root/net/bridge/netfilter/ebtable_broute.c

DEFINITIONS

1. check
2. ebt_broute
3. ebtable_broute_init
4. ebtable_broute_fini

/*
 *  ebtable_broute
 *
 *      Authors:
 *      Bart De Schuymer <bdschuym@pandora.be>
 *
 *  April, 2002
 *
 *  This table lets you choose between routing and bridging for frames
 *  entering on a bridge enslaved nic. This table is traversed before any
 *  other ebtables table. See net/bridge/br_input.c.
 */

#include <linux/netfilter_bridge/ebtables.h>
#include <linux/module.h>
#include <linux/if_bridge.h>

/* EBT_ACCEPT means the frame will be bridged
 * EBT_DROP means the frame will be routed
 */
static struct ebt_entries initial_chain = {
        .name           = "BROUTING",
        .policy         = EBT_ACCEPT,
};

static struct ebt_replace_kernel initial_table =
{
        .name           = "broute",
        .valid_hooks    = 1 << NF_BR_BROUTING,
        .entries_size   = sizeof(struct ebt_entries),
        .hook_entry     = {
                [NF_BR_BROUTING]        = &initial_chain,
        },
        .entries        = (char *)&initial_chain,
};

static int check(const struct ebt_table_info *info, unsigned int valid_hooks)
{
        if (valid_hooks & ~(1 << NF_BR_BROUTING))
                return -EINVAL;
        return 0;
}

static struct ebt_table broute_table =
{
        .name           = "broute",
        .table          = &initial_table,
        .valid_hooks    = 1 << NF_BR_BROUTING,
        .lock           = __RW_LOCK_UNLOCKED(broute_table.lock),
        .check          = check,
        .me             = THIS_MODULE,
};

static int ebt_broute(struct sk_buff *skb)
{
        int ret;

        ret = ebt_do_table(NF_BR_BROUTING, skb, skb->dev, NULL,
           &broute_table);
        if (ret == NF_DROP)
                return 1; /* route it */
        return 0; /* bridge it */
}

static int __init ebtable_broute_init(void)
{
        int ret;

        ret = ebt_register_table(&broute_table);
        if (ret < 0)
                return ret;
        /* see br_input.c */
        rcu_assign_pointer(br_should_route_hook, ebt_broute);
        return ret;
}

static void __exit ebtable_broute_fini(void)
{
        rcu_assign_pointer(br_should_route_hook, NULL);
        synchronize_net();
        ebt_unregister_table(&broute_table);
}

module_init(ebtable_broute_init);
module_exit(ebtable_broute_fini);
MODULE_LICENSE("GPL");