Expose a shadowsocks connection with net.Conn interface.

src/shadowsocks/conn.go

@@ -0,0 +1,79 @@
+package shadowsocks
+
+import (
+	"errors"
+	"net"
+	"strconv"
+	"strings"
+)
+
+var (
+	encTable []byte
+	decTable []byte
+)
+
+type Conn struct {
+	net.Conn
+}
+
+var initTableCalled = false
+
+func InitTable(passwd string) {
+	encTable, decTable = GetTable(passwd)
+	initTableCalled = true
+}
+
+// addr should be in the form of host:port
+func Dial(addr string, server string) (c Conn, err error) {
+	if !initTableCalled {
+		panic("shadowsocks internal error, must call InitTable first.")
+	}
+	conn, err := net.Dial("tcp", server)
+	if err != nil {
+		return
+	}
+
+	arr := strings.Split(addr, ":")
+	if len(arr) != 2 {
+		c.Close()
+		return Conn{}, errors.New("shadowsocks: malformed dial address")
+	}
+	host, portStr := arr[0], arr[1]
+	port, err := strconv.Atoi(portStr)
+	if err != nil {
+		c.Close()
+		return Conn{}, err
+	}
+
+	hostLen := len(host)
+	l := 1 + 1 + hostLen + 2 // addrType + lenByte + address + port
+	buf := make([]byte, l, l)
+	buf[0] = 3
+	buf[1] = byte(hostLen)
+	copy(buf[2:], host)
+	buf[2+hostLen] = byte(port >> 8 & 0xFF)
+	buf[2+hostLen+1] = byte(port) & 0xFF
+
+	c = Conn{conn}
+	_, err = c.Write(buf)
+	if err != nil {
+		c.Close()
+		return
+	}
+	return
+}
+
+func (c Conn) Read(b []byte) (n int, err error) {
+	buf := make([]byte, len(b), len(b))
+	n, err = c.Read(buf)
+	if n > 0 {
+		Encrypt2(decTable, buf[0:n], b[0:n])
+	}
+	return
+}
+
+func (c Conn) Write(b []byte) (n int, err error) {
+	buf := Encrypt(encTable, b)
+	n, err = c.Write(buf)
+	return
+}