// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Create default crypto algorithm instances.
 *
 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
 */

#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/signal.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;

        struct {
                struct rtattr attr;
                struct crypto_attr_alg data;
        } attrs[CRYPTO_MAX_ATTRS];

        char template[CRYPTO_MAX_ALG_NAME];

        struct crypto_larval *larval;

        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;
        int err = -ENOENT;

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

        do {
                err = tmpl->create(tmpl, param->tb);
        } while (err == -EAGAIN && !signal_pending(current));

        crypto_tmpl_put(tmpl);

out:
        param->larval->adult = ERR_PTR(err);
        param->larval->alg.cra_flags |= CRYPTO_ALG_DEAD;
        complete_all(&param->larval->completion);
        crypto_alg_put(&param->larval->alg);
        kfree(param);
        module_put_and_kthread_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_obj(*param);
        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 (;;) {
                name = ++p;

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

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

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

                        p++;
                }

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

                param->attrs[i].attr.rta_len = sizeof(param->attrs[i]);
                param->attrs[i].attr.rta_type = CRYPTOA_ALG;
                memcpy(param->attrs[i].data.name, name, len);

                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;
        }

        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;

        crypto_alg_get(&larval->alg);
        param->larval = larval;

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

        return NOTIFY_STOP;

err_put_larval:
        crypto_alg_put(&larval->alg);
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;

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

        crypto_alg_tested(param->driver, err);

        kfree(param);
        module_put_and_kthread_exit(0);
}

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

        if (!IS_ENABLED(CONFIG_CRYPTO_SELFTESTS))
                return NOTIFY_DONE;

        if (!try_module_get(THIS_MODULE))
                goto err;

        param = kzalloc_obj(*param);
        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));
        param->type = alg->cra_flags;

        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);
        case CRYPTO_MSG_ALG_LOADED:
                break;
        }

        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);
}

module_init(cryptomgr_init);
module_exit(cryptomgr_exit);

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