dnsforward: add tld to dhcp leased hostnames

internal/dnsforward/dns.go

@@ -230,12 +230,10 @@ func (s *Server) onDHCPLeaseChanged(flags int) {
 				)
 			}
 
-			lowhost := strings.ToLower(l.Hostname)
+			lowhost := strings.ToLower(l.Hostname + "." + s.localDomainSuffix)
+			ip := netutil.CloneIP(l.IP)
 
-			ipToHost.Set(l.IP, lowhost)
-
-			ip := make(net.IP, 4)
-			copy(ip, l.IP.To4())
+			ipToHost.Set(ip, lowhost)
 			hostToIP[lowhost] = ip
 		}
 
@@ -395,11 +393,10 @@ func (s *Server) processInternalHosts(dctx *dnsContext) (rc resultCode) {
 		return resultCodeSuccess
 	}
 
-	reqHost := strings.ToLower(q.Name)
+	reqHost := strings.ToLower(q.Name[:len(q.Name)-1])
 	// TODO(a.garipov): Move everything related to DHCP local domain to the DHCP
 	// server.
-	host := strings.TrimSuffix(reqHost, s.localDomainSuffix)
-	if host == reqHost {
+	if !strings.HasSuffix(reqHost, s.localDomainSuffix) {
 		return resultCodeSuccess
 	}
 
@@ -412,7 +409,7 @@ func (s *Server) processInternalHosts(dctx *dnsContext) (rc resultCode) {
 		return resultCodeFinish
 	}
 
-	ip, ok := s.hostToIP(host)
+	ip, ok := s.hostToIP(reqHost)
 	if !ok {
 		// TODO(e.burkov): Inspect special cases when user want to apply some
 		// rules handled by other processors to the hosts with TLD.

internal/dnsforward/dns_test.go

@@ -270,7 +270,7 @@ func TestServer_ProcessInternalHosts_localRestriction(t *testing.T) {
 				dhcpServer:        &testDHCP{},
 				localDomainSuffix: defaultLocalDomainSuffix,
 				tableHostToIP: hostToIPTable{
-					"example": knownIP,
+					"example." + defaultLocalDomainSuffix: knownIP,
 				},
 			}
 
@@ -321,7 +321,7 @@ func TestServer_ProcessInternalHosts_localRestriction(t *testing.T) {
 func TestServer_ProcessInternalHosts(t *testing.T) {
 	const (
 		examplecom = "example.com"
-		examplelan = "example.lan"
+		examplelan = "example." + defaultLocalDomainSuffix
 	)
 
 	knownIP := net.IP{1, 2, 3, 4}
@@ -370,40 +370,40 @@ func TestServer_ProcessInternalHosts(t *testing.T) {
 	}, {
 		name:    "success_custom_suffix",
 		host:    "example.custom",
-		suffix:  ".custom.",
+		suffix:  "custom",
 		wantIP:  knownIP,
 		wantRes: resultCodeSuccess,
 		qtyp:    dns.TypeA,
 	}}
 
 	for _, tc := range testCases {
-		t.Run(tc.name, func(t *testing.T) {
-			s := &Server{
-				dhcpServer:        &testDHCP{},
-				localDomainSuffix: tc.suffix,
-				tableHostToIP: hostToIPTable{
-					"example": knownIP,
-				},
-			}
+		s := &Server{
+			dhcpServer:        &testDHCP{},
+			localDomainSuffix: tc.suffix,
+			tableHostToIP: hostToIPTable{
+				"example." + tc.suffix: knownIP,
+			},
+		}
 
-			req := &dns.Msg{
-				MsgHdr: dns.MsgHdr{
-					Id: 1234,
-				},
-				Question: []dns.Question{{
-					Name:   dns.Fqdn(tc.host),
-					Qtype:  tc.qtyp,
-					Qclass: dns.ClassINET,
-				}},
-			}
+		req := &dns.Msg{
+			MsgHdr: dns.MsgHdr{
+				Id: 1234,
+			},
+			Question: []dns.Question{{
+				Name:   dns.Fqdn(tc.host),
+				Qtype:  tc.qtyp,
+				Qclass: dns.ClassINET,
+			}},
+		}
 
-			dctx := &dnsContext{
-				proxyCtx: &proxy.DNSContext{
-					Req: req,
-				},
-				isLocalClient: true,
-			}
+		dctx := &dnsContext{
+			proxyCtx: &proxy.DNSContext{
+				Req: req,
+			},
+			isLocalClient: true,
+		}
 
+		t.Run(tc.name, func(t *testing.T) {
 			res := s.processInternalHosts(dctx)
 			pctx := dctx.proxyCtx
 			assert.Equal(t, tc.wantRes, res)

internal/dnsforward/dnsforward.go

@@ -107,7 +107,7 @@ type Server struct {
 // when no suffix is provided.
 //
 // See the documentation for Server.localDomainSuffix.
-const defaultLocalDomainSuffix = ".lan."
+const defaultLocalDomainSuffix = "lan"
 
 // DNSCreateParams are parameters to create a new server.
 type DNSCreateParams struct {
@@ -120,17 +120,6 @@ type DNSCreateParams struct {
 	LocalDomain string
 }
 
-// domainNameToSuffix converts a domain name into a local domain suffix.
-func domainNameToSuffix(tld string) (suffix string) {
-	l := len(tld) + 2
-	b := make([]byte, l)
-	b[0] = '.'
-	copy(b[1:], tld)
-	b[l-1] = '.'
-
-	return string(b)
-}
-
 const (
 	// recursionTTL is the time recursive request is cached for.
 	recursionTTL = 1 * time.Second
@@ -151,7 +140,7 @@ func NewServer(p DNSCreateParams) (s *Server, err error) {
 			return nil, fmt.Errorf("local domain: %w", err)
 		}
 
-		localDomainSuffix = domainNameToSuffix(p.LocalDomain)
+		localDomainSuffix = p.LocalDomain
 	}
 
 	if p.Anonymizer == nil {

internal/dnsforward/dnsforward_test.go

@@ -1016,10 +1016,13 @@ func (d *testDHCP) Leases(flags dhcpd.GetLeasesFlags) (leases []*dhcpd.Lease) {
 func (d *testDHCP) SetOnLeaseChanged(onLeaseChanged dhcpd.OnLeaseChangedT) {}
 
 func TestPTRResponseFromDHCPLeases(t *testing.T) {
+	const localDomain = "lan"
+
 	s, err := NewServer(DNSCreateParams{
 		DNSFilter:   filtering.New(&filtering.Config{}, nil),
 		DHCPServer:  &testDHCP{},
 		PrivateNets: netutil.SubnetSetFunc(netutil.IsLocallyServed),
+		LocalDomain: localDomain,
 	})
 	require.NoError(t, err)
 
@@ -1033,14 +1036,13 @@ func TestPTRResponseFromDHCPLeases(t *testing.T) {
 
 	err = s.Start()
 	require.NoError(t, err)
-
 	t.Cleanup(s.Close)
 
 	addr := s.dnsProxy.Addr(proxy.ProtoUDP)
 	req := createTestMessageWithType("34.12.168.192.in-addr.arpa.", dns.TypePTR)
 
 	resp, err := dns.Exchange(req, addr.String())
-	require.NoError(t, err)
+	require.NoErrorf(t, err, "%s", addr)
 
 	require.Len(t, resp.Answer, 1)
 
@@ -1049,7 +1051,7 @@ func TestPTRResponseFromDHCPLeases(t *testing.T) {
 
 	ptr, ok := resp.Answer[0].(*dns.PTR)
 	require.True(t, ok)
-	assert.Equal(t, "myhost.", ptr.Ptr)
+	assert.Equal(t, dns.Fqdn("myhost."+localDomain), ptr.Ptr)
 }
 
 func TestPTRResponseFromHosts(t *testing.T) {