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Commit | Line | Data |
---|---|---|
09e410de JE |
1 | /* |
2 | * xt_hashlimit - Netfilter module to limit the number of packets per time | |
3ad2f3fb | 3 | * separately for each hashbucket (sourceip/sourceport/dstip/dstport) |
1da177e4 | 4 | * |
09e410de JE |
5 | * (C) 2003-2004 by Harald Welte <laforge@netfilter.org> |
6 | * Copyright © CC Computer Consultants GmbH, 2007 - 2008 | |
1da177e4 LT |
7 | * |
8 | * Development of this code was funded by Astaro AG, http://www.astaro.com/ | |
1da177e4 | 9 | */ |
8bee4bad | 10 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
1da177e4 | 11 | #include <linux/module.h> |
1da177e4 LT |
12 | #include <linux/spinlock.h> |
13 | #include <linux/random.h> | |
14 | #include <linux/jhash.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/vmalloc.h> | |
1da177e4 LT |
17 | #include <linux/proc_fs.h> |
18 | #include <linux/seq_file.h> | |
19 | #include <linux/list.h> | |
39b46fc6 | 20 | #include <linux/skbuff.h> |
d7fe0f24 | 21 | #include <linux/mm.h> |
39b46fc6 PM |
22 | #include <linux/in.h> |
23 | #include <linux/ip.h> | |
7b21e09d | 24 | #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE) |
39b46fc6 | 25 | #include <linux/ipv6.h> |
193b23c5 | 26 | #include <net/ipv6.h> |
7b21e09d ED |
27 | #endif |
28 | ||
457c4cbc | 29 | #include <net/net_namespace.h> |
e89fc3f1 | 30 | #include <net/netns/generic.h> |
1da177e4 | 31 | |
39b46fc6 | 32 | #include <linux/netfilter/x_tables.h> |
1da177e4 | 33 | #include <linux/netfilter_ipv4/ip_tables.h> |
39b46fc6 PM |
34 | #include <linux/netfilter_ipv6/ip6_tables.h> |
35 | #include <linux/netfilter/xt_hashlimit.h> | |
14cc3e2b | 36 | #include <linux/mutex.h> |
1da177e4 LT |
37 | |
38 | MODULE_LICENSE("GPL"); | |
39 | MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); | |
408ffaa4 | 40 | MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>"); |
2ae15b64 | 41 | MODULE_DESCRIPTION("Xtables: per hash-bucket rate-limit match"); |
39b46fc6 PM |
42 | MODULE_ALIAS("ipt_hashlimit"); |
43 | MODULE_ALIAS("ip6t_hashlimit"); | |
1da177e4 | 44 | |
e89fc3f1 AD |
45 | struct hashlimit_net { |
46 | struct hlist_head htables; | |
47 | struct proc_dir_entry *ipt_hashlimit; | |
48 | struct proc_dir_entry *ip6t_hashlimit; | |
49 | }; | |
50 | ||
51 | static int hashlimit_net_id; | |
52 | static inline struct hashlimit_net *hashlimit_pernet(struct net *net) | |
53 | { | |
54 | return net_generic(net, hashlimit_net_id); | |
55 | } | |
56 | ||
1da177e4 | 57 | /* need to declare this at the top */ |
da7071d7 | 58 | static const struct file_operations dl_file_ops; |
1da177e4 LT |
59 | |
60 | /* hash table crap */ | |
1da177e4 | 61 | struct dsthash_dst { |
39b46fc6 PM |
62 | union { |
63 | struct { | |
64 | __be32 src; | |
65 | __be32 dst; | |
66 | } ip; | |
7b21e09d | 67 | #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE) |
39b46fc6 PM |
68 | struct { |
69 | __be32 src[4]; | |
70 | __be32 dst[4]; | |
71 | } ip6; | |
7b21e09d | 72 | #endif |
09e410de | 73 | }; |
6a19d614 AV |
74 | __be16 src_port; |
75 | __be16 dst_port; | |
1da177e4 LT |
76 | }; |
77 | ||
78 | struct dsthash_ent { | |
79 | /* static / read-only parts in the beginning */ | |
80 | struct hlist_node node; | |
81 | struct dsthash_dst dst; | |
82 | ||
83 | /* modified structure members in the end */ | |
84 | unsigned long expires; /* precalculated expiry time */ | |
85 | struct { | |
86 | unsigned long prev; /* last modification */ | |
87 | u_int32_t credit; | |
88 | u_int32_t credit_cap, cost; | |
89 | } rateinfo; | |
90 | }; | |
91 | ||
39b46fc6 | 92 | struct xt_hashlimit_htable { |
1da177e4 | 93 | struct hlist_node node; /* global list of all htables */ |
2eff25c1 | 94 | int use; |
76108cea | 95 | u_int8_t family; |
89bc7a0f | 96 | bool rnd_initialized; |
1da177e4 | 97 | |
09e410de | 98 | struct hashlimit_cfg1 cfg; /* config */ |
1da177e4 LT |
99 | |
100 | /* used internally */ | |
101 | spinlock_t lock; /* lock for list_head */ | |
102 | u_int32_t rnd; /* random seed for hash */ | |
39b46fc6 | 103 | unsigned int count; /* number entries in table */ |
1da177e4 | 104 | struct timer_list timer; /* timer for gc */ |
1da177e4 LT |
105 | |
106 | /* seq_file stuff */ | |
107 | struct proc_dir_entry *pde; | |
e89fc3f1 | 108 | struct net *net; |
1da177e4 LT |
109 | |
110 | struct hlist_head hash[0]; /* hashtable itself */ | |
111 | }; | |
112 | ||
2eff25c1 | 113 | static DEFINE_MUTEX(hashlimit_mutex); /* protects htables list */ |
e18b890b | 114 | static struct kmem_cache *hashlimit_cachep __read_mostly; |
1da177e4 | 115 | |
1d93a9cb | 116 | static inline bool dst_cmp(const struct dsthash_ent *ent, |
a47362a2 | 117 | const struct dsthash_dst *b) |
1da177e4 | 118 | { |
39b46fc6 | 119 | return !memcmp(&ent->dst, b, sizeof(ent->dst)); |
1da177e4 LT |
120 | } |
121 | ||
39b46fc6 PM |
122 | static u_int32_t |
123 | hash_dst(const struct xt_hashlimit_htable *ht, const struct dsthash_dst *dst) | |
1da177e4 | 124 | { |
e2f82ac3 ED |
125 | u_int32_t hash = jhash2((const u32 *)dst, |
126 | sizeof(*dst)/sizeof(u32), | |
127 | ht->rnd); | |
128 | /* | |
129 | * Instead of returning hash % ht->cfg.size (implying a divide) | |
130 | * we return the high 32 bits of the (hash * ht->cfg.size) that will | |
131 | * give results between [0 and cfg.size-1] and same hash distribution, | |
132 | * but using a multiply, less expensive than a divide | |
133 | */ | |
134 | return ((u64)hash * ht->cfg.size) >> 32; | |
1da177e4 LT |
135 | } |
136 | ||
39b46fc6 | 137 | static struct dsthash_ent * |
a47362a2 JE |
138 | dsthash_find(const struct xt_hashlimit_htable *ht, |
139 | const struct dsthash_dst *dst) | |
1da177e4 LT |
140 | { |
141 | struct dsthash_ent *ent; | |
142 | struct hlist_node *pos; | |
143 | u_int32_t hash = hash_dst(ht, dst); | |
144 | ||
39b46fc6 PM |
145 | if (!hlist_empty(&ht->hash[hash])) { |
146 | hlist_for_each_entry(ent, pos, &ht->hash[hash], node) | |
147 | if (dst_cmp(ent, dst)) | |
1da177e4 | 148 | return ent; |
39b46fc6 | 149 | } |
1da177e4 LT |
150 | return NULL; |
151 | } | |
152 | ||
153 | /* allocate dsthash_ent, initialize dst, put in htable and lock it */ | |
154 | static struct dsthash_ent * | |
a47362a2 JE |
155 | dsthash_alloc_init(struct xt_hashlimit_htable *ht, |
156 | const struct dsthash_dst *dst) | |
1da177e4 LT |
157 | { |
158 | struct dsthash_ent *ent; | |
159 | ||
160 | /* initialize hash with random val at the time we allocate | |
161 | * the first hashtable entry */ | |
bf0857ea | 162 | if (!ht->rnd_initialized) { |
af07d241 | 163 | get_random_bytes(&ht->rnd, sizeof(ht->rnd)); |
89bc7a0f | 164 | ht->rnd_initialized = true; |
bf0857ea | 165 | } |
1da177e4 | 166 | |
39b46fc6 | 167 | if (ht->cfg.max && ht->count >= ht->cfg.max) { |
1da177e4 LT |
168 | /* FIXME: do something. question is what.. */ |
169 | if (net_ratelimit()) | |
8bee4bad | 170 | pr_err("max count of %u reached\n", ht->cfg.max); |
1da177e4 LT |
171 | return NULL; |
172 | } | |
173 | ||
174 | ent = kmem_cache_alloc(hashlimit_cachep, GFP_ATOMIC); | |
175 | if (!ent) { | |
176 | if (net_ratelimit()) | |
8bee4bad | 177 | pr_err("cannot allocate dsthash_ent\n"); |
1da177e4 LT |
178 | return NULL; |
179 | } | |
39b46fc6 | 180 | memcpy(&ent->dst, dst, sizeof(ent->dst)); |
1da177e4 LT |
181 | |
182 | hlist_add_head(&ent->node, &ht->hash[hash_dst(ht, dst)]); | |
39b46fc6 | 183 | ht->count++; |
1da177e4 LT |
184 | return ent; |
185 | } | |
186 | ||
39b46fc6 PM |
187 | static inline void |
188 | dsthash_free(struct xt_hashlimit_htable *ht, struct dsthash_ent *ent) | |
1da177e4 LT |
189 | { |
190 | hlist_del(&ent->node); | |
191 | kmem_cache_free(hashlimit_cachep, ent); | |
39b46fc6 | 192 | ht->count--; |
1da177e4 LT |
193 | } |
194 | static void htable_gc(unsigned long htlong); | |
195 | ||
e89fc3f1 AD |
196 | static int htable_create(struct net *net, struct xt_hashlimit_mtinfo1 *minfo, |
197 | u_int8_t family) | |
09e410de | 198 | { |
e89fc3f1 | 199 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); |
09e410de JE |
200 | struct xt_hashlimit_htable *hinfo; |
201 | unsigned int size; | |
202 | unsigned int i; | |
203 | ||
204 | if (minfo->cfg.size) { | |
205 | size = minfo->cfg.size; | |
206 | } else { | |
4481374c | 207 | size = (totalram_pages << PAGE_SHIFT) / 16384 / |
09e410de | 208 | sizeof(struct list_head); |
4481374c | 209 | if (totalram_pages > 1024 * 1024 * 1024 / PAGE_SIZE) |
09e410de JE |
210 | size = 8192; |
211 | if (size < 16) | |
212 | size = 16; | |
213 | } | |
214 | /* FIXME: don't use vmalloc() here or anywhere else -HW */ | |
215 | hinfo = vmalloc(sizeof(struct xt_hashlimit_htable) + | |
216 | sizeof(struct list_head) * size); | |
85bc3f38 | 217 | if (hinfo == NULL) |
4a5a5c73 | 218 | return -ENOMEM; |
09e410de JE |
219 | minfo->hinfo = hinfo; |
220 | ||
221 | /* copy match config into hashtable config */ | |
222 | memcpy(&hinfo->cfg, &minfo->cfg, sizeof(hinfo->cfg)); | |
223 | hinfo->cfg.size = size; | |
224 | if (hinfo->cfg.max == 0) | |
225 | hinfo->cfg.max = 8 * hinfo->cfg.size; | |
226 | else if (hinfo->cfg.max < hinfo->cfg.size) | |
227 | hinfo->cfg.max = hinfo->cfg.size; | |
228 | ||
229 | for (i = 0; i < hinfo->cfg.size; i++) | |
230 | INIT_HLIST_HEAD(&hinfo->hash[i]); | |
231 | ||
2eff25c1 | 232 | hinfo->use = 1; |
09e410de JE |
233 | hinfo->count = 0; |
234 | hinfo->family = family; | |
89bc7a0f | 235 | hinfo->rnd_initialized = false; |
09e410de JE |
236 | spin_lock_init(&hinfo->lock); |
237 | ||
ee999d8b JE |
238 | hinfo->pde = proc_create_data(minfo->name, 0, |
239 | (family == NFPROTO_IPV4) ? | |
e89fc3f1 | 240 | hashlimit_net->ipt_hashlimit : hashlimit_net->ip6t_hashlimit, |
ee999d8b | 241 | &dl_file_ops, hinfo); |
09e410de JE |
242 | if (hinfo->pde == NULL) { |
243 | vfree(hinfo); | |
4a5a5c73 | 244 | return -ENOMEM; |
09e410de | 245 | } |
e89fc3f1 | 246 | hinfo->net = net; |
09e410de JE |
247 | |
248 | setup_timer(&hinfo->timer, htable_gc, (unsigned long)hinfo); | |
249 | hinfo->timer.expires = jiffies + msecs_to_jiffies(hinfo->cfg.gc_interval); | |
250 | add_timer(&hinfo->timer); | |
251 | ||
e89fc3f1 | 252 | hlist_add_head(&hinfo->node, &hashlimit_net->htables); |
09e410de JE |
253 | |
254 | return 0; | |
255 | } | |
256 | ||
a47362a2 JE |
257 | static bool select_all(const struct xt_hashlimit_htable *ht, |
258 | const struct dsthash_ent *he) | |
1da177e4 LT |
259 | { |
260 | return 1; | |
261 | } | |
262 | ||
a47362a2 JE |
263 | static bool select_gc(const struct xt_hashlimit_htable *ht, |
264 | const struct dsthash_ent *he) | |
1da177e4 | 265 | { |
cbebc51f | 266 | return time_after_eq(jiffies, he->expires); |
1da177e4 LT |
267 | } |
268 | ||
39b46fc6 | 269 | static void htable_selective_cleanup(struct xt_hashlimit_htable *ht, |
a47362a2 JE |
270 | bool (*select)(const struct xt_hashlimit_htable *ht, |
271 | const struct dsthash_ent *he)) | |
1da177e4 | 272 | { |
39b46fc6 | 273 | unsigned int i; |
1da177e4 LT |
274 | |
275 | /* lock hash table and iterate over it */ | |
276 | spin_lock_bh(&ht->lock); | |
277 | for (i = 0; i < ht->cfg.size; i++) { | |
278 | struct dsthash_ent *dh; | |
279 | struct hlist_node *pos, *n; | |
280 | hlist_for_each_entry_safe(dh, pos, n, &ht->hash[i], node) { | |
281 | if ((*select)(ht, dh)) | |
39b46fc6 | 282 | dsthash_free(ht, dh); |
1da177e4 LT |
283 | } |
284 | } | |
285 | spin_unlock_bh(&ht->lock); | |
286 | } | |
287 | ||
288 | /* hash table garbage collector, run by timer */ | |
289 | static void htable_gc(unsigned long htlong) | |
290 | { | |
39b46fc6 | 291 | struct xt_hashlimit_htable *ht = (struct xt_hashlimit_htable *)htlong; |
1da177e4 LT |
292 | |
293 | htable_selective_cleanup(ht, select_gc); | |
294 | ||
295 | /* re-add the timer accordingly */ | |
296 | ht->timer.expires = jiffies + msecs_to_jiffies(ht->cfg.gc_interval); | |
297 | add_timer(&ht->timer); | |
298 | } | |
299 | ||
39b46fc6 | 300 | static void htable_destroy(struct xt_hashlimit_htable *hinfo) |
1da177e4 | 301 | { |
e89fc3f1 AD |
302 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(hinfo->net); |
303 | struct proc_dir_entry *parent; | |
304 | ||
967ab999 | 305 | del_timer_sync(&hinfo->timer); |
1da177e4 | 306 | |
e89fc3f1 AD |
307 | if (hinfo->family == NFPROTO_IPV4) |
308 | parent = hashlimit_net->ipt_hashlimit; | |
309 | else | |
310 | parent = hashlimit_net->ip6t_hashlimit; | |
311 | remove_proc_entry(hinfo->pde->name, parent); | |
1da177e4 LT |
312 | htable_selective_cleanup(hinfo, select_all); |
313 | vfree(hinfo); | |
314 | } | |
315 | ||
e89fc3f1 AD |
316 | static struct xt_hashlimit_htable *htable_find_get(struct net *net, |
317 | const char *name, | |
76108cea | 318 | u_int8_t family) |
1da177e4 | 319 | { |
e89fc3f1 | 320 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); |
39b46fc6 | 321 | struct xt_hashlimit_htable *hinfo; |
1da177e4 LT |
322 | struct hlist_node *pos; |
323 | ||
e89fc3f1 | 324 | hlist_for_each_entry(hinfo, pos, &hashlimit_net->htables, node) { |
39b46fc6 PM |
325 | if (!strcmp(name, hinfo->pde->name) && |
326 | hinfo->family == family) { | |
2eff25c1 | 327 | hinfo->use++; |
1da177e4 LT |
328 | return hinfo; |
329 | } | |
330 | } | |
1da177e4 LT |
331 | return NULL; |
332 | } | |
333 | ||
39b46fc6 | 334 | static void htable_put(struct xt_hashlimit_htable *hinfo) |
1da177e4 | 335 | { |
2eff25c1 PM |
336 | mutex_lock(&hashlimit_mutex); |
337 | if (--hinfo->use == 0) { | |
1da177e4 | 338 | hlist_del(&hinfo->node); |
1da177e4 LT |
339 | htable_destroy(hinfo); |
340 | } | |
2eff25c1 | 341 | mutex_unlock(&hashlimit_mutex); |
1da177e4 LT |
342 | } |
343 | ||
1da177e4 LT |
344 | /* The algorithm used is the Simple Token Bucket Filter (TBF) |
345 | * see net/sched/sch_tbf.c in the linux source tree | |
346 | */ | |
347 | ||
348 | /* Rusty: This is my (non-mathematically-inclined) understanding of | |
349 | this algorithm. The `average rate' in jiffies becomes your initial | |
350 | amount of credit `credit' and the most credit you can ever have | |
351 | `credit_cap'. The `peak rate' becomes the cost of passing the | |
352 | test, `cost'. | |
353 | ||
354 | `prev' tracks the last packet hit: you gain one credit per jiffy. | |
355 | If you get credit balance more than this, the extra credit is | |
356 | discarded. Every time the match passes, you lose `cost' credits; | |
357 | if you don't have that many, the test fails. | |
358 | ||
359 | See Alexey's formal explanation in net/sched/sch_tbf.c. | |
360 | ||
361 | To get the maximum range, we multiply by this factor (ie. you get N | |
362 | credits per jiffy). We want to allow a rate as low as 1 per day | |
363 | (slowest userspace tool allows), which means | |
364 | CREDITS_PER_JIFFY*HZ*60*60*24 < 2^32 ie. | |
365 | */ | |
366 | #define MAX_CPJ (0xFFFFFFFF / (HZ*60*60*24)) | |
367 | ||
368 | /* Repeated shift and or gives us all 1s, final shift and add 1 gives | |
369 | * us the power of 2 below the theoretical max, so GCC simply does a | |
370 | * shift. */ | |
371 | #define _POW2_BELOW2(x) ((x)|((x)>>1)) | |
372 | #define _POW2_BELOW4(x) (_POW2_BELOW2(x)|_POW2_BELOW2((x)>>2)) | |
373 | #define _POW2_BELOW8(x) (_POW2_BELOW4(x)|_POW2_BELOW4((x)>>4)) | |
374 | #define _POW2_BELOW16(x) (_POW2_BELOW8(x)|_POW2_BELOW8((x)>>8)) | |
375 | #define _POW2_BELOW32(x) (_POW2_BELOW16(x)|_POW2_BELOW16((x)>>16)) | |
376 | #define POW2_BELOW32(x) ((_POW2_BELOW32(x)>>1) + 1) | |
377 | ||
378 | #define CREDITS_PER_JIFFY POW2_BELOW32(MAX_CPJ) | |
379 | ||
380 | /* Precision saver. */ | |
381 | static inline u_int32_t | |
382 | user2credits(u_int32_t user) | |
383 | { | |
384 | /* If multiplying would overflow... */ | |
385 | if (user > 0xFFFFFFFF / (HZ*CREDITS_PER_JIFFY)) | |
386 | /* Divide first. */ | |
39b46fc6 | 387 | return (user / XT_HASHLIMIT_SCALE) * HZ * CREDITS_PER_JIFFY; |
1da177e4 | 388 | |
39b46fc6 | 389 | return (user * HZ * CREDITS_PER_JIFFY) / XT_HASHLIMIT_SCALE; |
1da177e4 LT |
390 | } |
391 | ||
392 | static inline void rateinfo_recalc(struct dsthash_ent *dh, unsigned long now) | |
393 | { | |
39b46fc6 | 394 | dh->rateinfo.credit += (now - dh->rateinfo.prev) * CREDITS_PER_JIFFY; |
1da177e4 LT |
395 | if (dh->rateinfo.credit > dh->rateinfo.credit_cap) |
396 | dh->rateinfo.credit = dh->rateinfo.credit_cap; | |
39b46fc6 PM |
397 | dh->rateinfo.prev = now; |
398 | } | |
399 | ||
09e410de JE |
400 | static inline __be32 maskl(__be32 a, unsigned int l) |
401 | { | |
1b9b70ea | 402 | return l ? htonl(ntohl(a) & ~0 << (32 - l)) : 0; |
09e410de JE |
403 | } |
404 | ||
3ed5df44 | 405 | #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE) |
09e410de JE |
406 | static void hashlimit_ipv6_mask(__be32 *i, unsigned int p) |
407 | { | |
408 | switch (p) { | |
1b9b70ea | 409 | case 0 ... 31: |
09e410de JE |
410 | i[0] = maskl(i[0], p); |
411 | i[1] = i[2] = i[3] = 0; | |
412 | break; | |
1b9b70ea | 413 | case 32 ... 63: |
09e410de JE |
414 | i[1] = maskl(i[1], p - 32); |
415 | i[2] = i[3] = 0; | |
416 | break; | |
1b9b70ea | 417 | case 64 ... 95: |
09e410de JE |
418 | i[2] = maskl(i[2], p - 64); |
419 | i[3] = 0; | |
1b9b70ea | 420 | case 96 ... 127: |
09e410de JE |
421 | i[3] = maskl(i[3], p - 96); |
422 | break; | |
423 | case 128: | |
424 | break; | |
425 | } | |
426 | } | |
3ed5df44 | 427 | #endif |
09e410de | 428 | |
39b46fc6 | 429 | static int |
a47362a2 JE |
430 | hashlimit_init_dst(const struct xt_hashlimit_htable *hinfo, |
431 | struct dsthash_dst *dst, | |
39b46fc6 PM |
432 | const struct sk_buff *skb, unsigned int protoff) |
433 | { | |
434 | __be16 _ports[2], *ports; | |
193b23c5 | 435 | u8 nexthdr; |
39b46fc6 PM |
436 | |
437 | memset(dst, 0, sizeof(*dst)); | |
438 | ||
439 | switch (hinfo->family) { | |
ee999d8b | 440 | case NFPROTO_IPV4: |
39b46fc6 | 441 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP) |
09e410de JE |
442 | dst->ip.dst = maskl(ip_hdr(skb)->daddr, |
443 | hinfo->cfg.dstmask); | |
39b46fc6 | 444 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP) |
09e410de JE |
445 | dst->ip.src = maskl(ip_hdr(skb)->saddr, |
446 | hinfo->cfg.srcmask); | |
39b46fc6 PM |
447 | |
448 | if (!(hinfo->cfg.mode & | |
449 | (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT))) | |
450 | return 0; | |
eddc9ec5 | 451 | nexthdr = ip_hdr(skb)->protocol; |
39b46fc6 | 452 | break; |
02dba025 | 453 | #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE) |
ee999d8b | 454 | case NFPROTO_IPV6: |
09e410de JE |
455 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP) { |
456 | memcpy(&dst->ip6.dst, &ipv6_hdr(skb)->daddr, | |
457 | sizeof(dst->ip6.dst)); | |
458 | hashlimit_ipv6_mask(dst->ip6.dst, hinfo->cfg.dstmask); | |
459 | } | |
460 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP) { | |
461 | memcpy(&dst->ip6.src, &ipv6_hdr(skb)->saddr, | |
462 | sizeof(dst->ip6.src)); | |
463 | hashlimit_ipv6_mask(dst->ip6.src, hinfo->cfg.srcmask); | |
464 | } | |
39b46fc6 PM |
465 | |
466 | if (!(hinfo->cfg.mode & | |
467 | (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT))) | |
468 | return 0; | |
193b23c5 PM |
469 | nexthdr = ipv6_hdr(skb)->nexthdr; |
470 | protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr); | |
471 | if ((int)protoff < 0) | |
39b46fc6 PM |
472 | return -1; |
473 | break; | |
474 | #endif | |
475 | default: | |
476 | BUG(); | |
477 | return 0; | |
478 | } | |
479 | ||
480 | switch (nexthdr) { | |
481 | case IPPROTO_TCP: | |
482 | case IPPROTO_UDP: | |
a8d0f952 | 483 | case IPPROTO_UDPLITE: |
39b46fc6 PM |
484 | case IPPROTO_SCTP: |
485 | case IPPROTO_DCCP: | |
486 | ports = skb_header_pointer(skb, protoff, sizeof(_ports), | |
487 | &_ports); | |
488 | break; | |
489 | default: | |
490 | _ports[0] = _ports[1] = 0; | |
491 | ports = _ports; | |
492 | break; | |
493 | } | |
494 | if (!ports) | |
495 | return -1; | |
496 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SPT) | |
497 | dst->src_port = ports[0]; | |
498 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DPT) | |
499 | dst->dst_port = ports[1]; | |
500 | return 0; | |
1da177e4 LT |
501 | } |
502 | ||
ccb79bdc | 503 | static bool |
f7108a20 | 504 | hashlimit_mt(const struct sk_buff *skb, const struct xt_match_param *par) |
09e410de | 505 | { |
f7108a20 | 506 | const struct xt_hashlimit_mtinfo1 *info = par->matchinfo; |
09e410de JE |
507 | struct xt_hashlimit_htable *hinfo = info->hinfo; |
508 | unsigned long now = jiffies; | |
509 | struct dsthash_ent *dh; | |
510 | struct dsthash_dst dst; | |
511 | ||
f7108a20 | 512 | if (hashlimit_init_dst(hinfo, &dst, skb, par->thoff) < 0) |
09e410de JE |
513 | goto hotdrop; |
514 | ||
515 | spin_lock_bh(&hinfo->lock); | |
516 | dh = dsthash_find(hinfo, &dst); | |
517 | if (dh == NULL) { | |
518 | dh = dsthash_alloc_init(hinfo, &dst); | |
519 | if (dh == NULL) { | |
520 | spin_unlock_bh(&hinfo->lock); | |
521 | goto hotdrop; | |
522 | } | |
523 | ||
524 | dh->expires = jiffies + msecs_to_jiffies(hinfo->cfg.expire); | |
525 | dh->rateinfo.prev = jiffies; | |
526 | dh->rateinfo.credit = user2credits(hinfo->cfg.avg * | |
527 | hinfo->cfg.burst); | |
528 | dh->rateinfo.credit_cap = user2credits(hinfo->cfg.avg * | |
529 | hinfo->cfg.burst); | |
530 | dh->rateinfo.cost = user2credits(hinfo->cfg.avg); | |
531 | } else { | |
532 | /* update expiration timeout */ | |
533 | dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire); | |
534 | rateinfo_recalc(dh, now); | |
535 | } | |
536 | ||
537 | if (dh->rateinfo.credit >= dh->rateinfo.cost) { | |
538 | /* below the limit */ | |
539 | dh->rateinfo.credit -= dh->rateinfo.cost; | |
540 | spin_unlock_bh(&hinfo->lock); | |
541 | return !(info->cfg.mode & XT_HASHLIMIT_INVERT); | |
542 | } | |
543 | ||
544 | spin_unlock_bh(&hinfo->lock); | |
545 | /* default match is underlimit - so over the limit, we need to invert */ | |
546 | return info->cfg.mode & XT_HASHLIMIT_INVERT; | |
547 | ||
548 | hotdrop: | |
f7108a20 | 549 | *par->hotdrop = true; |
09e410de JE |
550 | return false; |
551 | } | |
552 | ||
b0f38452 | 553 | static int hashlimit_mt_check(const struct xt_mtchk_param *par) |
09e410de | 554 | { |
e89fc3f1 | 555 | struct net *net = par->net; |
9b4fce7a | 556 | struct xt_hashlimit_mtinfo1 *info = par->matchinfo; |
4a5a5c73 | 557 | int ret; |
09e410de JE |
558 | |
559 | /* Check for overflow. */ | |
560 | if (info->cfg.burst == 0 || | |
561 | user2credits(info->cfg.avg * info->cfg.burst) < | |
562 | user2credits(info->cfg.avg)) { | |
8bee4bad JE |
563 | pr_info("overflow, try lower: %u/%u\n", |
564 | info->cfg.avg, info->cfg.burst); | |
4a5a5c73 | 565 | return -ERANGE; |
09e410de JE |
566 | } |
567 | if (info->cfg.gc_interval == 0 || info->cfg.expire == 0) | |
bd414ee6 | 568 | return -EINVAL; |
09e410de | 569 | if (info->name[sizeof(info->name)-1] != '\0') |
bd414ee6 | 570 | return -EINVAL; |
aa5fa318 | 571 | if (par->family == NFPROTO_IPV4) { |
09e410de | 572 | if (info->cfg.srcmask > 32 || info->cfg.dstmask > 32) |
bd414ee6 | 573 | return -EINVAL; |
09e410de JE |
574 | } else { |
575 | if (info->cfg.srcmask > 128 || info->cfg.dstmask > 128) | |
bd414ee6 | 576 | return -EINVAL; |
09e410de JE |
577 | } |
578 | ||
2eff25c1 | 579 | mutex_lock(&hashlimit_mutex); |
aa5fa318 | 580 | info->hinfo = htable_find_get(net, info->name, par->family); |
4a5a5c73 JE |
581 | if (info->hinfo == NULL) { |
582 | ret = htable_create(net, info, par->family); | |
583 | if (ret < 0) { | |
584 | mutex_unlock(&hashlimit_mutex); | |
585 | return ret; | |
586 | } | |
09e410de | 587 | } |
2eff25c1 | 588 | mutex_unlock(&hashlimit_mutex); |
bd414ee6 | 589 | return 0; |
09e410de JE |
590 | } |
591 | ||
6be3d859 | 592 | static void hashlimit_mt_destroy(const struct xt_mtdtor_param *par) |
09e410de | 593 | { |
6be3d859 | 594 | const struct xt_hashlimit_mtinfo1 *info = par->matchinfo; |
09e410de JE |
595 | |
596 | htable_put(info->hinfo); | |
597 | } | |
598 | ||
d3c5ee6d | 599 | static struct xt_match hashlimit_mt_reg[] __read_mostly = { |
09e410de JE |
600 | { |
601 | .name = "hashlimit", | |
602 | .revision = 1, | |
ee999d8b | 603 | .family = NFPROTO_IPV4, |
09e410de JE |
604 | .match = hashlimit_mt, |
605 | .matchsize = sizeof(struct xt_hashlimit_mtinfo1), | |
606 | .checkentry = hashlimit_mt_check, | |
607 | .destroy = hashlimit_mt_destroy, | |
608 | .me = THIS_MODULE, | |
609 | }, | |
7b21e09d | 610 | #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE) |
09e410de JE |
611 | { |
612 | .name = "hashlimit", | |
613 | .revision = 1, | |
ee999d8b | 614 | .family = NFPROTO_IPV6, |
09e410de JE |
615 | .match = hashlimit_mt, |
616 | .matchsize = sizeof(struct xt_hashlimit_mtinfo1), | |
617 | .checkentry = hashlimit_mt_check, | |
618 | .destroy = hashlimit_mt_destroy, | |
619 | .me = THIS_MODULE, | |
620 | }, | |
7b21e09d | 621 | #endif |
1da177e4 LT |
622 | }; |
623 | ||
624 | /* PROC stuff */ | |
1da177e4 | 625 | static void *dl_seq_start(struct seq_file *s, loff_t *pos) |
f4f6fb71 | 626 | __acquires(htable->lock) |
1da177e4 | 627 | { |
a1004d8e | 628 | struct xt_hashlimit_htable *htable = s->private; |
1da177e4 LT |
629 | unsigned int *bucket; |
630 | ||
631 | spin_lock_bh(&htable->lock); | |
632 | if (*pos >= htable->cfg.size) | |
633 | return NULL; | |
634 | ||
635 | bucket = kmalloc(sizeof(unsigned int), GFP_ATOMIC); | |
636 | if (!bucket) | |
637 | return ERR_PTR(-ENOMEM); | |
638 | ||
639 | *bucket = *pos; | |
640 | return bucket; | |
641 | } | |
642 | ||
643 | static void *dl_seq_next(struct seq_file *s, void *v, loff_t *pos) | |
644 | { | |
a1004d8e | 645 | struct xt_hashlimit_htable *htable = s->private; |
1da177e4 LT |
646 | unsigned int *bucket = (unsigned int *)v; |
647 | ||
648 | *pos = ++(*bucket); | |
649 | if (*pos >= htable->cfg.size) { | |
650 | kfree(v); | |
651 | return NULL; | |
652 | } | |
653 | return bucket; | |
654 | } | |
655 | ||
656 | static void dl_seq_stop(struct seq_file *s, void *v) | |
f4f6fb71 | 657 | __releases(htable->lock) |
1da177e4 | 658 | { |
a1004d8e | 659 | struct xt_hashlimit_htable *htable = s->private; |
1da177e4 LT |
660 | unsigned int *bucket = (unsigned int *)v; |
661 | ||
662 | kfree(bucket); | |
1da177e4 LT |
663 | spin_unlock_bh(&htable->lock); |
664 | } | |
665 | ||
76108cea | 666 | static int dl_seq_real_show(struct dsthash_ent *ent, u_int8_t family, |
39b46fc6 | 667 | struct seq_file *s) |
1da177e4 LT |
668 | { |
669 | /* recalculate to show accurate numbers */ | |
670 | rateinfo_recalc(ent, jiffies); | |
671 | ||
39b46fc6 | 672 | switch (family) { |
ee999d8b | 673 | case NFPROTO_IPV4: |
14d5e834 | 674 | return seq_printf(s, "%ld %pI4:%u->%pI4:%u %u %u %u\n", |
39b46fc6 | 675 | (long)(ent->expires - jiffies)/HZ, |
14d5e834 | 676 | &ent->dst.ip.src, |
39b46fc6 | 677 | ntohs(ent->dst.src_port), |
14d5e834 | 678 | &ent->dst.ip.dst, |
39b46fc6 PM |
679 | ntohs(ent->dst.dst_port), |
680 | ent->rateinfo.credit, ent->rateinfo.credit_cap, | |
681 | ent->rateinfo.cost); | |
7b21e09d | 682 | #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE) |
ee999d8b | 683 | case NFPROTO_IPV6: |
5b095d98 | 684 | return seq_printf(s, "%ld %pI6:%u->%pI6:%u %u %u %u\n", |
39b46fc6 | 685 | (long)(ent->expires - jiffies)/HZ, |
38ff4fa4 | 686 | &ent->dst.ip6.src, |
39b46fc6 | 687 | ntohs(ent->dst.src_port), |
38ff4fa4 | 688 | &ent->dst.ip6.dst, |
39b46fc6 PM |
689 | ntohs(ent->dst.dst_port), |
690 | ent->rateinfo.credit, ent->rateinfo.credit_cap, | |
691 | ent->rateinfo.cost); | |
7b21e09d | 692 | #endif |
39b46fc6 PM |
693 | default: |
694 | BUG(); | |
695 | return 0; | |
696 | } | |
1da177e4 LT |
697 | } |
698 | ||
699 | static int dl_seq_show(struct seq_file *s, void *v) | |
700 | { | |
a1004d8e | 701 | struct xt_hashlimit_htable *htable = s->private; |
1da177e4 LT |
702 | unsigned int *bucket = (unsigned int *)v; |
703 | struct dsthash_ent *ent; | |
704 | struct hlist_node *pos; | |
705 | ||
39b46fc6 PM |
706 | if (!hlist_empty(&htable->hash[*bucket])) { |
707 | hlist_for_each_entry(ent, pos, &htable->hash[*bucket], node) | |
708 | if (dl_seq_real_show(ent, htable->family, s)) | |
683a04ce | 709 | return -1; |
39b46fc6 | 710 | } |
1da177e4 LT |
711 | return 0; |
712 | } | |
713 | ||
56b3d975 | 714 | static const struct seq_operations dl_seq_ops = { |
1da177e4 LT |
715 | .start = dl_seq_start, |
716 | .next = dl_seq_next, | |
717 | .stop = dl_seq_stop, | |
718 | .show = dl_seq_show | |
719 | }; | |
720 | ||
721 | static int dl_proc_open(struct inode *inode, struct file *file) | |
722 | { | |
723 | int ret = seq_open(file, &dl_seq_ops); | |
724 | ||
725 | if (!ret) { | |
726 | struct seq_file *sf = file->private_data; | |
a1004d8e | 727 | sf->private = PDE(inode)->data; |
1da177e4 LT |
728 | } |
729 | return ret; | |
730 | } | |
731 | ||
da7071d7 | 732 | static const struct file_operations dl_file_ops = { |
1da177e4 LT |
733 | .owner = THIS_MODULE, |
734 | .open = dl_proc_open, | |
735 | .read = seq_read, | |
736 | .llseek = seq_lseek, | |
737 | .release = seq_release | |
738 | }; | |
739 | ||
e89fc3f1 AD |
740 | static int __net_init hashlimit_proc_net_init(struct net *net) |
741 | { | |
742 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); | |
743 | ||
744 | hashlimit_net->ipt_hashlimit = proc_mkdir("ipt_hashlimit", net->proc_net); | |
745 | if (!hashlimit_net->ipt_hashlimit) | |
746 | return -ENOMEM; | |
747 | #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE) | |
748 | hashlimit_net->ip6t_hashlimit = proc_mkdir("ip6t_hashlimit", net->proc_net); | |
749 | if (!hashlimit_net->ip6t_hashlimit) { | |
750 | proc_net_remove(net, "ipt_hashlimit"); | |
751 | return -ENOMEM; | |
752 | } | |
753 | #endif | |
754 | return 0; | |
755 | } | |
756 | ||
757 | static void __net_exit hashlimit_proc_net_exit(struct net *net) | |
758 | { | |
759 | proc_net_remove(net, "ipt_hashlimit"); | |
760 | #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE) | |
761 | proc_net_remove(net, "ip6t_hashlimit"); | |
762 | #endif | |
763 | } | |
764 | ||
765 | static int __net_init hashlimit_net_init(struct net *net) | |
766 | { | |
767 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); | |
768 | ||
769 | INIT_HLIST_HEAD(&hashlimit_net->htables); | |
770 | return hashlimit_proc_net_init(net); | |
771 | } | |
772 | ||
773 | static void __net_exit hashlimit_net_exit(struct net *net) | |
774 | { | |
775 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); | |
776 | ||
777 | BUG_ON(!hlist_empty(&hashlimit_net->htables)); | |
778 | hashlimit_proc_net_exit(net); | |
779 | } | |
780 | ||
781 | static struct pernet_operations hashlimit_net_ops = { | |
782 | .init = hashlimit_net_init, | |
783 | .exit = hashlimit_net_exit, | |
784 | .id = &hashlimit_net_id, | |
785 | .size = sizeof(struct hashlimit_net), | |
786 | }; | |
787 | ||
d3c5ee6d | 788 | static int __init hashlimit_mt_init(void) |
1da177e4 | 789 | { |
39b46fc6 | 790 | int err; |
1da177e4 | 791 | |
e89fc3f1 AD |
792 | err = register_pernet_subsys(&hashlimit_net_ops); |
793 | if (err < 0) | |
794 | return err; | |
d3c5ee6d JE |
795 | err = xt_register_matches(hashlimit_mt_reg, |
796 | ARRAY_SIZE(hashlimit_mt_reg)); | |
39b46fc6 PM |
797 | if (err < 0) |
798 | goto err1; | |
1da177e4 | 799 | |
39b46fc6 PM |
800 | err = -ENOMEM; |
801 | hashlimit_cachep = kmem_cache_create("xt_hashlimit", | |
802 | sizeof(struct dsthash_ent), 0, 0, | |
20c2df83 | 803 | NULL); |
1da177e4 | 804 | if (!hashlimit_cachep) { |
8bee4bad | 805 | pr_warning("unable to create slab cache\n"); |
39b46fc6 | 806 | goto err2; |
1da177e4 | 807 | } |
e89fc3f1 AD |
808 | return 0; |
809 | ||
39b46fc6 | 810 | err2: |
d3c5ee6d | 811 | xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg)); |
39b46fc6 | 812 | err1: |
e89fc3f1 | 813 | unregister_pernet_subsys(&hashlimit_net_ops); |
39b46fc6 | 814 | return err; |
1da177e4 | 815 | |
1da177e4 LT |
816 | } |
817 | ||
d3c5ee6d | 818 | static void __exit hashlimit_mt_exit(void) |
1da177e4 | 819 | { |
39b46fc6 | 820 | kmem_cache_destroy(hashlimit_cachep); |
d3c5ee6d | 821 | xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg)); |
e89fc3f1 | 822 | unregister_pernet_subsys(&hashlimit_net_ops); |
1da177e4 LT |
823 | } |
824 | ||
d3c5ee6d JE |
825 | module_init(hashlimit_mt_init); |
826 | module_exit(hashlimit_mt_exit); |