/*

 * Copyright (c) Meta Platforms, Inc. and affiliates.

 * All rights reserved.

 *

 * This source code is licensed under both the BSD-style license (found in the

 * LICENSE file in the root directory of this source tree) and the GPLv2 (found

 * in the COPYING file in the root directory of this source tree).

 * You may select, at your option, one of the above-listed licenses.

 */

/**

 * This fuzz target attempts to decompress the fuzzed data with the dictionary

 * decompression function to ensure the decompressor never crashes. It does not

 * fuzz the dictionary.

 */

#include <stddef.h>

#include <stdlib.h>

#include <stdio.h>

#include "fuzz_helpers.h"

#include "zstd_helpers.h"

#include "fuzz_data_producer.h"

#include "fuzz_third_party_seq_prod.h"

static ZSTD_DCtx *dctx = NULL;

int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)

{

    FUZZ_SEQ_PROD_SETUP();

    /* Give a random portion of src data to the producer, to use for

    parameter generation. The rest will be used for (de)compression */

    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);

    size = FUZZ_dataProducer_reserveDataPrefix(producer);

    FUZZ_dict_t dict;

    ZSTD_DDict* ddict = NULL;

    if (!dctx) {

        dctx = ZSTD_createDCtx();

        FUZZ_ASSERT(dctx);

    }

    dict = FUZZ_train(src, size, producer);

    if (FUZZ_dataProducer_uint32Range(producer, 0, 1) == 0) {

        ddict = ZSTD_createDDict(dict.buff, dict.size);

        FUZZ_ASSERT(ddict);

    } else {

        if (FUZZ_dataProducer_uint32Range(producer, 0, 1) == 0)

            FUZZ_ZASSERT(ZSTD_DCtx_loadDictionary_advanced(

                dctx, dict.buff, dict.size,

                (ZSTD_dictLoadMethod_e)FUZZ_dataProducer_uint32Range(producer, 0, 1),

                (ZSTD_dictContentType_e)FUZZ_dataProducer_uint32Range(producer, 0, 2)));

        else

            FUZZ_ZASSERT(ZSTD_DCtx_refPrefix_advanced(

                dctx, dict.buff, dict.size,

                (ZSTD_dictContentType_e)FUZZ_dataProducer_uint32Range(producer, 0, 2)));

    }

    {

        size_t const bufSize = FUZZ_dataProducer_uint32Range(producer, 0, 10 * size);

        void* rBuf = FUZZ_malloc(bufSize);

        if (ddict) {

            ZSTD_decompress_usingDDict(dctx, rBuf, bufSize, src, size, ddict);

        } else {

            ZSTD_decompressDCtx(dctx, rBuf, bufSize, src, size);

        }

        free(rBuf);

    }

    free(dict.buff);

    FUZZ_dataProducer_free(producer);

    ZSTD_freeDDict(ddict);

#ifndef STATEFUL_FUZZING

    ZSTD_freeDCtx(dctx); dctx = NULL;

#endif

    FUZZ_SEQ_PROD_TEARDOWN();

    return 0;

}