1 /******************************************************************************
2 *
3 * Nagios check_ntp_peer plugin
4 *
5 * License: GPL
6 * Copyright (c) 2006 sean finney <seanius@seanius.net>
7 * Copyright (c) 2007 nagios-plugins team
8 *
9 * Last Modified: $Date$
10 *
11 * Description:
12 *
13 * This file contains the check_ntp_peer plugin
14 *
15 * This plugin checks an NTP server independent of any commandline
16 * programs or external libraries.
17 *
18 * Use this plugin to check the health of an NTP server. It supports
19 * checking the offset with the sync peer, the jitter and stratum. This
20 * plugin will not check the clock offset between the local host and NTP
21 * server; please use check_ntp_time for that purpose.
22 *
23 *
24 * License Information:
25 *
26 * This program is free software; you can redistribute it and/or modify
27 * it under the terms of the GNU General Public License as published by
28 * the Free Software Foundation; either version 2 of the License, or
29 * (at your option) any later version.
30 *
31 * This program is distributed in the hope that it will be useful,
32 * but WITHOUT ANY WARRANTY; without even the implied warranty of
33 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
34 * GNU General Public License for more details.
35 *
36 * You should have received a copy of the GNU General Public License
37 * along with this program; if not, write to the Free Software
38 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
40 $Id$
42 *****************************************************************************/
44 const char *progname = "check_ntp_peer";
45 const char *revision = "$Revision$";
46 const char *copyright = "2007";
47 const char *email = "nagiosplug-devel@lists.sourceforge.net";
49 #include "common.h"
50 #include "netutils.h"
51 #include "utils.h"
53 static char *server_address=NULL;
54 static int verbose=0;
55 static int quiet=0;
56 static short do_offset=0;
57 static char *owarn="60";
58 static char *ocrit="120";
59 static short do_stratum=0;
60 static char *swarn="-1:16";
61 static char *scrit="-1:16";
62 static short do_jitter=0;
63 static char *jwarn="-1:5000";
64 static char *jcrit="-1:10000";
65 static int syncsource_found=0;
67 int process_arguments (int, char **);
68 thresholds *offset_thresholds = NULL;
69 thresholds *jitter_thresholds = NULL;
70 thresholds *stratum_thresholds = NULL;
71 void print_help (void);
72 void print_usage (void);
74 /* max size of control message data */
75 #define MAX_CM_SIZE 468
77 /* this structure holds everything in an ntp control message as per rfc1305 */
78 typedef struct {
79 uint8_t flags; /* byte with leapindicator,vers,mode. see macros */
80 uint8_t op; /* R,E,M bits and Opcode */
81 uint16_t seq; /* Packet sequence */
82 uint16_t status; /* Clock status */
83 uint16_t assoc; /* Association */
84 uint16_t offset; /* Similar to TCP sequence # */
85 uint16_t count; /* # bytes of data */
86 char data[MAX_CM_SIZE]; /* ASCII data of the request */
87 /* NB: not necessarily NULL terminated! */
88 } ntp_control_message;
90 /* this is an association/status-word pair found in control packet reponses */
91 typedef struct {
92 uint16_t assoc;
93 uint16_t status;
94 } ntp_assoc_status_pair;
96 /* bits 1,2 are the leap indicator */
97 #define LI_MASK 0xc0
98 #define LI(x) ((x&LI_MASK)>>6)
99 #define LI_SET(x,y) do{ x |= ((y<<6)&LI_MASK); }while(0)
100 /* and these are the values of the leap indicator */
101 #define LI_NOWARNING 0x00
102 #define LI_EXTRASEC 0x01
103 #define LI_MISSINGSEC 0x02
104 #define LI_ALARM 0x03
105 /* bits 3,4,5 are the ntp version */
106 #define VN_MASK 0x38
107 #define VN(x) ((x&VN_MASK)>>3)
108 #define VN_SET(x,y) do{ x |= ((y<<3)&VN_MASK); }while(0)
109 #define VN_RESERVED 0x02
110 /* bits 6,7,8 are the ntp mode */
111 #define MODE_MASK 0x07
112 #define MODE(x) (x&MODE_MASK)
113 #define MODE_SET(x,y) do{ x |= (y&MODE_MASK); }while(0)
114 /* here are some values */
115 #define MODE_CLIENT 0x03
116 #define MODE_CONTROLMSG 0x06
117 /* In control message, bits 8-10 are R,E,M bits */
118 #define REM_MASK 0xe0
119 #define REM_RESP 0x80
120 #define REM_ERROR 0x40
121 #define REM_MORE 0x20
122 /* In control message, bits 11 - 15 are opcode */
123 #define OP_MASK 0x1f
124 #define OP_SET(x,y) do{ x |= (y&OP_MASK); }while(0)
125 #define OP_READSTAT 0x01
126 #define OP_READVAR 0x02
127 /* In peer status bytes, bits 6,7,8 determine clock selection status */
128 #define PEER_SEL(x) ((ntohs(x)>>8)&0x07)
129 #define PEER_INCLUDED 0x04
130 #define PEER_SYNCSOURCE 0x06
132 /* NTP control message header is 12 bytes, plus any data in the data
133 * field, plus null padding to the nearest 32-bit boundary per rfc.
134 */
135 #define SIZEOF_NTPCM(m) (12+ntohs(m.count)+((m.count)?4-(ntohs(m.count)%4):0))
137 /* finally, a little helper or two for debugging: */
138 #define DBG(x) do{if(verbose>1){ x; }}while(0);
139 #define PRINTSOCKADDR(x) \
140 do{ \
141 printf("%u.%u.%u.%u", (x>>24)&0xff, (x>>16)&0xff, (x>>8)&0xff, x&0xff);\
142 }while(0);
144 void print_ntp_control_message(const ntp_control_message *p){
145 int i=0, numpeers=0;
146 const ntp_assoc_status_pair *peer=NULL;
148 printf("control packet contents:\n");
149 printf("\tflags: 0x%.2x , 0x%.2x\n", p->flags, p->op);
150 printf("\t li=%d (0x%.2x)\n", LI(p->flags), p->flags&LI_MASK);
151 printf("\t vn=%d (0x%.2x)\n", VN(p->flags), p->flags&VN_MASK);
152 printf("\t mode=%d (0x%.2x)\n", MODE(p->flags), p->flags&MODE_MASK);
153 printf("\t response=%d (0x%.2x)\n", (p->op&REM_RESP)>0, p->op&REM_RESP);
154 printf("\t more=%d (0x%.2x)\n", (p->op&REM_MORE)>0, p->op&REM_MORE);
155 printf("\t error=%d (0x%.2x)\n", (p->op&REM_ERROR)>0, p->op&REM_ERROR);
156 printf("\t op=%d (0x%.2x)\n", p->op&OP_MASK, p->op&OP_MASK);
157 printf("\tsequence: %d (0x%.2x)\n", ntohs(p->seq), ntohs(p->seq));
158 printf("\tstatus: %d (0x%.2x)\n", ntohs(p->status), ntohs(p->status));
159 printf("\tassoc: %d (0x%.2x)\n", ntohs(p->assoc), ntohs(p->assoc));
160 printf("\toffset: %d (0x%.2x)\n", ntohs(p->offset), ntohs(p->offset));
161 printf("\tcount: %d (0x%.2x)\n", ntohs(p->count), ntohs(p->count));
162 numpeers=ntohs(p->count)/(sizeof(ntp_assoc_status_pair));
163 if(p->op&REM_RESP && p->op&OP_READSTAT){
164 peer=(ntp_assoc_status_pair*)p->data;
165 for(i=0;i<numpeers;i++){
166 printf("\tpeer id %.2x status %.2x",
167 ntohs(peer[i].assoc), ntohs(peer[i].status));
168 if (PEER_SEL(peer[i].status) >= PEER_INCLUDED){
169 if(PEER_SEL(peer[i].status) >= PEER_SYNCSOURCE){
170 printf(" <-- current sync source");
171 } else {
172 printf(" <-- current sync candidate");
173 }
174 }
175 printf("\n");
176 }
177 }
178 }
180 char *extract_value(const char *varlist, const char *name){
181 char *tmpvarlist=NULL, *tmpkey=NULL, *value=NULL;
182 int last=0;
184 /* The following code require a non-empty varlist */
185 if(strlen(varlist) == 0)
186 return NULL;
188 tmpvarlist = strdup(varlist);
189 tmpkey = strtok(tmpvarlist, "=");
191 do {
192 if(strstr(tmpkey, name) != NULL) {
193 value = strtok(NULL, ",");
194 last = 1;
195 }
196 } while (last == 0 && (tmpkey = strtok(NULL, "=")));
198 return value;
199 }
201 void
202 setup_control_request(ntp_control_message *p, uint8_t opcode, uint16_t seq){
203 memset(p, 0, sizeof(ntp_control_message));
204 LI_SET(p->flags, LI_NOWARNING);
205 VN_SET(p->flags, VN_RESERVED);
206 MODE_SET(p->flags, MODE_CONTROLMSG);
207 OP_SET(p->op, opcode);
208 p->seq = htons(seq);
209 /* Remaining fields are zero for requests */
210 }
212 /* This function does all the actual work; roughly here's what it does
213 * beside setting the offest, jitter and stratum passed as argument:
214 * - offset can be negative, so if it cannot get the offset, offset_result
215 * is set to UNKNOWN, otherwise OK.
216 * - jitter and stratum are set to -1 if they cannot be retrieved so any
217 * positive value means a success retrieving the value.
218 * - status is set to WARNING if there's no sync.peer (otherwise OK) and is
219 * the return value of the function.
220 * status is pretty much useless as syncsource_found is a global variable
221 * used later in main to check is the server was synchronized. It works
222 * so I left it alone */
223 int ntp_request(const char *host, double *offset, int *offset_result, double *jitter, int *stratum){
224 int conn=-1, i, npeers=0, num_candidates=0;
225 double tmp_offset = 0;
226 int min_peer_sel=PEER_INCLUDED;
227 int peers_size=0, peer_offset=0;
228 int status;
229 ntp_assoc_status_pair *peers=NULL;
230 ntp_control_message req;
231 const char *getvar = "stratum,offset,jitter";
232 char *data, *value, *nptr;
233 void *tmp;
235 status = STATE_OK;
236 *offset_result = STATE_UNKNOWN;
237 *jitter = *stratum = -1;
239 /* Long-winded explanation:
240 * Getting the sync peer offset, jitter and stratum requires a number of
241 * steps:
242 * 1) Send a READSTAT request.
243 * 2) Interpret the READSTAT reply
244 * a) The data section contains a list of peer identifiers (16 bits)
245 * and associated status words (16 bits)
246 * b) We want the value of 0x06 in the SEL (peer selection) value,
247 * which means "current synchronizatin source". If that's missing,
248 * we take anything better than 0x04 (see the rfc for details) but
249 * set a minimum of warning.
250 * 3) Send a READVAR request for information on each peer identified
251 * in 2b greater than the minimum selection value.
252 * 4) Extract the offset, jitter and stratum value from the data[]
253 * (it's ASCII)
254 */
255 my_udp_connect(server_address, 123, &conn);
257 /* keep sending requests until the server stops setting the
258 * REM_MORE bit, though usually this is only 1 packet. */
259 do{
260 setup_control_request(&req, OP_READSTAT, 1);
261 DBG(printf("sending READSTAT request"));
262 write(conn, &req, SIZEOF_NTPCM(req));
263 DBG(print_ntp_control_message(&req));
264 /* Attempt to read the largest size packet possible */
265 req.count=htons(MAX_CM_SIZE);
266 DBG(printf("recieving READSTAT response"))
267 read(conn, &req, SIZEOF_NTPCM(req));
268 DBG(print_ntp_control_message(&req));
269 /* Each peer identifier is 4 bytes in the data section, which
270 * we represent as a ntp_assoc_status_pair datatype.
271 */
272 peers_size+=ntohs(req.count);
273 if((tmp=realloc(peers, peers_size)) == NULL)
274 free(peers), die(STATE_UNKNOWN, "can not (re)allocate 'peers' buffer\n");
275 peers=tmp;
276 memcpy((void*)((ptrdiff_t)peers+peer_offset), (void*)req.data, ntohs(req.count));
277 npeers=peers_size/sizeof(ntp_assoc_status_pair);
278 peer_offset+=ntohs(req.count);
279 } while(req.op&REM_MORE);
281 /* first, let's find out if we have a sync source, or if there are
282 * at least some candidates. In the latter case we'll issue
283 * a warning but go ahead with the check on them. */
284 for (i = 0; i < npeers; i++){
285 if (PEER_SEL(peers[i].status) >= PEER_INCLUDED){
286 num_candidates++;
287 if(PEER_SEL(peers[i].status) >= PEER_SYNCSOURCE){
288 syncsource_found=1;
289 min_peer_sel=PEER_SYNCSOURCE;
290 }
291 }
292 }
293 if(verbose) printf("%d candiate peers available\n", num_candidates);
294 if(verbose && syncsource_found) printf("synchronization source found\n");
295 if(! syncsource_found){
296 status = STATE_WARNING;
297 if(verbose) printf("warning: no synchronization source found\n");
298 }
301 for (i = 0; i < npeers; i++){
302 /* Only query this server if it is the current sync source */
303 /* If there's no sync.peer, query all candidates and use the best one */
304 if (PEER_SEL(peers[i].status) >= min_peer_sel){
305 if(verbose) printf("Getting offset, jitter and stratum for peer %.2x\n", ntohs(peers[i].assoc));
306 asprintf(&data, "");
307 do{
308 setup_control_request(&req, OP_READVAR, 2);
309 req.assoc = peers[i].assoc;
310 /* Putting the wanted variable names in the request
311 * cause the server to provide _only_ the requested values.
312 * thus reducing net traffic, guaranteeing us only a single
313 * datagram in reply, and making intepretation much simpler
314 */
315 /* Older servers doesn't know what jitter is, so if we get an
316 * error on the first pass we redo it with "dispersion" */
317 strncpy(req.data, getvar, MAX_CM_SIZE-1);
318 req.count = htons(strlen(getvar));
319 DBG(printf("sending READVAR request...\n"));
320 write(conn, &req, SIZEOF_NTPCM(req));
321 DBG(print_ntp_control_message(&req));
323 req.count = htons(MAX_CM_SIZE);
324 DBG(printf("receiving READVAR response...\n"));
325 read(conn, &req, SIZEOF_NTPCM(req));
326 DBG(print_ntp_control_message(&req));
328 if(!(req.op&REM_ERROR))
329 asprintf(&data, "%s%s", data, req.data);
330 } while(req.op&REM_MORE);
332 if(req.op&REM_ERROR) {
333 if(strstr(getvar, "jitter")) {
334 if(verbose) printf("The command failed. This is usually caused by servers refusing the 'jitter'\nvariable. Restarting with 'dispersion'...\n");
335 getvar = "stratum,offset,dispersion";
336 i--;
337 continue;
338 } else if(strlen(getvar)) {
339 if(verbose) printf("Server didn't like dispersion either; will retrieve everything\n");
340 getvar = "";
341 i--;
342 continue;
343 }
344 }
346 if(verbose > 1)
347 printf("Server responded: >>>%s<<<\n", data);
349 /* get the offset */
350 if(verbose)
351 printf("parsing offset from peer %.2x: ", ntohs(peers[i].assoc));
353 value = extract_value(data, "offset");
354 nptr=NULL;
355 /* Convert the value if we have one */
356 if(value != NULL)
357 tmp_offset = strtod(value, &nptr) / 1000;
358 /* If value is null or no conversion was performed */
359 if(value == NULL || value==nptr) {
360 if(verbose) printf("error: unable to read server offset response.\n");
361 } else {
362 if(verbose) printf("%.10g\n", tmp_offset);
363 if(*offset_result == STATE_UNKNOWN || fabs(tmp_offset) < fabs(*offset)) {
364 *offset = tmp_offset;
365 *offset_result = STATE_OK;
366 } else {
367 /* Skip this one; move to the next */
368 continue;
369 }
370 }
372 if(do_jitter) {
373 /* get the jitter */
374 if(verbose) {
375 printf("parsing %s from peer %.2x: ", strstr(getvar, "dispersion") != NULL ? "dispersion" : "jitter", ntohs(peers[i].assoc));
376 }
377 value = extract_value(data, strstr(getvar, "dispersion") != NULL ? "dispersion" : "jitter");
378 nptr=NULL;
379 /* Convert the value if we have one */
380 if(value != NULL)
381 *jitter = strtod(value, &nptr);
382 /* If value is null or no conversion was performed */
383 if(value == NULL || value==nptr) {
384 if(verbose) printf("error: unable to read server jitter/dispersion response.\n");
385 *jitter = -1;
386 } else if(verbose) {
387 printf("%.10g\n", *jitter);
388 }
389 }
391 if(do_stratum) {
392 /* get the stratum */
393 if(verbose) {
394 printf("parsing stratum from peer %.2x: ", ntohs(peers[i].assoc));
395 }
396 value = extract_value(data, "stratum");
397 nptr=NULL;
398 /* Convert the value if we have one */
399 if(value != NULL)
400 *stratum = strtol(value, &nptr, 10);
401 if(value == NULL || value==nptr) {
402 if(verbose) printf("error: unable to read server stratum response.\n");
403 *stratum = -1;
404 } else {
405 if(verbose) printf("%i\n", *stratum);
406 }
407 }
408 } /* if (PEER_SEL(peers[i].status) >= min_peer_sel) */
409 } /* for (i = 0; i < npeers; i++) */
411 close(conn);
412 if(peers!=NULL) free(peers);
414 return status;
415 }
417 int process_arguments(int argc, char **argv){
418 int c;
419 int option=0;
420 static struct option longopts[] = {
421 {"version", no_argument, 0, 'V'},
422 {"help", no_argument, 0, 'h'},
423 {"verbose", no_argument, 0, 'v'},
424 {"use-ipv4", no_argument, 0, '4'},
425 {"use-ipv6", no_argument, 0, '6'},
426 {"quiet", no_argument, 0, 'q'},
427 {"warning", required_argument, 0, 'w'},
428 {"critical", required_argument, 0, 'c'},
429 {"swarn", required_argument, 0, 'W'},
430 {"scrit", required_argument, 0, 'C'},
431 {"jwarn", required_argument, 0, 'j'},
432 {"jcrit", required_argument, 0, 'k'},
433 {"timeout", required_argument, 0, 't'},
434 {"hostname", required_argument, 0, 'H'},
435 {0, 0, 0, 0}
436 };
439 if (argc < 2)
440 usage ("\n");
442 while (1) {
443 c = getopt_long (argc, argv, "Vhv46qw:c:W:C:j:k:t:H:", longopts, &option);
444 if (c == -1 || c == EOF || c == 1)
445 break;
447 switch (c) {
448 case 'h':
449 print_help();
450 exit(STATE_OK);
451 break;
452 case 'V':
453 print_revision(progname, revision);
454 exit(STATE_OK);
455 break;
456 case 'v':
457 verbose++;
458 break;
459 case 'q':
460 quiet = 1;
461 break;
462 case 'w':
463 do_offset=1;
464 owarn = optarg;
465 break;
466 case 'c':
467 do_offset=1;
468 ocrit = optarg;
469 break;
470 case 'W':
471 do_stratum=1;
472 swarn = optarg;
473 break;
474 case 'C':
475 do_stratum=1;
476 scrit = optarg;
477 break;
478 case 'j':
479 do_jitter=1;
480 jwarn = optarg;
481 break;
482 case 'k':
483 do_jitter=1;
484 jcrit = optarg;
485 break;
486 case 'H':
487 if(is_host(optarg) == FALSE)
488 usage2(_("Invalid hostname/address"), optarg);
489 server_address = strdup(optarg);
490 break;
491 case 't':
492 socket_timeout=atoi(optarg);
493 break;
494 case '4':
495 address_family = AF_INET;
496 break;
497 case '6':
498 #ifdef USE_IPV6
499 address_family = AF_INET6;
500 #else
501 usage4 (_("IPv6 support not available"));
502 #endif
503 break;
504 case '?':
505 /* print short usage statement if args not parsable */
506 usage5 ();
507 break;
508 }
509 }
511 if(server_address == NULL){
512 usage4(_("Hostname was not supplied"));
513 }
515 return 0;
516 }
518 char *perfd_offset (double offset)
519 {
520 return fperfdata ("offset", offset, "s",
521 TRUE, offset_thresholds->warning->end,
522 TRUE, offset_thresholds->critical->end,
523 FALSE, 0, FALSE, 0);
524 }
526 char *perfd_jitter (double jitter)
527 {
528 return fperfdata ("jitter", jitter, "",
529 do_jitter, jitter_thresholds->warning->end,
530 do_jitter, jitter_thresholds->critical->end,
531 TRUE, 0, FALSE, 0);
532 }
534 char *perfd_stratum (int stratum)
535 {
536 return perfdata ("stratum", stratum, "",
537 do_stratum, (int)stratum_thresholds->warning->end,
538 do_stratum, (int)stratum_thresholds->critical->end,
539 TRUE, 0, TRUE, 16);
540 }
542 int main(int argc, char *argv[]){
543 int result, offset_result, stratum;
544 double offset=0, jitter=0;
545 char *result_line, *perfdata_line;
547 if (process_arguments (argc, argv) == ERROR)
548 usage4 (_("Could not parse arguments"));
550 set_thresholds(&offset_thresholds, owarn, ocrit);
551 set_thresholds(&jitter_thresholds, jwarn, jcrit);
552 set_thresholds(&stratum_thresholds, swarn, scrit);
554 /* initialize alarm signal handling */
555 signal (SIGALRM, socket_timeout_alarm_handler);
557 /* set socket timeout */
558 alarm (socket_timeout);
560 /* This returns either OK or WARNING (See comment preceeding ntp_request) */
561 result = ntp_request(server_address, &offset, &offset_result, &jitter, &stratum);
563 if(offset_result == STATE_UNKNOWN) {
564 /* if there's no sync peer (this overrides ntp_request output): */
565 result = (quiet == 1 ? STATE_UNKNOWN : STATE_CRITICAL);
566 } else {
567 /* Be quiet if there's no candidates either */
568 if (quiet == 1 && result == STATE_WARNING)
569 result = STATE_UNKNOWN;
570 result = max_state_alt(result, get_status(fabs(offset), offset_thresholds));
571 }
573 if(do_stratum)
574 result = max_state_alt(result, get_status(stratum, stratum_thresholds));
576 if(do_jitter)
577 result = max_state_alt(result, get_status(jitter, jitter_thresholds));
579 switch (result) {
580 case STATE_CRITICAL :
581 asprintf(&result_line, _("NTP CRITICAL:"));
582 break;
583 case STATE_WARNING :
584 asprintf(&result_line, _("NTP WARNING:"));
585 break;
586 case STATE_OK :
587 asprintf(&result_line, _("NTP OK:"));
588 break;
589 default :
590 asprintf(&result_line, _("NTP UNKNOWN:"));
591 break;
592 }
593 if(!syncsource_found)
594 asprintf(&result_line, "%s %s,", result_line, _("Server not synchronized"));
596 if(offset_result == STATE_UNKNOWN){
597 asprintf(&result_line, "%s %s", result_line, _("Offset unknown"));
598 asprintf(&perfdata_line, "");
599 } else {
600 asprintf(&result_line, "%s %s %.10g secs", result_line, _("Offset"), offset);
601 asprintf(&perfdata_line, "%s", perfd_offset(offset));
602 }
603 if (do_jitter) {
604 asprintf(&result_line, "%s, jitter=%f", result_line, jitter);
605 asprintf(&perfdata_line, "%s %s", perfdata_line, perfd_jitter(jitter));
606 }
607 if (do_stratum) {
608 asprintf(&result_line, "%s, stratum=%i", result_line, stratum);
609 asprintf(&perfdata_line, "%s %s", perfdata_line, perfd_stratum(stratum));
610 }
611 printf("%s|%s\n", result_line, perfdata_line);
613 if(server_address!=NULL) free(server_address);
614 return result;
615 }
619 void print_help(void){
620 print_revision(progname, revision);
622 printf ("Copyright (c) 2006 Sean Finney\n");
623 printf (COPYRIGHT, copyright, email);
625 printf ("%s\n", _("This plugin checks the selected ntp server"));
627 printf ("\n\n");
629 print_usage();
630 printf (_(UT_HELP_VRSN));
631 printf (_(UT_HOST_PORT), 'p', "123");
632 printf (" %s\n", "-q, --quiet");
633 printf (" %s\n", _("Returns UNKNOWN instead of CRITICAL or WARNING if server isn't synchronized"));
634 printf (" %s\n", "-w, --warning=THRESHOLD");
635 printf (" %s\n", _("Offset to result in warning status (seconds)"));
636 printf (" %s\n", "-c, --critical=THRESHOLD");
637 printf (" %s\n", _("Offset to result in critical status (seconds)"));
638 printf (" %s\n", "-W, --warning=THRESHOLD");
639 printf (" %s\n", _("Warning threshold for stratum"));
640 printf (" %s\n", "-W, --critical=THRESHOLD");
641 printf (" %s\n", _("Critical threshold for stratum"));
642 printf (" %s\n", "-j, --warning=THRESHOLD");
643 printf (" %s\n", _("Warning threshold for jitter"));
644 printf (" %s\n", "-k, --critical=THRESHOLD");
645 printf (" %s\n", _("Critical threshold for jitter"));
646 printf (_(UT_TIMEOUT), DEFAULT_SOCKET_TIMEOUT);
647 printf (_(UT_VERBOSE));
649 printf("\n");
650 printf("%s\n", _("Notes:"));
651 printf(" %s\n", _("This plugin checks an NTP server independent of any commandline"));
652 printf(" %s\n\n", _("programs or external libraries."));
653 printf(" %s\n", _("Use this plugin to check the health of an NTP server. It supports"));
654 printf(" %s\n", _("checking the offset with the sync peer, the jitter and stratum. This"));
655 printf(" %s\n", _("plugin will not check the clock offset between the local host and NTP"));
656 printf(" %s\n\n", _("server; please use check_ntp_time for that purpose."));
658 printf(" %s\n", _("See:"));
659 printf(" %s\n", ("http://nagiosplug.sourceforge.net/developer-guidelines.html#THRESHOLDFORMAT"));
660 printf(" %s\n", _("for THRESHOLD format and examples."));
662 printf("\n");
663 printf("%s\n", _("Examples:"));
664 printf(" %s\n", _("Simple NTP server check:"));
665 printf(" %s\n", ("./check_ntp_peer -H ntpserv -w 0.5 -c 1"));
666 printf(" %s\n", _("Check jitter too, avoiding critical notifications if jitter isn't available"));
667 printf(" %s\n", _("(See Notes above for more details on thresholds formats):"));
668 printf(" %s\n", ("./check_ntp_peer -H ntpserv -w 0.5 -c 1 -j -1:100 -k -1:200"));
669 printf(" %s\n", _("Check only stratum:"));
670 printf(" %s\n", ("./check_ntp_peer -H ntpserv -W 4 -C 6"));
672 printf (_(UT_SUPPORT));
673 }
675 void
676 print_usage(void)
677 {
678 printf (_("Usage:"));
679 printf(" %s -H <host> [-w <warn>] [-c <crit>] [-W <warn>] [-C <crit>]\n", progname);
680 printf(" [-j <warn>] [-k <crit>] [-v verbose]\n");
681 }