Merge pull request #16 from FireTail-io/reopen-packetsource

Reinitialise packetsource

Author: rileyfiretail

src/main.go

@@ -128,6 +128,10 @@ func main() {
 				"Content-Length", strconv.Itoa(int(requestAndResponse.request.ContentLength)),
 			)
 			requestAndResponse.request.Header.Set("Host", requestAndResponse.request.Host)
+			var responseRecorder *httptest.ResponseRecorder
+			if devEnabled {
+				responseRecorder = httptest.NewRecorder()
+			}
 			firetailMiddleware(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 				w.WriteHeader(requestAndResponse.response.StatusCode)
 				for key, values := range requestAndResponse.response.Header {
@@ -145,9 +149,17 @@ func main() {
 				}
 				w.Write(capturedResponseBody)
 			})).ServeHTTP(
-				httptest.NewRecorder(),
+				responseRecorder,
 				requestAndResponse.request,
 			)
+			if responseRecorder != nil {
+				slog.Debug(
+					"Response from Firetail middleware:",
+					"StatusCode", responseRecorder.Code,
+					"Header", responseRecorder.Header(),
+					"Body", responseRecorder.Body.String(),
+				)
+			}
 		default:
 		}
 	}

src/request_and_response.go

@@ -29,18 +29,20 @@ type httpRequestAndResponseStreamer struct {
 	maxBodySize               int64
 }
 
-func (s *httpRequestAndResponseStreamer) start() {
+func (s *httpRequestAndResponseStreamer) getHandleAndPacketsChannel() (*pcap.Handle, <-chan gopacket.Packet) {
 	handle, err := pcap.OpenLive("any", 1600, true, pcap.BlockForever)
 	if err != nil {
 		log.Fatal(err)
 	}
-	defer handle.Close()
-
 	err = handle.SetBPFFilter(s.bpfExpression)
 	if err != nil {
 		log.Fatal(err)
 	}
+	packetsChannel := gopacket.NewPacketSource(handle, handle.LinkType()).Packets()
+	return handle, packetsChannel
+}
 
+func (s *httpRequestAndResponseStreamer) start() {
 	assembler := tcpassembly.NewAssembler(
 		tcpassembly.NewStreamPool(
 			&bidirectionalStreamFactory{
@@ -50,11 +52,18 @@ func (s *httpRequestAndResponseStreamer) start() {
 			},
 		),
 	)
+
+	handler, packetsChannel := s.getHandleAndPacketsChannel()
+
 	ticker := time.Tick(time.Minute)
-	packetsChannel := gopacket.NewPacketSource(handle, handle.LinkType()).Packets()
 	for {
 		select {
-		case packet := <-packetsChannel:
+		case packet, ok := <-packetsChannel:
+			if !ok {
+				slog.Warn("Packet channel closed. Reinitializing...")
+				handler.Close()
+				handler, packetsChannel = s.getHandleAndPacketsChannel()
+			}
 			if packet.NetworkLayer() == nil || packet.TransportLayer() == nil {
 				continue
 			}