Linux Audio

Check our new training course

Loading...
Note: File does not exist in v3.15.
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * net/sched/act_connmark.c  netfilter connmark retriever action
  4 * skb mark is over-written
  5 *
  6 * Copyright (c) 2011 Felix Fietkau <nbd@openwrt.org>
  7*/
  8
  9#include <linux/module.h>
 10#include <linux/init.h>
 11#include <linux/kernel.h>
 12#include <linux/skbuff.h>
 13#include <linux/rtnetlink.h>
 14#include <linux/pkt_cls.h>
 15#include <linux/ip.h>
 16#include <linux/ipv6.h>
 17#include <net/netlink.h>
 18#include <net/pkt_sched.h>
 19#include <net/act_api.h>
 20#include <net/pkt_cls.h>
 21#include <uapi/linux/tc_act/tc_connmark.h>
 22#include <net/tc_act/tc_connmark.h>
 23#include <net/tc_wrapper.h>
 24
 25#include <net/netfilter/nf_conntrack.h>
 26#include <net/netfilter/nf_conntrack_core.h>
 27#include <net/netfilter/nf_conntrack_zones.h>
 28
 29static struct tc_action_ops act_connmark_ops;
 30
 31TC_INDIRECT_SCOPE int tcf_connmark_act(struct sk_buff *skb,
 32				       const struct tc_action *a,
 33				       struct tcf_result *res)
 34{
 35	const struct nf_conntrack_tuple_hash *thash;
 36	struct nf_conntrack_tuple tuple;
 37	enum ip_conntrack_info ctinfo;
 38	struct tcf_connmark_info *ca = to_connmark(a);
 39	struct nf_conntrack_zone zone;
 40	struct nf_conn *c;
 41	int proto;
 42
 43	spin_lock(&ca->tcf_lock);
 44	tcf_lastuse_update(&ca->tcf_tm);
 45	bstats_update(&ca->tcf_bstats, skb);
 46
 47	switch (skb_protocol(skb, true)) {
 48	case htons(ETH_P_IP):
 49		if (skb->len < sizeof(struct iphdr))
 50			goto out;
 51
 52		proto = NFPROTO_IPV4;
 53		break;
 54	case htons(ETH_P_IPV6):
 55		if (skb->len < sizeof(struct ipv6hdr))
 56			goto out;
 57
 58		proto = NFPROTO_IPV6;
 59		break;
 60	default:
 61		goto out;
 62	}
 63
 64	c = nf_ct_get(skb, &ctinfo);
 65	if (c) {
 66		skb->mark = READ_ONCE(c->mark);
 67		/* using overlimits stats to count how many packets marked */
 68		ca->tcf_qstats.overlimits++;
 69		goto out;
 70	}
 71
 72	if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb),
 73			       proto, ca->net, &tuple))
 74		goto out;
 75
 76	zone.id = ca->zone;
 77	zone.dir = NF_CT_DEFAULT_ZONE_DIR;
 78
 79	thash = nf_conntrack_find_get(ca->net, &zone, &tuple);
 80	if (!thash)
 81		goto out;
 82
 83	c = nf_ct_tuplehash_to_ctrack(thash);
 84	/* using overlimits stats to count how many packets marked */
 85	ca->tcf_qstats.overlimits++;
 86	skb->mark = READ_ONCE(c->mark);
 87	nf_ct_put(c);
 88
 89out:
 90	spin_unlock(&ca->tcf_lock);
 91	return ca->tcf_action;
 92}
 93
 94static const struct nla_policy connmark_policy[TCA_CONNMARK_MAX + 1] = {
 95	[TCA_CONNMARK_PARMS] = { .len = sizeof(struct tc_connmark) },
 96};
 97
 98static int tcf_connmark_init(struct net *net, struct nlattr *nla,
 99			     struct nlattr *est, struct tc_action **a,
100			     struct tcf_proto *tp, u32 flags,
101			     struct netlink_ext_ack *extack)
102{
103	struct tc_action_net *tn = net_generic(net, act_connmark_ops.net_id);
104	struct nlattr *tb[TCA_CONNMARK_MAX + 1];
105	bool bind = flags & TCA_ACT_FLAGS_BIND;
106	struct tcf_chain *goto_ch = NULL;
107	struct tcf_connmark_info *ci;
108	struct tc_connmark *parm;
109	int ret = 0, err;
110	u32 index;
111
112	if (!nla)
113		return -EINVAL;
114
115	ret = nla_parse_nested_deprecated(tb, TCA_CONNMARK_MAX, nla,
116					  connmark_policy, NULL);
117	if (ret < 0)
118		return ret;
119
120	if (!tb[TCA_CONNMARK_PARMS])
121		return -EINVAL;
122
123	parm = nla_data(tb[TCA_CONNMARK_PARMS]);
124	index = parm->index;
125	ret = tcf_idr_check_alloc(tn, &index, a, bind);
126	if (!ret) {
127		ret = tcf_idr_create(tn, index, est, a,
128				     &act_connmark_ops, bind, false, flags);
129		if (ret) {
130			tcf_idr_cleanup(tn, index);
131			return ret;
132		}
133
134		ci = to_connmark(*a);
135		err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch,
136					       extack);
137		if (err < 0)
138			goto release_idr;
139		tcf_action_set_ctrlact(*a, parm->action, goto_ch);
140		ci->net = net;
141		ci->zone = parm->zone;
142
143		ret = ACT_P_CREATED;
144	} else if (ret > 0) {
145		ci = to_connmark(*a);
146		if (bind)
147			return 0;
148		if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
149			tcf_idr_release(*a, bind);
150			return -EEXIST;
151		}
152		err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch,
153					       extack);
154		if (err < 0)
155			goto release_idr;
156		/* replacing action and zone */
157		spin_lock_bh(&ci->tcf_lock);
158		goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
159		ci->zone = parm->zone;
160		spin_unlock_bh(&ci->tcf_lock);
161		if (goto_ch)
162			tcf_chain_put_by_act(goto_ch);
163		ret = 0;
164	}
165
166	return ret;
167release_idr:
168	tcf_idr_release(*a, bind);
169	return err;
170}
171
172static inline int tcf_connmark_dump(struct sk_buff *skb, struct tc_action *a,
173				    int bind, int ref)
174{
175	unsigned char *b = skb_tail_pointer(skb);
176	struct tcf_connmark_info *ci = to_connmark(a);
177	struct tc_connmark opt = {
178		.index   = ci->tcf_index,
179		.refcnt  = refcount_read(&ci->tcf_refcnt) - ref,
180		.bindcnt = atomic_read(&ci->tcf_bindcnt) - bind,
181	};
182	struct tcf_t t;
183
184	spin_lock_bh(&ci->tcf_lock);
185	opt.action = ci->tcf_action;
186	opt.zone = ci->zone;
187	if (nla_put(skb, TCA_CONNMARK_PARMS, sizeof(opt), &opt))
188		goto nla_put_failure;
189
190	tcf_tm_dump(&t, &ci->tcf_tm);
191	if (nla_put_64bit(skb, TCA_CONNMARK_TM, sizeof(t), &t,
192			  TCA_CONNMARK_PAD))
193		goto nla_put_failure;
194	spin_unlock_bh(&ci->tcf_lock);
195
196	return skb->len;
197
198nla_put_failure:
199	spin_unlock_bh(&ci->tcf_lock);
200	nlmsg_trim(skb, b);
201	return -1;
202}
203
204static struct tc_action_ops act_connmark_ops = {
205	.kind		=	"connmark",
206	.id		=	TCA_ID_CONNMARK,
207	.owner		=	THIS_MODULE,
208	.act		=	tcf_connmark_act,
209	.dump		=	tcf_connmark_dump,
210	.init		=	tcf_connmark_init,
211	.size		=	sizeof(struct tcf_connmark_info),
212};
213
214static __net_init int connmark_init_net(struct net *net)
215{
216	struct tc_action_net *tn = net_generic(net, act_connmark_ops.net_id);
217
218	return tc_action_net_init(net, tn, &act_connmark_ops);
219}
220
221static void __net_exit connmark_exit_net(struct list_head *net_list)
222{
223	tc_action_net_exit(net_list, act_connmark_ops.net_id);
224}
225
226static struct pernet_operations connmark_net_ops = {
227	.init = connmark_init_net,
228	.exit_batch = connmark_exit_net,
229	.id   = &act_connmark_ops.net_id,
230	.size = sizeof(struct tc_action_net),
231};
232
233static int __init connmark_init_module(void)
234{
235	return tcf_register_action(&act_connmark_ops, &connmark_net_ops);
236}
237
238static void __exit connmark_cleanup_module(void)
239{
240	tcf_unregister_action(&act_connmark_ops, &connmark_net_ops);
241}
242
243module_init(connmark_init_module);
244module_exit(connmark_cleanup_module);
245MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>");
246MODULE_DESCRIPTION("Connection tracking mark restoring");
247MODULE_LICENSE("GPL");