bus: set cookie_reply and update kdbus.h

diff --git a/src/libsystemd-bus/bus-kernel.c b/src/libsystemd-bus/bus-kernel.c
index 8a5b210..c15218f 100644 (file)
--- a/src/libsystemd-bus/bus-kernel.c
+++ b/src/libsystemd-bus/bus-kernel.c
@@ -257,7 +257,7 @@ static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) {
                 m->destination ? unique : KDBUS_DST_ID_BROADCAST;
         m->kdbus->payload_type = KDBUS_PAYLOAD_DBUS;
         m->kdbus->cookie = m->header->serial;
-
+        m->kdbus->cookie_reply = m->reply_serial;
         m->kdbus->timeout_ns = m->timeout * NSEC_PER_USEC;
 
         d = m->kdbus->items;

diff --git a/src/libsystemd-bus/kdbus.h b/src/libsystemd-bus/kdbus.h
index 48a8440..8db165c 100644 (file)
--- a/src/libsystemd-bus/kdbus.h
+++ b/src/libsystemd-bus/kdbus.h
@@ -314,8 +314,9 @@ struct kdbus_item {
 /**
  * enum kdbus_msg_flags - type of message
  * @KDBUS_MSG_FLAGS_EXPECT_REPLY:      Expect a reply message, used for method
- *                                     calls. The cookie identifies the
- *                                     message and the respective reply
+ *                                     calls. The userspace-supplied cookie identifies
+ *                                     the message and the respective reply
+ *                                     carries the cookie in cookie_reply
  * @KDBUS_MSG_FLAGS_NO_AUTO_START:     Do not start a service, if the addressed
  *                                     name is not currently active
  */
@@ -341,9 +342,11 @@ enum kdbus_payload_type {
  * @dst_id:            64-bit ID of the destination connection
  * @src_id:            64-bit ID of the source connection
  * @payload_type:      Payload type (KDBUS_PAYLOAD_*)
- * @cookie:            Userspace-supplied cookie
- * @cookie_reply:      For kernel-generated messages, this is the cookie
- *                     the message is a reply to
+ * @cookie:            Userspace-supplied cookie to uniquely identify a
+ *                     message, unsually all messages carry this
+ * @cookie_reply:      A reply to the message with the same cookie. The
+ *                     reply itself has its own unique cookie, @cookie_reply
+ *                     connects the reply to 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
@@ -365,10 +368,8 @@ struct kdbus_msg {
        __u64 src_id;
        __u64 payload_type;
        __u64 cookie;
-       union {
-               __u64 cookie_reply;
-               __u64 timeout_ns;
-       };
+       __u64 cookie_reply;
+       __u64 timeout_ns;
        struct kdbus_item items[0];
 } __attribute__((aligned(8)));
 
@@ -528,8 +529,9 @@ enum kdbus_name_flags {
  * struct kdbus_cmd_name - struct to describe a well-known name
  * @size:              The total size of the struct
  * @flags:             Flags for a name entry (KDBUS_NAME_*)
- * @owner_id:          Privileged users may use this field to (de)register
- *                     names on behalf of other peers.
+ * @owner_id:          The current owner of the name. For requests,
+ *                     privileged users may set this field to
+ *                     (de)register names on behalf of other connections.
  * @conn_flags:                The flags of the owning connection (KDBUS_HELLO_*)
  * @name:              The well-known name
  *
@@ -630,9 +632,9 @@ struct kdbus_conn_info {
  * struct kdbus_cmd_match - struct to add or remove matches
  * @size:              The total size of the struct
  * @owner_id:          Privileged users may (de)register matches on behalf
- *                     of other peers. In other cases, set to 0.
+ *                     of other peers
  * @cookie:            Userspace supplied cookie. When removing, the cookie
- *                     identifies the match to remove.
+ *                     identifies the match to remove
  * @items:             A list of items for additional information
  *
  * This structure is used with the KDBUS_CMD_ADD_MATCH and