xref: /openbsd-src/usr.sbin/ntpd/sensors.c (revision a28daedfc357b214be5c701aa8ba8adb29a7f1c2)
1 /*	$OpenBSD: sensors.c,v 1.43 2009/02/08 23:57:08 stevesk Exp $ */
2 
3 /*
4  * Copyright (c) 2006 Henning Brauer <henning@openbsd.org>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
15  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
16  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/param.h>
20 #include <sys/queue.h>
21 #include <sys/sensors.h>
22 #include <sys/sysctl.h>
23 #include <sys/device.h>
24 #include <sys/hotplug.h>
25 
26 #include <errno.h>
27 #include <fcntl.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <unistd.h>
32 
33 #include "ntpd.h"
34 
35 #define MAXDEVNAMLEN		16
36 #define	_PATH_DEV_HOTPLUG	"/dev/hotplug"
37 
38 int	sensor_probe(int, char *, struct sensor *);
39 void	sensor_add(int, char *);
40 void	sensor_remove(struct ntp_sensor *);
41 void	sensor_update(struct ntp_sensor *);
42 
43 void
44 sensor_init(void)
45 {
46 	TAILQ_INIT(&conf->ntp_sensors);
47 }
48 
49 int
50 sensor_scan(void)
51 {
52 	int		i, n;
53 	char		d[MAXDEVNAMLEN];
54 	struct sensor	s;
55 
56 	n = 0;
57 	for (i = 0; i < MAXSENSORDEVICES; i++)
58 		if (sensor_probe(i, d, &s)) {
59 			sensor_add(i, d);
60 			n++;
61 		}
62 
63 	return n;
64 }
65 
66 int
67 sensor_probe(int devid, char *dxname, struct sensor *sensor)
68 {
69 	int			mib[5];
70 	size_t			slen, sdlen;
71 	struct sensordev	sensordev;
72 
73 	mib[0] = CTL_HW;
74 	mib[1] = HW_SENSORS;
75 	mib[2] = devid;
76 	mib[3] = SENSOR_TIMEDELTA;
77 	mib[4] = 0;
78 
79 	sdlen = sizeof(sensordev);
80 	if (sysctl(mib, 3, &sensordev, &sdlen, NULL, 0) == -1) {
81 		if (errno != ENOENT)
82 			log_warn("sensor_probe sysctl");
83 		return (0);
84 	}
85 
86 	if (sensordev.maxnumt[SENSOR_TIMEDELTA] == 0)
87 		return (0);
88 
89 	strlcpy(dxname, sensordev.xname, MAXDEVNAMLEN);
90 
91 	slen = sizeof(*sensor);
92 	if (sysctl(mib, 5, sensor, &slen, NULL, 0) == -1) {
93 		if (errno != ENOENT)
94 			log_warn("sensor_probe sysctl");
95 		return (0);
96 	}
97 
98 	return (1);
99 }
100 
101 void
102 sensor_add(int sensordev, char *dxname)
103 {
104 	struct ntp_sensor	*s;
105 	struct ntp_conf_sensor	*cs;
106 
107 	/* check whether it is already there */
108 	TAILQ_FOREACH(s, &conf->ntp_sensors, entry)
109 		if (!strcmp(s->device, dxname))
110 			return;
111 
112 	/* check whether it is requested in the config file */
113 	for (cs = TAILQ_FIRST(&conf->ntp_conf_sensors); cs != NULL &&
114 	    strcmp(cs->device, dxname) && strcmp(cs->device, "*");
115 	    cs = TAILQ_NEXT(cs, entry))
116 		; /* nothing */
117 	if (cs == NULL)
118 		return;
119 
120 	if ((s = calloc(1, sizeof(*s))) == NULL)
121 		fatal("sensor_add calloc");
122 
123 	s->next = getmonotime();
124 	s->weight = cs->weight;
125 	s->correction = cs->correction;
126 	if ((s->device = strdup(dxname)) == NULL)
127 		fatal("sensor_add strdup");
128 	s->sensordevid = sensordev;
129 
130 	if (cs->refstr == NULL)
131 		memcpy(&s->refid, "HARD", sizeof(s->refid));
132 	else {
133 		s->refid = 0;
134 		strncpy((char *)&s->refid, cs->refstr, sizeof(s->refid));
135 	}
136 
137 	TAILQ_INSERT_TAIL(&conf->ntp_sensors, s, entry);
138 
139 	log_debug("sensor %s added (weight %d, correction %.6f, refstr %.4s)",
140 	    s->device, s->weight, s->correction / 1e6, &s->refid);
141 }
142 
143 void
144 sensor_remove(struct ntp_sensor *s)
145 {
146 	TAILQ_REMOVE(&conf->ntp_sensors, s, entry);
147 	free(s->device);
148 	free(s);
149 }
150 
151 void
152 sensor_query(struct ntp_sensor *s)
153 {
154 	char		 dxname[MAXDEVNAMLEN];
155 	struct sensor	 sensor;
156 
157 	s->next = getmonotime() + SENSOR_QUERY_INTERVAL;
158 
159 	/* rcvd is walltime here, monotime in client.c. not used elsewhere */
160 	if (s->update.rcvd < time(NULL) - SENSOR_DATA_MAXAGE)
161 		s->update.good = 0;
162 
163 	if (!sensor_probe(s->sensordevid, dxname, &sensor)) {
164 		sensor_remove(s);
165 		return;
166 	}
167 
168 	if (sensor.flags & SENSOR_FINVALID ||
169 	    sensor.status != SENSOR_S_OK)
170 		return;
171 
172 	if (strcmp(dxname, s->device)) {
173 		sensor_remove(s);
174 		return;
175 	}
176 
177 	if (sensor.tv.tv_sec == s->last)	/* already seen */
178 		return;
179 
180 	s->last = sensor.tv.tv_sec;
181 	/*
182 	 * TD = device time
183 	 * TS = system time
184 	 * sensor.value = TS - TD in ns
185 	 * if value is positive, system time is ahead
186 	 */
187 	s->offsets[s->shift].offset = (sensor.value / -1e9) - getoffset() +
188 	    (s->correction / 1e6);
189 	s->offsets[s->shift].rcvd = sensor.tv.tv_sec;
190 	s->offsets[s->shift].good = 1;
191 
192 	s->offsets[s->shift].status.send_refid = s->refid;
193 	s->offsets[s->shift].status.stratum = 0;	/* increased when sent out */
194 	s->offsets[s->shift].status.rootdelay = 0;
195 	s->offsets[s->shift].status.rootdispersion = 0;
196 	s->offsets[s->shift].status.reftime = sensor.tv.tv_sec;
197 	s->offsets[s->shift].status.synced = 1;
198 
199 	log_debug("sensor %s: offset %f", s->device,
200 	    s->offsets[s->shift].offset);
201 
202 	if (++s->shift >= SENSOR_OFFSETS) {
203 		s->shift = 0;
204 		sensor_update(s);
205 	}
206 
207 }
208 
209 void
210 sensor_update(struct ntp_sensor *s)
211 {
212 	struct ntp_offset	**offsets;
213 	int			  i;
214 
215 	if ((offsets = calloc(SENSOR_OFFSETS, sizeof(struct ntp_offset *))) ==
216 	    NULL)
217 		fatal("calloc sensor_update");
218 
219 	for (i = 0; i < SENSOR_OFFSETS; i++)
220 		offsets[i] = &s->offsets[i];
221 
222 	qsort(offsets, SENSOR_OFFSETS, sizeof(struct ntp_offset *),
223 	    offset_compare);
224 
225 	i = SENSOR_OFFSETS / 2;
226 	memcpy(&s->update, offsets[i], sizeof(s->update));
227 	if (SENSOR_OFFSETS % 2 == 0) {
228 		s->update.offset =
229 		    (offsets[i - 1]->offset + offsets[i]->offset) / 2;
230 	}
231 	free(offsets);
232 
233 	log_debug("sensor update %s: offset %f", s->device, s->update.offset);
234 	priv_adjtime();
235 }
236 
237 int
238 sensor_hotplugfd(void)
239 {
240 #ifdef notyet
241 	int	fd, flags;
242 
243 	if ((fd = open(_PATH_DEV_HOTPLUG, O_RDONLY, 0)) == -1) {
244 		log_warn("open %s", _PATH_DEV_HOTPLUG);
245 		return (-1);
246 	}
247 
248 	if ((flags = fcntl(fd, F_GETFL, 0)) == -1)
249 		fatal("fcntl F_GETFL");
250 	flags |= O_NONBLOCK;
251 	if ((flags = fcntl(fd, F_SETFL, flags)) == -1)
252 		fatal("fcntl F_SETFL");
253 
254 	return (fd);
255 #else
256 	return (-1);
257 #endif
258 }
259 
260 void
261 sensor_hotplugevent(int fd)
262 {
263 	struct hotplug_event	he;
264 	ssize_t			n;
265 
266 	do {
267 		if ((n = read(fd, &he, sizeof(he))) == -1 &&
268 		    errno != EINTR && errno != EAGAIN)
269 			fatal("sensor_hotplugevent read");
270 
271 		if (n == sizeof(he))
272 			switch (he.he_type) {
273 			case HOTPLUG_DEVAT:
274 				if (he.he_devclass == DV_DULL &&
275 				    !strcmp(he.he_devname, "sensordev"))
276 					sensor_scan();
277 				break;
278 			default:		/* ignore */
279 				break;
280 			}
281 		else if (n > 0)
282 			fatal("sensor_hotplugevent: short read");
283 	} while (n > 0 || (n == -1 && errno == EINTR));
284 }
285