Commit bf63e250 authored by David Howells's avatar David Howells Committed by Paolo Abeni
Browse files

crypto: af_alg: Support MSG_SPLICE_PAGES 



Make AF_ALG sendmsg() support MSG_SPLICE_PAGES.  This causes pages to be
spliced from the source iterator.

This allows ->sendpage() to be replaced by something that can handle
multiple multipage folios in a single transaction.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
cc: Herbert Xu <herbert@gondor.apana.org.au>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: Jens Axboe <axboe@kernel.dk>
cc: Matthew Wilcox <willy@infradead.org>
cc: linux-crypto@vger.kernel.org
cc: netdev@vger.kernel.org
Acked-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 73d7409c

crypto/af_alg.c

+22 −2
Original line number Diff line number Diff line
@@ -985,7 +985,7 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size, 
	while (size) {

		struct scatterlist *sg;

		size_t len = size;

		size_t plen;

		ssize_t plen;



		/* use the existing memory in an allocated page */

		if (ctx->merge) {
@@ -1030,7 +1030,27 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size, 
		if (sgl->cur)

			sg_unmark_end(sg + sgl->cur - 1);



		if (1 /* TODO check MSG_SPLICE_PAGES */) {

		if (msg->msg_flags & MSG_SPLICE_PAGES) {

			struct sg_table sgtable = {

				.sgl		= sg,

				.nents		= sgl->cur,

				.orig_nents	= sgl->cur,

			};



			plen = extract_iter_to_sg(&msg->msg_iter, len, &sgtable,

						  MAX_SGL_ENTS, 0);

			if (plen < 0) {

				err = plen;

				goto unlock;

			}



			for (; sgl->cur < sgtable.nents; sgl->cur++)

				get_page(sg_page(&sg[sgl->cur]));

			len -= plen;

			ctx->used += plen;

			copied += plen;

			size -= plen;

		} else {

			do {

				struct page *pg;

				unsigned int i = sgl->cur;

crypto/algif_aead.c

+11 −11
Original line number Diff line number Diff line
@@ -9,8 +9,8 @@ 
 * The following concept of the memory management is used:

 *

 * The kernel maintains two SGLs, the TX SGL and the RX SGL. The TX SGL is

 * filled by user space with the data submitted via sendpage/sendmsg. Filling

 * up the TX SGL does not cause a crypto operation -- the data will only be

 * filled by user space with the data submitted via sendpage. Filling up

 * the TX SGL does not cause a crypto operation -- the data will only be

 * tracked by the kernel. Upon receipt of one recvmsg call, the caller must

 * provide a buffer which is tracked with the RX SGL.

 *
@@ -113,19 +113,19 @@ static int _aead_recvmsg(struct socket *sock, struct msghdr *msg, 
	}



	/*

	 * Data length provided by caller via sendmsg/sendpage that has not

	 * yet been processed.

	 * Data length provided by caller via sendmsg that has not yet been

	 * processed.

	 */

	used = ctx->used;



	/*

	 * Make sure sufficient data is present -- note, the same check is

	 * also present in sendmsg/sendpage. The checks in sendpage/sendmsg

	 * shall provide an information to the data sender that something is

	 * wrong, but they are irrelevant to maintain the kernel integrity.

	 * We need this check here too in case user space decides to not honor

	 * the error message in sendmsg/sendpage and still call recvmsg. This

	 * check here protects the kernel integrity.

	 * Make sure sufficient data is present -- note, the same check is also

	 * present in sendmsg. The checks in sendmsg shall provide an

	 * information to the data sender that something is wrong, but they are

	 * irrelevant to maintain the kernel integrity.  We need this check

	 * here too in case user space decides to not honor the error message

	 * in sendmsg and still call recvmsg. This check here protects the

	 * kernel integrity.

	 */

	if (!aead_sufficient_data(sk))

		return -EINVAL;

crypto/algif_skcipher.c

+4 −4
Original line number Diff line number Diff line
@@ -9,10 +9,10 @@ 
 * The following concept of the memory management is used:

 *

 * The kernel maintains two SGLs, the TX SGL and the RX SGL. The TX SGL is

 * filled by user space with the data submitted via sendpage/sendmsg. Filling

 * up the TX SGL does not cause a crypto operation -- the data will only be

 * tracked by the kernel. Upon receipt of one recvmsg call, the caller must

 * provide a buffer which is tracked with the RX SGL.

 * filled by user space with the data submitted via sendmsg. Filling up the TX

 * SGL does not cause a crypto operation -- the data will only be tracked by

 * the kernel. Upon receipt of one recvmsg call, the caller must provide a

 * buffer which is tracked with the RX SGL.

 *

 * During the processing of the recvmsg operation, the cipher request is

 * allocated and prepared. As part of the recvmsg operation, the processed