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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11 #include <linux/module.h>
12 #include <linux/spinlock.h>
13 #include <linux/random.h>
14 #include <linux/jhash.h>
15 #include <linux/slab.h>
16 #include <linux/vmalloc.h>
17 #include <linux/proc_fs.h>
18 #include <linux/seq_file.h>
19 #include <linux/list.h>
20 #include <linux/skbuff.h>
24 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
25 #include <linux/ipv6.h>
29 #include <net/net_namespace.h>
30 #include <net/netns/generic.h>
32 #include <linux/netfilter/x_tables.h>
33 #include <linux/netfilter_ipv4/ip_tables.h>
34 #include <linux/netfilter_ipv6/ip6_tables.h>
35 #include <linux/netfilter/xt_hashlimit.h>
36 #include <linux/mutex.h>
38 MODULE_LICENSE("GPL");
39 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
40 MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
41 MODULE_DESCRIPTION("Xtables: per hash-bucket rate-limit match");
42 MODULE_ALIAS("ipt_hashlimit");
43 MODULE_ALIAS("ip6t_hashlimit");
45 struct hashlimit_net {
46 struct hlist_head htables;
47 struct proc_dir_entry *ipt_hashlimit;
48 struct proc_dir_entry *ip6t_hashlimit;
51 static int hashlimit_net_id;
52 static inline struct hashlimit_net *hashlimit_pernet(struct net *net)
54 return net_generic(net, hashlimit_net_id);
57 /* need to declare this at the top */
58 static const struct file_operations dl_file_ops;
67 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
79 /* static / read-only parts in the beginning */
80 struct hlist_node node;
81 struct dsthash_dst dst;
83 /* modified structure members in the end */
84 unsigned long expires; /* precalculated expiry time */
86 unsigned long prev; /* last modification */
88 u_int32_t credit_cap, cost;
92 struct xt_hashlimit_htable {
93 struct hlist_node node; /* global list of all htables */
98 struct hashlimit_cfg1 cfg; /* config */
100 /* used internally */
101 spinlock_t lock; /* lock for list_head */
102 u_int32_t rnd; /* random seed for hash */
103 unsigned int count; /* number entries in table */
104 struct timer_list timer; /* timer for gc */
107 struct proc_dir_entry *pde;
110 struct hlist_head hash[0]; /* hashtable itself */
113 static DEFINE_MUTEX(hashlimit_mutex); /* protects htables list */
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.. */
170 pr_err("max count of %u reached\n", ht->cfg.max);
174 ent = kmem_cache_alloc(hashlimit_cachep, GFP_ATOMIC);
177 pr_err("cannot allocate dsthash_ent\n");
180 memcpy(&ent->dst, dst, sizeof(ent->dst));
182 hlist_add_head(&ent->node, &ht->hash[hash_dst(ht, dst)]);
188 dsthash_free(struct xt_hashlimit_htable *ht, struct dsthash_ent *ent)
190 hlist_del(&ent->node);
191 kmem_cache_free(hashlimit_cachep, ent);
194 static void htable_gc(unsigned long htlong);
196 static int htable_create_v0(struct net *net, struct xt_hashlimit_info *minfo, u_int8_t family)
198 struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
199 struct xt_hashlimit_htable *hinfo;
204 size = minfo->cfg.size;
206 size = ((totalram_pages << PAGE_SHIFT) / 16384) /
207 sizeof(struct list_head);
208 if (totalram_pages > (1024 * 1024 * 1024 / PAGE_SIZE))
213 /* FIXME: don't use vmalloc() here or anywhere else -HW */
214 hinfo = vmalloc(sizeof(struct xt_hashlimit_htable) +
215 sizeof(struct list_head) * size);
218 minfo->hinfo = hinfo;
220 /* copy match config into hashtable config */
221 hinfo->cfg.mode = minfo->cfg.mode;
222 hinfo->cfg.avg = minfo->cfg.avg;
223 hinfo->cfg.burst = minfo->cfg.burst;
224 hinfo->cfg.max = minfo->cfg.max;
225 hinfo->cfg.gc_interval = minfo->cfg.gc_interval;
226 hinfo->cfg.expire = minfo->cfg.expire;
228 if (family == NFPROTO_IPV4)
229 hinfo->cfg.srcmask = hinfo->cfg.dstmask = 32;
231 hinfo->cfg.srcmask = hinfo->cfg.dstmask = 128;
233 hinfo->cfg.size = size;
235 hinfo->cfg.max = 8 * hinfo->cfg.size;
236 else if (hinfo->cfg.max < hinfo->cfg.size)
237 hinfo->cfg.max = hinfo->cfg.size;
239 for (i = 0; i < hinfo->cfg.size; i++)
240 INIT_HLIST_HEAD(&hinfo->hash[i]);
244 hinfo->family = family;
245 hinfo->rnd_initialized = false;
246 spin_lock_init(&hinfo->lock);
247 hinfo->pde = proc_create_data(minfo->name, 0,
248 (family == NFPROTO_IPV4) ?
249 hashlimit_net->ipt_hashlimit : hashlimit_net->ip6t_hashlimit,
250 &dl_file_ops, hinfo);
257 setup_timer(&hinfo->timer, htable_gc, (unsigned long )hinfo);
258 hinfo->timer.expires = jiffies + msecs_to_jiffies(hinfo->cfg.gc_interval);
259 add_timer(&hinfo->timer);
261 hlist_add_head(&hinfo->node, &hashlimit_net->htables);
266 static int htable_create(struct net *net, struct xt_hashlimit_mtinfo1 *minfo,
269 struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
270 struct xt_hashlimit_htable *hinfo;
274 if (minfo->cfg.size) {
275 size = minfo->cfg.size;
277 size = (totalram_pages << PAGE_SHIFT) / 16384 /
278 sizeof(struct list_head);
279 if (totalram_pages > 1024 * 1024 * 1024 / PAGE_SIZE)
284 /* FIXME: don't use vmalloc() here or anywhere else -HW */
285 hinfo = vmalloc(sizeof(struct xt_hashlimit_htable) +
286 sizeof(struct list_head) * size);
289 minfo->hinfo = hinfo;
291 /* copy match config into hashtable config */
292 memcpy(&hinfo->cfg, &minfo->cfg, sizeof(hinfo->cfg));
293 hinfo->cfg.size = size;
294 if (hinfo->cfg.max == 0)
295 hinfo->cfg.max = 8 * hinfo->cfg.size;
296 else if (hinfo->cfg.max < hinfo->cfg.size)
297 hinfo->cfg.max = hinfo->cfg.size;
299 for (i = 0; i < hinfo->cfg.size; i++)
300 INIT_HLIST_HEAD(&hinfo->hash[i]);
304 hinfo->family = family;
305 hinfo->rnd_initialized = false;
306 spin_lock_init(&hinfo->lock);
308 hinfo->pde = proc_create_data(minfo->name, 0,
309 (family == NFPROTO_IPV4) ?
310 hashlimit_net->ipt_hashlimit : hashlimit_net->ip6t_hashlimit,
311 &dl_file_ops, hinfo);
312 if (hinfo->pde == NULL) {
318 setup_timer(&hinfo->timer, htable_gc, (unsigned long)hinfo);
319 hinfo->timer.expires = jiffies + msecs_to_jiffies(hinfo->cfg.gc_interval);
320 add_timer(&hinfo->timer);
322 hlist_add_head(&hinfo->node, &hashlimit_net->htables);
327 static bool select_all(const struct xt_hashlimit_htable *ht,
328 const struct dsthash_ent *he)
333 static bool select_gc(const struct xt_hashlimit_htable *ht,
334 const struct dsthash_ent *he)
336 return time_after_eq(jiffies, he->expires);
339 static void htable_selective_cleanup(struct xt_hashlimit_htable *ht,
340 bool (*select)(const struct xt_hashlimit_htable *ht,
341 const struct dsthash_ent *he))
345 /* lock hash table and iterate over it */
346 spin_lock_bh(&ht->lock);
347 for (i = 0; i < ht->cfg.size; i++) {
348 struct dsthash_ent *dh;
349 struct hlist_node *pos, *n;
350 hlist_for_each_entry_safe(dh, pos, n, &ht->hash[i], node) {
351 if ((*select)(ht, dh))
352 dsthash_free(ht, dh);
355 spin_unlock_bh(&ht->lock);
358 /* hash table garbage collector, run by timer */
359 static void htable_gc(unsigned long htlong)
361 struct xt_hashlimit_htable *ht = (struct xt_hashlimit_htable *)htlong;
363 htable_selective_cleanup(ht, select_gc);
365 /* re-add the timer accordingly */
366 ht->timer.expires = jiffies + msecs_to_jiffies(ht->cfg.gc_interval);
367 add_timer(&ht->timer);
370 static void htable_destroy(struct xt_hashlimit_htable *hinfo)
372 struct hashlimit_net *hashlimit_net = hashlimit_pernet(hinfo->net);
373 struct proc_dir_entry *parent;
375 del_timer_sync(&hinfo->timer);
377 if (hinfo->family == NFPROTO_IPV4)
378 parent = hashlimit_net->ipt_hashlimit;
380 parent = hashlimit_net->ip6t_hashlimit;
381 remove_proc_entry(hinfo->pde->name, parent);
382 htable_selective_cleanup(hinfo, select_all);
386 static struct xt_hashlimit_htable *htable_find_get(struct net *net,
390 struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
391 struct xt_hashlimit_htable *hinfo;
392 struct hlist_node *pos;
394 hlist_for_each_entry(hinfo, pos, &hashlimit_net->htables, node) {
395 if (!strcmp(name, hinfo->pde->name) &&
396 hinfo->family == family) {
404 static void htable_put(struct xt_hashlimit_htable *hinfo)
406 mutex_lock(&hashlimit_mutex);
407 if (--hinfo->use == 0) {
408 hlist_del(&hinfo->node);
409 htable_destroy(hinfo);
411 mutex_unlock(&hashlimit_mutex);
414 /* The algorithm used is the Simple Token Bucket Filter (TBF)
415 * see net/sched/sch_tbf.c in the linux source tree
418 /* Rusty: This is my (non-mathematically-inclined) understanding of
419 this algorithm. The `average rate' in jiffies becomes your initial
420 amount of credit `credit' and the most credit you can ever have
421 `credit_cap'. The `peak rate' becomes the cost of passing the
424 `prev' tracks the last packet hit: you gain one credit per jiffy.
425 If you get credit balance more than this, the extra credit is
426 discarded. Every time the match passes, you lose `cost' credits;
427 if you don't have that many, the test fails.
429 See Alexey's formal explanation in net/sched/sch_tbf.c.
431 To get the maximum range, we multiply by this factor (ie. you get N
432 credits per jiffy). We want to allow a rate as low as 1 per day
433 (slowest userspace tool allows), which means
434 CREDITS_PER_JIFFY*HZ*60*60*24 < 2^32 ie.
436 #define MAX_CPJ (0xFFFFFFFF / (HZ*60*60*24))
438 /* Repeated shift and or gives us all 1s, final shift and add 1 gives
439 * us the power of 2 below the theoretical max, so GCC simply does a
441 #define _POW2_BELOW2(x) ((x)|((x)>>1))
442 #define _POW2_BELOW4(x) (_POW2_BELOW2(x)|_POW2_BELOW2((x)>>2))
443 #define _POW2_BELOW8(x) (_POW2_BELOW4(x)|_POW2_BELOW4((x)>>4))
444 #define _POW2_BELOW16(x) (_POW2_BELOW8(x)|_POW2_BELOW8((x)>>8))
445 #define _POW2_BELOW32(x) (_POW2_BELOW16(x)|_POW2_BELOW16((x)>>16))
446 #define POW2_BELOW32(x) ((_POW2_BELOW32(x)>>1) + 1)
448 #define CREDITS_PER_JIFFY POW2_BELOW32(MAX_CPJ)
450 /* Precision saver. */
451 static inline u_int32_t
452 user2credits(u_int32_t user)
454 /* If multiplying would overflow... */
455 if (user > 0xFFFFFFFF / (HZ*CREDITS_PER_JIFFY))
457 return (user / XT_HASHLIMIT_SCALE) * HZ * CREDITS_PER_JIFFY;
459 return (user * HZ * CREDITS_PER_JIFFY) / XT_HASHLIMIT_SCALE;
462 static inline void rateinfo_recalc(struct dsthash_ent *dh, unsigned long now)
464 dh->rateinfo.credit += (now - dh->rateinfo.prev) * CREDITS_PER_JIFFY;
465 if (dh->rateinfo.credit > dh->rateinfo.credit_cap)
466 dh->rateinfo.credit = dh->rateinfo.credit_cap;
467 dh->rateinfo.prev = now;
470 static inline __be32 maskl(__be32 a, unsigned int l)
472 return l ? htonl(ntohl(a) & ~0 << (32 - l)) : 0;
475 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
476 static void hashlimit_ipv6_mask(__be32 *i, unsigned int p)
480 i[0] = maskl(i[0], p);
481 i[1] = i[2] = i[3] = 0;
484 i[1] = maskl(i[1], p - 32);
488 i[2] = maskl(i[2], p - 64);
491 i[3] = maskl(i[3], p - 96);
500 hashlimit_init_dst(const struct xt_hashlimit_htable *hinfo,
501 struct dsthash_dst *dst,
502 const struct sk_buff *skb, unsigned int protoff)
504 __be16 _ports[2], *ports;
507 memset(dst, 0, sizeof(*dst));
509 switch (hinfo->family) {
511 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP)
512 dst->ip.dst = maskl(ip_hdr(skb)->daddr,
514 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP)
515 dst->ip.src = maskl(ip_hdr(skb)->saddr,
518 if (!(hinfo->cfg.mode &
519 (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT)))
521 nexthdr = ip_hdr(skb)->protocol;
523 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
525 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP) {
526 memcpy(&dst->ip6.dst, &ipv6_hdr(skb)->daddr,
527 sizeof(dst->ip6.dst));
528 hashlimit_ipv6_mask(dst->ip6.dst, hinfo->cfg.dstmask);
530 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP) {
531 memcpy(&dst->ip6.src, &ipv6_hdr(skb)->saddr,
532 sizeof(dst->ip6.src));
533 hashlimit_ipv6_mask(dst->ip6.src, hinfo->cfg.srcmask);
536 if (!(hinfo->cfg.mode &
537 (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT)))
539 nexthdr = ipv6_hdr(skb)->nexthdr;
540 protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr);
541 if ((int)protoff < 0)
553 case IPPROTO_UDPLITE:
556 ports = skb_header_pointer(skb, protoff, sizeof(_ports),
560 _ports[0] = _ports[1] = 0;
566 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SPT)
567 dst->src_port = ports[0];
568 if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DPT)
569 dst->dst_port = ports[1];
574 hashlimit_mt_v0(const struct sk_buff *skb, const struct xt_match_param *par)
576 const struct xt_hashlimit_info *r = par->matchinfo;
577 struct xt_hashlimit_htable *hinfo = r->hinfo;
578 unsigned long now = jiffies;
579 struct dsthash_ent *dh;
580 struct dsthash_dst dst;
582 if (hashlimit_init_dst(hinfo, &dst, skb, par->thoff) < 0)
585 spin_lock_bh(&hinfo->lock);
586 dh = dsthash_find(hinfo, &dst);
588 dh = dsthash_alloc_init(hinfo, &dst);
590 spin_unlock_bh(&hinfo->lock);
594 dh->expires = jiffies + msecs_to_jiffies(hinfo->cfg.expire);
595 dh->rateinfo.prev = jiffies;
596 dh->rateinfo.credit = user2credits(hinfo->cfg.avg *
598 dh->rateinfo.credit_cap = user2credits(hinfo->cfg.avg *
600 dh->rateinfo.cost = user2credits(hinfo->cfg.avg);
602 /* update expiration timeout */
603 dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire);
604 rateinfo_recalc(dh, now);
607 if (dh->rateinfo.credit >= dh->rateinfo.cost) {
608 /* We're underlimit. */
609 dh->rateinfo.credit -= dh->rateinfo.cost;
610 spin_unlock_bh(&hinfo->lock);
614 spin_unlock_bh(&hinfo->lock);
616 /* default case: we're overlimit, thus don't match */
620 *par->hotdrop = true;
625 hashlimit_mt(const struct sk_buff *skb, const struct xt_match_param *par)
627 const struct xt_hashlimit_mtinfo1 *info = par->matchinfo;
628 struct xt_hashlimit_htable *hinfo = info->hinfo;
629 unsigned long now = jiffies;
630 struct dsthash_ent *dh;
631 struct dsthash_dst dst;
633 if (hashlimit_init_dst(hinfo, &dst, skb, par->thoff) < 0)
636 spin_lock_bh(&hinfo->lock);
637 dh = dsthash_find(hinfo, &dst);
639 dh = dsthash_alloc_init(hinfo, &dst);
641 spin_unlock_bh(&hinfo->lock);
645 dh->expires = jiffies + msecs_to_jiffies(hinfo->cfg.expire);
646 dh->rateinfo.prev = jiffies;
647 dh->rateinfo.credit = user2credits(hinfo->cfg.avg *
649 dh->rateinfo.credit_cap = user2credits(hinfo->cfg.avg *
651 dh->rateinfo.cost = user2credits(hinfo->cfg.avg);
653 /* update expiration timeout */
654 dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire);
655 rateinfo_recalc(dh, now);
658 if (dh->rateinfo.credit >= dh->rateinfo.cost) {
659 /* below the limit */
660 dh->rateinfo.credit -= dh->rateinfo.cost;
661 spin_unlock_bh(&hinfo->lock);
662 return !(info->cfg.mode & XT_HASHLIMIT_INVERT);
665 spin_unlock_bh(&hinfo->lock);
666 /* default match is underlimit - so over the limit, we need to invert */
667 return info->cfg.mode & XT_HASHLIMIT_INVERT;
670 *par->hotdrop = true;
674 static bool hashlimit_mt_check_v0(const struct xt_mtchk_param *par)
676 struct net *net = par->net;
677 struct xt_hashlimit_info *r = par->matchinfo;
679 /* Check for overflow. */
680 if (r->cfg.burst == 0 ||
681 user2credits(r->cfg.avg * r->cfg.burst) < user2credits(r->cfg.avg)) {
682 pr_info("overflow, try lower: %u/%u\n",
683 r->cfg.avg, r->cfg.burst);
686 if (r->cfg.mode == 0 ||
687 r->cfg.mode > (XT_HASHLIMIT_HASH_DPT |
688 XT_HASHLIMIT_HASH_DIP |
689 XT_HASHLIMIT_HASH_SIP |
690 XT_HASHLIMIT_HASH_SPT))
692 if (!r->cfg.gc_interval)
696 if (r->name[sizeof(r->name) - 1] != '\0')
699 mutex_lock(&hashlimit_mutex);
700 r->hinfo = htable_find_get(net, r->name, par->family);
701 if (!r->hinfo && htable_create_v0(net, r, par->family) != 0) {
702 mutex_unlock(&hashlimit_mutex);
705 mutex_unlock(&hashlimit_mutex);
710 static bool hashlimit_mt_check(const struct xt_mtchk_param *par)
712 struct net *net = par->net;
713 struct xt_hashlimit_mtinfo1 *info = par->matchinfo;
715 /* Check for overflow. */
716 if (info->cfg.burst == 0 ||
717 user2credits(info->cfg.avg * info->cfg.burst) <
718 user2credits(info->cfg.avg)) {
719 pr_info("overflow, try lower: %u/%u\n",
720 info->cfg.avg, info->cfg.burst);
723 if (info->cfg.gc_interval == 0 || info->cfg.expire == 0)
725 if (info->name[sizeof(info->name)-1] != '\0')
727 if (par->family == NFPROTO_IPV4) {
728 if (info->cfg.srcmask > 32 || info->cfg.dstmask > 32)
731 if (info->cfg.srcmask > 128 || info->cfg.dstmask > 128)
735 mutex_lock(&hashlimit_mutex);
736 info->hinfo = htable_find_get(net, info->name, par->family);
737 if (!info->hinfo && htable_create(net, info, par->family) != 0) {
738 mutex_unlock(&hashlimit_mutex);
741 mutex_unlock(&hashlimit_mutex);
746 hashlimit_mt_destroy_v0(const struct xt_mtdtor_param *par)
748 const struct xt_hashlimit_info *r = par->matchinfo;
750 htable_put(r->hinfo);
753 static void hashlimit_mt_destroy(const struct xt_mtdtor_param *par)
755 const struct xt_hashlimit_mtinfo1 *info = par->matchinfo;
757 htable_put(info->hinfo);
761 struct compat_xt_hashlimit_info {
763 struct hashlimit_cfg cfg;
765 compat_uptr_t master;
768 static void hashlimit_mt_compat_from_user(void *dst, const void *src)
770 int off = offsetof(struct compat_xt_hashlimit_info, hinfo);
772 memcpy(dst, src, off);
773 memset(dst + off, 0, sizeof(struct compat_xt_hashlimit_info) - off);
776 static int hashlimit_mt_compat_to_user(void __user *dst, const void *src)
778 int off = offsetof(struct compat_xt_hashlimit_info, hinfo);
780 return copy_to_user(dst, src, off) ? -EFAULT : 0;
784 static struct xt_match hashlimit_mt_reg[] __read_mostly = {
788 .family = NFPROTO_IPV4,
789 .match = hashlimit_mt_v0,
790 .matchsize = sizeof(struct xt_hashlimit_info),
792 .compatsize = sizeof(struct compat_xt_hashlimit_info),
793 .compat_from_user = hashlimit_mt_compat_from_user,
794 .compat_to_user = hashlimit_mt_compat_to_user,
796 .checkentry = hashlimit_mt_check_v0,
797 .destroy = hashlimit_mt_destroy_v0,
803 .family = NFPROTO_IPV4,
804 .match = hashlimit_mt,
805 .matchsize = sizeof(struct xt_hashlimit_mtinfo1),
806 .checkentry = hashlimit_mt_check,
807 .destroy = hashlimit_mt_destroy,
810 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
813 .family = NFPROTO_IPV6,
814 .match = hashlimit_mt_v0,
815 .matchsize = sizeof(struct xt_hashlimit_info),
817 .compatsize = sizeof(struct compat_xt_hashlimit_info),
818 .compat_from_user = hashlimit_mt_compat_from_user,
819 .compat_to_user = hashlimit_mt_compat_to_user,
821 .checkentry = hashlimit_mt_check_v0,
822 .destroy = hashlimit_mt_destroy_v0,
828 .family = NFPROTO_IPV6,
829 .match = hashlimit_mt,
830 .matchsize = sizeof(struct xt_hashlimit_mtinfo1),
831 .checkentry = hashlimit_mt_check,
832 .destroy = hashlimit_mt_destroy,
839 static void *dl_seq_start(struct seq_file *s, loff_t *pos)
840 __acquires(htable->lock)
842 struct xt_hashlimit_htable *htable = s->private;
843 unsigned int *bucket;
845 spin_lock_bh(&htable->lock);
846 if (*pos >= htable->cfg.size)
849 bucket = kmalloc(sizeof(unsigned int), GFP_ATOMIC);
851 return ERR_PTR(-ENOMEM);
857 static void *dl_seq_next(struct seq_file *s, void *v, loff_t *pos)
859 struct xt_hashlimit_htable *htable = s->private;
860 unsigned int *bucket = (unsigned int *)v;
863 if (*pos >= htable->cfg.size) {
870 static void dl_seq_stop(struct seq_file *s, void *v)
871 __releases(htable->lock)
873 struct xt_hashlimit_htable *htable = s->private;
874 unsigned int *bucket = (unsigned int *)v;
877 spin_unlock_bh(&htable->lock);
880 static int dl_seq_real_show(struct dsthash_ent *ent, u_int8_t family,
883 /* recalculate to show accurate numbers */
884 rateinfo_recalc(ent, jiffies);
888 return seq_printf(s, "%ld %pI4:%u->%pI4:%u %u %u %u\n",
889 (long)(ent->expires - jiffies)/HZ,
891 ntohs(ent->dst.src_port),
893 ntohs(ent->dst.dst_port),
894 ent->rateinfo.credit, ent->rateinfo.credit_cap,
896 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
898 return seq_printf(s, "%ld %pI6:%u->%pI6:%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,
913 static int dl_seq_show(struct seq_file *s, void *v)
915 struct xt_hashlimit_htable *htable = s->private;
916 unsigned int *bucket = (unsigned int *)v;
917 struct dsthash_ent *ent;
918 struct hlist_node *pos;
920 if (!hlist_empty(&htable->hash[*bucket])) {
921 hlist_for_each_entry(ent, pos, &htable->hash[*bucket], node)
922 if (dl_seq_real_show(ent, htable->family, s))
928 static const struct seq_operations dl_seq_ops = {
929 .start = dl_seq_start,
935 static int dl_proc_open(struct inode *inode, struct file *file)
937 int ret = seq_open(file, &dl_seq_ops);
940 struct seq_file *sf = file->private_data;
941 sf->private = PDE(inode)->data;
946 static const struct file_operations dl_file_ops = {
947 .owner = THIS_MODULE,
948 .open = dl_proc_open,
951 .release = seq_release
954 static int __net_init hashlimit_proc_net_init(struct net *net)
956 struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
958 hashlimit_net->ipt_hashlimit = proc_mkdir("ipt_hashlimit", net->proc_net);
959 if (!hashlimit_net->ipt_hashlimit)
961 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
962 hashlimit_net->ip6t_hashlimit = proc_mkdir("ip6t_hashlimit", net->proc_net);
963 if (!hashlimit_net->ip6t_hashlimit) {
964 proc_net_remove(net, "ipt_hashlimit");
971 static void __net_exit hashlimit_proc_net_exit(struct net *net)
973 proc_net_remove(net, "ipt_hashlimit");
974 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
975 proc_net_remove(net, "ip6t_hashlimit");
979 static int __net_init hashlimit_net_init(struct net *net)
981 struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
983 INIT_HLIST_HEAD(&hashlimit_net->htables);
984 return hashlimit_proc_net_init(net);
987 static void __net_exit hashlimit_net_exit(struct net *net)
989 struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
991 BUG_ON(!hlist_empty(&hashlimit_net->htables));
992 hashlimit_proc_net_exit(net);
995 static struct pernet_operations hashlimit_net_ops = {
996 .init = hashlimit_net_init,
997 .exit = hashlimit_net_exit,
998 .id = &hashlimit_net_id,
999 .size = sizeof(struct hashlimit_net),
1002 static int __init hashlimit_mt_init(void)
1006 err = register_pernet_subsys(&hashlimit_net_ops);
1009 err = xt_register_matches(hashlimit_mt_reg,
1010 ARRAY_SIZE(hashlimit_mt_reg));
1015 hashlimit_cachep = kmem_cache_create("xt_hashlimit",
1016 sizeof(struct dsthash_ent), 0, 0,
1018 if (!hashlimit_cachep) {
1019 pr_warning("unable to create slab cache\n");
1025 xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg));
1027 unregister_pernet_subsys(&hashlimit_net_ops);
1032 static void __exit hashlimit_mt_exit(void)
1034 kmem_cache_destroy(hashlimit_cachep);
1035 xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg));
1036 unregister_pernet_subsys(&hashlimit_net_ops);
1039 module_init(hashlimit_mt_init);
1040 module_exit(hashlimit_mt_exit);