Add native protocol service plugins

plugins/services/tftp_test.go

@@ -0,0 +1,21 @@
+//go:build plugin_tftp || !plugin_selective
+
+package services
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestTFTPReadRequestAndResponse(t *testing.T) {
+	req := buildTFTPReadRequest("probe")
+	want := []byte{0x00, 0x01, 'p', 'r', 'o', 'b', 'e', 0x00, 'o', 'c', 't', 'e', 't', 0x00}
+	if string(req) != string(want) {
+		t.Fatalf("unexpected tftp request: %#v", req)
+	}
+
+	banner, ok := parseTFTPResponse([]byte{0x00, 0x05, 0x00, 0x01, 'n', 'o', 't', ' ', 'f', 'o', 'u', 'n', 'd', 0x00})
+	if !ok || !strings.Contains(banner, "not found") {
+		t.Fatalf("unexpected tftp banner: %q ok=%v", banner, ok)
+	}
+}