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-rw-r--r--plugins/check_ntp.c355
1 files changed, 355 insertions, 0 deletions
diff --git a/plugins/check_ntp.c b/plugins/check_ntp.c
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1/******************************************************************************
2 check_ntp.c: utility to check ntp servers independant of any commandline
3 programs or external libraries.
4 original author: sean finney <seanius@seanius.net>
5 ******************************************************************************
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19
20 $Id$
21
22*****************************************************************************/
23
24const char *progname = "check_ntp";
25const char *revision = "$Revision$";
26const char *copyright = "2006";
27const char *email = "nagiosplug-devel@lists.sourceforge.net";
28
29#include "common.h"
30#include "netutils.h"
31#include "utils.h"
32
33static char *server_address=NULL;
34static int verbose=0;
35static int zero_offset_bad=0;
36static double owarn=0;
37static double ocrit=0;
38static short do_jitter=0;
39static double jwarn=0;
40static double jcrit=0;
41
42int process_arguments (int, char **);
43void print_help (void);
44void print_usage (void);
45
46/* this structure holds everything in an ntp request/response as per rfc1305 */
47typedef struct {
48 uint8_t flags; /* byte with leapindicator,vers,mode. see macros */
49 uint8_t stratum; /* clock stratum */
50 int8_t poll; /* polling interval */
51 int8_t precision; /* precision of the local clock */
52 int32_t rtdelay; /* total rt delay, as a fixed point num. see macros */
53 uint32_t rtdisp; /* like above, but for max err to primary src */
54 uint32_t refid; /* ref clock identifier */
55 uint64_t refts; /* reference timestamp. local time local clock */
56 uint64_t origts; /* time at which request departed client */
57 uint64_t rxts; /* time at which request arrived at server */
58 uint64_t txts; /* time at which request departed server */
59} ntp_message;
60
61/* bits 1,2 are the leap indicator */
62#define LI_MASK 0xc0
63#define LI(x) ((x&LI_MASK)>>6)
64#define LI_SET(x,y) do{ x |= ((y<<6)&LI_MASK); }while(0)
65/* and these are the values of the leap indicator */
66#define LI_NOWARNING 0x00
67#define LI_EXTRASEC 0x01
68#define LI_MISSINGSEC 0x02
69#define LI_ALARM 0x03
70/* bits 3,4,5 are the ntp version */
71#define VN_MASK 0x38
72#define VN(x) ((x&VN_MASK)>>3)
73#define VN_SET(x,y) do{ x |= ((y<<3)&VN_MASK); }while(0)
74/* bits 6,7,8 are the ntp mode */
75#define MODE_MASK 0x07
76#define MODE(x) (x&MODE_MASK)
77#define MODE_SET(x,y) do{ x |= (y&MODE_MASK); }while(0)
78/* here are some values */
79#define MODE_CLIENT 0x03
80
81/**
82 ** a note about the 32-bit "fixed point" numbers:
83 **
84 they are divided into halves, each being a 16-bit int in network byte order:
85 - the first 16 bits are an int on the left side of a decimal point.
86 - the second 16 bits represent a fraction n/(2^16)
87 likewise for the 64-bit "fixed point" numbers with everything doubled :)
88 **/
89
90/* macros to access the left/right 16 bits of a 32-bit ntp "fixed point"
91 number. note that these can be used as lvalues too */
92#define L16(x) (((uint16_t*)&x)[0])
93#define R16(x) (((uint16_t*)&x)[1])
94/* macros to access the left/right 32 bits of a 64-bit ntp "fixed point"
95 number. these too can be used as lvalues */
96#define L32(x) (((uint32_t*)&x)[0])
97#define R32(x) (((uint32_t*)&x)[1])
98
99/* ntp wants seconds since 1/1/00, epoch is 1/1/70. this is the difference */
100#define EPOCHDIFF 0x83aa7e80UL
101
102/* extract a 32-bit ntp fixed point number into a double */
103#define NTP32asDOUBLE(x) (ntohs(L16(x)) + (double)ntohs(R16(x))/65536.0)
104
105/* likewise for a 64-bit ntp fp number */
106#define NTP64asDOUBLE(n) (double)(((uint64_t)n)?\
107 (ntohl(L32(n))-EPOCHDIFF) + \
108 (.00000001*(0.5+(double)(ntohl(R32(n))/42.94967296))):\
109 0)
110
111/* convert a struct timeval to a double */
112#define TVasDOUBLE(x) (double)(x.tv_sec+(0.000001*x.tv_usec))
113
114/* convert an ntp 64-bit fp number to a struct timeval */
115#define NTP64toTV(n,t) \
116 do{ if(!n) t.tv_sec = t.tv_usec = 0; \
117 else { \
118 t.tv_sec=ntohl(L32(n))-EPOCHDIFF; \
119 t.tv_usec=(int)(0.5+(double)(ntohl(R32(n))/4294.967296)); \
120 } \
121 }while(0)
122
123/* convert a struct timeval to an ntp 64-bit fp number */
124#define TVtoNTP64(t,n) \
125 do{ if(!t.tv_usec && !t.tv_sec) n=0x0UL; \
126 else { \
127 L32(n)=htonl(t.tv_sec + EPOCHDIFF); \
128 R32(n)=htonl((4294.967296*t.tv_usec)+.5); \
129 } \
130 } while(0)
131
132
133/* calculate the offset of the local clock */
134static inline double calc_offset(const ntp_message *m, const struct timeval *t){
135 double client_tx, peer_rx, peer_tx, client_rx, rtdelay;
136 client_tx = NTP64asDOUBLE(m->origts);
137 peer_rx = NTP64asDOUBLE(m->rxts);
138 peer_tx = NTP64asDOUBLE(m->txts);
139 client_rx=TVasDOUBLE((*t));
140 rtdelay=NTP32asDOUBLE(m->rtdelay);
141 return (.5*((peer_tx-client_rx)+(peer_rx-client_tx)))-rtdelay;
142}
143
144/* print out a ntp packet in human readable/debuggable format */
145void print_packet(const ntp_message *p){
146 struct timeval ref, orig, rx, tx;
147
148 NTP64toTV(p->refts,ref);
149 NTP64toTV(p->origts,orig);
150 NTP64toTV(p->rxts,rx);
151 NTP64toTV(p->txts,tx);
152
153 printf("packet contents:\n");
154 printf("\tflags: 0x%.2x\n", p->flags);
155 printf("\t li=%d (0x%.2x)\n", LI(p->flags), p->flags&LI_MASK);
156 printf("\t vn=%d (0x%.2x)\n", VN(p->flags), p->flags&VN_MASK);
157 printf("\t mode=%d (0x%.2x)\n", MODE(p->flags), p->flags&MODE_MASK);
158 printf("\tstratum = %d\n", p->stratum);
159 printf("\tpoll = %g\n", pow(2, p->poll));
160 printf("\tprecision = %g\n", pow(2, p->precision));
161 printf("\trtdelay = %-.16g\n", NTP32asDOUBLE(p->rtdelay));
162 printf("\trtdisp = %-.16g\n", NTP32asDOUBLE(p->rtdisp));
163 printf("\trefid = %x\n", p->refid);
164 printf("\trefts = %-.16g\n", NTP64asDOUBLE(p->refts));
165 printf("\torigts = %-.16g\n", NTP64asDOUBLE(p->origts));
166 printf("\trxts = %-.16g\n", NTP64asDOUBLE(p->rxts));
167 printf("\ttxts = %-.16g\n", NTP64asDOUBLE(p->txts));
168}
169
170void setup_request(ntp_message *p){
171 struct timeval t;
172
173 memset(p, 0, sizeof(ntp_message));
174 LI_SET(p->flags, LI_ALARM);
175 VN_SET(p->flags, 4);
176 MODE_SET(p->flags, MODE_CLIENT);
177 p->poll=4;
178 p->precision=0xfa;
179 L16(p->rtdelay)=htons(1);
180 L16(p->rtdisp)=htons(1);
181
182 gettimeofday(&t, NULL);
183 TVtoNTP64(t,p->txts);
184}
185
186int process_arguments(int argc, char **argv){
187 int c;
188 int option=0;
189 static struct option longopts[] = {
190 {"version", no_argument, 0, 'V'},
191 {"help", no_argument, 0, 'h'},
192 {"verbose", no_argument, 0, 'v'},
193 {"use-ipv4", no_argument, 0, '4'},
194/* {"use-ipv6", no_argument, 0, '6'}, */
195 {"warning", required_argument, 0, 'w'},
196 {"critical", required_argument, 0, 'c'},
197 {"zero-offset", no_argument, 0, 'O'},
198 {"jwarn", required_argument, 0, 'j'},
199 {"jcrit", required_argument, 0, 'k'},
200 {"timeout", required_argument, 0, 't'},
201 {"hostname", required_argument, 0, 'H'},
202 {0, 0, 0, 0}
203 };
204
205
206 if (argc < 2)
207 usage ("\n");
208
209 while (1) {
210 c = getopt_long (argc, argv, "Vhv4w:c:Oj:k:t:H:", longopts, &option);
211 if (c == -1 || c == EOF || c == 1)
212 break;
213
214 switch (c) {
215 case 'h':
216 print_help();
217 exit(STATE_OK);
218 break;
219 case 'V':
220 print_revision(progname, revision);
221 exit(STATE_OK);
222 break;
223 case 'v':
224 verbose = 1;
225 break;
226 case 'w':
227 owarn = atof(optarg);
228 break;
229 case 'c':
230 ocrit = atof(optarg);
231 break;
232 case 'j':
233 do_jitter=1;
234 jwarn = atof(optarg);
235 break;
236 case 'k':
237 do_jitter=1;
238 jcrit = atof(optarg);
239 break;
240 case 'H':
241 if(is_host(optarg) == FALSE)
242 usage2(_("Invalid hostname/address"), optarg);
243 server_address = strdup(optarg);
244 break;
245 case 't':
246 socket_timeout=atoi(optarg);
247 break;
248 case 'O':
249 zero_offset_bad=1;
250 break;
251 case '?':
252 /* print short usage statement if args not parsable */
253 usage2 (_("Unknown argument"), optarg);
254 break;
255 }
256 }
257
258 if (ocrit < owarn){
259 usage4(_("Critical offset should be larger than warning offset"));
260 }
261
262 if (ocrit < owarn){
263 usage4(_("Critical jitter should be larger than warning jitter"));
264 }
265
266 if(server_address == NULL){
267 usage4(_("Hostname was not supplied"));
268 }
269
270 return 0;
271}
272
273int main(int argc, char *argv[]){
274 int result = STATE_UNKNOWN;
275 int conn;
276 ntp_message m;
277 struct timeval recv_time;
278 double offset=0, jitter=0;
279
280 if (process_arguments (argc, argv) == ERROR)
281 usage4 (_("Could not parse arguments"));
282
283 /* initialize alarm signal handling */
284 signal (SIGALRM, socket_timeout_alarm_handler);
285
286 /* set socket timeout */
287 alarm (socket_timeout);
288
289 setup_request(&m);
290 if(verbose) print_packet(&m);
291 my_udp_connect(server_address, 123, &conn);
292 write(conn, &m, sizeof(ntp_message));
293 read(conn, &m, sizeof(ntp_message));
294 gettimeofday(&recv_time, NULL);
295 if(verbose) print_packet(&m);
296 close(conn);
297
298 offset=calc_offset(&m, &recv_time);
299 printf("total offset: %g\n", offset);
300
301 if(offset > ocrit){
302 printf("NTP CRITICAL: ");
303 result = STATE_CRITICAL;
304 } else if(offset > owarn) {
305 printf("NTP WARNING: ");
306 result = STATE_WARNING;
307 } else {
308 printf("NTP OK: ");
309 result = STATE_OK;
310 }
311
312 /* not implemented yet:
313 jitter=calc_jitter(&m, &recv_time);
314
315 if(do_jitter){
316 if(offset > ocrit){
317 printf("NTP CRITICAL: ");
318 result = STATE_CRITICAL;
319 } else if(offset > owarn) {
320 printf("NTP WARNING: ");
321 result = STATE_WARNING;
322 } else {
323 printf("NTP OK: ");
324 result = STATE_OK;
325 }
326 }
327 */
328
329 printf("Offset %g secs|offset=%g\n", offset, offset);
330
331 if(server_address!=NULL) free(server_address);
332 return result;
333}
334
335
336void print_usage(void){
337 printf("\
338Usage: %s -H <host> [-O] [-w <warn>] [-c <crit>] [-j <warn>] [-k <crit>] [-v verbose]\
339\n", progname);
340}
341
342void print_help(void){
343 print_revision(progname, revision);
344
345 printf ("Copyright (c) 1999 Ethan Galstad\n");
346 printf (COPYRIGHT, copyright, email);
347
348 print_usage();
349 printf (_(UT_HELP_VRSN));
350 printf (_(UT_HOST_PORT), 'p', "123");
351 printf (_(UT_WARN_CRIT));
352 printf (_(UT_TIMEOUT), DEFAULT_SOCKET_TIMEOUT);
353 printf (_(UT_VERBOSE));
354 printf(_(UT_SUPPORT));
355}