修复代理与日志链路的可靠性问题

proxy/capture.go

@@ -5,21 +5,30 @@ import (
 	"crypto/rand"
 	"encoding/hex"
 	"encoding/json"
+	"errors"
 	"io"
 	"net/http"
 	"net/netip"
 	"strings"
 )
 
+var errRequestBodyTooLarge = errors.New("request body too large")
+
 // readRequestBody 在转发前完整读取请求体，确保读取失败时不会向上游发送损坏请求。
-func readRequestBody(r *http.Request, max int64) (captured []byte, truncated bool, err error) {
+func readRequestBody(r *http.Request, max, requestLimit int64) (captured []byte, truncated bool, err error) {
 	if r.Body == nil || r.Body == http.NoBody {
 		return nil, false, nil
 	}
-	body, err := io.ReadAll(r.Body)
+	if r.ContentLength > requestLimit {
+		return nil, false, errRequestBodyTooLarge
+	}
+	body, err := io.ReadAll(io.LimitReader(r.Body, requestLimit+1))
 	if err != nil {
 		return nil, false, err
 	}
+	if int64(len(body)) > requestLimit {
+		return nil, false, errRequestBodyTooLarge
+	}
 	if err := r.Body.Close(); err != nil {
 		return nil, false, err
 	}