lib/route/link/api.c

/*
 * lib/route/link/api.c         Link Info API
 *
 *      This library is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU Lesser General Public
 *      License as published by the Free Software Foundation version 2.1
 *      of the License.
 *
 * Copyright (c) 2003-2008 Thomas Graf <tgraf@suug.ch>
 */

/**
 * @ingroup link
 * @defgroup link_info Link Info API
 * @brief
 *
 * @par 1) Registering/Unregistering a new link info type
 * @code
 * static struct rtnl_link_info_ops vlan_info_ops = {
 *      .io_name                = "vlan",
 *      .io_alloc               = vlan_alloc,
 *      .io_parse               = vlan_parse,
 *      .io_dump[NL_DUMP_BRIEF] = vlan_dump_brief,
 *      .io_dump[NL_DUMP_FULL]  = vlan_dump_full,
 *      .io_free                = vlan_free,
 * };
 *
 * static void __init vlan_init(void)
 * {
 *      rtnl_link_register_info(&vlan_info_ops);
 * }
 *
 * static void __exit vlan_exit(void)
 * {
 *      rtnl_link_unregister_info(&vlan_info_ops);
 * }
 * @endcode
 *
 * @{
 */

#include <netlink-local.h>
#include <netlink/netlink.h>
#include <netlink/utils.h>
#include <netlink/route/link.h>
#include <netlink/route/link/info-api.h>

static struct rtnl_link_info_ops *info_ops;

struct rtnl_link_info_ops *rtnl_link_info_ops_lookup(const char *name)
{
        struct rtnl_link_info_ops *ops;

        for (ops = info_ops; ops; ops = ops->io_next)
                if (!strcmp(ops->io_name, name))
                        return ops;

        return NULL;
}

int rtnl_link_register_info(struct rtnl_link_info_ops *ops)
{
        if (ops->io_name == NULL)
                return nl_error(EINVAL, "No name specified");

        if (rtnl_link_info_ops_lookup(ops->io_name))
                return nl_error(EEXIST, "Link info operations already exist");

        NL_DBG(1, "Registered link info operations %s\n", ops->io_name);

        ops->io_next = info_ops;
        info_ops = ops;

        return 0;
}

int rtnl_link_unregister_info(struct rtnl_link_info_ops *ops)
{
        struct rtnl_link_info_ops *t, **tp;

        for (tp = &info_ops; (t=*tp) != NULL; tp = &t->io_next)
                if (t == ops)
                        break;

        if (!t)
                return nl_error(ENOENT, "No such link info operations");

        if (t->io_refcnt > 0)
                return nl_error(EBUSY, "Info operations in use");

        NL_DBG(1, "Unregistered link info perations %s\n", ops->io_name);

        *tp = t->io_next;
        return 0;
}

/** @} */

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