crypto: algif_aead - Revert to operating out-of-place (a664bf3d) · Commits · git / linux-net

crypto/af_alg.c

+10 −39

Original line number	Diff line number	Diff line
		@@ -637,15 +637,13 @@ static int af_alg_alloc_tsgl(struct sock *sk)
		/**
		* af_alg_count_tsgl - Count number of TX SG entries
		*
		* The counting starts from the beginning of the SGL to @bytes. If
		* an @offset is provided, the counting of the SG entries starts at the @offset.
		* The counting starts from the beginning of the SGL to @bytes.
		*
		* @sk: socket of connection to user space
		* @bytes: Count the number of SG entries holding given number of bytes.
		* @offset: Start the counting of SG entries from the given offset.
		* Return: Number of TX SG entries found given the constraints
		*/
		unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
		unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes)
		{
		const struct alg_sock *ask = alg_sk(sk);
		const struct af_alg_ctx *ctx = ask->private;
		@@ -660,25 +658,11 @@ unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
		const struct scatterlist *sg = sgl->sg;

		for (i = 0; i < sgl->cur; i++) {
		size_t bytes_count;

		/* Skip offset */
		if (offset >= sg[i].length) {
		offset -= sg[i].length;
		bytes -= sg[i].length;
		continue;
		}

		bytes_count = sg[i].length - offset;

		offset = 0;
		sgl_count++;

		/* If we have seen requested number of bytes, stop */
		if (bytes_count >= bytes)
		if (sg[i].length >= bytes)
		return sgl_count;

		bytes -= bytes_count;
		bytes -= sg[i].length;
		}
		}

		@@ -690,19 +674,14 @@ EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
		* af_alg_pull_tsgl - Release the specified buffers from TX SGL
		*
		* If @dst is non-null, reassign the pages to @dst. The caller must release
		* the pages. If @dst_offset is given only reassign the pages to @dst starting
		* at the @dst_offset (byte). The caller must ensure that @dst is large
		* enough (e.g. by using af_alg_count_tsgl with the same offset).
		* the pages.
		*
		* @sk: socket of connection to user space
		* @used: Number of bytes to pull from TX SGL
		* @dst: If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
		* caller must release the buffers in dst.
		* @dst_offset: Reassign the TX SGL from given offset. All buffers before
		* reaching the offset is released.
		*/
		void af_alg_pull_tsgl(struct sock sk, size_t used, struct scatterlist dst,
		size_t dst_offset)
		void af_alg_pull_tsgl(struct sock sk, size_t used, struct scatterlist dst)
		{
		struct alg_sock *ask = alg_sk(sk);
		struct af_alg_ctx *ctx = ask->private;
		@@ -727,19 +706,11 @@ void af_alg_pull_tsgl(struct sock sk, size_t used, struct scatterlist dst,
		* SG entries in dst.
		*/
		if (dst) {
		if (dst_offset >= plen) {
		/* discard page before offset */
		dst_offset -= plen;
		} else {
		/* reassign page to dst after offset */
		get_page(page);
		sg_set_page(dst + j, page,
		plen - dst_offset,
		sg[i].offset + dst_offset);
		dst_offset = 0;
		sg_set_page(dst + j, page, plen, sg[i].offset);
		j++;
		}
		}

		sg[i].length -= plen;
		sg[i].offset += plen;

crypto/algif_aead.c

+19 −81

Original line number	Diff line number	Diff line
		@@ -26,7 +26,6 @@
		#include <crypto/internal/aead.h>
		#include <crypto/scatterwalk.h>
		#include <crypto/if_alg.h>
		#include <crypto/skcipher.h>
		#include <linux/init.h>
		#include <linux/list.h>
		#include <linux/kernel.h>
		@@ -72,9 +71,8 @@ static int _aead_recvmsg(struct socket sock, struct msghdr msg,
		struct alg_sock *pask = alg_sk(psk);
		struct af_alg_ctx *ctx = ask->private;
		struct crypto_aead *tfm = pask->private;
		unsigned int i, as = crypto_aead_authsize(tfm);
		unsigned int as = crypto_aead_authsize(tfm);
		struct af_alg_async_req *areq;
		struct af_alg_tsgl tsgl, tmp;
		struct scatterlist rsgl_src, tsgl_src = NULL;
		int err = 0;
		size_t used = 0; /* [in] TX bufs to be en/decrypted */
		@@ -154,23 +152,24 @@ static int _aead_recvmsg(struct socket sock, struct msghdr msg,
		outlen -= less;
		}

		/*
		* Create a per request TX SGL for this request which tracks the
		* SG entries from the global TX SGL.
		*/
		processed = used + ctx->aead_assoclen;
		list_for_each_entry_safe(tsgl, tmp, &ctx->tsgl_list, list) {
		for (i = 0; i < tsgl->cur; i++) {
		struct scatterlist *process_sg = tsgl->sg + i;

		if (!(process_sg->length) \|\| !sg_page(process_sg))
		continue;
		tsgl_src = process_sg;
		break;
		}
		if (tsgl_src)
		break;
		}
		if (processed && !tsgl_src) {
		err = -EFAULT;
		areq->tsgl_entries = af_alg_count_tsgl(sk, processed);
		if (!areq->tsgl_entries)
		areq->tsgl_entries = 1;
		areq->tsgl = sock_kmalloc(sk, array_size(sizeof(*areq->tsgl),
		areq->tsgl_entries),
		GFP_KERNEL);
		if (!areq->tsgl) {
		err = -ENOMEM;
		goto free;
		}
		sg_init_table(areq->tsgl, areq->tsgl_entries);
		af_alg_pull_tsgl(sk, processed, areq->tsgl);
		tsgl_src = areq->tsgl;

		/*
		* Copy of AAD from source to destination
		@@ -179,76 +178,15 @@ static int _aead_recvmsg(struct socket sock, struct msghdr msg,
		* when user space uses an in-place cipher operation, the kernel
		* will copy the data as it does not see whether such in-place operation
		* is initiated.
		*
		* To ensure efficiency, the following implementation ensure that the
		* ciphers are invoked to perform a crypto operation in-place. This
		* is achieved by memory management specified as follows.
		*/

		/* Use the RX SGL as source (and destination) for crypto op. */
		rsgl_src = areq->first_rsgl.sgl.sgt.sgl;

		if (ctx->enc) {
		/*
		* Encryption operation - The in-place cipher operation is
		* achieved by the following operation:
		*
		* TX SGL: AAD \|\| PT
		* \| \|
		* \| copy \|
		* v v
		* RX SGL: AAD \|\| PT \|\| Tag
		*/
		memcpy_sglist(areq->first_rsgl.sgl.sgt.sgl, tsgl_src,
		processed);
		af_alg_pull_tsgl(sk, processed, NULL, 0);
		} else {
		/*
		* Decryption operation - To achieve an in-place cipher
		* operation, the following SGL structure is used:
		*
		* TX SGL: AAD \|\| CT \|\| Tag
		* \| \| ^
		* \| copy \| \| Create SGL link.
		* v v \|
		* RX SGL: AAD \|\| CT ----+
		*/

		/* Copy AAD \|\| CT to RX SGL buffer for in-place operation. */
		memcpy_sglist(areq->first_rsgl.sgl.sgt.sgl, tsgl_src, outlen);

		/* Create TX SGL for tag and chain it to RX SGL. */
		areq->tsgl_entries = af_alg_count_tsgl(sk, processed,
		processed - as);
		if (!areq->tsgl_entries)
		areq->tsgl_entries = 1;
		areq->tsgl = sock_kmalloc(sk, array_size(sizeof(*areq->tsgl),
		areq->tsgl_entries),
		GFP_KERNEL);
		if (!areq->tsgl) {
		err = -ENOMEM;
		goto free;
		}
		sg_init_table(areq->tsgl, areq->tsgl_entries);

		/* Release TX SGL, except for tag data and reassign tag data. */
		af_alg_pull_tsgl(sk, processed, areq->tsgl, processed - as);

		/* chain the areq TX SGL holding the tag with RX SGL */
		if (usedpages) {
		/* RX SGL present */
		struct af_alg_sgl *sgl_prev = &areq->last_rsgl->sgl;
		struct scatterlist *sg = sgl_prev->sgt.sgl;

		sg_unmark_end(sg + sgl_prev->sgt.nents - 1);
		sg_chain(sg, sgl_prev->sgt.nents + 1, areq->tsgl);
		} else
		/* no RX SGL present (e.g. authentication only) */
		rsgl_src = areq->tsgl;
		}
		memcpy_sglist(rsgl_src, tsgl_src, ctx->aead_assoclen);

		/* Initialize the crypto operation */
		aead_request_set_crypt(&areq->cra_u.aead_req, rsgl_src,
		aead_request_set_crypt(&areq->cra_u.aead_req, tsgl_src,
		areq->first_rsgl.sgl.sgt.sgl, used, ctx->iv);
		aead_request_set_ad(&areq->cra_u.aead_req, ctx->aead_assoclen);
		aead_request_set_tfm(&areq->cra_u.aead_req, tfm);
		@@ -450,7 +388,7 @@ static void aead_sock_destruct(struct sock *sk)
		struct crypto_aead *tfm = pask->private;
		unsigned int ivlen = crypto_aead_ivsize(tfm);

		af_alg_pull_tsgl(sk, ctx->used, NULL, 0);
		af_alg_pull_tsgl(sk, ctx->used, NULL);
		sock_kzfree_s(sk, ctx->iv, ivlen);
		sock_kfree_s(sk, ctx, ctx->len);
		af_alg_release_parent(sk);

crypto/algif_skcipher.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -138,7 +138,7 @@ static int _skcipher_recvmsg(struct socket sock, struct msghdr msg,
		* Create a per request TX SGL for this request which tracks the
		* SG entries from the global TX SGL.
		*/
		areq->tsgl_entries = af_alg_count_tsgl(sk, len, 0);
		areq->tsgl_entries = af_alg_count_tsgl(sk, len);
		if (!areq->tsgl_entries)
		areq->tsgl_entries = 1;
		areq->tsgl = sock_kmalloc(sk, array_size(sizeof(*areq->tsgl),
		@@ -149,7 +149,7 @@ static int _skcipher_recvmsg(struct socket sock, struct msghdr msg,
		goto free;
		}
		sg_init_table(areq->tsgl, areq->tsgl_entries);
		af_alg_pull_tsgl(sk, len, areq->tsgl, 0);
		af_alg_pull_tsgl(sk, len, areq->tsgl);

		/* Initialize the crypto operation */
		skcipher_request_set_tfm(&areq->cra_u.skcipher_req, tfm);
		@@ -363,7 +363,7 @@ static void skcipher_sock_destruct(struct sock *sk)
		struct alg_sock *pask = alg_sk(psk);
		struct crypto_skcipher *tfm = pask->private;

		af_alg_pull_tsgl(sk, ctx->used, NULL, 0);
		af_alg_pull_tsgl(sk, ctx->used, NULL);
		sock_kzfree_s(sk, ctx->iv, crypto_skcipher_ivsize(tfm));
		if (ctx->state)
		sock_kzfree_s(sk, ctx->state, crypto_skcipher_statesize(tfm));

include/crypto/if_alg.h

+2 −3

Original line number	Diff line number	Diff line
		@@ -230,9 +230,8 @@ static inline bool af_alg_readable(struct sock *sk)
		return PAGE_SIZE <= af_alg_rcvbuf(sk);
		}

		unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset);
		void af_alg_pull_tsgl(struct sock sk, size_t used, struct scatterlist dst,
		size_t dst_offset);
		unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes);
		void af_alg_pull_tsgl(struct sock sk, size_t used, struct scatterlist dst);
		void af_alg_wmem_wakeup(struct sock *sk);
		int af_alg_wait_for_data(struct sock *sk, unsigned flags, unsigned min);
		int af_alg_sendmsg(struct socket sock, struct msghdr msg, size_t size,