Pull request: proxy: fix tcp conn loop

Updates AdguardTeam/AdGuardHome#4042.

Squashed commit of the following:

commit 42f92b4
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Wed Dec 29 21:56:42 2021 +0300

    proxy: fix logs

commit a5b56fa
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Wed Dec 29 21:54:21 2021 +0300

    proxy: fix tcp conn loop

proxy/server_quic.go

@@ -57,6 +57,7 @@ func (p *Proxy) quicPacketLoop(l quic.Listener, requestGoroutinesSema semaphore)
 			} else {
 				log.Info("got error when reading from QUIC listen: %s", err)
 			}
+
 			break
 		} else {
 			requestGoroutinesSema.acquire()
@@ -86,8 +87,10 @@ func (p *Proxy) handleQUICSession(session quic.Session, requestGoroutinesSema se
 			} else {
 				log.Info("got error when accepting a new QUIC stream: %s", err)
 			}
+
 			// Close the session to make sure resources are freed
 			_ = session.CloseWithError(0, "")
+
 			return
 		}
 

proxy/server_tcp.go

@@ -53,7 +53,7 @@ func (p *Proxy) tcpPacketLoop(l net.Listener, proto Proto, requestGoroutinesSema
 
 		if err != nil {
 			if errors.Is(err, net.ErrClosed) {
-				log.Debug("tcpPacketLoop: connection closed")
+				log.Debug("tcpPacketLoop: connection closed: %s", err)
 			} else {
 				log.Info("got error when reading from TCP listen: %s", err)
 			}
@@ -98,12 +98,12 @@ func (p *Proxy) handleTCPConnection(conn net.Conn, proto Proto) {
 		packet, err := proxyutil.ReadPrefixed(conn)
 		if err != nil {
 			if errors.Is(err, io.EOF) || errors.Is(err, net.ErrClosed) {
-				continue
+				log.Debug("handling tcp: connection closed: %s", err)
+			} else {
+				log.Error("handling tcp: reading msg: %s", err)
 			}
 
-			log.Error("handling tcp: reading msg: %s", err)
-
-			return
+			break
 		}
 
 		req := &dns.Msg{}