From: David Howells <dhowells@redhat.com>
To: netdev@vger.kernel.org
Cc: David Howells <dhowells@redhat.com>,
Herbert Xu <herbert@gondor.apana.org.au>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Willem de Bruijn <willemdebruijn.kernel@gmail.com>,
David Ahern <dsahern@kernel.org>,
Matthew Wilcox <willy@infradead.org>,
Jens Axboe <axboe@kernel.dk>,
linux-crypto@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: [PATCH net-next v2 08/10] crypto: af_alg: Support MSG_SPLICE_PAGES
Date: Tue, 30 May 2023 15:16:32 +0100 [thread overview]
Message-ID: <20230530141635.136968-9-dhowells@redhat.com> (raw)
In-Reply-To: <20230530141635.136968-1-dhowells@redhat.com>
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: David 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
---
crypto/af_alg.c | 28 ++++++++++++++++++++++++++--
crypto/algif_aead.c | 22 +++++++++++-----------
crypto/algif_skcipher.c | 8 ++++----
3 files changed, 41 insertions(+), 17 deletions(-)
diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index fd56ccff6fed..62f4205d42e3 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -940,6 +940,10 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
bool init = false;
int err = 0;
+ if ((msg->msg_flags & MSG_SPLICE_PAGES) &&
+ !iov_iter_is_bvec(&msg->msg_iter))
+ return -EINVAL;
+
if (msg->msg_controllen) {
err = af_alg_cmsg_send(msg, &con);
if (err)
@@ -985,7 +989,7 @@ 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 +1034,27 @@ 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;
diff --git a/crypto/algif_aead.c b/crypto/algif_aead.c
index 829878025dba..35bfa283748d 100644
--- a/crypto/algif_aead.c
+++ b/crypto/algif_aead.c
@@ -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;
diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c
index a251cd6bd5b9..b1f321b9f846 100644
--- a/crypto/algif_skcipher.c
+++ b/crypto/algif_skcipher.c
@@ -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
next prev parent reply other threads:[~2023-05-30 14:17 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-30 14:16 [PATCH net-next v2 00/10] crypto, splice, net: Make AF_ALG handle sendmsg(MSG_SPLICE_PAGES) David Howells
2023-05-30 14:16 ` [PATCH net-next v2 01/10] Drop the netfs_ prefix from netfs_extract_iter_to_sg() David Howells
2023-05-30 14:16 ` [PATCH net-next v2 02/10] Fix a couple of spelling mistakes David Howells
2023-05-30 19:55 ` Simon Horman
2023-05-30 14:16 ` [PATCH net-next v2 03/10] Wrap lines at 80 David Howells
2023-05-30 14:16 ` [PATCH net-next v2 04/10] Move netfs_extract_iter_to_sg() to lib/scatterlist.c David Howells
2023-05-30 14:16 ` [PATCH net-next v2 05/10] crypto: af_alg: Pin pages rather than ref'ing if appropriate David Howells
2023-05-30 14:16 ` [PATCH net-next v2 06/10] crypto: af_alg: Use extract_iter_to_sg() to create scatterlists David Howells
2023-05-30 14:16 ` [PATCH net-next v2 07/10] crypto: af_alg: Indent the loop in af_alg_sendmsg() David Howells
2023-05-30 14:16 ` David Howells [this message]
2023-05-30 14:16 ` [PATCH net-next v2 09/10] crypto: af_alg: Convert af_alg_sendpage() to use MSG_SPLICE_PAGES David Howells
2023-05-30 14:16 ` [PATCH net-next v2 10/10] crypto: af_alg/hash: Support MSG_SPLICE_PAGES David Howells
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