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1/******************************************************************************
2*
3* Nagios check_ntp 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 plugin
14*
15* This plugin to check ntp servers independant of any commandline
16* programs or external libraries.
17*
18*
19* License Information:
20*
21* This program is free software; you can redistribute it and/or modify
22* it under the terms of the GNU General Public License as published by
23* the Free Software Foundation; either version 2 of the License, or
24* (at your option) any later version.
25*
26* This program is distributed in the hope that it will be useful,
27* but WITHOUT ANY WARRANTY; without even the implied warranty of
28* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
29* GNU General Public License for more details.
30*
31* You should have received a copy of the GNU General Public License
32* along with this program; if not, write to the Free Software
33* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
34
35 $Id$
36
37*****************************************************************************/
38
39const char *progname = "check_ntp";
40const char *revision = "$Revision$";
41const char *copyright = "2007";
42const char *email = "nagiosplug-devel@lists.sourceforge.net";
43
44#include "common.h"
45#include "netutils.h"
46#include "utils.h"
47
48static char *server_address=NULL;
49static int verbose=0;
50static short do_offset=0;
51static char *owarn="60";
52static char *ocrit="120";
53static short do_jitter=0;
54static char *jwarn="5000";
55static char *jcrit="10000";
56
57int process_arguments (int, char **);
58thresholds *offset_thresholds = NULL;
59thresholds *jitter_thresholds = NULL;
60void print_help (void);
61void print_usage (void);
62
63/* number of times to perform each request to get a good average. */
64#define AVG_NUM 4
65
66/* max size of control message data */
67#define MAX_CM_SIZE 468
68
69/* this structure holds everything in an ntp request/response as per rfc1305 */
70typedef struct {
71 uint8_t flags; /* byte with leapindicator,vers,mode. see macros */
72 uint8_t stratum; /* clock stratum */
73 int8_t poll; /* polling interval */
74 int8_t precision; /* precision of the local clock */
75 int32_t rtdelay; /* total rt delay, as a fixed point num. see macros */
76 uint32_t rtdisp; /* like above, but for max err to primary src */
77 uint32_t refid; /* ref clock identifier */
78 uint64_t refts; /* reference timestamp. local time local clock */
79 uint64_t origts; /* time at which request departed client */
80 uint64_t rxts; /* time at which request arrived at server */
81 uint64_t txts; /* time at which request departed server */
82} ntp_message;
83
84/* this structure holds data about results from querying offset from a peer */
85typedef struct {
86 time_t waiting; /* ts set when we started waiting for a response */
87 int num_responses; /* number of successfully recieved responses */
88 uint8_t stratum; /* copied verbatim from the ntp_message */
89 double rtdelay; /* converted from the ntp_message */
90 double rtdisp; /* converted from the ntp_message */
91 double offset[AVG_NUM]; /* offsets from each response */
92 uint8_t flags; /* byte with leapindicator,vers,mode. see macros */
93} ntp_server_results;
94
95/* this structure holds everything in an ntp control message as per rfc1305 */
96typedef struct {
97 uint8_t flags; /* byte with leapindicator,vers,mode. see macros */
98 uint8_t op; /* R,E,M bits and Opcode */
99 uint16_t seq; /* Packet sequence */
100 uint16_t status; /* Clock status */
101 uint16_t assoc; /* Association */
102 uint16_t offset; /* Similar to TCP sequence # */
103 uint16_t count; /* # bytes of data */
104 char data[MAX_CM_SIZE]; /* ASCII data of the request */
105 /* NB: not necessarily NULL terminated! */
106} ntp_control_message;
107
108/* this is an association/status-word pair found in control packet reponses */
109typedef struct {
110 uint16_t assoc;
111 uint16_t status;
112} ntp_assoc_status_pair;
113
114/* bits 1,2 are the leap indicator */
115#define LI_MASK 0xc0
116#define LI(x) ((x&LI_MASK)>>6)
117#define LI_SET(x,y) do{ x |= ((y<<6)&LI_MASK); }while(0)
118/* and these are the values of the leap indicator */
119#define LI_NOWARNING 0x00
120#define LI_EXTRASEC 0x01
121#define LI_MISSINGSEC 0x02
122#define LI_ALARM 0x03
123/* bits 3,4,5 are the ntp version */
124#define VN_MASK 0x38
125#define VN(x) ((x&VN_MASK)>>3)
126#define VN_SET(x,y) do{ x |= ((y<<3)&VN_MASK); }while(0)
127#define VN_RESERVED 0x02
128/* bits 6,7,8 are the ntp mode */
129#define MODE_MASK 0x07
130#define MODE(x) (x&MODE_MASK)
131#define MODE_SET(x,y) do{ x |= (y&MODE_MASK); }while(0)
132/* here are some values */
133#define MODE_CLIENT 0x03
134#define MODE_CONTROLMSG 0x06
135/* In control message, bits 8-10 are R,E,M bits */
136#define REM_MASK 0xe0
137#define REM_RESP 0x80
138#define REM_ERROR 0x40
139#define REM_MORE 0x20
140/* In control message, bits 11 - 15 are opcode */
141#define OP_MASK 0x1f
142#define OP_SET(x,y) do{ x |= (y&OP_MASK); }while(0)
143#define OP_READSTAT 0x01
144#define OP_READVAR 0x02
145/* In peer status bytes, bits 6,7,8 determine clock selection status */
146#define PEER_SEL(x) ((ntohs(x)>>8)&0x07)
147#define PEER_INCLUDED 0x04
148#define PEER_SYNCSOURCE 0x06
149
150/**
151 ** a note about the 32-bit "fixed point" numbers:
152 **
153 they are divided into halves, each being a 16-bit int in network byte order:
154 - the first 16 bits are an int on the left side of a decimal point.
155 - the second 16 bits represent a fraction n/(2^16)
156 likewise for the 64-bit "fixed point" numbers with everything doubled :)
157 **/
158
159/* macros to access the left/right 16 bits of a 32-bit ntp "fixed point"
160 number. note that these can be used as lvalues too */
161#define L16(x) (((uint16_t*)&x)[0])
162#define R16(x) (((uint16_t*)&x)[1])
163/* macros to access the left/right 32 bits of a 64-bit ntp "fixed point"
164 number. these too can be used as lvalues */
165#define L32(x) (((uint32_t*)&x)[0])
166#define R32(x) (((uint32_t*)&x)[1])
167
168/* ntp wants seconds since 1/1/00, epoch is 1/1/70. this is the difference */
169#define EPOCHDIFF 0x83aa7e80UL
170
171/* extract a 32-bit ntp fixed point number into a double */
172#define NTP32asDOUBLE(x) (ntohs(L16(x)) + (double)ntohs(R16(x))/65536.0)
173
174/* likewise for a 64-bit ntp fp number */
175#define NTP64asDOUBLE(n) (double)(((uint64_t)n)?\
176 (ntohl(L32(n))-EPOCHDIFF) + \
177 (.00000001*(0.5+(double)(ntohl(R32(n))/42.94967296))):\
178 0)
179
180/* convert a struct timeval to a double */
181#define TVasDOUBLE(x) (double)(x.tv_sec+(0.000001*x.tv_usec))
182
183/* convert an ntp 64-bit fp number to a struct timeval */
184#define NTP64toTV(n,t) \
185 do{ if(!n) t.tv_sec = t.tv_usec = 0; \
186 else { \
187 t.tv_sec=ntohl(L32(n))-EPOCHDIFF; \
188 t.tv_usec=(int)(0.5+(double)(ntohl(R32(n))/4294.967296)); \
189 } \
190 }while(0)
191
192/* convert a struct timeval to an ntp 64-bit fp number */
193#define TVtoNTP64(t,n) \
194 do{ if(!t.tv_usec && !t.tv_sec) n=0x0UL; \
195 else { \
196 L32(n)=htonl(t.tv_sec + EPOCHDIFF); \
197 R32(n)=htonl((uint64_t)((4294.967296*t.tv_usec)+.5)); \
198 } \
199 } while(0)
200
201/* NTP control message header is 12 bytes, plus any data in the data
202 * field, plus null padding to the nearest 32-bit boundary per rfc.
203 */
204#define SIZEOF_NTPCM(m) (12+ntohs(m.count)+((m.count)?4-(ntohs(m.count)%4):0))
205
206/* finally, a little helper or two for debugging: */
207#define DBG(x) do{if(verbose>1){ x; }}while(0);
208#define PRINTSOCKADDR(x) \
209 do{ \
210 printf("%u.%u.%u.%u", (x>>24)&0xff, (x>>16)&0xff, (x>>8)&0xff, x&0xff);\
211 }while(0);
212
213/* calculate the offset of the local clock */
214static inline double calc_offset(const ntp_message *m, const struct timeval *t){
215 double client_tx, peer_rx, peer_tx, client_rx;
216 client_tx = NTP64asDOUBLE(m->origts);
217 peer_rx = NTP64asDOUBLE(m->rxts);
218 peer_tx = NTP64asDOUBLE(m->txts);
219 client_rx=TVasDOUBLE((*t));
220 return (.5*((peer_tx-client_rx)+(peer_rx-client_tx)));
221}
222
223/* print out a ntp packet in human readable/debuggable format */
224void print_ntp_message(const ntp_message *p){
225 struct timeval ref, orig, rx, tx;
226
227 NTP64toTV(p->refts,ref);
228 NTP64toTV(p->origts,orig);
229 NTP64toTV(p->rxts,rx);
230 NTP64toTV(p->txts,tx);
231
232 printf("packet contents:\n");
233 printf("\tflags: 0x%.2x\n", p->flags);
234 printf("\t li=%d (0x%.2x)\n", LI(p->flags), p->flags&LI_MASK);
235 printf("\t vn=%d (0x%.2x)\n", VN(p->flags), p->flags&VN_MASK);
236 printf("\t mode=%d (0x%.2x)\n", MODE(p->flags), p->flags&MODE_MASK);
237 printf("\tstratum = %d\n", p->stratum);
238 printf("\tpoll = %g\n", pow(2, p->poll));
239 printf("\tprecision = %g\n", pow(2, p->precision));
240 printf("\trtdelay = %-.16g\n", NTP32asDOUBLE(p->rtdelay));
241 printf("\trtdisp = %-.16g\n", NTP32asDOUBLE(p->rtdisp));
242 printf("\trefid = %x\n", p->refid);
243 printf("\trefts = %-.16g\n", NTP64asDOUBLE(p->refts));
244 printf("\torigts = %-.16g\n", NTP64asDOUBLE(p->origts));
245 printf("\trxts = %-.16g\n", NTP64asDOUBLE(p->rxts));
246 printf("\ttxts = %-.16g\n", NTP64asDOUBLE(p->txts));
247}
248
249void print_ntp_control_message(const ntp_control_message *p){
250 int i=0, numpeers=0;
251 const ntp_assoc_status_pair *peer=NULL;
252
253 printf("control packet contents:\n");
254 printf("\tflags: 0x%.2x , 0x%.2x\n", p->flags, p->op);
255 printf("\t li=%d (0x%.2x)\n", LI(p->flags), p->flags&LI_MASK);
256 printf("\t vn=%d (0x%.2x)\n", VN(p->flags), p->flags&VN_MASK);
257 printf("\t mode=%d (0x%.2x)\n", MODE(p->flags), p->flags&MODE_MASK);
258 printf("\t response=%d (0x%.2x)\n", (p->op&REM_RESP)>0, p->op&REM_RESP);
259 printf("\t more=%d (0x%.2x)\n", (p->op&REM_MORE)>0, p->op&REM_MORE);
260 printf("\t error=%d (0x%.2x)\n", (p->op&REM_ERROR)>0, p->op&REM_ERROR);
261 printf("\t op=%d (0x%.2x)\n", p->op&OP_MASK, p->op&OP_MASK);
262 printf("\tsequence: %d (0x%.2x)\n", ntohs(p->seq), ntohs(p->seq));
263 printf("\tstatus: %d (0x%.2x)\n", ntohs(p->status), ntohs(p->status));
264 printf("\tassoc: %d (0x%.2x)\n", ntohs(p->assoc), ntohs(p->assoc));
265 printf("\toffset: %d (0x%.2x)\n", ntohs(p->offset), ntohs(p->offset));
266 printf("\tcount: %d (0x%.2x)\n", ntohs(p->count), ntohs(p->count));
267 numpeers=ntohs(p->count)/(sizeof(ntp_assoc_status_pair));
268 if(p->op&REM_RESP && p->op&OP_READSTAT){
269 peer=(ntp_assoc_status_pair*)p->data;
270 for(i=0;i<numpeers;i++){
271 printf("\tpeer id %.2x status %.2x",
272 ntohs(peer[i].assoc), ntohs(peer[i].status));
273 if (PEER_SEL(peer[i].status) >= PEER_INCLUDED){
274 if(PEER_SEL(peer[i].status) >= PEER_SYNCSOURCE){
275 printf(" <-- current sync source");
276 } else {
277 printf(" <-- current sync candidate");
278 }
279 }
280 printf("\n");
281 }
282 }
283}
284
285void setup_request(ntp_message *p){
286 struct timeval t;
287
288 memset(p, 0, sizeof(ntp_message));
289 LI_SET(p->flags, LI_ALARM);
290 VN_SET(p->flags, 4);
291 MODE_SET(p->flags, MODE_CLIENT);
292 p->poll=4;
293 p->precision=(int8_t)0xfa;
294 L16(p->rtdelay)=htons(1);
295 L16(p->rtdisp)=htons(1);
296
297 gettimeofday(&t, NULL);
298 TVtoNTP64(t,p->txts);
299}
300
301/* select the "best" server from a list of servers, and return its index.
302 * this is done by filtering servers based on stratum, dispersion, and
303 * finally round-trip delay. */
304int best_offset_server(const ntp_server_results *slist, int nservers){
305 int i=0, j=0, cserver=0, candidates[5], csize=0;
306
307 /* for each server */
308 for(cserver=0; cserver<nservers; cserver++){
309 /* sort out servers with error flags */
310 if ( LI(slist[cserver].flags) != LI_NOWARNING ){
311 if (verbose) printf("discarding peer id %d: flags=%d\n", cserver, LI(slist[cserver].flags));
312 break;
313 }
314
315 /* compare it to each of the servers already in the candidate list */
316 for(i=0; i<csize; i++){
317 /* does it have an equal or better stratum? */
318 if(slist[cserver].stratum <= slist[i].stratum){
319 /* does it have an equal or better dispersion? */
320 if(slist[cserver].rtdisp <= slist[i].rtdisp){
321 /* does it have a better rtdelay? */
322 if(slist[cserver].rtdelay < slist[i].rtdelay){
323 break;
324 }
325 }
326 }
327 }
328
329 /* if we haven't reached the current list's end, move everyone
330 * over one to the right, and insert the new candidate */
331 if(i<csize){
332 for(j=5; j>i; j--){
333 candidates[j]=candidates[j-1];
334 }
335 }
336 /* regardless, if they should be on the list... */
337 if(i<5) {
338 candidates[i]=cserver;
339 if(csize<5) csize++;
340 /* otherwise discard the server */
341 } else {
342 DBG(printf("discarding peer id %d\n", cserver));
343 }
344 }
345
346 if(csize>0) {
347 DBG(printf("best server selected: peer %d\n", candidates[0]));
348 return candidates[0];
349 } else {
350 DBG(printf("no peers meeting synchronization criteria :(\n"));
351 return -1;
352 }
353}
354
355/* do everything we need to get the total average offset
356 * - we use a certain amount of parallelization with poll() to ensure
357 * we don't waste time sitting around waiting for single packets.
358 * - we also "manually" handle resolving host names and connecting, because
359 * we have to do it in a way that our lazy macros don't handle currently :( */
360double offset_request(const char *host, int *status){
361 int i=0, j=0, ga_result=0, num_hosts=0, *socklist=NULL, respnum=0;
362 int servers_completed=0, one_written=0, one_read=0, servers_readable=0, best_index=-1;
363 time_t now_time=0, start_ts=0;
364 ntp_message *req=NULL;
365 double avg_offset=0.;
366 struct timeval recv_time;
367 struct addrinfo *ai=NULL, *ai_tmp=NULL, hints;
368 struct pollfd *ufds=NULL;
369 ntp_server_results *servers=NULL;
370
371 /* setup hints to only return results from getaddrinfo that we'd like */
372 memset(&hints, 0, sizeof(struct addrinfo));
373 hints.ai_family = address_family;
374 hints.ai_protocol = IPPROTO_UDP;
375 hints.ai_socktype = SOCK_DGRAM;
376
377 /* fill in ai with the list of hosts resolved by the host name */
378 ga_result = getaddrinfo(host, "123", &hints, &ai);
379 if(ga_result!=0){
380 die(STATE_UNKNOWN, "error getting address for %s: %s\n",
381 host, gai_strerror(ga_result));
382 }
383
384 /* count the number of returned hosts, and allocate stuff accordingly */
385 for(ai_tmp=ai; ai_tmp!=NULL; ai_tmp=ai_tmp->ai_next){ num_hosts++; }
386 req=(ntp_message*)malloc(sizeof(ntp_message)*num_hosts);
387 if(req==NULL) die(STATE_UNKNOWN, "can not allocate ntp message array");
388 socklist=(int*)malloc(sizeof(int)*num_hosts);
389 if(socklist==NULL) die(STATE_UNKNOWN, "can not allocate socket array");
390 ufds=(struct pollfd*)malloc(sizeof(struct pollfd)*num_hosts);
391 if(ufds==NULL) die(STATE_UNKNOWN, "can not allocate socket array");
392 servers=(ntp_server_results*)malloc(sizeof(ntp_server_results)*num_hosts);
393 if(servers==NULL) die(STATE_UNKNOWN, "can not allocate server array");
394 memset(servers, 0, sizeof(ntp_server_results)*num_hosts);
395
396 /* setup each socket for writing, and the corresponding struct pollfd */
397 ai_tmp=ai;
398 for(i=0;ai_tmp;i++){
399 socklist[i]=socket(ai_tmp->ai_family, SOCK_DGRAM, IPPROTO_UDP);
400 if(socklist[i] == -1) {
401 perror(NULL);
402 die(STATE_UNKNOWN, "can not create new socket");
403 }
404 if(connect(socklist[i], ai_tmp->ai_addr, ai_tmp->ai_addrlen)){
405 die(STATE_UNKNOWN, "can't create socket connection");
406 } else {
407 ufds[i].fd=socklist[i];
408 ufds[i].events=POLLIN;
409 ufds[i].revents=0;
410 }
411 ai_tmp = ai_tmp->ai_next;
412 }
413
414 /* now do AVG_NUM checks to each host. we stop before timeout/2 seconds
415 * have passed in order to ensure post-processing and jitter time. */
416 now_time=start_ts=time(NULL);
417 while(servers_completed<num_hosts && now_time-start_ts <= socket_timeout/2){
418 /* loop through each server and find each one which hasn't
419 * been touched in the past second or so and is still lacking
420 * some responses. for each of these servers, send a new request,
421 * and update the "waiting" timestamp with the current time. */
422 one_written=0;
423 now_time=time(NULL);
424
425 for(i=0; i<num_hosts; i++){
426 if(servers[i].waiting<now_time && servers[i].num_responses<AVG_NUM){
427 if(verbose && servers[i].waiting != 0) printf("re-");
428 if(verbose) printf("sending request to peer %d\n", i);
429 setup_request(&req[i]);
430 write(socklist[i], &req[i], sizeof(ntp_message));
431 servers[i].waiting=now_time;
432 one_written=1;
433 break;
434 }
435 }
436
437 /* quickly poll for any sockets with pending data */
438 servers_readable=poll(ufds, num_hosts, 100);
439 if(servers_readable==-1){
440 perror("polling ntp sockets");
441 die(STATE_UNKNOWN, "communication errors");
442 }
443
444 /* read from any sockets with pending data */
445 for(i=0; servers_readable && i<num_hosts; i++){
446 if(ufds[i].revents&POLLIN && servers[i].num_responses < AVG_NUM){
447 if(verbose) {
448 printf("response from peer %d: ", i);
449 }
450
451 read(ufds[i].fd, &req[i], sizeof(ntp_message));
452 gettimeofday(&recv_time, NULL);
453 DBG(print_ntp_message(&req[i]));
454 respnum=servers[i].num_responses++;
455 servers[i].offset[respnum]=calc_offset(&req[i], &recv_time);
456 if(verbose) {
457 printf("offset %.10g\n", servers[i].offset[respnum]);
458 }
459 servers[i].stratum=req[i].stratum;
460 servers[i].rtdisp=NTP32asDOUBLE(req[i].rtdisp);
461 servers[i].rtdelay=NTP32asDOUBLE(req[i].rtdelay);
462 servers[i].waiting=0;
463 servers[i].flags=req[i].flags;
464 servers_readable--;
465 one_read = 1;
466 if(servers[i].num_responses==AVG_NUM) servers_completed++;
467 }
468 }
469 /* lather, rinse, repeat. */
470 }
471
472 if (one_read == 0) {
473 die(STATE_CRITICAL, "NTP CRITICAL: No response from NTP server\n");
474 }
475
476 /* now, pick the best server from the list */
477 best_index=best_offset_server(servers, num_hosts);
478 if(best_index < 0){
479 *status=STATE_UNKNOWN;
480 } else {
481 /* finally, calculate the average offset */
482 for(i=0; i<servers[best_index].num_responses;i++){
483 avg_offset+=servers[best_index].offset[j];
484 }
485 avg_offset/=servers[best_index].num_responses;
486 }
487
488 /* cleanup */
489 /* FIXME: Not closing the socket to avoid re-use of the local port
490 * which can cause old NTP packets to be read instead of NTP control
491 * pactets in jitter_request(). THERE MUST BE ANOTHER WAY...
492 * for(j=0; j<num_hosts; j++){ close(socklist[j]); } */
493 free(socklist);
494 free(ufds);
495 free(servers);
496 free(req);
497 freeaddrinfo(ai);
498
499 if(verbose) printf("overall average offset: %.10g\n", avg_offset);
500 return avg_offset;
501}
502
503void
504setup_control_request(ntp_control_message *p, uint8_t opcode, uint16_t seq){
505 memset(p, 0, sizeof(ntp_control_message));
506 LI_SET(p->flags, LI_NOWARNING);
507 VN_SET(p->flags, VN_RESERVED);
508 MODE_SET(p->flags, MODE_CONTROLMSG);
509 OP_SET(p->op, opcode);
510 p->seq = htons(seq);
511 /* Remaining fields are zero for requests */
512}
513
514/* XXX handle responses with the error bit set */
515double jitter_request(const char *host, int *status){
516 int conn=-1, i, npeers=0, num_candidates=0, syncsource_found=0;
517 int run=0, min_peer_sel=PEER_INCLUDED, num_selected=0, num_valid=0;
518 int peers_size=0, peer_offset=0;
519 ntp_assoc_status_pair *peers=NULL;
520 ntp_control_message req;
521 const char *getvar = "jitter";
522 double rval = 0.0, jitter = -1.0;
523 char *startofvalue=NULL, *nptr=NULL;
524 void *tmp;
525
526 /* Long-winded explanation:
527 * Getting the jitter requires a number of steps:
528 * 1) Send a READSTAT request.
529 * 2) Interpret the READSTAT reply
530 * a) The data section contains a list of peer identifiers (16 bits)
531 * and associated status words (16 bits)
532 * b) We want the value of 0x06 in the SEL (peer selection) value,
533 * which means "current synchronizatin source". If that's missing,
534 * we take anything better than 0x04 (see the rfc for details) but
535 * set a minimum of warning.
536 * 3) Send a READVAR request for information on each peer identified
537 * in 2b greater than the minimum selection value.
538 * 4) Extract the jitter value from the data[] (it's ASCII)
539 */
540 my_udp_connect(server_address, 123, &conn);
541
542 /* keep sending requests until the server stops setting the
543 * REM_MORE bit, though usually this is only 1 packet. */
544 do{
545 setup_control_request(&req, OP_READSTAT, 1);
546 DBG(printf("sending READSTAT request"));
547 write(conn, &req, SIZEOF_NTPCM(req));
548 DBG(print_ntp_control_message(&req));
549 /* Attempt to read the largest size packet possible */
550 req.count=htons(MAX_CM_SIZE);
551 DBG(printf("recieving READSTAT response"))
552 read(conn, &req, SIZEOF_NTPCM(req));
553 DBG(print_ntp_control_message(&req));
554 /* Each peer identifier is 4 bytes in the data section, which
555 * we represent as a ntp_assoc_status_pair datatype.
556 */
557 peers_size+=ntohs(req.count);
558 if((tmp=realloc(peers, peers_size)) == NULL)
559 free(peers), die(STATE_UNKNOWN, "can not (re)allocate 'peers' buffer\n");
560 peers=tmp;
561 memcpy((void*)((ptrdiff_t)peers+peer_offset), (void*)req.data, ntohs(req.count));
562 npeers=peers_size/sizeof(ntp_assoc_status_pair);
563 peer_offset+=ntohs(req.count);
564 } while(req.op&REM_MORE);
565
566 /* first, let's find out if we have a sync source, or if there are
567 * at least some candidates. in the case of the latter we'll issue
568 * a warning but go ahead with the check on them. */
569 for (i = 0; i < npeers; i++){
570 if (PEER_SEL(peers[i].status) >= PEER_INCLUDED){
571 num_candidates++;
572 if(PEER_SEL(peers[i].status) >= PEER_SYNCSOURCE){
573 syncsource_found=1;
574 min_peer_sel=PEER_SYNCSOURCE;
575 }
576 }
577 }
578 if(verbose) printf("%d candiate peers available\n", num_candidates);
579 if(verbose && syncsource_found) printf("synchronization source found\n");
580 if(! syncsource_found){
581 *status = STATE_UNKNOWN;
582 if(verbose) printf("warning: no synchronization source found\n");
583 }
584
585
586 for (run=0; run<AVG_NUM; run++){
587 if(verbose) printf("jitter run %d of %d\n", run+1, AVG_NUM);
588 for (i = 0; i < npeers; i++){
589 /* Only query this server if it is the current sync source */
590 if (PEER_SEL(peers[i].status) >= min_peer_sel){
591 num_selected++;
592 setup_control_request(&req, OP_READVAR, 2);
593 req.assoc = peers[i].assoc;
594 /* By spec, putting the variable name "jitter" in the request
595 * should cause the server to provide _only_ the jitter value.
596 * thus reducing net traffic, guaranteeing us only a single
597 * datagram in reply, and making intepretation much simpler
598 */
599 /* Older servers doesn't know what jitter is, so if we get an
600 * error on the first pass we redo it with "dispersion" */
601 strncpy(req.data, getvar, MAX_CM_SIZE-1);
602 req.count = htons(strlen(getvar));
603 DBG(printf("sending READVAR request...\n"));
604 write(conn, &req, SIZEOF_NTPCM(req));
605 DBG(print_ntp_control_message(&req));
606
607 req.count = htons(MAX_CM_SIZE);
608 DBG(printf("recieving READVAR response...\n"));
609 read(conn, &req, SIZEOF_NTPCM(req));
610 DBG(print_ntp_control_message(&req));
611
612 if(req.op&REM_ERROR && strstr(getvar, "jitter")) {
613 if(verbose) printf("The 'jitter' command failed (old ntp server?)\nRestarting with 'dispersion'...\n");
614 getvar = "dispersion";
615 num_selected--;
616 i--;
617 continue;
618 }
619
620 /* get to the float value */
621 if(verbose) {
622 printf("parsing jitter from peer %.2x: ", ntohs(peers[i].assoc));
623 }
624 startofvalue = strchr(req.data, '=');
625 if(startofvalue != NULL) {
626 startofvalue++;
627 jitter = strtod(startofvalue, &nptr);
628 }
629 if(startofvalue == NULL || startofvalue==nptr){
630 printf("warning: unable to read server jitter response.\n");
631 *status = STATE_UNKNOWN;
632 } else {
633 if(verbose) printf("%g\n", jitter);
634 num_valid++;
635 rval += jitter;
636 }
637 }
638 }
639 if(verbose){
640 printf("jitter parsed from %d/%d peers\n", num_valid, num_selected);
641 }
642 }
643
644 rval = num_valid ? rval / num_valid : -1.0;
645
646 close(conn);
647 if(peers!=NULL) free(peers);
648 /* If we return -1.0, it means no synchronization source was found */
649 return rval;
650}
651
652int process_arguments(int argc, char **argv){
653 int c;
654 int option=0;
655 static struct option longopts[] = {
656 {"version", no_argument, 0, 'V'},
657 {"help", no_argument, 0, 'h'},
658 {"verbose", no_argument, 0, 'v'},
659 {"use-ipv4", no_argument, 0, '4'},
660 {"use-ipv6", no_argument, 0, '6'},
661 {"warning", required_argument, 0, 'w'},
662 {"critical", required_argument, 0, 'c'},
663 {"jwarn", required_argument, 0, 'j'},
664 {"jcrit", required_argument, 0, 'k'},
665 {"timeout", required_argument, 0, 't'},
666 {"hostname", required_argument, 0, 'H'},
667 {0, 0, 0, 0}
668 };
669
670
671 if (argc < 2)
672 usage ("\n");
673
674 while (1) {
675 c = getopt_long (argc, argv, "Vhv46w:c:j:k:t:H:", longopts, &option);
676 if (c == -1 || c == EOF || c == 1)
677 break;
678
679 switch (c) {
680 case 'h':
681 print_help();
682 exit(STATE_OK);
683 break;
684 case 'V':
685 print_revision(progname, revision);
686 exit(STATE_OK);
687 break;
688 case 'v':
689 verbose++;
690 break;
691 case 'w':
692 do_offset=1;
693 owarn = optarg;
694 break;
695 case 'c':
696 do_offset=1;
697 ocrit = optarg;
698 break;
699 case 'j':
700 do_jitter=1;
701 jwarn = optarg;
702 break;
703 case 'k':
704 do_jitter=1;
705 jcrit = optarg;
706 break;
707 case 'H':
708 if(is_host(optarg) == FALSE)
709 usage2(_("Invalid hostname/address"), optarg);
710 server_address = strdup(optarg);
711 break;
712 case 't':
713 socket_timeout=atoi(optarg);
714 break;
715 case '4':
716 address_family = AF_INET;
717 break;
718 case '6':
719#ifdef USE_IPV6
720 address_family = AF_INET6;
721#else
722 usage4 (_("IPv6 support not available"));
723#endif
724 break;
725 case '?':
726 /* print short usage statement if args not parsable */
727 usage5 ();
728 break;
729 }
730 }
731
732 if(server_address == NULL){
733 usage4(_("Hostname was not supplied"));
734 }
735
736 return 0;
737}
738
739char *perfd_offset (double offset)
740{
741 return fperfdata ("offset", offset, "s",
742 TRUE, offset_thresholds->warning->end,
743 TRUE, offset_thresholds->critical->end,
744 FALSE, 0, FALSE, 0);
745}
746
747char *perfd_jitter (double jitter)
748{
749 return fperfdata ("jitter", jitter, "s",
750 do_jitter, jitter_thresholds->warning->end,
751 do_jitter, jitter_thresholds->critical->end,
752 TRUE, 0, FALSE, 0);
753}
754
755int main(int argc, char *argv[]){
756 int result, offset_result, jitter_result;
757 double offset=0, jitter=0;
758 char *result_line, *perfdata_line;
759
760 result = offset_result = jitter_result = STATE_OK;
761
762 if (process_arguments (argc, argv) == ERROR)
763 usage4 (_("Could not parse arguments"));
764
765 set_thresholds(&offset_thresholds, owarn, ocrit);
766 set_thresholds(&jitter_thresholds, jwarn, jcrit);
767
768 /* initialize alarm signal handling */
769 signal (SIGALRM, socket_timeout_alarm_handler);
770
771 /* set socket timeout */
772 alarm (socket_timeout);
773
774 offset = offset_request(server_address, &offset_result);
775 /* check_ntp used to always return CRITICAL if offset_result == STATE_UNKNOWN.
776 * Now we'll only do that is the offset thresholds were set */
777 if (do_offset && offset_result == STATE_UNKNOWN) {
778 result = STATE_CRITICAL;
779 } else {
780 result = get_status(fabs(offset), offset_thresholds);
781 }
782
783 /* If not told to check the jitter, we don't even send packets.
784 * jitter is checked using NTP control packets, which not all
785 * servers recognize. Trying to check the jitter on OpenNTPD
786 * (for example) will result in an error
787 */
788 if(do_jitter){
789 jitter=jitter_request(server_address, &jitter_result);
790 result = max_state_alt(result, get_status(jitter, jitter_thresholds));
791 /* -1 indicates that we couldn't calculate the jitter
792 * Only overrides STATE_OK from the offset */
793 if(jitter == -1.0 && result == STATE_OK)
794 result = STATE_UNKNOWN;
795 }
796 result = max_state_alt(result, jitter_result);
797
798 switch (result) {
799 case STATE_CRITICAL :
800 asprintf(&result_line, "NTP CRITICAL:");
801 break;
802 case STATE_WARNING :
803 asprintf(&result_line, "NTP WARNING:");
804 break;
805 case STATE_OK :
806 asprintf(&result_line, "NTP OK:");
807 break;
808 default :
809 asprintf(&result_line, "NTP UNKNOWN:");
810 break;
811 }
812 if(offset_result == STATE_UNKNOWN){
813 asprintf(&result_line, "%s %s", result_line, _("Offset unknown"));
814 asprintf(&perfdata_line, "");
815 } else {
816 asprintf(&result_line, "%s Offset %.10g secs", result_line, offset);
817 asprintf(&perfdata_line, "%s", perfd_offset(offset));
818 }
819 if (do_jitter) {
820 asprintf(&result_line, "%s, jitter=%f", result_line, jitter);
821 asprintf(&perfdata_line, "%s %s", perfdata_line, perfd_jitter(jitter));
822 }
823 printf("%s|%s\n", result_line, perfdata_line);
824
825 if(server_address!=NULL) free(server_address);
826 return result;
827}
828
829
830
831void print_help(void){
832 print_revision(progname, revision);
833
834 printf ("Copyright (c) 2006 Sean Finney\n");
835 printf (COPYRIGHT, copyright, email);
836
837 printf ("%s\n", _("This plugin checks the selected ntp server"));
838
839 printf ("\n\n");
840
841 print_usage();
842 printf (_(UT_HELP_VRSN));
843 printf (_(UT_HOST_PORT), 'p', "123");
844 printf (" %s\n", "-w, --warning=THRESHOLD");
845 printf (" %s\n", _("Offset to result in warning status (seconds)"));
846 printf (" %s\n", "-c, --critical=THRESHOLD");
847 printf (" %s\n", _("Offset to result in critical status (seconds)"));
848 printf (" %s\n", "-j, --warning=THRESHOLD");
849 printf (" %s\n", _("Warning threshold for jitter"));
850 printf (" %s\n", "-k, --critical=THRESHOLD");
851 printf (" %s\n", _("Critical threshold for jitter"));
852 printf (_(UT_TIMEOUT), DEFAULT_SOCKET_TIMEOUT);
853 printf (_(UT_VERBOSE));
854
855 printf("\n");
856 printf("%s\n", _("Notes:"));
857 printf(" %s\n", _("See:"));
858 printf(" %s\n", ("http://nagiosplug.sourceforge.net/developer-guidelines.html#THRESHOLDFORMAT"));
859 printf(" %s\n", _("for THRESHOLD format and examples."));
860
861 printf("\n");
862 printf("%s\n", _("Examples:"));
863 printf(" %s\n", _("Normal offset check:"));
864 printf(" %s\n", ("./check_ntp -H ntpserv -w 0.5 -c 1"));
865 printf(" %s\n", _("Check jitter too, avoiding critical notifications if jitter isn't available"));
866 printf(" %s\n", _("(See Notes above for more details on thresholds formats):"));
867 printf(" %s\n", ("./check_ntp -H ntpserv -w 0.5 -c 1 -j -1:100 -k -1:200"));
868
869 printf (_(UT_SUPPORT));
870}
871
872void
873print_usage(void)
874{
875 printf (_("Usage:"));
876 printf(" %s -H <host> [-w <warn>] [-c <crit>] [-j <warn>] [-k <crit>] [-v verbose]\n", progname);
877}