1 /*****************************************************************************
2 *
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation; either version 2 of the License, or
6 * (at your option) any later version.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program; if not, write to the Free Software
15 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
16 *
17 *****************************************************************************/
19 const char *progname = "check_dig";
20 const char *revision = "$Revision$";
21 const char *copyright = "2002-2003";
22 const char *authors = "Nagios Plugin Development Team";
23 const char *email = "nagiosplug-devel@lists.sourceforge.net";
25 const char *summary = "Test the DNS service on the specified host using dig\n";
27 const char *option_summary = "-H host -l lookup [-t timeout] [-v]";
29 const char *options = "\
30 -H, --hostname=STRING or IPADDRESS\n\
31 Check server on the indicated host\n\
32 -l, --lookup=STRING\n\
33 machine name to lookup\n\
34 -t, --timeout=INTEGER\n\
35 Seconds before connection attempt times out (default: %d)\n\
36 -v, --verbose\n\
37 Print extra information (command-line use only)\n";
39 const char *standard_options = "\
40 -h, --help\n\
41 Print detailed help screen\n\
42 -V, --version\n\
43 Print version information\n\n";
45 #include "config.h"
46 #include "common.h"
47 #include "utils.h"
48 #include "popen.h"
50 int process_arguments (int, char **);
51 int validate_arguments (void);
52 void print_help (void);
53 void print_usage (void);
55 char *query_address = NULL;
56 char *dns_server = NULL;
57 int verbose = FALSE;
59 int
60 main (int argc, char **argv)
61 {
62 char input_buffer[MAX_INPUT_BUFFER];
63 char *command_line = NULL;
64 char *output = "";
65 int result = STATE_UNKNOWN;
67 /* Set signal handling and alarm */
68 if (signal (SIGALRM, popen_timeout_alarm_handler) == SIG_ERR)
69 usage ("Cannot catch SIGALRM\n");
71 if (process_arguments (argc, argv) != OK)
72 usage ("Could not parse arguments\n");
74 /* get the command to run */
75 asprintf (&command_line, "%s @%s %s", PATH_TO_DIG, dns_server, query_address);
77 alarm (timeout_interval);
78 time (&start_time);
80 if (verbose)
81 printf ("%s\n", command_line);
82 /* run the command */
83 child_process = spopen (command_line);
84 if (child_process == NULL) {
85 printf ("Could not open pipe: %s\n", command_line);
86 return STATE_UNKNOWN;
87 }
89 child_stderr = fdopen (child_stderr_array[fileno (child_process)], "r");
90 if (child_stderr == NULL)
91 printf ("Could not open stderr for %s\n", command_line);
93 while (fgets (input_buffer, MAX_INPUT_BUFFER - 1, child_process)) {
95 /* the server is responding, we just got the host name... */
96 if (strstr (input_buffer, ";; ANSWER SECTION:")) {
98 /* get the host address */
99 if (!fgets (input_buffer, MAX_INPUT_BUFFER - 1, child_process))
100 break;
102 if (strpbrk (input_buffer, "\r\n"))
103 input_buffer[strcspn (input_buffer, "\r\n")] = '\0';
105 if (strstr (input_buffer, query_address) == input_buffer) {
106 asprintf (&output, input_buffer);
107 result = STATE_OK;
108 }
109 else {
110 asprintf (&output, "Server not found in ANSWER SECTION");
111 result = STATE_WARNING;
112 }
114 continue;
115 }
117 }
119 if (result != STATE_OK) {
120 asprintf (&output, "No ANSWER SECTION found");
121 }
123 while (fgets (input_buffer, MAX_INPUT_BUFFER - 1, child_stderr)) {
124 /* If we get anything on STDERR, at least set warning */
125 result = max_state (result, STATE_WARNING);
126 printf ("%s", input_buffer);
127 if (strlen (output) == 0)
128 asprintf (&output, 1 + index (input_buffer, ':'));
129 }
131 (void) fclose (child_stderr);
133 /* close the pipe */
134 if (spclose (child_process)) {
135 result = max_state (result, STATE_WARNING);
136 if (strlen (output) == 0)
137 asprintf (&output, "dig returned error status");
138 }
140 (void) time (&end_time);
142 if (output == NULL || strlen (output) == 0)
143 asprintf (&output, " Probably a non-existent host/domain");
145 if (result == STATE_OK)
146 printf ("DNS OK - %d seconds response time (%s)\n",
147 (int) (end_time - start_time), output);
148 else if (result == STATE_WARNING)
149 printf ("DNS WARNING - %s\n", output);
150 else if (result == STATE_CRITICAL)
151 printf ("DNS CRITICAL - %s\n", output);
152 else
153 printf ("DNS problem - %s\n", output);
155 return result;
156 }
158 /* process command-line arguments */
159 int
160 process_arguments (int argc, char **argv)
161 {
162 int c;
164 int option_index = 0;
165 static struct option long_options[] = {
166 {"hostname", required_argument, 0, 'H'},
167 {"query_address", required_argument, 0, 'e'},
168 {"verbose", no_argument, 0, 'v'},
169 {"version", no_argument, 0, 'V'},
170 {"help", no_argument, 0, 'h'},
171 {0, 0, 0, 0}
172 };
174 if (argc < 2)
175 return ERROR;
177 while (1) {
178 c = getopt_long (argc, argv, "hVvt:l:H:", long_options, &option_index);
180 if (c == -1 || c == EOF)
181 break;
183 switch (c) {
184 case '?': /* help */
185 usage3 ("Unknown argument", optopt);
186 case 'H': /* hostname */
187 if (is_host (optarg)) {
188 dns_server = optarg;
189 }
190 else {
191 usage ("Invalid host name\n");
192 }
193 break;
194 case 'l': /* username */
195 query_address = optarg;
196 break;
197 case 'v': /* verbose */
198 verbose = TRUE;
199 break;
200 case 't': /* timeout */
201 if (is_intnonneg (optarg)) {
202 timeout_interval = atoi (optarg);
203 }
204 else {
205 usage ("Time interval must be a nonnegative integer\n");
206 }
207 break;
208 case 'V': /* version */
209 print_revision (progname, "$Revision$");
210 exit (STATE_OK);
211 case 'h': /* help */
212 print_help ();
213 exit (STATE_OK);
214 }
215 }
217 c = optind;
218 if (dns_server == NULL) {
219 if (c < argc) {
220 if (is_host (argv[c])) {
221 dns_server = argv[c];
222 }
223 else {
224 usage ("Invalid host name");
225 }
226 }
227 else {
228 dns_server = strdup ("127.0.0.1");
229 }
230 }
232 return validate_arguments ();
233 }
239 int
240 validate_arguments (void)
241 {
242 return OK;
243 }
244 \f
249 void
250 print_help (void)
251 {
252 print_revision (progname, revision);
253 printf ("Copyright (c) %s %s\n\t<%s>\n\n", copyright, authors, email);
254 printf (summary);
255 print_usage ();
256 printf ("\nOptions:\n");
257 printf (options, DEFAULT_SOCKET_TIMEOUT);
258 printf (standard_options);
259 support ();
260 }
266 void
267 print_usage (void)
268 {
269 printf ("Usage: %s %s\n", progname, option_summary);
270 printf (" %s (-h|--help)\n", progname);
271 printf (" %s (-V|--version)\n", progname);
272 }