feat: add proxy cors

Signed-off-by: rogerogers <rogers@rogerogers.com>

proxy_cors.go

@@ -0,0 +1,85 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2016 Gin-Gonic
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+
+ * This file may have been modified by CloudWeGo authors. All CloudWeGo
+ * Modifications are Copyright 2024 CloudWeGo Authors.
+ */
+
+package cors
+
+import (
+	"bytes"
+	"context"
+
+	"github.com/cloudwego/hertz/pkg/app/client"
+	"github.com/cloudwego/hertz/pkg/protocol"
+)
+
+func NewProxyCors(config Config) client.Middleware {
+	cors := newCors(config)
+	return func(e client.Endpoint) client.Endpoint {
+		return func(ctx context.Context, req *protocol.Request, resp *protocol.Response) error {
+			e(ctx, req, resp)
+			cors.applyProxyCors(req, resp)
+			return nil
+		}
+	}
+}
+
+func (cors *cors) handleProxyNormal(resp *protocol.Response) {
+	for key, value := range cors.normalHeaders {
+		if len(value) > 0 {
+			resp.Header.Set(key, value)
+		}
+	}
+}
+
+func (cors *cors) applyProxyCors(req *protocol.Request, resp *protocol.Response) {
+	origin := req.Header.Get("Origin")
+	if len(origin) == 0 {
+		return
+	}
+	host := req.Host()
+
+	o := str2bytes(origin)
+	if bytes.HasPrefix(o, DefaultSchemasBytes[0]) {
+		if compareByteSlices(o, DefaultSchemasBytes[0], host) == 0 {
+			return
+		}
+	}
+	if bytes.HasPrefix(o, DefaultSchemasBytes[1]) {
+		if compareByteSlices(o, DefaultSchemasBytes[1], host) == 0 {
+			return
+		}
+	}
+
+	if !cors.validateOrigin(origin) {
+		return
+	}
+
+	cors.handleProxyNormal(resp)
+
+	if !cors.allowAllOrigins {
+		resp.Header.Set("Access-Control-Allow-Origin", origin)
+	}
+}