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5859034d PM |
1 | /* |
2 | * (C) 2007 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 | #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> | |
5a0e3ad6 | 14 | #include <linux/slab.h> |
5859034d | 15 | #include <net/gen_stats.h> |
1e90474c | 16 | #include <net/netlink.h> |
5859034d PM |
17 | |
18 | #include <linux/netfilter/x_tables.h> | |
19 | #include <linux/netfilter/xt_RATEEST.h> | |
20 | #include <net/netfilter/xt_rateest.h> | |
21 | ||
22 | static DEFINE_MUTEX(xt_rateest_mutex); | |
23 | ||
24 | #define RATEEST_HSIZE 16 | |
25 | static struct hlist_head rateest_hash[RATEEST_HSIZE] __read_mostly; | |
26 | static unsigned int jhash_rnd __read_mostly; | |
27 | ||
28 | static unsigned int xt_rateest_hash(const char *name) | |
29 | { | |
30 | return jhash(name, FIELD_SIZEOF(struct xt_rateest, name), jhash_rnd) & | |
31 | (RATEEST_HSIZE - 1); | |
32 | } | |
33 | ||
34 | static void xt_rateest_hash_insert(struct xt_rateest *est) | |
35 | { | |
36 | unsigned int h; | |
37 | ||
38 | h = xt_rateest_hash(est->name); | |
39 | hlist_add_head(&est->list, &rateest_hash[h]); | |
40 | } | |
41 | ||
42 | struct xt_rateest *xt_rateest_lookup(const char *name) | |
43 | { | |
44 | struct xt_rateest *est; | |
5859034d PM |
45 | unsigned int h; |
46 | ||
47 | h = xt_rateest_hash(name); | |
48 | mutex_lock(&xt_rateest_mutex); | |
b67bfe0d | 49 | hlist_for_each_entry(est, &rateest_hash[h], list) { |
5859034d PM |
50 | if (strcmp(est->name, name) == 0) { |
51 | est->refcnt++; | |
52 | mutex_unlock(&xt_rateest_mutex); | |
53 | return est; | |
54 | } | |
55 | } | |
56 | mutex_unlock(&xt_rateest_mutex); | |
57 | return NULL; | |
58 | } | |
59 | EXPORT_SYMBOL_GPL(xt_rateest_lookup); | |
60 | ||
61 | void xt_rateest_put(struct xt_rateest *est) | |
62 | { | |
63 | mutex_lock(&xt_rateest_mutex); | |
64 | if (--est->refcnt == 0) { | |
65 | hlist_del(&est->list); | |
1c0d32fd | 66 | gen_kill_estimator(&est->rate_est); |
c7de2cf0 ED |
67 | /* |
68 | * gen_estimator est_timer() might access est->lock or bstats, | |
69 | * wait a RCU grace period before freeing 'est' | |
70 | */ | |
cefcb602 | 71 | kfree_rcu(est, rcu); |
5859034d PM |
72 | } |
73 | mutex_unlock(&xt_rateest_mutex); | |
74 | } | |
75 | EXPORT_SYMBOL_GPL(xt_rateest_put); | |
76 | ||
77 | static unsigned int | |
4b560b44 | 78 | xt_rateest_tg(struct sk_buff *skb, const struct xt_action_param *par) |
5859034d | 79 | { |
7eb35586 | 80 | const struct xt_rateest_target_info *info = par->targinfo; |
c1a8f1f1 | 81 | struct gnet_stats_basic_packed *stats = &info->est->bstats; |
5859034d PM |
82 | |
83 | spin_lock_bh(&info->est->lock); | |
84 | stats->bytes += skb->len; | |
85 | stats->packets++; | |
86 | spin_unlock_bh(&info->est->lock); | |
87 | ||
88 | return XT_CONTINUE; | |
89 | } | |
90 | ||
135367b8 | 91 | static int xt_rateest_tg_checkentry(const struct xt_tgchk_param *par) |
5859034d | 92 | { |
af5d6dc2 | 93 | struct xt_rateest_target_info *info = par->targinfo; |
5859034d PM |
94 | struct xt_rateest *est; |
95 | struct { | |
1e90474c | 96 | struct nlattr opt; |
5859034d PM |
97 | struct gnet_estimator est; |
98 | } cfg; | |
4a5a5c73 | 99 | int ret; |
5859034d | 100 | |
7bdc6624 | 101 | net_get_random_once(&jhash_rnd, sizeof(jhash_rnd)); |
5191d501 | 102 | |
5859034d PM |
103 | est = xt_rateest_lookup(info->name); |
104 | if (est) { | |
105 | /* | |
106 | * If estimator parameters are specified, they must match the | |
107 | * existing estimator. | |
108 | */ | |
109 | if ((!info->interval && !info->ewma_log) || | |
110 | (info->interval != est->params.interval || | |
111 | info->ewma_log != est->params.ewma_log)) { | |
112 | xt_rateest_put(est); | |
d6b00a53 | 113 | return -EINVAL; |
5859034d PM |
114 | } |
115 | info->est = est; | |
d6b00a53 | 116 | return 0; |
5859034d PM |
117 | } |
118 | ||
4a5a5c73 | 119 | ret = -ENOMEM; |
5859034d PM |
120 | est = kzalloc(sizeof(*est), GFP_KERNEL); |
121 | if (!est) | |
122 | goto err1; | |
123 | ||
124 | strlcpy(est->name, info->name, sizeof(est->name)); | |
125 | spin_lock_init(&est->lock); | |
126 | est->refcnt = 1; | |
127 | est->params.interval = info->interval; | |
128 | est->params.ewma_log = info->ewma_log; | |
129 | ||
1e90474c PM |
130 | cfg.opt.nla_len = nla_attr_size(sizeof(cfg.est)); |
131 | cfg.opt.nla_type = TCA_STATS_RATE_EST; | |
5859034d PM |
132 | cfg.est.interval = info->interval; |
133 | cfg.est.ewma_log = info->ewma_log; | |
134 | ||
1c0d32fd | 135 | ret = gen_new_estimator(&est->bstats, NULL, &est->rate_est, |
edb09eb1 | 136 | &est->lock, NULL, &cfg.opt); |
4a5a5c73 | 137 | if (ret < 0) |
5859034d PM |
138 | goto err2; |
139 | ||
140 | info->est = est; | |
141 | xt_rateest_hash_insert(est); | |
d6b00a53 | 142 | return 0; |
5859034d PM |
143 | |
144 | err2: | |
145 | kfree(est); | |
146 | err1: | |
4a5a5c73 | 147 | return ret; |
5859034d PM |
148 | } |
149 | ||
a2df1648 | 150 | static void xt_rateest_tg_destroy(const struct xt_tgdtor_param *par) |
5859034d | 151 | { |
a2df1648 | 152 | struct xt_rateest_target_info *info = par->targinfo; |
5859034d PM |
153 | |
154 | xt_rateest_put(info->est); | |
155 | } | |
156 | ||
55b69e91 JE |
157 | static struct xt_target xt_rateest_tg_reg __read_mostly = { |
158 | .name = "RATEEST", | |
159 | .revision = 0, | |
160 | .family = NFPROTO_UNSPEC, | |
161 | .target = xt_rateest_tg, | |
162 | .checkentry = xt_rateest_tg_checkentry, | |
163 | .destroy = xt_rateest_tg_destroy, | |
164 | .targetsize = sizeof(struct xt_rateest_target_info), | |
165 | .me = THIS_MODULE, | |
5859034d PM |
166 | }; |
167 | ||
168 | static int __init xt_rateest_tg_init(void) | |
169 | { | |
170 | unsigned int i; | |
171 | ||
172 | for (i = 0; i < ARRAY_SIZE(rateest_hash); i++) | |
173 | INIT_HLIST_HEAD(&rateest_hash[i]); | |
174 | ||
55b69e91 | 175 | return xt_register_target(&xt_rateest_tg_reg); |
5859034d PM |
176 | } |
177 | ||
178 | static void __exit xt_rateest_tg_fini(void) | |
179 | { | |
55b69e91 | 180 | xt_unregister_target(&xt_rateest_tg_reg); |
5859034d PM |
181 | } |
182 | ||
183 | ||
184 | MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); | |
185 | MODULE_LICENSE("GPL"); | |
2ae15b64 | 186 | MODULE_DESCRIPTION("Xtables: packet rate estimator"); |
5859034d PM |
187 | MODULE_ALIAS("ipt_RATEEST"); |
188 | MODULE_ALIAS("ip6t_RATEEST"); | |
189 | module_init(xt_rateest_tg_init); | |
190 | module_exit(xt_rateest_tg_fini); |