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_SPINLOCK(hashlimit_lock); /* protects htables list */
113 static DEFINE_MUTEX(hlimit_mutex); /* additional checkentry protection */
114 static struct kmem_cache *hashlimit_cachep __read_mostly;
116 static inline bool dst_cmp(const struct dsthash_ent *ent,
117 const struct dsthash_dst *b)
119 return !memcmp(&ent->dst, b, sizeof(ent->dst));
123 hash_dst(const struct xt_hashlimit_htable *ht, const struct dsthash_dst *dst)
125 u_int32_t hash = jhash2((const u32 *)dst,
126 sizeof(*dst)/sizeof(u32),
129 * Instead of returning hash % ht->cfg.size (implying a divide)
130 * we return the high 32 bits of the (hash * ht->cfg.size) that will
131 * give results between [0 and cfg.size-1] and same hash distribution,
132 * but using a multiply, less expensive than a divide
134 return ((u64)hash * ht->cfg.size) >> 32;
137 static struct dsthash_ent *
138 dsthash_find(const struct xt_hashlimit_htable *ht,
139 const struct dsthash_dst *dst)
141 struct dsthash_ent *ent;
142 struct hlist_node *pos;
143 u_int32_t hash = hash_dst(ht, dst);
145 if (!hlist_empty(&ht->hash[hash])) {
146 hlist_for_each_entry(ent, pos, &ht->hash[hash], node)
147 if (dst_cmp(ent, dst))
153 /* allocate dsthash_ent, initialize dst, put in htable and lock it */
154 static struct dsthash_ent *
155 dsthash_alloc_init(struct xt_hashlimit_htable *ht,
156 const struct dsthash_dst *dst)
158 struct dsthash_ent *ent;
160 /* initialize hash with random val at the time we allocate
161 * the first hashtable entry */
162 if (!ht->rnd_initialized) {
163 get_random_bytes(&ht->rnd, sizeof(ht->rnd));
164 ht->rnd_initialized = true;
167 if (ht->cfg.max && ht->count >= ht->cfg.max) {
168 /* FIXME: do something. question is what.. */
171 "xt_hashlimit: max count of %u reached\n",
176 ent = kmem_cache_alloc(hashlimit_cachep, GFP_ATOMIC);
180 "xt_hashlimit: can't allocate dsthash_ent\n");
183 memcpy(&ent->dst, dst, sizeof(ent->dst));
185 hlist_add_head(&ent->node, &ht->hash[hash_dst(ht, dst)]);
191 dsthash_free(struct xt_hashlimit_htable *ht, struct dsthash_ent *ent)
193 hlist_del(&ent->node);
194 kmem_cache_free(hashlimit_cachep, ent);
197 static void htable_gc(unsigned long htlong);
199 static int htable_create_v0(struct net *net, struct xt_hashlimit_info *minfo, u_int8_t family)
201 struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
202 struct xt_hashlimit_htable *hinfo;
207 size = minfo->cfg.size;
209 size = ((totalram_pages << PAGE_SHIFT) / 16384) /
210 sizeof(struct list_head);
211 if (totalram_pages > (1024 * 1024 * 1024 / PAGE_SIZE))
216 /* FIXME: don't use vmalloc() here or anywhere else -HW */
217 hinfo = vmalloc(sizeof(struct xt_hashlimit_htable) +
218 sizeof(struct list_head) * size);
220 printk(KERN_ERR "xt_hashlimit: unable to create hashtable\n");
223 minfo->hinfo = hinfo;
225 /* copy match config into hashtable config */
226 hinfo->cfg.mode = minfo->cfg.mode;
227 hinfo->cfg.avg = minfo->cfg.avg;
228 hinfo->cfg.burst = minfo->cfg.burst;
229 hinfo->cfg.max = minfo->cfg.max;
230 hinfo->cfg.gc_interval = minfo->cfg.gc_interval;
231 hinfo->cfg.expire = minfo->cfg.expire;
233 if (family == NFPROTO_IPV4)
234 hinfo->cfg.srcmask = hinfo->cfg.dstmask = 32;
236 hinfo->cfg.srcmask = hinfo->cfg.dstmask = 128;
238 hinfo->cfg.size = size;
240 hinfo->cfg.max = 8 * hinfo->cfg.size;
241 else if (hinfo->cfg.max < hinfo->cfg.size)
242 hinfo->cfg.max = hinfo->cfg.size;
244 for (i = 0; i < hinfo->cfg.size; i++)
245 INIT_HLIST_HEAD(&hinfo->hash[i]);
247 atomic_set(&hinfo->use, 1);
249 hinfo->family = family;
250 hinfo->rnd_initialized = false;
251 spin_lock_init(&hinfo->lock);
252 hinfo->pde = proc_create_data(minfo->name, 0,
253 (family == NFPROTO_IPV4) ?
254 hashlimit_net->ipt_hashlimit : hashlimit_net->ip6t_hashlimit,
255 &dl_file_ops, hinfo);
262 setup_timer(&hinfo->timer, htable_gc, (unsigned long )hinfo);
263 hinfo->timer.expires = jiffies + msecs_to_jiffies(hinfo->cfg.gc_interval);
264 add_timer(&hinfo->timer);
266 spin_lock_bh(&hashlimit_lock);
267 hlist_add_head(&hinfo->node, &hashlimit_net->htables);
268 spin_unlock_bh(&hashlimit_lock);
273 static int htable_create(struct net *net, struct xt_hashlimit_mtinfo1 *minfo,
276 struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
277 struct xt_hashlimit_htable *hinfo;
281 if (minfo->cfg.size) {
282 size = minfo->cfg.size;
284 size = (totalram_pages << PAGE_SHIFT) / 16384 /
285 sizeof(struct list_head);
286 if (totalram_pages > 1024 * 1024 * 1024 / PAGE_SIZE)
291 /* FIXME: don't use vmalloc() here or anywhere else -HW */
292 hinfo = vmalloc(sizeof(struct xt_hashlimit_htable) +
293 sizeof(struct list_head) * size);
295 printk(KERN_ERR "xt_hashlimit: unable to create hashtable\n");
298 minfo->hinfo = hinfo;
300 /* copy match config into hashtable config */
301 memcpy(&hinfo->cfg, &minfo->cfg, sizeof(hinfo->cfg));
302 hinfo->cfg.size = size;
303 if (hinfo->cfg.max == 0)
304 hinfo->cfg.max = 8 * hinfo->cfg.size;
305 else if (hinfo->cfg.max < hinfo->cfg.size)
306 hinfo->cfg.max = hinfo->cfg.size;
308 for (i = 0; i < hinfo->cfg.size; i++)
309 INIT_HLIST_HEAD(&hinfo->hash[i]);
311 atomic_set(&hinfo->use, 1);
313 hinfo->family = family;
314 hinfo->rnd_initialized = false;
315 spin_lock_init(&hinfo->lock);
317 hinfo->pde = proc_create_data(minfo->name, 0,
318 (family == NFPROTO_IPV4) ?
319 hashlimit_net->ipt_hashlimit : hashlimit_net->ip6t_hashlimit,
320 &dl_file_ops, hinfo);
321 if (hinfo->pde == NULL) {
327 setup_timer(&hinfo->timer, htable_gc, (unsigned long)hinfo);
328 hinfo->timer.expires = jiffies + msecs_to_jiffies(hinfo->cfg.gc_interval);
329 add_timer(&hinfo->timer);
331 spin_lock_bh(&hashlimit_lock);
332 hlist_add_head(&hinfo->node, &hashlimit_net->htables);
333 spin_unlock_bh(&hashlimit_lock);
338 static bool select_all(const struct xt_hashlimit_htable *ht,
339 const struct dsthash_ent *he)
344 static bool select_gc(const struct xt_hashlimit_htable *ht,
345 const struct dsthash_ent *he)
347 return time_after_eq(jiffies, he->expires);
350 static void htable_selective_cleanup(struct xt_hashlimit_htable *ht,
351 bool (*select)(const struct xt_hashlimit_htable *ht,
352 const struct dsthash_ent *he))
356 /* lock hash table and iterate over it */
357 spin_lock_bh(&ht->lock);
358 for (i = 0; i < ht->cfg.size; i++) {
359 struct dsthash_ent *dh;
360 struct hlist_node *pos, *n;
361 hlist_for_each_entry_safe(dh, pos, n, &ht->hash[i], node) {
362 if ((*select)(ht, dh))
363 dsthash_free(ht, dh);
366 spin_unlock_bh(&ht->lock);
369 /* hash table garbage collector, run by timer */
370 static void htable_gc(unsigned long htlong)
372 struct xt_hashlimit_htable *ht = (struct xt_hashlimit_htable *)htlong;
374 htable_selective_cleanup(ht, select_gc);
376 /* re-add the timer accordingly */
377 ht->timer.expires = jiffies + msecs_to_jiffies(ht->cfg.gc_interval);
378 add_timer(&ht->timer);
381 static void htable_destroy(struct xt_hashlimit_htable *hinfo)
383 struct hashlimit_net *hashlimit_net = hashlimit_pernet(hinfo->net);
384 struct proc_dir_entry *parent;
386 del_timer_sync(&hinfo->timer);
388 if (hinfo->family == NFPROTO_IPV4)
389 parent = hashlimit_net->ipt_hashlimit;
391 parent = hashlimit_net->ip6t_hashlimit;
392 remove_proc_entry(hinfo->pde->name, parent);
393 htable_selective_cleanup(hinfo, select_all);
397 static struct xt_hashlimit_htable *htable_find_get(struct net *net,
401 struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
402 struct xt_hashlimit_htable *hinfo;
403 struct hlist_node *pos;
405 spin_lock_bh(&hashlimit_lock);
406 hlist_for_each_entry(hinfo, pos, &hashlimit_net->htables, node) {
407 if (!strcmp(name, hinfo->pde->name) &&
408 hinfo->family == family) {
409 atomic_inc(&hinfo->use);
410 spin_unlock_bh(&hashlimit_lock);
414 spin_unlock_bh(&hashlimit_lock);
418 static void htable_put(struct xt_hashlimit_htable *hinfo)
420 if (atomic_dec_and_test(&hinfo->use)) {
421 spin_lock_bh(&hashlimit_lock);
422 hlist_del(&hinfo->node);
423 spin_unlock_bh(&hashlimit_lock);
424 htable_destroy(hinfo);
428 /* The algorithm used is the Simple Token Bucket Filter (TBF)
429 * see net/sched/sch_tbf.c in the linux source tree
432 /* Rusty: This is my (non-mathematically-inclined) understanding of
433 this algorithm. The `average rate' in jiffies becomes your initial
434 amount of credit `credit' and the most credit you can ever have
435 `credit_cap'. The `peak rate' becomes the cost of passing the
438 `prev' tracks the last packet hit: you gain one credit per jiffy.
439 If you get credit balance more than this, the extra credit is
440 discarded. Every time the match passes, you lose `cost' credits;
441 if you don't have that many, the test fails.
443 See Alexey's formal explanation in net/sched/sch_tbf.c.
445 To get the maximum range, we multiply by this factor (ie. you get N
446 credits per jiffy). We want to allow a rate as low as 1 per day
447 (slowest userspace tool allows), which means
448 CREDITS_PER_JIFFY*HZ*60*60*24 < 2^32 ie.
450 #define MAX_CPJ (0xFFFFFFFF / (HZ*60*60*24))
452 /* Repeated shift and or gives us all 1s, final shift and add 1 gives
453 * us the power of 2 below the theoretical max, so GCC simply does a
455 #define _POW2_BELOW2(x) ((x)|((x)>>1))
456 #define _POW2_BELOW4(x) (_POW2_BELOW2(x)|_POW2_BELOW2((x)>>2))
457 #define _POW2_BELOW8(x) (_POW2_BELOW4(x)|_POW2_BELOW4((x)>>4))
458 #define _POW2_BELOW16(x) (_POW2_BELOW8(x)|_POW2_BELOW8((x)>>8))
459 #define _POW2_BELOW32(x) (_POW2_BELOW16(x)|_POW2_BELOW16((x)>>16))
460 #define POW2_BELOW32(x) ((_POW2_BELOW32(x)>>1) + 1)
462 #define CREDITS_PER_JIFFY POW2_BELOW32(MAX_CPJ)
464 /* Precision saver. */
465 static inline u_int32_t
466 user2credits(u_int32_t user)
468 /* If multiplying would overflow... */
469 if (user > 0xFFFFFFFF / (HZ*CREDITS_PER_JIFFY))
471 return (user / XT_HASHLIMIT_SCALE) * HZ * CREDITS_PER_JIFFY;
473 return (user * HZ * CREDITS_PER_JIFFY) / XT_HASHLIMIT_SCALE;
476 static inline void rateinfo_recalc(struct dsthash_ent *dh, unsigned long now)
478 dh->rateinfo.credit += (now - dh->rateinfo.prev) * CREDITS_PER_JIFFY;
479 if (dh->rateinfo.credit > dh->rateinfo.credit_cap)
480 dh->rateinfo.credit = dh->rateinfo.credit_cap;
481 dh->rateinfo.prev = now;
484 static inline __be32 maskl(__be32 a, unsigned int l)
486 return l ? htonl(ntohl(a) & ~0 << (32 - l)) : 0;
489 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
490 static void hashlimit_ipv6_mask(__be32 *i, unsigned int p)
494 i[0] = maskl(i[0], p);
495 i[1] = i[2] = i[3] = 0;
498 i[1] = maskl(i[1], p - 32);
502 i[2] = maskl(i[2], p - 64);
505 i[3] = maskl(i[3], p - 96);
514 hashlimit_init_dst(const struct xt_hashlimit_htable *hinfo,
515 struct dsthash_dst *dst,
516 const struct sk_buff *skb, unsigned int protoff)
518 __be16 _ports[2], *ports;
521 memset(dst, 0, sizeof(*dst));
523 switch (hinfo->family) {
525 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP)
526 dst->ip.dst = maskl(ip_hdr(skb)->daddr,
528 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP)
529 dst->ip.src = maskl(ip_hdr(skb)->saddr,
532 if (!(hinfo->cfg.mode &
533 (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT)))
535 nexthdr = ip_hdr(skb)->protocol;
537 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
539 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP) {
540 memcpy(&dst->ip6.dst, &ipv6_hdr(skb)->daddr,
541 sizeof(dst->ip6.dst));
542 hashlimit_ipv6_mask(dst->ip6.dst, hinfo->cfg.dstmask);
544 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP) {
545 memcpy(&dst->ip6.src, &ipv6_hdr(skb)->saddr,
546 sizeof(dst->ip6.src));
547 hashlimit_ipv6_mask(dst->ip6.src, hinfo->cfg.srcmask);
550 if (!(hinfo->cfg.mode &
551 (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT)))
553 nexthdr = ipv6_hdr(skb)->nexthdr;
554 protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr);
555 if ((int)protoff < 0)
567 case IPPROTO_UDPLITE:
570 ports = skb_header_pointer(skb, protoff, sizeof(_ports),
574 _ports[0] = _ports[1] = 0;
580 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SPT)
581 dst->src_port = ports[0];
582 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DPT)
583 dst->dst_port = ports[1];
588 hashlimit_mt_v0(const struct sk_buff *skb, const struct xt_match_param *par)
590 const struct xt_hashlimit_info *r = par->matchinfo;
591 struct xt_hashlimit_htable *hinfo = r->hinfo;
592 unsigned long now = jiffies;
593 struct dsthash_ent *dh;
594 struct dsthash_dst dst;
596 if (hashlimit_init_dst(hinfo, &dst, skb, par->thoff) < 0)
599 spin_lock_bh(&hinfo->lock);
600 dh = dsthash_find(hinfo, &dst);
602 dh = dsthash_alloc_init(hinfo, &dst);
604 spin_unlock_bh(&hinfo->lock);
608 dh->expires = jiffies + msecs_to_jiffies(hinfo->cfg.expire);
609 dh->rateinfo.prev = jiffies;
610 dh->rateinfo.credit = user2credits(hinfo->cfg.avg *
612 dh->rateinfo.credit_cap = user2credits(hinfo->cfg.avg *
614 dh->rateinfo.cost = user2credits(hinfo->cfg.avg);
616 /* update expiration timeout */
617 dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire);
618 rateinfo_recalc(dh, now);
621 if (dh->rateinfo.credit >= dh->rateinfo.cost) {
622 /* We're underlimit. */
623 dh->rateinfo.credit -= dh->rateinfo.cost;
624 spin_unlock_bh(&hinfo->lock);
628 spin_unlock_bh(&hinfo->lock);
630 /* default case: we're overlimit, thus don't match */
634 *par->hotdrop = true;
639 hashlimit_mt(const struct sk_buff *skb, const struct xt_match_param *par)
641 const struct xt_hashlimit_mtinfo1 *info = par->matchinfo;
642 struct xt_hashlimit_htable *hinfo = info->hinfo;
643 unsigned long now = jiffies;
644 struct dsthash_ent *dh;
645 struct dsthash_dst dst;
647 if (hashlimit_init_dst(hinfo, &dst, skb, par->thoff) < 0)
650 spin_lock_bh(&hinfo->lock);
651 dh = dsthash_find(hinfo, &dst);
653 dh = dsthash_alloc_init(hinfo, &dst);
655 spin_unlock_bh(&hinfo->lock);
659 dh->expires = jiffies + msecs_to_jiffies(hinfo->cfg.expire);
660 dh->rateinfo.prev = jiffies;
661 dh->rateinfo.credit = user2credits(hinfo->cfg.avg *
663 dh->rateinfo.credit_cap = user2credits(hinfo->cfg.avg *
665 dh->rateinfo.cost = user2credits(hinfo->cfg.avg);
667 /* update expiration timeout */
668 dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire);
669 rateinfo_recalc(dh, now);
672 if (dh->rateinfo.credit >= dh->rateinfo.cost) {
673 /* below the limit */
674 dh->rateinfo.credit -= dh->rateinfo.cost;
675 spin_unlock_bh(&hinfo->lock);
676 return !(info->cfg.mode & XT_HASHLIMIT_INVERT);
679 spin_unlock_bh(&hinfo->lock);
680 /* default match is underlimit - so over the limit, we need to invert */
681 return info->cfg.mode & XT_HASHLIMIT_INVERT;
684 *par->hotdrop = true;
688 static bool hashlimit_mt_check_v0(const struct xt_mtchk_param *par)
690 struct net *net = par->net;
691 struct xt_hashlimit_info *r = par->matchinfo;
693 /* Check for overflow. */
694 if (r->cfg.burst == 0 ||
695 user2credits(r->cfg.avg * r->cfg.burst) < user2credits(r->cfg.avg)) {
696 printk(KERN_ERR "xt_hashlimit: overflow, try lower: %u/%u\n",
697 r->cfg.avg, r->cfg.burst);
700 if (r->cfg.mode == 0 ||
701 r->cfg.mode > (XT_HASHLIMIT_HASH_DPT |
702 XT_HASHLIMIT_HASH_DIP |
703 XT_HASHLIMIT_HASH_SIP |
704 XT_HASHLIMIT_HASH_SPT))
706 if (!r->cfg.gc_interval)
710 if (r->name[sizeof(r->name) - 1] != '\0')
713 /* This is the best we've got: We cannot release and re-grab lock,
714 * since checkentry() is called before x_tables.c grabs xt_mutex.
715 * We also cannot grab the hashtable spinlock, since htable_create will
716 * call vmalloc, and that can sleep. And we cannot just re-search
717 * the list of htable's in htable_create(), since then we would
718 * create duplicate proc files. -HW */
719 mutex_lock(&hlimit_mutex);
720 r->hinfo = htable_find_get(net, r->name, par->match->family);
721 if (!r->hinfo && htable_create_v0(net, r, par->match->family) != 0) {
722 mutex_unlock(&hlimit_mutex);
725 mutex_unlock(&hlimit_mutex);
730 static bool hashlimit_mt_check(const struct xt_mtchk_param *par)
732 struct net *net = par->net;
733 struct xt_hashlimit_mtinfo1 *info = par->matchinfo;
735 /* Check for overflow. */
736 if (info->cfg.burst == 0 ||
737 user2credits(info->cfg.avg * info->cfg.burst) <
738 user2credits(info->cfg.avg)) {
739 printk(KERN_ERR "xt_hashlimit: overflow, try lower: %u/%u\n",
740 info->cfg.avg, info->cfg.burst);
743 if (info->cfg.gc_interval == 0 || info->cfg.expire == 0)
745 if (info->name[sizeof(info->name)-1] != '\0')
747 if (par->match->family == NFPROTO_IPV4) {
748 if (info->cfg.srcmask > 32 || info->cfg.dstmask > 32)
751 if (info->cfg.srcmask > 128 || info->cfg.dstmask > 128)
755 /* This is the best we've got: We cannot release and re-grab lock,
756 * since checkentry() is called before x_tables.c grabs xt_mutex.
757 * We also cannot grab the hashtable spinlock, since htable_create will
758 * call vmalloc, and that can sleep. And we cannot just re-search
759 * the list of htable's in htable_create(), since then we would
760 * create duplicate proc files. -HW */
761 mutex_lock(&hlimit_mutex);
762 info->hinfo = htable_find_get(net, info->name, par->match->family);
763 if (!info->hinfo && htable_create(net, info, par->match->family) != 0) {
764 mutex_unlock(&hlimit_mutex);
767 mutex_unlock(&hlimit_mutex);
772 hashlimit_mt_destroy_v0(const struct xt_mtdtor_param *par)
774 const struct xt_hashlimit_info *r = par->matchinfo;
776 htable_put(r->hinfo);
779 static void hashlimit_mt_destroy(const struct xt_mtdtor_param *par)
781 const struct xt_hashlimit_mtinfo1 *info = par->matchinfo;
783 htable_put(info->hinfo);
787 struct compat_xt_hashlimit_info {
789 struct hashlimit_cfg cfg;
791 compat_uptr_t master;
794 static void hashlimit_mt_compat_from_user(void *dst, void *src)
796 int off = offsetof(struct compat_xt_hashlimit_info, hinfo);
798 memcpy(dst, src, off);
799 memset(dst + off, 0, sizeof(struct compat_xt_hashlimit_info) - off);
802 static int hashlimit_mt_compat_to_user(void __user *dst, void *src)
804 int off = offsetof(struct compat_xt_hashlimit_info, hinfo);
806 return copy_to_user(dst, src, off) ? -EFAULT : 0;
810 static struct xt_match hashlimit_mt_reg[] __read_mostly = {
814 .family = NFPROTO_IPV4,
815 .match = hashlimit_mt_v0,
816 .matchsize = sizeof(struct xt_hashlimit_info),
818 .compatsize = sizeof(struct compat_xt_hashlimit_info),
819 .compat_from_user = hashlimit_mt_compat_from_user,
820 .compat_to_user = hashlimit_mt_compat_to_user,
822 .checkentry = hashlimit_mt_check_v0,
823 .destroy = hashlimit_mt_destroy_v0,
829 .family = NFPROTO_IPV4,
830 .match = hashlimit_mt,
831 .matchsize = sizeof(struct xt_hashlimit_mtinfo1),
832 .checkentry = hashlimit_mt_check,
833 .destroy = hashlimit_mt_destroy,
836 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
839 .family = NFPROTO_IPV6,
840 .match = hashlimit_mt_v0,
841 .matchsize = sizeof(struct xt_hashlimit_info),
843 .compatsize = sizeof(struct compat_xt_hashlimit_info),
844 .compat_from_user = hashlimit_mt_compat_from_user,
845 .compat_to_user = hashlimit_mt_compat_to_user,
847 .checkentry = hashlimit_mt_check_v0,
848 .destroy = hashlimit_mt_destroy_v0,
854 .family = NFPROTO_IPV6,
855 .match = hashlimit_mt,
856 .matchsize = sizeof(struct xt_hashlimit_mtinfo1),
857 .checkentry = hashlimit_mt_check,
858 .destroy = hashlimit_mt_destroy,
865 static void *dl_seq_start(struct seq_file *s, loff_t *pos)
866 __acquires(htable->lock)
868 struct xt_hashlimit_htable *htable = s->private;
869 unsigned int *bucket;
871 spin_lock_bh(&htable->lock);
872 if (*pos >= htable->cfg.size)
875 bucket = kmalloc(sizeof(unsigned int), GFP_ATOMIC);
877 return ERR_PTR(-ENOMEM);
883 static void *dl_seq_next(struct seq_file *s, void *v, loff_t *pos)
885 struct xt_hashlimit_htable *htable = s->private;
886 unsigned int *bucket = (unsigned int *)v;
889 if (*pos >= htable->cfg.size) {
896 static void dl_seq_stop(struct seq_file *s, void *v)
897 __releases(htable->lock)
899 struct xt_hashlimit_htable *htable = s->private;
900 unsigned int *bucket = (unsigned int *)v;
903 spin_unlock_bh(&htable->lock);
906 static int dl_seq_real_show(struct dsthash_ent *ent, u_int8_t family,
909 /* recalculate to show accurate numbers */
910 rateinfo_recalc(ent, jiffies);
914 return seq_printf(s, "%ld %pI4:%u->%pI4:%u %u %u %u\n",
915 (long)(ent->expires - jiffies)/HZ,
917 ntohs(ent->dst.src_port),
919 ntohs(ent->dst.dst_port),
920 ent->rateinfo.credit, ent->rateinfo.credit_cap,
922 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
924 return seq_printf(s, "%ld %pI6:%u->%pI6:%u %u %u %u\n",
925 (long)(ent->expires - jiffies)/HZ,
927 ntohs(ent->dst.src_port),
929 ntohs(ent->dst.dst_port),
930 ent->rateinfo.credit, ent->rateinfo.credit_cap,
939 static int dl_seq_show(struct seq_file *s, void *v)
941 struct xt_hashlimit_htable *htable = s->private;
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)->data;
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 __net_init hashlimit_proc_net_init(struct net *net)
982 struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
984 hashlimit_net->ipt_hashlimit = proc_mkdir("ipt_hashlimit", net->proc_net);
985 if (!hashlimit_net->ipt_hashlimit)
987 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
988 hashlimit_net->ip6t_hashlimit = proc_mkdir("ip6t_hashlimit", net->proc_net);
989 if (!hashlimit_net->ip6t_hashlimit) {
990 proc_net_remove(net, "ipt_hashlimit");
997 static void __net_exit hashlimit_proc_net_exit(struct net *net)
999 proc_net_remove(net, "ipt_hashlimit");
1000 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
1001 proc_net_remove(net, "ip6t_hashlimit");
1005 static int __net_init hashlimit_net_init(struct net *net)
1007 struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
1009 INIT_HLIST_HEAD(&hashlimit_net->htables);
1010 return hashlimit_proc_net_init(net);
1013 static void __net_exit hashlimit_net_exit(struct net *net)
1015 struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
1017 BUG_ON(!hlist_empty(&hashlimit_net->htables));
1018 hashlimit_proc_net_exit(net);
1021 static struct pernet_operations hashlimit_net_ops = {
1022 .init = hashlimit_net_init,
1023 .exit = hashlimit_net_exit,
1024 .id = &hashlimit_net_id,
1025 .size = sizeof(struct hashlimit_net),
1028 static int __init hashlimit_mt_init(void)
1032 err = register_pernet_subsys(&hashlimit_net_ops);
1035 err = xt_register_matches(hashlimit_mt_reg,
1036 ARRAY_SIZE(hashlimit_mt_reg));
1041 hashlimit_cachep = kmem_cache_create("xt_hashlimit",
1042 sizeof(struct dsthash_ent), 0, 0,
1044 if (!hashlimit_cachep) {
1045 printk(KERN_ERR "xt_hashlimit: unable to create slab cache\n");
1051 xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg));
1053 unregister_pernet_subsys(&hashlimit_net_ops);
1058 static void __exit hashlimit_mt_exit(void)
1060 kmem_cache_destroy(hashlimit_cachep);
1061 xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg));
1062 unregister_pernet_subsys(&hashlimit_net_ops);
1065 module_init(hashlimit_mt_init);
1066 module_exit(hashlimit_mt_exit);