From 3db7457d303219130ff4131bcb91771e51a85c8d Mon Sep 17 00:00:00 2001
From: Daniel <dhaavi@users.noreply.github.com>
Date: Fri, 8 Jan 2021 16:37:00 +0100
Subject: [PATCH] Fix minor bugs

---
 intel/entity.go             |  9 +++++++--
 intel/filterlists/lookup.go | 19 +++++++++----------
 2 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/intel/entity.go b/intel/entity.go
index 16d83707..c98126f0 100644
--- a/intel/entity.go
+++ b/intel/entity.go
@@ -292,6 +292,7 @@ func (e *Entity) getDomainLists(ctx context.Context) {
 		return
 	}
 
+	var err error
 	e.loadDomainListOnce.Do(func() {
 		var domainsToInspect = []string{domain}
 
@@ -314,10 +315,10 @@ func (e *Entity) getDomainLists(ctx context.Context) {
 
 		for _, d := range domains {
 			log.Tracer(ctx).Tracef("intel: loading domain list for %s", d)
-			list, err := filterlists.LookupDomain(d)
+			var list []string
+			list, err = filterlists.LookupDomain(d)
 			if err != nil {
 				log.Tracer(ctx).Errorf("intel: failed to get domain blocklists for %s: %s", d, err)
-				e.loadDomainListOnce = sync.Once{}
 				return
 			}
 
@@ -325,6 +326,10 @@ func (e *Entity) getDomainLists(ctx context.Context) {
 		}
 		e.domainListLoaded = true
 	})
+
+	if err != nil {
+		e.loadDomainListOnce = sync.Once{}
+	}
 }
 
 func splitDomain(domain string) []string {
diff --git a/intel/filterlists/lookup.go b/intel/filterlists/lookup.go
index 827aeab9..a975c281 100644
--- a/intel/filterlists/lookup.go
+++ b/intel/filterlists/lookup.go
@@ -2,9 +2,7 @@ package filterlists
 
 import (
 	"errors"
-	"fmt"
 	"net"
-	"strings"
 
 	"github.com/safing/portbase/database"
 	"github.com/safing/portbase/log"
@@ -55,15 +53,16 @@ func LookupCountry(country string) ([]string, error) {
 
 // LookupDomain returns a list of sources that mark the domain
 // as blocked. If domain is not stored in the cache database
-// a nil slice is returned.
+// a nil slice is returned. The caller is responsible for making
+// sure that the given domain is valid and canonical.
 func LookupDomain(domain string) ([]string, error) {
-	// make sure we only fully qualified domains
-	// ending in a dot.
-	domain = strings.ToLower(domain)
-	if domain[len(domain)-1] != '.' {
-		domain += "."
+	switch domain {
+	case "", ".":
+		// Return no lists for empty domains and the root zone.
+		return nil, nil
+	default:
+		return lookupBlockLists("domain", domain)
 	}
-	return lookupBlockLists("domain", domain)
 }
 
 // LookupASNString returns a list of sources that mark the ASN
@@ -89,7 +88,7 @@ func LookupIP(ip net.IP) ([]string, error) {
 func LookupIPString(ipStr string) ([]string, error) {
 	ip := net.ParseIP(ipStr)
 	if ip == nil {
-		return nil, fmt.Errorf("invalid IP")
+		return nil, errors.New("invalid IP")
 	}
 
 	return LookupIP(ip)