Refine DNS strategies

app/dns/options.go

@@ -0,0 +1,24 @@
+package dns
+
+import "github.com/xtls/xray-core/features/dns"
+
+type Option interface {
+	queryIPv4() bool
+	queryIPv6() bool
+	queryIP() bool
+	queryFake() bool
+	canDoQuery(c *Client) bool
+}
+
+func isIPQuery(o dns.IPOption) bool {
+	return o.IPv4Enable || o.IPv6Enable
+}
+
+func canQueryOnClient(o dns.IPOption, c *Client) bool {
+	isIPClient := !(c.Name() == FakeDNSName)
+	return isIPClient && isIPQuery(o)
+}
+
+func isQuery(o dns.IPOption) bool {
+	return !(o.IPv4Enable || o.IPv6Enable || o.FakeEnable)
+}