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/*
* This file is Copyright 2010 by the GPSD project
* SPDX-License-Identifier: BSD-2-clause
*/
#include "../include/gpsd_config.h" // must be before all includes
#if defined(DBUS_EXPORT_ENABLE)
#include <dbus/dbus.h>
#include <errno.h>
#include <libgen.h>
#include <math.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <time.h>
#include <unistd.h>
#include "../include/gps.h"
#include "../include/libgps.h"
#include "../include/os_compat.h"
#include "../include/timespec.h"
/*
* Unpleasant that we have to declare a static context pointer here - means
* you can't have multiple DBUS sessions open (not that this matters
* much in practice). The problem is the DBUS API lacks some hook
* arguments that it ought to have.
*/
static struct gps_data_t *share_gpsdata;
static DBusConnection *connection;
static DBusHandlerResult handle_gps_fix(DBusMessage * message)
{
DBusError error;
const char *gpsd_devname = NULL;
double fix_time;
dbus_error_init(&error);
dbus_message_get_args(message,
&error,
DBUS_TYPE_DOUBLE, &fix_time,
DBUS_TYPE_INT32, &share_gpsdata->fix.mode,
DBUS_TYPE_DOUBLE, &share_gpsdata->fix.ept,
DBUS_TYPE_DOUBLE, &share_gpsdata->fix.latitude,
DBUS_TYPE_DOUBLE, &share_gpsdata->fix.longitude,
DBUS_TYPE_DOUBLE, &share_gpsdata->fix.eph,
/* The dbus doc does not seem to specify
* altHAE or altMSL */
DBUS_TYPE_DOUBLE, &share_gpsdata->fix.altHAE,
DBUS_TYPE_DOUBLE, &share_gpsdata->fix.epv,
DBUS_TYPE_DOUBLE, &share_gpsdata->fix.track,
DBUS_TYPE_DOUBLE, &share_gpsdata->fix.epd,
DBUS_TYPE_DOUBLE, &share_gpsdata->fix.speed,
DBUS_TYPE_DOUBLE, &share_gpsdata->fix.eps,
DBUS_TYPE_DOUBLE, &share_gpsdata->fix.climb,
DBUS_TYPE_DOUBLE, &share_gpsdata->fix.epc,
DBUS_TYPE_STRING, &gpsd_devname, DBUS_TYPE_INVALID);
// convert time as double back to timespec_t, potential loss of precision.
DTOTS(&share_gpsdata->fix.time, fix_time);
if (MODE_NO_FIX < share_gpsdata->fix.mode) {
share_gpsdata->fix.status = STATUS_GPS;
} else {
share_gpsdata->fix.status = STATUS_UNK;
}
dbus_error_free(&error);
PRIVATE(share_gpsdata)->handler(share_gpsdata);
return DBUS_HANDLER_RESULT_HANDLED;
}
/*
* Message dispatching function
*
*/
static DBusHandlerResult signal_handler(DBusConnection * connection UNUSED,
DBusMessage * message,
void *user_data UNUSED)
{
if (dbus_message_is_signal(message, "org.gpsd", "fix"))
return handle_gps_fix(message);
/*
* ignore all other messages
*/
return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}
int gps_dbus_open(struct gps_data_t *gpsdata)
{
DBusError error;
gpsdata->privdata =
(struct privdata_t *)calloc(1, sizeof(struct privdata_t));
if (NULL == gpsdata->privdata) {
return -1;
}
dbus_error_init(&error);
connection = dbus_bus_get(DBUS_BUS_SYSTEM, &error);
if (dbus_error_is_set(&error)) {
syslog(LOG_CRIT, "%s: %s", error.name, error.message);
dbus_error_free(&error);
return 3;
}
dbus_bus_add_match(connection, "type='signal'", &error);
if (dbus_error_is_set(&error)) {
syslog(LOG_CRIT, "unable to add match for signals %s: %s", error.name,
error.message);
dbus_error_free(&error);
return 4;
}
if (!dbus_connection_add_filter
(connection, (DBusHandleMessageFunction) signal_handler, NULL,
NULL)) {
syslog(LOG_CRIT, "unable to register filter with the connection");
return 5;
}
#ifndef USE_QT
gpsdata->gps_fd = DBUS_PSEUDO_FD;
#else
gpsdata->gps_fd = (void *)(intptr_t)DBUS_PSEUDO_FD;
#endif // USE_QT
share_gpsdata = gpsdata;
return 0;
}
/* run a DBUS main loop with a specified handler
*
* timeout is in micro seconds
*
* Returns: -1 on timeout
* -2 on error or disconnect
* FIXME: read error should return different than timeout
*/
int gps_dbus_mainloop(struct gps_data_t *gpsdata,
int timeout,
void (*hook)(struct gps_data_t *))
{
struct timespec ts_from, ts_to;
double d_timeout;
d_timeout = (double)timeout / 1000000; // timeout in seconds
share_gpsdata = gpsdata;
PRIVATE(share_gpsdata)->handler = (void (*)(struct gps_data_t *))hook;
for (;;) {
bool status;
double diff;
if (0 != clock_gettime(CLOCK_REALTIME, &ts_from)) {
return -2;
}
status = dbus_connection_read_write_dispatch(connection,
(int)(timeout/1000));
if (FALSE == status) {
// lost connection
break;
}
if (0 != clock_gettime(CLOCK_REALTIME, &ts_to)) {
return -2;
}
diff = TS_SUB_D(&ts_to, &ts_from);
if (d_timeout <= diff) {
// timeout
return -1;
}
}
return -2;
}
#endif // defined(DBUS_EXPORT_ENABLE)
// vim: set expandtab shiftwidth=4
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