TUN inbound: Add autoSystemWfpBlockLeak on Windows (blocks "dns" and "misconfigtun" IPv4/IPv6 traffic leaks outside the TUN); Rename autoSystemDNS to autoSystemDnsToGateway on Linux (and change some behaviors) (#6853)

https://github.com/XTLS/Xray-core/pull/6853#issuecomment-5899791359
https://github.com/XTLS/Xray-core/pull/6853#issuecomment-5901287980
https://github.com/XTLS/Xray-core/pull/6853#issuecomment-5903680113
https://github.com/XTLS/Xray-core/pull/6853#issuecomment-5904123488
https://github.com/XTLS/Xray-core/pull/6853#issuecomment-5904647772
https://github.com/XTLS/Xray-core/pull/6853#issuecomment-5905047424

Fixes https://github.com/XTLS/Xray-core/issues/6454#issuecomment-5863800676

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

features/dns/localdns/client.go

@@ -97,6 +97,9 @@ func New() *Client {
 	r := &net.Resolver{
 		PreferGo: true,
 		Dial: func(ctx context.Context, network, address string) (net.Conn, error) {
+			if internet.IsSkippedDNSServer(address) {
+				return nil, errors.New("skipped DNS server ", address)
+			}
 			return d.DialContext(ctx, network, address)
 		},
 	}

features/dns/localdns/client_test.go

@@ -0,0 +1,23 @@
+package localdns
+
+import (
+	"context"
+	"net/netip"
+	"testing"
+
+	"github.com/xtls/xray-core/transport/internet"
+)
+
+func TestSkippedDNSServers(t *testing.T) {
+	internet.SkipDNSServers([]netip.Addr{netip.MustParseAddr("203.0.113.53")})
+	t.Cleanup(func() { internet.SkipDNSServers(nil) })
+	c := New()
+	if _, err := c.r.Dial(context.Background(), "udp", "203.0.113.53:53"); err == nil {
+		t.Error("a skipped DNS server was dialed")
+	}
+	conn, err := c.r.Dial(context.Background(), "udp", "127.0.0.1:53")
+	if err != nil {
+		t.Fatal(err)
+	}
+	conn.Close()
+}