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";
24 const char *summary = "Test the DNS service on the specified host using dig\n";
26 const char *option_summary = "-H host -l lookup [-t timeout] [-v]";
28 const char *options = "\
29 -H, --hostname=STRING or IPADDRESS\n\
30 Check server on the indicated host\n\
31 -l, --lookup=STRING\n\
32 machine name to lookup\n\
33 -t, --timeout=INTEGER\n\
34 Seconds before connection attempt times out (default: %d)\n\
35 -v, --verbose\n\
36 Print extra information (command-line use only)\n\
37 -h, --help\n\
38 Print detailed help screen\n\
39 -V, --version\n\
40 Print version information\n\n";
42 #include "config.h"
43 #include "common.h"
44 #include "utils.h"
45 #include "popen.h"
47 int process_arguments (int, char **);
48 int validate_arguments (void);
49 void print_help (void);
50 void print_usage (void);
52 char *query_address = NULL;
53 char *dns_server = NULL;
54 int verbose = FALSE;
56 int
57 main (int argc, char **argv)
58 {
59 char input_buffer[MAX_INPUT_BUFFER];
60 char *command_line = NULL;
61 char *output = "";
62 int result = STATE_UNKNOWN;
64 /* Set signal handling and alarm */
65 if (signal (SIGALRM, popen_timeout_alarm_handler) == SIG_ERR)
66 usage ("Cannot catch SIGALRM\n");
68 if (process_arguments (argc, argv) != OK)
69 usage ("Could not parse arguments\n");
71 /* get the command to run */
72 asprintf (&command_line, "%s @%s %s", PATH_TO_DIG, dns_server, query_address);
74 alarm (timeout_interval);
75 time (&start_time);
77 if (verbose)
78 printf ("%s\n", command_line);
79 /* run the command */
80 child_process = spopen (command_line);
81 if (child_process == NULL) {
82 printf ("Could not open pipe: %s\n", command_line);
83 return STATE_UNKNOWN;
84 }
86 child_stderr = fdopen (child_stderr_array[fileno (child_process)], "r");
87 if (child_stderr == NULL)
88 printf ("Could not open stderr for %s\n", command_line);
90 while (fgets (input_buffer, MAX_INPUT_BUFFER - 1, child_process)) {
92 /* the server is responding, we just got the host name... */
93 if (strstr (input_buffer, ";; ANSWER SECTION:")) {
95 /* get the host address */
96 if (!fgets (input_buffer, MAX_INPUT_BUFFER - 1, child_process))
97 break;
99 if (strpbrk (input_buffer, "\r\n"))
100 input_buffer[strcspn (input_buffer, "\r\n")] = '\0';
102 if (strstr (input_buffer, query_address) == input_buffer) {
103 asprintf (&output, input_buffer);
104 result = STATE_OK;
105 }
106 else {
107 asprintf (&output, "Server not found in ANSWER SECTION");
108 result = STATE_WARNING;
109 }
111 continue;
112 }
114 }
116 if (result != STATE_OK) {
117 asprintf (&output, "No ANSWER SECTION found");
118 }
120 while (fgets (input_buffer, MAX_INPUT_BUFFER - 1, child_stderr)) {
121 /* If we get anything on STDERR, at least set warning */
122 result = max_state (result, STATE_WARNING);
123 printf ("%s", input_buffer);
124 if (strlen (output) == 0)
125 asprintf (&output, 1 + index (input_buffer, ':'));
126 }
128 (void) fclose (child_stderr);
130 /* close the pipe */
131 if (spclose (child_process)) {
132 result = max_state (result, STATE_WARNING);
133 if (strlen (output) == 0)
134 asprintf (&output, "dig returned error status");
135 }
137 (void) time (&end_time);
139 if (output == NULL || strlen (output) == 0)
140 asprintf (&output, " Probably a non-existent host/domain");
142 if (result == STATE_OK)
143 printf ("DNS OK - %d seconds response time (%s)\n",
144 (int) (end_time - start_time), output);
145 else if (result == STATE_WARNING)
146 printf ("DNS WARNING - %s\n", output);
147 else if (result == STATE_CRITICAL)
148 printf ("DNS CRITICAL - %s\n", output);
149 else
150 printf ("DNS problem - %s\n", output);
152 return result;
153 }
155 /* process command-line arguments */
156 int
157 process_arguments (int argc, char **argv)
158 {
159 int c;
161 int option_index = 0;
162 static struct option long_options[] = {
163 {"hostname", required_argument, 0, 'H'},
164 {"query_address", required_argument, 0, 'e'},
165 {"verbose", no_argument, 0, 'v'},
166 {"version", no_argument, 0, 'V'},
167 {"help", no_argument, 0, 'h'},
168 {0, 0, 0, 0}
169 };
171 if (argc < 2)
172 return ERROR;
174 while (1) {
175 c = getopt_long (argc, argv, "hVvt:l:H:", long_options, &option_index);
177 if (c == -1 || c == EOF)
178 break;
180 switch (c) {
181 case '?': /* help */
182 usage3 ("Unknown argument", optopt);
183 case 'H': /* hostname */
184 if (is_host (optarg)) {
185 dns_server = optarg;
186 }
187 else {
188 usage ("Invalid host name\n");
189 }
190 break;
191 case 'l': /* username */
192 query_address = optarg;
193 break;
194 case 'v': /* verbose */
195 verbose = TRUE;
196 break;
197 case 't': /* timeout */
198 if (is_intnonneg (optarg)) {
199 timeout_interval = atoi (optarg);
200 }
201 else {
202 usage ("Time interval must be a nonnegative integer\n");
203 }
204 break;
205 case 'V': /* version */
206 print_revision (progname, "$Revision$");
207 exit (STATE_OK);
208 case 'h': /* help */
209 print_help ();
210 exit (STATE_OK);
211 }
212 }
214 c = optind;
215 if (dns_server == NULL) {
216 if (c < argc) {
217 if (is_host (argv[c])) {
218 dns_server = argv[c];
219 }
220 else {
221 usage ("Invalid host name");
222 }
223 }
224 else {
225 dns_server = strdup ("127.0.0.1");
226 }
227 }
229 return validate_arguments ();
230 }
236 int
237 validate_arguments (void)
238 {
239 return OK;
240 }
246 void
247 print_help (void)
248 {
249 print_revision (progname, revision);
250 printf
251 ("Copyright (c) %s %s <%s>\n\n%s\n",
252 copyright, authors, email, summary);
253 print_usage ();
254 printf ("\nOptions:\n");
255 printf (options, DEFAULT_SOCKET_TIMEOUT);
256 support ();
257 }
263 void
264 print_usage (void)
265 {
266 printf ("Usage: %s %s\n", progname, option_summary);
267 printf (" %s (-h|--help)\n", progname);
268 printf (" %s (-V|--version)\n", progname);
269 }