Commit | Line | Data |
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09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
09e410de JE |
2 | /* |
3 | * xt_hashlimit - Netfilter module to limit the number of packets per time | |
3ad2f3fb | 4 | * separately for each hashbucket (sourceip/sourceport/dstip/dstport) |
1da177e4 | 5 | * |
09e410de | 6 | * (C) 2003-2004 by Harald Welte <laforge@netfilter.org> |
f229f6ce | 7 | * (C) 2006-2012 Patrick McHardy <kaber@trash.net> |
09e410de | 8 | * Copyright © CC Computer Consultants GmbH, 2007 - 2008 |
1da177e4 LT |
9 | * |
10 | * Development of this code was funded by Astaro AG, http://www.astaro.com/ | |
1da177e4 | 11 | */ |
8bee4bad | 12 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
1da177e4 | 13 | #include <linux/module.h> |
1da177e4 LT |
14 | #include <linux/spinlock.h> |
15 | #include <linux/random.h> | |
16 | #include <linux/jhash.h> | |
17 | #include <linux/slab.h> | |
18 | #include <linux/vmalloc.h> | |
1da177e4 LT |
19 | #include <linux/proc_fs.h> |
20 | #include <linux/seq_file.h> | |
21 | #include <linux/list.h> | |
39b46fc6 | 22 | #include <linux/skbuff.h> |
d7fe0f24 | 23 | #include <linux/mm.h> |
39b46fc6 PM |
24 | #include <linux/in.h> |
25 | #include <linux/ip.h> | |
c0cd1156 | 26 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
39b46fc6 | 27 | #include <linux/ipv6.h> |
193b23c5 | 28 | #include <net/ipv6.h> |
7b21e09d ED |
29 | #endif |
30 | ||
457c4cbc | 31 | #include <net/net_namespace.h> |
e89fc3f1 | 32 | #include <net/netns/generic.h> |
1da177e4 | 33 | |
39b46fc6 | 34 | #include <linux/netfilter/x_tables.h> |
1da177e4 | 35 | #include <linux/netfilter_ipv4/ip_tables.h> |
39b46fc6 | 36 | #include <linux/netfilter_ipv6/ip6_tables.h> |
14cc3e2b | 37 | #include <linux/mutex.h> |
90c4ae4e | 38 | #include <linux/kernel.h> |
85cfbc25 JS |
39 | #include <uapi/linux/netfilter/xt_hashlimit.h> |
40 | ||
41 | #define XT_HASHLIMIT_ALL (XT_HASHLIMIT_HASH_DIP | XT_HASHLIMIT_HASH_DPT | \ | |
42 | XT_HASHLIMIT_HASH_SIP | XT_HASHLIMIT_HASH_SPT | \ | |
43 | XT_HASHLIMIT_INVERT | XT_HASHLIMIT_BYTES |\ | |
44 | XT_HASHLIMIT_RATE_MATCH) | |
1da177e4 LT |
45 | |
46 | MODULE_LICENSE("GPL"); | |
47 | MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); | |
408ffaa4 | 48 | MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>"); |
2ae15b64 | 49 | MODULE_DESCRIPTION("Xtables: per hash-bucket rate-limit match"); |
39b46fc6 PM |
50 | MODULE_ALIAS("ipt_hashlimit"); |
51 | MODULE_ALIAS("ip6t_hashlimit"); | |
1da177e4 | 52 | |
e89fc3f1 AD |
53 | struct hashlimit_net { |
54 | struct hlist_head htables; | |
55 | struct proc_dir_entry *ipt_hashlimit; | |
56 | struct proc_dir_entry *ip6t_hashlimit; | |
57 | }; | |
58 | ||
c7d03a00 | 59 | static unsigned int hashlimit_net_id; |
e89fc3f1 AD |
60 | static inline struct hashlimit_net *hashlimit_pernet(struct net *net) |
61 | { | |
62 | return net_generic(net, hashlimit_net_id); | |
63 | } | |
64 | ||
1da177e4 | 65 | /* need to declare this at the top */ |
fd24de89 CH |
66 | static const struct seq_operations dl_seq_ops_v2; |
67 | static const struct seq_operations dl_seq_ops_v1; | |
68 | static const struct seq_operations dl_seq_ops; | |
1da177e4 LT |
69 | |
70 | /* hash table crap */ | |
1da177e4 | 71 | struct dsthash_dst { |
39b46fc6 PM |
72 | union { |
73 | struct { | |
74 | __be32 src; | |
75 | __be32 dst; | |
76 | } ip; | |
c0cd1156 | 77 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
39b46fc6 PM |
78 | struct { |
79 | __be32 src[4]; | |
80 | __be32 dst[4]; | |
81 | } ip6; | |
7b21e09d | 82 | #endif |
09e410de | 83 | }; |
6a19d614 AV |
84 | __be16 src_port; |
85 | __be16 dst_port; | |
1da177e4 LT |
86 | }; |
87 | ||
88 | struct dsthash_ent { | |
89 | /* static / read-only parts in the beginning */ | |
90 | struct hlist_node node; | |
91 | struct dsthash_dst dst; | |
92 | ||
93 | /* modified structure members in the end */ | |
02e4eb75 | 94 | spinlock_t lock; |
1da177e4 LT |
95 | unsigned long expires; /* precalculated expiry time */ |
96 | struct { | |
97 | unsigned long prev; /* last modification */ | |
bea74641 VP |
98 | union { |
99 | struct { | |
100 | u_int64_t credit; | |
101 | u_int64_t credit_cap; | |
102 | u_int64_t cost; | |
103 | }; | |
104 | struct { | |
105 | u_int32_t interval, prev_window; | |
106 | u_int64_t current_rate; | |
107 | u_int64_t rate; | |
108 | int64_t burst; | |
109 | }; | |
110 | }; | |
1da177e4 | 111 | } rateinfo; |
02e4eb75 | 112 | struct rcu_head rcu; |
1da177e4 LT |
113 | }; |
114 | ||
39b46fc6 | 115 | struct xt_hashlimit_htable { |
1da177e4 | 116 | struct hlist_node node; /* global list of all htables */ |
2eff25c1 | 117 | int use; |
76108cea | 118 | u_int8_t family; |
89bc7a0f | 119 | bool rnd_initialized; |
1da177e4 | 120 | |
bea74641 | 121 | struct hashlimit_cfg3 cfg; /* config */ |
1da177e4 LT |
122 | |
123 | /* used internally */ | |
124 | spinlock_t lock; /* lock for list_head */ | |
125 | u_int32_t rnd; /* random seed for hash */ | |
39b46fc6 | 126 | unsigned int count; /* number entries in table */ |
7bd8490e | 127 | struct delayed_work gc_work; |
1da177e4 LT |
128 | |
129 | /* seq_file stuff */ | |
130 | struct proc_dir_entry *pde; | |
14b872f0 | 131 | const char *name; |
e89fc3f1 | 132 | struct net *net; |
1da177e4 LT |
133 | |
134 | struct hlist_head hash[0]; /* hashtable itself */ | |
135 | }; | |
136 | ||
11d5f157 | 137 | static int |
bea74641 | 138 | cfg_copy(struct hashlimit_cfg3 *to, const void *from, int revision) |
11d5f157 VP |
139 | { |
140 | if (revision == 1) { | |
bea74641 | 141 | struct hashlimit_cfg1 *cfg = (struct hashlimit_cfg1 *)from; |
11d5f157 VP |
142 | |
143 | to->mode = cfg->mode; | |
144 | to->avg = cfg->avg; | |
145 | to->burst = cfg->burst; | |
146 | to->size = cfg->size; | |
147 | to->max = cfg->max; | |
148 | to->gc_interval = cfg->gc_interval; | |
149 | to->expire = cfg->expire; | |
150 | to->srcmask = cfg->srcmask; | |
151 | to->dstmask = cfg->dstmask; | |
152 | } else if (revision == 2) { | |
bea74641 VP |
153 | struct hashlimit_cfg2 *cfg = (struct hashlimit_cfg2 *)from; |
154 | ||
155 | to->mode = cfg->mode; | |
156 | to->avg = cfg->avg; | |
157 | to->burst = cfg->burst; | |
158 | to->size = cfg->size; | |
159 | to->max = cfg->max; | |
160 | to->gc_interval = cfg->gc_interval; | |
161 | to->expire = cfg->expire; | |
162 | to->srcmask = cfg->srcmask; | |
163 | to->dstmask = cfg->dstmask; | |
164 | } else if (revision == 3) { | |
165 | memcpy(to, from, sizeof(struct hashlimit_cfg3)); | |
11d5f157 VP |
166 | } else { |
167 | return -EINVAL; | |
168 | } | |
169 | ||
170 | return 0; | |
171 | } | |
172 | ||
2eff25c1 | 173 | static DEFINE_MUTEX(hashlimit_mutex); /* protects htables list */ |
e18b890b | 174 | static struct kmem_cache *hashlimit_cachep __read_mostly; |
1da177e4 | 175 | |
1d93a9cb | 176 | static inline bool dst_cmp(const struct dsthash_ent *ent, |
a47362a2 | 177 | const struct dsthash_dst *b) |
1da177e4 | 178 | { |
39b46fc6 | 179 | return !memcmp(&ent->dst, b, sizeof(ent->dst)); |
1da177e4 LT |
180 | } |
181 | ||
39b46fc6 PM |
182 | static u_int32_t |
183 | hash_dst(const struct xt_hashlimit_htable *ht, const struct dsthash_dst *dst) | |
1da177e4 | 184 | { |
e2f82ac3 ED |
185 | u_int32_t hash = jhash2((const u32 *)dst, |
186 | sizeof(*dst)/sizeof(u32), | |
187 | ht->rnd); | |
188 | /* | |
189 | * Instead of returning hash % ht->cfg.size (implying a divide) | |
190 | * we return the high 32 bits of the (hash * ht->cfg.size) that will | |
191 | * give results between [0 and cfg.size-1] and same hash distribution, | |
192 | * but using a multiply, less expensive than a divide | |
193 | */ | |
8fc54f68 | 194 | return reciprocal_scale(hash, ht->cfg.size); |
1da177e4 LT |
195 | } |
196 | ||
39b46fc6 | 197 | static struct dsthash_ent * |
a47362a2 JE |
198 | dsthash_find(const struct xt_hashlimit_htable *ht, |
199 | const struct dsthash_dst *dst) | |
1da177e4 LT |
200 | { |
201 | struct dsthash_ent *ent; | |
1da177e4 LT |
202 | u_int32_t hash = hash_dst(ht, dst); |
203 | ||
39b46fc6 | 204 | if (!hlist_empty(&ht->hash[hash])) { |
b67bfe0d | 205 | hlist_for_each_entry_rcu(ent, &ht->hash[hash], node) |
02e4eb75 ED |
206 | if (dst_cmp(ent, dst)) { |
207 | spin_lock(&ent->lock); | |
1da177e4 | 208 | return ent; |
02e4eb75 | 209 | } |
39b46fc6 | 210 | } |
1da177e4 LT |
211 | return NULL; |
212 | } | |
213 | ||
214 | /* allocate dsthash_ent, initialize dst, put in htable and lock it */ | |
215 | static struct dsthash_ent * | |
a47362a2 | 216 | dsthash_alloc_init(struct xt_hashlimit_htable *ht, |
09181842 | 217 | const struct dsthash_dst *dst, bool *race) |
1da177e4 LT |
218 | { |
219 | struct dsthash_ent *ent; | |
220 | ||
02e4eb75 | 221 | spin_lock(&ht->lock); |
09181842 PNA |
222 | |
223 | /* Two or more packets may race to create the same entry in the | |
224 | * hashtable, double check if this packet lost race. | |
225 | */ | |
226 | ent = dsthash_find(ht, dst); | |
227 | if (ent != NULL) { | |
228 | spin_unlock(&ht->lock); | |
229 | *race = true; | |
230 | return ent; | |
231 | } | |
232 | ||
1da177e4 LT |
233 | /* initialize hash with random val at the time we allocate |
234 | * the first hashtable entry */ | |
02e4eb75 | 235 | if (unlikely(!ht->rnd_initialized)) { |
af07d241 | 236 | get_random_bytes(&ht->rnd, sizeof(ht->rnd)); |
89bc7a0f | 237 | ht->rnd_initialized = true; |
bf0857ea | 238 | } |
1da177e4 | 239 | |
39b46fc6 | 240 | if (ht->cfg.max && ht->count >= ht->cfg.max) { |
1da177e4 | 241 | /* FIXME: do something. question is what.. */ |
e87cc472 | 242 | net_err_ratelimited("max count of %u reached\n", ht->cfg.max); |
02e4eb75 ED |
243 | ent = NULL; |
244 | } else | |
245 | ent = kmem_cache_alloc(hashlimit_cachep, GFP_ATOMIC); | |
0a9ee813 | 246 | if (ent) { |
02e4eb75 ED |
247 | memcpy(&ent->dst, dst, sizeof(ent->dst)); |
248 | spin_lock_init(&ent->lock); | |
1da177e4 | 249 | |
02e4eb75 ED |
250 | spin_lock(&ent->lock); |
251 | hlist_add_head_rcu(&ent->node, &ht->hash[hash_dst(ht, dst)]); | |
252 | ht->count++; | |
253 | } | |
254 | spin_unlock(&ht->lock); | |
1da177e4 LT |
255 | return ent; |
256 | } | |
257 | ||
02e4eb75 ED |
258 | static void dsthash_free_rcu(struct rcu_head *head) |
259 | { | |
260 | struct dsthash_ent *ent = container_of(head, struct dsthash_ent, rcu); | |
261 | ||
262 | kmem_cache_free(hashlimit_cachep, ent); | |
263 | } | |
264 | ||
39b46fc6 PM |
265 | static inline void |
266 | dsthash_free(struct xt_hashlimit_htable *ht, struct dsthash_ent *ent) | |
1da177e4 | 267 | { |
02e4eb75 | 268 | hlist_del_rcu(&ent->node); |
c8d1da40 | 269 | call_rcu(&ent->rcu, dsthash_free_rcu); |
39b46fc6 | 270 | ht->count--; |
1da177e4 | 271 | } |
7bd8490e | 272 | static void htable_gc(struct work_struct *work); |
1da177e4 | 273 | |
bea74641 | 274 | static int htable_create(struct net *net, struct hashlimit_cfg3 *cfg, |
11d5f157 VP |
275 | const char *name, u_int8_t family, |
276 | struct xt_hashlimit_htable **out_hinfo, | |
277 | int revision) | |
09e410de | 278 | { |
e89fc3f1 | 279 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); |
09e410de | 280 | struct xt_hashlimit_htable *hinfo; |
fd24de89 | 281 | const struct seq_operations *ops; |
11d5f157 | 282 | unsigned int size, i; |
ca79b0c2 | 283 | unsigned long nr_pages = totalram_pages(); |
11d5f157 | 284 | int ret; |
09e410de | 285 | |
11d5f157 VP |
286 | if (cfg->size) { |
287 | size = cfg->size; | |
09e410de | 288 | } else { |
3d6357de | 289 | size = (nr_pages << PAGE_SHIFT) / 16384 / |
05d0eae7 | 290 | sizeof(struct hlist_head); |
3d6357de | 291 | if (nr_pages > 1024 * 1024 * 1024 / PAGE_SIZE) |
09e410de JE |
292 | size = 8192; |
293 | if (size < 16) | |
294 | size = 16; | |
295 | } | |
296 | /* FIXME: don't use vmalloc() here or anywhere else -HW */ | |
eabb4782 | 297 | hinfo = vmalloc(struct_size(hinfo, hash, size)); |
85bc3f38 | 298 | if (hinfo == NULL) |
4a5a5c73 | 299 | return -ENOMEM; |
11d5f157 | 300 | *out_hinfo = hinfo; |
09e410de JE |
301 | |
302 | /* copy match config into hashtable config */ | |
bea74641 | 303 | ret = cfg_copy(&hinfo->cfg, (void *)cfg, 3); |
b4e955e9 TY |
304 | if (ret) { |
305 | vfree(hinfo); | |
11d5f157 | 306 | return ret; |
b4e955e9 | 307 | } |
11d5f157 | 308 | |
09e410de JE |
309 | hinfo->cfg.size = size; |
310 | if (hinfo->cfg.max == 0) | |
311 | hinfo->cfg.max = 8 * hinfo->cfg.size; | |
312 | else if (hinfo->cfg.max < hinfo->cfg.size) | |
313 | hinfo->cfg.max = hinfo->cfg.size; | |
314 | ||
315 | for (i = 0; i < hinfo->cfg.size; i++) | |
316 | INIT_HLIST_HEAD(&hinfo->hash[i]); | |
317 | ||
2eff25c1 | 318 | hinfo->use = 1; |
09e410de JE |
319 | hinfo->count = 0; |
320 | hinfo->family = family; | |
89bc7a0f | 321 | hinfo->rnd_initialized = false; |
11d5f157 | 322 | hinfo->name = kstrdup(name, GFP_KERNEL); |
14b872f0 AV |
323 | if (!hinfo->name) { |
324 | vfree(hinfo); | |
325 | return -ENOMEM; | |
326 | } | |
09e410de JE |
327 | spin_lock_init(&hinfo->lock); |
328 | ||
bea74641 VP |
329 | switch (revision) { |
330 | case 1: | |
fd24de89 | 331 | ops = &dl_seq_ops_v1; |
bea74641 VP |
332 | break; |
333 | case 2: | |
fd24de89 | 334 | ops = &dl_seq_ops_v2; |
bea74641 VP |
335 | break; |
336 | default: | |
fd24de89 | 337 | ops = &dl_seq_ops; |
bea74641 VP |
338 | } |
339 | ||
fd24de89 | 340 | hinfo->pde = proc_create_seq_data(name, 0, |
ee999d8b | 341 | (family == NFPROTO_IPV4) ? |
e89fc3f1 | 342 | hashlimit_net->ipt_hashlimit : hashlimit_net->ip6t_hashlimit, |
fd24de89 | 343 | ops, hinfo); |
09e410de | 344 | if (hinfo->pde == NULL) { |
14b872f0 | 345 | kfree(hinfo->name); |
09e410de | 346 | vfree(hinfo); |
4a5a5c73 | 347 | return -ENOMEM; |
09e410de | 348 | } |
e89fc3f1 | 349 | hinfo->net = net; |
09e410de | 350 | |
7bd8490e ED |
351 | INIT_DEFERRABLE_WORK(&hinfo->gc_work, htable_gc); |
352 | queue_delayed_work(system_power_efficient_wq, &hinfo->gc_work, | |
353 | msecs_to_jiffies(hinfo->cfg.gc_interval)); | |
09e410de | 354 | |
e89fc3f1 | 355 | hlist_add_head(&hinfo->node, &hashlimit_net->htables); |
09e410de JE |
356 | |
357 | return 0; | |
358 | } | |
359 | ||
a47362a2 JE |
360 | static bool select_all(const struct xt_hashlimit_htable *ht, |
361 | const struct dsthash_ent *he) | |
1da177e4 | 362 | { |
d384e65f | 363 | return true; |
1da177e4 LT |
364 | } |
365 | ||
a47362a2 JE |
366 | static bool select_gc(const struct xt_hashlimit_htable *ht, |
367 | const struct dsthash_ent *he) | |
1da177e4 | 368 | { |
cbebc51f | 369 | return time_after_eq(jiffies, he->expires); |
1da177e4 LT |
370 | } |
371 | ||
39b46fc6 | 372 | static void htable_selective_cleanup(struct xt_hashlimit_htable *ht, |
a47362a2 JE |
373 | bool (*select)(const struct xt_hashlimit_htable *ht, |
374 | const struct dsthash_ent *he)) | |
1da177e4 | 375 | { |
39b46fc6 | 376 | unsigned int i; |
1da177e4 | 377 | |
1da177e4 LT |
378 | for (i = 0; i < ht->cfg.size; i++) { |
379 | struct dsthash_ent *dh; | |
b67bfe0d | 380 | struct hlist_node *n; |
7bd8490e ED |
381 | |
382 | spin_lock_bh(&ht->lock); | |
b67bfe0d | 383 | hlist_for_each_entry_safe(dh, n, &ht->hash[i], node) { |
1da177e4 | 384 | if ((*select)(ht, dh)) |
39b46fc6 | 385 | dsthash_free(ht, dh); |
1da177e4 | 386 | } |
7bd8490e ED |
387 | spin_unlock_bh(&ht->lock); |
388 | cond_resched(); | |
1da177e4 | 389 | } |
1da177e4 LT |
390 | } |
391 | ||
7bd8490e | 392 | static void htable_gc(struct work_struct *work) |
1da177e4 | 393 | { |
7bd8490e ED |
394 | struct xt_hashlimit_htable *ht; |
395 | ||
396 | ht = container_of(work, struct xt_hashlimit_htable, gc_work.work); | |
1da177e4 LT |
397 | |
398 | htable_selective_cleanup(ht, select_gc); | |
399 | ||
7bd8490e ED |
400 | queue_delayed_work(system_power_efficient_wq, |
401 | &ht->gc_work, msecs_to_jiffies(ht->cfg.gc_interval)); | |
1da177e4 LT |
402 | } |
403 | ||
b4ef4ce0 | 404 | static void htable_remove_proc_entry(struct xt_hashlimit_htable *hinfo) |
1da177e4 | 405 | { |
e89fc3f1 AD |
406 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(hinfo->net); |
407 | struct proc_dir_entry *parent; | |
408 | ||
e89fc3f1 AD |
409 | if (hinfo->family == NFPROTO_IPV4) |
410 | parent = hashlimit_net->ipt_hashlimit; | |
411 | else | |
412 | parent = hashlimit_net->ip6t_hashlimit; | |
32263dd1 | 413 | |
b4ef4ce0 | 414 | if (parent != NULL) |
14b872f0 | 415 | remove_proc_entry(hinfo->name, parent); |
b4ef4ce0 | 416 | } |
32263dd1 | 417 | |
b4ef4ce0 SP |
418 | static void htable_destroy(struct xt_hashlimit_htable *hinfo) |
419 | { | |
7bd8490e | 420 | cancel_delayed_work_sync(&hinfo->gc_work); |
b4ef4ce0 | 421 | htable_remove_proc_entry(hinfo); |
1da177e4 | 422 | htable_selective_cleanup(hinfo, select_all); |
14b872f0 | 423 | kfree(hinfo->name); |
1da177e4 LT |
424 | vfree(hinfo); |
425 | } | |
426 | ||
e89fc3f1 AD |
427 | static struct xt_hashlimit_htable *htable_find_get(struct net *net, |
428 | const char *name, | |
76108cea | 429 | u_int8_t family) |
1da177e4 | 430 | { |
e89fc3f1 | 431 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); |
39b46fc6 | 432 | struct xt_hashlimit_htable *hinfo; |
1da177e4 | 433 | |
b67bfe0d | 434 | hlist_for_each_entry(hinfo, &hashlimit_net->htables, node) { |
14b872f0 | 435 | if (!strcmp(name, hinfo->name) && |
39b46fc6 | 436 | hinfo->family == family) { |
2eff25c1 | 437 | hinfo->use++; |
1da177e4 LT |
438 | return hinfo; |
439 | } | |
440 | } | |
1da177e4 LT |
441 | return NULL; |
442 | } | |
443 | ||
39b46fc6 | 444 | static void htable_put(struct xt_hashlimit_htable *hinfo) |
1da177e4 | 445 | { |
2eff25c1 PM |
446 | mutex_lock(&hashlimit_mutex); |
447 | if (--hinfo->use == 0) { | |
1da177e4 | 448 | hlist_del(&hinfo->node); |
1da177e4 LT |
449 | htable_destroy(hinfo); |
450 | } | |
2eff25c1 | 451 | mutex_unlock(&hashlimit_mutex); |
1da177e4 LT |
452 | } |
453 | ||
1da177e4 LT |
454 | /* The algorithm used is the Simple Token Bucket Filter (TBF) |
455 | * see net/sched/sch_tbf.c in the linux source tree | |
456 | */ | |
457 | ||
458 | /* Rusty: This is my (non-mathematically-inclined) understanding of | |
459 | this algorithm. The `average rate' in jiffies becomes your initial | |
460 | amount of credit `credit' and the most credit you can ever have | |
461 | `credit_cap'. The `peak rate' becomes the cost of passing the | |
462 | test, `cost'. | |
463 | ||
464 | `prev' tracks the last packet hit: you gain one credit per jiffy. | |
465 | If you get credit balance more than this, the extra credit is | |
466 | discarded. Every time the match passes, you lose `cost' credits; | |
467 | if you don't have that many, the test fails. | |
468 | ||
469 | See Alexey's formal explanation in net/sched/sch_tbf.c. | |
470 | ||
471 | To get the maximum range, we multiply by this factor (ie. you get N | |
472 | credits per jiffy). We want to allow a rate as low as 1 per day | |
473 | (slowest userspace tool allows), which means | |
474 | CREDITS_PER_JIFFY*HZ*60*60*24 < 2^32 ie. | |
475 | */ | |
0dc60a45 | 476 | #define MAX_CPJ_v1 (0xFFFFFFFF / (HZ*60*60*24)) |
1b203c13 | 477 | #define MAX_CPJ (0xFFFFFFFFFFFFFFFFULL / (HZ*60*60*24)) |
1da177e4 LT |
478 | |
479 | /* Repeated shift and or gives us all 1s, final shift and add 1 gives | |
480 | * us the power of 2 below the theoretical max, so GCC simply does a | |
481 | * shift. */ | |
482 | #define _POW2_BELOW2(x) ((x)|((x)>>1)) | |
483 | #define _POW2_BELOW4(x) (_POW2_BELOW2(x)|_POW2_BELOW2((x)>>2)) | |
484 | #define _POW2_BELOW8(x) (_POW2_BELOW4(x)|_POW2_BELOW4((x)>>4)) | |
485 | #define _POW2_BELOW16(x) (_POW2_BELOW8(x)|_POW2_BELOW8((x)>>8)) | |
486 | #define _POW2_BELOW32(x) (_POW2_BELOW16(x)|_POW2_BELOW16((x)>>16)) | |
11d5f157 | 487 | #define _POW2_BELOW64(x) (_POW2_BELOW32(x)|_POW2_BELOW32((x)>>32)) |
1da177e4 | 488 | #define POW2_BELOW32(x) ((_POW2_BELOW32(x)>>1) + 1) |
11d5f157 | 489 | #define POW2_BELOW64(x) ((_POW2_BELOW64(x)>>1) + 1) |
1da177e4 | 490 | |
11d5f157 | 491 | #define CREDITS_PER_JIFFY POW2_BELOW64(MAX_CPJ) |
0dc60a45 | 492 | #define CREDITS_PER_JIFFY_v1 POW2_BELOW32(MAX_CPJ_v1) |
1da177e4 | 493 | |
0197dee7 FW |
494 | /* in byte mode, the lowest possible rate is one packet/second. |
495 | * credit_cap is used as a counter that tells us how many times we can | |
496 | * refill the "credits available" counter when it becomes empty. | |
497 | */ | |
498 | #define MAX_CPJ_BYTES (0xFFFFFFFF / HZ) | |
499 | #define CREDITS_PER_JIFFY_BYTES POW2_BELOW32(MAX_CPJ_BYTES) | |
500 | ||
501 | static u32 xt_hashlimit_len_to_chunks(u32 len) | |
502 | { | |
503 | return (len >> XT_HASHLIMIT_BYTE_SHIFT) + 1; | |
504 | } | |
505 | ||
1da177e4 | 506 | /* Precision saver. */ |
11d5f157 | 507 | static u64 user2credits(u64 user, int revision) |
1da177e4 | 508 | { |
ad5b5576 AB |
509 | u64 scale = (revision == 1) ? |
510 | XT_HASHLIMIT_SCALE : XT_HASHLIMIT_SCALE_v2; | |
511 | u64 cpj = (revision == 1) ? | |
512 | CREDITS_PER_JIFFY_v1 : CREDITS_PER_JIFFY; | |
1da177e4 | 513 | |
ad5b5576 AB |
514 | /* Avoid overflow: divide the constant operands first */ |
515 | if (scale >= HZ * cpj) | |
516 | return div64_u64(user, div64_u64(scale, HZ * cpj)); | |
517 | ||
518 | return user * div64_u64(HZ * cpj, scale); | |
1da177e4 LT |
519 | } |
520 | ||
0197dee7 | 521 | static u32 user2credits_byte(u32 user) |
1da177e4 | 522 | { |
0197dee7 FW |
523 | u64 us = user; |
524 | us *= HZ * CREDITS_PER_JIFFY_BYTES; | |
525 | return (u32) (us >> 32); | |
526 | } | |
527 | ||
bea74641 VP |
528 | static u64 user2rate(u64 user) |
529 | { | |
530 | if (user != 0) { | |
531 | return div64_u64(XT_HASHLIMIT_SCALE_v2, user); | |
532 | } else { | |
b2606644 FW |
533 | pr_info_ratelimited("invalid rate from userspace: %llu\n", |
534 | user); | |
bea74641 VP |
535 | return 0; |
536 | } | |
537 | } | |
538 | ||
90c4ae4e | 539 | static u64 user2rate_bytes(u32 user) |
bea74641 VP |
540 | { |
541 | u64 r; | |
542 | ||
90c4ae4e | 543 | r = user ? U32_MAX / user : U32_MAX; |
c47d36b3 | 544 | return (r - 1) << XT_HASHLIMIT_BYTE_SHIFT; |
bea74641 VP |
545 | } |
546 | ||
11d5f157 VP |
547 | static void rateinfo_recalc(struct dsthash_ent *dh, unsigned long now, |
548 | u32 mode, int revision) | |
0197dee7 FW |
549 | { |
550 | unsigned long delta = now - dh->rateinfo.prev; | |
11d5f157 | 551 | u64 cap, cpj; |
0197dee7 FW |
552 | |
553 | if (delta == 0) | |
554 | return; | |
555 | ||
bea74641 VP |
556 | if (revision >= 3 && mode & XT_HASHLIMIT_RATE_MATCH) { |
557 | u64 interval = dh->rateinfo.interval * HZ; | |
558 | ||
559 | if (delta < interval) | |
560 | return; | |
561 | ||
562 | dh->rateinfo.prev = now; | |
563 | dh->rateinfo.prev_window = | |
564 | ((dh->rateinfo.current_rate * interval) > | |
565 | (delta * dh->rateinfo.rate)); | |
566 | dh->rateinfo.current_rate = 0; | |
567 | ||
568 | return; | |
569 | } | |
570 | ||
39b46fc6 | 571 | dh->rateinfo.prev = now; |
0197dee7 FW |
572 | |
573 | if (mode & XT_HASHLIMIT_BYTES) { | |
11d5f157 | 574 | u64 tmp = dh->rateinfo.credit; |
0197dee7 FW |
575 | dh->rateinfo.credit += CREDITS_PER_JIFFY_BYTES * delta; |
576 | cap = CREDITS_PER_JIFFY_BYTES * HZ; | |
577 | if (tmp >= dh->rateinfo.credit) {/* overflow */ | |
578 | dh->rateinfo.credit = cap; | |
579 | return; | |
580 | } | |
581 | } else { | |
11d5f157 VP |
582 | cpj = (revision == 1) ? |
583 | CREDITS_PER_JIFFY_v1 : CREDITS_PER_JIFFY; | |
584 | dh->rateinfo.credit += delta * cpj; | |
0197dee7 FW |
585 | cap = dh->rateinfo.credit_cap; |
586 | } | |
587 | if (dh->rateinfo.credit > cap) | |
588 | dh->rateinfo.credit = cap; | |
39b46fc6 PM |
589 | } |
590 | ||
817e076f | 591 | static void rateinfo_init(struct dsthash_ent *dh, |
11d5f157 | 592 | struct xt_hashlimit_htable *hinfo, int revision) |
817e076f FW |
593 | { |
594 | dh->rateinfo.prev = jiffies; | |
bea74641 VP |
595 | if (revision >= 3 && hinfo->cfg.mode & XT_HASHLIMIT_RATE_MATCH) { |
596 | dh->rateinfo.prev_window = 0; | |
597 | dh->rateinfo.current_rate = 0; | |
598 | if (hinfo->cfg.mode & XT_HASHLIMIT_BYTES) { | |
90c4ae4e VP |
599 | dh->rateinfo.rate = |
600 | user2rate_bytes((u32)hinfo->cfg.avg); | |
bea74641 VP |
601 | if (hinfo->cfg.burst) |
602 | dh->rateinfo.burst = | |
603 | hinfo->cfg.burst * dh->rateinfo.rate; | |
604 | else | |
605 | dh->rateinfo.burst = dh->rateinfo.rate; | |
606 | } else { | |
607 | dh->rateinfo.rate = user2rate(hinfo->cfg.avg); | |
608 | dh->rateinfo.burst = | |
609 | hinfo->cfg.burst + dh->rateinfo.rate; | |
610 | } | |
611 | dh->rateinfo.interval = hinfo->cfg.interval; | |
612 | } else if (hinfo->cfg.mode & XT_HASHLIMIT_BYTES) { | |
0197dee7 FW |
613 | dh->rateinfo.credit = CREDITS_PER_JIFFY_BYTES * HZ; |
614 | dh->rateinfo.cost = user2credits_byte(hinfo->cfg.avg); | |
615 | dh->rateinfo.credit_cap = hinfo->cfg.burst; | |
616 | } else { | |
617 | dh->rateinfo.credit = user2credits(hinfo->cfg.avg * | |
11d5f157 VP |
618 | hinfo->cfg.burst, revision); |
619 | dh->rateinfo.cost = user2credits(hinfo->cfg.avg, revision); | |
0197dee7 FW |
620 | dh->rateinfo.credit_cap = dh->rateinfo.credit; |
621 | } | |
817e076f FW |
622 | } |
623 | ||
09e410de JE |
624 | static inline __be32 maskl(__be32 a, unsigned int l) |
625 | { | |
1b9b70ea | 626 | return l ? htonl(ntohl(a) & ~0 << (32 - l)) : 0; |
09e410de JE |
627 | } |
628 | ||
c0cd1156 | 629 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
09e410de JE |
630 | static void hashlimit_ipv6_mask(__be32 *i, unsigned int p) |
631 | { | |
632 | switch (p) { | |
1b9b70ea | 633 | case 0 ... 31: |
09e410de JE |
634 | i[0] = maskl(i[0], p); |
635 | i[1] = i[2] = i[3] = 0; | |
636 | break; | |
1b9b70ea | 637 | case 32 ... 63: |
09e410de JE |
638 | i[1] = maskl(i[1], p - 32); |
639 | i[2] = i[3] = 0; | |
640 | break; | |
1b9b70ea | 641 | case 64 ... 95: |
09e410de JE |
642 | i[2] = maskl(i[2], p - 64); |
643 | i[3] = 0; | |
8f599229 | 644 | break; |
1b9b70ea | 645 | case 96 ... 127: |
09e410de JE |
646 | i[3] = maskl(i[3], p - 96); |
647 | break; | |
648 | case 128: | |
649 | break; | |
650 | } | |
651 | } | |
3ed5df44 | 652 | #endif |
09e410de | 653 | |
39b46fc6 | 654 | static int |
a47362a2 JE |
655 | hashlimit_init_dst(const struct xt_hashlimit_htable *hinfo, |
656 | struct dsthash_dst *dst, | |
39b46fc6 PM |
657 | const struct sk_buff *skb, unsigned int protoff) |
658 | { | |
659 | __be16 _ports[2], *ports; | |
193b23c5 | 660 | u8 nexthdr; |
aca071c1 | 661 | int poff; |
39b46fc6 PM |
662 | |
663 | memset(dst, 0, sizeof(*dst)); | |
664 | ||
665 | switch (hinfo->family) { | |
ee999d8b | 666 | case NFPROTO_IPV4: |
39b46fc6 | 667 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP) |
09e410de JE |
668 | dst->ip.dst = maskl(ip_hdr(skb)->daddr, |
669 | hinfo->cfg.dstmask); | |
39b46fc6 | 670 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP) |
09e410de JE |
671 | dst->ip.src = maskl(ip_hdr(skb)->saddr, |
672 | hinfo->cfg.srcmask); | |
39b46fc6 PM |
673 | |
674 | if (!(hinfo->cfg.mode & | |
675 | (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT))) | |
676 | return 0; | |
eddc9ec5 | 677 | nexthdr = ip_hdr(skb)->protocol; |
39b46fc6 | 678 | break; |
c0cd1156 | 679 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
ee999d8b | 680 | case NFPROTO_IPV6: |
412662d2 SR |
681 | { |
682 | __be16 frag_off; | |
683 | ||
09e410de JE |
684 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP) { |
685 | memcpy(&dst->ip6.dst, &ipv6_hdr(skb)->daddr, | |
686 | sizeof(dst->ip6.dst)); | |
687 | hashlimit_ipv6_mask(dst->ip6.dst, hinfo->cfg.dstmask); | |
688 | } | |
689 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP) { | |
690 | memcpy(&dst->ip6.src, &ipv6_hdr(skb)->saddr, | |
691 | sizeof(dst->ip6.src)); | |
692 | hashlimit_ipv6_mask(dst->ip6.src, hinfo->cfg.srcmask); | |
693 | } | |
39b46fc6 PM |
694 | |
695 | if (!(hinfo->cfg.mode & | |
696 | (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT))) | |
697 | return 0; | |
193b23c5 | 698 | nexthdr = ipv6_hdr(skb)->nexthdr; |
75f2811c | 699 | protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr, &frag_off); |
193b23c5 | 700 | if ((int)protoff < 0) |
39b46fc6 PM |
701 | return -1; |
702 | break; | |
412662d2 | 703 | } |
39b46fc6 PM |
704 | #endif |
705 | default: | |
706 | BUG(); | |
707 | return 0; | |
708 | } | |
709 | ||
aca071c1 CG |
710 | poff = proto_ports_offset(nexthdr); |
711 | if (poff >= 0) { | |
712 | ports = skb_header_pointer(skb, protoff + poff, sizeof(_ports), | |
39b46fc6 | 713 | &_ports); |
aca071c1 | 714 | } else { |
39b46fc6 PM |
715 | _ports[0] = _ports[1] = 0; |
716 | ports = _ports; | |
39b46fc6 PM |
717 | } |
718 | if (!ports) | |
719 | return -1; | |
720 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SPT) | |
721 | dst->src_port = ports[0]; | |
722 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DPT) | |
723 | dst->dst_port = ports[1]; | |
724 | return 0; | |
1da177e4 LT |
725 | } |
726 | ||
0197dee7 FW |
727 | static u32 hashlimit_byte_cost(unsigned int len, struct dsthash_ent *dh) |
728 | { | |
729 | u64 tmp = xt_hashlimit_len_to_chunks(len); | |
730 | tmp = tmp * dh->rateinfo.cost; | |
731 | ||
732 | if (unlikely(tmp > CREDITS_PER_JIFFY_BYTES * HZ)) | |
733 | tmp = CREDITS_PER_JIFFY_BYTES * HZ; | |
734 | ||
735 | if (dh->rateinfo.credit < tmp && dh->rateinfo.credit_cap) { | |
736 | dh->rateinfo.credit_cap--; | |
737 | dh->rateinfo.credit = CREDITS_PER_JIFFY_BYTES * HZ; | |
738 | } | |
739 | return (u32) tmp; | |
740 | } | |
741 | ||
ccb79bdc | 742 | static bool |
11d5f157 VP |
743 | hashlimit_mt_common(const struct sk_buff *skb, struct xt_action_param *par, |
744 | struct xt_hashlimit_htable *hinfo, | |
bea74641 | 745 | const struct hashlimit_cfg3 *cfg, int revision) |
09e410de | 746 | { |
09e410de JE |
747 | unsigned long now = jiffies; |
748 | struct dsthash_ent *dh; | |
749 | struct dsthash_dst dst; | |
09181842 | 750 | bool race = false; |
11d5f157 | 751 | u64 cost; |
09e410de | 752 | |
f7108a20 | 753 | if (hashlimit_init_dst(hinfo, &dst, skb, par->thoff) < 0) |
09e410de JE |
754 | goto hotdrop; |
755 | ||
0b35f603 | 756 | local_bh_disable(); |
09e410de JE |
757 | dh = dsthash_find(hinfo, &dst); |
758 | if (dh == NULL) { | |
09181842 | 759 | dh = dsthash_alloc_init(hinfo, &dst, &race); |
09e410de | 760 | if (dh == NULL) { |
0b35f603 | 761 | local_bh_enable(); |
09e410de | 762 | goto hotdrop; |
09181842 PNA |
763 | } else if (race) { |
764 | /* Already got an entry, update expiration timeout */ | |
765 | dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire); | |
11d5f157 | 766 | rateinfo_recalc(dh, now, hinfo->cfg.mode, revision); |
09181842 PNA |
767 | } else { |
768 | dh->expires = jiffies + msecs_to_jiffies(hinfo->cfg.expire); | |
11d5f157 | 769 | rateinfo_init(dh, hinfo, revision); |
09e410de | 770 | } |
09e410de JE |
771 | } else { |
772 | /* update expiration timeout */ | |
773 | dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire); | |
11d5f157 | 774 | rateinfo_recalc(dh, now, hinfo->cfg.mode, revision); |
09e410de JE |
775 | } |
776 | ||
bea74641 VP |
777 | if (cfg->mode & XT_HASHLIMIT_RATE_MATCH) { |
778 | cost = (cfg->mode & XT_HASHLIMIT_BYTES) ? skb->len : 1; | |
779 | dh->rateinfo.current_rate += cost; | |
780 | ||
781 | if (!dh->rateinfo.prev_window && | |
782 | (dh->rateinfo.current_rate <= dh->rateinfo.burst)) { | |
783 | spin_unlock(&dh->lock); | |
de526f40 | 784 | local_bh_enable(); |
bea74641 VP |
785 | return !(cfg->mode & XT_HASHLIMIT_INVERT); |
786 | } else { | |
787 | goto overlimit; | |
788 | } | |
789 | } | |
790 | ||
11d5f157 | 791 | if (cfg->mode & XT_HASHLIMIT_BYTES) |
0197dee7 FW |
792 | cost = hashlimit_byte_cost(skb->len, dh); |
793 | else | |
794 | cost = dh->rateinfo.cost; | |
795 | ||
796 | if (dh->rateinfo.credit >= cost) { | |
09e410de | 797 | /* below the limit */ |
0197dee7 | 798 | dh->rateinfo.credit -= cost; |
02e4eb75 | 799 | spin_unlock(&dh->lock); |
0b35f603 | 800 | local_bh_enable(); |
11d5f157 | 801 | return !(cfg->mode & XT_HASHLIMIT_INVERT); |
09e410de JE |
802 | } |
803 | ||
bea74641 | 804 | overlimit: |
02e4eb75 | 805 | spin_unlock(&dh->lock); |
0b35f603 | 806 | local_bh_enable(); |
09e410de | 807 | /* default match is underlimit - so over the limit, we need to invert */ |
11d5f157 | 808 | return cfg->mode & XT_HASHLIMIT_INVERT; |
09e410de JE |
809 | |
810 | hotdrop: | |
b4ba2611 | 811 | par->hotdrop = true; |
09e410de JE |
812 | return false; |
813 | } | |
814 | ||
11d5f157 VP |
815 | static bool |
816 | hashlimit_mt_v1(const struct sk_buff *skb, struct xt_action_param *par) | |
817 | { | |
818 | const struct xt_hashlimit_mtinfo1 *info = par->matchinfo; | |
819 | struct xt_hashlimit_htable *hinfo = info->hinfo; | |
bea74641 | 820 | struct hashlimit_cfg3 cfg = {}; |
11d5f157 VP |
821 | int ret; |
822 | ||
823 | ret = cfg_copy(&cfg, (void *)&info->cfg, 1); | |
11d5f157 VP |
824 | if (ret) |
825 | return ret; | |
826 | ||
827 | return hashlimit_mt_common(skb, par, hinfo, &cfg, 1); | |
828 | } | |
829 | ||
830 | static bool | |
bea74641 | 831 | hashlimit_mt_v2(const struct sk_buff *skb, struct xt_action_param *par) |
11d5f157 VP |
832 | { |
833 | const struct xt_hashlimit_mtinfo2 *info = par->matchinfo; | |
834 | struct xt_hashlimit_htable *hinfo = info->hinfo; | |
bea74641 VP |
835 | struct hashlimit_cfg3 cfg = {}; |
836 | int ret; | |
837 | ||
838 | ret = cfg_copy(&cfg, (void *)&info->cfg, 2); | |
bea74641 VP |
839 | if (ret) |
840 | return ret; | |
841 | ||
842 | return hashlimit_mt_common(skb, par, hinfo, &cfg, 2); | |
843 | } | |
844 | ||
845 | static bool | |
846 | hashlimit_mt(const struct sk_buff *skb, struct xt_action_param *par) | |
847 | { | |
848 | const struct xt_hashlimit_mtinfo3 *info = par->matchinfo; | |
849 | struct xt_hashlimit_htable *hinfo = info->hinfo; | |
11d5f157 | 850 | |
bea74641 | 851 | return hashlimit_mt_common(skb, par, hinfo, &info->cfg, 3); |
11d5f157 VP |
852 | } |
853 | ||
854 | static int hashlimit_mt_check_common(const struct xt_mtchk_param *par, | |
855 | struct xt_hashlimit_htable **hinfo, | |
bea74641 | 856 | struct hashlimit_cfg3 *cfg, |
11d5f157 | 857 | const char *name, int revision) |
09e410de | 858 | { |
e89fc3f1 | 859 | struct net *net = par->net; |
4a5a5c73 | 860 | int ret; |
09e410de | 861 | |
11d5f157 | 862 | if (cfg->gc_interval == 0 || cfg->expire == 0) |
bd414ee6 | 863 | return -EINVAL; |
aa5fa318 | 864 | if (par->family == NFPROTO_IPV4) { |
11d5f157 | 865 | if (cfg->srcmask > 32 || cfg->dstmask > 32) |
bd414ee6 | 866 | return -EINVAL; |
09e410de | 867 | } else { |
11d5f157 | 868 | if (cfg->srcmask > 128 || cfg->dstmask > 128) |
bd414ee6 | 869 | return -EINVAL; |
09e410de JE |
870 | } |
871 | ||
11d5f157 | 872 | if (cfg->mode & ~XT_HASHLIMIT_ALL) { |
b2606644 FW |
873 | pr_info_ratelimited("Unknown mode mask %X, kernel too old?\n", |
874 | cfg->mode); | |
0197dee7 FW |
875 | return -EINVAL; |
876 | } | |
877 | ||
878 | /* Check for overflow. */ | |
bea74641 | 879 | if (revision >= 3 && cfg->mode & XT_HASHLIMIT_RATE_MATCH) { |
90c4ae4e | 880 | if (cfg->avg == 0 || cfg->avg > U32_MAX) { |
b2606644 | 881 | pr_info_ratelimited("invalid rate\n"); |
bea74641 VP |
882 | return -ERANGE; |
883 | } | |
884 | ||
885 | if (cfg->interval == 0) { | |
b2606644 | 886 | pr_info_ratelimited("invalid interval\n"); |
bea74641 VP |
887 | return -EINVAL; |
888 | } | |
889 | } else if (cfg->mode & XT_HASHLIMIT_BYTES) { | |
11d5f157 | 890 | if (user2credits_byte(cfg->avg) == 0) { |
b2606644 FW |
891 | pr_info_ratelimited("overflow, rate too high: %llu\n", |
892 | cfg->avg); | |
0197dee7 FW |
893 | return -EINVAL; |
894 | } | |
11d5f157 | 895 | } else if (cfg->burst == 0 || |
b2606644 FW |
896 | user2credits(cfg->avg * cfg->burst, revision) < |
897 | user2credits(cfg->avg, revision)) { | |
898 | pr_info_ratelimited("overflow, try lower: %llu/%llu\n", | |
899 | cfg->avg, cfg->burst); | |
900 | return -ERANGE; | |
0197dee7 FW |
901 | } |
902 | ||
2eff25c1 | 903 | mutex_lock(&hashlimit_mutex); |
11d5f157 VP |
904 | *hinfo = htable_find_get(net, name, par->family); |
905 | if (*hinfo == NULL) { | |
906 | ret = htable_create(net, cfg, name, par->family, | |
907 | hinfo, revision); | |
4a5a5c73 JE |
908 | if (ret < 0) { |
909 | mutex_unlock(&hashlimit_mutex); | |
910 | return ret; | |
911 | } | |
09e410de | 912 | } |
2eff25c1 | 913 | mutex_unlock(&hashlimit_mutex); |
11d5f157 | 914 | |
bd414ee6 | 915 | return 0; |
09e410de JE |
916 | } |
917 | ||
11d5f157 VP |
918 | static int hashlimit_mt_check_v1(const struct xt_mtchk_param *par) |
919 | { | |
920 | struct xt_hashlimit_mtinfo1 *info = par->matchinfo; | |
bea74641 | 921 | struct hashlimit_cfg3 cfg = {}; |
11d5f157 VP |
922 | int ret; |
923 | ||
b1d0a5d0 FW |
924 | ret = xt_check_proc_name(info->name, sizeof(info->name)); |
925 | if (ret) | |
926 | return ret; | |
11d5f157 VP |
927 | |
928 | ret = cfg_copy(&cfg, (void *)&info->cfg, 1); | |
11d5f157 VP |
929 | if (ret) |
930 | return ret; | |
931 | ||
932 | return hashlimit_mt_check_common(par, &info->hinfo, | |
933 | &cfg, info->name, 1); | |
934 | } | |
935 | ||
bea74641 | 936 | static int hashlimit_mt_check_v2(const struct xt_mtchk_param *par) |
11d5f157 VP |
937 | { |
938 | struct xt_hashlimit_mtinfo2 *info = par->matchinfo; | |
bea74641 VP |
939 | struct hashlimit_cfg3 cfg = {}; |
940 | int ret; | |
941 | ||
b1d0a5d0 FW |
942 | ret = xt_check_proc_name(info->name, sizeof(info->name)); |
943 | if (ret) | |
944 | return ret; | |
bea74641 VP |
945 | |
946 | ret = cfg_copy(&cfg, (void *)&info->cfg, 2); | |
bea74641 VP |
947 | if (ret) |
948 | return ret; | |
949 | ||
950 | return hashlimit_mt_check_common(par, &info->hinfo, | |
951 | &cfg, info->name, 2); | |
952 | } | |
953 | ||
954 | static int hashlimit_mt_check(const struct xt_mtchk_param *par) | |
955 | { | |
956 | struct xt_hashlimit_mtinfo3 *info = par->matchinfo; | |
b1d0a5d0 | 957 | int ret; |
11d5f157 | 958 | |
b1d0a5d0 FW |
959 | ret = xt_check_proc_name(info->name, sizeof(info->name)); |
960 | if (ret) | |
961 | return ret; | |
11d5f157 VP |
962 | |
963 | return hashlimit_mt_check_common(par, &info->hinfo, &info->cfg, | |
bea74641 VP |
964 | info->name, 3); |
965 | } | |
966 | ||
967 | static void hashlimit_mt_destroy_v2(const struct xt_mtdtor_param *par) | |
968 | { | |
969 | const struct xt_hashlimit_mtinfo2 *info = par->matchinfo; | |
970 | ||
971 | htable_put(info->hinfo); | |
11d5f157 VP |
972 | } |
973 | ||
0dc60a45 | 974 | static void hashlimit_mt_destroy_v1(const struct xt_mtdtor_param *par) |
09e410de | 975 | { |
6be3d859 | 976 | const struct xt_hashlimit_mtinfo1 *info = par->matchinfo; |
09e410de JE |
977 | |
978 | htable_put(info->hinfo); | |
979 | } | |
980 | ||
11d5f157 VP |
981 | static void hashlimit_mt_destroy(const struct xt_mtdtor_param *par) |
982 | { | |
bea74641 | 983 | const struct xt_hashlimit_mtinfo3 *info = par->matchinfo; |
11d5f157 VP |
984 | |
985 | htable_put(info->hinfo); | |
986 | } | |
987 | ||
d3c5ee6d | 988 | static struct xt_match hashlimit_mt_reg[] __read_mostly = { |
09e410de JE |
989 | { |
990 | .name = "hashlimit", | |
991 | .revision = 1, | |
ee999d8b | 992 | .family = NFPROTO_IPV4, |
0dc60a45 | 993 | .match = hashlimit_mt_v1, |
09e410de | 994 | .matchsize = sizeof(struct xt_hashlimit_mtinfo1), |
ec231890 | 995 | .usersize = offsetof(struct xt_hashlimit_mtinfo1, hinfo), |
0dc60a45 VP |
996 | .checkentry = hashlimit_mt_check_v1, |
997 | .destroy = hashlimit_mt_destroy_v1, | |
09e410de JE |
998 | .me = THIS_MODULE, |
999 | }, | |
11d5f157 VP |
1000 | { |
1001 | .name = "hashlimit", | |
1002 | .revision = 2, | |
1003 | .family = NFPROTO_IPV4, | |
bea74641 | 1004 | .match = hashlimit_mt_v2, |
11d5f157 | 1005 | .matchsize = sizeof(struct xt_hashlimit_mtinfo2), |
ec231890 | 1006 | .usersize = offsetof(struct xt_hashlimit_mtinfo2, hinfo), |
bea74641 VP |
1007 | .checkentry = hashlimit_mt_check_v2, |
1008 | .destroy = hashlimit_mt_destroy_v2, | |
1009 | .me = THIS_MODULE, | |
1010 | }, | |
1011 | { | |
1012 | .name = "hashlimit", | |
1013 | .revision = 3, | |
1014 | .family = NFPROTO_IPV4, | |
1015 | .match = hashlimit_mt, | |
1016 | .matchsize = sizeof(struct xt_hashlimit_mtinfo3), | |
1017 | .usersize = offsetof(struct xt_hashlimit_mtinfo3, hinfo), | |
11d5f157 VP |
1018 | .checkentry = hashlimit_mt_check, |
1019 | .destroy = hashlimit_mt_destroy, | |
1020 | .me = THIS_MODULE, | |
1021 | }, | |
c0cd1156 | 1022 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
09e410de JE |
1023 | { |
1024 | .name = "hashlimit", | |
1025 | .revision = 1, | |
ee999d8b | 1026 | .family = NFPROTO_IPV6, |
0dc60a45 | 1027 | .match = hashlimit_mt_v1, |
09e410de | 1028 | .matchsize = sizeof(struct xt_hashlimit_mtinfo1), |
ec231890 | 1029 | .usersize = offsetof(struct xt_hashlimit_mtinfo1, hinfo), |
0dc60a45 VP |
1030 | .checkentry = hashlimit_mt_check_v1, |
1031 | .destroy = hashlimit_mt_destroy_v1, | |
09e410de JE |
1032 | .me = THIS_MODULE, |
1033 | }, | |
11d5f157 VP |
1034 | { |
1035 | .name = "hashlimit", | |
1036 | .revision = 2, | |
1037 | .family = NFPROTO_IPV6, | |
bea74641 | 1038 | .match = hashlimit_mt_v2, |
11d5f157 | 1039 | .matchsize = sizeof(struct xt_hashlimit_mtinfo2), |
ec231890 | 1040 | .usersize = offsetof(struct xt_hashlimit_mtinfo2, hinfo), |
bea74641 VP |
1041 | .checkentry = hashlimit_mt_check_v2, |
1042 | .destroy = hashlimit_mt_destroy_v2, | |
1043 | .me = THIS_MODULE, | |
1044 | }, | |
1045 | { | |
1046 | .name = "hashlimit", | |
1047 | .revision = 3, | |
1048 | .family = NFPROTO_IPV6, | |
1049 | .match = hashlimit_mt, | |
1050 | .matchsize = sizeof(struct xt_hashlimit_mtinfo3), | |
1051 | .usersize = offsetof(struct xt_hashlimit_mtinfo3, hinfo), | |
11d5f157 VP |
1052 | .checkentry = hashlimit_mt_check, |
1053 | .destroy = hashlimit_mt_destroy, | |
1054 | .me = THIS_MODULE, | |
1055 | }, | |
7b21e09d | 1056 | #endif |
1da177e4 LT |
1057 | }; |
1058 | ||
1059 | /* PROC stuff */ | |
1da177e4 | 1060 | static void *dl_seq_start(struct seq_file *s, loff_t *pos) |
f4f6fb71 | 1061 | __acquires(htable->lock) |
1da177e4 | 1062 | { |
1286df26 | 1063 | struct xt_hashlimit_htable *htable = PDE_DATA(file_inode(s->file)); |
1da177e4 LT |
1064 | unsigned int *bucket; |
1065 | ||
1066 | spin_lock_bh(&htable->lock); | |
1067 | if (*pos >= htable->cfg.size) | |
1068 | return NULL; | |
1069 | ||
1070 | bucket = kmalloc(sizeof(unsigned int), GFP_ATOMIC); | |
1071 | if (!bucket) | |
1072 | return ERR_PTR(-ENOMEM); | |
1073 | ||
1074 | *bucket = *pos; | |
1075 | return bucket; | |
1076 | } | |
1077 | ||
1078 | static void *dl_seq_next(struct seq_file *s, void *v, loff_t *pos) | |
1079 | { | |
1286df26 | 1080 | struct xt_hashlimit_htable *htable = PDE_DATA(file_inode(s->file)); |
68ad546a | 1081 | unsigned int *bucket = v; |
1da177e4 LT |
1082 | |
1083 | *pos = ++(*bucket); | |
1084 | if (*pos >= htable->cfg.size) { | |
1085 | kfree(v); | |
1086 | return NULL; | |
1087 | } | |
1088 | return bucket; | |
1089 | } | |
1090 | ||
1091 | static void dl_seq_stop(struct seq_file *s, void *v) | |
f4f6fb71 | 1092 | __releases(htable->lock) |
1da177e4 | 1093 | { |
1286df26 | 1094 | struct xt_hashlimit_htable *htable = PDE_DATA(file_inode(s->file)); |
68ad546a | 1095 | unsigned int *bucket = v; |
1da177e4 | 1096 | |
55e0d7cf ED |
1097 | if (!IS_ERR(bucket)) |
1098 | kfree(bucket); | |
1da177e4 LT |
1099 | spin_unlock_bh(&htable->lock); |
1100 | } | |
1101 | ||
11d5f157 VP |
1102 | static void dl_seq_print(struct dsthash_ent *ent, u_int8_t family, |
1103 | struct seq_file *s) | |
1da177e4 | 1104 | { |
39b46fc6 | 1105 | switch (family) { |
ee999d8b | 1106 | case NFPROTO_IPV4: |
11d5f157 | 1107 | seq_printf(s, "%ld %pI4:%u->%pI4:%u %llu %llu %llu\n", |
e71456ae SRRH |
1108 | (long)(ent->expires - jiffies)/HZ, |
1109 | &ent->dst.ip.src, | |
1110 | ntohs(ent->dst.src_port), | |
1111 | &ent->dst.ip.dst, | |
1112 | ntohs(ent->dst.dst_port), | |
1113 | ent->rateinfo.credit, ent->rateinfo.credit_cap, | |
1114 | ent->rateinfo.cost); | |
02e4eb75 | 1115 | break; |
c0cd1156 | 1116 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
ee999d8b | 1117 | case NFPROTO_IPV6: |
11d5f157 | 1118 | seq_printf(s, "%ld %pI6:%u->%pI6:%u %llu %llu %llu\n", |
e71456ae SRRH |
1119 | (long)(ent->expires - jiffies)/HZ, |
1120 | &ent->dst.ip6.src, | |
1121 | ntohs(ent->dst.src_port), | |
1122 | &ent->dst.ip6.dst, | |
1123 | ntohs(ent->dst.dst_port), | |
1124 | ent->rateinfo.credit, ent->rateinfo.credit_cap, | |
1125 | ent->rateinfo.cost); | |
02e4eb75 | 1126 | break; |
7b21e09d | 1127 | #endif |
39b46fc6 PM |
1128 | default: |
1129 | BUG(); | |
39b46fc6 | 1130 | } |
11d5f157 VP |
1131 | } |
1132 | ||
bea74641 VP |
1133 | static int dl_seq_real_show_v2(struct dsthash_ent *ent, u_int8_t family, |
1134 | struct seq_file *s) | |
1135 | { | |
1286df26 | 1136 | struct xt_hashlimit_htable *ht = PDE_DATA(file_inode(s->file)); |
bea74641 VP |
1137 | |
1138 | spin_lock(&ent->lock); | |
1139 | /* recalculate to show accurate numbers */ | |
1140 | rateinfo_recalc(ent, jiffies, ht->cfg.mode, 2); | |
1141 | ||
1142 | dl_seq_print(ent, family, s); | |
1143 | ||
1144 | spin_unlock(&ent->lock); | |
1145 | return seq_has_overflowed(s); | |
1146 | } | |
1147 | ||
11d5f157 VP |
1148 | static int dl_seq_real_show_v1(struct dsthash_ent *ent, u_int8_t family, |
1149 | struct seq_file *s) | |
1150 | { | |
1286df26 | 1151 | struct xt_hashlimit_htable *ht = PDE_DATA(file_inode(s->file)); |
11d5f157 VP |
1152 | |
1153 | spin_lock(&ent->lock); | |
1154 | /* recalculate to show accurate numbers */ | |
1155 | rateinfo_recalc(ent, jiffies, ht->cfg.mode, 1); | |
1156 | ||
1157 | dl_seq_print(ent, family, s); | |
1158 | ||
1159 | spin_unlock(&ent->lock); | |
1160 | return seq_has_overflowed(s); | |
1161 | } | |
1162 | ||
1163 | static int dl_seq_real_show(struct dsthash_ent *ent, u_int8_t family, | |
1164 | struct seq_file *s) | |
1165 | { | |
1286df26 | 1166 | struct xt_hashlimit_htable *ht = PDE_DATA(file_inode(s->file)); |
11d5f157 VP |
1167 | |
1168 | spin_lock(&ent->lock); | |
1169 | /* recalculate to show accurate numbers */ | |
bea74641 | 1170 | rateinfo_recalc(ent, jiffies, ht->cfg.mode, 3); |
11d5f157 VP |
1171 | |
1172 | dl_seq_print(ent, family, s); | |
1173 | ||
02e4eb75 | 1174 | spin_unlock(&ent->lock); |
e71456ae | 1175 | return seq_has_overflowed(s); |
1da177e4 LT |
1176 | } |
1177 | ||
bea74641 VP |
1178 | static int dl_seq_show_v2(struct seq_file *s, void *v) |
1179 | { | |
1286df26 | 1180 | struct xt_hashlimit_htable *htable = PDE_DATA(file_inode(s->file)); |
bea74641 VP |
1181 | unsigned int *bucket = (unsigned int *)v; |
1182 | struct dsthash_ent *ent; | |
1183 | ||
1184 | if (!hlist_empty(&htable->hash[*bucket])) { | |
1185 | hlist_for_each_entry(ent, &htable->hash[*bucket], node) | |
1186 | if (dl_seq_real_show_v2(ent, htable->family, s)) | |
1187 | return -1; | |
1188 | } | |
1189 | return 0; | |
1190 | } | |
1191 | ||
0dc60a45 | 1192 | static int dl_seq_show_v1(struct seq_file *s, void *v) |
1da177e4 | 1193 | { |
1286df26 | 1194 | struct xt_hashlimit_htable *htable = PDE_DATA(file_inode(s->file)); |
68ad546a | 1195 | unsigned int *bucket = v; |
1da177e4 | 1196 | struct dsthash_ent *ent; |
1da177e4 | 1197 | |
39b46fc6 | 1198 | if (!hlist_empty(&htable->hash[*bucket])) { |
b67bfe0d | 1199 | hlist_for_each_entry(ent, &htable->hash[*bucket], node) |
0dc60a45 | 1200 | if (dl_seq_real_show_v1(ent, htable->family, s)) |
683a04ce | 1201 | return -1; |
39b46fc6 | 1202 | } |
1da177e4 LT |
1203 | return 0; |
1204 | } | |
1205 | ||
11d5f157 VP |
1206 | static int dl_seq_show(struct seq_file *s, void *v) |
1207 | { | |
1286df26 | 1208 | struct xt_hashlimit_htable *htable = PDE_DATA(file_inode(s->file)); |
68ad546a | 1209 | unsigned int *bucket = v; |
11d5f157 VP |
1210 | struct dsthash_ent *ent; |
1211 | ||
1212 | if (!hlist_empty(&htable->hash[*bucket])) { | |
1213 | hlist_for_each_entry(ent, &htable->hash[*bucket], node) | |
1214 | if (dl_seq_real_show(ent, htable->family, s)) | |
1215 | return -1; | |
1216 | } | |
1217 | return 0; | |
1218 | } | |
1219 | ||
0dc60a45 | 1220 | static const struct seq_operations dl_seq_ops_v1 = { |
1da177e4 LT |
1221 | .start = dl_seq_start, |
1222 | .next = dl_seq_next, | |
1223 | .stop = dl_seq_stop, | |
0dc60a45 | 1224 | .show = dl_seq_show_v1 |
1da177e4 LT |
1225 | }; |
1226 | ||
bea74641 VP |
1227 | static const struct seq_operations dl_seq_ops_v2 = { |
1228 | .start = dl_seq_start, | |
1229 | .next = dl_seq_next, | |
1230 | .stop = dl_seq_stop, | |
1231 | .show = dl_seq_show_v2 | |
1232 | }; | |
1233 | ||
11d5f157 VP |
1234 | static const struct seq_operations dl_seq_ops = { |
1235 | .start = dl_seq_start, | |
1236 | .next = dl_seq_next, | |
1237 | .stop = dl_seq_stop, | |
1238 | .show = dl_seq_show | |
1239 | }; | |
1240 | ||
e89fc3f1 AD |
1241 | static int __net_init hashlimit_proc_net_init(struct net *net) |
1242 | { | |
1243 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); | |
1244 | ||
1245 | hashlimit_net->ipt_hashlimit = proc_mkdir("ipt_hashlimit", net->proc_net); | |
1246 | if (!hashlimit_net->ipt_hashlimit) | |
1247 | return -ENOMEM; | |
c0cd1156 | 1248 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
e89fc3f1 AD |
1249 | hashlimit_net->ip6t_hashlimit = proc_mkdir("ip6t_hashlimit", net->proc_net); |
1250 | if (!hashlimit_net->ip6t_hashlimit) { | |
ece31ffd | 1251 | remove_proc_entry("ipt_hashlimit", net->proc_net); |
e89fc3f1 AD |
1252 | return -ENOMEM; |
1253 | } | |
1254 | #endif | |
1255 | return 0; | |
1256 | } | |
1257 | ||
1258 | static void __net_exit hashlimit_proc_net_exit(struct net *net) | |
1259 | { | |
32263dd1 | 1260 | struct xt_hashlimit_htable *hinfo; |
32263dd1 VL |
1261 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); |
1262 | ||
b4ef4ce0 SP |
1263 | /* hashlimit_net_exit() is called before hashlimit_mt_destroy(). |
1264 | * Make sure that the parent ipt_hashlimit and ip6t_hashlimit proc | |
1265 | * entries is empty before trying to remove it. | |
32263dd1 VL |
1266 | */ |
1267 | mutex_lock(&hashlimit_mutex); | |
b67bfe0d | 1268 | hlist_for_each_entry(hinfo, &hashlimit_net->htables, node) |
b4ef4ce0 | 1269 | htable_remove_proc_entry(hinfo); |
32263dd1 VL |
1270 | hashlimit_net->ipt_hashlimit = NULL; |
1271 | hashlimit_net->ip6t_hashlimit = NULL; | |
1272 | mutex_unlock(&hashlimit_mutex); | |
1273 | ||
ece31ffd | 1274 | remove_proc_entry("ipt_hashlimit", net->proc_net); |
c0cd1156 | 1275 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
ece31ffd | 1276 | remove_proc_entry("ip6t_hashlimit", net->proc_net); |
e89fc3f1 AD |
1277 | #endif |
1278 | } | |
1279 | ||
1280 | static int __net_init hashlimit_net_init(struct net *net) | |
1281 | { | |
1282 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); | |
1283 | ||
1284 | INIT_HLIST_HEAD(&hashlimit_net->htables); | |
1285 | return hashlimit_proc_net_init(net); | |
1286 | } | |
1287 | ||
1288 | static void __net_exit hashlimit_net_exit(struct net *net) | |
1289 | { | |
e89fc3f1 AD |
1290 | hashlimit_proc_net_exit(net); |
1291 | } | |
1292 | ||
1293 | static struct pernet_operations hashlimit_net_ops = { | |
1294 | .init = hashlimit_net_init, | |
1295 | .exit = hashlimit_net_exit, | |
1296 | .id = &hashlimit_net_id, | |
1297 | .size = sizeof(struct hashlimit_net), | |
1298 | }; | |
1299 | ||
d3c5ee6d | 1300 | static int __init hashlimit_mt_init(void) |
1da177e4 | 1301 | { |
39b46fc6 | 1302 | int err; |
1da177e4 | 1303 | |
e89fc3f1 AD |
1304 | err = register_pernet_subsys(&hashlimit_net_ops); |
1305 | if (err < 0) | |
1306 | return err; | |
d3c5ee6d JE |
1307 | err = xt_register_matches(hashlimit_mt_reg, |
1308 | ARRAY_SIZE(hashlimit_mt_reg)); | |
39b46fc6 PM |
1309 | if (err < 0) |
1310 | goto err1; | |
1da177e4 | 1311 | |
39b46fc6 PM |
1312 | err = -ENOMEM; |
1313 | hashlimit_cachep = kmem_cache_create("xt_hashlimit", | |
1314 | sizeof(struct dsthash_ent), 0, 0, | |
20c2df83 | 1315 | NULL); |
1da177e4 | 1316 | if (!hashlimit_cachep) { |
b167a37c | 1317 | pr_warn("unable to create slab cache\n"); |
39b46fc6 | 1318 | goto err2; |
1da177e4 | 1319 | } |
e89fc3f1 AD |
1320 | return 0; |
1321 | ||
39b46fc6 | 1322 | err2: |
d3c5ee6d | 1323 | xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg)); |
39b46fc6 | 1324 | err1: |
e89fc3f1 | 1325 | unregister_pernet_subsys(&hashlimit_net_ops); |
39b46fc6 | 1326 | return err; |
1da177e4 | 1327 | |
1da177e4 LT |
1328 | } |
1329 | ||
d3c5ee6d | 1330 | static void __exit hashlimit_mt_exit(void) |
1da177e4 | 1331 | { |
d3c5ee6d | 1332 | xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg)); |
e89fc3f1 | 1333 | unregister_pernet_subsys(&hashlimit_net_ops); |
02e4eb75 | 1334 | |
c8d1da40 | 1335 | rcu_barrier(); |
02e4eb75 | 1336 | kmem_cache_destroy(hashlimit_cachep); |
1da177e4 LT |
1337 | } |
1338 | ||
d3c5ee6d JE |
1339 | module_init(hashlimit_mt_init); |
1340 | module_exit(hashlimit_mt_exit); |