2 * xt_hashlimit - Netfilter module to limit the number of packets per time
3 * separately 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>
29 #include <net/netns/generic.h>
31 #include <linux/netfilter/x_tables.h>
32 #include <linux/netfilter_ipv4/ip_tables.h>
33 #include <linux/netfilter_ipv6/ip6_tables.h>
34 #include <linux/netfilter/xt_hashlimit.h>
35 #include <linux/mutex.h>
37 MODULE_LICENSE("GPL");
38 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
39 MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
40 MODULE_DESCRIPTION("Xtables: per hash-bucket rate-limit match");
41 MODULE_ALIAS("ipt_hashlimit");
42 MODULE_ALIAS("ip6t_hashlimit");
44 struct hashlimit_net {
45 struct hlist_head htables;
46 struct proc_dir_entry *ipt_hashlimit;
47 struct proc_dir_entry *ip6t_hashlimit;
50 static int hashlimit_net_id;
51 static inline struct hashlimit_net *hashlimit_pernet(struct net *net)
53 return net_generic(net, hashlimit_net_id);
56 /* need to declare this at the top */
57 static const struct file_operations dl_file_ops;
66 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
78 /* static / read-only parts in the beginning */
79 struct hlist_node node;
80 struct dsthash_dst dst;
82 /* modified structure members in the end */
83 unsigned long expires; /* precalculated expiry time */
85 unsigned long prev; /* last modification */
87 u_int32_t credit_cap, cost;
91 struct xt_hashlimit_htable {
92 struct hlist_node node; /* global list of all htables */
97 struct hashlimit_cfg1 cfg; /* config */
100 spinlock_t lock; /* lock for list_head */
101 u_int32_t rnd; /* random seed for hash */
102 unsigned int count; /* number entries in table */
103 struct timer_list timer; /* timer for gc */
106 struct proc_dir_entry *pde;
109 struct hlist_head hash[0]; /* hashtable itself */
112 static DEFINE_MUTEX(hashlimit_mutex); /* protects htables list */
113 static struct kmem_cache *hashlimit_cachep __read_mostly;
115 static inline bool dst_cmp(const struct dsthash_ent *ent,
116 const struct dsthash_dst *b)
118 return !memcmp(&ent->dst, b, sizeof(ent->dst));
122 hash_dst(const struct xt_hashlimit_htable *ht, const struct dsthash_dst *dst)
124 u_int32_t hash = jhash2((const u32 *)dst,
125 sizeof(*dst)/sizeof(u32),
128 * Instead of returning hash % ht->cfg.size (implying a divide)
129 * we return the high 32 bits of the (hash * ht->cfg.size) that will
130 * give results between [0 and cfg.size-1] and same hash distribution,
131 * but using a multiply, less expensive than a divide
133 return ((u64)hash * ht->cfg.size) >> 32;
136 static struct dsthash_ent *
137 dsthash_find(const struct xt_hashlimit_htable *ht,
138 const struct dsthash_dst *dst)
140 struct dsthash_ent *ent;
141 struct hlist_node *pos;
142 u_int32_t hash = hash_dst(ht, dst);
144 if (!hlist_empty(&ht->hash[hash])) {
145 hlist_for_each_entry(ent, pos, &ht->hash[hash], node)
146 if (dst_cmp(ent, dst))
152 /* allocate dsthash_ent, initialize dst, put in htable and lock it */
153 static struct dsthash_ent *
154 dsthash_alloc_init(struct xt_hashlimit_htable *ht,
155 const struct dsthash_dst *dst)
157 struct dsthash_ent *ent;
159 /* initialize hash with random val at the time we allocate
160 * the first hashtable entry */
161 if (!ht->rnd_initialized) {
162 get_random_bytes(&ht->rnd, sizeof(ht->rnd));
163 ht->rnd_initialized = true;
166 if (ht->cfg.max && ht->count >= ht->cfg.max) {
167 /* FIXME: do something. question is what.. */
170 "xt_hashlimit: max count of %u reached\n",
175 ent = kmem_cache_alloc(hashlimit_cachep, GFP_ATOMIC);
179 "xt_hashlimit: can't allocate dsthash_ent\n");
182 memcpy(&ent->dst, dst, sizeof(ent->dst));
184 hlist_add_head(&ent->node, &ht->hash[hash_dst(ht, dst)]);
190 dsthash_free(struct xt_hashlimit_htable *ht, struct dsthash_ent *ent)
192 hlist_del(&ent->node);
193 kmem_cache_free(hashlimit_cachep, ent);
196 static void htable_gc(unsigned long htlong);
198 static int htable_create_v0(struct net *net, struct xt_hashlimit_info *minfo, u_int8_t family)
200 struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
201 struct xt_hashlimit_htable *hinfo;
206 size = minfo->cfg.size;
208 size = ((totalram_pages << PAGE_SHIFT) / 16384) /
209 sizeof(struct list_head);
210 if (totalram_pages > (1024 * 1024 * 1024 / PAGE_SIZE))
215 /* FIXME: don't use vmalloc() here or anywhere else -HW */
216 hinfo = vmalloc(sizeof(struct xt_hashlimit_htable) +
217 sizeof(struct list_head) * size);
220 minfo->hinfo = hinfo;
222 /* copy match config into hashtable config */
223 hinfo->cfg.mode = minfo->cfg.mode;
224 hinfo->cfg.avg = minfo->cfg.avg;
225 hinfo->cfg.burst = minfo->cfg.burst;
226 hinfo->cfg.max = minfo->cfg.max;
227 hinfo->cfg.gc_interval = minfo->cfg.gc_interval;
228 hinfo->cfg.expire = minfo->cfg.expire;
230 if (family == NFPROTO_IPV4)
231 hinfo->cfg.srcmask = hinfo->cfg.dstmask = 32;
233 hinfo->cfg.srcmask = hinfo->cfg.dstmask = 128;
235 hinfo->cfg.size = size;
237 hinfo->cfg.max = 8 * hinfo->cfg.size;
238 else if (hinfo->cfg.max < hinfo->cfg.size)
239 hinfo->cfg.max = hinfo->cfg.size;
241 for (i = 0; i < hinfo->cfg.size; i++)
242 INIT_HLIST_HEAD(&hinfo->hash[i]);
246 hinfo->family = family;
247 hinfo->rnd_initialized = false;
248 spin_lock_init(&hinfo->lock);
249 hinfo->pde = proc_create_data(minfo->name, 0,
250 (family == NFPROTO_IPV4) ?
251 hashlimit_net->ipt_hashlimit : hashlimit_net->ip6t_hashlimit,
252 &dl_file_ops, hinfo);
259 setup_timer(&hinfo->timer, htable_gc, (unsigned long )hinfo);
260 hinfo->timer.expires = jiffies + msecs_to_jiffies(hinfo->cfg.gc_interval);
261 add_timer(&hinfo->timer);
263 hlist_add_head(&hinfo->node, &hashlimit_net->htables);
268 static int htable_create(struct net *net, struct xt_hashlimit_mtinfo1 *minfo,
271 struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
272 struct xt_hashlimit_htable *hinfo;
276 if (minfo->cfg.size) {
277 size = minfo->cfg.size;
279 size = (totalram_pages << PAGE_SHIFT) / 16384 /
280 sizeof(struct list_head);
281 if (totalram_pages > 1024 * 1024 * 1024 / PAGE_SIZE)
286 /* FIXME: don't use vmalloc() here or anywhere else -HW */
287 hinfo = vmalloc(sizeof(struct xt_hashlimit_htable) +
288 sizeof(struct list_head) * size);
291 minfo->hinfo = hinfo;
293 /* copy match config into hashtable config */
294 memcpy(&hinfo->cfg, &minfo->cfg, sizeof(hinfo->cfg));
295 hinfo->cfg.size = size;
296 if (hinfo->cfg.max == 0)
297 hinfo->cfg.max = 8 * hinfo->cfg.size;
298 else if (hinfo->cfg.max < hinfo->cfg.size)
299 hinfo->cfg.max = hinfo->cfg.size;
301 for (i = 0; i < hinfo->cfg.size; i++)
302 INIT_HLIST_HEAD(&hinfo->hash[i]);
306 hinfo->family = family;
307 hinfo->rnd_initialized = false;
308 spin_lock_init(&hinfo->lock);
310 hinfo->pde = proc_create_data(minfo->name, 0,
311 (family == NFPROTO_IPV4) ?
312 hashlimit_net->ipt_hashlimit : hashlimit_net->ip6t_hashlimit,
313 &dl_file_ops, hinfo);
314 if (hinfo->pde == NULL) {
320 setup_timer(&hinfo->timer, htable_gc, (unsigned long)hinfo);
321 hinfo->timer.expires = jiffies + msecs_to_jiffies(hinfo->cfg.gc_interval);
322 add_timer(&hinfo->timer);
324 hlist_add_head(&hinfo->node, &hashlimit_net->htables);
329 static bool select_all(const struct xt_hashlimit_htable *ht,
330 const struct dsthash_ent *he)
335 static bool select_gc(const struct xt_hashlimit_htable *ht,
336 const struct dsthash_ent *he)
338 return time_after_eq(jiffies, he->expires);
341 static void htable_selective_cleanup(struct xt_hashlimit_htable *ht,
342 bool (*select)(const struct xt_hashlimit_htable *ht,
343 const struct dsthash_ent *he))
347 /* lock hash table and iterate over it */
348 spin_lock_bh(&ht->lock);
349 for (i = 0; i < ht->cfg.size; i++) {
350 struct dsthash_ent *dh;
351 struct hlist_node *pos, *n;
352 hlist_for_each_entry_safe(dh, pos, n, &ht->hash[i], node) {
353 if ((*select)(ht, dh))
354 dsthash_free(ht, dh);
357 spin_unlock_bh(&ht->lock);
360 /* hash table garbage collector, run by timer */
361 static void htable_gc(unsigned long htlong)
363 struct xt_hashlimit_htable *ht = (struct xt_hashlimit_htable *)htlong;
365 htable_selective_cleanup(ht, select_gc);
367 /* re-add the timer accordingly */
368 ht->timer.expires = jiffies + msecs_to_jiffies(ht->cfg.gc_interval);
369 add_timer(&ht->timer);
372 static void htable_destroy(struct xt_hashlimit_htable *hinfo)
374 struct hashlimit_net *hashlimit_net = hashlimit_pernet(hinfo->net);
375 struct proc_dir_entry *parent;
377 del_timer_sync(&hinfo->timer);
379 if (hinfo->family == NFPROTO_IPV4)
380 parent = hashlimit_net->ipt_hashlimit;
382 parent = hashlimit_net->ip6t_hashlimit;
383 remove_proc_entry(hinfo->pde->name, parent);
384 htable_selective_cleanup(hinfo, select_all);
388 static struct xt_hashlimit_htable *htable_find_get(struct net *net,
392 struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
393 struct xt_hashlimit_htable *hinfo;
394 struct hlist_node *pos;
396 hlist_for_each_entry(hinfo, pos, &hashlimit_net->htables, node) {
397 if (!strcmp(name, hinfo->pde->name) &&
398 hinfo->family == family) {
406 static void htable_put(struct xt_hashlimit_htable *hinfo)
408 mutex_lock(&hashlimit_mutex);
409 if (--hinfo->use == 0) {
410 hlist_del(&hinfo->node);
411 htable_destroy(hinfo);
413 mutex_unlock(&hashlimit_mutex);
416 /* The algorithm used is the Simple Token Bucket Filter (TBF)
417 * see net/sched/sch_tbf.c in the linux source tree
420 /* Rusty: This is my (non-mathematically-inclined) understanding of
421 this algorithm. The `average rate' in jiffies becomes your initial
422 amount of credit `credit' and the most credit you can ever have
423 `credit_cap'. The `peak rate' becomes the cost of passing the
426 `prev' tracks the last packet hit: you gain one credit per jiffy.
427 If you get credit balance more than this, the extra credit is
428 discarded. Every time the match passes, you lose `cost' credits;
429 if you don't have that many, the test fails.
431 See Alexey's formal explanation in net/sched/sch_tbf.c.
433 To get the maximum range, we multiply by this factor (ie. you get N
434 credits per jiffy). We want to allow a rate as low as 1 per day
435 (slowest userspace tool allows), which means
436 CREDITS_PER_JIFFY*HZ*60*60*24 < 2^32 ie.
438 #define MAX_CPJ (0xFFFFFFFF / (HZ*60*60*24))
440 /* Repeated shift and or gives us all 1s, final shift and add 1 gives
441 * us the power of 2 below the theoretical max, so GCC simply does a
443 #define _POW2_BELOW2(x) ((x)|((x)>>1))
444 #define _POW2_BELOW4(x) (_POW2_BELOW2(x)|_POW2_BELOW2((x)>>2))
445 #define _POW2_BELOW8(x) (_POW2_BELOW4(x)|_POW2_BELOW4((x)>>4))
446 #define _POW2_BELOW16(x) (_POW2_BELOW8(x)|_POW2_BELOW8((x)>>8))
447 #define _POW2_BELOW32(x) (_POW2_BELOW16(x)|_POW2_BELOW16((x)>>16))
448 #define POW2_BELOW32(x) ((_POW2_BELOW32(x)>>1) + 1)
450 #define CREDITS_PER_JIFFY POW2_BELOW32(MAX_CPJ)
452 /* Precision saver. */
453 static inline u_int32_t
454 user2credits(u_int32_t user)
456 /* If multiplying would overflow... */
457 if (user > 0xFFFFFFFF / (HZ*CREDITS_PER_JIFFY))
459 return (user / XT_HASHLIMIT_SCALE) * HZ * CREDITS_PER_JIFFY;
461 return (user * HZ * CREDITS_PER_JIFFY) / XT_HASHLIMIT_SCALE;
464 static inline void rateinfo_recalc(struct dsthash_ent *dh, unsigned long now)
466 dh->rateinfo.credit += (now - dh->rateinfo.prev) * CREDITS_PER_JIFFY;
467 if (dh->rateinfo.credit > dh->rateinfo.credit_cap)
468 dh->rateinfo.credit = dh->rateinfo.credit_cap;
469 dh->rateinfo.prev = now;
472 static inline __be32 maskl(__be32 a, unsigned int l)
474 return l ? htonl(ntohl(a) & ~0 << (32 - l)) : 0;
477 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
478 static void hashlimit_ipv6_mask(__be32 *i, unsigned int p)
482 i[0] = maskl(i[0], p);
483 i[1] = i[2] = i[3] = 0;
486 i[1] = maskl(i[1], p - 32);
490 i[2] = maskl(i[2], p - 64);
493 i[3] = maskl(i[3], p - 96);
502 hashlimit_init_dst(const struct xt_hashlimit_htable *hinfo,
503 struct dsthash_dst *dst,
504 const struct sk_buff *skb, unsigned int protoff)
506 __be16 _ports[2], *ports;
509 memset(dst, 0, sizeof(*dst));
511 switch (hinfo->family) {
513 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP)
514 dst->ip.dst = maskl(ip_hdr(skb)->daddr,
516 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP)
517 dst->ip.src = maskl(ip_hdr(skb)->saddr,
520 if (!(hinfo->cfg.mode &
521 (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT)))
523 nexthdr = ip_hdr(skb)->protocol;
525 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
527 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP) {
528 memcpy(&dst->ip6.dst, &ipv6_hdr(skb)->daddr,
529 sizeof(dst->ip6.dst));
530 hashlimit_ipv6_mask(dst->ip6.dst, hinfo->cfg.dstmask);
532 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP) {
533 memcpy(&dst->ip6.src, &ipv6_hdr(skb)->saddr,
534 sizeof(dst->ip6.src));
535 hashlimit_ipv6_mask(dst->ip6.src, hinfo->cfg.srcmask);
538 if (!(hinfo->cfg.mode &
539 (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT)))
541 nexthdr = ipv6_hdr(skb)->nexthdr;
542 protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr);
543 if ((int)protoff < 0)
555 case IPPROTO_UDPLITE:
558 ports = skb_header_pointer(skb, protoff, sizeof(_ports),
562 _ports[0] = _ports[1] = 0;
568 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SPT)
569 dst->src_port = ports[0];
570 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DPT)
571 dst->dst_port = ports[1];
576 hashlimit_mt_v0(const struct sk_buff *skb, const struct xt_match_param *par)
578 const struct xt_hashlimit_info *r = par->matchinfo;
579 struct xt_hashlimit_htable *hinfo = r->hinfo;
580 unsigned long now = jiffies;
581 struct dsthash_ent *dh;
582 struct dsthash_dst dst;
584 if (hashlimit_init_dst(hinfo, &dst, skb, par->thoff) < 0)
587 spin_lock_bh(&hinfo->lock);
588 dh = dsthash_find(hinfo, &dst);
590 dh = dsthash_alloc_init(hinfo, &dst);
592 spin_unlock_bh(&hinfo->lock);
596 dh->expires = jiffies + msecs_to_jiffies(hinfo->cfg.expire);
597 dh->rateinfo.prev = jiffies;
598 dh->rateinfo.credit = user2credits(hinfo->cfg.avg *
600 dh->rateinfo.credit_cap = user2credits(hinfo->cfg.avg *
602 dh->rateinfo.cost = user2credits(hinfo->cfg.avg);
604 /* update expiration timeout */
605 dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire);
606 rateinfo_recalc(dh, now);
609 if (dh->rateinfo.credit >= dh->rateinfo.cost) {
610 /* We're underlimit. */
611 dh->rateinfo.credit -= dh->rateinfo.cost;
612 spin_unlock_bh(&hinfo->lock);
616 spin_unlock_bh(&hinfo->lock);
618 /* default case: we're overlimit, thus don't match */
622 *par->hotdrop = true;
627 hashlimit_mt(const struct sk_buff *skb, const struct xt_match_param *par)
629 const struct xt_hashlimit_mtinfo1 *info = par->matchinfo;
630 struct xt_hashlimit_htable *hinfo = info->hinfo;
631 unsigned long now = jiffies;
632 struct dsthash_ent *dh;
633 struct dsthash_dst dst;
635 if (hashlimit_init_dst(hinfo, &dst, skb, par->thoff) < 0)
638 spin_lock_bh(&hinfo->lock);
639 dh = dsthash_find(hinfo, &dst);
641 dh = dsthash_alloc_init(hinfo, &dst);
643 spin_unlock_bh(&hinfo->lock);
647 dh->expires = jiffies + msecs_to_jiffies(hinfo->cfg.expire);
648 dh->rateinfo.prev = jiffies;
649 dh->rateinfo.credit = user2credits(hinfo->cfg.avg *
651 dh->rateinfo.credit_cap = user2credits(hinfo->cfg.avg *
653 dh->rateinfo.cost = user2credits(hinfo->cfg.avg);
655 /* update expiration timeout */
656 dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire);
657 rateinfo_recalc(dh, now);
660 if (dh->rateinfo.credit >= dh->rateinfo.cost) {
661 /* below the limit */
662 dh->rateinfo.credit -= dh->rateinfo.cost;
663 spin_unlock_bh(&hinfo->lock);
664 return !(info->cfg.mode & XT_HASHLIMIT_INVERT);
667 spin_unlock_bh(&hinfo->lock);
668 /* default match is underlimit - so over the limit, we need to invert */
669 return info->cfg.mode & XT_HASHLIMIT_INVERT;
672 *par->hotdrop = true;
676 static bool hashlimit_mt_check_v0(const struct xt_mtchk_param *par)
678 struct net *net = par->net;
679 struct xt_hashlimit_info *r = par->matchinfo;
681 /* Check for overflow. */
682 if (r->cfg.burst == 0 ||
683 user2credits(r->cfg.avg * r->cfg.burst) < user2credits(r->cfg.avg)) {
684 printk(KERN_ERR "xt_hashlimit: overflow, try lower: %u/%u\n",
685 r->cfg.avg, r->cfg.burst);
688 if (r->cfg.mode == 0 ||
689 r->cfg.mode > (XT_HASHLIMIT_HASH_DPT |
690 XT_HASHLIMIT_HASH_DIP |
691 XT_HASHLIMIT_HASH_SIP |
692 XT_HASHLIMIT_HASH_SPT))
694 if (!r->cfg.gc_interval)
698 if (r->name[sizeof(r->name) - 1] != '\0')
701 mutex_lock(&hashlimit_mutex);
702 r->hinfo = htable_find_get(net, r->name, par->family);
703 if (!r->hinfo && htable_create_v0(net, r, par->family) != 0) {
704 mutex_unlock(&hashlimit_mutex);
707 mutex_unlock(&hashlimit_mutex);
712 static bool hashlimit_mt_check(const struct xt_mtchk_param *par)
714 struct net *net = par->net;
715 struct xt_hashlimit_mtinfo1 *info = par->matchinfo;
717 /* Check for overflow. */
718 if (info->cfg.burst == 0 ||
719 user2credits(info->cfg.avg * info->cfg.burst) <
720 user2credits(info->cfg.avg)) {
721 printk(KERN_ERR "xt_hashlimit: overflow, try lower: %u/%u\n",
722 info->cfg.avg, info->cfg.burst);
725 if (info->cfg.gc_interval == 0 || info->cfg.expire == 0)
727 if (info->name[sizeof(info->name)-1] != '\0')
729 if (par->family == NFPROTO_IPV4) {
730 if (info->cfg.srcmask > 32 || info->cfg.dstmask > 32)
733 if (info->cfg.srcmask > 128 || info->cfg.dstmask > 128)
737 mutex_lock(&hashlimit_mutex);
738 info->hinfo = htable_find_get(net, info->name, par->family);
739 if (!info->hinfo && htable_create(net, info, par->family) != 0) {
740 mutex_unlock(&hashlimit_mutex);
743 mutex_unlock(&hashlimit_mutex);
748 hashlimit_mt_destroy_v0(const struct xt_mtdtor_param *par)
750 const struct xt_hashlimit_info *r = par->matchinfo;
752 htable_put(r->hinfo);
755 static void hashlimit_mt_destroy(const struct xt_mtdtor_param *par)
757 const struct xt_hashlimit_mtinfo1 *info = par->matchinfo;
759 htable_put(info->hinfo);
763 struct compat_xt_hashlimit_info {
765 struct hashlimit_cfg cfg;
767 compat_uptr_t master;
770 static void hashlimit_mt_compat_from_user(void *dst, const void *src)
772 int off = offsetof(struct compat_xt_hashlimit_info, hinfo);
774 memcpy(dst, src, off);
775 memset(dst + off, 0, sizeof(struct compat_xt_hashlimit_info) - off);
778 static int hashlimit_mt_compat_to_user(void __user *dst, const void *src)
780 int off = offsetof(struct compat_xt_hashlimit_info, hinfo);
782 return copy_to_user(dst, src, off) ? -EFAULT : 0;
786 static struct xt_match hashlimit_mt_reg[] __read_mostly = {
790 .family = NFPROTO_IPV4,
791 .match = hashlimit_mt_v0,
792 .matchsize = sizeof(struct xt_hashlimit_info),
794 .compatsize = sizeof(struct compat_xt_hashlimit_info),
795 .compat_from_user = hashlimit_mt_compat_from_user,
796 .compat_to_user = hashlimit_mt_compat_to_user,
798 .checkentry = hashlimit_mt_check_v0,
799 .destroy = hashlimit_mt_destroy_v0,
805 .family = NFPROTO_IPV4,
806 .match = hashlimit_mt,
807 .matchsize = sizeof(struct xt_hashlimit_mtinfo1),
808 .checkentry = hashlimit_mt_check,
809 .destroy = hashlimit_mt_destroy,
812 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
815 .family = NFPROTO_IPV6,
816 .match = hashlimit_mt_v0,
817 .matchsize = sizeof(struct xt_hashlimit_info),
819 .compatsize = sizeof(struct compat_xt_hashlimit_info),
820 .compat_from_user = hashlimit_mt_compat_from_user,
821 .compat_to_user = hashlimit_mt_compat_to_user,
823 .checkentry = hashlimit_mt_check_v0,
824 .destroy = hashlimit_mt_destroy_v0,
830 .family = NFPROTO_IPV6,
831 .match = hashlimit_mt,
832 .matchsize = sizeof(struct xt_hashlimit_mtinfo1),
833 .checkentry = hashlimit_mt_check,
834 .destroy = hashlimit_mt_destroy,
841 static void *dl_seq_start(struct seq_file *s, loff_t *pos)
842 __acquires(htable->lock)
844 struct xt_hashlimit_htable *htable = s->private;
845 unsigned int *bucket;
847 spin_lock_bh(&htable->lock);
848 if (*pos >= htable->cfg.size)
851 bucket = kmalloc(sizeof(unsigned int), GFP_ATOMIC);
853 return ERR_PTR(-ENOMEM);
859 static void *dl_seq_next(struct seq_file *s, void *v, loff_t *pos)
861 struct xt_hashlimit_htable *htable = s->private;
862 unsigned int *bucket = (unsigned int *)v;
865 if (*pos >= htable->cfg.size) {
872 static void dl_seq_stop(struct seq_file *s, void *v)
873 __releases(htable->lock)
875 struct xt_hashlimit_htable *htable = s->private;
876 unsigned int *bucket = (unsigned int *)v;
879 spin_unlock_bh(&htable->lock);
882 static int dl_seq_real_show(struct dsthash_ent *ent, u_int8_t family,
885 /* recalculate to show accurate numbers */
886 rateinfo_recalc(ent, jiffies);
890 return seq_printf(s, "%ld %pI4:%u->%pI4:%u %u %u %u\n",
891 (long)(ent->expires - jiffies)/HZ,
893 ntohs(ent->dst.src_port),
895 ntohs(ent->dst.dst_port),
896 ent->rateinfo.credit, ent->rateinfo.credit_cap,
898 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
900 return seq_printf(s, "%ld %pI6:%u->%pI6:%u %u %u %u\n",
901 (long)(ent->expires - jiffies)/HZ,
903 ntohs(ent->dst.src_port),
905 ntohs(ent->dst.dst_port),
906 ent->rateinfo.credit, ent->rateinfo.credit_cap,
915 static int dl_seq_show(struct seq_file *s, void *v)
917 struct xt_hashlimit_htable *htable = s->private;
918 unsigned int *bucket = (unsigned int *)v;
919 struct dsthash_ent *ent;
920 struct hlist_node *pos;
922 if (!hlist_empty(&htable->hash[*bucket])) {
923 hlist_for_each_entry(ent, pos, &htable->hash[*bucket], node)
924 if (dl_seq_real_show(ent, htable->family, s))
930 static const struct seq_operations dl_seq_ops = {
931 .start = dl_seq_start,
937 static int dl_proc_open(struct inode *inode, struct file *file)
939 int ret = seq_open(file, &dl_seq_ops);
942 struct seq_file *sf = file->private_data;
943 sf->private = PDE(inode)->data;
948 static const struct file_operations dl_file_ops = {
949 .owner = THIS_MODULE,
950 .open = dl_proc_open,
953 .release = seq_release
956 static int __net_init hashlimit_proc_net_init(struct net *net)
958 struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
960 hashlimit_net->ipt_hashlimit = proc_mkdir("ipt_hashlimit", net->proc_net);
961 if (!hashlimit_net->ipt_hashlimit)
963 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
964 hashlimit_net->ip6t_hashlimit = proc_mkdir("ip6t_hashlimit", net->proc_net);
965 if (!hashlimit_net->ip6t_hashlimit) {
966 proc_net_remove(net, "ipt_hashlimit");
973 static void __net_exit hashlimit_proc_net_exit(struct net *net)
975 proc_net_remove(net, "ipt_hashlimit");
976 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
977 proc_net_remove(net, "ip6t_hashlimit");
981 static int __net_init hashlimit_net_init(struct net *net)
983 struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
985 INIT_HLIST_HEAD(&hashlimit_net->htables);
986 return hashlimit_proc_net_init(net);
989 static void __net_exit hashlimit_net_exit(struct net *net)
991 struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
993 BUG_ON(!hlist_empty(&hashlimit_net->htables));
994 hashlimit_proc_net_exit(net);
997 static struct pernet_operations hashlimit_net_ops = {
998 .init = hashlimit_net_init,
999 .exit = hashlimit_net_exit,
1000 .id = &hashlimit_net_id,
1001 .size = sizeof(struct hashlimit_net),
1004 static int __init hashlimit_mt_init(void)
1008 err = register_pernet_subsys(&hashlimit_net_ops);
1011 err = xt_register_matches(hashlimit_mt_reg,
1012 ARRAY_SIZE(hashlimit_mt_reg));
1017 hashlimit_cachep = kmem_cache_create("xt_hashlimit",
1018 sizeof(struct dsthash_ent), 0, 0,
1020 if (!hashlimit_cachep) {
1021 printk(KERN_ERR "xt_hashlimit: unable to create slab cache\n");
1027 xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg));
1029 unregister_pernet_subsys(&hashlimit_net_ops);
1034 static void __exit hashlimit_mt_exit(void)
1036 kmem_cache_destroy(hashlimit_cachep);
1037 xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg));
1038 unregister_pernet_subsys(&hashlimit_net_ops);
1041 module_init(hashlimit_mt_init);
1042 module_exit(hashlimit_mt_exit);