// Run starts reading bytes from the serial port, (re)opening it if needed
// and sends the read bytes to the channel.
// Run blocks so should be called as a go routine.
func (sc *serialToChan) Run() {
// Ser is nil when closed.
var ser io.ReadWriteCloser
for {
// Open the serial port.
if ser == nil {
// Open serial port.
log.Printf("LoopSerial: Opening the port.\n")
var err error
// Open the serial port.
ser, err = openSerial(sc.port)
if err != nil {
log.Printf("LoopSerial: Error opening the port: %s.\n", err.Error())
ser = nil
time.Sleep(5 * time.Second)
}
}
// b is nil if no bytes were received.
var b []byte
if ser != nil {
// Read buf from serial.
b = getBuffer("LoopSerial: asking for buffer.")
n, err := ser.Read(b)
if err != nil || n == 0 {
// Error reading the serial port.
log.Printf("LoopSerial: Error reading the serial port. Closing it.")
// Return and invalidate the buffer.
putBuffer(b, "LoopSerial: returning buffer because of read error.")
b = nil
// Close serial.
ser.Close()
ser = nil
} else {
b = b[:n]
}
}
if b != nil {
// Send the bytes to the channel.
sc.bytesChan <- b
// Set b to nil to indicate that it has been sent.
b = nil
}
// Check if the done channel has been closed, but don't wait.
select {
case <-sc.done:
// Time to stop.
if ser != nil {
ser.Close()
}
close(sc.bytesChan)
return
default:
}
}
}
func PipeThenClose(src, dst io.ReadWriteCloser) {
defer dst.Close()
buf := make([]byte, MaxPacketSize)
for {
n, err := src.Read(buf)
// read may return EOF with n > 0
// should always process n > 0 bytes before handling error
if n > 0 {
// Note: avoid overwrite err returned by Read.
if _, err := dst.Write(buf[0:n]); err != nil {
log.Println("write:", err)
break
}
}
if err != nil {
// Always "use of closed network connection", but no easy way to
// identify this specific error. So just leave the error along for now.
// More info here: https://code.google.com/p/go/issues/detail?id=4373
/*
if bool(Debug) && err != io.EOF {
Debug.Println("read:", err)
}
*/
log.Println("read:", err)
break
}
}
}
func handleScgiRequest(fd io.ReadWriteCloser) {
var buf bytes.Buffer
var tmp [1024]byte
n, err := fd.Read(&tmp)
if err != nil || n == 0 {
return
}
colonPos := bytes.IndexByte(tmp[0:], ':')
read := n
length, _ := strconv.Atoi(string(tmp[0:colonPos]))
buf.Write(tmp[0:n])
for read < length {
n, err := fd.Read(&tmp)
if err != nil || n == 0 {
break
}
buf.Write(tmp[0:n])
read += n
}
req, err := readScgiRequest(&buf)
if err != nil {
log.Stderrf("SCGI read error", err.String())
return
}
sc := scgiConn{fd, make(map[string][]string), false}
routeHandler(req, &sc)
fd.Close()
}
func (s *Server) handleScgiRequest(fd io.ReadWriteCloser) {
var buf bytes.Buffer
tmp := make([]byte, 1024)
n, err := fd.Read(tmp)
if err != nil || n == 0 {
return
}
colonPos := bytes.IndexByte(tmp[0:], ':')
read := n
length, _ := strconv.Atoi(string(tmp[0:colonPos]))
buf.Write(tmp[0:n])
for read < length {
n, err := fd.Read(tmp)
if err != nil || n == 0 {
break
}
buf.Write(tmp[0:n])
read += n
}
req, err := readScgiRequest(&buf)
if err != nil {
s.Logger.Println("SCGI read error", err.Error())
return
}
sc := scgiConn{fd, req, make(map[string][]string), false}
s.routeHandler(req, &sc)
sc.finishRequest()
fd.Close()
}
func (client *Conn) proxy(rwc io.ReadWriteCloser) (bool, error) {
var closed bool
for job := range client.jobs {
if closed {
job.results <- rillResult{err: ErrClosedConnection{}}
continue
}
switch job.op {
case _read:
n, err := rwc.Read(job.data)
job.results <- rillResult{n, err}
if err != nil {
rwc.Close()
return false, err
}
case _write:
n, err := rwc.Write(job.data)
job.results <- rillResult{n, err}
if err != nil {
rwc.Close()
return false, err
}
case _close:
closed = true
err := rwc.Close()
job.results <- rillResult{err: err}
return true, err
}
}
return false, nil
}
// Write an image into the led matrix
func WriteLEDMatrix(image *image.RGBA, s io.ReadWriteCloser) {
//spew.Dump("writing image", image)
finalFrame := ConvertImage(image)
_, err := s.Write([]byte{cmdWriteBuffer})
if err != nil {
log.Fatalf("Failed writing write buffer command: %s", err)
}
_, err = s.Write(finalFrame[:])
if err != nil {
log.Fatalf("Failed writing frame: %s", err)
}
_, err = s.Write([]byte{cmdSwapBuffers})
if err != nil {
log.Fatalf("Failed writing swap buffer command: %s", err)
}
//log.Println("Wrote frame", n)
buf := make([]byte, 1)
_, err = s.Read(buf)
if err != nil {
log.Infof("Failed to read char after sending frame : %s", err)
}
if buf[0] != byte('F') {
log.Infof("Expected an 'F', got '%q'", buf[0])
}
}
func assertEcho(t *testing.T, rwc io.ReadWriteCloser, m ma.Multiaddr) {
str := "test string"
done := make(chan struct{})
defer rwc.Close()
go func() {
defer close(done)
_, err := fmt.Fprint(rwc, str)
if err != nil {
t.Error(err)
return
}
buf := make([]byte, 256)
n, err := rwc.Read(buf)
if err != nil {
t.Error(err)
return
}
got := string(buf[:n])
if got != str {
t.Errorf("expected \"%s\", got \"%s\"", str, got)
}
}()
select {
case <-done:
case <-time.After(time.Second):
t.Errorf("assertEcho: %s timed out", m.String())
}
}
func acceptAndWrite(rwc io.ReadWriteCloser, t *testing.T) {
// write
buf := []byte(msg)
for len(buf) > 0 {
n, err := rwc.Write(buf)
if err != nil {
t.Fatalf("write: %s", err)
}
buf = buf[n:]
}
// read
buf2 := make([]byte, len(msg))
free := buf2
for len(free) > 0 {
n, err := rwc.Read(free)
if err != nil {
t.Fatalf("write/read: %s", err)
}
free = free[n:]
}
if string(buf2) != msg {
t.Fatalf("write/read crc fail")
}
// close
if err := rwc.Close(); err != nil {
t.Fatalf("write/close: %s", err)
}
}
func ProcessTroubleShooting(rwc io.ReadWriteCloser) {
data := make([]byte, 0)
buf := make([]byte, 1024)
for {
n, err := rwc.Read(buf)
if nil != err {
break
}
if len(data) == 0 {
data = buf[0:n]
} else {
data = append(data, buf[0:n]...)
}
if len(data) > 1024 {
fmt.Fprintf(rwc, "Too long command from input.")
break
}
i := bytes.IndexByte(data, '\n')
if -1 == i {
continue
}
line := strings.TrimSpace(string(data[0:i]))
data = data[i+1:]
if len(line) == 0 {
continue
}
err = Handle(line, rwc)
if err == io.EOF {
break
}
}
rwc.Close()
}
func ReceiveConnRequest(c io.ReadWriteCloser) bool {
var buf [len("new")]byte
c.Read(buf[0:])
if string(buf[0:]) == "new" {
return true
}
return true
}
// CallTestSequence to Davis Weather Station
// it must return "TEST"
func CallTestSequence(connection io.ReadWriteCloser) string {
nb, err := connection.Write([]byte("TEST\n"))
check(err)
buf := make([]byte, 100)
nb, err = connection.Read(buf)
check(err)
log.Infof("%d bytes: %s\n", nb, string(buf))
return string(buf)
}
// clientWrite gets data from c and prints it to Stdin.
func clientWrite(c io.ReadWriteCloser) {
buf := make([]byte, 32000)
for {
n, err := c.Read(buf)
if err != nil {
log.Fatal(err)
}
fmt.Printf("[server]> %s\n>", buf[:n])
}
}
func echoMsg(s io.ReadWriteCloser) error {
b2 := make([]byte, 1024)
n, err := s.Read(b2)
if err != nil {
return err
}
n, err = s.Write(b2[:n])
if err != nil {
return err
}
return nil
}
func echo(rwc io.ReadWriteCloser, handler func(string) string) {
for {
buf := make([]byte, 256)
n, err := rwc.Read(buf)
if err != nil {
log.Println(err)
rwc.Close()
return
}
s := strings.TrimRight(string(buf[:n]), "\n")
s = handler(s)
_, err = rwc.Write([]byte(s))
}
}
func (p *Process) exitWaitChannel(exitFd io.ReadWriteCloser) chan int {
exitChan := make(chan int)
go func(exitFd io.Reader, exitChan chan<- int, streaming *sync.WaitGroup) {
b := make([]byte, 1)
n, err := exitFd.Read(b)
if n == 0 && err != nil {
b[0] = UnknownExitStatus
}
exitChan <- int(b[0])
}(exitFd, exitChan, p.streaming)
return exitChan
}
func (rpc *RPC) Accept(conn io.ReadWriteCloser) (*Peer, error) {
peer := NewPeer(rpc, conn)
buf := make([]byte, 32)
_, err := conn.Read(buf)
if err != nil {
return nil, err
}
// TODO: check handshake
_, err = conn.Write([]byte(HandshakeAccept))
if err != nil {
return nil, err
}
go peer.route()
return peer, nil
}
// WakeUp davis Station with sending bites sequence
func WakeUp(connection io.ReadWriteCloser) bool {
nb, err := connection.Write([]byte("\n"))
check(err)
buf := make([]byte, 10)
nb, err = connection.Read(buf)
check(err)
log.Infof("%d bytes read from USB port on Wake Up connection: %s\n", nb, string(buf))
if nb == 2 {
time.Sleep(time.Second * 2)
return true
} else {
return WakeUp(connection)
}
}
func sendJSON(conn io.ReadWriteCloser, json_data []byte, verb_type uint8) string {
// send the two header bytes
header := []byte{verb_type, uint8(len(json_data))} // len(json_data) MUST < 128
_, err := conn.Write(header)
checkErr("Unable to send header:", err)
// send the actual json-encoded data
_, err = conn.Write(json_data)
checkErr("Unable to send data:", err)
// wait for a response from the server
response := make([]byte, 255)
_, err = conn.Read(response)
checkErr("Unable to read response:", err)
return string(response)
}
// handshake implements the client/server key exchange
// and returns a secure io.ReadWriteCloser if successful
// else it returns an error.
// Reads and writes are preformed concurrently, allowing
// both the client and server to call the same function
// without knowing who will read/write first.
func handshake(pub, priv *[32]byte, conn io.ReadWriteCloser) (io.ReadWriteCloser, error) {
readDone := make(chan error)
writeDone := make(chan error)
peersPublicKey := make([]byte, 32)
ppkArray := [32]byte{}
go func(readDone chan<- error) {
if n, err := conn.Read(peersPublicKey); n != 32 {
readDone <- fmt.Errorf("key length error %d != 32\n", n)
return
} else if err != nil {
readDone <- err
return
}
for idx, val := range peersPublicKey {
ppkArray[idx] = val
}
readDone <- nil
}(readDone)
go func(writeDone chan<- error) {
if _, err := conn.Write(pub[:]); err != nil {
writeDone <- err
return
}
writeDone <- nil
}(writeDone)
// wait for read to finish
err := <-readDone
if err != nil {
return nil, err
}
// wait for write to finish
err = <-writeDone
if err != nil {
return nil, err
}
sr := NewSecureReader(conn, priv, &ppkArray)
sw := NewSecureWriter(conn, priv, &ppkArray)
return NewConnWrapper(sr, sw, conn), nil
}
func (rpc *RPC) Handshake(conn io.ReadWriteCloser) (*Peer, error) {
peer := NewPeer(rpc, conn)
handshake := []byte(fmt.Sprintf("%s/%s;%s",
ProtocolName, ProtocolVersion, rpc.codec.Name))
_, err := conn.Write(handshake)
if err != nil {
return nil, err
}
buf := make([]byte, 32)
_, err = conn.Read(buf)
if err != nil {
return nil, err
}
if buf[0] != '+' {
panic(string(buf))
}
go peer.route()
return peer, nil
}
func copypaste(in, out io.ReadWriteCloser, close_in bool, msg string) {
var buf [512]byte
defer func() {
if close_in {
l.Log("eof closing connection")
in.Close()
out.Close()
}
}()
for {
n, err := in.Read(buf[0:])
// on readerror, only bail if no other choice.
if err == io.EOF {
l.Log("msg: ", msg)
// fmt.Print(msg)
// time.Sleep(1e9)
l.Log("eof", msg)
return
}
l.Log("-- read ", n)
if err != nil {
l.Log("something wrong while copying in ot out ", msg)
l.Log("error: ", err)
return
}
// if n < 1 {
// fmt.Println("nothign to read")
// return
// }
l.Log("-- wrote msg bytes", n)
_, err = out.Write(buf[0:n])
if err != nil {
l.Log("something wrong while copying out to in ")
// l.Fatal("something wrong while copying out to in", err)
return
}
}
}
func parseHeader(rwc io.ReadWriteCloser, seq *uint64, method *string, plen *int32) error {
var err error
var sz int32
setError(&err, binary.Read(rwc, binary.LittleEndian, seq))
setError(&err, binary.Read(rwc, binary.LittleEndian, &sz))
setError(&err, binary.Read(rwc, binary.LittleEndian, plen))
if err != nil {
return err
}
buf := make([]byte, sz)
n, err := rwc.Read(buf)
if err != nil {
return err
}
if n != int(sz) {
return fmt.Errorf("Expected: %v. Got: %v\n", sz, n)
}
*method = string(buf)
return nil
}
func readSerial(s io.ReadWriteCloser) ([]byte, error) {
var inbuf, tmpbuf []byte
for {
tmpbuf = make([]byte, 256)
n, err := s.Read(tmpbuf)
inbuf = append(inbuf, tmpbuf[:n]...)
if err != nil {
// if err == io.EOF {
// break
// }
return nil, err
}
if len(inbuf) > 1 {
term := []byte{'\n', '\r'}
if bytes.Compare(inbuf[len(inbuf)-2:], term) == 0 {
break
}
}
}
return inbuf, nil
}
func echo(rwc io.ReadWriteCloser) (err error) {
/*
_, err = io.Copy(rwc, rwc)
if err != nil {
return err
}
return err
*/
buf := make([]byte, 1048)
n, err := rwc.Read(buf)
if err != nil {
fmt.Println("read completed", err)
return err
}
buf = buf[:n]
_, err = rwc.Write(buf)
if err != nil {
return err
}
return err
}
// Don't use this. It's used for the demo only.
func keyExchangeSendFirst(transport io.ReadWriteCloser) (*[32]byte, *[32]byte, *[32]byte) {
publicKey := new([32]byte)
privateKey := new([32]byte)
peerKey := new([32]byte)
publicKey, privateKey, err := box.GenerateKey(rand.Reader)
if err != nil {
defer transport.Close()
panic(err)
}
_, err = transport.Write(publicKey[:])
if err != nil {
defer transport.Close()
panic(err)
}
_, err = transport.Read(peerKey[:])
if err != nil {
defer transport.Close()
panic(err)
}
return publicKey, privateKey, peerKey
}
func GetCurrentData(connection io.ReadWriteCloser, loopNumber int16, dataChannel chan<- *WeatherData, wg *sync.WaitGroup) error {
_, err := connection.Write([]byte("LOOP " + string(loopNumber) + "\n"))
log.Infof("Asked for %d LOOP\n", loopNumber)
check(err)
i := loopNumber
ackBuf := make([]byte, 1)
//log.Info("try to read for ACK")
_, err = connection.Read(ackBuf)
check(err)
log.Infof("ACK bytes collected : %q\n", ackBuf)
if ackBuf[0] == ACK || string(ackBuf[0]) == "L" {
for i >= 1 {
buf := make([]byte, 99)
//log.Infof("Wait %d times for USB buffer read", i)
nb, err := connection.Read(buf)
if nb == 99 && err == nil {
//log.Printf("%d bytes collected on WeatherStation: %q\n", nb, buf)
weatherData := new(WeatherData)
err = DecodeData(buf, weatherData)
if err == nil {
dataChannel <- weatherData
time.Sleep(time.Second * 2)
}
} else {
//log.Infof("error is %q", err)
time.Sleep(time.Second * 2)
log.Warnf("cannot decode %d bytes collected : %q\n", nb, buf)
}
i--
}
} else {
log.Critical("can't get data from weather Station")
}
wg.Done()
return nil
}
func (link *Link) receive(port io.ReadWriteCloser) {
got := make([]byte, 1)
frame := make([]byte, 0)
rx := make([]byte, 0)
var xor byte
for {
n, err := port.Read(got)
if err != nil {
log.Fatal(err)
}
// log.Println("got", got[:n])
for _, ch := range got[:n] {
rx = append(rx, ch)
switch ch {
case Mark:
// log.Println("rx", len(rx), rx)
link.dispatch(frame)
frame = make([]byte, 0)
rx = make([]byte, 0)
case Escape:
xor = Xor
link.Escaped += 1
default:
frame = append(frame, ch^xor)
xor = 0
if len(frame) > 100 {
link.Overruns += 1
log.Println("err: overrun")
frame = make([]byte, 0)
}
}
}
}
}
func (pf *fakePortForwarder) PortForward(name string, uid types.UID, port uint16, stream io.ReadWriteCloser) error {
defer stream.Close()
// read from the client
received := make([]byte, len(pf.expected[port]))
n, err := stream.Read(received)
if err != nil {
return fmt.Errorf("error reading from client for port %d: %v", port, err)
}
if n != len(pf.expected[port]) {
return fmt.Errorf("unexpected length read from client for port %d: got %d, expected %d. data=%q", port, n, len(pf.expected[port]), string(received))
}
// store the received content
pf.lock.Lock()
pf.received[port] = string(received)
pf.lock.Unlock()
// send the hardcoded data to the client
io.Copy(stream, strings.NewReader(pf.send[port]))
return nil
}
func cpflate(dst, src io.ReadWriteCloser) {
w := lz4.NewWriter(dst)
errc := make(chan error)
rbuf := make(chan []byte)
go func() {
for {
buf := make([]byte, 32*512)
rlen, err := src.Read(buf)
if err != nil {
errc <- err
}
rbuf <- buf[0:rlen]
}
}()
loop:
for {
select {
case <-time.Tick(time.Millisecond * 16):
w.Flush()
case buf := <-rbuf:
_, err := w.Write(buf)
if err != nil {
break loop
}
w.Flush()
case <-errc:
break loop
}
}
}
// viaRTU is a private method which applies the given function validator,
// to make sure the functionCode passed is valid for the operation
// desired. If correct, it creates an RTUFrame given the corresponding
// information, attempts to open the serialDevice, and if successful, transmits
// it to the modbus server (slave device) specified by the given serial connection,
// and returns a byte array of the slave device's reply, and error (if any)
func viaRTU(connection io.ReadWriteCloser, fnValidator func(byte) bool, slaveAddress, functionCode byte, startRegister, numRegisters uint16, data []byte, timeOut int, debug bool) ([]byte, error) {
if fnValidator(functionCode) {
frame := new(RTUFrame)
frame.TimeoutInMilliseconds = timeOut
frame.SlaveAddress = slaveAddress
frame.FunctionCode = functionCode
frame.StartRegister = startRegister
frame.NumberOfRegisters = numRegisters
if len(data) > 0 {
frame.Data = data
}
// generate the ADU from the RTU frame
adu := frame.GenerateRTUFrame()
if debug {
log.Println(fmt.Sprintf("Tx: %x", adu))
}
// transmit the ADU to the slave device via the
// serial port represented by the fd pointer
_, werr := connection.Write(adu)
if werr != nil {
if debug {
log.Println(fmt.Sprintf("RTU Write Err: %s", werr))
}
return []byte{}, werr
}
// allow the slave device adequate time to respond
time.Sleep(time.Duration(frame.TimeoutInMilliseconds) * time.Millisecond)
// then attempt to read the reply
response := make([]byte, RTU_FRAME_MAXSIZE)
n, rerr := connection.Read(response)
if rerr != nil {
if debug {
log.Println(fmt.Sprintf("RTU Read Err: %s", rerr))
}
return []byte{}, rerr
}
// check the validity of the response
if response[0] != frame.SlaveAddress || response[1] != frame.FunctionCode {
if debug {
log.Println("RTU Response Invalid")
}
if response[0] == frame.SlaveAddress && (response[1]&0x7f) == frame.FunctionCode {
switch response[2] {
case EXCEPTION_ILLEGAL_FUNCTION:
return []byte{}, MODBUS_EXCEPTIONS[EXCEPTION_ILLEGAL_FUNCTION]
case EXCEPTION_DATA_ADDRESS:
return []byte{}, MODBUS_EXCEPTIONS[EXCEPTION_DATA_ADDRESS]
case EXCEPTION_DATA_VALUE:
return []byte{}, MODBUS_EXCEPTIONS[EXCEPTION_DATA_VALUE]
case EXCEPTION_SLAVE_DEVICE_FAILURE:
return []byte{}, MODBUS_EXCEPTIONS[EXCEPTION_SLAVE_DEVICE_FAILURE]
}
}
return []byte{}, MODBUS_EXCEPTIONS[EXCEPTION_UNSPECIFIED]
}
// confirm the checksum (crc)
response_crc := crc(response[:(n - 2)])
if response[(n-2)] != byte((response_crc&0xff)) ||
response[(n-1)] != byte((response_crc>>8)) {
// crc failed (odd that there's no specific code for it)
if debug {
log.Println("RTU Response Invalid: Bad Checksum")
}
// return the response bytes anyway, and let the caller decide
return response[:n], MODBUS_EXCEPTIONS[EXCEPTION_BAD_CHECKSUM]
}
// return only the number of bytes read
return response[:n], nil
}
return []byte{}, MODBUS_EXCEPTIONS[EXCEPTION_ILLEGAL_FUNCTION]
}