algapi.c

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/*
 * Cryptographic API for algorithms (i.e., low-level API).
 *
 * Copyright (c) 2006 Herbert Xu <[email protected]>
 *
 * 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 <linux/err.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/rtnetlink.h>
#include <linux/slab.h>
#include <linux/string.h>

#include "internal.h"

static LIST_HEAD(crypto_template_list);

static inline int crypto_set_driver_name(struct crypto_alg *alg)
{
    static const char suffix[] = "-generic";
    char *driver_name = alg->cra_driver_name;
    int len;

    if (*driver_name)
        return 0;

    len = strlcpy(driver_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
    if (len + sizeof(suffix) > CRYPTO_MAX_ALG_NAME)
        return -ENAMETOOLONG;

    memcpy(driver_name + len, suffix, sizeof(suffix));
    return 0;
}

static int crypto_check_alg(struct crypto_alg *alg)
{
    if (alg->cra_alignmask & (alg->cra_alignmask + 1))
        return -EINVAL;

    if (alg->cra_blocksize > PAGE_SIZE / 8)
        return -EINVAL;

    if (alg->cra_priority < 0)
        return -EINVAL;

    return crypto_set_driver_name(alg);
}

static void crypto_destroy_instance(struct crypto_alg *alg)
{
    struct crypto_instance *inst = (void *)alg;
    struct crypto_template *tmpl = inst->tmpl;

    tmpl->free(inst);
    crypto_tmpl_put(tmpl);
}

static struct list_head *crypto_more_spawns(struct crypto_alg *alg,
                        struct list_head *stack,
                        struct list_head *top,
                        struct list_head *secondary_spawns)
{
    struct crypto_spawn *spawn, *n;

    if (list_empty(stack))
        return NULL;

    spawn = list_first_entry(stack, struct crypto_spawn, list);
    n = list_entry(spawn->list.next, struct crypto_spawn, list);

    if (spawn->alg && &n->list != stack && !n->alg)
        n->alg = (n->list.next == stack) ? alg :
             &list_entry(n->list.next, struct crypto_spawn,
                     list)->inst->alg;

    list_move(&spawn->list, secondary_spawns);

    return &n->list == stack ? top : &n->inst->alg.cra_users;
}

static void crypto_remove_spawn(struct crypto_spawn *spawn,
                struct list_head *list)
{
    struct crypto_instance *inst = spawn->inst;
    struct crypto_template *tmpl = inst->tmpl;

    if (crypto_is_dead(&inst->alg))
        return;

    inst->alg.cra_flags |= CRYPTO_ALG_DEAD;
    if (hlist_unhashed(&inst->list))
        return;

    if (!tmpl || !crypto_tmpl_get(tmpl))
        return;

    crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, &inst->alg);
    list_move(&inst->alg.cra_list, list);
    hlist_del(&inst->list);
    inst->alg.cra_destroy = crypto_destroy_instance;

    BUG_ON(!list_empty(&inst->alg.cra_users));
}

void crypto_remove_spawns(struct crypto_alg *alg, struct list_head *list,
              struct crypto_alg *nalg)
{
    u32 new_type = (nalg ?: alg)->cra_flags;
    struct crypto_spawn *spawn, *n;
    LIST_HEAD(secondary_spawns);
    struct list_head *spawns;
    LIST_HEAD(stack);
    LIST_HEAD(top);

    spawns = &alg->cra_users;
    list_for_each_entry_safe(spawn, n, spawns, list) {
        if ((spawn->alg->cra_flags ^ new_type) & spawn->mask)
            continue;

        list_move(&spawn->list, &top);
    }

    spawns = &top;
    do {
        while (!list_empty(spawns)) {
            struct crypto_instance *inst;

            spawn = list_first_entry(spawns, struct crypto_spawn,
                         list);
            inst = spawn->inst;

            BUG_ON(&inst->alg == alg);

            list_move(&spawn->list, &stack);

            if (&inst->alg == nalg)
                break;

            spawn->alg = NULL;
            spawns = &inst->alg.cra_users;
        }
    } while ((spawns = crypto_more_spawns(alg, &stack, &top,
                          &secondary_spawns)));

    list_for_each_entry_safe(spawn, n, &secondary_spawns, list) {
        if (spawn->alg)
            list_move(&spawn->list, &spawn->alg->cra_users);
        else
            crypto_remove_spawn(spawn, list);
    }
}
EXPORT_SYMBOL_GPL(crypto_remove_spawns);

static struct crypto_larval *__crypto_register_alg(struct crypto_alg *alg)
{
    struct crypto_alg *q;
    struct crypto_larval *larval;
    int ret = -EAGAIN;

    if (crypto_is_dead(alg))
        goto err;

    INIT_LIST_HEAD(&alg->cra_users);

    /* No cheating! */
    alg->cra_flags &= ~CRYPTO_ALG_TESTED;

    ret = -EEXIST;

    atomic_set(&alg->cra_refcnt, 1);
    list_for_each_entry(q, &crypto_alg_list, cra_list) {
        if (q == alg)
            goto err;

        if (crypto_is_moribund(q))
            continue;

        if (crypto_is_larval(q)) {
            if (!strcmp(alg->cra_driver_name, q->cra_driver_name))
                goto err;
            continue;
        }

        if (!strcmp(q->cra_driver_name, alg->cra_name) ||
            !strcmp(q->cra_name, alg->cra_driver_name))
            goto err;
    }

    larval = crypto_larval_alloc(alg->cra_name,
                     alg->cra_flags | CRYPTO_ALG_TESTED, 0);
    if (IS_ERR(larval))
        goto out;

    ret = -ENOENT;
    larval->adult = crypto_mod_get(alg);
    if (!larval->adult)
        goto free_larval;

    atomic_set(&larval->alg.cra_refcnt, 1);
    memcpy(larval->alg.cra_driver_name, alg->cra_driver_name,
           CRYPTO_MAX_ALG_NAME);
    larval->alg.cra_priority = alg->cra_priority;

    list_add(&alg->cra_list, &crypto_alg_list);
    list_add(&larval->alg.cra_list, &crypto_alg_list);

out:
    return larval;

free_larval:
    kfree(larval);
err:
    larval = ERR_PTR(ret);
    goto out;
}

void crypto_alg_tested(const char *name, int err)
{
    struct crypto_larval *test;
    struct crypto_alg *alg;
    struct crypto_alg *q;
    LIST_HEAD(list);

    down_write(&crypto_alg_sem);
    list_for_each_entry(q, &crypto_alg_list, cra_list) {
        if (crypto_is_moribund(q) || !crypto_is_larval(q))
            continue;

        test = (struct crypto_larval *)q;

        if (!strcmp(q->cra_driver_name, name))
            goto found;
    }

    printk(KERN_ERR "alg: Unexpected test result for %s: %d\n", name, err);
    goto unlock;

found:
    q->cra_flags |= CRYPTO_ALG_DEAD;
    alg = test->adult;
    if (err || list_empty(&alg->cra_list))
        goto complete;

    alg->cra_flags |= CRYPTO_ALG_TESTED;

    list_for_each_entry(q, &crypto_alg_list, cra_list) {
        if (q == alg)
            continue;

        if (crypto_is_moribund(q))
            continue;

        if (crypto_is_larval(q)) {
            struct crypto_larval *larval = (void *)q;

            /*
             * Check to see if either our generic name or
             * specific name can satisfy the name requested
             * by the larval entry q.
             */
            if (strcmp(alg->cra_name, q->cra_name) &&
                strcmp(alg->cra_driver_name, q->cra_name))
                continue;

            if (larval->adult)
                continue;
            if ((q->cra_flags ^ alg->cra_flags) & larval->mask)
                continue;
            if (!crypto_mod_get(alg))
                continue;

            larval->adult = alg;
            continue;
        }

        if (strcmp(alg->cra_name, q->cra_name))
            continue;

        if (strcmp(alg->cra_driver_name, q->cra_driver_name) &&
            q->cra_priority > alg->cra_priority)
            continue;

        crypto_remove_spawns(q, &list, alg);
    }

complete:
    complete_all(&test->completion);

unlock:
    up_write(&crypto_alg_sem);

    crypto_remove_final(&list);
}
EXPORT_SYMBOL_GPL(crypto_alg_tested);

void crypto_remove_final(struct list_head *list)
{
    struct crypto_alg *alg;
    struct crypto_alg *n;

    list_for_each_entry_safe(alg, n, list, cra_list) {
        list_del_init(&alg->cra_list);
        crypto_alg_put(alg);
    }
}
EXPORT_SYMBOL_GPL(crypto_remove_final);

static void crypto_wait_for_test(struct crypto_larval *larval)
{
    int err;

    err = crypto_probing_notify(CRYPTO_MSG_ALG_REGISTER, larval->adult);
    if (err != NOTIFY_STOP) {
        if (WARN_ON(err != NOTIFY_DONE))
            goto out;
        crypto_alg_tested(larval->alg.cra_driver_name, 0);
    }

    err = wait_for_completion_interruptible(&larval->completion);
    WARN_ON(err);

out:
    crypto_larval_kill(&larval->alg);
}

int crypto_register_alg(struct crypto_alg *alg)
{
    struct crypto_larval *larval;
    int err;

    err = crypto_check_alg(alg);
    if (err)
        return err;

    down_write(&crypto_alg_sem);
    larval = __crypto_register_alg(alg);
    up_write(&crypto_alg_sem);

    if (IS_ERR(larval))
        return PTR_ERR(larval);

    crypto_wait_for_test(larval);
    return 0;
}
EXPORT_SYMBOL_GPL(crypto_register_alg);

static int crypto_remove_alg(struct crypto_alg *alg, struct list_head *list)
{
    if (unlikely(list_empty(&alg->cra_list)))
        return -ENOENT;

    alg->cra_flags |= CRYPTO_ALG_DEAD;

    crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, alg);
    list_del_init(&alg->cra_list);
    crypto_remove_spawns(alg, list, NULL);

    return 0;
}

int crypto_unregister_alg(struct crypto_alg *alg)
{
    int ret;
    LIST_HEAD(list);

    down_write(&crypto_alg_sem);
    ret = crypto_remove_alg(alg, &list);
    up_write(&crypto_alg_sem);

    if (ret)
        return ret;

    BUG_ON(atomic_read(&alg->cra_refcnt) != 1);
    if (alg->cra_destroy)
        alg->cra_destroy(alg);

    crypto_remove_final(&list);
    return 0;
}
EXPORT_SYMBOL_GPL(crypto_unregister_alg);

int crypto_register_algs(struct crypto_alg *algs, int count)
{
    int i, ret;

    for (i = 0; i < count; i++) {
        ret = crypto_register_alg(&algs[i]);
        if (ret)
            goto err;
    }

    return 0;

err:
    for (--i; i >= 0; --i)
        crypto_unregister_alg(&algs[i]);

    return ret;
}
EXPORT_SYMBOL_GPL(crypto_register_algs);

int crypto_unregister_algs(struct crypto_alg *algs, int count)
{
    int i, ret;

    for (i = 0; i < count; i++) {
        ret = crypto_unregister_alg(&algs[i]);
        if (ret)
            pr_err("Failed to unregister %s %s: %d\n",
                   algs[i].cra_driver_name, algs[i].cra_name, ret);
    }

    return 0;
}
EXPORT_SYMBOL_GPL(crypto_unregister_algs);

int crypto_register_template(struct crypto_template *tmpl)
{
    struct crypto_template *q;
    int err = -EEXIST;

    down_write(&crypto_alg_sem);

    list_for_each_entry(q, &crypto_template_list, list) {
        if (q == tmpl)
            goto out;
    }

    list_add(&tmpl->list, &crypto_template_list);
    crypto_notify(CRYPTO_MSG_TMPL_REGISTER, tmpl);
    err = 0;
out:
    up_write(&crypto_alg_sem);
    return err;
}
EXPORT_SYMBOL_GPL(crypto_register_template);

void crypto_unregister_template(struct crypto_template *tmpl)
{
    struct crypto_instance *inst;
    struct hlist_node *p, *n;
    struct hlist_head *list;
    LIST_HEAD(users);

    down_write(&crypto_alg_sem);

    BUG_ON(list_empty(&tmpl->list));
    list_del_init(&tmpl->list);

    list = &tmpl->instances;
    hlist_for_each_entry(inst, p, list, list) {
        int err = crypto_remove_alg(&inst->alg, &users);
        BUG_ON(err);
    }

    crypto_notify(CRYPTO_MSG_TMPL_UNREGISTER, tmpl);

    up_write(&crypto_alg_sem);

    hlist_for_each_entry_safe(inst, p, n, list, list) {
        BUG_ON(atomic_read(&inst->alg.cra_refcnt) != 1);
        tmpl->free(inst);
    }
    crypto_remove_final(&users);
}
EXPORT_SYMBOL_GPL(crypto_unregister_template);

static struct crypto_template *__crypto_lookup_template(const char *name)
{
    struct crypto_template *q, *tmpl = NULL;

    down_read(&crypto_alg_sem);
    list_for_each_entry(q, &crypto_template_list, list) {
        if (strcmp(q->name, name))
            continue;
        if (unlikely(!crypto_tmpl_get(q)))
            continue;

        tmpl = q;
        break;
    }
    up_read(&crypto_alg_sem);

    return tmpl;
}

struct crypto_template *crypto_lookup_template(const char *name)
{
    return try_then_request_module(__crypto_lookup_template(name), name);
}
EXPORT_SYMBOL_GPL(crypto_lookup_template);

int crypto_register_instance(struct crypto_template *tmpl,
                 struct crypto_instance *inst)
{
    struct crypto_larval *larval;
    int err;

    err = crypto_check_alg(&inst->alg);
    if (err)
        goto err;

    inst->alg.cra_module = tmpl->module;
    inst->alg.cra_flags |= CRYPTO_ALG_INSTANCE;

    down_write(&crypto_alg_sem);

    larval = __crypto_register_alg(&inst->alg);
    if (IS_ERR(larval))
        goto unlock;

    hlist_add_head(&inst->list, &tmpl->instances);
    inst->tmpl = tmpl;

unlock:
    up_write(&crypto_alg_sem);

    err = PTR_ERR(larval);
    if (IS_ERR(larval))
        goto err;

    crypto_wait_for_test(larval);
    err = 0;

err:
    return err;
}
EXPORT_SYMBOL_GPL(crypto_register_instance);

int crypto_unregister_instance(struct crypto_alg *alg)
{
    int err;
    struct crypto_instance *inst = (void *)alg;
    struct crypto_template *tmpl = inst->tmpl;
    LIST_HEAD(users);

    if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE))
        return -EINVAL;

    BUG_ON(atomic_read(&alg->cra_refcnt) != 1);

    down_write(&crypto_alg_sem);

    hlist_del_init(&inst->list);
    err = crypto_remove_alg(alg, &users);

    up_write(&crypto_alg_sem);

    if (err)
        return err;

    tmpl->free(inst);
    crypto_remove_final(&users);

    return 0;
}
EXPORT_SYMBOL_GPL(crypto_unregister_instance);

int crypto_init_spawn(struct crypto_spawn *spawn, struct crypto_alg *alg,
              struct crypto_instance *inst, u32 mask)
{
    int err = -EAGAIN;

    spawn->inst = inst;
    spawn->mask = mask;

    down_write(&crypto_alg_sem);
    if (!crypto_is_moribund(alg)) {
        list_add(&spawn->list, &alg->cra_users);
        spawn->alg = alg;
        err = 0;
    }
    up_write(&crypto_alg_sem);

    return err;
}
EXPORT_SYMBOL_GPL(crypto_init_spawn);

int crypto_init_spawn2(struct crypto_spawn *spawn, struct crypto_alg *alg,
               struct crypto_instance *inst,
               const struct crypto_type *frontend)
{
    int err = -EINVAL;

    if ((alg->cra_flags ^ frontend->type) & frontend->maskset)
        goto out;

    spawn->frontend = frontend;
    err = crypto_init_spawn(spawn, alg, inst, frontend->maskset);

out:
    return err;
}
EXPORT_SYMBOL_GPL(crypto_init_spawn2);

void crypto_drop_spawn(struct crypto_spawn *spawn)
{
    if (!spawn->alg)
        return;

    down_write(&crypto_alg_sem);
    list_del(&spawn->list);
    up_write(&crypto_alg_sem);
}
EXPORT_SYMBOL_GPL(crypto_drop_spawn);

static struct crypto_alg *crypto_spawn_alg(struct crypto_spawn *spawn)
{
    struct crypto_alg *alg;
    struct crypto_alg *alg2;

    down_read(&crypto_alg_sem);
    alg = spawn->alg;
    alg2 = alg;
    if (alg2)
        alg2 = crypto_mod_get(alg2);
    up_read(&crypto_alg_sem);

    if (!alg2) {
        if (alg)
            crypto_shoot_alg(alg);
        return ERR_PTR(-EAGAIN);
    }

    return alg;
}

struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn, u32 type,
                    u32 mask)
{
    struct crypto_alg *alg;
    struct crypto_tfm *tfm;

    alg = crypto_spawn_alg(spawn);
    if (IS_ERR(alg))
        return ERR_CAST(alg);

    tfm = ERR_PTR(-EINVAL);
    if (unlikely((alg->cra_flags ^ type) & mask))
        goto out_put_alg;

    tfm = __crypto_alloc_tfm(alg, type, mask);
    if (IS_ERR(tfm))
        goto out_put_alg;

    return tfm;

out_put_alg:
    crypto_mod_put(alg);
    return tfm;
}
EXPORT_SYMBOL_GPL(crypto_spawn_tfm);

void *crypto_spawn_tfm2(struct crypto_spawn *spawn)
{
    struct crypto_alg *alg;
    struct crypto_tfm *tfm;

    alg = crypto_spawn_alg(spawn);
    if (IS_ERR(alg))
        return ERR_CAST(alg);

    tfm = crypto_create_tfm(alg, spawn->frontend);
    if (IS_ERR(tfm))
        goto out_put_alg;

    return tfm;

out_put_alg:
    crypto_mod_put(alg);
    return tfm;
}
EXPORT_SYMBOL_GPL(crypto_spawn_tfm2);

int crypto_register_notifier(struct notifier_block *nb)
{
    return blocking_notifier_chain_register(&crypto_chain, nb);
}
EXPORT_SYMBOL_GPL(crypto_register_notifier);

int crypto_unregister_notifier(struct notifier_block *nb)
{
    return blocking_notifier_chain_unregister(&crypto_chain, nb);
}
EXPORT_SYMBOL_GPL(crypto_unregister_notifier);

struct crypto_attr_type *crypto_get_attr_type(struct rtattr **tb)
{
    struct rtattr *rta = tb[0];
    struct crypto_attr_type *algt;

    if (!rta)
        return ERR_PTR(-ENOENT);
    if (RTA_PAYLOAD(rta) < sizeof(*algt))
        return ERR_PTR(-EINVAL);
    if (rta->rta_type != CRYPTOA_TYPE)
        return ERR_PTR(-EINVAL);

    algt = RTA_DATA(rta);

    return algt;
}
EXPORT_SYMBOL_GPL(crypto_get_attr_type);

int crypto_check_attr_type(struct rtattr **tb, u32 type)
{
    struct crypto_attr_type *algt;

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

    if ((algt->type ^ type) & algt->mask)
        return -EINVAL;

    return 0;
}
EXPORT_SYMBOL_GPL(crypto_check_attr_type);

const char *crypto_attr_alg_name(struct rtattr *rta)
{
    struct crypto_attr_alg *alga;

    if (!rta)
        return ERR_PTR(-ENOENT);
    if (RTA_PAYLOAD(rta) < sizeof(*alga))
        return ERR_PTR(-EINVAL);
    if (rta->rta_type != CRYPTOA_ALG)
        return ERR_PTR(-EINVAL);

    alga = RTA_DATA(rta);
    alga->name[CRYPTO_MAX_ALG_NAME - 1] = 0;

    return alga->name;
}
EXPORT_SYMBOL_GPL(crypto_attr_alg_name);

struct crypto_alg *crypto_attr_alg2(struct rtattr *rta,
                    const struct crypto_type *frontend,
                    u32 type, u32 mask)
{
    const char *name;
    int err;

    name = crypto_attr_alg_name(rta);
    err = PTR_ERR(name);
    if (IS_ERR(name))
        return ERR_PTR(err);

    return crypto_find_alg(name, frontend, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_attr_alg2);

int crypto_attr_u32(struct rtattr *rta, u32 *num)
{
    struct crypto_attr_u32 *nu32;

    if (!rta)
        return -ENOENT;
    if (RTA_PAYLOAD(rta) < sizeof(*nu32))
        return -EINVAL;
    if (rta->rta_type != CRYPTOA_U32)
        return -EINVAL;

    nu32 = RTA_DATA(rta);
    *num = nu32->num;

    return 0;
}
EXPORT_SYMBOL_GPL(crypto_attr_u32);

void *crypto_alloc_instance2(const char *name, struct crypto_alg *alg,
                 unsigned int head)
{
    struct crypto_instance *inst;
    char *p;
    int err;

    p = kzalloc(head + sizeof(*inst) + sizeof(struct crypto_spawn),
            GFP_KERNEL);
    if (!p)
        return ERR_PTR(-ENOMEM);

    inst = (void *)(p + head);

    err = -ENAMETOOLONG;
    if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", name,
             alg->cra_name) >= CRYPTO_MAX_ALG_NAME)
        goto err_free_inst;

    if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
             name, alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
        goto err_free_inst;

    return p;

err_free_inst:
    kfree(p);
    return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(crypto_alloc_instance2);

struct crypto_instance *crypto_alloc_instance(const char *name,
                          struct crypto_alg *alg)
{
    struct crypto_instance *inst;
    struct crypto_spawn *spawn;
    int err;

    inst = crypto_alloc_instance2(name, alg, 0);
    if (IS_ERR(inst))
        goto out;

    spawn = crypto_instance_ctx(inst);
    err = crypto_init_spawn(spawn, alg, inst,
                CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC);

    if (err)
        goto err_free_inst;

    return inst;

err_free_inst:
    kfree(inst);
    inst = ERR_PTR(err);

out:
    return inst;
}
EXPORT_SYMBOL_GPL(crypto_alloc_instance);

void crypto_init_queue(struct crypto_queue *queue, unsigned int max_qlen)
{
    INIT_LIST_HEAD(&queue->list);
    queue->backlog = &queue->list;
    queue->qlen = 0;
    queue->max_qlen = max_qlen;
}
EXPORT_SYMBOL_GPL(crypto_init_queue);

int crypto_enqueue_request(struct crypto_queue *queue,
               struct crypto_async_request *request)
{
    int err = -EINPROGRESS;

    if (unlikely(queue->qlen >= queue->max_qlen)) {
        err = -EBUSY;
        if (!(request->flags & CRYPTO_TFM_REQ_MAY_BACKLOG))
            goto out;
        if (queue->backlog == &queue->list)
            queue->backlog = &request->list;
    }

    queue->qlen++;
    list_add_tail(&request->list, &queue->list);

out:
    return err;
}
EXPORT_SYMBOL_GPL(crypto_enqueue_request);

void *__crypto_dequeue_request(struct crypto_queue *queue, unsigned int offset)
{
    struct list_head *request;

    if (unlikely(!queue->qlen))
        return NULL;

    queue->qlen--;

    if (queue->backlog != &queue->list)
        queue->backlog = queue->backlog->next;

    request = queue->list.next;
    list_del(request);

    return (char *)list_entry(request, struct crypto_async_request, list) -
           offset;
}
EXPORT_SYMBOL_GPL(__crypto_dequeue_request);

struct crypto_async_request *crypto_dequeue_request(struct crypto_queue *queue)
{
    return __crypto_dequeue_request(queue, 0);
}
EXPORT_SYMBOL_GPL(crypto_dequeue_request);

int crypto_tfm_in_queue(struct crypto_queue *queue, struct crypto_tfm *tfm)
{
    struct crypto_async_request *req;

    list_for_each_entry(req, &queue->list, list) {
        if (req->tfm == tfm)
            return 1;
    }

    return 0;
}
EXPORT_SYMBOL_GPL(crypto_tfm_in_queue);

static inline void crypto_inc_byte(u8 *a, unsigned int size)
{
    u8 *b = (a + size);
    u8 c;

    for (; size; size--) {
        c = *--b + 1;
        *b = c;
        if (c)
            break;
    }
}

void crypto_inc(u8 *a, unsigned int size)
{
    __be32 *b = (__be32 *)(a + size);
    u32 c;

    for (; size >= 4; size -= 4) {
        c = be32_to_cpu(*--b) + 1;
        *b = cpu_to_be32(c);
        if (c)
            return;
    }

    crypto_inc_byte(a, size);
}
EXPORT_SYMBOL_GPL(crypto_inc);

static inline void crypto_xor_byte(u8 *a, const u8 *b, unsigned int size)
{
    for (; size; size--)
        *a++ ^= *b++;
}

void crypto_xor(u8 *dst, const u8 *src, unsigned int size)
{
    u32 *a = (u32 *)dst;
    u32 *b = (u32 *)src;

    for (; size >= 4; size -= 4)
        *a++ ^= *b++;

    crypto_xor_byte((u8 *)a, (u8 *)b, size);
}
EXPORT_SYMBOL_GPL(crypto_xor);

static int __init crypto_algapi_init(void)
{
    crypto_init_proc();
    return 0;
}

static void __exit crypto_algapi_exit(void)
{
    crypto_exit_proc();
}

module_init(crypto_algapi_init);
module_exit(crypto_algapi_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Cryptographic algorithms API");