diff options
Diffstat (limited to 'extras/dbus/udev_dbus.c')
| -rw-r--r-- | extras/dbus/udev_dbus.c | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/extras/dbus/udev_dbus.c b/extras/dbus/udev_dbus.c new file mode 100644 index 0000000000..955a3dbb49 --- /dev/null +++ b/extras/dbus/udev_dbus.c @@ -0,0 +1,178 @@ +#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_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; +} |