/****************************************************************************** * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * *****************************************************************************/ const char *progname = "check_smtp"; const char *revision = "$Revision$"; const char *copyright = "1999-2003"; const char *authors = "Nagios Plugin Development Team"; const char *email = "nagiosplug-devel@lists.sourceforge.net"; const char *summary = "\ This plugin will attempt to open an SMTP connection with the host.\n"; const char *description = "\ Successul connects return STATE_OK, refusals and timeouts return\n\ STATE_CRITICAL, other errors return STATE_UNKNOWN. Successful\n\ connects, but incorrect reponse messages from the host result in\n\ STATE_WARNING return values.\n"; const char *option_summary = "\ -H host [-p port] [-e expect] [-C command] [-f from addr]\n\ [-w warn] [-c crit] [-t timeout] [-n] [-v] [-4|-6]"; const char *options = "\ -H, --hostname=STRING or IPADDRESS\n\ Check server on the indicated host\n\ -4, --use-ipv4\n\ Use IPv4 protocol\n\ -6, --use-ipv6\n\ Use IPv6 protocol\n\ -p, --port=INTEGER\n\ Make connection on the indicated port (default: %d)\n\ -e, --expect=STRING\n\ String to expect in first line of server response (default: '%s')\n\ -n, nocommand\n\ Suppress SMTP command\n\ -C, --command=STRING\n\ SMTP command (default: '%s')\n\ -f, --from=STRING\n\ FROM-address to include in MAIL command, required by Exchange 2000\n\ (default: '%s')\n\ -w, --warning=INTEGER\n\ Seconds necessary to result in a warning status\n\ -c, --critical=INTEGER\n\ Seconds necessary to result in a critical status\n\ -t, --timeout=INTEGER\n\ Seconds before connection attempt times out (default: %d)\n\ -v, --verbose\n\ Print extra information (command-line use only)\n\ -h, --help\n\ Print detailed help screen\n\ -V, --version\n\ Print version information\n\n"; enum { SMTP_PORT = 25 }; const char *SMTP_EXPECT = "220"; const char *SMTP_HELO = "HELO "; const char *SMTP_QUIT = "QUIT\r\n"; #include "config.h" #include "common.h" #include "netutils.h" #include "utils.h" int process_arguments (int, char **); int validate_arguments (void); void print_help (void); void print_usage (void); int server_port = SMTP_PORT; char *server_address = NULL; char *server_expect = NULL; int smtp_use_dummycmd = 1; char *mail_command = "MAIL "; char *from_arg = " "; int warning_time = 0; int check_warning_time = FALSE; int critical_time = 0; int check_critical_time = FALSE; int verbose = 0; int main (int argc, char **argv) { int sd; double elapsed_time; int result = STATE_UNKNOWN; char buffer[MAX_INPUT_BUFFER] = ""; char *from_str = NULL; char *helocmd = NULL; struct timeval tv; if (process_arguments (argc, argv) != OK) usage ("Invalid command arguments supplied\n"); /* initialize the HELO command with the localhostname */ #ifndef HOST_MAX_BYTES #define HOST_MAX_BYTES 255 #endif helocmd = malloc (HOST_MAX_BYTES); gethostname(helocmd, HOST_MAX_BYTES); asprintf (&helocmd, "%s%s%s", SMTP_HELO, helocmd, "\r\n"); /* initialize the MAIL command with optional FROM command */ asprintf (&from_str, "%sFROM: %s%s", mail_command, from_arg, "\r\n"); if (verbose) printf ("FROMCMD: %s\n", from_str); /* initialize alarm signal handling */ (void) signal (SIGALRM, socket_timeout_alarm_handler); /* set socket timeout */ (void) alarm (socket_timeout); /* start timer */ gettimeofday (&tv, NULL); /* try to connect to the host at the given port number */ result = my_tcp_connect (server_address, server_port, &sd); /* we connected, so close connection before exiting */ if (result == STATE_OK) { /* watch for the SMTP connection string and */ /* return a WARNING status if we couldn't read any data */ if (recv (sd, buffer, MAX_INPUT_BUFFER - 1, 0) == -1) { printf ("recv() failed\n"); result = STATE_WARNING; } else { /* strip the buffer of carriage returns */ strip (buffer); /* make sure we find the response we are looking for */ if (!strstr (buffer, server_expect)) { if (server_port == SMTP_PORT) printf ("Invalid SMTP response received from host\n"); else printf ("Invalid SMTP response received from host on port %d\n", server_port); result = STATE_WARNING; } } /* send the HELO command */ send(sd, helocmd, strlen(helocmd), 0); /* allow for response to helo command to reach us */ recv(sd, buffer, MAX_INPUT_BUFFER-1, 0); /* sendmail will syslog a "NOQUEUE" error if session does not attempt * to do something useful. This can be prevented by giving a command * even if syntax is illegal (MAIL requires a FROM:<...> argument) * * According to rfc821 you can include a null reversepath in the from command * - but a log message is generated on the smtp server. * * You can disable sending mail_command with '--nocommand' * Use the -f option to provide a FROM address */ if (smtp_use_dummycmd) { send(sd, from_str, strlen(from_str), 0); /* allow for response to mail_command to reach us */ recv(sd, buffer, MAX_INPUT_BUFFER-1, 0); if (verbose) printf("DUMMYCMD: %s\n%s\n",from_str,buffer); } /* smtp_use_dummycmd */ /* tell the server we're done */ send (sd, SMTP_QUIT, strlen (SMTP_QUIT), 0); /* finally close the connection */ close (sd); } /* reset the alarm */ alarm (0); elapsed_time = delta_time (tv); if (check_critical_time && elapsed_time > (double) critical_time) result = STATE_CRITICAL; else if (check_warning_time && elapsed_time > (double) warning_time) result = STATE_WARNING; if (verbose) printf ("SMTP %s - %.3f sec. response time, %s|time=%.3f\n", state_text (result), elapsed_time, buffer, elapsed_time); else printf ("SMTP %s - %.3f second response time|time=%.3f\n", state_text (result), elapsed_time, elapsed_time); return result; } /* process command-line arguments */ int process_arguments (int argc, char **argv) { int c; int option_index = 0; static struct option long_options[] = { {"hostname", required_argument, 0, 'H'}, {"expect", required_argument, 0, 'e'}, {"critical", required_argument, 0, 'c'}, {"warning", required_argument, 0, 'w'}, {"timeout", required_argument, 0, 't'}, {"port", required_argument, 0, 'p'}, {"from", required_argument, 0, 'f'}, {"command", required_argument, 0, 'C'}, {"nocommand", required_argument, 0, 'n'}, {"verbose", no_argument, 0, 'v'}, {"version", no_argument, 0, 'V'}, {"use-ipv4", no_argument, 0, '4'}, {"use-ipv6", no_argument, 0, '6'}, {"help", no_argument, 0, 'h'}, {0, 0, 0, 0} }; if (argc < 2) return ERROR; for (c = 1; c < argc; c++) { if (strcmp ("-to", argv[c]) == 0) strcpy (argv[c], "-t"); else if (strcmp ("-wt", argv[c]) == 0) strcpy (argv[c], "-w"); else if (strcmp ("-ct", argv[c]) == 0) strcpy (argv[c], "-c"); } while (1) { c = getopt_long (argc, argv, "+hVv46t:p:f:e:c:w:H:C:", long_options, &option_index); if (c == -1 || c == EOF) break; switch (c) { case 'H': /* hostname */ if (is_host (optarg)) { server_address = optarg; } else { usage ("Invalid host name\n"); } break; case 'p': /* port */ if (is_intpos (optarg)) { server_port = atoi (optarg); } else { usage ("Server port must be a positive integer\n"); } break; case 'f': /* from argument */ from_arg = optarg; break; case 'e': /* server expect string on 220 */ server_expect = optarg; break; case 'C': /* server expect string on 220 */ mail_command = optarg; smtp_use_dummycmd = 1; break; case 'n': /* server expect string on 220 */ smtp_use_dummycmd = 0; break; case 'c': /* critical time threshold */ if (is_intnonneg (optarg)) { critical_time = atoi (optarg); check_critical_time = TRUE; } else { usage ("Critical time must be a nonnegative integer\n"); } break; case 'w': /* warning time threshold */ if (is_intnonneg (optarg)) { warning_time = atoi (optarg); check_warning_time = TRUE; } else { usage ("Warning time must be a nonnegative integer\n"); } break; case 'v': /* verbose */ verbose++; break; case 't': /* timeout */ if (is_intnonneg (optarg)) { socket_timeout = atoi (optarg); } else { usage ("Time interval must be a nonnegative integer\n"); } break; case '4': address_family = AF_INET; break; case '6': #ifdef USE_IPV6 address_family = AF_INET6; #else usage ("IPv6 support not available\n"); #endif break; case 'V': /* version */ print_revision (progname, revision); exit (STATE_OK); case 'h': /* help */ print_help (); exit (STATE_OK); case '?': /* help */ usage ("Invalid argument\n"); } } c = optind; if (server_address == NULL) { if (argv[c]) { if (is_host (argv[c])) server_address = argv[c]; else usage ("Invalid host name"); } else { asprintf (&server_address, "127.0.0.1"); } } if (server_expect == NULL) asprintf (&server_expect, SMTP_EXPECT); return validate_arguments (); } int validate_arguments (void) { return OK; } void print_help (void) { print_revision (progname, revision); printf ("Copyright (c) %s %s\n\t<%s>\n\n%s\n", copyright, authors, email, summary); print_usage (); printf ("\nOptions:\n"); printf (options, SMTP_PORT, SMTP_EXPECT, mail_command, from_arg, DEFAULT_SOCKET_TIMEOUT); support (); } void print_usage (void) { printf ("Usage: %s %s\n" " %s --help\n" " %s --version\n", progname, option_summary, progname, progname); }