448 lines
10 KiB
C
448 lines
10 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* net/sched/act_ipt.c iptables target interface
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*
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*TODO: Add other tables. For now we only support the ipv4 table targets
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*
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* Copyright: Jamal Hadi Salim (2002-13)
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*/
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/string.h>
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#include <linux/errno.h>
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#include <linux/skbuff.h>
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#include <linux/rtnetlink.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <net/netlink.h>
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#include <net/pkt_sched.h>
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#include <linux/tc_act/tc_ipt.h>
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#include <net/tc_act/tc_ipt.h>
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#include <linux/netfilter_ipv4/ip_tables.h>
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static unsigned int ipt_net_id;
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static struct tc_action_ops act_ipt_ops;
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static unsigned int xt_net_id;
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static struct tc_action_ops act_xt_ops;
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static int ipt_init_target(struct net *net, struct xt_entry_target *t,
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char *table, unsigned int hook)
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{
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struct xt_tgchk_param par;
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struct xt_target *target;
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struct ipt_entry e = {};
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int ret = 0;
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target = xt_request_find_target(AF_INET, t->u.user.name,
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t->u.user.revision);
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if (IS_ERR(target))
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return PTR_ERR(target);
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t->u.kernel.target = target;
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memset(&par, 0, sizeof(par));
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par.net = net;
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par.table = table;
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par.entryinfo = &e;
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par.target = target;
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par.targinfo = t->data;
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par.hook_mask = hook;
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par.family = NFPROTO_IPV4;
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ret = xt_check_target(&par, t->u.target_size - sizeof(*t), 0, false);
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if (ret < 0) {
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module_put(t->u.kernel.target->me);
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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 ipt_destroy_target(struct xt_entry_target *t, struct net *net)
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{
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struct xt_tgdtor_param par = {
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.target = t->u.kernel.target,
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.targinfo = t->data,
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.family = NFPROTO_IPV4,
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.net = net,
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};
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if (par.target->destroy != NULL)
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par.target->destroy(&par);
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module_put(par.target->me);
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}
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static void tcf_ipt_release(struct tc_action *a)
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{
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struct tcf_ipt *ipt = to_ipt(a);
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if (ipt->tcfi_t) {
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ipt_destroy_target(ipt->tcfi_t, a->idrinfo->net);
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kfree(ipt->tcfi_t);
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}
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kfree(ipt->tcfi_tname);
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}
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static const struct nla_policy ipt_policy[TCA_IPT_MAX + 1] = {
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[TCA_IPT_TABLE] = { .type = NLA_STRING, .len = IFNAMSIZ },
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[TCA_IPT_HOOK] = { .type = NLA_U32 },
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[TCA_IPT_INDEX] = { .type = NLA_U32 },
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[TCA_IPT_TARG] = { .len = sizeof(struct xt_entry_target) },
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};
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static int __tcf_ipt_init(struct net *net, unsigned int id, struct nlattr *nla,
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struct nlattr *est, struct tc_action **a,
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const struct tc_action_ops *ops,
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struct tcf_proto *tp, u32 flags)
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{
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struct tc_action_net *tn = net_generic(net, id);
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bool bind = flags & TCA_ACT_FLAGS_BIND;
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struct nlattr *tb[TCA_IPT_MAX + 1];
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struct tcf_ipt *ipt;
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struct xt_entry_target *td, *t;
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char *tname;
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bool exists = false;
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int ret = 0, err;
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u32 hook = 0;
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u32 index = 0;
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if (nla == NULL)
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return -EINVAL;
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err = nla_parse_nested_deprecated(tb, TCA_IPT_MAX, nla, ipt_policy,
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NULL);
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if (err < 0)
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return err;
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if (tb[TCA_IPT_INDEX] != NULL)
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index = nla_get_u32(tb[TCA_IPT_INDEX]);
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err = tcf_idr_check_alloc(tn, &index, a, bind);
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if (err < 0)
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return err;
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exists = err;
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if (exists && bind)
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return 0;
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if (tb[TCA_IPT_HOOK] == NULL || tb[TCA_IPT_TARG] == NULL) {
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if (exists)
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tcf_idr_release(*a, bind);
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else
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tcf_idr_cleanup(tn, index);
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return -EINVAL;
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}
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td = (struct xt_entry_target *)nla_data(tb[TCA_IPT_TARG]);
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if (nla_len(tb[TCA_IPT_TARG]) != td->u.target_size) {
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if (exists)
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tcf_idr_release(*a, bind);
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else
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tcf_idr_cleanup(tn, index);
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return -EINVAL;
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}
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if (!exists) {
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ret = tcf_idr_create(tn, index, est, a, ops, bind,
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false, flags);
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if (ret) {
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tcf_idr_cleanup(tn, index);
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return ret;
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}
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ret = ACT_P_CREATED;
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} else {
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if (bind)/* dont override defaults */
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return 0;
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if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
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tcf_idr_release(*a, bind);
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return -EEXIST;
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}
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}
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hook = nla_get_u32(tb[TCA_IPT_HOOK]);
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err = -ENOMEM;
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tname = kmalloc(IFNAMSIZ, GFP_KERNEL);
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if (unlikely(!tname))
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goto err1;
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if (tb[TCA_IPT_TABLE] == NULL ||
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nla_strscpy(tname, tb[TCA_IPT_TABLE], IFNAMSIZ) >= IFNAMSIZ)
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strcpy(tname, "mangle");
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t = kmemdup(td, td->u.target_size, GFP_KERNEL);
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if (unlikely(!t))
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goto err2;
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err = ipt_init_target(net, t, tname, hook);
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if (err < 0)
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goto err3;
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ipt = to_ipt(*a);
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spin_lock_bh(&ipt->tcf_lock);
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if (ret != ACT_P_CREATED) {
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ipt_destroy_target(ipt->tcfi_t, net);
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kfree(ipt->tcfi_tname);
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kfree(ipt->tcfi_t);
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}
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ipt->tcfi_tname = tname;
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ipt->tcfi_t = t;
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ipt->tcfi_hook = hook;
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spin_unlock_bh(&ipt->tcf_lock);
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return ret;
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err3:
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kfree(t);
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err2:
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kfree(tname);
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err1:
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tcf_idr_release(*a, bind);
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return err;
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}
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static int tcf_ipt_init(struct net *net, struct nlattr *nla,
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struct nlattr *est, struct tc_action **a,
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struct tcf_proto *tp,
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u32 flags, struct netlink_ext_ack *extack)
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{
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return __tcf_ipt_init(net, ipt_net_id, nla, est, a, &act_ipt_ops,
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tp, flags);
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}
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static int tcf_xt_init(struct net *net, struct nlattr *nla,
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struct nlattr *est, struct tc_action **a,
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struct tcf_proto *tp,
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u32 flags, struct netlink_ext_ack *extack)
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{
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return __tcf_ipt_init(net, xt_net_id, nla, est, a, &act_xt_ops,
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tp, flags);
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}
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static int tcf_ipt_act(struct sk_buff *skb, const struct tc_action *a,
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struct tcf_result *res)
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{
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int ret = 0, result = 0;
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struct tcf_ipt *ipt = to_ipt(a);
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struct xt_action_param par;
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struct nf_hook_state state = {
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.net = dev_net(skb->dev),
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.in = skb->dev,
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.hook = ipt->tcfi_hook,
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.pf = NFPROTO_IPV4,
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};
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if (skb_unclone(skb, GFP_ATOMIC))
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return TC_ACT_UNSPEC;
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spin_lock(&ipt->tcf_lock);
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tcf_lastuse_update(&ipt->tcf_tm);
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bstats_update(&ipt->tcf_bstats, skb);
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/* yes, we have to worry about both in and out dev
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* worry later - danger - this API seems to have changed
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* from earlier kernels
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*/
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par.state = &state;
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par.target = ipt->tcfi_t->u.kernel.target;
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par.targinfo = ipt->tcfi_t->data;
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ret = par.target->target(skb, &par);
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switch (ret) {
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case NF_ACCEPT:
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result = TC_ACT_OK;
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break;
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case NF_DROP:
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result = TC_ACT_SHOT;
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ipt->tcf_qstats.drops++;
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break;
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case XT_CONTINUE:
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result = TC_ACT_PIPE;
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break;
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default:
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net_notice_ratelimited("tc filter: Bogus netfilter code %d assume ACCEPT\n",
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ret);
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result = TC_ACT_OK;
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break;
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}
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spin_unlock(&ipt->tcf_lock);
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return result;
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}
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static int tcf_ipt_dump(struct sk_buff *skb, struct tc_action *a, int bind,
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int ref)
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{
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unsigned char *b = skb_tail_pointer(skb);
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struct tcf_ipt *ipt = to_ipt(a);
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struct xt_entry_target *t;
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struct tcf_t tm;
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struct tc_cnt c;
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/* for simple targets kernel size == user size
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* user name = target name
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* for foolproof you need to not assume this
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*/
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spin_lock_bh(&ipt->tcf_lock);
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t = kmemdup(ipt->tcfi_t, ipt->tcfi_t->u.user.target_size, GFP_ATOMIC);
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if (unlikely(!t))
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goto nla_put_failure;
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c.bindcnt = atomic_read(&ipt->tcf_bindcnt) - bind;
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c.refcnt = refcount_read(&ipt->tcf_refcnt) - ref;
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strcpy(t->u.user.name, ipt->tcfi_t->u.kernel.target->name);
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if (nla_put(skb, TCA_IPT_TARG, ipt->tcfi_t->u.user.target_size, t) ||
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nla_put_u32(skb, TCA_IPT_INDEX, ipt->tcf_index) ||
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nla_put_u32(skb, TCA_IPT_HOOK, ipt->tcfi_hook) ||
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nla_put(skb, TCA_IPT_CNT, sizeof(struct tc_cnt), &c) ||
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nla_put_string(skb, TCA_IPT_TABLE, ipt->tcfi_tname))
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goto nla_put_failure;
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tcf_tm_dump(&tm, &ipt->tcf_tm);
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if (nla_put_64bit(skb, TCA_IPT_TM, sizeof(tm), &tm, TCA_IPT_PAD))
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goto nla_put_failure;
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spin_unlock_bh(&ipt->tcf_lock);
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kfree(t);
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return skb->len;
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nla_put_failure:
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spin_unlock_bh(&ipt->tcf_lock);
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nlmsg_trim(skb, b);
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kfree(t);
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return -1;
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}
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static int tcf_ipt_walker(struct net *net, struct sk_buff *skb,
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struct netlink_callback *cb, int type,
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const struct tc_action_ops *ops,
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struct netlink_ext_ack *extack)
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{
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struct tc_action_net *tn = net_generic(net, ipt_net_id);
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return tcf_generic_walker(tn, skb, cb, type, ops, extack);
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}
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static int tcf_ipt_search(struct net *net, struct tc_action **a, u32 index)
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{
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struct tc_action_net *tn = net_generic(net, ipt_net_id);
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return tcf_idr_search(tn, a, index);
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}
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static struct tc_action_ops act_ipt_ops = {
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.kind = "ipt",
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.id = TCA_ID_IPT,
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.owner = THIS_MODULE,
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.act = tcf_ipt_act,
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.dump = tcf_ipt_dump,
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.cleanup = tcf_ipt_release,
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.init = tcf_ipt_init,
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.walk = tcf_ipt_walker,
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.lookup = tcf_ipt_search,
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.size = sizeof(struct tcf_ipt),
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};
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static __net_init int ipt_init_net(struct net *net)
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{
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struct tc_action_net *tn = net_generic(net, ipt_net_id);
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return tc_action_net_init(net, tn, &act_ipt_ops);
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}
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static void __net_exit ipt_exit_net(struct list_head *net_list)
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{
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tc_action_net_exit(net_list, ipt_net_id);
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}
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static struct pernet_operations ipt_net_ops = {
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.init = ipt_init_net,
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.exit_batch = ipt_exit_net,
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.id = &ipt_net_id,
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.size = sizeof(struct tc_action_net),
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};
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static int tcf_xt_walker(struct net *net, struct sk_buff *skb,
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struct netlink_callback *cb, int type,
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const struct tc_action_ops *ops,
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struct netlink_ext_ack *extack)
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{
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struct tc_action_net *tn = net_generic(net, xt_net_id);
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return tcf_generic_walker(tn, skb, cb, type, ops, extack);
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}
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static int tcf_xt_search(struct net *net, struct tc_action **a, u32 index)
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{
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struct tc_action_net *tn = net_generic(net, xt_net_id);
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return tcf_idr_search(tn, a, index);
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}
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static struct tc_action_ops act_xt_ops = {
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.kind = "xt",
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.id = TCA_ID_XT,
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.owner = THIS_MODULE,
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.act = tcf_ipt_act,
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.dump = tcf_ipt_dump,
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.cleanup = tcf_ipt_release,
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.init = tcf_xt_init,
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.walk = tcf_xt_walker,
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.lookup = tcf_xt_search,
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.size = sizeof(struct tcf_ipt),
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};
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static __net_init int xt_init_net(struct net *net)
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{
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struct tc_action_net *tn = net_generic(net, xt_net_id);
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return tc_action_net_init(net, tn, &act_xt_ops);
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}
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static void __net_exit xt_exit_net(struct list_head *net_list)
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{
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tc_action_net_exit(net_list, xt_net_id);
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}
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static struct pernet_operations xt_net_ops = {
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.init = xt_init_net,
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.exit_batch = xt_exit_net,
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.id = &xt_net_id,
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.size = sizeof(struct tc_action_net),
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};
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MODULE_AUTHOR("Jamal Hadi Salim(2002-13)");
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MODULE_DESCRIPTION("Iptables target actions");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("act_xt");
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static int __init ipt_init_module(void)
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{
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int ret1, ret2;
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ret1 = tcf_register_action(&act_xt_ops, &xt_net_ops);
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if (ret1 < 0)
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pr_err("Failed to load xt action\n");
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ret2 = tcf_register_action(&act_ipt_ops, &ipt_net_ops);
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if (ret2 < 0)
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pr_err("Failed to load ipt action\n");
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if (ret1 < 0 && ret2 < 0) {
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return ret1;
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} else
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return 0;
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}
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static void __exit ipt_cleanup_module(void)
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{
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tcf_unregister_action(&act_ipt_ops, &ipt_net_ops);
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tcf_unregister_action(&act_xt_ops, &xt_net_ops);
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}
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module_init(ipt_init_module);
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module_exit(ipt_cleanup_module);
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