1 /******************************************************************************
2 *
3 * Program: SNMP plugin for Nagios
4 * License: GPL
5 *
6 * License Information:
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 *****************************************************************************/
23 #include "config.h"
24 #include "common.h"
25 #include "utils.h"
26 #include "popen.h"
28 const char *progname = "check_dig";
29 #define REVISION "$Revision$"
30 #define COPYRIGHT "2000-2002"
31 #define AUTHOR "Karl DeBisschop"
32 #define EMAIL "karl@debisschop.net"
33 #define SUMMARY "Test the DNS service on the specified host using dig\n"
35 int process_arguments (int, char **);
36 int validate_arguments (void);
37 void print_help (void);
38 void print_usage (void);
40 char *query_address = NULL;
41 char *dns_server = NULL;
42 int verbose = FALSE;
44 int
45 main (int argc, char **argv)
46 {
47 char input_buffer[MAX_INPUT_BUFFER];
48 char *command_line = NULL;
49 char *output = "";
50 int result = STATE_UNKNOWN;
52 /* Set signal handling and alarm */
53 if (signal (SIGALRM, popen_timeout_alarm_handler) == SIG_ERR)
54 usage ("Cannot catch SIGALRM\n");
56 if (process_arguments (argc, argv) != OK)
57 usage ("Could not parse arguments\n");
59 /* get the command to run */
60 asprintf (&command_line, "%s @%s %s", PATH_TO_DIG, dns_server, query_address);
62 alarm (timeout_interval);
63 time (&start_time);
65 if (verbose)
66 printf ("%s\n", command_line);
67 /* run the command */
68 child_process = spopen (command_line);
69 if (child_process == NULL) {
70 printf ("Could not open pipe: %s\n", command_line);
71 return STATE_UNKNOWN;
72 }
74 child_stderr = fdopen (child_stderr_array[fileno (child_process)], "r");
75 if (child_stderr == NULL)
76 printf ("Could not open stderr for %s\n", command_line);
78 while (fgets (input_buffer, MAX_INPUT_BUFFER - 1, child_process)) {
80 /* the server is responding, we just got the host name... */
81 if (strstr (input_buffer, ";; ANSWER SECTION:")) {
83 /* get the host address */
84 if (!fgets (input_buffer, MAX_INPUT_BUFFER - 1, child_process))
85 break;
87 if (strpbrk (input_buffer, "\r\n"))
88 input_buffer[strcspn (input_buffer, "\r\n")] = '\0';
90 if (strstr (input_buffer, query_address) == input_buffer) {
91 asprintf (&output, input_buffer);
92 result = STATE_OK;
93 }
94 else {
95 asprintf (&output, "Server not found in ANSWER SECTION");
96 result = STATE_WARNING;
97 }
99 continue;
100 }
102 }
104 if (result != STATE_OK) {
105 asprintf (&output, "No ANSWER SECTION found");
106 }
108 while (fgets (input_buffer, MAX_INPUT_BUFFER - 1, child_stderr)) {
109 /* If we get anything on STDERR, at least set warning */
110 result = max_state (result, STATE_WARNING);
111 printf ("%s", input_buffer);
112 if (strlen (output) == 0)
113 asprintf (&output, 1 + index (input_buffer, ':'));
114 }
116 (void) fclose (child_stderr);
118 /* close the pipe */
119 if (spclose (child_process)) {
120 result = max_state (result, STATE_WARNING);
121 if (strlen (output) == 0)
122 asprintf (&output, "dig returned error status");
123 }
125 (void) time (&end_time);
127 if (output == NULL || strlen (output) == 0)
128 asprintf (&output, " Probably a non-existent host/domain");
130 if (result == STATE_OK)
131 printf ("DNS OK - %d seconds response time (%s)\n",
132 (int) (end_time - start_time), output);
133 else if (result == STATE_WARNING)
134 printf ("DNS WARNING - %s\n", output);
135 else if (result == STATE_CRITICAL)
136 printf ("DNS CRITICAL - %s\n", output);
137 else
138 printf ("DNS problem - %s\n", output);
140 return result;
141 }
143 /* process command-line arguments */
144 int
145 process_arguments (int argc, char **argv)
146 {
147 int c;
149 int option_index = 0;
150 static struct option long_options[] = {
151 {"hostname", required_argument, 0, 'H'},
152 {"query_address", required_argument, 0, 'e'},
153 {"verbose", no_argument, 0, 'v'},
154 {"version", no_argument, 0, 'V'},
155 {"help", no_argument, 0, 'h'},
156 {0, 0, 0, 0}
157 };
159 if (argc < 2)
160 return ERROR;
162 while (1) {
163 c = getopt_long (argc, argv, "hVvt:l:H:", long_options, &option_index);
165 if (c == -1 || c == EOF)
166 break;
168 switch (c) {
169 case '?': /* help */
170 usage3 ("Unknown argument", optopt);
171 case 'H': /* hostname */
172 if (is_host (optarg)) {
173 dns_server = optarg;
174 }
175 else {
176 usage ("Invalid host name\n");
177 }
178 break;
179 case 'l': /* username */
180 query_address = optarg;
181 break;
182 case 'v': /* verbose */
183 verbose = TRUE;
184 break;
185 case 't': /* timeout */
186 if (is_intnonneg (optarg)) {
187 timeout_interval = atoi (optarg);
188 }
189 else {
190 usage ("Time interval must be a nonnegative integer\n");
191 }
192 break;
193 case 'V': /* version */
194 print_revision (progname, "$Revision$");
195 exit (STATE_OK);
196 case 'h': /* help */
197 print_help ();
198 exit (STATE_OK);
199 }
200 }
202 c = optind;
203 if (dns_server == NULL) {
204 if (c < argc) {
205 if (is_host (argv[c])) {
206 dns_server = argv[c];
207 }
208 else {
209 usage ("Invalid host name");
210 }
211 }
212 else {
213 asprintf (&dns_server, "127.0.0.1");
214 }
215 }
217 return validate_arguments ();
218 }
224 int
225 validate_arguments (void)
226 {
227 return OK;
228 }
234 void
235 print_help (void)
236 {
237 print_revision (progname, "$Revision$");
238 printf
239 ("Copyright (c) %s %s <%s>\n\n%s\n",
240 COPYRIGHT, AUTHOR, EMAIL, SUMMARY);
241 print_usage ();
242 printf
243 ("\nOptions:\n"
244 " -H, --hostname=STRING or IPADDRESS\n"
245 " Check server on the indicated host\n"
246 " -l, --lookup=STRING\n"
247 " machine name to lookup\n"
248 " -t, --timeout=INTEGER\n"
249 " Seconds before connection attempt times out (default: %d)\n"
250 " -v, --verbose\n"
251 " Print extra information (command-line use only)\n"
252 " -h, --help\n"
253 " Print detailed help screen\n"
254 " -V, --version\n"
255 " Print version information\n\n", DEFAULT_SOCKET_TIMEOUT);
256 support ();
257 }
263 void
264 print_usage (void)
265 {
266 printf
267 ("Usage: %s -H host -l lookup [-t timeout] [-v]\n"
268 " %s --help\n"
269 " %s --version\n", progname, progname, progname);
270 }