Commit | Line | Data |
---|---|---|
09e410de JE |
1 | /* |
2 | * xt_hashlimit - Netfilter module to limit the number of packets per time | |
3ad2f3fb | 3 | * separately for each hashbucket (sourceip/sourceport/dstip/dstport) |
1da177e4 | 4 | * |
09e410de | 5 | * (C) 2003-2004 by Harald Welte <laforge@netfilter.org> |
f229f6ce | 6 | * (C) 2006-2012 Patrick McHardy <kaber@trash.net> |
09e410de | 7 | * Copyright © CC Computer Consultants GmbH, 2007 - 2008 |
1da177e4 LT |
8 | * |
9 | * Development of this code was funded by Astaro AG, http://www.astaro.com/ | |
1da177e4 | 10 | */ |
8bee4bad | 11 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
1da177e4 | 12 | #include <linux/module.h> |
1da177e4 LT |
13 | #include <linux/spinlock.h> |
14 | #include <linux/random.h> | |
15 | #include <linux/jhash.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/vmalloc.h> | |
1da177e4 LT |
18 | #include <linux/proc_fs.h> |
19 | #include <linux/seq_file.h> | |
20 | #include <linux/list.h> | |
39b46fc6 | 21 | #include <linux/skbuff.h> |
d7fe0f24 | 22 | #include <linux/mm.h> |
39b46fc6 PM |
23 | #include <linux/in.h> |
24 | #include <linux/ip.h> | |
c0cd1156 | 25 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
39b46fc6 | 26 | #include <linux/ipv6.h> |
193b23c5 | 27 | #include <net/ipv6.h> |
7b21e09d ED |
28 | #endif |
29 | ||
457c4cbc | 30 | #include <net/net_namespace.h> |
e89fc3f1 | 31 | #include <net/netns/generic.h> |
1da177e4 | 32 | |
39b46fc6 | 33 | #include <linux/netfilter/x_tables.h> |
1da177e4 | 34 | #include <linux/netfilter_ipv4/ip_tables.h> |
39b46fc6 PM |
35 | #include <linux/netfilter_ipv6/ip6_tables.h> |
36 | #include <linux/netfilter/xt_hashlimit.h> | |
14cc3e2b | 37 | #include <linux/mutex.h> |
90c4ae4e | 38 | #include <linux/kernel.h> |
1da177e4 LT |
39 | |
40 | MODULE_LICENSE("GPL"); | |
41 | MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); | |
408ffaa4 | 42 | MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>"); |
2ae15b64 | 43 | MODULE_DESCRIPTION("Xtables: per hash-bucket rate-limit match"); |
39b46fc6 PM |
44 | MODULE_ALIAS("ipt_hashlimit"); |
45 | MODULE_ALIAS("ip6t_hashlimit"); | |
1da177e4 | 46 | |
e89fc3f1 AD |
47 | struct hashlimit_net { |
48 | struct hlist_head htables; | |
49 | struct proc_dir_entry *ipt_hashlimit; | |
50 | struct proc_dir_entry *ip6t_hashlimit; | |
51 | }; | |
52 | ||
c7d03a00 | 53 | static unsigned int hashlimit_net_id; |
e89fc3f1 AD |
54 | static inline struct hashlimit_net *hashlimit_pernet(struct net *net) |
55 | { | |
56 | return net_generic(net, hashlimit_net_id); | |
57 | } | |
58 | ||
1da177e4 | 59 | /* need to declare this at the top */ |
bea74641 | 60 | static const struct file_operations dl_file_ops_v2; |
0dc60a45 | 61 | static const struct file_operations dl_file_ops_v1; |
11d5f157 | 62 | static const struct file_operations dl_file_ops; |
1da177e4 LT |
63 | |
64 | /* hash table crap */ | |
1da177e4 | 65 | struct dsthash_dst { |
39b46fc6 PM |
66 | union { |
67 | struct { | |
68 | __be32 src; | |
69 | __be32 dst; | |
70 | } ip; | |
c0cd1156 | 71 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
39b46fc6 PM |
72 | struct { |
73 | __be32 src[4]; | |
74 | __be32 dst[4]; | |
75 | } ip6; | |
7b21e09d | 76 | #endif |
09e410de | 77 | }; |
6a19d614 AV |
78 | __be16 src_port; |
79 | __be16 dst_port; | |
1da177e4 LT |
80 | }; |
81 | ||
82 | struct dsthash_ent { | |
83 | /* static / read-only parts in the beginning */ | |
84 | struct hlist_node node; | |
85 | struct dsthash_dst dst; | |
86 | ||
87 | /* modified structure members in the end */ | |
02e4eb75 | 88 | spinlock_t lock; |
1da177e4 LT |
89 | unsigned long expires; /* precalculated expiry time */ |
90 | struct { | |
91 | unsigned long prev; /* last modification */ | |
bea74641 VP |
92 | union { |
93 | struct { | |
94 | u_int64_t credit; | |
95 | u_int64_t credit_cap; | |
96 | u_int64_t cost; | |
97 | }; | |
98 | struct { | |
99 | u_int32_t interval, prev_window; | |
100 | u_int64_t current_rate; | |
101 | u_int64_t rate; | |
102 | int64_t burst; | |
103 | }; | |
104 | }; | |
1da177e4 | 105 | } rateinfo; |
02e4eb75 | 106 | struct rcu_head rcu; |
1da177e4 LT |
107 | }; |
108 | ||
39b46fc6 | 109 | struct xt_hashlimit_htable { |
1da177e4 | 110 | struct hlist_node node; /* global list of all htables */ |
2eff25c1 | 111 | int use; |
76108cea | 112 | u_int8_t family; |
89bc7a0f | 113 | bool rnd_initialized; |
1da177e4 | 114 | |
bea74641 | 115 | struct hashlimit_cfg3 cfg; /* config */ |
1da177e4 LT |
116 | |
117 | /* used internally */ | |
118 | spinlock_t lock; /* lock for list_head */ | |
119 | u_int32_t rnd; /* random seed for hash */ | |
39b46fc6 | 120 | unsigned int count; /* number entries in table */ |
7bd8490e | 121 | struct delayed_work gc_work; |
1da177e4 LT |
122 | |
123 | /* seq_file stuff */ | |
124 | struct proc_dir_entry *pde; | |
14b872f0 | 125 | const char *name; |
e89fc3f1 | 126 | struct net *net; |
1da177e4 LT |
127 | |
128 | struct hlist_head hash[0]; /* hashtable itself */ | |
129 | }; | |
130 | ||
11d5f157 | 131 | static int |
bea74641 | 132 | cfg_copy(struct hashlimit_cfg3 *to, const void *from, int revision) |
11d5f157 VP |
133 | { |
134 | if (revision == 1) { | |
bea74641 | 135 | struct hashlimit_cfg1 *cfg = (struct hashlimit_cfg1 *)from; |
11d5f157 VP |
136 | |
137 | to->mode = cfg->mode; | |
138 | to->avg = cfg->avg; | |
139 | to->burst = cfg->burst; | |
140 | to->size = cfg->size; | |
141 | to->max = cfg->max; | |
142 | to->gc_interval = cfg->gc_interval; | |
143 | to->expire = cfg->expire; | |
144 | to->srcmask = cfg->srcmask; | |
145 | to->dstmask = cfg->dstmask; | |
146 | } else if (revision == 2) { | |
bea74641 VP |
147 | struct hashlimit_cfg2 *cfg = (struct hashlimit_cfg2 *)from; |
148 | ||
149 | to->mode = cfg->mode; | |
150 | to->avg = cfg->avg; | |
151 | to->burst = cfg->burst; | |
152 | to->size = cfg->size; | |
153 | to->max = cfg->max; | |
154 | to->gc_interval = cfg->gc_interval; | |
155 | to->expire = cfg->expire; | |
156 | to->srcmask = cfg->srcmask; | |
157 | to->dstmask = cfg->dstmask; | |
158 | } else if (revision == 3) { | |
159 | memcpy(to, from, sizeof(struct hashlimit_cfg3)); | |
11d5f157 VP |
160 | } else { |
161 | return -EINVAL; | |
162 | } | |
163 | ||
164 | return 0; | |
165 | } | |
166 | ||
2eff25c1 | 167 | static DEFINE_MUTEX(hashlimit_mutex); /* protects htables list */ |
e18b890b | 168 | static struct kmem_cache *hashlimit_cachep __read_mostly; |
1da177e4 | 169 | |
1d93a9cb | 170 | static inline bool dst_cmp(const struct dsthash_ent *ent, |
a47362a2 | 171 | const struct dsthash_dst *b) |
1da177e4 | 172 | { |
39b46fc6 | 173 | return !memcmp(&ent->dst, b, sizeof(ent->dst)); |
1da177e4 LT |
174 | } |
175 | ||
39b46fc6 PM |
176 | static u_int32_t |
177 | hash_dst(const struct xt_hashlimit_htable *ht, const struct dsthash_dst *dst) | |
1da177e4 | 178 | { |
e2f82ac3 ED |
179 | u_int32_t hash = jhash2((const u32 *)dst, |
180 | sizeof(*dst)/sizeof(u32), | |
181 | ht->rnd); | |
182 | /* | |
183 | * Instead of returning hash % ht->cfg.size (implying a divide) | |
184 | * we return the high 32 bits of the (hash * ht->cfg.size) that will | |
185 | * give results between [0 and cfg.size-1] and same hash distribution, | |
186 | * but using a multiply, less expensive than a divide | |
187 | */ | |
8fc54f68 | 188 | return reciprocal_scale(hash, ht->cfg.size); |
1da177e4 LT |
189 | } |
190 | ||
39b46fc6 | 191 | static struct dsthash_ent * |
a47362a2 JE |
192 | dsthash_find(const struct xt_hashlimit_htable *ht, |
193 | const struct dsthash_dst *dst) | |
1da177e4 LT |
194 | { |
195 | struct dsthash_ent *ent; | |
1da177e4 LT |
196 | u_int32_t hash = hash_dst(ht, dst); |
197 | ||
39b46fc6 | 198 | if (!hlist_empty(&ht->hash[hash])) { |
b67bfe0d | 199 | hlist_for_each_entry_rcu(ent, &ht->hash[hash], node) |
02e4eb75 ED |
200 | if (dst_cmp(ent, dst)) { |
201 | spin_lock(&ent->lock); | |
1da177e4 | 202 | return ent; |
02e4eb75 | 203 | } |
39b46fc6 | 204 | } |
1da177e4 LT |
205 | return NULL; |
206 | } | |
207 | ||
208 | /* allocate dsthash_ent, initialize dst, put in htable and lock it */ | |
209 | static struct dsthash_ent * | |
a47362a2 | 210 | dsthash_alloc_init(struct xt_hashlimit_htable *ht, |
09181842 | 211 | const struct dsthash_dst *dst, bool *race) |
1da177e4 LT |
212 | { |
213 | struct dsthash_ent *ent; | |
214 | ||
02e4eb75 | 215 | spin_lock(&ht->lock); |
09181842 PNA |
216 | |
217 | /* Two or more packets may race to create the same entry in the | |
218 | * hashtable, double check if this packet lost race. | |
219 | */ | |
220 | ent = dsthash_find(ht, dst); | |
221 | if (ent != NULL) { | |
222 | spin_unlock(&ht->lock); | |
223 | *race = true; | |
224 | return ent; | |
225 | } | |
226 | ||
1da177e4 LT |
227 | /* initialize hash with random val at the time we allocate |
228 | * the first hashtable entry */ | |
02e4eb75 | 229 | if (unlikely(!ht->rnd_initialized)) { |
af07d241 | 230 | get_random_bytes(&ht->rnd, sizeof(ht->rnd)); |
89bc7a0f | 231 | ht->rnd_initialized = true; |
bf0857ea | 232 | } |
1da177e4 | 233 | |
39b46fc6 | 234 | if (ht->cfg.max && ht->count >= ht->cfg.max) { |
1da177e4 | 235 | /* FIXME: do something. question is what.. */ |
e87cc472 | 236 | net_err_ratelimited("max count of %u reached\n", ht->cfg.max); |
02e4eb75 ED |
237 | ent = NULL; |
238 | } else | |
239 | ent = kmem_cache_alloc(hashlimit_cachep, GFP_ATOMIC); | |
0a9ee813 | 240 | if (ent) { |
02e4eb75 ED |
241 | memcpy(&ent->dst, dst, sizeof(ent->dst)); |
242 | spin_lock_init(&ent->lock); | |
1da177e4 | 243 | |
02e4eb75 ED |
244 | spin_lock(&ent->lock); |
245 | hlist_add_head_rcu(&ent->node, &ht->hash[hash_dst(ht, dst)]); | |
246 | ht->count++; | |
247 | } | |
248 | spin_unlock(&ht->lock); | |
1da177e4 LT |
249 | return ent; |
250 | } | |
251 | ||
02e4eb75 ED |
252 | static void dsthash_free_rcu(struct rcu_head *head) |
253 | { | |
254 | struct dsthash_ent *ent = container_of(head, struct dsthash_ent, rcu); | |
255 | ||
256 | kmem_cache_free(hashlimit_cachep, ent); | |
257 | } | |
258 | ||
39b46fc6 PM |
259 | static inline void |
260 | dsthash_free(struct xt_hashlimit_htable *ht, struct dsthash_ent *ent) | |
1da177e4 | 261 | { |
02e4eb75 ED |
262 | hlist_del_rcu(&ent->node); |
263 | call_rcu_bh(&ent->rcu, dsthash_free_rcu); | |
39b46fc6 | 264 | ht->count--; |
1da177e4 | 265 | } |
7bd8490e | 266 | static void htable_gc(struct work_struct *work); |
1da177e4 | 267 | |
bea74641 | 268 | static int htable_create(struct net *net, struct hashlimit_cfg3 *cfg, |
11d5f157 VP |
269 | const char *name, u_int8_t family, |
270 | struct xt_hashlimit_htable **out_hinfo, | |
271 | int revision) | |
09e410de | 272 | { |
e89fc3f1 | 273 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); |
09e410de | 274 | struct xt_hashlimit_htable *hinfo; |
bea74641 | 275 | const struct file_operations *fops; |
11d5f157 VP |
276 | unsigned int size, i; |
277 | int ret; | |
09e410de | 278 | |
11d5f157 VP |
279 | if (cfg->size) { |
280 | size = cfg->size; | |
09e410de | 281 | } else { |
4481374c | 282 | size = (totalram_pages << PAGE_SHIFT) / 16384 / |
05d0eae7 | 283 | sizeof(struct hlist_head); |
4481374c | 284 | if (totalram_pages > 1024 * 1024 * 1024 / PAGE_SIZE) |
09e410de JE |
285 | size = 8192; |
286 | if (size < 16) | |
287 | size = 16; | |
288 | } | |
289 | /* FIXME: don't use vmalloc() here or anywhere else -HW */ | |
290 | hinfo = vmalloc(sizeof(struct xt_hashlimit_htable) + | |
05d0eae7 | 291 | sizeof(struct hlist_head) * size); |
85bc3f38 | 292 | if (hinfo == NULL) |
4a5a5c73 | 293 | return -ENOMEM; |
11d5f157 | 294 | *out_hinfo = hinfo; |
09e410de JE |
295 | |
296 | /* copy match config into hashtable config */ | |
bea74641 | 297 | ret = cfg_copy(&hinfo->cfg, (void *)cfg, 3); |
f500a4ef TY |
298 | if (ret) { |
299 | vfree(hinfo); | |
11d5f157 | 300 | return ret; |
f500a4ef | 301 | } |
11d5f157 | 302 | |
09e410de JE |
303 | hinfo->cfg.size = size; |
304 | if (hinfo->cfg.max == 0) | |
305 | hinfo->cfg.max = 8 * hinfo->cfg.size; | |
306 | else if (hinfo->cfg.max < hinfo->cfg.size) | |
307 | hinfo->cfg.max = hinfo->cfg.size; | |
308 | ||
309 | for (i = 0; i < hinfo->cfg.size; i++) | |
310 | INIT_HLIST_HEAD(&hinfo->hash[i]); | |
311 | ||
2eff25c1 | 312 | hinfo->use = 1; |
09e410de JE |
313 | hinfo->count = 0; |
314 | hinfo->family = family; | |
89bc7a0f | 315 | hinfo->rnd_initialized = false; |
11d5f157 | 316 | hinfo->name = kstrdup(name, GFP_KERNEL); |
14b872f0 AV |
317 | if (!hinfo->name) { |
318 | vfree(hinfo); | |
319 | return -ENOMEM; | |
320 | } | |
09e410de JE |
321 | spin_lock_init(&hinfo->lock); |
322 | ||
bea74641 VP |
323 | switch (revision) { |
324 | case 1: | |
325 | fops = &dl_file_ops_v1; | |
326 | break; | |
327 | case 2: | |
328 | fops = &dl_file_ops_v2; | |
329 | break; | |
330 | default: | |
331 | fops = &dl_file_ops; | |
332 | } | |
333 | ||
11d5f157 | 334 | hinfo->pde = proc_create_data(name, 0, |
ee999d8b | 335 | (family == NFPROTO_IPV4) ? |
e89fc3f1 | 336 | hashlimit_net->ipt_hashlimit : hashlimit_net->ip6t_hashlimit, |
bea74641 | 337 | fops, hinfo); |
09e410de | 338 | if (hinfo->pde == NULL) { |
14b872f0 | 339 | kfree(hinfo->name); |
09e410de | 340 | vfree(hinfo); |
4a5a5c73 | 341 | return -ENOMEM; |
09e410de | 342 | } |
e89fc3f1 | 343 | hinfo->net = net; |
09e410de | 344 | |
7bd8490e ED |
345 | INIT_DEFERRABLE_WORK(&hinfo->gc_work, htable_gc); |
346 | queue_delayed_work(system_power_efficient_wq, &hinfo->gc_work, | |
347 | msecs_to_jiffies(hinfo->cfg.gc_interval)); | |
09e410de | 348 | |
e89fc3f1 | 349 | hlist_add_head(&hinfo->node, &hashlimit_net->htables); |
09e410de JE |
350 | |
351 | return 0; | |
352 | } | |
353 | ||
a47362a2 JE |
354 | static bool select_all(const struct xt_hashlimit_htable *ht, |
355 | const struct dsthash_ent *he) | |
1da177e4 LT |
356 | { |
357 | return 1; | |
358 | } | |
359 | ||
a47362a2 JE |
360 | static bool select_gc(const struct xt_hashlimit_htable *ht, |
361 | const struct dsthash_ent *he) | |
1da177e4 | 362 | { |
cbebc51f | 363 | return time_after_eq(jiffies, he->expires); |
1da177e4 LT |
364 | } |
365 | ||
39b46fc6 | 366 | static void htable_selective_cleanup(struct xt_hashlimit_htable *ht, |
a47362a2 JE |
367 | bool (*select)(const struct xt_hashlimit_htable *ht, |
368 | const struct dsthash_ent *he)) | |
1da177e4 | 369 | { |
39b46fc6 | 370 | unsigned int i; |
1da177e4 | 371 | |
1da177e4 LT |
372 | for (i = 0; i < ht->cfg.size; i++) { |
373 | struct dsthash_ent *dh; | |
b67bfe0d | 374 | struct hlist_node *n; |
7bd8490e ED |
375 | |
376 | spin_lock_bh(&ht->lock); | |
b67bfe0d | 377 | hlist_for_each_entry_safe(dh, n, &ht->hash[i], node) { |
1da177e4 | 378 | if ((*select)(ht, dh)) |
39b46fc6 | 379 | dsthash_free(ht, dh); |
1da177e4 | 380 | } |
7bd8490e ED |
381 | spin_unlock_bh(&ht->lock); |
382 | cond_resched(); | |
1da177e4 | 383 | } |
1da177e4 LT |
384 | } |
385 | ||
7bd8490e | 386 | static void htable_gc(struct work_struct *work) |
1da177e4 | 387 | { |
7bd8490e ED |
388 | struct xt_hashlimit_htable *ht; |
389 | ||
390 | ht = container_of(work, struct xt_hashlimit_htable, gc_work.work); | |
1da177e4 LT |
391 | |
392 | htable_selective_cleanup(ht, select_gc); | |
393 | ||
7bd8490e ED |
394 | queue_delayed_work(system_power_efficient_wq, |
395 | &ht->gc_work, msecs_to_jiffies(ht->cfg.gc_interval)); | |
1da177e4 LT |
396 | } |
397 | ||
b4ef4ce0 | 398 | static void htable_remove_proc_entry(struct xt_hashlimit_htable *hinfo) |
1da177e4 | 399 | { |
e89fc3f1 AD |
400 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(hinfo->net); |
401 | struct proc_dir_entry *parent; | |
402 | ||
e89fc3f1 AD |
403 | if (hinfo->family == NFPROTO_IPV4) |
404 | parent = hashlimit_net->ipt_hashlimit; | |
405 | else | |
406 | parent = hashlimit_net->ip6t_hashlimit; | |
32263dd1 | 407 | |
b4ef4ce0 | 408 | if (parent != NULL) |
14b872f0 | 409 | remove_proc_entry(hinfo->name, parent); |
b4ef4ce0 | 410 | } |
32263dd1 | 411 | |
b4ef4ce0 SP |
412 | static void htable_destroy(struct xt_hashlimit_htable *hinfo) |
413 | { | |
7bd8490e | 414 | cancel_delayed_work_sync(&hinfo->gc_work); |
b4ef4ce0 | 415 | htable_remove_proc_entry(hinfo); |
1da177e4 | 416 | htable_selective_cleanup(hinfo, select_all); |
14b872f0 | 417 | kfree(hinfo->name); |
1da177e4 LT |
418 | vfree(hinfo); |
419 | } | |
420 | ||
e89fc3f1 AD |
421 | static struct xt_hashlimit_htable *htable_find_get(struct net *net, |
422 | const char *name, | |
76108cea | 423 | u_int8_t family) |
1da177e4 | 424 | { |
e89fc3f1 | 425 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); |
39b46fc6 | 426 | struct xt_hashlimit_htable *hinfo; |
1da177e4 | 427 | |
b67bfe0d | 428 | hlist_for_each_entry(hinfo, &hashlimit_net->htables, node) { |
14b872f0 | 429 | if (!strcmp(name, hinfo->name) && |
39b46fc6 | 430 | hinfo->family == family) { |
2eff25c1 | 431 | hinfo->use++; |
1da177e4 LT |
432 | return hinfo; |
433 | } | |
434 | } | |
1da177e4 LT |
435 | return NULL; |
436 | } | |
437 | ||
39b46fc6 | 438 | static void htable_put(struct xt_hashlimit_htable *hinfo) |
1da177e4 | 439 | { |
2eff25c1 PM |
440 | mutex_lock(&hashlimit_mutex); |
441 | if (--hinfo->use == 0) { | |
1da177e4 | 442 | hlist_del(&hinfo->node); |
1da177e4 LT |
443 | htable_destroy(hinfo); |
444 | } | |
2eff25c1 | 445 | mutex_unlock(&hashlimit_mutex); |
1da177e4 LT |
446 | } |
447 | ||
1da177e4 LT |
448 | /* The algorithm used is the Simple Token Bucket Filter (TBF) |
449 | * see net/sched/sch_tbf.c in the linux source tree | |
450 | */ | |
451 | ||
452 | /* Rusty: This is my (non-mathematically-inclined) understanding of | |
453 | this algorithm. The `average rate' in jiffies becomes your initial | |
454 | amount of credit `credit' and the most credit you can ever have | |
455 | `credit_cap'. The `peak rate' becomes the cost of passing the | |
456 | test, `cost'. | |
457 | ||
458 | `prev' tracks the last packet hit: you gain one credit per jiffy. | |
459 | If you get credit balance more than this, the extra credit is | |
460 | discarded. Every time the match passes, you lose `cost' credits; | |
461 | if you don't have that many, the test fails. | |
462 | ||
463 | See Alexey's formal explanation in net/sched/sch_tbf.c. | |
464 | ||
465 | To get the maximum range, we multiply by this factor (ie. you get N | |
466 | credits per jiffy). We want to allow a rate as low as 1 per day | |
467 | (slowest userspace tool allows), which means | |
468 | CREDITS_PER_JIFFY*HZ*60*60*24 < 2^32 ie. | |
469 | */ | |
0dc60a45 | 470 | #define MAX_CPJ_v1 (0xFFFFFFFF / (HZ*60*60*24)) |
1b203c13 | 471 | #define MAX_CPJ (0xFFFFFFFFFFFFFFFFULL / (HZ*60*60*24)) |
1da177e4 LT |
472 | |
473 | /* Repeated shift and or gives us all 1s, final shift and add 1 gives | |
474 | * us the power of 2 below the theoretical max, so GCC simply does a | |
475 | * shift. */ | |
476 | #define _POW2_BELOW2(x) ((x)|((x)>>1)) | |
477 | #define _POW2_BELOW4(x) (_POW2_BELOW2(x)|_POW2_BELOW2((x)>>2)) | |
478 | #define _POW2_BELOW8(x) (_POW2_BELOW4(x)|_POW2_BELOW4((x)>>4)) | |
479 | #define _POW2_BELOW16(x) (_POW2_BELOW8(x)|_POW2_BELOW8((x)>>8)) | |
480 | #define _POW2_BELOW32(x) (_POW2_BELOW16(x)|_POW2_BELOW16((x)>>16)) | |
11d5f157 | 481 | #define _POW2_BELOW64(x) (_POW2_BELOW32(x)|_POW2_BELOW32((x)>>32)) |
1da177e4 | 482 | #define POW2_BELOW32(x) ((_POW2_BELOW32(x)>>1) + 1) |
11d5f157 | 483 | #define POW2_BELOW64(x) ((_POW2_BELOW64(x)>>1) + 1) |
1da177e4 | 484 | |
11d5f157 | 485 | #define CREDITS_PER_JIFFY POW2_BELOW64(MAX_CPJ) |
0dc60a45 | 486 | #define CREDITS_PER_JIFFY_v1 POW2_BELOW32(MAX_CPJ_v1) |
1da177e4 | 487 | |
0197dee7 FW |
488 | /* in byte mode, the lowest possible rate is one packet/second. |
489 | * credit_cap is used as a counter that tells us how many times we can | |
490 | * refill the "credits available" counter when it becomes empty. | |
491 | */ | |
492 | #define MAX_CPJ_BYTES (0xFFFFFFFF / HZ) | |
493 | #define CREDITS_PER_JIFFY_BYTES POW2_BELOW32(MAX_CPJ_BYTES) | |
494 | ||
495 | static u32 xt_hashlimit_len_to_chunks(u32 len) | |
496 | { | |
497 | return (len >> XT_HASHLIMIT_BYTE_SHIFT) + 1; | |
498 | } | |
499 | ||
1da177e4 | 500 | /* Precision saver. */ |
11d5f157 | 501 | static u64 user2credits(u64 user, int revision) |
1da177e4 | 502 | { |
ad5b5576 AB |
503 | u64 scale = (revision == 1) ? |
504 | XT_HASHLIMIT_SCALE : XT_HASHLIMIT_SCALE_v2; | |
505 | u64 cpj = (revision == 1) ? | |
506 | CREDITS_PER_JIFFY_v1 : CREDITS_PER_JIFFY; | |
1da177e4 | 507 | |
ad5b5576 AB |
508 | /* Avoid overflow: divide the constant operands first */ |
509 | if (scale >= HZ * cpj) | |
510 | return div64_u64(user, div64_u64(scale, HZ * cpj)); | |
511 | ||
512 | return user * div64_u64(HZ * cpj, scale); | |
1da177e4 LT |
513 | } |
514 | ||
0197dee7 | 515 | static u32 user2credits_byte(u32 user) |
1da177e4 | 516 | { |
0197dee7 FW |
517 | u64 us = user; |
518 | us *= HZ * CREDITS_PER_JIFFY_BYTES; | |
519 | return (u32) (us >> 32); | |
520 | } | |
521 | ||
bea74641 VP |
522 | static u64 user2rate(u64 user) |
523 | { | |
524 | if (user != 0) { | |
525 | return div64_u64(XT_HASHLIMIT_SCALE_v2, user); | |
526 | } else { | |
527 | pr_warn("invalid rate from userspace: %llu\n", user); | |
528 | return 0; | |
529 | } | |
530 | } | |
531 | ||
90c4ae4e | 532 | static u64 user2rate_bytes(u32 user) |
bea74641 VP |
533 | { |
534 | u64 r; | |
535 | ||
90c4ae4e VP |
536 | r = user ? U32_MAX / user : U32_MAX; |
537 | r = (r - 1) << XT_HASHLIMIT_BYTE_SHIFT; | |
bea74641 VP |
538 | return r; |
539 | } | |
540 | ||
11d5f157 VP |
541 | static void rateinfo_recalc(struct dsthash_ent *dh, unsigned long now, |
542 | u32 mode, int revision) | |
0197dee7 FW |
543 | { |
544 | unsigned long delta = now - dh->rateinfo.prev; | |
11d5f157 | 545 | u64 cap, cpj; |
0197dee7 FW |
546 | |
547 | if (delta == 0) | |
548 | return; | |
549 | ||
bea74641 VP |
550 | if (revision >= 3 && mode & XT_HASHLIMIT_RATE_MATCH) { |
551 | u64 interval = dh->rateinfo.interval * HZ; | |
552 | ||
553 | if (delta < interval) | |
554 | return; | |
555 | ||
556 | dh->rateinfo.prev = now; | |
557 | dh->rateinfo.prev_window = | |
558 | ((dh->rateinfo.current_rate * interval) > | |
559 | (delta * dh->rateinfo.rate)); | |
560 | dh->rateinfo.current_rate = 0; | |
561 | ||
562 | return; | |
563 | } | |
564 | ||
39b46fc6 | 565 | dh->rateinfo.prev = now; |
0197dee7 FW |
566 | |
567 | if (mode & XT_HASHLIMIT_BYTES) { | |
11d5f157 | 568 | u64 tmp = dh->rateinfo.credit; |
0197dee7 FW |
569 | dh->rateinfo.credit += CREDITS_PER_JIFFY_BYTES * delta; |
570 | cap = CREDITS_PER_JIFFY_BYTES * HZ; | |
571 | if (tmp >= dh->rateinfo.credit) {/* overflow */ | |
572 | dh->rateinfo.credit = cap; | |
573 | return; | |
574 | } | |
575 | } else { | |
11d5f157 VP |
576 | cpj = (revision == 1) ? |
577 | CREDITS_PER_JIFFY_v1 : CREDITS_PER_JIFFY; | |
578 | dh->rateinfo.credit += delta * cpj; | |
0197dee7 FW |
579 | cap = dh->rateinfo.credit_cap; |
580 | } | |
581 | if (dh->rateinfo.credit > cap) | |
582 | dh->rateinfo.credit = cap; | |
39b46fc6 PM |
583 | } |
584 | ||
817e076f | 585 | static void rateinfo_init(struct dsthash_ent *dh, |
11d5f157 | 586 | struct xt_hashlimit_htable *hinfo, int revision) |
817e076f FW |
587 | { |
588 | dh->rateinfo.prev = jiffies; | |
bea74641 VP |
589 | if (revision >= 3 && hinfo->cfg.mode & XT_HASHLIMIT_RATE_MATCH) { |
590 | dh->rateinfo.prev_window = 0; | |
591 | dh->rateinfo.current_rate = 0; | |
592 | if (hinfo->cfg.mode & XT_HASHLIMIT_BYTES) { | |
90c4ae4e VP |
593 | dh->rateinfo.rate = |
594 | user2rate_bytes((u32)hinfo->cfg.avg); | |
bea74641 VP |
595 | if (hinfo->cfg.burst) |
596 | dh->rateinfo.burst = | |
597 | hinfo->cfg.burst * dh->rateinfo.rate; | |
598 | else | |
599 | dh->rateinfo.burst = dh->rateinfo.rate; | |
600 | } else { | |
601 | dh->rateinfo.rate = user2rate(hinfo->cfg.avg); | |
602 | dh->rateinfo.burst = | |
603 | hinfo->cfg.burst + dh->rateinfo.rate; | |
604 | } | |
605 | dh->rateinfo.interval = hinfo->cfg.interval; | |
606 | } else if (hinfo->cfg.mode & XT_HASHLIMIT_BYTES) { | |
0197dee7 FW |
607 | dh->rateinfo.credit = CREDITS_PER_JIFFY_BYTES * HZ; |
608 | dh->rateinfo.cost = user2credits_byte(hinfo->cfg.avg); | |
609 | dh->rateinfo.credit_cap = hinfo->cfg.burst; | |
610 | } else { | |
611 | dh->rateinfo.credit = user2credits(hinfo->cfg.avg * | |
11d5f157 VP |
612 | hinfo->cfg.burst, revision); |
613 | dh->rateinfo.cost = user2credits(hinfo->cfg.avg, revision); | |
0197dee7 FW |
614 | dh->rateinfo.credit_cap = dh->rateinfo.credit; |
615 | } | |
817e076f FW |
616 | } |
617 | ||
09e410de JE |
618 | static inline __be32 maskl(__be32 a, unsigned int l) |
619 | { | |
1b9b70ea | 620 | return l ? htonl(ntohl(a) & ~0 << (32 - l)) : 0; |
09e410de JE |
621 | } |
622 | ||
c0cd1156 | 623 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
09e410de JE |
624 | static void hashlimit_ipv6_mask(__be32 *i, unsigned int p) |
625 | { | |
626 | switch (p) { | |
1b9b70ea | 627 | case 0 ... 31: |
09e410de JE |
628 | i[0] = maskl(i[0], p); |
629 | i[1] = i[2] = i[3] = 0; | |
630 | break; | |
1b9b70ea | 631 | case 32 ... 63: |
09e410de JE |
632 | i[1] = maskl(i[1], p - 32); |
633 | i[2] = i[3] = 0; | |
634 | break; | |
1b9b70ea | 635 | case 64 ... 95: |
09e410de JE |
636 | i[2] = maskl(i[2], p - 64); |
637 | i[3] = 0; | |
8f599229 | 638 | break; |
1b9b70ea | 639 | case 96 ... 127: |
09e410de JE |
640 | i[3] = maskl(i[3], p - 96); |
641 | break; | |
642 | case 128: | |
643 | break; | |
644 | } | |
645 | } | |
3ed5df44 | 646 | #endif |
09e410de | 647 | |
39b46fc6 | 648 | static int |
a47362a2 JE |
649 | hashlimit_init_dst(const struct xt_hashlimit_htable *hinfo, |
650 | struct dsthash_dst *dst, | |
39b46fc6 PM |
651 | const struct sk_buff *skb, unsigned int protoff) |
652 | { | |
653 | __be16 _ports[2], *ports; | |
193b23c5 | 654 | u8 nexthdr; |
aca071c1 | 655 | int poff; |
39b46fc6 PM |
656 | |
657 | memset(dst, 0, sizeof(*dst)); | |
658 | ||
659 | switch (hinfo->family) { | |
ee999d8b | 660 | case NFPROTO_IPV4: |
39b46fc6 | 661 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP) |
09e410de JE |
662 | dst->ip.dst = maskl(ip_hdr(skb)->daddr, |
663 | hinfo->cfg.dstmask); | |
39b46fc6 | 664 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP) |
09e410de JE |
665 | dst->ip.src = maskl(ip_hdr(skb)->saddr, |
666 | hinfo->cfg.srcmask); | |
39b46fc6 PM |
667 | |
668 | if (!(hinfo->cfg.mode & | |
669 | (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT))) | |
670 | return 0; | |
eddc9ec5 | 671 | nexthdr = ip_hdr(skb)->protocol; |
39b46fc6 | 672 | break; |
c0cd1156 | 673 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
ee999d8b | 674 | case NFPROTO_IPV6: |
412662d2 SR |
675 | { |
676 | __be16 frag_off; | |
677 | ||
09e410de JE |
678 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP) { |
679 | memcpy(&dst->ip6.dst, &ipv6_hdr(skb)->daddr, | |
680 | sizeof(dst->ip6.dst)); | |
681 | hashlimit_ipv6_mask(dst->ip6.dst, hinfo->cfg.dstmask); | |
682 | } | |
683 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP) { | |
684 | memcpy(&dst->ip6.src, &ipv6_hdr(skb)->saddr, | |
685 | sizeof(dst->ip6.src)); | |
686 | hashlimit_ipv6_mask(dst->ip6.src, hinfo->cfg.srcmask); | |
687 | } | |
39b46fc6 PM |
688 | |
689 | if (!(hinfo->cfg.mode & | |
690 | (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT))) | |
691 | return 0; | |
193b23c5 | 692 | nexthdr = ipv6_hdr(skb)->nexthdr; |
75f2811c | 693 | protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr, &frag_off); |
193b23c5 | 694 | if ((int)protoff < 0) |
39b46fc6 PM |
695 | return -1; |
696 | break; | |
412662d2 | 697 | } |
39b46fc6 PM |
698 | #endif |
699 | default: | |
700 | BUG(); | |
701 | return 0; | |
702 | } | |
703 | ||
aca071c1 CG |
704 | poff = proto_ports_offset(nexthdr); |
705 | if (poff >= 0) { | |
706 | ports = skb_header_pointer(skb, protoff + poff, sizeof(_ports), | |
39b46fc6 | 707 | &_ports); |
aca071c1 | 708 | } else { |
39b46fc6 PM |
709 | _ports[0] = _ports[1] = 0; |
710 | ports = _ports; | |
39b46fc6 PM |
711 | } |
712 | if (!ports) | |
713 | return -1; | |
714 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SPT) | |
715 | dst->src_port = ports[0]; | |
716 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DPT) | |
717 | dst->dst_port = ports[1]; | |
718 | return 0; | |
1da177e4 LT |
719 | } |
720 | ||
0197dee7 FW |
721 | static u32 hashlimit_byte_cost(unsigned int len, struct dsthash_ent *dh) |
722 | { | |
723 | u64 tmp = xt_hashlimit_len_to_chunks(len); | |
724 | tmp = tmp * dh->rateinfo.cost; | |
725 | ||
726 | if (unlikely(tmp > CREDITS_PER_JIFFY_BYTES * HZ)) | |
727 | tmp = CREDITS_PER_JIFFY_BYTES * HZ; | |
728 | ||
729 | if (dh->rateinfo.credit < tmp && dh->rateinfo.credit_cap) { | |
730 | dh->rateinfo.credit_cap--; | |
731 | dh->rateinfo.credit = CREDITS_PER_JIFFY_BYTES * HZ; | |
732 | } | |
733 | return (u32) tmp; | |
734 | } | |
735 | ||
ccb79bdc | 736 | static bool |
11d5f157 VP |
737 | hashlimit_mt_common(const struct sk_buff *skb, struct xt_action_param *par, |
738 | struct xt_hashlimit_htable *hinfo, | |
bea74641 | 739 | const struct hashlimit_cfg3 *cfg, int revision) |
09e410de | 740 | { |
09e410de JE |
741 | unsigned long now = jiffies; |
742 | struct dsthash_ent *dh; | |
743 | struct dsthash_dst dst; | |
09181842 | 744 | bool race = false; |
11d5f157 | 745 | u64 cost; |
09e410de | 746 | |
f7108a20 | 747 | if (hashlimit_init_dst(hinfo, &dst, skb, par->thoff) < 0) |
09e410de JE |
748 | goto hotdrop; |
749 | ||
0b35f603 | 750 | local_bh_disable(); |
09e410de JE |
751 | dh = dsthash_find(hinfo, &dst); |
752 | if (dh == NULL) { | |
09181842 | 753 | dh = dsthash_alloc_init(hinfo, &dst, &race); |
09e410de | 754 | if (dh == NULL) { |
0b35f603 | 755 | local_bh_enable(); |
09e410de | 756 | goto hotdrop; |
09181842 PNA |
757 | } else if (race) { |
758 | /* Already got an entry, update expiration timeout */ | |
759 | dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire); | |
11d5f157 | 760 | rateinfo_recalc(dh, now, hinfo->cfg.mode, revision); |
09181842 PNA |
761 | } else { |
762 | dh->expires = jiffies + msecs_to_jiffies(hinfo->cfg.expire); | |
11d5f157 | 763 | rateinfo_init(dh, hinfo, revision); |
09e410de | 764 | } |
09e410de JE |
765 | } else { |
766 | /* update expiration timeout */ | |
767 | dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire); | |
11d5f157 | 768 | rateinfo_recalc(dh, now, hinfo->cfg.mode, revision); |
09e410de JE |
769 | } |
770 | ||
bea74641 VP |
771 | if (cfg->mode & XT_HASHLIMIT_RATE_MATCH) { |
772 | cost = (cfg->mode & XT_HASHLIMIT_BYTES) ? skb->len : 1; | |
773 | dh->rateinfo.current_rate += cost; | |
774 | ||
775 | if (!dh->rateinfo.prev_window && | |
776 | (dh->rateinfo.current_rate <= dh->rateinfo.burst)) { | |
777 | spin_unlock(&dh->lock); | |
2a7ebc07 | 778 | local_bh_enable(); |
bea74641 VP |
779 | return !(cfg->mode & XT_HASHLIMIT_INVERT); |
780 | } else { | |
781 | goto overlimit; | |
782 | } | |
783 | } | |
784 | ||
11d5f157 | 785 | if (cfg->mode & XT_HASHLIMIT_BYTES) |
0197dee7 FW |
786 | cost = hashlimit_byte_cost(skb->len, dh); |
787 | else | |
788 | cost = dh->rateinfo.cost; | |
789 | ||
790 | if (dh->rateinfo.credit >= cost) { | |
09e410de | 791 | /* below the limit */ |
0197dee7 | 792 | dh->rateinfo.credit -= cost; |
02e4eb75 | 793 | spin_unlock(&dh->lock); |
0b35f603 | 794 | local_bh_enable(); |
11d5f157 | 795 | return !(cfg->mode & XT_HASHLIMIT_INVERT); |
09e410de JE |
796 | } |
797 | ||
bea74641 | 798 | overlimit: |
02e4eb75 | 799 | spin_unlock(&dh->lock); |
0b35f603 | 800 | local_bh_enable(); |
09e410de | 801 | /* default match is underlimit - so over the limit, we need to invert */ |
11d5f157 | 802 | return cfg->mode & XT_HASHLIMIT_INVERT; |
09e410de JE |
803 | |
804 | hotdrop: | |
b4ba2611 | 805 | par->hotdrop = true; |
09e410de JE |
806 | return false; |
807 | } | |
808 | ||
11d5f157 VP |
809 | static bool |
810 | hashlimit_mt_v1(const struct sk_buff *skb, struct xt_action_param *par) | |
811 | { | |
812 | const struct xt_hashlimit_mtinfo1 *info = par->matchinfo; | |
813 | struct xt_hashlimit_htable *hinfo = info->hinfo; | |
bea74641 | 814 | struct hashlimit_cfg3 cfg = {}; |
11d5f157 VP |
815 | int ret; |
816 | ||
817 | ret = cfg_copy(&cfg, (void *)&info->cfg, 1); | |
11d5f157 VP |
818 | if (ret) |
819 | return ret; | |
820 | ||
821 | return hashlimit_mt_common(skb, par, hinfo, &cfg, 1); | |
822 | } | |
823 | ||
824 | static bool | |
bea74641 | 825 | hashlimit_mt_v2(const struct sk_buff *skb, struct xt_action_param *par) |
11d5f157 VP |
826 | { |
827 | const struct xt_hashlimit_mtinfo2 *info = par->matchinfo; | |
828 | struct xt_hashlimit_htable *hinfo = info->hinfo; | |
bea74641 VP |
829 | struct hashlimit_cfg3 cfg = {}; |
830 | int ret; | |
831 | ||
832 | ret = cfg_copy(&cfg, (void *)&info->cfg, 2); | |
bea74641 VP |
833 | if (ret) |
834 | return ret; | |
835 | ||
836 | return hashlimit_mt_common(skb, par, hinfo, &cfg, 2); | |
837 | } | |
838 | ||
839 | static bool | |
840 | hashlimit_mt(const struct sk_buff *skb, struct xt_action_param *par) | |
841 | { | |
842 | const struct xt_hashlimit_mtinfo3 *info = par->matchinfo; | |
843 | struct xt_hashlimit_htable *hinfo = info->hinfo; | |
11d5f157 | 844 | |
bea74641 | 845 | return hashlimit_mt_common(skb, par, hinfo, &info->cfg, 3); |
11d5f157 VP |
846 | } |
847 | ||
848 | static int hashlimit_mt_check_common(const struct xt_mtchk_param *par, | |
849 | struct xt_hashlimit_htable **hinfo, | |
bea74641 | 850 | struct hashlimit_cfg3 *cfg, |
11d5f157 | 851 | const char *name, int revision) |
09e410de | 852 | { |
e89fc3f1 | 853 | struct net *net = par->net; |
4a5a5c73 | 854 | int ret; |
09e410de | 855 | |
11d5f157 | 856 | if (cfg->gc_interval == 0 || cfg->expire == 0) |
bd414ee6 | 857 | return -EINVAL; |
aa5fa318 | 858 | if (par->family == NFPROTO_IPV4) { |
11d5f157 | 859 | if (cfg->srcmask > 32 || cfg->dstmask > 32) |
bd414ee6 | 860 | return -EINVAL; |
09e410de | 861 | } else { |
11d5f157 | 862 | if (cfg->srcmask > 128 || cfg->dstmask > 128) |
bd414ee6 | 863 | return -EINVAL; |
09e410de JE |
864 | } |
865 | ||
11d5f157 | 866 | if (cfg->mode & ~XT_HASHLIMIT_ALL) { |
0197dee7 | 867 | pr_info("Unknown mode mask %X, kernel too old?\n", |
11d5f157 | 868 | cfg->mode); |
0197dee7 FW |
869 | return -EINVAL; |
870 | } | |
871 | ||
872 | /* Check for overflow. */ | |
bea74641 | 873 | if (revision >= 3 && cfg->mode & XT_HASHLIMIT_RATE_MATCH) { |
90c4ae4e | 874 | if (cfg->avg == 0 || cfg->avg > U32_MAX) { |
bea74641 VP |
875 | pr_info("hashlimit invalid rate\n"); |
876 | return -ERANGE; | |
877 | } | |
878 | ||
879 | if (cfg->interval == 0) { | |
880 | pr_info("hashlimit invalid interval\n"); | |
881 | return -EINVAL; | |
882 | } | |
883 | } else if (cfg->mode & XT_HASHLIMIT_BYTES) { | |
11d5f157 VP |
884 | if (user2credits_byte(cfg->avg) == 0) { |
885 | pr_info("overflow, rate too high: %llu\n", cfg->avg); | |
0197dee7 FW |
886 | return -EINVAL; |
887 | } | |
11d5f157 VP |
888 | } else if (cfg->burst == 0 || |
889 | user2credits(cfg->avg * cfg->burst, revision) < | |
890 | user2credits(cfg->avg, revision)) { | |
891 | pr_info("overflow, try lower: %llu/%llu\n", | |
892 | cfg->avg, cfg->burst); | |
0197dee7 FW |
893 | return -ERANGE; |
894 | } | |
895 | ||
2eff25c1 | 896 | mutex_lock(&hashlimit_mutex); |
11d5f157 VP |
897 | *hinfo = htable_find_get(net, name, par->family); |
898 | if (*hinfo == NULL) { | |
899 | ret = htable_create(net, cfg, name, par->family, | |
900 | hinfo, revision); | |
4a5a5c73 JE |
901 | if (ret < 0) { |
902 | mutex_unlock(&hashlimit_mutex); | |
903 | return ret; | |
904 | } | |
09e410de | 905 | } |
2eff25c1 | 906 | mutex_unlock(&hashlimit_mutex); |
11d5f157 | 907 | |
bd414ee6 | 908 | return 0; |
09e410de JE |
909 | } |
910 | ||
11d5f157 VP |
911 | static int hashlimit_mt_check_v1(const struct xt_mtchk_param *par) |
912 | { | |
913 | struct xt_hashlimit_mtinfo1 *info = par->matchinfo; | |
bea74641 | 914 | struct hashlimit_cfg3 cfg = {}; |
11d5f157 VP |
915 | int ret; |
916 | ||
839a4c3b FW |
917 | ret = xt_check_proc_name(info->name, sizeof(info->name)); |
918 | if (ret) | |
919 | return ret; | |
11d5f157 VP |
920 | |
921 | ret = cfg_copy(&cfg, (void *)&info->cfg, 1); | |
11d5f157 VP |
922 | if (ret) |
923 | return ret; | |
924 | ||
925 | return hashlimit_mt_check_common(par, &info->hinfo, | |
926 | &cfg, info->name, 1); | |
927 | } | |
928 | ||
bea74641 | 929 | static int hashlimit_mt_check_v2(const struct xt_mtchk_param *par) |
11d5f157 VP |
930 | { |
931 | struct xt_hashlimit_mtinfo2 *info = par->matchinfo; | |
bea74641 VP |
932 | struct hashlimit_cfg3 cfg = {}; |
933 | int ret; | |
934 | ||
839a4c3b FW |
935 | ret = xt_check_proc_name(info->name, sizeof(info->name)); |
936 | if (ret) | |
937 | return ret; | |
bea74641 VP |
938 | |
939 | ret = cfg_copy(&cfg, (void *)&info->cfg, 2); | |
bea74641 VP |
940 | if (ret) |
941 | return ret; | |
942 | ||
943 | return hashlimit_mt_check_common(par, &info->hinfo, | |
944 | &cfg, info->name, 2); | |
945 | } | |
946 | ||
947 | static int hashlimit_mt_check(const struct xt_mtchk_param *par) | |
948 | { | |
949 | struct xt_hashlimit_mtinfo3 *info = par->matchinfo; | |
839a4c3b | 950 | int ret; |
11d5f157 | 951 | |
839a4c3b FW |
952 | ret = xt_check_proc_name(info->name, sizeof(info->name)); |
953 | if (ret) | |
954 | return ret; | |
11d5f157 VP |
955 | |
956 | return hashlimit_mt_check_common(par, &info->hinfo, &info->cfg, | |
bea74641 VP |
957 | info->name, 3); |
958 | } | |
959 | ||
960 | static void hashlimit_mt_destroy_v2(const struct xt_mtdtor_param *par) | |
961 | { | |
962 | const struct xt_hashlimit_mtinfo2 *info = par->matchinfo; | |
963 | ||
964 | htable_put(info->hinfo); | |
11d5f157 VP |
965 | } |
966 | ||
0dc60a45 | 967 | static void hashlimit_mt_destroy_v1(const struct xt_mtdtor_param *par) |
09e410de | 968 | { |
6be3d859 | 969 | const struct xt_hashlimit_mtinfo1 *info = par->matchinfo; |
09e410de JE |
970 | |
971 | htable_put(info->hinfo); | |
972 | } | |
973 | ||
11d5f157 VP |
974 | static void hashlimit_mt_destroy(const struct xt_mtdtor_param *par) |
975 | { | |
bea74641 | 976 | const struct xt_hashlimit_mtinfo3 *info = par->matchinfo; |
11d5f157 VP |
977 | |
978 | htable_put(info->hinfo); | |
979 | } | |
980 | ||
d3c5ee6d | 981 | static struct xt_match hashlimit_mt_reg[] __read_mostly = { |
09e410de JE |
982 | { |
983 | .name = "hashlimit", | |
984 | .revision = 1, | |
ee999d8b | 985 | .family = NFPROTO_IPV4, |
0dc60a45 | 986 | .match = hashlimit_mt_v1, |
09e410de | 987 | .matchsize = sizeof(struct xt_hashlimit_mtinfo1), |
ec231890 | 988 | .usersize = offsetof(struct xt_hashlimit_mtinfo1, hinfo), |
0dc60a45 VP |
989 | .checkentry = hashlimit_mt_check_v1, |
990 | .destroy = hashlimit_mt_destroy_v1, | |
09e410de JE |
991 | .me = THIS_MODULE, |
992 | }, | |
11d5f157 VP |
993 | { |
994 | .name = "hashlimit", | |
995 | .revision = 2, | |
996 | .family = NFPROTO_IPV4, | |
bea74641 | 997 | .match = hashlimit_mt_v2, |
11d5f157 | 998 | .matchsize = sizeof(struct xt_hashlimit_mtinfo2), |
ec231890 | 999 | .usersize = offsetof(struct xt_hashlimit_mtinfo2, hinfo), |
bea74641 VP |
1000 | .checkentry = hashlimit_mt_check_v2, |
1001 | .destroy = hashlimit_mt_destroy_v2, | |
1002 | .me = THIS_MODULE, | |
1003 | }, | |
1004 | { | |
1005 | .name = "hashlimit", | |
1006 | .revision = 3, | |
1007 | .family = NFPROTO_IPV4, | |
1008 | .match = hashlimit_mt, | |
1009 | .matchsize = sizeof(struct xt_hashlimit_mtinfo3), | |
1010 | .usersize = offsetof(struct xt_hashlimit_mtinfo3, hinfo), | |
11d5f157 VP |
1011 | .checkentry = hashlimit_mt_check, |
1012 | .destroy = hashlimit_mt_destroy, | |
1013 | .me = THIS_MODULE, | |
1014 | }, | |
c0cd1156 | 1015 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
09e410de JE |
1016 | { |
1017 | .name = "hashlimit", | |
1018 | .revision = 1, | |
ee999d8b | 1019 | .family = NFPROTO_IPV6, |
0dc60a45 | 1020 | .match = hashlimit_mt_v1, |
09e410de | 1021 | .matchsize = sizeof(struct xt_hashlimit_mtinfo1), |
ec231890 | 1022 | .usersize = offsetof(struct xt_hashlimit_mtinfo1, hinfo), |
0dc60a45 VP |
1023 | .checkentry = hashlimit_mt_check_v1, |
1024 | .destroy = hashlimit_mt_destroy_v1, | |
09e410de JE |
1025 | .me = THIS_MODULE, |
1026 | }, | |
11d5f157 VP |
1027 | { |
1028 | .name = "hashlimit", | |
1029 | .revision = 2, | |
1030 | .family = NFPROTO_IPV6, | |
bea74641 | 1031 | .match = hashlimit_mt_v2, |
11d5f157 | 1032 | .matchsize = sizeof(struct xt_hashlimit_mtinfo2), |
ec231890 | 1033 | .usersize = offsetof(struct xt_hashlimit_mtinfo2, hinfo), |
bea74641 VP |
1034 | .checkentry = hashlimit_mt_check_v2, |
1035 | .destroy = hashlimit_mt_destroy_v2, | |
1036 | .me = THIS_MODULE, | |
1037 | }, | |
1038 | { | |
1039 | .name = "hashlimit", | |
1040 | .revision = 3, | |
1041 | .family = NFPROTO_IPV6, | |
1042 | .match = hashlimit_mt, | |
1043 | .matchsize = sizeof(struct xt_hashlimit_mtinfo3), | |
1044 | .usersize = offsetof(struct xt_hashlimit_mtinfo3, hinfo), | |
11d5f157 VP |
1045 | .checkentry = hashlimit_mt_check, |
1046 | .destroy = hashlimit_mt_destroy, | |
1047 | .me = THIS_MODULE, | |
1048 | }, | |
7b21e09d | 1049 | #endif |
1da177e4 LT |
1050 | }; |
1051 | ||
1052 | /* PROC stuff */ | |
1da177e4 | 1053 | static void *dl_seq_start(struct seq_file *s, loff_t *pos) |
f4f6fb71 | 1054 | __acquires(htable->lock) |
1da177e4 | 1055 | { |
a1004d8e | 1056 | struct xt_hashlimit_htable *htable = s->private; |
1da177e4 LT |
1057 | unsigned int *bucket; |
1058 | ||
1059 | spin_lock_bh(&htable->lock); | |
1060 | if (*pos >= htable->cfg.size) | |
1061 | return NULL; | |
1062 | ||
1063 | bucket = kmalloc(sizeof(unsigned int), GFP_ATOMIC); | |
1064 | if (!bucket) | |
1065 | return ERR_PTR(-ENOMEM); | |
1066 | ||
1067 | *bucket = *pos; | |
1068 | return bucket; | |
1069 | } | |
1070 | ||
1071 | static void *dl_seq_next(struct seq_file *s, void *v, loff_t *pos) | |
1072 | { | |
a1004d8e | 1073 | struct xt_hashlimit_htable *htable = s->private; |
68ad546a | 1074 | unsigned int *bucket = v; |
1da177e4 LT |
1075 | |
1076 | *pos = ++(*bucket); | |
1077 | if (*pos >= htable->cfg.size) { | |
1078 | kfree(v); | |
1079 | return NULL; | |
1080 | } | |
1081 | return bucket; | |
1082 | } | |
1083 | ||
1084 | static void dl_seq_stop(struct seq_file *s, void *v) | |
f4f6fb71 | 1085 | __releases(htable->lock) |
1da177e4 | 1086 | { |
a1004d8e | 1087 | struct xt_hashlimit_htable *htable = s->private; |
68ad546a | 1088 | unsigned int *bucket = v; |
1da177e4 | 1089 | |
55e0d7cf ED |
1090 | if (!IS_ERR(bucket)) |
1091 | kfree(bucket); | |
1da177e4 LT |
1092 | spin_unlock_bh(&htable->lock); |
1093 | } | |
1094 | ||
11d5f157 VP |
1095 | static void dl_seq_print(struct dsthash_ent *ent, u_int8_t family, |
1096 | struct seq_file *s) | |
1da177e4 | 1097 | { |
39b46fc6 | 1098 | switch (family) { |
ee999d8b | 1099 | case NFPROTO_IPV4: |
11d5f157 | 1100 | seq_printf(s, "%ld %pI4:%u->%pI4:%u %llu %llu %llu\n", |
e71456ae SRRH |
1101 | (long)(ent->expires - jiffies)/HZ, |
1102 | &ent->dst.ip.src, | |
1103 | ntohs(ent->dst.src_port), | |
1104 | &ent->dst.ip.dst, | |
1105 | ntohs(ent->dst.dst_port), | |
1106 | ent->rateinfo.credit, ent->rateinfo.credit_cap, | |
1107 | ent->rateinfo.cost); | |
02e4eb75 | 1108 | break; |
c0cd1156 | 1109 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
ee999d8b | 1110 | case NFPROTO_IPV6: |
11d5f157 | 1111 | seq_printf(s, "%ld %pI6:%u->%pI6:%u %llu %llu %llu\n", |
e71456ae SRRH |
1112 | (long)(ent->expires - jiffies)/HZ, |
1113 | &ent->dst.ip6.src, | |
1114 | ntohs(ent->dst.src_port), | |
1115 | &ent->dst.ip6.dst, | |
1116 | ntohs(ent->dst.dst_port), | |
1117 | ent->rateinfo.credit, ent->rateinfo.credit_cap, | |
1118 | ent->rateinfo.cost); | |
02e4eb75 | 1119 | break; |
7b21e09d | 1120 | #endif |
39b46fc6 PM |
1121 | default: |
1122 | BUG(); | |
39b46fc6 | 1123 | } |
11d5f157 VP |
1124 | } |
1125 | ||
bea74641 VP |
1126 | static int dl_seq_real_show_v2(struct dsthash_ent *ent, u_int8_t family, |
1127 | struct seq_file *s) | |
1128 | { | |
1129 | const struct xt_hashlimit_htable *ht = s->private; | |
1130 | ||
1131 | spin_lock(&ent->lock); | |
1132 | /* recalculate to show accurate numbers */ | |
1133 | rateinfo_recalc(ent, jiffies, ht->cfg.mode, 2); | |
1134 | ||
1135 | dl_seq_print(ent, family, s); | |
1136 | ||
1137 | spin_unlock(&ent->lock); | |
1138 | return seq_has_overflowed(s); | |
1139 | } | |
1140 | ||
11d5f157 VP |
1141 | static int dl_seq_real_show_v1(struct dsthash_ent *ent, u_int8_t family, |
1142 | struct seq_file *s) | |
1143 | { | |
1144 | const struct xt_hashlimit_htable *ht = s->private; | |
1145 | ||
1146 | spin_lock(&ent->lock); | |
1147 | /* recalculate to show accurate numbers */ | |
1148 | rateinfo_recalc(ent, jiffies, ht->cfg.mode, 1); | |
1149 | ||
1150 | dl_seq_print(ent, family, s); | |
1151 | ||
1152 | spin_unlock(&ent->lock); | |
1153 | return seq_has_overflowed(s); | |
1154 | } | |
1155 | ||
1156 | static int dl_seq_real_show(struct dsthash_ent *ent, u_int8_t family, | |
1157 | struct seq_file *s) | |
1158 | { | |
1159 | const struct xt_hashlimit_htable *ht = s->private; | |
1160 | ||
1161 | spin_lock(&ent->lock); | |
1162 | /* recalculate to show accurate numbers */ | |
bea74641 | 1163 | rateinfo_recalc(ent, jiffies, ht->cfg.mode, 3); |
11d5f157 VP |
1164 | |
1165 | dl_seq_print(ent, family, s); | |
1166 | ||
02e4eb75 | 1167 | spin_unlock(&ent->lock); |
e71456ae | 1168 | return seq_has_overflowed(s); |
1da177e4 LT |
1169 | } |
1170 | ||
bea74641 VP |
1171 | static int dl_seq_show_v2(struct seq_file *s, void *v) |
1172 | { | |
1173 | struct xt_hashlimit_htable *htable = s->private; | |
1174 | unsigned int *bucket = (unsigned int *)v; | |
1175 | struct dsthash_ent *ent; | |
1176 | ||
1177 | if (!hlist_empty(&htable->hash[*bucket])) { | |
1178 | hlist_for_each_entry(ent, &htable->hash[*bucket], node) | |
1179 | if (dl_seq_real_show_v2(ent, htable->family, s)) | |
1180 | return -1; | |
1181 | } | |
1182 | return 0; | |
1183 | } | |
1184 | ||
0dc60a45 | 1185 | static int dl_seq_show_v1(struct seq_file *s, void *v) |
1da177e4 | 1186 | { |
a1004d8e | 1187 | struct xt_hashlimit_htable *htable = s->private; |
68ad546a | 1188 | unsigned int *bucket = v; |
1da177e4 | 1189 | struct dsthash_ent *ent; |
1da177e4 | 1190 | |
39b46fc6 | 1191 | if (!hlist_empty(&htable->hash[*bucket])) { |
b67bfe0d | 1192 | hlist_for_each_entry(ent, &htable->hash[*bucket], node) |
0dc60a45 | 1193 | if (dl_seq_real_show_v1(ent, htable->family, s)) |
683a04ce | 1194 | return -1; |
39b46fc6 | 1195 | } |
1da177e4 LT |
1196 | return 0; |
1197 | } | |
1198 | ||
11d5f157 VP |
1199 | static int dl_seq_show(struct seq_file *s, void *v) |
1200 | { | |
1201 | struct xt_hashlimit_htable *htable = s->private; | |
68ad546a | 1202 | unsigned int *bucket = v; |
11d5f157 VP |
1203 | struct dsthash_ent *ent; |
1204 | ||
1205 | if (!hlist_empty(&htable->hash[*bucket])) { | |
1206 | hlist_for_each_entry(ent, &htable->hash[*bucket], node) | |
1207 | if (dl_seq_real_show(ent, htable->family, s)) | |
1208 | return -1; | |
1209 | } | |
1210 | return 0; | |
1211 | } | |
1212 | ||
0dc60a45 | 1213 | static const struct seq_operations dl_seq_ops_v1 = { |
1da177e4 LT |
1214 | .start = dl_seq_start, |
1215 | .next = dl_seq_next, | |
1216 | .stop = dl_seq_stop, | |
0dc60a45 | 1217 | .show = dl_seq_show_v1 |
1da177e4 LT |
1218 | }; |
1219 | ||
bea74641 VP |
1220 | static const struct seq_operations dl_seq_ops_v2 = { |
1221 | .start = dl_seq_start, | |
1222 | .next = dl_seq_next, | |
1223 | .stop = dl_seq_stop, | |
1224 | .show = dl_seq_show_v2 | |
1225 | }; | |
1226 | ||
11d5f157 VP |
1227 | static const struct seq_operations dl_seq_ops = { |
1228 | .start = dl_seq_start, | |
1229 | .next = dl_seq_next, | |
1230 | .stop = dl_seq_stop, | |
1231 | .show = dl_seq_show | |
1232 | }; | |
1233 | ||
bea74641 VP |
1234 | static int dl_proc_open_v2(struct inode *inode, struct file *file) |
1235 | { | |
1236 | int ret = seq_open(file, &dl_seq_ops_v2); | |
1237 | ||
1238 | if (!ret) { | |
1239 | struct seq_file *sf = file->private_data; | |
1240 | ||
1241 | sf->private = PDE_DATA(inode); | |
1242 | } | |
1243 | return ret; | |
1244 | } | |
1245 | ||
0dc60a45 | 1246 | static int dl_proc_open_v1(struct inode *inode, struct file *file) |
1da177e4 | 1247 | { |
0dc60a45 | 1248 | int ret = seq_open(file, &dl_seq_ops_v1); |
1da177e4 LT |
1249 | |
1250 | if (!ret) { | |
1251 | struct seq_file *sf = file->private_data; | |
d9dda78b | 1252 | sf->private = PDE_DATA(inode); |
1da177e4 LT |
1253 | } |
1254 | return ret; | |
1255 | } | |
1256 | ||
11d5f157 VP |
1257 | static int dl_proc_open(struct inode *inode, struct file *file) |
1258 | { | |
1259 | int ret = seq_open(file, &dl_seq_ops); | |
1260 | ||
1261 | if (!ret) { | |
1262 | struct seq_file *sf = file->private_data; | |
1263 | ||
1264 | sf->private = PDE_DATA(inode); | |
1265 | } | |
1266 | return ret; | |
1267 | } | |
1268 | ||
bea74641 VP |
1269 | static const struct file_operations dl_file_ops_v2 = { |
1270 | .owner = THIS_MODULE, | |
1271 | .open = dl_proc_open_v2, | |
1272 | .read = seq_read, | |
1273 | .llseek = seq_lseek, | |
1274 | .release = seq_release | |
1275 | }; | |
1276 | ||
0dc60a45 | 1277 | static const struct file_operations dl_file_ops_v1 = { |
1da177e4 | 1278 | .owner = THIS_MODULE, |
0dc60a45 | 1279 | .open = dl_proc_open_v1, |
1da177e4 LT |
1280 | .read = seq_read, |
1281 | .llseek = seq_lseek, | |
1282 | .release = seq_release | |
1283 | }; | |
1284 | ||
11d5f157 VP |
1285 | static const struct file_operations dl_file_ops = { |
1286 | .owner = THIS_MODULE, | |
1287 | .open = dl_proc_open, | |
1288 | .read = seq_read, | |
1289 | .llseek = seq_lseek, | |
1290 | .release = seq_release | |
1291 | }; | |
1292 | ||
e89fc3f1 AD |
1293 | static int __net_init hashlimit_proc_net_init(struct net *net) |
1294 | { | |
1295 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); | |
1296 | ||
1297 | hashlimit_net->ipt_hashlimit = proc_mkdir("ipt_hashlimit", net->proc_net); | |
1298 | if (!hashlimit_net->ipt_hashlimit) | |
1299 | return -ENOMEM; | |
c0cd1156 | 1300 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
e89fc3f1 AD |
1301 | hashlimit_net->ip6t_hashlimit = proc_mkdir("ip6t_hashlimit", net->proc_net); |
1302 | if (!hashlimit_net->ip6t_hashlimit) { | |
ece31ffd | 1303 | remove_proc_entry("ipt_hashlimit", net->proc_net); |
e89fc3f1 AD |
1304 | return -ENOMEM; |
1305 | } | |
1306 | #endif | |
1307 | return 0; | |
1308 | } | |
1309 | ||
1310 | static void __net_exit hashlimit_proc_net_exit(struct net *net) | |
1311 | { | |
32263dd1 | 1312 | struct xt_hashlimit_htable *hinfo; |
32263dd1 VL |
1313 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); |
1314 | ||
b4ef4ce0 SP |
1315 | /* hashlimit_net_exit() is called before hashlimit_mt_destroy(). |
1316 | * Make sure that the parent ipt_hashlimit and ip6t_hashlimit proc | |
1317 | * entries is empty before trying to remove it. | |
32263dd1 VL |
1318 | */ |
1319 | mutex_lock(&hashlimit_mutex); | |
b67bfe0d | 1320 | hlist_for_each_entry(hinfo, &hashlimit_net->htables, node) |
b4ef4ce0 | 1321 | htable_remove_proc_entry(hinfo); |
32263dd1 VL |
1322 | hashlimit_net->ipt_hashlimit = NULL; |
1323 | hashlimit_net->ip6t_hashlimit = NULL; | |
1324 | mutex_unlock(&hashlimit_mutex); | |
1325 | ||
ece31ffd | 1326 | remove_proc_entry("ipt_hashlimit", net->proc_net); |
c0cd1156 | 1327 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
ece31ffd | 1328 | remove_proc_entry("ip6t_hashlimit", net->proc_net); |
e89fc3f1 AD |
1329 | #endif |
1330 | } | |
1331 | ||
1332 | static int __net_init hashlimit_net_init(struct net *net) | |
1333 | { | |
1334 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); | |
1335 | ||
1336 | INIT_HLIST_HEAD(&hashlimit_net->htables); | |
1337 | return hashlimit_proc_net_init(net); | |
1338 | } | |
1339 | ||
1340 | static void __net_exit hashlimit_net_exit(struct net *net) | |
1341 | { | |
e89fc3f1 AD |
1342 | hashlimit_proc_net_exit(net); |
1343 | } | |
1344 | ||
1345 | static struct pernet_operations hashlimit_net_ops = { | |
1346 | .init = hashlimit_net_init, | |
1347 | .exit = hashlimit_net_exit, | |
1348 | .id = &hashlimit_net_id, | |
1349 | .size = sizeof(struct hashlimit_net), | |
1350 | }; | |
1351 | ||
d3c5ee6d | 1352 | static int __init hashlimit_mt_init(void) |
1da177e4 | 1353 | { |
39b46fc6 | 1354 | int err; |
1da177e4 | 1355 | |
e89fc3f1 AD |
1356 | err = register_pernet_subsys(&hashlimit_net_ops); |
1357 | if (err < 0) | |
1358 | return err; | |
d3c5ee6d JE |
1359 | err = xt_register_matches(hashlimit_mt_reg, |
1360 | ARRAY_SIZE(hashlimit_mt_reg)); | |
39b46fc6 PM |
1361 | if (err < 0) |
1362 | goto err1; | |
1da177e4 | 1363 | |
39b46fc6 PM |
1364 | err = -ENOMEM; |
1365 | hashlimit_cachep = kmem_cache_create("xt_hashlimit", | |
1366 | sizeof(struct dsthash_ent), 0, 0, | |
20c2df83 | 1367 | NULL); |
1da177e4 | 1368 | if (!hashlimit_cachep) { |
b167a37c | 1369 | pr_warn("unable to create slab cache\n"); |
39b46fc6 | 1370 | goto err2; |
1da177e4 | 1371 | } |
e89fc3f1 AD |
1372 | return 0; |
1373 | ||
39b46fc6 | 1374 | err2: |
d3c5ee6d | 1375 | xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg)); |
39b46fc6 | 1376 | err1: |
e89fc3f1 | 1377 | unregister_pernet_subsys(&hashlimit_net_ops); |
39b46fc6 | 1378 | return err; |
1da177e4 | 1379 | |
1da177e4 LT |
1380 | } |
1381 | ||
d3c5ee6d | 1382 | static void __exit hashlimit_mt_exit(void) |
1da177e4 | 1383 | { |
d3c5ee6d | 1384 | xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg)); |
e89fc3f1 | 1385 | unregister_pernet_subsys(&hashlimit_net_ops); |
02e4eb75 ED |
1386 | |
1387 | rcu_barrier_bh(); | |
1388 | kmem_cache_destroy(hashlimit_cachep); | |
1da177e4 LT |
1389 | } |
1390 | ||
d3c5ee6d JE |
1391 | module_init(hashlimit_mt_init); |
1392 | module_exit(hashlimit_mt_exit); |