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root/crypto/cryptd.c

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DEFINITIONS

This source file includes following definitions.
  1. cryptd_get_state
  2. cryptd_blkcipher_setkey
  3. cryptd_blkcipher_crypt
  4. cryptd_blkcipher_encrypt
  5. cryptd_blkcipher_decrypt
  6. cryptd_blkcipher_enqueue
  7. cryptd_blkcipher_encrypt_enqueue
  8. cryptd_blkcipher_decrypt_enqueue
  9. cryptd_blkcipher_init_tfm
  10. cryptd_blkcipher_exit_tfm
  11. cryptd_alloc_instance
  12. cryptd_alloc_blkcipher
  13. cryptd_hash_init_tfm
  14. cryptd_hash_exit_tfm
  15. cryptd_hash_setkey
  16. cryptd_hash_enqueue
  17. cryptd_hash_init
  18. cryptd_hash_init_enqueue
  19. cryptd_hash_update
  20. cryptd_hash_update_enqueue
  21. cryptd_hash_final
  22. cryptd_hash_final_enqueue
  23. cryptd_hash_digest
  24. cryptd_hash_digest_enqueue
  25. cryptd_alloc_hash
  26. cryptd_alloc
  27. cryptd_free
  28. cryptd_create_thread
  29. cryptd_stop_thread
  30. cryptd_thread
  31. cryptd_init
  32. cryptd_exit

/*
 * Software async crypto daemon.
 *
 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 */

#include <crypto/algapi.h>
#include <crypto/internal/hash.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/scatterlist.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>

#define CRYPTD_MAX_QLEN 100

struct cryptd_state {
        spinlock_t lock;
        struct mutex mutex;
        struct crypto_queue queue;
        struct task_struct *task;
};

struct cryptd_instance_ctx {
        struct crypto_spawn spawn;
        struct cryptd_state *state;
};

struct cryptd_blkcipher_ctx {
        struct crypto_blkcipher *child;
};

struct cryptd_blkcipher_request_ctx {
        crypto_completion_t complete;
};

struct cryptd_hash_ctx {
        struct crypto_hash *child;
};

struct cryptd_hash_request_ctx {
        crypto_completion_t complete;
};

static inline struct cryptd_state *cryptd_get_state(struct crypto_tfm *tfm)
{
        struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
        struct cryptd_instance_ctx *ictx = crypto_instance_ctx(inst);
        return ictx->state;
}

static int cryptd_blkcipher_setkey(struct crypto_ablkcipher *parent,
                                   const u8 *key, unsigned int keylen)
{
        struct cryptd_blkcipher_ctx *ctx = crypto_ablkcipher_ctx(parent);
        struct crypto_blkcipher *child = ctx->child;
        int err;

        crypto_blkcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
        crypto_blkcipher_set_flags(child, crypto_ablkcipher_get_flags(parent) &
                                          CRYPTO_TFM_REQ_MASK);
        err = crypto_blkcipher_setkey(child, key, keylen);
        crypto_ablkcipher_set_flags(parent, crypto_blkcipher_get_flags(child) &
                                            CRYPTO_TFM_RES_MASK);
        return err;
}

static void cryptd_blkcipher_crypt(struct ablkcipher_request *req,
                                   struct crypto_blkcipher *child,
                                   int err,
                                   int (*crypt)(struct blkcipher_desc *desc,
                                                struct scatterlist *dst,
                                                struct scatterlist *src,
                                                unsigned int len))
{
        struct cryptd_blkcipher_request_ctx *rctx;
        struct blkcipher_desc desc;

        rctx = ablkcipher_request_ctx(req);

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

        desc.tfm = child;
        desc.info = req->info;
        desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;

        err = crypt(&desc, req->dst, req->src, req->nbytes);

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

out:
        local_bh_disable();
        rctx->complete(&req->base, err);
        local_bh_enable();
}

static void cryptd_blkcipher_encrypt(struct crypto_async_request *req, int err)
{
        struct cryptd_blkcipher_ctx *ctx = crypto_tfm_ctx(req->tfm);
        struct crypto_blkcipher *child = ctx->child;

        cryptd_blkcipher_crypt(ablkcipher_request_cast(req), child, err,
                               crypto_blkcipher_crt(child)->encrypt);
}

static void cryptd_blkcipher_decrypt(struct crypto_async_request *req, int err)
{
        struct cryptd_blkcipher_ctx *ctx = crypto_tfm_ctx(req->tfm);
        struct crypto_blkcipher *child = ctx->child;

        cryptd_blkcipher_crypt(ablkcipher_request_cast(req), child, err,
                               crypto_blkcipher_crt(child)->decrypt);
}

static int cryptd_blkcipher_enqueue(struct ablkcipher_request *req,
                                    crypto_completion_t complete)
{
        struct cryptd_blkcipher_request_ctx *rctx = ablkcipher_request_ctx(req);
        struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(req);
        struct cryptd_state *state =
                cryptd_get_state(crypto_ablkcipher_tfm(tfm));
        int err;

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

        spin_lock_bh(&state->lock);
        err = ablkcipher_enqueue_request(&state->queue, req);
        spin_unlock_bh(&state->lock);

        wake_up_process(state->task);
        return err;
}

static int cryptd_blkcipher_encrypt_enqueue(struct ablkcipher_request *req)
{
        return cryptd_blkcipher_enqueue(req, cryptd_blkcipher_encrypt);
}

static int cryptd_blkcipher_decrypt_enqueue(struct ablkcipher_request *req)
{
        return cryptd_blkcipher_enqueue(req, cryptd_blkcipher_decrypt);
}

static int cryptd_blkcipher_init_tfm(struct crypto_tfm *tfm)
{
        struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
        struct cryptd_instance_ctx *ictx = crypto_instance_ctx(inst);
        struct crypto_spawn *spawn = &ictx->spawn;
        struct cryptd_blkcipher_ctx *ctx = crypto_tfm_ctx(tfm);
        struct crypto_blkcipher *cipher;

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

        ctx->child = cipher;
        tfm->crt_ablkcipher.reqsize =
                sizeof(struct cryptd_blkcipher_request_ctx);
        return 0;
}

static void cryptd_blkcipher_exit_tfm(struct crypto_tfm *tfm)
{
        struct cryptd_blkcipher_ctx *ctx = crypto_tfm_ctx(tfm);
        struct cryptd_state *state = cryptd_get_state(tfm);
        int active;

        mutex_lock(&state->mutex);
        active = ablkcipher_tfm_in_queue(&state->queue,
                                         __crypto_ablkcipher_cast(tfm));
        mutex_unlock(&state->mutex);

        BUG_ON(active);

        crypto_free_blkcipher(ctx->child);
}

static struct crypto_instance *cryptd_alloc_instance(struct crypto_alg *alg,
                                                     struct cryptd_state *state)
{
        struct crypto_instance *inst;
        struct cryptd_instance_ctx *ctx;
        int err;

        inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
        if (!inst) {
                inst = ERR_PTR(-ENOMEM);
                goto out;
        }

        err = -ENAMETOOLONG;
        if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
                     "cryptd(%s)", alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
                goto out_free_inst;

        ctx = crypto_instance_ctx(inst);
        err = crypto_init_spawn(&ctx->spawn, alg, inst,
                                CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC);
        if (err)
                goto out_free_inst;

        ctx->state = state;

        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;

out:
        return inst;

out_free_inst:
        kfree(inst);
        inst = ERR_PTR(err);
        goto out;
}

static struct crypto_instance *cryptd_alloc_blkcipher(
        struct rtattr **tb, struct cryptd_state *state)
{
        struct crypto_instance *inst;
        struct crypto_alg *alg;

        alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_BLKCIPHER,
                                  CRYPTO_ALG_TYPE_MASK);
        if (IS_ERR(alg))
                return ERR_CAST(alg);

        inst = cryptd_alloc_instance(alg, state);
        if (IS_ERR(inst))
                goto out_put_alg;

        inst->alg.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC;
        inst->alg.cra_type = &crypto_ablkcipher_type;

        inst->alg.cra_ablkcipher.ivsize = alg->cra_blkcipher.ivsize;
        inst->alg.cra_ablkcipher.min_keysize = alg->cra_blkcipher.min_keysize;
        inst->alg.cra_ablkcipher.max_keysize = alg->cra_blkcipher.max_keysize;

        inst->alg.cra_ablkcipher.geniv = alg->cra_blkcipher.geniv;

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

        inst->alg.cra_init = cryptd_blkcipher_init_tfm;
        inst->alg.cra_exit = cryptd_blkcipher_exit_tfm;

        inst->alg.cra_ablkcipher.setkey = cryptd_blkcipher_setkey;
        inst->alg.cra_ablkcipher.encrypt = cryptd_blkcipher_encrypt_enqueue;
        inst->alg.cra_ablkcipher.decrypt = cryptd_blkcipher_decrypt_enqueue;

out_put_alg:
        crypto_mod_put(alg);
        return inst;
}

static int cryptd_hash_init_tfm(struct crypto_tfm *tfm)
{
        struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
        struct cryptd_instance_ctx *ictx = crypto_instance_ctx(inst);
        struct crypto_spawn *spawn = &ictx->spawn;
        struct cryptd_hash_ctx *ctx = crypto_tfm_ctx(tfm);
        struct crypto_hash *cipher;

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

        ctx->child = cipher;
        tfm->crt_ahash.reqsize =
                sizeof(struct cryptd_hash_request_ctx);
        return 0;
}

static void cryptd_hash_exit_tfm(struct crypto_tfm *tfm)
{
        struct cryptd_hash_ctx *ctx = crypto_tfm_ctx(tfm);
        struct cryptd_state *state = cryptd_get_state(tfm);
        int active;

        mutex_lock(&state->mutex);
        active = ahash_tfm_in_queue(&state->queue,
                                __crypto_ahash_cast(tfm));
        mutex_unlock(&state->mutex);

        BUG_ON(active);

        crypto_free_hash(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_hash     *child = ctx->child;
        int err;

        crypto_hash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
        crypto_hash_set_flags(child, crypto_ahash_get_flags(parent) &
                                          CRYPTO_TFM_REQ_MASK);
        err = crypto_hash_setkey(child, key, keylen);
        crypto_ahash_set_flags(parent, crypto_hash_get_flags(child) &
                                            CRYPTO_TFM_RES_MASK);
        return err;
}

static int cryptd_hash_enqueue(struct ahash_request *req,
                                crypto_completion_t complete)
{
        struct cryptd_hash_request_ctx *rctx = ahash_request_ctx(req);
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
        struct cryptd_state *state =
                cryptd_get_state(crypto_ahash_tfm(tfm));
        int err;

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

        spin_lock_bh(&state->lock);
        err = ahash_enqueue_request(&state->queue, req);
        spin_unlock_bh(&state->lock);

        wake_up_process(state->task);
        return err;
}

static void cryptd_hash_init(struct crypto_async_request *req_async, int err)
{
        struct cryptd_hash_ctx *ctx   = crypto_tfm_ctx(req_async->tfm);
        struct crypto_hash     *child = ctx->child;
        struct ahash_request    *req = ahash_request_cast(req_async);
        struct cryptd_hash_request_ctx *rctx;
        struct hash_desc desc;

        rctx = ahash_request_ctx(req);

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

        desc.tfm = child;
        desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;

        err = crypto_hash_crt(child)->init(&desc);

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

out:
        local_bh_disable();
        rctx->complete(&req->base, err);
        local_bh_enable();
}

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

static void cryptd_hash_update(struct crypto_async_request *req_async, int err)
{
        struct cryptd_hash_ctx *ctx   = crypto_tfm_ctx(req_async->tfm);
        struct crypto_hash     *child = ctx->child;
        struct ahash_request    *req = ahash_request_cast(req_async);
        struct cryptd_hash_request_ctx *rctx;
        struct hash_desc desc;

        rctx = ahash_request_ctx(req);

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

        desc.tfm = child;
        desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;

        err = crypto_hash_crt(child)->update(&desc,
                                                req->src,
                                                req->nbytes);

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

out:
        local_bh_disable();
        rctx->complete(&req->base, err);
        local_bh_enable();
}

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

static void cryptd_hash_final(struct crypto_async_request *req_async, int err)
{
        struct cryptd_hash_ctx *ctx   = crypto_tfm_ctx(req_async->tfm);
        struct crypto_hash     *child = ctx->child;
        struct ahash_request    *req = ahash_request_cast(req_async);
        struct cryptd_hash_request_ctx *rctx;
        struct hash_desc desc;

        rctx = ahash_request_ctx(req);

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

        desc.tfm = child;
        desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;

        err = crypto_hash_crt(child)->final(&desc, req->result);

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

out:
        local_bh_disable();
        rctx->complete(&req->base, err);
        local_bh_enable();
}

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

static void cryptd_hash_digest(struct crypto_async_request *req_async, int err)
{
        struct cryptd_hash_ctx *ctx   = crypto_tfm_ctx(req_async->tfm);
        struct crypto_hash     *child = ctx->child;
        struct ahash_request    *req = ahash_request_cast(req_async);
        struct cryptd_hash_request_ctx *rctx;
        struct hash_desc desc;

        rctx = ahash_request_ctx(req);

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

        desc.tfm = child;
        desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;

        err = crypto_hash_crt(child)->digest(&desc,
                                                req->src,
                                                req->nbytes,
                                                req->result);

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

out:
        local_bh_disable();
        rctx->complete(&req->base, err);
        local_bh_enable();
}

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

static struct crypto_instance *cryptd_alloc_hash(
        struct rtattr **tb, struct cryptd_state *state)
{
        struct crypto_instance *inst;
        struct crypto_alg *alg;

        alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_HASH,
                                  CRYPTO_ALG_TYPE_HASH_MASK);
        if (IS_ERR(alg))
                return ERR_PTR(PTR_ERR(alg));

        inst = cryptd_alloc_instance(alg, state);
        if (IS_ERR(inst))
                goto out_put_alg;

        inst->alg.cra_flags = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC;
        inst->alg.cra_type = &crypto_ahash_type;

        inst->alg.cra_ahash.digestsize = alg->cra_hash.digestsize;
        inst->alg.cra_ctxsize = sizeof(struct cryptd_hash_ctx);

        inst->alg.cra_init = cryptd_hash_init_tfm;
        inst->alg.cra_exit = cryptd_hash_exit_tfm;

        inst->alg.cra_ahash.init   = cryptd_hash_init_enqueue;
        inst->alg.cra_ahash.update = cryptd_hash_update_enqueue;
        inst->alg.cra_ahash.final  = cryptd_hash_final_enqueue;
        inst->alg.cra_ahash.setkey = cryptd_hash_setkey;
        inst->alg.cra_ahash.digest = cryptd_hash_digest_enqueue;

out_put_alg:
        crypto_mod_put(alg);
        return inst;
}

static struct cryptd_state state;

static struct crypto_instance *cryptd_alloc(struct rtattr **tb)
{
        struct crypto_attr_type *algt;

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

        switch (algt->type & algt->mask & CRYPTO_ALG_TYPE_MASK) {
        case CRYPTO_ALG_TYPE_BLKCIPHER:
                return cryptd_alloc_blkcipher(tb, &state);
        case CRYPTO_ALG_TYPE_DIGEST:
                return cryptd_alloc_hash(tb, &state);
        }

        return ERR_PTR(-EINVAL);
}

static void cryptd_free(struct crypto_instance *inst)
{
        struct cryptd_instance_ctx *ctx = crypto_instance_ctx(inst);

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

static struct crypto_template cryptd_tmpl = {
        .name = "cryptd",
        .alloc = cryptd_alloc,
        .free = cryptd_free,
        .module = THIS_MODULE,
};

static inline int cryptd_create_thread(struct cryptd_state *state,
                                       int (*fn)(void *data), const char *name)
{
        spin_lock_init(&state->lock);
        mutex_init(&state->mutex);
        crypto_init_queue(&state->queue, CRYPTD_MAX_QLEN);

        state->task = kthread_run(fn, state, name);
        if (IS_ERR(state->task))
                return PTR_ERR(state->task);

        return 0;
}

static inline void cryptd_stop_thread(struct cryptd_state *state)
{
        BUG_ON(state->queue.qlen);
        kthread_stop(state->task);
}

static int cryptd_thread(void *data)
{
        struct cryptd_state *state = data;
        int stop;

        current->flags |= PF_NOFREEZE;

        do {
                struct crypto_async_request *req, *backlog;

                mutex_lock(&state->mutex);
                __set_current_state(TASK_INTERRUPTIBLE);

                spin_lock_bh(&state->lock);
                backlog = crypto_get_backlog(&state->queue);
                req = crypto_dequeue_request(&state->queue);
                spin_unlock_bh(&state->lock);

                stop = kthread_should_stop();

                if (stop || req) {
                        __set_current_state(TASK_RUNNING);
                        if (req) {
                                if (backlog)
                                        backlog->complete(backlog,
                                                          -EINPROGRESS);
                                req->complete(req, 0);
                        }
                }

                mutex_unlock(&state->mutex);

                schedule();
        } while (!stop);

        return 0;
}

static int __init cryptd_init(void)
{
        int err;

        err = cryptd_create_thread(&state, cryptd_thread, "cryptd");
        if (err)
                return err;

        err = crypto_register_template(&cryptd_tmpl);
        if (err)
                kthread_stop(state.task);

        return err;
}

static void __exit cryptd_exit(void)
{
        cryptd_stop_thread(&state);
        crypto_unregister_template(&cryptd_tmpl);
}

module_init(cryptd_init);
module_exit(cryptd_exit);

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

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