man: document sd_bus_message_get_cookie()

[elogind.git] / src / libsystemd-bus / kdbus.h

diff --git a/src/libsystemd-bus/kdbus.h b/src/libsystemd-bus/kdbus.h
index 71bf86d063547ec5260ced38047473688c84fcb9..71cfe06eac1b37eace0f0b65ae8b8f05cf751087 100644 (file)
--- a/src/libsystemd-bus/kdbus.h
+++ b/src/libsystemd-bus/kdbus.h
@@ -345,21 +345,13 @@ enum kdbus_payload_type {
  * @payload_type:      Payload type (KDBUS_PAYLOAD_*)
  * @cookie:            Userspace-supplied cookie, for the connection
  *                     to identify its messages
- * @cookie_reply:      A reply to the message with the same cookie. The
- *                     reply itself has its own cookie, @cookie_reply
- *                     corresponds to the cookie of the request message
- * @timeout_ns:                For non-kernel-generated messages, this denotes the
- *                     message timeout in nanoseconds. A message has to be
- *                     received with KDBUS_CMD_MSG_RECV by the destination
- *                     connection within this time frame. For messages that
- *                     have KDBUS_MSG_FLAGS_EXPECT_REPLY set in @flags,
- *                     this value also denotes the timeout for the reply to
- *                     this message. If there is no reply, or the message is
- *                     not received in time by the other side, a
- *                     kernel-generated message with an attached
- *                     KDBUS_ITEM_REPLY_TIMEOUT item is sent to @src_id.
- *                     A 0-value is only valid if KDBUS_MSG_FLAGS_EXPECT_REPLY
- *                     is unset in @flags.
+ * @cookie_reply:      A reply to the requesting message with the same
+ *                     cookie. The requesting connection can match its
+ *                     request and the reply with this value
+ * @timeout_ns:                The time to wait for a message reply from the peer.
+ *                     If there is no reply, a kernel-generated message
+ *                     with an attached KDBUS_ITEM_REPLY_TIMEOUT item
+ *                     is sent to @src_id.
  * @items:             A list of kdbus_items containing the message payload
  */
 struct kdbus_msg {
@@ -369,8 +361,10 @@ struct kdbus_msg {
        __u64 src_id;
        __u64 payload_type;
        __u64 cookie;
-       __u64 cookie_reply;
-       __u64 timeout_ns;
+       union {
+               __u64 cookie_reply;
+               __u64 timeout_ns;
+       };
        struct kdbus_item items[0];
 } __attribute__((aligned(8)));