Pull request: all: imp code, decr cyclo

Updates #2646.

Squashed commit of the following:

commit c83c230f3d2c542d7b1a4bc0e1c503d5bbc16cb8
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Mar 25 19:47:11 2021 +0300

    all: imp code, decr cyclo

internal/dnsfilter/blocked.go

@@ -254,7 +254,7 @@ func BlockedSvcKnown(s string) bool {
 }
 
 // ApplyBlockedServices - set blocked services settings for this DNS request
-func (d *DNSFilter) ApplyBlockedServices(setts *RequestFilteringSettings, list []string, global bool) {
+func (d *DNSFilter) ApplyBlockedServices(setts *FilteringSettings, list []string, global bool) {
 	setts.ServicesRules = []ServiceEntry{}
 	if global {
 		d.confLock.RLock()

internal/dnsfilter/dnsfilter.go

@@ -29,18 +29,18 @@ type ServiceEntry struct {
 	Rules []*rules.NetworkRule
 }
 
-// RequestFilteringSettings is custom filtering settings
+// FilteringSettings are custom filtering settings for a client.
-type RequestFilteringSettings struct {
+type FilteringSettings struct {
-	FilteringEnabled    bool
-	SafeSearchEnabled   bool
-	SafeBrowsingEnabled bool
-	ParentalEnabled     bool
-
 	ClientName string
 	ClientIP   net.IP
 	ClientTags []string
 
 	ServicesRules []ServiceEntry
+
+	FilteringEnabled    bool
+	SafeSearchEnabled   bool
+	SafeBrowsingEnabled bool
+	ParentalEnabled     bool
 }
 
 // Resolver is the interface for net.Resolver to simplify testing.
@@ -99,6 +99,11 @@ type filtersInitializerParams struct {
 	blockFilters []Filter
 }
 
+type hostChecker struct {
+	check func(host string, qtype uint16, setts *FilteringSettings) (res Result, err error)
+	name  string
+}
+
 // DNSFilter matches hostnames and DNS requests against filtering rules.
 type DNSFilter struct {
 	rulesStorage         *filterlist.RuleStorage
@@ -123,6 +128,8 @@ type DNSFilter struct {
 	//
 	// TODO(e.burkov): Use upstream that configured in dnsforward instead.
 	resolver Resolver
+
+	hostCheckers []hostChecker
 }
 
 // Filter represents a filter list
@@ -216,8 +223,8 @@ func (r Reason) In(reasons ...Reason) bool {
 }
 
 // GetConfig - get configuration
-func (d *DNSFilter) GetConfig() RequestFilteringSettings {
+func (d *DNSFilter) GetConfig() FilteringSettings {
-	c := RequestFilteringSettings{}
+	c := FilteringSettings{}
 	// d.confLock.RLock()
 	c.SafeSearchEnabled = d.Config.SafeSearchEnabled
 	c.SafeBrowsingEnabled = d.Config.SafeBrowsingEnabled
@@ -372,122 +379,85 @@ func (r Reason) Matched() bool {
 }
 
 // CheckHostRules tries to match the host against filtering rules only.
-func (d *DNSFilter) CheckHostRules(host string, qtype uint16, setts *RequestFilteringSettings) (Result, error) {
+func (d *DNSFilter) CheckHostRules(host string, qtype uint16, setts *FilteringSettings) (Result, error) {
 	if !setts.FilteringEnabled {
 		return Result{}, nil
 	}
 
-	return d.matchHost(host, qtype, *setts)
+	return d.matchHost(host, qtype, setts)
 }
 
-// CheckHost tries to match the host against filtering rules, then
+// CheckHost tries to match the host against filtering rules, then safebrowsing
-// safebrowsing and parental control rules, if they are enabled.
+// and parental control rules, if they are enabled.
-func (d *DNSFilter) CheckHost(host string, qtype uint16, setts *RequestFilteringSettings) (Result, error) {
+func (d *DNSFilter) CheckHost(
-	// sometimes DNS clients will try to resolve ".", which is a request to get root servers
+	host string,
+	qtype uint16,
+	setts *FilteringSettings,
+) (res Result, err error) {
+	// Sometimes clients try to resolve ".", which is a request to get root
+	// servers.
 	if host == "" {
 		return Result{Reason: NotFilteredNotFound}, nil
 	}
+
 	host = strings.ToLower(host)
 
-	var result Result
+	res = d.processRewrites(host, qtype)
-	var err error
+	if res.Reason == Rewritten {
-
+		return res, nil
-	// first - check rewrites, they have the highest priority
-	result = d.processRewrites(host, qtype)
-	if result.Reason == Rewritten {
-		return result, nil
 	}
 
-	// Now check the hosts file -- do we have any rules for it?
+	for _, hc := range d.hostCheckers {
-	// just like DNS rewrites, it has higher priority than filtering rules.
+		res, err = hc.check(host, qtype, setts)
-	if d.Config.AutoHosts != nil {
-		matched := d.checkAutoHosts(host, qtype, &result)
-		if matched {
-			return result, nil
-		}
-	}
-
-	if setts.FilteringEnabled {
-		result, err = d.matchHost(host, qtype, *setts)
 		if err != nil {
-			return result, err
+			return Result{}, fmt.Errorf("%s: %w", hc.name, err)
-		}
-		if result.Reason.Matched() {
-			return result, nil
-		}
 		}
 
-	// are there any blocked services?
+		if res.Reason.Matched() {
-	if len(setts.ServicesRules) != 0 {
+			return res, nil
-		result = matchBlockedServicesRules(host, setts.ServicesRules)
-		if result.Reason.Matched() {
-			return result, nil
-		}
-	}
-
-	// browsing security web service
-	if setts.SafeBrowsingEnabled {
-		result, err = d.checkSafeBrowsing(host)
-		if err != nil {
-			log.Info("SafeBrowsing: failed: %v", err)
-			return Result{}, nil
-		}
-		if result.Reason.Matched() {
-			return result, nil
-		}
-	}
-
-	// parental control web service
-	if setts.ParentalEnabled {
-		result, err = d.checkParental(host)
-		if err != nil {
-			log.Printf("Parental: failed: %v", err)
-			return Result{}, nil
-		}
-		if result.Reason.Matched() {
-			return result, nil
-		}
-	}
-
-	// apply safe search if needed
-	if setts.SafeSearchEnabled {
-		result, err = d.checkSafeSearch(host)
-		if err != nil {
-			log.Info("SafeSearch: failed: %v", err)
-			return Result{}, nil
-		}
-
-		if result.Reason.Matched() {
-			return result, nil
 		}
 	}
 
 	return Result{}, nil
 }
 
-func (d *DNSFilter) checkAutoHosts(host string, qtype uint16, result *Result) (matched bool) {
+// checkAutoHosts compares the host against our autohosts table.  The err is
+// always nil, it is only there to make this a valid hostChecker function.
+func (d *DNSFilter) checkAutoHosts(
+	host string,
+	qtype uint16,
+	_ *FilteringSettings,
+) (res Result, err error) {
+	if d.Config.AutoHosts == nil {
+		return Result{}, nil
+	}
+
 	ips := d.Config.AutoHosts.Process(host, qtype)
 	if ips != nil {
-		result.Reason = RewrittenAutoHosts
+		res = Result{
-		result.IPList = ips
+			Reason: RewrittenAutoHosts,
+			IPList: ips,
+		}
 
-		return true
+		return res, nil
 	}
 
 	revHosts := d.Config.AutoHosts.ProcessReverse(host, qtype)
 	if len(revHosts) != 0 {
-		result.Reason = RewrittenAutoHosts
+		res = Result{
+			Reason: RewrittenAutoHosts,
+		}
 
 		// TODO(a.garipov): Optimize this with a buffer.
-		result.ReverseHosts = make([]string, len(revHosts))
+		res.ReverseHosts = make([]string, len(revHosts))
 		for i := range revHosts {
-			result.ReverseHosts[i] = revHosts[i] + "."
+			res.ReverseHosts[i] = revHosts[i] + "."
 		}
 
-		return true
+		return res, nil
 	}
 
-	return false
+	return Result{}, nil
 }
 
 // Process rewrites table
@@ -545,10 +515,20 @@ func (d *DNSFilter) processRewrites(host string, qtype uint16) (res Result) {
 	return res
 }
 
-func matchBlockedServicesRules(host string, svcs []ServiceEntry) Result {
+// matchBlockedServicesRules checks the host against the blocked services rules
-	req := rules.NewRequestForHostname(host)
+// in settings, if any.  The err is always nil, it is only there to make this
-	res := Result{}
+// a valid hostChecker function.
+func matchBlockedServicesRules(
+	host string,
+	_ uint16,
+	setts *FilteringSettings,
+) (res Result, err error) {
+	svcs := setts.ServicesRules
+	if len(svcs) == 0 {
+		return Result{}, nil
+	}
 
+	req := rules.NewRequestForHostname(host)
 	for _, s := range svcs {
 		for _, rule := range s.Rules {
 			if rule.Match(req) {
@@ -565,11 +545,12 @@ func matchBlockedServicesRules(host string, svcs []ServiceEntry) Result {
 				log.Debug("blocked services: matched rule: %s  host: %s  service: %s",
 					ruleText, host, s.Name)
 
-				return res
+				return res, nil
 			}
 		}
 	}
-	return res
+
+	return res, nil
 }
 
 //
@@ -680,7 +661,15 @@ func (d *DNSFilter) matchHostProcessAllowList(host string, dnsres urlfilter.DNSR
 
 // matchHost is a low-level way to check only if hostname is filtered by rules,
 // skipping expensive safebrowsing and parental lookups.
-func (d *DNSFilter) matchHost(host string, qtype uint16, setts RequestFilteringSettings) (res Result, err error) {
+func (d *DNSFilter) matchHost(
+	host string,
+	qtype uint16,
+	setts *FilteringSettings,
+) (res Result, err error) {
+	if !setts.FilteringEnabled {
+		return Result{}, nil
+	}
+
 	d.engineLock.RLock()
 	// Keep in mind that this lock must be held no just when calling Match()
 	//  but also while using the rules returned by it.
@@ -827,6 +816,26 @@ func New(c *Config, blockFilters []Filter) *DNSFilter {
 		resolver: resolver,
 	}
 
+	d.hostCheckers = []hostChecker{{
+		check: d.checkAutoHosts,
+		name:  "autohosts",
+	}, {
+		check: d.matchHost,
+		name:  "filtering",
+	}, {
+		check: matchBlockedServicesRules,
+		name:  "blocked services",
+	}, {
+		check: d.checkSafeBrowsing,
+		name:  "safe browsing",
+	}, {
+		check: d.checkParental,
+		name:  "parental",
+	}, {
+		check: d.checkSafeSearch,
+		name:  "safe search",
+	}}
+
 	err := d.initSecurityServices()
 	if err != nil {
 		log.Error("dnsfilter: initialize services: %s", err)

internal/dnsfilter/dnsfilter_test.go

@@ -21,7 +21,7 @@ func TestMain(m *testing.M) {
 	aghtest.DiscardLogOutput(m)
 }
 
-var setts RequestFilteringSettings
+var setts FilteringSettings
 
 // Helpers.
 
@@ -38,7 +38,7 @@ func purgeCaches() {
 }
 
 func newForTest(c *Config, filters []Filter) *DNSFilter {
-	setts = RequestFilteringSettings{
+	setts = FilteringSettings{
 		FilteringEnabled: true,
 	}
 	setts.FilteringEnabled = true
@@ -699,7 +699,7 @@ func TestWhitelist(t *testing.T) {
 
 // Client Settings.
 
-func applyClientSettings(setts *RequestFilteringSettings) {
+func applyClientSettings(setts *FilteringSettings) {
 	setts.FilteringEnabled = false
 	setts.ParentalEnabled = false
 	setts.SafeBrowsingEnabled = true

internal/dnsfilter/dnsrewrite_test.go

@@ -47,7 +47,7 @@ func TestDNSFilter_CheckHostRules_dnsrewrite(t *testing.T) {
 `
 
 	f := newForTest(nil, []Filter{{ID: 0, Data: []byte(text)}})
-	setts := &RequestFilteringSettings{
+	setts := &FilteringSettings{
 		FilteringEnabled: true,
 	}
 

internal/dnsfilter/safebrowsing.go

@@ -304,46 +304,70 @@ func check(c *sbCtx, r Result, u upstream.Upstream) (Result, error) {
 	return Result{}, nil
 }
 
-func (d *DNSFilter) checkSafeBrowsing(host string) (Result, error) {
+// TODO(a.garipov): Unify with checkParental.
+func (d *DNSFilter) checkSafeBrowsing(
+	host string,
+	_ uint16,
+	setts *FilteringSettings,
+) (res Result, err error) {
+	if !setts.SafeBrowsingEnabled {
+		return Result{}, nil
+	}
+
 	if log.GetLevel() >= log.DEBUG {
 		timer := log.StartTimer()
 		defer timer.LogElapsed("SafeBrowsing lookup for %s", host)
 	}
-	ctx := &sbCtx{
+
+	sctx := &sbCtx{
 		host:      host,
 		svc:       "SafeBrowsing",
 		cache:     gctx.safebrowsingCache,
 		cacheTime: d.Config.CacheTime,
 	}
-	res := Result{
+
+	res = Result{
 		IsFiltered: true,
 		Reason:     FilteredSafeBrowsing,
 		Rules: []*ResultRule{{
 			Text: "adguard-malware-shavar",
 		}},
 	}
-	return check(ctx, res, d.safeBrowsingUpstream)
+
+	return check(sctx, res, d.safeBrowsingUpstream)
+}
+
+// TODO(a.garipov): Unify with checkSafeBrowsing.
+func (d *DNSFilter) checkParental(
+	host string,
+	_ uint16,
+	setts *FilteringSettings,
+) (res Result, err error) {
+	if !setts.ParentalEnabled {
+		return Result{}, nil
 	}
 
-func (d *DNSFilter) checkParental(host string) (Result, error) {
 	if log.GetLevel() >= log.DEBUG {
 		timer := log.StartTimer()
 		defer timer.LogElapsed("Parental lookup for %s", host)
 	}
-	ctx := &sbCtx{
+
+	sctx := &sbCtx{
 		host:      host,
 		svc:       "Parental",
 		cache:     gctx.parentalCache,
 		cacheTime: d.Config.CacheTime,
 	}
-	res := Result{
+
+	res = Result{
 		IsFiltered: true,
 		Reason:     FilteredParental,
 		Rules: []*ResultRule{{
 			Text: "parental CATEGORY_BLACKLISTED",
 		}},
 	}
-	return check(ctx, res, d.parentalUpstream)
+
+	return check(sctx, res, d.parentalUpstream)
 }
 
 func httpError(r *http.Request, w http.ResponseWriter, code int, format string, args ...interface{}) {

internal/dnsfilter/safebrowsing_test.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/AdguardTeam/AdGuardHome/internal/aghtest"
 	"github.com/AdguardTeam/golibs/cache"
+	"github.com/miekg/dns"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -115,11 +116,16 @@ func TestSBPC_checkErrorUpstream(t *testing.T) {
 	d.SetSafeBrowsingUpstream(ups)
 	d.SetParentalUpstream(ups)
 
-	_, err := d.checkSafeBrowsing("smthng.com")
+	setts := &FilteringSettings{
-	assert.NotNil(t, err)
+		SafeBrowsingEnabled: true,
+		ParentalEnabled:     true,
+	}
 
-	_, err = d.checkParental("smthng.com")
+	_, err := d.checkSafeBrowsing("smthng.com", dns.TypeA, setts)
-	assert.NotNil(t, err)
+	assert.Error(t, err)
+
+	_, err = d.checkParental("smthng.com", dns.TypeA, setts)
+	assert.Error(t, err)
 }
 
 func TestSBPC(t *testing.T) {
@@ -128,10 +134,15 @@ func TestSBPC(t *testing.T) {
 
 	const hostname = "example.org"
 
+	setts := &FilteringSettings{
+		SafeBrowsingEnabled: true,
+		ParentalEnabled:     true,
+	}
+
 	testCases := []struct {
 		name      string
 		block     bool
-		testFunc  func(string) (Result, error)
+		testFunc  func(host string, _ uint16, _ *FilteringSettings) (res Result, err error)
 		testCache cache.Cache
 	}{{
 		name:      "sb_no_block",
@@ -167,8 +178,9 @@ func TestSBPC(t *testing.T) {
 		t.Run(tc.name, func(t *testing.T) {
 			// Firstly, check the request blocking.
 			hits := 0
-			res, err := tc.testFunc(hostname)
+			res, err := tc.testFunc(hostname, dns.TypeA, setts)
-			require.Nil(t, err)
+			require.NoError(t, err)
+
 			if tc.block {
 				assert.True(t, res.IsFiltered)
 				require.Len(t, res.Rules, 1)
@@ -185,8 +197,9 @@ func TestSBPC(t *testing.T) {
 			assert.Equal(t, 1, ups.RequestsCount())
 
 			// Now make the same request to check the cache was used.
-			res, err = tc.testFunc(hostname)
+			res, err = tc.testFunc(hostname, dns.TypeA, setts)
-			require.Nil(t, err)
+			require.NoError(t, err)
+
 			if tc.block {
 				assert.True(t, res.IsFiltered)
 				require.Len(t, res.Rules, 1)

internal/dnsfilter/safesearch.go

@@ -69,7 +69,15 @@ func (d *DNSFilter) SafeSearchDomain(host string) (string, bool) {
 	return val, ok
 }
 
-func (d *DNSFilter) checkSafeSearch(host string) (Result, error) {
+func (d *DNSFilter) checkSafeSearch(
+	host string,
+	_ uint16,
+	setts *FilteringSettings,
+) (res Result, err error) {
+	if !setts.SafeSearchEnabled {
+		return Result{}, nil
+	}
+
 	if log.GetLevel() >= log.DEBUG {
 		timer := log.StartTimer()
 		defer timer.LogElapsed("SafeSearch: lookup for %s", host)
@@ -88,7 +96,7 @@ func (d *DNSFilter) checkSafeSearch(host string) (Result, error) {
 		return Result{}, nil
 	}
 
-	res := Result{
+	res = Result{
 		IsFiltered: true,
 		Reason:     FilteredSafeSearch,
 		Rules:      []*ResultRule{{}},

internal/dnsforward/config.go

@@ -25,7 +25,7 @@ type FilteringConfig struct {
 	// --
 
 	// FilterHandler is an optional additional filtering callback.
-	FilterHandler func(clientAddr net.IP, clientID string, settings *dnsfilter.RequestFilteringSettings) `yaml:"-"`
+	FilterHandler func(clientAddr net.IP, clientID string, settings *dnsfilter.FilteringSettings) `yaml:"-"`
 
 	// GetCustomUpstreamByClient - a callback function that returns upstreams configuration
 	// based on the client IP address. Returns nil if there are no custom upstreams for the client

internal/dnsforward/dns.go

@@ -20,7 +20,7 @@ type dnsContext struct {
 	srv      *Server
 	proxyCtx *proxy.DNSContext
 	// setts are the filtering settings for the client.
-	setts     *dnsfilter.RequestFilteringSettings
+	setts     *dnsfilter.FilteringSettings
 	startTime time.Time
 	result    *dnsfilter.Result
 	// origResp is the response received from upstream.  It is set when the

internal/dnsforward/dnsforward_test.go

@@ -632,7 +632,7 @@ func TestClientRulesForCNAMEMatching(t *testing.T) {
 		TCPListenAddrs: []*net.TCPAddr{{}},
 		FilteringConfig: FilteringConfig{
 			ProtectionEnabled: true,
-			FilterHandler: func(_ net.IP, _ string, settings *dnsfilter.RequestFilteringSettings) {
+			FilterHandler: func(_ net.IP, _ string, settings *dnsfilter.FilteringSettings) {
 				settings.FilteringEnabled = false
 			},
 		},

internal/dnsforward/filter.go

@@ -32,7 +32,7 @@ func (s *Server) beforeRequestHandler(_ *proxy.Proxy, d *proxy.DNSContext) (bool
 
 // getClientRequestFilteringSettings looks up client filtering settings using
 // the client's IP address and ID, if any, from ctx.
-func (s *Server) getClientRequestFilteringSettings(ctx *dnsContext) *dnsfilter.RequestFilteringSettings {
+func (s *Server) getClientRequestFilteringSettings(ctx *dnsContext) *dnsfilter.FilteringSettings {
 	setts := s.dnsFilter.GetConfig()
 	setts.FilteringEnabled = true
 	if s.conf.FilterHandler != nil {

internal/home/dns.go

@@ -276,7 +276,7 @@ func getDNSEncryption() (de dnsEncryption) {
 
 // applyAdditionalFiltering adds additional client information and settings if
 // the client has them.
-func applyAdditionalFiltering(clientAddr net.IP, clientID string, setts *dnsfilter.RequestFilteringSettings) {
+func applyAdditionalFiltering(clientAddr net.IP, clientID string, setts *dnsfilter.FilteringSettings) {
 	Context.dnsFilter.ApplyBlockedServices(setts, nil, true)
 
 	if clientAddr == nil {

internal/querylog/decode.go

@@ -375,6 +375,64 @@ func decodeResultIPList(dec *json.Decoder, ent *logEntry) {
 	}
 }
 
+func decodeResultDNSRewriteResultKey(key string, dec *json.Decoder, ent *logEntry) {
+	var err error
+
+	switch key {
+	case "RCode":
+		var vToken json.Token
+		vToken, err = dec.Token()
+		if err != nil {
+			if err != io.EOF {
+				log.Debug("decodeResultDNSRewriteResultKey err: %s", err)
+			}
+
+			return
+		}
+
+		if ent.Result.DNSRewriteResult == nil {
+			ent.Result.DNSRewriteResult = &dnsfilter.DNSRewriteResult{}
+		}
+
+		if n, ok := vToken.(json.Number); ok {
+			rcode64, _ := n.Int64()
+			ent.Result.DNSRewriteResult.RCode = rules.RCode(rcode64)
+		}
+	case "Response":
+		if ent.Result.DNSRewriteResult == nil {
+			ent.Result.DNSRewriteResult = &dnsfilter.DNSRewriteResult{}
+		}
+
+		if ent.Result.DNSRewriteResult.Response == nil {
+			ent.Result.DNSRewriteResult.Response = dnsfilter.DNSRewriteResultResponse{}
+		}
+
+		// TODO(a.garipov): I give up.  This whole file is a mess.
+		// Luckily, we can assume that this field is relatively rare and
+		// just use the normal decoding and correct the values.
+		err = dec.Decode(&ent.Result.DNSRewriteResult.Response)
+		if err != nil {
+			log.Debug("decodeResultDNSRewriteResultKey response err: %s", err)
+		}
+
+		for rrType, rrValues := range ent.Result.DNSRewriteResult.Response {
+			switch rrType {
+			case
+				dns.TypeA,
+				dns.TypeAAAA:
+				for i, v := range rrValues {
+					s, _ := v.(string)
+					rrValues[i] = net.ParseIP(s)
+				}
+			default:
+				// Go on.
+			}
+		}
+	default:
+		// Go on.
+	}
+}
+
 func decodeResultDNSRewriteResult(dec *json.Decoder, ent *logEntry) {
 	for {
 		keyToken, err := dec.Token()
@@ -401,66 +459,7 @@ func decodeResultDNSRewriteResult(dec *json.Decoder, ent *logEntry) {
 			return
 		}
 
-		// TODO(a.garipov): Refactor this into a separate
+		decodeResultDNSRewriteResultKey(key, dec, ent)
-		// function à la decodeResultRuleKey if we keep this
-		// code for a longer time than planned.
-		switch key {
-		case "RCode":
-			var vToken json.Token
-			vToken, err = dec.Token()
-			if err != nil {
-				if err != io.EOF {
-					log.Debug("decodeResultDNSRewriteResult err: %s", err)
-				}
-
-				return
-			}
-
-			if ent.Result.DNSRewriteResult == nil {
-				ent.Result.DNSRewriteResult = &dnsfilter.DNSRewriteResult{}
-			}
-
-			var n json.Number
-			if n, ok = vToken.(json.Number); ok {
-				rcode64, _ := n.Int64()
-				ent.Result.DNSRewriteResult.RCode = rules.RCode(rcode64)
-			}
-
-			continue
-		case "Response":
-			if ent.Result.DNSRewriteResult == nil {
-				ent.Result.DNSRewriteResult = &dnsfilter.DNSRewriteResult{}
-			}
-
-			if ent.Result.DNSRewriteResult.Response == nil {
-				ent.Result.DNSRewriteResult.Response = dnsfilter.DNSRewriteResultResponse{}
-			}
-
-			// TODO(a.garipov): I give up.  This whole file
-			// is a mess.  Luckily, we can assume that this
-			// field is relatively rare and just use the
-			// normal decoding and correct the values.
-			err = dec.Decode(&ent.Result.DNSRewriteResult.Response)
-			if err != nil {
-				log.Debug("decodeResultDNSRewriteResult response err: %s", err)
-			}
-
-			for rrType, rrValues := range ent.Result.DNSRewriteResult.Response {
-				switch rrType {
-				case dns.TypeA, dns.TypeAAAA:
-					for i, v := range rrValues {
-						s, _ := v.(string)
-						rrValues[i] = net.ParseIP(s)
-					}
-				default:
-					// Go on.
-				}
-			}
-
-			continue
-		default:
-			// Go on.
-		}
 	}
 }