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"
27 #define MODULE_NAME "ntpd"
29 #if HAVE_SYS_SOCKET_H
30 # define NTPD_HAVE_READ 1
31 #else
32 # define NTPD_HAVE_READ 0
33 #endif
35 #if HAVE_STDINT_H
36 # include <stdint.h>
37 #endif
38 #if HAVE_NETDB_H
39 # include <netdb.h>
40 #endif
41 #if HAVE_SYS_SOCKET_H
42 # include <sys/socket.h>
43 #endif
44 #if HAVE_NETINET_IN_H
45 # include <netinet/in.h>
46 #endif
47 #if HAVE_NETINET_TCP_H
48 # include <netinet/tcp.h>
49 #endif
51 /* drift */
52 static char *time_offset_file = "ntpd/time_offset-%s.rrd";
53 static char *time_offset_ds_def[] =
54 {
55 "DS:ms:GAUGE:"COLLECTD_HEARTBEAT":0:100",
56 NULL
57 };
58 static int time_offset_ds_num = 1;
60 static char *frequency_offset_file = "ntpd/frequency_offset-%s.rrd";
61 static char *frequency_offset_ds_def[] =
62 {
63 "DS:ppm:GAUGE:"COLLECTD_HEARTBEAT":0:100",
64 NULL
65 };
66 static int frequency_offset_ds_num = 1;
68 #if NTPD_HAVE_READ
69 # define NTPD_DEFAULT_HOST "localhost"
70 # define NTPD_DEFAULT_PORT "123"
71 static int sock_descr = -1;
72 static char *ntpd_host = NULL;
73 static char *ntpd_port = NULL;
74 #endif
76 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
77 * The following definitions were copied from the NTPd distribution *
78 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
79 #define MAXFILENAME 128
80 #define MAXSEQ 127
81 #define MODE_PRIVATE 7
82 #define NTP_OLDVERSION ((u_char) 1) /* oldest credible version */
83 #define IMPL_XNTPD 3
85 /* This structure is missing the message authentication code, since collectd
86 * doesn't use it. */
87 struct req_pkt
88 {
89 uint8_t rm_vn_mode;
90 uint8_t auth_seq;
91 uint8_t implementation; /* implementation number */
92 uint8_t request; /* request number */
93 uint16_t err_nitems; /* error code/number of data items */
94 uint16_t mbz_itemsize; /* item size */
95 char data[MAXFILENAME + 48]; /* data area [32 prev](176 byte max) */
96 /* struct conf_peer must fit */
97 };
98 #define REQ_LEN_NOMAC (sizeof(struct req_pkt))
100 /*
101 * A response packet. The length here is variable, this is a
102 * maximally sized one. Note that this implementation doesn't
103 * authenticate responses.
104 */
105 #define RESP_HEADER_SIZE (8)
106 #define RESP_DATA_SIZE (500)
108 struct resp_pkt
109 {
110 uint8_t rm_vn_mode; /* response, more, version, mode */
111 uint8_t auth_seq; /* key, sequence number */
112 uint8_t implementation; /* implementation number */
113 uint8_t request; /* request number */
114 uint16_t err_nitems; /* error code/number of data items */
115 uint16_t mbz_itemsize; /* item size */
116 char data[RESP_DATA_SIZE]; /* data area */
117 };
119 /*
120 * Bit setting macros for multifield items.
121 */
122 #define RESP_BIT 0x80
123 #define MORE_BIT 0x40
125 #define ISRESPONSE(rm_vn_mode) (((rm_vn_mode)&RESP_BIT)!=0)
126 #define ISMORE(rm_vn_mode) (((rm_vn_mode)&MORE_BIT)!=0)
127 #define INFO_VERSION(rm_vn_mode) ((u_char)(((rm_vn_mode)>>3)&0x7))
128 #define INFO_MODE(rm_vn_mode) ((rm_vn_mode)&0x7)
130 #define RM_VN_MODE(resp, more, version) \
131 ((u_char)(((resp)?RESP_BIT:0)\
132 |((more)?MORE_BIT:0)\
133 |((version?version:(NTP_OLDVERSION+1))<<3)\
134 |(MODE_PRIVATE)))
136 #define INFO_IS_AUTH(auth_seq) (((auth_seq) & 0x80) != 0)
137 #define INFO_SEQ(auth_seq) ((auth_seq)&0x7f)
138 #define AUTH_SEQ(auth, seq) ((u_char)((((auth)!=0)?0x80:0)|((seq)&0x7f)))
140 #define INFO_ERR(err_nitems) ((u_short)((ntohs(err_nitems)>>12)&0xf))
141 #define INFO_NITEMS(err_nitems) ((u_short)(ntohs(err_nitems)&0xfff))
142 #define ERR_NITEMS(err, nitems) (htons((u_short)((((u_short)(err)<<12)&0xf000)\
143 |((u_short)(nitems)&0xfff))))
145 #define INFO_MBZ(mbz_itemsize) ((ntohs(mbz_itemsize)>>12)&0xf)
146 #define INFO_ITEMSIZE(mbz_itemsize) ((u_short)(ntohs(mbz_itemsize)&0xfff))
147 #define MBZ_ITEMSIZE(itemsize) (htons((u_short)(itemsize)))
149 static void ntpd_init (void)
150 {
151 return;
152 }
154 static void ntpd_write (char *host, char *inst, char *val)
155 {
156 rrd_update_file (host, time_offset_file, val,
157 time_offset_ds_def, time_offset_ds_num); /* FIXME filename incorrect */
158 }
160 #if NTPD_HAVE_READ
161 static void ntpd_submit (double snum, double mnum, double lnum)
162 {
163 char buf[256];
165 if (snprintf (buf, 256, "%u:%.2f:%.2f:%.2f", (unsigned int) curtime,
166 snum, mnum, lnum) >= 256)
167 return;
169 plugin_submit (MODULE_NAME, "-", buf);
170 }
172 static int ntpd_connect (void)
173 {
174 char *host;
175 char *port;
177 struct addrinfo ai_hints;
178 struct addrinfo *ai_list;
179 struct addrinfo *ai_ptr;
180 int status;
182 if (sock_descr >= 0)
183 return (sock_descr);
185 host = ntpd_host;
186 if (host == NULL)
187 host = NTPD_DEFAULT_HOST;
189 port = ntpd_port;
190 if (port == NULL)
191 port = NTPD_DEFAULT_PORT;
193 memset (&ai_hints, '\0', sizeof (ai_hints));
194 ai_hints.ai_flags = AI_ADDRCONFIG;
195 ai_hints.ai_family = PF_UNSPEC;
196 ai_hints.ai_socktype = SOCK_DGRAM;
197 ai_hints.ai_protocol = IPPROTO_UDP;
199 if ((status = getaddrinfo (host, port, &ai_hints, &ai_list)) != 0)
200 {
201 syslog (LOG_ERR, "ntpd plugin: getaddrinfo (%s, %s): %s",
202 host, port,
203 status == EAI_SYSTEM ? strerror (errno) : gai_strerror (status));
204 return (-1);
205 }
207 for (ai_ptr = ai_list; ai_ptr != NULL; ai_ptr = ai_ptr->ai_next)
208 {
209 /* create our socket descriptor */
210 if ((sock_descr = socket (ai_ptr->ai_family,
211 ai_ptr->ai_socktype,
212 ai_ptr->ai_protocol)) < 0)
213 continue;
215 /* connect to the ntpd */
216 if (connect (sock_descr, ai_ptr->ai_addr, ai_ptr->ai_addrlen))
217 {
218 close (sock_descr);
219 sock_descr = -1;
220 continue;
221 }
223 break;
224 }
226 freeaddrinfo (ai_list);
228 if (sock_descr < 0)
229 syslog (LOG_ERR, "ntpd plugin: Unable to connect to server.");
231 return (sock_descr);
232 }
234 /* For a description of the arguments see `ntpd_do_query' below. */
235 static int ntpd_receive_response (int req_code, int *res_items, int *res_size,
236 char **res_data, int res_item_size)
237 {
238 int sd;
239 struct resp_pkt res;
240 ssize_t status;
241 int done;
242 int i;
244 char *items;
245 size_t items_num;
247 int pkt_item_num; /* items in this packet */
248 int pkt_item_len; /* size of the items in this packet */
249 int pkt_sequence;
250 char pkt_recvd[MAXSEQ+1]; /* sequence numbers that have been received */
251 int pkt_recvd_num; /* number of packets that have been received */
252 int pkt_lastseq; /* the last sequence number */
253 ssize_t pkt_padding; /* Padding in this packet */
255 if ((sd = ntpd_connect ()) < 0)
256 return (-1);
258 items = NULL;
259 items_num = 0;
261 memset (pkt_recvd, '\0', sizeof (pkt_recvd));
262 pkt_recvd_num = 0;
263 pkt_lastseq = -1;
265 *res_items = 0;
266 *res_size = 0;
267 *res_data = NULL;
269 done = 0;
270 while (done == 0)
271 {
272 /* TODO calculate time */
273 /* TODO poll(2) */
275 memset ((void *) &res, '\0', sizeof (res));
276 status = recv (sd, (void *) &res, sizeof (res), 0 /* no flags */);
278 if ((status < 0) && ((errno == EAGAIN) || (errno == EINTR)))
279 continue;
281 if (status < 0)
282 return (-1);
284 /*
285 * Do some sanity checks first
286 */
287 if (status < RESP_HEADER_SIZE)
288 {
289 syslog (LOG_WARNING, "ntpd plugin: Short (%i bytes) packet received",
290 (int) status);
291 continue;
292 }
293 if (INFO_MODE (res.rm_vn_mode) != MODE_PRIVATE)
294 {
295 syslog (LOG_NOTICE, "ntpd plugin: Packet received with mode %i",
296 INFO_MODE (res.rm_vn_mode));
297 continue;
298 }
299 if (INFO_IS_AUTH (res.auth_seq))
300 {
301 syslog (LOG_NOTICE, "ntpd plugin: Encrypted packet received");
302 continue;
303 }
304 if (!ISRESPONSE (res.rm_vn_mode))
305 {
306 syslog (LOG_NOTICE, "ntpd plugin: Received request packet, "
307 "wanted response");
308 continue;
309 }
310 if (INFO_MBZ (res.mbz_itemsize))
311 {
312 syslog (LOG_WARNING, "ntpd plugin: Received packet with nonzero "
313 "MBZ field!");
314 continue;
315 }
316 if (res.implementation != req_code)
317 {
318 syslog (LOG_WARNING, "ntpd plugin: Asked for request of type %i, "
319 "got %i", (int) req_code, (int) res.implementation);
320 continue;
321 }
323 /* Check for error code */
324 if (INFO_ERR (res.err_nitems) != 0)
325 {
326 syslog (LOG_ERR, "ntpd plugin: Received error code %i",
327 (int) INFO_ERR(res.err_nitems));
328 return ((int) INFO_ERR (res.err_nitems));
329 }
331 /* extract number of items in this packet and the size of these items */
332 pkt_item_num = INFO_NITEMS (res.err_nitems);
333 pkt_item_len = INFO_ITEMSIZE (res.mbz_itemsize);
335 /* Check if the reported items fit in the packet */
336 if ((pkt_item_num * pkt_item_len) > (status - RESP_HEADER_SIZE))
337 {
338 syslog (LOG_ERR, "ntpd plugin: %i items * %i bytes > "
339 "%i bytes - %i bytes header",
340 (int) pkt_item_num, (int) pkt_item_len,
341 (int) status, (int) RESP_HEADER_SIZE);
342 continue;
343 }
345 /* If this is the first packet (time wise, not sequence wise),
346 * set `res_size'. If it's not the first packet check if the
347 * items have the same size. Discard invalid packets. */
348 if (items_num == 0) /* first packet */
349 {
350 *res_size = pkt_item_len;
351 }
352 else if (*res_size != pkt_item_len)
353 {
354 syslog (LOG_ERR, "Item sizes differ.");
355 continue;
356 }
358 /* Calculate the padding. No idea why there might be any padding.. */
359 pkt_padding = 0;
360 if (res_item_size > pkt_item_len)
361 pkt_padding = res_item_size - pkt_item_len;
363 /* Extract the sequence number */
364 pkt_sequence = INFO_SEQ (res.auth_seq);
365 if ((pkt_sequence < 0) || (pkt_sequence > MAXSEQ))
366 {
367 syslog (LOG_ERR, "ntpd plugin: Received packet with sequence %i",
368 pkt_sequence);
369 continue;
370 }
372 /* Check if this sequence has been received before. If so, discard it. */
373 if (pkt_recvd[pkt_sequence] != '\0')
374 {
375 syslog (LOG_NOTICE, "ntpd plugin: Sequence %i received twice",
376 pkt_sequence);
377 continue;
378 }
380 /* If `pkt_lastseq != -1' another packet without `more bit' has
381 * been received. */
382 if (!ISMORE (res.rm_vn_mode))
383 {
384 if (pkt_lastseq != -1)
385 {
386 syslog (LOG_ERR, "ntpd plugin: Two packets which both "
387 "claim to be the last one in the "
388 "sequence have been received.");
389 continue;
390 }
391 pkt_lastseq = pkt_sequence;
392 }
394 /*
395 * Enough with the checks. Copy the data now.
396 * We start by allocating some more memory.
397 */
398 items = realloc ((void *) *res_data,
399 (items_num + pkt_item_num) * res_item_size);
400 if (items == NULL)
401 {
402 items = *res_data;
403 syslog (LOG_ERR, "ntpd plugin: realloc failed.");
404 continue;
405 }
406 *res_data = items;
408 for (i = 0; i < pkt_item_num; i++)
409 {
410 void *dst = (void *) (*res_data + ((*res_items) * res_item_size));
411 void *src = (void *) (((char *) res.data) + (i * pkt_item_len));
413 /* Set the padding to zeros */
414 if (pkt_padding != 0)
415 memset (dst, '\0', res_item_size);
416 memcpy (dst, src, (size_t) pkt_item_len);
418 (*res_items)++;
419 }
421 pkt_recvd[pkt_sequence] = (char) 1;
422 pkt_recvd_num++;
424 if ((pkt_recvd_num - 1) == pkt_lastseq)
425 done = 1;
426 } /* while (done == 0) */
428 return (0);
429 }
431 /* For a description of the arguments see `ntpd_do_query' below. */
432 static int ntpd_send_request (int req_code, int req_items, int req_size, char *req_data)
433 {
434 int sd;
435 struct req_pkt req;
436 size_t req_data_len;
437 int status;
439 assert (req_items >= 0);
440 assert (req_size >= 0);
442 if ((sd = ntpd_connect ()) < 0)
443 return (-1);
445 memset ((void *) &req, '\0', sizeof (req));
446 req.rm_vn_mode = RM_VN_MODE(0, 0, 0);
447 req.auth_seq = AUTH_SEQ (0, 0);
448 req.implementation = IMPL_XNTPD;
449 req.request = (unsigned char) req_code;
451 req_data_len = (size_t) (req_items * req_size);
453 assert (((req_data != NULL) && (req_data_len > 0))
454 || ((req_data == NULL) && (req_items == 0) && (req_size == 0)));
456 req.err_nitems = ERR_NITEMS (0, req_items);
457 req.mbz_itemsize = MBZ_ITEMSIZE (req_size);
459 if (req_data != NULL)
460 memcpy ((void *) req.data, (const void *) req_data, req_data_len);
462 status = swrite (sd, (const char *) &req, REQ_LEN_NOMAC);
463 if (status < 0)
464 return (status);
466 return (0);
467 }
469 /*
470 * ntpd_do_query:
471 *
472 * req_code: Type of request packet
473 * req_items: Numver of items in the request
474 * req_size: Size of one item in the request
475 * req_data: Data of the request packet
476 * res_items: Pointer to where the number returned items will be stored.
477 * res_size: Pointer to where the size of one returned item will be stored.
478 * res_data: This is where a pointer to the (allocated) data will be stored.
479 * res_item_size: Size of one returned item. (used to calculate padding)
480 *
481 * returns: zero upon success, non-zero otherwise.
482 */
483 static int ntpd_do_query (int req_code, int req_items, int req_size, char *req_data,
484 int *res_items, int *res_size, char **res_data, int res_item_size)
485 {
486 int status;
488 status = ntpd_send_request (req_code, req_items, req_size, req_data);
489 if (status != 0)
490 return (status);
492 status = ntpd_receive_response (req_code, res_items, res_size, res_data,
493 res_item_size);
494 return (status);
495 }
497 static void ntpd_read (void)
498 {
499 return;
500 }
501 #else
502 # define ntpd_read NULL
503 #endif /* NTPD_HAVE_READ */
505 void module_register (void)
506 {
507 plugin_register (MODULE_NAME, ntpd_init, ntpd_read, ntpd_write);
508 }
510 #undef MODULE_NAME