init

2022-09-01 15:24:36 +08:00
commit 7213e64b89
15 changed files with 631 additions and 0 deletions
--- a/shadow/server.go
+++ b/shadow/server.go
@ -0,0 +1,127 @@
+package shadow
+
+import (
+	"fmt"
+	"github.com/xtaci/smux"
+	"io"
+	"net"
+)
+
+type Server struct {
+	ListenAddress string
+	TargetAddress string
+	FakeAddress   string
+}
+
+func NewServer(listenAddress string, targetAddress string, fakeAddress string) *Server {
+	server := &Server{
+		ListenAddress: listenAddress,
+		TargetAddress: targetAddress,
+		FakeAddress:   fakeAddress,
+	}
+	return server
+}
+
+func (s *Server) Start() {
+	listen, err := net.Listen("tcp", s.ListenAddress)
+	if err != nil {
+		fmt.Printf("[Server] Start server error: %v\n", err)
+		return
+	}
+	defer listen.Close()
+	fmt.Printf("[Server] Listening at:%v\n", s.ListenAddress)
+	for {
+		conn, err := listen.Accept()
+		if err != nil {
+			fmt.Printf("[Server] Accept error: %v\n", err)
+			continue
+		}
+		go handler(conn, s.TargetAddress, s.FakeAddress)
+	}
+}
+
+func handler(conn net.Conn, targetAddress string, fakeAddress string) {
+
+	//Process fake TLS handshake
+	fmt.Println("[Server] Perform handshake")
+	fakeConn, err := net.Dial("tcp", fakeAddress)
+	if err != nil {
+		fmt.Printf("[Server] Dial fake error : %v\n", err)
+		return
+	}
+	waitCh := make(chan int, 2)
+
+	go processHandshake(conn, fakeConn, waitCh)
+	go processHandshake(fakeConn, conn, waitCh)
+
+	<-waitCh
+	<-waitCh
+
+	//Process real tcp connection
+	session, err := smux.Server(conn, nil)
+	if err != nil {
+		fmt.Printf("[Server] smux error: %v\n", err)
+		return
+	}
+	for {
+		stream, err := session.AcceptStream()
+		if err != nil {
+			fmt.Printf("[Server] AcceptStream error: %v\n", err)
+			break
+		}
+		go handlerMux(stream, targetAddress)
+	}
+
+}
+
+func processHandshake(src net.Conn, dst net.Conn, waitCh chan int) {
+	buf := make([]byte, 32*1024)
+	for {
+		nr, er := src.Read(buf)
+		if nr > 0 {
+
+			header := ParseAndVerifyTLSHeader(buf[0:nr])
+			nw, ew := dst.Write(buf[0:nr])
+			if header != nil && header.Type == ChangeCipherSpec {
+				fmt.Println("[Server] handshake complete")
+				dst.Close()
+				break
+			}
+			if nw < 0 || nr < nw {
+				nw = 0
+				if ew == nil {
+					//fmt.Printf("ERR1 %v \n", ew)
+				}
+			}
+			if ew != nil {
+				//fmt.Printf("ERR2 %v \n", ew)
+				break
+			}
+			if nr != nw {
+				//fmt.Printf("ERR3 %v \n", "shortwrite")
+				break
+			}
+		}
+		if er != nil {
+			if er != io.EOF {
+				//fmt.Printf("ERR4 %v \n", er)
+			}
+			break
+		}
+	}
+	waitCh <- 1
+}
+
+func handlerMux(conn *smux.Stream, targetAddress string) {
+
+	realConnection, err := net.Dial("tcp", targetAddress)
+	if err != nil {
+		fmt.Printf("[Server] Dial target error : %v\n", err)
+		return
+	}
+	if err != nil {
+		return
+	}
+	go io.Copy(realConnection, conn)
+	go io.Copy(conn, realConnection)
+}