add plugins

pkg/plugin/wasm/module.go

@@ -0,0 +1,148 @@
+package wasm
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+
+	"github.com/gotunnel/pkg/plugin"
+	"github.com/tetratelabs/wazero"
+	"github.com/tetratelabs/wazero/api"
+)
+
+// WASMPlugin 封装 WASM 模块作为 ProxyHandler
+type WASMPlugin struct {
+	name     string
+	metadata plugin.PluginMetadata
+	runtime  *Runtime
+	compiled wazero.CompiledModule
+	config   map[string]string
+}
+
+// NewWASMPlugin 从 WASM 字节创建 plugin
+func NewWASMPlugin(ctx context.Context, rt *Runtime, name string, wasmBytes []byte) (*WASMPlugin, error) {
+	compiled, err := rt.runtime.CompileModule(ctx, wasmBytes)
+	if err != nil {
+		return nil, fmt.Errorf("compile module: %w", err)
+	}
+
+	p := &WASMPlugin{
+		name:     name,
+		runtime:  rt,
+		compiled: compiled,
+	}
+
+	// 尝试获取元数据
+	if err := p.loadMetadata(ctx); err != nil {
+		// 使用默认元数据
+		p.metadata = plugin.PluginMetadata{
+			Name:   name,
+			Type:   plugin.PluginTypeProxy,
+			Source: plugin.PluginSourceWASM,
+		}
+	}
+
+	return p, nil
+}
+
+// loadMetadata 从 WASM 模块加载元数据
+func (p *WASMPlugin) loadMetadata(ctx context.Context) error {
+	// 创建临时实例获取元数据
+	inst, err := p.runtime.runtime.InstantiateModule(ctx, p.compiled, wazero.NewModuleConfig())
+	if err != nil {
+		return err
+	}
+	defer inst.Close(ctx)
+
+	metadataFn := inst.ExportedFunction("metadata")
+	if metadataFn == nil {
+		return fmt.Errorf("metadata function not exported")
+	}
+
+	allocFn := inst.ExportedFunction("alloc")
+	if allocFn == nil {
+		return fmt.Errorf("alloc function not exported")
+	}
+
+	// 分配缓冲区
+	results, err := allocFn.Call(ctx, 1024)
+	if err != nil {
+		return err
+	}
+	bufPtr := uint32(results[0])
+
+	// 调用 metadata 函数
+	results, err = metadataFn.Call(ctx, uint64(bufPtr), 1024)
+	if err != nil {
+		return err
+	}
+	actualLen := uint32(results[0])
+
+	// 读取元数据
+	mem := inst.Memory()
+	data, ok := mem.Read(bufPtr, actualLen)
+	if !ok {
+		return fmt.Errorf("failed to read metadata")
+	}
+
+	return json.Unmarshal(data, &p.metadata)
+}
+
+// Metadata 返回 plugin 信息
+func (p *WASMPlugin) Metadata() plugin.PluginMetadata {
+	return p.metadata
+}
+
+// Init 初始化 plugin
+func (p *WASMPlugin) Init(config map[string]string) error {
+	p.config = config
+	return nil
+}
+
+// HandleConn 处理连接
+func (p *WASMPlugin) HandleConn(conn interface{}, dialer plugin.Dialer) error {
+	// WASM plugin 的连接处理需要更复杂的实现
+	// 这里提供基础框架，实际实现需要注册 host functions
+	return fmt.Errorf("WASM plugin HandleConn not fully implemented")
+}
+
+// Close 关闭 plugin
+func (p *WASMPlugin) Close() error {
+	return p.compiled.Close(context.Background())
+}
+
+// RegisterHostFunctions 注册 host functions 到 wazero 运行时
+func RegisterHostFunctions(ctx context.Context, r wazero.Runtime) (wazero.CompiledModule, error) {
+	return r.NewHostModuleBuilder("env").
+		NewFunctionBuilder().
+		WithFunc(hostLog).
+		Export("log").
+		NewFunctionBuilder().
+		WithFunc(hostNow).
+		Export("now").
+		Compile(ctx)
+}
+
+// host function 实现
+func hostLog(ctx context.Context, m api.Module, level uint32, msgPtr, msgLen uint32) {
+	data, ok := m.Memory().Read(msgPtr, msgLen)
+	if !ok {
+		return
+	}
+	prefix := "[WASM]"
+	switch plugin.LogLevel(level) {
+	case plugin.LogDebug:
+		prefix = "[WASM DEBUG]"
+	case plugin.LogInfo:
+		prefix = "[WASM INFO]"
+	case plugin.LogWarn:
+		prefix = "[WASM WARN]"
+	case plugin.LogError:
+		prefix = "[WASM ERROR]"
+	}
+	fmt.Printf("%s %s\n", prefix, string(data))
+}
+
+func hostNow(ctx context.Context) int64 {
+	return ctx.Value("now").(func() int64)()
+}