Add a pcap-split tool

internal/web/split_test.go

@@ -0,0 +1,128 @@
+package web
+
+import (
+	"archive/zip"
+	"bytes"
+	"mime/multipart"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+
+	"pcap-web-tools/internal/pcap"
+)
+
+func testPcap(t *testing.T, packets int) []byte {
+	t.Helper()
+	var buf bytes.Buffer
+	w, err := pcap.NewWriter(&buf, pcap.LinkTypeEthernet)
+	if err != nil {
+		t.Fatal(err)
+	}
+	for i := range packets {
+		if err := w.WritePacket(time.Unix(int64(i), 0), make([]byte, 100)); err != nil {
+			t.Fatal(err)
+		}
+	}
+	return buf.Bytes()
+}
+
+func postSplit(t *testing.T, srv *Server, filename string, file []byte, fields map[string]string) *httptest.ResponseRecorder {
+	t.Helper()
+	var body bytes.Buffer
+	mw := multipart.NewWriter(&body)
+	for k, v := range fields {
+		mw.WriteField(k, v)
+	}
+	if file != nil {
+		fw, err := mw.CreateFormFile("file", filename)
+		if err != nil {
+			t.Fatal(err)
+		}
+		fw.Write(file)
+	}
+	mw.Close()
+	req := httptest.NewRequest("POST", "/split", &body)
+	req.Header.Set("Content-Type", mw.FormDataContentType())
+	rec := httptest.NewRecorder()
+	srv.ServeHTTP(rec, req)
+	return rec
+}
+
+func TestSplitHandler(t *testing.T) {
+	srv, err := New(Config{MaxUploadBytes: 1 << 20})
+	if err != nil {
+		t.Fatal(err)
+	}
+	in := testPcap(t, 25)
+
+	tests := []struct {
+		name   string
+		fields map[string]string
+		want   []int // packets per part
+	}{
+		{"by packets", map[string]string{"mode": "packets", "packets": "10"}, []int{10, 10, 5}},
+		// Each record is 116 bytes: 24 + 8*116 = 952 <= 1000, a ninth does not fit.
+		{"by size", map[string]string{"mode": "size", "size": "1", "unit": "KB"}, []int{8, 8, 8, 1}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			rec := postSplit(t, srv, `C:\caps\my capture.pcap`, in, tt.fields)
+			if rec.Code != http.StatusOK || rec.Header().Get("Content-Type") != "application/zip" {
+				t.Fatalf("status %d %s: %s", rec.Code, rec.Header().Get("Content-Type"), rec.Body)
+			}
+			if cd := rec.Header().Get("Content-Disposition"); cd != `attachment; filename="my_capture_split.zip"` {
+				t.Errorf("Content-Disposition %q", cd)
+			}
+			zr, err := zip.NewReader(bytes.NewReader(rec.Body.Bytes()), int64(rec.Body.Len()))
+			if err != nil {
+				t.Fatal(err)
+			}
+			if len(zr.File) != len(tt.want) {
+				t.Fatalf("got %d files, want %d", len(zr.File), len(tt.want))
+			}
+			for i, f := range zr.File {
+				if want := "my_capture_00" + string(rune('1'+i)) + ".pcap"; f.Name != want {
+					t.Errorf("file %d named %q, want %q", i, f.Name, want)
+				}
+				if want := int64(24 + tt.want[i]*116); int64(f.UncompressedSize64) != want {
+					t.Errorf("%s: %d bytes, want %d", f.Name, f.UncompressedSize64, want)
+				}
+			}
+		})
+	}
+}
+
+func TestSplitHandlerErrors(t *testing.T) {
+	srv, err := New(Config{MaxUploadBytes: 4000})
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func(n int) { maxSplitParts = n }(maxSplitParts)
+	maxSplitParts = 5
+
+	ok := map[string]string{"mode": "packets", "packets": "1"}
+	tests := []struct {
+		name   string
+		file   []byte
+		fields map[string]string
+		status int
+		want   string
+	}{
+		{"no file", nil, ok, http.StatusBadRequest, "choose a pcap file"},
+		{"not pcap", []byte(strings.Repeat("x", 100)), ok, http.StatusBadRequest, "not a pcap file"},
+		{"too large", testPcap(t, 700), ok, http.StatusRequestEntityTooLarge, "file too large"},
+		{"too many parts", testPcap(t, 6), ok, http.StatusBadRequest, "more than 5 files"},
+		{"bad packets", testPcap(t, 1), map[string]string{"mode": "packets", "packets": "0"}, http.StatusBadRequest, "at least 1"},
+		{"bad size", testPcap(t, 1), map[string]string{"mode": "size", "size": "abc", "unit": "MB"}, http.StatusBadRequest, "positive number"},
+		{"bad unit", testPcap(t, 1), map[string]string{"mode": "size", "size": "1", "unit": "XB"}, http.StatusBadRequest, "unknown size unit"},
+		{"no mode", testPcap(t, 1), map[string]string{}, http.StatusBadRequest, "choose whether"},
+	}
+	for _, tt := range tests {
+		rec := postSplit(t, srv, "x.pcap", tt.file, tt.fields)
+		if rec.Code != tt.status || !strings.Contains(rec.Body.String(), tt.want) {
+			t.Errorf("%s: status %d, body %.300s", tt.name, rec.Code, rec.Body)
+		}
+	}
+}