Add KDBUS_CMD_CONN_UPDATE

Implement a method to update the connection's attach_flags at runtime.

5 files changed, 44 insertions, 2 deletions

diff --git a/TODO b/TODO
index 581b626b85a..1feabc1f6b0 100644
--- a/TODO
+++ b/TODO
@@ -29,8 +29,6 @@ Features:
     for another connection, like a connection can have a maximum of 100
     messages in-flight, but only 10 of them for the same connection
 
-  - allow to update the metadata subscription bit mask
-
   - support the creation of anonymous buses
 
   - actually return compatible/incompatible flags to users
diff --git a/connection.c b/connection.c
index dfac9435abc..49f3d4651a4 100644
--- a/connection.c
+++ b/connection.c
@@ -1646,6 +1646,26 @@ exit:
 }
 
 /**
+ * kdbus_conn_update() - update flags for a connection
+ * @conn:		Connection
+ * @buf:		The struct containing the new flags
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+int kdbus_cmd_conn_update(struct kdbus_conn *conn,
+			  void __user *buf)
+{
+	struct kdbus_cmd_conn_update cmd_update;
+
+	if (copy_from_user(&cmd_update, buf, sizeof(cmd_update)))
+		return -EFAULT;
+
+	conn->attach_flags = cmd_update.attach_flags;
+
+	return 0;
+}
+
+/**
  * kdbus_conn_new() - create a new connection
  * @ep:			The endpoint the connection is connected to
  * @hello:		The kdbus_cmd_hello as passed in by the user
diff --git a/connection.h b/connection.h
index 624cbd0de4e..c50d4266bee 100644
--- a/connection.h
+++ b/connection.h
@@ -97,6 +97,8 @@ int kdbus_conn_recv_msg_user(struct kdbus_conn *conn,
 			     struct kdbus_cmd_recv __user *recv);
 int kdbus_cmd_conn_info(struct kdbus_conn *conn,
 			void __user *buf);
+int kdbus_cmd_conn_update(struct kdbus_conn *conn,
+			  void __user *buf);
 int kdbus_conn_kmsg_send(struct kdbus_ep *ep,
 			 struct kdbus_conn *conn_src,
 			 struct kdbus_kmsg *kmsg);
diff --git a/handle.c b/handle.c
index c11195a6937..9dc0ee58d58 100644
--- a/handle.c
+++ b/handle.c
@@ -577,6 +577,16 @@ static long kdbus_handle_ioctl_ep_connected(struct file *file, unsigned int cmd,
 		ret = kdbus_cmd_conn_info(conn, buf);
 		break;
 
+	case KDBUS_CMD_CONN_UPDATE:
+		/* update flags for a connection */
+		if (!KDBUS_IS_ALIGNED8((uintptr_t)buf)) {
+			ret = -EFAULT;
+			break;
+		}
+
+		ret = kdbus_cmd_conn_update(conn, buf);
+		break;
+
 	case KDBUS_CMD_MATCH_ADD:
 		/* subscribe to/filter for broadcast messages */
 		if (!KDBUS_IS_ALIGNED8((uintptr_t)buf)) {
diff --git a/kdbus.h b/kdbus.h
index 36b362d449a..2abe53e8679 100644
--- a/kdbus.h
+++ b/kdbus.h
@@ -692,6 +692,16 @@ struct kdbus_conn_info {
 };
 
 /**
+ * struct kdbus_cmd_conn_update - update flags of a connection
+ * @attach_flags:	The new attach flags
+ *
+ * This struct is used with the KDBUS_CMD_CONN_UPDATE ioctl.
+ */
+struct kdbus_cmd_conn_update {
+	__u64 attach_flags;
+} __attribute__((aligned(8)));
+
+/**
  * 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
@@ -767,6 +777,7 @@ struct kdbus_cmd_memfd_make {
  *				stored at registration time and does not
  *				necessarily represent the connected process or
  *				the actual state of the process.
+ * @KDBUS_CMD_CONN_UPDATE:	Update flags for a connection.
  * @KDBUS_CMD_MATCH_ADD:	Install a match which broadcast messages should
  *				be delivered to the connection.
  * @KDBUS_CMD_MATCH_REMOVE:	Remove a current match for broadcast messages.
@@ -817,6 +828,7 @@ enum kdbus_ioctl_type {
 	KDBUS_CMD_NAME_LIST =		_IOWR(KDBUS_IOC_MAGIC, 0x52, struct kdbus_cmd_name_list),
 
 	KDBUS_CMD_CONN_INFO =		_IOWR(KDBUS_IOC_MAGIC, 0x60, struct kdbus_cmd_conn_info),
+	KDBUS_CMD_CONN_UPDATE =		_IOW (KDBUS_IOC_MAGIC, 0x61, struct kdbus_cmd_conn_update),
 
 	KDBUS_CMD_MATCH_ADD =		_IOW (KDBUS_IOC_MAGIC, 0x70, struct kdbus_cmd_match),
 	KDBUS_CMD_MATCH_REMOVE =	_IOW (KDBUS_IOC_MAGIC, 0x71, struct kdbus_cmd_match),