cherry-pick: 1730 bogus cidr

Merge in DNS/adguard-home from 1730-bogus-cidr to master

Closes #1730.

Squashed commit of the following:

commit 0be54259ca4edb8752e9f7e5ea5104a2b51ed440
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Tue Jan 25 18:50:01 2022 +0300

    all: imp log of changes

commit 59fb7a8c469216823ff54621ec40a4d084836132
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Tue Jan 25 18:46:34 2022 +0300

    all: log changes

commit 9206b13dd715fdf1180d1d572d1b80024b9e6592
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Tue Jan 25 18:41:26 2022 +0300

    all: upd dnsproxy

internal/dnsforward/clientid.go

@@ -65,7 +65,7 @@ func clientIDFromClientServerName(
 		return "", err
 	}
 
-	return clientID, nil
+	return strings.ToLower(clientID), nil
 }
 
 // clientIDFromDNSContextHTTPS extracts the client's ID from the path of the
@@ -104,7 +104,7 @@ func clientIDFromDNSContextHTTPS(pctx *proxy.DNSContext) (clientID string, err e
 		return "", fmt.Errorf("clientid check: %w", err)
 	}
 
-	return clientID, nil
+	return strings.ToLower(clientID), nil
 }
 
 // tlsConn is a narrow interface for *tls.Conn to simplify testing.
@@ -112,8 +112,8 @@ type tlsConn interface {
 	ConnectionState() (cs tls.ConnectionState)
 }
 
-// quicSession is a narrow interface for quic.Session to simplify testing.
-type quicSession interface {
+// quicConnection is a narrow interface for quic.Connection to simplify testing.
+type quicConnection interface {
 	ConnectionState() (cs quic.ConnectionState)
 }
 
@@ -148,16 +148,16 @@ func (s *Server) clientIDFromDNSContext(pctx *proxy.DNSContext) (clientID string
 
 		cliSrvName = tc.ConnectionState().ServerName
 	case proxy.ProtoQUIC:
-		qs, ok := pctx.QUICSession.(quicSession)
+		conn, ok := pctx.QUICConnection.(quicConnection)
 		if !ok {
 			return "", fmt.Errorf(
-				"proxy ctx quic session of proto %s is %T, want quic.Session",
+				"proxy ctx quic conn of proto %s is %T, want quic.Connection",
 				proto,
-				pctx.QUICSession,
+				pctx.QUICConnection,
 			)
 		}
 
-		cliSrvName = qs.ConnectionState().TLS.ServerName
+		cliSrvName = conn.ConnectionState().TLS.ServerName
 	}
 
 	clientID, err = clientIDFromClientServerName(

internal/dnsforward/clientid_test.go

@@ -29,17 +29,18 @@ func (c testTLSConn) ConnectionState() (cs tls.ConnectionState) {
 	return cs
 }
 
-// testQUICSession is a quicSession for tests.
-type testQUICSession struct {
-	// Session is embedded here simply to make testQUICSession a quic.Session
-	// without actually implementing all methods.
-	quic.Session
+// testQUICConnection is a quicConnection for tests.
+type testQUICConnection struct {
+	// Connection is embedded here simply to make testQUICConnection a
+	// quic.Connection without actually implementing all methods.
+	quic.Connection
 
 	serverName string
 }
 
-// ConnectionState implements the quicSession interface for testQUICSession.
-func (c testQUICSession) ConnectionState() (cs quic.ConnectionState) {
+// ConnectionState implements the quicConnection interface for
+// testQUICConnection.
+func (c testQUICConnection) ConnectionState() (cs quic.ConnectionState) {
 	cs.TLS.ServerName = c.serverName
 
 	return cs
@@ -143,6 +144,22 @@ func TestServer_clientIDFromDNSContext(t *testing.T) {
 		wantErrMsg: `clientid check: client server name "cli.myexample.com" ` +
 			`doesn't match host server name "example.com"`,
 		strictSNI: true,
+	}, {
+		name:         "tls_case",
+		proto:        proxy.ProtoTLS,
+		hostSrvName:  "example.com",
+		cliSrvName:   "InSeNsItIvE.example.com",
+		wantClientID: "insensitive",
+		wantErrMsg:   ``,
+		strictSNI:    true,
+	}, {
+		name:         "quic_case",
+		proto:        proxy.ProtoQUIC,
+		hostSrvName:  "example.com",
+		cliSrvName:   "InSeNsItIvE.example.com",
+		wantClientID: "insensitive",
+		wantErrMsg:   ``,
+		strictSNI:    true,
 	}}
 
 	for _, tc := range testCases {
@@ -163,17 +180,17 @@ func TestServer_clientIDFromDNSContext(t *testing.T) {
 				}
 			}
 
-			var qs quic.Session
+			var qconn quic.Connection
 			if tc.proto == proxy.ProtoQUIC {
-				qs = testQUICSession{
+				qconn = testQUICConnection{
 					serverName: tc.cliSrvName,
 				}
 			}
 
 			pctx := &proxy.DNSContext{
-				Proto:       tc.proto,
-				Conn:        conn,
-				QUICSession: qs,
+				Proto:          tc.proto,
+				Conn:           conn,
+				QUICConnection: qconn,
 			}
 
 			clientID, err := srv.clientIDFromDNSContext(pctx)
@@ -210,6 +227,11 @@ func TestClientIDFromDNSContextHTTPS(t *testing.T) {
 		path:         "/dns-query/cli/",
 		wantClientID: "cli",
 		wantErrMsg:   "",
+	}, {
+		name:         "clientid_case",
+		path:         "/dns-query/InSeNsItIvE",
+		wantClientID: "insensitive",
+		wantErrMsg:   ``,
 	}, {
 		name:         "bad_url",
 		path:         "/foo",

internal/dnsforward/config.go

@@ -243,18 +243,15 @@ func (s *Server) createProxyConfig() (proxy.Config, error) {
 		proxyConfig.FastestPingTimeout = s.conf.FastestTimeout.Duration
 	}
 
-	if len(s.conf.BogusNXDomain) > 0 {
-		for _, s := range s.conf.BogusNXDomain {
-			ip := net.ParseIP(s)
-			if ip == nil {
-				log.Error("Invalid bogus IP: %s", s)
-			} else {
-				proxyConfig.BogusNXDomain = append(
-					proxyConfig.BogusNXDomain,
-					netutil.SingleIPSubnet(ip),
-				)
-			}
+	for i, s := range s.conf.BogusNXDomain {
+		subnet, err := netutil.ParseSubnet(s)
+		if err != nil {
+			log.Error("subnet at index %d: %s", i, err)
+
+			continue
 		}
+
+		proxyConfig.BogusNXDomain = append(proxyConfig.BogusNXDomain, subnet)
 	}
 
 	// TLS settings