summaryrefslogtreecommitdiff
path: root/net/netfilter/nft_rbtree.c
blob: 1c30f41cff5b44c5059e159fe269ed33aea3b824 (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
267
268
269
270
271
272
273
274
275
276
277
278
279
280
/*
 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Development of this code funded by Astaro AG (http://www.astaro.com/)
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/rbtree.h>
#include <linux/netlink.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables.h>

static DEFINE_SPINLOCK(nft_rbtree_lock);

struct nft_rbtree {
	struct rb_root		root;
};

struct nft_rbtree_elem {
	struct rb_node		node;
	struct nft_set_ext	ext;
};


static bool nft_rbtree_lookup(const struct nft_set *set, const u32 *key,
			      const struct nft_set_ext **ext)
{
	const struct nft_rbtree *priv = nft_set_priv(set);
	const struct nft_rbtree_elem *rbe, *interval = NULL;
	const struct rb_node *parent;
	u8 genmask = nft_genmask_cur(read_pnet(&set->pnet));
	int d;

	spin_lock_bh(&nft_rbtree_lock);
	parent = priv->root.rb_node;
	while (parent != NULL) {
		rbe = rb_entry(parent, struct nft_rbtree_elem, node);

		d = memcmp(nft_set_ext_key(&rbe->ext), key, set->klen);
		if (d < 0) {
			parent = parent->rb_left;
			interval = rbe;
		} else if (d > 0)
			parent = parent->rb_right;
		else {
found:
			if (!nft_set_elem_active(&rbe->ext, genmask)) {
				parent = parent->rb_left;
				continue;
			}
			if (nft_set_ext_exists(&rbe->ext, NFT_SET_EXT_FLAGS) &&
			    *nft_set_ext_flags(&rbe->ext) &
			    NFT_SET_ELEM_INTERVAL_END)
				goto out;
			spin_unlock_bh(&nft_rbtree_lock);

			*ext = &rbe->ext;
			return true;
		}
	}

	if (set->flags & NFT_SET_INTERVAL && interval != NULL) {
		rbe = interval;
		goto found;
	}
out:
	spin_unlock_bh(&nft_rbtree_lock);
	return false;
}

static int __nft_rbtree_insert(const struct nft_set *set,
			       struct nft_rbtree_elem *new)
{
	struct nft_rbtree *priv = nft_set_priv(set);
	struct nft_rbtree_elem *rbe;
	struct rb_node *parent, **p;
	u8 genmask = nft_genmask_next(read_pnet(&set->pnet));
	int d;

	parent = NULL;
	p = &priv->root.rb_node;
	while (*p != NULL) {
		parent = *p;
		rbe = rb_entry(parent, struct nft_rbtree_elem, node);
		d = memcmp(nft_set_ext_key(&rbe->ext),
			   nft_set_ext_key(&new->ext),
			   set->klen);
		if (d < 0)
			p = &parent->rb_left;
		else if (d > 0)
			p = &parent->rb_right;
		else {
			if (nft_set_elem_active(&rbe->ext, genmask))
				return -EEXIST;
			p = &parent->rb_left;
		}
	}
	rb_link_node(&new->node, parent, p);
	rb_insert_color(&new->node, &priv->root);
	return 0;
}

static int nft_rbtree_insert(const struct nft_set *set,
			     const struct nft_set_elem *elem)
{
	struct nft_rbtree_elem *rbe = elem->priv;
	int err;

	spin_lock_bh(&nft_rbtree_lock);
	err = __nft_rbtree_insert(set, rbe);
	spin_unlock_bh(&nft_rbtree_lock);

	return err;
}

static void nft_rbtree_remove(const struct nft_set *set,
			      const struct nft_set_elem *elem)
{
	struct nft_rbtree *priv = nft_set_priv(set);
	struct nft_rbtree_elem *rbe = elem->priv;

	spin_lock_bh(&nft_rbtree_lock);
	rb_erase(&rbe->node, &priv->root);
	spin_unlock_bh(&nft_rbtree_lock);
}

static void nft_rbtree_activate(const struct nft_set *set,
				const struct nft_set_elem *elem)
{
	struct nft_rbtree_elem *rbe = elem->priv;

	nft_set_elem_change_active(set, &rbe->ext);
}

static void *nft_rbtree_deactivate(const struct nft_set *set,
				   const struct nft_set_elem *elem)
{
	const struct nft_rbtree *priv = nft_set_priv(set);
	const struct rb_node *parent = priv->root.rb_node;
	struct nft_rbtree_elem *rbe;
	u8 genmask = nft_genmask_cur(read_pnet(&set->pnet));
	int d;

	while (parent != NULL) {
		rbe = rb_entry(parent, struct nft_rbtree_elem, node);

		d = memcmp(nft_set_ext_key(&rbe->ext), &elem->key.val,
					   set->klen);
		if (d < 0)
			parent = parent->rb_left;
		else if (d > 0)
			parent = parent->rb_right;
		else {
			if (!nft_set_elem_active(&rbe->ext, genmask)) {
				parent = parent->rb_left;
				continue;
			}
			nft_set_elem_change_active(set, &rbe->ext);
			return rbe;
		}
	}
	return NULL;
}

static void nft_rbtree_walk(const struct nft_ctx *ctx,
			    const struct nft_set *set,
			    struct nft_set_iter *iter)
{
	const struct nft_rbtree *priv = nft_set_priv(set);
	struct nft_rbtree_elem *rbe;
	struct nft_set_elem elem;
	struct rb_node *node;
	u8 genmask = nft_genmask_cur(read_pnet(&set->pnet));

	spin_lock_bh(&nft_rbtree_lock);
	for (node = rb_first(&priv->root); node != NULL; node = rb_next(node)) {
		rbe = rb_entry(node, struct nft_rbtree_elem, node);

		if (iter->count < iter->skip)
			goto cont;
		if (!nft_set_elem_active(&rbe->ext, genmask))
			goto cont;

		elem.priv = rbe;

		iter->err = iter->fn(ctx, set, iter, &elem);
		if (iter->err < 0) {
			spin_unlock_bh(&nft_rbtree_lock);
			return;
		}
cont:
		iter->count++;
	}
	spin_unlock_bh(&nft_rbtree_lock);
}

static unsigned int nft_rbtree_privsize(const struct nlattr * const nla[])
{
	return sizeof(struct nft_rbtree);
}

static int nft_rbtree_init(const struct nft_set *set,
			   const struct nft_set_desc *desc,
			   const struct nlattr * const nla[])
{
	struct nft_rbtree *priv = nft_set_priv(set);

	priv->root = RB_ROOT;
	return 0;
}

static void nft_rbtree_destroy(const struct nft_set *set)
{
	struct nft_rbtree *priv = nft_set_priv(set);
	struct nft_rbtree_elem *rbe;
	struct rb_node *node;

	while ((node = priv->root.rb_node) != NULL) {
		rb_erase(node, &priv->root);
		rbe = rb_entry(node, struct nft_rbtree_elem, node);
		nft_set_elem_destroy(set, rbe);
	}
}

static bool nft_rbtree_estimate(const struct nft_set_desc *desc, u32 features,
				struct nft_set_estimate *est)
{
	unsigned int nsize;

	nsize = sizeof(struct nft_rbtree_elem);
	if (desc->size)
		est->size = sizeof(struct nft_rbtree) + desc->size * nsize;
	else
		est->size = nsize;

	est->class = NFT_SET_CLASS_O_LOG_N;

	return true;
}

static struct nft_set_ops nft_rbtree_ops __read_mostly = {
	.privsize	= nft_rbtree_privsize,
	.elemsize	= offsetof(struct nft_rbtree_elem, ext),
	.estimate	= nft_rbtree_estimate,
	.init		= nft_rbtree_init,
	.destroy	= nft_rbtree_destroy,
	.insert		= nft_rbtree_insert,
	.remove		= nft_rbtree_remove,
	.deactivate	= nft_rbtree_deactivate,
	.activate	= nft_rbtree_activate,
	.lookup		= nft_rbtree_lookup,
	.walk		= nft_rbtree_walk,
	.features	= NFT_SET_INTERVAL | NFT_SET_MAP,
	.owner		= THIS_MODULE,
};

static int __init nft_rbtree_module_init(void)
{
	return nft_register_set(&nft_rbtree_ops);
}

static void __exit nft_rbtree_module_exit(void)
{
	nft_unregister_set(&nft_rbtree_ops);
}

module_init(nft_rbtree_module_init);
module_exit(nft_rbtree_module_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
MODULE_ALIAS_NFT_SET();