/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

 * Copyright by The HDF Group.                                               *

 * All rights reserved.                                                      *

 *                                                                           *

 * This file is part of HDF5.  The full HDF5 copyright notice, including     *

 * terms governing use, modification, and redistribution, is contained in    *

 * the COPYING file, which can be found at the root of the source code       *

 * distribution tree, or in https://www.hdfgroup.org/licenses.               *

 * If you do not have access to either file, you may request a copy from     *

 * help@hdfgroup.org.                                                        *

 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/*

 * Purpose: Internal routines for managing plugins.

 *

 */

/****************/

/* Module Setup */

/****************/

#include "H5PLmodule.h" /* This source code file is part of the H5PL module */

/***********/

/* Headers */

/***********/

#include "H5private.h"  /* Generic Functions            */

#include "H5Eprivate.h" /* Error handling               */

#include "H5PLpkg.h"    /* Plugin                       */

#include "H5Zprivate.h" /* Filter pipeline              */

/****************/

/* Local Macros */

/****************/

/******************/

/* Local Typedefs */

/******************/

/********************/

/* Local Prototypes */

/********************/

/*********************/

/* Package Variables */

/*********************/

/*****************************/

/* Library Private Variables */

/*****************************/

/*******************/

/* Local Variables */

/*******************/

/* Bitmask that controls whether classes of plugins

 * (e.g.: filters, VOL drivers) can be loaded.

 */

static unsigned int H5PL_plugin_control_mask_g = H5PL_ALL_PLUGIN;

/* This flag will be set to false if the HDF5_PLUGIN_PRELOAD

 * environment variable was set to H5PL_NO_PLUGIN at

 * package initialization.

 */

static bool H5PL_allow_plugins_g = true;

/*-------------------------------------------------------------------------

 * Function:    H5PL__get_plugin_control_mask

 *

 * Purpose:     Gets the internal plugin control mask value.

 *

 * Return:      SUCCEED/FAIL

 *

 *-------------------------------------------------------------------------

 */

herr_t

H5PL__get_plugin_control_mask(unsigned int *mask /*out*/)

{

    herr_t ret_value = SUCCEED; /* Return value */

    FUNC_ENTER_PACKAGE_NOERR

    /* Check args - Just assert on package functions */

    assert(mask);

    /* Return the mask */

    *mask = H5PL_plugin_control_mask_g;

    FUNC_LEAVE_NOAPI(ret_value)

} /* end H5PL__get_plugin_control_mask() */

/*-------------------------------------------------------------------------

 * Function:    H5PL__set_plugin_control_mask

 *

 * Purpose:     Sets the internal plugin control mask value.

 *

 * Return:      SUCCEED/FAIL

 *

 *-------------------------------------------------------------------------

 */

herr_t

H5PL__set_plugin_control_mask(unsigned int mask)

{

    herr_t ret_value = SUCCEED; /* Return value */

    FUNC_ENTER_PACKAGE_NOERR

    /* Only allow setting this if plugins have not been disabled.

     * XXX: Note that we don't consider this an error, but instead

     *      silently ignore it. We may want to consider this behavior

     *      more carefully.

     */

    if (H5PL_allow_plugins_g)

        H5PL_plugin_control_mask_g = mask;

    FUNC_LEAVE_NOAPI(ret_value)

} /* end H5PL__set_plugin_control_mask() */

/*-------------------------------------------------------------------------

 * Function:    H5PL_init

 *

 * Purpose:     Initialize the interface from some other layer.

 *

 * Return:      Success:        non-negative

 *              Failure:        negative

 *-------------------------------------------------------------------------

 */

herr_t

H5PL_init(void)

{

    char  *env_var   = NULL;

    herr_t ret_value = SUCCEED;

    FUNC_ENTER_NOAPI(FAIL)

    /* Check the environment variable to determine if the user wants

     * to ignore plugins. The special symbol H5PL_NO_PLUGIN (defined in

     * H5PLpublic.h) means we don't want to load plugins.

     */

    if (NULL != (env_var = getenv(HDF5_PLUGIN_PRELOAD)))

        if (!strcmp(env_var, H5PL_NO_PLUGIN)) {

            H5PL_plugin_control_mask_g = 0;

            H5PL_allow_plugins_g       = false;

        }

    /* Create the table of previously-loaded plugins */

    if (H5PL__create_plugin_cache() < 0)

        HGOTO_ERROR(H5E_PLUGIN, H5E_CANTINIT, FAIL, "can't create plugin cache");

    /* Create the table of search paths for dynamic libraries */

    if (H5PL__create_path_table() < 0)

        HGOTO_ERROR(H5E_PLUGIN, H5E_CANTINIT, FAIL, "can't create plugin search path table");

done:

    FUNC_LEAVE_NOAPI(ret_value)

}

/*-------------------------------------------------------------------------

 * Function:    H5PL_term_package

 *

 * Purpose:     Terminate the H5PL interface: release all memory, reset all

 *              global variables to initial values. This only happens if all

 *              types have been destroyed from other interfaces.

 *

 * Return:      Success:    Positive if any action was taken that might

 *                          affect some other interface; zero otherwise

 *              Failure:    Negative

 *

 *-------------------------------------------------------------------------

 */

int

H5PL_term_package(void)

{

    bool already_closed = false;

    int  ret_value      = 0;

    FUNC_ENTER_NOAPI_NOINIT

    /* Close the plugin cache.

     * We need to bump the return value if we did any real work here.

     */

    if (H5PL__close_plugin_cache(&already_closed) < 0)

        HGOTO_ERROR(H5E_PLUGIN, H5E_CANTFREE, (-1), "problem closing plugin cache");

    if (!already_closed)

        ret_value++;

    /* Close the search path table and free the paths */

    if (H5PL__close_path_table() < 0)

        HGOTO_ERROR(H5E_PLUGIN, H5E_CANTFREE, (-1), "problem closing search path table");

done:

    FUNC_LEAVE_NOAPI(ret_value)

} /* end H5PL_term_package() */

/*-------------------------------------------------------------------------

 * Function:    H5PL_load

 *

 * Purpose:     Given the plugin type and identifier, this function searches

 *              for and, if found, loads a dynamic plugin library.

 *

 *              The function searches first in the cached plugins and then

 *              in the paths listed in the path table.

 *

 * Return:      Success:    A pointer to the plugin info

 *              Failure:    NULL

 *

 *-------------------------------------------------------------------------

 */

const void *

H5PL_load(H5PL_type_t type, const H5PL_key_t *key)

{

    H5PL_search_params_t search_params;       /* Plugin search parameters     */

    bool                 found       = false; /* Whether the plugin was found */

    const void          *plugin_info = NULL;  /* Information from the plugin  */

    const void          *ret_value   = NULL;

    FUNC_ENTER_NOAPI(NULL)

    /* Check if plugins can be loaded for this plugin type */

    switch (type) {

        case H5PL_TYPE_FILTER:

            if ((H5PL_plugin_control_mask_g & H5PL_FILTER_PLUGIN) == 0)

                HGOTO_ERROR(H5E_PLUGIN, H5E_CANTLOAD, NULL, "filter plugins disabled");

            break;

        case H5PL_TYPE_VOL:

            if ((H5PL_plugin_control_mask_g & H5PL_VOL_PLUGIN) == 0)

                HGOTO_ERROR(H5E_PLUGIN, H5E_CANTLOAD, NULL,

                            "Virtual Object Layer (VOL) driver plugins disabled");

            break;

        case H5PL_TYPE_VFD:

            if ((H5PL_plugin_control_mask_g & H5PL_VFD_PLUGIN) == 0)

                HGOTO_ERROR(H5E_PLUGIN, H5E_CANTLOAD, NULL, "Virtual File Driver (VFD) plugins disabled");

            break;

        case H5PL_TYPE_ERROR:

        case H5PL_TYPE_NONE:

        default:

            HGOTO_ERROR(H5E_PLUGIN, H5E_CANTLOAD, NULL, "Invalid plugin type specified");

    }

    /* Set up the search parameters */

    search_params.type = type;

    search_params.key  = key;

    /* Search in the table of already loaded plugin libraries */

    if (H5PL__find_plugin_in_cache(&search_params, &found, &plugin_info) < 0)

        HGOTO_ERROR(H5E_PLUGIN, H5E_CANTGET, NULL, "search in plugin cache failed");

    /* If not found, try iterating through the path table to find an appropriate plugin */

    if (!found)

        if (H5PL__find_plugin_in_path_table(&search_params, &found, &plugin_info) < 0)

            HGOTO_ERROR(H5E_PLUGIN, H5E_CANTGET, NULL,

                        "can't find plugin in the paths either set by HDF5_PLUGIN_PATH, or default location, "

                        "or set by H5PLxxx functions");

    /* Set the return value we found the plugin */

    if (found)

        ret_value = plugin_info;

    else

        HGOTO_ERROR(H5E_PLUGIN, H5E_NOTFOUND, NULL,

                    "can't find plugin. Check either HDF5_VOL_CONNECTOR, HDF5_PLUGIN_PATH, default location, "

                    "or path set by H5PLxxx functions");

done:

    FUNC_LEAVE_NOAPI(ret_value)

} /* end H5PL_load() */

/*-------------------------------------------------------------------------

 * Function:    H5PL__open

 *

 * Purpose:     Opens a plugin.

 *

 *              `path` specifies the path to the plugin library file.

 *

 *              `type` specifies the type of plugin being searched for and

 *              will be used to verify that a loaded plugin matches the

 *              type requested. H5PL_TYPE_NONE may be passed, in which case

 *              no plugin type verification is performed. This is most

 *              useful when iterating over available plugins without regard

 *              to their types.

 *

 *              `key` specifies the information that will be used to find a

 *              specific plugin. For filter plugins, this is typically an

 *              integer identifier. For VOL connector and VFD plugins, this

 *              is typically either an integer identifier or a name string.

 *              After a plugin has been opened, this information will be

 *              compared against the relevant information provided by the

 *              plugin to ensure that the plugin is a match. If

 *              H5PL_TYPE_NONE is provided for `type`, then `key` should be

 *              NULL.

 *

 *              On successful open of a plugin, the `success` parameter

 *              will be set to true and the `plugin_type` and `plugin_info`

 *              parameters will be filled appropriately. On failure, the

 *              `success` parameter will be set to false, the `plugin_type`

 *              parameter will be set to H5PL_TYPE_ERROR and the

 *              `plugin_info` parameter will be set to NULL.

 *

 * Return:      SUCCEED/FAIL

 *

 *-------------------------------------------------------------------------

 */

/* NOTE: We turn off -Wpedantic in gcc to quiet a warning about converting

 *       object pointers to function pointers, which is undefined in ANSI C.

 *       This is basically unavoidable due to the nature of dlsym() and *is*

 *       defined in POSIX, so it's fine.

 *

 *       This pragma only needs to surround the assignment of the

 *       get_plugin_info function pointer, but early (4.4.7, at least) gcc

 *       only allows diagnostic pragmas to be toggled outside of functions.

 */

H5_GCC_CLANG_DIAG_OFF("pedantic")

herr_t

H5PL__open(const char *path, H5PL_type_t type, const H5PL_key_t *key, bool *success, H5PL_type_t *plugin_type,

           const void **plugin_info)

{

    H5PL_HANDLE            handle          = NULL;

    H5PL_get_plugin_type_t get_plugin_type = NULL;

    H5PL_get_plugin_info_t get_plugin_info = NULL;

    H5PL_type_t            loaded_plugin_type;

    H5PL_key_t             tmp_key;

    herr_t                 ret_value = SUCCEED;

    FUNC_ENTER_PACKAGE

    /* Check args - Just assert on package functions */

    assert(path);

    if (type == H5PL_TYPE_NONE)

        assert(!key);

    assert(success);

    assert(plugin_info);

    /* Initialize out parameters */

    *success     = false;

    *plugin_info = NULL;

    if (plugin_type)

        *plugin_type = H5PL_TYPE_ERROR;

    /* There are different reasons why a library can't be open, e.g. wrong architecture.

     * If we can't open the library, just return.

     */

    if (NULL == (handle = H5PL_OPEN_DLIB(path))) {

        H5PL_CLR_ERROR; /* clear error */

        HGOTO_DONE(SUCCEED);

    }

    /* Return a handle for the function H5PLget_plugin_type in the dynamic library.

     * The plugin library is supposed to define this function.

     */

    if (NULL == (get_plugin_type = (H5PL_get_plugin_type_t)H5PL_GET_LIB_FUNC(handle, "H5PLget_plugin_type")))

        HGOTO_DONE(SUCCEED);

    /* Return a handle for the function H5PLget_plugin_info in the dynamic library.

     * The plugin library is supposed to define this function.

     */

    if (NULL == (get_plugin_info = (H5PL_get_plugin_info_t)H5PL_GET_LIB_FUNC(handle, "H5PLget_plugin_info")))

        HGOTO_DONE(SUCCEED);

    /* Check the plugin type and return if it doesn't match the one passed in */

    loaded_plugin_type = (H5PL_type_t)(*get_plugin_type)();

    if ((type != H5PL_TYPE_NONE) && (type != loaded_plugin_type))

        HGOTO_DONE(SUCCEED);

    /* Get the plugin information */

    switch (loaded_plugin_type) {

        case H5PL_TYPE_FILTER: {

            const H5Z_class2_t *filter_info;

            /* Get the plugin info */

            if (NULL == (filter_info = (const H5Z_class2_t *)(*get_plugin_info)()))

                HGOTO_ERROR(H5E_PLUGIN, H5E_CANTGET, FAIL, "can't get filter info from plugin");

            /* Setup temporary plugin key if one wasn't supplied */

            if (!key) {

                tmp_key.id = filter_info->id;

                key        = &tmp_key;

            }

            /* If the filter IDs match, we're done. Set the output parameters. */

            if (filter_info->id == key->id) {

                if (plugin_type)

                    *plugin_type = H5PL_TYPE_FILTER;

                *plugin_info = (const void *)filter_info;

                *success     = true;

            }

            break;

        }

        case H5PL_TYPE_VOL: {

            const void *cls;

            /* Get the plugin info */

            if (NULL == (cls = (const void *)(*get_plugin_info)()))

                HGOTO_ERROR(H5E_PLUGIN, H5E_CANTGET, FAIL, "can't get VOL connector info from plugin");

            /* Setup temporary plugin key if one wasn't supplied */

            if (!key) {

                tmp_key.vol.kind   = H5VL_GET_CONNECTOR_BY_NAME;

                tmp_key.vol.u.name = ((const H5VL_class_t *)cls)->name;

                key                = &tmp_key;

            }

            /* Ask VOL interface if this class is the one we are looking for and is compatible, etc */

            if (H5VL_check_plugin_load(cls, key, success) < 0)

                HGOTO_ERROR(H5E_PLUGIN, H5E_CANTLOAD, FAIL, "VOL connector compatibility check failed");

            /* Check for finding the correct plugin */

            if (*success) {

                if (plugin_type)

                    *plugin_type = H5PL_TYPE_VOL;

                *plugin_info = cls;

            }

            break;

        }

        case H5PL_TYPE_VFD: {

            const void *cls;

            /* Get the plugin info */

            if (NULL == (cls = (const void *)(*get_plugin_info)()))

                HGOTO_ERROR(H5E_PLUGIN, H5E_CANTGET, FAIL, "can't get VFD info from plugin");

            /* Setup temporary plugin key if one wasn't supplied */

            if (!key) {

                tmp_key.vfd.kind   = H5FD_GET_DRIVER_BY_NAME;

                tmp_key.vfd.u.name = ((const H5FD_class_t *)cls)->name;

                key                = &tmp_key;

            }

            /* Ask VFD interface if this class is the one we are looking for and is compatible, etc */

            if (H5FD_check_plugin_load(cls, key, success) < 0)

                HGOTO_ERROR(H5E_PLUGIN, H5E_CANTLOAD, FAIL, "VFD compatibility check failed");

            /* Check for finding the correct plugin */

            if (*success) {

                if (plugin_type)

                    *plugin_type = H5PL_TYPE_VFD;

                *plugin_info = cls;

            }

            break;

        }

        case H5PL_TYPE_ERROR:

        case H5PL_TYPE_NONE:

        default:

            HGOTO_ERROR(H5E_PLUGIN, H5E_CANTGET, FAIL, "Invalid plugin type specified");

    } /* end switch */

    /* If we found the correct plugin, store it in the cache */

    if (*success)

        if (H5PL__add_plugin(loaded_plugin_type, key, handle))

            HGOTO_ERROR(H5E_PLUGIN, H5E_CANTINSERT, FAIL, "unable to add new plugin to plugin cache");

done:

    if (!(*success) && handle)

        if (H5PL__close(handle) < 0)

            HDONE_ERROR(H5E_PLUGIN, H5E_CLOSEERROR, FAIL, "can't close dynamic library");

    FUNC_LEAVE_NOAPI(ret_value)

} /* end H5PL__open() */

H5_GCC_CLANG_DIAG_ON("pedantic")

/*-------------------------------------------------------------------------

 * Function:    H5PL__close

 *

 * Purpose:     Closes the handle for dynamic library

 *

 * Return:      SUCCEED/FAIL

 *

 *-------------------------------------------------------------------------

 */

herr_t

H5PL__close(H5PL_HANDLE handle)

{

    FUNC_ENTER_PACKAGE_NOERR

    H5PL_CLOSE_LIB(handle);

    FUNC_LEAVE_NOAPI(SUCCEED)

} /* end H5PL__close() */

/*-------------------------------------------------------------------------

 * Function:    H5PL_iterate

 *

 * Purpose:     Iterates over all the available plugins and calls the

 *              specified callback function on each plugin.

 *

 * Return:      H5_ITER_CONT if all plugins are processed successfully

 *              H5_ITER_STOP if short-circuit success occurs while

 *                  processing plugins

 *              H5_ITER_ERROR if an error occurs while processing plugins

 *

 *-------------------------------------------------------------------------

 */

herr_t

H5PL_iterate(H5PL_iterate_type_t iter_type, H5PL_iterate_t iter_op, void *op_data)

{

    herr_t ret_value = H5_ITER_CONT;

    FUNC_ENTER_NOAPI_NOERR

    ret_value = H5PL__path_table_iterate(iter_type, iter_op, op_data);

    FUNC_LEAVE_NOAPI(ret_value)

} /* end H5PL_iterate() */