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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_lib.h"
#include "logging.h"
#ifdef LOG
unsigned char logname[LOGNAME_SIZE];
void log_message(int level, const char *format, ...)
{
va_list args;
if (!udev_log)
return;
va_start(args, format);
vsyslog(level, format, args);
va_end(args);
}
#endif
/** 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 */
static void sysbus_disconnect(void)
{
if (sysbus_connection == NULL)
return;
dbus_connection_disconnect(sysbus_connection);
sysbus_connection = NULL;
}
/** Connect to the system message bus */
static 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 devnode name of the device node, e.g. /dev/sda1
* @param path Sysfs path of device
*/
static void sysbus_send_create(const char *devnode, const char *path)
{
DBusMessage* message;
DBusMessageIter iter;
/* 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, devnode);
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 devnode Name of the device node, e.g. /udev/sda1
* @param path Sysfs path of device
*/
static void sysbus_send_remove(const char *devnode, const char *path)
{
DBusMessage* message;
DBusMessageIter iter;
/* 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, devnode);
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);
}
int main(int argc, char *argv[], char *envp[])
{
char *action;
char *devpath;
char *devnode;
int retval = 0;
init_logging("udev_dbus");
sysbus_connect();
if (sysbus_connection == NULL)
return 0;
action = get_action();
if (!action) {
dbg("no action?");
goto exit;
}
devpath = get_devpath();
if (!devpath) {
dbg("no devpath?");
goto exit;
}
devnode = get_devnode();
if (!devnode) {
dbg("no devnode?");
goto exit;
}
if (strcmp(action, "add") == 0) {
sysbus_send_create(devnode, devpath);
} else {
if (strcmp(action, "remove") == 0) {
sysbus_send_remove(devnode, devpath);
} else {
dbg("unknown action '%s'", action);
retval = -EINVAL;
}
}
exit:
sysbus_disconnect();
return retval;
}
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