BPF_CALL_4(bpf_skb_load_bytes, const struct sk_buff *, skb, u32, offset,
	   void *, to, u32, len)
{
	void *ptr;

	if (unlikely(offset > 0xffff))
		goto err_clear;

	ptr = skb_header_pointer(skb, offset, len, to);
	if (unlikely(!ptr))
		goto err_clear;
	if (ptr != to)
		memcpy(to, ptr, len);

	return 0;
err_clear:
	memset(to, 0, len);
	return -EFAULT;
}
Unknown