pnp_scan
rv = pnp_scan(&p, maxlen - (p - *bufp),
static int pnp_scan(const uint8_t **, size_t,
res = pnp_scan(&p, len - 12, &r, 0);
res = pnp_scan(&p, len - (p - buf), &s, 0);
res = pnp_scan(&p, len - (p - buf), &s, 0);