From a596999b7ddfe7fc5b7b8adf9536ab1c39cb12d2 Mon Sep 17 00:00:00 2001 From: Tadeusz Struk Date: Thu, 19 Mar 2015 12:31:40 -0700 Subject: [PATCH] crypto: algif - change algif_skcipher to be asynchronous 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 Signed-off-by: David S. Miller --- crypto/algif_skcipher.c | 233 ++++++++++++++++++++++++++++++++++++++-- 1 file changed, 226 insertions(+), 7 deletions(-) diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c index b9743dc35801..8276f21ea7be 100644 --- a/crypto/algif_skcipher.c +++ b/crypto/algif_skcipher.c @@ -39,6 +39,7 @@ struct skcipher_ctx { struct af_alg_completion completion; + atomic_t inflight; unsigned used; unsigned int len; @@ -49,9 +50,65 @@ 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); + kfree(req); + aio_complete(iocb, err, err); +} + static inline int skcipher_sndbuf(struct sock *sk) { struct alg_sock *ask = alg_sk(sk); @@ -96,7 +153,7 @@ 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 +180,8 @@ 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 +200,7 @@ 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 +481,149 @@ unlock: return err ?: size; } -static int skcipher_recvmsg(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 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); + unsigned int reqlen = sizeof(struct skcipher_async_req) + + GET_REQ_SIZE(ctx) + GET_IV_SIZE(ctx); + int i = 0; + int err = -ENOMEM; + + lock_sock(sk); + req = kmalloc(reqlen, GFP_KERNEL); + if (unlikely(!req)) + goto unlock; + + sreq = GET_SREQ(req, ctx); + sreq->iocb = msg->msg_iocb; + memset(&sreq->first_sgl, '\0', sizeof(struct skcipher_async_rsgl)); + INIT_LIST_HEAD(&sreq->list); + sreq->tsg = kcalloc(tx_nents, sizeof(*sg), GFP_KERNEL); + if (unlikely(!sreq->tsg)) { + kfree(req); + goto unlock; + } + sg_init_table(sreq->tsg, tx_nents); + memcpy(sreq->iv, ctx->iv, GET_IV_SIZE(ctx)); + ablkcipher_request_set_tfm(req, crypto_ablkcipher_reqtfm(&ctx->req)); + ablkcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG, + skcipher_async_cb, sk); + + 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); + kfree(req); +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 +682,7 @@ 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 +695,13 @@ unlock: return copied ?: err; } +static int skcipher_recvmsg(struct socket *sock, struct msghdr *msg, + size_t ignored, int flags) +{ + return (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) ? + skcipher_recvmsg_async(sock, msg, flags) : + skcipher_recvmsg_sync(sock, msg, flags); +} static unsigned int skcipher_poll(struct file *file, struct socket *sock, poll_table *wait) @@ -555,12 +760,25 @@ 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_free_sgl(sk); sock_kzfree_s(sk, ctx->iv, crypto_ablkcipher_ivsize(tfm)); sock_kfree_s(sk, ctx, ctx->len); @@ -592,6 +810,7 @@ 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; -- 2.34.1