add traffic limiter for proxy handler

limiter/traffic/plugin.go

@@ -0,0 +1,235 @@
+package traffic
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"io"
+	"net/http"
+
+	"github.com/go-gost/core/limiter/traffic"
+	"github.com/go-gost/core/logger"
+	"github.com/go-gost/plugin/limiter/traffic/proto"
+	"github.com/go-gost/x/internal/plugin"
+	"google.golang.org/grpc"
+)
+
+type grpcPlugin struct {
+	conn   grpc.ClientConnInterface
+	client proto.LimiterClient
+	log    logger.Logger
+}
+
+// NewGRPCPlugin creates a traffic limiter plugin based on gRPC.
+func NewGRPCPlugin(name string, addr string, opts ...plugin.Option) traffic.TrafficLimiter {
+	var options plugin.Options
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	log := logger.Default().WithFields(map[string]any{
+		"kind":    "limiter",
+		"limiter": name,
+	})
+	conn, err := plugin.NewGRPCConn(addr, &options)
+	if err != nil {
+		log.Error(err)
+	}
+
+	p := &grpcPlugin{
+		conn: conn,
+		log:  log,
+	}
+	if conn != nil {
+		p.client = proto.NewLimiterClient(conn)
+	}
+	return p
+}
+
+func (p *grpcPlugin) In(ctx context.Context, key string, opts ...traffic.Option) traffic.Limiter {
+	if p.client == nil {
+		return nil
+	}
+
+	var options traffic.Options
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	r, err := p.client.Limit(ctx,
+		&proto.LimitRequest{
+			Network: options.Network,
+			Addr:    options.Addr,
+			Client:  options.Client,
+			Src:     options.Src,
+		})
+	if err != nil {
+		p.log.Error(err)
+		return nil
+	}
+
+	return NewLimiter(int(r.In))
+}
+
+func (p *grpcPlugin) Out(ctx context.Context, key string, opts ...traffic.Option) traffic.Limiter {
+	if p.client == nil {
+		return nil
+	}
+
+	var options traffic.Options
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	r, err := p.client.Limit(ctx,
+		&proto.LimitRequest{
+			Network: options.Network,
+			Addr:    options.Addr,
+			Client:  options.Client,
+			Src:     options.Src,
+		})
+	if err != nil {
+		p.log.Error(err)
+		return nil
+	}
+
+	return NewLimiter(int(r.Out))
+}
+
+func (p *grpcPlugin) Close() error {
+	if closer, ok := p.conn.(io.Closer); ok {
+		return closer.Close()
+	}
+	return nil
+}
+
+type httpPluginRequest struct {
+	Network string `json:"network"`
+	Addr    string `json:"addr"`
+	Client  string `json:"client"`
+	Src     string `json:"src"`
+}
+
+type httpPluginResponse struct {
+	In  int64 `json:"in"`
+	Out int64 `json:"out"`
+}
+
+type httpPlugin struct {
+	url    string
+	client *http.Client
+	header http.Header
+	log    logger.Logger
+}
+
+// NewHTTPPlugin creates a traffic limiter plugin based on HTTP.
+func NewHTTPPlugin(name string, url string, opts ...plugin.Option) traffic.TrafficLimiter {
+	var options plugin.Options
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	return &httpPlugin{
+		url:    url,
+		client: plugin.NewHTTPClient(&options),
+		header: options.Header,
+		log: logger.Default().WithFields(map[string]any{
+			"kind":    "limiter",
+			"limiter": name,
+		}),
+	}
+}
+
+func (p *httpPlugin) In(ctx context.Context, key string, opts ...traffic.Option) traffic.Limiter {
+	if p.client == nil {
+		return nil
+	}
+
+	var options traffic.Options
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	rb := httpPluginRequest{
+		Network: options.Network,
+		Addr:    options.Addr,
+		Client:  options.Client,
+		Src:     options.Src,
+	}
+	v, err := json.Marshal(&rb)
+	if err != nil {
+		return nil
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, p.url, bytes.NewReader(v))
+	if err != nil {
+		return nil
+	}
+
+	if p.header != nil {
+		req.Header = p.header.Clone()
+	}
+	req.Header.Set("Content-Type", "application/json")
+	resp, err := p.client.Do(req)
+	if err != nil {
+		return nil
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return nil
+	}
+
+	res := httpPluginResponse{}
+	if err := json.NewDecoder(resp.Body).Decode(&res); err != nil {
+		return nil
+	}
+	return NewLimiter(int(res.In))
+}
+
+func (p *httpPlugin) Out(ctx context.Context, key string, opts ...traffic.Option) traffic.Limiter {
+	if p.client == nil {
+		return nil
+	}
+
+	var options traffic.Options
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	rb := httpPluginRequest{
+		Network: options.Network,
+		Addr:    options.Addr,
+		Client:  options.Client,
+		Src:     options.Src,
+	}
+	v, err := json.Marshal(&rb)
+	if err != nil {
+		return nil
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, p.url, bytes.NewReader(v))
+	if err != nil {
+		return nil
+	}
+
+	if p.header != nil {
+		req.Header = p.header.Clone()
+	}
+	req.Header.Set("Content-Type", "application/json")
+	resp, err := p.client.Do(req)
+	if err != nil {
+		return nil
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return nil
+	}
+
+	res := httpPluginResponse{}
+	if err := json.NewDecoder(resp.Body).Decode(&res); err != nil {
+		return nil
+	}
+	return NewLimiter(int(res.Out))
+}