- b = vlib_get_buffer (vm, bi);
- n = b->pre_data[0];
-
- fformat (stderr, "Context trace for bi %d b 0x%llx, visited %d\n",
- bi, b, n);
-
- if (n == 0 || n > 20)
- {
- fformat (stderr, "n is unreasonable\n");
- return;
- }
-
-
- for (i = 0; i < n; i++)
- {
- u32 node_index;
-
- node_index = b->pre_data[i + 1];