refactor: DNS

constant/dns.go

@@ -1,5 +1,34 @@
 package constant
 
+const (
+	DefaultDNSTTL = 600
+)
+
+type DomainStrategy = uint8
+
+const (
+	DomainStrategyAsIS DomainStrategy = iota
+	DomainStrategyPreferIPv4
+	DomainStrategyPreferIPv6
+	DomainStrategyIPv4Only
+	DomainStrategyIPv6Only
+)
+
+const (
+	DNSTypeLegacy     = "legacy"
+	DNSTypeUDP        = "udp"
+	DNSTypeTCP        = "tcp"
+	DNSTypeTLS        = "tls"
+	DNSTypeHTTPS      = "https"
+	DNSTypeQUIC       = "quic"
+	DNSTypeHTTP3      = "h3"
+	DNSTypeHosts      = "hosts"
+	DNSTypeLocal      = "local"
+	DNSTypePreDefined = "predefined"
+	DNSTypeFakeIP     = "fakeip"
+	DNSTypeDHCP       = "dhcp"
+)
+
 const (
 	DNSProviderAliDNS     = "alidns"
 	DNSProviderCloudflare = "cloudflare"