plugins/check_smtp.c

   1 /*****************************************************************************
   2 *
   3 * Monitoring check_smtp plugin
   4 *
   5 * License: GPL
   6 * Copyright (c) 2000-2024 Monitoring Plugins Development Team
   7 *
   8 * Description:
   9 *
  10 * This file contains the check_smtp plugin
  11 *
  12 * This plugin will attempt to open an SMTP connection with the host.
  13 *
  14 *
  15 * This program is free software: you can redistribute it and/or modify
  16 * it under the terms of the GNU General Public License as published by
  17 * the Free Software Foundation, either version 3 of the License, or
  18 * (at your option) any later version.
  19 *
  20 * This program is distributed in the hope that it will be useful,
  21 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  22 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23 * GNU General Public License for more details.
  24 *
  25 * You should have received a copy of the GNU General Public License
  26 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  27 *
  28 *
  29 *****************************************************************************/
  30
  31 const char *progname = "check_smtp";
  32 const char *copyright = "2000-2024";
  33 const char *email = "devel@monitoring-plugins.org";
  34
  35 #include "common.h"
  36 #include "netutils.h"
  37 #include "utils.h"
  38 #include "base64.h"
  39
  40 #include <ctype.h>
  41
  42 #ifdef HAVE_SSL
  43 static bool check_cert = false;
  44 static int days_till_exp_warn, days_till_exp_crit;
  45 #  define my_recv(buf, len) (((use_starttls || use_ssl) && ssl_established) ? np_net_ssl_read(buf, len) : read(sd, buf, len))
  46 #  define my_send(buf, len) (((use_starttls || use_ssl) && ssl_established) ? np_net_ssl_write(buf, len) : send(sd, buf, len, 0))
  47 #else /* ifndef HAVE_SSL */
  48 #  define my_recv(buf, len) read(sd, buf, len)
  49 #  define my_send(buf, len) send(sd, buf, len, 0)
  50 #endif
  51
  52 enum {
  53         SMTP_PORT       = 25,
  54         SMTPS_PORT      = 465
  55 };
  56 #define PROXY_PREFIX "PROXY TCP4 0.0.0.0 0.0.0.0 25 25\r\n"
  57 #define SMTP_EXPECT "220"
  58 #define SMTP_HELO "HELO "
  59 #define SMTP_EHLO "EHLO "
  60 #define SMTP_LHLO "LHLO "
  61 #define SMTP_QUIT "QUIT\r\n"
  62 #define SMTP_STARTTLS "STARTTLS\r\n"
  63 #define SMTP_AUTH_LOGIN "AUTH LOGIN\r\n"
  64
  65 #define EHLO_SUPPORTS_STARTTLS 1
  66
  67 static int process_arguments (int, char **);
  68 static int validate_arguments (void);
  69 static void print_help (void);
  70 void print_usage (void);
  71 static void smtp_quit(void);
  72 static int recvline(char *, size_t);
  73 static int recvlines(char *, size_t);
  74 static int my_close(void);
  75
  76 #include "regex.h"
  77 static regex_t preg;
  78 static regmatch_t pmatch[10];
  79 static char errbuf[MAX_INPUT_BUFFER];
  80 static int cflags = REG_EXTENDED | REG_NOSUB | REG_NEWLINE;
  81 static int eflags = 0;
  82 static int errcode, excode;
  83
  84 static int server_port = SMTP_PORT;
  85 static int server_port_option = 0;
  86 static char *server_address = NULL;
  87 static char *server_expect = NULL;
  88 static char *mail_command = NULL;
  89 static char *from_arg = NULL;
  90 static int send_mail_from=0;
  91 static int ncommands=0;
  92 static int command_size=0;
  93 static int nresponses=0;
  94 static int response_size=0;
  95 static char **commands = NULL;
  96 static char **responses = NULL;
  97 static char *authtype = NULL;
  98 static char *authuser = NULL;
  99 static char *authpass = NULL;
 100 static double warning_time = 0;
 101 static bool check_warning_time = false;
 102 static double critical_time = 0;
 103 static bool check_critical_time = false;
 104 static int verbose = 0;
 105 static bool use_ssl = false;
 106 static bool use_starttls = false;
 107 static bool use_sni = false;
 108 static bool use_proxy_prefix = false;
 109 static bool use_ehlo = false;
 110 static bool use_lhlo = false;
 111 static bool ssl_established = false;
 112 static char *localhostname = NULL;
 113 static int sd;
 114 static char buffer[MAX_INPUT_BUFFER];
 115 enum {
 116   TCP_PROTOCOL = 1,
 117   UDP_PROTOCOL = 2,
 118 };
 119 static bool ignore_send_quit_failure = false;
 120
 121
 122 int
 123 main (int argc, char **argv)
 124 {
 125         bool supports_tls = false;
 126         int n = 0;
 127         double elapsed_time;
 128         long microsec;
 129         int result = STATE_UNKNOWN;
 130         char *cmd_str = NULL;
 131         char *helocmd = NULL;
 132         char *error_msg = "";
 133         char *server_response = NULL;
 134         struct timeval tv;
 135
 136         /* Catch pipe errors in read/write - sometimes occurs when writing QUIT */
 137         (void) signal (SIGPIPE, SIG_IGN);
 138
 139         setlocale (LC_ALL, "");
 140         bindtextdomain (PACKAGE, LOCALEDIR);
 141         textdomain (PACKAGE);
 142
 143         /* Parse extra opts if any */
 144         argv=np_extra_opts (&argc, argv, progname);
 145
 146         if (process_arguments (argc, argv) == ERROR)
 147                 usage4 (_("Could not parse arguments"));
 148
 149         /* If localhostname not set on command line, use gethostname to set */
 150         if(! localhostname){
 151                 localhostname = malloc (HOST_MAX_BYTES);
 152                 if(!localhostname){
 153                         printf(_("malloc() failed!\n"));
 154                         return STATE_CRITICAL;
 155                 }
 156                 if(gethostname(localhostname, HOST_MAX_BYTES)){
 157                         printf(_("gethostname() failed!\n"));
 158                         return STATE_CRITICAL;
 159                 }
 160         }
 161         if(use_lhlo)
 162                 xasprintf (&helocmd, "%s%s%s", SMTP_LHLO, localhostname, "\r\n");
 163         else if(use_ehlo)
 164                 xasprintf (&helocmd, "%s%s%s", SMTP_EHLO, localhostname, "\r\n");
 165         else
 166                 xasprintf (&helocmd, "%s%s%s", SMTP_HELO, localhostname, "\r\n");
 167
 168         if (verbose)
 169                 printf("HELOCMD: %s", helocmd);
 170
 171         /* initialize the MAIL command with optional FROM command  */
 172         xasprintf (&cmd_str, "%sFROM:<%s>%s", mail_command, from_arg, "\r\n");
 173
 174         if (verbose && send_mail_from)
 175                 printf ("FROM CMD: %s", cmd_str);
 176
 177         /* initialize alarm signal handling */
 178         (void) signal (SIGALRM, socket_timeout_alarm_handler);
 179
 180         /* set socket timeout */
 181         (void) alarm (socket_timeout);
 182
 183         /* start timer */
 184         gettimeofday (&tv, NULL);
 185
 186         /* try to connect to the host at the given port number */
 187         result = my_tcp_connect (server_address, server_port, &sd);
 188
 189         if (result == STATE_OK) { /* we connected */
 190                 /* If requested, send PROXY header */
 191                 if (use_proxy_prefix) {
 192                         if (verbose)
 193                                 printf ("Sending header %s\n", PROXY_PREFIX);
 194                         my_send(PROXY_PREFIX, strlen(PROXY_PREFIX));
 195                 }
 196
 197 #ifdef HAVE_SSL
 198                 if (use_ssl) {
 199                         result = np_net_ssl_init_with_hostname(sd, (use_sni ? server_address : NULL));
 200                         if (result != STATE_OK) {
 201                                 printf (_("CRITICAL - Cannot create SSL context.\n"));
 202                                 close(sd);
 203                                 np_net_ssl_cleanup();
 204                                 return STATE_CRITICAL;
 205                         } else {
 206                                 ssl_established = 1;
 207                         }
 208                 }
 209 #endif
 210
 211                 /* watch for the SMTP connection string and */
 212                 /* return a WARNING status if we couldn't read any data */
 213                 if (recvlines(buffer, MAX_INPUT_BUFFER) <= 0) {
 214                         printf (_("recv() failed\n"));
 215                         return STATE_WARNING;
 216                 }
 217
 218                 /* save connect return (220 hostname ..) for later use */
 219                 xasprintf(&server_response, "%s", buffer);
 220
 221                 /* send the HELO/EHLO command */
 222                 my_send(helocmd, strlen(helocmd));
 223
 224                 /* allow for response to helo command to reach us */
 225                 if (recvlines(buffer, MAX_INPUT_BUFFER) <= 0) {
 226                         printf (_("recv() failed\n"));
 227                         return STATE_WARNING;
 228                 } else if(use_ehlo || use_lhlo){
 229                         if(strstr(buffer, "250 STARTTLS") != NULL ||
 230                            strstr(buffer, "250-STARTTLS") != NULL){
 231                                 supports_tls=true;
 232                         }
 233                 }
 234
 235                 if(use_starttls && ! supports_tls){
 236                         printf(_("WARNING - TLS not supported by server\n"));
 237                         smtp_quit();
 238                         return STATE_WARNING;
 239                 }
 240
 241 #ifdef HAVE_SSL
 242                 if(use_starttls) {
 243                   /* send the STARTTLS command */
 244                   send(sd, SMTP_STARTTLS, strlen(SMTP_STARTTLS), 0);
 245
 246                   recvlines(buffer, MAX_INPUT_BUFFER); /* wait for it */
 247                   if (!strstr (buffer, SMTP_EXPECT)) {
 248                     printf (_("Server does not support STARTTLS\n"));
 249                     smtp_quit();
 250                     return STATE_UNKNOWN;
 251                   }
 252                   result = np_net_ssl_init_with_hostname(sd, (use_sni ? server_address : NULL));
 253                   if(result != STATE_OK) {
 254                     printf (_("CRITICAL - Cannot create SSL context.\n"));
 255                     close(sd);
 256                     np_net_ssl_cleanup();
 257                     return STATE_CRITICAL;
 258                   } else {
 259                         ssl_established = 1;
 260                   }
 261
 262                 /*
 263                  * Resend the EHLO command.
 264                  *
 265                  * RFC 3207 (4.2) says: ``The client MUST discard any knowledge
 266                  * obtained from the server, such as the list of SMTP service
 267                  * extensions, which was not obtained from the TLS negotiation
 268                  * itself.  The client SHOULD send an EHLO command as the first
 269                  * command after a successful TLS negotiation.''  For this
 270                  * reason, some MTAs will not allow an AUTH LOGIN command before
 271                  * we resent EHLO via TLS.
 272                  */
 273                 if (my_send(helocmd, strlen(helocmd)) <= 0) {
 274                         printf("%s\n", _("SMTP UNKNOWN - Cannot send EHLO command via TLS."));
 275                         my_close();
 276                         return STATE_UNKNOWN;
 277                 }
 278                 if (verbose)
 279                         printf(_("sent %s"), helocmd);
 280                 if ((n = recvlines(buffer, MAX_INPUT_BUFFER)) <= 0) {
 281                         printf("%s\n", _("SMTP UNKNOWN - Cannot read EHLO response via TLS."));
 282                         my_close();
 283                         return STATE_UNKNOWN;
 284                 }
 285                 if (verbose) {
 286                         printf("%s", buffer);
 287                 }
 288
 289 #  ifdef USE_OPENSSL
 290                   if ( check_cert ) {
 291                     result = np_net_ssl_check_cert(days_till_exp_warn, days_till_exp_crit);
 292                     smtp_quit();
 293                     my_close();
 294                     return result;
 295                   }
 296 #  endif /* USE_OPENSSL */
 297                 }
 298 #endif
 299
 300                 if (verbose)
 301                         printf ("%s", buffer);
 302
 303                 /* save buffer for later use */
 304                 xasprintf(&server_response, "%s%s", server_response, buffer);
 305                 /* strip the buffer of carriage returns */
 306                 strip (server_response);
 307
 308                 /* make sure we find the droids we are looking for */
 309                 if (!strstr (server_response, server_expect)) {
 310                         if (server_port == SMTP_PORT)
 311                                 printf (_("Invalid SMTP response received from host: %s\n"), server_response);
 312                         else
 313                                 printf (_("Invalid SMTP response received from host on port %d: %s\n"),
 314                                                                                 server_port, server_response);
 315                         return STATE_WARNING;
 316                 }
 317
 318                 if (send_mail_from) {
 319                   my_send(cmd_str, strlen(cmd_str));
 320                   if (recvlines(buffer, MAX_INPUT_BUFFER) >= 1 && verbose)
 321                     printf("%s", buffer);
 322                 }
 323
 324                 n = 0;
 325                 while (n < ncommands) {
 326                         xasprintf (&cmd_str, "%s%s", commands[n], "\r\n");
 327                         my_send(cmd_str, strlen(cmd_str));
 328                         if (recvlines(buffer, MAX_INPUT_BUFFER) >= 1 && verbose)
 329                                 printf("%s", buffer);
 330                         strip (buffer);
 331                         if (n < nresponses) {
 332                                 cflags |= REG_EXTENDED | REG_NOSUB | REG_NEWLINE;
 333                                 errcode = regcomp (&preg, responses[n], cflags);
 334                                 if (errcode != 0) {
 335                                         regerror (errcode, &preg, errbuf, MAX_INPUT_BUFFER);
 336                                         printf (_("Could Not Compile Regular Expression"));
 337                                         return ERROR;
 338                                 }
 339                                 excode = regexec (&preg, buffer, 10, pmatch, eflags);
 340                                 if (excode == 0) {
 341                                         result = STATE_OK;
 342                                 }
 343                                 else if (excode == REG_NOMATCH) {
 344                                         result = STATE_WARNING;
 345                                         printf (_("SMTP %s - Invalid response '%s' to command '%s'\n"), state_text (result), buffer, commands[n]);
 346                                 }
 347                                 else {
 348                                         regerror (excode, &preg, errbuf, MAX_INPUT_BUFFER);
 349                                         printf (_("Execute Error: %s\n"), errbuf);
 350                                         result = STATE_UNKNOWN;
 351                                 }
 352                         }
 353                         n++;
 354                 }
 355
 356                 if (authtype != NULL) {
 357                         if (strcmp (authtype, "LOGIN") == 0) {
 358                                 char *abuf;
 359                                 int ret;
 360                                 do {
 361                                         if (authuser == NULL) {
 362                                                 result = STATE_CRITICAL;
 363                                                 xasprintf(&error_msg, _("no authuser specified, "));
 364                                                 break;
 365                                         }
 366                                         if (authpass == NULL) {
 367                                                 result = STATE_CRITICAL;
 368                                                 xasprintf(&error_msg, _("no authpass specified, "));
 369                                                 break;
 370                                         }
 371
 372                                         /* send AUTH LOGIN */
 373                                         my_send(SMTP_AUTH_LOGIN, strlen(SMTP_AUTH_LOGIN));
 374                                         if (verbose)
 375                                                 printf (_("sent %s\n"), "AUTH LOGIN");
 376
 377                                         if ((ret = recvlines(buffer, MAX_INPUT_BUFFER)) <= 0) {
 378                                                 xasprintf(&error_msg, _("recv() failed after AUTH LOGIN, "));
 379                                                 result = STATE_WARNING;
 380                                                 break;
 381                                         }
 382                                         if (verbose)
 383                                                 printf (_("received %s\n"), buffer);
 384
 385                                         if (strncmp (buffer, "334", 3) != 0) {
 386                                                 result = STATE_CRITICAL;
 387                                                 xasprintf(&error_msg, _("invalid response received after AUTH LOGIN, "));
 388                                                 break;
 389                                         }
 390
 391                                         /* encode authuser with base64 */
 392                                         base64_encode_alloc (authuser, strlen(authuser), &abuf);
 393                                         xasprintf(&abuf, "%s\r\n", abuf);
 394                                         my_send(abuf, strlen(abuf));
 395                                         if (verbose)
 396                                                 printf (_("sent %s\n"), abuf);
 397
 398                                         if ((ret = recvlines(buffer, MAX_INPUT_BUFFER)) <= 0) {
 399                                                 result = STATE_CRITICAL;
 400                                                 xasprintf(&error_msg, _("recv() failed after sending authuser, "));
 401                                                 break;
 402                                         }
 403                                         if (verbose) {
 404                                                 printf (_("received %s\n"), buffer);
 405                                         }
 406                                         if (strncmp (buffer, "334", 3) != 0) {
 407                                                 result = STATE_CRITICAL;
 408                                                 xasprintf(&error_msg, _("invalid response received after authuser, "));
 409                                                 break;
 410                                         }
 411                                         /* encode authpass with base64 */
 412                                         base64_encode_alloc (authpass, strlen(authpass), &abuf);
 413                                         xasprintf(&abuf, "%s\r\n", abuf);
 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                                                 xasprintf(&error_msg, _("recv() failed after sending authpass, "));
 421                                                 break;
 422                                         }
 423                                         if (verbose) {
 424                                                 printf (_("received %s\n"), buffer);
 425                                         }
 426                                         if (strncmp (buffer, "235", 3) != 0) {
 427                                                 result = STATE_CRITICAL;
 428                                                 xasprintf(&error_msg, _("invalid response received after authpass, "));
 429                                                 break;
 430                                         }
 431                                         break;
 432                                 } while (0);
 433                         } else {
 434                                 result = STATE_CRITICAL;
 435                                 xasprintf(&error_msg, _("only authtype LOGIN is supported, "));
 436                         }
 437                 }
 438
 439                 /* tell the server we're done */
 440                 smtp_quit();
 441
 442                 /* finally close the connection */
 443                 close (sd);
 444         }
 445
 446         /* reset the alarm */
 447         alarm (0);
 448
 449         microsec = deltime (tv);
 450         elapsed_time = (double)microsec / 1.0e6;
 451
 452         if (result == STATE_OK) {
 453                 if (check_critical_time && elapsed_time > critical_time)
 454                         result = STATE_CRITICAL;
 455                 else if (check_warning_time && elapsed_time > warning_time)
 456                         result = STATE_WARNING;
 457         }
 458
 459         printf (_("SMTP %s - %s%.3f sec. response time%s%s|%s\n"),
 460                         state_text (result),
 461                         error_msg,
 462                         elapsed_time,
 463                         verbose?", ":"", verbose?buffer:"",
 464                         fperfdata ("time", elapsed_time, "s",
 465                                 (int)check_warning_time, warning_time,
 466                                 (int)check_critical_time, critical_time,
 467                                 true, 0, false, 0));
 468
 469         return result;
 470 }
 471
 472
 473
 474 /* process command-line arguments */
 475 int
 476 process_arguments (int argc, char **argv)
 477 {
 478         int c;
 479         char* temp;
 480
 481         bool implicit_tls = false;
 482
 483         enum {
 484           SNI_OPTION
 485         };
 486
 487         int option = 0;
 488         static struct option longopts[] = {
 489                 {"hostname", required_argument, 0, 'H'},
 490                 {"expect", required_argument, 0, 'e'},
 491                 {"critical", required_argument, 0, 'c'},
 492                 {"warning", required_argument, 0, 'w'},
 493                 {"timeout", required_argument, 0, 't'},
 494                 {"port", required_argument, 0, 'p'},
 495                 {"from", required_argument, 0, 'f'},
 496                 {"fqdn", required_argument, 0, 'F'},
 497                 {"authtype", required_argument, 0, 'A'},
 498                 {"authuser", required_argument, 0, 'U'},
 499                 {"authpass", required_argument, 0, 'P'},
 500                 {"command", required_argument, 0, 'C'},
 501                 {"response", required_argument, 0, 'R'},
 502                 {"verbose", no_argument, 0, 'v'},
 503                 {"version", no_argument, 0, 'V'},
 504                 {"use-ipv4", no_argument, 0, '4'},
 505                 {"use-ipv6", no_argument, 0, '6'},
 506                 {"help", no_argument, 0, 'h'},
 507                 {"lmtp", no_argument, 0, 'L'},
 508                 {"ssl", no_argument, 0, 's'},
 509                 {"tls", no_argument, 0, 's'},
 510                 {"starttls",no_argument,0,'S'},
 511                 {"sni", no_argument, 0, SNI_OPTION},
 512                 {"certificate",required_argument,0,'D'},
 513                 {"ignore-quit-failure",no_argument,0,'q'},
 514                 {"proxy",no_argument,0,'r'},
 515                 {0, 0, 0, 0}
 516         };
 517
 518         if (argc < 2)
 519                 return ERROR;
 520
 521         for (c = 1; c < argc; c++) {
 522                 if (strcmp ("-to", argv[c]) == 0)
 523                         strcpy (argv[c], "-t");
 524                 else if (strcmp ("-wt", argv[c]) == 0)
 525                         strcpy (argv[c], "-w");
 526                 else if (strcmp ("-ct", argv[c]) == 0)
 527                         strcpy (argv[c], "-c");
 528         }
 529
 530         while (1) {
 531                 c = getopt_long (argc, argv, "+hVv46Lrt:p:f:e:c:w:H:C:R:sSD:F:A:U:P:q",
 532                                  longopts, &option);
 533
 534                 if (c == -1 || c == EOF)
 535                         break;
 536
 537                 switch (c) {
 538                 case 'H':                                                                       /* hostname */
 539                         if (is_host (optarg)) {
 540                                 server_address = optarg;
 541                         }
 542                         else {
 543                                 usage2 (_("Invalid hostname/address"), optarg);
 544                         }
 545                         break;
 546                 case 'p':                                                                       /* port */
 547                         if (is_intpos (optarg))
 548                                 server_port_option = atoi (optarg);
 549                         else
 550                                 usage4 (_("Port must be a positive integer"));
 551                         break;
 552                 case 'F':
 553                 /* localhostname */
 554                         localhostname = strdup(optarg);
 555                         break;
 556                 case 'f':                                                                       /* from argument */
 557                         from_arg = optarg + strspn(optarg, "<");
 558                         from_arg = strndup(from_arg, strcspn(from_arg, ">"));
 559                         send_mail_from = 1;
 560                         break;
 561                 case 'A':
 562                         authtype = optarg;
 563                         use_ehlo = true;
 564                         break;
 565                 case 'U':
 566                         authuser = optarg;
 567                         break;
 568                 case 'P':
 569                         authpass = optarg;
 570                         break;
 571                 case 'e':                                                                       /* server expect string on 220  */
 572                         server_expect = optarg;
 573                         break;
 574                 case 'C':                                                                       /* commands  */
 575                         if (ncommands >= command_size) {
 576                                 command_size+=8;
 577                                 commands = realloc (commands, sizeof(char *) * command_size);
 578                                 if (commands == NULL)
 579                                         die (STATE_UNKNOWN,
 580                                              _("Could not realloc() units [%d]\n"), ncommands);
 581                         }
 582                         commands[ncommands] = (char *) malloc (sizeof(char) * 255);
 583                         strncpy (commands[ncommands], optarg, 255);
 584                         ncommands++;
 585                         break;
 586                 case 'R':                                                                       /* server responses */
 587                         if (nresponses >= response_size) {
 588                                 response_size += 8;
 589                                 responses = realloc (responses, sizeof(char *) * response_size);
 590                                 if (responses == NULL)
 591                                         die (STATE_UNKNOWN,
 592                                              _("Could not realloc() units [%d]\n"), nresponses);
 593                         }
 594                         responses[nresponses] = (char *) malloc (sizeof(char) * 255);
 595                         strncpy (responses[nresponses], optarg, 255);
 596                         nresponses++;
 597                         break;
 598                 case 'c':                                                                       /* critical time threshold */
 599                         if (!is_nonnegative (optarg))
 600                                 usage4 (_("Critical time must be a positive"));
 601                         else {
 602                                 critical_time = strtod (optarg, NULL);
 603                                 check_critical_time = true;
 604                         }
 605                         break;
 606                 case 'w':                                                                       /* warning time threshold */
 607                         if (!is_nonnegative (optarg))
 608                                 usage4 (_("Warning time must be a positive"));
 609                         else {
 610                                 warning_time = strtod (optarg, NULL);
 611                                 check_warning_time = true;
 612                         }
 613                         break;
 614                 case 'v':                                                                       /* verbose */
 615                         verbose++;
 616                         break;
 617                 case 'q':
 618                         ignore_send_quit_failure = true;             /* ignore problem sending QUIT */
 619                         break;
 620                 case 't':                                                                       /* timeout */
 621                         if (is_intnonneg (optarg)) {
 622                                 socket_timeout = atoi (optarg);
 623                         }
 624                         else {
 625                                 usage4 (_("Timeout interval must be a positive integer"));
 626                         }
 627                         break;
 628                 case 'D':
 629                 /* Check SSL cert validity */
 630 #ifdef USE_OPENSSL
 631                         if ((temp=strchr(optarg,','))!=NULL) {
 632                             *temp='\0';
 633                             if (!is_intnonneg (optarg))
 634                                usage2 ("Invalid certificate expiration period", optarg);
 635                             days_till_exp_warn = atoi(optarg);
 636                             *temp=',';
 637                             temp++;
 638                             if (!is_intnonneg (temp))
 639                                 usage2 (_("Invalid certificate expiration period"), temp);
 640                             days_till_exp_crit = atoi (temp);
 641                         }
 642                         else {
 643                             days_till_exp_crit=0;
 644                             if (!is_intnonneg (optarg))
 645                                 usage2 ("Invalid certificate expiration period", optarg);
 646                             days_till_exp_warn = atoi (optarg);
 647                         }
 648                         check_cert = true;
 649                         ignore_send_quit_failure = true;
 650 #else
 651                         usage (_("SSL support not available - install OpenSSL and recompile"));
 652 #endif
 653                         implicit_tls = true;
 654                         // fallthrough
 655                 case 's':
 656                 /* ssl */
 657                         use_ssl = true;
 658                         server_port = SMTPS_PORT;
 659                         break;
 660                 case 'S':
 661                 /* starttls */
 662                         use_starttls = true;
 663                         use_ehlo = true;
 664                         break;
 665                 case SNI_OPTION:
 666 #ifdef HAVE_SSL
 667                         use_sni = true;
 668 #else
 669                         usage (_("SSL support not available - install OpenSSL and recompile"));
 670 #endif
 671                         break;
 672                 case 'r':
 673                         use_proxy_prefix = true;
 674                         break;
 675                 case 'L':
 676                         use_lhlo = true;
 677                         break;
 678                 case '4':
 679                         address_family = AF_INET;
 680                         break;
 681                 case '6':
 682 #ifdef USE_IPV6
 683                         address_family = AF_INET6;
 684 #else
 685                         usage4 (_("IPv6 support not available"));
 686 #endif
 687                         break;
 688                 case 'V':                                                                       /* version */
 689                         print_revision (progname, NP_VERSION);
 690                         exit (STATE_UNKNOWN);
 691                 case 'h':                                                                       /* help */
 692                         print_help ();
 693                         exit (STATE_UNKNOWN);
 694                 case '?':                                                                       /* help */
 695                         usage5 ();
 696                 }
 697         }
 698
 699         c = optind;
 700         if (server_address == NULL) {
 701                 if (argv[c]) {
 702                         if (is_host (argv[c]))
 703                                 server_address = argv[c];
 704                         else
 705                                 usage2 (_("Invalid hostname/address"), argv[c]);
 706                 }
 707                 else {
 708                         xasprintf (&server_address, "127.0.0.1");
 709                 }
 710         }
 711
 712         if (server_expect == NULL)
 713                 server_expect = strdup (SMTP_EXPECT);
 714
 715         if (mail_command == NULL)
 716                 mail_command = strdup("MAIL ");
 717
 718         if (from_arg==NULL)
 719                 from_arg = strdup(" ");
 720
 721         if (use_starttls && use_ssl) {
 722                 if (implicit_tls) {
 723                         use_ssl = false;
 724                         server_port = SMTP_PORT;
 725                 } else {
 726                         usage4 (_("Set either -s/--ssl/--tls or -S/--starttls"));
 727                 }
 728         }
 729
 730         if (server_port_option != 0) {
 731                 server_port = server_port_option;
 732         }
 733
 734         return validate_arguments ();
 735 }
 736
 737
 738
 739 int
 740 validate_arguments (void)
 741 {
 742         return OK;
 743 }
 744
 745
 746 void
 747 smtp_quit(void)
 748 {
 749         int bytes;
 750         int n;
 751
 752         n = my_send(SMTP_QUIT, strlen(SMTP_QUIT));
 753         if(n < 0) {
 754                 if(ignore_send_quit_failure) {
 755                         if(verbose) {
 756                                 printf(_("Connection closed by server before sending QUIT command\n"));
 757                         }
 758                         return;
 759                 }
 760                 die (STATE_UNKNOWN,
 761                         _("Connection closed by server before sending QUIT command\n"));
 762         }
 763
 764         if (verbose)
 765                 printf(_("sent %s\n"), "QUIT");
 766
 767         /* read the response but don't care about problems */
 768         bytes = recvlines(buffer, MAX_INPUT_BUFFER);
 769         if (verbose) {
 770                 if (bytes < 0)
 771                         printf(_("recv() failed after QUIT."));
 772                 else if (bytes == 0)
 773                         printf(_("Connection reset by peer."));
 774                 else {
 775                         buffer[bytes] = '\0';
 776                         printf(_("received %s\n"), buffer);
 777                 }
 778         }
 779 }
 780
 781
 782 /*
 783  * Receive one line, copy it into buf and nul-terminate it.  Returns the
 784  * number of bytes written to buf (excluding the '\0') or 0 on EOF or <0 on
 785  * error.
 786  *
 787  * TODO: Reading one byte at a time is very inefficient.  Replace this by a
 788  * function which buffers the data, move that to netutils.c and change
 789  * check_smtp and other plugins to use that.  Also, remove (\r)\n.
 790  */
 791 int
 792 recvline(char *buf, size_t bufsize)
 793 {
 794         int result;
 795         unsigned i;
 796
 797         for (i = result = 0; i < bufsize - 1; i++) {
 798                 if ((result = my_recv(&buf[i], 1)) != 1)
 799                         break;
 800                 if (buf[i] == '\n') {
 801                         buf[++i] = '\0';
 802                         return i;
 803                 }
 804         }
 805         return (result == 1 || i == 0) ? -2 : result;   /* -2 if out of space */
 806 }
 807
 808
 809 /*
 810  * Receive one or more lines, copy them into buf and nul-terminate it.  Returns
 811  * the number of bytes written to buf (excluding the '\0') or 0 on EOF or <0 on
 812  * error.  Works for all protocols which format multiline replies as follows:
 813  *
 814  * ``The format for multiline replies requires that every line, except the last,
 815  * begin with the reply code, followed immediately by a hyphen, `-' (also known
 816  * as minus), followed by text.  The last line will begin with the reply code,
 817  * followed immediately by <SP>, optionally some text, and <CRLF>.  As noted
 818  * above, servers SHOULD send the <SP> if subsequent text is not sent, but
 819  * clients MUST be prepared for it to be omitted.'' (RFC 2821, 4.2.1)
 820  *
 821  * TODO: Move this to netutils.c.  Also, remove \r and possibly the final \n.
 822  */
 823 int
 824 recvlines(char *buf, size_t bufsize)
 825 {
 826         int result, i;
 827
 828         for (i = 0; /* forever */; i += result)
 829                 if (!((result = recvline(buf + i, bufsize - i)) > 3 &&
 830                     isdigit((int)buf[i]) &&
 831                     isdigit((int)buf[i + 1]) &&
 832                     isdigit((int)buf[i + 2]) &&
 833                     buf[i + 3] == '-'))
 834                         break;
 835
 836         return (result <= 0) ? result : result + i;
 837 }
 838
 839
 840 int
 841 my_close (void)
 842 {
 843         int result;
 844         result = close(sd);
 845 #ifdef HAVE_SSL
 846         np_net_ssl_cleanup();
 847 #endif
 848         return result;
 849 }
 850
 851
 852 void
 853 print_help (void)
 854 {
 855         char *myport;
 856         xasprintf (&myport, "%d", SMTP_PORT);
 857
 858         print_revision (progname, NP_VERSION);
 859
 860         printf ("Copyright (c) 1999-2001 Ethan Galstad <nagios@nagios.org>\n");
 861         printf (COPYRIGHT, copyright, email);
 862
 863         printf("%s\n", _("This plugin will attempt to open an SMTP connection with the host."));
 864
 865   printf ("\n\n");
 866
 867         print_usage ();
 868
 869         printf (UT_HELP_VRSN);
 870         printf (UT_EXTRA_OPTS);
 871
 872         printf (UT_HOST_PORT, 'p', myport);
 873
 874         printf (UT_IPv46);
 875
 876         printf (" %s\n", "-e, --expect=STRING");
 877   printf (_("    String to expect in first line of server response (default: '%s')\n"), SMTP_EXPECT);
 878   printf (" %s\n", "-C, --command=STRING");
 879   printf ("    %s\n", _("SMTP command (may be used repeatedly)"));
 880   printf (" %s\n", "-R, --response=STRING");
 881   printf ("    %s\n", _("Expected response to command (may be used repeatedly)"));
 882   printf (" %s\n", "-f, --from=STRING");
 883   printf ("    %s\n", _("FROM-address to include in MAIL command, required by Exchange 2000")),
 884   printf (" %s\n", "-F, --fqdn=STRING");
 885   printf ("    %s\n", _("FQDN used for HELO"));
 886   printf (" %s\n", "-r, --proxy");
 887   printf ("    %s\n", _("Use PROXY protocol prefix for the connection."));
 888 #ifdef HAVE_SSL
 889   printf (" %s\n", "-D, --certificate=INTEGER[,INTEGER]");
 890   printf ("    %s\n", _("Minimum number of days a certificate has to be valid."));
 891   printf (" %s\n", "-s, --ssl, --tls");
 892   printf ("    %s\n", _("Use SSL/TLS for the connection."));
 893   printf (_("    Sets default port to %d.\n"), SMTPS_PORT);
 894   printf (" %s\n", "-S, --starttls");
 895   printf ("    %s\n", _("Use STARTTLS for the connection."));
 896   printf (" %s\n", "--sni");
 897   printf ("    %s\n", _("Enable SSL/TLS hostname extension support (SNI)"));
 898 #endif
 899
 900         printf (" %s\n", "-A, --authtype=STRING");
 901   printf ("    %s\n", _("SMTP AUTH type to check (default none, only LOGIN supported)"));
 902   printf (" %s\n", "-U, --authuser=STRING");
 903   printf ("    %s\n", _("SMTP AUTH username"));
 904   printf (" %s\n", "-P, --authpass=STRING");
 905   printf ("    %s\n", _("SMTP AUTH password"));
 906   printf (" %s\n", "-L, --lmtp");
 907   printf ("    %s\n", _("Send LHLO instead of HELO/EHLO"));
 908   printf (" %s\n", "-q, --ignore-quit-failure");
 909   printf ("    %s\n", _("Ignore failure when sending QUIT command to server"));
 910
 911         printf (UT_WARN_CRIT);
 912
 913         printf (UT_CONN_TIMEOUT, DEFAULT_SOCKET_TIMEOUT);
 914
 915         printf (UT_VERBOSE);
 916
 917         printf("\n");
 918         printf ("%s\n", _("Successful connects return STATE_OK, refusals and timeouts return"));
 919   printf ("%s\n", _("STATE_CRITICAL, other errors return STATE_UNKNOWN.  Successful"));
 920   printf ("%s\n", _("connects, but incorrect response messages from the host result in"));
 921   printf ("%s\n", _("STATE_WARNING return values."));
 922
 923         printf (UT_SUPPORT);
 924 }
 925
 926
 927
 928 void
 929 print_usage (void)
 930 {
 931   printf ("%s\n", _("Usage:"));
 932   printf ("%s -H host [-p port] [-4|-6] [-e expect] [-C command] [-R response] [-f from addr]\n", progname);
 933   printf ("[-A authtype -U authuser -P authpass] [-w warn] [-c crit] [-t timeout] [-q]\n");
 934   printf ("[-F fqdn] [-S] [-L] [-D warn days cert expire[,crit days cert expire]] [-r] [--sni] [-v] \n");
 935 }
 936