Commit 65d69e25 authored by Sagi Grimberg's avatar Sagi Grimberg Committed by Christoph Hellwig
Browse files

datagram: introduce skb_copy_and_hash_datagram_iter helper 



Introduce a helper to copy datagram into an iovec iterator
but also update a predefined hash. This is useful for
consumers of skb_copy_datagram_iter to also support inflight
data digest without having to finish to copy and only then
traverse the iovec and calculate the digest hash.

Acked-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarSagi Grimberg <sagi@lightbitslabs.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
parent d05f4435

include/linux/skbuff.h

+3 −0
Original line number Diff line number Diff line
@@ -3325,6 +3325,9 @@ static inline int skb_copy_datagram_msg(const struct sk_buff *from, int offset, 
}

int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, int hlen,

				   struct msghdr *msg);

int skb_copy_and_hash_datagram_iter(const struct sk_buff *skb, int offset,

			   struct iov_iter *to, int len,

			   struct ahash_request *hash);

int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,

				 struct iov_iter *from, int len);

int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *frm);

net/core/datagram.c

+19 −1
Original line number Diff line number Diff line
@@ -465,7 +465,7 @@ int __skb_datagram_iter(const struct sk_buff *skb, int offset, 
			if (copy > len)

				copy = len;

			if (__skb_datagram_iter(frag_iter, offset - start,

						to, copy, short_copy, cb, data))

						to, copy, fault_short, cb, data))

				goto fault;

			if ((len -= copy) == 0)

				return 0;
@@ -492,6 +492,24 @@ short_copy: 
	return 0;

}



/**

 *	skb_copy_and_hash_datagram_iter - Copy datagram to an iovec iterator

 *          and update a hash.

 *	@skb: buffer to copy

 *	@offset: offset in the buffer to start copying from

 *	@to: iovec iterator to copy to

 *	@len: amount of data to copy from buffer to iovec

 *      @hash: hash request to update

 */

int skb_copy_and_hash_datagram_iter(const struct sk_buff *skb, int offset,

			   struct iov_iter *to, int len,

			   struct ahash_request *hash)

{

	return __skb_datagram_iter(skb, offset, to, len, true,

			hash_and_copy_to_iter, hash);

}

EXPORT_SYMBOL(skb_copy_and_hash_datagram_iter);



static size_t simple_copy_to_iter(const void *addr, size_t bytes,

		void *data __always_unused, struct iov_iter *i)

{

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