proxy: imp code

proxy/proxy.go

@@ -340,6 +340,14 @@ func (p *Proxy) validateBasicAuth() (err error) {
 	return nil
 }
 
+// Returns true if proxy is started.  It is safe for concurrent use.
+func (p *Proxy) isStarted() (ok bool) {
+	p.RLock()
+	defer p.RUnlock()
+
+	return p.started
+}
+
 // type check
 var _ service.Interface = (*Proxy)(nil)
 

proxy/server_tcp.go

@@ -107,11 +107,9 @@ func (p *Proxy) handleTCPConnection(conn net.Conn, proto Proto) {
 	}()
 
 	for {
-		p.RLock()
-		if !p.started {
+		if !p.isStarted() {
 			return
 		}
-		p.RUnlock()
 
 		err := conn.SetDeadline(time.Now().Add(defaultTimeout))
 		if err != nil {

proxy/server_udp.go

@@ -67,17 +67,16 @@ func (p *Proxy) udpPacketLoop(conn *net.UDPConn, reqSema syncutil.Semaphore) {
 
 	b := make([]byte, dns.MaxMsgSize)
 	for {
-		p.RLock()
-		if !p.started {
+		if !p.isStarted() {
 			return
 		}
-		p.RUnlock()
 
 		n, localIP, remoteAddr, err := proxynetutil.UDPRead(conn, b, p.udpOOBSize)
-		// documentation says to handle the packet even if err occurs, so do that first
+		// The documentation says to handle the packet even if err occurs.
 		if n > 0 {
-			// make a copy of all bytes because ReadFrom() will overwrite contents of b on next call
-			// we need the contents to survive the call because we're handling them in goroutine
+			// Make a copy of all bytes because ReadFrom() will overwrite the
+			// contents of b on the next call.  We need that contents to sustain
+			// the call because we're handling them in goroutines.
 			packet := make([]byte, n)
 			copy(packet, b)
 
@@ -94,18 +93,24 @@ func (p *Proxy) udpPacketLoop(conn *net.UDPConn, reqSema syncutil.Semaphore) {
 				p.udpHandlePacket(packet, localIP, remoteAddr, conn)
 			}()
 		}
+
 		if err != nil {
-			if errors.Is(err, net.ErrClosed) {
-				log.Debug("dnsproxy: udp connection %s closed", conn.LocalAddr())
-			} else {
-				log.Error("dnsproxy: reading from udp: %s", err)
-			}
+			logError(err, conn)
 
 			break
 		}
 	}
 }
 
+// logError writes suitable log message for given err.
+func logError(err error, conn *net.UDPConn) {
+	if errors.Is(err, net.ErrClosed) {
+		log.Debug("dnsproxy: udp connection %s closed", conn.LocalAddr())
+	} else {
+		log.Error("dnsproxy: reading from udp: %s", err)
+	}
+}
+
 // udpHandlePacket processes the incoming UDP packet and sends a DNS response
 func (p *Proxy) udpHandlePacket(
 	packet []byte,

scripts/make/go-lint.sh

@@ -174,7 +174,7 @@ run_linter gocognit --over 10\
 	;
 
 run_linter gocognit --over 35 ./main.go
-run_linter gocognit --over 14 ./proxy/
+run_linter gocognit --over 13 ./proxy/
 
 run_linter ineffassign ./...