From 09a39cce03f69b1f9801e66d763d7b5208411336 Mon Sep 17 00:00:00 2001
From: Eugene Bujak <hmage@hmage.net>
Date: Tue, 25 Sep 2018 19:26:26 +0300
Subject: [PATCH] Allow disabling of filtering but keeping querylog,
 safebrowsing, safesearch and parental working.

---
 config.go                             | 10 ++---
 coredns_plugin/coredns_plugin.go      | 55 ++++++++++++++-------------
 coredns_plugin/coredns_plugin_test.go |  3 +-
 3 files changed, 36 insertions(+), 32 deletions(-)

diff --git a/config.go b/config.go
index ee3d91df..e44345b4 100644
--- a/config.go
+++ b/config.go
@@ -160,16 +160,16 @@ func writeAllConfigs() error {
 }
 
 const coreDNSConfigTemplate = `. {
-    {{if .FilteringEnabled}}dnsfilter {{.FilterFile}} {
+    dnsfilter {{if .FilteringEnabled}}{{.FilterFile}}{{end}} {
         {{if .SafeBrowsingEnabled}}safebrowsing{{end}}
         {{if .ParentalEnabled}}parental {{.ParentalSensitivity}}{{end}}
         {{if .SafeSearchEnabled}}safesearch{{end}}
         {{if .QueryLogEnabled}}querylog{{end}}
-    }{{end}}
+    }
     {{.Pprof}}
-	hosts {
-		fallthrough
-	}
+    hosts {
+        fallthrough
+    }
     {{if .UpstreamDNS}}forward . {{range .UpstreamDNS}}{{.}} {{end}}{{end}}
     {{.Cache}}
     {{.Prometheus}}
diff --git a/coredns_plugin/coredns_plugin.go b/coredns_plugin/coredns_plugin.go
index 0000156c..09b64a9e 100644
--- a/coredns_plugin/coredns_plugin.go
+++ b/coredns_plugin/coredns_plugin.go
@@ -92,14 +92,12 @@ func setupPlugin(c *caddy.Controller) (*plug, error) {
 	p.d = dnsfilter.New()
 	p.hosts = make(map[string]net.IP)
 
-	var filterFileName string
+	filterFileNames := []string{}
 	for c.Next() {
 		args := c.RemainingArgs()
-		if len(args) == 0 {
-			// must have at least one argument
-			return nil, c.ArgErr()
+		if len(args) > 0 {
+			filterFileNames = append(filterFileNames, args...)
 		}
-		filterFileName = args[0]
 		for c.NextBlock() {
 			switch c.Val() {
 			case "safebrowsing":
@@ -139,34 +137,39 @@ func setupPlugin(c *caddy.Controller) (*plug, error) {
 		}
 	}
 
-	file, err := os.Open(filterFileName)
-	if err != nil {
-		return nil, err
-	}
-	defer file.Close()
+	log.Printf("filterFileNames = %+v", filterFileNames)
 
-	count := 0
-	scanner := bufio.NewScanner(file)
-	for scanner.Scan() {
-		text := scanner.Text()
-		if p.parseEtcHosts(text) {
-			continue
-		}
-		err = p.d.AddRule(text, 0)
-		if err == dnsfilter.ErrInvalidSyntax {
-			continue
-		}
+	for i, filterFileName := range filterFileNames {
+		file, err := os.Open(filterFileName)
 		if err != nil {
 			return nil, err
 		}
-		count++
-	}
-	log.Printf("Added %d rules from %s", count, filterFileName)
+		defer file.Close()
 
-	if err = scanner.Err(); err != nil {
-		return nil, err
+		count := 0
+		scanner := bufio.NewScanner(file)
+		for scanner.Scan() {
+			text := scanner.Text()
+			if p.parseEtcHosts(text) {
+				continue
+			}
+			err = p.d.AddRule(text, uint32(i))
+			if err == dnsfilter.ErrInvalidSyntax {
+				continue
+			}
+			if err != nil {
+				return nil, err
+			}
+			count++
+		}
+		log.Printf("Added %d rules from %s", count, filterFileName)
+
+		if err = scanner.Err(); err != nil {
+			return nil, err
+		}
 	}
 
+	var err error
 	p.upstream, err = upstream.New(nil)
 	if err != nil {
 		return nil, err
diff --git a/coredns_plugin/coredns_plugin_test.go b/coredns_plugin/coredns_plugin_test.go
index 5c309269..17210b63 100644
--- a/coredns_plugin/coredns_plugin_test.go
+++ b/coredns_plugin/coredns_plugin_test.go
@@ -20,7 +20,8 @@ func TestSetup(t *testing.T) {
 		config  string
 		failing bool
 	}{
-		{`dnsfilter`, true},
+		{`dnsfilter`, false},
+		{`dnsfilter /dev/nonexistent/abcdef`, true},
 		{`dnsfilter ../tests/dns.txt`, false},
 		{`dnsfilter ../tests/dns.txt { safebrowsing }`, false},
 		{`dnsfilter ../tests/dns.txt { parental }`, true},