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DEFINITIONS
This source file includes following definitions.
- ipt_init_target
- ipt_destroy_target
- tcf_ipt_release
- tcf_ipt_init
- tcf_ipt_cleanup
- tcf_ipt
- tcf_ipt_dump
- ipt_init_module
- ipt_cleanup_module
/*
* net/sched/ipt.c iptables target interface
*
*TODO: Add other tables. For now we only support the ipv4 table targets
*
* 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.
*
* Copyright: Jamal Hadi Salim (2002-4)
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <linux/module.h>
#include <linux/init.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <linux/tc_act/tc_ipt.h>
#include <net/tc_act/tc_ipt.h>
#include <linux/netfilter_ipv4/ip_tables.h>
#define IPT_TAB_MASK 15
static struct tcf_common *tcf_ipt_ht[IPT_TAB_MASK + 1];
static u32 ipt_idx_gen;
static DEFINE_RWLOCK(ipt_lock);
static struct tcf_hashinfo ipt_hash_info = {
.htab = tcf_ipt_ht,
.hmask = IPT_TAB_MASK,
.lock = &ipt_lock,
};
static int ipt_init_target(struct ipt_entry_target *t, char *table, unsigned int hook)
{
struct xt_tgchk_param par;
struct xt_target *target;
int ret = 0;
target = xt_request_find_target(AF_INET, t->u.user.name,
t->u.user.revision);
if (!target)
return -ENOENT;
t->u.kernel.target = target;
par.table = table;
par.entryinfo = NULL;
par.target = target;
par.targinfo = t->data;
par.hook_mask = hook;
par.family = NFPROTO_IPV4;
ret = xt_check_target(&par, t->u.target_size - sizeof(*t), 0, false);
if (ret < 0) {
module_put(t->u.kernel.target->me);
return ret;
}
return 0;
}
static void ipt_destroy_target(struct ipt_entry_target *t)
{
struct xt_tgdtor_param par = {
.target = t->u.kernel.target,
.targinfo = t->data,
};
if (par.target->destroy != NULL)
par.target->destroy(&par);
module_put(par.target->me);
}
static int tcf_ipt_release(struct tcf_ipt *ipt, int bind)
{
int ret = 0;
if (ipt) {
if (bind)
ipt->tcf_bindcnt--;
ipt->tcf_refcnt--;
if (ipt->tcf_bindcnt <= 0 && ipt->tcf_refcnt <= 0) {
ipt_destroy_target(ipt->tcfi_t);
kfree(ipt->tcfi_tname);
kfree(ipt->tcfi_t);
tcf_hash_destroy(&ipt->common, &ipt_hash_info);
ret = ACT_P_DELETED;
}
}
return ret;
}
static const struct nla_policy ipt_policy[TCA_IPT_MAX + 1] = {
[TCA_IPT_TABLE] = { .type = NLA_STRING, .len = IFNAMSIZ },
[TCA_IPT_HOOK] = { .type = NLA_U32 },
[TCA_IPT_INDEX] = { .type = NLA_U32 },
[TCA_IPT_TARG] = { .len = sizeof(struct ipt_entry_target) },
};
static int tcf_ipt_init(struct nlattr *nla, struct nlattr *est,
struct tc_action *a, int ovr, int bind)
{
struct nlattr *tb[TCA_IPT_MAX + 1];
struct tcf_ipt *ipt;
struct tcf_common *pc;
struct ipt_entry_target *td, *t;
char *tname;
int ret = 0, err;
u32 hook = 0;
u32 index = 0;
if (nla == NULL)
return -EINVAL;
err = nla_parse_nested(tb, TCA_IPT_MAX, nla, ipt_policy);
if (err < 0)
return err;
if (tb[TCA_IPT_HOOK] == NULL)
return -EINVAL;
if (tb[TCA_IPT_TARG] == NULL)
return -EINVAL;
td = (struct ipt_entry_target *)nla_data(tb[TCA_IPT_TARG]);
if (nla_len(tb[TCA_IPT_TARG]) < td->u.target_size)
return -EINVAL;
if (tb[TCA_IPT_INDEX] != NULL)
index = nla_get_u32(tb[TCA_IPT_INDEX]);
pc = tcf_hash_check(index, a, bind, &ipt_hash_info);
if (!pc) {
pc = tcf_hash_create(index, est, a, sizeof(*ipt), bind,
&ipt_idx_gen, &ipt_hash_info);
if (unlikely(!pc))
return -ENOMEM;
ret = ACT_P_CREATED;
} else {
if (!ovr) {
tcf_ipt_release(to_ipt(pc), bind);
return -EEXIST;
}
}
ipt = to_ipt(pc);
hook = nla_get_u32(tb[TCA_IPT_HOOK]);
err = -ENOMEM;
tname = kmalloc(IFNAMSIZ, GFP_KERNEL);
if (unlikely(!tname))
goto err1;
if (tb[TCA_IPT_TABLE] == NULL ||
nla_strlcpy(tname, tb[TCA_IPT_TABLE], IFNAMSIZ) >= IFNAMSIZ)
strcpy(tname, "mangle");
t = kmemdup(td, td->u.target_size, GFP_KERNEL);
if (unlikely(!t))
goto err2;
if ((err = ipt_init_target(t, tname, hook)) < 0)
goto err3;
spin_lock_bh(&ipt->tcf_lock);
if (ret != ACT_P_CREATED) {
ipt_destroy_target(ipt->tcfi_t);
kfree(ipt->tcfi_tname);
kfree(ipt->tcfi_t);
}
ipt->tcfi_tname = tname;
ipt->tcfi_t = t;
ipt->tcfi_hook = hook;
spin_unlock_bh(&ipt->tcf_lock);
if (ret == ACT_P_CREATED)
tcf_hash_insert(pc, &ipt_hash_info);
return ret;
err3:
kfree(t);
err2:
kfree(tname);
err1:
kfree(pc);
return err;
}
static int tcf_ipt_cleanup(struct tc_action *a, int bind)
{
struct tcf_ipt *ipt = a->priv;
return tcf_ipt_release(ipt, bind);
}
static int tcf_ipt(struct sk_buff *skb, struct tc_action *a,
struct tcf_result *res)
{
int ret = 0, result = 0;
struct tcf_ipt *ipt = a->priv;
struct xt_target_param par;
if (skb_cloned(skb)) {
if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
return TC_ACT_UNSPEC;
}
spin_lock(&ipt->tcf_lock);
ipt->tcf_tm.lastuse = jiffies;
ipt->tcf_bstats.bytes += qdisc_pkt_len(skb);
ipt->tcf_bstats.packets++;
/* yes, we have to worry about both in and out dev
worry later - danger - this API seems to have changed
from earlier kernels */
par.in = skb->dev;
par.out = NULL;
par.hooknum = ipt->tcfi_hook;
par.target = ipt->tcfi_t->u.kernel.target;
par.targinfo = ipt->tcfi_t->data;
ret = par.target->target(skb, &par);
switch (ret) {
case NF_ACCEPT:
result = TC_ACT_OK;
break;
case NF_DROP:
result = TC_ACT_SHOT;
ipt->tcf_qstats.drops++;
break;
case IPT_CONTINUE:
result = TC_ACT_PIPE;
break;
default:
if (net_ratelimit())
printk("Bogus netfilter code %d assume ACCEPT\n", ret);
result = TC_POLICE_OK;
break;
}
spin_unlock(&ipt->tcf_lock);
return result;
}
static int tcf_ipt_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
{
unsigned char *b = skb_tail_pointer(skb);
struct tcf_ipt *ipt = a->priv;
struct ipt_entry_target *t;
struct tcf_t tm;
struct tc_cnt c;
/* for simple targets kernel size == user size
** user name = target name
** for foolproof you need to not assume this
*/
t = kmemdup(ipt->tcfi_t, ipt->tcfi_t->u.user.target_size, GFP_ATOMIC);
if (unlikely(!t))
goto nla_put_failure;
c.bindcnt = ipt->tcf_bindcnt - bind;
c.refcnt = ipt->tcf_refcnt - ref;
strcpy(t->u.user.name, ipt->tcfi_t->u.kernel.target->name);
NLA_PUT(skb, TCA_IPT_TARG, ipt->tcfi_t->u.user.target_size, t);
NLA_PUT_U32(skb, TCA_IPT_INDEX, ipt->tcf_index);
NLA_PUT_U32(skb, TCA_IPT_HOOK, ipt->tcfi_hook);
NLA_PUT(skb, TCA_IPT_CNT, sizeof(struct tc_cnt), &c);
NLA_PUT_STRING(skb, TCA_IPT_TABLE, ipt->tcfi_tname);
tm.install = jiffies_to_clock_t(jiffies - ipt->tcf_tm.install);
tm.lastuse = jiffies_to_clock_t(jiffies - ipt->tcf_tm.lastuse);
tm.expires = jiffies_to_clock_t(ipt->tcf_tm.expires);
NLA_PUT(skb, TCA_IPT_TM, sizeof (tm), &tm);
kfree(t);
return skb->len;
nla_put_failure:
nlmsg_trim(skb, b);
kfree(t);
return -1;
}
static struct tc_action_ops act_ipt_ops = {
.kind = "ipt",
.hinfo = &ipt_hash_info,
.type = TCA_ACT_IPT,
.capab = TCA_CAP_NONE,
.owner = THIS_MODULE,
.act = tcf_ipt,
.dump = tcf_ipt_dump,
.cleanup = tcf_ipt_cleanup,
.lookup = tcf_hash_search,
.init = tcf_ipt_init,
.walk = tcf_generic_walker
};
MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
MODULE_DESCRIPTION("Iptables target actions");
MODULE_LICENSE("GPL");
static int __init ipt_init_module(void)
{
return tcf_register_action(&act_ipt_ops);
}
static void __exit ipt_cleanup_module(void)
{
tcf_unregister_action(&act_ipt_ops);
}
module_init(ipt_init_module);
module_exit(ipt_cleanup_module);