Feature: add geoip-code option

config/config.go

@@ -72,6 +72,7 @@ type DNS struct {
 // FallbackFilter config
 type FallbackFilter struct {
 	GeoIP     bool         `yaml:"geoip"`
+	GeoIPCode string       `yaml:"geoip-code"`
 	IPCIDR    []*net.IPNet `yaml:"ipcidr"`
 	Domain    []string     `yaml:"domain"`
 }
@@ -114,6 +115,7 @@ type RawDNS struct {
 
 type RawFallbackFilter struct {
 	GeoIP     bool     `yaml:"geoip"`
+	GeoIPCode string   `yaml:"geoip-code"`
 	IPCIDR    []string `yaml:"ipcidr"`
 	Domain    []string `yaml:"domain"`
 }
@@ -173,6 +175,7 @@ func UnmarshalRawConfig(buf []byte) (*RawConfig, error) {
 			FakeIPRange: "198.18.0.1/16",
 			FallbackFilter: RawFallbackFilter{
 				GeoIP:     true,
+				GeoIPCode: "CN",
 				IPCIDR:    []string{},
 			},
 			DefaultNameserver: []string{
@@ -600,6 +603,7 @@ func parseDNS(cfg RawDNS, hosts *trie.DomainTrie) (*DNS, error) {
 	}
 
 	dnsCfg.FallbackFilter.GeoIP = cfg.FallbackFilter.GeoIP
+	dnsCfg.FallbackFilter.GeoIPCode = cfg.FallbackFilter.GeoIPCode
 	if fallbackip, err := parseFallbackIPCIDR(cfg.FallbackFilter.IPCIDR); err == nil {
 		dnsCfg.FallbackFilter.IPCIDR = fallbackip
 	}

dns/filters.go

@@ -11,11 +11,13 @@ type fallbackIPFilter interface {
 	Match(net.IP) bool
 }
 
-type geoipFilter struct{}
+type geoipFilter struct {
+	code string
+}
 
 func (gf *geoipFilter) Match(ip net.IP) bool {
 	record, _ := mmdb.Instance().Country(ip)
-	return record.Country.IsoCode != "CN" && !ip.IsPrivate()
+	return record.Country.IsoCode != gf.code && !ip.IsPrivate()
 }
 
 type ipnetFilter struct {

dns/resolver.go

@@ -303,6 +303,7 @@ type NameServer struct {
 
 type FallbackFilter struct {
 	GeoIP     bool
+	GeoIPCode string
 	IPCIDR    []*net.IPNet
 	Domain    []string
 }
@@ -344,7 +345,9 @@ func NewResolver(config Config) *Resolver {
 
 	fallbackIPFilters := []fallbackIPFilter{}
 	if config.FallbackFilter.GeoIP {
-		fallbackIPFilters = append(fallbackIPFilters, &geoipFilter{})
+		fallbackIPFilters = append(fallbackIPFilters, &geoipFilter{
+			code: config.FallbackFilter.GeoIPCode,
+		})
 	}
 	for _, ipnet := range config.FallbackFilter.IPCIDR {
 		fallbackIPFilters = append(fallbackIPFilters, &ipnetFilter{ipnet: ipnet})

hub/executor/executor.go

@@ -124,6 +124,7 @@ func updateDNS(c *config.DNS) {
 		Hosts:        c.Hosts,
 		FallbackFilter: dns.FallbackFilter{
 			GeoIP:     c.FallbackFilter.GeoIP,
+			GeoIPCode: c.FallbackFilter.GeoIPCode,
 			IPCIDR:    c.FallbackFilter.IPCIDR,
 			Domain:    c.FallbackFilter.Domain,
 		},