2 * (C) 2007 Patrick McHardy <kaber@trash.net>
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.
8 #include <linux/module.h>
9 #include <linux/skbuff.h>
10 #include <linux/gen_stats.h>
11 #include <linux/jhash.h>
12 #include <linux/rtnetlink.h>
13 #include <linux/random.h>
14 #include <net/gen_stats.h>
15 #include <net/netlink.h>
17 #include <linux/netfilter/x_tables.h>
18 #include <linux/netfilter/xt_RATEEST.h>
19 #include <net/netfilter/xt_rateest.h>
21 static DEFINE_MUTEX(xt_rateest_mutex);
23 #define RATEEST_HSIZE 16
24 static struct hlist_head rateest_hash[RATEEST_HSIZE] __read_mostly;
25 static unsigned int jhash_rnd __read_mostly;
27 static unsigned int xt_rateest_hash(const char *name)
29 return jhash(name, FIELD_SIZEOF(struct xt_rateest, name), jhash_rnd) &
33 static void xt_rateest_hash_insert(struct xt_rateest *est)
37 h = xt_rateest_hash(est->name);
38 hlist_add_head(&est->list, &rateest_hash[h]);
41 struct xt_rateest *xt_rateest_lookup(const char *name)
43 struct xt_rateest *est;
47 h = xt_rateest_hash(name);
48 mutex_lock(&xt_rateest_mutex);
49 hlist_for_each_entry(est, n, &rateest_hash[h], list) {
50 if (strcmp(est->name, name) == 0) {
52 mutex_unlock(&xt_rateest_mutex);
56 mutex_unlock(&xt_rateest_mutex);
59 EXPORT_SYMBOL_GPL(xt_rateest_lookup);
61 void xt_rateest_put(struct xt_rateest *est)
63 mutex_lock(&xt_rateest_mutex);
64 if (--est->refcnt == 0) {
65 hlist_del(&est->list);
66 gen_kill_estimator(&est->bstats, &est->rstats);
69 mutex_unlock(&xt_rateest_mutex);
71 EXPORT_SYMBOL_GPL(xt_rateest_put);
74 xt_rateest_tg(struct sk_buff *skb, const struct xt_target_param *par)
76 const struct xt_rateest_target_info *info = par->targinfo;
77 struct gnet_stats_basic *stats = &info->est->bstats;
79 spin_lock_bh(&info->est->lock);
80 stats->bytes += skb->len;
82 spin_unlock_bh(&info->est->lock);
87 static bool xt_rateest_tg_checkentry(const struct xt_tgchk_param *par)
89 struct xt_rateest_target_info *info = par->targinfo;
90 struct xt_rateest *est;
93 struct gnet_estimator est;
96 est = xt_rateest_lookup(info->name);
99 * If estimator parameters are specified, they must match the
100 * existing estimator.
102 if ((!info->interval && !info->ewma_log) ||
103 (info->interval != est->params.interval ||
104 info->ewma_log != est->params.ewma_log)) {
112 est = kzalloc(sizeof(*est), GFP_KERNEL);
116 strlcpy(est->name, info->name, sizeof(est->name));
117 spin_lock_init(&est->lock);
119 est->params.interval = info->interval;
120 est->params.ewma_log = info->ewma_log;
122 cfg.opt.nla_len = nla_attr_size(sizeof(cfg.est));
123 cfg.opt.nla_type = TCA_STATS_RATE_EST;
124 cfg.est.interval = info->interval;
125 cfg.est.ewma_log = info->ewma_log;
127 if (gen_new_estimator(&est->bstats, &est->rstats, &est->lock,
132 xt_rateest_hash_insert(est);
142 static void xt_rateest_tg_destroy(const struct xt_tgdtor_param *par)
144 struct xt_rateest_target_info *info = par->targinfo;
146 xt_rateest_put(info->est);
149 static struct xt_target xt_rateest_tg_reg __read_mostly = {
152 .family = NFPROTO_UNSPEC,
153 .target = xt_rateest_tg,
154 .checkentry = xt_rateest_tg_checkentry,
155 .destroy = xt_rateest_tg_destroy,
156 .targetsize = sizeof(struct xt_rateest_target_info),
160 static int __init xt_rateest_tg_init(void)
164 for (i = 0; i < ARRAY_SIZE(rateest_hash); i++)
165 INIT_HLIST_HEAD(&rateest_hash[i]);
167 get_random_bytes(&jhash_rnd, sizeof(jhash_rnd));
168 return xt_register_target(&xt_rateest_tg_reg);
171 static void __exit xt_rateest_tg_fini(void)
173 xt_unregister_target(&xt_rateest_tg_reg);
177 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
178 MODULE_LICENSE("GPL");
179 MODULE_DESCRIPTION("Xtables: packet rate estimator");
180 MODULE_ALIAS("ipt_RATEEST");
181 MODULE_ALIAS("ip6t_RATEEST");
182 module_init(xt_rateest_tg_init);
183 module_exit(xt_rateest_tg_fini);