1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
|
/******************************************************************************
*
* Program: SNMP plugin for Nagios
* License: GPL
*
* 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 "config.h"
#include "common.h"
#include "utils.h"
#include "popen.h"
const char *progname = "check_dig";
#define REVISION "$Revision$"
#define COPYRIGHT "2000-2002"
#define AUTHOR "Karl DeBisschop"
#define EMAIL "karl@debisschop.net"
#define SUMMARY "Test the DNS service on the specified host using dig\n"
int process_arguments (int, char **);
int validate_arguments (void);
void print_help (void);
void print_usage (void);
char *query_address = NULL;
char *dns_server = NULL;
int verbose = FALSE;
int
main (int argc, char **argv)
{
char input_buffer[MAX_INPUT_BUFFER];
char *command_line = NULL;
char *output = "";
int result = STATE_UNKNOWN;
/* Set signal handling and alarm */
if (signal (SIGALRM, popen_timeout_alarm_handler) == SIG_ERR)
usage ("Cannot catch SIGALRM\n");
if (process_arguments (argc, argv) != OK)
usage ("Could not parse arguments\n");
/* get the command to run */
asprintf (&command_line, "%s @%s %s", PATH_TO_DIG, dns_server, query_address);
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);
while (fgets (input_buffer, MAX_INPUT_BUFFER - 1, child_process)) {
/* the server is responding, we just got the host name... */
if (strstr (input_buffer, ";; ANSWER SECTION:")) {
/* get the host address */
if (!fgets (input_buffer, MAX_INPUT_BUFFER - 1, child_process))
break;
if (strpbrk (input_buffer, "\r\n"))
input_buffer[strcspn (input_buffer, "\r\n")] = '\0';
if (strstr (input_buffer, query_address) == input_buffer) {
asprintf (&output, input_buffer);
result = STATE_OK;
}
else {
asprintf (&output, "Server not found in ANSWER SECTION");
result = STATE_WARNING;
}
continue;
}
}
if (result != STATE_OK) {
asprintf (&output, "No ANSWER SECTION found");
}
while (fgets (input_buffer, MAX_INPUT_BUFFER - 1, child_stderr)) {
/* If we get anything on STDERR, at least set warning */
result = max_state (result, STATE_WARNING);
printf ("%s", input_buffer);
if (strlen (output) == 0)
asprintf (&output, 1 + index (input_buffer, ':'));
}
(void) fclose (child_stderr);
/* close the pipe */
if (spclose (child_process)) {
result = max_state (result, STATE_WARNING);
if (strlen (output) == 0)
asprintf (&output, "dig returned error status");
}
(void) time (&end_time);
if (output == NULL || strlen (output) == 0)
asprintf (&output, " Probably a non-existent host/domain");
if (result == STATE_OK)
printf ("DNS ok - %d seconds response time (%s)\n",
(int) (end_time - start_time), output);
else if (result == STATE_WARNING)
printf ("DNS WARNING - %s\n", output);
else if (result == STATE_CRITICAL)
printf ("DNS CRITICAL - %s\n", output);
else
printf ("DNS problem - %s\n", output);
return result;
}
/* process command-line arguments */
int
process_arguments (int argc, char **argv)
{
int c;
int option_index = 0;
static struct option long_options[] = {
{"hostname", required_argument, 0, 'H'},
{"query_address", required_argument, 0, 'e'},
{"verbose", no_argument, 0, 'v'},
{"version", no_argument, 0, 'V'},
{"help", no_argument, 0, 'h'},
{0, 0, 0, 0}
};
if (argc < 2)
return ERROR;
while (1) {
c = getopt_long (argc, argv, "hVvt:l:H:", long_options, &option_index);
if (c == -1 || c == EOF)
break;
switch (c) {
case '?': /* help */
usage3 ("Unknown argument", optopt);
case 'H': /* hostname */
if (is_host (optarg)) {
dns_server = optarg;
}
else {
usage ("Invalid host name\n");
}
break;
case 'l': /* username */
query_address = optarg;
break;
case 'v': /* verbose */
verbose = TRUE;
break;
case 't': /* timeout */
if (is_intnonneg (optarg)) {
timeout_interval = atoi (optarg);
}
else {
usage ("Time interval must be a nonnegative integer\n");
}
break;
case 'V': /* version */
print_revision (progname, "$Revision$");
exit (STATE_OK);
case 'h': /* help */
print_help ();
exit (STATE_OK);
}
}
c = optind;
if (dns_server == NULL) {
if (c < argc) {
if (is_host (argv[c])) {
dns_server = argv[c];
}
else {
usage ("Invalid host name");
}
}
else {
asprintf (&dns_server, "127.0.0.1");
}
}
return validate_arguments ();
}
int
validate_arguments (void)
{
return OK;
}
void
print_help (void)
{
print_revision (progname, "$Revision$");
printf
("Copyright (c) %s %s <%s>\n\n%s\n",
COPYRIGHT, AUTHOR, EMAIL, SUMMARY);
print_usage ();
printf
("\nOptions:\n"
" -H, --hostname=STRING or IPADDRESS\n"
" Check server on the indicated host\n"
" -l, --lookup=STRING\n"
" machine name to lookup\n"
" -t, --timeout=INTEGER\n"
" Seconds before connection attempt times out (default: %d)\n"
" -v, --verbose\n"
" Print extra information (command-line use only)\n"
" -h, --help\n"
" Print detailed help screen\n"
" -V, --version\n"
" Print version information\n\n", DEFAULT_SOCKET_TIMEOUT);
support ();
}
void
print_usage (void)
{
printf
("Usage: %s -H host -l lookup [-t timeout] [-v]\n"
" %s --help\n"
" %s --version\n", progname, progname, progname);
}
|