Fix host parsing bug (#486)

pkg/internal/ebpf/httpfltr/httpfltr.go

@@ -435,7 +435,7 @@ func (event *BPFHTTPInfo) method() string {
 }
 
 func (event *BPFHTTPInfo) hostFromBuf() (string, int) {
-	buf := string(event.Buf[:])
+	buf := cstr(event.Buf[:])
 	idx := strings.Index(buf, "Host: ")
 
 	if idx < 0 {
@@ -446,6 +446,10 @@ func (event *BPFHTTPInfo) hostFromBuf() (string, int) {
 
 	rIdx := strings.Index(buf, "\r")
 
+	if rIdx < 0 {
+		rIdx = len(buf)
+	}
+
 	host, portStr, err := net.SplitHostPort(buf[:rIdx])
 
 	if err != nil {

pkg/internal/ebpf/httpfltr/httpfltr_test.go

@@ -244,3 +244,64 @@ func TestExtractTraceParent(t *testing.T) {
 			"Content-Type:application/json\r\n"+
 			"TraceParent: \r\n\r\n")))
 }
+
+func TestToRequestTrace_BadHost(t *testing.T) {
+	var record BPFHTTPInfo
+	record.Type = 1
+	record.StartMonotimeNs = 123456
+	record.EndMonotimeNs = 789012
+	record.Status = 200
+	record.ConnInfo.D_port = 0
+	record.ConnInfo.S_port = 0
+	record.ConnInfo.S_addr = [16]byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff, 192, 168, 0, 1}
+	record.ConnInfo.D_addr = [16]byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff, 8, 8, 8, 8}
+	copy(record.Buf[:], "GET /hello HTTP/1.1\r\nHost: example.c")
+
+	buf := new(bytes.Buffer)
+	err := binary.Write(buf, binary.LittleEndian, &record)
+	assert.NoError(t, err)
+
+	tracer := Tracer{cfg: &pipe.Config{}}
+	result, _, err := tracer.readHTTPInfoIntoSpan(&ringbuf.Record{RawSample: buf.Bytes()})
+	assert.NoError(t, err)
+
+	expected := request.Span{
+		Host:         "",
+		Peer:         "",
+		Path:         "/hello",
+		Method:       "GET",
+		Status:       200,
+		Type:         request.EventTypeHTTP,
+		RequestStart: 123456,
+		Start:        123456,
+		End:          789012,
+		HostPort:     0,
+		ServiceID:    svc.ID{SDKLanguage: svc.InstrumentableGeneric},
+	}
+	assert.Equal(t, expected, result)
+
+	s, p := record.hostFromBuf()
+	assert.Equal(t, s, "")
+	assert.Equal(t, p, -1)
+
+	var record1 BPFHTTPInfo
+	copy(record1.Buf[:], "GET /hello HTTP/1.1\r\nHost: example.c:23")
+
+	s, p = record1.hostFromBuf()
+	assert.Equal(t, s, "example.c")
+	assert.Equal(t, p, 23)
+
+	var record2 BPFHTTPInfo
+	copy(record2.Buf[:], "GET /hello HTTP/1.1\r\nHost: ")
+
+	s, p = record2.hostFromBuf()
+	assert.Equal(t, s, "")
+	assert.Equal(t, p, -1)
+
+	var record3 BPFHTTPInfo
+	copy(record3.Buf[:], "GET /hello HTTP/1.1\r\nHost")
+
+	s, p = record3.hostFromBuf()
+	assert.Equal(t, s, "")
+	assert.Equal(t, p, -1)
+}