Pull request: 2843 upd dnsproxy

Merge in DNS/adguard-home from 2843-upd-dnsproxy to master

Closes #2843.

Squashed commit of the following:

commit c3ffddcbf85cbd2542c5bb111984a8f422113a24
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Tue Apr 20 19:39:11 2021 +0300

    all: fix docs

commit 4b596e4776bfc05e4171bc53e8f9c55c88e1e6a5
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Tue Apr 20 19:25:24 2021 +0300

    all: imp code, docs

commit 8e3655f4f888ccc2c0902373cf8dd2aa4e113857
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Tue Apr 20 18:41:14 2021 +0300

    all: upd dnsproxy

internal/dnsforward/clientid.go

@@ -142,7 +142,7 @@ func processClientID(dctx *dnsContext) (rc resultCode) {
 			return resultCodeError
 		}
 
-		cliSrvName = qs.ConnectionState().ServerName
+		cliSrvName = qs.ConnectionState().TLS.ServerName
 	}
 
 	clientID, err := clientIDFromClientServerName(hostSrvName, cliSrvName, srvConf.StrictSNICheck)

internal/dnsforward/clientid_test.go

@@ -40,7 +40,7 @@ type testQUICSession struct {
 
 // ConnectionState implements the quicSession interface for testQUICSession.
 func (c testQUICSession) ConnectionState() (cs quic.ConnectionState) {
-	cs.ServerName = c.serverName
+	cs.TLS.ServerName = c.serverName
 
 	return cs
 }

internal/dnsforward/dnsforward_test.go

@@ -334,7 +334,7 @@ func TestDoTServer(t *testing.T) {
 
 func TestDoQServer(t *testing.T) {
 	s, _ := createTestTLS(t, TLSConfig{
-		QUICListenAddrs: []*net.UDPAddr{{}},
+		QUICListenAddrs: []*net.UDPAddr{{IP: net.IP{127, 0, 0, 1}}},
 	})
 	s.conf.UpstreamConfig.Upstreams = []upstream.Upstream{
 		&aghtest.TestUpstream{