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
 21struct nft_rbtree {
 22	struct rb_root		root;
 23};
 24
 25struct nft_rbtree_elem {
 26	struct rb_node		node;
 27	u16			flags;
 28	struct nft_data		key;
 29	struct nft_data		data[];
 30};
 31
 32static bool nft_rbtree_lookup(const struct nft_set *set,
 33			      const struct nft_data *key,
 34			      struct nft_data *data)
 35{
 36	const struct nft_rbtree *priv = nft_set_priv(set);
 37	const struct nft_rbtree_elem *rbe, *interval = NULL;
 38	const struct rb_node *parent = priv->root.rb_node;
 39	int d;
 40
 41	while (parent != NULL) {
 42		rbe = rb_entry(parent, struct nft_rbtree_elem, node);
 43
 44		d = nft_data_cmp(&rbe->key, key, set->klen);
 45		if (d < 0) {
 46			parent = parent->rb_left;
 47			interval = rbe;
 48		} else if (d > 0)
 49			parent = parent->rb_right;
 50		else {
 51found:
 52			if (rbe->flags & NFT_SET_ELEM_INTERVAL_END)
 53				goto out;
 54			if (set->flags & NFT_SET_MAP)
 55				nft_data_copy(data, rbe->data);
 56			return true;
 57		}
 58	}
 59
 60	if (set->flags & NFT_SET_INTERVAL && interval != NULL) {
 61		rbe = interval;
 62		goto found;
 63	}
 64out:
 65	return false;
 66}
 67
 68static void nft_rbtree_elem_destroy(const struct nft_set *set,
 69				    struct nft_rbtree_elem *rbe)
 70{
 71	nft_data_uninit(&rbe->key, NFT_DATA_VALUE);
 72	if (set->flags & NFT_SET_MAP &&
 73	    !(rbe->flags & NFT_SET_ELEM_INTERVAL_END))
 74		nft_data_uninit(rbe->data, set->dtype);
 75
 76	kfree(rbe);
 77}
 78
 79static int __nft_rbtree_insert(const struct nft_set *set,
 80			       struct nft_rbtree_elem *new)
 81{
 82	struct nft_rbtree *priv = nft_set_priv(set);
 83	struct nft_rbtree_elem *rbe;
 84	struct rb_node *parent, **p;
 85	int d;
 86
 87	parent = NULL;
 88	p = &priv->root.rb_node;
 89	while (*p != NULL) {
 90		parent = *p;
 91		rbe = rb_entry(parent, struct nft_rbtree_elem, node);
 92		d = nft_data_cmp(&rbe->key, &new->key, set->klen);
 93		if (d < 0)
 94			p = &parent->rb_left;
 95		else if (d > 0)
 96			p = &parent->rb_right;
 97		else
 98			return -EEXIST;
 99	}
100	rb_link_node(&new->node, parent, p);
101	rb_insert_color(&new->node, &priv->root);
102	return 0;
103}
104
105static int nft_rbtree_insert(const struct nft_set *set,
106			     const struct nft_set_elem *elem)
107{
108	struct nft_rbtree_elem *rbe;
109	unsigned int size;
110	int err;
111
112	size = sizeof(*rbe);
113	if (set->flags & NFT_SET_MAP &&
114	    !(elem->flags & NFT_SET_ELEM_INTERVAL_END))
115		size += sizeof(rbe->data[0]);
116
117	rbe = kzalloc(size, GFP_KERNEL);
118	if (rbe == NULL)
119		return -ENOMEM;
120
121	rbe->flags = elem->flags;
122	nft_data_copy(&rbe->key, &elem->key);
123	if (set->flags & NFT_SET_MAP &&
124	    !(rbe->flags & NFT_SET_ELEM_INTERVAL_END))
125		nft_data_copy(rbe->data, &elem->data);
126
127	err = __nft_rbtree_insert(set, rbe);
128	if (err < 0)
129		kfree(rbe);
130	return err;
131}
132
133static void nft_rbtree_remove(const struct nft_set *set,
134			      const struct nft_set_elem *elem)
135{
136	struct nft_rbtree *priv = nft_set_priv(set);
137	struct nft_rbtree_elem *rbe = elem->cookie;
138
139	rb_erase(&rbe->node, &priv->root);
140	kfree(rbe);
141}
142
143static int nft_rbtree_get(const struct nft_set *set, struct nft_set_elem *elem)
144{
145	const struct nft_rbtree *priv = nft_set_priv(set);
146	const struct rb_node *parent = priv->root.rb_node;
147	struct nft_rbtree_elem *rbe;
148	int d;
149
150	while (parent != NULL) {
151		rbe = rb_entry(parent, struct nft_rbtree_elem, node);
152
153		d = nft_data_cmp(&rbe->key, &elem->key, set->klen);
154		if (d < 0)
155			parent = parent->rb_left;
156		else if (d > 0)
157			parent = parent->rb_right;
158		else {
159			elem->cookie = rbe;
160			if (set->flags & NFT_SET_MAP &&
161			    !(rbe->flags & NFT_SET_ELEM_INTERVAL_END))
162				nft_data_copy(&elem->data, rbe->data);
163			elem->flags = rbe->flags;
164			return 0;
165		}
166	}
167	return -ENOENT;
168}
169
170static void nft_rbtree_walk(const struct nft_ctx *ctx,
171			    const struct nft_set *set,
172			    struct nft_set_iter *iter)
173{
174	const struct nft_rbtree *priv = nft_set_priv(set);
175	const struct nft_rbtree_elem *rbe;
176	struct nft_set_elem elem;
177	struct rb_node *node;
178
179	for (node = rb_first(&priv->root); node != NULL; node = rb_next(node)) {
180		if (iter->count < iter->skip)
181			goto cont;
182
183		rbe = rb_entry(node, struct nft_rbtree_elem, node);
184		nft_data_copy(&elem.key, &rbe->key);
185		if (set->flags & NFT_SET_MAP &&
186		    !(rbe->flags & NFT_SET_ELEM_INTERVAL_END))
187			nft_data_copy(&elem.data, rbe->data);
188		elem.flags = rbe->flags;
189
190		iter->err = iter->fn(ctx, set, iter, &elem);
191		if (iter->err < 0)
192			return;
193cont:
194		iter->count++;
195	}
196}
197
198static unsigned int nft_rbtree_privsize(const struct nlattr * const nla[])
199{
200	return sizeof(struct nft_rbtree);
201}
202
203static int nft_rbtree_init(const struct nft_set *set,
204			   const struct nlattr * const nla[])
205{
206	struct nft_rbtree *priv = nft_set_priv(set);
207
208	priv->root = RB_ROOT;
209	return 0;
210}
211
212static void nft_rbtree_destroy(const struct nft_set *set)
213{
214	struct nft_rbtree *priv = nft_set_priv(set);
215	struct nft_rbtree_elem *rbe;
216	struct rb_node *node;
217
218	while ((node = priv->root.rb_node) != NULL) {
219		rb_erase(node, &priv->root);
220		rbe = rb_entry(node, struct nft_rbtree_elem, node);
221		nft_rbtree_elem_destroy(set, rbe);
222	}
223}
224
225static struct nft_set_ops nft_rbtree_ops __read_mostly = {
226	.privsize	= nft_rbtree_privsize,
227	.init		= nft_rbtree_init,
228	.destroy	= nft_rbtree_destroy,
229	.insert		= nft_rbtree_insert,
230	.remove		= nft_rbtree_remove,
231	.get		= nft_rbtree_get,
232	.lookup		= nft_rbtree_lookup,
233	.walk		= nft_rbtree_walk,
234	.features	= NFT_SET_INTERVAL | NFT_SET_MAP,
235	.owner		= THIS_MODULE,
236};
237
238static int __init nft_rbtree_module_init(void)
239{
240	return nft_register_set(&nft_rbtree_ops);
241}
242
243static void __exit nft_rbtree_module_exit(void)
244{
245	nft_unregister_set(&nft_rbtree_ops);
246}
247
248module_init(nft_rbtree_module_init);
249module_exit(nft_rbtree_module_exit);
250
251MODULE_LICENSE("GPL");
252MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
253MODULE_ALIAS_NFT_SET();