The way the algif_skcipher works currently is that on sendmsg/sendpage it
builds an sgl for the input data and then on read/recvmsg it sends the job
for encryption putting the user to sleep till the data is processed.
This way it can only handle one job at a given time.
This patch changes it to be asynchronous by adding AIO support.
Signed-off-by: Tadeusz Struk <tadeusz.struk@xxxxxxxxx>
---
crypto/algif_skcipher.c | 308 ++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 301 insertions(+), 7 deletions(-)
diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c
index 0c8a1e5..d035d10 100644
--- a/crypto/algif_skcipher.c
+++ b/crypto/algif_skcipher.c
@@ -19,6 +19,7 @@
#include <linux/list.h>
#include <linux/kernel.h>
#include <linux/mm.h>
+#include <linux/mempool.h>
#include <linux/module.h>
#include <linux/net.h>
#include <net/sock.h>
@@ -39,6 +40,9 @@ struct skcipher_ctx {
struct af_alg_completion completion;
+ struct kmem_cache *cache;
+ mempool_t *pool;
+ atomic_t inflight;
unsigned used;
unsigned int len;
@@ -49,9 +53,135 @@ struct skcipher_ctx {
struct ablkcipher_request req;
};
+struct skcipher_async_rsgl {
+ struct af_alg_sgl sgl;
+ struct list_head list;
+};
+
+struct skcipher_async_req {
+ struct kiocb *iocb;
+ struct skcipher_async_rsgl first_sgl;
+ struct list_head list;
+ struct scatterlist *tsg;
+ char iv[];
+};
+
+#define GET_SREQ(areq, ctx) (struct skcipher_async_req *)((char *)areq + \
+ crypto_ablkcipher_reqsize(crypto_ablkcipher_reqtfm(&ctx->req)))
+
+#define GET_REQ_SIZE(ctx) \
+ crypto_ablkcipher_reqsize(crypto_ablkcipher_reqtfm(&ctx->req))
+
+#define GET_IV_SIZE(ctx) \
+ crypto_ablkcipher_ivsize(crypto_ablkcipher_reqtfm(&ctx->req))
+
#define MAX_SGL_ENTS ((4096 - sizeof(struct skcipher_sg_list)) / \
sizeof(struct scatterlist) - 1)
+static void skcipher_free_async_sgls(struct skcipher_async_req *sreq)
+{
+ struct skcipher_async_rsgl *rsgl, *tmp;
+ struct scatterlist *sgl;
+ struct scatterlist *sg;
+ int i, n;
+
+ list_for_each_entry_safe(rsgl, tmp, &sreq->list, list) {
+ af_alg_free_sg(&rsgl->sgl);
+ if (rsgl != &sreq->first_sgl)
+ kfree(rsgl);
+ }
+ sgl = sreq->tsg;
+ n = sg_nents(sgl);
+ for_each_sg(sgl, sg, n, i)
+ put_page(sg_page(sg));
+
+ kfree(sreq->tsg);
+}
+
+static void skcipher_async_cb(struct crypto_async_request *req, int err)
+{
+ struct sock *sk = req->data;
+ struct alg_sock *ask = alg_sk(sk);
+ struct skcipher_ctx *ctx = ask->private;
+ struct skcipher_async_req *sreq = GET_SREQ(req, ctx);
+ struct kiocb *iocb = sreq->iocb;
+
+ atomic_dec(&ctx->inflight);
+ skcipher_free_async_sgls(sreq);
+ mempool_free(req, ctx->pool);
+ aio_complete(iocb, err, err);
+}
+
+static void skcipher_mempool_free(void *_req, void *_sk)
+{
+ struct sock *sk = _sk;
+ struct alg_sock *ask = alg_sk(sk);
+ struct skcipher_ctx *ctx = ask->private;
+ struct kmem_cache *cache = ctx->cache;
+
+ kmem_cache_free(cache, _req);
+}
+
+static void *skcipher_mempool_alloc(gfp_t gfp_mask, void *_sk)
+{
+ struct sock *sk = _sk;
+ struct alg_sock *ask = alg_sk(sk);
+ struct skcipher_ctx *ctx = ask->private;
+ struct kmem_cache *cache = ctx->cache;
+ struct ablkcipher_request *req;
+
+ req = kmem_cache_alloc(cache, gfp_mask);
+ if (req) {
+ ablkcipher_request_set_tfm(req,
+ crypto_ablkcipher_reqtfm(&ctx->req));
+ ablkcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
+ skcipher_async_cb, sk);
+ }
+ return req;
+}
+
+static void skcipher_cache_constructor(void *v)
+{
+ memset(v, 0, sizeof(struct skcipher_async_req));
+}
+
+static int skcipher_mempool_create(struct sock *sk)
+{
+ struct alg_sock *ask = alg_sk(sk);
+ struct skcipher_ctx *ctx = ask->private;
+ unsigned int len = sizeof(struct skcipher_async_req) +
+ GET_REQ_SIZE(ctx) + GET_IV_SIZE(ctx);
+ char buf[32];
+
+ snprintf(buf, sizeof(buf), "skcipher_%p", ctx);
+ ctx->cache = kmem_cache_create(buf, len, 0, SLAB_HWCACHE_ALIGN |
+ SLAB_TEMPORARY,
+ skcipher_cache_constructor);
+ if (unlikely(!ctx->cache))
+ return -ENOMEM;
+
+ ctx->pool = mempool_create(128, skcipher_mempool_alloc,
+ skcipher_mempool_free, sk);
+
+ if (unlikely(!ctx->pool)) {
+ kmem_cache_destroy(ctx->cache);
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+static void skcipher_mempool_destroy(struct skcipher_ctx *ctx)
+{
+ if (ctx->pool)
+ mempool_destroy(ctx->pool);
+
+ if (ctx->cache)
+ kmem_cache_destroy(ctx->cache);
+
+ ctx->cache = NULL;
+ ctx->pool = NULL;
+}
+
static inline int skcipher_sndbuf(struct sock *sk)
{
struct alg_sock *ask = alg_sk(sk);
@@ -96,7 +226,7 @@ static int skcipher_alloc_sgl(struct sock *sk)
return 0;
}
-static void skcipher_pull_sgl(struct sock *sk, int used)
+static void skcipher_pull_sgl(struct sock *sk, int used, int put)
{
struct alg_sock *ask = alg_sk(sk);
struct skcipher_ctx *ctx = ask->private;
@@ -123,8 +253,8 @@ static void skcipher_pull_sgl(struct sock *sk, int used)
if (sg[i].length)
return;
-
- put_page(sg_page(sg + i));
+ if (put)
+ put_page(sg_page(sg + i));
sg_assign_page(sg + i, NULL);
}
@@ -143,7 +273,7 @@ static void skcipher_free_sgl(struct sock *sk)
struct alg_sock *ask = alg_sk(sk);
struct skcipher_ctx *ctx = ask->private;
- skcipher_pull_sgl(sk, ctx->used);
+ skcipher_pull_sgl(sk, ctx->used, 1);
}
static int skcipher_wait_for_wmem(struct sock *sk, unsigned flags)
@@ -424,8 +554,144 @@ unlock:
return err ?: size;
}
-static int skcipher_recvmsg(struct kiocb *unused, struct socket *sock,
- struct msghdr *msg, size_t ignored, int flags)
+static int skcipher_all_sg_nents(struct skcipher_ctx *ctx)
+{
+ struct skcipher_sg_list *sgl;
+ struct scatterlist *sg;
+ int nents = 0;
+
+ list_for_each_entry(sgl, &ctx->tsgl, list) {
+ sg = sgl->sg;
+
+ while (!sg->length)
+ sg++;
+
+ nents += sg_nents(sg);
+ }
+ return nents;
+}
+
+static int skcipher_recvmsg_async(struct kiocb *iocb, struct socket *sock,
+ struct msghdr *msg, int flags)
+{
+ struct sock *sk = sock->sk;
+ struct alg_sock *ask = alg_sk(sk);
+ struct skcipher_ctx *ctx = ask->private;
+ struct skcipher_sg_list *sgl;
+ struct scatterlist *sg;
+ struct skcipher_async_req *sreq;
+ struct ablkcipher_request *req;
+ struct skcipher_async_rsgl *last_rsgl = NULL;
+ unsigned int len = 0, tx_nents = skcipher_all_sg_nents(ctx);
+ int i = 0;
+ int err = -ENOMEM;
+
+ lock_sock(sk);
+ req = mempool_alloc(ctx->pool, GFP_KERNEL);
+ if (unlikely(!req))
+ goto unlock;
+
+ sreq = GET_SREQ(req, ctx);
+ sreq->iocb = iocb;
+ INIT_LIST_HEAD(&sreq->list);
+ memcpy(sreq->iv, ctx->iv, GET_IV_SIZE(ctx));
+ sreq->tsg = kcalloc(tx_nents, sizeof(*sg), GFP_KERNEL);
+
+ if (!sreq->tsg) {
+ mempool_free(req, ctx->pool);
+ goto unlock;
+ }
+ sg_init_table(sreq->tsg, tx_nents);
+
+ while (iov_iter_count(&msg->msg_iter)) {
+ struct skcipher_async_rsgl *rsgl;
+ unsigned long used;
+
+ if (!ctx->used) {
+ err = skcipher_wait_for_data(sk, flags);
+ if (err)
+ goto free;
+ }
+ sgl = list_first_entry(&ctx->tsgl,
+ struct skcipher_sg_list, list);
+ sg = sgl->sg;
+
+ while (!sg->length)
+ sg++;
+
+ used = min_t(unsigned long, ctx->used,
+ iov_iter_count(&msg->msg_iter));
+ used = min_t(unsigned long, used, sg->length);
+
+ if (i == tx_nents) {
+ struct scatterlist *tmp;
+ int x;
+ /* Ran out of tx slots in async request
+ * need to expand */
+ tmp = kcalloc(tx_nents * 2, sizeof(*tmp),
+ GFP_KERNEL);
+ if (!tmp)
+ goto free;
+
+ sg_init_table(tmp, tx_nents * 2);
+ for (x = 0; x < tx_nents; x++)
+ sg_set_page(&tmp[x], sg_page(&sreq->tsg[x]),
+ sreq->tsg[x].length,
+ sreq->tsg[x].offset);
+ kfree(sreq->tsg);
+ sreq->tsg = tmp;
+ tx_nents *= 2;
+ }
+ /* Need to take over the tx sgl from ctx
+ * to the asynch req - these sgls will be freed later */
+ sg_set_page(sreq->tsg + i++, sg_page(sg), sg->length,
+ sg->offset);
+
+ if (list_empty(&sreq->list)) {
+ rsgl = &sreq->first_sgl;
+ list_add_tail(&rsgl->list, &sreq->list);
+ } else {
+ rsgl = kzalloc(sizeof(*rsgl), GFP_KERNEL);
+ if (!rsgl) {
+ err = -ENOMEM;
+ goto free;
+ }
+ list_add_tail(&rsgl->list, &sreq->list);
+ }
+
+ used = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, used);
+ err = used;
+ if (used < 0)
+ goto free;
+ if (last_rsgl)
+ af_alg_link_sg(&last_rsgl->sgl, &rsgl->sgl);
+
+ last_rsgl = rsgl;
+ len += used;
+ skcipher_pull_sgl(sk, used, 0);
+ iov_iter_advance(&msg->msg_iter, used);
+ }
+
+ ablkcipher_request_set_crypt(req, sreq->tsg, sreq->first_sgl.sgl.sg,
+ len, sreq->iv);
+ err = ctx->enc ? crypto_ablkcipher_encrypt(req) :
+ crypto_ablkcipher_decrypt(req);
+ if (err == -EINPROGRESS) {
+ atomic_inc(&ctx->inflight);
+ err = -EIOCBQUEUED;
+ goto unlock;
+ }
+free:
+ skcipher_free_async_sgls(sreq);
+ mempool_free(req, ctx->pool);
+unlock:
+ skcipher_wmem_wakeup(sk);
+ release_sock(sk);
+ return err;
+}
+
+static int skcipher_recvmsg_sync(struct socket *sock, struct msghdr *msg,
+ int flags)
{
struct sock *sk = sock->sk;
struct alg_sock *ask = alg_sk(sk);
@@ -484,7 +750,7 @@ free:
goto unlock;
copied += used;
- skcipher_pull_sgl(sk, used);
+ skcipher_pull_sgl(sk, used, 1);
iov_iter_advance(&msg->msg_iter, used);
}
@@ -497,6 +763,13 @@ unlock:
return copied ?: err;
}
+static int skcipher_recvmsg(struct kiocb *iocb, struct socket *sock,
+ struct msghdr *msg, size_t ignored, int flags)
+{
+ return is_sync_kiocb(iocb) ?
+ skcipher_recvmsg_sync(sock, msg, flags) :
+ skcipher_recvmsg_async(iocb, sock, msg, flags);
+}
static unsigned int skcipher_poll(struct file *file, struct socket *sock,
poll_table *wait)
@@ -555,12 +828,26 @@ static int skcipher_setkey(void *private, const u8 *key, unsigned int keylen)
return crypto_ablkcipher_setkey(private, key, keylen);
}
+static void skcipher_wait(struct sock *sk)
+{
+ struct alg_sock *ask = alg_sk(sk);
+ struct skcipher_ctx *ctx = ask->private;
+ int ctr = 0;
+
+ while (atomic_read(&ctx->inflight) && ctr++ < 100)
+ msleep(100);
+}
+
static void skcipher_sock_destruct(struct sock *sk)
{
struct alg_sock *ask = alg_sk(sk);
struct skcipher_ctx *ctx = ask->private;
struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(&ctx->req);
+ if (atomic_read(&ctx->inflight))
+ skcipher_wait(sk);
+
+ skcipher_mempool_destroy(ctx);
skcipher_free_sgl(sk);
sock_kzfree_s(sk, ctx->iv, crypto_ablkcipher_ivsize(tfm));
sock_kfree_s(sk, ctx, ctx->len);
@@ -592,6 +879,7 @@ static int skcipher_accept_parent(void *private, struct sock *sk)
ctx->more = 0;
ctx->merge = 0;
ctx->enc = 0;
+ atomic_set(&ctx->inflight, 0);
af_alg_init_completion(&ctx->completion);
ask->private = ctx;
@@ -600,6 +888,12 @@ static int skcipher_accept_parent(void *private, struct sock *sk)
ablkcipher_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
af_alg_complete, &ctx->completion);
+ if (skcipher_mempool_create(sk)) {
+ sock_kzfree_s(sk, ctx->iv, crypto_ablkcipher_ivsize(private));
+ sock_kfree_s(sk, ctx, ctx->len);
+ return -ENOMEM;
+ }
+
sk->sk_destruct = skcipher_sock_destruct;
return 0;
--
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