Use buffered number to calculate header length

Author: AlexanderYastrebov

header.go

@@ -42,7 +42,6 @@ type Header struct {
 	SourceAddr        net.Addr
 	DestinationAddr   net.Addr
 	rawTLVs           []byte
-	length            int
 }
 
 // HeaderProxyFromAddrs creates a new PROXY header from a source and a

protocol.go

@@ -295,13 +295,12 @@ func (p *Conn) readHeader() error {
 	const bufSize = 256
 
 	bb := bytes.NewBuffer(make([]byte, 0, bufSize))
-	tr := io.TeeReader(p.conn, bb)
-	br := bufio.NewReaderSize(tr, bufSize)
+	br := bufio.NewReaderSize(io.TeeReader(p.conn, bb), bufSize)
 
 	header, err := Read(br)
 
 	if err == nil {
-		_, err = io.CopyN(io.Discard, bb, int64(header.length))
+		_, err = io.CopyN(io.Discard, bb, int64(bb.Len()-br.Buffered()))
 	}
 
 	if bb.Len() == 0 {

v1.go

@@ -125,7 +125,6 @@ func parseVersion1(reader *bufio.Reader) (*Header, error) {
 	// Command doesn't exist in v1 but set it for other parts of this library
 	// to rely on it for determining connection details.
 	header := initVersion1()
-	header.length = len(buf)
 
 	// Transport protocol has been processed already.
 	header.TransportProtocol = transportProtocol

v2.go

@@ -100,7 +100,6 @@ func parseVersion2(reader *bufio.Reader) (header *Header, err error) {
 	if !header.validateLength(length) {
 		return nil, ErrInvalidLength
 	}
-	header.length = 16 + int(length)
 
 	// Return early if the length is zero, which means that
 	// there's no address information and TLVs present for UNSPEC.