diff options
Diffstat (limited to 'udev_dbus.c')
| -rw-r--r-- | udev_dbus.c | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/udev_dbus.c b/udev_dbus.c new file mode 100644 index 0000000000..57685163c5 --- /dev/null +++ b/udev_dbus.c @@ -0,0 +1,126 @@ +#define DBUS_API_SUBJECT_TO_CHANGE +#include <dbus/dbus.h> + +#include "udev_dbus.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); +} + + |