Add client connection number in server debug msg.

cmd/shadowsocks-server/server.go

@@ -79,13 +79,24 @@ func getRequest(conn *ss.Conn) (host string, extra []byte, err error) {
 	return
 }
 
+var connCnt int32
+
 func handleConnection(conn *ss.Conn) {
+	var host string
 	if debug {
 		// function arguments are always evaluated, so surround debug
 		// statement with if statement
-		debug.Printf("socks connect from %s\n", conn.RemoteAddr().String())
+		debug.Printf("new client %s->%s\n", conn.RemoteAddr().String(), conn.LocalAddr())
+		atomic.AddInt32(&connCnt, 1)
+		defer func() {
+			atomic.AddInt32(&connCnt, -1)
+			debug.Printf("closing pipe %s<->%s\n", conn.RemoteAddr(), host)
+			conn.Close()
+			debug.Printf("%d concurrent client connections\n", connCnt)
+		}()
+	} else {
+		defer conn.Close()
 	}
-	defer conn.Close()
 
 	host, extra, err := getRequest(conn)
 	if err != nil {
@@ -107,18 +118,19 @@ func handleConnection(conn *ss.Conn) {
 	defer remote.Close()
 	// write extra bytes read from 
 	if extra != nil {
-		debug.Println("getRequest read extra data, writing to remote, len", len(extra))
+		// debug.Println("getRequest read extra data, writing to remote, len", len(extra))
 		if _, err = remote.Write(extra); err != nil {
 			debug.Println("write request extra error:", err)
 			return
 		}
 	}
-	debug.Println("piping", host)
+	if debug {
+		debug.Printf("piping %s<->%s", conn.RemoteAddr(), host)
+	}
 	c := make(chan byte, 2)
 	go ss.Pipe(conn, remote, c)
 	go ss.Pipe(remote, conn, c)
 	<-c // close the other connection whenever one connection is closed
-	debug.Println("closing", host)
 	return
 }
 

shadowsocks/pipe.go

@@ -1,7 +1,7 @@
 package shadowsocks
 
 import (
-	"io"
+	// "io"
 	"net"
 	"time"
 )
@@ -31,9 +31,13 @@ func Pipe(src, dst net.Conn, end chan byte) {
 			}
 		}
 		if err != nil {
-			if err != io.EOF {
-				Debug.Println("read:", err)
-			}
+			// always "use of closed network connection", but no easy way to
+			// identify this specific error. So just leave the error along
+			/*
+				if bool(Debug) && err != io.EOF {
+					Debug.Println("read:", err)
+				}
+			*/
 			break
 		}
 	}