From 83094e5e9e49f893403d6fad20c9c06c980c2d1b Mon Sep 17 00:00:00 2001 From: Tadeusz Struk Date: Fri, 11 Mar 2016 11:50:33 -0800 Subject: [PATCH] crypto: af_alg - add async support to algif_aead Following the async change for algif_skcipher this patch adds similar async read to algif_aead. changes in v3: - add call to aead_reset_ctx directly from aead_put_sgl instead of calling them separatelly one after the other - remove wait from aead_sock_destruct function as it is not needed when sock_hold is used changes in v2: - change internal data structures from fixed size arrays, limited to RSGL_MAX_ENTRIES, to linked list model with no artificial limitation. - use sock_kmalloc instead of kmalloc for memory allocation - use sock_hold instead of separate atomic ctr to wait for outstanding request Signed-off-by: Tadeusz Struk Signed-off-by: Herbert Xu --- crypto/algif_aead.c | 268 +++++++++++++++++++++++++++++++++++++++----- 1 file changed, 237 insertions(+), 31 deletions(-) diff --git a/crypto/algif_aead.c b/crypto/algif_aead.c index 147069c9afd0..80a0f1a78551 100644 --- a/crypto/algif_aead.c +++ b/crypto/algif_aead.c @@ -13,7 +13,7 @@ * any later version. */ -#include +#include #include #include #include @@ -29,15 +29,24 @@ struct aead_sg_list { struct scatterlist sg[ALG_MAX_PAGES]; }; +struct aead_async_rsgl { + struct af_alg_sgl sgl; + struct list_head list; +}; + +struct aead_async_req { + struct scatterlist *tsgl; + struct aead_async_rsgl first_rsgl; + struct list_head list; + struct kiocb *iocb; + unsigned int tsgls; + char iv[]; +}; + struct aead_ctx { struct aead_sg_list tsgl; - /* - * RSGL_MAX_ENTRIES is an artificial limit where user space at maximum - * can cause the kernel to allocate RSGL_MAX_ENTRIES * ALG_MAX_PAGES - * pages - */ -#define RSGL_MAX_ENTRIES ALG_MAX_PAGES - struct af_alg_sgl rsgl[RSGL_MAX_ENTRIES]; + struct aead_async_rsgl first_rsgl; + struct list_head list; void *iv; @@ -75,6 +84,17 @@ static inline bool aead_sufficient_data(struct aead_ctx *ctx) return ctx->used >= ctx->aead_assoclen + as; } +static void aead_reset_ctx(struct aead_ctx *ctx) +{ + struct aead_sg_list *sgl = &ctx->tsgl; + + sg_init_table(sgl->sg, ALG_MAX_PAGES); + sgl->cur = 0; + ctx->used = 0; + ctx->more = 0; + ctx->merge = 0; +} + static void aead_put_sgl(struct sock *sk) { struct alg_sock *ask = alg_sk(sk); @@ -90,11 +110,7 @@ static void aead_put_sgl(struct sock *sk) put_page(sg_page(sg + i)); sg_assign_page(sg + i, NULL); } - sg_init_table(sg, ALG_MAX_PAGES); - sgl->cur = 0; - ctx->used = 0; - ctx->more = 0; - ctx->merge = 0; + aead_reset_ctx(ctx); } static void aead_wmem_wakeup(struct sock *sk) @@ -349,23 +365,188 @@ unlock: return err ?: size; } -static int aead_recvmsg(struct socket *sock, struct msghdr *msg, size_t ignored, int flags) +#define GET_ASYM_REQ(req, tfm) (struct aead_async_req *) \ + ((char *)req + sizeof(struct aead_request) + \ + crypto_aead_reqsize(tfm)) + + #define GET_REQ_SIZE(tfm) sizeof(struct aead_async_req) + \ + crypto_aead_reqsize(tfm) + crypto_aead_ivsize(tfm) + \ + sizeof(struct aead_request) + +static void aead_async_cb(struct crypto_async_request *_req, int err) +{ + struct sock *sk = _req->data; + struct alg_sock *ask = alg_sk(sk); + struct aead_ctx *ctx = ask->private; + struct crypto_aead *tfm = crypto_aead_reqtfm(&ctx->aead_req); + struct aead_request *req = aead_request_cast(_req); + struct aead_async_req *areq = GET_ASYM_REQ(req, tfm); + struct scatterlist *sg = areq->tsgl; + struct aead_async_rsgl *rsgl; + struct kiocb *iocb = areq->iocb; + unsigned int i, reqlen = GET_REQ_SIZE(tfm); + + list_for_each_entry(rsgl, &areq->list, list) { + af_alg_free_sg(&rsgl->sgl); + if (rsgl != &areq->first_rsgl) + sock_kfree_s(sk, rsgl, sizeof(*rsgl)); + } + + for (i = 0; i < areq->tsgls; i++) + put_page(sg_page(sg + i)); + + sock_kfree_s(sk, areq->tsgl, sizeof(*areq->tsgl) * areq->tsgls); + sock_kfree_s(sk, req, reqlen); + __sock_put(sk); + iocb->ki_complete(iocb, err, err); +} + +static int aead_recvmsg_async(struct socket *sock, struct msghdr *msg, + int flags) +{ + struct sock *sk = sock->sk; + struct alg_sock *ask = alg_sk(sk); + struct aead_ctx *ctx = ask->private; + struct crypto_aead *tfm = crypto_aead_reqtfm(&ctx->aead_req); + struct aead_async_req *areq; + struct aead_request *req = NULL; + struct aead_sg_list *sgl = &ctx->tsgl; + struct aead_async_rsgl *last_rsgl = NULL, *rsgl; + unsigned int as = crypto_aead_authsize(tfm); + unsigned int i, reqlen = GET_REQ_SIZE(tfm); + int err = -ENOMEM; + unsigned long used; + size_t outlen; + size_t usedpages = 0; + + lock_sock(sk); + if (ctx->more) { + err = aead_wait_for_data(sk, flags); + if (err) + goto unlock; + } + + used = ctx->used; + outlen = used; + + if (!aead_sufficient_data(ctx)) + goto unlock; + + req = sock_kmalloc(sk, reqlen, GFP_KERNEL); + if (unlikely(!req)) + goto unlock; + + areq = GET_ASYM_REQ(req, tfm); + memset(&areq->first_rsgl, '\0', sizeof(areq->first_rsgl)); + INIT_LIST_HEAD(&areq->list); + areq->iocb = msg->msg_iocb; + memcpy(areq->iv, ctx->iv, crypto_aead_ivsize(tfm)); + aead_request_set_tfm(req, tfm); + aead_request_set_ad(req, ctx->aead_assoclen); + aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG, + aead_async_cb, sk); + used -= ctx->aead_assoclen + (ctx->enc ? as : 0); + + /* take over all tx sgls from ctx */ + areq->tsgl = sock_kmalloc(sk, sizeof(*areq->tsgl) * sgl->cur, + GFP_KERNEL); + if (unlikely(!areq->tsgl)) + goto free; + + sg_init_table(areq->tsgl, sgl->cur); + for (i = 0; i < sgl->cur; i++) + sg_set_page(&areq->tsgl[i], sg_page(&sgl->sg[i]), + sgl->sg[i].length, sgl->sg[i].offset); + + areq->tsgls = sgl->cur; + + /* create rx sgls */ + while (iov_iter_count(&msg->msg_iter)) { + size_t seglen = min_t(size_t, iov_iter_count(&msg->msg_iter), + (outlen - usedpages)); + + if (list_empty(&areq->list)) { + rsgl = &areq->first_rsgl; + + } else { + rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL); + if (unlikely(!rsgl)) { + err = -ENOMEM; + goto free; + } + } + rsgl->sgl.npages = 0; + list_add_tail(&rsgl->list, &areq->list); + + /* make one iovec available as scatterlist */ + err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen); + if (err < 0) + goto free; + + usedpages += err; + + /* chain the new scatterlist with previous one */ + if (last_rsgl) + af_alg_link_sg(&last_rsgl->sgl, &rsgl->sgl); + + last_rsgl = rsgl; + + /* we do not need more iovecs as we have sufficient memory */ + if (outlen <= usedpages) + break; + + iov_iter_advance(&msg->msg_iter, err); + } + err = -EINVAL; + /* ensure output buffer is sufficiently large */ + if (usedpages < outlen) + goto free; + + aead_request_set_crypt(req, areq->tsgl, areq->first_rsgl.sgl.sg, used, + areq->iv); + err = ctx->enc ? crypto_aead_encrypt(req) : crypto_aead_decrypt(req); + if (err) { + if (err == -EINPROGRESS) { + sock_hold(sk); + err = -EIOCBQUEUED; + aead_reset_ctx(ctx); + goto unlock; + } else if (err == -EBADMSG) { + aead_put_sgl(sk); + } + goto free; + } + aead_put_sgl(sk); + +free: + list_for_each_entry(rsgl, &areq->list, list) { + af_alg_free_sg(&rsgl->sgl); + if (rsgl != &areq->first_rsgl) + sock_kfree_s(sk, rsgl, sizeof(*rsgl)); + } + if (areq->tsgl) + sock_kfree_s(sk, areq->tsgl, sizeof(*areq->tsgl) * areq->tsgls); + if (req) + sock_kfree_s(sk, req, reqlen); +unlock: + aead_wmem_wakeup(sk); + release_sock(sk); + return err ? err : outlen; +} + +static int aead_recvmsg_sync(struct socket *sock, struct msghdr *msg, int flags) { struct sock *sk = sock->sk; struct alg_sock *ask = alg_sk(sk); struct aead_ctx *ctx = ask->private; unsigned as = crypto_aead_authsize(crypto_aead_reqtfm(&ctx->aead_req)); struct aead_sg_list *sgl = &ctx->tsgl; - unsigned int i = 0; + struct aead_async_rsgl *last_rsgl = NULL; + struct aead_async_rsgl *rsgl, *tmp; int err = -EINVAL; unsigned long used = 0; size_t outlen = 0; size_t usedpages = 0; - unsigned int cnt = 0; - - /* Limit number of IOV blocks to be accessed below */ - if (msg->msg_iter.nr_segs > RSGL_MAX_ENTRIES) - return -ENOMSG; lock_sock(sk); @@ -417,21 +598,33 @@ static int aead_recvmsg(struct socket *sock, struct msghdr *msg, size_t ignored, size_t seglen = min_t(size_t, iov_iter_count(&msg->msg_iter), (outlen - usedpages)); + if (list_empty(&ctx->list)) { + rsgl = &ctx->first_rsgl; + } else { + rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL); + if (unlikely(!rsgl)) { + err = -ENOMEM; + goto unlock; + } + } + rsgl->sgl.npages = 0; + list_add_tail(&rsgl->list, &ctx->list); + /* make one iovec available as scatterlist */ - err = af_alg_make_sg(&ctx->rsgl[cnt], &msg->msg_iter, - seglen); + err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen); if (err < 0) goto unlock; usedpages += err; /* chain the new scatterlist with previous one */ - if (cnt) - af_alg_link_sg(&ctx->rsgl[cnt-1], &ctx->rsgl[cnt]); + if (last_rsgl) + af_alg_link_sg(&last_rsgl->sgl, &rsgl->sgl); + + last_rsgl = rsgl; /* we do not need more iovecs as we have sufficient memory */ if (outlen <= usedpages) break; iov_iter_advance(&msg->msg_iter, err); - cnt++; } err = -EINVAL; @@ -440,8 +633,7 @@ static int aead_recvmsg(struct socket *sock, struct msghdr *msg, size_t ignored, goto unlock; sg_mark_end(sgl->sg + sgl->cur - 1); - - aead_request_set_crypt(&ctx->aead_req, sgl->sg, ctx->rsgl[0].sg, + aead_request_set_crypt(&ctx->aead_req, sgl->sg, ctx->first_rsgl.sgl.sg, used, ctx->iv); aead_request_set_ad(&ctx->aead_req, ctx->aead_assoclen); @@ -454,23 +646,35 @@ static int aead_recvmsg(struct socket *sock, struct msghdr *msg, size_t ignored, /* EBADMSG implies a valid cipher operation took place */ if (err == -EBADMSG) aead_put_sgl(sk); + goto unlock; } aead_put_sgl(sk); - err = 0; unlock: - for (i = 0; i < cnt; i++) - af_alg_free_sg(&ctx->rsgl[i]); - + list_for_each_entry_safe(rsgl, tmp, &ctx->list, list) { + af_alg_free_sg(&rsgl->sgl); + if (rsgl != &ctx->first_rsgl) + sock_kfree_s(sk, rsgl, sizeof(*rsgl)); + list_del(&rsgl->list); + } + INIT_LIST_HEAD(&ctx->list); aead_wmem_wakeup(sk); release_sock(sk); return err ? err : outlen; } +static int aead_recvmsg(struct socket *sock, struct msghdr *msg, size_t ignored, + int flags) +{ + return (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) ? + aead_recvmsg_async(sock, msg, flags) : + aead_recvmsg_sync(sock, msg, flags); +} + static unsigned int aead_poll(struct file *file, struct socket *sock, poll_table *wait) { @@ -540,6 +744,7 @@ static void aead_sock_destruct(struct sock *sk) unsigned int ivlen = crypto_aead_ivsize( crypto_aead_reqtfm(&ctx->aead_req)); + WARN_ON(atomic_read(&sk->sk_refcnt) != 0); aead_put_sgl(sk); sock_kzfree_s(sk, ctx->iv, ivlen); sock_kfree_s(sk, ctx, ctx->len); @@ -574,6 +779,7 @@ static int aead_accept_parent(void *private, struct sock *sk) ctx->aead_assoclen = 0; af_alg_init_completion(&ctx->completion); sg_init_table(ctx->tsgl.sg, ALG_MAX_PAGES); + INIT_LIST_HEAD(&ctx->list); ask->private = ctx; -- 2.20.1