Respect proxy.mainProto in forward plugin (#1259)

* Respect proxy.mainProto in forward plugin

* Make the serverProtocol part of pluginsState instead

dnscrypt-proxy/plugin_forward.go

@@ -41,7 +41,10 @@ func (plugin *PluginForward) Init(proxy *Proxy) error {
 		}
 		domain, serversStr, ok := StringTwoFields(line)
 		if !ok {
-			return fmt.Errorf("Syntax error for a forwarding rule at line %d. Expected syntax: example.com: 9.9.9.9,8.8.8.8", 1+lineNo)
+			return fmt.Errorf(
+				"syntax error for a forwarding rule at line %d. Expected syntax: example.com 9.9.9.9,8.8.8.8",
+				1+lineNo,
+			)
 		}
 		domain = strings.ToLower(domain)
 		var servers []string
@@ -56,7 +59,8 @@ func (plugin *PluginForward) Init(proxy *Proxy) error {
 			continue
 		}
 		plugin.forwardMap = append(plugin.forwardMap, PluginForwardEntry{
-			domain: domain, servers: servers,
+			domain:  domain,
+			servers: servers,
 		})
 	}
 	return nil
@@ -89,7 +93,7 @@ func (plugin *PluginForward) Eval(pluginsState *PluginsState, msg *dns.Msg) erro
 	}
 	server := servers[rand.Intn(len(servers))]
 	pluginsState.serverName = server
-	client := dns.Client{Net: "udp"}
+	client := dns.Client{Net: pluginsState.serverProto}
 	respMsg, _, err := client.Exchange(msg, server)
 	if err != nil {
 		return err

dnscrypt-proxy/plugins.go

@@ -86,6 +86,7 @@ type PluginsState struct {
 	cacheHit                         bool
 	returnCode                       PluginsReturnCode
 	serverName                       string
+	serverProto                      string
 }
 
 func (proxy *Proxy) InitPluginsGlobals() error {
@@ -222,7 +223,7 @@ type Plugin interface {
 	Eval(pluginsState *PluginsState, msg *dns.Msg) error
 }
 
-func NewPluginsState(proxy *Proxy, clientProto string, clientAddr *net.Addr, start time.Time) PluginsState {
+func NewPluginsState(proxy *Proxy, clientProto string, clientAddr *net.Addr, serverProto string, start time.Time) PluginsState {
 	return PluginsState{
 		action:                           PluginsActionContinue,
 		returnCode:                       PluginsReturnCodePass,
@@ -238,6 +239,7 @@ func NewPluginsState(proxy *Proxy, clientProto string, clientAddr *net.Addr, sta
 		questionMsg:                      nil,
 		qName:                            "",
 		serverName:                       "-",
+		serverProto:                      serverProto,
 		requestStart:                     start,
 		maxUnencryptedUDPSafePayloadSize: MaxDNSUDPSafePacketSize,
 		sessionData:                      make(map[string]interface{}),

dnscrypt-proxy/proxy.go

@@ -443,7 +443,7 @@ func (proxy *Proxy) processIncomingQuery(clientProto string, serverProto string,
 	if len(query) < MinDNSPacketSize {
 		return
 	}
-	pluginsState := NewPluginsState(proxy, clientProto, clientAddr, start)
+	pluginsState := NewPluginsState(proxy, clientProto, clientAddr, serverProto, start)
 	serverName := "-"
 	needsEDNS0Padding := false
 	serverInfo := proxy.serversInfo.getOne()