[funini.com] -> [kei@sodan] -> Kernel Reading

root/crypto/algapi.c

/* [<][>][^][v][top][bottom][index][help] */

DEFINITIONS

This source file includes following definitions.
  1. crypto_larval_error
  2. crypto_set_driver_name
  3. crypto_check_alg
  4. crypto_destroy_instance
  5. crypto_remove_spawn
  6. crypto_remove_spawns
  7. __crypto_register_alg
  8. crypto_alg_tested
  9. crypto_remove_final
  10. crypto_wait_for_test
  11. crypto_register_alg
  12. crypto_remove_alg
  13. crypto_unregister_alg
  14. crypto_register_template
  15. crypto_unregister_template
  16. __crypto_lookup_template
  17. crypto_lookup_template
  18. crypto_register_instance
  19. crypto_init_spawn
  20. crypto_drop_spawn
  21. crypto_spawn_tfm
  22. crypto_register_notifier
  23. crypto_unregister_notifier
  24. crypto_get_attr_type
  25. crypto_check_attr_type
  26. crypto_attr_alg_name
  27. crypto_attr_alg
  28. crypto_attr_u32
  29. crypto_alloc_instance
  30. crypto_init_queue
  31. crypto_enqueue_request
  32. crypto_dequeue_request
  33. crypto_tfm_in_queue
  34. crypto_inc_byte
  35. crypto_inc
  36. crypto_xor_byte
  37. crypto_xor
  38. crypto_algapi_init
  39. crypto_algapi_exit

/*
 * Cryptographic API for algorithms (i.e., low-level API).
 *
 * 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 <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/string.h>

#include "internal.h"

static void crypto_remove_final(struct list_head *list);

static LIST_HEAD(crypto_template_list);

void crypto_larval_error(const char *name, u32 type, u32 mask)
{
        struct crypto_alg *alg;

        alg = crypto_alg_lookup(name, type, mask);

        if (alg) {
                if (crypto_is_larval(alg)) {
                        struct crypto_larval *larval = (void *)alg;
                        complete_all(&larval->completion);
                }
                crypto_mod_put(alg);
        }
}
EXPORT_SYMBOL_GPL(crypto_larval_error);

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

        list_del_init(&spawn->list);
        spawn->alg = NULL;

        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;

        list_splice(&inst->alg.cra_users, secondary_spawns);
}

static void crypto_remove_spawns(struct list_head *spawns,
                                 struct list_head *list, u32 new_type)
{
        struct crypto_spawn *spawn, *n;
        LIST_HEAD(secondary_spawns);

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

                crypto_remove_spawn(spawn, list, &secondary_spawns);
        }

        while (!list_empty(&secondary_spawns)) {
                list_for_each_entry_safe(spawn, n, &secondary_spawns, list)
                        crypto_remove_spawn(spawn, list, &secondary_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_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_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:
        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;
                        complete_all(&larval->completion);
                        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->cra_users, &list, alg->cra_flags);
        }

complete:
        complete_all(&test->completion);

unlock:
        up_write(&crypto_alg_sem);

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

static 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);
        }
}

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->cra_users, list, alg->cra_flags);

        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_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;

        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_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);

void crypto_drop_spawn(struct crypto_spawn *spawn)
{
        down_write(&crypto_alg_sem);
        list_del(&spawn->list);
        up_write(&crypto_alg_sem);
}
EXPORT_SYMBOL_GPL(crypto_drop_spawn);

struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn, u32 type,
                                    u32 mask)
{
        struct crypto_alg *alg;
        struct crypto_alg *alg2;
        struct crypto_tfm *tfm;

        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);
        }

        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);

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_alg(struct rtattr *rta, 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_alg_mod_lookup(name, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_attr_alg);

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);

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

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

        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;

        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);
        return ERR_PTR(err);
}
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);

struct crypto_async_request *crypto_dequeue_request(struct crypto_queue *queue)
{
        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 list_entry(request, struct crypto_async_request, list);
}
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");

/* [<][>][^][v][top][bottom][index][help] */

[funini.com] -> [kei@sodan] -> Kernel Reading