Refactoring of FilterDNSResponse and DecideOnConnection

intel/block_reason.go

@@ -1,8 +1,12 @@
 package intel
 
 import (
+	"encoding/json"
 	"fmt"
 	"strings"
+
+	"github.com/miekg/dns"
+	"github.com/safing/portbase/log"
 )
 
 // ListMatch represents an entity that has been
@@ -45,7 +49,49 @@ func (br ListBlockReason) String() string {
 // Context returns br wrapped into a map. It implements
 // the endpoints.Reason interface.
 func (br ListBlockReason) Context() interface{} {
-	return map[string]interface{}{
-		"filterlists": br,
-	}
+	return br
+}
+
+// MarshalJSON marshals the list block reason into a map
+// prefixed with filterlists.
+func (br ListBlockReason) MarshalJSON() ([]byte, error) {
+	return json.Marshal(map[string]interface{}{
+		// we convert to []ListMatch to avoid recursing
+		// here.
+		"filterlists": []ListMatch(br),
+	})
+}
+
+// ToRRs returns a set of dns TXT records that describe the
+// block reason.
+func (br ListBlockReason) ToRRs() []dns.RR {
+	rrs := make([]dns.RR, 0, len(br))
+
+	for _, lm := range br {
+		blockedBy, err := dns.NewRR(fmt.Sprintf(
+			"%s-blockedBy.		0	IN	TXT 	%q",
+			strings.TrimRight(lm.Entity, "."),
+			strings.Join(lm.ActiveLists, ","),
+		))
+		if err == nil {
+			rrs = append(rrs, blockedBy)
+		} else {
+			log.Errorf("intel: failed to create TXT RR for block reason: %s", err)
+		}
+
+		if len(lm.InactiveLists) > 0 {
+			wouldBeBlockedBy, err := dns.NewRR(fmt.Sprintf(
+				"%s-wouldBeBlockedBy.		0	IN	TXT 	%q",
+				strings.TrimRight(lm.Entity, "."),
+				strings.Join(lm.ActiveLists, ","),
+			))
+			if err == nil {
+				rrs = append(rrs, wouldBeBlockedBy)
+			} else {
+				log.Errorf("intel: failed to create TXT RR for block reason: %s", err)
+			}
+		}
+	}
+
+	return rrs
 }

intel/entity.go

@@ -101,10 +101,10 @@ func (e *Entity) ResetLists() {
 	// list right now so we could be more efficient by keeping
 	// the other lists around.
 
-	// FIXME
-	//e.Lists = nil
-	//e.ListsMap = nil
+	e.BlockedByLists = nil
+	e.BlockedEntities = nil
 	e.ListOccurences = nil
+
 	e.domainListLoaded = false
 	e.ipListLoaded = false
 	e.countryListLoaded = false
@@ -421,15 +421,12 @@ func (e *Entity) getIPLists() {
 	})
 }
 
-// LoadLists searches all filterlists for all occurences of
+// LoadLists searches all filterlists for all occurrences of
 // this entity.
 func (e *Entity) LoadLists() bool {
 	e.getLists()
 
-	if e.ListOccurences == nil {
-		return false
-	}
-	return true
+	return e.ListOccurences != nil
 }
 
 // MatchLists matches the entities lists against a slice
@@ -450,6 +447,7 @@ func (e *Entity) MatchLists(lists []string) bool {
 	}
 
 	makeDistinct(e.BlockedByLists)
+	makeDistinct(e.BlockedEntities)
 
 	return len(e.BlockedByLists) > 0
 }
@@ -503,7 +501,7 @@ func mergeStringList(a, b []string) []string {
 
 func makeDistinct(slice []string) []string {
 	m := make(map[string]struct{}, len(slice))
-	var result []string
+	result := make([]string, 0, len(slice))
 
 	for _, v := range slice {
 		if _, ok := m[v]; ok {