1 /*
2 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * Development of this code funded by Astaro AG (http://www.astaro.com/)
9 */
10
11 #include <linux/kernel.h>
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/list.h>
15 #include <linux/rbtree.h>
16 #include <linux/netlink.h>
17 #include <linux/netfilter.h>
18 #include <linux/netfilter/nf_tables.h>
19 #include <net/netfilter/nf_tables.h>
20
21 static DEFINE_SPINLOCK(nft_rbtree_lock);
22
23 struct nft_rbtree {
24 struct rb_root root;
25 };
26
27 struct nft_rbtree_elem {
28 struct rb_node node;
29 struct nft_set_ext ext;
30 };
31
nft_rbtree_interval_end(const struct nft_rbtree_elem * rbe)32 static bool nft_rbtree_interval_end(const struct nft_rbtree_elem *rbe)
33 {
34 return nft_set_ext_exists(&rbe->ext, NFT_SET_EXT_FLAGS) &&
35 (*nft_set_ext_flags(&rbe->ext) & NFT_SET_ELEM_INTERVAL_END);
36 }
37
nft_rbtree_equal(const struct nft_set * set,const void * this,const struct nft_rbtree_elem * interval)38 static bool nft_rbtree_equal(const struct nft_set *set, const void *this,
39 const struct nft_rbtree_elem *interval)
40 {
41 return memcmp(this, nft_set_ext_key(&interval->ext), set->klen) == 0;
42 }
43
nft_rbtree_lookup(const struct net * net,const struct nft_set * set,const u32 * key,const struct nft_set_ext ** ext)44 static bool nft_rbtree_lookup(const struct net *net, const struct nft_set *set,
45 const u32 *key, const struct nft_set_ext **ext)
46 {
47 const struct nft_rbtree *priv = nft_set_priv(set);
48 const struct nft_rbtree_elem *rbe, *interval = NULL;
49 u8 genmask = nft_genmask_cur(net);
50 const struct rb_node *parent;
51 const void *this;
52 int d;
53
54 spin_lock_bh(&nft_rbtree_lock);
55 parent = priv->root.rb_node;
56 while (parent != NULL) {
57 rbe = rb_entry(parent, struct nft_rbtree_elem, node);
58
59 this = nft_set_ext_key(&rbe->ext);
60 d = memcmp(this, key, set->klen);
61 if (d < 0) {
62 parent = parent->rb_left;
63 /* In case of adjacent ranges, we always see the high
64 * part of the range in first place, before the low one.
65 * So don't update interval if the keys are equal.
66 */
67 if (interval && nft_rbtree_equal(set, this, interval))
68 continue;
69 interval = rbe;
70 } else if (d > 0)
71 parent = parent->rb_right;
72 else {
73 if (!nft_set_elem_active(&rbe->ext, genmask)) {
74 parent = parent->rb_left;
75 continue;
76 }
77 if (nft_rbtree_interval_end(rbe))
78 goto out;
79 spin_unlock_bh(&nft_rbtree_lock);
80
81 *ext = &rbe->ext;
82 return true;
83 }
84 }
85
86 if (set->flags & NFT_SET_INTERVAL && interval != NULL &&
87 nft_set_elem_active(&interval->ext, genmask) &&
88 !nft_rbtree_interval_end(interval)) {
89 spin_unlock_bh(&nft_rbtree_lock);
90 *ext = &interval->ext;
91 return true;
92 }
93 out:
94 spin_unlock_bh(&nft_rbtree_lock);
95 return false;
96 }
97
__nft_rbtree_insert(const struct net * net,const struct nft_set * set,struct nft_rbtree_elem * new,struct nft_set_ext ** ext)98 static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
99 struct nft_rbtree_elem *new,
100 struct nft_set_ext **ext)
101 {
102 struct nft_rbtree *priv = nft_set_priv(set);
103 u8 genmask = nft_genmask_next(net);
104 struct nft_rbtree_elem *rbe;
105 struct rb_node *parent, **p;
106 int d;
107
108 parent = NULL;
109 p = &priv->root.rb_node;
110 while (*p != NULL) {
111 parent = *p;
112 rbe = rb_entry(parent, struct nft_rbtree_elem, node);
113 d = memcmp(nft_set_ext_key(&rbe->ext),
114 nft_set_ext_key(&new->ext),
115 set->klen);
116 if (d < 0)
117 p = &parent->rb_left;
118 else if (d > 0)
119 p = &parent->rb_right;
120 else {
121 if (nft_rbtree_interval_end(rbe) &&
122 !nft_rbtree_interval_end(new)) {
123 p = &parent->rb_left;
124 } else if (!nft_rbtree_interval_end(rbe) &&
125 nft_rbtree_interval_end(new)) {
126 p = &parent->rb_right;
127 } else if (nft_set_elem_active(&rbe->ext, genmask)) {
128 *ext = &rbe->ext;
129 return -EEXIST;
130 } else {
131 p = &parent->rb_left;
132 }
133 }
134 }
135 rb_link_node(&new->node, parent, p);
136 rb_insert_color(&new->node, &priv->root);
137 return 0;
138 }
139
nft_rbtree_insert(const struct net * net,const struct nft_set * set,const struct nft_set_elem * elem,struct nft_set_ext ** ext)140 static int nft_rbtree_insert(const struct net *net, const struct nft_set *set,
141 const struct nft_set_elem *elem,
142 struct nft_set_ext **ext)
143 {
144 struct nft_rbtree_elem *rbe = elem->priv;
145 int err;
146
147 spin_lock_bh(&nft_rbtree_lock);
148 err = __nft_rbtree_insert(net, set, rbe, ext);
149 spin_unlock_bh(&nft_rbtree_lock);
150
151 return err;
152 }
153
nft_rbtree_remove(const struct nft_set * set,const struct nft_set_elem * elem)154 static void nft_rbtree_remove(const struct nft_set *set,
155 const struct nft_set_elem *elem)
156 {
157 struct nft_rbtree *priv = nft_set_priv(set);
158 struct nft_rbtree_elem *rbe = elem->priv;
159
160 spin_lock_bh(&nft_rbtree_lock);
161 rb_erase(&rbe->node, &priv->root);
162 spin_unlock_bh(&nft_rbtree_lock);
163 }
164
nft_rbtree_activate(const struct net * net,const struct nft_set * set,const struct nft_set_elem * elem)165 static void nft_rbtree_activate(const struct net *net,
166 const struct nft_set *set,
167 const struct nft_set_elem *elem)
168 {
169 struct nft_rbtree_elem *rbe = elem->priv;
170
171 nft_set_elem_change_active(net, set, &rbe->ext);
172 }
173
nft_rbtree_deactivate(const struct net * net,const struct nft_set * set,const struct nft_set_elem * elem)174 static void *nft_rbtree_deactivate(const struct net *net,
175 const struct nft_set *set,
176 const struct nft_set_elem *elem)
177 {
178 const struct nft_rbtree *priv = nft_set_priv(set);
179 const struct rb_node *parent = priv->root.rb_node;
180 struct nft_rbtree_elem *rbe, *this = elem->priv;
181 u8 genmask = nft_genmask_next(net);
182 int d;
183
184 while (parent != NULL) {
185 rbe = rb_entry(parent, struct nft_rbtree_elem, node);
186
187 d = memcmp(nft_set_ext_key(&rbe->ext), &elem->key.val,
188 set->klen);
189 if (d < 0)
190 parent = parent->rb_left;
191 else if (d > 0)
192 parent = parent->rb_right;
193 else {
194 if (!nft_set_elem_active(&rbe->ext, genmask)) {
195 parent = parent->rb_left;
196 continue;
197 }
198 if (nft_rbtree_interval_end(rbe) &&
199 !nft_rbtree_interval_end(this)) {
200 parent = parent->rb_left;
201 continue;
202 } else if (!nft_rbtree_interval_end(rbe) &&
203 nft_rbtree_interval_end(this)) {
204 parent = parent->rb_right;
205 continue;
206 }
207 nft_set_elem_change_active(net, set, &rbe->ext);
208 return rbe;
209 }
210 }
211 return NULL;
212 }
213
nft_rbtree_walk(const struct nft_ctx * ctx,const struct nft_set * set,struct nft_set_iter * iter)214 static void nft_rbtree_walk(const struct nft_ctx *ctx,
215 const struct nft_set *set,
216 struct nft_set_iter *iter)
217 {
218 const struct nft_rbtree *priv = nft_set_priv(set);
219 struct nft_rbtree_elem *rbe;
220 struct nft_set_elem elem;
221 struct rb_node *node;
222
223 spin_lock_bh(&nft_rbtree_lock);
224 for (node = rb_first(&priv->root); node != NULL; node = rb_next(node)) {
225 rbe = rb_entry(node, struct nft_rbtree_elem, node);
226
227 if (iter->count < iter->skip)
228 goto cont;
229 if (!nft_set_elem_active(&rbe->ext, iter->genmask))
230 goto cont;
231
232 elem.priv = rbe;
233
234 iter->err = iter->fn(ctx, set, iter, &elem);
235 if (iter->err < 0) {
236 spin_unlock_bh(&nft_rbtree_lock);
237 return;
238 }
239 cont:
240 iter->count++;
241 }
242 spin_unlock_bh(&nft_rbtree_lock);
243 }
244
nft_rbtree_privsize(const struct nlattr * const nla[])245 static unsigned int nft_rbtree_privsize(const struct nlattr * const nla[])
246 {
247 return sizeof(struct nft_rbtree);
248 }
249
nft_rbtree_init(const struct nft_set * set,const struct nft_set_desc * desc,const struct nlattr * const nla[])250 static int nft_rbtree_init(const struct nft_set *set,
251 const struct nft_set_desc *desc,
252 const struct nlattr * const nla[])
253 {
254 struct nft_rbtree *priv = nft_set_priv(set);
255
256 priv->root = RB_ROOT;
257 return 0;
258 }
259
nft_rbtree_destroy(const struct nft_set * set)260 static void nft_rbtree_destroy(const struct nft_set *set)
261 {
262 struct nft_rbtree *priv = nft_set_priv(set);
263 struct nft_rbtree_elem *rbe;
264 struct rb_node *node;
265
266 while ((node = priv->root.rb_node) != NULL) {
267 rb_erase(node, &priv->root);
268 rbe = rb_entry(node, struct nft_rbtree_elem, node);
269 nft_set_elem_destroy(set, rbe, true);
270 }
271 }
272
nft_rbtree_estimate(const struct nft_set_desc * desc,u32 features,struct nft_set_estimate * est)273 static bool nft_rbtree_estimate(const struct nft_set_desc *desc, u32 features,
274 struct nft_set_estimate *est)
275 {
276 unsigned int nsize;
277
278 nsize = sizeof(struct nft_rbtree_elem);
279 if (desc->size)
280 est->size = sizeof(struct nft_rbtree) + desc->size * nsize;
281 else
282 est->size = nsize;
283
284 est->class = NFT_SET_CLASS_O_LOG_N;
285
286 return true;
287 }
288
289 static struct nft_set_ops nft_rbtree_ops __read_mostly = {
290 .privsize = nft_rbtree_privsize,
291 .elemsize = offsetof(struct nft_rbtree_elem, ext),
292 .estimate = nft_rbtree_estimate,
293 .init = nft_rbtree_init,
294 .destroy = nft_rbtree_destroy,
295 .insert = nft_rbtree_insert,
296 .remove = nft_rbtree_remove,
297 .deactivate = nft_rbtree_deactivate,
298 .activate = nft_rbtree_activate,
299 .lookup = nft_rbtree_lookup,
300 .walk = nft_rbtree_walk,
301 .features = NFT_SET_INTERVAL | NFT_SET_MAP,
302 .owner = THIS_MODULE,
303 };
304
nft_rbtree_module_init(void)305 static int __init nft_rbtree_module_init(void)
306 {
307 return nft_register_set(&nft_rbtree_ops);
308 }
309
nft_rbtree_module_exit(void)310 static void __exit nft_rbtree_module_exit(void)
311 {
312 nft_unregister_set(&nft_rbtree_ops);
313 }
314
315 module_init(nft_rbtree_module_init);
316 module_exit(nft_rbtree_module_exit);
317
318 MODULE_LICENSE("GPL");
319 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
320 MODULE_ALIAS_NFT_SET();
321