/*

 * ID Mapping Plugin interface for cifs-utils

 * Copyright (C) 2012 Jeff Layton (jlayton@samba.org)

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 3 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program.  If not, see <http://www.gnu.org/licenses/>.

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif /* HAVE_CONFIG_H */

#include <dlfcn.h>

#include <errno.h>

#include <stdint.h>

#include <sys/types.h>

#include "cifsidmap.h"

#include "idmap_plugin.h"

const char *plugin_errmsg;

static void *plugin;

static void *

resolve_symbol(const char *symbol_name)

{

	void *symbol;

	dlerror();

	symbol = dlsym(plugin, symbol_name);

	if (!symbol)

		plugin_errmsg = dlerror();

	return symbol;

}

/*

 * open the plugin. Note that we leave it open over the life of the

 * program. It gets closed on exit.

 */

static int

open_plugin(void)

{

	if (plugin)

		return 0;

	plugin = dlopen(IDMAP_PLUGIN_PATH, RTLD_LAZY);

	if (!plugin) {

		plugin_errmsg = dlerror();

		return -EIO;

	}

	return 0;

}

int

init_plugin(void **handle)

{

	int ret;

	int (*init)(void **, const char **);

	ret = open_plugin();

	if (ret)

		return ret;

	init = resolve_symbol("cifs_idmap_init_plugin");

	if (!init) {

		plugin_errmsg = "cifs_idmap_init_plugin not implemented";

		return -ENOSYS;

	}

	return (*init)(handle, &plugin_errmsg);

}

void

exit_plugin(void *handle)

{

	int (*exit)(void *);

	exit = resolve_symbol("cifs_idmap_exit_plugin");

	if (exit)

		(*exit)(handle);

}

int

sid_to_str(void *handle, const struct cifs_sid *sid, char **name)

{

	int (*entry)(void *, const struct cifs_sid *, char **);

	*(void **)(&entry) = resolve_symbol("cifs_idmap_sid_to_str");

	if (!entry) {

		plugin_errmsg = "cifs_idmap_sid_to_str not implemented";

		return -ENOSYS;

	}

	return (*entry)(handle, sid, name);

}

int

str_to_sid(void *handle, const char *name, struct cifs_sid *sid)

{

	int (*entry)(void *, const char *, struct cifs_sid *);

	*(void **)(&entry) = resolve_symbol("cifs_idmap_str_to_sid");

	if (!entry) {

		plugin_errmsg = "cifs_idmap_str_to_sid not implemented";

		return -ENOSYS;

	}

	return (*entry)(handle, name, sid);

}

int

sids_to_ids(void *handle, const struct cifs_sid *sid, const size_t num,

	  struct cifs_uxid *cuxid)

{

	int (*entry)(void *handle, const struct cifs_sid *sids,

			const size_t num, struct cifs_uxid *cuxid);

	*(void **)(&entry) = resolve_symbol("cifs_idmap_sids_to_ids");

	if (!entry) {

		plugin_errmsg = "cifs_idmap_sids_to_ids not implemented";

		return -ENOSYS;

	}

	return (*entry)(handle, sid, num, cuxid);

}

int

ids_to_sids(void *handle, const struct cifs_uxid *cuxid, const size_t num,

		struct cifs_sid *sid)

{

	int (*entry)(void *handle, const struct cifs_uxid *cuxid,

			const size_t num, struct cifs_sid *sid);

	*(void **)(&entry) = resolve_symbol("cifs_idmap_ids_to_sids");

	if (!entry) {

		plugin_errmsg = "cifs_idmap_ids_to_sids not implemented";

		return -ENOSYS;

	}

	return (*entry)(handle, cuxid, num, sid);

}