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