virtual-net: initial (#4751)

pkg/plugin/visitor/plugin.go

@@ -0,0 +1,58 @@
+// Copyright 2025 The frp Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package visitor
+
+import (
+	"context"
+	"fmt"
+	"net"
+
+	v1 "github.com/fatedier/frp/pkg/config/v1"
+	"github.com/fatedier/frp/pkg/vnet"
+)
+
+type PluginContext struct {
+	Name           string
+	Ctx            context.Context
+	VnetController *vnet.Controller
+	HandleConn     func(net.Conn)
+}
+
+// Creators is used for create plugins to handle connections.
+var creators = make(map[string]CreatorFn)
+
+type CreatorFn func(pluginCtx PluginContext, options v1.VisitorPluginOptions) (Plugin, error)
+
+func Register(name string, fn CreatorFn) {
+	if _, exist := creators[name]; exist {
+		panic(fmt.Sprintf("plugin [%s] is already registered", name))
+	}
+	creators[name] = fn
+}
+
+func Create(pluginName string, pluginCtx PluginContext, options v1.VisitorPluginOptions) (p Plugin, err error) {
+	if fn, ok := creators[pluginName]; ok {
+		p, err = fn(pluginCtx, options)
+	} else {
+		err = fmt.Errorf("plugin [%s] is not registered", pluginName)
+	}
+	return
+}
+
+type Plugin interface {
+	Name() string
+	Start()
+	Close() error
+}