add network feature for relay

internal/util/serial/conn.go

@@ -0,0 +1,72 @@
+package serial
+
+import (
+	"context"
+	"errors"
+	"io"
+	"net"
+	"time"
+)
+
+type conn struct {
+	port   io.ReadWriteCloser
+	laddr  net.Addr
+	raddr  net.Addr
+	cancel context.CancelFunc
+}
+
+func NewConn(port io.ReadWriteCloser, addr net.Addr, cancel context.CancelFunc) net.Conn {
+	return &conn{
+		port:   port,
+		laddr:  addr,
+		raddr:  addr,
+		cancel: cancel,
+	}
+}
+
+func (c *conn) Read(b []byte) (n int, err error) {
+	return c.port.Read(b)
+}
+
+func (c *conn) Write(b []byte) (n int, err error) {
+	return c.port.Write(b)
+}
+
+func (c *conn) LocalAddr() net.Addr {
+	return c.laddr
+}
+
+func (c *conn) RemoteAddr() net.Addr {
+	return c.raddr
+}
+
+func (c *conn) SetDeadline(t time.Time) error {
+	return &net.OpError{Op: "set", Net: "com", Source: nil, Addr: nil, Err: errors.New("deadline not supported")}
+}
+
+func (c *conn) SetReadDeadline(t time.Time) error {
+	return &net.OpError{Op: "set", Net: "com", Source: nil, Addr: nil, Err: errors.New("deadline not supported")}
+}
+
+func (c *conn) SetWriteDeadline(t time.Time) error {
+	return &net.OpError{Op: "set", Net: "com", Source: nil, Addr: nil, Err: errors.New("deadline not supported")}
+}
+
+func (c *conn) Close() (err error) {
+	if c.cancel != nil {
+		c.cancel()
+	}
+	return c.port.Close()
+}
+
+type Addr struct {
+	Port string
+}
+
+func (a *Addr) Network() string {
+	return "serial"
+}
+
+func (a *Addr) String() string {
+	return a.Port
+}

internal/util/serial/serial.go

@@ -0,0 +1,50 @@
+package serial
+
+import (
+	"strconv"
+	"strings"
+
+	goserial "github.com/tarm/serial"
+)
+
+const (
+	DefaultPort     = "COM1"
+	DefaultBaudRate = 9600
+	DefaultParity   = "none"
+)
+
+// COM1,9600,odd
+func ParseConfigFromAddr(addr string) *goserial.Config {
+	cfg := &goserial.Config{
+		Name: DefaultPort,
+		Baud: DefaultBaudRate,
+	}
+	ss := strings.Split(addr, ",")
+	switch len(ss) {
+	case 1:
+		cfg.Name = ss[0]
+	case 2:
+		cfg.Name = ss[0]
+		cfg.Baud, _ = strconv.Atoi(ss[1])
+	case 3:
+		cfg.Name = ss[0]
+		cfg.Baud, _ = strconv.Atoi(ss[1])
+		cfg.Parity = parseParity(ss[2])
+	}
+	return cfg
+}
+
+func parseParity(s string) goserial.Parity {
+	switch strings.ToLower(s) {
+	case "o", "odd":
+		return goserial.ParityOdd
+	case "e", "even":
+		return goserial.ParityEven
+	case "m", "mark":
+		return goserial.ParityMark
+	case "s", "space":
+		return goserial.ParitySpace
+	default:
+		return goserial.ParityNone
+	}
+}