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
);