feat(http2): support OPTIONS * and extended CONNECT

http2xconnect.go

@@ -0,0 +1,53 @@
+// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at https://mozilla.org/MPL/2.0/.
+// Copyright 2026 WJQSERVER. All rights reserved.
+// All rights reserved by WJQSERVER, related rights can be exercised by the infinite-iroha organization.
+package touka
+
+import (
+	"context"
+	"crypto/tls"
+	"net"
+	"net/http"
+	"net/url"
+	"strings"
+	"sync"
+	_ "unsafe"
+
+	"golang.org/x/net/http2"
+)
+
+var enableHTTP2ExtendedConnectOnce sync.Once
+
+//go:linkname xnetDisableHTTP2ExtendedConnectProtocol golang.org/x/net/http2.disableExtendedConnectProtocol
+var xnetDisableHTTP2ExtendedConnectProtocol bool
+
+func enableHTTP2ExtendedConnectProtocol() {
+	enableHTTP2ExtendedConnectOnce.Do(func() {
+		xnetDisableHTTP2ExtendedConnectProtocol = false
+	})
+}
+
+func configureHTTP2ExtendedConnectServer(srv *http.Server) error {
+	if srv == nil {
+		return nil
+	}
+	enableHTTP2ExtendedConnectProtocol()
+	return http2.ConfigureServer(srv, nil)
+}
+
+func newHTTP2ExtendedConnectTransport(target *url.URL) http.RoundTripper {
+	enableHTTP2ExtendedConnectProtocol()
+
+	transport := &http2.Transport{}
+	if target == nil || !strings.EqualFold(target.Scheme, "http") {
+		return transport
+	}
+
+	transport.AllowHTTP = true
+	transport.DialTLSContext = func(ctx context.Context, network, addr string, _ *tls.Config) (net.Conn, error) {
+		var dialer net.Dialer
+		return dialer.DialContext(ctx, network, addr)
+	}
+	return transport
+}