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#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <ctype.h>
#define DBUS_API_SUBJECT_TO_CHANGE
#include <dbus/dbus.h>
#include "udev.h"
#include "udev_version.h"
#include "udev_dbus.h"
#include "logging.h"
/** variable for the connection the to system message bus or #NULL
* if we cannot connect or acquire the org.kernel.udev service
*/
static DBusConnection* sysbus_connection;
/** Disconnect from the system message bus */
void sysbus_disconnect(void)
{
if (sysbus_connection == NULL)
return;
dbus_connection_disconnect(sysbus_connection);
sysbus_connection = NULL;
}
/** Connect to the system message bus */
void sysbus_connect(void)
{
DBusError error;
/* Connect to a well-known bus instance, the system bus */
dbus_error_init(&error);
sysbus_connection = dbus_bus_get(DBUS_BUS_SYSTEM, &error);
if (sysbus_connection == NULL) {
dbg("cannot connect to system message bus, error %s: %s",
error.name, error.message);
dbus_error_free(&error);
return;
}
/* Acquire the org.kernel.udev service such that listeners
* know that the message is really from us and not from a
* random attacker. See the file udev_sysbus_policy.conf for
* details.
*
* Note that a service can have multiple owners (though there
* is a concept of a primary owner for reception of messages)
* so no race is introduced if two copies of udev is running
* at the same time.
*/
dbus_bus_acquire_service(sysbus_connection, "org.kernel.udev", 0,
&error);
if (dbus_error_is_set(&error)) {
printf("cannot acquire org.kernel.udev service, error %s: %s'",
error.name, error.message);
sysbus_disconnect();
return;
}
}
/** Send out a signal that a device node is created
*
* @param dev udevice object
* @param path Sysfs path of device
*/
void sysbus_send_create(struct udevice *dev, const char *path)
{
char filename[255];
DBusMessage* message;
DBusMessageIter iter;
if (sysbus_connection == NULL)
return;
strncpy(filename, udev_root, sizeof(filename));
strncat(filename, dev->name, sizeof(filename));
/* object, interface, member */
message = dbus_message_new_signal("/org/kernel/udev/NodeMonitor",
"org.kernel.udev.NodeMonitor",
"NodeCreated");
dbus_message_iter_init(message, &iter);
dbus_message_iter_append_string(&iter, filename);
dbus_message_iter_append_string(&iter, path);
if ( !dbus_connection_send(sysbus_connection, message, NULL) )
dbg("error sending d-bus signal");
dbus_message_unref(message);
dbus_connection_flush(sysbus_connection);
}
/** Send out a signal that a device node is deleted
*
* @param name Name of the device node, e.g. /udev/sda1
* @param path Sysfs path of device
*/
void sysbus_send_remove(const char* name, const char *path)
{
char filename[255];
DBusMessage* message;
DBusMessageIter iter;
if (sysbus_connection == NULL)
return;
strncpy(filename, udev_root, sizeof(filename));
strncat(filename, name, sizeof(filename));
/* object, interface, member */
message = dbus_message_new_signal("/org/kernel/udev/NodeMonitor",
"org.kernel.udev.NodeMonitor",
"NodeDeleted");
dbus_message_iter_init(message, &iter);
dbus_message_iter_append_string(&iter, filename);
dbus_message_iter_append_string(&iter, path);
if ( !dbus_connection_send(sysbus_connection, message, NULL) )
dbg("error sending d-bus signal");
dbus_message_unref(message);
dbus_connection_flush(sysbus_connection);
}
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