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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; | |
1da177e4 LT |
144 | u_int32_t hash = hash_dst(ht, dst); |
145 | ||
39b46fc6 | 146 | if (!hlist_empty(&ht->hash[hash])) { |
b67bfe0d | 147 | hlist_for_each_entry_rcu(ent, &ht->hash[hash], node) |
02e4eb75 ED |
148 | if (dst_cmp(ent, dst)) { |
149 | spin_lock(&ent->lock); | |
1da177e4 | 150 | return ent; |
02e4eb75 | 151 | } |
39b46fc6 | 152 | } |
1da177e4 LT |
153 | return NULL; |
154 | } | |
155 | ||
156 | /* allocate dsthash_ent, initialize dst, put in htable and lock it */ | |
157 | static struct dsthash_ent * | |
a47362a2 | 158 | dsthash_alloc_init(struct xt_hashlimit_htable *ht, |
09181842 | 159 | const struct dsthash_dst *dst, bool *race) |
1da177e4 LT |
160 | { |
161 | struct dsthash_ent *ent; | |
162 | ||
02e4eb75 | 163 | spin_lock(&ht->lock); |
09181842 PNA |
164 | |
165 | /* Two or more packets may race to create the same entry in the | |
166 | * hashtable, double check if this packet lost race. | |
167 | */ | |
168 | ent = dsthash_find(ht, dst); | |
169 | if (ent != NULL) { | |
170 | spin_unlock(&ht->lock); | |
171 | *race = true; | |
172 | return ent; | |
173 | } | |
174 | ||
1da177e4 LT |
175 | /* initialize hash with random val at the time we allocate |
176 | * the first hashtable entry */ | |
02e4eb75 | 177 | if (unlikely(!ht->rnd_initialized)) { |
af07d241 | 178 | get_random_bytes(&ht->rnd, sizeof(ht->rnd)); |
89bc7a0f | 179 | ht->rnd_initialized = true; |
bf0857ea | 180 | } |
1da177e4 | 181 | |
39b46fc6 | 182 | if (ht->cfg.max && ht->count >= ht->cfg.max) { |
1da177e4 | 183 | /* FIXME: do something. question is what.. */ |
e87cc472 | 184 | net_err_ratelimited("max count of %u reached\n", ht->cfg.max); |
02e4eb75 ED |
185 | ent = NULL; |
186 | } else | |
187 | ent = kmem_cache_alloc(hashlimit_cachep, GFP_ATOMIC); | |
0a9ee813 | 188 | if (ent) { |
02e4eb75 ED |
189 | memcpy(&ent->dst, dst, sizeof(ent->dst)); |
190 | spin_lock_init(&ent->lock); | |
1da177e4 | 191 | |
02e4eb75 ED |
192 | spin_lock(&ent->lock); |
193 | hlist_add_head_rcu(&ent->node, &ht->hash[hash_dst(ht, dst)]); | |
194 | ht->count++; | |
195 | } | |
196 | spin_unlock(&ht->lock); | |
1da177e4 LT |
197 | return ent; |
198 | } | |
199 | ||
02e4eb75 ED |
200 | static void dsthash_free_rcu(struct rcu_head *head) |
201 | { | |
202 | struct dsthash_ent *ent = container_of(head, struct dsthash_ent, rcu); | |
203 | ||
204 | kmem_cache_free(hashlimit_cachep, ent); | |
205 | } | |
206 | ||
39b46fc6 PM |
207 | static inline void |
208 | dsthash_free(struct xt_hashlimit_htable *ht, struct dsthash_ent *ent) | |
1da177e4 | 209 | { |
02e4eb75 ED |
210 | hlist_del_rcu(&ent->node); |
211 | call_rcu_bh(&ent->rcu, dsthash_free_rcu); | |
39b46fc6 | 212 | ht->count--; |
1da177e4 LT |
213 | } |
214 | static void htable_gc(unsigned long htlong); | |
215 | ||
e89fc3f1 AD |
216 | static int htable_create(struct net *net, struct xt_hashlimit_mtinfo1 *minfo, |
217 | u_int8_t family) | |
09e410de | 218 | { |
e89fc3f1 | 219 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); |
09e410de JE |
220 | struct xt_hashlimit_htable *hinfo; |
221 | unsigned int size; | |
222 | unsigned int i; | |
223 | ||
224 | if (minfo->cfg.size) { | |
225 | size = minfo->cfg.size; | |
226 | } else { | |
4481374c | 227 | size = (totalram_pages << PAGE_SHIFT) / 16384 / |
09e410de | 228 | sizeof(struct list_head); |
4481374c | 229 | if (totalram_pages > 1024 * 1024 * 1024 / PAGE_SIZE) |
09e410de JE |
230 | size = 8192; |
231 | if (size < 16) | |
232 | size = 16; | |
233 | } | |
234 | /* FIXME: don't use vmalloc() here or anywhere else -HW */ | |
235 | hinfo = vmalloc(sizeof(struct xt_hashlimit_htable) + | |
236 | sizeof(struct list_head) * size); | |
85bc3f38 | 237 | if (hinfo == NULL) |
4a5a5c73 | 238 | return -ENOMEM; |
09e410de JE |
239 | minfo->hinfo = hinfo; |
240 | ||
241 | /* copy match config into hashtable config */ | |
242 | memcpy(&hinfo->cfg, &minfo->cfg, sizeof(hinfo->cfg)); | |
243 | hinfo->cfg.size = size; | |
244 | if (hinfo->cfg.max == 0) | |
245 | hinfo->cfg.max = 8 * hinfo->cfg.size; | |
246 | else if (hinfo->cfg.max < hinfo->cfg.size) | |
247 | hinfo->cfg.max = hinfo->cfg.size; | |
248 | ||
249 | for (i = 0; i < hinfo->cfg.size; i++) | |
250 | INIT_HLIST_HEAD(&hinfo->hash[i]); | |
251 | ||
2eff25c1 | 252 | hinfo->use = 1; |
09e410de JE |
253 | hinfo->count = 0; |
254 | hinfo->family = family; | |
89bc7a0f | 255 | hinfo->rnd_initialized = false; |
09e410de JE |
256 | spin_lock_init(&hinfo->lock); |
257 | ||
ee999d8b JE |
258 | hinfo->pde = proc_create_data(minfo->name, 0, |
259 | (family == NFPROTO_IPV4) ? | |
e89fc3f1 | 260 | hashlimit_net->ipt_hashlimit : hashlimit_net->ip6t_hashlimit, |
ee999d8b | 261 | &dl_file_ops, hinfo); |
09e410de JE |
262 | if (hinfo->pde == NULL) { |
263 | vfree(hinfo); | |
4a5a5c73 | 264 | return -ENOMEM; |
09e410de | 265 | } |
e89fc3f1 | 266 | hinfo->net = net; |
09e410de JE |
267 | |
268 | setup_timer(&hinfo->timer, htable_gc, (unsigned long)hinfo); | |
269 | hinfo->timer.expires = jiffies + msecs_to_jiffies(hinfo->cfg.gc_interval); | |
270 | add_timer(&hinfo->timer); | |
271 | ||
e89fc3f1 | 272 | hlist_add_head(&hinfo->node, &hashlimit_net->htables); |
09e410de JE |
273 | |
274 | return 0; | |
275 | } | |
276 | ||
a47362a2 JE |
277 | static bool select_all(const struct xt_hashlimit_htable *ht, |
278 | const struct dsthash_ent *he) | |
1da177e4 LT |
279 | { |
280 | return 1; | |
281 | } | |
282 | ||
a47362a2 JE |
283 | static bool select_gc(const struct xt_hashlimit_htable *ht, |
284 | const struct dsthash_ent *he) | |
1da177e4 | 285 | { |
cbebc51f | 286 | return time_after_eq(jiffies, he->expires); |
1da177e4 LT |
287 | } |
288 | ||
39b46fc6 | 289 | static void htable_selective_cleanup(struct xt_hashlimit_htable *ht, |
a47362a2 JE |
290 | bool (*select)(const struct xt_hashlimit_htable *ht, |
291 | const struct dsthash_ent *he)) | |
1da177e4 | 292 | { |
39b46fc6 | 293 | unsigned int i; |
1da177e4 LT |
294 | |
295 | /* lock hash table and iterate over it */ | |
296 | spin_lock_bh(&ht->lock); | |
297 | for (i = 0; i < ht->cfg.size; i++) { | |
298 | struct dsthash_ent *dh; | |
b67bfe0d SL |
299 | struct hlist_node *n; |
300 | hlist_for_each_entry_safe(dh, n, &ht->hash[i], node) { | |
1da177e4 | 301 | if ((*select)(ht, dh)) |
39b46fc6 | 302 | dsthash_free(ht, dh); |
1da177e4 LT |
303 | } |
304 | } | |
305 | spin_unlock_bh(&ht->lock); | |
306 | } | |
307 | ||
308 | /* hash table garbage collector, run by timer */ | |
309 | static void htable_gc(unsigned long htlong) | |
310 | { | |
39b46fc6 | 311 | struct xt_hashlimit_htable *ht = (struct xt_hashlimit_htable *)htlong; |
1da177e4 LT |
312 | |
313 | htable_selective_cleanup(ht, select_gc); | |
314 | ||
315 | /* re-add the timer accordingly */ | |
316 | ht->timer.expires = jiffies + msecs_to_jiffies(ht->cfg.gc_interval); | |
317 | add_timer(&ht->timer); | |
318 | } | |
319 | ||
39b46fc6 | 320 | static void htable_destroy(struct xt_hashlimit_htable *hinfo) |
1da177e4 | 321 | { |
e89fc3f1 AD |
322 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(hinfo->net); |
323 | struct proc_dir_entry *parent; | |
324 | ||
967ab999 | 325 | del_timer_sync(&hinfo->timer); |
1da177e4 | 326 | |
e89fc3f1 AD |
327 | if (hinfo->family == NFPROTO_IPV4) |
328 | parent = hashlimit_net->ipt_hashlimit; | |
329 | else | |
330 | parent = hashlimit_net->ip6t_hashlimit; | |
32263dd1 VL |
331 | |
332 | if(parent != NULL) | |
333 | remove_proc_entry(hinfo->pde->name, parent); | |
334 | ||
1da177e4 LT |
335 | htable_selective_cleanup(hinfo, select_all); |
336 | vfree(hinfo); | |
337 | } | |
338 | ||
e89fc3f1 AD |
339 | static struct xt_hashlimit_htable *htable_find_get(struct net *net, |
340 | const char *name, | |
76108cea | 341 | u_int8_t family) |
1da177e4 | 342 | { |
e89fc3f1 | 343 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); |
39b46fc6 | 344 | struct xt_hashlimit_htable *hinfo; |
1da177e4 | 345 | |
b67bfe0d | 346 | hlist_for_each_entry(hinfo, &hashlimit_net->htables, node) { |
39b46fc6 PM |
347 | if (!strcmp(name, hinfo->pde->name) && |
348 | hinfo->family == family) { | |
2eff25c1 | 349 | hinfo->use++; |
1da177e4 LT |
350 | return hinfo; |
351 | } | |
352 | } | |
1da177e4 LT |
353 | return NULL; |
354 | } | |
355 | ||
39b46fc6 | 356 | static void htable_put(struct xt_hashlimit_htable *hinfo) |
1da177e4 | 357 | { |
2eff25c1 PM |
358 | mutex_lock(&hashlimit_mutex); |
359 | if (--hinfo->use == 0) { | |
1da177e4 | 360 | hlist_del(&hinfo->node); |
1da177e4 LT |
361 | htable_destroy(hinfo); |
362 | } | |
2eff25c1 | 363 | mutex_unlock(&hashlimit_mutex); |
1da177e4 LT |
364 | } |
365 | ||
1da177e4 LT |
366 | /* The algorithm used is the Simple Token Bucket Filter (TBF) |
367 | * see net/sched/sch_tbf.c in the linux source tree | |
368 | */ | |
369 | ||
370 | /* Rusty: This is my (non-mathematically-inclined) understanding of | |
371 | this algorithm. The `average rate' in jiffies becomes your initial | |
372 | amount of credit `credit' and the most credit you can ever have | |
373 | `credit_cap'. The `peak rate' becomes the cost of passing the | |
374 | test, `cost'. | |
375 | ||
376 | `prev' tracks the last packet hit: you gain one credit per jiffy. | |
377 | If you get credit balance more than this, the extra credit is | |
378 | discarded. Every time the match passes, you lose `cost' credits; | |
379 | if you don't have that many, the test fails. | |
380 | ||
381 | See Alexey's formal explanation in net/sched/sch_tbf.c. | |
382 | ||
383 | To get the maximum range, we multiply by this factor (ie. you get N | |
384 | credits per jiffy). We want to allow a rate as low as 1 per day | |
385 | (slowest userspace tool allows), which means | |
386 | CREDITS_PER_JIFFY*HZ*60*60*24 < 2^32 ie. | |
387 | */ | |
388 | #define MAX_CPJ (0xFFFFFFFF / (HZ*60*60*24)) | |
389 | ||
390 | /* Repeated shift and or gives us all 1s, final shift and add 1 gives | |
391 | * us the power of 2 below the theoretical max, so GCC simply does a | |
392 | * shift. */ | |
393 | #define _POW2_BELOW2(x) ((x)|((x)>>1)) | |
394 | #define _POW2_BELOW4(x) (_POW2_BELOW2(x)|_POW2_BELOW2((x)>>2)) | |
395 | #define _POW2_BELOW8(x) (_POW2_BELOW4(x)|_POW2_BELOW4((x)>>4)) | |
396 | #define _POW2_BELOW16(x) (_POW2_BELOW8(x)|_POW2_BELOW8((x)>>8)) | |
397 | #define _POW2_BELOW32(x) (_POW2_BELOW16(x)|_POW2_BELOW16((x)>>16)) | |
398 | #define POW2_BELOW32(x) ((_POW2_BELOW32(x)>>1) + 1) | |
399 | ||
400 | #define CREDITS_PER_JIFFY POW2_BELOW32(MAX_CPJ) | |
401 | ||
0197dee7 FW |
402 | /* in byte mode, the lowest possible rate is one packet/second. |
403 | * credit_cap is used as a counter that tells us how many times we can | |
404 | * refill the "credits available" counter when it becomes empty. | |
405 | */ | |
406 | #define MAX_CPJ_BYTES (0xFFFFFFFF / HZ) | |
407 | #define CREDITS_PER_JIFFY_BYTES POW2_BELOW32(MAX_CPJ_BYTES) | |
408 | ||
409 | static u32 xt_hashlimit_len_to_chunks(u32 len) | |
410 | { | |
411 | return (len >> XT_HASHLIMIT_BYTE_SHIFT) + 1; | |
412 | } | |
413 | ||
1da177e4 | 414 | /* Precision saver. */ |
7a909ac7 | 415 | static u32 user2credits(u32 user) |
1da177e4 LT |
416 | { |
417 | /* If multiplying would overflow... */ | |
418 | if (user > 0xFFFFFFFF / (HZ*CREDITS_PER_JIFFY)) | |
419 | /* Divide first. */ | |
39b46fc6 | 420 | return (user / XT_HASHLIMIT_SCALE) * HZ * CREDITS_PER_JIFFY; |
1da177e4 | 421 | |
39b46fc6 | 422 | return (user * HZ * CREDITS_PER_JIFFY) / XT_HASHLIMIT_SCALE; |
1da177e4 LT |
423 | } |
424 | ||
0197dee7 | 425 | static u32 user2credits_byte(u32 user) |
1da177e4 | 426 | { |
0197dee7 FW |
427 | u64 us = user; |
428 | us *= HZ * CREDITS_PER_JIFFY_BYTES; | |
429 | return (u32) (us >> 32); | |
430 | } | |
431 | ||
432 | static void rateinfo_recalc(struct dsthash_ent *dh, unsigned long now, u32 mode) | |
433 | { | |
434 | unsigned long delta = now - dh->rateinfo.prev; | |
435 | u32 cap; | |
436 | ||
437 | if (delta == 0) | |
438 | return; | |
439 | ||
39b46fc6 | 440 | dh->rateinfo.prev = now; |
0197dee7 FW |
441 | |
442 | if (mode & XT_HASHLIMIT_BYTES) { | |
443 | u32 tmp = dh->rateinfo.credit; | |
444 | dh->rateinfo.credit += CREDITS_PER_JIFFY_BYTES * delta; | |
445 | cap = CREDITS_PER_JIFFY_BYTES * HZ; | |
446 | if (tmp >= dh->rateinfo.credit) {/* overflow */ | |
447 | dh->rateinfo.credit = cap; | |
448 | return; | |
449 | } | |
450 | } else { | |
451 | dh->rateinfo.credit += delta * CREDITS_PER_JIFFY; | |
452 | cap = dh->rateinfo.credit_cap; | |
453 | } | |
454 | if (dh->rateinfo.credit > cap) | |
455 | dh->rateinfo.credit = cap; | |
39b46fc6 PM |
456 | } |
457 | ||
817e076f FW |
458 | static void rateinfo_init(struct dsthash_ent *dh, |
459 | struct xt_hashlimit_htable *hinfo) | |
460 | { | |
461 | dh->rateinfo.prev = jiffies; | |
0197dee7 FW |
462 | if (hinfo->cfg.mode & XT_HASHLIMIT_BYTES) { |
463 | dh->rateinfo.credit = CREDITS_PER_JIFFY_BYTES * HZ; | |
464 | dh->rateinfo.cost = user2credits_byte(hinfo->cfg.avg); | |
465 | dh->rateinfo.credit_cap = hinfo->cfg.burst; | |
466 | } else { | |
467 | dh->rateinfo.credit = user2credits(hinfo->cfg.avg * | |
468 | hinfo->cfg.burst); | |
469 | dh->rateinfo.cost = user2credits(hinfo->cfg.avg); | |
470 | dh->rateinfo.credit_cap = dh->rateinfo.credit; | |
471 | } | |
817e076f FW |
472 | } |
473 | ||
09e410de JE |
474 | static inline __be32 maskl(__be32 a, unsigned int l) |
475 | { | |
1b9b70ea | 476 | return l ? htonl(ntohl(a) & ~0 << (32 - l)) : 0; |
09e410de JE |
477 | } |
478 | ||
c0cd1156 | 479 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
09e410de JE |
480 | static void hashlimit_ipv6_mask(__be32 *i, unsigned int p) |
481 | { | |
482 | switch (p) { | |
1b9b70ea | 483 | case 0 ... 31: |
09e410de JE |
484 | i[0] = maskl(i[0], p); |
485 | i[1] = i[2] = i[3] = 0; | |
486 | break; | |
1b9b70ea | 487 | case 32 ... 63: |
09e410de JE |
488 | i[1] = maskl(i[1], p - 32); |
489 | i[2] = i[3] = 0; | |
490 | break; | |
1b9b70ea | 491 | case 64 ... 95: |
09e410de JE |
492 | i[2] = maskl(i[2], p - 64); |
493 | i[3] = 0; | |
8f599229 | 494 | break; |
1b9b70ea | 495 | case 96 ... 127: |
09e410de JE |
496 | i[3] = maskl(i[3], p - 96); |
497 | break; | |
498 | case 128: | |
499 | break; | |
500 | } | |
501 | } | |
3ed5df44 | 502 | #endif |
09e410de | 503 | |
39b46fc6 | 504 | static int |
a47362a2 JE |
505 | hashlimit_init_dst(const struct xt_hashlimit_htable *hinfo, |
506 | struct dsthash_dst *dst, | |
39b46fc6 PM |
507 | const struct sk_buff *skb, unsigned int protoff) |
508 | { | |
509 | __be16 _ports[2], *ports; | |
193b23c5 | 510 | u8 nexthdr; |
aca071c1 | 511 | int poff; |
39b46fc6 PM |
512 | |
513 | memset(dst, 0, sizeof(*dst)); | |
514 | ||
515 | switch (hinfo->family) { | |
ee999d8b | 516 | case NFPROTO_IPV4: |
39b46fc6 | 517 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP) |
09e410de JE |
518 | dst->ip.dst = maskl(ip_hdr(skb)->daddr, |
519 | hinfo->cfg.dstmask); | |
39b46fc6 | 520 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP) |
09e410de JE |
521 | dst->ip.src = maskl(ip_hdr(skb)->saddr, |
522 | hinfo->cfg.srcmask); | |
39b46fc6 PM |
523 | |
524 | if (!(hinfo->cfg.mode & | |
525 | (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT))) | |
526 | return 0; | |
eddc9ec5 | 527 | nexthdr = ip_hdr(skb)->protocol; |
39b46fc6 | 528 | break; |
c0cd1156 | 529 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
ee999d8b | 530 | case NFPROTO_IPV6: |
412662d2 SR |
531 | { |
532 | __be16 frag_off; | |
533 | ||
09e410de JE |
534 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP) { |
535 | memcpy(&dst->ip6.dst, &ipv6_hdr(skb)->daddr, | |
536 | sizeof(dst->ip6.dst)); | |
537 | hashlimit_ipv6_mask(dst->ip6.dst, hinfo->cfg.dstmask); | |
538 | } | |
539 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP) { | |
540 | memcpy(&dst->ip6.src, &ipv6_hdr(skb)->saddr, | |
541 | sizeof(dst->ip6.src)); | |
542 | hashlimit_ipv6_mask(dst->ip6.src, hinfo->cfg.srcmask); | |
543 | } | |
39b46fc6 PM |
544 | |
545 | if (!(hinfo->cfg.mode & | |
546 | (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT))) | |
547 | return 0; | |
193b23c5 | 548 | nexthdr = ipv6_hdr(skb)->nexthdr; |
75f2811c | 549 | protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr, &frag_off); |
193b23c5 | 550 | if ((int)protoff < 0) |
39b46fc6 PM |
551 | return -1; |
552 | break; | |
412662d2 | 553 | } |
39b46fc6 PM |
554 | #endif |
555 | default: | |
556 | BUG(); | |
557 | return 0; | |
558 | } | |
559 | ||
aca071c1 CG |
560 | poff = proto_ports_offset(nexthdr); |
561 | if (poff >= 0) { | |
562 | ports = skb_header_pointer(skb, protoff + poff, sizeof(_ports), | |
39b46fc6 | 563 | &_ports); |
aca071c1 | 564 | } else { |
39b46fc6 PM |
565 | _ports[0] = _ports[1] = 0; |
566 | ports = _ports; | |
39b46fc6 PM |
567 | } |
568 | if (!ports) | |
569 | return -1; | |
570 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SPT) | |
571 | dst->src_port = ports[0]; | |
572 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DPT) | |
573 | dst->dst_port = ports[1]; | |
574 | return 0; | |
1da177e4 LT |
575 | } |
576 | ||
0197dee7 FW |
577 | static u32 hashlimit_byte_cost(unsigned int len, struct dsthash_ent *dh) |
578 | { | |
579 | u64 tmp = xt_hashlimit_len_to_chunks(len); | |
580 | tmp = tmp * dh->rateinfo.cost; | |
581 | ||
582 | if (unlikely(tmp > CREDITS_PER_JIFFY_BYTES * HZ)) | |
583 | tmp = CREDITS_PER_JIFFY_BYTES * HZ; | |
584 | ||
585 | if (dh->rateinfo.credit < tmp && dh->rateinfo.credit_cap) { | |
586 | dh->rateinfo.credit_cap--; | |
587 | dh->rateinfo.credit = CREDITS_PER_JIFFY_BYTES * HZ; | |
588 | } | |
589 | return (u32) tmp; | |
590 | } | |
591 | ||
ccb79bdc | 592 | static bool |
62fc8051 | 593 | hashlimit_mt(const struct sk_buff *skb, struct xt_action_param *par) |
09e410de | 594 | { |
f7108a20 | 595 | const struct xt_hashlimit_mtinfo1 *info = par->matchinfo; |
09e410de JE |
596 | struct xt_hashlimit_htable *hinfo = info->hinfo; |
597 | unsigned long now = jiffies; | |
598 | struct dsthash_ent *dh; | |
599 | struct dsthash_dst dst; | |
09181842 | 600 | bool race = false; |
0197dee7 | 601 | u32 cost; |
09e410de | 602 | |
f7108a20 | 603 | if (hashlimit_init_dst(hinfo, &dst, skb, par->thoff) < 0) |
09e410de JE |
604 | goto hotdrop; |
605 | ||
02e4eb75 | 606 | rcu_read_lock_bh(); |
09e410de JE |
607 | dh = dsthash_find(hinfo, &dst); |
608 | if (dh == NULL) { | |
09181842 | 609 | dh = dsthash_alloc_init(hinfo, &dst, &race); |
09e410de | 610 | if (dh == NULL) { |
02e4eb75 | 611 | rcu_read_unlock_bh(); |
09e410de | 612 | goto hotdrop; |
09181842 PNA |
613 | } else if (race) { |
614 | /* Already got an entry, update expiration timeout */ | |
615 | dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire); | |
616 | rateinfo_recalc(dh, now, hinfo->cfg.mode); | |
617 | } else { | |
618 | dh->expires = jiffies + msecs_to_jiffies(hinfo->cfg.expire); | |
619 | rateinfo_init(dh, hinfo); | |
09e410de | 620 | } |
09e410de JE |
621 | } else { |
622 | /* update expiration timeout */ | |
623 | dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire); | |
0197dee7 | 624 | rateinfo_recalc(dh, now, hinfo->cfg.mode); |
09e410de JE |
625 | } |
626 | ||
0197dee7 FW |
627 | if (info->cfg.mode & XT_HASHLIMIT_BYTES) |
628 | cost = hashlimit_byte_cost(skb->len, dh); | |
629 | else | |
630 | cost = dh->rateinfo.cost; | |
631 | ||
632 | if (dh->rateinfo.credit >= cost) { | |
09e410de | 633 | /* below the limit */ |
0197dee7 | 634 | dh->rateinfo.credit -= cost; |
02e4eb75 ED |
635 | spin_unlock(&dh->lock); |
636 | rcu_read_unlock_bh(); | |
09e410de JE |
637 | return !(info->cfg.mode & XT_HASHLIMIT_INVERT); |
638 | } | |
639 | ||
02e4eb75 ED |
640 | spin_unlock(&dh->lock); |
641 | rcu_read_unlock_bh(); | |
09e410de JE |
642 | /* default match is underlimit - so over the limit, we need to invert */ |
643 | return info->cfg.mode & XT_HASHLIMIT_INVERT; | |
644 | ||
645 | hotdrop: | |
b4ba2611 | 646 | par->hotdrop = true; |
09e410de JE |
647 | return false; |
648 | } | |
649 | ||
b0f38452 | 650 | static int hashlimit_mt_check(const struct xt_mtchk_param *par) |
09e410de | 651 | { |
e89fc3f1 | 652 | struct net *net = par->net; |
9b4fce7a | 653 | struct xt_hashlimit_mtinfo1 *info = par->matchinfo; |
4a5a5c73 | 654 | int ret; |
09e410de | 655 | |
09e410de | 656 | if (info->cfg.gc_interval == 0 || info->cfg.expire == 0) |
bd414ee6 | 657 | return -EINVAL; |
09e410de | 658 | if (info->name[sizeof(info->name)-1] != '\0') |
bd414ee6 | 659 | return -EINVAL; |
aa5fa318 | 660 | if (par->family == NFPROTO_IPV4) { |
09e410de | 661 | if (info->cfg.srcmask > 32 || info->cfg.dstmask > 32) |
bd414ee6 | 662 | return -EINVAL; |
09e410de JE |
663 | } else { |
664 | if (info->cfg.srcmask > 128 || info->cfg.dstmask > 128) | |
bd414ee6 | 665 | return -EINVAL; |
09e410de JE |
666 | } |
667 | ||
1f27e251 | 668 | if (info->cfg.mode & ~XT_HASHLIMIT_ALL) { |
0197dee7 FW |
669 | pr_info("Unknown mode mask %X, kernel too old?\n", |
670 | info->cfg.mode); | |
671 | return -EINVAL; | |
672 | } | |
673 | ||
674 | /* Check for overflow. */ | |
675 | if (info->cfg.mode & XT_HASHLIMIT_BYTES) { | |
676 | if (user2credits_byte(info->cfg.avg) == 0) { | |
677 | pr_info("overflow, rate too high: %u\n", info->cfg.avg); | |
678 | return -EINVAL; | |
679 | } | |
680 | } else if (info->cfg.burst == 0 || | |
681 | user2credits(info->cfg.avg * info->cfg.burst) < | |
682 | user2credits(info->cfg.avg)) { | |
683 | pr_info("overflow, try lower: %u/%u\n", | |
684 | info->cfg.avg, info->cfg.burst); | |
685 | return -ERANGE; | |
686 | } | |
687 | ||
2eff25c1 | 688 | mutex_lock(&hashlimit_mutex); |
aa5fa318 | 689 | info->hinfo = htable_find_get(net, info->name, par->family); |
4a5a5c73 JE |
690 | if (info->hinfo == NULL) { |
691 | ret = htable_create(net, info, par->family); | |
692 | if (ret < 0) { | |
693 | mutex_unlock(&hashlimit_mutex); | |
694 | return ret; | |
695 | } | |
09e410de | 696 | } |
2eff25c1 | 697 | mutex_unlock(&hashlimit_mutex); |
bd414ee6 | 698 | return 0; |
09e410de JE |
699 | } |
700 | ||
6be3d859 | 701 | static void hashlimit_mt_destroy(const struct xt_mtdtor_param *par) |
09e410de | 702 | { |
6be3d859 | 703 | const struct xt_hashlimit_mtinfo1 *info = par->matchinfo; |
09e410de JE |
704 | |
705 | htable_put(info->hinfo); | |
706 | } | |
707 | ||
d3c5ee6d | 708 | static struct xt_match hashlimit_mt_reg[] __read_mostly = { |
09e410de JE |
709 | { |
710 | .name = "hashlimit", | |
711 | .revision = 1, | |
ee999d8b | 712 | .family = NFPROTO_IPV4, |
09e410de JE |
713 | .match = hashlimit_mt, |
714 | .matchsize = sizeof(struct xt_hashlimit_mtinfo1), | |
715 | .checkentry = hashlimit_mt_check, | |
716 | .destroy = hashlimit_mt_destroy, | |
717 | .me = THIS_MODULE, | |
718 | }, | |
c0cd1156 | 719 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
09e410de JE |
720 | { |
721 | .name = "hashlimit", | |
722 | .revision = 1, | |
ee999d8b | 723 | .family = NFPROTO_IPV6, |
09e410de JE |
724 | .match = hashlimit_mt, |
725 | .matchsize = sizeof(struct xt_hashlimit_mtinfo1), | |
726 | .checkentry = hashlimit_mt_check, | |
727 | .destroy = hashlimit_mt_destroy, | |
728 | .me = THIS_MODULE, | |
729 | }, | |
7b21e09d | 730 | #endif |
1da177e4 LT |
731 | }; |
732 | ||
733 | /* PROC stuff */ | |
1da177e4 | 734 | static void *dl_seq_start(struct seq_file *s, loff_t *pos) |
f4f6fb71 | 735 | __acquires(htable->lock) |
1da177e4 | 736 | { |
a1004d8e | 737 | struct xt_hashlimit_htable *htable = s->private; |
1da177e4 LT |
738 | unsigned int *bucket; |
739 | ||
740 | spin_lock_bh(&htable->lock); | |
741 | if (*pos >= htable->cfg.size) | |
742 | return NULL; | |
743 | ||
744 | bucket = kmalloc(sizeof(unsigned int), GFP_ATOMIC); | |
745 | if (!bucket) | |
746 | return ERR_PTR(-ENOMEM); | |
747 | ||
748 | *bucket = *pos; | |
749 | return bucket; | |
750 | } | |
751 | ||
752 | static void *dl_seq_next(struct seq_file *s, void *v, loff_t *pos) | |
753 | { | |
a1004d8e | 754 | struct xt_hashlimit_htable *htable = s->private; |
1da177e4 LT |
755 | unsigned int *bucket = (unsigned int *)v; |
756 | ||
757 | *pos = ++(*bucket); | |
758 | if (*pos >= htable->cfg.size) { | |
759 | kfree(v); | |
760 | return NULL; | |
761 | } | |
762 | return bucket; | |
763 | } | |
764 | ||
765 | static void dl_seq_stop(struct seq_file *s, void *v) | |
f4f6fb71 | 766 | __releases(htable->lock) |
1da177e4 | 767 | { |
a1004d8e | 768 | struct xt_hashlimit_htable *htable = s->private; |
1da177e4 LT |
769 | unsigned int *bucket = (unsigned int *)v; |
770 | ||
55e0d7cf ED |
771 | if (!IS_ERR(bucket)) |
772 | kfree(bucket); | |
1da177e4 LT |
773 | spin_unlock_bh(&htable->lock); |
774 | } | |
775 | ||
76108cea | 776 | static int dl_seq_real_show(struct dsthash_ent *ent, u_int8_t family, |
39b46fc6 | 777 | struct seq_file *s) |
1da177e4 | 778 | { |
02e4eb75 | 779 | int res; |
0197dee7 | 780 | const struct xt_hashlimit_htable *ht = s->private; |
02e4eb75 ED |
781 | |
782 | spin_lock(&ent->lock); | |
1da177e4 | 783 | /* recalculate to show accurate numbers */ |
0197dee7 | 784 | rateinfo_recalc(ent, jiffies, ht->cfg.mode); |
1da177e4 | 785 | |
39b46fc6 | 786 | switch (family) { |
ee999d8b | 787 | case NFPROTO_IPV4: |
02e4eb75 | 788 | res = seq_printf(s, "%ld %pI4:%u->%pI4:%u %u %u %u\n", |
39b46fc6 | 789 | (long)(ent->expires - jiffies)/HZ, |
14d5e834 | 790 | &ent->dst.ip.src, |
39b46fc6 | 791 | ntohs(ent->dst.src_port), |
14d5e834 | 792 | &ent->dst.ip.dst, |
39b46fc6 PM |
793 | ntohs(ent->dst.dst_port), |
794 | ent->rateinfo.credit, ent->rateinfo.credit_cap, | |
795 | ent->rateinfo.cost); | |
02e4eb75 | 796 | break; |
c0cd1156 | 797 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
ee999d8b | 798 | case NFPROTO_IPV6: |
02e4eb75 | 799 | res = seq_printf(s, "%ld %pI6:%u->%pI6:%u %u %u %u\n", |
39b46fc6 | 800 | (long)(ent->expires - jiffies)/HZ, |
38ff4fa4 | 801 | &ent->dst.ip6.src, |
39b46fc6 | 802 | ntohs(ent->dst.src_port), |
38ff4fa4 | 803 | &ent->dst.ip6.dst, |
39b46fc6 PM |
804 | ntohs(ent->dst.dst_port), |
805 | ent->rateinfo.credit, ent->rateinfo.credit_cap, | |
806 | ent->rateinfo.cost); | |
02e4eb75 | 807 | break; |
7b21e09d | 808 | #endif |
39b46fc6 PM |
809 | default: |
810 | BUG(); | |
02e4eb75 | 811 | res = 0; |
39b46fc6 | 812 | } |
02e4eb75 ED |
813 | spin_unlock(&ent->lock); |
814 | return res; | |
1da177e4 LT |
815 | } |
816 | ||
817 | static int dl_seq_show(struct seq_file *s, void *v) | |
818 | { | |
a1004d8e | 819 | struct xt_hashlimit_htable *htable = s->private; |
1da177e4 LT |
820 | unsigned int *bucket = (unsigned int *)v; |
821 | struct dsthash_ent *ent; | |
1da177e4 | 822 | |
39b46fc6 | 823 | if (!hlist_empty(&htable->hash[*bucket])) { |
b67bfe0d | 824 | hlist_for_each_entry(ent, &htable->hash[*bucket], node) |
39b46fc6 | 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) { | |
ece31ffd | 867 | remove_proc_entry("ipt_hashlimit", net->proc_net); |
e89fc3f1 AD |
868 | return -ENOMEM; |
869 | } | |
870 | #endif | |
871 | return 0; | |
872 | } | |
873 | ||
874 | static void __net_exit hashlimit_proc_net_exit(struct net *net) | |
875 | { | |
32263dd1 | 876 | struct xt_hashlimit_htable *hinfo; |
32263dd1 VL |
877 | struct proc_dir_entry *pde; |
878 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); | |
879 | ||
880 | /* recent_net_exit() is called before recent_mt_destroy(). Make sure | |
881 | * that the parent xt_recent proc entry is is empty before trying to | |
882 | * remove it. | |
883 | */ | |
884 | mutex_lock(&hashlimit_mutex); | |
885 | pde = hashlimit_net->ipt_hashlimit; | |
886 | if (pde == NULL) | |
887 | pde = hashlimit_net->ip6t_hashlimit; | |
888 | ||
b67bfe0d | 889 | hlist_for_each_entry(hinfo, &hashlimit_net->htables, node) |
32263dd1 VL |
890 | remove_proc_entry(hinfo->pde->name, pde); |
891 | ||
892 | hashlimit_net->ipt_hashlimit = NULL; | |
893 | hashlimit_net->ip6t_hashlimit = NULL; | |
894 | mutex_unlock(&hashlimit_mutex); | |
895 | ||
ece31ffd | 896 | remove_proc_entry("ipt_hashlimit", net->proc_net); |
c0cd1156 | 897 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
ece31ffd | 898 | remove_proc_entry("ip6t_hashlimit", net->proc_net); |
e89fc3f1 AD |
899 | #endif |
900 | } | |
901 | ||
902 | static int __net_init hashlimit_net_init(struct net *net) | |
903 | { | |
904 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); | |
905 | ||
906 | INIT_HLIST_HEAD(&hashlimit_net->htables); | |
907 | return hashlimit_proc_net_init(net); | |
908 | } | |
909 | ||
910 | static void __net_exit hashlimit_net_exit(struct net *net) | |
911 | { | |
e89fc3f1 AD |
912 | hashlimit_proc_net_exit(net); |
913 | } | |
914 | ||
915 | static struct pernet_operations hashlimit_net_ops = { | |
916 | .init = hashlimit_net_init, | |
917 | .exit = hashlimit_net_exit, | |
918 | .id = &hashlimit_net_id, | |
919 | .size = sizeof(struct hashlimit_net), | |
920 | }; | |
921 | ||
d3c5ee6d | 922 | static int __init hashlimit_mt_init(void) |
1da177e4 | 923 | { |
39b46fc6 | 924 | int err; |
1da177e4 | 925 | |
e89fc3f1 AD |
926 | err = register_pernet_subsys(&hashlimit_net_ops); |
927 | if (err < 0) | |
928 | return err; | |
d3c5ee6d JE |
929 | err = xt_register_matches(hashlimit_mt_reg, |
930 | ARRAY_SIZE(hashlimit_mt_reg)); | |
39b46fc6 PM |
931 | if (err < 0) |
932 | goto err1; | |
1da177e4 | 933 | |
39b46fc6 PM |
934 | err = -ENOMEM; |
935 | hashlimit_cachep = kmem_cache_create("xt_hashlimit", | |
936 | sizeof(struct dsthash_ent), 0, 0, | |
20c2df83 | 937 | NULL); |
1da177e4 | 938 | if (!hashlimit_cachep) { |
8bee4bad | 939 | pr_warning("unable to create slab cache\n"); |
39b46fc6 | 940 | goto err2; |
1da177e4 | 941 | } |
e89fc3f1 AD |
942 | return 0; |
943 | ||
39b46fc6 | 944 | err2: |
d3c5ee6d | 945 | xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg)); |
39b46fc6 | 946 | err1: |
e89fc3f1 | 947 | unregister_pernet_subsys(&hashlimit_net_ops); |
39b46fc6 | 948 | return err; |
1da177e4 | 949 | |
1da177e4 LT |
950 | } |
951 | ||
d3c5ee6d | 952 | static void __exit hashlimit_mt_exit(void) |
1da177e4 | 953 | { |
d3c5ee6d | 954 | xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg)); |
e89fc3f1 | 955 | unregister_pernet_subsys(&hashlimit_net_ops); |
02e4eb75 ED |
956 | |
957 | rcu_barrier_bh(); | |
958 | kmem_cache_destroy(hashlimit_cachep); | |
1da177e4 LT |
959 | } |
960 | ||
d3c5ee6d JE |
961 | module_init(hashlimit_mt_init); |
962 | module_exit(hashlimit_mt_exit); |