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/******************************************************************************
*
* CHECK_SMTP.C
*
* Program: SMTP plugin for Nagios
* License: GPL
* Copyright (c) 1999 Ethan Galstad (nagios@nagios.org)
*
* $Id$
*
* Description:
*
* This plugin will attempt to open an SMTP connection with the host.
* Successul connects return STATE_OK, refusals and timeouts return
* STATE_CRITICAL, other errors return STATE_UNKNOWN. Successful
* connects, but incorrect reponse messages from the host result in
* STATE_WARNING return values.
*
* License Information:
*
* 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.
*
*****************************************************************************/
#include "config.h"
#include "common.h"
#include "netutils.h"
#include "utils.h"
#define PROGNAME "check_smtp"
#define SMTP_PORT 25
#define SMTP_EXPECT "220"
#define SMTP_HELO "HELO "
/* 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)
* You can disable sending DUMMYCMD by undefining SMTP_USE_DUMMYCMD.
*
* According to rfc821 you can include a null reversepath in the from command
* - but a log message is generated on the smtp server.
*
* Use the -f option to provide a FROM address
*/
#define SMTP_DUMMYCMD "MAIL "
#define SMTP_USE_DUMMYCMD 1
#define SMTP_QUIT "QUIT\r\n"
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;
char *from_arg = " ";
int warning_time = 0;
int check_warning_time = FALSE;
int critical_time = 0;
int check_critical_time = FALSE;
int verbose = FALSE;
int
main (int argc, char **argv)
{
int sd, c;
int result;
char buffer[MAX_INPUT_BUFFER] = "";
char *from_str = NULL;
char *helocmd = NULL;
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", SMTP_DUMMYCMD, from_arg, "\r\n");
if (verbose == TRUE)
printf ("FROMCMD: %s\n", from_str);
/* initialize alarm signal handling */
signal (SIGALRM, socket_timeout_alarm_handler);
/* set socket timeout */
alarm (socket_timeout);
/* try to connect to the host at the given port number */
time (&start_time);
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 */
result = recv (sd, buffer, MAX_INPUT_BUFFER - 1, 0);
/* strip the buffer of carriage returns */
strip (buffer);
/* return a WARNING status if we couldn't read any data */
if (result == -1) {
printf ("recv() failed\n");
result = STATE_WARNING;
}
else {
/* 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;
}
else {
time (&end_time);
result = STATE_OK;
if (check_critical_time == TRUE
&& (end_time - start_time) > critical_time) result =
STATE_CRITICAL;
else if (check_warning_time == TRUE
&& (end_time - start_time) > warning_time) result =
STATE_WARNING;
if (verbose == TRUE)
printf ("SMTP %s - %d sec. response time, %s\n",
state_text (result), (int) (end_time - start_time), buffer);
else
printf ("SMTP %s - %d second response time\n", state_text (result),
(int) (end_time - start_time));
}
}
/* close the connection */
/* first 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);
#ifdef SMTP_USE_DUMMYCMD
send(sd, from_str, strlen(from_str), 0);
/* allow for response to DUMMYCMD to reach us */
recv(sd, buffer, MAX_INPUT_BUFFER-1, 0);
if (verbose == TRUE)
printf("DUMMYCMD: %s\n%s\n",from_str,buffer);
#endif /* 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);
return result;
}
/* process command-line arguments */
int
process_arguments (int argc, char **argv)
{
int c;
#ifdef HAVE_GETOPT_H
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'},
{"port", required_argument, 0, 'p'},
{"from", required_argument, 0, 'f'},
{"verbose", no_argument, 0, 'v'},
{"version", no_argument, 0, 'V'},
{"help", no_argument, 0, 'h'},
{0, 0, 0, 0}
};
#endif
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) {
#ifdef HAVE_GETOPT_H
c =
getopt_long (argc, argv, "+hVvt:p:f:e:c:w:H:", long_options,
&option_index);
#else
c = getopt (argc, argv, "+?hVvt:p:f:e:c:w:H:");
#endif
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': /* 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 = TRUE;
break;
case 't': /* timeout */
if (is_intnonneg (optarg)) {
socket_timeout = atoi (optarg);
}
else {
usage ("Time interval must be a nonnegative integer\n");
}
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) 2000 Ethan Galstad/Karl DeBisschop\n\n"
"This plugin test the SMTP service on the specified host.\n\n");
print_usage ();
printf
("\nOptions:\n"
" -H, --hostname=STRING or IPADDRESS\n"
" Check server on the indicated host\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"
" -f, --from=STRING\n"
" from address to include in MAIL command (default NULL, Exchange2000 requires one)\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",
SMTP_PORT, SMTP_EXPECT, DEFAULT_SOCKET_TIMEOUT);
support ();
}
void
print_usage (void)
{
printf
("Usage: %s -H host [-e expect] [-p port] [-f from addr] [-w warn] [-c crit] [-t timeout] [-v]\n"
" %s --help\n"
" %s --version\n", PROGNAME, PROGNAME, PROGNAME);
}
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