fix: correct race condition from connection params in HCI implementation.

Basically it was responding by calling a function that retriggered asking to change the
parameters yet again. Yet we are not actually doing anything about this request at present.

Signed-off-by: deadprogram <[email protected]>

Author: deadprogram

att_hci.go

@@ -72,6 +72,7 @@ var (
 	ErrATTUnknown           = errors.New("bluetooth: ATT unknown error")
 	ErrATTOp                = errors.New("bluetooth: ATT OP error")
 	ErrATTUnknownConnection = errors.New("bluetooth: ATT unknown connection")
+	ErrATTAttributeNotFound = errors.New("bluetooth: ATT attribute not found")
 )
 
 const defaultTimeoutSeconds = 10
@@ -528,7 +529,12 @@ func (a *att) handleData(handle uint16, buf []byte) error {
 			println("att.handleData: attOpERROR", handle, cd.lastErrorOpcode, cd.lastErrorCode)
 		}
 
-		return ErrATTOp
+		switch cd.lastErrorCode {
+		case attErrorAttrNotFound:
+			return ErrATTAttributeNotFound
+		default:
+			return ErrATTOp
+		}
 
 	case attOpMTUReq:
 		if debug {

gap_hci.go

@@ -148,9 +148,18 @@ func (a *Adapter) Connect(address Address, params ConnectionParams) (Device, err
 	if address.isRandom {
 		random = 1
 	}
-	if err := a.hci.leCreateConn(0x0060, 0x0030, 0x00,
-		random, makeNINAAddress(address.MAC),
-		0x00, 0x0006, 0x000c, 0x0000, 0x00c8, 0x0004, 0x0006); err != nil {
+	if err := a.hci.leCreateConn(0x0060, // interval
+		0x0030,                       // window
+		0x00,                         // initiatorFilter
+		random,                       // peerBdaddrType
+		makeNINAAddress(address.MAC), // peerBdaddr
+		0x00,                         // ownBdaddrType
+		0x0006,                       // minInterval
+		0x000c,                       // maxInterval
+		0x0000,                       // latency
+		0x00c8,                       // supervisionTimeout
+		0x0004,                       // minCeLength
+		0x0006); err != nil {         // maxCeLength
 		return Device{}, err
 	}
 

gattc_hci.go

@@ -69,6 +69,9 @@ func (d Device) DiscoverServices(uuids []UUID) ([]DeviceService, error) {
 	for endHandle == uint16(0xffff) {
 		err := d.adapter.att.readByGroupReq(d.handle, startHandle, endHandle, gattServiceUUID)
 		if err != nil {
+			if err == ErrATTAttributeNotFound {
+				break
+			}
 			return nil, err
 		}
 

hci.go

@@ -262,7 +262,7 @@ func (h *hci) processPacket() (bool, error) {
 				return false, nil
 			case h.pos >= hciACLLenPos+pktlen:
 				if debug {
-					println("hci acl data:", h.pos, hex.EncodeToString(h.buf[:hciACLLenPos+pktlen+1]))
+					println("hci acl data recv:", h.pos, hex.EncodeToString(h.buf[:hciACLLenPos+pktlen+1]))
 				}
 
 				h.pos = hciACLLenPos + pktlen + 1
@@ -280,7 +280,7 @@ func (h *hci) processPacket() (bool, error) {
 				return false, nil
 			case h.pos >= hciEvtLenPos+pktlen:
 				if debug {
-					println("hci event data:", h.pos, hex.EncodeToString(h.buf[:hciEvtLenPos+pktlen+1]))
+					println("hci event data recv:", h.pos, hex.EncodeToString(h.buf[:hciEvtLenPos+pktlen+1]))
 				}
 
 				h.pos = hciEvtLenPos + pktlen + 1
@@ -293,7 +293,7 @@ func (h *hci) processPacket() (bool, error) {
 		if h.pos > 3 {
 			pktlen := int(h.buf[3])
 			if debug {
-				println("hci synchronous data:", h.pos, pktlen, hex.EncodeToString(h.buf[:1+3+pktlen]))
+				println("hci synchronous data recv:", h.pos, pktlen, hex.EncodeToString(h.buf[:1+3+pktlen]))
 			}
 
 			// move to next packet
@@ -304,7 +304,7 @@ func (h *hci) processPacket() (bool, error) {
 
 	default:
 		if debug {
-			println("unknown packet data:", h.pos, h.end, hex.EncodeToString(h.buf[:h.pos]))
+			println("unknown packet data recv:", h.pos, h.end, hex.EncodeToString(h.buf[:h.pos]))
 		}
 		return true, ErrHCIUnknown
 	}
@@ -678,7 +678,11 @@ func (h *hci) handleEventData(buf []byte) error {
 		switch buf[2] {
 		case leMetaEventConnComplete, leMetaEventEnhancedConnectionComplete:
 			if debug {
-				println("leMetaEventConnComplete")
+				if buf[2] == leMetaEventConnComplete {
+					println("leMetaEventConnComplete", hex.EncodeToString(buf))
+				} else {
+					println("leMetaEventEnhancedConnectionComplete", hex.EncodeToString(buf))
+				}
 			}
 
 			h.connectData.connected = true
@@ -691,10 +695,10 @@ func (h *hci) handleEventData(buf []byte) error {
 			switch buf[2] {
 			case leMetaEventConnComplete:
 				h.connectData.interval = binary.LittleEndian.Uint16(buf[14:])
-				h.connectData.timeout = binary.LittleEndian.Uint16(buf[16:])
+				h.connectData.timeout = binary.LittleEndian.Uint16(buf[18:])
 			case leMetaEventEnhancedConnectionComplete:
 				h.connectData.interval = binary.LittleEndian.Uint16(buf[26:])
-				h.connectData.timeout = binary.LittleEndian.Uint16(buf[28:])
+				h.connectData.timeout = binary.LittleEndian.Uint16(buf[30:])
 			}
 
 			h.att.addConnection(h.connectData.handle)

l2cap_hci.go

@@ -68,6 +68,10 @@ func (l *l2cap) addConnection(handle uint16, role uint8, interval, timeout uint1
 		return nil
 	}
 
+	if timeout == 0 {
+		timeout = 0x0c80
+	}
+
 	var b [12]byte
 	b[0] = connectionParamUpdateRequest
 	b[1] = 0x01
@@ -108,7 +112,7 @@ func (l *l2cap) handleData(handle uint16, buf []byte) error {
 
 func (l *l2cap) handleParameterUpdateRequest(connectionHandle uint16, identifier uint8, data []byte) error {
 	if debug {
-		println("l2cap.handleParameterUpdateRequest:", connectionHandle, "data:", hex.EncodeToString(data))
+		println("l2cap.handleParameterUpdateRequest:", connectionHandle, "identifier:", identifier, "data:", hex.EncodeToString(data))
 	}
 
 	req := l2capConnectionParamReqPkt{}
@@ -130,11 +134,6 @@ func (l *l2cap) handleParameterUpdateRequest(connectionHandle uint16, identifier
 		return err
 	}
 
-	// valid so update connection parameters
-	if resp.value == 0 {
-		return l.hci.leConnUpdate(connectionHandle, req.minInterval, req.maxInterval, req.latency, req.timeout)
-	}
-
 	return nil
 }