linux/net/sched/act_ipt.c
Cong Wang c7e460ce55 Revert "net_sched: hold netns refcnt for each action"
This reverts commit ceffcc5e25.
If we hold that refcnt, the netns can never be destroyed until
all actions are destroyed by user, this breaks our netns design
which we expect all actions are destroyed when we destroy the
whole netns.

Cc: Lucas Bates <lucasb@mojatatu.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-09 10:03:09 +09:00

435 lines
10 KiB
C

/*
* net/sched/act_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 (2002-13)
*/
#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 <linux/slab.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>
static unsigned int ipt_net_id;
static struct tc_action_ops act_ipt_ops;
static unsigned int xt_net_id;
static struct tc_action_ops act_xt_ops;
static int ipt_init_target(struct net *net, struct xt_entry_target *t,
char *table, unsigned int hook)
{
struct xt_tgchk_param par;
struct xt_target *target;
struct ipt_entry e = {};
int ret = 0;
target = xt_request_find_target(AF_INET, t->u.user.name,
t->u.user.revision);
if (IS_ERR(target))
return PTR_ERR(target);
t->u.kernel.target = target;
memset(&par, 0, sizeof(par));
par.net = net;
par.table = table;
par.entryinfo = &e;
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 xt_entry_target *t)
{
struct xt_tgdtor_param par = {
.target = t->u.kernel.target,
.targinfo = t->data,
.family = NFPROTO_IPV4,
};
if (par.target->destroy != NULL)
par.target->destroy(&par);
module_put(par.target->me);
}
static void tcf_ipt_release(struct tc_action *a, int bind)
{
struct tcf_ipt *ipt = to_ipt(a);
ipt_destroy_target(ipt->tcfi_t);
kfree(ipt->tcfi_tname);
kfree(ipt->tcfi_t);
}
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 xt_entry_target) },
};
static int __tcf_ipt_init(struct net *net, unsigned int id, struct nlattr *nla,
struct nlattr *est, struct tc_action **a,
const struct tc_action_ops *ops, int ovr, int bind)
{
struct tc_action_net *tn = net_generic(net, id);
struct nlattr *tb[TCA_IPT_MAX + 1];
struct tcf_ipt *ipt;
struct xt_entry_target *td, *t;
char *tname;
bool exists = false;
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, NULL);
if (err < 0)
return err;
if (tb[TCA_IPT_INDEX] != NULL)
index = nla_get_u32(tb[TCA_IPT_INDEX]);
exists = tcf_idr_check(tn, index, a, bind);
if (exists && bind)
return 0;
if (tb[TCA_IPT_HOOK] == NULL || tb[TCA_IPT_TARG] == NULL) {
if (exists)
tcf_idr_release(*a, bind);
return -EINVAL;
}
td = (struct xt_entry_target *)nla_data(tb[TCA_IPT_TARG]);
if (nla_len(tb[TCA_IPT_TARG]) < td->u.target_size) {
if (exists)
tcf_idr_release(*a, bind);
return -EINVAL;
}
if (!exists) {
ret = tcf_idr_create(tn, index, est, a, ops, bind,
false);
if (ret)
return ret;
ret = ACT_P_CREATED;
} else {
if (bind)/* dont override defaults */
return 0;
tcf_idr_release(*a, bind);
if (!ovr)
return -EEXIST;
}
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;
err = ipt_init_target(net, t, tname, hook);
if (err < 0)
goto err3;
ipt = to_ipt(*a);
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_idr_insert(tn, *a);
return ret;
err3:
kfree(t);
err2:
kfree(tname);
err1:
if (ret == ACT_P_CREATED)
tcf_idr_cleanup(*a, est);
return err;
}
static int tcf_ipt_init(struct net *net, struct nlattr *nla,
struct nlattr *est, struct tc_action **a, int ovr,
int bind)
{
return __tcf_ipt_init(net, ipt_net_id, nla, est, a, &act_ipt_ops, ovr,
bind);
}
static int tcf_xt_init(struct net *net, struct nlattr *nla,
struct nlattr *est, struct tc_action **a, int ovr,
int bind)
{
return __tcf_ipt_init(net, xt_net_id, nla, est, a, &act_xt_ops, ovr,
bind);
}
static int tcf_ipt(struct sk_buff *skb, const struct tc_action *a,
struct tcf_result *res)
{
int ret = 0, result = 0;
struct tcf_ipt *ipt = to_ipt(a);
struct xt_action_param par;
struct nf_hook_state state = {
.net = dev_net(skb->dev),
.in = skb->dev,
.hook = ipt->tcfi_hook,
.pf = NFPROTO_IPV4,
};
if (skb_unclone(skb, GFP_ATOMIC))
return TC_ACT_UNSPEC;
spin_lock(&ipt->tcf_lock);
tcf_lastuse_update(&ipt->tcf_tm);
bstats_update(&ipt->tcf_bstats, skb);
/* yes, we have to worry about both in and out dev
* worry later - danger - this API seems to have changed
* from earlier kernels
*/
par.state = &state;
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 XT_CONTINUE:
result = TC_ACT_PIPE;
break;
default:
net_notice_ratelimited("tc filter: Bogus netfilter code %d assume ACCEPT\n",
ret);
result = TC_ACT_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 = to_ipt(a);
struct xt_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);
if (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))
goto nla_put_failure;
tcf_tm_dump(&tm, &ipt->tcf_tm);
if (nla_put_64bit(skb, TCA_IPT_TM, sizeof(tm), &tm, TCA_IPT_PAD))
goto nla_put_failure;
kfree(t);
return skb->len;
nla_put_failure:
nlmsg_trim(skb, b);
kfree(t);
return -1;
}
static int tcf_ipt_walker(struct net *net, struct sk_buff *skb,
struct netlink_callback *cb, int type,
const struct tc_action_ops *ops)
{
struct tc_action_net *tn = net_generic(net, ipt_net_id);
return tcf_generic_walker(tn, skb, cb, type, ops);
}
static int tcf_ipt_search(struct net *net, struct tc_action **a, u32 index)
{
struct tc_action_net *tn = net_generic(net, ipt_net_id);
return tcf_idr_search(tn, a, index);
}
static struct tc_action_ops act_ipt_ops = {
.kind = "ipt",
.type = TCA_ACT_IPT,
.owner = THIS_MODULE,
.act = tcf_ipt,
.dump = tcf_ipt_dump,
.cleanup = tcf_ipt_release,
.init = tcf_ipt_init,
.walk = tcf_ipt_walker,
.lookup = tcf_ipt_search,
.size = sizeof(struct tcf_ipt),
};
static __net_init int ipt_init_net(struct net *net)
{
struct tc_action_net *tn = net_generic(net, ipt_net_id);
return tc_action_net_init(tn, &act_ipt_ops);
}
static void __net_exit ipt_exit_net(struct net *net)
{
struct tc_action_net *tn = net_generic(net, ipt_net_id);
tc_action_net_exit(tn);
}
static struct pernet_operations ipt_net_ops = {
.init = ipt_init_net,
.exit = ipt_exit_net,
.id = &ipt_net_id,
.size = sizeof(struct tc_action_net),
};
static int tcf_xt_walker(struct net *net, struct sk_buff *skb,
struct netlink_callback *cb, int type,
const struct tc_action_ops *ops)
{
struct tc_action_net *tn = net_generic(net, xt_net_id);
return tcf_generic_walker(tn, skb, cb, type, ops);
}
static int tcf_xt_search(struct net *net, struct tc_action **a, u32 index)
{
struct tc_action_net *tn = net_generic(net, xt_net_id);
return tcf_idr_search(tn, a, index);
}
static struct tc_action_ops act_xt_ops = {
.kind = "xt",
.type = TCA_ACT_XT,
.owner = THIS_MODULE,
.act = tcf_ipt,
.dump = tcf_ipt_dump,
.cleanup = tcf_ipt_release,
.init = tcf_xt_init,
.walk = tcf_xt_walker,
.lookup = tcf_xt_search,
.size = sizeof(struct tcf_ipt),
};
static __net_init int xt_init_net(struct net *net)
{
struct tc_action_net *tn = net_generic(net, xt_net_id);
return tc_action_net_init(tn, &act_xt_ops);
}
static void __net_exit xt_exit_net(struct net *net)
{
struct tc_action_net *tn = net_generic(net, xt_net_id);
tc_action_net_exit(tn);
}
static struct pernet_operations xt_net_ops = {
.init = xt_init_net,
.exit = xt_exit_net,
.id = &xt_net_id,
.size = sizeof(struct tc_action_net),
};
MODULE_AUTHOR("Jamal Hadi Salim(2002-13)");
MODULE_DESCRIPTION("Iptables target actions");
MODULE_LICENSE("GPL");
MODULE_ALIAS("act_xt");
static int __init ipt_init_module(void)
{
int ret1, ret2;
ret1 = tcf_register_action(&act_xt_ops, &xt_net_ops);
if (ret1 < 0)
pr_err("Failed to load xt action\n");
ret2 = tcf_register_action(&act_ipt_ops, &ipt_net_ops);
if (ret2 < 0)
pr_err("Failed to load ipt action\n");
if (ret1 < 0 && ret2 < 0) {
return ret1;
} else
return 0;
}
static void __exit ipt_cleanup_module(void)
{
tcf_unregister_action(&act_ipt_ops, &ipt_net_ops);
tcf_unregister_action(&act_xt_ops, &xt_net_ops);
}
module_init(ipt_init_module);
module_exit(ipt_cleanup_module);