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>
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@computergmbh.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);
219 printk(KERN_ERR "xt_hashlimit: unable to create hashtable\n");
222 minfo->hinfo = hinfo;
224 /* copy match config into hashtable config */
225 hinfo->cfg.mode = minfo->cfg.mode;
226 hinfo->cfg.avg = minfo->cfg.avg;
227 hinfo->cfg.burst = minfo->cfg.burst;
228 hinfo->cfg.max = minfo->cfg.max;
229 hinfo->cfg.gc_interval = minfo->cfg.gc_interval;
230 hinfo->cfg.expire = minfo->cfg.expire;
232 if (family == NFPROTO_IPV4)
233 hinfo->cfg.srcmask = hinfo->cfg.dstmask = 32;
235 hinfo->cfg.srcmask = hinfo->cfg.dstmask = 128;
237 hinfo->cfg.size = size;
239 hinfo->cfg.max = 8 * hinfo->cfg.size;
240 else if (hinfo->cfg.max < hinfo->cfg.size)
241 hinfo->cfg.max = hinfo->cfg.size;
243 for (i = 0; i < hinfo->cfg.size; i++)
244 INIT_HLIST_HEAD(&hinfo->hash[i]);
248 hinfo->family = family;
249 hinfo->rnd_initialized = false;
250 spin_lock_init(&hinfo->lock);
251 hinfo->pde = proc_create_data(minfo->name, 0,
252 (family == NFPROTO_IPV4) ?
253 hashlimit_net->ipt_hashlimit : hashlimit_net->ip6t_hashlimit,
254 &dl_file_ops, hinfo);
261 setup_timer(&hinfo->timer, htable_gc, (unsigned long )hinfo);
262 hinfo->timer.expires = jiffies + msecs_to_jiffies(hinfo->cfg.gc_interval);
263 add_timer(&hinfo->timer);
265 mutex_lock(&hashlimit_mutex);
266 hlist_add_head(&hinfo->node, &hashlimit_net->htables);
267 mutex_unlock(&hashlimit_mutex);
272 static int htable_create(struct net *net, struct xt_hashlimit_mtinfo1 *minfo,
275 struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
276 struct xt_hashlimit_htable *hinfo;
280 if (minfo->cfg.size) {
281 size = minfo->cfg.size;
283 size = (totalram_pages << PAGE_SHIFT) / 16384 /
284 sizeof(struct list_head);
285 if (totalram_pages > 1024 * 1024 * 1024 / PAGE_SIZE)
290 /* FIXME: don't use vmalloc() here or anywhere else -HW */
291 hinfo = vmalloc(sizeof(struct xt_hashlimit_htable) +
292 sizeof(struct list_head) * size);
294 printk(KERN_ERR "xt_hashlimit: unable to create hashtable\n");
297 minfo->hinfo = hinfo;
299 /* copy match config into hashtable config */
300 memcpy(&hinfo->cfg, &minfo->cfg, sizeof(hinfo->cfg));
301 hinfo->cfg.size = size;
302 if (hinfo->cfg.max == 0)
303 hinfo->cfg.max = 8 * hinfo->cfg.size;
304 else if (hinfo->cfg.max < hinfo->cfg.size)
305 hinfo->cfg.max = hinfo->cfg.size;
307 for (i = 0; i < hinfo->cfg.size; i++)
308 INIT_HLIST_HEAD(&hinfo->hash[i]);
312 hinfo->family = family;
313 hinfo->rnd_initialized = false;
314 spin_lock_init(&hinfo->lock);
316 hinfo->pde = proc_create_data(minfo->name, 0,
317 (family == NFPROTO_IPV4) ?
318 hashlimit_net->ipt_hashlimit : hashlimit_net->ip6t_hashlimit,
319 &dl_file_ops, hinfo);
320 if (hinfo->pde == NULL) {
326 setup_timer(&hinfo->timer, htable_gc, (unsigned long)hinfo);
327 hinfo->timer.expires = jiffies + msecs_to_jiffies(hinfo->cfg.gc_interval);
328 add_timer(&hinfo->timer);
330 mutex_lock(&hashlimit_mutex);
331 hlist_add_head(&hinfo->node, &hashlimit_net->htables);
332 mutex_unlock(&hashlimit_mutex);
337 static bool select_all(const struct xt_hashlimit_htable *ht,
338 const struct dsthash_ent *he)
343 static bool select_gc(const struct xt_hashlimit_htable *ht,
344 const struct dsthash_ent *he)
346 return time_after_eq(jiffies, he->expires);
349 static void htable_selective_cleanup(struct xt_hashlimit_htable *ht,
350 bool (*select)(const struct xt_hashlimit_htable *ht,
351 const struct dsthash_ent *he))
355 /* lock hash table and iterate over it */
356 spin_lock_bh(&ht->lock);
357 for (i = 0; i < ht->cfg.size; i++) {
358 struct dsthash_ent *dh;
359 struct hlist_node *pos, *n;
360 hlist_for_each_entry_safe(dh, pos, n, &ht->hash[i], node) {
361 if ((*select)(ht, dh))
362 dsthash_free(ht, dh);
365 spin_unlock_bh(&ht->lock);
368 /* hash table garbage collector, run by timer */
369 static void htable_gc(unsigned long htlong)
371 struct xt_hashlimit_htable *ht = (struct xt_hashlimit_htable *)htlong;
373 htable_selective_cleanup(ht, select_gc);
375 /* re-add the timer accordingly */
376 ht->timer.expires = jiffies + msecs_to_jiffies(ht->cfg.gc_interval);
377 add_timer(&ht->timer);
380 static void htable_destroy(struct xt_hashlimit_htable *hinfo)
382 struct hashlimit_net *hashlimit_net = hashlimit_pernet(hinfo->net);
383 struct proc_dir_entry *parent;
385 del_timer_sync(&hinfo->timer);
387 if (hinfo->family == NFPROTO_IPV4)
388 parent = hashlimit_net->ipt_hashlimit;
390 parent = hashlimit_net->ip6t_hashlimit;
391 remove_proc_entry(hinfo->pde->name, parent);
392 htable_selective_cleanup(hinfo, select_all);
396 static struct xt_hashlimit_htable *htable_find_get(struct net *net,
400 struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
401 struct xt_hashlimit_htable *hinfo;
402 struct hlist_node *pos;
404 hlist_for_each_entry(hinfo, pos, &hashlimit_net->htables, node) {
405 if (!strcmp(name, hinfo->pde->name) &&
406 hinfo->family == family) {
414 static void htable_put(struct xt_hashlimit_htable *hinfo)
416 mutex_lock(&hashlimit_mutex);
417 if (--hinfo->use == 0) {
418 hlist_del(&hinfo->node);
419 htable_destroy(hinfo);
421 mutex_unlock(&hashlimit_mutex);
424 /* The algorithm used is the Simple Token Bucket Filter (TBF)
425 * see net/sched/sch_tbf.c in the linux source tree
428 /* Rusty: This is my (non-mathematically-inclined) understanding of
429 this algorithm. The `average rate' in jiffies becomes your initial
430 amount of credit `credit' and the most credit you can ever have
431 `credit_cap'. The `peak rate' becomes the cost of passing the
434 `prev' tracks the last packet hit: you gain one credit per jiffy.
435 If you get credit balance more than this, the extra credit is
436 discarded. Every time the match passes, you lose `cost' credits;
437 if you don't have that many, the test fails.
439 See Alexey's formal explanation in net/sched/sch_tbf.c.
441 To get the maximum range, we multiply by this factor (ie. you get N
442 credits per jiffy). We want to allow a rate as low as 1 per day
443 (slowest userspace tool allows), which means
444 CREDITS_PER_JIFFY*HZ*60*60*24 < 2^32 ie.
446 #define MAX_CPJ (0xFFFFFFFF / (HZ*60*60*24))
448 /* Repeated shift and or gives us all 1s, final shift and add 1 gives
449 * us the power of 2 below the theoretical max, so GCC simply does a
451 #define _POW2_BELOW2(x) ((x)|((x)>>1))
452 #define _POW2_BELOW4(x) (_POW2_BELOW2(x)|_POW2_BELOW2((x)>>2))
453 #define _POW2_BELOW8(x) (_POW2_BELOW4(x)|_POW2_BELOW4((x)>>4))
454 #define _POW2_BELOW16(x) (_POW2_BELOW8(x)|_POW2_BELOW8((x)>>8))
455 #define _POW2_BELOW32(x) (_POW2_BELOW16(x)|_POW2_BELOW16((x)>>16))
456 #define POW2_BELOW32(x) ((_POW2_BELOW32(x)>>1) + 1)
458 #define CREDITS_PER_JIFFY POW2_BELOW32(MAX_CPJ)
460 /* Precision saver. */
461 static inline u_int32_t
462 user2credits(u_int32_t user)
464 /* If multiplying would overflow... */
465 if (user > 0xFFFFFFFF / (HZ*CREDITS_PER_JIFFY))
467 return (user / XT_HASHLIMIT_SCALE) * HZ * CREDITS_PER_JIFFY;
469 return (user * HZ * CREDITS_PER_JIFFY) / XT_HASHLIMIT_SCALE;
472 static inline void rateinfo_recalc(struct dsthash_ent *dh, unsigned long now)
474 dh->rateinfo.credit += (now - dh->rateinfo.prev) * CREDITS_PER_JIFFY;
475 if (dh->rateinfo.credit > dh->rateinfo.credit_cap)
476 dh->rateinfo.credit = dh->rateinfo.credit_cap;
477 dh->rateinfo.prev = now;
480 static inline __be32 maskl(__be32 a, unsigned int l)
482 return l ? htonl(ntohl(a) & ~0 << (32 - l)) : 0;
485 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
486 static void hashlimit_ipv6_mask(__be32 *i, unsigned int p)
490 i[0] = maskl(i[0], p);
491 i[1] = i[2] = i[3] = 0;
494 i[1] = maskl(i[1], p - 32);
498 i[2] = maskl(i[2], p - 64);
501 i[3] = maskl(i[3], p - 96);
510 hashlimit_init_dst(const struct xt_hashlimit_htable *hinfo,
511 struct dsthash_dst *dst,
512 const struct sk_buff *skb, unsigned int protoff)
514 __be16 _ports[2], *ports;
517 memset(dst, 0, sizeof(*dst));
519 switch (hinfo->family) {
521 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP)
522 dst->ip.dst = maskl(ip_hdr(skb)->daddr,
524 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP)
525 dst->ip.src = maskl(ip_hdr(skb)->saddr,
528 if (!(hinfo->cfg.mode &
529 (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT)))
531 nexthdr = ip_hdr(skb)->protocol;
533 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
535 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP) {
536 memcpy(&dst->ip6.dst, &ipv6_hdr(skb)->daddr,
537 sizeof(dst->ip6.dst));
538 hashlimit_ipv6_mask(dst->ip6.dst, hinfo->cfg.dstmask);
540 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP) {
541 memcpy(&dst->ip6.src, &ipv6_hdr(skb)->saddr,
542 sizeof(dst->ip6.src));
543 hashlimit_ipv6_mask(dst->ip6.src, hinfo->cfg.srcmask);
546 if (!(hinfo->cfg.mode &
547 (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT)))
549 nexthdr = ipv6_hdr(skb)->nexthdr;
550 protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr);
551 if ((int)protoff < 0)
563 case IPPROTO_UDPLITE:
566 ports = skb_header_pointer(skb, protoff, sizeof(_ports),
570 _ports[0] = _ports[1] = 0;
576 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SPT)
577 dst->src_port = ports[0];
578 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DPT)
579 dst->dst_port = ports[1];
584 hashlimit_mt_v0(const struct sk_buff *skb, const struct xt_match_param *par)
586 const struct xt_hashlimit_info *r = par->matchinfo;
587 struct xt_hashlimit_htable *hinfo = r->hinfo;
588 unsigned long now = jiffies;
589 struct dsthash_ent *dh;
590 struct dsthash_dst dst;
592 if (hashlimit_init_dst(hinfo, &dst, skb, par->thoff) < 0)
595 spin_lock_bh(&hinfo->lock);
596 dh = dsthash_find(hinfo, &dst);
598 dh = dsthash_alloc_init(hinfo, &dst);
600 spin_unlock_bh(&hinfo->lock);
604 dh->expires = jiffies + msecs_to_jiffies(hinfo->cfg.expire);
605 dh->rateinfo.prev = jiffies;
606 dh->rateinfo.credit = user2credits(hinfo->cfg.avg *
608 dh->rateinfo.credit_cap = user2credits(hinfo->cfg.avg *
610 dh->rateinfo.cost = user2credits(hinfo->cfg.avg);
612 /* update expiration timeout */
613 dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire);
614 rateinfo_recalc(dh, now);
617 if (dh->rateinfo.credit >= dh->rateinfo.cost) {
618 /* We're underlimit. */
619 dh->rateinfo.credit -= dh->rateinfo.cost;
620 spin_unlock_bh(&hinfo->lock);
624 spin_unlock_bh(&hinfo->lock);
626 /* default case: we're overlimit, thus don't match */
630 *par->hotdrop = true;
635 hashlimit_mt(const struct sk_buff *skb, const struct xt_match_param *par)
637 const struct xt_hashlimit_mtinfo1 *info = par->matchinfo;
638 struct xt_hashlimit_htable *hinfo = info->hinfo;
639 unsigned long now = jiffies;
640 struct dsthash_ent *dh;
641 struct dsthash_dst dst;
643 if (hashlimit_init_dst(hinfo, &dst, skb, par->thoff) < 0)
646 spin_lock_bh(&hinfo->lock);
647 dh = dsthash_find(hinfo, &dst);
649 dh = dsthash_alloc_init(hinfo, &dst);
651 spin_unlock_bh(&hinfo->lock);
655 dh->expires = jiffies + msecs_to_jiffies(hinfo->cfg.expire);
656 dh->rateinfo.prev = jiffies;
657 dh->rateinfo.credit = user2credits(hinfo->cfg.avg *
659 dh->rateinfo.credit_cap = user2credits(hinfo->cfg.avg *
661 dh->rateinfo.cost = user2credits(hinfo->cfg.avg);
663 /* update expiration timeout */
664 dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire);
665 rateinfo_recalc(dh, now);
668 if (dh->rateinfo.credit >= dh->rateinfo.cost) {
669 /* below the limit */
670 dh->rateinfo.credit -= dh->rateinfo.cost;
671 spin_unlock_bh(&hinfo->lock);
672 return !(info->cfg.mode & XT_HASHLIMIT_INVERT);
675 spin_unlock_bh(&hinfo->lock);
676 /* default match is underlimit - so over the limit, we need to invert */
677 return info->cfg.mode & XT_HASHLIMIT_INVERT;
680 *par->hotdrop = true;
684 static bool hashlimit_mt_check_v0(const struct xt_mtchk_param *par)
686 struct net *net = par->net;
687 struct xt_hashlimit_info *r = par->matchinfo;
689 /* Check for overflow. */
690 if (r->cfg.burst == 0 ||
691 user2credits(r->cfg.avg * r->cfg.burst) < user2credits(r->cfg.avg)) {
692 printk(KERN_ERR "xt_hashlimit: overflow, try lower: %u/%u\n",
693 r->cfg.avg, r->cfg.burst);
696 if (r->cfg.mode == 0 ||
697 r->cfg.mode > (XT_HASHLIMIT_HASH_DPT |
698 XT_HASHLIMIT_HASH_DIP |
699 XT_HASHLIMIT_HASH_SIP |
700 XT_HASHLIMIT_HASH_SPT))
702 if (!r->cfg.gc_interval)
706 if (r->name[sizeof(r->name) - 1] != '\0')
709 mutex_lock(&hashlimit_mutex);
710 r->hinfo = htable_find_get(net, r->name, par->match->family);
711 if (!r->hinfo && htable_create_v0(net, r, par->match->family) != 0) {
712 mutex_unlock(&hashlimit_mutex);
715 mutex_unlock(&hashlimit_mutex);
720 static bool hashlimit_mt_check(const struct xt_mtchk_param *par)
722 struct net *net = par->net;
723 struct xt_hashlimit_mtinfo1 *info = par->matchinfo;
725 /* Check for overflow. */
726 if (info->cfg.burst == 0 ||
727 user2credits(info->cfg.avg * info->cfg.burst) <
728 user2credits(info->cfg.avg)) {
729 printk(KERN_ERR "xt_hashlimit: overflow, try lower: %u/%u\n",
730 info->cfg.avg, info->cfg.burst);
733 if (info->cfg.gc_interval == 0 || info->cfg.expire == 0)
735 if (info->name[sizeof(info->name)-1] != '\0')
737 if (par->match->family == NFPROTO_IPV4) {
738 if (info->cfg.srcmask > 32 || info->cfg.dstmask > 32)
741 if (info->cfg.srcmask > 128 || info->cfg.dstmask > 128)
745 mutex_lock(&hashlimit_mutex);
746 info->hinfo = htable_find_get(net, info->name, par->match->family);
747 if (!info->hinfo && htable_create(net, info, par->match->family) != 0) {
748 mutex_unlock(&hashlimit_mutex);
751 mutex_unlock(&hashlimit_mutex);
756 hashlimit_mt_destroy_v0(const struct xt_mtdtor_param *par)
758 const struct xt_hashlimit_info *r = par->matchinfo;
760 htable_put(r->hinfo);
763 static void hashlimit_mt_destroy(const struct xt_mtdtor_param *par)
765 const struct xt_hashlimit_mtinfo1 *info = par->matchinfo;
767 htable_put(info->hinfo);
771 struct compat_xt_hashlimit_info {
773 struct hashlimit_cfg cfg;
775 compat_uptr_t master;
778 static void hashlimit_mt_compat_from_user(void *dst, void *src)
780 int off = offsetof(struct compat_xt_hashlimit_info, hinfo);
782 memcpy(dst, src, off);
783 memset(dst + off, 0, sizeof(struct compat_xt_hashlimit_info) - off);
786 static int hashlimit_mt_compat_to_user(void __user *dst, void *src)
788 int off = offsetof(struct compat_xt_hashlimit_info, hinfo);
790 return copy_to_user(dst, src, off) ? -EFAULT : 0;
794 static struct xt_match hashlimit_mt_reg[] __read_mostly = {
798 .family = NFPROTO_IPV4,
799 .match = hashlimit_mt_v0,
800 .matchsize = sizeof(struct xt_hashlimit_info),
802 .compatsize = sizeof(struct compat_xt_hashlimit_info),
803 .compat_from_user = hashlimit_mt_compat_from_user,
804 .compat_to_user = hashlimit_mt_compat_to_user,
806 .checkentry = hashlimit_mt_check_v0,
807 .destroy = hashlimit_mt_destroy_v0,
813 .family = NFPROTO_IPV4,
814 .match = hashlimit_mt,
815 .matchsize = sizeof(struct xt_hashlimit_mtinfo1),
816 .checkentry = hashlimit_mt_check,
817 .destroy = hashlimit_mt_destroy,
820 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
823 .family = NFPROTO_IPV6,
824 .match = hashlimit_mt_v0,
825 .matchsize = sizeof(struct xt_hashlimit_info),
827 .compatsize = sizeof(struct compat_xt_hashlimit_info),
828 .compat_from_user = hashlimit_mt_compat_from_user,
829 .compat_to_user = hashlimit_mt_compat_to_user,
831 .checkentry = hashlimit_mt_check_v0,
832 .destroy = hashlimit_mt_destroy_v0,
838 .family = NFPROTO_IPV6,
839 .match = hashlimit_mt,
840 .matchsize = sizeof(struct xt_hashlimit_mtinfo1),
841 .checkentry = hashlimit_mt_check,
842 .destroy = hashlimit_mt_destroy,
849 static void *dl_seq_start(struct seq_file *s, loff_t *pos)
850 __acquires(htable->lock)
852 struct xt_hashlimit_htable *htable = s->private;
853 unsigned int *bucket;
855 spin_lock_bh(&htable->lock);
856 if (*pos >= htable->cfg.size)
859 bucket = kmalloc(sizeof(unsigned int), GFP_ATOMIC);
861 return ERR_PTR(-ENOMEM);
867 static void *dl_seq_next(struct seq_file *s, void *v, loff_t *pos)
869 struct xt_hashlimit_htable *htable = s->private;
870 unsigned int *bucket = (unsigned int *)v;
873 if (*pos >= htable->cfg.size) {
880 static void dl_seq_stop(struct seq_file *s, void *v)
881 __releases(htable->lock)
883 struct xt_hashlimit_htable *htable = s->private;
884 unsigned int *bucket = (unsigned int *)v;
887 spin_unlock_bh(&htable->lock);
890 static int dl_seq_real_show(struct dsthash_ent *ent, u_int8_t family,
893 /* recalculate to show accurate numbers */
894 rateinfo_recalc(ent, jiffies);
898 return seq_printf(s, "%ld %pI4:%u->%pI4:%u %u %u %u\n",
899 (long)(ent->expires - jiffies)/HZ,
901 ntohs(ent->dst.src_port),
903 ntohs(ent->dst.dst_port),
904 ent->rateinfo.credit, ent->rateinfo.credit_cap,
906 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
908 return seq_printf(s, "%ld %pI6:%u->%pI6:%u %u %u %u\n",
909 (long)(ent->expires - jiffies)/HZ,
911 ntohs(ent->dst.src_port),
913 ntohs(ent->dst.dst_port),
914 ent->rateinfo.credit, ent->rateinfo.credit_cap,
923 static int dl_seq_show(struct seq_file *s, void *v)
925 struct xt_hashlimit_htable *htable = s->private;
926 unsigned int *bucket = (unsigned int *)v;
927 struct dsthash_ent *ent;
928 struct hlist_node *pos;
930 if (!hlist_empty(&htable->hash[*bucket])) {
931 hlist_for_each_entry(ent, pos, &htable->hash[*bucket], node)
932 if (dl_seq_real_show(ent, htable->family, s))
938 static const struct seq_operations dl_seq_ops = {
939 .start = dl_seq_start,
945 static int dl_proc_open(struct inode *inode, struct file *file)
947 int ret = seq_open(file, &dl_seq_ops);
950 struct seq_file *sf = file->private_data;
951 sf->private = PDE(inode)->data;
956 static const struct file_operations dl_file_ops = {
957 .owner = THIS_MODULE,
958 .open = dl_proc_open,
961 .release = seq_release
964 static int __net_init hashlimit_proc_net_init(struct net *net)
966 struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
968 hashlimit_net->ipt_hashlimit = proc_mkdir("ipt_hashlimit", net->proc_net);
969 if (!hashlimit_net->ipt_hashlimit)
971 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
972 hashlimit_net->ip6t_hashlimit = proc_mkdir("ip6t_hashlimit", net->proc_net);
973 if (!hashlimit_net->ip6t_hashlimit) {
974 proc_net_remove(net, "ipt_hashlimit");
981 static void __net_exit hashlimit_proc_net_exit(struct net *net)
983 proc_net_remove(net, "ipt_hashlimit");
984 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
985 proc_net_remove(net, "ip6t_hashlimit");
989 static int __net_init hashlimit_net_init(struct net *net)
991 struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
993 INIT_HLIST_HEAD(&hashlimit_net->htables);
994 return hashlimit_proc_net_init(net);
997 static void __net_exit hashlimit_net_exit(struct net *net)
999 struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
1001 BUG_ON(!hlist_empty(&hashlimit_net->htables));
1002 hashlimit_proc_net_exit(net);
1005 static struct pernet_operations hashlimit_net_ops = {
1006 .init = hashlimit_net_init,
1007 .exit = hashlimit_net_exit,
1008 .id = &hashlimit_net_id,
1009 .size = sizeof(struct hashlimit_net),
1012 static int __init hashlimit_mt_init(void)
1016 err = register_pernet_subsys(&hashlimit_net_ops);
1019 err = xt_register_matches(hashlimit_mt_reg,
1020 ARRAY_SIZE(hashlimit_mt_reg));
1025 hashlimit_cachep = kmem_cache_create("xt_hashlimit",
1026 sizeof(struct dsthash_ent), 0, 0,
1028 if (!hashlimit_cachep) {
1029 printk(KERN_ERR "xt_hashlimit: unable to create slab cache\n");
1035 xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg));
1037 unregister_pernet_subsys(&hashlimit_net_ops);
1042 static void __exit hashlimit_mt_exit(void)
1044 kmem_cache_destroy(hashlimit_cachep);
1045 xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg));
1046 unregister_pernet_subsys(&hashlimit_net_ops);
1049 module_init(hashlimit_mt_init);
1050 module_exit(hashlimit_mt_exit);