#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; strfieldcpy(filename, udev_root); strfieldcat(filename, dev->name); /* 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; strfieldcpy(filename, udev_root); strfieldcat(filename, name); /* 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); }