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x86: add PAGE_KERNEL_EXEC_NOCACHE
[wrt350n-kernel.git] / net / netfilter / xt_hashlimit.c
blobd479ca980115af614e25ef411917d7f83c4e4044
1 /* iptables match extension to limit the number of packets per second
2 * seperately for each hashbucket (sourceip/sourceport/dstip/dstport)
3 *
4 * (C) 2003-2004 by Harald Welte <laforge@netfilter.org>
5 *
6 * $Id: ipt_hashlimit.c 3244 2004-10-20 16:24:29Z laforge@netfilter.org $
7 *
8 * Development of this code was funded by Astaro AG, http://www.astaro.com/
9 */
10 #include <linux/module.h>
11 #include <linux/spinlock.h>
12 #include <linux/random.h>
13 #include <linux/jhash.h>
14 #include <linux/slab.h>
15 #include <linux/vmalloc.h>
16 #include <linux/proc_fs.h>
17 #include <linux/seq_file.h>
18 #include <linux/list.h>
19 #include <linux/skbuff.h>
20 #include <linux/mm.h>
21 #include <linux/in.h>
22 #include <linux/ip.h>
23 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
24 #include <linux/ipv6.h>
25 #include <net/ipv6.h>
26 #endif
27
28 #include <net/net_namespace.h>
29
30 #include <linux/netfilter/x_tables.h>
31 #include <linux/netfilter_ipv4/ip_tables.h>
32 #include <linux/netfilter_ipv6/ip6_tables.h>
33 #include <linux/netfilter/xt_hashlimit.h>
34 #include <linux/mutex.h>
35
36 MODULE_LICENSE("GPL");
37 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
38 MODULE_DESCRIPTION("Xtables: per hash-bucket rate-limit match");
39 MODULE_ALIAS("ipt_hashlimit");
40 MODULE_ALIAS("ip6t_hashlimit");
41
42 /* need to declare this at the top */
43 static struct proc_dir_entry *hashlimit_procdir4;
44 static struct proc_dir_entry *hashlimit_procdir6;
45 static const struct file_operations dl_file_ops;
46
47 /* hash table crap */
48 struct dsthash_dst {
49 union {
50 struct {
51 __be32 src;
52 __be32 dst;
53 } ip;
54 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
55 struct {
56 __be32 src[4];
57 __be32 dst[4];
58 } ip6;
59 #endif
60 } addr;
61 __be16 src_port;
62 __be16 dst_port;
63 };
64
65 struct dsthash_ent {
66 /* static / read-only parts in the beginning */
67 struct hlist_node node;
68 struct dsthash_dst dst;
69
70 /* modified structure members in the end */
71 unsigned long expires; /* precalculated expiry time */
72 struct {
73 unsigned long prev; /* last modification */
74 u_int32_t credit;
75 u_int32_t credit_cap, cost;
76 } rateinfo;
77 };
78
79 struct xt_hashlimit_htable {
80 struct hlist_node node; /* global list of all htables */
81 atomic_t use;
82 int family;
83
84 struct hashlimit_cfg cfg; /* config */
85
86 /* used internally */
87 spinlock_t lock; /* lock for list_head */
88 u_int32_t rnd; /* random seed for hash */
89 int rnd_initialized;
90 unsigned int count; /* number entries in table */
91 struct timer_list timer; /* timer for gc */
92
93 /* seq_file stuff */
94 struct proc_dir_entry *pde;
95
96 struct hlist_head hash[0]; /* hashtable itself */
97 };
98
99 static DEFINE_SPINLOCK(hashlimit_lock); /* protects htables list */
100 static DEFINE_MUTEX(hlimit_mutex); /* additional checkentry protection */
101 static HLIST_HEAD(hashlimit_htables);
102 static struct kmem_cache *hashlimit_cachep __read_mostly;
103
104 static inline bool dst_cmp(const struct dsthash_ent *ent,
105 const struct dsthash_dst *b)
106 {
107 return !memcmp(&ent->dst, b, sizeof(ent->dst));
108 }
109
110 static u_int32_t
111 hash_dst(const struct xt_hashlimit_htable *ht, const struct dsthash_dst *dst)
112 {
113 u_int32_t hash = jhash2((const u32 *)dst,
114 sizeof(*dst)/sizeof(u32),
115 ht->rnd);
116 /*
117 * Instead of returning hash % ht->cfg.size (implying a divide)
118 * we return the high 32 bits of the (hash * ht->cfg.size) that will
119 * give results between [0 and cfg.size-1] and same hash distribution,
120 * but using a multiply, less expensive than a divide
121 */
122 return ((u64)hash * ht->cfg.size) >> 32;
123 }
124
125 static struct dsthash_ent *
126 dsthash_find(const struct xt_hashlimit_htable *ht,
127 const struct dsthash_dst *dst)
128 {
129 struct dsthash_ent *ent;
130 struct hlist_node *pos;
131 u_int32_t hash = hash_dst(ht, dst);
132
133 if (!hlist_empty(&ht->hash[hash])) {
134 hlist_for_each_entry(ent, pos, &ht->hash[hash], node)
135 if (dst_cmp(ent, dst))
136 return ent;
137 }
138 return NULL;
139 }
140
141 /* allocate dsthash_ent, initialize dst, put in htable and lock it */
142 static struct dsthash_ent *
143 dsthash_alloc_init(struct xt_hashlimit_htable *ht,
144 const struct dsthash_dst *dst)
145 {
146 struct dsthash_ent *ent;
147
148 /* initialize hash with random val at the time we allocate
149 * the first hashtable entry */
150 if (!ht->rnd_initialized) {
151 get_random_bytes(&ht->rnd, 4);
152 ht->rnd_initialized = 1;
153 }
154
155 if (ht->cfg.max && ht->count >= ht->cfg.max) {
156 /* FIXME: do something. question is what.. */
157 if (net_ratelimit())
158 printk(KERN_WARNING
159 "xt_hashlimit: max count of %u reached\n",
160 ht->cfg.max);
161 return NULL;
162 }
163
164 ent = kmem_cache_alloc(hashlimit_cachep, GFP_ATOMIC);
165 if (!ent) {
166 if (net_ratelimit())
167 printk(KERN_ERR
168 "xt_hashlimit: can't allocate dsthash_ent\n");
169 return NULL;
170 }
171 memcpy(&ent->dst, dst, sizeof(ent->dst));
172
173 hlist_add_head(&ent->node, &ht->hash[hash_dst(ht, dst)]);
174 ht->count++;
175 return ent;
176 }
177
178 static inline void
179 dsthash_free(struct xt_hashlimit_htable *ht, struct dsthash_ent *ent)
180 {
181 hlist_del(&ent->node);
182 kmem_cache_free(hashlimit_cachep, ent);
183 ht->count--;
184 }
185 static void htable_gc(unsigned long htlong);
186
187 static int htable_create(struct xt_hashlimit_info *minfo, int family)
188 {
189 struct xt_hashlimit_htable *hinfo;
190 unsigned int size;
191 unsigned int i;
192
193 if (minfo->cfg.size)
194 size = minfo->cfg.size;
195 else {
196 size = ((num_physpages << PAGE_SHIFT) / 16384) /
197 sizeof(struct list_head);
198 if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE))
199 size = 8192;
200 if (size < 16)
201 size = 16;
202 }
203 /* FIXME: don't use vmalloc() here or anywhere else -HW */
204 hinfo = vmalloc(sizeof(struct xt_hashlimit_htable) +
205 sizeof(struct list_head) * size);
206 if (!hinfo) {
207 printk(KERN_ERR "xt_hashlimit: unable to create hashtable\n");
208 return -1;
209 }
210 minfo->hinfo = hinfo;
211
212 /* copy match config into hashtable config */
213 memcpy(&hinfo->cfg, &minfo->cfg, sizeof(hinfo->cfg));
214 hinfo->cfg.size = size;
215 if (!hinfo->cfg.max)
216 hinfo->cfg.max = 8 * hinfo->cfg.size;
217 else if (hinfo->cfg.max < hinfo->cfg.size)
218 hinfo->cfg.max = hinfo->cfg.size;
219
220 for (i = 0; i < hinfo->cfg.size; i++)
221 INIT_HLIST_HEAD(&hinfo->hash[i]);
222
223 atomic_set(&hinfo->use, 1);
224 hinfo->count = 0;
225 hinfo->family = family;
226 hinfo->rnd_initialized = 0;
227 spin_lock_init(&hinfo->lock);
228 hinfo->pde = create_proc_entry(minfo->name, 0,
229 family == AF_INET ? hashlimit_procdir4 :
230 hashlimit_procdir6);
231 if (!hinfo->pde) {
232 vfree(hinfo);
233 return -1;
234 }
235 hinfo->pde->proc_fops = &dl_file_ops;
236 hinfo->pde->data = hinfo;
237
238 setup_timer(&hinfo->timer, htable_gc, (unsigned long )hinfo);
239 hinfo->timer.expires = jiffies + msecs_to_jiffies(hinfo->cfg.gc_interval);
240 add_timer(&hinfo->timer);
241
242 spin_lock_bh(&hashlimit_lock);
243 hlist_add_head(&hinfo->node, &hashlimit_htables);
244 spin_unlock_bh(&hashlimit_lock);
245
246 return 0;
247 }
248
249 static bool select_all(const struct xt_hashlimit_htable *ht,
250 const struct dsthash_ent *he)
251 {
252 return 1;
253 }
254
255 static bool select_gc(const struct xt_hashlimit_htable *ht,
256 const struct dsthash_ent *he)
257 {
258 return time_after_eq(jiffies, he->expires);
259 }
260
261 static void htable_selective_cleanup(struct xt_hashlimit_htable *ht,
262 bool (*select)(const struct xt_hashlimit_htable *ht,
263 const struct dsthash_ent *he))
264 {
265 unsigned int i;
266
267 /* lock hash table and iterate over it */
268 spin_lock_bh(&ht->lock);
269 for (i = 0; i < ht->cfg.size; i++) {
270 struct dsthash_ent *dh;
271 struct hlist_node *pos, *n;
272 hlist_for_each_entry_safe(dh, pos, n, &ht->hash[i], node) {
273 if ((*select)(ht, dh))
274 dsthash_free(ht, dh);
275 }
276 }
277 spin_unlock_bh(&ht->lock);
278 }
279
280 /* hash table garbage collector, run by timer */
281 static void htable_gc(unsigned long htlong)
282 {
283 struct xt_hashlimit_htable *ht = (struct xt_hashlimit_htable *)htlong;
284
285 htable_selective_cleanup(ht, select_gc);
286
287 /* re-add the timer accordingly */
288 ht->timer.expires = jiffies + msecs_to_jiffies(ht->cfg.gc_interval);
289 add_timer(&ht->timer);
290 }
291
292 static void htable_destroy(struct xt_hashlimit_htable *hinfo)
293 {
294 /* remove timer, if it is pending */
295 if (timer_pending(&hinfo->timer))
296 del_timer(&hinfo->timer);
297
298 /* remove proc entry */
299 remove_proc_entry(hinfo->pde->name,
300 hinfo->family == AF_INET ? hashlimit_procdir4 :
301 hashlimit_procdir6);
302 htable_selective_cleanup(hinfo, select_all);
303 vfree(hinfo);
304 }
305
306 static struct xt_hashlimit_htable *htable_find_get(const char *name,
307 int family)
308 {
309 struct xt_hashlimit_htable *hinfo;
310 struct hlist_node *pos;
311
312 spin_lock_bh(&hashlimit_lock);
313 hlist_for_each_entry(hinfo, pos, &hashlimit_htables, node) {
314 if (!strcmp(name, hinfo->pde->name) &&
315 hinfo->family == family) {
316 atomic_inc(&hinfo->use);
317 spin_unlock_bh(&hashlimit_lock);
318 return hinfo;
319 }
320 }
321 spin_unlock_bh(&hashlimit_lock);
322 return NULL;
323 }
324
325 static void htable_put(struct xt_hashlimit_htable *hinfo)
326 {
327 if (atomic_dec_and_test(&hinfo->use)) {
328 spin_lock_bh(&hashlimit_lock);
329 hlist_del(&hinfo->node);
330 spin_unlock_bh(&hashlimit_lock);
331 htable_destroy(hinfo);
332 }
333 }
334
335 /* The algorithm used is the Simple Token Bucket Filter (TBF)
336 * see net/sched/sch_tbf.c in the linux source tree
337 */
338
339 /* Rusty: This is my (non-mathematically-inclined) understanding of
340 this algorithm. The `average rate' in jiffies becomes your initial
341 amount of credit `credit' and the most credit you can ever have
342 `credit_cap'. The `peak rate' becomes the cost of passing the
343 test, `cost'.
344
345 `prev' tracks the last packet hit: you gain one credit per jiffy.
346 If you get credit balance more than this, the extra credit is
347 discarded. Every time the match passes, you lose `cost' credits;
348 if you don't have that many, the test fails.
349
350 See Alexey's formal explanation in net/sched/sch_tbf.c.
351
352 To get the maximum range, we multiply by this factor (ie. you get N
353 credits per jiffy). We want to allow a rate as low as 1 per day
354 (slowest userspace tool allows), which means
355 CREDITS_PER_JIFFY*HZ*60*60*24 < 2^32 ie.
356 */
357 #define MAX_CPJ (0xFFFFFFFF / (HZ*60*60*24))
358
359 /* Repeated shift and or gives us all 1s, final shift and add 1 gives
360 * us the power of 2 below the theoretical max, so GCC simply does a
361 * shift. */
362 #define _POW2_BELOW2(x) ((x)|((x)>>1))
363 #define _POW2_BELOW4(x) (_POW2_BELOW2(x)|_POW2_BELOW2((x)>>2))
364 #define _POW2_BELOW8(x) (_POW2_BELOW4(x)|_POW2_BELOW4((x)>>4))
365 #define _POW2_BELOW16(x) (_POW2_BELOW8(x)|_POW2_BELOW8((x)>>8))
366 #define _POW2_BELOW32(x) (_POW2_BELOW16(x)|_POW2_BELOW16((x)>>16))
367 #define POW2_BELOW32(x) ((_POW2_BELOW32(x)>>1) + 1)
368
369 #define CREDITS_PER_JIFFY POW2_BELOW32(MAX_CPJ)
370
371 /* Precision saver. */
372 static inline u_int32_t
373 user2credits(u_int32_t user)
374 {
375 /* If multiplying would overflow... */
376 if (user > 0xFFFFFFFF / (HZ*CREDITS_PER_JIFFY))
377 /* Divide first. */
378 return (user / XT_HASHLIMIT_SCALE) * HZ * CREDITS_PER_JIFFY;
379
380 return (user * HZ * CREDITS_PER_JIFFY) / XT_HASHLIMIT_SCALE;
381 }
382
383 static inline void rateinfo_recalc(struct dsthash_ent *dh, unsigned long now)
384 {
385 dh->rateinfo.credit += (now - dh->rateinfo.prev) * CREDITS_PER_JIFFY;
386 if (dh->rateinfo.credit > dh->rateinfo.credit_cap)
387 dh->rateinfo.credit = dh->rateinfo.credit_cap;
388 dh->rateinfo.prev = now;
389 }
390
391 static int
392 hashlimit_init_dst(const struct xt_hashlimit_htable *hinfo,
393 struct dsthash_dst *dst,
394 const struct sk_buff *skb, unsigned int protoff)
395 {
396 __be16 _ports[2], *ports;
397 u8 nexthdr;
398
399 memset(dst, 0, sizeof(*dst));
400
401 switch (hinfo->family) {
402 case AF_INET:
403 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP)
404 dst->addr.ip.dst = ip_hdr(skb)->daddr;
405 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP)
406 dst->addr.ip.src = ip_hdr(skb)->saddr;
407
408 if (!(hinfo->cfg.mode &
409 (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT)))
410 return 0;
411 nexthdr = ip_hdr(skb)->protocol;
412 break;
413 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
414 case AF_INET6:
415 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP)
416 memcpy(&dst->addr.ip6.dst, &ipv6_hdr(skb)->daddr,
417 sizeof(dst->addr.ip6.dst));
418 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP)
419 memcpy(&dst->addr.ip6.src, &ipv6_hdr(skb)->saddr,
420 sizeof(dst->addr.ip6.src));
421
422 if (!(hinfo->cfg.mode &
423 (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT)))
424 return 0;
425 nexthdr = ipv6_hdr(skb)->nexthdr;
426 protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr);
427 if ((int)protoff < 0)
428 return -1;
429 break;
430 #endif
431 default:
432 BUG();
433 return 0;
434 }
435
436 switch (nexthdr) {
437 case IPPROTO_TCP:
438 case IPPROTO_UDP:
439 case IPPROTO_UDPLITE:
440 case IPPROTO_SCTP:
441 case IPPROTO_DCCP:
442 ports = skb_header_pointer(skb, protoff, sizeof(_ports),
443 &_ports);
444 break;
445 default:
446 _ports[0] = _ports[1] = 0;
447 ports = _ports;
448 break;
449 }
450 if (!ports)
451 return -1;
452 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SPT)
453 dst->src_port = ports[0];
454 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DPT)
455 dst->dst_port = ports[1];
456 return 0;
457 }
458
459 static bool
460 hashlimit_mt(const struct sk_buff *skb, const struct net_device *in,
461 const struct net_device *out, const struct xt_match *match,
462 const void *matchinfo, int offset, unsigned int protoff,
463 bool *hotdrop)
464 {
465 const struct xt_hashlimit_info *r =
466 ((const struct xt_hashlimit_info *)matchinfo)->u.master;
467 struct xt_hashlimit_htable *hinfo = r->hinfo;
468 unsigned long now = jiffies;
469 struct dsthash_ent *dh;
470 struct dsthash_dst dst;
471
472 if (hashlimit_init_dst(hinfo, &dst, skb, protoff) < 0)
473 goto hotdrop;
474
475 spin_lock_bh(&hinfo->lock);
476 dh = dsthash_find(hinfo, &dst);
477 if (!dh) {
478 dh = dsthash_alloc_init(hinfo, &dst);
479 if (!dh) {
480 spin_unlock_bh(&hinfo->lock);
481 goto hotdrop;
482 }
483
484 dh->expires = jiffies + msecs_to_jiffies(hinfo->cfg.expire);
485 dh->rateinfo.prev = jiffies;
486 dh->rateinfo.credit = user2credits(hinfo->cfg.avg *
487 hinfo->cfg.burst);
488 dh->rateinfo.credit_cap = user2credits(hinfo->cfg.avg *
489 hinfo->cfg.burst);
490 dh->rateinfo.cost = user2credits(hinfo->cfg.avg);
491 } else {
492 /* update expiration timeout */
493 dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire);
494 rateinfo_recalc(dh, now);
495 }
496
497 if (dh->rateinfo.credit >= dh->rateinfo.cost) {
498 /* We're underlimit. */
499 dh->rateinfo.credit -= dh->rateinfo.cost;
500 spin_unlock_bh(&hinfo->lock);
501 return true;
502 }
503
504 spin_unlock_bh(&hinfo->lock);
505
506 /* default case: we're overlimit, thus don't match */
507 return false;
508
509 hotdrop:
510 *hotdrop = true;
511 return false;
512 }
513
514 static bool
515 hashlimit_mt_check(const char *tablename, const void *inf,
516 const struct xt_match *match, void *matchinfo,
517 unsigned int hook_mask)
518 {
519 struct xt_hashlimit_info *r = matchinfo;
520
521 /* Check for overflow. */
522 if (r->cfg.burst == 0 ||
523 user2credits(r->cfg.avg * r->cfg.burst) < user2credits(r->cfg.avg)) {
524 printk(KERN_ERR "xt_hashlimit: overflow, try lower: %u/%u\n",
525 r->cfg.avg, r->cfg.burst);
526 return false;
527 }
528 if (r->cfg.mode == 0 ||
529 r->cfg.mode > (XT_HASHLIMIT_HASH_DPT |
530 XT_HASHLIMIT_HASH_DIP |
531 XT_HASHLIMIT_HASH_SIP |
532 XT_HASHLIMIT_HASH_SPT))
533 return false;
534 if (!r->cfg.gc_interval)
535 return false;
536 if (!r->cfg.expire)
537 return false;
538 if (r->name[sizeof(r->name) - 1] != '\0')
539 return false;
540
541 /* This is the best we've got: We cannot release and re-grab lock,
542 * since checkentry() is called before x_tables.c grabs xt_mutex.
543 * We also cannot grab the hashtable spinlock, since htable_create will
544 * call vmalloc, and that can sleep. And we cannot just re-search
545 * the list of htable's in htable_create(), since then we would
546 * create duplicate proc files. -HW */
547 mutex_lock(&hlimit_mutex);
548 r->hinfo = htable_find_get(r->name, match->family);
549 if (!r->hinfo && htable_create(r, match->family) != 0) {
550 mutex_unlock(&hlimit_mutex);
551 return false;
552 }
553 mutex_unlock(&hlimit_mutex);
554
555 /* Ugly hack: For SMP, we only want to use one set */
556 r->u.master = r;
557 return true;
558 }
559
560 static void
561 hashlimit_mt_destroy(const struct xt_match *match, void *matchinfo)
562 {
563 const struct xt_hashlimit_info *r = matchinfo;
564
565 htable_put(r->hinfo);
566 }
567
568 #ifdef CONFIG_COMPAT
569 struct compat_xt_hashlimit_info {
570 char name[IFNAMSIZ];
571 struct hashlimit_cfg cfg;
572 compat_uptr_t hinfo;
573 compat_uptr_t master;
574 };
575
576 static void hashlimit_mt_compat_from_user(void *dst, void *src)
577 {
578 int off = offsetof(struct compat_xt_hashlimit_info, hinfo);
579
580 memcpy(dst, src, off);
581 memset(dst + off, 0, sizeof(struct compat_xt_hashlimit_info) - off);
582 }
583
584 static int hashlimit_mt_compat_to_user(void __user *dst, void *src)
585 {
586 int off = offsetof(struct compat_xt_hashlimit_info, hinfo);
587
588 return copy_to_user(dst, src, off) ? -EFAULT : 0;
589 }
590 #endif
591
592 static struct xt_match hashlimit_mt_reg[] __read_mostly = {
593 {
594 .name = "hashlimit",
595 .family = AF_INET,
596 .match = hashlimit_mt,
597 .matchsize = sizeof(struct xt_hashlimit_info),
598 #ifdef CONFIG_COMPAT
599 .compatsize = sizeof(struct compat_xt_hashlimit_info),
600 .compat_from_user = hashlimit_mt_compat_from_user,
601 .compat_to_user = hashlimit_mt_compat_to_user,
602 #endif
603 .checkentry = hashlimit_mt_check,
604 .destroy = hashlimit_mt_destroy,
605 .me = THIS_MODULE
606 },
607 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
608 {
609 .name = "hashlimit",
610 .family = AF_INET6,
611 .match = hashlimit_mt,
612 .matchsize = sizeof(struct xt_hashlimit_info),
613 #ifdef CONFIG_COMPAT
614 .compatsize = sizeof(struct compat_xt_hashlimit_info),
615 .compat_from_user = hashlimit_mt_compat_from_user,
616 .compat_to_user = hashlimit_mt_compat_to_user,
617 #endif
618 .checkentry = hashlimit_mt_check,
619 .destroy = hashlimit_mt_destroy,
620 .me = THIS_MODULE
621 },
622 #endif
623 };
624
625 /* PROC stuff */
626 static void *dl_seq_start(struct seq_file *s, loff_t *pos)
627 {
628 struct proc_dir_entry *pde = s->private;
629 struct xt_hashlimit_htable *htable = pde->data;
630 unsigned int *bucket;
631
632 spin_lock_bh(&htable->lock);
633 if (*pos >= htable->cfg.size)
634 return NULL;
635
636 bucket = kmalloc(sizeof(unsigned int), GFP_ATOMIC);
637 if (!bucket)
638 return ERR_PTR(-ENOMEM);
639
640 *bucket = *pos;
641 return bucket;
642 }
643
644 static void *dl_seq_next(struct seq_file *s, void *v, loff_t *pos)
645 {
646 struct proc_dir_entry *pde = s->private;
647 struct xt_hashlimit_htable *htable = pde->data;
648 unsigned int *bucket = (unsigned int *)v;
649
650 *pos = ++(*bucket);
651 if (*pos >= htable->cfg.size) {
652 kfree(v);
653 return NULL;
654 }
655 return bucket;
656 }
657
658 static void dl_seq_stop(struct seq_file *s, void *v)
659 {
660 struct proc_dir_entry *pde = s->private;
661 struct xt_hashlimit_htable *htable = pde->data;
662 unsigned int *bucket = (unsigned int *)v;
663
664 kfree(bucket);
665 spin_unlock_bh(&htable->lock);
666 }
667
668 static int dl_seq_real_show(struct dsthash_ent *ent, int family,
669 struct seq_file *s)
670 {
671 /* recalculate to show accurate numbers */
672 rateinfo_recalc(ent, jiffies);
673
674 switch (family) {
675 case AF_INET:
676 return seq_printf(s, "%ld %u.%u.%u.%u:%u->"
677 "%u.%u.%u.%u:%u %u %u %u\n",
678 (long)(ent->expires - jiffies)/HZ,
679 NIPQUAD(ent->dst.addr.ip.src),
680 ntohs(ent->dst.src_port),
681 NIPQUAD(ent->dst.addr.ip.dst),
682 ntohs(ent->dst.dst_port),
683 ent->rateinfo.credit, ent->rateinfo.credit_cap,
684 ent->rateinfo.cost);
685 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
686 case AF_INET6:
687 return seq_printf(s, "%ld " NIP6_FMT ":%u->"
688 NIP6_FMT ":%u %u %u %u\n",
689 (long)(ent->expires - jiffies)/HZ,
690 NIP6(*(struct in6_addr *)&ent->dst.addr.ip6.src),
691 ntohs(ent->dst.src_port),
692 NIP6(*(struct in6_addr *)&ent->dst.addr.ip6.dst),
693 ntohs(ent->dst.dst_port),
694 ent->rateinfo.credit, ent->rateinfo.credit_cap,
695 ent->rateinfo.cost);
696 #endif
697 default:
698 BUG();
699 return 0;
700 }
701 }
702
703 static int dl_seq_show(struct seq_file *s, void *v)
704 {
705 struct proc_dir_entry *pde = s->private;
706 struct xt_hashlimit_htable *htable = pde->data;
707 unsigned int *bucket = (unsigned int *)v;
708 struct dsthash_ent *ent;
709 struct hlist_node *pos;
710
711 if (!hlist_empty(&htable->hash[*bucket])) {
712 hlist_for_each_entry(ent, pos, &htable->hash[*bucket], node)
713 if (dl_seq_real_show(ent, htable->family, s))
714 return 1;
715 }
716 return 0;
717 }
718
719 static const struct seq_operations dl_seq_ops = {
720 .start = dl_seq_start,
721 .next = dl_seq_next,
722 .stop = dl_seq_stop,
723 .show = dl_seq_show
724 };
725
726 static int dl_proc_open(struct inode *inode, struct file *file)
727 {
728 int ret = seq_open(file, &dl_seq_ops);
729
730 if (!ret) {
731 struct seq_file *sf = file->private_data;
732 sf->private = PDE(inode);
733 }
734 return ret;
735 }
736
737 static const struct file_operations dl_file_ops = {
738 .owner = THIS_MODULE,
739 .open = dl_proc_open,
740 .read = seq_read,
741 .llseek = seq_lseek,
742 .release = seq_release
743 };
744
745 static int __init hashlimit_mt_init(void)
746 {
747 int err;
748
749 err = xt_register_matches(hashlimit_mt_reg,
750 ARRAY_SIZE(hashlimit_mt_reg));
751 if (err < 0)
752 goto err1;
753
754 err = -ENOMEM;
755 hashlimit_cachep = kmem_cache_create("xt_hashlimit",
756 sizeof(struct dsthash_ent), 0, 0,
757 NULL);
758 if (!hashlimit_cachep) {
759 printk(KERN_ERR "xt_hashlimit: unable to create slab cache\n");
760 goto err2;
761 }
762 hashlimit_procdir4 = proc_mkdir("ipt_hashlimit", init_net.proc_net);
763 if (!hashlimit_procdir4) {
764 printk(KERN_ERR "xt_hashlimit: unable to create proc dir "
765 "entry\n");
766 goto err3;
767 }
768 err = 0;
769 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
770 hashlimit_procdir6 = proc_mkdir("ip6t_hashlimit", init_net.proc_net);
771 if (!hashlimit_procdir6) {
772 printk(KERN_ERR "xt_hashlimit: unable to create proc dir "
773 "entry\n");
774 err = -ENOMEM;
775 }
776 #endif
777 if (!err)
778 return 0;
779 remove_proc_entry("ipt_hashlimit", init_net.proc_net);
780 err3:
781 kmem_cache_destroy(hashlimit_cachep);
782 err2:
783 xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg));
784 err1:
785 return err;
786
787 }
788
789 static void __exit hashlimit_mt_exit(void)
790 {
791 remove_proc_entry("ipt_hashlimit", init_net.proc_net);
792 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
793 remove_proc_entry("ip6t_hashlimit", init_net.proc_net);
794 #endif
795 kmem_cache_destroy(hashlimit_cachep);
796 xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg));
797 }
798
799 module_init(hashlimit_mt_init);
800 module_exit(hashlimit_mt_exit);
WRT350N Kernel Patches