all: sync with master; upd chlog

internal/filtering/dnsrewrite.go

@@ -1,6 +1,8 @@
 package filtering
 
 import (
+	"github.com/AdguardTeam/golibs/hostsfile"
+	"github.com/AdguardTeam/urlfilter"
 	"github.com/AdguardTeam/urlfilter/rules"
 	"github.com/miekg/dns"
 )
@@ -73,3 +75,59 @@ func (d *DNSFilter) processDNSRewrites(dnsr []*rules.NetworkRule) (res Result) {
 		Reason:           RewrittenRule,
 	}
 }
+
+// processDNSResultRewrites returns an empty Result if there are no dnsrewrite
+// rules in dnsres.  Otherwise, it returns the processed Result.
+func (d *DNSFilter) processDNSResultRewrites(
+	dnsres *urlfilter.DNSResult,
+	host string,
+) (dnsRWRes Result) {
+	dnsr := dnsres.DNSRewrites()
+	if len(dnsr) == 0 {
+		return Result{}
+	}
+
+	res := d.processDNSRewrites(dnsr)
+	if res.Reason == RewrittenRule && res.CanonName == host {
+		// A rewrite of a host to itself.  Go on and try matching other things.
+		return Result{}
+	}
+
+	return res
+}
+
+// appendRewriteResultFromHost appends the rewrite result from rec to vals and
+// resRules.
+func appendRewriteResultFromHost(
+	vals []rules.RRValue,
+	resRules []*ResultRule,
+	rec *hostsfile.Record,
+	qtype uint16,
+) (updatedVals []rules.RRValue, updatedRules []*ResultRule) {
+	switch qtype {
+	case dns.TypeA:
+		if !rec.Addr.Is4() {
+			return vals, resRules
+		}
+
+		vals = append(vals, rec.Addr)
+	case dns.TypeAAAA:
+		if !rec.Addr.Is6() {
+			return vals, resRules
+		}
+
+		vals = append(vals, rec.Addr)
+	case dns.TypePTR:
+		for _, name := range rec.Names {
+			vals = append(vals, name)
+		}
+	}
+
+	recText, _ := rec.MarshalText()
+	resRules = append(resRules, &ResultRule{
+		FilterListID: SysHostsListID,
+		Text:         string(recText),
+	})
+
+	return vals, resRules
+}