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 * (C) 2006-2012 Patrick McHardy <kaber@trash.net>
7 * Copyright © CC Computer Consultants GmbH, 2007 - 2008
9 * Development of this code was funded by Astaro AG, http://www.astaro.com/
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 #include <linux/module.h>
13 #include <linux/spinlock.h>
14 #include <linux/random.h>
15 #include <linux/jhash.h>
16 #include <linux/slab.h>
17 #include <linux/vmalloc.h>
18 #include <linux/proc_fs.h>
19 #include <linux/seq_file.h>
20 #include <linux/list.h>
21 #include <linux/skbuff.h>
25 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
26 #include <linux/ipv6.h>
30 #include <net/net_namespace.h>
31 #include <net/netns/generic.h>
33 #include <linux/netfilter/x_tables.h>
34 #include <linux/netfilter_ipv4/ip_tables.h>
35 #include <linux/netfilter_ipv6/ip6_tables.h>
36 #include <linux/netfilter/xt_hashlimit.h>
37 #include <linux/mutex.h>
39 MODULE_LICENSE("GPL");
40 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
41 MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
42 MODULE_DESCRIPTION("Xtables: per hash-bucket rate-limit match");
43 MODULE_ALIAS("ipt_hashlimit");
44 MODULE_ALIAS("ip6t_hashlimit");
46 struct hashlimit_net
{
47 struct hlist_head htables
;
48 struct proc_dir_entry
*ipt_hashlimit
;
49 struct proc_dir_entry
*ip6t_hashlimit
;
52 static int hashlimit_net_id
;
53 static inline struct hashlimit_net
*hashlimit_pernet(struct net
*net
)
55 return net_generic(net
, hashlimit_net_id
);
58 /* need to declare this at the top */
59 static const struct file_operations dl_file_ops
;
68 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
80 /* static / read-only parts in the beginning */
81 struct hlist_node node
;
82 struct dsthash_dst dst
;
84 /* modified structure members in the end */
86 unsigned long expires
; /* precalculated expiry time */
88 unsigned long prev
; /* last modification */
90 u_int32_t credit_cap
, cost
;
95 struct xt_hashlimit_htable
{
96 struct hlist_node node
; /* global list of all htables */
101 struct hashlimit_cfg1 cfg
; /* config */
103 /* used internally */
104 spinlock_t lock
; /* lock for list_head */
105 u_int32_t rnd
; /* random seed for hash */
106 unsigned int count
; /* number entries in table */
107 struct timer_list timer
; /* timer for gc */
110 struct proc_dir_entry
*pde
;
114 struct hlist_head hash
[0]; /* hashtable itself */
117 static DEFINE_MUTEX(hashlimit_mutex
); /* protects htables list */
118 static struct kmem_cache
*hashlimit_cachep __read_mostly
;
120 static inline bool dst_cmp(const struct dsthash_ent
*ent
,
121 const struct dsthash_dst
*b
)
123 return !memcmp(&ent
->dst
, b
, sizeof(ent
->dst
));
127 hash_dst(const struct xt_hashlimit_htable
*ht
, const struct dsthash_dst
*dst
)
129 u_int32_t hash
= jhash2((const u32
*)dst
,
130 sizeof(*dst
)/sizeof(u32
),
133 * Instead of returning hash % ht->cfg.size (implying a divide)
134 * we return the high 32 bits of the (hash * ht->cfg.size) that will
135 * give results between [0 and cfg.size-1] and same hash distribution,
136 * but using a multiply, less expensive than a divide
138 return ((u64
)hash
* ht
->cfg
.size
) >> 32;
141 static struct dsthash_ent
*
142 dsthash_find(const struct xt_hashlimit_htable
*ht
,
143 const struct dsthash_dst
*dst
)
145 struct dsthash_ent
*ent
;
146 u_int32_t hash
= hash_dst(ht
, dst
);
148 if (!hlist_empty(&ht
->hash
[hash
])) {
149 hlist_for_each_entry_rcu(ent
, &ht
->hash
[hash
], node
)
150 if (dst_cmp(ent
, dst
)) {
151 spin_lock(&ent
->lock
);
158 /* allocate dsthash_ent, initialize dst, put in htable and lock it */
159 static struct dsthash_ent
*
160 dsthash_alloc_init(struct xt_hashlimit_htable
*ht
,
161 const struct dsthash_dst
*dst
, bool *race
)
163 struct dsthash_ent
*ent
;
165 spin_lock(&ht
->lock
);
167 /* Two or more packets may race to create the same entry in the
168 * hashtable, double check if this packet lost race.
170 ent
= dsthash_find(ht
, dst
);
172 spin_unlock(&ht
->lock
);
177 /* initialize hash with random val at the time we allocate
178 * the first hashtable entry */
179 if (unlikely(!ht
->rnd_initialized
)) {
180 get_random_bytes(&ht
->rnd
, sizeof(ht
->rnd
));
181 ht
->rnd_initialized
= true;
184 if (ht
->cfg
.max
&& ht
->count
>= ht
->cfg
.max
) {
185 /* FIXME: do something. question is what.. */
186 net_err_ratelimited("max count of %u reached\n", ht
->cfg
.max
);
189 ent
= kmem_cache_alloc(hashlimit_cachep
, GFP_ATOMIC
);
191 memcpy(&ent
->dst
, dst
, sizeof(ent
->dst
));
192 spin_lock_init(&ent
->lock
);
194 spin_lock(&ent
->lock
);
195 hlist_add_head_rcu(&ent
->node
, &ht
->hash
[hash_dst(ht
, dst
)]);
198 spin_unlock(&ht
->lock
);
202 static void dsthash_free_rcu(struct rcu_head
*head
)
204 struct dsthash_ent
*ent
= container_of(head
, struct dsthash_ent
, rcu
);
206 kmem_cache_free(hashlimit_cachep
, ent
);
210 dsthash_free(struct xt_hashlimit_htable
*ht
, struct dsthash_ent
*ent
)
212 hlist_del_rcu(&ent
->node
);
213 call_rcu_bh(&ent
->rcu
, dsthash_free_rcu
);
216 static void htable_gc(unsigned long htlong
);
218 static int htable_create(struct net
*net
, struct xt_hashlimit_mtinfo1
*minfo
,
221 struct hashlimit_net
*hashlimit_net
= hashlimit_pernet(net
);
222 struct xt_hashlimit_htable
*hinfo
;
226 if (minfo
->cfg
.size
) {
227 size
= minfo
->cfg
.size
;
229 size
= (totalram_pages
<< PAGE_SHIFT
) / 16384 /
230 sizeof(struct list_head
);
231 if (totalram_pages
> 1024 * 1024 * 1024 / PAGE_SIZE
)
236 /* FIXME: don't use vmalloc() here or anywhere else -HW */
237 hinfo
= vmalloc(sizeof(struct xt_hashlimit_htable
) +
238 sizeof(struct list_head
) * size
);
241 minfo
->hinfo
= hinfo
;
243 /* copy match config into hashtable config */
244 memcpy(&hinfo
->cfg
, &minfo
->cfg
, sizeof(hinfo
->cfg
));
245 hinfo
->cfg
.size
= size
;
246 if (hinfo
->cfg
.max
== 0)
247 hinfo
->cfg
.max
= 8 * hinfo
->cfg
.size
;
248 else if (hinfo
->cfg
.max
< hinfo
->cfg
.size
)
249 hinfo
->cfg
.max
= hinfo
->cfg
.size
;
251 for (i
= 0; i
< hinfo
->cfg
.size
; i
++)
252 INIT_HLIST_HEAD(&hinfo
->hash
[i
]);
256 hinfo
->family
= family
;
257 hinfo
->rnd_initialized
= false;
258 hinfo
->name
= kstrdup(minfo
->name
, GFP_KERNEL
);
263 spin_lock_init(&hinfo
->lock
);
265 hinfo
->pde
= proc_create_data(minfo
->name
, 0,
266 (family
== NFPROTO_IPV4
) ?
267 hashlimit_net
->ipt_hashlimit
: hashlimit_net
->ip6t_hashlimit
,
268 &dl_file_ops
, hinfo
);
269 if (hinfo
->pde
== NULL
) {
276 setup_timer(&hinfo
->timer
, htable_gc
, (unsigned long)hinfo
);
277 hinfo
->timer
.expires
= jiffies
+ msecs_to_jiffies(hinfo
->cfg
.gc_interval
);
278 add_timer(&hinfo
->timer
);
280 hlist_add_head(&hinfo
->node
, &hashlimit_net
->htables
);
285 static bool select_all(const struct xt_hashlimit_htable
*ht
,
286 const struct dsthash_ent
*he
)
291 static bool select_gc(const struct xt_hashlimit_htable
*ht
,
292 const struct dsthash_ent
*he
)
294 return time_after_eq(jiffies
, he
->expires
);
297 static void htable_selective_cleanup(struct xt_hashlimit_htable
*ht
,
298 bool (*select
)(const struct xt_hashlimit_htable
*ht
,
299 const struct dsthash_ent
*he
))
303 /* lock hash table and iterate over it */
304 spin_lock_bh(&ht
->lock
);
305 for (i
= 0; i
< ht
->cfg
.size
; i
++) {
306 struct dsthash_ent
*dh
;
307 struct hlist_node
*n
;
308 hlist_for_each_entry_safe(dh
, n
, &ht
->hash
[i
], node
) {
309 if ((*select
)(ht
, dh
))
310 dsthash_free(ht
, dh
);
313 spin_unlock_bh(&ht
->lock
);
316 /* hash table garbage collector, run by timer */
317 static void htable_gc(unsigned long htlong
)
319 struct xt_hashlimit_htable
*ht
= (struct xt_hashlimit_htable
*)htlong
;
321 htable_selective_cleanup(ht
, select_gc
);
323 /* re-add the timer accordingly */
324 ht
->timer
.expires
= jiffies
+ msecs_to_jiffies(ht
->cfg
.gc_interval
);
325 add_timer(&ht
->timer
);
328 static void htable_remove_proc_entry(struct xt_hashlimit_htable
*hinfo
)
330 struct hashlimit_net
*hashlimit_net
= hashlimit_pernet(hinfo
->net
);
331 struct proc_dir_entry
*parent
;
333 if (hinfo
->family
== NFPROTO_IPV4
)
334 parent
= hashlimit_net
->ipt_hashlimit
;
336 parent
= hashlimit_net
->ip6t_hashlimit
;
339 remove_proc_entry(hinfo
->name
, parent
);
342 static void htable_destroy(struct xt_hashlimit_htable
*hinfo
)
344 del_timer_sync(&hinfo
->timer
);
345 htable_remove_proc_entry(hinfo
);
346 htable_selective_cleanup(hinfo
, select_all
);
351 static struct xt_hashlimit_htable
*htable_find_get(struct net
*net
,
355 struct hashlimit_net
*hashlimit_net
= hashlimit_pernet(net
);
356 struct xt_hashlimit_htable
*hinfo
;
358 hlist_for_each_entry(hinfo
, &hashlimit_net
->htables
, node
) {
359 if (!strcmp(name
, hinfo
->name
) &&
360 hinfo
->family
== family
) {
368 static void htable_put(struct xt_hashlimit_htable
*hinfo
)
370 mutex_lock(&hashlimit_mutex
);
371 if (--hinfo
->use
== 0) {
372 hlist_del(&hinfo
->node
);
373 htable_destroy(hinfo
);
375 mutex_unlock(&hashlimit_mutex
);
378 /* The algorithm used is the Simple Token Bucket Filter (TBF)
379 * see net/sched/sch_tbf.c in the linux source tree
382 /* Rusty: This is my (non-mathematically-inclined) understanding of
383 this algorithm. The `average rate' in jiffies becomes your initial
384 amount of credit `credit' and the most credit you can ever have
385 `credit_cap'. The `peak rate' becomes the cost of passing the
388 `prev' tracks the last packet hit: you gain one credit per jiffy.
389 If you get credit balance more than this, the extra credit is
390 discarded. Every time the match passes, you lose `cost' credits;
391 if you don't have that many, the test fails.
393 See Alexey's formal explanation in net/sched/sch_tbf.c.
395 To get the maximum range, we multiply by this factor (ie. you get N
396 credits per jiffy). We want to allow a rate as low as 1 per day
397 (slowest userspace tool allows), which means
398 CREDITS_PER_JIFFY*HZ*60*60*24 < 2^32 ie.
400 #define MAX_CPJ (0xFFFFFFFF / (HZ*60*60*24))
402 /* Repeated shift and or gives us all 1s, final shift and add 1 gives
403 * us the power of 2 below the theoretical max, so GCC simply does a
405 #define _POW2_BELOW2(x) ((x)|((x)>>1))
406 #define _POW2_BELOW4(x) (_POW2_BELOW2(x)|_POW2_BELOW2((x)>>2))
407 #define _POW2_BELOW8(x) (_POW2_BELOW4(x)|_POW2_BELOW4((x)>>4))
408 #define _POW2_BELOW16(x) (_POW2_BELOW8(x)|_POW2_BELOW8((x)>>8))
409 #define _POW2_BELOW32(x) (_POW2_BELOW16(x)|_POW2_BELOW16((x)>>16))
410 #define POW2_BELOW32(x) ((_POW2_BELOW32(x)>>1) + 1)
412 #define CREDITS_PER_JIFFY POW2_BELOW32(MAX_CPJ)
414 /* in byte mode, the lowest possible rate is one packet/second.
415 * credit_cap is used as a counter that tells us how many times we can
416 * refill the "credits available" counter when it becomes empty.
418 #define MAX_CPJ_BYTES (0xFFFFFFFF / HZ)
419 #define CREDITS_PER_JIFFY_BYTES POW2_BELOW32(MAX_CPJ_BYTES)
421 static u32
xt_hashlimit_len_to_chunks(u32 len
)
423 return (len
>> XT_HASHLIMIT_BYTE_SHIFT
) + 1;
426 /* Precision saver. */
427 static u32
user2credits(u32 user
)
429 /* If multiplying would overflow... */
430 if (user
> 0xFFFFFFFF / (HZ
*CREDITS_PER_JIFFY
))
432 return (user
/ XT_HASHLIMIT_SCALE
) * HZ
* CREDITS_PER_JIFFY
;
434 return (user
* HZ
* CREDITS_PER_JIFFY
) / XT_HASHLIMIT_SCALE
;
437 static u32
user2credits_byte(u32 user
)
440 us
*= HZ
* CREDITS_PER_JIFFY_BYTES
;
441 return (u32
) (us
>> 32);
444 static void rateinfo_recalc(struct dsthash_ent
*dh
, unsigned long now
, u32 mode
)
446 unsigned long delta
= now
- dh
->rateinfo
.prev
;
452 dh
->rateinfo
.prev
= now
;
454 if (mode
& XT_HASHLIMIT_BYTES
) {
455 u32 tmp
= dh
->rateinfo
.credit
;
456 dh
->rateinfo
.credit
+= CREDITS_PER_JIFFY_BYTES
* delta
;
457 cap
= CREDITS_PER_JIFFY_BYTES
* HZ
;
458 if (tmp
>= dh
->rateinfo
.credit
) {/* overflow */
459 dh
->rateinfo
.credit
= cap
;
463 dh
->rateinfo
.credit
+= delta
* CREDITS_PER_JIFFY
;
464 cap
= dh
->rateinfo
.credit_cap
;
466 if (dh
->rateinfo
.credit
> cap
)
467 dh
->rateinfo
.credit
= cap
;
470 static void rateinfo_init(struct dsthash_ent
*dh
,
471 struct xt_hashlimit_htable
*hinfo
)
473 dh
->rateinfo
.prev
= jiffies
;
474 if (hinfo
->cfg
.mode
& XT_HASHLIMIT_BYTES
) {
475 dh
->rateinfo
.credit
= CREDITS_PER_JIFFY_BYTES
* HZ
;
476 dh
->rateinfo
.cost
= user2credits_byte(hinfo
->cfg
.avg
);
477 dh
->rateinfo
.credit_cap
= hinfo
->cfg
.burst
;
479 dh
->rateinfo
.credit
= user2credits(hinfo
->cfg
.avg
*
481 dh
->rateinfo
.cost
= user2credits(hinfo
->cfg
.avg
);
482 dh
->rateinfo
.credit_cap
= dh
->rateinfo
.credit
;
486 static inline __be32
maskl(__be32 a
, unsigned int l
)
488 return l
? htonl(ntohl(a
) & ~0 << (32 - l
)) : 0;
491 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
492 static void hashlimit_ipv6_mask(__be32
*i
, unsigned int p
)
496 i
[0] = maskl(i
[0], p
);
497 i
[1] = i
[2] = i
[3] = 0;
500 i
[1] = maskl(i
[1], p
- 32);
504 i
[2] = maskl(i
[2], p
- 64);
508 i
[3] = maskl(i
[3], p
- 96);
517 hashlimit_init_dst(const struct xt_hashlimit_htable
*hinfo
,
518 struct dsthash_dst
*dst
,
519 const struct sk_buff
*skb
, unsigned int protoff
)
521 __be16 _ports
[2], *ports
;
525 memset(dst
, 0, sizeof(*dst
));
527 switch (hinfo
->family
) {
529 if (hinfo
->cfg
.mode
& XT_HASHLIMIT_HASH_DIP
)
530 dst
->ip
.dst
= maskl(ip_hdr(skb
)->daddr
,
532 if (hinfo
->cfg
.mode
& XT_HASHLIMIT_HASH_SIP
)
533 dst
->ip
.src
= maskl(ip_hdr(skb
)->saddr
,
536 if (!(hinfo
->cfg
.mode
&
537 (XT_HASHLIMIT_HASH_DPT
| XT_HASHLIMIT_HASH_SPT
)))
539 nexthdr
= ip_hdr(skb
)->protocol
;
541 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
546 if (hinfo
->cfg
.mode
& XT_HASHLIMIT_HASH_DIP
) {
547 memcpy(&dst
->ip6
.dst
, &ipv6_hdr(skb
)->daddr
,
548 sizeof(dst
->ip6
.dst
));
549 hashlimit_ipv6_mask(dst
->ip6
.dst
, hinfo
->cfg
.dstmask
);
551 if (hinfo
->cfg
.mode
& XT_HASHLIMIT_HASH_SIP
) {
552 memcpy(&dst
->ip6
.src
, &ipv6_hdr(skb
)->saddr
,
553 sizeof(dst
->ip6
.src
));
554 hashlimit_ipv6_mask(dst
->ip6
.src
, hinfo
->cfg
.srcmask
);
557 if (!(hinfo
->cfg
.mode
&
558 (XT_HASHLIMIT_HASH_DPT
| XT_HASHLIMIT_HASH_SPT
)))
560 nexthdr
= ipv6_hdr(skb
)->nexthdr
;
561 protoff
= ipv6_skip_exthdr(skb
, sizeof(struct ipv6hdr
), &nexthdr
, &frag_off
);
562 if ((int)protoff
< 0)
572 poff
= proto_ports_offset(nexthdr
);
574 ports
= skb_header_pointer(skb
, protoff
+ poff
, sizeof(_ports
),
577 _ports
[0] = _ports
[1] = 0;
582 if (hinfo
->cfg
.mode
& XT_HASHLIMIT_HASH_SPT
)
583 dst
->src_port
= ports
[0];
584 if (hinfo
->cfg
.mode
& XT_HASHLIMIT_HASH_DPT
)
585 dst
->dst_port
= ports
[1];
589 static u32
hashlimit_byte_cost(unsigned int len
, struct dsthash_ent
*dh
)
591 u64 tmp
= xt_hashlimit_len_to_chunks(len
);
592 tmp
= tmp
* dh
->rateinfo
.cost
;
594 if (unlikely(tmp
> CREDITS_PER_JIFFY_BYTES
* HZ
))
595 tmp
= CREDITS_PER_JIFFY_BYTES
* HZ
;
597 if (dh
->rateinfo
.credit
< tmp
&& dh
->rateinfo
.credit_cap
) {
598 dh
->rateinfo
.credit_cap
--;
599 dh
->rateinfo
.credit
= CREDITS_PER_JIFFY_BYTES
* HZ
;
605 hashlimit_mt(const struct sk_buff
*skb
, struct xt_action_param
*par
)
607 const struct xt_hashlimit_mtinfo1
*info
= par
->matchinfo
;
608 struct xt_hashlimit_htable
*hinfo
= info
->hinfo
;
609 unsigned long now
= jiffies
;
610 struct dsthash_ent
*dh
;
611 struct dsthash_dst dst
;
615 if (hashlimit_init_dst(hinfo
, &dst
, skb
, par
->thoff
) < 0)
619 dh
= dsthash_find(hinfo
, &dst
);
621 dh
= dsthash_alloc_init(hinfo
, &dst
, &race
);
623 rcu_read_unlock_bh();
626 /* Already got an entry, update expiration timeout */
627 dh
->expires
= now
+ msecs_to_jiffies(hinfo
->cfg
.expire
);
628 rateinfo_recalc(dh
, now
, hinfo
->cfg
.mode
);
630 dh
->expires
= jiffies
+ msecs_to_jiffies(hinfo
->cfg
.expire
);
631 rateinfo_init(dh
, hinfo
);
634 /* update expiration timeout */
635 dh
->expires
= now
+ msecs_to_jiffies(hinfo
->cfg
.expire
);
636 rateinfo_recalc(dh
, now
, hinfo
->cfg
.mode
);
639 if (info
->cfg
.mode
& XT_HASHLIMIT_BYTES
)
640 cost
= hashlimit_byte_cost(skb
->len
, dh
);
642 cost
= dh
->rateinfo
.cost
;
644 if (dh
->rateinfo
.credit
>= cost
) {
645 /* below the limit */
646 dh
->rateinfo
.credit
-= cost
;
647 spin_unlock(&dh
->lock
);
648 rcu_read_unlock_bh();
649 return !(info
->cfg
.mode
& XT_HASHLIMIT_INVERT
);
652 spin_unlock(&dh
->lock
);
653 rcu_read_unlock_bh();
654 /* default match is underlimit - so over the limit, we need to invert */
655 return info
->cfg
.mode
& XT_HASHLIMIT_INVERT
;
662 static int hashlimit_mt_check(const struct xt_mtchk_param
*par
)
664 struct net
*net
= par
->net
;
665 struct xt_hashlimit_mtinfo1
*info
= par
->matchinfo
;
668 if (info
->cfg
.gc_interval
== 0 || info
->cfg
.expire
== 0)
670 if (info
->name
[sizeof(info
->name
)-1] != '\0')
672 if (par
->family
== NFPROTO_IPV4
) {
673 if (info
->cfg
.srcmask
> 32 || info
->cfg
.dstmask
> 32)
676 if (info
->cfg
.srcmask
> 128 || info
->cfg
.dstmask
> 128)
680 if (info
->cfg
.mode
& ~XT_HASHLIMIT_ALL
) {
681 pr_info("Unknown mode mask %X, kernel too old?\n",
686 /* Check for overflow. */
687 if (info
->cfg
.mode
& XT_HASHLIMIT_BYTES
) {
688 if (user2credits_byte(info
->cfg
.avg
) == 0) {
689 pr_info("overflow, rate too high: %u\n", info
->cfg
.avg
);
692 } else if (info
->cfg
.burst
== 0 ||
693 user2credits(info
->cfg
.avg
* info
->cfg
.burst
) <
694 user2credits(info
->cfg
.avg
)) {
695 pr_info("overflow, try lower: %u/%u\n",
696 info
->cfg
.avg
, info
->cfg
.burst
);
700 mutex_lock(&hashlimit_mutex
);
701 info
->hinfo
= htable_find_get(net
, info
->name
, par
->family
);
702 if (info
->hinfo
== NULL
) {
703 ret
= htable_create(net
, info
, par
->family
);
705 mutex_unlock(&hashlimit_mutex
);
709 mutex_unlock(&hashlimit_mutex
);
713 static void hashlimit_mt_destroy(const struct xt_mtdtor_param
*par
)
715 const struct xt_hashlimit_mtinfo1
*info
= par
->matchinfo
;
717 htable_put(info
->hinfo
);
720 static struct xt_match hashlimit_mt_reg
[] __read_mostly
= {
724 .family
= NFPROTO_IPV4
,
725 .match
= hashlimit_mt
,
726 .matchsize
= sizeof(struct xt_hashlimit_mtinfo1
),
727 .checkentry
= hashlimit_mt_check
,
728 .destroy
= hashlimit_mt_destroy
,
731 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
735 .family
= NFPROTO_IPV6
,
736 .match
= hashlimit_mt
,
737 .matchsize
= sizeof(struct xt_hashlimit_mtinfo1
),
738 .checkentry
= hashlimit_mt_check
,
739 .destroy
= hashlimit_mt_destroy
,
746 static void *dl_seq_start(struct seq_file
*s
, loff_t
*pos
)
747 __acquires(htable
->lock
)
749 struct xt_hashlimit_htable
*htable
= s
->private;
750 unsigned int *bucket
;
752 spin_lock_bh(&htable
->lock
);
753 if (*pos
>= htable
->cfg
.size
)
756 bucket
= kmalloc(sizeof(unsigned int), GFP_ATOMIC
);
758 return ERR_PTR(-ENOMEM
);
764 static void *dl_seq_next(struct seq_file
*s
, void *v
, loff_t
*pos
)
766 struct xt_hashlimit_htable
*htable
= s
->private;
767 unsigned int *bucket
= (unsigned int *)v
;
770 if (*pos
>= htable
->cfg
.size
) {
777 static void dl_seq_stop(struct seq_file
*s
, void *v
)
778 __releases(htable
->lock
)
780 struct xt_hashlimit_htable
*htable
= s
->private;
781 unsigned int *bucket
= (unsigned int *)v
;
785 spin_unlock_bh(&htable
->lock
);
788 static int dl_seq_real_show(struct dsthash_ent
*ent
, u_int8_t family
,
792 const struct xt_hashlimit_htable
*ht
= s
->private;
794 spin_lock(&ent
->lock
);
795 /* recalculate to show accurate numbers */
796 rateinfo_recalc(ent
, jiffies
, ht
->cfg
.mode
);
800 res
= seq_printf(s
, "%ld %pI4:%u->%pI4:%u %u %u %u\n",
801 (long)(ent
->expires
- jiffies
)/HZ
,
803 ntohs(ent
->dst
.src_port
),
805 ntohs(ent
->dst
.dst_port
),
806 ent
->rateinfo
.credit
, ent
->rateinfo
.credit_cap
,
809 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
811 res
= seq_printf(s
, "%ld %pI6:%u->%pI6:%u %u %u %u\n",
812 (long)(ent
->expires
- jiffies
)/HZ
,
814 ntohs(ent
->dst
.src_port
),
816 ntohs(ent
->dst
.dst_port
),
817 ent
->rateinfo
.credit
, ent
->rateinfo
.credit_cap
,
825 spin_unlock(&ent
->lock
);
829 static int dl_seq_show(struct seq_file
*s
, void *v
)
831 struct xt_hashlimit_htable
*htable
= s
->private;
832 unsigned int *bucket
= (unsigned int *)v
;
833 struct dsthash_ent
*ent
;
835 if (!hlist_empty(&htable
->hash
[*bucket
])) {
836 hlist_for_each_entry(ent
, &htable
->hash
[*bucket
], node
)
837 if (dl_seq_real_show(ent
, htable
->family
, s
))
843 static const struct seq_operations dl_seq_ops
= {
844 .start
= dl_seq_start
,
850 static int dl_proc_open(struct inode
*inode
, struct file
*file
)
852 int ret
= seq_open(file
, &dl_seq_ops
);
855 struct seq_file
*sf
= file
->private_data
;
856 sf
->private = PDE_DATA(inode
);
861 static const struct file_operations dl_file_ops
= {
862 .owner
= THIS_MODULE
,
863 .open
= dl_proc_open
,
866 .release
= seq_release
869 static int __net_init
hashlimit_proc_net_init(struct net
*net
)
871 struct hashlimit_net
*hashlimit_net
= hashlimit_pernet(net
);
873 hashlimit_net
->ipt_hashlimit
= proc_mkdir("ipt_hashlimit", net
->proc_net
);
874 if (!hashlimit_net
->ipt_hashlimit
)
876 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
877 hashlimit_net
->ip6t_hashlimit
= proc_mkdir("ip6t_hashlimit", net
->proc_net
);
878 if (!hashlimit_net
->ip6t_hashlimit
) {
879 remove_proc_entry("ipt_hashlimit", net
->proc_net
);
886 static void __net_exit
hashlimit_proc_net_exit(struct net
*net
)
888 struct xt_hashlimit_htable
*hinfo
;
889 struct hashlimit_net
*hashlimit_net
= hashlimit_pernet(net
);
891 /* hashlimit_net_exit() is called before hashlimit_mt_destroy().
892 * Make sure that the parent ipt_hashlimit and ip6t_hashlimit proc
893 * entries is empty before trying to remove it.
895 mutex_lock(&hashlimit_mutex
);
896 hlist_for_each_entry(hinfo
, &hashlimit_net
->htables
, node
)
897 htable_remove_proc_entry(hinfo
);
898 hashlimit_net
->ipt_hashlimit
= NULL
;
899 hashlimit_net
->ip6t_hashlimit
= NULL
;
900 mutex_unlock(&hashlimit_mutex
);
902 remove_proc_entry("ipt_hashlimit", net
->proc_net
);
903 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
904 remove_proc_entry("ip6t_hashlimit", net
->proc_net
);
908 static int __net_init
hashlimit_net_init(struct net
*net
)
910 struct hashlimit_net
*hashlimit_net
= hashlimit_pernet(net
);
912 INIT_HLIST_HEAD(&hashlimit_net
->htables
);
913 return hashlimit_proc_net_init(net
);
916 static void __net_exit
hashlimit_net_exit(struct net
*net
)
918 hashlimit_proc_net_exit(net
);
921 static struct pernet_operations hashlimit_net_ops
= {
922 .init
= hashlimit_net_init
,
923 .exit
= hashlimit_net_exit
,
924 .id
= &hashlimit_net_id
,
925 .size
= sizeof(struct hashlimit_net
),
928 static int __init
hashlimit_mt_init(void)
932 err
= register_pernet_subsys(&hashlimit_net_ops
);
935 err
= xt_register_matches(hashlimit_mt_reg
,
936 ARRAY_SIZE(hashlimit_mt_reg
));
941 hashlimit_cachep
= kmem_cache_create("xt_hashlimit",
942 sizeof(struct dsthash_ent
), 0, 0,
944 if (!hashlimit_cachep
) {
945 pr_warning("unable to create slab cache\n");
951 xt_unregister_matches(hashlimit_mt_reg
, ARRAY_SIZE(hashlimit_mt_reg
));
953 unregister_pernet_subsys(&hashlimit_net_ops
);
958 static void __exit
hashlimit_mt_exit(void)
960 xt_unregister_matches(hashlimit_mt_reg
, ARRAY_SIZE(hashlimit_mt_reg
));
961 unregister_pernet_subsys(&hashlimit_net_ops
);
964 kmem_cache_destroy(hashlimit_cachep
);
967 module_init(hashlimit_mt_init
);
968 module_exit(hashlimit_mt_exit
);