/* ====================================================================

 * Copyright (c) 2001 The OpenSSL Project.  All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 *

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in

 *    the documentation and/or other materials provided with the

 *    distribution.

 *

 * 3. All advertising materials mentioning features or use of this

 *    software must display the following acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"

 *

 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to

 *    endorse or promote products derived from this software without

 *    prior written permission. For written permission, please contact

 *    licensing@OpenSSL.org.

 *

 * 5. Products derived from this software may not be called "OpenSSL"

 *    nor may "OpenSSL" appear in their names without prior written

 *    permission of the OpenSSL Project.

 *

 * 6. Redistributions of any form whatsoever must retain the following

 *    acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"

 *

 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY

 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR

 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,

 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED

 * OF THE POSSIBILITY OF SUCH DAMAGE.

 * ====================================================================

 *

 * This product includes cryptographic software written by Eric Young

 * (eay@cryptsoft.com).  This product includes software written by Tim

 * Hudson (tjh@cryptsoft.com).

 *

 */

#include "cryptlib.h"

#include <openssl/evp.h>

#include <openssl/lhash.h>

#include "eng_int.h"

/* The type of the items in the table */

typedef struct st_engine_pile {

    /* The 'nid' of this algorithm/mode */

    int nid;

    /* ENGINEs that implement this algorithm/mode. */

    STACK_OF(ENGINE) *sk;

    /* The default ENGINE to perform this algorithm/mode. */

    ENGINE *funct;

    /*

     * Zero if 'sk' is newer than the cached 'funct', non-zero otherwise

     */

    int uptodate;

} ENGINE_PILE;

DECLARE_LHASH_OF(ENGINE_PILE);

/* The type exposed in eng_int.h */

struct st_engine_table {

    LHASH_OF(ENGINE_PILE) piles;

};                              /* ENGINE_TABLE */

typedef struct st_engine_pile_doall {

    engine_table_doall_cb *cb;

    void *arg;

} ENGINE_PILE_DOALL;

/* Global flags (ENGINE_TABLE_FLAG_***). */

static unsigned int table_flags = 0;

/* API function manipulating 'table_flags' */

unsigned int ENGINE_get_table_flags(void)

{

    return table_flags;

}

void ENGINE_set_table_flags(unsigned int flags)

{

    table_flags = flags;

}

/* Internal functions for the "piles" hash table */

static unsigned long engine_pile_hash(const ENGINE_PILE *c)

{

    return c->nid;

}

static int engine_pile_cmp(const ENGINE_PILE *a, const ENGINE_PILE *b)

{

    return a->nid - b->nid;

}

static IMPLEMENT_LHASH_HASH_FN(engine_pile, ENGINE_PILE)

static IMPLEMENT_LHASH_COMP_FN(engine_pile, ENGINE_PILE)

static int int_table_check(ENGINE_TABLE **t, int create)

{

    LHASH_OF(ENGINE_PILE) *lh;

    if (*t)

        return 1;

    if (!create)

        return 0;

    if ((lh = lh_ENGINE_PILE_new()) == NULL)

        return 0;

    *t = (ENGINE_TABLE *)lh;

    return 1;

}

/*

 * Privately exposed (via eng_int.h) functions for adding and/or removing

 * ENGINEs from the implementation table

 */

int engine_table_register(ENGINE_TABLE **table, ENGINE_CLEANUP_CB *cleanup,

                          ENGINE *e, const int *nids, int num_nids,

                          int setdefault)

{

    int ret = 0, added = 0;

    ENGINE_PILE tmplate, *fnd;

    CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);

    if (!(*table))

        added = 1;

    if (!int_table_check(table, 1))

        goto end;

    if (added)

        /* The cleanup callback needs to be added */

        engine_cleanup_add_first(cleanup);

    while (num_nids--) {

        tmplate.nid = *nids;

        fnd = lh_ENGINE_PILE_retrieve(&(*table)->piles, &tmplate);

        if (!fnd) {

            fnd = OPENSSL_malloc(sizeof(ENGINE_PILE));

            if (!fnd)

                goto end;

            fnd->uptodate = 1;

            fnd->nid = *nids;

            fnd->sk = sk_ENGINE_new_null();

            if (!fnd->sk) {

                OPENSSL_free(fnd);

                goto end;

            }

            fnd->funct = NULL;

            (void)lh_ENGINE_PILE_insert(&(*table)->piles, fnd);

        }

        /* A registration shouldn't add duplciate entries */

        (void)sk_ENGINE_delete_ptr(fnd->sk, e);

        /*

         * if 'setdefault', this ENGINE goes to the head of the list

         */

        if (!sk_ENGINE_push(fnd->sk, e))

            goto end;

        /* "touch" this ENGINE_PILE */

        fnd->uptodate = 0;

        if (setdefault) {

            if (!engine_unlocked_init(e)) {

                ENGINEerr(ENGINE_F_ENGINE_TABLE_REGISTER,

                          ENGINE_R_INIT_FAILED);

                goto end;

            }

            if (fnd->funct)

                engine_unlocked_finish(fnd->funct, 0);

            fnd->funct = e;

            fnd->uptodate = 1;

        }

        nids++;

    }

    ret = 1;

 end:

    CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);

    return ret;

}

static void int_unregister_cb_doall_arg(ENGINE_PILE *pile, ENGINE *e)

{

    int n;

    /* Iterate the 'c->sk' stack removing any occurance of 'e' */

    while ((n = sk_ENGINE_find(pile->sk, e)) >= 0) {

        (void)sk_ENGINE_delete(pile->sk, n);

        pile->uptodate = 0;

    }

    if (pile->funct == e) {

        engine_unlocked_finish(e, 0);

        pile->funct = NULL;

    }

}

static IMPLEMENT_LHASH_DOALL_ARG_FN(int_unregister_cb, ENGINE_PILE, ENGINE)

void engine_table_unregister(ENGINE_TABLE **table, ENGINE *e)

{

    CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);

    if (int_table_check(table, 0))

        lh_ENGINE_PILE_doall_arg(&(*table)->piles,

                                 LHASH_DOALL_ARG_FN(int_unregister_cb),

                                 ENGINE, e);

    CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);

}

static void int_cleanup_cb_doall(ENGINE_PILE *p)

{

    sk_ENGINE_free(p->sk);

    if (p->funct)

        engine_unlocked_finish(p->funct, 0);

    OPENSSL_free(p);

}

static IMPLEMENT_LHASH_DOALL_FN(int_cleanup_cb, ENGINE_PILE)

void engine_table_cleanup(ENGINE_TABLE **table)

{

    CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);

    if (*table) {

        lh_ENGINE_PILE_doall(&(*table)->piles,

                             LHASH_DOALL_FN(int_cleanup_cb));

        lh_ENGINE_PILE_free(&(*table)->piles);

        *table = NULL;

    }

    CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);

}

/* return a functional reference for a given 'nid' */

#ifndef ENGINE_TABLE_DEBUG

ENGINE *engine_table_select(ENGINE_TABLE **table, int nid)

#else

ENGINE *engine_table_select_tmp(ENGINE_TABLE **table, int nid, const char *f,

                                int l)

#endif

{

    ENGINE *ret = NULL;

    ENGINE_PILE tmplate, *fnd = NULL;

    int initres, loop = 0;

    if (!(*table)) {

#ifdef ENGINE_TABLE_DEBUG

        fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, nothing "

                "registered!\n", f, l, nid);

#endif

        return NULL;

    }

    ERR_set_mark();

    CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);

    /*

     * Check again inside the lock otherwise we could race against cleanup

     * operations. But don't worry about a fprintf(stderr).

     */

    if (!int_table_check(table, 0))

        goto end;

    tmplate.nid = nid;

    fnd = lh_ENGINE_PILE_retrieve(&(*table)->piles, &tmplate);

    if (!fnd)

        goto end;

    if (fnd->funct && engine_unlocked_init(fnd->funct)) {

#ifdef ENGINE_TABLE_DEBUG

        fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, using "

                "ENGINE '%s' cached\n", f, l, nid, fnd->funct->id);

#endif

        ret = fnd->funct;

        goto end;

    }

    if (fnd->uptodate) {

        ret = fnd->funct;

        goto end;

    }

 trynext:

    ret = sk_ENGINE_value(fnd->sk, loop++);

    if (!ret) {

#ifdef ENGINE_TABLE_DEBUG

        fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, no "

                "registered implementations would initialise\n", f, l, nid);

#endif

        goto end;

    }

    /* Try to initialise the ENGINE? */

    if ((ret->funct_ref > 0) || !(table_flags & ENGINE_TABLE_FLAG_NOINIT))

        initres = engine_unlocked_init(ret);

    else

        initres = 0;

    if (initres) {

        /* Update 'funct' */

        if ((fnd->funct != ret) && engine_unlocked_init(ret)) {

            /* If there was a previous default we release it. */

            if (fnd->funct)

                engine_unlocked_finish(fnd->funct, 0);

            fnd->funct = ret;

#ifdef ENGINE_TABLE_DEBUG

            fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, "

                    "setting default to '%s'\n", f, l, nid, ret->id);

#endif

        }

#ifdef ENGINE_TABLE_DEBUG

        fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, using "

                "newly initialised '%s'\n", f, l, nid, ret->id);

#endif

        goto end;

    }

    goto trynext;

 end:

    /*

     * If it failed, it is unlikely to succeed again until some future

     * registrations have taken place. In all cases, we cache.

     */

    if (fnd)

        fnd->uptodate = 1;

#ifdef ENGINE_TABLE_DEBUG

    if (ret)

        fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, caching "

                "ENGINE '%s'\n", f, l, nid, ret->id);

    else

        fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, caching "

                "'no matching ENGINE'\n", f, l, nid);

#endif

    CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);

    /*

     * Whatever happened, any failed init()s are not failures in this

     * context, so clear our error state.

     */

    ERR_pop_to_mark();

    return ret;

}

/* Table enumeration */

static void int_cb_doall_arg(ENGINE_PILE *pile, ENGINE_PILE_DOALL *dall)

{

    dall->cb(pile->nid, pile->sk, pile->funct, dall->arg);

}

static IMPLEMENT_LHASH_DOALL_ARG_FN(int_cb, ENGINE_PILE, ENGINE_PILE_DOALL)

void engine_table_doall(ENGINE_TABLE *table, engine_table_doall_cb *cb,

                        void *arg)

{

    ENGINE_PILE_DOALL dall;

    dall.cb = cb;

    dall.arg = arg;

    if (table)

        lh_ENGINE_PILE_doall_arg(&table->piles,

                                 LHASH_DOALL_ARG_FN(int_cb),

                                 ENGINE_PILE_DOALL, &dall);

}