C++ (Cpp) skb_copy_and_csum_datagram Examples

Example #1

int skb_copy_and_csum_datagram_iovec(const struct sk_buff *skb, int hlen, struct iovec *iov)
{
	unsigned int csum;
	int chunk = skb->len - hlen;

	/* Skip filled elements. Pretty silly, look at memcpy_toiovec, though 8) */
	while (iov->iov_len == 0)
		iov++;

	if (iov->iov_len < chunk) {
		if ((unsigned short)csum_fold(skb_checksum(skb, 0, chunk+hlen, skb->csum)))
			goto csum_error;
		if (skb_copy_datagram_iovec(skb, hlen, iov, chunk))
			goto fault;
	} else {
		csum = csum_partial(skb->data, hlen, skb->csum);
		if (skb_copy_and_csum_datagram(skb, hlen, iov->iov_base, chunk, &csum))
			goto fault;
		if ((unsigned short)csum_fold(csum))
			goto csum_error;
		iov->iov_len -= chunk;
		iov->iov_base += chunk;
	}
	return 0;

csum_error:
	return -EINVAL;

fault:
	return -EFAULT;
}

Example #2

File: datagram.c Project: millken/zhuxianB30

/**
 *	skb_copy_and_csum_datagram_iovec - Copy and checkum skb to user iovec.
 *	@skb: skbuff
 *	@hlen: hardware length
 *	@iov: io vector
 *
 *	Caller _must_ check that skb will fit to this iovec.
 *
 *	Returns: 0       - success.
 *		 -EINVAL - checksum failure.
 *		 -EFAULT - fault during copy. Beware, in this case iovec
 *			   can be modified!
 */
int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb,
				     int hlen, struct iovec *iov)
{
	__wsum csum;
	int chunk = skb->len - hlen;

	/* Skip filled elements.
	 * Pretty silly, look at memcpy_toiovec, though 8)
	 */
	while (!iov->iov_len)
		iov++;

	if (iov->iov_len < chunk) {
		if (__skb_checksum_complete(skb))
			goto csum_error;
		if (skb_copy_datagram_iovec(skb, hlen, iov, chunk))
			goto fault;
	} else {
		csum = csum_partial(skb->data, hlen, skb->csum);
		if (skb_copy_and_csum_datagram(skb, hlen, iov->iov_base,
					       chunk, &csum))
			goto fault;
		if (csum_fold(csum))
			goto csum_error;
		if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE))
			netdev_rx_csum_fault(skb->dev);
		iov->iov_len -= chunk;
		iov->iov_base += chunk;
	}
	return 0;
csum_error:
	return -EINVAL;
fault:
	return -EFAULT;
}

Example #3

int skb_copy_and_csum_datagram(const struct sk_buff *skb, int offset, u8 *to, int len, unsigned int *csump)
{
	int i, copy;
	int start = skb->len - skb->data_len;
	int pos = 0;

	/* Copy header. */
	if ((copy = start-offset) > 0) {
		int err = 0;
		if (copy > len)
			copy = len;
		*csump = csum_and_copy_to_user(skb->data+offset, to, copy, *csump, &err);
		if (err)
			goto fault;
		if ((len -= copy) == 0)
			return 0;
		offset += copy;
		to += copy;
		pos = copy;
	}

	for (i=0; i<skb_shinfo(skb)->nr_frags; i++) {
		int end;

		BUG_TRAP(start <= offset+len);

		end = start + skb_shinfo(skb)->frags[i].size;
		if ((copy = end-offset) > 0) {
			unsigned int csum2;
			int err = 0;
			u8  *vaddr;
			skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
			struct page *page = frag->page;

			if (copy > len)
				copy = len;
			vaddr = kmap(page);
			csum2 = csum_and_copy_to_user(vaddr + frag->page_offset +
						      offset-start, to, copy, 0, &err);
			kunmap(page);
			if (err)
				goto fault;
			*csump = csum_block_add(*csump, csum2, pos);
			if (!(len -= copy))
				return 0;
			offset += copy;
			to += copy;
			pos += copy;
		}
		start = end;
	}

	if (skb_shinfo(skb)->frag_list) {
		struct sk_buff *list;

		for (list = skb_shinfo(skb)->frag_list; list; list=list->next) {
			int end;

			BUG_TRAP(start <= offset+len);

			end = start + list->len;
			if ((copy = end-offset) > 0) {
				unsigned int csum2 = 0;
				if (copy > len)
					copy = len;
				if (skb_copy_and_csum_datagram(list, offset-start, to, copy, &csum2))
					goto fault;
				*csump = csum_block_add(*csump, csum2, pos);
				if ((len -= copy) == 0)
					return 0;
				offset += copy;
				to += copy;
				pos += copy;
			}
			start = end;
		}
	}
	if (len == 0)
		return 0;

fault:
	return -EFAULT;
}