perf: reuse allocated buffer. add config parameter

proxy/http.go

@@ -39,7 +39,7 @@ func (pxy *Proxy) handleHttp(lConn *net.TCPConn, pkt *packet.HttpPacket, ip stri
 
 	log.Debug("[HTTP] New connection to the server ", pkt.Domain(), " ", rConn.LocalAddr())
 
-	go Serve(rConn, lConn, "[HTTP]", lConn.RemoteAddr().String(), pkt.Domain(), pxy.timeout)
+	go Serve(rConn, lConn, "[HTTP]", lConn.RemoteAddr().String(), pkt.Domain(), pxy.timeout, pxy.bufferSize)
 
 	_, err = rConn.Write(pkt.Raw())
 	if err != nil {
@@ -49,5 +49,5 @@ func (pxy *Proxy) handleHttp(lConn *net.TCPConn, pkt *packet.HttpPacket, ip stri
 
 	log.Debug("[HTTP] Sent a request to ", pkt.Domain())
 
-	Serve(lConn, rConn, "[HTTP]", lConn.RemoteAddr().String(), pkt.Domain(), pxy.timeout)
+	Serve(lConn, rConn, "[HTTP]", lConn.RemoteAddr().String(), pkt.Domain(), pxy.timeout, pxy.bufferSize)
 }

proxy/https.go

@@ -45,7 +45,8 @@ func (pxy *Proxy) handleHttps(lConn *net.TCPConn, exploit bool, initPkt *packet.
 	log.Debug("[HTTPS] Sent 200 Connection Estabalished to ", lConn.RemoteAddr())
 
 	// Read client hello
-	clientHello, err := ReadBytes(lConn)
+	tmpBuffer := make([]byte, pxy.bufferSize)
+	clientHello, err := ReadBytes(lConn, tmpBuffer)
 	if err != nil {
 		log.Debug("[HTTPS] Error reading client hello from the client", err)
 		return
@@ -60,7 +61,7 @@ func (pxy *Proxy) handleHttps(lConn *net.TCPConn, exploit bool, initPkt *packet.
 	// lConn.SetLinger(3)
 	// rConn.SetLinger(3)
 
-	go Serve(rConn, lConn, "[HTTPS]", rConn.RemoteAddr().String(), initPkt.Domain(), pxy.timeout)
+	go Serve(rConn, lConn, "[HTTPS]", rConn.RemoteAddr().String(), initPkt.Domain(), pxy.timeout, pxy.bufferSize)
 
 	if exploit {
 		log.Debug("[HTTPS] Writing chunked client hello to ", initPkt.Domain())
@@ -77,7 +78,7 @@ func (pxy *Proxy) handleHttps(lConn *net.TCPConn, exploit bool, initPkt *packet.
 		}
 	}
 
-	Serve(lConn, rConn, "[HTTPS]", lConn.RemoteAddr().String(), initPkt.Domain(), pxy.timeout)
+	Serve(lConn, rConn, "[HTTPS]", lConn.RemoteAddr().String(), initPkt.Domain(), pxy.timeout, pxy.bufferSize)
 }
 
 func splitInChunks(bytes []byte, size int) [][]byte {

proxy/io.go

@@ -9,8 +9,6 @@ import (
 	log "github.com/sirupsen/logrus"
 )
 
-const BUF_SIZE = 1024
-
 func WriteChunks(conn *net.TCPConn, c [][]byte) (n int, err error) {
 	total := 0
 	for i := 0; i < len(c); i++ {
@@ -25,37 +23,34 @@ func WriteChunks(conn *net.TCPConn, c [][]byte) (n int, err error) {
 	return total, nil
 }
 
-func ReadBytes(conn *net.TCPConn) ([]byte, error) {
+func ReadBytes(conn *net.TCPConn, dest []byte) ([]byte, error) {
-	ret := make([]byte, 0)
+	n, err := readBytesInternal(conn, dest)
-	buf := make([]byte, BUF_SIZE)
+	return dest[:n], err
-
-	for {
-		n, err := conn.Read(buf)
-		if err != nil {
-			switch err.(type) {
-			case *net.OpError:
-				return nil, errors.New("timed out")
-			default:
-				return nil, err
-			}
-		}
-		ret = append(ret, buf[:n]...)
-
-		if n < BUF_SIZE {
-			break
-		}
-	}
-
-	if len(ret) == 0 {
-		return nil, io.EOF
-	}
-
-	return ret, nil
 }
 
-func Serve(from *net.TCPConn, to *net.TCPConn, proto string, fd string, td string, timeout int) {
+func readBytesInternal(in io.Reader, dest []byte) (int, error) {
-	proto += " "
+	totalRead := 0
+	for {
+		numRead, readErr := in.Read(dest[totalRead:])
+		totalRead += numRead
+		if readErr != nil {
+			switch readErr.(type) {
+			case *net.OpError:
+				return totalRead, errors.New("timed out")
+			default:
+				return totalRead, readErr
+			}
+		}
+		if totalRead == 0 {
+			return 0, io.EOF
+		}
+		return totalRead, nil
+	}
+}
 
+func Serve(from *net.TCPConn, to *net.TCPConn, proto string, fd string, td string, timeout int, bufferSize int) {
+	proto += " "
+	buf := make([]byte, bufferSize)
 	for {
 		if timeout > 0 {
 			from.SetReadDeadline(
@@ -63,7 +58,7 @@ func Serve(from *net.TCPConn, to *net.TCPConn, proto string, fd string, td strin
 			)
 		}
 
-		buf, err := ReadBytes(from)
+		bytesRead, err := ReadBytes(from, buf)
 		if err != nil {
 			if err == io.EOF {
 				log.Debug(proto, "Finished ", fd)
@@ -73,7 +68,7 @@ func Serve(from *net.TCPConn, to *net.TCPConn, proto string, fd string, td strin
 			return
 		}
 
-		if _, err := to.Write(buf); err != nil {
+		if _, err := to.Write(bytesRead); err != nil {
 			log.Debug(proto, "Error Writing to ", td)
 			return
 		}

proxy/proxy.go

@@ -20,6 +20,7 @@ type Proxy struct {
 	resolver       *dns.DnsResolver
 	windowSize     int
 	allowedPattern []*regexp.Regexp
+	bufferSize     int
 }
 
 func New(config *util.Config) *Proxy {
@@ -30,6 +31,7 @@ func New(config *util.Config) *Proxy {
 		windowSize:     *config.WindowSize,
 		allowedPattern: config.AllowedPattern,
 		resolver:       dns.NewResolver(config),
+		bufferSize:     *config.BufferSize,
 	}
 }
 
@@ -57,7 +59,8 @@ func (pxy *Proxy) Start() {
 		}
 
 		go func() {
-			b, err := ReadBytes(conn.(*net.TCPConn))
+			tmpBuf := make([]byte, pxy.bufferSize)
+			b, err := ReadBytes(conn.(*net.TCPConn), tmpBuf)
 			if err != nil {
 				return
 			}

util/config.go

@@ -22,6 +22,7 @@ type Config struct {
 	AllowedPattern []*regexp.Regexp
 	WindowSize     *int
 	Version        *bool
+	BufferSize     *int
 }
 
 type StringArray []string
@@ -58,7 +59,7 @@ when not given, the client hello packet will be sent in two parts:
 fragmentation for the first data packet and the rest
 `)
 	config.Version = flag.Bool("v", false, "print spoof-dpi's version; this may contain some other relevant information")
-
+	config.BufferSize = flag.Int("buffer-size", 1024, "buffer size, in number of bytes, is the maximum amount of data that can be read at once from a remote resource")
 	var allowedPattern StringArray
 	flag.Var(
 		&allowedPattern,