Bluetooth: Add signal handlers for channel moves

AMP channels can be moved between BR/EDR and AMP controllers using a
sequence of signals. Every attempted channel move involves a series of
four signals:

   Move Initiator                 Move Responder
        |                                 |
        |       Move Channel Request      |
        |  ---------------------------->  |
        |                                 |
        |       Move Channel Response     |
        |  <----------------------------  |
        |                                 |
        |       Move Channel Confirm      |
        |  ---------------------------->  |
        |                                 |
        |  Move Channel Confirm Response  |
	|  <----------------------------  |

All four signals are sent even if the move fails.
Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Acked-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>

net/bluetooth/l2cap_core.c

@@ -3149,6 +3149,126 @@ static inline int l2cap_create_channel_rsp(struct l2cap_conn *conn,
 	return l2cap_connect_rsp(conn, cmd, data);
 }
 
+static void l2cap_send_move_chan_rsp(struct l2cap_conn *conn, u8 ident,
+							u16 icid, u16 result)
+{
+	struct l2cap_move_chan_rsp rsp;
+
+	BT_DBG("icid %d, result %d", icid, result);
+
+	rsp.icid = cpu_to_le16(icid);
+	rsp.result = cpu_to_le16(result);
+
+	l2cap_send_cmd(conn, ident, L2CAP_MOVE_CHAN_RSP, sizeof(rsp), &rsp);
+}
+
+static void l2cap_send_move_chan_cfm(struct l2cap_conn *conn,
+				struct l2cap_chan *chan, u16 icid, u16 result)
+{
+	struct l2cap_move_chan_cfm cfm;
+	u8 ident;
+
+	BT_DBG("icid %d, result %d", icid, result);
+
+	ident = l2cap_get_ident(conn);
+	if (chan)
+		chan->ident = ident;
+
+	cfm.icid = cpu_to_le16(icid);
+	cfm.result = cpu_to_le16(result);
+
+	l2cap_send_cmd(conn, ident, L2CAP_MOVE_CHAN_CFM, sizeof(cfm), &cfm);
+}
+
+static void l2cap_send_move_chan_cfm_rsp(struct l2cap_conn *conn, u8 ident,
+								u16 icid)
+{
+	struct l2cap_move_chan_cfm_rsp rsp;
+
+	BT_DBG("icid %d", icid);
+
+	rsp.icid = cpu_to_le16(icid);
+	l2cap_send_cmd(conn, ident, L2CAP_MOVE_CHAN_CFM_RSP, sizeof(rsp), &rsp);
+}
+
+static inline int l2cap_move_channel_req(struct l2cap_conn *conn,
+			struct l2cap_cmd_hdr *cmd, u16 cmd_len, void *data)
+{
+	struct l2cap_move_chan_req *req = data;
+	u16 icid = 0;
+	u16 result = L2CAP_MR_NOT_ALLOWED;
+
+	if (cmd_len != sizeof(*req))
+		return -EPROTO;
+
+	icid = le16_to_cpu(req->icid);
+
+	BT_DBG("icid %d, dest_amp_id %d", icid, req->dest_amp_id);
+
+	if (!enable_hs)
+		return -EINVAL;
+
+	/* Placeholder: Always refuse */
+	l2cap_send_move_chan_rsp(conn, cmd->ident, icid, result);
+
+	return 0;
+}
+
+static inline int l2cap_move_channel_rsp(struct l2cap_conn *conn,
+			struct l2cap_cmd_hdr *cmd, u16 cmd_len, void *data)
+{
+	struct l2cap_move_chan_rsp *rsp = data;
+	u16 icid, result;
+
+	if (cmd_len != sizeof(*rsp))
+		return -EPROTO;
+
+	icid = le16_to_cpu(rsp->icid);
+	result = le16_to_cpu(rsp->result);
+
+	BT_DBG("icid %d, result %d", icid, result);
+
+	/* Placeholder: Always unconfirmed */
+	l2cap_send_move_chan_cfm(conn, NULL, icid, L2CAP_MC_UNCONFIRMED);
+
+	return 0;
+}
+
+static inline int l2cap_move_channel_confirm(struct l2cap_conn *conn,
+			struct l2cap_cmd_hdr *cmd, u16 cmd_len, void *data)
+{
+	struct l2cap_move_chan_cfm *cfm = data;
+	u16 icid, result;
+
+	if (cmd_len != sizeof(*cfm))
+		return -EPROTO;
+
+	icid = le16_to_cpu(cfm->icid);
+	result = le16_to_cpu(cfm->result);
+
+	BT_DBG("icid %d, result %d", icid, result);
+
+	l2cap_send_move_chan_cfm_rsp(conn, cmd->ident, icid);
+
+	return 0;
+}
+
+static inline int l2cap_move_channel_confirm_rsp(struct l2cap_conn *conn,
+			struct l2cap_cmd_hdr *cmd, u16 cmd_len, void *data)
+{
+	struct l2cap_move_chan_cfm_rsp *rsp = data;
+	u16 icid;
+
+	if (cmd_len != sizeof(*rsp))
+		return -EPROTO;
+
+	icid = le16_to_cpu(rsp->icid);
+
+	BT_DBG("icid %d", icid);
+
+	return 0;
+}
+
 static inline int l2cap_check_conn_param(u16 min, u16 max, u16 latency,
 							u16 to_multiplier)
 {
@@ -3269,6 +3389,22 @@ static inline int l2cap_bredr_sig_cmd(struct l2cap_conn *conn,
 		err = l2cap_create_channel_rsp(conn, cmd, data);
 		break;
 
+	case L2CAP_MOVE_CHAN_REQ:
+		err = l2cap_move_channel_req(conn, cmd, cmd_len, data);
+		break;
+
+	case L2CAP_MOVE_CHAN_RSP:
+		err = l2cap_move_channel_rsp(conn, cmd, cmd_len, data);
+		break;
+
+	case L2CAP_MOVE_CHAN_CFM:
+		err = l2cap_move_channel_confirm(conn, cmd, cmd_len, data);
+		break;
+
+	case L2CAP_MOVE_CHAN_CFM_RSP:
+		err = l2cap_move_channel_confirm_rsp(conn, cmd, cmd_len, data);
+		break;
+
 	default:
 		BT_ERR("Unknown BR/EDR signaling command 0x%2.2x", cmd->code);
 		err = -EINVAL;