root/net/netfilter/xt_connmark.c

DEFINITIONS

1. connmark_mt
2. connmark_mt_v0
3. connmark_mt_check_v0
4. connmark_mt_check
5. connmark_mt_destroy
6. connmark_mt_compat_from_user_v0
7. connmark_mt_compat_to_user_v0
8. connmark_mt_init
9. connmark_mt_exit

/*
 *      xt_connmark - Netfilter module to match connection mark values
 *
 *      Copyright (C) 2002,2004 MARA Systems AB <http://www.marasystems.com>
 *      by Henrik Nordstrom <hno@marasystems.com>
 *      Copyright © CC Computer Consultants GmbH, 2007 - 2008
 *      Jan Engelhardt <jengelh@computergmbh.de>
 *
 * 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 2 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/module.h>
#include <linux/skbuff.h>
#include <net/netfilter/nf_conntrack.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_connmark.h>

MODULE_AUTHOR("Henrik Nordstrom <hno@marasystems.com>");
MODULE_DESCRIPTION("Xtables: connection mark match");
MODULE_LICENSE("GPL");
MODULE_ALIAS("ipt_connmark");
MODULE_ALIAS("ip6t_connmark");

static bool
connmark_mt(const struct sk_buff *skb, const struct xt_match_param *par)
{
        const struct xt_connmark_mtinfo1 *info = par->matchinfo;
        enum ip_conntrack_info ctinfo;
        const struct nf_conn *ct;

        ct = nf_ct_get(skb, &ctinfo);
        if (ct == NULL)
                return false;

        return ((ct->mark & info->mask) == info->mark) ^ info->invert;
}

static bool
connmark_mt_v0(const struct sk_buff *skb, const struct xt_match_param *par)
{
        const struct xt_connmark_info *info = par->matchinfo;
        const struct nf_conn *ct;
        enum ip_conntrack_info ctinfo;

        ct = nf_ct_get(skb, &ctinfo);
        if (!ct)
                return false;

        return ((ct->mark & info->mask) == info->mark) ^ info->invert;
}

static bool connmark_mt_check_v0(const struct xt_mtchk_param *par)
{
        const struct xt_connmark_info *cm = par->matchinfo;

        if (cm->mark > 0xffffffff || cm->mask > 0xffffffff) {
                printk(KERN_WARNING "connmark: only support 32bit mark\n");
                return false;
        }
        if (nf_ct_l3proto_try_module_get(par->family) < 0) {
                printk(KERN_WARNING "can't load conntrack support for "
                                    "proto=%u\n", par->family);
                return false;
        }
        return true;
}

static bool connmark_mt_check(const struct xt_mtchk_param *par)
{
        if (nf_ct_l3proto_try_module_get(par->family) < 0) {
                printk(KERN_WARNING "cannot load conntrack support for "
                       "proto=%u\n", par->family);
                return false;
        }
        return true;
}

static void connmark_mt_destroy(const struct xt_mtdtor_param *par)
{
        nf_ct_l3proto_module_put(par->family);
}

#ifdef CONFIG_COMPAT
struct compat_xt_connmark_info {
        compat_ulong_t  mark, mask;
        u_int8_t        invert;
        u_int8_t        __pad1;
        u_int16_t       __pad2;
};

static void connmark_mt_compat_from_user_v0(void *dst, void *src)
{
        const struct compat_xt_connmark_info *cm = src;
        struct xt_connmark_info m = {
                .mark   = cm->mark,
                .mask   = cm->mask,
                .invert = cm->invert,
        };
        memcpy(dst, &m, sizeof(m));
}

static int connmark_mt_compat_to_user_v0(void __user *dst, void *src)
{
        const struct xt_connmark_info *m = src;
        struct compat_xt_connmark_info cm = {
                .mark   = m->mark,
                .mask   = m->mask,
                .invert = m->invert,
        };
        return copy_to_user(dst, &cm, sizeof(cm)) ? -EFAULT : 0;
}
#endif /* CONFIG_COMPAT */

static struct xt_match connmark_mt_reg[] __read_mostly = {
        {
                .name           = "connmark",
                .revision       = 0,
                .family         = NFPROTO_UNSPEC,
                .checkentry     = connmark_mt_check_v0,
                .match          = connmark_mt_v0,
                .destroy        = connmark_mt_destroy,
                .matchsize      = sizeof(struct xt_connmark_info),
#ifdef CONFIG_COMPAT
                .compatsize     = sizeof(struct compat_xt_connmark_info),
                .compat_from_user = connmark_mt_compat_from_user_v0,
                .compat_to_user = connmark_mt_compat_to_user_v0,
#endif
                .me             = THIS_MODULE
        },
        {
                .name           = "connmark",
                .revision       = 1,
                .family         = NFPROTO_UNSPEC,
                .checkentry     = connmark_mt_check,
                .match          = connmark_mt,
                .matchsize      = sizeof(struct xt_connmark_mtinfo1),
                .destroy        = connmark_mt_destroy,
                .me             = THIS_MODULE,
        },
};

static int __init connmark_mt_init(void)
{
        return xt_register_matches(connmark_mt_reg,
               ARRAY_SIZE(connmark_mt_reg));
}

static void __exit connmark_mt_exit(void)
{
        xt_unregister_matches(connmark_mt_reg, ARRAY_SIZE(connmark_mt_reg));
}

module_init(connmark_mt_init);
module_exit(connmark_mt_exit);