/*

 * Copyright 2019-2022 The OpenSSL Project Authors. All Rights Reserved.

 * Copyright (c) 2019, Oracle and/or its affiliates.  All rights reserved.

 *

 * Licensed under the Apache License 2.0 (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */

#include <string.h>

#include <openssl/err.h>

#include <openssl/lhash.h>

#include "internal/propertyerr.h"

#include "internal/property.h"

#include "internal/core.h"

#include "property_local.h"

/*

 * Implement a property definition cache.

 * These functions assume that they are called under a write lock.

 * No attempt is made to clean out the cache, except when it is shut down.

 */

typedef struct {

    const char *prop;

    OSSL_PROPERTY_LIST *defn;

    char body[1];

} PROPERTY_DEFN_ELEM;

DEFINE_LHASH_OF(PROPERTY_DEFN_ELEM);

static unsigned long property_defn_hash(const PROPERTY_DEFN_ELEM *a)

{

    return OPENSSL_LH_strhash(a->prop);

}

static int property_defn_cmp(const PROPERTY_DEFN_ELEM *a,

                             const PROPERTY_DEFN_ELEM *b)

{

    return strcmp(a->prop, b->prop);

}

static void property_defn_free(PROPERTY_DEFN_ELEM *elem)

{

    ossl_property_free(elem->defn);

    OPENSSL_free(elem);

}

static void property_defns_free(void *vproperty_defns)

{

    LHASH_OF(PROPERTY_DEFN_ELEM) *property_defns = vproperty_defns;

    if (property_defns != NULL) {

        lh_PROPERTY_DEFN_ELEM_doall(property_defns,

                                    &property_defn_free);

        lh_PROPERTY_DEFN_ELEM_free(property_defns);

    }

}

static void *property_defns_new(OSSL_LIB_CTX *ctx) {

    return lh_PROPERTY_DEFN_ELEM_new(&property_defn_hash, &property_defn_cmp);

}

static const OSSL_LIB_CTX_METHOD property_defns_method = {

    OSSL_LIB_CTX_METHOD_DEFAULT_PRIORITY,

    property_defns_new,

    property_defns_free,

};

OSSL_PROPERTY_LIST *ossl_prop_defn_get(OSSL_LIB_CTX *ctx, const char *prop)

{

    PROPERTY_DEFN_ELEM elem, *r;

    LHASH_OF(PROPERTY_DEFN_ELEM) *property_defns;

    property_defns = ossl_lib_ctx_get_data(ctx,

                                           OSSL_LIB_CTX_PROPERTY_DEFN_INDEX,

                                           &property_defns_method);

    if (property_defns == NULL || !ossl_lib_ctx_read_lock(ctx))

        return NULL;

    elem.prop = prop;

    r = lh_PROPERTY_DEFN_ELEM_retrieve(property_defns, &elem);

    ossl_lib_ctx_unlock(ctx);

    if (r == NULL || !ossl_assert(r->defn != NULL))

        return NULL;

    return r->defn;

}

/*

 * Cache the property list for a given property string *pl.

 * If an entry already exists in the cache *pl is freed and

 * overwritten with the existing entry from the cache.

 */

int ossl_prop_defn_set(OSSL_LIB_CTX *ctx, const char *prop,

                       OSSL_PROPERTY_LIST **pl)

{

    PROPERTY_DEFN_ELEM elem, *old, *p = NULL;

    size_t len;

    LHASH_OF(PROPERTY_DEFN_ELEM) *property_defns;

    int res = 1;

    property_defns = ossl_lib_ctx_get_data(ctx,

                                           OSSL_LIB_CTX_PROPERTY_DEFN_INDEX,

                                           &property_defns_method);

    if (property_defns == NULL)

        return 0;

    if (prop == NULL)

        return 1;

    if (!ossl_lib_ctx_write_lock(ctx))

        return 0;

    elem.prop = prop;

    if (pl == NULL) {

        lh_PROPERTY_DEFN_ELEM_delete(property_defns, &elem);

        goto end;

    }

    /* check if property definition is in the cache already */

    if ((p = lh_PROPERTY_DEFN_ELEM_retrieve(property_defns, &elem)) != NULL) {

        ossl_property_free(*pl);

        *pl = p->defn;

        goto end;

    }

    len = strlen(prop);

    p = OPENSSL_malloc(sizeof(*p) + len);

    if (p != NULL) {

        p->prop = p->body;

        p->defn = *pl;

        memcpy(p->body, prop, len + 1);

        old = lh_PROPERTY_DEFN_ELEM_insert(property_defns, p);

        if (!ossl_assert(old == NULL))

            /* This should not happen. An existing entry is handled above. */

            goto end;

        if (!lh_PROPERTY_DEFN_ELEM_error(property_defns))

            goto end;

    }

    OPENSSL_free(p);

    res = 0;

 end:

    ossl_lib_ctx_unlock(ctx);

    return res;

}