linux/net/sched/act_connmark.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

242 lines
5.9 KiB
C

/*
* net/sched/act_connmark.c netfilter connmark retriever action
* skb mark is over-written
*
* Copyright (c) 2011 Felix Fietkau <nbd@openwrt.org>
*
* 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.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <linux/pkt_cls.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <net/act_api.h>
#include <uapi/linux/tc_act/tc_connmark.h>
#include <net/tc_act/tc_connmark.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/nf_conntrack_zones.h>
static unsigned int connmark_net_id;
static struct tc_action_ops act_connmark_ops;
static int tcf_connmark(struct sk_buff *skb, const struct tc_action *a,
struct tcf_result *res)
{
const struct nf_conntrack_tuple_hash *thash;
struct nf_conntrack_tuple tuple;
enum ip_conntrack_info ctinfo;
struct tcf_connmark_info *ca = to_connmark(a);
struct nf_conntrack_zone zone;
struct nf_conn *c;
int proto;
spin_lock(&ca->tcf_lock);
tcf_lastuse_update(&ca->tcf_tm);
bstats_update(&ca->tcf_bstats, skb);
if (skb->protocol == htons(ETH_P_IP)) {
if (skb->len < sizeof(struct iphdr))
goto out;
proto = NFPROTO_IPV4;
} else if (skb->protocol == htons(ETH_P_IPV6)) {
if (skb->len < sizeof(struct ipv6hdr))
goto out;
proto = NFPROTO_IPV6;
} else {
goto out;
}
c = nf_ct_get(skb, &ctinfo);
if (c) {
skb->mark = c->mark;
/* using overlimits stats to count how many packets marked */
ca->tcf_qstats.overlimits++;
goto out;
}
if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb),
proto, ca->net, &tuple))
goto out;
zone.id = ca->zone;
zone.dir = NF_CT_DEFAULT_ZONE_DIR;
thash = nf_conntrack_find_get(ca->net, &zone, &tuple);
if (!thash)
goto out;
c = nf_ct_tuplehash_to_ctrack(thash);
/* using overlimits stats to count how many packets marked */
ca->tcf_qstats.overlimits++;
skb->mark = c->mark;
nf_ct_put(c);
out:
spin_unlock(&ca->tcf_lock);
return ca->tcf_action;
}
static const struct nla_policy connmark_policy[TCA_CONNMARK_MAX + 1] = {
[TCA_CONNMARK_PARMS] = { .len = sizeof(struct tc_connmark) },
};
static int tcf_connmark_init(struct net *net, struct nlattr *nla,
struct nlattr *est, struct tc_action **a,
int ovr, int bind)
{
struct tc_action_net *tn = net_generic(net, connmark_net_id);
struct nlattr *tb[TCA_CONNMARK_MAX + 1];
struct tcf_connmark_info *ci;
struct tc_connmark *parm;
int ret = 0;
if (!nla)
return -EINVAL;
ret = nla_parse_nested(tb, TCA_CONNMARK_MAX, nla, connmark_policy,
NULL);
if (ret < 0)
return ret;
if (!tb[TCA_CONNMARK_PARMS])
return -EINVAL;
parm = nla_data(tb[TCA_CONNMARK_PARMS]);
if (!tcf_idr_check(tn, parm->index, a, bind)) {
ret = tcf_idr_create(tn, parm->index, est, a,
&act_connmark_ops, bind, false);
if (ret)
return ret;
ci = to_connmark(*a);
ci->tcf_action = parm->action;
ci->net = net;
ci->zone = parm->zone;
tcf_idr_insert(tn, *a);
ret = ACT_P_CREATED;
} else {
ci = to_connmark(*a);
if (bind)
return 0;
tcf_idr_release(*a, bind);
if (!ovr)
return -EEXIST;
/* replacing action and zone */
ci->tcf_action = parm->action;
ci->zone = parm->zone;
}
return ret;
}
static inline int tcf_connmark_dump(struct sk_buff *skb, struct tc_action *a,
int bind, int ref)
{
unsigned char *b = skb_tail_pointer(skb);
struct tcf_connmark_info *ci = to_connmark(a);
struct tc_connmark opt = {
.index = ci->tcf_index,
.refcnt = ci->tcf_refcnt - ref,
.bindcnt = ci->tcf_bindcnt - bind,
.action = ci->tcf_action,
.zone = ci->zone,
};
struct tcf_t t;
if (nla_put(skb, TCA_CONNMARK_PARMS, sizeof(opt), &opt))
goto nla_put_failure;
tcf_tm_dump(&t, &ci->tcf_tm);
if (nla_put_64bit(skb, TCA_CONNMARK_TM, sizeof(t), &t,
TCA_CONNMARK_PAD))
goto nla_put_failure;
return skb->len;
nla_put_failure:
nlmsg_trim(skb, b);
return -1;
}
static int tcf_connmark_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, connmark_net_id);
return tcf_generic_walker(tn, skb, cb, type, ops);
}
static int tcf_connmark_search(struct net *net, struct tc_action **a, u32 index)
{
struct tc_action_net *tn = net_generic(net, connmark_net_id);
return tcf_idr_search(tn, a, index);
}
static struct tc_action_ops act_connmark_ops = {
.kind = "connmark",
.type = TCA_ACT_CONNMARK,
.owner = THIS_MODULE,
.act = tcf_connmark,
.dump = tcf_connmark_dump,
.init = tcf_connmark_init,
.walk = tcf_connmark_walker,
.lookup = tcf_connmark_search,
.size = sizeof(struct tcf_connmark_info),
};
static __net_init int connmark_init_net(struct net *net)
{
struct tc_action_net *tn = net_generic(net, connmark_net_id);
return tc_action_net_init(tn, &act_connmark_ops);
}
static void __net_exit connmark_exit_net(struct net *net)
{
struct tc_action_net *tn = net_generic(net, connmark_net_id);
tc_action_net_exit(tn);
}
static struct pernet_operations connmark_net_ops = {
.init = connmark_init_net,
.exit = connmark_exit_net,
.id = &connmark_net_id,
.size = sizeof(struct tc_action_net),
};
static int __init connmark_init_module(void)
{
return tcf_register_action(&act_connmark_ops, &connmark_net_ops);
}
static void __exit connmark_cleanup_module(void)
{
tcf_unregister_action(&act_connmark_ops, &connmark_net_ops);
}
module_init(connmark_init_module);
module_exit(connmark_cleanup_module);
MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>");
MODULE_DESCRIPTION("Connection tracking mark restoring");
MODULE_LICENSE("GPL");