summaryrefslogtreecommitdiff
path: root/net/sched/act_connmark.c
blob: f901421b0634d4408d4d7cc6881fa5e1716a471a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
// 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/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_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 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);

	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 = 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, bool rtnl_held,
			     struct tcf_proto *tp, u32 flags,
			     struct netlink_ext_ack *extack)
{
	struct tc_action_net *tn = net_generic(net, connmark_net_id);
	struct nlattr *tb[TCA_CONNMARK_MAX + 1];
	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;

	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(tn, index, est, a,
				     &act_connmark_ops, bind, false, 0);
		if (ret) {
			tcf_idr_cleanup(tn, index);
			return ret;
		}

		ci = to_connmark(*a);
		err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch,
					       extack);
		if (err < 0)
			goto release_idr;
		tcf_action_set_ctrlact(*a, parm->action, goto_ch);
		ci->net = net;
		ci->zone = parm->zone;

		tcf_idr_insert(tn, *a);
		ret = ACT_P_CREATED;
	} else if (ret > 0) {
		ci = to_connmark(*a);
		if (bind)
			return 0;
		if (!ovr) {
			tcf_idr_release(*a, bind);
			return -EEXIST;
		}
		err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch,
					       extack);
		if (err < 0)
			goto release_idr;
		/* replacing action and zone */
		spin_lock_bh(&ci->tcf_lock);
		goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
		ci->zone = parm->zone;
		spin_unlock_bh(&ci->tcf_lock);
		if (goto_ch)
			tcf_chain_put_by_act(goto_ch);
		ret = 0;
	}

	return ret;
release_idr:
	tcf_idr_release(*a, bind);
	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_t t;

	spin_lock_bh(&ci->tcf_lock);
	opt.action = ci->tcf_action;
	opt.zone = ci->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 int tcf_connmark_walker(struct net *net, struct sk_buff *skb,
			       struct netlink_callback *cb, int type,
			       const struct tc_action_ops *ops,
			       struct netlink_ext_ack *extack)
{
	struct tc_action_net *tn = net_generic(net, connmark_net_id);

	return tcf_generic_walker(tn, skb, cb, type, ops, extack);
}

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",
	.id		=	TCA_ID_CONNMARK,
	.owner		=	THIS_MODULE,
	.act		=	tcf_connmark_act,
	.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(net, tn, &act_connmark_ops);
}

static void __net_exit connmark_exit_net(struct list_head *net_list)
{
	tc_action_net_exit(net_list, connmark_net_id);
}

static struct pernet_operations connmark_net_ops = {
	.init = connmark_init_net,
	.exit_batch = 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");