// SPDX-License-Identifier: GPL-2.0-only
/*
 * Cryptographic API.
 *
 * Copyright (c) 2013 Chanho Min <chanho.min@lge.com>
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/crypto.h>
#include <linux/vmalloc.h>
#include <linux/lz4.h>
#include <crypto/internal/scompress.h>

static void *lz4_alloc_ctx(void)
{
        void *ctx;

        ctx = vmalloc(LZ4_MEM_COMPRESS);
        if (!ctx)
                return ERR_PTR(-ENOMEM);

        return ctx;
}

static void lz4_free_ctx(void *ctx)
{
        vfree(ctx);
}

static int __lz4_compress_crypto(const u8 *src, unsigned int slen,
                                 u8 *dst, unsigned int *dlen, void *ctx)
{
        int out_len = LZ4_compress_default(src, dst,
                slen, *dlen, ctx);

        if (!out_len)
                return -EINVAL;

        *dlen = out_len;
        return 0;
}

static int lz4_scompress(struct crypto_scomp *tfm, const u8 *src,
                         unsigned int slen, u8 *dst, unsigned int *dlen,
                         void *ctx)
{
        return __lz4_compress_crypto(src, slen, dst, dlen, ctx);
}

static int __lz4_decompress_crypto(const u8 *src, unsigned int slen,
                                   u8 *dst, unsigned int *dlen, void *ctx)
{
        int out_len = LZ4_decompress_safe(src, dst, slen, *dlen);

        if (out_len < 0)
                return -EINVAL;

        *dlen = out_len;
        return 0;
}

static int lz4_sdecompress(struct crypto_scomp *tfm, const u8 *src,
                           unsigned int slen, u8 *dst, unsigned int *dlen,
                           void *ctx)
{
        return __lz4_decompress_crypto(src, slen, dst, dlen, NULL);
}

static struct scomp_alg scomp = {
        .streams                = {
                .alloc_ctx      = lz4_alloc_ctx,
                .free_ctx       = lz4_free_ctx,
        },
        .compress               = lz4_scompress,
        .decompress             = lz4_sdecompress,
        .base                   = {
                .cra_name       = "lz4",
                .cra_driver_name = "lz4-scomp",
                .cra_module      = THIS_MODULE,
        }
};

static int __init lz4_mod_init(void)
{
        return crypto_register_scomp(&scomp);
}

static void __exit lz4_mod_fini(void)
{
        crypto_unregister_scomp(&scomp);
}

module_init(lz4_mod_init);
module_exit(lz4_mod_fini);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("LZ4 Compression Algorithm");
MODULE_ALIAS_CRYPTO("lz4");