235 lines
6.0 KiB
C
235 lines
6.0 KiB
C
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/*
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* xt_connmark - Netfilter module to operate on connection marks
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*
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* Copyright (C) 2002,2004 MARA Systems AB <http://www.marasystems.com>
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* by Henrik Nordstrom <hno@marasystems.com>
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* Copyright © CC Computer Consultants GmbH, 2007 - 2008
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* Jan Engelhardt <jengelh@medozas.de>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <net/netfilter/nf_conntrack.h>
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#include <net/netfilter/nf_conntrack_ecache.h>
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#include <linux/netfilter/x_tables.h>
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#include <linux/netfilter/xt_connmark.h>
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// ------------- START of KNOX_VPN ------------------//
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#include <linux/types.h>
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#include <linux/tcp.h>
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#include <linux/ip.h>
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#include <net/ip.h>
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// ------------- END of KNOX_VPN -------------------//
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MODULE_AUTHOR("Henrik Nordstrom <hno@marasystems.com>");
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MODULE_DESCRIPTION("Xtables: connection mark operations");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("ipt_CONNMARK");
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MODULE_ALIAS("ip6t_CONNMARK");
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MODULE_ALIAS("ipt_connmark");
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MODULE_ALIAS("ip6t_connmark");
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// ------------- START of KNOX_VPN ------------------//
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/* KNOX framework uses mark value 100 to 500
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* when the special meta data is added
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* This will indicate to the kernel code that
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* it needs to append meta data to the packets
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*/
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#define META_MARK_BASE_LOWER 100
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#define META_MARK_BASE_UPPER 500
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/* Structure to hold metadata values
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* intended for VPN clients to make
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* more intelligent decisions
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* when the KNOX meta mark
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* feature is enabled
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*/
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struct knox_meta_param {
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uid_t uid;
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pid_t pid;
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};
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static unsigned int knoxvpn_uidpid(struct sk_buff *skb, u_int32_t newmark)
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{
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int szMetaData;
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struct skb_shared_info *knox_shinfo = NULL;
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szMetaData = sizeof(struct knox_meta_param);
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if (skb != NULL) {
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knox_shinfo = skb_shinfo(skb);
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} else {
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pr_err("KNOX: NULL SKB - no KNOX processing");
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return -1;
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}
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if( skb->sk == NULL) {
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pr_err("KNOX: skb->sk value is null");
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return -1;
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}
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if( knox_shinfo == NULL) {
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pr_err("KNOX: knox_shinfo is null");
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return -1;
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}
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if (newmark < META_MARK_BASE_LOWER || newmark > META_MARK_BASE_UPPER) {
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pr_err("KNOX: The mark is out of range");
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return -1;
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} else {
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knox_shinfo->uid = skb->sk->knox_uid;
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knox_shinfo->pid = skb->sk->knox_pid;
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knox_shinfo->knox_mark = newmark;
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}
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return 0;
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}
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// ------------- END of KNOX_VPN -------------------//
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static unsigned int
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connmark_tg(struct sk_buff *skb, const struct xt_action_param *par)
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{
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const struct xt_connmark_tginfo1 *info = par->targinfo;
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enum ip_conntrack_info ctinfo;
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struct nf_conn *ct;
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u_int32_t newmark;
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ct = nf_ct_get(skb, &ctinfo);
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if (ct == NULL)
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return XT_CONTINUE;
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switch (info->mode) {
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case XT_CONNMARK_SET:
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newmark = (ct->mark & ~info->ctmask) ^ info->ctmark;
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if (ct->mark != newmark) {
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ct->mark = newmark;
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nf_conntrack_event_cache(IPCT_MARK, ct);
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}
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break;
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case XT_CONNMARK_SAVE:
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newmark = (ct->mark & ~info->ctmask) ^
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(skb->mark & info->nfmask);
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if (ct->mark != newmark) {
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ct->mark = newmark;
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nf_conntrack_event_cache(IPCT_MARK, ct);
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}
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break;
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case XT_CONNMARK_RESTORE:
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newmark = (skb->mark & ~info->nfmask) ^
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(ct->mark & info->ctmask);
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skb->mark = newmark;
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// ------------- START of KNOX_VPN -----------------//
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knoxvpn_uidpid(skb, newmark);
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// ------------- END of KNOX_VPN -------------------//
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break;
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}
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return XT_CONTINUE;
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}
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static int connmark_tg_check(const struct xt_tgchk_param *par)
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{
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int ret;
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ret = nf_ct_netns_get(par->net, par->family);
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if (ret < 0)
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pr_info("cannot load conntrack support for proto=%u\n",
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par->family);
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return ret;
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}
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static void connmark_tg_destroy(const struct xt_tgdtor_param *par)
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{
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nf_ct_netns_put(par->net, par->family);
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}
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static bool
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connmark_mt(const struct sk_buff *skb, struct xt_action_param *par)
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{
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const struct xt_connmark_mtinfo1 *info = par->matchinfo;
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enum ip_conntrack_info ctinfo;
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const struct nf_conn *ct;
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ct = nf_ct_get(skb, &ctinfo);
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if (ct == NULL)
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return false;
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return ((ct->mark & info->mask) == info->mark) ^ info->invert;
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}
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static int connmark_mt_check(const struct xt_mtchk_param *par)
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{
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int ret;
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ret = nf_ct_netns_get(par->net, par->family);
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if (ret < 0)
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pr_info("cannot load conntrack support for proto=%u\n",
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par->family);
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return ret;
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}
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static void connmark_mt_destroy(const struct xt_mtdtor_param *par)
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{
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nf_ct_netns_put(par->net, par->family);
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}
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static struct xt_target connmark_tg_reg __read_mostly = {
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.name = "CONNMARK",
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.revision = 1,
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.family = NFPROTO_UNSPEC,
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.checkentry = connmark_tg_check,
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.target = connmark_tg,
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.targetsize = sizeof(struct xt_connmark_tginfo1),
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.destroy = connmark_tg_destroy,
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.me = THIS_MODULE,
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};
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static struct xt_match connmark_mt_reg __read_mostly = {
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.name = "connmark",
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.revision = 1,
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.family = NFPROTO_UNSPEC,
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.checkentry = connmark_mt_check,
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.match = connmark_mt,
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.matchsize = sizeof(struct xt_connmark_mtinfo1),
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.destroy = connmark_mt_destroy,
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.me = THIS_MODULE,
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};
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static int __init connmark_mt_init(void)
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{
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int ret;
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ret = xt_register_target(&connmark_tg_reg);
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if (ret < 0)
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return ret;
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ret = xt_register_match(&connmark_mt_reg);
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if (ret < 0) {
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xt_unregister_target(&connmark_tg_reg);
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return ret;
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}
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return 0;
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}
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static void __exit connmark_mt_exit(void)
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{
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xt_unregister_match(&connmark_mt_reg);
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xt_unregister_target(&connmark_tg_reg);
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}
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module_init(connmark_mt_init);
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module_exit(connmark_mt_exit);
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