Convert domain names to lowercase before matching (#195)

Co-authored-by: RPRX <63339210+rprx@users.noreply.github.com>

app/dns/server.go

@@ -364,6 +364,7 @@ func (s *Server) lookupIPInternal(domain string, option IPOption) ([]net.IP, err
 	if domain == "" {
 		return nil, newError("empty domain name")
 	}
+	domain = strings.ToLower(domain)
 
 	// normalize the FQDN form query
 	if domain[len(domain)-1] == '.' {

app/router/condition.go

@@ -91,7 +91,7 @@ func (m *DomainMatcher) Apply(ctx routing.Context) bool {
 	if len(domain) == 0 {
 		return false
 	}
-	return m.ApplyDomain(domain)
+	return m.ApplyDomain(strings.ToLower(domain))
 }
 
 type MultiGeoIPMatcher struct {