algboss.c

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/*
 * Create default crypto algorithm instances.
 *
 * 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 <crypto/internal/aead.h>
#include <linux/completion.h>
#include <linux/ctype.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/rtnetlink.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/string.h>

#include "internal.h"

struct cryptomgr_param {
    struct rtattr *tb[CRYPTO_MAX_ATTRS + 2];

    struct {
        struct rtattr attr;
        struct crypto_attr_type data;
    } type;

    union {
        struct rtattr attr;
        struct {
            struct rtattr attr;
            struct crypto_attr_alg data;
        } alg;
        struct {
            struct rtattr attr;
            struct crypto_attr_u32 data;
        } nu32;
    } attrs[CRYPTO_MAX_ATTRS];

    char larval[CRYPTO_MAX_ALG_NAME];
    char template[CRYPTO_MAX_ALG_NAME];

    struct completion *completion;

    u32 otype;
    u32 omask;
};

struct crypto_test_param {
    char driver[CRYPTO_MAX_ALG_NAME];
    char alg[CRYPTO_MAX_ALG_NAME];
    u32 type;
};

static int cryptomgr_probe(void *data)
{
    struct cryptomgr_param *param = data;
    struct crypto_template *tmpl;
    struct crypto_instance *inst;
    int err;

    tmpl = crypto_lookup_template(param->template);
    if (!tmpl)
        goto out;

    do {
        if (tmpl->create) {
            err = tmpl->create(tmpl, param->tb);
            continue;
        }

        inst = tmpl->alloc(param->tb);
        if (IS_ERR(inst))
            err = PTR_ERR(inst);
        else if ((err = crypto_register_instance(tmpl, inst)))
            tmpl->free(inst);
    } while (err == -EAGAIN && !signal_pending(current));

    crypto_tmpl_put(tmpl);

out:
    complete_all(param->completion);
    kfree(param);
    module_put_and_exit(0);
}

static int cryptomgr_schedule_probe(struct crypto_larval *larval)
{
    struct task_struct *thread;
    struct cryptomgr_param *param;
    const char *name = larval->alg.cra_name;
    const char *p;
    unsigned int len;
    int i;

    if (!try_module_get(THIS_MODULE))
        goto err;

    param = kzalloc(sizeof(*param), GFP_KERNEL);
    if (!param)
        goto err_put_module;

    for (p = name; isalnum(*p) || *p == '-' || *p == '_'; p++)
        ;

    len = p - name;
    if (!len || *p != '(')
        goto err_free_param;

    memcpy(param->template, name, len);

    i = 0;
    for (;;) {
        int notnum = 0;

        name = ++p;
        len = 0;

        for (; isalnum(*p) || *p == '-' || *p == '_'; p++)
            notnum |= !isdigit(*p);

        if (*p == '(') {
            int recursion = 0;

            for (;;) {
                if (!*++p)
                    goto err_free_param;
                if (*p == '(')
                    recursion++;
                else if (*p == ')' && !recursion--)
                    break;
            }

            notnum = 1;
            p++;
        }

        len = p - name;
        if (!len)
            goto err_free_param;

        if (notnum) {
            param->attrs[i].alg.attr.rta_len =
                sizeof(param->attrs[i].alg);
            param->attrs[i].alg.attr.rta_type = CRYPTOA_ALG;
            memcpy(param->attrs[i].alg.data.name, name, len);
        } else {
            param->attrs[i].nu32.attr.rta_len =
                sizeof(param->attrs[i].nu32);
            param->attrs[i].nu32.attr.rta_type = CRYPTOA_U32;
            param->attrs[i].nu32.data.num =
                simple_strtol(name, NULL, 0);
        }

        param->tb[i + 1] = &param->attrs[i].attr;
        i++;

        if (i >= CRYPTO_MAX_ATTRS)
            goto err_free_param;

        if (*p == ')')
            break;

        if (*p != ',')
            goto err_free_param;
    }

    if (!i)
        goto err_free_param;

    param->tb[i + 1] = NULL;

    param->type.attr.rta_len = sizeof(param->type);
    param->type.attr.rta_type = CRYPTOA_TYPE;
    param->type.data.type = larval->alg.cra_flags & ~CRYPTO_ALG_TESTED;
    param->type.data.mask = larval->mask & ~CRYPTO_ALG_TESTED;
    param->tb[0] = &param->type.attr;

    param->otype = larval->alg.cra_flags;
    param->omask = larval->mask;

    memcpy(param->larval, larval->alg.cra_name, CRYPTO_MAX_ALG_NAME);

    param->completion = &larval->completion;

    thread = kthread_run(cryptomgr_probe, param, "cryptomgr_probe");
    if (IS_ERR(thread))
        goto err_free_param;

    wait_for_completion_interruptible(&larval->completion);

    return NOTIFY_STOP;

err_free_param:
    kfree(param);
err_put_module:
    module_put(THIS_MODULE);
err:
    return NOTIFY_OK;
}

static int cryptomgr_test(void *data)
{
    struct crypto_test_param *param = data;
    u32 type = param->type;
    int err = 0;

#ifdef CONFIG_CRYPTO_MANAGER_DISABLE_TESTS
    goto skiptest;
#endif

    if (type & CRYPTO_ALG_TESTED)
        goto skiptest;

    err = alg_test(param->driver, param->alg, type, CRYPTO_ALG_TESTED);

skiptest:
    crypto_alg_tested(param->driver, err);

    kfree(param);
    module_put_and_exit(0);
}

static int cryptomgr_schedule_test(struct crypto_alg *alg)
{
    struct task_struct *thread;
    struct crypto_test_param *param;
    u32 type;

    if (!try_module_get(THIS_MODULE))
        goto err;

    param = kzalloc(sizeof(*param), GFP_KERNEL);
    if (!param)
        goto err_put_module;

    memcpy(param->driver, alg->cra_driver_name, sizeof(param->driver));
    memcpy(param->alg, alg->cra_name, sizeof(param->alg));
    type = alg->cra_flags;

    /* This piece of crap needs to disappear into per-type test hooks. */
    if ((!((type ^ CRYPTO_ALG_TYPE_BLKCIPHER) &
           CRYPTO_ALG_TYPE_BLKCIPHER_MASK) && !(type & CRYPTO_ALG_GENIV) &&
         ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
          CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
                      alg->cra_ablkcipher.ivsize)) ||
        (!((type ^ CRYPTO_ALG_TYPE_AEAD) & CRYPTO_ALG_TYPE_MASK) &&
         alg->cra_type == &crypto_nivaead_type && alg->cra_aead.ivsize))
        type |= CRYPTO_ALG_TESTED;

    param->type = type;

    thread = kthread_run(cryptomgr_test, param, "cryptomgr_test");
    if (IS_ERR(thread))
        goto err_free_param;

    return NOTIFY_STOP;

err_free_param:
    kfree(param);
err_put_module:
    module_put(THIS_MODULE);
err:
    return NOTIFY_OK;
}

static int cryptomgr_notify(struct notifier_block *this, unsigned long msg,
                void *data)
{
    switch (msg) {
    case CRYPTO_MSG_ALG_REQUEST:
        return cryptomgr_schedule_probe(data);
    case CRYPTO_MSG_ALG_REGISTER:
        return cryptomgr_schedule_test(data);
    }

    return NOTIFY_DONE;
}

static struct notifier_block cryptomgr_notifier = {
    .notifier_call = cryptomgr_notify,
};

static int __init cryptomgr_init(void)
{
    return crypto_register_notifier(&cryptomgr_notifier);
}

static void __exit cryptomgr_exit(void)
{
    int err = crypto_unregister_notifier(&cryptomgr_notifier);
    BUG_ON(err);
}

subsys_initcall(cryptomgr_init);
module_exit(cryptomgr_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Crypto Algorithm Manager");