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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* net/sched/act_connmark.c netfilter connmark retriever action
* skb mark is over-written
*
* Copyright (c) 2011 Felix Fietkau <nbd@openwrt.org>
*/
#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 <net/pkt_cls.h>
#include <uapi/linux/tc_act/tc_connmark.h>
#include <net/tc_act/tc_connmark.h>
#include <net/tc_wrapper.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/nf_conntrack_zones.h>
static struct tc_action_ops act_connmark_ops;
TC_INDIRECT_SCOPE int tcf_connmark_act(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 tcf_connmark_parms *parms;
struct nf_conntrack_zone zone;
struct nf_conn *c;
int proto;
tcf_lastuse_update(&ca->tcf_tm);
tcf_action_update_bstats(&ca->common, skb);
parms = rcu_dereference_bh(ca->parms);
switch (skb_protocol(skb, true)) {
case htons(ETH_P_IP):
if (skb->len < sizeof(struct iphdr))
goto out;
proto = NFPROTO_IPV4;
break;
case htons(ETH_P_IPV6):
if (skb->len < sizeof(struct ipv6hdr))
goto out;
proto = NFPROTO_IPV6;
break;
default:
goto out;
}
c = nf_ct_get(skb, &ctinfo);
if (c) {
skb->mark = READ_ONCE(c->mark);
goto count;
}
if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, parms->net,
&tuple))
goto out;
zone.id = parms->zone;
zone.dir = NF_CT_DEFAULT_ZONE_DIR;
thash = nf_conntrack_find_get(parms->net, &zone, &tuple);
if (!thash)
goto out;
c = nf_ct_tuplehash_to_ctrack(thash);
skb->mark = READ_ONCE(c->mark);
nf_ct_put(c);
count:
/* using overlimits stats to count how many packets marked */
tcf_action_inc_overlimit_qstats(&ca->common);
out:
return READ_ONCE(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,
struct tcf_proto *tp, u32 flags,
struct netlink_ext_ack *extack)
{
struct tc_action_net *tn = net_generic(net, act_connmark_ops.net_id);
struct tcf_connmark_parms *nparms, *oparms;
struct nlattr *tb[TCA_CONNMARK_MAX + 1];
bool bind = flags & TCA_ACT_FLAGS_BIND;
struct tcf_chain *goto_ch = NULL;
struct tcf_connmark_info *ci;
struct tc_connmark *parm;
int ret = 0, err;
u32 index;
if (!nla)
return -EINVAL;
ret = nla_parse_nested_deprecated(tb, TCA_CONNMARK_MAX, nla,
connmark_policy, NULL);
if (ret < 0)
return ret;
if (!tb[TCA_CONNMARK_PARMS])
return -EINVAL;
nparms = kzalloc(sizeof(*nparms), GFP_KERNEL);
if (!nparms)
return -ENOMEM;
parm = nla_data(tb[TCA_CONNMARK_PARMS]);
index = parm->index;
ret = tcf_idr_check_alloc(tn, &index, a, bind);
if (!ret) {
ret = tcf_idr_create_from_flags(tn, index, est, a,
&act_connmark_ops, bind, flags);
if (ret) {
tcf_idr_cleanup(tn, index);
err = ret;
goto out_free;
}
ci = to_connmark(*a);
nparms->net = net;
nparms->zone = parm->zone;
ret = ACT_P_CREATED;
} else if (ret > 0) {
ci = to_connmark(*a);
if (bind) {
err = ACT_P_BOUND;
goto out_free;
}
if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
err = -EEXIST;
goto release_idr;
}
nparms->net = rtnl_dereference(ci->parms)->net;
nparms->zone = parm->zone;
ret = 0;
} else {
err = ret;
goto out_free;
}
err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
if (err < 0)
goto release_idr;
spin_lock_bh(&ci->tcf_lock);
goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
oparms = rcu_replace_pointer(ci->parms, nparms, lockdep_is_held(&ci->tcf_lock));
spin_unlock_bh(&ci->tcf_lock);
if (goto_ch)
tcf_chain_put_by_act(goto_ch);
if (oparms)
kfree_rcu(oparms, rcu);
return ret;
release_idr:
tcf_idr_release(*a, bind);
out_free:
kfree(nparms);
return err;
}
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 = refcount_read(&ci->tcf_refcnt) - ref,
.bindcnt = atomic_read(&ci->tcf_bindcnt) - bind,
};
struct tcf_connmark_parms *parms;
struct tcf_t t;
spin_lock_bh(&ci->tcf_lock);
parms = rcu_dereference_protected(ci->parms, lockdep_is_held(&ci->tcf_lock));
opt.action = ci->tcf_action;
opt.zone = parms->zone;
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;
spin_unlock_bh(&ci->tcf_lock);
return skb->len;
nla_put_failure:
spin_unlock_bh(&ci->tcf_lock);
nlmsg_trim(skb, b);
return -1;
}
static void tcf_connmark_cleanup(struct tc_action *a)
{
struct tcf_connmark_info *ci = to_connmark(a);
struct tcf_connmark_parms *parms;
parms = rcu_dereference_protected(ci->parms, 1);
if (parms)
kfree_rcu(parms, rcu);
}
static struct tc_action_ops act_connmark_ops = {
.kind = "connmark",
.id = TCA_ID_CONNMARK,
.owner = THIS_MODULE,
.act = tcf_connmark_act,
.dump = tcf_connmark_dump,
.init = tcf_connmark_init,
.cleanup = tcf_connmark_cleanup,
.size = sizeof(struct tcf_connmark_info),
};
MODULE_ALIAS_NET_ACT("connmark");
static __net_init int connmark_init_net(struct net *net)
{
struct tc_action_net *tn = net_generic(net, act_connmark_ops.net_id);
return tc_action_net_init(net, tn, &act_connmark_ops);
}
static void __net_exit connmark_exit_net(struct list_head *net_list)
{
tc_action_net_exit(net_list, act_connmark_ops.net_id);
}
static struct pernet_operations connmark_net_ops = {
.init = connmark_init_net,
.exit_batch = connmark_exit_net,
.id = &act_connmark_ops.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");
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