1 files changed, 415 insertions, 0 deletions

diff --git a/plugins/check_dns.c b/plugins/check_dns.c
new file mode 100644
index 0000000..eaff437
--- /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);
+}