a2b554ebb6bc0450eacd7e6c7d72165e0350ffd2
1 /**
2 * collectd - src/ntpd.c
3 * Copyright (C) 2006 Florian octo Forster
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; only version 2 of the License is applicable.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 *
18 * Authors:
19 * Florian octo Forster <octo at verplant.org>
20 **/
22 #include "collectd.h"
23 #include "common.h"
24 #include "plugin.h"
25 #include "configfile.h"
26 #include "utils_debug.h"
28 #define MODULE_NAME "ntpd"
30 #if HAVE_SYS_SOCKET_H
31 # define NTPD_HAVE_READ 1
32 #else
33 # define NTPD_HAVE_READ 0
34 #endif
36 #if HAVE_STDINT_H
37 # include <stdint.h>
38 #endif
39 #if HAVE_NETDB_H
40 # include <netdb.h>
41 #endif
42 #if HAVE_SYS_SOCKET_H
43 # include <sys/socket.h>
44 #endif
45 #if HAVE_NETINET_IN_H
46 # include <netinet/in.h>
47 #endif
48 #if HAVE_NETINET_TCP_H
49 # include <netinet/tcp.h>
50 #endif
51 #if HAVE_SYS_POLL_H
52 # include <sys/poll.h>
53 #endif
55 /* drift */
56 static char *time_offset_file = "ntpd/time_offset-%s.rrd";
57 static char *time_offset_ds_def[] =
58 {
59 "DS:ms:GAUGE:"COLLECTD_HEARTBEAT":0:100",
60 NULL
61 };
62 static int time_offset_ds_num = 1;
64 static char *frequency_offset_file = "ntpd/frequency_offset-%s.rrd";
65 static char *frequency_offset_ds_def[] =
66 {
67 "DS:ppm:GAUGE:"COLLECTD_HEARTBEAT":0:100",
68 NULL
69 };
70 static int frequency_offset_ds_num = 1;
72 #if NTPD_HAVE_READ
73 # define NTPD_DEFAULT_HOST "localhost"
74 # define NTPD_DEFAULT_PORT "123"
75 static int sock_descr = -1;
76 static char *ntpd_host = NULL;
77 static char *ntpd_port = NULL;
78 #endif
80 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
81 * The following definitions were copied from the NTPd distribution *
82 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
83 #define MAXFILENAME 128
84 #define MAXSEQ 127
85 #define MODE_PRIVATE 7
86 #define NTP_OLDVERSION ((u_char) 1) /* oldest credible version */
87 #define IMPL_XNTPD 3
88 #define FP_FRAC 65536.0
90 /* This structure is missing the message authentication code, since collectd
91 * doesn't use it. */
92 struct req_pkt
93 {
94 uint8_t rm_vn_mode;
95 uint8_t auth_seq;
96 uint8_t implementation; /* implementation number */
97 uint8_t request; /* request number */
98 uint16_t err_nitems; /* error code/number of data items */
99 uint16_t mbz_itemsize; /* item size */
100 char data[MAXFILENAME + 48]; /* data area [32 prev](176 byte max) */
101 /* struct conf_peer must fit */
102 };
103 #define REQ_LEN_NOMAC (sizeof(struct req_pkt))
105 /*
106 * A response packet. The length here is variable, this is a
107 * maximally sized one. Note that this implementation doesn't
108 * authenticate responses.
109 */
110 #define RESP_HEADER_SIZE (8)
111 #define RESP_DATA_SIZE (500)
113 struct resp_pkt
114 {
115 uint8_t rm_vn_mode; /* response, more, version, mode */
116 uint8_t auth_seq; /* key, sequence number */
117 uint8_t implementation; /* implementation number */
118 uint8_t request; /* request number */
119 uint16_t err_nitems; /* error code/number of data items */
120 uint16_t mbz_itemsize; /* item size */
121 char data[RESP_DATA_SIZE]; /* data area */
122 };
124 /*
125 * Bit setting macros for multifield items.
126 */
127 #define RESP_BIT 0x80
128 #define MORE_BIT 0x40
130 #define ISRESPONSE(rm_vn_mode) (((rm_vn_mode)&RESP_BIT)!=0)
131 #define ISMORE(rm_vn_mode) (((rm_vn_mode)&MORE_BIT)!=0)
132 #define INFO_VERSION(rm_vn_mode) ((u_char)(((rm_vn_mode)>>3)&0x7))
133 #define INFO_MODE(rm_vn_mode) ((rm_vn_mode)&0x7)
135 #define RM_VN_MODE(resp, more, version) \
136 ((u_char)(((resp)?RESP_BIT:0)\
137 |((more)?MORE_BIT:0)\
138 |((version?version:(NTP_OLDVERSION+1))<<3)\
139 |(MODE_PRIVATE)))
141 #define INFO_IS_AUTH(auth_seq) (((auth_seq) & 0x80) != 0)
142 #define INFO_SEQ(auth_seq) ((auth_seq)&0x7f)
143 #define AUTH_SEQ(auth, seq) ((u_char)((((auth)!=0)?0x80:0)|((seq)&0x7f)))
145 #define INFO_ERR(err_nitems) ((u_short)((ntohs(err_nitems)>>12)&0xf))
146 #define INFO_NITEMS(err_nitems) ((u_short)(ntohs(err_nitems)&0xfff))
147 #define ERR_NITEMS(err, nitems) (htons((u_short)((((u_short)(err)<<12)&0xf000)\
148 |((u_short)(nitems)&0xfff))))
150 #define INFO_MBZ(mbz_itemsize) ((ntohs(mbz_itemsize)>>12)&0xf)
151 #define INFO_ITEMSIZE(mbz_itemsize) ((u_short)(ntohs(mbz_itemsize)&0xfff))
152 #define MBZ_ITEMSIZE(itemsize) (htons((u_short)(itemsize)))
154 #define REQ_SYS_INFO 4
155 struct info_sys
156 {
157 uint32_t peer; /* system peer address (v4) */
158 uint8_t peer_mode; /* mode we are syncing to peer in */
159 uint8_t leap; /* system leap bits */
160 uint8_t stratum; /* our stratum */
161 int8_t precision; /* local clock precision */
162 int32_t rootdelay; /* distance from sync source */
163 uint32_t rootdispersion; /* dispersion from sync source */
164 uint32_t refid; /* reference ID of sync source */
165 uint64_t reftime; /* system reference time */
166 uint32_t poll; /* system poll interval */
167 uint8_t flags; /* system flags */
168 uint8_t unused1; /* unused */
169 uint8_t unused2; /* unused */
170 uint8_t unused3; /* unused */
171 int32_t bdelay; /* default broadcast offset */
172 int32_t frequency; /* frequency residual (scaled ppm) */
173 uint64_t authdelay; /* default authentication delay */
174 uint32_t stability; /* clock stability (scaled ppm) */
175 int32_t v6_flag; /* is this v6 or not */
176 int32_t unused4; /* unused, padding for peer6 */
177 struct in6_addr peer6; /* system peer address (v6) */
178 };
180 #define REQ_GET_KERNEL 38
181 struct info_kernel
182 {
183 int32_t offset;
184 int32_t freq;
185 int32_t maxerror;
186 int32_t esterror;
187 uint16_t status;
188 uint16_t shift;
189 int32_t constant;
190 int32_t precision;
191 int32_t tolerance;
192 /* pps stuff */
193 int32_t ppsfreq;
194 int32_t jitter;
195 int32_t stabil;
196 int32_t jitcnt;
197 int32_t calcnt;
198 int32_t errcnt;
199 int32_t stbcnt;
200 };
201 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
202 * End of the copied stuff.. *
203 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
205 static void ntpd_init (void)
206 {
207 return;
208 }
210 static void ntpd_write_time_offset (char *host, char *inst, char *val)
211 {
212 char buf[256];
213 int status;
215 status = snprintf (buf, 256, time_offset_file, inst);
216 if ((status < 1) || (status >= 256))
217 return;
219 rrd_update_file (host, buf, val,
220 time_offset_ds_def, time_offset_ds_num);
221 }
223 static void ntpd_write_frequency_offset (char *host, char *inst, char *val)
224 {
225 char buf[256];
226 int status;
228 status = snprintf (buf, 256, frequency_offset_file, inst);
229 if ((status < 1) || (status >= 256))
230 return;
232 rrd_update_file (host, buf, val,
233 frequency_offset_ds_def, frequency_offset_ds_num);
234 }
236 #if NTPD_HAVE_READ
237 static void ntpd_submit (char *type, char *inst, double value)
238 {
239 char buf[256];
241 if (snprintf (buf, 256, "%u:%.8f", (unsigned int) curtime, value) >= 256)
242 return;
244 DBG ("type = %s; inst = %s; value = %s;",
245 type, inst, buf);
247 plugin_submit (type, inst, buf);
248 }
250 /* returns `tv0 - tv1' in milliseconds or 0 if `tv1 > tv0' */
251 static int timeval_sub (const struct timeval *tv0, const struct timeval *tv1)
252 {
253 int sec;
254 int usec;
256 if ((tv0->tv_sec < tv1->tv_sec)
257 || ((tv0->tv_sec == tv1->tv_sec) && (tv0->tv_usec < tv1->tv_usec)))
258 return (0);
260 sec = tv0->tv_sec - tv1->tv_sec;
261 usec = tv0->tv_usec - tv1->tv_usec;
263 while (usec < 0)
264 {
265 usec += 1000000;
266 sec -= 1;
267 }
269 if (sec < 0)
270 return (0);
272 return ((sec * 1000) + ((usec + 500) / 1000));
273 }
275 static int ntpd_connect (void)
276 {
277 char *host;
278 char *port;
280 struct addrinfo ai_hints;
281 struct addrinfo *ai_list;
282 struct addrinfo *ai_ptr;
283 int status;
285 if (sock_descr >= 0)
286 return (sock_descr);
288 DBG ("Opening a new socket");
290 host = ntpd_host;
291 if (host == NULL)
292 host = NTPD_DEFAULT_HOST;
294 port = ntpd_port;
295 if (port == NULL)
296 port = NTPD_DEFAULT_PORT;
298 memset (&ai_hints, '\0', sizeof (ai_hints));
299 ai_hints.ai_flags = AI_ADDRCONFIG;
300 ai_hints.ai_family = PF_UNSPEC;
301 ai_hints.ai_socktype = SOCK_DGRAM;
302 ai_hints.ai_protocol = IPPROTO_UDP;
304 if ((status = getaddrinfo (host, port, &ai_hints, &ai_list)) != 0)
305 {
306 DBG ("getaddrinfo (%s, %s): %s",
307 host, port,
308 status == EAI_SYSTEM ? strerror (errno) : gai_strerror (status));
309 syslog (LOG_ERR, "ntpd plugin: getaddrinfo (%s, %s): %s",
310 host, port,
311 status == EAI_SYSTEM ? strerror (errno) : gai_strerror (status));
312 return (-1);
313 }
315 for (ai_ptr = ai_list; ai_ptr != NULL; ai_ptr = ai_ptr->ai_next)
316 {
317 /* create our socket descriptor */
318 if ((sock_descr = socket (ai_ptr->ai_family,
319 ai_ptr->ai_socktype,
320 ai_ptr->ai_protocol)) < 0)
321 continue;
323 /* connect to the ntpd */
324 if (connect (sock_descr, ai_ptr->ai_addr, ai_ptr->ai_addrlen))
325 {
326 close (sock_descr);
327 sock_descr = -1;
328 continue;
329 }
331 break;
332 }
334 freeaddrinfo (ai_list);
336 if (sock_descr < 0)
337 {
338 DBG ("Unable to connect to server.");
339 syslog (LOG_ERR, "ntpd plugin: Unable to connect to server.");
340 }
342 return (sock_descr);
343 }
345 /* For a description of the arguments see `ntpd_do_query' below. */
346 static int ntpd_receive_response (int req_code, int *res_items, int *res_size,
347 char **res_data, int res_item_size)
348 {
349 int sd;
350 struct pollfd poll_s;
351 struct resp_pkt res;
352 int status;
353 int done;
354 int i;
356 char *items;
357 size_t items_num;
359 struct timeval time_end;
360 struct timeval time_now;
361 int timeout;
363 int pkt_item_num; /* items in this packet */
364 int pkt_item_len; /* size of the items in this packet */
365 int pkt_sequence;
366 char pkt_recvd[MAXSEQ+1]; /* sequence numbers that have been received */
367 int pkt_recvd_num; /* number of packets that have been received */
368 int pkt_lastseq; /* the last sequence number */
369 ssize_t pkt_padding; /* Padding in this packet */
371 if ((sd = ntpd_connect ()) < 0)
372 return (-1);
374 items = NULL;
375 items_num = 0;
377 memset (pkt_recvd, '\0', sizeof (pkt_recvd));
378 pkt_recvd_num = 0;
379 pkt_lastseq = -1;
381 *res_items = 0;
382 *res_size = 0;
383 *res_data = NULL;
385 if (gettimeofday (&time_end, NULL) < 0)
386 {
387 syslog (LOG_ERR, "ntpd plugin: gettimeofday failed: %s",
388 strerror (errno));
389 return (-1);
390 }
391 time_end.tv_sec++; /* wait for a most one second */
393 done = 0;
394 while (done == 0)
395 {
396 if (gettimeofday (&time_now, NULL) < 0)
397 {
398 syslog (LOG_ERR, "ntpd plugin: gettimeofday failed: %s",
399 strerror (errno));
400 return (-1);
401 }
403 /* timeout reached */
404 if ((timeout = timeval_sub (&time_end, &time_now)) == 0)
405 break;
407 poll_s.fd = sd;
408 poll_s.events = POLLIN | POLLPRI;
409 poll_s.revents = 0;
411 DBG ("Polling for %ims", timeout);
412 status = poll (&poll_s, 1, timeout);
414 if ((status < 0) && ((errno == EAGAIN) || (errno == EINTR)))
415 continue;
417 if (status < 0)
418 {
419 DBG ("poll failed: %s", strerror (errno));
420 syslog (LOG_ERR, "ntpd plugin: poll failed: %s",
421 strerror (errno));
422 return (-1);
423 }
425 if (status == 0) /* timeout */
426 {
427 DBG ("timeout reached.");
428 break;
429 }
431 memset ((void *) &res, '\0', sizeof (res));
432 status = recv (sd, (void *) &res, sizeof (res), 0 /* no flags */);
434 if ((status < 0) && ((errno == EAGAIN) || (errno == EINTR)))
435 continue;
437 if (status < 0)
438 {
439 DBG ("recv(2) failed: %s", strerror (errno));
440 return (-1);
441 }
443 DBG ("recv'd %i bytes", status);
445 /*
446 * Do some sanity checks first
447 */
448 if (status < RESP_HEADER_SIZE)
449 {
450 syslog (LOG_WARNING, "ntpd plugin: Short (%i bytes) packet received",
451 (int) status);
452 continue;
453 }
454 if (INFO_MODE (res.rm_vn_mode) != MODE_PRIVATE)
455 {
456 syslog (LOG_NOTICE, "ntpd plugin: Packet received with mode %i",
457 INFO_MODE (res.rm_vn_mode));
458 continue;
459 }
460 if (INFO_IS_AUTH (res.auth_seq))
461 {
462 syslog (LOG_NOTICE, "ntpd plugin: Encrypted packet received");
463 continue;
464 }
465 if (!ISRESPONSE (res.rm_vn_mode))
466 {
467 syslog (LOG_NOTICE, "ntpd plugin: Received request packet, "
468 "wanted response");
469 continue;
470 }
471 if (INFO_MBZ (res.mbz_itemsize))
472 {
473 syslog (LOG_WARNING, "ntpd plugin: Received packet with nonzero "
474 "MBZ field!");
475 continue;
476 }
477 if (res.implementation != IMPL_XNTPD)
478 {
479 syslog (LOG_WARNING, "ntpd plugin: Asked for request of type %i, "
480 "got %i", (int) IMPL_XNTPD, (int) res.implementation);
481 continue;
482 }
484 /* Check for error code */
485 if (INFO_ERR (res.err_nitems) != 0)
486 {
487 syslog (LOG_ERR, "ntpd plugin: Received error code %i",
488 (int) INFO_ERR(res.err_nitems));
489 return ((int) INFO_ERR (res.err_nitems));
490 }
492 /* extract number of items in this packet and the size of these items */
493 pkt_item_num = INFO_NITEMS (res.err_nitems);
494 pkt_item_len = INFO_ITEMSIZE (res.mbz_itemsize);
495 DBG ("pkt_item_num = %i; pkt_item_len = %i;",
496 pkt_item_num, pkt_item_len);
498 /* Check if the reported items fit in the packet */
499 if ((pkt_item_num * pkt_item_len) > (status - RESP_HEADER_SIZE))
500 {
501 syslog (LOG_ERR, "ntpd plugin: %i items * %i bytes > "
502 "%i bytes - %i bytes header",
503 (int) pkt_item_num, (int) pkt_item_len,
504 (int) status, (int) RESP_HEADER_SIZE);
505 continue;
506 }
508 /* If this is the first packet (time wise, not sequence wise),
509 * set `res_size'. If it's not the first packet check if the
510 * items have the same size. Discard invalid packets. */
511 if (items_num == 0) /* first packet */
512 {
513 DBG ("*res_size = %i", pkt_item_len);
514 *res_size = pkt_item_len;
515 }
516 else if (*res_size != pkt_item_len)
517 {
518 DBG ("Error: *res_size = %i; pkt_item_len = %i;",
519 *res_size, pkt_item_len);
520 syslog (LOG_ERR, "Item sizes differ.");
521 continue;
522 }
524 /* Calculate the padding. No idea why there might be any padding.. */
525 pkt_padding = 0;
526 if (res_item_size > pkt_item_len)
527 pkt_padding = res_item_size - pkt_item_len;
528 DBG ("res_item_size = %i; pkt_padding = %i;",
529 res_item_size, pkt_padding);
531 /* Extract the sequence number */
532 pkt_sequence = INFO_SEQ (res.auth_seq);
533 if ((pkt_sequence < 0) || (pkt_sequence > MAXSEQ))
534 {
535 syslog (LOG_ERR, "ntpd plugin: Received packet with sequence %i",
536 pkt_sequence);
537 continue;
538 }
540 /* Check if this sequence has been received before. If so, discard it. */
541 if (pkt_recvd[pkt_sequence] != '\0')
542 {
543 syslog (LOG_NOTICE, "ntpd plugin: Sequence %i received twice",
544 pkt_sequence);
545 continue;
546 }
548 /* If `pkt_lastseq != -1' another packet without `more bit' has
549 * been received. */
550 if (!ISMORE (res.rm_vn_mode))
551 {
552 if (pkt_lastseq != -1)
553 {
554 syslog (LOG_ERR, "ntpd plugin: Two packets which both "
555 "claim to be the last one in the "
556 "sequence have been received.");
557 continue;
558 }
559 pkt_lastseq = pkt_sequence;
560 DBG ("Last sequence = %i;", pkt_lastseq);
561 }
563 /*
564 * Enough with the checks. Copy the data now.
565 * We start by allocating some more memory.
566 */
567 DBG ("realloc (%p, %i)", (void *) *res_data,
568 (items_num + pkt_item_num) * res_item_size);
569 items = realloc ((void *) *res_data,
570 (items_num + pkt_item_num) * res_item_size);
571 if (items == NULL)
572 {
573 items = *res_data;
574 syslog (LOG_ERR, "ntpd plugin: realloc failed.");
575 continue;
576 }
577 *res_data = items;
579 for (i = 0; i < pkt_item_num; i++)
580 {
581 void *dst = (void *) (*res_data + ((*res_items) * res_item_size));
582 void *src = (void *) (((char *) res.data) + (i * pkt_item_len));
584 /* Set the padding to zeros */
585 if (pkt_padding != 0)
586 memset (dst, '\0', res_item_size);
587 memcpy (dst, src, (size_t) pkt_item_len);
589 (*res_items)++;
590 }
592 pkt_recvd[pkt_sequence] = (char) 1;
593 pkt_recvd_num++;
595 if ((pkt_recvd_num - 1) == pkt_lastseq)
596 done = 1;
597 } /* while (done == 0) */
599 return (0);
600 }
602 /* For a description of the arguments see `ntpd_do_query' below. */
603 static int ntpd_send_request (int req_code, int req_items, int req_size, char *req_data)
604 {
605 int sd;
606 struct req_pkt req;
607 size_t req_data_len;
608 int status;
610 assert (req_items >= 0);
611 assert (req_size >= 0);
613 if ((sd = ntpd_connect ()) < 0)
614 return (-1);
616 memset ((void *) &req, '\0', sizeof (req));
617 req.rm_vn_mode = RM_VN_MODE(0, 0, 0);
618 req.auth_seq = AUTH_SEQ (0, 0);
619 req.implementation = IMPL_XNTPD;
620 req.request = (unsigned char) req_code;
622 req_data_len = (size_t) (req_items * req_size);
624 assert (((req_data != NULL) && (req_data_len > 0))
625 || ((req_data == NULL) && (req_items == 0) && (req_size == 0)));
627 req.err_nitems = ERR_NITEMS (0, req_items);
628 req.mbz_itemsize = MBZ_ITEMSIZE (req_size);
630 if (req_data != NULL)
631 memcpy ((void *) req.data, (const void *) req_data, req_data_len);
633 DBG ("req_items = %i; req_size = %i; req_data = %p;",
634 req_items, req_size, (void *) req_data);
636 status = swrite (sd, (const char *) &req, REQ_LEN_NOMAC);
637 if (status < 0)
638 return (status);
640 return (0);
641 }
643 /*
644 * ntpd_do_query:
645 *
646 * req_code: Type of request packet
647 * req_items: Numver of items in the request
648 * req_size: Size of one item in the request
649 * req_data: Data of the request packet
650 * res_items: Pointer to where the number returned items will be stored.
651 * res_size: Pointer to where the size of one returned item will be stored.
652 * res_data: This is where a pointer to the (allocated) data will be stored.
653 * res_item_size: Size of one returned item. (used to calculate padding)
654 *
655 * returns: zero upon success, non-zero otherwise.
656 */
657 static int ntpd_do_query (int req_code, int req_items, int req_size, char *req_data,
658 int *res_items, int *res_size, char **res_data, int res_item_size)
659 {
660 int status;
662 status = ntpd_send_request (req_code, req_items, req_size, req_data);
663 if (status != 0)
664 return (status);
666 status = ntpd_receive_response (req_code, res_items, res_size, res_data,
667 res_item_size);
668 return (status);
669 }
671 static double ntpd_read_fp (int32_t val_int)
672 {
673 double val_double;
675 val_int = ntohl (val_int);
676 val_double = ((double) val_int) / FP_FRAC;
678 return (val_double);
679 }
681 static void ntpd_read (void)
682 {
683 struct info_kernel *ik;
684 int ik_num;
685 int ik_size;
686 int status;
688 ik = NULL;
689 ik_num = 0;
690 ik_size = 0;
692 status = ntpd_do_query (REQ_GET_KERNEL,
693 0, 0, NULL, /* request data */
694 &ik_num, &ik_size, (char **) ((void *) &ik), /* response data */
695 sizeof (struct info_kernel));
697 if (status != 0)
698 {
699 DBG ("ntpd_do_query failed with status %i", status);
700 return;
701 }
702 if ((ik == NULL) || (ik_num == 0) || (ik_size == 0))
703 {
704 DBG ("ntpd_do_query returned: is = %p; ik_num = %i; ik_size = %i;",
705 (void *) ik, ik_num, ik_size);
706 return;
707 }
709 /* kerninfo -> estimated error */
711 DBG ("info_kernel:\n"
712 " pll offset = %.8f\n"
713 " pll frequency = %.8f\n" /* drift compensation */
714 " est error = %.8f\n",
715 ntpd_read_fp (ik->offset),
716 ntpd_read_fp (ik->freq),
717 ntpd_read_fp (ik->esterror));
719 ntpd_submit ("ntpd_frequency_offset", "loop", ntpd_read_fp (ik->freq));
721 free (ik);
722 ik = NULL;
724 return;
725 }
726 #else
727 # define ntpd_read NULL
728 #endif /* NTPD_HAVE_READ */
730 void module_register (void)
731 {
732 plugin_register (MODULE_NAME, ntpd_init, ntpd_read, NULL);
733 plugin_register ("ntpd_time_offset", NULL, NULL, ntpd_write_time_offset);
734 plugin_register ("ntpd_frequency_offset", NULL, NULL, ntpd_write_frequency_offset);
735 }
737 #undef MODULE_NAME