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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
5859034d PM |
2 | /* |
3 | * (C) 2007 Patrick McHardy <kaber@trash.net> | |
5859034d PM |
4 | */ |
5 | #include <linux/module.h> | |
6 | #include <linux/skbuff.h> | |
7 | #include <linux/gen_stats.h> | |
8 | #include <linux/jhash.h> | |
9 | #include <linux/rtnetlink.h> | |
10 | #include <linux/random.h> | |
5a0e3ad6 | 11 | #include <linux/slab.h> |
5859034d | 12 | #include <net/gen_stats.h> |
1e90474c | 13 | #include <net/netlink.h> |
3427b2ab | 14 | #include <net/netns/generic.h> |
5859034d PM |
15 | |
16 | #include <linux/netfilter/x_tables.h> | |
17 | #include <linux/netfilter/xt_RATEEST.h> | |
18 | #include <net/netfilter/xt_rateest.h> | |
19 | ||
5859034d | 20 | #define RATEEST_HSIZE 16 |
3427b2ab CW |
21 | |
22 | struct xt_rateest_net { | |
23 | struct mutex hash_lock; | |
24 | struct hlist_head hash[RATEEST_HSIZE]; | |
25 | }; | |
26 | ||
27 | static unsigned int xt_rateest_id; | |
28 | ||
5859034d PM |
29 | static unsigned int jhash_rnd __read_mostly; |
30 | ||
31 | static unsigned int xt_rateest_hash(const char *name) | |
32 | { | |
33 | return jhash(name, FIELD_SIZEOF(struct xt_rateest, name), jhash_rnd) & | |
34 | (RATEEST_HSIZE - 1); | |
35 | } | |
36 | ||
3427b2ab CW |
37 | static void xt_rateest_hash_insert(struct xt_rateest_net *xn, |
38 | struct xt_rateest *est) | |
5859034d PM |
39 | { |
40 | unsigned int h; | |
41 | ||
42 | h = xt_rateest_hash(est->name); | |
3427b2ab | 43 | hlist_add_head(&est->list, &xn->hash[h]); |
5859034d PM |
44 | } |
45 | ||
3427b2ab CW |
46 | static struct xt_rateest *__xt_rateest_lookup(struct xt_rateest_net *xn, |
47 | const char *name) | |
5859034d PM |
48 | { |
49 | struct xt_rateest *est; | |
5859034d PM |
50 | unsigned int h; |
51 | ||
52 | h = xt_rateest_hash(name); | |
3427b2ab | 53 | hlist_for_each_entry(est, &xn->hash[h], list) { |
5859034d PM |
54 | if (strcmp(est->name, name) == 0) { |
55 | est->refcnt++; | |
5859034d PM |
56 | return est; |
57 | } | |
58 | } | |
7dc68e98 | 59 | |
5859034d PM |
60 | return NULL; |
61 | } | |
7dc68e98 | 62 | |
3427b2ab | 63 | struct xt_rateest *xt_rateest_lookup(struct net *net, const char *name) |
7dc68e98 | 64 | { |
3427b2ab | 65 | struct xt_rateest_net *xn = net_generic(net, xt_rateest_id); |
7dc68e98 CW |
66 | struct xt_rateest *est; |
67 | ||
3427b2ab CW |
68 | mutex_lock(&xn->hash_lock); |
69 | est = __xt_rateest_lookup(xn, name); | |
70 | mutex_unlock(&xn->hash_lock); | |
7dc68e98 CW |
71 | return est; |
72 | } | |
5859034d PM |
73 | EXPORT_SYMBOL_GPL(xt_rateest_lookup); |
74 | ||
3427b2ab | 75 | void xt_rateest_put(struct net *net, struct xt_rateest *est) |
5859034d | 76 | { |
3427b2ab CW |
77 | struct xt_rateest_net *xn = net_generic(net, xt_rateest_id); |
78 | ||
79 | mutex_lock(&xn->hash_lock); | |
5859034d PM |
80 | if (--est->refcnt == 0) { |
81 | hlist_del(&est->list); | |
1c0d32fd | 82 | gen_kill_estimator(&est->rate_est); |
c7de2cf0 ED |
83 | /* |
84 | * gen_estimator est_timer() might access est->lock or bstats, | |
85 | * wait a RCU grace period before freeing 'est' | |
86 | */ | |
cefcb602 | 87 | kfree_rcu(est, rcu); |
5859034d | 88 | } |
3427b2ab | 89 | mutex_unlock(&xn->hash_lock); |
5859034d PM |
90 | } |
91 | EXPORT_SYMBOL_GPL(xt_rateest_put); | |
92 | ||
93 | static unsigned int | |
4b560b44 | 94 | xt_rateest_tg(struct sk_buff *skb, const struct xt_action_param *par) |
5859034d | 95 | { |
7eb35586 | 96 | const struct xt_rateest_target_info *info = par->targinfo; |
c1a8f1f1 | 97 | struct gnet_stats_basic_packed *stats = &info->est->bstats; |
5859034d PM |
98 | |
99 | spin_lock_bh(&info->est->lock); | |
100 | stats->bytes += skb->len; | |
101 | stats->packets++; | |
102 | spin_unlock_bh(&info->est->lock); | |
103 | ||
104 | return XT_CONTINUE; | |
105 | } | |
106 | ||
135367b8 | 107 | static int xt_rateest_tg_checkentry(const struct xt_tgchk_param *par) |
5859034d | 108 | { |
3427b2ab | 109 | struct xt_rateest_net *xn = net_generic(par->net, xt_rateest_id); |
af5d6dc2 | 110 | struct xt_rateest_target_info *info = par->targinfo; |
5859034d PM |
111 | struct xt_rateest *est; |
112 | struct { | |
1e90474c | 113 | struct nlattr opt; |
5859034d PM |
114 | struct gnet_estimator est; |
115 | } cfg; | |
4a5a5c73 | 116 | int ret; |
5859034d | 117 | |
7bdc6624 | 118 | net_get_random_once(&jhash_rnd, sizeof(jhash_rnd)); |
5191d501 | 119 | |
3427b2ab CW |
120 | mutex_lock(&xn->hash_lock); |
121 | est = __xt_rateest_lookup(xn, info->name); | |
5859034d | 122 | if (est) { |
3427b2ab | 123 | mutex_unlock(&xn->hash_lock); |
5859034d PM |
124 | /* |
125 | * If estimator parameters are specified, they must match the | |
126 | * existing estimator. | |
127 | */ | |
128 | if ((!info->interval && !info->ewma_log) || | |
129 | (info->interval != est->params.interval || | |
130 | info->ewma_log != est->params.ewma_log)) { | |
3427b2ab | 131 | xt_rateest_put(par->net, est); |
d6b00a53 | 132 | return -EINVAL; |
5859034d PM |
133 | } |
134 | info->est = est; | |
d6b00a53 | 135 | return 0; |
5859034d PM |
136 | } |
137 | ||
4a5a5c73 | 138 | ret = -ENOMEM; |
5859034d PM |
139 | est = kzalloc(sizeof(*est), GFP_KERNEL); |
140 | if (!est) | |
141 | goto err1; | |
142 | ||
143 | strlcpy(est->name, info->name, sizeof(est->name)); | |
144 | spin_lock_init(&est->lock); | |
145 | est->refcnt = 1; | |
146 | est->params.interval = info->interval; | |
147 | est->params.ewma_log = info->ewma_log; | |
148 | ||
1e90474c PM |
149 | cfg.opt.nla_len = nla_attr_size(sizeof(cfg.est)); |
150 | cfg.opt.nla_type = TCA_STATS_RATE_EST; | |
5859034d PM |
151 | cfg.est.interval = info->interval; |
152 | cfg.est.ewma_log = info->ewma_log; | |
153 | ||
1c0d32fd | 154 | ret = gen_new_estimator(&est->bstats, NULL, &est->rate_est, |
edb09eb1 | 155 | &est->lock, NULL, &cfg.opt); |
4a5a5c73 | 156 | if (ret < 0) |
5859034d PM |
157 | goto err2; |
158 | ||
159 | info->est = est; | |
3427b2ab CW |
160 | xt_rateest_hash_insert(xn, est); |
161 | mutex_unlock(&xn->hash_lock); | |
d6b00a53 | 162 | return 0; |
5859034d PM |
163 | |
164 | err2: | |
165 | kfree(est); | |
166 | err1: | |
3427b2ab | 167 | mutex_unlock(&xn->hash_lock); |
4a5a5c73 | 168 | return ret; |
5859034d PM |
169 | } |
170 | ||
a2df1648 | 171 | static void xt_rateest_tg_destroy(const struct xt_tgdtor_param *par) |
5859034d | 172 | { |
a2df1648 | 173 | struct xt_rateest_target_info *info = par->targinfo; |
5859034d | 174 | |
3427b2ab | 175 | xt_rateest_put(par->net, info->est); |
5859034d PM |
176 | } |
177 | ||
55b69e91 JE |
178 | static struct xt_target xt_rateest_tg_reg __read_mostly = { |
179 | .name = "RATEEST", | |
180 | .revision = 0, | |
181 | .family = NFPROTO_UNSPEC, | |
182 | .target = xt_rateest_tg, | |
183 | .checkentry = xt_rateest_tg_checkentry, | |
184 | .destroy = xt_rateest_tg_destroy, | |
185 | .targetsize = sizeof(struct xt_rateest_target_info), | |
ec231890 | 186 | .usersize = offsetof(struct xt_rateest_target_info, est), |
55b69e91 | 187 | .me = THIS_MODULE, |
5859034d PM |
188 | }; |
189 | ||
3427b2ab CW |
190 | static __net_init int xt_rateest_net_init(struct net *net) |
191 | { | |
192 | struct xt_rateest_net *xn = net_generic(net, xt_rateest_id); | |
193 | int i; | |
194 | ||
195 | mutex_init(&xn->hash_lock); | |
196 | for (i = 0; i < ARRAY_SIZE(xn->hash); i++) | |
197 | INIT_HLIST_HEAD(&xn->hash[i]); | |
198 | return 0; | |
199 | } | |
200 | ||
3427b2ab CW |
201 | static struct pernet_operations xt_rateest_net_ops = { |
202 | .init = xt_rateest_net_init, | |
3427b2ab CW |
203 | .id = &xt_rateest_id, |
204 | .size = sizeof(struct xt_rateest_net), | |
205 | }; | |
206 | ||
207 | static int __init xt_rateest_tg_init(void) | |
208 | { | |
209 | int err = register_pernet_subsys(&xt_rateest_net_ops); | |
5859034d | 210 | |
3427b2ab CW |
211 | if (err) |
212 | return err; | |
55b69e91 | 213 | return xt_register_target(&xt_rateest_tg_reg); |
5859034d PM |
214 | } |
215 | ||
216 | static void __exit xt_rateest_tg_fini(void) | |
217 | { | |
55b69e91 | 218 | xt_unregister_target(&xt_rateest_tg_reg); |
3427b2ab | 219 | unregister_pernet_subsys(&xt_rateest_net_ops); |
5859034d PM |
220 | } |
221 | ||
222 | ||
223 | MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); | |
224 | MODULE_LICENSE("GPL"); | |
2ae15b64 | 225 | MODULE_DESCRIPTION("Xtables: packet rate estimator"); |
5859034d PM |
226 | MODULE_ALIAS("ipt_RATEEST"); |
227 | MODULE_ALIAS("ip6t_RATEEST"); | |
228 | module_init(xt_rateest_tg_init); | |
229 | module_exit(xt_rateest_tg_fini); |