root/sys/modules/examples/properties/properties.c
/*      $NetBSD: properties.c,v 1.1 2015/05/13 07:07:36 pgoyette Exp $  */

/*-
 * Copyright (c) 2008 The NetBSD Foundation, Inc.
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS 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 FOUNDATION OR 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.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: properties.c,v 1.1 2015/05/13 07:07:36 pgoyette Exp $");

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/module.h>

MODULE(MODULE_CLASS_MISC, properties, NULL);

static void
handle_props(prop_dictionary_t props)
{
        const char *msg;
        prop_string_t str;

        if (props != NULL) {
                str = prop_dictionary_get(props, "msg");
        } else {
                printf("No property dictionary was provided.\n");
                str = NULL;
        }
        if (str == NULL)
                printf("The 'msg' property was not given.\n");
        else if (prop_object_type(str) != PROP_TYPE_STRING)
                printf("The 'msg' property is not a string.\n");
        else {
                msg = prop_string_cstring_nocopy(str);
                if (msg == NULL)
                        printf("Failed to process the 'msg' property.\n");
                else
                        printf("The 'msg' property is: %s\n", msg);
        }
}

static int
properties_modcmd(modcmd_t cmd, void *arg)
{
        switch (cmd) {
        case MODULE_CMD_INIT:
                handle_props(arg);
                return 0;
        case MODULE_CMD_FINI:
                return 0;
        default:
                return ENOTTY;
        }
}