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 JE |
5 | * (C) 2003-2004 by Harald Welte <laforge@netfilter.org> |
6 | * Copyright © CC Computer Consultants GmbH, 2007 - 2008 | |
1da177e4 LT |
7 | * |
8 | * Development of this code was funded by Astaro AG, http://www.astaro.com/ | |
1da177e4 | 9 | */ |
8bee4bad | 10 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
1da177e4 | 11 | #include <linux/module.h> |
1da177e4 LT |
12 | #include <linux/spinlock.h> |
13 | #include <linux/random.h> | |
14 | #include <linux/jhash.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/vmalloc.h> | |
1da177e4 LT |
17 | #include <linux/proc_fs.h> |
18 | #include <linux/seq_file.h> | |
19 | #include <linux/list.h> | |
39b46fc6 | 20 | #include <linux/skbuff.h> |
d7fe0f24 | 21 | #include <linux/mm.h> |
39b46fc6 PM |
22 | #include <linux/in.h> |
23 | #include <linux/ip.h> | |
c0cd1156 | 24 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
39b46fc6 | 25 | #include <linux/ipv6.h> |
193b23c5 | 26 | #include <net/ipv6.h> |
7b21e09d ED |
27 | #endif |
28 | ||
457c4cbc | 29 | #include <net/net_namespace.h> |
e89fc3f1 | 30 | #include <net/netns/generic.h> |
1da177e4 | 31 | |
39b46fc6 | 32 | #include <linux/netfilter/x_tables.h> |
1da177e4 | 33 | #include <linux/netfilter_ipv4/ip_tables.h> |
39b46fc6 PM |
34 | #include <linux/netfilter_ipv6/ip6_tables.h> |
35 | #include <linux/netfilter/xt_hashlimit.h> | |
14cc3e2b | 36 | #include <linux/mutex.h> |
1da177e4 LT |
37 | |
38 | MODULE_LICENSE("GPL"); | |
39 | MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); | |
408ffaa4 | 40 | MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>"); |
2ae15b64 | 41 | MODULE_DESCRIPTION("Xtables: per hash-bucket rate-limit match"); |
39b46fc6 PM |
42 | MODULE_ALIAS("ipt_hashlimit"); |
43 | MODULE_ALIAS("ip6t_hashlimit"); | |
1da177e4 | 44 | |
e89fc3f1 AD |
45 | struct hashlimit_net { |
46 | struct hlist_head htables; | |
47 | struct proc_dir_entry *ipt_hashlimit; | |
48 | struct proc_dir_entry *ip6t_hashlimit; | |
49 | }; | |
50 | ||
51 | static int hashlimit_net_id; | |
52 | static inline struct hashlimit_net *hashlimit_pernet(struct net *net) | |
53 | { | |
54 | return net_generic(net, hashlimit_net_id); | |
55 | } | |
56 | ||
1da177e4 | 57 | /* need to declare this at the top */ |
da7071d7 | 58 | static const struct file_operations dl_file_ops; |
1da177e4 LT |
59 | |
60 | /* hash table crap */ | |
1da177e4 | 61 | struct dsthash_dst { |
39b46fc6 PM |
62 | union { |
63 | struct { | |
64 | __be32 src; | |
65 | __be32 dst; | |
66 | } ip; | |
c0cd1156 | 67 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
39b46fc6 PM |
68 | struct { |
69 | __be32 src[4]; | |
70 | __be32 dst[4]; | |
71 | } ip6; | |
7b21e09d | 72 | #endif |
09e410de | 73 | }; |
6a19d614 AV |
74 | __be16 src_port; |
75 | __be16 dst_port; | |
1da177e4 LT |
76 | }; |
77 | ||
78 | struct dsthash_ent { | |
79 | /* static / read-only parts in the beginning */ | |
80 | struct hlist_node node; | |
81 | struct dsthash_dst dst; | |
82 | ||
83 | /* modified structure members in the end */ | |
02e4eb75 | 84 | spinlock_t lock; |
1da177e4 LT |
85 | unsigned long expires; /* precalculated expiry time */ |
86 | struct { | |
87 | unsigned long prev; /* last modification */ | |
88 | u_int32_t credit; | |
89 | u_int32_t credit_cap, cost; | |
90 | } rateinfo; | |
02e4eb75 | 91 | struct rcu_head rcu; |
1da177e4 LT |
92 | }; |
93 | ||
39b46fc6 | 94 | struct xt_hashlimit_htable { |
1da177e4 | 95 | struct hlist_node node; /* global list of all htables */ |
2eff25c1 | 96 | int use; |
76108cea | 97 | u_int8_t family; |
89bc7a0f | 98 | bool rnd_initialized; |
1da177e4 | 99 | |
09e410de | 100 | struct hashlimit_cfg1 cfg; /* config */ |
1da177e4 LT |
101 | |
102 | /* used internally */ | |
103 | spinlock_t lock; /* lock for list_head */ | |
104 | u_int32_t rnd; /* random seed for hash */ | |
39b46fc6 | 105 | unsigned int count; /* number entries in table */ |
1da177e4 | 106 | struct timer_list timer; /* timer for gc */ |
1da177e4 LT |
107 | |
108 | /* seq_file stuff */ | |
109 | struct proc_dir_entry *pde; | |
e89fc3f1 | 110 | struct net *net; |
1da177e4 LT |
111 | |
112 | struct hlist_head hash[0]; /* hashtable itself */ | |
113 | }; | |
114 | ||
2eff25c1 | 115 | static DEFINE_MUTEX(hashlimit_mutex); /* protects htables list */ |
e18b890b | 116 | static struct kmem_cache *hashlimit_cachep __read_mostly; |
1da177e4 | 117 | |
1d93a9cb | 118 | static inline bool dst_cmp(const struct dsthash_ent *ent, |
a47362a2 | 119 | const struct dsthash_dst *b) |
1da177e4 | 120 | { |
39b46fc6 | 121 | return !memcmp(&ent->dst, b, sizeof(ent->dst)); |
1da177e4 LT |
122 | } |
123 | ||
39b46fc6 PM |
124 | static u_int32_t |
125 | hash_dst(const struct xt_hashlimit_htable *ht, const struct dsthash_dst *dst) | |
1da177e4 | 126 | { |
e2f82ac3 ED |
127 | u_int32_t hash = jhash2((const u32 *)dst, |
128 | sizeof(*dst)/sizeof(u32), | |
129 | ht->rnd); | |
130 | /* | |
131 | * Instead of returning hash % ht->cfg.size (implying a divide) | |
132 | * we return the high 32 bits of the (hash * ht->cfg.size) that will | |
133 | * give results between [0 and cfg.size-1] and same hash distribution, | |
134 | * but using a multiply, less expensive than a divide | |
135 | */ | |
136 | return ((u64)hash * ht->cfg.size) >> 32; | |
1da177e4 LT |
137 | } |
138 | ||
39b46fc6 | 139 | static struct dsthash_ent * |
a47362a2 JE |
140 | dsthash_find(const struct xt_hashlimit_htable *ht, |
141 | const struct dsthash_dst *dst) | |
1da177e4 LT |
142 | { |
143 | struct dsthash_ent *ent; | |
144 | struct hlist_node *pos; | |
145 | u_int32_t hash = hash_dst(ht, dst); | |
146 | ||
39b46fc6 | 147 | if (!hlist_empty(&ht->hash[hash])) { |
02e4eb75 ED |
148 | hlist_for_each_entry_rcu(ent, pos, &ht->hash[hash], node) |
149 | if (dst_cmp(ent, dst)) { | |
150 | spin_lock(&ent->lock); | |
1da177e4 | 151 | return ent; |
02e4eb75 | 152 | } |
39b46fc6 | 153 | } |
1da177e4 LT |
154 | return NULL; |
155 | } | |
156 | ||
157 | /* allocate dsthash_ent, initialize dst, put in htable and lock it */ | |
158 | static struct dsthash_ent * | |
a47362a2 | 159 | dsthash_alloc_init(struct xt_hashlimit_htable *ht, |
09181842 | 160 | const struct dsthash_dst *dst, bool *race) |
1da177e4 LT |
161 | { |
162 | struct dsthash_ent *ent; | |
163 | ||
02e4eb75 | 164 | spin_lock(&ht->lock); |
09181842 PNA |
165 | |
166 | /* Two or more packets may race to create the same entry in the | |
167 | * hashtable, double check if this packet lost race. | |
168 | */ | |
169 | ent = dsthash_find(ht, dst); | |
170 | if (ent != NULL) { | |
171 | spin_unlock(&ht->lock); | |
172 | *race = true; | |
173 | return ent; | |
174 | } | |
175 | ||
1da177e4 LT |
176 | /* initialize hash with random val at the time we allocate |
177 | * the first hashtable entry */ | |
02e4eb75 | 178 | if (unlikely(!ht->rnd_initialized)) { |
af07d241 | 179 | get_random_bytes(&ht->rnd, sizeof(ht->rnd)); |
89bc7a0f | 180 | ht->rnd_initialized = true; |
bf0857ea | 181 | } |
1da177e4 | 182 | |
39b46fc6 | 183 | if (ht->cfg.max && ht->count >= ht->cfg.max) { |
1da177e4 | 184 | /* FIXME: do something. question is what.. */ |
e87cc472 | 185 | net_err_ratelimited("max count of %u reached\n", ht->cfg.max); |
02e4eb75 ED |
186 | ent = NULL; |
187 | } else | |
188 | ent = kmem_cache_alloc(hashlimit_cachep, GFP_ATOMIC); | |
0a9ee813 | 189 | if (ent) { |
02e4eb75 ED |
190 | memcpy(&ent->dst, dst, sizeof(ent->dst)); |
191 | spin_lock_init(&ent->lock); | |
1da177e4 | 192 | |
02e4eb75 ED |
193 | spin_lock(&ent->lock); |
194 | hlist_add_head_rcu(&ent->node, &ht->hash[hash_dst(ht, dst)]); | |
195 | ht->count++; | |
196 | } | |
197 | spin_unlock(&ht->lock); | |
1da177e4 LT |
198 | return ent; |
199 | } | |
200 | ||
02e4eb75 ED |
201 | static void dsthash_free_rcu(struct rcu_head *head) |
202 | { | |
203 | struct dsthash_ent *ent = container_of(head, struct dsthash_ent, rcu); | |
204 | ||
205 | kmem_cache_free(hashlimit_cachep, ent); | |
206 | } | |
207 | ||
39b46fc6 PM |
208 | static inline void |
209 | dsthash_free(struct xt_hashlimit_htable *ht, struct dsthash_ent *ent) | |
1da177e4 | 210 | { |
02e4eb75 ED |
211 | hlist_del_rcu(&ent->node); |
212 | call_rcu_bh(&ent->rcu, dsthash_free_rcu); | |
39b46fc6 | 213 | ht->count--; |
1da177e4 LT |
214 | } |
215 | static void htable_gc(unsigned long htlong); | |
216 | ||
e89fc3f1 AD |
217 | static int htable_create(struct net *net, struct xt_hashlimit_mtinfo1 *minfo, |
218 | u_int8_t family) | |
09e410de | 219 | { |
e89fc3f1 | 220 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); |
09e410de JE |
221 | struct xt_hashlimit_htable *hinfo; |
222 | unsigned int size; | |
223 | unsigned int i; | |
224 | ||
225 | if (minfo->cfg.size) { | |
226 | size = minfo->cfg.size; | |
227 | } else { | |
4481374c | 228 | size = (totalram_pages << PAGE_SHIFT) / 16384 / |
09e410de | 229 | sizeof(struct list_head); |
4481374c | 230 | if (totalram_pages > 1024 * 1024 * 1024 / PAGE_SIZE) |
09e410de JE |
231 | size = 8192; |
232 | if (size < 16) | |
233 | size = 16; | |
234 | } | |
235 | /* FIXME: don't use vmalloc() here or anywhere else -HW */ | |
236 | hinfo = vmalloc(sizeof(struct xt_hashlimit_htable) + | |
237 | sizeof(struct list_head) * size); | |
85bc3f38 | 238 | if (hinfo == NULL) |
4a5a5c73 | 239 | return -ENOMEM; |
09e410de JE |
240 | minfo->hinfo = hinfo; |
241 | ||
242 | /* copy match config into hashtable config */ | |
243 | memcpy(&hinfo->cfg, &minfo->cfg, sizeof(hinfo->cfg)); | |
244 | hinfo->cfg.size = size; | |
245 | if (hinfo->cfg.max == 0) | |
246 | hinfo->cfg.max = 8 * hinfo->cfg.size; | |
247 | else if (hinfo->cfg.max < hinfo->cfg.size) | |
248 | hinfo->cfg.max = hinfo->cfg.size; | |
249 | ||
250 | for (i = 0; i < hinfo->cfg.size; i++) | |
251 | INIT_HLIST_HEAD(&hinfo->hash[i]); | |
252 | ||
2eff25c1 | 253 | hinfo->use = 1; |
09e410de JE |
254 | hinfo->count = 0; |
255 | hinfo->family = family; | |
89bc7a0f | 256 | hinfo->rnd_initialized = false; |
09e410de JE |
257 | spin_lock_init(&hinfo->lock); |
258 | ||
ee999d8b JE |
259 | hinfo->pde = proc_create_data(minfo->name, 0, |
260 | (family == NFPROTO_IPV4) ? | |
e89fc3f1 | 261 | hashlimit_net->ipt_hashlimit : hashlimit_net->ip6t_hashlimit, |
ee999d8b | 262 | &dl_file_ops, hinfo); |
09e410de JE |
263 | if (hinfo->pde == NULL) { |
264 | vfree(hinfo); | |
4a5a5c73 | 265 | return -ENOMEM; |
09e410de | 266 | } |
e89fc3f1 | 267 | hinfo->net = net; |
09e410de JE |
268 | |
269 | setup_timer(&hinfo->timer, htable_gc, (unsigned long)hinfo); | |
270 | hinfo->timer.expires = jiffies + msecs_to_jiffies(hinfo->cfg.gc_interval); | |
271 | add_timer(&hinfo->timer); | |
272 | ||
e89fc3f1 | 273 | hlist_add_head(&hinfo->node, &hashlimit_net->htables); |
09e410de JE |
274 | |
275 | return 0; | |
276 | } | |
277 | ||
a47362a2 JE |
278 | static bool select_all(const struct xt_hashlimit_htable *ht, |
279 | const struct dsthash_ent *he) | |
1da177e4 LT |
280 | { |
281 | return 1; | |
282 | } | |
283 | ||
a47362a2 JE |
284 | static bool select_gc(const struct xt_hashlimit_htable *ht, |
285 | const struct dsthash_ent *he) | |
1da177e4 | 286 | { |
cbebc51f | 287 | return time_after_eq(jiffies, he->expires); |
1da177e4 LT |
288 | } |
289 | ||
39b46fc6 | 290 | static void htable_selective_cleanup(struct xt_hashlimit_htable *ht, |
a47362a2 JE |
291 | bool (*select)(const struct xt_hashlimit_htable *ht, |
292 | const struct dsthash_ent *he)) | |
1da177e4 | 293 | { |
39b46fc6 | 294 | unsigned int i; |
1da177e4 LT |
295 | |
296 | /* lock hash table and iterate over it */ | |
297 | spin_lock_bh(&ht->lock); | |
298 | for (i = 0; i < ht->cfg.size; i++) { | |
299 | struct dsthash_ent *dh; | |
300 | struct hlist_node *pos, *n; | |
301 | hlist_for_each_entry_safe(dh, pos, n, &ht->hash[i], node) { | |
302 | if ((*select)(ht, dh)) | |
39b46fc6 | 303 | dsthash_free(ht, dh); |
1da177e4 LT |
304 | } |
305 | } | |
306 | spin_unlock_bh(&ht->lock); | |
307 | } | |
308 | ||
309 | /* hash table garbage collector, run by timer */ | |
310 | static void htable_gc(unsigned long htlong) | |
311 | { | |
39b46fc6 | 312 | struct xt_hashlimit_htable *ht = (struct xt_hashlimit_htable *)htlong; |
1da177e4 LT |
313 | |
314 | htable_selective_cleanup(ht, select_gc); | |
315 | ||
316 | /* re-add the timer accordingly */ | |
317 | ht->timer.expires = jiffies + msecs_to_jiffies(ht->cfg.gc_interval); | |
318 | add_timer(&ht->timer); | |
319 | } | |
320 | ||
39b46fc6 | 321 | static void htable_destroy(struct xt_hashlimit_htable *hinfo) |
1da177e4 | 322 | { |
e89fc3f1 AD |
323 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(hinfo->net); |
324 | struct proc_dir_entry *parent; | |
325 | ||
967ab999 | 326 | del_timer_sync(&hinfo->timer); |
1da177e4 | 327 | |
e89fc3f1 AD |
328 | if (hinfo->family == NFPROTO_IPV4) |
329 | parent = hashlimit_net->ipt_hashlimit; | |
330 | else | |
331 | parent = hashlimit_net->ip6t_hashlimit; | |
332 | remove_proc_entry(hinfo->pde->name, parent); | |
1da177e4 LT |
333 | htable_selective_cleanup(hinfo, select_all); |
334 | vfree(hinfo); | |
335 | } | |
336 | ||
e89fc3f1 AD |
337 | static struct xt_hashlimit_htable *htable_find_get(struct net *net, |
338 | const char *name, | |
76108cea | 339 | u_int8_t family) |
1da177e4 | 340 | { |
e89fc3f1 | 341 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); |
39b46fc6 | 342 | struct xt_hashlimit_htable *hinfo; |
1da177e4 LT |
343 | struct hlist_node *pos; |
344 | ||
e89fc3f1 | 345 | hlist_for_each_entry(hinfo, pos, &hashlimit_net->htables, node) { |
39b46fc6 PM |
346 | if (!strcmp(name, hinfo->pde->name) && |
347 | hinfo->family == family) { | |
2eff25c1 | 348 | hinfo->use++; |
1da177e4 LT |
349 | return hinfo; |
350 | } | |
351 | } | |
1da177e4 LT |
352 | return NULL; |
353 | } | |
354 | ||
39b46fc6 | 355 | static void htable_put(struct xt_hashlimit_htable *hinfo) |
1da177e4 | 356 | { |
2eff25c1 PM |
357 | mutex_lock(&hashlimit_mutex); |
358 | if (--hinfo->use == 0) { | |
1da177e4 | 359 | hlist_del(&hinfo->node); |
1da177e4 LT |
360 | htable_destroy(hinfo); |
361 | } | |
2eff25c1 | 362 | mutex_unlock(&hashlimit_mutex); |
1da177e4 LT |
363 | } |
364 | ||
1da177e4 LT |
365 | /* The algorithm used is the Simple Token Bucket Filter (TBF) |
366 | * see net/sched/sch_tbf.c in the linux source tree | |
367 | */ | |
368 | ||
369 | /* Rusty: This is my (non-mathematically-inclined) understanding of | |
370 | this algorithm. The `average rate' in jiffies becomes your initial | |
371 | amount of credit `credit' and the most credit you can ever have | |
372 | `credit_cap'. The `peak rate' becomes the cost of passing the | |
373 | test, `cost'. | |
374 | ||
375 | `prev' tracks the last packet hit: you gain one credit per jiffy. | |
376 | If you get credit balance more than this, the extra credit is | |
377 | discarded. Every time the match passes, you lose `cost' credits; | |
378 | if you don't have that many, the test fails. | |
379 | ||
380 | See Alexey's formal explanation in net/sched/sch_tbf.c. | |
381 | ||
382 | To get the maximum range, we multiply by this factor (ie. you get N | |
383 | credits per jiffy). We want to allow a rate as low as 1 per day | |
384 | (slowest userspace tool allows), which means | |
385 | CREDITS_PER_JIFFY*HZ*60*60*24 < 2^32 ie. | |
386 | */ | |
387 | #define MAX_CPJ (0xFFFFFFFF / (HZ*60*60*24)) | |
388 | ||
389 | /* Repeated shift and or gives us all 1s, final shift and add 1 gives | |
390 | * us the power of 2 below the theoretical max, so GCC simply does a | |
391 | * shift. */ | |
392 | #define _POW2_BELOW2(x) ((x)|((x)>>1)) | |
393 | #define _POW2_BELOW4(x) (_POW2_BELOW2(x)|_POW2_BELOW2((x)>>2)) | |
394 | #define _POW2_BELOW8(x) (_POW2_BELOW4(x)|_POW2_BELOW4((x)>>4)) | |
395 | #define _POW2_BELOW16(x) (_POW2_BELOW8(x)|_POW2_BELOW8((x)>>8)) | |
396 | #define _POW2_BELOW32(x) (_POW2_BELOW16(x)|_POW2_BELOW16((x)>>16)) | |
397 | #define POW2_BELOW32(x) ((_POW2_BELOW32(x)>>1) + 1) | |
398 | ||
399 | #define CREDITS_PER_JIFFY POW2_BELOW32(MAX_CPJ) | |
400 | ||
0197dee7 FW |
401 | /* in byte mode, the lowest possible rate is one packet/second. |
402 | * credit_cap is used as a counter that tells us how many times we can | |
403 | * refill the "credits available" counter when it becomes empty. | |
404 | */ | |
405 | #define MAX_CPJ_BYTES (0xFFFFFFFF / HZ) | |
406 | #define CREDITS_PER_JIFFY_BYTES POW2_BELOW32(MAX_CPJ_BYTES) | |
407 | ||
408 | static u32 xt_hashlimit_len_to_chunks(u32 len) | |
409 | { | |
410 | return (len >> XT_HASHLIMIT_BYTE_SHIFT) + 1; | |
411 | } | |
412 | ||
1da177e4 | 413 | /* Precision saver. */ |
7a909ac7 | 414 | static u32 user2credits(u32 user) |
1da177e4 LT |
415 | { |
416 | /* If multiplying would overflow... */ | |
417 | if (user > 0xFFFFFFFF / (HZ*CREDITS_PER_JIFFY)) | |
418 | /* Divide first. */ | |
39b46fc6 | 419 | return (user / XT_HASHLIMIT_SCALE) * HZ * CREDITS_PER_JIFFY; |
1da177e4 | 420 | |
39b46fc6 | 421 | return (user * HZ * CREDITS_PER_JIFFY) / XT_HASHLIMIT_SCALE; |
1da177e4 LT |
422 | } |
423 | ||
0197dee7 | 424 | static u32 user2credits_byte(u32 user) |
1da177e4 | 425 | { |
0197dee7 FW |
426 | u64 us = user; |
427 | us *= HZ * CREDITS_PER_JIFFY_BYTES; | |
428 | return (u32) (us >> 32); | |
429 | } | |
430 | ||
431 | static void rateinfo_recalc(struct dsthash_ent *dh, unsigned long now, u32 mode) | |
432 | { | |
433 | unsigned long delta = now - dh->rateinfo.prev; | |
434 | u32 cap; | |
435 | ||
436 | if (delta == 0) | |
437 | return; | |
438 | ||
39b46fc6 | 439 | dh->rateinfo.prev = now; |
0197dee7 FW |
440 | |
441 | if (mode & XT_HASHLIMIT_BYTES) { | |
442 | u32 tmp = dh->rateinfo.credit; | |
443 | dh->rateinfo.credit += CREDITS_PER_JIFFY_BYTES * delta; | |
444 | cap = CREDITS_PER_JIFFY_BYTES * HZ; | |
445 | if (tmp >= dh->rateinfo.credit) {/* overflow */ | |
446 | dh->rateinfo.credit = cap; | |
447 | return; | |
448 | } | |
449 | } else { | |
450 | dh->rateinfo.credit += delta * CREDITS_PER_JIFFY; | |
451 | cap = dh->rateinfo.credit_cap; | |
452 | } | |
453 | if (dh->rateinfo.credit > cap) | |
454 | dh->rateinfo.credit = cap; | |
39b46fc6 PM |
455 | } |
456 | ||
817e076f FW |
457 | static void rateinfo_init(struct dsthash_ent *dh, |
458 | struct xt_hashlimit_htable *hinfo) | |
459 | { | |
460 | dh->rateinfo.prev = jiffies; | |
0197dee7 FW |
461 | if (hinfo->cfg.mode & XT_HASHLIMIT_BYTES) { |
462 | dh->rateinfo.credit = CREDITS_PER_JIFFY_BYTES * HZ; | |
463 | dh->rateinfo.cost = user2credits_byte(hinfo->cfg.avg); | |
464 | dh->rateinfo.credit_cap = hinfo->cfg.burst; | |
465 | } else { | |
466 | dh->rateinfo.credit = user2credits(hinfo->cfg.avg * | |
467 | hinfo->cfg.burst); | |
468 | dh->rateinfo.cost = user2credits(hinfo->cfg.avg); | |
469 | dh->rateinfo.credit_cap = dh->rateinfo.credit; | |
470 | } | |
817e076f FW |
471 | } |
472 | ||
09e410de JE |
473 | static inline __be32 maskl(__be32 a, unsigned int l) |
474 | { | |
1b9b70ea | 475 | return l ? htonl(ntohl(a) & ~0 << (32 - l)) : 0; |
09e410de JE |
476 | } |
477 | ||
c0cd1156 | 478 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
09e410de JE |
479 | static void hashlimit_ipv6_mask(__be32 *i, unsigned int p) |
480 | { | |
481 | switch (p) { | |
1b9b70ea | 482 | case 0 ... 31: |
09e410de JE |
483 | i[0] = maskl(i[0], p); |
484 | i[1] = i[2] = i[3] = 0; | |
485 | break; | |
1b9b70ea | 486 | case 32 ... 63: |
09e410de JE |
487 | i[1] = maskl(i[1], p - 32); |
488 | i[2] = i[3] = 0; | |
489 | break; | |
1b9b70ea | 490 | case 64 ... 95: |
09e410de JE |
491 | i[2] = maskl(i[2], p - 64); |
492 | i[3] = 0; | |
8f599229 | 493 | break; |
1b9b70ea | 494 | case 96 ... 127: |
09e410de JE |
495 | i[3] = maskl(i[3], p - 96); |
496 | break; | |
497 | case 128: | |
498 | break; | |
499 | } | |
500 | } | |
3ed5df44 | 501 | #endif |
09e410de | 502 | |
39b46fc6 | 503 | static int |
a47362a2 JE |
504 | hashlimit_init_dst(const struct xt_hashlimit_htable *hinfo, |
505 | struct dsthash_dst *dst, | |
39b46fc6 PM |
506 | const struct sk_buff *skb, unsigned int protoff) |
507 | { | |
508 | __be16 _ports[2], *ports; | |
193b23c5 | 509 | u8 nexthdr; |
aca071c1 | 510 | int poff; |
39b46fc6 PM |
511 | |
512 | memset(dst, 0, sizeof(*dst)); | |
513 | ||
514 | switch (hinfo->family) { | |
ee999d8b | 515 | case NFPROTO_IPV4: |
39b46fc6 | 516 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP) |
09e410de JE |
517 | dst->ip.dst = maskl(ip_hdr(skb)->daddr, |
518 | hinfo->cfg.dstmask); | |
39b46fc6 | 519 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP) |
09e410de JE |
520 | dst->ip.src = maskl(ip_hdr(skb)->saddr, |
521 | hinfo->cfg.srcmask); | |
39b46fc6 PM |
522 | |
523 | if (!(hinfo->cfg.mode & | |
524 | (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT))) | |
525 | return 0; | |
eddc9ec5 | 526 | nexthdr = ip_hdr(skb)->protocol; |
39b46fc6 | 527 | break; |
c0cd1156 | 528 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
ee999d8b | 529 | case NFPROTO_IPV6: |
412662d2 SR |
530 | { |
531 | __be16 frag_off; | |
532 | ||
09e410de JE |
533 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP) { |
534 | memcpy(&dst->ip6.dst, &ipv6_hdr(skb)->daddr, | |
535 | sizeof(dst->ip6.dst)); | |
536 | hashlimit_ipv6_mask(dst->ip6.dst, hinfo->cfg.dstmask); | |
537 | } | |
538 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP) { | |
539 | memcpy(&dst->ip6.src, &ipv6_hdr(skb)->saddr, | |
540 | sizeof(dst->ip6.src)); | |
541 | hashlimit_ipv6_mask(dst->ip6.src, hinfo->cfg.srcmask); | |
542 | } | |
39b46fc6 PM |
543 | |
544 | if (!(hinfo->cfg.mode & | |
545 | (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT))) | |
546 | return 0; | |
193b23c5 | 547 | nexthdr = ipv6_hdr(skb)->nexthdr; |
75f2811c | 548 | protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr, &frag_off); |
193b23c5 | 549 | if ((int)protoff < 0) |
39b46fc6 PM |
550 | return -1; |
551 | break; | |
412662d2 | 552 | } |
39b46fc6 PM |
553 | #endif |
554 | default: | |
555 | BUG(); | |
556 | return 0; | |
557 | } | |
558 | ||
aca071c1 CG |
559 | poff = proto_ports_offset(nexthdr); |
560 | if (poff >= 0) { | |
561 | ports = skb_header_pointer(skb, protoff + poff, sizeof(_ports), | |
39b46fc6 | 562 | &_ports); |
aca071c1 | 563 | } else { |
39b46fc6 PM |
564 | _ports[0] = _ports[1] = 0; |
565 | ports = _ports; | |
39b46fc6 PM |
566 | } |
567 | if (!ports) | |
568 | return -1; | |
569 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SPT) | |
570 | dst->src_port = ports[0]; | |
571 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DPT) | |
572 | dst->dst_port = ports[1]; | |
573 | return 0; | |
1da177e4 LT |
574 | } |
575 | ||
0197dee7 FW |
576 | static u32 hashlimit_byte_cost(unsigned int len, struct dsthash_ent *dh) |
577 | { | |
578 | u64 tmp = xt_hashlimit_len_to_chunks(len); | |
579 | tmp = tmp * dh->rateinfo.cost; | |
580 | ||
581 | if (unlikely(tmp > CREDITS_PER_JIFFY_BYTES * HZ)) | |
582 | tmp = CREDITS_PER_JIFFY_BYTES * HZ; | |
583 | ||
584 | if (dh->rateinfo.credit < tmp && dh->rateinfo.credit_cap) { | |
585 | dh->rateinfo.credit_cap--; | |
586 | dh->rateinfo.credit = CREDITS_PER_JIFFY_BYTES * HZ; | |
587 | } | |
588 | return (u32) tmp; | |
589 | } | |
590 | ||
ccb79bdc | 591 | static bool |
62fc8051 | 592 | hashlimit_mt(const struct sk_buff *skb, struct xt_action_param *par) |
09e410de | 593 | { |
f7108a20 | 594 | const struct xt_hashlimit_mtinfo1 *info = par->matchinfo; |
09e410de JE |
595 | struct xt_hashlimit_htable *hinfo = info->hinfo; |
596 | unsigned long now = jiffies; | |
597 | struct dsthash_ent *dh; | |
598 | struct dsthash_dst dst; | |
09181842 | 599 | bool race = false; |
0197dee7 | 600 | u32 cost; |
09e410de | 601 | |
f7108a20 | 602 | if (hashlimit_init_dst(hinfo, &dst, skb, par->thoff) < 0) |
09e410de JE |
603 | goto hotdrop; |
604 | ||
02e4eb75 | 605 | rcu_read_lock_bh(); |
09e410de JE |
606 | dh = dsthash_find(hinfo, &dst); |
607 | if (dh == NULL) { | |
09181842 | 608 | dh = dsthash_alloc_init(hinfo, &dst, &race); |
09e410de | 609 | if (dh == NULL) { |
02e4eb75 | 610 | rcu_read_unlock_bh(); |
09e410de | 611 | goto hotdrop; |
09181842 PNA |
612 | } else if (race) { |
613 | /* Already got an entry, update expiration timeout */ | |
614 | dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire); | |
615 | rateinfo_recalc(dh, now, hinfo->cfg.mode); | |
616 | } else { | |
617 | dh->expires = jiffies + msecs_to_jiffies(hinfo->cfg.expire); | |
618 | rateinfo_init(dh, hinfo); | |
09e410de | 619 | } |
09e410de JE |
620 | } else { |
621 | /* update expiration timeout */ | |
622 | dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire); | |
0197dee7 | 623 | rateinfo_recalc(dh, now, hinfo->cfg.mode); |
09e410de JE |
624 | } |
625 | ||
0197dee7 FW |
626 | if (info->cfg.mode & XT_HASHLIMIT_BYTES) |
627 | cost = hashlimit_byte_cost(skb->len, dh); | |
628 | else | |
629 | cost = dh->rateinfo.cost; | |
630 | ||
631 | if (dh->rateinfo.credit >= cost) { | |
09e410de | 632 | /* below the limit */ |
0197dee7 | 633 | dh->rateinfo.credit -= cost; |
02e4eb75 ED |
634 | spin_unlock(&dh->lock); |
635 | rcu_read_unlock_bh(); | |
09e410de JE |
636 | return !(info->cfg.mode & XT_HASHLIMIT_INVERT); |
637 | } | |
638 | ||
02e4eb75 ED |
639 | spin_unlock(&dh->lock); |
640 | rcu_read_unlock_bh(); | |
09e410de JE |
641 | /* default match is underlimit - so over the limit, we need to invert */ |
642 | return info->cfg.mode & XT_HASHLIMIT_INVERT; | |
643 | ||
644 | hotdrop: | |
b4ba2611 | 645 | par->hotdrop = true; |
09e410de JE |
646 | return false; |
647 | } | |
648 | ||
b0f38452 | 649 | static int hashlimit_mt_check(const struct xt_mtchk_param *par) |
09e410de | 650 | { |
e89fc3f1 | 651 | struct net *net = par->net; |
9b4fce7a | 652 | struct xt_hashlimit_mtinfo1 *info = par->matchinfo; |
4a5a5c73 | 653 | int ret; |
09e410de | 654 | |
09e410de | 655 | if (info->cfg.gc_interval == 0 || info->cfg.expire == 0) |
bd414ee6 | 656 | return -EINVAL; |
09e410de | 657 | if (info->name[sizeof(info->name)-1] != '\0') |
bd414ee6 | 658 | return -EINVAL; |
aa5fa318 | 659 | if (par->family == NFPROTO_IPV4) { |
09e410de | 660 | if (info->cfg.srcmask > 32 || info->cfg.dstmask > 32) |
bd414ee6 | 661 | return -EINVAL; |
09e410de JE |
662 | } else { |
663 | if (info->cfg.srcmask > 128 || info->cfg.dstmask > 128) | |
bd414ee6 | 664 | return -EINVAL; |
09e410de JE |
665 | } |
666 | ||
1f27e251 | 667 | if (info->cfg.mode & ~XT_HASHLIMIT_ALL) { |
0197dee7 FW |
668 | pr_info("Unknown mode mask %X, kernel too old?\n", |
669 | info->cfg.mode); | |
670 | return -EINVAL; | |
671 | } | |
672 | ||
673 | /* Check for overflow. */ | |
674 | if (info->cfg.mode & XT_HASHLIMIT_BYTES) { | |
675 | if (user2credits_byte(info->cfg.avg) == 0) { | |
676 | pr_info("overflow, rate too high: %u\n", info->cfg.avg); | |
677 | return -EINVAL; | |
678 | } | |
679 | } else if (info->cfg.burst == 0 || | |
680 | user2credits(info->cfg.avg * info->cfg.burst) < | |
681 | user2credits(info->cfg.avg)) { | |
682 | pr_info("overflow, try lower: %u/%u\n", | |
683 | info->cfg.avg, info->cfg.burst); | |
684 | return -ERANGE; | |
685 | } | |
686 | ||
2eff25c1 | 687 | mutex_lock(&hashlimit_mutex); |
aa5fa318 | 688 | info->hinfo = htable_find_get(net, info->name, par->family); |
4a5a5c73 JE |
689 | if (info->hinfo == NULL) { |
690 | ret = htable_create(net, info, par->family); | |
691 | if (ret < 0) { | |
692 | mutex_unlock(&hashlimit_mutex); | |
693 | return ret; | |
694 | } | |
09e410de | 695 | } |
2eff25c1 | 696 | mutex_unlock(&hashlimit_mutex); |
bd414ee6 | 697 | return 0; |
09e410de JE |
698 | } |
699 | ||
6be3d859 | 700 | static void hashlimit_mt_destroy(const struct xt_mtdtor_param *par) |
09e410de | 701 | { |
6be3d859 | 702 | const struct xt_hashlimit_mtinfo1 *info = par->matchinfo; |
09e410de JE |
703 | |
704 | htable_put(info->hinfo); | |
705 | } | |
706 | ||
d3c5ee6d | 707 | static struct xt_match hashlimit_mt_reg[] __read_mostly = { |
09e410de JE |
708 | { |
709 | .name = "hashlimit", | |
710 | .revision = 1, | |
ee999d8b | 711 | .family = NFPROTO_IPV4, |
09e410de JE |
712 | .match = hashlimit_mt, |
713 | .matchsize = sizeof(struct xt_hashlimit_mtinfo1), | |
714 | .checkentry = hashlimit_mt_check, | |
715 | .destroy = hashlimit_mt_destroy, | |
716 | .me = THIS_MODULE, | |
717 | }, | |
c0cd1156 | 718 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
09e410de JE |
719 | { |
720 | .name = "hashlimit", | |
721 | .revision = 1, | |
ee999d8b | 722 | .family = NFPROTO_IPV6, |
09e410de JE |
723 | .match = hashlimit_mt, |
724 | .matchsize = sizeof(struct xt_hashlimit_mtinfo1), | |
725 | .checkentry = hashlimit_mt_check, | |
726 | .destroy = hashlimit_mt_destroy, | |
727 | .me = THIS_MODULE, | |
728 | }, | |
7b21e09d | 729 | #endif |
1da177e4 LT |
730 | }; |
731 | ||
732 | /* PROC stuff */ | |
1da177e4 | 733 | static void *dl_seq_start(struct seq_file *s, loff_t *pos) |
f4f6fb71 | 734 | __acquires(htable->lock) |
1da177e4 | 735 | { |
a1004d8e | 736 | struct xt_hashlimit_htable *htable = s->private; |
1da177e4 LT |
737 | unsigned int *bucket; |
738 | ||
739 | spin_lock_bh(&htable->lock); | |
740 | if (*pos >= htable->cfg.size) | |
741 | return NULL; | |
742 | ||
743 | bucket = kmalloc(sizeof(unsigned int), GFP_ATOMIC); | |
744 | if (!bucket) | |
745 | return ERR_PTR(-ENOMEM); | |
746 | ||
747 | *bucket = *pos; | |
748 | return bucket; | |
749 | } | |
750 | ||
751 | static void *dl_seq_next(struct seq_file *s, void *v, loff_t *pos) | |
752 | { | |
a1004d8e | 753 | struct xt_hashlimit_htable *htable = s->private; |
1da177e4 LT |
754 | unsigned int *bucket = (unsigned int *)v; |
755 | ||
756 | *pos = ++(*bucket); | |
757 | if (*pos >= htable->cfg.size) { | |
758 | kfree(v); | |
759 | return NULL; | |
760 | } | |
761 | return bucket; | |
762 | } | |
763 | ||
764 | static void dl_seq_stop(struct seq_file *s, void *v) | |
f4f6fb71 | 765 | __releases(htable->lock) |
1da177e4 | 766 | { |
a1004d8e | 767 | struct xt_hashlimit_htable *htable = s->private; |
1da177e4 LT |
768 | unsigned int *bucket = (unsigned int *)v; |
769 | ||
55e0d7cf ED |
770 | if (!IS_ERR(bucket)) |
771 | kfree(bucket); | |
1da177e4 LT |
772 | spin_unlock_bh(&htable->lock); |
773 | } | |
774 | ||
76108cea | 775 | static int dl_seq_real_show(struct dsthash_ent *ent, u_int8_t family, |
39b46fc6 | 776 | struct seq_file *s) |
1da177e4 | 777 | { |
02e4eb75 | 778 | int res; |
0197dee7 | 779 | const struct xt_hashlimit_htable *ht = s->private; |
02e4eb75 ED |
780 | |
781 | spin_lock(&ent->lock); | |
1da177e4 | 782 | /* recalculate to show accurate numbers */ |
0197dee7 | 783 | rateinfo_recalc(ent, jiffies, ht->cfg.mode); |
1da177e4 | 784 | |
39b46fc6 | 785 | switch (family) { |
ee999d8b | 786 | case NFPROTO_IPV4: |
02e4eb75 | 787 | res = seq_printf(s, "%ld %pI4:%u->%pI4:%u %u %u %u\n", |
39b46fc6 | 788 | (long)(ent->expires - jiffies)/HZ, |
14d5e834 | 789 | &ent->dst.ip.src, |
39b46fc6 | 790 | ntohs(ent->dst.src_port), |
14d5e834 | 791 | &ent->dst.ip.dst, |
39b46fc6 PM |
792 | ntohs(ent->dst.dst_port), |
793 | ent->rateinfo.credit, ent->rateinfo.credit_cap, | |
794 | ent->rateinfo.cost); | |
02e4eb75 | 795 | break; |
c0cd1156 | 796 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
ee999d8b | 797 | case NFPROTO_IPV6: |
02e4eb75 | 798 | res = seq_printf(s, "%ld %pI6:%u->%pI6:%u %u %u %u\n", |
39b46fc6 | 799 | (long)(ent->expires - jiffies)/HZ, |
38ff4fa4 | 800 | &ent->dst.ip6.src, |
39b46fc6 | 801 | ntohs(ent->dst.src_port), |
38ff4fa4 | 802 | &ent->dst.ip6.dst, |
39b46fc6 PM |
803 | ntohs(ent->dst.dst_port), |
804 | ent->rateinfo.credit, ent->rateinfo.credit_cap, | |
805 | ent->rateinfo.cost); | |
02e4eb75 | 806 | break; |
7b21e09d | 807 | #endif |
39b46fc6 PM |
808 | default: |
809 | BUG(); | |
02e4eb75 | 810 | res = 0; |
39b46fc6 | 811 | } |
02e4eb75 ED |
812 | spin_unlock(&ent->lock); |
813 | return res; | |
1da177e4 LT |
814 | } |
815 | ||
816 | static int dl_seq_show(struct seq_file *s, void *v) | |
817 | { | |
a1004d8e | 818 | struct xt_hashlimit_htable *htable = s->private; |
1da177e4 LT |
819 | unsigned int *bucket = (unsigned int *)v; |
820 | struct dsthash_ent *ent; | |
821 | struct hlist_node *pos; | |
822 | ||
39b46fc6 PM |
823 | if (!hlist_empty(&htable->hash[*bucket])) { |
824 | hlist_for_each_entry(ent, pos, &htable->hash[*bucket], node) | |
825 | if (dl_seq_real_show(ent, htable->family, s)) | |
683a04ce | 826 | return -1; |
39b46fc6 | 827 | } |
1da177e4 LT |
828 | return 0; |
829 | } | |
830 | ||
56b3d975 | 831 | static const struct seq_operations dl_seq_ops = { |
1da177e4 LT |
832 | .start = dl_seq_start, |
833 | .next = dl_seq_next, | |
834 | .stop = dl_seq_stop, | |
835 | .show = dl_seq_show | |
836 | }; | |
837 | ||
838 | static int dl_proc_open(struct inode *inode, struct file *file) | |
839 | { | |
840 | int ret = seq_open(file, &dl_seq_ops); | |
841 | ||
842 | if (!ret) { | |
843 | struct seq_file *sf = file->private_data; | |
a1004d8e | 844 | sf->private = PDE(inode)->data; |
1da177e4 LT |
845 | } |
846 | return ret; | |
847 | } | |
848 | ||
da7071d7 | 849 | static const struct file_operations dl_file_ops = { |
1da177e4 LT |
850 | .owner = THIS_MODULE, |
851 | .open = dl_proc_open, | |
852 | .read = seq_read, | |
853 | .llseek = seq_lseek, | |
854 | .release = seq_release | |
855 | }; | |
856 | ||
e89fc3f1 AD |
857 | static int __net_init hashlimit_proc_net_init(struct net *net) |
858 | { | |
859 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); | |
860 | ||
861 | hashlimit_net->ipt_hashlimit = proc_mkdir("ipt_hashlimit", net->proc_net); | |
862 | if (!hashlimit_net->ipt_hashlimit) | |
863 | return -ENOMEM; | |
c0cd1156 | 864 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
e89fc3f1 AD |
865 | hashlimit_net->ip6t_hashlimit = proc_mkdir("ip6t_hashlimit", net->proc_net); |
866 | if (!hashlimit_net->ip6t_hashlimit) { | |
867 | proc_net_remove(net, "ipt_hashlimit"); | |
868 | return -ENOMEM; | |
869 | } | |
870 | #endif | |
871 | return 0; | |
872 | } | |
873 | ||
874 | static void __net_exit hashlimit_proc_net_exit(struct net *net) | |
875 | { | |
876 | proc_net_remove(net, "ipt_hashlimit"); | |
c0cd1156 | 877 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
e89fc3f1 AD |
878 | proc_net_remove(net, "ip6t_hashlimit"); |
879 | #endif | |
880 | } | |
881 | ||
882 | static int __net_init hashlimit_net_init(struct net *net) | |
883 | { | |
884 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); | |
885 | ||
886 | INIT_HLIST_HEAD(&hashlimit_net->htables); | |
887 | return hashlimit_proc_net_init(net); | |
888 | } | |
889 | ||
890 | static void __net_exit hashlimit_net_exit(struct net *net) | |
891 | { | |
892 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); | |
893 | ||
894 | BUG_ON(!hlist_empty(&hashlimit_net->htables)); | |
895 | hashlimit_proc_net_exit(net); | |
896 | } | |
897 | ||
898 | static struct pernet_operations hashlimit_net_ops = { | |
899 | .init = hashlimit_net_init, | |
900 | .exit = hashlimit_net_exit, | |
901 | .id = &hashlimit_net_id, | |
902 | .size = sizeof(struct hashlimit_net), | |
903 | }; | |
904 | ||
d3c5ee6d | 905 | static int __init hashlimit_mt_init(void) |
1da177e4 | 906 | { |
39b46fc6 | 907 | int err; |
1da177e4 | 908 | |
e89fc3f1 AD |
909 | err = register_pernet_subsys(&hashlimit_net_ops); |
910 | if (err < 0) | |
911 | return err; | |
d3c5ee6d JE |
912 | err = xt_register_matches(hashlimit_mt_reg, |
913 | ARRAY_SIZE(hashlimit_mt_reg)); | |
39b46fc6 PM |
914 | if (err < 0) |
915 | goto err1; | |
1da177e4 | 916 | |
39b46fc6 PM |
917 | err = -ENOMEM; |
918 | hashlimit_cachep = kmem_cache_create("xt_hashlimit", | |
919 | sizeof(struct dsthash_ent), 0, 0, | |
20c2df83 | 920 | NULL); |
1da177e4 | 921 | if (!hashlimit_cachep) { |
8bee4bad | 922 | pr_warning("unable to create slab cache\n"); |
39b46fc6 | 923 | goto err2; |
1da177e4 | 924 | } |
e89fc3f1 AD |
925 | return 0; |
926 | ||
39b46fc6 | 927 | err2: |
d3c5ee6d | 928 | xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg)); |
39b46fc6 | 929 | err1: |
e89fc3f1 | 930 | unregister_pernet_subsys(&hashlimit_net_ops); |
39b46fc6 | 931 | return err; |
1da177e4 | 932 | |
1da177e4 LT |
933 | } |
934 | ||
d3c5ee6d | 935 | static void __exit hashlimit_mt_exit(void) |
1da177e4 | 936 | { |
d3c5ee6d | 937 | xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg)); |
e89fc3f1 | 938 | unregister_pernet_subsys(&hashlimit_net_ops); |
02e4eb75 ED |
939 | |
940 | rcu_barrier_bh(); | |
941 | kmem_cache_destroy(hashlimit_cachep); | |
1da177e4 LT |
942 | } |
943 | ||
d3c5ee6d JE |
944 | module_init(hashlimit_mt_init); |
945 | module_exit(hashlimit_mt_exit); |