Initial revision

git-svn-id: https://nagiosplug.svn.sourceforge.net/svnroot/nagiosplug/nagiosplug/trunk@2 f882894a-f735-0410-b71e-b25c423dba1c

1 files changed, 415 insertions, 0 deletions

diff --git a/plugins/check_dns.c b/plugins/check_dns.c
new file mode 100644
index 00000000..eaff4372
--- /dev/null
+++ b/plugins/check_dns.c
@@ -0,0 +1,415 @@
+/******************************************************************************
+ *
+ * CHECK_DNS.C
+ *
+ * Program: DNS plugin for Nagios
+ * License: GPL
+ * Copyright (c) 1999 Ethan Galstad (nagios@nagios.org)
+ *
+ * Last Modified: $Date$
+ *
+ * Notes:
+ *  - Safe popen added by Karl DeBisschop 9-11-99
+ *
+ * Command line: CHECK_DNS <query_address> [dns_server]
+ *
+ * Description:
+ *
+ * This program will use the nslookup program to obtain the IP address
+ * for a given host name.  A optional DNS server may be specified.  If
+ * no DNS server is specified, the default server(s) for the system
+ * are used.
+ *
+ * Return Values:
+ *  OK           The DNS query was successful (host IP address was returned).
+ *  WARNING      The DNS server responded, but could not fulfill the request.
+ *  CRITICAL     The DNS server is not responding or encountered an error.
+ *
+ * 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 "common.h"
+#include "popen.h"
+#include "utils.h"
+
+int process_arguments (int, char **);
+int call_getopt (int, char **);
+int validate_arguments (void);
+void print_usage (char *);
+void print_help (char *);
+int error_scan (char *);
+
+#define ADDRESS_LENGTH 256
+char query_address[ADDRESS_LENGTH] = "";
+char dns_server[ADDRESS_LENGTH] = "";
+char ptr_server[ADDRESS_LENGTH] = "";
+int verbose = FALSE;
+
+int
+main (int argc, char **argv)
+{
+	char *command_line = NULL;
+	char input_buffer[MAX_INPUT_BUFFER];
+	char *output = NULL;
+	char *address = NULL;
+	char *temp_buffer = NULL;
+	int result = STATE_UNKNOWN;
+
+	/* Set signal handling and alarm */
+	if (signal (SIGALRM, popen_timeout_alarm_handler) == SIG_ERR) {
+		printf ("Cannot catch SIGALRM");
+		return STATE_UNKNOWN;
+	}
+
+	if (process_arguments (argc, argv) != OK) {
+		print_usage (my_basename (argv[0]));
+		return STATE_UNKNOWN;
+	}
+
+	/* get the command to run */
+	command_line = ssprintf (command_line, "%s %s %s", NSLOOKUP_COMMAND,
+		query_address, dns_server);
+
+	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);
+
+	/* scan stdout */
+	while (fgets (input_buffer, MAX_INPUT_BUFFER - 1, child_process)) {
+
+		if (verbose)
+			printf ("%s\n", input_buffer);
+
+		if (strstr (input_buffer, ".in-addr.arpa")) {
+			if ((temp_buffer = strstr (input_buffer, "name = ")))
+				address = strscpy (address, temp_buffer + 7);
+			else {
+				output = strscpy (output, "Unknown error (plugin)");
+				result = STATE_WARNING;
+			}
+		}
+
+		/* the server is responding, we just got the host name... */
+		if (strstr (input_buffer, "Name:")) {
+
+			/* get the host address */
+			if (!fgets (input_buffer, MAX_INPUT_BUFFER - 1, child_process))
+				break;
+
+			if (verbose)
+				printf ("%s\n", input_buffer);
+
+			if ((temp_buffer = index (input_buffer, ':'))) {
+				address = strscpy (address, temp_buffer + 2);
+				strip (address);
+				result = STATE_OK;
+			}
+			else {
+				output = strscpy (output, "Unknown error (plugin)");
+				result = STATE_WARNING;
+			}
+
+			break;
+		}
+
+		result = error_scan (input_buffer);
+		if (result != STATE_OK) {
+			output = strscpy (output, 1 + index (input_buffer, ':'));
+			break;
+		}
+
+	}
+
+	/* scan stderr */
+	while (fgets (input_buffer, MAX_INPUT_BUFFER - 1, child_stderr)) {
+		if (error_scan (input_buffer) != STATE_OK) {
+			result = max (result, error_scan (input_buffer));
+			output = strscpy (output, 1 + index (input_buffer, ':'));
+		}
+	}
+
+	/* close stderr */
+	(void) fclose (child_stderr);
+
+	/* close stdout */
+	if (spclose (child_process)) {
+		result = max (result, STATE_WARNING);
+		if (!strcmp (output, ""))
+			output = strscpy (output, "nslookup returned error status");
+	}
+
+	(void) time (&end_time);
+
+	if (result == STATE_OK)
+		printf ("DNS ok - %d seconds response time, Address(es) is/are %s\n",
+						(int) (end_time - start_time), address);
+	else if (result == STATE_WARNING)
+		printf ("DNS WARNING - %s\n",
+			!strcmp (output, "") ? " Probably a non-existent host/domain" : output);
+	else if (result == STATE_CRITICAL)
+		printf ("DNS CRITICAL - %s\n",
+			!strcmp (output, "") ? " Probably a non-existent host/domain" : output);
+	else
+		printf ("DNS problem - %s\n",
+			!strcmp (output, "") ? " Probably a non-existent host/domain" : output);
+
+	return result;
+}
+
+int
+error_scan (char *input_buffer)
+{
+
+	/* the DNS lookup timed out */
+	if (strstr (input_buffer,
+	     "Note:  nslookup is deprecated and may be removed from future releases.")
+	    || strstr (input_buffer,
+	     "Consider using the `dig' or `host' programs instead.  Run nslookup with")
+	    || strstr (input_buffer,
+	     "the `-sil[ent]' option to prevent this message from appearing."))
+		return STATE_OK;
+
+	/* the DNS lookup timed out */
+	else if (strstr (input_buffer, "Timed out"))
+		return STATE_WARNING;
+
+	/* DNS server is not running... */
+	else if (strstr (input_buffer, "No response from server"))
+		return STATE_CRITICAL;
+
+	/* Host name is valid, but server doesn't have records... */
+	else if (strstr (input_buffer, "No records"))
+		return STATE_WARNING;
+
+	/* Host or domain name does not exist */
+	else if (strstr (input_buffer, "Non-existent"))
+		return STATE_CRITICAL;
+	else if (strstr (input_buffer, "** server can't find"))
+		return STATE_CRITICAL;
+	else if(strstr(input_buffer,"NXDOMAIN")) /* 9.x */
+		return STATE_CRITICAL;
+
+	/* Connection was refused */
+	else if (strstr (input_buffer, "Connection refused"))
+		return STATE_CRITICAL;
+
+	/* Network is unreachable */
+	else if (strstr (input_buffer, "Network is unreachable"))
+		return STATE_CRITICAL;
+
+	/* Internal server failure */
+	else if (strstr (input_buffer, "Server failure"))
+		return STATE_CRITICAL;
+
+	/* DNS server refused to service request */
+	else if (strstr (input_buffer, "Refused"))
+		return STATE_CRITICAL;
+
+	/* Request error */
+	else if (strstr (input_buffer, "Format error"))
+		return STATE_WARNING;
+
+	else
+		return STATE_OK;
+
+}
+
+/* process command-line arguments */
+int
+process_arguments (int argc, char **argv)
+{
+	int c;
+
+	if (argc < 2)
+		return ERROR;
+
+	for (c = 1; c < argc; c++)
+		if (strcmp ("-to", argv[c]) == 0)
+			strcpy (argv[c], "-t");
+
+	c = 0;
+	while (c += (call_getopt (argc - c, &argv[c]))) {
+		if (argc <= c)
+			break;
+		if (query_address[0] == 0) {
+			if (is_host (argv[c]) == FALSE) {
+				printf ("Invalid name/address: %s\n\n", argv[c]);
+				return ERROR;
+			}
+			if (strlen (argv[c]) >= ADDRESS_LENGTH)
+				terminate (STATE_UNKNOWN, "Input buffer overflow\n");
+			strcpy (query_address, argv[c]);
+		}
+		else if (dns_server[0] == 0) {
+			if (is_host (argv[c]) == FALSE) {
+				printf ("Invalid name/address: %s\n\n", argv[c]);
+				return ERROR;
+			}
+			if (strlen (argv[c]) >= ADDRESS_LENGTH)
+				terminate (STATE_UNKNOWN, "Input buffer overflow\n");
+			strcpy (dns_server, argv[c]);
+		}
+	}
+
+	return validate_arguments ();
+
+}
+
+int
+call_getopt (int argc, char **argv)
+{
+	int c, i = 1;
+
+#ifdef HAVE_GETOPT_H
+	int opt_index = 0;
+	static struct option long_opts[] = {
+		{"help", no_argument, 0, 'h'},
+		{"version", no_argument, 0, 'V'},
+		{"verbose", no_argument, 0, 'v'},
+		{"timeout", required_argument, 0, 't'},
+		{"hostname", required_argument, 0, 'H'},
+		{"server", required_argument, 0, 's'},
+		{"reverse-server", required_argument, 0, 'r'},
+		{0, 0, 0, 0}
+	};
+#endif
+
+
+	while (1) {
+#ifdef HAVE_GETOPT_H
+		c = getopt_long (argc, argv, "+?hVvt:H:s:r:", long_opts, &opt_index);
+#else
+		c = getopt (argc, argv, "+?hVvt:H:s:r:");
+#endif
+
+		if (c == -1 || c == EOF)
+			break;
+
+		i++;
+		switch (c) {
+		case 't':
+		case 'H':
+		case 's':
+		case 'r':
+			i++;
+		}
+
+		switch (c) {
+		case '?': /* args not parsable */
+			printf ("%s: Unknown argument: %s\n\n", my_basename (argv[0]), optarg);
+			print_usage (my_basename (argv[0]));
+			exit (STATE_UNKNOWN);
+		case 'h': /* help */
+			print_help (my_basename (argv[0]));
+			exit (STATE_OK);
+		case 'V': /* version */
+			print_revision (my_basename (argv[0]), "$Revision$");
+			exit (STATE_OK);
+		case 'v': /* version */
+			verbose = TRUE;
+			break;
+		case 't': /* timeout period */
+			timeout_interval = atoi (optarg);
+			break;
+		case 'H': /* hostname */
+			if (is_host (optarg) == FALSE) {
+				printf ("Invalid host name/address\n\n");
+				print_usage (my_basename (argv[0]));
+				exit (STATE_UNKNOWN);
+			}
+			if (strlen (optarg) >= ADDRESS_LENGTH)
+				terminate (STATE_UNKNOWN, "Input buffer overflow\n");
+			strcpy (query_address, optarg);
+			break;
+		case 's': /* server name */
+			if (is_host (optarg) == FALSE) {
+				printf ("Invalid server name/address\n\n");
+				print_usage (my_basename (argv[0]));
+				exit (STATE_UNKNOWN);
+			}
+			if (strlen (optarg) >= ADDRESS_LENGTH)
+				terminate (STATE_UNKNOWN, "Input buffer overflow\n");
+			strcpy (dns_server, optarg);
+			break;
+		case 'r': /* reverse server name */
+			if (is_host (optarg) == FALSE) {
+				printf ("Invalid host name/address\n\n");
+				print_usage (my_basename (argv[0]));
+				exit (STATE_UNKNOWN);
+			}
+			if (strlen (optarg) >= ADDRESS_LENGTH)
+				terminate (STATE_UNKNOWN, "Input buffer overflow\n");
+			strcpy (ptr_server, optarg);
+			break;
+		}
+	}
+	return i;
+}
+
+int
+validate_arguments ()
+{
+	if (query_address[0] == 0)
+		return ERROR;
+	else
+		return OK;
+}
+
+void
+print_usage (char *cmd)
+{
+	printf ("Usage: %s -H host [-s server] [-t timeout]\n" "       %s --help\n"
+					"       %s --version\n", cmd, cmd, cmd);
+}
+
+void
+print_help (char *cmd)
+{
+	print_revision (cmd, "$Revision$");
+	printf ("Copyright (c) 1999 Ethan Galstad (nagios@nagios.org)\n\n");
+	print_usage (cmd);
+	printf ("\n");
+	printf
+		("-H, --hostname=HOST\n"
+		 "   The name or address you want to query\n"
+		 "-s, --server=HOST\n"
+		 "   Optional DNS server you want to use for the lookup\n"
+		 "-t, --timeout=INTEGER\n"
+		 "   Seconds before connection times out (default: %d)\n"
+		 "-h, --help\n"
+		 "   Print detailed help\n"
+		 "-V, --version\n"
+		 "   Print version numbers and license information\n"
+		 "\n"
+		 "This plugin uses the nslookup program to obtain the IP address\n"
+		 "for the given host/domain query.  A optional DNS server to use may\n"
+		 "be specified.  If no DNS server is specified, the default server(s)\n"
+		 "specified in /etc/resolv.conf will be used.\n", DEFAULT_SOCKET_TIMEOUT);
+}