fix get wrong remote addr issue

when call RemoteAddr before Read, will get wrong remote addr

proxy_protocol.go

@@ -4,6 +4,7 @@ import (
 	"bufio"
 	"net"
 
+	"github.com/fangdingjun/go-log"
 	proxyproto "github.com/pires/go-proxyproto"
 )
 
@@ -16,6 +17,7 @@ type protoConn struct {
 	headerDone bool
 	r          *bufio.Reader
 	proxy      *proxyproto.Header
+	err        error
 }
 
 // New create a wrapped listener
@@ -31,12 +33,24 @@ func (l *protoListener) Accept() (net.Conn, error) {
 	return &protoConn{Conn: c}, err
 }
 
-func (c *protoConn) Read(buf []byte) (int, error) {
+func (c *protoConn) readHeader() error {
 	var err error
+	c.r = bufio.NewReader(c.Conn)
+	c.proxy, err = proxyproto.Read(c.r)
+	if err != nil && err != proxyproto.ErrNoProxyProtocol {
+		c.err = err
+		return err
+	}
+	return nil
+}
+
+func (c *protoConn) Read(buf []byte) (int, error) {
+	if c.err != nil {
+		return 0, c.err
+	}
 	if !c.headerDone {
-		c.r = bufio.NewReader(c.Conn)
-		c.proxy, err = proxyproto.Read(c.r)
-		if err != nil && err != proxyproto.ErrNoProxyProtocol {
+		if err := c.readHeader(); err != nil {
+			c.headerDone = true
 			return 0, err
 		}
 		c.headerDone = true
@@ -46,6 +60,12 @@ func (c *protoConn) Read(buf []byte) (int, error) {
 }
 
 func (c *protoConn) RemoteAddr() net.Addr {
+	if !c.headerDone {
+		if err := c.readHeader(); err != nil {
+			log.Errorln(err)
+		}
+		c.headerDone = true
+	}
 	if c.proxy == nil {
 		return c.Conn.RemoteAddr()
 	}