Client driver for WiFiNINA firmware (#98)

* wifinina: implementation of WiFiNINA driver, including:
   - TCP client example is working
   - reading sockets and mqtt working
   - switched over to common net package also used by espat package
   - smoke tests and updated README for wifinina

wifinina/protocol/readme.md

@@ -0,0 +1,3 @@
+WiFiNINA protocol
+=================
+

wifinina/tcp.go

@@ -0,0 +1,213 @@
+package wifinina
+
+import (
+	"fmt"
+	"strconv"
+	"time"
+
+	"tinygo.org/x/drivers/net"
+)
+
+const (
+	ReadBufferSize = 128
+)
+
+func (d *Device) NewDriver() net.DeviceDriver {
+	return &Driver{dev: d, sock: NoSocketAvail}
+}
+
+type Driver struct {
+	dev     *Device
+	sock    uint8
+	readBuf readBuffer
+}
+
+type readBuffer struct {
+	data [ReadBufferSize]byte
+	head int
+	size int
+}
+
+func (drv *Driver) GetDNS(domain string) (string, error) {
+	ipAddr, err := drv.dev.GetHostByName(domain)
+	return ipAddr.String(), err
+}
+
+func (drv *Driver) ConnectTCPSocket(addr, portStr string) error {
+	return drv.connectSocket(addr, portStr, ProtoModeTCP)
+}
+
+func (drv *Driver) ConnectSSLSocket(addr, portStr string) error {
+	return drv.connectSocket(addr, portStr, ProtoModeTLS)
+}
+
+func (drv *Driver) connectSocket(addr, portStr string, mode uint8) error {
+
+	// convert port to uint16
+	p64, err := strconv.ParseUint(portStr, 10, 16)
+	if err != nil {
+		return fmt.Errorf("could not convert port to uint16: %s", err.Error())
+	}
+	port := uint16(p64)
+
+	// look up the hostname if necessary; if an IP address was specified, the
+	// same will be returned.  Otherwise, an IPv4 for the hostname is returned.
+	ipAddr, err := drv.dev.GetHostByName(addr)
+	if err != nil {
+		return err
+	}
+	ip := ipAddr.AsUint32()
+
+	// check to see if socket is already set; if so, stop it
+	if drv.sock != NoSocketAvail {
+		if err := drv.stop(); err != nil {
+			return err
+		}
+	}
+
+	// get a socket from the device
+	if drv.sock, err = drv.dev.GetSocket(); err != nil {
+		return err
+	}
+
+	// attempt to start the client
+	if err := drv.dev.StartClient(ip, port, drv.sock, mode); err != nil {
+		return err
+	}
+
+	// FIXME: this 4 second timeout is simply mimicking the Arduino driver
+	for t := newTimer(4 * time.Second); !t.Expired(); {
+		connected, err := drv.IsConnected()
+		if err != nil {
+			return err
+		}
+		if connected {
+			return nil
+		}
+		wait(1 * time.Millisecond)
+	}
+
+	return ErrConnectionTimeout
+}
+
+func (drv *Driver) ConnectUDPSocket(addr, sport, lport string) error {
+	return ErrNotImplemented
+}
+
+func (drv *Driver) DisconnectSocket() error {
+	return drv.stop()
+}
+
+func (drv *Driver) StartSocketSend(size int) error {
+	// not needed for WiFiNINA???
+	return nil
+}
+
+func (drv *Driver) Response(timeout int) ([]byte, error) {
+	return nil, nil
+}
+
+func (drv *Driver) Write(b []byte) (n int, err error) {
+	if drv.sock == NoSocketAvail {
+		return 0, ErrNoSocketAvail
+	}
+	if len(b) == 0 {
+		return 0, ErrNoData
+	}
+	written, err := drv.dev.SendData(b, drv.sock)
+	if err != nil {
+		return 0, err
+	}
+	if written == 0 {
+		return 0, ErrDataNotWritten
+	}
+	if sent, _ := drv.dev.CheckDataSent(drv.sock); !sent {
+		return 0, ErrCheckDataError
+	}
+	return len(b), nil
+}
+
+func (drv *Driver) ReadSocket(b []byte) (n int, err error) {
+	avail, err := drv.available()
+	if err != nil {
+		println("ReadSocket error: " + err.Error())
+		return 0, err
+	}
+	if avail == 0 {
+		return 0, nil
+	}
+	length := len(b)
+	if avail < length {
+		length = avail
+	}
+	copy(b, drv.readBuf.data[drv.readBuf.head:drv.readBuf.head+length])
+	drv.readBuf.head += length
+	drv.readBuf.size -= length
+	return length, nil
+}
+
+// IsSocketDataAvailable returns of there is socket data available
+func (drv *Driver) IsSocketDataAvailable() bool {
+	n, err := drv.available()
+	return err == nil && n > 0
+}
+
+func (drv *Driver) available() (int, error) {
+	if drv.readBuf.size == 0 {
+		n, err := drv.dev.GetDataBuf(drv.sock, drv.readBuf.data[:])
+		if n > 0 {
+			drv.readBuf.head = 0
+			drv.readBuf.size = n
+		}
+		if err != nil {
+			return int(n), err
+		}
+	}
+	return drv.readBuf.size, nil
+}
+
+func (drv *Driver) IsConnected() (bool, error) {
+	if drv.sock == NoSocketAvail {
+		return false, nil
+	}
+	s, err := drv.status()
+	if err != nil {
+		return false, err
+	}
+	isConnected := !(s == TCPStateListen || s == TCPStateClosed ||
+		s == TCPStateFinWait1 || s == TCPStateFinWait2 || s == TCPStateTimeWait ||
+		s == TCPStateSynSent || s == TCPStateSynRcvd || s == TCPStateCloseWait)
+	// TODO: investigate if the below is necessary (as per Arduino driver)
+	//if !isConnected {
+	//	//close socket buffer?
+	//	WiFiSocketBuffer.close(_sock);
+	//	_sock = 255;
+	//}
+	return isConnected, nil
+}
+
+func (drv *Driver) status() (uint8, error) {
+	if drv.sock == NoSocketAvail {
+		return TCPStateClosed, nil
+	}
+	return drv.dev.GetClientState(drv.sock)
+}
+
+func (drv *Driver) stop() error {
+	if drv.sock == NoSocketAvail {
+		return nil
+	}
+	drv.dev.StopClient(drv.sock)
+	for t := newTimer(5 * time.Second); !t.Expired(); {
+		st, _ := drv.status()
+		if st == TCPStateClosed {
+			break
+		}
+		// FIXME: without the time.Sleep below this blocks until TCPStateClosed,
+		// however with it got goroutine stack overflows; not sure if this is still
+		// an issue so should investigate further
+		//time.Sleep(1 * time.Millisecond)
+	}
+	drv.sock = NoSocketAvail
+	return nil
+}

wifinina/timer.go

@@ -0,0 +1,28 @@
+package wifinina
+
+import "time"
+
+func wait(duration time.Duration) {
+	newTimer(duration).WaitUntilExpired()
+}
+
+type timer struct {
+	start    int64
+	interval int64
+}
+
+func newTimer(interval time.Duration) timer {
+	return timer{
+		start:    time.Now().UnixNano(),
+		interval: int64(interval),
+	}
+}
+
+func (t timer) Expired() bool {
+	return time.Now().UnixNano() > (t.start + t.interval)
+}
+
+func (t timer) WaitUntilExpired() {
+	for !t.Expired() {
+	}
+}