bus: sync with kdbus.git

Sync up with recent kdbus changed:
 * several ioctls gained .size and .items members (but still unused)
 * CMD_SEND gained its own ioctl structure
 * several members of kdbus_msg were dropped as they were only used during
   SEND, not during RECV etc.
 * CMD_RECV and CMD_SEND now share a kdbus_reply member which contains the
   offset and size of the returned message.

3 files changed, 166 insertions, 88 deletions

diff --git a/src/libsystemd/sd-bus/bus-control.c b/src/libsystemd/sd-bus/bus-control.c
index 813c97f65..e86546c34 100644
--- a/src/libsystemd/sd-bus/bus-control.c
+++ b/src/libsystemd/sd-bus/bus-control.c
@@ -232,6 +232,7 @@ static int kernel_get_list(sd_bus *bus, uint64_t flags, char ***x) {
 
         /* Caller will free half-constructed list on failure... */
 
+        cmd.size = sizeof(cmd);
         cmd.flags = flags;
 
         r = ioctl(bus->input_fd, KDBUS_CMD_NAME_LIST, &cmd);
diff --git a/src/libsystemd/sd-bus/bus-kernel.c b/src/libsystemd/sd-bus/bus-kernel.c
index 752c63adb..2978b0a28 100644
--- a/src/libsystemd/sd-bus/bus-kernel.c
+++ b/src/libsystemd/sd-bus/bus-kernel.c
@@ -294,8 +294,8 @@ static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) {
         memzero(m->kdbus, sz);
 
         m->kdbus->flags =
-                ((m->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED) ? 0 : KDBUS_MSG_FLAGS_EXPECT_REPLY) |
-                ((m->header->flags & BUS_MESSAGE_NO_AUTO_START) ? KDBUS_MSG_FLAGS_NO_AUTO_START : 0);
+                ((m->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED) ? 0 : KDBUS_MSG_EXPECT_REPLY) |
+                ((m->header->flags & BUS_MESSAGE_NO_AUTO_START) ? KDBUS_MSG_NO_AUTO_START : 0);
 
         if (well_known)
                 /* verify_destination_id will usually be 0, which makes the kernel driver only look
@@ -761,7 +761,7 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k) {
         }
 
         /* Refuse messages where the reply flag doesn't match up */
-        if (!(m->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED) != !!(k->flags & KDBUS_MSG_FLAGS_EXPECT_REPLY)) {
+        if (!(m->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED) != !!(k->flags & KDBUS_MSG_EXPECT_REPLY)) {
                 r = -EBADMSG;
                 goto fail;
         }
@@ -773,7 +773,7 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k) {
         }
 
         /* Refuse messages where the autostart flag doesn't match up */
-        if (!(m->header->flags & BUS_MESSAGE_NO_AUTO_START) != !(k->flags & KDBUS_MSG_FLAGS_NO_AUTO_START)) {
+        if (!(m->header->flags & BUS_MESSAGE_NO_AUTO_START) != !(k->flags & KDBUS_MSG_NO_AUTO_START)) {
                 r = -EBADMSG;
                 goto fail;
         }
@@ -1012,6 +1012,7 @@ static void close_kdbus_msg(sd_bus *bus, struct kdbus_msg *k) {
 }
 
 int bus_kernel_write_message(sd_bus *bus, sd_bus_message *m, bool hint_sync_call) {
+        struct kdbus_cmd_send cmd = { };
         int r;
 
         assert(bus);
@@ -1027,15 +1028,20 @@ int bus_kernel_write_message(sd_bus *bus, sd_bus_message *m, bool hint_sync_call
         if (r < 0)
                 return r;
 
+        cmd.size = sizeof(cmd);
+        cmd.msg_address = (uintptr_t)m->kdbus;
+
         /* If this is a synchronous method call, then let's tell the
          * kernel, so that it can pass CPU time/scheduling to the
          * destination for the time, if it wants to. If we
          * synchronously wait for the result anyway, we won't need CPU
          * anyway. */
-        if (hint_sync_call)
-                m->kdbus->flags |= KDBUS_MSG_FLAGS_EXPECT_REPLY|KDBUS_MSG_FLAGS_SYNC_REPLY;
+        if (hint_sync_call) {
+                m->kdbus->flags |= KDBUS_MSG_EXPECT_REPLY;
+                cmd.flags |= KDBUS_SEND_SYNC_REPLY;
+        }
 
-        r = ioctl(bus->output_fd, KDBUS_CMD_MSG_SEND, m->kdbus);
+        r = ioctl(bus->output_fd, KDBUS_CMD_SEND, &cmd);
         if (r < 0) {
                 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
                 sd_bus_message *reply;
@@ -1085,7 +1091,7 @@ int bus_kernel_write_message(sd_bus *bus, sd_bus_message *m, bool hint_sync_call
         } else if (hint_sync_call) {
                 struct kdbus_msg *k;
 
-                k = (struct kdbus_msg *)((uint8_t *)bus->kdbus_buffer + m->kdbus->offset_reply);
+                k = (struct kdbus_msg *)((uint8_t *)bus->kdbus_buffer + cmd.reply.offset);
                 assert(k);
 
                 if (k->payload_type == KDBUS_PAYLOAD_DBUS) {
@@ -1246,7 +1252,7 @@ static int bus_kernel_translate_message(sd_bus *bus, struct kdbus_msg *k) {
 }
 
 int bus_kernel_read_message(sd_bus *bus, bool hint_priority, int64_t priority) {
-        struct kdbus_cmd_recv recv = {};
+        struct kdbus_cmd_recv recv = { .size = sizeof(recv) };
         struct kdbus_msg *k;
         int r;
 
@@ -1261,7 +1267,7 @@ int bus_kernel_read_message(sd_bus *bus, bool hint_priority, int64_t priority) {
                 recv.priority = priority;
         }
 
-        r = ioctl(bus->input_fd, KDBUS_CMD_MSG_RECV, &recv);
+        r = ioctl(bus->input_fd, KDBUS_CMD_RECV, &recv);
         if (r < 0) {
                 if (errno == EAGAIN)
                         return 0;
@@ -1274,7 +1280,7 @@ int bus_kernel_read_message(sd_bus *bus, bool hint_priority, int64_t priority) {
                 return -errno;
         }
 
-        k = (struct kdbus_msg *)((uint8_t *)bus->kdbus_buffer + recv.offset);
+        k = (struct kdbus_msg *)((uint8_t *)bus->kdbus_buffer + recv.reply.offset);
         if (k->payload_type == KDBUS_PAYLOAD_DBUS) {
                 r = bus_kernel_make_message(bus, k);
 
@@ -1798,12 +1804,13 @@ int bus_kernel_try_close(sd_bus *bus) {
 
 int bus_kernel_drop_one(int fd) {
         struct kdbus_cmd_recv recv = {
-                .flags = KDBUS_RECV_DROP
+                .size = sizeof(recv),
+                .flags = KDBUS_RECV_DROP,
         };
 
         assert(fd >= 0);
 
-        if (ioctl(fd, KDBUS_CMD_MSG_RECV, &recv) < 0)
+        if (ioctl(fd, KDBUS_CMD_RECV, &recv) < 0)
                 return -errno;
 
         return 0;
diff --git a/src/libsystemd/sd-bus/kdbus.h b/src/libsystemd/sd-bus/kdbus.h
index e2262de6b..bd51e3759 100644
--- a/src/libsystemd/sd-bus/kdbus.h
+++ b/src/libsystemd/sd-bus/kdbus.h
@@ -84,6 +84,7 @@ struct kdbus_creds {
  * struct kdbus_pids - process identifiers
  * @pid:		Process ID
  * @tid:		Thread ID
+ * @ppid:		Parent process ID
  *
  * The PID and TID of a process.
  *
@@ -93,6 +94,7 @@ struct kdbus_creds {
 struct kdbus_pids {
 	__u64 pid;
 	__u64 tid;
+	__u64 ppid;
 };
 
 /**
@@ -383,34 +385,26 @@ struct kdbus_item {
 
 /**
  * enum kdbus_msg_flags - type of message
- * @KDBUS_MSG_FLAGS_EXPECT_REPLY:	Expect a reply message, used for
- *					method calls. The userspace-supplied
- *					cookie identifies the message and the
- *					respective reply carries the cookie
- *					in cookie_reply
- * @KDBUS_MSG_FLAGS_SYNC_REPLY:		Wait for destination connection to
- *					reply to this message. The
- *					KDBUS_CMD_MSG_SEND ioctl() will block
- *					until the reply is received, and
- *					offset_reply in struct kdbus_msg will
- *					yield the offset in the sender's pool
- *					where the reply can be found.
- *					This flag is only valid if
- *					@KDBUS_MSG_FLAGS_EXPECT_REPLY is set as
- *					well.
- * @KDBUS_MSG_FLAGS_NO_AUTO_START:	Do not start a service, if the addressed
- *					name is not currently active
+ * @KDBUS_MSG_EXPECT_REPLY:	Expect a reply message, used for
+ *				method calls. The userspace-supplied
+ *				cookie identifies the message and the
+ *				respective reply carries the cookie
+ *				in cookie_reply
+ * @KDBUS_MSG_NO_AUTO_START:	Do not start a service, if the addressed
+ *				name is not currently active
  */
 enum kdbus_msg_flags {
-	KDBUS_MSG_FLAGS_EXPECT_REPLY	= 1ULL << 0,
-	KDBUS_MSG_FLAGS_SYNC_REPLY	= 1ULL << 1,
-	KDBUS_MSG_FLAGS_NO_AUTO_START	= 1ULL << 2,
+	KDBUS_MSG_EXPECT_REPLY	= 1ULL << 0,
+	KDBUS_MSG_NO_AUTO_START	= 1ULL << 1,
 };
 
 /**
  * enum kdbus_payload_type - type of payload carried by message
  * @KDBUS_PAYLOAD_KERNEL:	Kernel-generated simple message
  * @KDBUS_PAYLOAD_DBUS:		D-Bus marshalling "DBusDBus"
+ *
+ * Any payload-type is accepted. Common types will get added here once
+ * established.
  */
 enum kdbus_payload_type {
 	KDBUS_PAYLOAD_KERNEL,
@@ -420,8 +414,7 @@ enum kdbus_payload_type {
 /**
  * struct kdbus_msg - the representation of a kdbus message
  * @size:		Total size of the message
- * @flags:		Message flags (KDBUS_MSG_FLAGS_*), userspace → kernel
- * @kernel_flags:	Supported message flags, kernel → userspace
+ * @flags:		Message flags (KDBUS_MSG_*), userspace → kernel
  * @priority:		Message queue priority value
  * @dst_id:		64-bit ID of the destination connection
  * @src_id:		64-bit ID of the source connection
@@ -436,15 +429,11 @@ enum kdbus_payload_type {
  * @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
- * @offset_reply:	If KDBUS_MSG_FLAGS_EXPECT_REPLY, this field will
- *			contain the offset in the sender's pool where the
- *			reply is stored.
  * @items:		A list of kdbus_items containing the message payload
  */
 struct kdbus_msg {
 	__u64 size;
 	__u64 flags;
-	__u64 kernel_flags;
 	__s64 priority;
 	__u64 dst_id;
 	__u64 src_id;
@@ -453,12 +442,62 @@ struct kdbus_msg {
 	union {
 		__u64 timeout_ns;
 		__u64 cookie_reply;
-		__u64 offset_reply;
 	};
 	struct kdbus_item items[0];
 } __attribute__((aligned(8)));
 
 /**
+ * struct kdbus_reply - reply container
+ * @offset:		Offset of kdbus_msg slice in pool
+ * @msg_size:		Copy of the kdbus_msg.size field
+ * @return_flags:	Command return flags, kernel → userspace
+ */
+struct kdbus_reply {
+	__u64 offset;
+	__u64 msg_size;
+	__u64 return_flags;
+};
+
+/**
+ * enum kdbus_send_flags - flags for sending messages
+ * @KDBUS_SEND_SYNC_REPLY:	Wait for destination connection to
+ *				reply to this message. The
+ *				KDBUS_CMD_SEND ioctl() will block
+ *				until the reply is received, and
+ *				offset_reply in struct kdbus_msg will
+ *				yield the offset in the sender's pool
+ *				where the reply can be found.
+ *				This flag is only valid if
+ *				@KDBUS_MSG_EXPECT_REPLY is set as well.
+ */
+enum kdbus_send_flags {
+	KDBUS_SEND_SYNC_REPLY		= 1ULL << 0,
+};
+
+/**
+ * struct kdbus_cmd_send - send message
+ * @size:		Overall size of this structure
+ * @flags:		Flags to change send behavior (KDBUS_SEND_*)
+ * @kernel_flags:	Supported send flags, kernel → userspace
+ * @kernel_msg_flags:	Supported message flags, kernel → userspace
+ * @return_flags:	Command return flags, kernel → userspace
+ * @msg_address:	Storage address of the kdbus_msg to send
+ * @reply:		Storage for message reply if KDBUS_SEND_SYNC_REPLY
+ *			was given
+ * @items:		Additional items for this command
+ */
+struct kdbus_cmd_send {
+	__u64 size;
+	__u64 flags;
+	__u64 kernel_flags;
+	__u64 kernel_msg_flags;
+	__u64 return_flags;
+	__u64 msg_address;
+	struct kdbus_reply reply;
+	struct kdbus_item items[0];
+} __attribute__((aligned(8)));
+
+/**
  * enum kdbus_recv_flags - flags for de-queuing messages
  * @KDBUS_RECV_PEEK:		Return the next queued message without
  *				actually de-queuing it, and without installing
@@ -478,48 +517,61 @@ enum kdbus_recv_flags {
 };
 
 /**
+ * enum kdbus_recv_return_flags - return flags for message receive commands
+ * @KDBUS_RECV_RETURN_INCOMPLETE_FDS:	One or more file descriptors could not
+ *					be installed. These descriptors in
+ *					KDBUS_ITEM_FDS will carry the value -1.
+ */
+enum kdbus_recv_return_flags {
+	KDBUS_RECV_RETURN_INCOMPLETE_FDS	= 1ULL <<  0,
+};
+
+/**
  * struct kdbus_cmd_recv - struct to de-queue a buffered message
+ * @size:		Overall size of this object
  * @flags:		KDBUS_RECV_* flags, userspace → kernel
  * @kernel_flags:	Supported KDBUS_RECV_* flags, kernel → userspace
+ * @return_flags:	Command return flags, kernel → userspace
  * @priority:		Minimum priority of the messages to de-queue. Lowest
  *			values have the highest priority.
- * @offset:		Returned offset in the pool where the message is
- *			stored. The user must use KDBUS_CMD_FREE to free
- *			the allocated memory.
- * @dropped_msgs:	In case the KDBUS_CMD_MSG_RECV ioctl returns
+ * @dropped_msgs:	In case the KDBUS_CMD_RECV ioctl returns
  *			-EOVERFLOW, this field will contain the number of
  *			broadcast messages that have been lost since the
  *			last call.
- * @msg_size:		Filled by the kernel with the actual message size. This
- *			is the full size of the slice placed at @offset. It
- *			includes the memory used for the kdbus_msg object, but
- *			also for all appended VECs. By using @msg_size and
- *			@offset, you can map a single message, instead of
- *			mapping the whole pool.
+ * @reply:		Return storage for received message.
+ * @items:		Additional items for this command.
  *
- * This struct is used with the KDBUS_CMD_MSG_RECV ioctl.
+ * This struct is used with the KDBUS_CMD_RECV ioctl.
  */
 struct kdbus_cmd_recv {
+	__u64 size;
 	__u64 flags;
 	__u64 kernel_flags;
+	__u64 return_flags;
 	__s64 priority;
-	union {
-		__u64 offset;
-		__u64 dropped_msgs;
-	};
-	__u64 msg_size;
+	__u64 dropped_msgs;
+	struct kdbus_reply reply;
+	struct kdbus_item items[0];
 } __attribute__((aligned(8)));
 
 /**
  * struct kdbus_cmd_cancel - struct to cancel a synchronously pending message
- * @cookie:		The cookie of the pending message
+ * @size:		Overall size of this object
  * @flags:		Flags for the free command. Currently unused.
+ * @kernel_flags:	Supported flags of CANCEL, kernel → userspace
+ * @return_flags:	Command return flags, kernel → userspace
+ * @cookie:		The cookie of the pending message
+ * @items:		Items to modify the command behavior
  *
  * This struct is used with the KDBUS_CMD_CANCEL ioctl.
  */
 struct kdbus_cmd_cancel {
-	__u64 cookie;
+	__u64 size;
 	__u64 flags;
+	__u64 kernel_flags;
+	__u64 return_flags;
+	__u64 cookie;
+	struct kdbus_item items[0];
 } __attribute__((aligned(8)));
 
 /**
@@ -527,6 +579,7 @@ struct kdbus_cmd_cancel {
  * @offset:		The offset of the memory slice, as returned by other
  *			ioctls
  * @flags:		Flags for the free command, userspace → kernel
+ * @return_flags:	Command return flags, kernel → userspace
  * @kernel_flags:	Supported flags of the free command, userspace → kernel
  *
  * This struct is used with the KDBUS_CMD_FREE ioctl.
@@ -535,6 +588,7 @@ struct kdbus_cmd_free {
 	__u64 offset;
 	__u64 flags;
 	__u64 kernel_flags;
+	__u64 return_flags;
 } __attribute__((aligned(8)));
 
 /**
@@ -576,7 +630,7 @@ enum kdbus_policy_type {
  *				policy entries for a name. The provided name
  *				is not activated and not registered with the
  *				name database, it only allows unprivileged
- *				connections to aquire a name, talk or discover
+ *				connections to acquire a name, talk or discover
  *				a service
  * @KDBUS_HELLO_MONITOR:	Special-purpose connection to monitor
  *				bus traffic
@@ -635,6 +689,7 @@ enum kdbus_attach_flags {
  * @size:		The total size of the structure
  * @flags:		Connection flags (KDBUS_HELLO_*), userspace → kernel
  * @kernel_flags:	Supported connection flags, kernel → userspace
+ * @return_flags:	Command return flags, kernel → userspace
  * @attach_flags_send:	Mask of metadata to attach to each message sent
  *			off by this connection (KDBUS_ATTACH_*)
  * @attach_flags_recv:	Mask of metadata to attach to each message receieved
@@ -657,6 +712,7 @@ struct kdbus_cmd_hello {
 	__u64 size;
 	__u64 flags;
 	__u64 kernel_flags;
+	__u64 return_flags;
 	__u64 attach_flags_send;
 	__u64 attach_flags_recv;
 	__u64 bus_flags;
@@ -683,6 +739,7 @@ enum kdbus_make_flags {
  * @flags:		Properties for the bus/ep/domain to create,
  *			userspace → kernel
  * @kernel_flags:	Supported flags for the used command, kernel → userspace
+ * @return_flags:	Command return flags, kernel → userspace
  * @items:		Items describing details
  *
  * This structure is used with the KDBUS_CMD_BUS_MAKE and
@@ -692,6 +749,7 @@ struct kdbus_cmd_make {
 	__u64 size;
 	__u64 flags;
 	__u64 kernel_flags;
+	__u64 return_flags;
 	struct kdbus_item items[0];
 } __attribute__((aligned(8)));
 
@@ -717,6 +775,7 @@ enum kdbus_name_flags {
  * @flags:		Flags for a name entry (KDBUS_NAME_*),
  *			userspace → kernel, kernel → userspace
  * @kernel_flags:	Supported flags for a name entry, kernel → userspace
+ * @return_flags:	Command return flags, kernel → userspace
  * @items:		Item list, containing the well-known name as
  *			KDBUS_ITEM_NAME
  *
@@ -726,6 +785,7 @@ struct kdbus_cmd_name {
 	__u64 size;
 	__u64 flags;
 	__u64 kernel_flags;
+	__u64 return_flags;
 	struct kdbus_item items[0];
 } __attribute__((aligned(8)));
 
@@ -747,6 +807,19 @@ struct kdbus_name_info {
 } __attribute__((aligned(8)));
 
 /**
+ * struct kdbus_name_list - information returned by KDBUS_CMD_NAME_LIST
+ * @size:		The total size of the structure
+ * @names:		A list of names
+ *
+ * Note that the user is responsible for freeing the allocated memory with
+ * the KDBUS_CMD_FREE ioctl.
+ */
+struct kdbus_name_list {
+	__u64 size;
+	struct kdbus_name_info names[0];
+};
+
+/**
  * enum kdbus_name_list_flags - what to include into the returned list
  * @KDBUS_NAME_LIST_UNIQUE:	All active connections
  * @KDBUS_NAME_LIST_NAMES:	All known well-known names
@@ -765,6 +838,7 @@ enum kdbus_name_list_flags {
  * @flags:		Flags for the query (KDBUS_NAME_LIST_*),
  *			userspace → kernel
  * @kernel_flags:	Supported flags for queries, kernel → userspace
+ * @return_flags:	Command return flags, kernel → userspace
  * @offset:		The returned offset in the caller's pool buffer.
  *			The user must use KDBUS_CMD_FREE to free the
  *			allocated memory.
@@ -773,23 +847,30 @@ enum kdbus_name_list_flags {
  * This structure is used with the KDBUS_CMD_NAME_LIST ioctl.
  */
 struct kdbus_cmd_name_list {
+	__u64 size;
 	__u64 flags;
 	__u64 kernel_flags;
+	__u64 return_flags;
 	__u64 offset;
-	__u64 size;
+	__u64 list_size;
+	struct kdbus_item items[0];
 } __attribute__((aligned(8)));
 
 /**
- * struct kdbus_name_list - information returned by KDBUS_CMD_NAME_LIST
- * @size:		The total size of the structure
- * @names:		A list of names
+ * struct kdbus_info - information returned by KDBUS_CMD_*_INFO
+ * @size:		The total size of the struct
+ * @id:			The connection's or bus' 64-bit ID
+ * @flags:		The connection's or bus' flags
+ * @items:		A list of struct kdbus_item
  *
  * Note that the user is responsible for freeing the allocated memory with
  * the KDBUS_CMD_FREE ioctl.
  */
-struct kdbus_name_list {
+struct kdbus_info {
 	__u64 size;
-	struct kdbus_name_info names[0];
+	__u64 id;
+	__u64 flags;
+	struct kdbus_item items[0];
 };
 
 /**
@@ -797,6 +878,7 @@ struct kdbus_name_list {
  * @size:		The total size of the struct
  * @flags:		KDBUS_ATTACH_* flags, userspace → kernel
  * @kernel_flags:	Supported KDBUS_ATTACH_* flags, kernel → userspace
+ * @return_flags:	Command return flags, kernel → userspace
  * @id:			The 64-bit ID of the connection. If set to zero, passing
  *			@name is required. kdbus will look up the name to
  *			determine the ID in this case.
@@ -816,6 +898,7 @@ struct kdbus_cmd_info {
 	__u64 size;
 	__u64 flags;
 	__u64 kernel_flags;
+	__u64 return_flags;
 	__u64 id;
 	__u64 offset;
 	__u64 info_size;
@@ -823,27 +906,11 @@ struct kdbus_cmd_info {
 } __attribute__((aligned(8)));
 
 /**
- * struct kdbus_info - information returned by KDBUS_CMD_*_INFO
- * @size:		The total size of the struct
- * @id:			The connection's or bus' 64-bit ID
- * @flags:		The connection's or bus' flags
- * @items:		A list of struct kdbus_item
- *
- * Note that the user is responsible for freeing the allocated memory with
- * the KDBUS_CMD_FREE ioctl.
- */
-struct kdbus_info {
-	__u64 size;
-	__u64 id;
-	__u64 flags;
-	struct kdbus_item items[0];
-};
-
-/**
  * struct kdbus_cmd_update - update flags of a connection
  * @size:		The total size of the struct
  * @flags:		Flags for the update command, userspace → kernel
  * @kernel_flags:	Supported flags for this command, kernel → userspace
+ * @return_flags:	Command return flags, kernel → userspace
  * @items:		A list of struct kdbus_item
  *
  * This struct is used with the KDBUS_CMD_CONN_UPDATE ioctl.
@@ -852,6 +919,7 @@ struct kdbus_cmd_update {
 	__u64 size;
 	__u64 flags;
 	__u64 kernel_flags;
+	__u64 return_flags;
 	struct kdbus_item items[0];
 } __attribute__((aligned(8)));
 
@@ -873,6 +941,7 @@ enum kdbus_cmd_match_flags {
  * @flags:		Flags for match command (KDBUS_MATCH_*),
  *			userspace → kernel
  * @kernel_flags:	Supported flags of the used command, kernel → userspace
+ * @return_flags:	Command return flags, kernel → userspace
  * @items:		A list of items for additional information
  *
  * This structure is used with the KDBUS_CMD_MATCH_ADD and
@@ -883,6 +952,7 @@ struct kdbus_cmd_match {
 	__u64 cookie;
 	__u64 flags;
 	__u64 kernel_flags;
+	__u64 return_flags;
 	struct kdbus_item items[0];
 } __attribute__((aligned(8)));
 
@@ -905,11 +975,11 @@ struct kdbus_cmd_match {
  *				the call succeeds, and the handle is rendered
  *				unusable. Otherwise, -EBUSY is returned without
  *				any further side-effects.
- * KDBUS_CMD_MSG_SEND:		Send a message and pass data from userspace to
+ * KDBUS_CMD_SEND:		Send a message and pass data from userspace to
  *				the kernel.
- * KDBUS_CMD_MSG_RECV:		Receive a message from the kernel which is
+ * KDBUS_CMD_RECV:		Receive a message from the kernel which is
  *				placed in the receiver's pool.
- * KDBUS_CMD_MSG_CANCEL:	Cancel a pending request of a message that
+ * KDBUS_CMD_CANCEL:		Cancel a pending request of a message that
  *				blocks while waiting for a reply. The parameter
  *				denotes the cookie of the message in flight.
  * KDBUS_CMD_FREE:		Release the allocated memory in the receiver's
@@ -946,11 +1016,11 @@ struct kdbus_cmd_match {
 					      struct kdbus_cmd_hello)
 #define KDBUS_CMD_BYEBYE		_IO(KDBUS_IOCTL_MAGIC, 0x21)	\
 
-#define KDBUS_CMD_MSG_SEND		_IOWR(KDBUS_IOCTL_MAGIC, 0x30,	\
+#define KDBUS_CMD_SEND			_IOWR(KDBUS_IOCTL_MAGIC, 0x30,	\
 					      struct kdbus_msg)
-#define KDBUS_CMD_MSG_RECV		_IOWR(KDBUS_IOCTL_MAGIC, 0x31,	\
+#define KDBUS_CMD_RECV			_IOWR(KDBUS_IOCTL_MAGIC, 0x31,	\
 					      struct kdbus_cmd_recv)
-#define KDBUS_CMD_MSG_CANCEL		_IOW(KDBUS_IOCTL_MAGIC, 0x32,	\
+#define KDBUS_CMD_CANCEL		_IOW(KDBUS_IOCTL_MAGIC, 0x32,	\
 					     struct kdbus_cmd_cancel)
 #define KDBUS_CMD_FREE			_IOW(KDBUS_IOCTL_MAGIC, 0x33,	\
 					     struct kdbus_cmd_free)