/* $OpenBSD: dso_lib.c,v 1.20 2018/08/24 19:27:01 tb Exp $ */
/* Written by Geoff Thorpe (geoff@geoffthorpe.net) for the OpenSSL
 * project 2000.
 */
/* ====================================================================
 * Copyright (c) 2000 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 <stdio.h>
#include <string.h>

#include <openssl/crypto.h>
#include <openssl/dso.h>
#include <openssl/err.h>

static DSO_METHOD *default_DSO_meth = NULL;

DSO *
DSO_new(void)
{
        return (DSO_new_method(NULL));
}

void
DSO_set_default_method(DSO_METHOD *meth)
{
        default_DSO_meth = meth;
}

DSO_METHOD *
DSO_get_default_method(void)
{
        return (default_DSO_meth);
}

DSO_METHOD *
DSO_get_method(DSO *dso)
{
        return (dso->meth);
}

DSO_METHOD *
DSO_set_method(DSO *dso, DSO_METHOD *meth)
{
        DSO_METHOD *mtmp;

        mtmp = dso->meth;
        dso->meth = meth;
        return (mtmp);
}

DSO *
DSO_new_method(DSO_METHOD *meth)
{
        DSO *ret;

        if (default_DSO_meth == NULL)
                /* We default to DSO_METH_openssl() which in turn defaults
                 * to stealing the "best available" method. Will fallback
                 * to DSO_METH_null() in the worst case. */
                default_DSO_meth = DSO_METHOD_openssl();
        ret = calloc(1, sizeof(DSO));
        if (ret == NULL) {
                DSOerror(ERR_R_MALLOC_FAILURE);
                return (NULL);
        }
        ret->meth_data = sk_void_new_null();
        if (ret->meth_data == NULL) {
                /* sk_new doesn't generate any errors so we do */
                DSOerror(ERR_R_MALLOC_FAILURE);
                free(ret);
                return (NULL);
        }
        if (meth == NULL)
                ret->meth = default_DSO_meth;
        else
                ret->meth = meth;
        ret->references = 1;
        if ((ret->meth->init != NULL) && !ret->meth->init(ret)) {
                free(ret);
                ret = NULL;
        }
        return (ret);
}

int
DSO_free(DSO *dso)
{
        int i;

        if (dso == NULL) {
                DSOerror(ERR_R_PASSED_NULL_PARAMETER);
                return (0);
        }

        i = CRYPTO_add(&dso->references, -1, CRYPTO_LOCK_DSO);
        if (i > 0)
                return (1);

        if ((dso->meth->dso_unload != NULL) && !dso->meth->dso_unload(dso)) {
                DSOerror(DSO_R_UNLOAD_FAILED);
                return (0);
        }

        if ((dso->meth->finish != NULL) && !dso->meth->finish(dso)) {
                DSOerror(DSO_R_FINISH_FAILED);
                return (0);
        }

        sk_void_free(dso->meth_data);
        free(dso->filename);
        free(dso->loaded_filename);
        free(dso);
        return (1);
}

int
DSO_flags(DSO *dso)
{
        return ((dso == NULL) ? 0 : dso->flags);
}


int
DSO_up_ref(DSO *dso)
{
        int refs;

        if (dso == NULL) {
                DSOerror(ERR_R_PASSED_NULL_PARAMETER);
                return (0);
        }

        refs = CRYPTO_add(&dso->references, 1, CRYPTO_LOCK_DSO);
        return ((refs > 1) ? 1 : 0);
}

DSO *
DSO_load(DSO *dso, const char *filename, DSO_METHOD *meth, int flags)
{
        DSO *ret;
        int allocated = 0;

        if (dso == NULL) {
                ret = DSO_new_method(meth);
                if (ret == NULL) {
                        DSOerror(ERR_R_MALLOC_FAILURE);
                        goto err;
                }
                allocated = 1;
                /* Pass the provided flags to the new DSO object */
                if (DSO_ctrl(ret, DSO_CTRL_SET_FLAGS, flags, NULL) < 0) {
                        DSOerror(DSO_R_CTRL_FAILED);
                        goto err;
                }
        } else
                ret = dso;
        /* Don't load if we're currently already loaded */
        if (ret->filename != NULL) {
                DSOerror(DSO_R_DSO_ALREADY_LOADED);
                goto err;
        }
        /* filename can only be NULL if we were passed a dso that already has
         * one set. */
        if (filename != NULL)
                if (!DSO_set_filename(ret, filename)) {
                DSOerror(DSO_R_SET_FILENAME_FAILED);
                goto err;
        }
        filename = ret->filename;
        if (filename == NULL) {
                DSOerror(DSO_R_NO_FILENAME);
                goto err;
        }
        if (ret->meth->dso_load == NULL) {
                DSOerror(DSO_R_UNSUPPORTED);
                goto err;
        }
        if (!ret->meth->dso_load(ret)) {
                DSOerror(DSO_R_LOAD_FAILED);
                goto err;
        }
        /* Load succeeded */
        return (ret);

err:
        if (allocated)
                DSO_free(ret);
        return (NULL);
}

void *
DSO_bind_var(DSO *dso, const char *symname)
{
        void *ret = NULL;

        if ((dso == NULL) || (symname == NULL)) {
                DSOerror(ERR_R_PASSED_NULL_PARAMETER);
                return (NULL);
        }
        if (dso->meth->dso_bind_var == NULL) {
                DSOerror(DSO_R_UNSUPPORTED);
                return (NULL);
        }
        if ((ret = dso->meth->dso_bind_var(dso, symname)) == NULL) {
                DSOerror(DSO_R_SYM_FAILURE);
                return (NULL);
        }
        /* Success */
        return (ret);
}

DSO_FUNC_TYPE
DSO_bind_func(DSO *dso, const char *symname)
{
        DSO_FUNC_TYPE ret = NULL;

        if ((dso == NULL) || (symname == NULL)) {
                DSOerror(ERR_R_PASSED_NULL_PARAMETER);
                return (NULL);
        }
        if (dso->meth->dso_bind_func == NULL) {
                DSOerror(DSO_R_UNSUPPORTED);
                return (NULL);
        }
        if ((ret = dso->meth->dso_bind_func(dso, symname)) == NULL) {
                DSOerror(DSO_R_SYM_FAILURE);
                return (NULL);
        }
        /* Success */
        return (ret);
}

/* I don't really like these *_ctrl functions very much to be perfectly
 * honest. For one thing, I think I have to return a negative value for
 * any error because possible DSO_ctrl() commands may return values
 * such as "size"s that can legitimately be zero (making the standard
 * "if(DSO_cmd(...))" form that works almost everywhere else fail at
 * odd times. I'd prefer "output" values to be passed by reference and
 * the return value as success/failure like usual ... but we conform
 * when we must... :-) */
long
DSO_ctrl(DSO *dso, int cmd, long larg, void *parg)
{
        if (dso == NULL) {
                DSOerror(ERR_R_PASSED_NULL_PARAMETER);
                return (-1);
        }
        /* We should intercept certain generic commands and only pass control
         * to the method-specific ctrl() function if it's something we don't
         * handle. */
        switch (cmd) {
        case DSO_CTRL_GET_FLAGS:
                return dso->flags;
        case DSO_CTRL_SET_FLAGS:
                dso->flags = (int)larg;
                return (0);
        case DSO_CTRL_OR_FLAGS:
                dso->flags |= (int)larg;
                return (0);
        default:
                break;
        }
        if ((dso->meth == NULL) || (dso->meth->dso_ctrl == NULL)) {
                DSOerror(DSO_R_UNSUPPORTED);
                return (-1);
        }
        return (dso->meth->dso_ctrl(dso, cmd, larg, parg));
}

int
DSO_set_name_converter(DSO *dso, DSO_NAME_CONVERTER_FUNC cb,
    DSO_NAME_CONVERTER_FUNC *oldcb)
{
        if (dso == NULL) {
                DSOerror(ERR_R_PASSED_NULL_PARAMETER);
                return (0);
        }
        if (oldcb)
                *oldcb = dso->name_converter;
        dso->name_converter = cb;
        return (1);
}

const char *
DSO_get_filename(DSO *dso)
{
        if (dso == NULL) {
                DSOerror(ERR_R_PASSED_NULL_PARAMETER);
                return (NULL);
        }
        return (dso->filename);
}

int
DSO_set_filename(DSO *dso, const char *filename)
{
        char *copied;

        if ((dso == NULL) || (filename == NULL)) {
                DSOerror(ERR_R_PASSED_NULL_PARAMETER);
                return (0);
        }
        if (dso->loaded_filename) {
                DSOerror(DSO_R_DSO_ALREADY_LOADED);
                return (0);
        }
        /* We'll duplicate filename */
        copied = strdup(filename);
        if (copied == NULL) {
                DSOerror(ERR_R_MALLOC_FAILURE);
                return (0);
        }
        free(dso->filename);
        dso->filename = copied;
        return (1);
}

char *
DSO_merge(DSO *dso, const char *filespec1, const char *filespec2)
{
        char *result = NULL;

        if (dso == NULL || filespec1 == NULL) {
                DSOerror(ERR_R_PASSED_NULL_PARAMETER);
                return (NULL);
        }
        if ((dso->flags & DSO_FLAG_NO_NAME_TRANSLATION) == 0) {
                if (dso->merger != NULL)
                        result = dso->merger(dso, filespec1, filespec2);
                else if (dso->meth->dso_merger != NULL)
                        result = dso->meth->dso_merger(dso,
                            filespec1, filespec2);
        }
        return (result);
}

char *
DSO_convert_filename(DSO *dso, const char *filename)
{
        char *result = NULL;

        if (dso == NULL) {
                DSOerror(ERR_R_PASSED_NULL_PARAMETER);
                return (NULL);
        }
        if (filename == NULL)
                filename = dso->filename;
        if (filename == NULL) {
                DSOerror(DSO_R_NO_FILENAME);
                return (NULL);
        }
        if ((dso->flags & DSO_FLAG_NO_NAME_TRANSLATION) == 0) {
                if (dso->name_converter != NULL)
                        result = dso->name_converter(dso, filename);
                else if (dso->meth->dso_name_converter != NULL)
                        result = dso->meth->dso_name_converter(dso, filename);
        }
        if (result == NULL) {
                result = strdup(filename);
                if (result == NULL) {
                        DSOerror(ERR_R_MALLOC_FAILURE);
                        return (NULL);
                }
        }
        return (result);
}

const char *
DSO_get_loaded_filename(DSO *dso)
{
        if (dso == NULL) {
                DSOerror(ERR_R_PASSED_NULL_PARAMETER);
                return (NULL);
        }
        return (dso->loaded_filename);
}

int
DSO_pathbyaddr(void *addr, char *path, int sz)
{
        DSO_METHOD *meth = default_DSO_meth;
        if (meth == NULL)
                meth = DSO_METHOD_openssl();
        if (meth->pathbyaddr == NULL) {
                DSOerror(DSO_R_UNSUPPORTED);
                return -1;
        }
        return (*meth->pathbyaddr)(addr, path, sz);
}

void *
DSO_global_lookup(const char *name)
{
        DSO_METHOD *meth = default_DSO_meth;
        if (meth == NULL)
                meth = DSO_METHOD_openssl();
        if (meth->globallookup == NULL) {
                DSOerror(DSO_R_UNSUPPORTED);
                return NULL;
        }
        return (*meth->globallookup)(name);
}