Timestamp from socket via ioctl syscall

Signed-off-by: Terekhin Alexander <alex@bearns.me>

Makefile

@@ -7,8 +7,7 @@ LDFLAGS = -ldflags "-s -w -buildid=$(git rev-parse HEAD)"
 all: clean test linux darwin windows
 
 linux:
-	GOOS=linux GOARCH=${GOARCH} go build ${LDFLAGS} -tags netgo -o ${BINARY}-linux-${GOARCH} . ; \
-	cd - >/dev/null
+	GOOS=linux GOARCH=${GOARCH} go build ${LDFLAGS} -tags netgo -o ${BINARY}-linux-${GOARCH} .
 
 darwin:
 	GOOS=darwin GOARCH=${GOARCH} go build ${LDFLAGS} -tags netgo -o ${BINARY}-darwin-${GOARCH} . ; \

can/can.go

@@ -60,23 +60,39 @@ func (sck *Socket) Bind(addr string, filter []unix.CanFilter) error {
 
 // Receive receives data from the CAN socket.
 // id is the CAN_frame id the data was originated from.
-func (sck *Socket) Receive() (id uint32, data *[]byte, err error) {
+func (sck *Socket) Receive() (id uint32, now time.Time, data *[]byte, err error) {
 	var buf [frameSize]byte
 	n, err := io.ReadFull(sck.dev, buf[:])
 	if err != nil {
-		return id, data, err
+		return id, time.Now(), data, err
 	}
 
 	if n != len(buf) {
-		return id, data, io.ErrUnexpectedEOF
+		return id, time.Now(), data, io.ErrUnexpectedEOF
 	}
 
+	var tv unix.Timeval
+
+	// Get timestamp
+	_, _, errno := unix.Syscall(
+		unix.SYS_IOCTL,
+		uintptr(sck.dev.fd),
+		uintptr(unix.SIOCGSTAMP),
+		uintptr(unsafe.Pointer(&tv)),
+	)
+
+	if errno != 0 {
+		return id, time.Now(), data, errors.New("Can't get timestamp")
+	}
+
+	now = time.Unix(tv.Sec, tv.Usec*1000)
+
 	id = binary.LittleEndian.Uint32(buf[:4])
 	//TODO make correct switch betwin EFF and SFF
 	id &= unix.CAN_EFF_MASK
 	payload := make([]byte, buf[4])
 	copy(payload, buf[8:])
-	return id, &payload, nil
+	return id, now, &payload, nil
 }
 
 // Send sends the provided frame on the CAN bus.
@@ -134,8 +150,7 @@ func StartCan(fromBus chan<- *CanFrame, toBus <-chan *CanFrame, canbus string, f
 				defer socket.Close()
 
 				for { //TODO implement stop
-					if id, data, serr := socket.Receive(); serr == nil {
-						var now = time.Now()
+					if id, now, data, serr := socket.Receive(); serr == nil {
 						fromBus <- &CanFrame{
 							Date:    &now,
 							CanId:   id,