// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Software async crypto daemon.
 *
 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * Added AEAD support to cryptd.
 *    Authors: Tadeusz Struk (tadeusz.struk@intel.com)
 *             Adrian Hoban <adrian.hoban@intel.com>
 *             Gabriele Paoloni <gabriele.paoloni@intel.com>
 *             Aidan O'Mahony (aidan.o.mahony@intel.com)
 *    Copyright (c) 2010, Intel Corporation.
 */

#include <crypto/internal/hash.h>
#include <crypto/internal/aead.h>
#include <crypto/internal/skcipher.h>
#include <crypto/cryptd.h>
#include <linux/refcount.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/workqueue.h>

static unsigned int cryptd_max_cpu_qlen = 1000;
module_param(cryptd_max_cpu_qlen, uint, 0);
MODULE_PARM_DESC(cryptd_max_cpu_qlen, "Set cryptd Max queue depth");

static struct workqueue_struct *cryptd_wq;

struct cryptd_cpu_queue {
        struct crypto_queue queue;
        struct work_struct work;
};

struct cryptd_queue {
        /*
         * Protected by disabling BH to allow enqueueing from softinterrupt and
         * dequeuing from kworker (cryptd_queue_worker()).
         */
        struct cryptd_cpu_queue __percpu *cpu_queue;
};

struct cryptd_instance_ctx {
        struct crypto_spawn spawn;
        struct cryptd_queue *queue;
};

struct skcipherd_instance_ctx {
        struct crypto_skcipher_spawn spawn;
        struct cryptd_queue *queue;
};

struct hashd_instance_ctx {
        struct crypto_shash_spawn spawn;
        struct cryptd_queue *queue;
};

struct aead_instance_ctx {
        struct crypto_aead_spawn aead_spawn;
        struct cryptd_queue *queue;
};

struct cryptd_skcipher_ctx {
        refcount_t refcnt;
        struct crypto_skcipher *child;
};

struct cryptd_skcipher_request_ctx {
        struct skcipher_request req;
};

struct cryptd_hash_ctx {
        refcount_t refcnt;
        struct crypto_shash *child;
};

struct cryptd_hash_request_ctx {
        crypto_completion_t complete;
        void *data;
        struct shash_desc desc;
};

struct cryptd_aead_ctx {
        refcount_t refcnt;
        struct crypto_aead *child;
};

struct cryptd_aead_request_ctx {
        struct aead_request req;
};

static void cryptd_queue_worker(struct work_struct *work);

static int cryptd_init_queue(struct cryptd_queue *queue,
                             unsigned int max_cpu_qlen)
{
        int cpu;
        struct cryptd_cpu_queue *cpu_queue;

        queue->cpu_queue = alloc_percpu(struct cryptd_cpu_queue);
        if (!queue->cpu_queue)
                return -ENOMEM;
        for_each_possible_cpu(cpu) {
                cpu_queue = per_cpu_ptr(queue->cpu_queue, cpu);
                crypto_init_queue(&cpu_queue->queue, max_cpu_qlen);
                INIT_WORK(&cpu_queue->work, cryptd_queue_worker);
        }
        pr_info("cryptd: max_cpu_qlen set to %d\n", max_cpu_qlen);
        return 0;
}

static void cryptd_fini_queue(struct cryptd_queue *queue)
{
        int cpu;
        struct cryptd_cpu_queue *cpu_queue;

        for_each_possible_cpu(cpu) {
                cpu_queue = per_cpu_ptr(queue->cpu_queue, cpu);
                BUG_ON(cpu_queue->queue.qlen);
        }
        free_percpu(queue->cpu_queue);
}

static int cryptd_enqueue_request(struct cryptd_queue *queue,
                                  struct crypto_async_request *request)
{
        int err;
        struct cryptd_cpu_queue *cpu_queue;
        refcount_t *refcnt;

        local_bh_disable();
        cpu_queue = this_cpu_ptr(queue->cpu_queue);
        err = crypto_enqueue_request(&cpu_queue->queue, request);

        refcnt = crypto_tfm_ctx(request->tfm);

        if (err == -ENOSPC)
                goto out;

        queue_work_on(smp_processor_id(), cryptd_wq, &cpu_queue->work);

        if (!refcount_read(refcnt))
                goto out;

        refcount_inc(refcnt);

out:
        local_bh_enable();

        return err;
}

/* Called in workqueue context, do one real cryption work (via
 * req->complete) and reschedule itself if there are more work to
 * do. */
static void cryptd_queue_worker(struct work_struct *work)
{
        struct cryptd_cpu_queue *cpu_queue;
        struct crypto_async_request *req, *backlog;

        cpu_queue = container_of(work, struct cryptd_cpu_queue, work);
        /*
         * Only handle one request at a time to avoid hogging crypto workqueue.
         */
        local_bh_disable();
        backlog = crypto_get_backlog(&cpu_queue->queue);
        req = crypto_dequeue_request(&cpu_queue->queue);
        local_bh_enable();

        if (!req)
                return;

        if (backlog)
                crypto_request_complete(backlog, -EINPROGRESS);
        crypto_request_complete(req, 0);

        if (cpu_queue->queue.qlen)
                queue_work(cryptd_wq, &cpu_queue->work);
}

static inline struct cryptd_queue *cryptd_get_queue(struct crypto_tfm *tfm)
{
        struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
        struct cryptd_instance_ctx *ictx = crypto_instance_ctx(inst);
        return ictx->queue;
}

static void cryptd_type_and_mask(struct crypto_attr_type *algt,
                                 u32 *type, u32 *mask)
{
        /*
         * cryptd is allowed to wrap internal algorithms, but in that case the
         * resulting cryptd instance will be marked as internal as well.
         */
        *type = algt->type & CRYPTO_ALG_INTERNAL;
        *mask = algt->mask & CRYPTO_ALG_INTERNAL;

        /* No point in cryptd wrapping an algorithm that's already async. */
        *mask |= CRYPTO_ALG_ASYNC;

        *mask |= crypto_algt_inherited_mask(algt);
}

static int cryptd_init_instance(struct crypto_instance *inst,
                                struct crypto_alg *alg)
{
        if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
                     "cryptd(%s)",
                     alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
                return -ENAMETOOLONG;

        memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);

        inst->alg.cra_priority = alg->cra_priority + 50;
        inst->alg.cra_blocksize = alg->cra_blocksize;
        inst->alg.cra_alignmask = alg->cra_alignmask;

        return 0;
}

static int cryptd_skcipher_setkey(struct crypto_skcipher *parent,
                                  const u8 *key, unsigned int keylen)
{
        struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(parent);
        struct crypto_skcipher *child = ctx->child;

        crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
        crypto_skcipher_set_flags(child,
                                  crypto_skcipher_get_flags(parent) &
                                  CRYPTO_TFM_REQ_MASK);
        return crypto_skcipher_setkey(child, key, keylen);
}

static struct skcipher_request *cryptd_skcipher_prepare(
        struct skcipher_request *req, int err)
{
        struct cryptd_skcipher_request_ctx *rctx = skcipher_request_ctx(req);
        struct skcipher_request *subreq = &rctx->req;
        struct cryptd_skcipher_ctx *ctx;
        struct crypto_skcipher *child;

        req->base.complete = subreq->base.complete;
        req->base.data = subreq->base.data;

        if (unlikely(err == -EINPROGRESS))
                return NULL;

        ctx = crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
        child = ctx->child;

        skcipher_request_set_tfm(subreq, child);
        skcipher_request_set_callback(subreq, CRYPTO_TFM_REQ_MAY_SLEEP,
                                      NULL, NULL);
        skcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen,
                                   req->iv);

        return subreq;
}

static void cryptd_skcipher_complete(struct skcipher_request *req, int err,
                                     crypto_completion_t complete)
{
        struct cryptd_skcipher_request_ctx *rctx = skcipher_request_ctx(req);
        struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
        struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
        struct skcipher_request *subreq = &rctx->req;
        int refcnt = refcount_read(&ctx->refcnt);

        local_bh_disable();
        skcipher_request_complete(req, err);
        local_bh_enable();

        if (unlikely(err == -EINPROGRESS)) {
                subreq->base.complete = req->base.complete;
                subreq->base.data = req->base.data;
                req->base.complete = complete;
                req->base.data = req;
        } else if (refcnt && refcount_dec_and_test(&ctx->refcnt))
                crypto_free_skcipher(tfm);
}

static void cryptd_skcipher_encrypt(void *data, int err)
{
        struct skcipher_request *req = data;
        struct skcipher_request *subreq;

        subreq = cryptd_skcipher_prepare(req, err);
        if (likely(subreq))
                err = crypto_skcipher_encrypt(subreq);

        cryptd_skcipher_complete(req, err, cryptd_skcipher_encrypt);
}

static void cryptd_skcipher_decrypt(void *data, int err)
{
        struct skcipher_request *req = data;
        struct skcipher_request *subreq;

        subreq = cryptd_skcipher_prepare(req, err);
        if (likely(subreq))
                err = crypto_skcipher_decrypt(subreq);

        cryptd_skcipher_complete(req, err, cryptd_skcipher_decrypt);
}

static int cryptd_skcipher_enqueue(struct skcipher_request *req,
                                   crypto_completion_t compl)
{
        struct cryptd_skcipher_request_ctx *rctx = skcipher_request_ctx(req);
        struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
        struct skcipher_request *subreq = &rctx->req;
        struct cryptd_queue *queue;

        queue = cryptd_get_queue(crypto_skcipher_tfm(tfm));
        subreq->base.complete = req->base.complete;
        subreq->base.data = req->base.data;
        req->base.complete = compl;
        req->base.data = req;

        return cryptd_enqueue_request(queue, &req->base);
}

static int cryptd_skcipher_encrypt_enqueue(struct skcipher_request *req)
{
        return cryptd_skcipher_enqueue(req, cryptd_skcipher_encrypt);
}

static int cryptd_skcipher_decrypt_enqueue(struct skcipher_request *req)
{
        return cryptd_skcipher_enqueue(req, cryptd_skcipher_decrypt);
}

static int cryptd_skcipher_init_tfm(struct crypto_skcipher *tfm)
{
        struct skcipher_instance *inst = skcipher_alg_instance(tfm);
        struct skcipherd_instance_ctx *ictx = skcipher_instance_ctx(inst);
        struct crypto_skcipher_spawn *spawn = &ictx->spawn;
        struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
        struct crypto_skcipher *cipher;

        cipher = crypto_spawn_skcipher(spawn);
        if (IS_ERR(cipher))
                return PTR_ERR(cipher);

        ctx->child = cipher;
        crypto_skcipher_set_reqsize(
                tfm, sizeof(struct cryptd_skcipher_request_ctx) +
                     crypto_skcipher_reqsize(cipher));
        return 0;
}

static void cryptd_skcipher_exit_tfm(struct crypto_skcipher *tfm)
{
        struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);

        crypto_free_skcipher(ctx->child);
}

static void cryptd_skcipher_free(struct skcipher_instance *inst)
{
        struct skcipherd_instance_ctx *ctx = skcipher_instance_ctx(inst);

        crypto_drop_skcipher(&ctx->spawn);
        kfree(inst);
}

static int cryptd_create_skcipher(struct crypto_template *tmpl,
                                  struct rtattr **tb,
                                  struct crypto_attr_type *algt,
                                  struct cryptd_queue *queue)
{
        struct skcipherd_instance_ctx *ctx;
        struct skcipher_instance *inst;
        struct skcipher_alg_common *alg;
        u32 type;
        u32 mask;
        int err;

        cryptd_type_and_mask(algt, &type, &mask);

        inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
        if (!inst)
                return -ENOMEM;

        ctx = skcipher_instance_ctx(inst);
        ctx->queue = queue;

        err = crypto_grab_skcipher(&ctx->spawn, skcipher_crypto_instance(inst),
                                   crypto_attr_alg_name(tb[1]), type, mask);
        if (err)
                goto err_free_inst;

        alg = crypto_spawn_skcipher_alg_common(&ctx->spawn);
        err = cryptd_init_instance(skcipher_crypto_instance(inst), &alg->base);
        if (err)
                goto err_free_inst;

        inst->alg.base.cra_flags |= CRYPTO_ALG_ASYNC |
                (alg->base.cra_flags & CRYPTO_ALG_INTERNAL);
        inst->alg.ivsize = alg->ivsize;
        inst->alg.chunksize = alg->chunksize;
        inst->alg.min_keysize = alg->min_keysize;
        inst->alg.max_keysize = alg->max_keysize;

        inst->alg.base.cra_ctxsize = sizeof(struct cryptd_skcipher_ctx);

        inst->alg.init = cryptd_skcipher_init_tfm;
        inst->alg.exit = cryptd_skcipher_exit_tfm;

        inst->alg.setkey = cryptd_skcipher_setkey;
        inst->alg.encrypt = cryptd_skcipher_encrypt_enqueue;
        inst->alg.decrypt = cryptd_skcipher_decrypt_enqueue;

        inst->free = cryptd_skcipher_free;

        err = skcipher_register_instance(tmpl, inst);
        if (err) {
err_free_inst:
                cryptd_skcipher_free(inst);
        }
        return err;
}

static int cryptd_hash_init_tfm(struct crypto_ahash *tfm)
{
        struct ahash_instance *inst = ahash_alg_instance(tfm);
        struct hashd_instance_ctx *ictx = ahash_instance_ctx(inst);
        struct crypto_shash_spawn *spawn = &ictx->spawn;
        struct cryptd_hash_ctx *ctx = crypto_ahash_ctx(tfm);
        struct crypto_shash *hash;

        hash = crypto_spawn_shash(spawn);
        if (IS_ERR(hash))
                return PTR_ERR(hash);

        ctx->child = hash;
        crypto_ahash_set_reqsize(tfm,
                                 sizeof(struct cryptd_hash_request_ctx) +
                                 crypto_shash_descsize(hash));
        return 0;
}

static int cryptd_hash_clone_tfm(struct crypto_ahash *ntfm,
                                 struct crypto_ahash *tfm)
{
        struct cryptd_hash_ctx *nctx = crypto_ahash_ctx(ntfm);
        struct cryptd_hash_ctx *ctx = crypto_ahash_ctx(tfm);
        struct crypto_shash *hash;

        hash = crypto_clone_shash(ctx->child);
        if (IS_ERR(hash))
                return PTR_ERR(hash);

        nctx->child = hash;
        return 0;
}

static void cryptd_hash_exit_tfm(struct crypto_ahash *tfm)
{
        struct cryptd_hash_ctx *ctx = crypto_ahash_ctx(tfm);

        crypto_free_shash(ctx->child);
}

static int cryptd_hash_setkey(struct crypto_ahash *parent,
                                   const u8 *key, unsigned int keylen)
{
        struct cryptd_hash_ctx *ctx   = crypto_ahash_ctx(parent);
        struct crypto_shash *child = ctx->child;

        crypto_shash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
        crypto_shash_set_flags(child, crypto_ahash_get_flags(parent) &
                                      CRYPTO_TFM_REQ_MASK);
        return crypto_shash_setkey(child, key, keylen);
}

static int cryptd_hash_enqueue(struct ahash_request *req,
                                crypto_completion_t compl)
{
        struct cryptd_hash_request_ctx *rctx = ahash_request_ctx(req);
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
        struct cryptd_queue *queue =
                cryptd_get_queue(crypto_ahash_tfm(tfm));

        rctx->complete = req->base.complete;
        rctx->data = req->base.data;
        req->base.complete = compl;
        req->base.data = req;

        return cryptd_enqueue_request(queue, &req->base);
}

static struct shash_desc *cryptd_hash_prepare(struct ahash_request *req,
                                              int err)
{
        struct cryptd_hash_request_ctx *rctx = ahash_request_ctx(req);

        req->base.complete = rctx->complete;
        req->base.data = rctx->data;

        if (unlikely(err == -EINPROGRESS))
                return NULL;

        return &rctx->desc;
}

static void cryptd_hash_complete(struct ahash_request *req, int err,
                                 crypto_completion_t complete)
{
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
        struct cryptd_hash_ctx *ctx = crypto_ahash_ctx(tfm);
        int refcnt = refcount_read(&ctx->refcnt);

        local_bh_disable();
        ahash_request_complete(req, err);
        local_bh_enable();

        if (err == -EINPROGRESS) {
                req->base.complete = complete;
                req->base.data = req;
        } else if (refcnt && refcount_dec_and_test(&ctx->refcnt))
                crypto_free_ahash(tfm);
}

static void cryptd_hash_init(void *data, int err)
{
        struct ahash_request *req = data;
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
        struct cryptd_hash_ctx *ctx = crypto_ahash_ctx(tfm);
        struct crypto_shash *child = ctx->child;
        struct shash_desc *desc;

        desc = cryptd_hash_prepare(req, err);
        if (unlikely(!desc))
                goto out;

        desc->tfm = child;

        err = crypto_shash_init(desc);

out:
        cryptd_hash_complete(req, err, cryptd_hash_init);
}

static int cryptd_hash_init_enqueue(struct ahash_request *req)
{
        return cryptd_hash_enqueue(req, cryptd_hash_init);
}

static void cryptd_hash_update(void *data, int err)
{
        struct ahash_request *req = data;
        struct shash_desc *desc;

        desc = cryptd_hash_prepare(req, err);
        if (likely(desc))
                err = shash_ahash_update(req, desc);

        cryptd_hash_complete(req, err, cryptd_hash_update);
}

static int cryptd_hash_update_enqueue(struct ahash_request *req)
{
        return cryptd_hash_enqueue(req, cryptd_hash_update);
}

static void cryptd_hash_final(void *data, int err)
{
        struct ahash_request *req = data;
        struct shash_desc *desc;

        desc = cryptd_hash_prepare(req, err);
        if (likely(desc))
                err = crypto_shash_final(desc, req->result);

        cryptd_hash_complete(req, err, cryptd_hash_final);
}

static int cryptd_hash_final_enqueue(struct ahash_request *req)
{
        return cryptd_hash_enqueue(req, cryptd_hash_final);
}

static void cryptd_hash_finup(void *data, int err)
{
        struct ahash_request *req = data;
        struct shash_desc *desc;

        desc = cryptd_hash_prepare(req, err);
        if (likely(desc))
                err = shash_ahash_finup(req, desc);

        cryptd_hash_complete(req, err, cryptd_hash_finup);
}

static int cryptd_hash_finup_enqueue(struct ahash_request *req)
{
        return cryptd_hash_enqueue(req, cryptd_hash_finup);
}

static void cryptd_hash_digest(void *data, int err)
{
        struct ahash_request *req = data;
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
        struct cryptd_hash_ctx *ctx = crypto_ahash_ctx(tfm);
        struct crypto_shash *child = ctx->child;
        struct shash_desc *desc;

        desc = cryptd_hash_prepare(req, err);
        if (unlikely(!desc))
                goto out;

        desc->tfm = child;

        err = shash_ahash_digest(req, desc);

out:
        cryptd_hash_complete(req, err, cryptd_hash_digest);
}

static int cryptd_hash_digest_enqueue(struct ahash_request *req)
{
        return cryptd_hash_enqueue(req, cryptd_hash_digest);
}

static int cryptd_hash_export(struct ahash_request *req, void *out)
{
        struct cryptd_hash_request_ctx *rctx = ahash_request_ctx(req);

        return crypto_shash_export(&rctx->desc, out);
}

static int cryptd_hash_import(struct ahash_request *req, const void *in)
{
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
        struct cryptd_hash_ctx *ctx = crypto_ahash_ctx(tfm);
        struct shash_desc *desc = cryptd_shash_desc(req);

        desc->tfm = ctx->child;

        return crypto_shash_import(desc, in);
}

static void cryptd_hash_free(struct ahash_instance *inst)
{
        struct hashd_instance_ctx *ctx = ahash_instance_ctx(inst);

        crypto_drop_shash(&ctx->spawn);
        kfree(inst);
}

static int cryptd_create_hash(struct crypto_template *tmpl, struct rtattr **tb,
                              struct crypto_attr_type *algt,
                              struct cryptd_queue *queue)
{
        struct hashd_instance_ctx *ctx;
        struct ahash_instance *inst;
        struct shash_alg *alg;
        u32 type;
        u32 mask;
        int err;

        cryptd_type_and_mask(algt, &type, &mask);

        inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
        if (!inst)
                return -ENOMEM;

        ctx = ahash_instance_ctx(inst);
        ctx->queue = queue;

        err = crypto_grab_shash(&ctx->spawn, ahash_crypto_instance(inst),
                                crypto_attr_alg_name(tb[1]), type, mask);
        if (err)
                goto err_free_inst;
        alg = crypto_spawn_shash_alg(&ctx->spawn);

        err = cryptd_init_instance(ahash_crypto_instance(inst), &alg->base);
        if (err)
                goto err_free_inst;

        inst->alg.halg.base.cra_flags |= CRYPTO_ALG_ASYNC |
                (alg->base.cra_flags & (CRYPTO_ALG_INTERNAL|
                                        CRYPTO_ALG_OPTIONAL_KEY));
        inst->alg.halg.digestsize = alg->digestsize;
        inst->alg.halg.statesize = alg->statesize;
        inst->alg.halg.base.cra_ctxsize = sizeof(struct cryptd_hash_ctx);

        inst->alg.init_tfm = cryptd_hash_init_tfm;
        inst->alg.clone_tfm = cryptd_hash_clone_tfm;
        inst->alg.exit_tfm = cryptd_hash_exit_tfm;

        inst->alg.init   = cryptd_hash_init_enqueue;
        inst->alg.update = cryptd_hash_update_enqueue;
        inst->alg.final  = cryptd_hash_final_enqueue;
        inst->alg.finup  = cryptd_hash_finup_enqueue;
        inst->alg.export = cryptd_hash_export;
        inst->alg.import = cryptd_hash_import;
        if (crypto_shash_alg_has_setkey(alg))
                inst->alg.setkey = cryptd_hash_setkey;
        inst->alg.digest = cryptd_hash_digest_enqueue;

        inst->free = cryptd_hash_free;

        err = ahash_register_instance(tmpl, inst);
        if (err) {
err_free_inst:
                cryptd_hash_free(inst);
        }
        return err;
}

static int cryptd_aead_setkey(struct crypto_aead *parent,
                              const u8 *key, unsigned int keylen)
{
        struct cryptd_aead_ctx *ctx = crypto_aead_ctx(parent);
        struct crypto_aead *child = ctx->child;

        return crypto_aead_setkey(child, key, keylen);
}

static int cryptd_aead_setauthsize(struct crypto_aead *parent,
                                   unsigned int authsize)
{
        struct cryptd_aead_ctx *ctx = crypto_aead_ctx(parent);
        struct crypto_aead *child = ctx->child;

        return crypto_aead_setauthsize(child, authsize);
}

static void cryptd_aead_crypt(struct aead_request *req,
                              struct crypto_aead *child, int err,
                              int (*crypt)(struct aead_request *req),
                              crypto_completion_t compl)
{
        struct cryptd_aead_request_ctx *rctx;
        struct aead_request *subreq;
        struct cryptd_aead_ctx *ctx;
        struct crypto_aead *tfm;
        int refcnt;

        rctx = aead_request_ctx(req);
        subreq = &rctx->req;
        req->base.complete = subreq->base.complete;
        req->base.data = subreq->base.data;

        tfm = crypto_aead_reqtfm(req);

        if (unlikely(err == -EINPROGRESS))
                goto out;

        aead_request_set_tfm(subreq, child);
        aead_request_set_callback(subreq, CRYPTO_TFM_REQ_MAY_SLEEP,
                                  NULL, NULL);
        aead_request_set_crypt(subreq, req->src, req->dst, req->cryptlen,
                               req->iv);
        aead_request_set_ad(subreq, req->assoclen);

        err = crypt(subreq);

out:
        ctx = crypto_aead_ctx(tfm);
        refcnt = refcount_read(&ctx->refcnt);

        local_bh_disable();
        aead_request_complete(req, err);
        local_bh_enable();

        if (err == -EINPROGRESS) {
                subreq->base.complete = req->base.complete;
                subreq->base.data = req->base.data;
                req->base.complete = compl;
                req->base.data = req;
        } else if (refcnt && refcount_dec_and_test(&ctx->refcnt))
                crypto_free_aead(tfm);
}

static void cryptd_aead_encrypt(void *data, int err)
{
        struct aead_request *req = data;
        struct cryptd_aead_ctx *ctx;
        struct crypto_aead *child;

        ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
        child = ctx->child;
        cryptd_aead_crypt(req, child, err, crypto_aead_alg(child)->encrypt,
                          cryptd_aead_encrypt);
}

static void cryptd_aead_decrypt(void *data, int err)
{
        struct aead_request *req = data;
        struct cryptd_aead_ctx *ctx;
        struct crypto_aead *child;

        ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
        child = ctx->child;
        cryptd_aead_crypt(req, child, err, crypto_aead_alg(child)->decrypt,
                          cryptd_aead_decrypt);
}

static int cryptd_aead_enqueue(struct aead_request *req,
                                    crypto_completion_t compl)
{
        struct cryptd_aead_request_ctx *rctx = aead_request_ctx(req);
        struct crypto_aead *tfm = crypto_aead_reqtfm(req);
        struct cryptd_queue *queue = cryptd_get_queue(crypto_aead_tfm(tfm));
        struct aead_request *subreq = &rctx->req;

        subreq->base.complete = req->base.complete;
        subreq->base.data = req->base.data;
        req->base.complete = compl;
        req->base.data = req;
        return cryptd_enqueue_request(queue, &req->base);
}

static int cryptd_aead_encrypt_enqueue(struct aead_request *req)
{
        return cryptd_aead_enqueue(req, cryptd_aead_encrypt );
}

static int cryptd_aead_decrypt_enqueue(struct aead_request *req)
{
        return cryptd_aead_enqueue(req, cryptd_aead_decrypt );
}

static int cryptd_aead_init_tfm(struct crypto_aead *tfm)
{
        struct aead_instance *inst = aead_alg_instance(tfm);
        struct aead_instance_ctx *ictx = aead_instance_ctx(inst);
        struct crypto_aead_spawn *spawn = &ictx->aead_spawn;
        struct cryptd_aead_ctx *ctx = crypto_aead_ctx(tfm);
        struct crypto_aead *cipher;

        cipher = crypto_spawn_aead(spawn);
        if (IS_ERR(cipher))
                return PTR_ERR(cipher);

        ctx->child = cipher;
        crypto_aead_set_reqsize(
                tfm, sizeof(struct cryptd_aead_request_ctx) +
                     crypto_aead_reqsize(cipher));
        return 0;
}

static void cryptd_aead_exit_tfm(struct crypto_aead *tfm)
{
        struct cryptd_aead_ctx *ctx = crypto_aead_ctx(tfm);
        crypto_free_aead(ctx->child);
}

static void cryptd_aead_free(struct aead_instance *inst)
{
        struct aead_instance_ctx *ctx = aead_instance_ctx(inst);

        crypto_drop_aead(&ctx->aead_spawn);
        kfree(inst);
}

static int cryptd_create_aead(struct crypto_template *tmpl,
                              struct rtattr **tb,
                              struct crypto_attr_type *algt,
                              struct cryptd_queue *queue)
{
        struct aead_instance_ctx *ctx;
        struct aead_instance *inst;
        struct aead_alg *alg;
        u32 type;
        u32 mask;
        int err;

        cryptd_type_and_mask(algt, &type, &mask);

        inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
        if (!inst)
                return -ENOMEM;

        ctx = aead_instance_ctx(inst);
        ctx->queue = queue;

        err = crypto_grab_aead(&ctx->aead_spawn, aead_crypto_instance(inst),
                               crypto_attr_alg_name(tb[1]), type, mask);
        if (err)
                goto err_free_inst;

        alg = crypto_spawn_aead_alg(&ctx->aead_spawn);
        err = cryptd_init_instance(aead_crypto_instance(inst), &alg->base);
        if (err)
                goto err_free_inst;

        inst->alg.base.cra_flags |= CRYPTO_ALG_ASYNC |
                (alg->base.cra_flags & CRYPTO_ALG_INTERNAL);
        inst->alg.base.cra_ctxsize = sizeof(struct cryptd_aead_ctx);

        inst->alg.ivsize = crypto_aead_alg_ivsize(alg);
        inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg);

        inst->alg.init = cryptd_aead_init_tfm;
        inst->alg.exit = cryptd_aead_exit_tfm;
        inst->alg.setkey = cryptd_aead_setkey;
        inst->alg.setauthsize = cryptd_aead_setauthsize;
        inst->alg.encrypt = cryptd_aead_encrypt_enqueue;
        inst->alg.decrypt = cryptd_aead_decrypt_enqueue;

        inst->free = cryptd_aead_free;

        err = aead_register_instance(tmpl, inst);
        if (err) {
err_free_inst:
                cryptd_aead_free(inst);
        }
        return err;
}

static struct cryptd_queue queue;

static int cryptd_create(struct crypto_template *tmpl, struct rtattr **tb)
{
        struct crypto_attr_type *algt;

        algt = crypto_get_attr_type(tb);
        if (IS_ERR(algt))
                return PTR_ERR(algt);

        switch (algt->type & algt->mask & CRYPTO_ALG_TYPE_MASK) {
        case CRYPTO_ALG_TYPE_LSKCIPHER:
                return cryptd_create_skcipher(tmpl, tb, algt, &queue);
        case CRYPTO_ALG_TYPE_HASH:
                return cryptd_create_hash(tmpl, tb, algt, &queue);
        case CRYPTO_ALG_TYPE_AEAD:
                return cryptd_create_aead(tmpl, tb, algt, &queue);
        }

        return -EINVAL;
}

static struct crypto_template cryptd_tmpl = {
        .name = "cryptd",
        .create = cryptd_create,
        .module = THIS_MODULE,
};

struct cryptd_skcipher *cryptd_alloc_skcipher(const char *alg_name,
                                              u32 type, u32 mask)
{
        char cryptd_alg_name[CRYPTO_MAX_ALG_NAME];
        struct cryptd_skcipher_ctx *ctx;
        struct crypto_skcipher *tfm;

        if (snprintf(cryptd_alg_name, CRYPTO_MAX_ALG_NAME,
                     "cryptd(%s)", alg_name) >= CRYPTO_MAX_ALG_NAME)
                return ERR_PTR(-EINVAL);

        tfm = crypto_alloc_skcipher(cryptd_alg_name, type, mask);
        if (IS_ERR(tfm))
                return ERR_CAST(tfm);

        if (tfm->base.__crt_alg->cra_module != THIS_MODULE) {
                crypto_free_skcipher(tfm);
                return ERR_PTR(-EINVAL);
        }

        ctx = crypto_skcipher_ctx(tfm);
        refcount_set(&ctx->refcnt, 1);

        return container_of(tfm, struct cryptd_skcipher, base);
}
EXPORT_SYMBOL_GPL(cryptd_alloc_skcipher);

struct crypto_skcipher *cryptd_skcipher_child(struct cryptd_skcipher *tfm)
{
        struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(&tfm->base);

        return ctx->child;
}
EXPORT_SYMBOL_GPL(cryptd_skcipher_child);

bool cryptd_skcipher_queued(struct cryptd_skcipher *tfm)
{
        struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(&tfm->base);

        return refcount_read(&ctx->refcnt) - 1;
}
EXPORT_SYMBOL_GPL(cryptd_skcipher_queued);

void cryptd_free_skcipher(struct cryptd_skcipher *tfm)
{
        struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(&tfm->base);

        if (refcount_dec_and_test(&ctx->refcnt))
                crypto_free_skcipher(&tfm->base);
}
EXPORT_SYMBOL_GPL(cryptd_free_skcipher);

struct cryptd_ahash *cryptd_alloc_ahash(const char *alg_name,
                                        u32 type, u32 mask)
{
        char cryptd_alg_name[CRYPTO_MAX_ALG_NAME];
        struct cryptd_hash_ctx *ctx;
        struct crypto_ahash *tfm;

        if (snprintf(cryptd_alg_name, CRYPTO_MAX_ALG_NAME,
                     "cryptd(%s)", alg_name) >= CRYPTO_MAX_ALG_NAME)
                return ERR_PTR(-EINVAL);
        tfm = crypto_alloc_ahash(cryptd_alg_name, type, mask);
        if (IS_ERR(tfm))
                return ERR_CAST(tfm);
        if (tfm->base.__crt_alg->cra_module != THIS_MODULE) {
                crypto_free_ahash(tfm);
                return ERR_PTR(-EINVAL);
        }

        ctx = crypto_ahash_ctx(tfm);
        refcount_set(&ctx->refcnt, 1);

        return __cryptd_ahash_cast(tfm);
}
EXPORT_SYMBOL_GPL(cryptd_alloc_ahash);

struct crypto_shash *cryptd_ahash_child(struct cryptd_ahash *tfm)
{
        struct cryptd_hash_ctx *ctx = crypto_ahash_ctx(&tfm->base);

        return ctx->child;
}
EXPORT_SYMBOL_GPL(cryptd_ahash_child);

struct shash_desc *cryptd_shash_desc(struct ahash_request *req)
{
        struct cryptd_hash_request_ctx *rctx = ahash_request_ctx(req);
        return &rctx->desc;
}
EXPORT_SYMBOL_GPL(cryptd_shash_desc);

bool cryptd_ahash_queued(struct cryptd_ahash *tfm)
{
        struct cryptd_hash_ctx *ctx = crypto_ahash_ctx(&tfm->base);

        return refcount_read(&ctx->refcnt) - 1;
}
EXPORT_SYMBOL_GPL(cryptd_ahash_queued);

void cryptd_free_ahash(struct cryptd_ahash *tfm)
{
        struct cryptd_hash_ctx *ctx = crypto_ahash_ctx(&tfm->base);

        if (refcount_dec_and_test(&ctx->refcnt))
                crypto_free_ahash(&tfm->base);
}
EXPORT_SYMBOL_GPL(cryptd_free_ahash);

struct cryptd_aead *cryptd_alloc_aead(const char *alg_name,
                                                  u32 type, u32 mask)
{
        char cryptd_alg_name[CRYPTO_MAX_ALG_NAME];
        struct cryptd_aead_ctx *ctx;
        struct crypto_aead *tfm;

        if (snprintf(cryptd_alg_name, CRYPTO_MAX_ALG_NAME,
                     "cryptd(%s)", alg_name) >= CRYPTO_MAX_ALG_NAME)
                return ERR_PTR(-EINVAL);
        tfm = crypto_alloc_aead(cryptd_alg_name, type, mask);
        if (IS_ERR(tfm))
                return ERR_CAST(tfm);
        if (tfm->base.__crt_alg->cra_module != THIS_MODULE) {
                crypto_free_aead(tfm);
                return ERR_PTR(-EINVAL);
        }

        ctx = crypto_aead_ctx(tfm);
        refcount_set(&ctx->refcnt, 1);

        return __cryptd_aead_cast(tfm);
}
EXPORT_SYMBOL_GPL(cryptd_alloc_aead);

struct crypto_aead *cryptd_aead_child(struct cryptd_aead *tfm)
{
        struct cryptd_aead_ctx *ctx;
        ctx = crypto_aead_ctx(&tfm->base);
        return ctx->child;
}
EXPORT_SYMBOL_GPL(cryptd_aead_child);

bool cryptd_aead_queued(struct cryptd_aead *tfm)
{
        struct cryptd_aead_ctx *ctx = crypto_aead_ctx(&tfm->base);

        return refcount_read(&ctx->refcnt) - 1;
}
EXPORT_SYMBOL_GPL(cryptd_aead_queued);

void cryptd_free_aead(struct cryptd_aead *tfm)
{
        struct cryptd_aead_ctx *ctx = crypto_aead_ctx(&tfm->base);

        if (refcount_dec_and_test(&ctx->refcnt))
                crypto_free_aead(&tfm->base);
}
EXPORT_SYMBOL_GPL(cryptd_free_aead);

static int __init cryptd_init(void)
{
        int err;

        cryptd_wq = alloc_workqueue("cryptd", WQ_MEM_RECLAIM | WQ_CPU_INTENSIVE,
                                    1);
        if (!cryptd_wq)
                return -ENOMEM;

        err = cryptd_init_queue(&queue, cryptd_max_cpu_qlen);
        if (err)
                goto err_destroy_wq;

        err = crypto_register_template(&cryptd_tmpl);
        if (err)
                goto err_fini_queue;

        return 0;

err_fini_queue:
        cryptd_fini_queue(&queue);
err_destroy_wq:
        destroy_workqueue(cryptd_wq);
        return err;
}

static void __exit cryptd_exit(void)
{
        destroy_workqueue(cryptd_wq);
        cryptd_fini_queue(&queue);
        crypto_unregister_template(&cryptd_tmpl);
}

subsys_initcall(cryptd_init);
module_exit(cryptd_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Software async crypto daemon");
MODULE_ALIAS_CRYPTO("cryptd");