2 * xt_hashlimit - Netfilter module to limit the number of packets per time
3 * seperately for each hashbucket (sourceip/sourceport/dstip/dstport)
5 * (C) 2003-2004 by Harald Welte <laforge@netfilter.org>
6 * Copyright © CC Computer Consultants GmbH, 2007 - 2008
8 * Development of this code was funded by Astaro AG, http://www.astaro.com/
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>
23 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
24 #include <linux/ipv6.h>
28 #include <net/net_namespace.h>
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>
36 MODULE_LICENSE("GPL");
37 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
38 MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
39 MODULE_DESCRIPTION("Xtables: per hash-bucket rate-limit match");
40 MODULE_ALIAS("ipt_hashlimit");
41 MODULE_ALIAS("ip6t_hashlimit");
43 /* need to declare this at the top */
44 static struct proc_dir_entry *hashlimit_procdir4;
45 static struct proc_dir_entry *hashlimit_procdir6;
46 static const struct file_operations dl_file_ops;
55 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
67 /* static / read-only parts in the beginning */
68 struct hlist_node node;
69 struct dsthash_dst dst;
71 /* modified structure members in the end */
72 unsigned long expires; /* precalculated expiry time */
74 unsigned long prev; /* last modification */
76 u_int32_t credit_cap, cost;
80 struct xt_hashlimit_htable {
81 struct hlist_node node; /* global list of all htables */
85 struct hashlimit_cfg1 cfg; /* config */
88 spinlock_t lock; /* lock for list_head */
89 u_int32_t rnd; /* random seed for hash */
91 unsigned int count; /* number entries in table */
92 struct timer_list timer; /* timer for gc */
95 struct proc_dir_entry *pde;
97 struct hlist_head hash[0]; /* hashtable itself */
100 static DEFINE_SPINLOCK(hashlimit_lock); /* protects htables list */
101 static DEFINE_MUTEX(hlimit_mutex); /* additional checkentry protection */
102 static HLIST_HEAD(hashlimit_htables);
103 static struct kmem_cache *hashlimit_cachep __read_mostly;
105 static inline bool dst_cmp(const struct dsthash_ent *ent,
106 const struct dsthash_dst *b)
108 return !memcmp(&ent->dst, b, sizeof(ent->dst));
112 hash_dst(const struct xt_hashlimit_htable *ht, const struct dsthash_dst *dst)
114 u_int32_t hash = jhash2((const u32 *)dst,
115 sizeof(*dst)/sizeof(u32),
118 * Instead of returning hash % ht->cfg.size (implying a divide)
119 * we return the high 32 bits of the (hash * ht->cfg.size) that will
120 * give results between [0 and cfg.size-1] and same hash distribution,
121 * but using a multiply, less expensive than a divide
123 return ((u64)hash * ht->cfg.size) >> 32;
126 static struct dsthash_ent *
127 dsthash_find(const struct xt_hashlimit_htable *ht,
128 const struct dsthash_dst *dst)
130 struct dsthash_ent *ent;
131 struct hlist_node *pos;
132 u_int32_t hash = hash_dst(ht, dst);
134 if (!hlist_empty(&ht->hash[hash])) {
135 hlist_for_each_entry(ent, pos, &ht->hash[hash], node)
136 if (dst_cmp(ent, dst))
142 /* allocate dsthash_ent, initialize dst, put in htable and lock it */
143 static struct dsthash_ent *
144 dsthash_alloc_init(struct xt_hashlimit_htable *ht,
145 const struct dsthash_dst *dst)
147 struct dsthash_ent *ent;
149 /* initialize hash with random val at the time we allocate
150 * the first hashtable entry */
151 if (!ht->rnd_initialized) {
152 get_random_bytes(&ht->rnd, 4);
153 ht->rnd_initialized = 1;
156 if (ht->cfg.max && ht->count >= ht->cfg.max) {
157 /* FIXME: do something. question is what.. */
160 "xt_hashlimit: max count of %u reached\n",
165 ent = kmem_cache_alloc(hashlimit_cachep, GFP_ATOMIC);
169 "xt_hashlimit: can't allocate dsthash_ent\n");
172 memcpy(&ent->dst, dst, sizeof(ent->dst));
174 hlist_add_head(&ent->node, &ht->hash[hash_dst(ht, dst)]);
180 dsthash_free(struct xt_hashlimit_htable *ht, struct dsthash_ent *ent)
182 hlist_del(&ent->node);
183 kmem_cache_free(hashlimit_cachep, ent);
186 static void htable_gc(unsigned long htlong);
188 static int htable_create_v0(struct xt_hashlimit_info *minfo, u_int8_t family)
190 struct xt_hashlimit_htable *hinfo;
195 size = minfo->cfg.size;
197 size = ((num_physpages << PAGE_SHIFT) / 16384) /
198 sizeof(struct list_head);
199 if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE))
204 /* FIXME: don't use vmalloc() here or anywhere else -HW */
205 hinfo = vmalloc(sizeof(struct xt_hashlimit_htable) +
206 sizeof(struct list_head) * size);
208 printk(KERN_ERR "xt_hashlimit: unable to create hashtable\n");
211 minfo->hinfo = hinfo;
213 /* copy match config into hashtable config */
214 hinfo->cfg.mode = minfo->cfg.mode;
215 hinfo->cfg.avg = minfo->cfg.avg;
216 hinfo->cfg.burst = minfo->cfg.burst;
217 hinfo->cfg.max = minfo->cfg.max;
218 hinfo->cfg.gc_interval = minfo->cfg.gc_interval;
219 hinfo->cfg.expire = minfo->cfg.expire;
221 if (family == AF_INET)
222 hinfo->cfg.srcmask = hinfo->cfg.dstmask = 32;
224 hinfo->cfg.srcmask = hinfo->cfg.dstmask = 128;
226 hinfo->cfg.size = size;
228 hinfo->cfg.max = 8 * hinfo->cfg.size;
229 else if (hinfo->cfg.max < hinfo->cfg.size)
230 hinfo->cfg.max = hinfo->cfg.size;
232 for (i = 0; i < hinfo->cfg.size; i++)
233 INIT_HLIST_HEAD(&hinfo->hash[i]);
235 atomic_set(&hinfo->use, 1);
237 hinfo->family = family;
238 hinfo->rnd_initialized = 0;
239 spin_lock_init(&hinfo->lock);
241 proc_create_data(minfo->name, 0,
242 family == AF_INET ? hashlimit_procdir4 :
244 &dl_file_ops, hinfo);
250 setup_timer(&hinfo->timer, htable_gc, (unsigned long )hinfo);
251 hinfo->timer.expires = jiffies + msecs_to_jiffies(hinfo->cfg.gc_interval);
252 add_timer(&hinfo->timer);
254 spin_lock_bh(&hashlimit_lock);
255 hlist_add_head(&hinfo->node, &hashlimit_htables);
256 spin_unlock_bh(&hashlimit_lock);
261 static int htable_create(struct xt_hashlimit_mtinfo1 *minfo, u_int8_t family)
263 struct xt_hashlimit_htable *hinfo;
267 if (minfo->cfg.size) {
268 size = minfo->cfg.size;
270 size = (num_physpages << PAGE_SHIFT) / 16384 /
271 sizeof(struct list_head);
272 if (num_physpages > 1024 * 1024 * 1024 / PAGE_SIZE)
277 /* FIXME: don't use vmalloc() here or anywhere else -HW */
278 hinfo = vmalloc(sizeof(struct xt_hashlimit_htable) +
279 sizeof(struct list_head) * size);
281 printk(KERN_ERR "xt_hashlimit: unable to create hashtable\n");
284 minfo->hinfo = hinfo;
286 /* copy match config into hashtable config */
287 memcpy(&hinfo->cfg, &minfo->cfg, sizeof(hinfo->cfg));
288 hinfo->cfg.size = size;
289 if (hinfo->cfg.max == 0)
290 hinfo->cfg.max = 8 * hinfo->cfg.size;
291 else if (hinfo->cfg.max < hinfo->cfg.size)
292 hinfo->cfg.max = hinfo->cfg.size;
294 for (i = 0; i < hinfo->cfg.size; i++)
295 INIT_HLIST_HEAD(&hinfo->hash[i]);
297 atomic_set(&hinfo->use, 1);
299 hinfo->family = family;
300 hinfo->rnd_initialized = 0;
301 spin_lock_init(&hinfo->lock);
304 proc_create_data(minfo->name, 0,
305 family == AF_INET ? hashlimit_procdir4 :
307 &dl_file_ops, hinfo);
308 if (hinfo->pde == NULL) {
313 setup_timer(&hinfo->timer, htable_gc, (unsigned long)hinfo);
314 hinfo->timer.expires = jiffies + msecs_to_jiffies(hinfo->cfg.gc_interval);
315 add_timer(&hinfo->timer);
317 spin_lock_bh(&hashlimit_lock);
318 hlist_add_head(&hinfo->node, &hashlimit_htables);
319 spin_unlock_bh(&hashlimit_lock);
324 static bool select_all(const struct xt_hashlimit_htable *ht,
325 const struct dsthash_ent *he)
330 static bool select_gc(const struct xt_hashlimit_htable *ht,
331 const struct dsthash_ent *he)
333 return time_after_eq(jiffies, he->expires);
336 static void htable_selective_cleanup(struct xt_hashlimit_htable *ht,
337 bool (*select)(const struct xt_hashlimit_htable *ht,
338 const struct dsthash_ent *he))
342 /* lock hash table and iterate over it */
343 spin_lock_bh(&ht->lock);
344 for (i = 0; i < ht->cfg.size; i++) {
345 struct dsthash_ent *dh;
346 struct hlist_node *pos, *n;
347 hlist_for_each_entry_safe(dh, pos, n, &ht->hash[i], node) {
348 if ((*select)(ht, dh))
349 dsthash_free(ht, dh);
352 spin_unlock_bh(&ht->lock);
355 /* hash table garbage collector, run by timer */
356 static void htable_gc(unsigned long htlong)
358 struct xt_hashlimit_htable *ht = (struct xt_hashlimit_htable *)htlong;
360 htable_selective_cleanup(ht, select_gc);
362 /* re-add the timer accordingly */
363 ht->timer.expires = jiffies + msecs_to_jiffies(ht->cfg.gc_interval);
364 add_timer(&ht->timer);
367 static void htable_destroy(struct xt_hashlimit_htable *hinfo)
369 del_timer_sync(&hinfo->timer);
371 /* remove proc entry */
372 remove_proc_entry(hinfo->pde->name,
373 hinfo->family == AF_INET ? hashlimit_procdir4 :
375 htable_selective_cleanup(hinfo, select_all);
379 static struct xt_hashlimit_htable *htable_find_get(const char *name,
382 struct xt_hashlimit_htable *hinfo;
383 struct hlist_node *pos;
385 spin_lock_bh(&hashlimit_lock);
386 hlist_for_each_entry(hinfo, pos, &hashlimit_htables, node) {
387 if (!strcmp(name, hinfo->pde->name) &&
388 hinfo->family == family) {
389 atomic_inc(&hinfo->use);
390 spin_unlock_bh(&hashlimit_lock);
394 spin_unlock_bh(&hashlimit_lock);
398 static void htable_put(struct xt_hashlimit_htable *hinfo)
400 if (atomic_dec_and_test(&hinfo->use)) {
401 spin_lock_bh(&hashlimit_lock);
402 hlist_del(&hinfo->node);
403 spin_unlock_bh(&hashlimit_lock);
404 htable_destroy(hinfo);
408 /* The algorithm used is the Simple Token Bucket Filter (TBF)
409 * see net/sched/sch_tbf.c in the linux source tree
412 /* Rusty: This is my (non-mathematically-inclined) understanding of
413 this algorithm. The `average rate' in jiffies becomes your initial
414 amount of credit `credit' and the most credit you can ever have
415 `credit_cap'. The `peak rate' becomes the cost of passing the
418 `prev' tracks the last packet hit: you gain one credit per jiffy.
419 If you get credit balance more than this, the extra credit is
420 discarded. Every time the match passes, you lose `cost' credits;
421 if you don't have that many, the test fails.
423 See Alexey's formal explanation in net/sched/sch_tbf.c.
425 To get the maximum range, we multiply by this factor (ie. you get N
426 credits per jiffy). We want to allow a rate as low as 1 per day
427 (slowest userspace tool allows), which means
428 CREDITS_PER_JIFFY*HZ*60*60*24 < 2^32 ie.
430 #define MAX_CPJ (0xFFFFFFFF / (HZ*60*60*24))
432 /* Repeated shift and or gives us all 1s, final shift and add 1 gives
433 * us the power of 2 below the theoretical max, so GCC simply does a
435 #define _POW2_BELOW2(x) ((x)|((x)>>1))
436 #define _POW2_BELOW4(x) (_POW2_BELOW2(x)|_POW2_BELOW2((x)>>2))
437 #define _POW2_BELOW8(x) (_POW2_BELOW4(x)|_POW2_BELOW4((x)>>4))
438 #define _POW2_BELOW16(x) (_POW2_BELOW8(x)|_POW2_BELOW8((x)>>8))
439 #define _POW2_BELOW32(x) (_POW2_BELOW16(x)|_POW2_BELOW16((x)>>16))
440 #define POW2_BELOW32(x) ((_POW2_BELOW32(x)>>1) + 1)
442 #define CREDITS_PER_JIFFY POW2_BELOW32(MAX_CPJ)
444 /* Precision saver. */
445 static inline u_int32_t
446 user2credits(u_int32_t user)
448 /* If multiplying would overflow... */
449 if (user > 0xFFFFFFFF / (HZ*CREDITS_PER_JIFFY))
451 return (user / XT_HASHLIMIT_SCALE) * HZ * CREDITS_PER_JIFFY;
453 return (user * HZ * CREDITS_PER_JIFFY) / XT_HASHLIMIT_SCALE;
456 static inline void rateinfo_recalc(struct dsthash_ent *dh, unsigned long now)
458 dh->rateinfo.credit += (now - dh->rateinfo.prev) * CREDITS_PER_JIFFY;
459 if (dh->rateinfo.credit > dh->rateinfo.credit_cap)
460 dh->rateinfo.credit = dh->rateinfo.credit_cap;
461 dh->rateinfo.prev = now;
464 static inline __be32 maskl(__be32 a, unsigned int l)
466 return l ? htonl(ntohl(a) & ~0 << (32 - l)) : 0;
469 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
470 static void hashlimit_ipv6_mask(__be32 *i, unsigned int p)
474 i[0] = maskl(i[0], p);
475 i[1] = i[2] = i[3] = 0;
478 i[1] = maskl(i[1], p - 32);
482 i[2] = maskl(i[2], p - 64);
485 i[3] = maskl(i[3], p - 96);
494 hashlimit_init_dst(const struct xt_hashlimit_htable *hinfo,
495 struct dsthash_dst *dst,
496 const struct sk_buff *skb, unsigned int protoff)
498 __be16 _ports[2], *ports;
501 memset(dst, 0, sizeof(*dst));
503 switch (hinfo->family) {
505 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP)
506 dst->ip.dst = maskl(ip_hdr(skb)->daddr,
508 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP)
509 dst->ip.src = maskl(ip_hdr(skb)->saddr,
512 if (!(hinfo->cfg.mode &
513 (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT)))
515 nexthdr = ip_hdr(skb)->protocol;
517 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
519 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP) {
520 memcpy(&dst->ip6.dst, &ipv6_hdr(skb)->daddr,
521 sizeof(dst->ip6.dst));
522 hashlimit_ipv6_mask(dst->ip6.dst, hinfo->cfg.dstmask);
524 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP) {
525 memcpy(&dst->ip6.src, &ipv6_hdr(skb)->saddr,
526 sizeof(dst->ip6.src));
527 hashlimit_ipv6_mask(dst->ip6.src, hinfo->cfg.srcmask);
530 if (!(hinfo->cfg.mode &
531 (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT)))
533 nexthdr = ipv6_hdr(skb)->nexthdr;
534 protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr);
535 if ((int)protoff < 0)
547 case IPPROTO_UDPLITE:
550 ports = skb_header_pointer(skb, protoff, sizeof(_ports),
554 _ports[0] = _ports[1] = 0;
560 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SPT)
561 dst->src_port = ports[0];
562 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DPT)
563 dst->dst_port = ports[1];
568 hashlimit_mt_v0(const struct sk_buff *skb, const struct net_device *in,
569 const struct net_device *out, const struct xt_match *match,
570 const void *matchinfo, int offset, unsigned int protoff,
573 const struct xt_hashlimit_info *r =
574 ((const struct xt_hashlimit_info *)matchinfo)->u.master;
575 struct xt_hashlimit_htable *hinfo = r->hinfo;
576 unsigned long now = jiffies;
577 struct dsthash_ent *dh;
578 struct dsthash_dst dst;
580 if (hashlimit_init_dst(hinfo, &dst, skb, protoff) < 0)
583 spin_lock_bh(&hinfo->lock);
584 dh = dsthash_find(hinfo, &dst);
586 dh = dsthash_alloc_init(hinfo, &dst);
588 spin_unlock_bh(&hinfo->lock);
592 dh->expires = jiffies + msecs_to_jiffies(hinfo->cfg.expire);
593 dh->rateinfo.prev = jiffies;
594 dh->rateinfo.credit = user2credits(hinfo->cfg.avg *
596 dh->rateinfo.credit_cap = user2credits(hinfo->cfg.avg *
598 dh->rateinfo.cost = user2credits(hinfo->cfg.avg);
600 /* update expiration timeout */
601 dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire);
602 rateinfo_recalc(dh, now);
605 if (dh->rateinfo.credit >= dh->rateinfo.cost) {
606 /* We're underlimit. */
607 dh->rateinfo.credit -= dh->rateinfo.cost;
608 spin_unlock_bh(&hinfo->lock);
612 spin_unlock_bh(&hinfo->lock);
614 /* default case: we're overlimit, thus don't match */
623 hashlimit_mt(const struct sk_buff *skb, const struct net_device *in,
624 const struct net_device *out, const struct xt_match *match,
625 const void *matchinfo, int offset, unsigned int protoff,
628 const struct xt_hashlimit_mtinfo1 *info = matchinfo;
629 struct xt_hashlimit_htable *hinfo = info->hinfo;
630 unsigned long now = jiffies;
631 struct dsthash_ent *dh;
632 struct dsthash_dst dst;
634 if (hashlimit_init_dst(hinfo, &dst, skb, protoff) < 0)
637 spin_lock_bh(&hinfo->lock);
638 dh = dsthash_find(hinfo, &dst);
640 dh = dsthash_alloc_init(hinfo, &dst);
642 spin_unlock_bh(&hinfo->lock);
646 dh->expires = jiffies + msecs_to_jiffies(hinfo->cfg.expire);
647 dh->rateinfo.prev = jiffies;
648 dh->rateinfo.credit = user2credits(hinfo->cfg.avg *
650 dh->rateinfo.credit_cap = user2credits(hinfo->cfg.avg *
652 dh->rateinfo.cost = user2credits(hinfo->cfg.avg);
654 /* update expiration timeout */
655 dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire);
656 rateinfo_recalc(dh, now);
659 if (dh->rateinfo.credit >= dh->rateinfo.cost) {
660 /* below the limit */
661 dh->rateinfo.credit -= dh->rateinfo.cost;
662 spin_unlock_bh(&hinfo->lock);
663 return !(info->cfg.mode & XT_HASHLIMIT_INVERT);
666 spin_unlock_bh(&hinfo->lock);
667 /* default match is underlimit - so over the limit, we need to invert */
668 return info->cfg.mode & XT_HASHLIMIT_INVERT;
676 hashlimit_mt_check_v0(const char *tablename, const void *inf,
677 const struct xt_match *match, void *matchinfo,
678 unsigned int hook_mask)
680 struct xt_hashlimit_info *r = matchinfo;
682 /* Check for overflow. */
683 if (r->cfg.burst == 0 ||
684 user2credits(r->cfg.avg * r->cfg.burst) < user2credits(r->cfg.avg)) {
685 printk(KERN_ERR "xt_hashlimit: overflow, try lower: %u/%u\n",
686 r->cfg.avg, r->cfg.burst);
689 if (r->cfg.mode == 0 ||
690 r->cfg.mode > (XT_HASHLIMIT_HASH_DPT |
691 XT_HASHLIMIT_HASH_DIP |
692 XT_HASHLIMIT_HASH_SIP |
693 XT_HASHLIMIT_HASH_SPT))
695 if (!r->cfg.gc_interval)
699 if (r->name[sizeof(r->name) - 1] != '\0')
702 /* This is the best we've got: We cannot release and re-grab lock,
703 * since checkentry() is called before x_tables.c grabs xt_mutex.
704 * We also cannot grab the hashtable spinlock, since htable_create will
705 * call vmalloc, and that can sleep. And we cannot just re-search
706 * the list of htable's in htable_create(), since then we would
707 * create duplicate proc files. -HW */
708 mutex_lock(&hlimit_mutex);
709 r->hinfo = htable_find_get(r->name, match->family);
710 if (!r->hinfo && htable_create_v0(r, match->family) != 0) {
711 mutex_unlock(&hlimit_mutex);
714 mutex_unlock(&hlimit_mutex);
716 /* Ugly hack: For SMP, we only want to use one set */
722 hashlimit_mt_check(const char *tablename, const void *inf,
723 const struct xt_match *match, void *matchinfo,
724 unsigned int hook_mask)
726 struct xt_hashlimit_mtinfo1 *info = matchinfo;
728 /* Check for overflow. */
729 if (info->cfg.burst == 0 ||
730 user2credits(info->cfg.avg * info->cfg.burst) <
731 user2credits(info->cfg.avg)) {
732 printk(KERN_ERR "xt_hashlimit: overflow, try lower: %u/%u\n",
733 info->cfg.avg, info->cfg.burst);
736 if (info->cfg.gc_interval == 0 || info->cfg.expire == 0)
738 if (info->name[sizeof(info->name)-1] != '\0')
740 if (match->family == AF_INET) {
741 if (info->cfg.srcmask > 32 || info->cfg.dstmask > 32)
744 if (info->cfg.srcmask > 128 || info->cfg.dstmask > 128)
748 /* This is the best we've got: We cannot release and re-grab lock,
749 * since checkentry() is called before x_tables.c grabs xt_mutex.
750 * We also cannot grab the hashtable spinlock, since htable_create will
751 * call vmalloc, and that can sleep. And we cannot just re-search
752 * the list of htable's in htable_create(), since then we would
753 * create duplicate proc files. -HW */
754 mutex_lock(&hlimit_mutex);
755 info->hinfo = htable_find_get(info->name, match->family);
756 if (!info->hinfo && htable_create(info, match->family) != 0) {
757 mutex_unlock(&hlimit_mutex);
760 mutex_unlock(&hlimit_mutex);
765 hashlimit_mt_destroy_v0(const struct xt_match *match, void *matchinfo)
767 const struct xt_hashlimit_info *r = matchinfo;
769 htable_put(r->hinfo);
773 hashlimit_mt_destroy(const struct xt_match *match, void *matchinfo)
775 const struct xt_hashlimit_mtinfo1 *info = matchinfo;
777 htable_put(info->hinfo);
781 struct compat_xt_hashlimit_info {
783 struct hashlimit_cfg cfg;
785 compat_uptr_t master;
788 static void hashlimit_mt_compat_from_user(void *dst, void *src)
790 int off = offsetof(struct compat_xt_hashlimit_info, hinfo);
792 memcpy(dst, src, off);
793 memset(dst + off, 0, sizeof(struct compat_xt_hashlimit_info) - off);
796 static int hashlimit_mt_compat_to_user(void __user *dst, void *src)
798 int off = offsetof(struct compat_xt_hashlimit_info, hinfo);
800 return copy_to_user(dst, src, off) ? -EFAULT : 0;
804 static struct xt_match hashlimit_mt_reg[] __read_mostly = {
809 .match = hashlimit_mt_v0,
810 .matchsize = sizeof(struct xt_hashlimit_info),
812 .compatsize = sizeof(struct compat_xt_hashlimit_info),
813 .compat_from_user = hashlimit_mt_compat_from_user,
814 .compat_to_user = hashlimit_mt_compat_to_user,
816 .checkentry = hashlimit_mt_check_v0,
817 .destroy = hashlimit_mt_destroy_v0,
824 .match = hashlimit_mt,
825 .matchsize = sizeof(struct xt_hashlimit_mtinfo1),
826 .checkentry = hashlimit_mt_check,
827 .destroy = hashlimit_mt_destroy,
830 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
834 .match = hashlimit_mt_v0,
835 .matchsize = sizeof(struct xt_hashlimit_info),
837 .compatsize = sizeof(struct compat_xt_hashlimit_info),
838 .compat_from_user = hashlimit_mt_compat_from_user,
839 .compat_to_user = hashlimit_mt_compat_to_user,
841 .checkentry = hashlimit_mt_check_v0,
842 .destroy = hashlimit_mt_destroy_v0,
849 .match = hashlimit_mt,
850 .matchsize = sizeof(struct xt_hashlimit_mtinfo1),
851 .checkentry = hashlimit_mt_check,
852 .destroy = hashlimit_mt_destroy,
859 static void *dl_seq_start(struct seq_file *s, loff_t *pos)
860 __acquires(htable->lock)
862 struct proc_dir_entry *pde = s->private;
863 struct xt_hashlimit_htable *htable = pde->data;
864 unsigned int *bucket;
866 spin_lock_bh(&htable->lock);
867 if (*pos >= htable->cfg.size)
870 bucket = kmalloc(sizeof(unsigned int), GFP_ATOMIC);
872 return ERR_PTR(-ENOMEM);
878 static void *dl_seq_next(struct seq_file *s, void *v, loff_t *pos)
880 struct proc_dir_entry *pde = s->private;
881 struct xt_hashlimit_htable *htable = pde->data;
882 unsigned int *bucket = (unsigned int *)v;
885 if (*pos >= htable->cfg.size) {
892 static void dl_seq_stop(struct seq_file *s, void *v)
893 __releases(htable->lock)
895 struct proc_dir_entry *pde = s->private;
896 struct xt_hashlimit_htable *htable = pde->data;
897 unsigned int *bucket = (unsigned int *)v;
900 spin_unlock_bh(&htable->lock);
903 static int dl_seq_real_show(struct dsthash_ent *ent, u_int8_t family,
906 /* recalculate to show accurate numbers */
907 rateinfo_recalc(ent, jiffies);
911 return seq_printf(s, "%ld %u.%u.%u.%u:%u->"
912 "%u.%u.%u.%u:%u %u %u %u\n",
913 (long)(ent->expires - jiffies)/HZ,
914 NIPQUAD(ent->dst.ip.src),
915 ntohs(ent->dst.src_port),
916 NIPQUAD(ent->dst.ip.dst),
917 ntohs(ent->dst.dst_port),
918 ent->rateinfo.credit, ent->rateinfo.credit_cap,
920 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
922 return seq_printf(s, "%ld " NIP6_FMT ":%u->"
923 NIP6_FMT ":%u %u %u %u\n",
924 (long)(ent->expires - jiffies)/HZ,
925 NIP6(*(struct in6_addr *)&ent->dst.ip6.src),
926 ntohs(ent->dst.src_port),
927 NIP6(*(struct in6_addr *)&ent->dst.ip6.dst),
928 ntohs(ent->dst.dst_port),
929 ent->rateinfo.credit, ent->rateinfo.credit_cap,
938 static int dl_seq_show(struct seq_file *s, void *v)
940 struct proc_dir_entry *pde = s->private;
941 struct xt_hashlimit_htable *htable = pde->data;
942 unsigned int *bucket = (unsigned int *)v;
943 struct dsthash_ent *ent;
944 struct hlist_node *pos;
946 if (!hlist_empty(&htable->hash[*bucket])) {
947 hlist_for_each_entry(ent, pos, &htable->hash[*bucket], node)
948 if (dl_seq_real_show(ent, htable->family, s))
954 static const struct seq_operations dl_seq_ops = {
955 .start = dl_seq_start,
961 static int dl_proc_open(struct inode *inode, struct file *file)
963 int ret = seq_open(file, &dl_seq_ops);
966 struct seq_file *sf = file->private_data;
967 sf->private = PDE(inode);
972 static const struct file_operations dl_file_ops = {
973 .owner = THIS_MODULE,
974 .open = dl_proc_open,
977 .release = seq_release
980 static int __init hashlimit_mt_init(void)
984 err = xt_register_matches(hashlimit_mt_reg,
985 ARRAY_SIZE(hashlimit_mt_reg));
990 hashlimit_cachep = kmem_cache_create("xt_hashlimit",
991 sizeof(struct dsthash_ent), 0, 0,
993 if (!hashlimit_cachep) {
994 printk(KERN_ERR "xt_hashlimit: unable to create slab cache\n");
997 hashlimit_procdir4 = proc_mkdir("ipt_hashlimit", init_net.proc_net);
998 if (!hashlimit_procdir4) {
999 printk(KERN_ERR "xt_hashlimit: unable to create proc dir "
1004 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
1005 hashlimit_procdir6 = proc_mkdir("ip6t_hashlimit", init_net.proc_net);
1006 if (!hashlimit_procdir6) {
1007 printk(KERN_ERR "xt_hashlimit: unable to create proc dir "
1014 remove_proc_entry("ipt_hashlimit", init_net.proc_net);
1016 kmem_cache_destroy(hashlimit_cachep);
1018 xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg));
1024 static void __exit hashlimit_mt_exit(void)
1026 remove_proc_entry("ipt_hashlimit", init_net.proc_net);
1027 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
1028 remove_proc_entry("ip6t_hashlimit", init_net.proc_net);
1030 kmem_cache_destroy(hashlimit_cachep);
1031 xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg));
1034 module_init(hashlimit_mt_init);
1035 module_exit(hashlimit_mt_exit);