/*

 * Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the OpenSSL license (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 "dso_locl.h"

#include "internal/refcount.h"

static DSO_METHOD *default_DSO_meth = NULL;

static 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 = OPENSSL_zalloc(sizeof(*ret));

    if (ret == NULL) {

        DSOerr(DSO_F_DSO_NEW_METHOD, 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 */

        DSOerr(DSO_F_DSO_NEW_METHOD, ERR_R_MALLOC_FAILURE);

        OPENSSL_free(ret);

        return NULL;

    }

    ret->meth = default_DSO_meth;

    ret->references = 1;

    ret->lock = CRYPTO_THREAD_lock_new();

    if (ret->lock == NULL) {

        DSOerr(DSO_F_DSO_NEW_METHOD, ERR_R_MALLOC_FAILURE);

        sk_void_free(ret->meth_data);

        OPENSSL_free(ret);

        return NULL;

    }

    if ((ret->meth->init != NULL) && !ret->meth->init(ret)) {

        DSO_free(ret);

        ret = NULL;

    }

    return ret;

}

DSO *DSO_new(void)

{

    return DSO_new_method(NULL);

}

int DSO_free(DSO *dso)

{

    int i;

    if (dso == NULL)

        return 1;

    if (CRYPTO_DOWN_REF(&dso->references, &i, dso->lock) <= 0)

        return 0;

    REF_PRINT_COUNT("DSO", dso);

    if (i > 0)

        return 1;

    REF_ASSERT_ISNT(i < 0);

    if ((dso->flags & DSO_FLAG_NO_UNLOAD_ON_FREE) == 0) {

        if ((dso->meth->dso_unload != NULL) && !dso->meth->dso_unload(dso)) {

            DSOerr(DSO_F_DSO_FREE, DSO_R_UNLOAD_FAILED);

            return 0;

        }

    }

    if ((dso->meth->finish != NULL) && !dso->meth->finish(dso)) {

        DSOerr(DSO_F_DSO_FREE, DSO_R_FINISH_FAILED);

        return 0;

    }

    sk_void_free(dso->meth_data);

    OPENSSL_free(dso->filename);

    OPENSSL_free(dso->loaded_filename);

    CRYPTO_THREAD_lock_free(dso->lock);

    OPENSSL_free(dso);

    return 1;

}

int DSO_flags(DSO *dso)

{

    return ((dso == NULL) ? 0 : dso->flags);

}

int DSO_up_ref(DSO *dso)

{

    int i;

    if (dso == NULL) {

        DSOerr(DSO_F_DSO_UP_REF, ERR_R_PASSED_NULL_PARAMETER);

        return 0;

    }

    if (CRYPTO_UP_REF(&dso->references, &i, dso->lock) <= 0)

        return 0;

    REF_PRINT_COUNT("DSO", r);

    REF_ASSERT_ISNT(i < 2);

    return ((i > 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) {

            DSOerr(DSO_F_DSO_LOAD, 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) {

            DSOerr(DSO_F_DSO_LOAD, DSO_R_CTRL_FAILED);

            goto err;

        }

    } else

        ret = dso;

    /* Don't load if we're currently already loaded */

    if (ret->filename != NULL) {

        DSOerr(DSO_F_DSO_LOAD, 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)) {

            DSOerr(DSO_F_DSO_LOAD, DSO_R_SET_FILENAME_FAILED);

            goto err;

        }

    filename = ret->filename;

    if (filename == NULL) {

        DSOerr(DSO_F_DSO_LOAD, DSO_R_NO_FILENAME);

        goto err;

    }

    if (ret->meth->dso_load == NULL) {

        DSOerr(DSO_F_DSO_LOAD, DSO_R_UNSUPPORTED);

        goto err;

    }

    if (!ret->meth->dso_load(ret)) {

        DSOerr(DSO_F_DSO_LOAD, DSO_R_LOAD_FAILED);

        goto err;

    }

    /* Load succeeded */

    return ret;

 err:

    if (allocated)

        DSO_free(ret);

    return NULL;

}

DSO_FUNC_TYPE DSO_bind_func(DSO *dso, const char *symname)

{

    DSO_FUNC_TYPE ret = NULL;

    if ((dso == NULL) || (symname == NULL)) {

        DSOerr(DSO_F_DSO_BIND_FUNC, ERR_R_PASSED_NULL_PARAMETER);

        return NULL;

    }

    if (dso->meth->dso_bind_func == NULL) {

        DSOerr(DSO_F_DSO_BIND_FUNC, DSO_R_UNSUPPORTED);

        return NULL;

    }

    if ((ret = dso->meth->dso_bind_func(dso, symname)) == NULL) {

        DSOerr(DSO_F_DSO_BIND_FUNC, 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) {

        DSOerr(DSO_F_DSO_CTRL, 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)) {

        DSOerr(DSO_F_DSO_CTRL, DSO_R_UNSUPPORTED);

        return -1;

    }

    return dso->meth->dso_ctrl(dso, cmd, larg, parg);

}

const char *DSO_get_filename(DSO *dso)

{

    if (dso == NULL) {

        DSOerr(DSO_F_DSO_GET_FILENAME, 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)) {

        DSOerr(DSO_F_DSO_SET_FILENAME, ERR_R_PASSED_NULL_PARAMETER);

        return 0;

    }

    if (dso->loaded_filename) {

        DSOerr(DSO_F_DSO_SET_FILENAME, DSO_R_DSO_ALREADY_LOADED);

        return 0;

    }

    /* We'll duplicate filename */

    copied = OPENSSL_strdup(filename);

    if (copied == NULL) {

        DSOerr(DSO_F_DSO_SET_FILENAME, ERR_R_MALLOC_FAILURE);

        return 0;

    }

    OPENSSL_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) {

        DSOerr(DSO_F_DSO_MERGE, 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) {

        DSOerr(DSO_F_DSO_CONVERT_FILENAME, ERR_R_PASSED_NULL_PARAMETER);

        return NULL;

    }

    if (filename == NULL)

        filename = dso->filename;

    if (filename == NULL) {

        DSOerr(DSO_F_DSO_CONVERT_FILENAME, 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 = OPENSSL_strdup(filename);

        if (result == NULL) {

            DSOerr(DSO_F_DSO_CONVERT_FILENAME, ERR_R_MALLOC_FAILURE);

            return NULL;

        }

    }

    return result;

}

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) {

        DSOerr(DSO_F_DSO_PATHBYADDR, DSO_R_UNSUPPORTED);

        return -1;

    }

    return (*meth->pathbyaddr) (addr, path, sz);

}

DSO *DSO_dsobyaddr(void *addr, int flags)

{

    DSO *ret = NULL;

    char *filename = NULL;

    int len = DSO_pathbyaddr(addr, NULL, 0);

    if (len < 0)

        return NULL;

    filename = OPENSSL_malloc(len);

    if (filename != NULL

            && DSO_pathbyaddr(addr, filename, len) == len)

        ret = DSO_load(NULL, filename, NULL, flags);

    OPENSSL_free(filename);

    return ret;

}

void *DSO_global_lookup(const char *name)

{

    DSO_METHOD *meth = default_DSO_meth;

    if (meth == NULL)

        meth = DSO_METHOD_openssl();

    if (meth->globallookup == NULL) {

        DSOerr(DSO_F_DSO_GLOBAL_LOOKUP, DSO_R_UNSUPPORTED);

        return NULL;

    }

    return (*meth->globallookup) (name);

}