summaryrefslogtreecommitdiff
path: root/net/sched/cls_cgroup.c
blob: ed00001b528a6c63e7122fb38aa9ad9fb928acb7 (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
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * net/sched/cls_cgroup.c	Control Group Classifier
 *
 * Authors:	Thomas Graf <tgraf@suug.ch>
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/rcupdate.h>
#include <net/rtnetlink.h>
#include <net/pkt_cls.h>
#include <net/sock.h>
#include <net/cls_cgroup.h>

struct cls_cgroup_head {
	u32			handle;
	struct tcf_exts		exts;
	struct tcf_ematch_tree	ematches;
	struct tcf_proto	*tp;
	struct rcu_work		rwork;
};

static int cls_cgroup_classify(struct sk_buff *skb, const struct tcf_proto *tp,
			       struct tcf_result *res)
{
	struct cls_cgroup_head *head = rcu_dereference_bh(tp->root);
	u32 classid = task_get_classid(skb);

	if (unlikely(!head))
		return -1;
	if (!classid)
		return -1;
	if (!tcf_em_tree_match(skb, &head->ematches, NULL))
		return -1;

	res->classid = classid;
	res->class = 0;

	return tcf_exts_exec(skb, &head->exts, res);
}

static void *cls_cgroup_get(struct tcf_proto *tp, u32 handle)
{
	return NULL;
}

static int cls_cgroup_init(struct tcf_proto *tp)
{
	return 0;
}

static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = {
	[TCA_CGROUP_EMATCHES]	= { .type = NLA_NESTED },
};

static void __cls_cgroup_destroy(struct cls_cgroup_head *head)
{
	tcf_exts_destroy(&head->exts);
	tcf_em_tree_destroy(&head->ematches);
	tcf_exts_put_net(&head->exts);
	kfree(head);
}

static void cls_cgroup_destroy_work(struct work_struct *work)
{
	struct cls_cgroup_head *head = container_of(to_rcu_work(work),
						    struct cls_cgroup_head,
						    rwork);
	rtnl_lock();
	__cls_cgroup_destroy(head);
	rtnl_unlock();
}

static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb,
			     struct tcf_proto *tp, unsigned long base,
			     u32 handle, struct nlattr **tca,
			     void **arg, u32 flags,
			     struct netlink_ext_ack *extack)
{
	struct nlattr *tb[TCA_CGROUP_MAX + 1];
	struct cls_cgroup_head *head = rtnl_dereference(tp->root);
	struct cls_cgroup_head *new;
	int err;

	if (!tca[TCA_OPTIONS])
		return -EINVAL;

	if (!head && !handle)
		return -EINVAL;

	if (head && handle != head->handle)
		return -ENOENT;

	new = kzalloc(sizeof(*head), GFP_KERNEL);
	if (!new)
		return -ENOBUFS;

	err = tcf_exts_init(&new->exts, net, TCA_CGROUP_ACT, TCA_CGROUP_POLICE);
	if (err < 0)
		goto errout;
	new->handle = handle;
	new->tp = tp;
	err = nla_parse_nested_deprecated(tb, TCA_CGROUP_MAX,
					  tca[TCA_OPTIONS], cgroup_policy,
					  NULL);
	if (err < 0)
		goto errout;

	err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &new->exts, flags,
				extack);
	if (err < 0)
		goto errout;

	err = tcf_em_tree_validate(tp, tb[TCA_CGROUP_EMATCHES], &new->ematches);
	if (err < 0)
		goto errout;

	rcu_assign_pointer(tp->root, new);
	if (head) {
		tcf_exts_get_net(&head->exts);
		tcf_queue_work(&head->rwork, cls_cgroup_destroy_work);
	}
	return 0;
errout:
	tcf_exts_destroy(&new->exts);
	kfree(new);
	return err;
}

static void cls_cgroup_destroy(struct tcf_proto *tp, bool rtnl_held,
			       struct netlink_ext_ack *extack)
{
	struct cls_cgroup_head *head = rtnl_dereference(tp->root);

	/* Head can still be NULL due to cls_cgroup_init(). */
	if (head) {
		if (tcf_exts_get_net(&head->exts))
			tcf_queue_work(&head->rwork, cls_cgroup_destroy_work);
		else
			__cls_cgroup_destroy(head);
	}
}

static int cls_cgroup_delete(struct tcf_proto *tp, void *arg, bool *last,
			     bool rtnl_held, struct netlink_ext_ack *extack)
{
	return -EOPNOTSUPP;
}

static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg,
			    bool rtnl_held)
{
	struct cls_cgroup_head *head = rtnl_dereference(tp->root);

	if (arg->count < arg->skip)
		goto skip;

	if (!head)
		return;
	if (arg->fn(tp, head, arg) < 0) {
		arg->stop = 1;
		return;
	}
skip:
	arg->count++;
}

static int cls_cgroup_dump(struct net *net, struct tcf_proto *tp, void *fh,
			   struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
{
	struct cls_cgroup_head *head = rtnl_dereference(tp->root);
	struct nlattr *nest;

	t->tcm_handle = head->handle;

	nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
	if (nest == NULL)
		goto nla_put_failure;

	if (tcf_exts_dump(skb, &head->exts) < 0 ||
	    tcf_em_tree_dump(skb, &head->ematches, TCA_CGROUP_EMATCHES) < 0)
		goto nla_put_failure;

	nla_nest_end(skb, nest);

	if (tcf_exts_dump_stats(skb, &head->exts) < 0)
		goto nla_put_failure;

	return skb->len;

nla_put_failure:
	nla_nest_cancel(skb, nest);
	return -1;
}

static struct tcf_proto_ops cls_cgroup_ops __read_mostly = {
	.kind		=	"cgroup",
	.init		=	cls_cgroup_init,
	.change		=	cls_cgroup_change,
	.classify	=	cls_cgroup_classify,
	.destroy	=	cls_cgroup_destroy,
	.get		=	cls_cgroup_get,
	.delete		=	cls_cgroup_delete,
	.walk		=	cls_cgroup_walk,
	.dump		=	cls_cgroup_dump,
	.owner		=	THIS_MODULE,
};

static int __init init_cgroup_cls(void)
{
	return register_tcf_proto_ops(&cls_cgroup_ops);
}

static void __exit exit_cgroup_cls(void)
{
	unregister_tcf_proto_ops(&cls_cgroup_ops);
}

module_init(init_cgroup_cls);
module_exit(exit_cgroup_cls);
MODULE_LICENSE("GPL");