         }
 465
 466         /* reset the alarm */
 467         alarm (0);
 468
 469         microsec = deltime (tv);
 470         elapsed_time = (double)microsec / 1.0e6;
 471
 472         if (result == STATE_OK) {
 473                 if (check_critical_time && elapsed_time > (double) critical_time)
 474                         result = STATE_CRITICAL;
 475                 else if (check_warning_time && elapsed_time > (double) warning_time)
 476                         result = STATE_WARNING;
 477         }
 478
 479         printf (_("SMTP %s - %s%.3f sec. response time%s%s|%s\n"),
 480                         state_text (result),
 481                         error_msg,
 482                         elapsed_time,
 483                         verbose?", ":"", verbose?buffer:"",
 484                         fperfdata ("time", elapsed_time, "s",
 485                                 (int)check_warning_time, warning_time,
 486                                 (int)check_critical_time, critical_time,
 487                                 TRUE, 0, FALSE, 0));
 488
 489         return result;
 490 }
 491
 492
 493
 494 /* process command-line arguments */
 495 int
 496 process_arguments (int argc, char **argv)
 497 {
 498         int c;
 499
 500         int option = 0;
 501         static struct option longopts[] = {
 502                 {"hostname", required_argument, 0, 'H'},
 503                 {"expect", required_argument, 0, 'e'},
 504                 {"critical", required_argument, 0, 'c'},
 505                 {"warning", required_argument, 0, 'w'},
 506                 {"timeout", required_argument, 0, 't'},
 507                 {"port", required_argument, 0, 'p'},
 508                 {"from", required_argument, 0, 'f'},
 509                 {"fqdn", required_argument, 0, 'F'},
 510                 {"authtype", required_argument, 0, 'A'},
 511                 {"authuser", required_argument, 0, 'U'},
 512                 {"authpass", required_argument, 0, 'P'},
 513                 {"command", required_argument, 0, 'C'},
 514                 {"response", required_argument, 0, 'R'},
 515                 {"nocommand", required_argument, 0, 'n'},
 516                 {"verbose", no_argument, 0, 'v'},
 517                 {"version", no_argument, 0, 'V'},
 518                 {"use-ipv4", no_argument, 0, '4'},
 519                 {"use-ipv6", no_argument, 0, '6'},
 520                 {"help", no_argument, 0, 'h'},
 521                 {"starttls",no_argument,0,'S'},
 522                 {"certificate",required_argument,0,'D'},
 523                 {0, 0, 0, 0}
 524         };
 525
 526         if (argc < 2)
 527                 return ERROR;
 528
 529         for (c = 1; c < argc; c++) {
 530                 if (strcmp ("-to", argv[c]) == 0)
 531                         strcpy (argv[c], "-t");
 532                 else if (strcmp ("-wt", argv[c]) == 0)
 533                         strcpy (argv[c], "-w");
 534                 else if (strcmp ("-ct", argv[c]) == 0)
 535                         strcpy (argv[c], "-c");
 536         }
 537
 538         while (1) {
 539                 c = getopt_long (argc, argv, "+hVv46t:p:f:e:c:w:H:C:R:SD:F:A:U:P:",
 540                                  longopts, &option);
 541
 542                 if (c == -1 || c == EOF)
 543                         break;
 544
 545                 switch (c) {
 546                 case 'H':                                                                       /* hostname */
 547                         if (is_host (optarg)) {
 548                                 server_address = optarg;
 549                         }
 550                         else {
 551                                 usage2 (_("Invalid hostname/address"), optarg);
 552                         }
 553                         break;
 554                 case 'p':                                                                       /* port */
 555                         if (is_intpos (optarg))
 556                                 server_port = atoi (optarg);
 557                         else
 558                                 usage4 (_("Port must be a positive integer"));
 559                         break;
 560                 case 'F':
 561                 /* localhostname */
 562                         localhostname = strdup(optarg);
 563                         break;
 564                 case 'f':                                                                       /* from argument */
 565                         from_arg = optarg;
 566                         smtp_use_dummycmd = 1;
 567                         break;
 568                 case 'A':
 569                         authtype = optarg;
 570                         break;
 571                 case 'U':
 572                         authuser = optarg;
 573                         break;
 574                 case 'P':
 575                         authpass = optarg;
 576                         break;
 577                 case 'e':                                                                       /* server expect string on 220  */
 578                         server_expect = optarg;
 579                         break;
 580                 case 'C':                                                                       /* commands  */
 581                         if (ncommands >= command_size) {
 582                                 command_size+=8;
 583                                 commands = realloc (commands, sizeof(char *) * command_size);
 584                                 if (commands == NULL)
 585                                         die (STATE_UNKNOWN,
 586                                              _("Could not realloc() units [%d]\n"), ncommands);
 587                         }
 588                         commands[ncommands] = (char *) malloc (sizeof(char) * 255);
 589                         strncpy (commands[ncommands], optarg, 255);
 590                         ncommands++;
 591                         break;
 592                 case 'R':                                                                       /* server responses */
 593                         if (nresponses >= response_size) {
 594                                 response_size += 8;
 595                                 responses = realloc (responses, sizeof(char *) * response_size);
 596                                 if (responses == NULL)
 597                                         die (STATE_UNKNOWN,
 598                                              _("Could not realloc() units [%d]\n"), nresponses);
 599                         }
 600                         responses[nresponses] = (char *) malloc (sizeof(char) * 255);
 601                         strncpy (responses[nresponses], optarg, 255);
 602                         nresponses++;
 603                         break;
 604                 case 'c':                                                                       /* critical time threshold */
 605                         if (is_intnonneg (optarg)) {
 606                                 critical_time = atoi (optarg);
 607                                 check_critical_time = TRUE;
 608                         }
 609                         else {
 610                                 usage4 (_("Critical time must be a positive integer"));
 611                         }
 612                         break;
 613                 case 'w':                                                                       /* warning time threshold */
 614                         if (is_intnonneg (optarg)) {
 615                                 warning_time = atoi (optarg);
 616                                 check_warning_time = TRUE;
 617                         }
 618                         else {
 619                                 usage4 (_("Warning time must be a positive integer"));
 620                         }
 621                         break;
 622                 case 'v':                                                                       /* verbose */
 623                         verbose++;
 624                         break;
 625                 case 't':                                                                       /* timeout */
 626                         if (is_intnonneg (optarg)) {
 627                                 socket_timeout = atoi (optarg);
 628                         }
 629                         else {
 630                                 usage4 (_("Timeout interval must be a positive integer"));
 631                         }
 632                         break;
 633                 case 'S':
 634                 /* starttls */
 635                         use_ssl = TRUE;
 636                         use_ehlo = TRUE;
 637                         break;
 638                 case 'D':
 639                 /* Check SSL cert validity */
 640 #ifdef USE_OPENSSL
 641                         if (!is_intnonneg (optarg))
 642                                 usage2 ("Invalid certificate expiration period",optarg);
 643                                 days_till_exp = atoi (optarg);
 644                                 check_cert = TRUE;
 645 #else
 646                                 usage (_("SSL support not available - install OpenSSL and recompile"));
 647 #endif
 648                         break;
 649                 case '4':
 650                         address_family = AF_INET;
 651                         break;
 652                 case '6':
 653 #ifdef USE_IPV6
 654                         address_family = AF_INET6;
 655 #else
 656                         usage4 (_("IPv6 support not available"));
 657 #endif
 658                         break;
 659                 case 'V':                                                                       /* version */
 660                         print_revision (progname, revision);
 661                         exit (STATE_OK);
 662                 case 'h':                                                                       /* help */
 663                         print_help ();
 664                         exit (STATE_OK);
 665                 case '?':                                                                       /* help */
 666                         usage5 ();
 667                 }
 668         }
 669
 670         c = optind;
 671         if (server_address == NULL) {
 672                 if (argv[c]) {
 673                         if (is_host (argv[c]))
 674                                 server_address = argv[c];
 675                         else
 676                                 usage2 (_("Invalid hostname/address"), argv[c]);
 677                 }
 678                 else {
 679                         asprintf (&server_address, "127.0.0.1");
 680                 }
 681         }
 682
 683         if (server_expect == NULL)
 684                 server_expect = strdup (SMTP_EXPECT);
 685
 686         if (mail_command == NULL)
 687                 mail_command = strdup("MAIL ");
 688
 689         if (from_arg==NULL)
 690                 from_arg = strdup(" ");
 691
 692         return validate_arguments ();
 693 }
 694
 695
 696
 697 int
 698 validate_arguments (void)
 699 {
 700         return OK;
 701 }
 702
 703
 704 void
 705 smtp_quit(void)
 706 {
 707         int bytes;
 708
 709         my_send(SMTP_QUIT, strlen(SMTP_QUIT));
 710         if (verbose)
 711                 printf(_("sent %s\n"), "QUIT");
 712
 713         /* read the response but don't care about problems */
 714         bytes = recvlines(buffer, MAX_INPUT_BUFFER);
 715         if (verbose) {
 716                 if (bytes < 0)
 717                         printf(_("recv() failed after QUIT."));
 718                 else if (bytes == 0)
 719                         printf(_("Connection reset by peer."));
 720                 else {
 721                         buffer[bytes] = '\0';
 722                         printf(_("received %s\n"), buffer);
 723                 }
 724         }
 725 }
 726
 727
 728 /*
 729  * Receive one line, copy it into buf and nul-terminate it.  Returns the
 730  * number of bytes written to buf (excluding the '\0') or 0 on EOF or <0 on
 731  * error.
 732  *
 733  * TODO: Reading one byte at a time is very inefficient.  Replace this by a
 734  * function which buffers the data, move that to netutils.c and change
 735  * check_smtp and other plugins to use that.  Also, remove (\r)\n.
 736  */
 737 int
 738 recvline(char *buf, size_t bufsize)
 739 {
 740         int result;
 741         unsigned i;
 742
 743         for (i = result = 0; i < bufsize - 1; i++) {
 744                 if ((result = my_recv(&buf[i], 1)) != 1)
 745                         break;
 746                 if (buf[i] == '\n') {
 747                         buf[++i] = '\0';
 748                         return i;
 749                 }
 750         }
 751         return (result == 1 || i == 0) ? -2 : result;   /* -2 if out of space */
 752 }
 753
 754
 755 /*
 756  * Receive one or more lines, copy them into buf and nul-terminate it.  Returns
 757  * the number of bytes written to buf (excluding the '\0') or 0 on EOF or <0 on
 758  * error.  Works for all protocols which format multiline replies as follows:
 759  *
 760  * ``The format for multiline replies requires that every line, except the last,
 761  * begin with the reply code, followed immediately by a hyphen, `-' (also known
 762  * as minus), followed by text.  The last line will begin with the reply code,
 763  * followed immediately by <SP>, optionally some text, and <CRLF>.  As noted
 764  * above, servers SHOULD send the <SP> if subsequent text is not sent, but
 765  * clients MUST be prepared for it to be omitted.'' (RFC 2821, 4.2.1)
 766  *
 767  * TODO: Move this to netutils.c.  Also, remove \r and possibly the final \n.
 768  */
 769 int
 770 recvlines(char *buf, size_t bufsize)
 771 {
 772         int result, i;
 773
 774         for (i = 0; /* forever */; i += result)
 775                 if (!((result = recvline(buf + i, bufsize - i)) > 3 &&
 776                     isdigit((int)buf[i]) &&
 777                     isdigit((int)buf[i + 1]) &&
 778                     isdigit((int)buf[i + 2]) &&
 779                     buf[i + 3] == '-'))
 780                         break;
 781
 782         return (result <= 0) ? result : result + i;
 783 }
 784
 785
 786 int
 787 my_close (void)
 788 {
 789 #ifdef HAVE_SSL
 790   np_net_ssl_cleanup();
 791 #endif
 792   return close(sd);
 793 }
 794
 795
 796 void
 797 print_help (void)
 798 {
 799         char *myport;
 800         asprintf (&myport, "%d", SMTP_PORT);
 801
 802         print_revision (progname, revision);
 803
 804         printf ("Copyright (c) 1999-2001 Ethan Galstad <nagios@nagios.org>\n");
 805         printf (COPYRIGHT, copyright, email);
 806
 807         printf("%s\n", _("This plugin will attempt to open an SMTP connection with the host."));
 808
 809   printf ("\n\n");
 810
 811         print_usage ();
 812
 813         printf (_(UT_HELP_VRSN));
 814
 815         printf (_(UT_HOST_PORT), 'p', myport);
 816
 817         printf (_(UT_IPv46));
 818
 819         printf (" %s\n", "-e, --expect=STRING");
 820   printf (_("    String to expect in first line of server response (default: '%s')\n"), SMTP_EXPECT);
 821   printf (" %s\n", "-n, nocommand");
 822   printf ("    %s\n", _("Suppress SMTP command"));
 823   printf (" %s\n", "-C, --command=STRING");
 824   printf ("    %s\n", _("SMTP command (may be used repeatedly)"));
 825   printf (" %s\n", "-R, --command=STRING");
 826   printf ("    %s\n", _("Expected response to command (may be used repeatedly)"));
 827   printf (" %s\n", "-f, --from=STRING");
 828   printf ("    %s\n", _("FROM-address to include in MAIL command, required by Exchange 2000")),
 829 #ifdef HAVE_SSL
 830   printf (" %s\n", "-D, --certificate=INTEGER");
 831   printf ("    %s\n", _("Minimum number of days a certificate has to be valid."));
 832   printf (" %s\n", "-S, --starttls");
 833   printf ("    %s\n", _("Use STARTTLS for the connection."));
 834 #endif
 835
 836         printf (" %s\n", "-A, --authtype=STRING");
 837   printf ("    %s\n", _("SMTP AUTH type to check (default none, only LOGIN supported)"));
 838   printf (" %s\n", "-U, --authuser=STRING");
 839   printf ("    %s\n", _("SMTP AUTH username"));
 840   printf (" %s\n", "-P, --authpass=STRING");
 841   printf ("    %s\n", _("SMTP AUTH password"));
 842
 843         printf (_(UT_WARN_CRIT));
 844
 845         printf (_(UT_TIMEOUT), DEFAULT_SOCKET_TIMEOUT);
 846
 847         printf (_(UT_VERBOSE));
 848
 849         printf("\n");
 850         printf ("%s\n", _("Successul connects return STATE_OK, refusals and timeouts return"));
 851   printf ("%s\n", _("STATE_CRITICAL, other errors return STATE_UNKNOWN.  Successful"));
 852   printf ("%s\n", _("connects, but incorrect reponse messages from the host result in"));
 853   printf ("%s\n", _("STATE_WARNING return values."));
 854
 855         printf (_(UT_SUPPORT));
 856 }
 857
 858
 859
 860 void
 861 print_usage (void)
 862 {
 863   printf (_("Usage:"));
 864         printf ("%s -H host [-p port] [-e expect] [-C command] [-f from addr]", progname);
 865   printf ("[-A authtype -U authuser -P authpass] [-w warn] [-c crit] [-t timeout]\n");
 866   printf ("[-S] [-D days] [-n] [-v] [-4|-6]\n");
 867 }
 868