/*	$OpenBSD: sensors.c,v 1.7 2006/05/28 02:06:46 henning Exp $ */

/*
 * Copyright (c) 2006 Henning Brauer <henning@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/param.h>
#include <sys/queue.h>
#include <sys/sensors.h>
#include <sys/sysctl.h>
#include <sys/device.h>
#include <sys/hotplug.h>

#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "ntpd.h"

#define SENSORS_MAX	255
#define	_PATH_DEV_HOTPLUG               "/dev/hotplug"

void			 sensor_probe(int);
void			 sensor_add(struct sensor *);
struct ntp_sensor	*sensor_byid(int);

struct ntpd_conf *conf;

void
sensor_init(struct ntpd_conf *c)
{
	conf = c;
	TAILQ_INIT(&conf->ntp_sensors);
}

void
sensor_scan(void)
{
	int		i;

	for (i = 0; i < SENSORS_MAX; i++)
		sensor_probe(i);
}

void
sensor_probe(int id)
{
	int		mib[3];
	size_t		len;
	struct sensor	sensor;

	mib[0] = CTL_HW;
	mib[1] = HW_SENSORS;
	mib[2] = id;

	len = sizeof(sensor);
	if (sysctl(mib, 3, &sensor, &len, NULL, 0) == -1) {
		if (errno != ENOENT)
			log_warn("sensor_probe sysctl");
		return;
	}

	if (sensor.type == SENSOR_TIMEDELTA)
		sensor_add(&sensor);
}

void
sensor_add(struct sensor *sensor)
{
	struct ntp_sensor	*s;
	struct ntp_conf_sensor	*cs;

	/* check wether it is already there */
	TAILQ_FOREACH(s, &conf->ntp_sensors, entry)
		if (!strcmp(s->device, sensor->device))
			return;

	/* check wether it is requested in the config file */
	for (cs = TAILQ_FIRST(&conf->ntp_conf_sensors); cs != NULL &&
	    strcmp(cs->device, sensor->device) && strcmp(cs->device, "*");
	    cs = TAILQ_NEXT(cs, entry))
		; /* nothing */
	if (cs == NULL)
		return;

	if ((s = calloc(1, sizeof(*s))) == NULL)
		fatal("sensor_add calloc");

	s->next = time(NULL);
	if ((s->device = strdup(sensor->device)) == NULL)
		fatal("sensor_add strdup");
	s->sensorid = sensor->num;

	TAILQ_INSERT_TAIL(&conf->ntp_sensors, s, entry);

	log_debug("sensor %s added", s->device);
}

void
sensor_remove(struct ntp_sensor *s)
{
	TAILQ_REMOVE(&conf->ntp_sensors, s, entry);
	free(s->device);
	free(s);
}

struct ntp_sensor *
sensor_byid(int id)
{
	struct ntp_sensor	*s;

	TAILQ_FOREACH(s, &conf->ntp_sensors, entry)
		if (s->sensorid == id)
			return(s);

	return (NULL);
}

int
sensor_query(struct ntp_sensor *s)
{
	struct sensor	 sensor;
	int		 mib[3];
	size_t		 len;

	s->next = time(NULL) + SENSOR_QUERY_INTERVAL;
	if (s->update.rcvd < time(NULL) - SENSOR_DATA_MAXAGE)
		s->update.good = 0;

	mib[0] = CTL_HW;
	mib[1] = HW_SENSORS;
	mib[2] = s->sensorid;
	len = sizeof(sensor);
	if (sysctl(mib, 3, &sensor, &len, NULL, 0) == -1) {
		log_warn("sensor_query sysctl");
		return (0);
	}

	if (sensor.flags & SENSOR_FINVALID ||
	    sensor.status != SENSOR_S_OK)
		return (0);

	if (sensor.type != SENSOR_TIMEDELTA ||
	    strcmp(sensor.device, s->device))
		return (-1);	/* causes sensor removal */

	if (sensor.tv.tv_sec == s->update.rcvd)	/* already seen */
		return (0);

	s->update.offset = 0 - (float)sensor.value / 1000000000.0;
	s->update.status.stratum = 0;	/* increased when sent out */
	s->update.status.rootdelay = 0;
	s->update.status.rootdispersion = 0;
	s->update.status.reftime = sensor.tv.tv_sec;

	/* XXX 4 char, 'DCF ', 'GPS ', 'PPS ' and the like */
	s->update.status.refid = 0;
	s->update.rcvd = sensor.tv.tv_sec;
	s->update.good = 1;

	log_debug("sensor %s: offset %f", s->device, s->update.offset);

	return (0);
}

int
sensor_hotplugfd(void)
{
	int	fd, flags;

	if ((fd = open(_PATH_DEV_HOTPLUG, O_RDONLY, 0)) == -1)
		fatal(NULL);

	if ((flags = fcntl(fd, F_GETFL, 0)) == -1)
		fatal("fnctl F_GETFL");
	flags |= O_NONBLOCK;
	if ((flags = fcntl(fd, F_SETFL, flags)) == -1)
		fatal("fnctl F_SETFL");

	return (fd);
}

void
sensor_hotplugevent(int fd)
{
	struct hotplug_event	he;
	ssize_t			n;

	do {
		if ((n = read(fd, &he, sizeof(he))) == -1 &&
		    errno != EINTR && errno != EAGAIN)
			fatal("sensor_hotplugevent read");

		if (n == sizeof(he))
			switch (he.he_type) {
			case HOTPLUG_DEVAT:
				if (he.he_devclass == DV_SENSOR)
					sensor_probe(he.he_devid);
				break;
			case HOTPLUG_DEVDT:
				if (he.he_devclass == DV_SENSOR) {
					struct ntp_sensor	*s;

					s = sensor_byid(he.he_devid);
					if (s != NULL)
						sensor_remove(s);
				}
				break;
			default:		/* ignore */
				break;
			}
		else if (n > 0)
			fatal("sensor_hotplugevent: short read");
	} while (n > 0 || (n == -1 && errno == EINTR));
}