mirror of
https://github.com/monitoring-plugins/monitoring-plugins.git
synced 2026-03-14 06:32:45 -04:00
46e26edd7f
git-svn-id: https://nagiosplug.svn.sourceforge.net/svnroot/nagiosplug/nagiosplug/trunk@703 f882894a-f735-0410-b71e-b25c423dba1c
443 lines
12 KiB
C
443 lines
12 KiB
C
/******************************************************************************
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*
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* CHECK_DNS.C
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*
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* Program: DNS plugin for Nagios
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* License: GPL
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* Copyright (c) 1999 Ethan Galstad (nagios@nagios.org)
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*
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* Last Modified: $Date$
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*
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* Notes:
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* - Safe popen added by Karl DeBisschop 9-11-99
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* - expected-address parameter added by Alex Chaffee - 7 Oct 2002
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*
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* Command line: (see print_usage)
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*
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* Description:
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*
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* This program will use the nslookup program to obtain the IP address
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* for a given host name. A optional DNS server may be specified. If
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* no DNS server is specified, the default server(s) for the system
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* are used.
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*
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* Return Values:
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* OK The DNS query was successful (host IP address was returned).
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* WARNING The DNS server responded, but could not fulfill the request.
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* CRITICAL The DNS server is not responding or encountered an error.
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*
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* License Information:
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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*****************************************************************************/
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#include "common.h"
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#include "popen.h"
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#include "utils.h"
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#include "netutils.h"
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const char *progname = "check_dns";
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const char *revision = "$Revision$";
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const char *copyright = "2000-2003";
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const char *email = "nagiosplug-devel@lists.sourceforge.net";
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int process_arguments (int, char **);
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int validate_arguments (void);
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int error_scan (char *);
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void print_help (void);
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void print_usage (void);
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#define ADDRESS_LENGTH 256
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char query_address[ADDRESS_LENGTH] = "";
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char dns_server[ADDRESS_LENGTH] = "";
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char ptr_server[ADDRESS_LENGTH] = "";
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int verbose = FALSE;
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char expected_address[ADDRESS_LENGTH] = "";
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int match_expected_address = FALSE;
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int
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main (int argc, char **argv)
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{
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char *command_line = NULL;
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char input_buffer[MAX_INPUT_BUFFER];
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char *output = NULL;
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char *address = NULL;
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char *temp_buffer = NULL;
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int result = STATE_UNKNOWN;
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double elapsed_time;
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long microsec;
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struct timeval tv;
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int multi_address;
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setlocale (LC_ALL, "");
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bindtextdomain (PACKAGE, LOCALEDIR);
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textdomain (PACKAGE);
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/* Set signal handling and alarm */
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if (signal (SIGALRM, popen_timeout_alarm_handler) == SIG_ERR) {
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printf (_("Cannot catch SIGALRM"));
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return STATE_UNKNOWN;
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}
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if (process_arguments (argc, argv) != OK) {
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print_usage ();
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return STATE_UNKNOWN;
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}
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/* get the command to run */
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asprintf (&command_line, "%s %s %s", NSLOOKUP_COMMAND, query_address, dns_server);
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alarm (timeout_interval);
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gettimeofday (&tv, NULL);
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if (verbose)
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printf ("%s\n", command_line);
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/* run the command */
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child_process = spopen (command_line);
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if (child_process == NULL) {
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printf (_("Could not open pipe: %s\n"), command_line);
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return STATE_UNKNOWN;
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}
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child_stderr = fdopen (child_stderr_array[fileno (child_process)], "r");
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if (child_stderr == NULL)
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printf (_("Could not open stderr for %s\n"), command_line);
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/* scan stdout */
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while (fgets (input_buffer, MAX_INPUT_BUFFER - 1, child_process)) {
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if (verbose)
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printf ("%s\n", input_buffer);
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if (strstr (input_buffer, ".in-addr.arpa")) {
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if ((temp_buffer = strstr (input_buffer, "name = ")))
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address = strdup (temp_buffer + 7);
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else {
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output = strdup (_("Unknown error (plugin)"));
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result = STATE_WARNING;
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}
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}
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/* the server is responding, we just got the host name... */
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if (strstr (input_buffer, "Name:")) {
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/* get the host address */
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if (!fgets (input_buffer, MAX_INPUT_BUFFER - 1, child_process))
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break;
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if (verbose)
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printf ("%s\n", input_buffer);
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if ((temp_buffer = index (input_buffer, ':'))) {
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temp_buffer++;
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/* Strip leading spaces */
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for (; *temp_buffer != '\0' && *temp_buffer == ' '; temp_buffer++)
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/* NOOP */;
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address = strdup (temp_buffer);
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strip (address);
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if (address==NULL || strlen(address)==0)
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die (STATE_CRITICAL,
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_("DNS CRITICAL - '%s' returned empty host name string\n"),
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NSLOOKUP_COMMAND);
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result = STATE_OK;
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}
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else {
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output = strdup (_("Unknown error (plugin)"));
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result = STATE_WARNING;
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}
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break;
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}
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result = error_scan (input_buffer);
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if (result != STATE_OK) {
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output = strdup (1 + index (input_buffer, ':'));
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strip (output);
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break;
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}
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}
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/* scan stderr */
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while (fgets (input_buffer, MAX_INPUT_BUFFER - 1, child_stderr)) {
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if (error_scan (input_buffer) != STATE_OK) {
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result = max_state (result, error_scan (input_buffer));
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output = strdup (1 + index (input_buffer, ':'));
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strip (output);
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}
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}
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/* close stderr */
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(void) fclose (child_stderr);
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/* close stdout */
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if (spclose (child_process)) {
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result = max_state (result, STATE_WARNING);
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if (!strcmp (output, ""))
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output = strdup (_("nslookup returned error status"));
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}
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/* If we got here, we should have an address string,
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and we can segfault if we do not */
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if (address==NULL || strlen(address)==0)
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die (STATE_CRITICAL,
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_("DNS CRITICAL - '%s' output parsing exited with no address\n"),
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NSLOOKUP_COMMAND);
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/* compare to expected address */
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if (result == STATE_OK && match_expected_address && strcmp(address, expected_address)) {
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result = STATE_CRITICAL;
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asprintf(&output, _("expected %s but got %s"), expected_address, address);
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}
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microsec = deltime (tv);
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elapsed_time = (double)microsec / 1.0e6;
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if (result == STATE_OK) {
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if (strchr (address, ',') == NULL)
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multi_address = FALSE;
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else
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multi_address = TRUE;
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printf (_("DNS ok - %.3f seconds response time, address%s %s|%s\n"),
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elapsed_time, (multi_address==TRUE ? "es are" : " is"), address,
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perfdata ("time", microsec, "us", FALSE, 0, FALSE, 0, TRUE, 0, FALSE, 0));
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}
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else if (result == STATE_WARNING)
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printf (_("DNS WARNING - %s\n"),
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!strcmp (output, "") ? _(" Probably a non-existent host/domain") : output);
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else if (result == STATE_CRITICAL)
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printf (_("DNS CRITICAL - %s\n"),
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!strcmp (output, "") ? _(" Probably a non-existent host/domain") : output);
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else
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printf (_("DNS problem - %s\n"),
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!strcmp (output, "") ? _(" Probably a non-existent host/domain") : output);
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return result;
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}
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int
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error_scan (char *input_buffer)
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{
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/* the DNS lookup timed out */
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if (strstr (input_buffer, "Note: nslookup is deprecated and may be removed from future releases.") ||
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strstr (input_buffer, "Consider using the `dig' or `host' programs instead. Run nslookup with") ||
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strstr (input_buffer, "the `-sil[ent]' option to prevent this message from appearing."))
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return STATE_OK;
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/* DNS server is not running... */
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else if (strstr (input_buffer, "No response from server"))
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die (STATE_CRITICAL, _("No response from name server %s\n"), dns_server);
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/* Host name is valid, but server doesn't have records... */
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else if (strstr (input_buffer, "No records"))
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die (STATE_CRITICAL, _("Name server %s has no records\n"), dns_server);
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/* Connection was refused */
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else if (strstr (input_buffer, "Connection refused") ||
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(strstr (input_buffer, "** server can't find") &&
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strstr (input_buffer, ": REFUSED")) ||
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(strstr (input_buffer, "Refused")))
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die (STATE_CRITICAL, _("Connection to name server %s was refused\n"), dns_server);
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/* Host or domain name does not exist */
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else if (strstr (input_buffer, "Non-existent") ||
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strstr (input_buffer, "** server can't find") ||
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strstr (input_buffer,"NXDOMAIN"))
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die (STATE_CRITICAL, _("Domain %s was not found by the server\n"), query_address);
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/* Network is unreachable */
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else if (strstr (input_buffer, "Network is unreachable"))
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die (STATE_CRITICAL, _("Network is unreachable\n"));
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/* Internal server failure */
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else if (strstr (input_buffer, "Server failure"))
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die (STATE_CRITICAL, _("Server failure for %s\n"), dns_server);
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/* Request error or the DNS lookup timed out */
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else if (strstr (input_buffer, "Format error") ||
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strstr (input_buffer, "Timed out"))
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return STATE_WARNING;
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return STATE_OK;
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}
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/* process command-line arguments */
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int
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process_arguments (int argc, char **argv)
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{
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int c;
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int opt_index = 0;
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static struct option long_opts[] = {
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{"help", no_argument, 0, 'h'},
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{"version", no_argument, 0, 'V'},
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{"verbose", no_argument, 0, 'v'},
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{"timeout", required_argument, 0, 't'},
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{"hostname", required_argument, 0, 'H'},
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{"server", required_argument, 0, 's'},
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{"reverse-server", required_argument, 0, 'r'},
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{"expected-address", required_argument, 0, 'a'},
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{0, 0, 0, 0}
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};
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if (argc < 2)
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return ERROR;
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for (c = 1; c < argc; c++)
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if (strcmp ("-to", argv[c]) == 0)
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strcpy (argv[c], "-t");
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while (1) {
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c = getopt_long (argc, argv, "hVvt:H:s:r:a:", long_opts, &opt_index);
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if (c == -1 || c == EOF)
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break;
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switch (c) {
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case '?': /* args not parsable */
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printf (_("%s: Unknown argument: %s\n\n"), progname, optarg);
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print_usage ();
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exit (STATE_UNKNOWN);
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case 'h': /* help */
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print_help ();
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exit (STATE_OK);
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case 'V': /* version */
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print_revision (progname, revision);
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exit (STATE_OK);
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case 'v': /* version */
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verbose = TRUE;
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break;
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case 't': /* timeout period */
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timeout_interval = atoi (optarg);
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break;
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case 'H': /* hostname */
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if (strlen (optarg) >= ADDRESS_LENGTH)
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die (STATE_UNKNOWN, _("Input buffer overflow\n"));
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strcpy (query_address, optarg);
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break;
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case 's': /* server name */
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/* TODO: this is_host check is probably unnecessary. Better to confirm nslookup
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response matches */
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if (is_host (optarg) == FALSE) {
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printf (_("Invalid server name/address\n\n"));
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print_usage ();
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exit (STATE_UNKNOWN);
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}
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if (strlen (optarg) >= ADDRESS_LENGTH)
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die (STATE_UNKNOWN, _("Input buffer overflow\n"));
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strcpy (dns_server, optarg);
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break;
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case 'r': /* reverse server name */
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/* TODO: Is this is_host necessary? */
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if (is_host (optarg) == FALSE) {
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printf (_("Invalid host name/address\n\n"));
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print_usage ();
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exit (STATE_UNKNOWN);
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}
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if (strlen (optarg) >= ADDRESS_LENGTH)
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die (STATE_UNKNOWN, _("Input buffer overflow\n"));
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strcpy (ptr_server, optarg);
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break;
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case 'a': /* expected address */
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if (strlen (optarg) >= ADDRESS_LENGTH)
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die (STATE_UNKNOWN, _("Input buffer overflow\n"));
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strcpy (expected_address, optarg);
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match_expected_address = TRUE;
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break;
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}
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}
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c = optind;
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if (strlen(query_address)==0 && c<argc) {
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if (strlen(argv[c])>=ADDRESS_LENGTH)
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die (STATE_UNKNOWN, _("Input buffer overflow\n"));
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strcpy (query_address, argv[c++]);
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}
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if (strlen(dns_server)==0 && c<argc) {
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/* TODO: See -s option */
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if (is_host(argv[c]) == FALSE) {
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printf (_("Invalid name/address: %s\n\n"), argv[c]);
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return ERROR;
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}
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if (strlen(argv[c]) >= ADDRESS_LENGTH)
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die (STATE_UNKNOWN, _("Input buffer overflow\n"));
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strcpy (dns_server, argv[c++]);
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}
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return validate_arguments ();
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}
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int
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validate_arguments ()
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{
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if (query_address[0] == 0)
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return ERROR;
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else
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return OK;
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}
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void
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print_help (void)
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{
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print_revision (progname, revision);
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printf (_("Copyright (c) 1999 Ethan Galstad <nagios@nagios.org>\n"));
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printf (_(COPYRIGHT), copyright, email);
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print_usage ();
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printf (_(UT_HELP_VRSN));
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printf (_("\
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-H, --hostname=HOST\n\
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The name or address you want to query\n\
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-s, --server=HOST\n\
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Optional DNS server you want to use for the lookup\n\
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-a, --expected-address=IP-ADDRESS\n\
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Optional IP address you expect the DNS server to return\n"));
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printf (_(UT_TIMEOUT), DEFAULT_SOCKET_TIMEOUT);
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printf (_("\n\
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This plugin uses the nslookup program to obtain the IP address\n\
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for the given host/domain query. A optional DNS server to use may\n\
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be specified. If no DNS server is specified, the default server(s)\n\
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specified in /etc/resolv.conf will be used.\n"));
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printf (_(UT_SUPPORT));
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}
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void
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print_usage (void)
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{
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printf (_("\
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Usage: %s -H host [-s server] [-a expected-address] [-t timeout]\n\
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%s --help\n\
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%s --version\n"),
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progname, progname, progname);
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}
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