Bluetooth: Fix handling of L2CAP Command Reject over LE

If we receive an L2CAP command reject message over LE we should take
appropriate action on the corresponding channel. This is particularly
important when trying to interact with a remote pre-4.1 system using LE
CoC signaling messages. If we don't react to the command reject the
corresponding socket would not be notified until a connection timeout
occurs.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

net/bluetooth/l2cap_core.c

@@ -5736,6 +5736,31 @@ static inline int l2cap_le_credits(struct l2cap_conn *conn,
 	return 0;
 }
 
+static inline int l2cap_le_command_rej(struct l2cap_conn *conn,
+				       struct l2cap_cmd_hdr *cmd, u16 cmd_len,
+				       u8 *data)
+{
+	struct l2cap_cmd_rej_unk *rej = (struct l2cap_cmd_rej_unk *) data;
+	struct l2cap_chan *chan;
+
+	if (cmd_len < sizeof(*rej))
+		return -EPROTO;
+
+	mutex_lock(&conn->chan_lock);
+
+	chan = __l2cap_get_chan_by_ident(conn, cmd->ident);
+	if (!chan)
+		goto done;
+
+	l2cap_chan_lock(chan);
+	l2cap_chan_del(chan, ECONNREFUSED);
+	l2cap_chan_unlock(chan);
+
+done:
+	mutex_unlock(&conn->chan_lock);
+	return 0;
+}
+
 static inline int l2cap_le_sig_cmd(struct l2cap_conn *conn,
 				   struct l2cap_cmd_hdr *cmd, u16 cmd_len,
 				   u8 *data)
@@ -5755,6 +5780,7 @@ static inline int l2cap_le_sig_cmd(struct l2cap_conn *conn,
 
 	switch (cmd->code) {
 	case L2CAP_COMMAND_REJ:
+		l2cap_le_command_rej(conn, cmd, cmd_len, data);
 		break;
 
 	case L2CAP_CONN_PARAM_UPDATE_REQ: