/*****************************************************************************
*
* 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_dig";
const char *revision = "$Revision$";
const char *copyright = "2002-2003";
const char *authors = "Nagios Plugin Development Team";
const char *email = "nagiosplug-devel@lists.sourceforge.net";
const char *summary = "Test the DNS service on the specified host using dig\n";
const char *option_summary = "-H host -l lookup [-t timeout] [-v]";
const char *options = "\
-H, --hostname=STRING or IPADDRESS\n\
Check server on the indicated host\n\
-l, --lookup=STRING\n\
machine name to lookup\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";
const char *standard_options = "\
-h, --help\n\
Print detailed help screen\n\
-V, --version\n\
Print version information\n\n";
#include "config.h"
#include "common.h"
#include "utils.h"
#include "popen.h"
int process_arguments (int, char **);
int validate_arguments (void);
void print_help (void);
void print_usage (void);
char *query_address = NULL;
char *dns_server = NULL;
int verbose = FALSE;
int
main (int argc, char **argv)
{
char input_buffer[MAX_INPUT_BUFFER];
char *command_line = NULL;
char *output = "";
int result = STATE_UNKNOWN;
/* Set signal handling and alarm */
if (signal (SIGALRM, popen_timeout_alarm_handler) == SIG_ERR)
usage ("Cannot catch SIGALRM\n");
if (process_arguments (argc, argv) != OK)
usage ("Could not parse arguments\n");
/* get the command to run */
asprintf (&command_line, "%s @%s %s", PATH_TO_DIG, dns_server, query_address);
alarm (timeout_interval);
time (&start_time);
if (verbose)
printf ("%s\n", command_line);
/* run the command */
child_process = spopen (command_line);
if (child_process == NULL) {
printf ("Could not open pipe: %s\n", command_line);
return STATE_UNKNOWN;
}
child_stderr = fdopen (child_stderr_array[fileno (child_process)], "r");
if (child_stderr == NULL)
printf ("Could not open stderr for %s\n", command_line);
while (fgets (input_buffer, MAX_INPUT_BUFFER - 1, child_process)) {
/* the server is responding, we just got the host name... */
if (strstr (input_buffer, ";; ANSWER SECTION:")) {
/* get the host address */
if (!fgets (input_buffer, MAX_INPUT_BUFFER - 1, child_process))
break;
if (strpbrk (input_buffer, "\r\n"))
input_buffer[strcspn (input_buffer, "\r\n")] = '\0';
if (strstr (input_buffer, query_address) == input_buffer) {
asprintf (&output, input_buffer);
result = STATE_OK;
}
else {
asprintf (&output, "Server not found in ANSWER SECTION");
result = STATE_WARNING;
}
continue;
}
}
if (result != STATE_OK) {
asprintf (&output, "No ANSWER SECTION found");
}
while (fgets (input_buffer, MAX_INPUT_BUFFER - 1, child_stderr)) {
/* If we get anything on STDERR, at least set warning */
result = max_state (result, STATE_WARNING);
printf ("%s", input_buffer);
if (strlen (output) == 0)
asprintf (&output, 1 + index (input_buffer, ':'));
}
(void) fclose (child_stderr);
/* close the pipe */
if (spclose (child_process)) {
result = max_state (result, STATE_WARNING);
if (strlen (output) == 0)
asprintf (&output, "dig returned error status");
}
(void) time (&end_time);
if (output == NULL || strlen (output) == 0)
asprintf (&output, " Probably a non-existent host/domain");
if (result == STATE_OK)
printf ("DNS OK - %d seconds response time (%s)\n",
(int) (end_time - start_time), output);
else if (result == STATE_WARNING)
printf ("DNS WARNING - %s\n", output);
else if (result == STATE_CRITICAL)
printf ("DNS CRITICAL - %s\n", output);
else
printf ("DNS problem - %s\n", output);
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'},
{"query_address", required_argument, 0, 'e'},
{"verbose", no_argument, 0, 'v'},
{"version", no_argument, 0, 'V'},
{"help", no_argument, 0, 'h'},
{0, 0, 0, 0}
};
if (argc < 2)
return ERROR;
while (1) {
c = getopt_long (argc, argv, "hVvt:l:H:", long_options, &option_index);
if (c == -1 || c == EOF)
break;
switch (c) {
case '?': /* help */
usage3 ("Unknown argument", optopt);
case 'H': /* hostname */
if (is_host (optarg)) {
dns_server = optarg;
}
else {
usage ("Invalid host name\n");
}
break;
case 'l': /* username */
query_address = optarg;
break;
case 'v': /* verbose */
verbose = TRUE;
break;
case 't': /* timeout */
if (is_intnonneg (optarg)) {
timeout_interval = 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);
}
}
c = optind;
if (dns_server == NULL) {
if (c < argc) {
if (is_host (argv[c])) {
dns_server = argv[c];
}
else {
usage ("Invalid host name");
}
}
else {
dns_server = strdup ("127.0.0.1");
}
}
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", copyright, authors, email);
printf (summary);
print_usage ();
printf ("\nOptions:\n");
printf (options, DEFAULT_SOCKET_TIMEOUT);
printf (standard_options);
support ();
}
void
print_usage (void)
{
printf ("Usage: %s %s\n", progname, option_summary);
printf (" %s (-h|--help)\n", progname);
printf (" %s (-V|--version)\n", progname);
}