dnsforward: add todo

internal/dnsforward/config.go

@@ -200,7 +200,7 @@ type FilteringConfig struct {
 // EDNSClientSubnet is the settings list for EDNS Client Subnet.
 type EDNSClientSubnet struct {
 	// CustomIP for EDNS Client Subnet.
-	CustomIP string `yaml:"custom_ip"`
+	CustomIP netip.Addr `yaml:"custom_ip"`
 
 	// Enabled defines if EDNS Client Subnet is enabled.
 	Enabled bool `yaml:"enabled"`
@@ -340,15 +340,8 @@ func (s *Server) createProxyConfig() (conf proxy.Config, err error) {
 	}
 
 	if srvConf.EDNSClientSubnet.UseCustom {
-		// TODO(s.chzhen):  Add wrapper around netip.Addr.
-		var ip net.IP
-		ip, err = netutil.ParseIP(srvConf.EDNSClientSubnet.CustomIP)
-		if err != nil {
-			return conf, fmt.Errorf("edns: %w", err)
-		}
-
 		// TODO(s.chzhen):  Use netip.Addr instead of net.IP inside dnsproxy.
-		conf.EDNSAddr = ip
+		conf.EDNSAddr = net.IP(srvConf.EDNSClientSubnet.CustomIP.AsSlice())
 	}
 
 	if srvConf.CacheSize != 0 {
@@ -377,7 +370,7 @@ func (s *Server) createProxyConfig() (conf proxy.Config, err error) {
 
 	err = s.prepareTLS(&conf)
 	if err != nil {
-		return conf, fmt.Errorf("validating tls: %w", err)
+		return proxy.Config{}, fmt.Errorf("validating tls: %w", err)
 	}
 
 	if c := srvConf.DNSCryptConfig; c.Enabled {
@@ -388,7 +381,7 @@ func (s *Server) createProxyConfig() (conf proxy.Config, err error) {
 	}
 
 	if conf.UpstreamConfig == nil || len(conf.UpstreamConfig.Upstreams) == 0 {
-		return conf, errors.Error("no default upstream servers configured")
+		return proxy.Config{}, errors.Error("no default upstream servers configured")
 	}
 
 	return conf, nil

internal/dnsforward/http.go

@@ -23,6 +23,8 @@ import (
 )
 
 // jsonDNSConfig is the JSON representation of the DNS server configuration.
+//
+// TODO(s.chzhen):  Split it into smaller pieces.
 type jsonDNSConfig struct {
 	// Upstreams is the list of upstream DNS servers.
 	Upstreams *[]string `json:"upstream_dns"`
@@ -86,7 +88,7 @@ type jsonDNSConfig struct {
 	BlockingIPv6 net.IP `json:"blocking_ipv6"`
 
 	// EDNSCSCustomIP is custom IP for EDNS Client Subnet.
-	EDNSCSCustomIP net.IP `json:"edns_cs_custom_ip"`
+	EDNSCSCustomIP netip.Addr `json:"edns_cs_custom_ip"`
 
 	// DefaultLocalPTRUpstreams is used to pass the addresses from
 	// systemResolvers to the front-end.  It's not a pointer to the slice since
@@ -107,19 +109,10 @@ func (s *Server) getDNSConfig() (c *jsonDNSConfig, err error) {
 	blockingIPv6 := s.conf.BlockingIPv6
 	ratelimit := s.conf.Ratelimit
 
-	var customIP net.IP
+	customIP := s.conf.EDNSClientSubnet.CustomIP
 	enableEDNSClientSubnet := s.conf.EDNSClientSubnet.Enabled
 	useCustom := s.conf.EDNSClientSubnet.UseCustom
 
-	if useCustom {
-		customIP, err = netutil.ParseIP(s.conf.EDNSClientSubnet.CustomIP)
-		if err != nil {
-			log.Debug("getting edns client subnet: %s", err)
-
-			return nil, err
-		}
-	}
-
 	enableDNSSEC := s.conf.EnableDNSSEC
 	aaaaDisabled := s.conf.AAAADisabled
 	cacheSize := s.conf.CacheSize
@@ -232,11 +225,6 @@ func (req *jsonDNSConfig) validate(privateNets netutil.SubnetSet) (err error) {
 		}
 	}
 
-	err = validateEDNSCustomIP(req.EDNSCSUseCustom, req.EDNSCSCustomIP)
-	if err != nil {
-		return fmt.Errorf("validating edns client subnet: %w", err)
-	}
-
 	err = req.checkBootstrap()
 	if err != nil {
 		return err
@@ -321,7 +309,7 @@ func (s *Server) setConfig(dc *jsonDNSConfig) (shouldRestart bool) {
 	}
 
 	if dc.EDNSCSUseCustom != nil && *dc.EDNSCSUseCustom {
-		s.conf.EDNSClientSubnet.CustomIP = dc.EDNSCSCustomIP.String()
+		s.conf.EDNSClientSubnet.CustomIP = dc.EDNSCSCustomIP
 	}
 
 	setIfNotNil(&s.conf.ProtectionEnabled, dc.ProtectionEnabled)
@@ -530,15 +518,6 @@ func validateUpstream(u string, domains []string) (useDefault bool, err error) {
 	return false, err
 }
 
-// validateEDNSCustomIP validates parameters for EDNS Client Subnet.
-func validateEDNSCustomIP(useCustom *bool, customIP net.IP) (err error) {
-	if useCustom == nil || !*useCustom {
-		return nil
-	}
-
-	return netutil.ValidateIP(customIP)
-}
-
 // separateUpstream returns the upstream and the specified domains.  domains is
 // nil when the upstream is not domains-specific.  Otherwise it may also be
 // empty.

internal/dnsforward/http_test.go

@@ -186,7 +186,7 @@ func TestDNSForwardHTTP_handleSetConfig(t *testing.T) {
 		wantSet: "",
 	}, {
 		name:    "edns_cs_use_custom_bad_ip",
-		wantSet: "decoding request: invalid IP address: bad.ip",
+		wantSet: "decoding request: ParseAddr(\"bad.ip\"): unexpected character (at \"bad.ip\")",
 	}, {
 		name:    "dnssec_enabled",
 		wantSet: "",