1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * xt_hashlimit - Netfilter module to limit the number of packets per time |
4 | * separately for each hashbucket (sourceip/sourceport/dstip/dstport) |
5 | * |
6 | * (C) 2003-2004 by Harald Welte <laforge@netfilter.org> |
7 | * (C) 2006-2012 Patrick McHardy <kaber@trash.net> |
8 | * Copyright © CC Computer Consultants GmbH, 2007 - 2008 |
9 | * |
10 | * Development of this code was funded by Astaro AG, http://www.astaro.com/ |
11 | */ |
12 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
13 | #include <linux/module.h> |
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> |
19 | #include <linux/proc_fs.h> |
20 | #include <linux/seq_file.h> |
21 | #include <linux/list.h> |
22 | #include <linux/skbuff.h> |
23 | #include <linux/mm.h> |
24 | #include <linux/in.h> |
25 | #include <linux/ip.h> |
26 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
27 | #include <linux/ipv6.h> |
28 | #include <net/ipv6.h> |
29 | #endif |
30 | |
31 | #include <net/net_namespace.h> |
32 | #include <net/netns/generic.h> |
33 | |
34 | #include <linux/netfilter/x_tables.h> |
35 | #include <linux/netfilter_ipv4/ip_tables.h> |
36 | #include <linux/netfilter_ipv6/ip6_tables.h> |
37 | #include <linux/mutex.h> |
38 | #include <linux/kernel.h> |
39 | #include <linux/refcount.h> |
40 | #include <uapi/linux/netfilter/xt_hashlimit.h> |
41 | |
42 | #define XT_HASHLIMIT_ALL (XT_HASHLIMIT_HASH_DIP | XT_HASHLIMIT_HASH_DPT | \ |
43 | XT_HASHLIMIT_HASH_SIP | XT_HASHLIMIT_HASH_SPT | \ |
44 | XT_HASHLIMIT_INVERT | XT_HASHLIMIT_BYTES |\ |
45 | XT_HASHLIMIT_RATE_MATCH) |
46 | |
47 | MODULE_LICENSE("GPL" ); |
48 | MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>" ); |
49 | MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>" ); |
50 | MODULE_DESCRIPTION("Xtables: per hash-bucket rate-limit match" ); |
51 | MODULE_ALIAS("ipt_hashlimit" ); |
52 | MODULE_ALIAS("ip6t_hashlimit" ); |
53 | |
54 | struct hashlimit_net { |
55 | struct hlist_head htables; |
56 | struct proc_dir_entry *ipt_hashlimit; |
57 | struct proc_dir_entry *ip6t_hashlimit; |
58 | }; |
59 | |
60 | static unsigned int hashlimit_net_id; |
61 | static inline struct hashlimit_net *hashlimit_pernet(struct net *net) |
62 | { |
63 | return net_generic(net, id: hashlimit_net_id); |
64 | } |
65 | |
66 | /* need to declare this at the top */ |
67 | static const struct seq_operations dl_seq_ops_v2; |
68 | static const struct seq_operations dl_seq_ops_v1; |
69 | static const struct seq_operations dl_seq_ops; |
70 | |
71 | /* hash table crap */ |
72 | struct dsthash_dst { |
73 | union { |
74 | struct { |
75 | __be32 src; |
76 | __be32 dst; |
77 | } ip; |
78 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
79 | struct { |
80 | __be32 src[4]; |
81 | __be32 dst[4]; |
82 | } ip6; |
83 | #endif |
84 | }; |
85 | __be16 src_port; |
86 | __be16 dst_port; |
87 | }; |
88 | |
89 | struct dsthash_ent { |
90 | /* static / read-only parts in the beginning */ |
91 | struct hlist_node node; |
92 | struct dsthash_dst dst; |
93 | |
94 | /* modified structure members in the end */ |
95 | spinlock_t lock; |
96 | unsigned long expires; /* precalculated expiry time */ |
97 | struct { |
98 | unsigned long prev; /* last modification */ |
99 | union { |
100 | struct { |
101 | u_int64_t credit; |
102 | u_int64_t credit_cap; |
103 | u_int64_t cost; |
104 | }; |
105 | struct { |
106 | u_int32_t interval, prev_window; |
107 | u_int64_t current_rate; |
108 | u_int64_t rate; |
109 | int64_t burst; |
110 | }; |
111 | }; |
112 | } rateinfo; |
113 | struct rcu_head rcu; |
114 | }; |
115 | |
116 | struct xt_hashlimit_htable { |
117 | struct hlist_node node; /* global list of all htables */ |
118 | refcount_t use; |
119 | u_int8_t family; |
120 | bool rnd_initialized; |
121 | |
122 | struct hashlimit_cfg3 cfg; /* config */ |
123 | |
124 | /* used internally */ |
125 | spinlock_t lock; /* lock for list_head */ |
126 | u_int32_t rnd; /* random seed for hash */ |
127 | unsigned int count; /* number entries in table */ |
128 | struct delayed_work gc_work; |
129 | |
130 | /* seq_file stuff */ |
131 | struct proc_dir_entry *pde; |
132 | const char *name; |
133 | struct net *net; |
134 | |
135 | struct hlist_head hash[]; /* hashtable itself */ |
136 | }; |
137 | |
138 | static int |
139 | cfg_copy(struct hashlimit_cfg3 *to, const void *from, int revision) |
140 | { |
141 | if (revision == 1) { |
142 | struct hashlimit_cfg1 *cfg = (struct hashlimit_cfg1 *)from; |
143 | |
144 | to->mode = cfg->mode; |
145 | to->avg = cfg->avg; |
146 | to->burst = cfg->burst; |
147 | to->size = cfg->size; |
148 | to->max = cfg->max; |
149 | to->gc_interval = cfg->gc_interval; |
150 | to->expire = cfg->expire; |
151 | to->srcmask = cfg->srcmask; |
152 | to->dstmask = cfg->dstmask; |
153 | } else if (revision == 2) { |
154 | struct hashlimit_cfg2 *cfg = (struct hashlimit_cfg2 *)from; |
155 | |
156 | to->mode = cfg->mode; |
157 | to->avg = cfg->avg; |
158 | to->burst = cfg->burst; |
159 | to->size = cfg->size; |
160 | to->max = cfg->max; |
161 | to->gc_interval = cfg->gc_interval; |
162 | to->expire = cfg->expire; |
163 | to->srcmask = cfg->srcmask; |
164 | to->dstmask = cfg->dstmask; |
165 | } else if (revision == 3) { |
166 | memcpy(to, from, sizeof(struct hashlimit_cfg3)); |
167 | } else { |
168 | return -EINVAL; |
169 | } |
170 | |
171 | return 0; |
172 | } |
173 | |
174 | static DEFINE_MUTEX(hashlimit_mutex); /* protects htables list */ |
175 | static struct kmem_cache *hashlimit_cachep __read_mostly; |
176 | |
177 | static inline bool dst_cmp(const struct dsthash_ent *ent, |
178 | const struct dsthash_dst *b) |
179 | { |
180 | return !memcmp(p: &ent->dst, q: b, size: sizeof(ent->dst)); |
181 | } |
182 | |
183 | static u_int32_t |
184 | hash_dst(const struct xt_hashlimit_htable *ht, const struct dsthash_dst *dst) |
185 | { |
186 | u_int32_t hash = jhash2(k: (const u32 *)dst, |
187 | length: sizeof(*dst)/sizeof(u32), |
188 | initval: ht->rnd); |
189 | /* |
190 | * Instead of returning hash % ht->cfg.size (implying a divide) |
191 | * we return the high 32 bits of the (hash * ht->cfg.size) that will |
192 | * give results between [0 and cfg.size-1] and same hash distribution, |
193 | * but using a multiply, less expensive than a divide |
194 | */ |
195 | return reciprocal_scale(val: hash, ep_ro: ht->cfg.size); |
196 | } |
197 | |
198 | static struct dsthash_ent * |
199 | dsthash_find(const struct xt_hashlimit_htable *ht, |
200 | const struct dsthash_dst *dst) |
201 | { |
202 | struct dsthash_ent *ent; |
203 | u_int32_t hash = hash_dst(ht, dst); |
204 | |
205 | if (!hlist_empty(h: &ht->hash[hash])) { |
206 | hlist_for_each_entry_rcu(ent, &ht->hash[hash], node) |
207 | if (dst_cmp(ent, b: dst)) { |
208 | spin_lock(lock: &ent->lock); |
209 | return ent; |
210 | } |
211 | } |
212 | return NULL; |
213 | } |
214 | |
215 | /* allocate dsthash_ent, initialize dst, put in htable and lock it */ |
216 | static struct dsthash_ent * |
217 | dsthash_alloc_init(struct xt_hashlimit_htable *ht, |
218 | const struct dsthash_dst *dst, bool *race) |
219 | { |
220 | struct dsthash_ent *ent; |
221 | |
222 | spin_lock(lock: &ht->lock); |
223 | |
224 | /* Two or more packets may race to create the same entry in the |
225 | * hashtable, double check if this packet lost race. |
226 | */ |
227 | ent = dsthash_find(ht, dst); |
228 | if (ent != NULL) { |
229 | spin_unlock(lock: &ht->lock); |
230 | *race = true; |
231 | return ent; |
232 | } |
233 | |
234 | /* initialize hash with random val at the time we allocate |
235 | * the first hashtable entry */ |
236 | if (unlikely(!ht->rnd_initialized)) { |
237 | get_random_bytes(buf: &ht->rnd, len: sizeof(ht->rnd)); |
238 | ht->rnd_initialized = true; |
239 | } |
240 | |
241 | if (ht->cfg.max && ht->count >= ht->cfg.max) { |
242 | /* FIXME: do something. question is what.. */ |
243 | net_err_ratelimited("max count of %u reached\n" , ht->cfg.max); |
244 | ent = NULL; |
245 | } else |
246 | ent = kmem_cache_alloc(cachep: hashlimit_cachep, GFP_ATOMIC); |
247 | if (ent) { |
248 | memcpy(&ent->dst, dst, sizeof(ent->dst)); |
249 | spin_lock_init(&ent->lock); |
250 | |
251 | spin_lock(lock: &ent->lock); |
252 | hlist_add_head_rcu(n: &ent->node, h: &ht->hash[hash_dst(ht, dst)]); |
253 | ht->count++; |
254 | } |
255 | spin_unlock(lock: &ht->lock); |
256 | return ent; |
257 | } |
258 | |
259 | static void dsthash_free_rcu(struct rcu_head *head) |
260 | { |
261 | struct dsthash_ent *ent = container_of(head, struct dsthash_ent, rcu); |
262 | |
263 | kmem_cache_free(s: hashlimit_cachep, objp: ent); |
264 | } |
265 | |
266 | static inline void |
267 | dsthash_free(struct xt_hashlimit_htable *ht, struct dsthash_ent *ent) |
268 | { |
269 | hlist_del_rcu(n: &ent->node); |
270 | call_rcu(head: &ent->rcu, func: dsthash_free_rcu); |
271 | ht->count--; |
272 | } |
273 | static void htable_gc(struct work_struct *work); |
274 | |
275 | static int htable_create(struct net *net, struct hashlimit_cfg3 *cfg, |
276 | const char *name, u_int8_t family, |
277 | struct xt_hashlimit_htable **out_hinfo, |
278 | int revision) |
279 | { |
280 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); |
281 | struct xt_hashlimit_htable *hinfo; |
282 | const struct seq_operations *ops; |
283 | unsigned int size, i; |
284 | unsigned long nr_pages = totalram_pages(); |
285 | int ret; |
286 | |
287 | if (cfg->size) { |
288 | size = cfg->size; |
289 | } else { |
290 | size = (nr_pages << PAGE_SHIFT) / 16384 / |
291 | sizeof(struct hlist_head); |
292 | if (nr_pages > 1024 * 1024 * 1024 / PAGE_SIZE) |
293 | size = 8192; |
294 | if (size < 16) |
295 | size = 16; |
296 | } |
297 | /* FIXME: don't use vmalloc() here or anywhere else -HW */ |
298 | hinfo = vmalloc(struct_size(hinfo, hash, size)); |
299 | if (hinfo == NULL) |
300 | return -ENOMEM; |
301 | *out_hinfo = hinfo; |
302 | |
303 | /* copy match config into hashtable config */ |
304 | ret = cfg_copy(to: &hinfo->cfg, from: (void *)cfg, revision: 3); |
305 | if (ret) { |
306 | vfree(addr: hinfo); |
307 | return ret; |
308 | } |
309 | |
310 | hinfo->cfg.size = size; |
311 | if (hinfo->cfg.max == 0) |
312 | hinfo->cfg.max = 8 * hinfo->cfg.size; |
313 | else if (hinfo->cfg.max < hinfo->cfg.size) |
314 | hinfo->cfg.max = hinfo->cfg.size; |
315 | |
316 | for (i = 0; i < hinfo->cfg.size; i++) |
317 | INIT_HLIST_HEAD(&hinfo->hash[i]); |
318 | |
319 | refcount_set(r: &hinfo->use, n: 1); |
320 | hinfo->count = 0; |
321 | hinfo->family = family; |
322 | hinfo->rnd_initialized = false; |
323 | hinfo->name = kstrdup(s: name, GFP_KERNEL); |
324 | if (!hinfo->name) { |
325 | vfree(addr: hinfo); |
326 | return -ENOMEM; |
327 | } |
328 | spin_lock_init(&hinfo->lock); |
329 | |
330 | switch (revision) { |
331 | case 1: |
332 | ops = &dl_seq_ops_v1; |
333 | break; |
334 | case 2: |
335 | ops = &dl_seq_ops_v2; |
336 | break; |
337 | default: |
338 | ops = &dl_seq_ops; |
339 | } |
340 | |
341 | hinfo->pde = proc_create_seq_data(name, 0, |
342 | (family == NFPROTO_IPV4) ? |
343 | hashlimit_net->ipt_hashlimit : hashlimit_net->ip6t_hashlimit, |
344 | ops, hinfo); |
345 | if (hinfo->pde == NULL) { |
346 | kfree(objp: hinfo->name); |
347 | vfree(addr: hinfo); |
348 | return -ENOMEM; |
349 | } |
350 | hinfo->net = net; |
351 | |
352 | INIT_DEFERRABLE_WORK(&hinfo->gc_work, htable_gc); |
353 | queue_delayed_work(wq: system_power_efficient_wq, dwork: &hinfo->gc_work, |
354 | delay: msecs_to_jiffies(m: hinfo->cfg.gc_interval)); |
355 | |
356 | hlist_add_head(n: &hinfo->node, h: &hashlimit_net->htables); |
357 | |
358 | return 0; |
359 | } |
360 | |
361 | static void htable_selective_cleanup(struct xt_hashlimit_htable *ht, bool select_all) |
362 | { |
363 | unsigned int i; |
364 | |
365 | for (i = 0; i < ht->cfg.size; i++) { |
366 | struct dsthash_ent *dh; |
367 | struct hlist_node *n; |
368 | |
369 | spin_lock_bh(lock: &ht->lock); |
370 | hlist_for_each_entry_safe(dh, n, &ht->hash[i], node) { |
371 | if (time_after_eq(jiffies, dh->expires) || select_all) |
372 | dsthash_free(ht, ent: dh); |
373 | } |
374 | spin_unlock_bh(lock: &ht->lock); |
375 | cond_resched(); |
376 | } |
377 | } |
378 | |
379 | static void htable_gc(struct work_struct *work) |
380 | { |
381 | struct xt_hashlimit_htable *ht; |
382 | |
383 | ht = container_of(work, struct xt_hashlimit_htable, gc_work.work); |
384 | |
385 | htable_selective_cleanup(ht, select_all: false); |
386 | |
387 | queue_delayed_work(wq: system_power_efficient_wq, |
388 | dwork: &ht->gc_work, delay: msecs_to_jiffies(m: ht->cfg.gc_interval)); |
389 | } |
390 | |
391 | static void htable_remove_proc_entry(struct xt_hashlimit_htable *hinfo) |
392 | { |
393 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net: hinfo->net); |
394 | struct proc_dir_entry *parent; |
395 | |
396 | if (hinfo->family == NFPROTO_IPV4) |
397 | parent = hashlimit_net->ipt_hashlimit; |
398 | else |
399 | parent = hashlimit_net->ip6t_hashlimit; |
400 | |
401 | if (parent != NULL) |
402 | remove_proc_entry(hinfo->name, parent); |
403 | } |
404 | |
405 | static struct xt_hashlimit_htable *htable_find_get(struct net *net, |
406 | const char *name, |
407 | u_int8_t family) |
408 | { |
409 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); |
410 | struct xt_hashlimit_htable *hinfo; |
411 | |
412 | hlist_for_each_entry(hinfo, &hashlimit_net->htables, node) { |
413 | if (!strcmp(name, hinfo->name) && |
414 | hinfo->family == family) { |
415 | refcount_inc(r: &hinfo->use); |
416 | return hinfo; |
417 | } |
418 | } |
419 | return NULL; |
420 | } |
421 | |
422 | static void htable_put(struct xt_hashlimit_htable *hinfo) |
423 | { |
424 | if (refcount_dec_and_mutex_lock(r: &hinfo->use, lock: &hashlimit_mutex)) { |
425 | hlist_del(n: &hinfo->node); |
426 | htable_remove_proc_entry(hinfo); |
427 | mutex_unlock(lock: &hashlimit_mutex); |
428 | |
429 | cancel_delayed_work_sync(dwork: &hinfo->gc_work); |
430 | htable_selective_cleanup(ht: hinfo, select_all: true); |
431 | kfree(objp: hinfo->name); |
432 | vfree(addr: hinfo); |
433 | } |
434 | } |
435 | |
436 | /* The algorithm used is the Simple Token Bucket Filter (TBF) |
437 | * see net/sched/sch_tbf.c in the linux source tree |
438 | */ |
439 | |
440 | /* Rusty: This is my (non-mathematically-inclined) understanding of |
441 | this algorithm. The `average rate' in jiffies becomes your initial |
442 | amount of credit `credit' and the most credit you can ever have |
443 | `credit_cap'. The `peak rate' becomes the cost of passing the |
444 | test, `cost'. |
445 | |
446 | `prev' tracks the last packet hit: you gain one credit per jiffy. |
447 | If you get credit balance more than this, the extra credit is |
448 | discarded. Every time the match passes, you lose `cost' credits; |
449 | if you don't have that many, the test fails. |
450 | |
451 | See Alexey's formal explanation in net/sched/sch_tbf.c. |
452 | |
453 | To get the maximum range, we multiply by this factor (ie. you get N |
454 | credits per jiffy). We want to allow a rate as low as 1 per day |
455 | (slowest userspace tool allows), which means |
456 | CREDITS_PER_JIFFY*HZ*60*60*24 < 2^32 ie. |
457 | */ |
458 | #define MAX_CPJ_v1 (0xFFFFFFFF / (HZ*60*60*24)) |
459 | #define MAX_CPJ (0xFFFFFFFFFFFFFFFFULL / (HZ*60*60*24)) |
460 | |
461 | /* Repeated shift and or gives us all 1s, final shift and add 1 gives |
462 | * us the power of 2 below the theoretical max, so GCC simply does a |
463 | * shift. */ |
464 | #define _POW2_BELOW2(x) ((x)|((x)>>1)) |
465 | #define _POW2_BELOW4(x) (_POW2_BELOW2(x)|_POW2_BELOW2((x)>>2)) |
466 | #define _POW2_BELOW8(x) (_POW2_BELOW4(x)|_POW2_BELOW4((x)>>4)) |
467 | #define _POW2_BELOW16(x) (_POW2_BELOW8(x)|_POW2_BELOW8((x)>>8)) |
468 | #define _POW2_BELOW32(x) (_POW2_BELOW16(x)|_POW2_BELOW16((x)>>16)) |
469 | #define _POW2_BELOW64(x) (_POW2_BELOW32(x)|_POW2_BELOW32((x)>>32)) |
470 | #define POW2_BELOW32(x) ((_POW2_BELOW32(x)>>1) + 1) |
471 | #define POW2_BELOW64(x) ((_POW2_BELOW64(x)>>1) + 1) |
472 | |
473 | #define CREDITS_PER_JIFFY POW2_BELOW64(MAX_CPJ) |
474 | #define CREDITS_PER_JIFFY_v1 POW2_BELOW32(MAX_CPJ_v1) |
475 | |
476 | /* in byte mode, the lowest possible rate is one packet/second. |
477 | * credit_cap is used as a counter that tells us how many times we can |
478 | * refill the "credits available" counter when it becomes empty. |
479 | */ |
480 | #define MAX_CPJ_BYTES (0xFFFFFFFF / HZ) |
481 | #define CREDITS_PER_JIFFY_BYTES POW2_BELOW32(MAX_CPJ_BYTES) |
482 | |
483 | static u32 xt_hashlimit_len_to_chunks(u32 len) |
484 | { |
485 | return (len >> XT_HASHLIMIT_BYTE_SHIFT) + 1; |
486 | } |
487 | |
488 | /* Precision saver. */ |
489 | static u64 user2credits(u64 user, int revision) |
490 | { |
491 | u64 scale = (revision == 1) ? |
492 | XT_HASHLIMIT_SCALE : XT_HASHLIMIT_SCALE_v2; |
493 | u64 cpj = (revision == 1) ? |
494 | CREDITS_PER_JIFFY_v1 : CREDITS_PER_JIFFY; |
495 | |
496 | /* Avoid overflow: divide the constant operands first */ |
497 | if (scale >= HZ * cpj) |
498 | return div64_u64(dividend: user, divisor: div64_u64(dividend: scale, HZ * cpj)); |
499 | |
500 | return user * div64_u64(HZ * cpj, divisor: scale); |
501 | } |
502 | |
503 | static u32 user2credits_byte(u32 user) |
504 | { |
505 | u64 us = user; |
506 | us *= HZ * CREDITS_PER_JIFFY_BYTES; |
507 | return (u32) (us >> 32); |
508 | } |
509 | |
510 | static u64 user2rate(u64 user) |
511 | { |
512 | if (user != 0) { |
513 | return div64_u64(XT_HASHLIMIT_SCALE_v2, divisor: user); |
514 | } else { |
515 | pr_info_ratelimited("invalid rate from userspace: %llu\n" , |
516 | user); |
517 | return 0; |
518 | } |
519 | } |
520 | |
521 | static u64 user2rate_bytes(u32 user) |
522 | { |
523 | u64 r; |
524 | |
525 | r = user ? U32_MAX / user : U32_MAX; |
526 | return (r - 1) << XT_HASHLIMIT_BYTE_SHIFT; |
527 | } |
528 | |
529 | static void rateinfo_recalc(struct dsthash_ent *dh, unsigned long now, |
530 | u32 mode, int revision) |
531 | { |
532 | unsigned long delta = now - dh->rateinfo.prev; |
533 | u64 cap, cpj; |
534 | |
535 | if (delta == 0) |
536 | return; |
537 | |
538 | if (revision >= 3 && mode & XT_HASHLIMIT_RATE_MATCH) { |
539 | u64 interval = dh->rateinfo.interval * HZ; |
540 | |
541 | if (delta < interval) |
542 | return; |
543 | |
544 | dh->rateinfo.prev = now; |
545 | dh->rateinfo.prev_window = |
546 | ((dh->rateinfo.current_rate * interval) > |
547 | (delta * dh->rateinfo.rate)); |
548 | dh->rateinfo.current_rate = 0; |
549 | |
550 | return; |
551 | } |
552 | |
553 | dh->rateinfo.prev = now; |
554 | |
555 | if (mode & XT_HASHLIMIT_BYTES) { |
556 | u64 tmp = dh->rateinfo.credit; |
557 | dh->rateinfo.credit += CREDITS_PER_JIFFY_BYTES * delta; |
558 | cap = CREDITS_PER_JIFFY_BYTES * HZ; |
559 | if (tmp >= dh->rateinfo.credit) {/* overflow */ |
560 | dh->rateinfo.credit = cap; |
561 | return; |
562 | } |
563 | } else { |
564 | cpj = (revision == 1) ? |
565 | CREDITS_PER_JIFFY_v1 : CREDITS_PER_JIFFY; |
566 | dh->rateinfo.credit += delta * cpj; |
567 | cap = dh->rateinfo.credit_cap; |
568 | } |
569 | if (dh->rateinfo.credit > cap) |
570 | dh->rateinfo.credit = cap; |
571 | } |
572 | |
573 | static void rateinfo_init(struct dsthash_ent *dh, |
574 | struct xt_hashlimit_htable *hinfo, int revision) |
575 | { |
576 | dh->rateinfo.prev = jiffies; |
577 | if (revision >= 3 && hinfo->cfg.mode & XT_HASHLIMIT_RATE_MATCH) { |
578 | dh->rateinfo.prev_window = 0; |
579 | dh->rateinfo.current_rate = 0; |
580 | if (hinfo->cfg.mode & XT_HASHLIMIT_BYTES) { |
581 | dh->rateinfo.rate = |
582 | user2rate_bytes(user: (u32)hinfo->cfg.avg); |
583 | if (hinfo->cfg.burst) |
584 | dh->rateinfo.burst = |
585 | hinfo->cfg.burst * dh->rateinfo.rate; |
586 | else |
587 | dh->rateinfo.burst = dh->rateinfo.rate; |
588 | } else { |
589 | dh->rateinfo.rate = user2rate(user: hinfo->cfg.avg); |
590 | dh->rateinfo.burst = |
591 | hinfo->cfg.burst + dh->rateinfo.rate; |
592 | } |
593 | dh->rateinfo.interval = hinfo->cfg.interval; |
594 | } else if (hinfo->cfg.mode & XT_HASHLIMIT_BYTES) { |
595 | dh->rateinfo.credit = CREDITS_PER_JIFFY_BYTES * HZ; |
596 | dh->rateinfo.cost = user2credits_byte(user: hinfo->cfg.avg); |
597 | dh->rateinfo.credit_cap = hinfo->cfg.burst; |
598 | } else { |
599 | dh->rateinfo.credit = user2credits(user: hinfo->cfg.avg * |
600 | hinfo->cfg.burst, revision); |
601 | dh->rateinfo.cost = user2credits(user: hinfo->cfg.avg, revision); |
602 | dh->rateinfo.credit_cap = dh->rateinfo.credit; |
603 | } |
604 | } |
605 | |
606 | static inline __be32 maskl(__be32 a, unsigned int l) |
607 | { |
608 | return l ? htonl(ntohl(a) & ~0 << (32 - l)) : 0; |
609 | } |
610 | |
611 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
612 | static void hashlimit_ipv6_mask(__be32 *i, unsigned int p) |
613 | { |
614 | switch (p) { |
615 | case 0 ... 31: |
616 | i[0] = maskl(a: i[0], l: p); |
617 | i[1] = i[2] = i[3] = 0; |
618 | break; |
619 | case 32 ... 63: |
620 | i[1] = maskl(a: i[1], l: p - 32); |
621 | i[2] = i[3] = 0; |
622 | break; |
623 | case 64 ... 95: |
624 | i[2] = maskl(a: i[2], l: p - 64); |
625 | i[3] = 0; |
626 | break; |
627 | case 96 ... 127: |
628 | i[3] = maskl(a: i[3], l: p - 96); |
629 | break; |
630 | case 128: |
631 | break; |
632 | } |
633 | } |
634 | #endif |
635 | |
636 | static int |
637 | hashlimit_init_dst(const struct xt_hashlimit_htable *hinfo, |
638 | struct dsthash_dst *dst, |
639 | const struct sk_buff *skb, unsigned int protoff) |
640 | { |
641 | __be16 _ports[2], *ports; |
642 | u8 nexthdr; |
643 | int poff; |
644 | |
645 | memset(dst, 0, sizeof(*dst)); |
646 | |
647 | switch (hinfo->family) { |
648 | case NFPROTO_IPV4: |
649 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP) |
650 | dst->ip.dst = maskl(a: ip_hdr(skb)->daddr, |
651 | l: hinfo->cfg.dstmask); |
652 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP) |
653 | dst->ip.src = maskl(a: ip_hdr(skb)->saddr, |
654 | l: hinfo->cfg.srcmask); |
655 | |
656 | if (!(hinfo->cfg.mode & |
657 | (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT))) |
658 | return 0; |
659 | nexthdr = ip_hdr(skb)->protocol; |
660 | break; |
661 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
662 | case NFPROTO_IPV6: |
663 | { |
664 | __be16 frag_off; |
665 | |
666 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP) { |
667 | memcpy(&dst->ip6.dst, &ipv6_hdr(skb)->daddr, |
668 | sizeof(dst->ip6.dst)); |
669 | hashlimit_ipv6_mask(i: dst->ip6.dst, p: hinfo->cfg.dstmask); |
670 | } |
671 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP) { |
672 | memcpy(&dst->ip6.src, &ipv6_hdr(skb)->saddr, |
673 | sizeof(dst->ip6.src)); |
674 | hashlimit_ipv6_mask(i: dst->ip6.src, p: hinfo->cfg.srcmask); |
675 | } |
676 | |
677 | if (!(hinfo->cfg.mode & |
678 | (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT))) |
679 | return 0; |
680 | nexthdr = ipv6_hdr(skb)->nexthdr; |
681 | protoff = ipv6_skip_exthdr(skb, start: sizeof(struct ipv6hdr), nexthdrp: &nexthdr, frag_offp: &frag_off); |
682 | if ((int)protoff < 0) |
683 | return -1; |
684 | break; |
685 | } |
686 | #endif |
687 | default: |
688 | BUG(); |
689 | return 0; |
690 | } |
691 | |
692 | poff = proto_ports_offset(proto: nexthdr); |
693 | if (poff >= 0) { |
694 | ports = skb_header_pointer(skb, offset: protoff + poff, len: sizeof(_ports), |
695 | buffer: &_ports); |
696 | } else { |
697 | _ports[0] = _ports[1] = 0; |
698 | ports = _ports; |
699 | } |
700 | if (!ports) |
701 | return -1; |
702 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SPT) |
703 | dst->src_port = ports[0]; |
704 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DPT) |
705 | dst->dst_port = ports[1]; |
706 | return 0; |
707 | } |
708 | |
709 | static u32 hashlimit_byte_cost(unsigned int len, struct dsthash_ent *dh) |
710 | { |
711 | u64 tmp = xt_hashlimit_len_to_chunks(len); |
712 | tmp = tmp * dh->rateinfo.cost; |
713 | |
714 | if (unlikely(tmp > CREDITS_PER_JIFFY_BYTES * HZ)) |
715 | tmp = CREDITS_PER_JIFFY_BYTES * HZ; |
716 | |
717 | if (dh->rateinfo.credit < tmp && dh->rateinfo.credit_cap) { |
718 | dh->rateinfo.credit_cap--; |
719 | dh->rateinfo.credit = CREDITS_PER_JIFFY_BYTES * HZ; |
720 | } |
721 | return (u32) tmp; |
722 | } |
723 | |
724 | static bool |
725 | hashlimit_mt_common(const struct sk_buff *skb, struct xt_action_param *par, |
726 | struct xt_hashlimit_htable *hinfo, |
727 | const struct hashlimit_cfg3 *cfg, int revision) |
728 | { |
729 | unsigned long now = jiffies; |
730 | struct dsthash_ent *dh; |
731 | struct dsthash_dst dst; |
732 | bool race = false; |
733 | u64 cost; |
734 | |
735 | if (hashlimit_init_dst(hinfo, dst: &dst, skb, protoff: par->thoff) < 0) |
736 | goto hotdrop; |
737 | |
738 | local_bh_disable(); |
739 | dh = dsthash_find(ht: hinfo, dst: &dst); |
740 | if (dh == NULL) { |
741 | dh = dsthash_alloc_init(ht: hinfo, dst: &dst, race: &race); |
742 | if (dh == NULL) { |
743 | local_bh_enable(); |
744 | goto hotdrop; |
745 | } else if (race) { |
746 | /* Already got an entry, update expiration timeout */ |
747 | dh->expires = now + msecs_to_jiffies(m: hinfo->cfg.expire); |
748 | rateinfo_recalc(dh, now, mode: hinfo->cfg.mode, revision); |
749 | } else { |
750 | dh->expires = jiffies + msecs_to_jiffies(m: hinfo->cfg.expire); |
751 | rateinfo_init(dh, hinfo, revision); |
752 | } |
753 | } else { |
754 | /* update expiration timeout */ |
755 | dh->expires = now + msecs_to_jiffies(m: hinfo->cfg.expire); |
756 | rateinfo_recalc(dh, now, mode: hinfo->cfg.mode, revision); |
757 | } |
758 | |
759 | if (cfg->mode & XT_HASHLIMIT_RATE_MATCH) { |
760 | cost = (cfg->mode & XT_HASHLIMIT_BYTES) ? skb->len : 1; |
761 | dh->rateinfo.current_rate += cost; |
762 | |
763 | if (!dh->rateinfo.prev_window && |
764 | (dh->rateinfo.current_rate <= dh->rateinfo.burst)) { |
765 | spin_unlock(lock: &dh->lock); |
766 | local_bh_enable(); |
767 | return !(cfg->mode & XT_HASHLIMIT_INVERT); |
768 | } else { |
769 | goto overlimit; |
770 | } |
771 | } |
772 | |
773 | if (cfg->mode & XT_HASHLIMIT_BYTES) |
774 | cost = hashlimit_byte_cost(len: skb->len, dh); |
775 | else |
776 | cost = dh->rateinfo.cost; |
777 | |
778 | if (dh->rateinfo.credit >= cost) { |
779 | /* below the limit */ |
780 | dh->rateinfo.credit -= cost; |
781 | spin_unlock(lock: &dh->lock); |
782 | local_bh_enable(); |
783 | return !(cfg->mode & XT_HASHLIMIT_INVERT); |
784 | } |
785 | |
786 | overlimit: |
787 | spin_unlock(lock: &dh->lock); |
788 | local_bh_enable(); |
789 | /* default match is underlimit - so over the limit, we need to invert */ |
790 | return cfg->mode & XT_HASHLIMIT_INVERT; |
791 | |
792 | hotdrop: |
793 | par->hotdrop = true; |
794 | return false; |
795 | } |
796 | |
797 | static bool |
798 | hashlimit_mt_v1(const struct sk_buff *skb, struct xt_action_param *par) |
799 | { |
800 | const struct xt_hashlimit_mtinfo1 *info = par->matchinfo; |
801 | struct xt_hashlimit_htable *hinfo = info->hinfo; |
802 | struct hashlimit_cfg3 cfg = {}; |
803 | int ret; |
804 | |
805 | ret = cfg_copy(to: &cfg, from: (void *)&info->cfg, revision: 1); |
806 | if (ret) |
807 | return ret; |
808 | |
809 | return hashlimit_mt_common(skb, par, hinfo, cfg: &cfg, revision: 1); |
810 | } |
811 | |
812 | static bool |
813 | hashlimit_mt_v2(const struct sk_buff *skb, struct xt_action_param *par) |
814 | { |
815 | const struct xt_hashlimit_mtinfo2 *info = par->matchinfo; |
816 | struct xt_hashlimit_htable *hinfo = info->hinfo; |
817 | struct hashlimit_cfg3 cfg = {}; |
818 | int ret; |
819 | |
820 | ret = cfg_copy(to: &cfg, from: (void *)&info->cfg, revision: 2); |
821 | if (ret) |
822 | return ret; |
823 | |
824 | return hashlimit_mt_common(skb, par, hinfo, cfg: &cfg, revision: 2); |
825 | } |
826 | |
827 | static bool |
828 | hashlimit_mt(const struct sk_buff *skb, struct xt_action_param *par) |
829 | { |
830 | const struct xt_hashlimit_mtinfo3 *info = par->matchinfo; |
831 | struct xt_hashlimit_htable *hinfo = info->hinfo; |
832 | |
833 | return hashlimit_mt_common(skb, par, hinfo, cfg: &info->cfg, revision: 3); |
834 | } |
835 | |
836 | #define HASHLIMIT_MAX_SIZE 1048576 |
837 | |
838 | static int hashlimit_mt_check_common(const struct xt_mtchk_param *par, |
839 | struct xt_hashlimit_htable **hinfo, |
840 | struct hashlimit_cfg3 *cfg, |
841 | const char *name, int revision) |
842 | { |
843 | struct net *net = par->net; |
844 | int ret; |
845 | |
846 | if (cfg->gc_interval == 0 || cfg->expire == 0) |
847 | return -EINVAL; |
848 | if (cfg->size > HASHLIMIT_MAX_SIZE) { |
849 | cfg->size = HASHLIMIT_MAX_SIZE; |
850 | pr_info_ratelimited("size too large, truncated to %u\n" , cfg->size); |
851 | } |
852 | if (cfg->max > HASHLIMIT_MAX_SIZE) { |
853 | cfg->max = HASHLIMIT_MAX_SIZE; |
854 | pr_info_ratelimited("max too large, truncated to %u\n" , cfg->max); |
855 | } |
856 | if (par->family == NFPROTO_IPV4) { |
857 | if (cfg->srcmask > 32 || cfg->dstmask > 32) |
858 | return -EINVAL; |
859 | } else { |
860 | if (cfg->srcmask > 128 || cfg->dstmask > 128) |
861 | return -EINVAL; |
862 | } |
863 | |
864 | if (cfg->mode & ~XT_HASHLIMIT_ALL) { |
865 | pr_info_ratelimited("Unknown mode mask %X, kernel too old?\n" , |
866 | cfg->mode); |
867 | return -EINVAL; |
868 | } |
869 | |
870 | /* Check for overflow. */ |
871 | if (revision >= 3 && cfg->mode & XT_HASHLIMIT_RATE_MATCH) { |
872 | if (cfg->avg == 0 || cfg->avg > U32_MAX) { |
873 | pr_info_ratelimited("invalid rate\n" ); |
874 | return -ERANGE; |
875 | } |
876 | |
877 | if (cfg->interval == 0) { |
878 | pr_info_ratelimited("invalid interval\n" ); |
879 | return -EINVAL; |
880 | } |
881 | } else if (cfg->mode & XT_HASHLIMIT_BYTES) { |
882 | if (user2credits_byte(user: cfg->avg) == 0) { |
883 | pr_info_ratelimited("overflow, rate too high: %llu\n" , |
884 | cfg->avg); |
885 | return -EINVAL; |
886 | } |
887 | } else if (cfg->burst == 0 || |
888 | user2credits(user: cfg->avg * cfg->burst, revision) < |
889 | user2credits(user: cfg->avg, revision)) { |
890 | pr_info_ratelimited("overflow, try lower: %llu/%llu\n" , |
891 | cfg->avg, cfg->burst); |
892 | return -ERANGE; |
893 | } |
894 | |
895 | mutex_lock(&hashlimit_mutex); |
896 | *hinfo = htable_find_get(net, name, family: par->family); |
897 | if (*hinfo == NULL) { |
898 | ret = htable_create(net, cfg, name, family: par->family, |
899 | out_hinfo: hinfo, revision); |
900 | if (ret < 0) { |
901 | mutex_unlock(lock: &hashlimit_mutex); |
902 | return ret; |
903 | } |
904 | } |
905 | mutex_unlock(lock: &hashlimit_mutex); |
906 | |
907 | return 0; |
908 | } |
909 | |
910 | static int hashlimit_mt_check_v1(const struct xt_mtchk_param *par) |
911 | { |
912 | struct xt_hashlimit_mtinfo1 *info = par->matchinfo; |
913 | struct hashlimit_cfg3 cfg = {}; |
914 | int ret; |
915 | |
916 | ret = xt_check_proc_name(name: info->name, size: sizeof(info->name)); |
917 | if (ret) |
918 | return ret; |
919 | |
920 | ret = cfg_copy(to: &cfg, from: (void *)&info->cfg, revision: 1); |
921 | if (ret) |
922 | return ret; |
923 | |
924 | return hashlimit_mt_check_common(par, hinfo: &info->hinfo, |
925 | cfg: &cfg, name: info->name, revision: 1); |
926 | } |
927 | |
928 | static int hashlimit_mt_check_v2(const struct xt_mtchk_param *par) |
929 | { |
930 | struct xt_hashlimit_mtinfo2 *info = par->matchinfo; |
931 | struct hashlimit_cfg3 cfg = {}; |
932 | int ret; |
933 | |
934 | ret = xt_check_proc_name(name: info->name, size: sizeof(info->name)); |
935 | if (ret) |
936 | return ret; |
937 | |
938 | ret = cfg_copy(to: &cfg, from: (void *)&info->cfg, revision: 2); |
939 | if (ret) |
940 | return ret; |
941 | |
942 | return hashlimit_mt_check_common(par, hinfo: &info->hinfo, |
943 | cfg: &cfg, name: info->name, revision: 2); |
944 | } |
945 | |
946 | static int hashlimit_mt_check(const struct xt_mtchk_param *par) |
947 | { |
948 | struct xt_hashlimit_mtinfo3 *info = par->matchinfo; |
949 | int ret; |
950 | |
951 | ret = xt_check_proc_name(name: info->name, size: sizeof(info->name)); |
952 | if (ret) |
953 | return ret; |
954 | |
955 | return hashlimit_mt_check_common(par, hinfo: &info->hinfo, cfg: &info->cfg, |
956 | name: info->name, revision: 3); |
957 | } |
958 | |
959 | static void hashlimit_mt_destroy_v2(const struct xt_mtdtor_param *par) |
960 | { |
961 | const struct xt_hashlimit_mtinfo2 *info = par->matchinfo; |
962 | |
963 | htable_put(hinfo: info->hinfo); |
964 | } |
965 | |
966 | static void hashlimit_mt_destroy_v1(const struct xt_mtdtor_param *par) |
967 | { |
968 | const struct xt_hashlimit_mtinfo1 *info = par->matchinfo; |
969 | |
970 | htable_put(hinfo: info->hinfo); |
971 | } |
972 | |
973 | static void hashlimit_mt_destroy(const struct xt_mtdtor_param *par) |
974 | { |
975 | const struct xt_hashlimit_mtinfo3 *info = par->matchinfo; |
976 | |
977 | htable_put(hinfo: info->hinfo); |
978 | } |
979 | |
980 | static struct xt_match hashlimit_mt_reg[] __read_mostly = { |
981 | { |
982 | .name = "hashlimit" , |
983 | .revision = 1, |
984 | .family = NFPROTO_IPV4, |
985 | .match = hashlimit_mt_v1, |
986 | .matchsize = sizeof(struct xt_hashlimit_mtinfo1), |
987 | .usersize = offsetof(struct xt_hashlimit_mtinfo1, hinfo), |
988 | .checkentry = hashlimit_mt_check_v1, |
989 | .destroy = hashlimit_mt_destroy_v1, |
990 | .me = THIS_MODULE, |
991 | }, |
992 | { |
993 | .name = "hashlimit" , |
994 | .revision = 2, |
995 | .family = NFPROTO_IPV4, |
996 | .match = hashlimit_mt_v2, |
997 | .matchsize = sizeof(struct xt_hashlimit_mtinfo2), |
998 | .usersize = offsetof(struct xt_hashlimit_mtinfo2, hinfo), |
999 | .checkentry = hashlimit_mt_check_v2, |
1000 | .destroy = hashlimit_mt_destroy_v2, |
1001 | .me = THIS_MODULE, |
1002 | }, |
1003 | { |
1004 | .name = "hashlimit" , |
1005 | .revision = 3, |
1006 | .family = NFPROTO_IPV4, |
1007 | .match = hashlimit_mt, |
1008 | .matchsize = sizeof(struct xt_hashlimit_mtinfo3), |
1009 | .usersize = offsetof(struct xt_hashlimit_mtinfo3, hinfo), |
1010 | .checkentry = hashlimit_mt_check, |
1011 | .destroy = hashlimit_mt_destroy, |
1012 | .me = THIS_MODULE, |
1013 | }, |
1014 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
1015 | { |
1016 | .name = "hashlimit" , |
1017 | .revision = 1, |
1018 | .family = NFPROTO_IPV6, |
1019 | .match = hashlimit_mt_v1, |
1020 | .matchsize = sizeof(struct xt_hashlimit_mtinfo1), |
1021 | .usersize = offsetof(struct xt_hashlimit_mtinfo1, hinfo), |
1022 | .checkentry = hashlimit_mt_check_v1, |
1023 | .destroy = hashlimit_mt_destroy_v1, |
1024 | .me = THIS_MODULE, |
1025 | }, |
1026 | { |
1027 | .name = "hashlimit" , |
1028 | .revision = 2, |
1029 | .family = NFPROTO_IPV6, |
1030 | .match = hashlimit_mt_v2, |
1031 | .matchsize = sizeof(struct xt_hashlimit_mtinfo2), |
1032 | .usersize = offsetof(struct xt_hashlimit_mtinfo2, hinfo), |
1033 | .checkentry = hashlimit_mt_check_v2, |
1034 | .destroy = hashlimit_mt_destroy_v2, |
1035 | .me = THIS_MODULE, |
1036 | }, |
1037 | { |
1038 | .name = "hashlimit" , |
1039 | .revision = 3, |
1040 | .family = NFPROTO_IPV6, |
1041 | .match = hashlimit_mt, |
1042 | .matchsize = sizeof(struct xt_hashlimit_mtinfo3), |
1043 | .usersize = offsetof(struct xt_hashlimit_mtinfo3, hinfo), |
1044 | .checkentry = hashlimit_mt_check, |
1045 | .destroy = hashlimit_mt_destroy, |
1046 | .me = THIS_MODULE, |
1047 | }, |
1048 | #endif |
1049 | }; |
1050 | |
1051 | /* PROC stuff */ |
1052 | static void *dl_seq_start(struct seq_file *s, loff_t *pos) |
1053 | __acquires(htable->lock) |
1054 | { |
1055 | struct xt_hashlimit_htable *htable = pde_data(inode: file_inode(f: s->file)); |
1056 | unsigned int *bucket; |
1057 | |
1058 | spin_lock_bh(lock: &htable->lock); |
1059 | if (*pos >= htable->cfg.size) |
1060 | return NULL; |
1061 | |
1062 | bucket = kmalloc(size: sizeof(unsigned int), GFP_ATOMIC); |
1063 | if (!bucket) |
1064 | return ERR_PTR(error: -ENOMEM); |
1065 | |
1066 | *bucket = *pos; |
1067 | return bucket; |
1068 | } |
1069 | |
1070 | static void *dl_seq_next(struct seq_file *s, void *v, loff_t *pos) |
1071 | { |
1072 | struct xt_hashlimit_htable *htable = pde_data(inode: file_inode(f: s->file)); |
1073 | unsigned int *bucket = v; |
1074 | |
1075 | *pos = ++(*bucket); |
1076 | if (*pos >= htable->cfg.size) { |
1077 | kfree(objp: v); |
1078 | return NULL; |
1079 | } |
1080 | return bucket; |
1081 | } |
1082 | |
1083 | static void dl_seq_stop(struct seq_file *s, void *v) |
1084 | __releases(htable->lock) |
1085 | { |
1086 | struct xt_hashlimit_htable *htable = pde_data(inode: file_inode(f: s->file)); |
1087 | unsigned int *bucket = v; |
1088 | |
1089 | if (!IS_ERR(ptr: bucket)) |
1090 | kfree(objp: bucket); |
1091 | spin_unlock_bh(lock: &htable->lock); |
1092 | } |
1093 | |
1094 | static void dl_seq_print(struct dsthash_ent *ent, u_int8_t family, |
1095 | struct seq_file *s) |
1096 | { |
1097 | switch (family) { |
1098 | case NFPROTO_IPV4: |
1099 | seq_printf(m: s, fmt: "%ld %pI4:%u->%pI4:%u %llu %llu %llu\n" , |
1100 | (long)(ent->expires - jiffies)/HZ, |
1101 | &ent->dst.ip.src, |
1102 | ntohs(ent->dst.src_port), |
1103 | &ent->dst.ip.dst, |
1104 | ntohs(ent->dst.dst_port), |
1105 | ent->rateinfo.credit, ent->rateinfo.credit_cap, |
1106 | ent->rateinfo.cost); |
1107 | break; |
1108 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
1109 | case NFPROTO_IPV6: |
1110 | seq_printf(m: s, fmt: "%ld %pI6:%u->%pI6:%u %llu %llu %llu\n" , |
1111 | (long)(ent->expires - jiffies)/HZ, |
1112 | &ent->dst.ip6.src, |
1113 | ntohs(ent->dst.src_port), |
1114 | &ent->dst.ip6.dst, |
1115 | ntohs(ent->dst.dst_port), |
1116 | ent->rateinfo.credit, ent->rateinfo.credit_cap, |
1117 | ent->rateinfo.cost); |
1118 | break; |
1119 | #endif |
1120 | default: |
1121 | BUG(); |
1122 | } |
1123 | } |
1124 | |
1125 | static int dl_seq_real_show_v2(struct dsthash_ent *ent, u_int8_t family, |
1126 | struct seq_file *s) |
1127 | { |
1128 | struct xt_hashlimit_htable *ht = pde_data(inode: file_inode(f: s->file)); |
1129 | |
1130 | spin_lock(lock: &ent->lock); |
1131 | /* recalculate to show accurate numbers */ |
1132 | rateinfo_recalc(dh: ent, now: jiffies, mode: ht->cfg.mode, revision: 2); |
1133 | |
1134 | dl_seq_print(ent, family, s); |
1135 | |
1136 | spin_unlock(lock: &ent->lock); |
1137 | return seq_has_overflowed(m: s); |
1138 | } |
1139 | |
1140 | static int dl_seq_real_show_v1(struct dsthash_ent *ent, u_int8_t family, |
1141 | struct seq_file *s) |
1142 | { |
1143 | struct xt_hashlimit_htable *ht = pde_data(inode: file_inode(f: s->file)); |
1144 | |
1145 | spin_lock(lock: &ent->lock); |
1146 | /* recalculate to show accurate numbers */ |
1147 | rateinfo_recalc(dh: ent, now: jiffies, mode: ht->cfg.mode, revision: 1); |
1148 | |
1149 | dl_seq_print(ent, family, s); |
1150 | |
1151 | spin_unlock(lock: &ent->lock); |
1152 | return seq_has_overflowed(m: s); |
1153 | } |
1154 | |
1155 | static int dl_seq_real_show(struct dsthash_ent *ent, u_int8_t family, |
1156 | struct seq_file *s) |
1157 | { |
1158 | struct xt_hashlimit_htable *ht = pde_data(inode: file_inode(f: s->file)); |
1159 | |
1160 | spin_lock(lock: &ent->lock); |
1161 | /* recalculate to show accurate numbers */ |
1162 | rateinfo_recalc(dh: ent, now: jiffies, mode: ht->cfg.mode, revision: 3); |
1163 | |
1164 | dl_seq_print(ent, family, s); |
1165 | |
1166 | spin_unlock(lock: &ent->lock); |
1167 | return seq_has_overflowed(m: s); |
1168 | } |
1169 | |
1170 | static int dl_seq_show_v2(struct seq_file *s, void *v) |
1171 | { |
1172 | struct xt_hashlimit_htable *htable = pde_data(inode: file_inode(f: s->file)); |
1173 | unsigned int *bucket = (unsigned int *)v; |
1174 | struct dsthash_ent *ent; |
1175 | |
1176 | if (!hlist_empty(h: &htable->hash[*bucket])) { |
1177 | hlist_for_each_entry(ent, &htable->hash[*bucket], node) |
1178 | if (dl_seq_real_show_v2(ent, family: htable->family, s)) |
1179 | return -1; |
1180 | } |
1181 | return 0; |
1182 | } |
1183 | |
1184 | static int dl_seq_show_v1(struct seq_file *s, void *v) |
1185 | { |
1186 | struct xt_hashlimit_htable *htable = pde_data(inode: file_inode(f: s->file)); |
1187 | unsigned int *bucket = v; |
1188 | struct dsthash_ent *ent; |
1189 | |
1190 | if (!hlist_empty(h: &htable->hash[*bucket])) { |
1191 | hlist_for_each_entry(ent, &htable->hash[*bucket], node) |
1192 | if (dl_seq_real_show_v1(ent, family: htable->family, s)) |
1193 | return -1; |
1194 | } |
1195 | return 0; |
1196 | } |
1197 | |
1198 | static int dl_seq_show(struct seq_file *s, void *v) |
1199 | { |
1200 | struct xt_hashlimit_htable *htable = pde_data(inode: file_inode(f: s->file)); |
1201 | unsigned int *bucket = v; |
1202 | struct dsthash_ent *ent; |
1203 | |
1204 | if (!hlist_empty(h: &htable->hash[*bucket])) { |
1205 | hlist_for_each_entry(ent, &htable->hash[*bucket], node) |
1206 | if (dl_seq_real_show(ent, family: htable->family, s)) |
1207 | return -1; |
1208 | } |
1209 | return 0; |
1210 | } |
1211 | |
1212 | static const struct seq_operations dl_seq_ops_v1 = { |
1213 | .start = dl_seq_start, |
1214 | .next = dl_seq_next, |
1215 | .stop = dl_seq_stop, |
1216 | .show = dl_seq_show_v1 |
1217 | }; |
1218 | |
1219 | static const struct seq_operations dl_seq_ops_v2 = { |
1220 | .start = dl_seq_start, |
1221 | .next = dl_seq_next, |
1222 | .stop = dl_seq_stop, |
1223 | .show = dl_seq_show_v2 |
1224 | }; |
1225 | |
1226 | static const struct seq_operations dl_seq_ops = { |
1227 | .start = dl_seq_start, |
1228 | .next = dl_seq_next, |
1229 | .stop = dl_seq_stop, |
1230 | .show = dl_seq_show |
1231 | }; |
1232 | |
1233 | static int __net_init hashlimit_proc_net_init(struct net *net) |
1234 | { |
1235 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); |
1236 | |
1237 | hashlimit_net->ipt_hashlimit = proc_mkdir("ipt_hashlimit" , net->proc_net); |
1238 | if (!hashlimit_net->ipt_hashlimit) |
1239 | return -ENOMEM; |
1240 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
1241 | hashlimit_net->ip6t_hashlimit = proc_mkdir("ip6t_hashlimit" , net->proc_net); |
1242 | if (!hashlimit_net->ip6t_hashlimit) { |
1243 | remove_proc_entry("ipt_hashlimit" , net->proc_net); |
1244 | return -ENOMEM; |
1245 | } |
1246 | #endif |
1247 | return 0; |
1248 | } |
1249 | |
1250 | static void __net_exit hashlimit_proc_net_exit(struct net *net) |
1251 | { |
1252 | struct xt_hashlimit_htable *hinfo; |
1253 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); |
1254 | |
1255 | /* hashlimit_net_exit() is called before hashlimit_mt_destroy(). |
1256 | * Make sure that the parent ipt_hashlimit and ip6t_hashlimit proc |
1257 | * entries is empty before trying to remove it. |
1258 | */ |
1259 | mutex_lock(&hashlimit_mutex); |
1260 | hlist_for_each_entry(hinfo, &hashlimit_net->htables, node) |
1261 | htable_remove_proc_entry(hinfo); |
1262 | hashlimit_net->ipt_hashlimit = NULL; |
1263 | hashlimit_net->ip6t_hashlimit = NULL; |
1264 | mutex_unlock(lock: &hashlimit_mutex); |
1265 | |
1266 | remove_proc_entry("ipt_hashlimit" , net->proc_net); |
1267 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
1268 | remove_proc_entry("ip6t_hashlimit" , net->proc_net); |
1269 | #endif |
1270 | } |
1271 | |
1272 | static int __net_init hashlimit_net_init(struct net *net) |
1273 | { |
1274 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); |
1275 | |
1276 | INIT_HLIST_HEAD(&hashlimit_net->htables); |
1277 | return hashlimit_proc_net_init(net); |
1278 | } |
1279 | |
1280 | static void __net_exit hashlimit_net_exit(struct net *net) |
1281 | { |
1282 | hashlimit_proc_net_exit(net); |
1283 | } |
1284 | |
1285 | static struct pernet_operations hashlimit_net_ops = { |
1286 | .init = hashlimit_net_init, |
1287 | .exit = hashlimit_net_exit, |
1288 | .id = &hashlimit_net_id, |
1289 | .size = sizeof(struct hashlimit_net), |
1290 | }; |
1291 | |
1292 | static int __init hashlimit_mt_init(void) |
1293 | { |
1294 | int err; |
1295 | |
1296 | err = register_pernet_subsys(&hashlimit_net_ops); |
1297 | if (err < 0) |
1298 | return err; |
1299 | err = xt_register_matches(match: hashlimit_mt_reg, |
1300 | ARRAY_SIZE(hashlimit_mt_reg)); |
1301 | if (err < 0) |
1302 | goto err1; |
1303 | |
1304 | err = -ENOMEM; |
1305 | hashlimit_cachep = kmem_cache_create(name: "xt_hashlimit" , |
1306 | size: sizeof(struct dsthash_ent), align: 0, flags: 0, |
1307 | NULL); |
1308 | if (!hashlimit_cachep) { |
1309 | pr_warn("unable to create slab cache\n" ); |
1310 | goto err2; |
1311 | } |
1312 | return 0; |
1313 | |
1314 | err2: |
1315 | xt_unregister_matches(match: hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg)); |
1316 | err1: |
1317 | unregister_pernet_subsys(&hashlimit_net_ops); |
1318 | return err; |
1319 | |
1320 | } |
1321 | |
1322 | static void __exit hashlimit_mt_exit(void) |
1323 | { |
1324 | xt_unregister_matches(match: hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg)); |
1325 | unregister_pernet_subsys(&hashlimit_net_ops); |
1326 | |
1327 | rcu_barrier(); |
1328 | kmem_cache_destroy(s: hashlimit_cachep); |
1329 | } |
1330 | |
1331 | module_init(hashlimit_mt_init); |
1332 | module_exit(hashlimit_mt_exit); |
1333 | |