a5b122f39b94ce132d2665a70520174e33e8a6c6
1 /*****************************************************************************
2 *
3 * Nagios check_ntp_time plugin
4 *
5 * License: GPL
6 * Copyright (c) 2006 Sean Finney <seanius@seanius.net>
7 * Copyright (c) 2006-2008 Nagios Plugins Development Team
8 *
9 * Last Modified: $Date$
10 *
11 * Description:
12 *
13 * This file contains the check_ntp_time plugin
14 *
15 * This plugin checks the clock offset between the local host and a
16 * remote NTP server. It is independent of any commandline programs or
17 * external libraries.
18 *
19 * If you'd rather want to monitor an NTP server, please use
20 * check_ntp_peer.
21 *
22 *
23 * This program is free software: you can redistribute it and/or modify
24 * it under the terms of the GNU General Public License as published by
25 * the Free Software Foundation, either version 3 of the License, or
26 * (at your option) any later version.
27 *
28 * This program is distributed in the hope that it will be useful,
29 * but WITHOUT ANY WARRANTY; without even the implied warranty of
30 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
31 * GNU General Public License for more details.
32 *
33 * You should have received a copy of the GNU General Public License
34 * along with this program. If not, see <http://www.gnu.org/licenses/>.
35 *
36 * $Id$
37 *
38 *****************************************************************************/
40 const char *progname = "check_ntp_time";
41 const char *revision = "$Revision$";
42 const char *copyright = "2006-2008";
43 const char *email = "nagiosplug-devel@lists.sourceforge.net";
45 #include "common.h"
46 #include "netutils.h"
47 #include "utils.h"
49 static char *server_address=NULL;
50 static char *port="123";
51 static int verbose=0;
52 static int quiet=0;
53 static char *owarn="60";
54 static char *ocrit="120";
56 int process_arguments (int, char **);
57 thresholds *offset_thresholds = NULL;
58 void print_help (void);
59 void print_usage (void);
61 /* number of times to perform each request to get a good average. */
62 #define AVG_NUM 4
64 /* max size of control message data */
65 #define MAX_CM_SIZE 468
67 /* this structure holds everything in an ntp request/response as per rfc1305 */
68 typedef struct {
69 uint8_t flags; /* byte with leapindicator,vers,mode. see macros */
70 uint8_t stratum; /* clock stratum */
71 int8_t poll; /* polling interval */
72 int8_t precision; /* precision of the local clock */
73 int32_t rtdelay; /* total rt delay, as a fixed point num. see macros */
74 uint32_t rtdisp; /* like above, but for max err to primary src */
75 uint32_t refid; /* ref clock identifier */
76 uint64_t refts; /* reference timestamp. local time local clock */
77 uint64_t origts; /* time at which request departed client */
78 uint64_t rxts; /* time at which request arrived at server */
79 uint64_t txts; /* time at which request departed server */
80 } ntp_message;
82 /* this structure holds data about results from querying offset from a peer */
83 typedef struct {
84 time_t waiting; /* ts set when we started waiting for a response */
85 int num_responses; /* number of successfully recieved responses */
86 uint8_t stratum; /* copied verbatim from the ntp_message */
87 double rtdelay; /* converted from the ntp_message */
88 double rtdisp; /* converted from the ntp_message */
89 double offset[AVG_NUM]; /* offsets from each response */
90 uint8_t flags; /* byte with leapindicator,vers,mode. see macros */
91 } ntp_server_results;
93 /* bits 1,2 are the leap indicator */
94 #define LI_MASK 0xc0
95 #define LI(x) ((x&LI_MASK)>>6)
96 #define LI_SET(x,y) do{ x |= ((y<<6)&LI_MASK); }while(0)
97 /* and these are the values of the leap indicator */
98 #define LI_NOWARNING 0x00
99 #define LI_EXTRASEC 0x01
100 #define LI_MISSINGSEC 0x02
101 #define LI_ALARM 0x03
102 /* bits 3,4,5 are the ntp version */
103 #define VN_MASK 0x38
104 #define VN(x) ((x&VN_MASK)>>3)
105 #define VN_SET(x,y) do{ x |= ((y<<3)&VN_MASK); }while(0)
106 #define VN_RESERVED 0x02
107 /* bits 6,7,8 are the ntp mode */
108 #define MODE_MASK 0x07
109 #define MODE(x) (x&MODE_MASK)
110 #define MODE_SET(x,y) do{ x |= (y&MODE_MASK); }while(0)
111 /* here are some values */
112 #define MODE_CLIENT 0x03
113 #define MODE_CONTROLMSG 0x06
114 /* In control message, bits 8-10 are R,E,M bits */
115 #define REM_MASK 0xe0
116 #define REM_RESP 0x80
117 #define REM_ERROR 0x40
118 #define REM_MORE 0x20
119 /* In control message, bits 11 - 15 are opcode */
120 #define OP_MASK 0x1f
121 #define OP_SET(x,y) do{ x |= (y&OP_MASK); }while(0)
122 #define OP_READSTAT 0x01
123 #define OP_READVAR 0x02
124 /* In peer status bytes, bits 6,7,8 determine clock selection status */
125 #define PEER_SEL(x) ((ntohs(x)>>8)&0x07)
126 #define PEER_INCLUDED 0x04
127 #define PEER_SYNCSOURCE 0x06
129 /**
130 ** a note about the 32-bit "fixed point" numbers:
131 **
132 they are divided into halves, each being a 16-bit int in network byte order:
133 - the first 16 bits are an int on the left side of a decimal point.
134 - the second 16 bits represent a fraction n/(2^16)
135 likewise for the 64-bit "fixed point" numbers with everything doubled :)
136 **/
138 /* macros to access the left/right 16 bits of a 32-bit ntp "fixed point"
139 number. note that these can be used as lvalues too */
140 #define L16(x) (((uint16_t*)&x)[0])
141 #define R16(x) (((uint16_t*)&x)[1])
142 /* macros to access the left/right 32 bits of a 64-bit ntp "fixed point"
143 number. these too can be used as lvalues */
144 #define L32(x) (((uint32_t*)&x)[0])
145 #define R32(x) (((uint32_t*)&x)[1])
147 /* ntp wants seconds since 1/1/00, epoch is 1/1/70. this is the difference */
148 #define EPOCHDIFF 0x83aa7e80UL
150 /* extract a 32-bit ntp fixed point number into a double */
151 #define NTP32asDOUBLE(x) (ntohs(L16(x)) + (double)ntohs(R16(x))/65536.0)
153 /* likewise for a 64-bit ntp fp number */
154 #define NTP64asDOUBLE(n) (double)(((uint64_t)n)?\
155 (ntohl(L32(n))-EPOCHDIFF) + \
156 (.00000001*(0.5+(double)(ntohl(R32(n))/42.94967296))):\
157 0)
159 /* convert a struct timeval to a double */
160 #define TVasDOUBLE(x) (double)(x.tv_sec+(0.000001*x.tv_usec))
162 /* convert an ntp 64-bit fp number to a struct timeval */
163 #define NTP64toTV(n,t) \
164 do{ if(!n) t.tv_sec = t.tv_usec = 0; \
165 else { \
166 t.tv_sec=ntohl(L32(n))-EPOCHDIFF; \
167 t.tv_usec=(int)(0.5+(double)(ntohl(R32(n))/4294.967296)); \
168 } \
169 }while(0)
171 /* convert a struct timeval to an ntp 64-bit fp number */
172 #define TVtoNTP64(t,n) \
173 do{ if(!t.tv_usec && !t.tv_sec) n=0x0UL; \
174 else { \
175 L32(n)=htonl(t.tv_sec + EPOCHDIFF); \
176 R32(n)=htonl((uint64_t)((4294.967296*t.tv_usec)+.5)); \
177 } \
178 } while(0)
180 /* NTP control message header is 12 bytes, plus any data in the data
181 * field, plus null padding to the nearest 32-bit boundary per rfc.
182 */
183 #define SIZEOF_NTPCM(m) (12+ntohs(m.count)+((m.count)?4-(ntohs(m.count)%4):0))
185 /* finally, a little helper or two for debugging: */
186 #define DBG(x) do{if(verbose>1){ x; }}while(0);
187 #define PRINTSOCKADDR(x) \
188 do{ \
189 printf("%u.%u.%u.%u", (x>>24)&0xff, (x>>16)&0xff, (x>>8)&0xff, x&0xff);\
190 }while(0);
192 /* calculate the offset of the local clock */
193 static inline double calc_offset(const ntp_message *m, const struct timeval *t){
194 double client_tx, peer_rx, peer_tx, client_rx;
195 client_tx = NTP64asDOUBLE(m->origts);
196 peer_rx = NTP64asDOUBLE(m->rxts);
197 peer_tx = NTP64asDOUBLE(m->txts);
198 client_rx=TVasDOUBLE((*t));
199 return (.5*((peer_tx-client_rx)+(peer_rx-client_tx)));
200 }
202 /* print out a ntp packet in human readable/debuggable format */
203 void print_ntp_message(const ntp_message *p){
204 struct timeval ref, orig, rx, tx;
206 NTP64toTV(p->refts,ref);
207 NTP64toTV(p->origts,orig);
208 NTP64toTV(p->rxts,rx);
209 NTP64toTV(p->txts,tx);
211 printf("packet contents:\n");
212 printf("\tflags: 0x%.2x\n", p->flags);
213 printf("\t li=%d (0x%.2x)\n", LI(p->flags), p->flags&LI_MASK);
214 printf("\t vn=%d (0x%.2x)\n", VN(p->flags), p->flags&VN_MASK);
215 printf("\t mode=%d (0x%.2x)\n", MODE(p->flags), p->flags&MODE_MASK);
216 printf("\tstratum = %d\n", p->stratum);
217 printf("\tpoll = %g\n", pow(2, p->poll));
218 printf("\tprecision = %g\n", pow(2, p->precision));
219 printf("\trtdelay = %-.16g\n", NTP32asDOUBLE(p->rtdelay));
220 printf("\trtdisp = %-.16g\n", NTP32asDOUBLE(p->rtdisp));
221 printf("\trefid = %x\n", p->refid);
222 printf("\trefts = %-.16g\n", NTP64asDOUBLE(p->refts));
223 printf("\torigts = %-.16g\n", NTP64asDOUBLE(p->origts));
224 printf("\trxts = %-.16g\n", NTP64asDOUBLE(p->rxts));
225 printf("\ttxts = %-.16g\n", NTP64asDOUBLE(p->txts));
226 }
228 void setup_request(ntp_message *p){
229 struct timeval t;
231 memset(p, 0, sizeof(ntp_message));
232 LI_SET(p->flags, LI_ALARM);
233 VN_SET(p->flags, 4);
234 MODE_SET(p->flags, MODE_CLIENT);
235 p->poll=4;
236 p->precision=(int8_t)0xfa;
237 L16(p->rtdelay)=htons(1);
238 L16(p->rtdisp)=htons(1);
240 gettimeofday(&t, NULL);
241 TVtoNTP64(t,p->txts);
242 }
244 /* select the "best" server from a list of servers, and return its index.
245 * this is done by filtering servers based on stratum, dispersion, and
246 * finally round-trip delay. */
247 int best_offset_server(const ntp_server_results *slist, int nservers){
248 int i=0, cserver=0, best_server=-1;
250 /* for each server */
251 for(cserver=0; cserver<nservers; cserver++){
252 /* We don't want any servers that fails these tests */
253 /* Sort out servers that didn't respond or responede with a 0 stratum;
254 * stratum 0 is for reference clocks so no NTP server should ever report
255 * a stratum 0 */
256 if ( slist[cserver].stratum == 0){
257 if (verbose) printf("discarding peer %d: stratum=%d\n", cserver, slist[cserver].stratum);
258 continue;
259 }
260 /* Sort out servers with error flags */
261 if ( LI(slist[cserver].flags) == LI_ALARM ){
262 if (verbose) printf("discarding peer %d: flags=%d\n", cserver, LI(slist[cserver].flags));
263 continue;
264 }
266 /* If we don't have a server yet, use the first one */
267 if (best_server == -1) {
268 best_server = cserver;
269 DBG(printf("using peer %d as our first candidate\n", best_server));
270 continue;
271 }
273 /* compare the server to the best one we've seen so far */
274 /* does it have an equal or better stratum? */
275 DBG(printf("comparing peer %d with peer %d\n", cserver, best_server));
276 if(slist[cserver].stratum <= slist[best_server].stratum){
277 DBG(printf("stratum for peer %d <= peer %d\n", cserver, best_server));
278 /* does it have an equal or better dispersion? */
279 if(slist[cserver].rtdisp <= slist[best_server].rtdisp){
280 DBG(printf("dispersion for peer %d <= peer %d\n", cserver, best_server));
281 /* does it have a better rtdelay? */
282 if(slist[cserver].rtdelay < slist[best_server].rtdelay){
283 DBG(printf("rtdelay for peer %d < peer %d\n", cserver, best_server));
284 best_server = cserver;
285 DBG(printf("peer %d is now our best candidate\n", best_server));
286 }
287 }
288 }
289 }
291 if(best_server >= 0) {
292 DBG(printf("best server selected: peer %d\n", best_server));
293 return best_server;
294 } else {
295 DBG(printf("no peers meeting synchronization criteria :(\n"));
296 return -1;
297 }
298 }
300 /* do everything we need to get the total average offset
301 * - we use a certain amount of parallelization with poll() to ensure
302 * we don't waste time sitting around waiting for single packets.
303 * - we also "manually" handle resolving host names and connecting, because
304 * we have to do it in a way that our lazy macros don't handle currently :( */
305 double offset_request(const char *host, int *status){
306 int i=0, j=0, ga_result=0, num_hosts=0, *socklist=NULL, respnum=0;
307 int servers_completed=0, one_written=0, one_read=0, servers_readable=0, best_index=-1;
308 time_t now_time=0, start_ts=0;
309 ntp_message *req=NULL;
310 double avg_offset=0.;
311 struct timeval recv_time;
312 struct addrinfo *ai=NULL, *ai_tmp=NULL, hints;
313 struct pollfd *ufds=NULL;
314 ntp_server_results *servers=NULL;
316 /* setup hints to only return results from getaddrinfo that we'd like */
317 memset(&hints, 0, sizeof(struct addrinfo));
318 hints.ai_family = address_family;
319 hints.ai_protocol = IPPROTO_UDP;
320 hints.ai_socktype = SOCK_DGRAM;
322 /* fill in ai with the list of hosts resolved by the host name */
323 ga_result = getaddrinfo(host, port, &hints, &ai);
324 if(ga_result!=0){
325 die(STATE_UNKNOWN, "error getting address for %s: %s\n",
326 host, gai_strerror(ga_result));
327 }
329 /* count the number of returned hosts, and allocate stuff accordingly */
330 for(ai_tmp=ai; ai_tmp!=NULL; ai_tmp=ai_tmp->ai_next){ num_hosts++; }
331 req=(ntp_message*)malloc(sizeof(ntp_message)*num_hosts);
332 if(req==NULL) die(STATE_UNKNOWN, "can not allocate ntp message array");
333 socklist=(int*)malloc(sizeof(int)*num_hosts);
334 if(socklist==NULL) die(STATE_UNKNOWN, "can not allocate socket array");
335 ufds=(struct pollfd*)malloc(sizeof(struct pollfd)*num_hosts);
336 if(ufds==NULL) die(STATE_UNKNOWN, "can not allocate socket array");
337 servers=(ntp_server_results*)malloc(sizeof(ntp_server_results)*num_hosts);
338 if(servers==NULL) die(STATE_UNKNOWN, "can not allocate server array");
339 memset(servers, 0, sizeof(ntp_server_results)*num_hosts);
340 DBG(printf("Found %d peers to check\n", num_hosts));
342 /* setup each socket for writing, and the corresponding struct pollfd */
343 ai_tmp=ai;
344 for(i=0;ai_tmp;i++){
345 socklist[i]=socket(ai_tmp->ai_family, SOCK_DGRAM, IPPROTO_UDP);
346 if(socklist[i] == -1) {
347 perror(NULL);
348 die(STATE_UNKNOWN, "can not create new socket");
349 }
350 if(connect(socklist[i], ai_tmp->ai_addr, ai_tmp->ai_addrlen)){
351 die(STATE_UNKNOWN, "can't create socket connection");
352 } else {
353 ufds[i].fd=socklist[i];
354 ufds[i].events=POLLIN;
355 ufds[i].revents=0;
356 }
357 ai_tmp = ai_tmp->ai_next;
358 }
360 /* now do AVG_NUM checks to each host. We stop before timeout/2 seconds
361 * have passed in order to ensure post-processing and jitter time. */
362 now_time=start_ts=time(NULL);
363 while(servers_completed<num_hosts && now_time-start_ts <= socket_timeout/2){
364 /* loop through each server and find each one which hasn't
365 * been touched in the past second or so and is still lacking
366 * some responses. For each of these servers, send a new request,
367 * and update the "waiting" timestamp with the current time. */
368 one_written=0;
369 now_time=time(NULL);
371 for(i=0; i<num_hosts; i++){
372 if(servers[i].waiting<now_time && servers[i].num_responses<AVG_NUM){
373 if(verbose && servers[i].waiting != 0) printf("re-");
374 if(verbose) printf("sending request to peer %d\n", i);
375 setup_request(&req[i]);
376 write(socklist[i], &req[i], sizeof(ntp_message));
377 servers[i].waiting=now_time;
378 one_written=1;
379 break;
380 }
381 }
383 /* quickly poll for any sockets with pending data */
384 servers_readable=poll(ufds, num_hosts, 100);
385 if(servers_readable==-1){
386 perror("polling ntp sockets");
387 die(STATE_UNKNOWN, "communication errors");
388 }
390 /* read from any sockets with pending data */
391 for(i=0; servers_readable && i<num_hosts; i++){
392 if(ufds[i].revents&POLLIN && servers[i].num_responses < AVG_NUM){
393 if(verbose) {
394 printf("response from peer %d: ", i);
395 }
397 read(ufds[i].fd, &req[i], sizeof(ntp_message));
398 gettimeofday(&recv_time, NULL);
399 DBG(print_ntp_message(&req[i]));
400 respnum=servers[i].num_responses++;
401 servers[i].offset[respnum]=calc_offset(&req[i], &recv_time);
402 if(verbose) {
403 printf("offset %.10g\n", servers[i].offset[respnum]);
404 }
405 servers[i].stratum=req[i].stratum;
406 servers[i].rtdisp=NTP32asDOUBLE(req[i].rtdisp);
407 servers[i].rtdelay=NTP32asDOUBLE(req[i].rtdelay);
408 servers[i].waiting=0;
409 servers[i].flags=req[i].flags;
410 servers_readable--;
411 one_read = 1;
412 if(servers[i].num_responses==AVG_NUM) servers_completed++;
413 }
414 }
415 /* lather, rinse, repeat. */
416 }
418 if (one_read == 0) {
419 die(STATE_CRITICAL, "NTP CRITICAL: No response from NTP server\n");
420 }
422 /* now, pick the best server from the list */
423 best_index=best_offset_server(servers, num_hosts);
424 if(best_index < 0){
425 *status=STATE_UNKNOWN;
426 } else {
427 /* finally, calculate the average offset */
428 for(i=0; i<servers[best_index].num_responses;i++){
429 avg_offset+=servers[best_index].offset[j];
430 }
431 avg_offset/=servers[best_index].num_responses;
432 }
434 /* cleanup */
435 for(j=0; j<num_hosts; j++){ close(socklist[j]); }
436 free(socklist);
437 free(ufds);
438 free(servers);
439 free(req);
440 freeaddrinfo(ai);
442 if(verbose) printf("overall average offset: %.10g\n", avg_offset);
443 return avg_offset;
444 }
446 int process_arguments(int argc, char **argv){
447 int c;
448 int option=0;
449 static struct option longopts[] = {
450 {"version", no_argument, 0, 'V'},
451 {"help", no_argument, 0, 'h'},
452 {"verbose", no_argument, 0, 'v'},
453 {"use-ipv4", no_argument, 0, '4'},
454 {"use-ipv6", no_argument, 0, '6'},
455 {"quiet", no_argument, 0, 'q'},
456 {"warning", required_argument, 0, 'w'},
457 {"critical", required_argument, 0, 'c'},
458 {"timeout", required_argument, 0, 't'},
459 {"hostname", required_argument, 0, 'H'},
460 {"port", required_argument, 0, 'p'},
461 {0, 0, 0, 0}
462 };
465 if (argc < 2)
466 usage ("\n");
468 while (1) {
469 c = getopt_long (argc, argv, "Vhv46qw:c:t:H:p:", longopts, &option);
470 if (c == -1 || c == EOF || c == 1)
471 break;
473 switch (c) {
474 case 'h':
475 print_help();
476 exit(STATE_OK);
477 break;
478 case 'V':
479 print_revision(progname, revision);
480 exit(STATE_OK);
481 break;
482 case 'v':
483 verbose++;
484 break;
485 case 'q':
486 quiet = 1;
487 break;
488 case 'w':
489 owarn = optarg;
490 break;
491 case 'c':
492 ocrit = optarg;
493 break;
494 case 'H':
495 if(is_host(optarg) == FALSE)
496 usage2(_("Invalid hostname/address"), optarg);
497 server_address = strdup(optarg);
498 break;
499 case 'p':
500 port = strdup(optarg);
501 break;
502 case 't':
503 socket_timeout=atoi(optarg);
504 break;
505 case '4':
506 address_family = AF_INET;
507 break;
508 case '6':
509 #ifdef USE_IPV6
510 address_family = AF_INET6;
511 #else
512 usage4 (_("IPv6 support not available"));
513 #endif
514 break;
515 case '?':
516 /* print short usage statement if args not parsable */
517 usage5 ();
518 break;
519 }
520 }
522 if(server_address == NULL){
523 usage4(_("Hostname was not supplied"));
524 }
526 return 0;
527 }
529 char *perfd_offset (double offset)
530 {
531 return fperfdata ("offset", offset, "s",
532 TRUE, offset_thresholds->warning->end,
533 TRUE, offset_thresholds->critical->end,
534 FALSE, 0, FALSE, 0);
535 }
537 int main(int argc, char *argv[]){
538 int result, offset_result;
539 double offset=0;
540 char *result_line, *perfdata_line;
542 setlocale (LC_ALL, "");
543 bindtextdomain (PACKAGE, LOCALEDIR);
544 textdomain (PACKAGE);
546 result = offset_result = STATE_OK;
548 /* Parse extra opts if any */
549 argv=np_extra_opts (&argc, argv, progname);
551 if (process_arguments (argc, argv) == ERROR)
552 usage4 (_("Could not parse arguments"));
554 set_thresholds(&offset_thresholds, owarn, ocrit);
556 /* initialize alarm signal handling */
557 signal (SIGALRM, socket_timeout_alarm_handler);
559 /* set socket timeout */
560 alarm (socket_timeout);
562 offset = offset_request(server_address, &offset_result);
563 if (offset_result == STATE_UNKNOWN) {
564 result = (quiet == 1 ? STATE_UNKNOWN : STATE_CRITICAL);
565 } else {
566 result = get_status(fabs(offset), offset_thresholds);
567 }
569 switch (result) {
570 case STATE_CRITICAL :
571 asprintf(&result_line, _("NTP CRITICAL:"));
572 break;
573 case STATE_WARNING :
574 asprintf(&result_line, _("NTP WARNING:"));
575 break;
576 case STATE_OK :
577 asprintf(&result_line, _("NTP OK:"));
578 break;
579 default :
580 asprintf(&result_line, _("NTP UNKNOWN:"));
581 break;
582 }
583 if(offset_result == STATE_UNKNOWN){
584 asprintf(&result_line, "%s %s", result_line, _("Offset unknown"));
585 asprintf(&perfdata_line, "");
586 } else {
587 asprintf(&result_line, "%s %s %.10g secs", result_line, _("Offset"), offset);
588 asprintf(&perfdata_line, "%s", perfd_offset(offset));
589 }
590 printf("%s|%s\n", result_line, perfdata_line);
592 if(server_address!=NULL) free(server_address);
593 return result;
594 }
596 void print_help(void){
597 print_revision(progname, revision);
599 printf ("Copyright (c) 2006 Sean Finney\n");
600 printf (COPYRIGHT, copyright, email);
602 printf ("%s\n", _("This plugin checks the clock offset with the ntp server"));
604 printf ("\n\n");
606 print_usage();
607 printf (_(UT_HELP_VRSN));
608 printf (_(UT_EXTRA_OPTS));
609 printf (_(UT_HOST_PORT), 'p', "123");
610 printf (" %s\n", "-q, --quiet");
611 printf (" %s\n", _("Returns UNKNOWN instead of CRITICAL if offset cannot be found"));
612 printf (" %s\n", "-w, --warning=THRESHOLD");
613 printf (" %s\n", _("Offset to result in warning status (seconds)"));
614 printf (" %s\n", "-c, --critical=THRESHOLD");
615 printf (" %s\n", _("Offset to result in critical status (seconds)"));
616 printf (_(UT_TIMEOUT), DEFAULT_SOCKET_TIMEOUT);
617 printf (_(UT_VERBOSE));
619 printf("\n");
620 printf("%s\n", _("This plugin checks the clock offset between the local host and a"));
621 printf("%s\n", _("remote NTP server. It is independent of any commandline programs or"));
622 printf("%s\n", _("external libraries."));
624 printf("\n");
625 printf("%s\n", _("Notes:"));
626 printf(" %s\n", _("If you'd rather want to monitor an NTP server, please use"));
627 printf(" %s\n", _("check_ntp_peer."));
628 printf("\n");
629 printf(_(UT_THRESHOLDS_NOTES));
630 #ifdef NP_EXTRA_OPTS
631 printf("\n");
632 printf(_(UT_EXTRA_OPTS_NOTES));
633 #endif
635 printf("\n");
636 printf("%s\n", _("Examples:"));
637 printf(" %s\n", ("./check_ntp_time -H ntpserv -w 0.5 -c 1"));
639 printf (_(UT_SUPPORT));
640 }
642 void
643 print_usage(void)
644 {
645 printf (_("Usage:"));
646 printf(" %s -H <host> [-w <warn>] [-c <crit>] [-v verbose]\n", progname);
647 }