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 IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
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 IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
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 */
85 unsigned long expires
; /* precalculated expiry time */
87 unsigned long prev
; /* last modification */
89 u_int32_t credit_cap
, cost
;
94 struct xt_hashlimit_htable
{
95 struct hlist_node node
; /* global list of all htables */
100 struct hashlimit_cfg1 cfg
; /* config */
102 /* used internally */
103 spinlock_t lock
; /* lock for list_head */
104 u_int32_t rnd
; /* random seed for hash */
105 unsigned int count
; /* number entries in table */
106 struct timer_list timer
; /* timer for gc */
109 struct proc_dir_entry
*pde
;
112 struct hlist_head hash
[0]; /* hashtable itself */
115 static DEFINE_MUTEX(hashlimit_mutex
); /* protects htables list */
116 static struct kmem_cache
*hashlimit_cachep __read_mostly
;
118 static inline bool dst_cmp(const struct dsthash_ent
*ent
,
119 const struct dsthash_dst
*b
)
121 return !memcmp(&ent
->dst
, b
, sizeof(ent
->dst
));
125 hash_dst(const struct xt_hashlimit_htable
*ht
, const struct dsthash_dst
*dst
)
127 u_int32_t hash
= jhash2((const u32
*)dst
,
128 sizeof(*dst
)/sizeof(u32
),
131 * Instead of returning hash % ht->cfg.size (implying a divide)
132 * we return the high 32 bits of the (hash * ht->cfg.size) that will
133 * give results between [0 and cfg.size-1] and same hash distribution,
134 * but using a multiply, less expensive than a divide
136 return ((u64
)hash
* ht
->cfg
.size
) >> 32;
139 static struct dsthash_ent
*
140 dsthash_find(const struct xt_hashlimit_htable
*ht
,
141 const struct dsthash_dst
*dst
)
143 struct dsthash_ent
*ent
;
144 u_int32_t hash
= hash_dst(ht
, dst
);
146 if (!hlist_empty(&ht
->hash
[hash
])) {
147 hlist_for_each_entry_rcu(ent
, &ht
->hash
[hash
], node
)
148 if (dst_cmp(ent
, dst
)) {
149 spin_lock(&ent
->lock
);
156 /* allocate dsthash_ent, initialize dst, put in htable and lock it */
157 static struct dsthash_ent
*
158 dsthash_alloc_init(struct xt_hashlimit_htable
*ht
,
159 const struct dsthash_dst
*dst
, bool *race
)
161 struct dsthash_ent
*ent
;
163 spin_lock(&ht
->lock
);
165 /* Two or more packets may race to create the same entry in the
166 * hashtable, double check if this packet lost race.
168 ent
= dsthash_find(ht
, dst
);
170 spin_unlock(&ht
->lock
);
175 /* initialize hash with random val at the time we allocate
176 * the first hashtable entry */
177 if (unlikely(!ht
->rnd_initialized
)) {
178 get_random_bytes(&ht
->rnd
, sizeof(ht
->rnd
));
179 ht
->rnd_initialized
= true;
182 if (ht
->cfg
.max
&& ht
->count
>= ht
->cfg
.max
) {
183 /* FIXME: do something. question is what.. */
184 net_err_ratelimited("max count of %u reached\n", ht
->cfg
.max
);
187 ent
= kmem_cache_alloc(hashlimit_cachep
, GFP_ATOMIC
);
189 memcpy(&ent
->dst
, dst
, sizeof(ent
->dst
));
190 spin_lock_init(&ent
->lock
);
192 spin_lock(&ent
->lock
);
193 hlist_add_head_rcu(&ent
->node
, &ht
->hash
[hash_dst(ht
, dst
)]);
196 spin_unlock(&ht
->lock
);
200 static void dsthash_free_rcu(struct rcu_head
*head
)
202 struct dsthash_ent
*ent
= container_of(head
, struct dsthash_ent
, rcu
);
204 kmem_cache_free(hashlimit_cachep
, ent
);
208 dsthash_free(struct xt_hashlimit_htable
*ht
, struct dsthash_ent
*ent
)
210 hlist_del_rcu(&ent
->node
);
211 call_rcu_bh(&ent
->rcu
, dsthash_free_rcu
);
214 static void htable_gc(unsigned long htlong
);
216 static int htable_create(struct net
*net
, struct xt_hashlimit_mtinfo1
*minfo
,
219 struct hashlimit_net
*hashlimit_net
= hashlimit_pernet(net
);
220 struct xt_hashlimit_htable
*hinfo
;
224 if (minfo
->cfg
.size
) {
225 size
= minfo
->cfg
.size
;
227 size
= (totalram_pages
<< PAGE_SHIFT
) / 16384 /
228 sizeof(struct list_head
);
229 if (totalram_pages
> 1024 * 1024 * 1024 / PAGE_SIZE
)
234 /* FIXME: don't use vmalloc() here or anywhere else -HW */
235 hinfo
= vmalloc(sizeof(struct xt_hashlimit_htable
) +
236 sizeof(struct list_head
) * size
);
239 minfo
->hinfo
= hinfo
;
241 /* copy match config into hashtable config */
242 memcpy(&hinfo
->cfg
, &minfo
->cfg
, sizeof(hinfo
->cfg
));
243 hinfo
->cfg
.size
= size
;
244 if (hinfo
->cfg
.max
== 0)
245 hinfo
->cfg
.max
= 8 * hinfo
->cfg
.size
;
246 else if (hinfo
->cfg
.max
< hinfo
->cfg
.size
)
247 hinfo
->cfg
.max
= hinfo
->cfg
.size
;
249 for (i
= 0; i
< hinfo
->cfg
.size
; i
++)
250 INIT_HLIST_HEAD(&hinfo
->hash
[i
]);
254 hinfo
->family
= family
;
255 hinfo
->rnd_initialized
= false;
256 spin_lock_init(&hinfo
->lock
);
258 hinfo
->pde
= proc_create_data(minfo
->name
, 0,
259 (family
== NFPROTO_IPV4
) ?
260 hashlimit_net
->ipt_hashlimit
: hashlimit_net
->ip6t_hashlimit
,
261 &dl_file_ops
, hinfo
);
262 if (hinfo
->pde
== NULL
) {
268 setup_timer(&hinfo
->timer
, htable_gc
, (unsigned long)hinfo
);
269 hinfo
->timer
.expires
= jiffies
+ msecs_to_jiffies(hinfo
->cfg
.gc_interval
);
270 add_timer(&hinfo
->timer
);
272 hlist_add_head(&hinfo
->node
, &hashlimit_net
->htables
);
277 static bool select_all(const struct xt_hashlimit_htable
*ht
,
278 const struct dsthash_ent
*he
)
283 static bool select_gc(const struct xt_hashlimit_htable
*ht
,
284 const struct dsthash_ent
*he
)
286 return time_after_eq(jiffies
, he
->expires
);
289 static void htable_selective_cleanup(struct xt_hashlimit_htable
*ht
,
290 bool (*select
)(const struct xt_hashlimit_htable
*ht
,
291 const struct dsthash_ent
*he
))
295 /* lock hash table and iterate over it */
296 spin_lock_bh(&ht
->lock
);
297 for (i
= 0; i
< ht
->cfg
.size
; i
++) {
298 struct dsthash_ent
*dh
;
299 struct hlist_node
*n
;
300 hlist_for_each_entry_safe(dh
, n
, &ht
->hash
[i
], node
) {
301 if ((*select
)(ht
, dh
))
302 dsthash_free(ht
, dh
);
305 spin_unlock_bh(&ht
->lock
);
308 /* hash table garbage collector, run by timer */
309 static void htable_gc(unsigned long htlong
)
311 struct xt_hashlimit_htable
*ht
= (struct xt_hashlimit_htable
*)htlong
;
313 htable_selective_cleanup(ht
, select_gc
);
315 /* re-add the timer accordingly */
316 ht
->timer
.expires
= jiffies
+ msecs_to_jiffies(ht
->cfg
.gc_interval
);
317 add_timer(&ht
->timer
);
320 static void htable_destroy(struct xt_hashlimit_htable
*hinfo
)
322 struct hashlimit_net
*hashlimit_net
= hashlimit_pernet(hinfo
->net
);
323 struct proc_dir_entry
*parent
;
325 del_timer_sync(&hinfo
->timer
);
327 if (hinfo
->family
== NFPROTO_IPV4
)
328 parent
= hashlimit_net
->ipt_hashlimit
;
330 parent
= hashlimit_net
->ip6t_hashlimit
;
333 remove_proc_entry(hinfo
->pde
->name
, parent
);
335 htable_selective_cleanup(hinfo
, select_all
);
339 static struct xt_hashlimit_htable
*htable_find_get(struct net
*net
,
343 struct hashlimit_net
*hashlimit_net
= hashlimit_pernet(net
);
344 struct xt_hashlimit_htable
*hinfo
;
346 hlist_for_each_entry(hinfo
, &hashlimit_net
->htables
, node
) {
347 if (!strcmp(name
, hinfo
->pde
->name
) &&
348 hinfo
->family
== family
) {
356 static void htable_put(struct xt_hashlimit_htable
*hinfo
)
358 mutex_lock(&hashlimit_mutex
);
359 if (--hinfo
->use
== 0) {
360 hlist_del(&hinfo
->node
);
361 htable_destroy(hinfo
);
363 mutex_unlock(&hashlimit_mutex
);
366 /* The algorithm used is the Simple Token Bucket Filter (TBF)
367 * see net/sched/sch_tbf.c in the linux source tree
370 /* Rusty: This is my (non-mathematically-inclined) understanding of
371 this algorithm. The `average rate' in jiffies becomes your initial
372 amount of credit `credit' and the most credit you can ever have
373 `credit_cap'. The `peak rate' becomes the cost of passing the
376 `prev' tracks the last packet hit: you gain one credit per jiffy.
377 If you get credit balance more than this, the extra credit is
378 discarded. Every time the match passes, you lose `cost' credits;
379 if you don't have that many, the test fails.
381 See Alexey's formal explanation in net/sched/sch_tbf.c.
383 To get the maximum range, we multiply by this factor (ie. you get N
384 credits per jiffy). We want to allow a rate as low as 1 per day
385 (slowest userspace tool allows), which means
386 CREDITS_PER_JIFFY*HZ*60*60*24 < 2^32 ie.
388 #define MAX_CPJ (0xFFFFFFFF / (HZ*60*60*24))
390 /* Repeated shift and or gives us all 1s, final shift and add 1 gives
391 * us the power of 2 below the theoretical max, so GCC simply does a
393 #define _POW2_BELOW2(x) ((x)|((x)>>1))
394 #define _POW2_BELOW4(x) (_POW2_BELOW2(x)|_POW2_BELOW2((x)>>2))
395 #define _POW2_BELOW8(x) (_POW2_BELOW4(x)|_POW2_BELOW4((x)>>4))
396 #define _POW2_BELOW16(x) (_POW2_BELOW8(x)|_POW2_BELOW8((x)>>8))
397 #define _POW2_BELOW32(x) (_POW2_BELOW16(x)|_POW2_BELOW16((x)>>16))
398 #define POW2_BELOW32(x) ((_POW2_BELOW32(x)>>1) + 1)
400 #define CREDITS_PER_JIFFY POW2_BELOW32(MAX_CPJ)
402 /* in byte mode, the lowest possible rate is one packet/second.
403 * credit_cap is used as a counter that tells us how many times we can
404 * refill the "credits available" counter when it becomes empty.
406 #define MAX_CPJ_BYTES (0xFFFFFFFF / HZ)
407 #define CREDITS_PER_JIFFY_BYTES POW2_BELOW32(MAX_CPJ_BYTES)
409 static u32
xt_hashlimit_len_to_chunks(u32 len
)
411 return (len
>> XT_HASHLIMIT_BYTE_SHIFT
) + 1;
414 /* Precision saver. */
415 static u32
user2credits(u32 user
)
417 /* If multiplying would overflow... */
418 if (user
> 0xFFFFFFFF / (HZ
*CREDITS_PER_JIFFY
))
420 return (user
/ XT_HASHLIMIT_SCALE
) * HZ
* CREDITS_PER_JIFFY
;
422 return (user
* HZ
* CREDITS_PER_JIFFY
) / XT_HASHLIMIT_SCALE
;
425 static u32
user2credits_byte(u32 user
)
428 us
*= HZ
* CREDITS_PER_JIFFY_BYTES
;
429 return (u32
) (us
>> 32);
432 static void rateinfo_recalc(struct dsthash_ent
*dh
, unsigned long now
, u32 mode
)
434 unsigned long delta
= now
- dh
->rateinfo
.prev
;
440 dh
->rateinfo
.prev
= now
;
442 if (mode
& XT_HASHLIMIT_BYTES
) {
443 u32 tmp
= dh
->rateinfo
.credit
;
444 dh
->rateinfo
.credit
+= CREDITS_PER_JIFFY_BYTES
* delta
;
445 cap
= CREDITS_PER_JIFFY_BYTES
* HZ
;
446 if (tmp
>= dh
->rateinfo
.credit
) {/* overflow */
447 dh
->rateinfo
.credit
= cap
;
451 dh
->rateinfo
.credit
+= delta
* CREDITS_PER_JIFFY
;
452 cap
= dh
->rateinfo
.credit_cap
;
454 if (dh
->rateinfo
.credit
> cap
)
455 dh
->rateinfo
.credit
= cap
;
458 static void rateinfo_init(struct dsthash_ent
*dh
,
459 struct xt_hashlimit_htable
*hinfo
)
461 dh
->rateinfo
.prev
= jiffies
;
462 if (hinfo
->cfg
.mode
& XT_HASHLIMIT_BYTES
) {
463 dh
->rateinfo
.credit
= CREDITS_PER_JIFFY_BYTES
* HZ
;
464 dh
->rateinfo
.cost
= user2credits_byte(hinfo
->cfg
.avg
);
465 dh
->rateinfo
.credit_cap
= hinfo
->cfg
.burst
;
467 dh
->rateinfo
.credit
= user2credits(hinfo
->cfg
.avg
*
469 dh
->rateinfo
.cost
= user2credits(hinfo
->cfg
.avg
);
470 dh
->rateinfo
.credit_cap
= dh
->rateinfo
.credit
;
474 static inline __be32
maskl(__be32 a
, unsigned int l
)
476 return l
? htonl(ntohl(a
) & ~0 << (32 - l
)) : 0;
479 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
480 static void hashlimit_ipv6_mask(__be32
*i
, unsigned int p
)
484 i
[0] = maskl(i
[0], p
);
485 i
[1] = i
[2] = i
[3] = 0;
488 i
[1] = maskl(i
[1], p
- 32);
492 i
[2] = maskl(i
[2], p
- 64);
496 i
[3] = maskl(i
[3], p
- 96);
505 hashlimit_init_dst(const struct xt_hashlimit_htable
*hinfo
,
506 struct dsthash_dst
*dst
,
507 const struct sk_buff
*skb
, unsigned int protoff
)
509 __be16 _ports
[2], *ports
;
513 memset(dst
, 0, sizeof(*dst
));
515 switch (hinfo
->family
) {
517 if (hinfo
->cfg
.mode
& XT_HASHLIMIT_HASH_DIP
)
518 dst
->ip
.dst
= maskl(ip_hdr(skb
)->daddr
,
520 if (hinfo
->cfg
.mode
& XT_HASHLIMIT_HASH_SIP
)
521 dst
->ip
.src
= maskl(ip_hdr(skb
)->saddr
,
524 if (!(hinfo
->cfg
.mode
&
525 (XT_HASHLIMIT_HASH_DPT
| XT_HASHLIMIT_HASH_SPT
)))
527 nexthdr
= ip_hdr(skb
)->protocol
;
529 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
534 if (hinfo
->cfg
.mode
& XT_HASHLIMIT_HASH_DIP
) {
535 memcpy(&dst
->ip6
.dst
, &ipv6_hdr(skb
)->daddr
,
536 sizeof(dst
->ip6
.dst
));
537 hashlimit_ipv6_mask(dst
->ip6
.dst
, hinfo
->cfg
.dstmask
);
539 if (hinfo
->cfg
.mode
& XT_HASHLIMIT_HASH_SIP
) {
540 memcpy(&dst
->ip6
.src
, &ipv6_hdr(skb
)->saddr
,
541 sizeof(dst
->ip6
.src
));
542 hashlimit_ipv6_mask(dst
->ip6
.src
, hinfo
->cfg
.srcmask
);
545 if (!(hinfo
->cfg
.mode
&
546 (XT_HASHLIMIT_HASH_DPT
| XT_HASHLIMIT_HASH_SPT
)))
548 nexthdr
= ipv6_hdr(skb
)->nexthdr
;
549 protoff
= ipv6_skip_exthdr(skb
, sizeof(struct ipv6hdr
), &nexthdr
, &frag_off
);
550 if ((int)protoff
< 0)
560 poff
= proto_ports_offset(nexthdr
);
562 ports
= skb_header_pointer(skb
, protoff
+ poff
, sizeof(_ports
),
565 _ports
[0] = _ports
[1] = 0;
570 if (hinfo
->cfg
.mode
& XT_HASHLIMIT_HASH_SPT
)
571 dst
->src_port
= ports
[0];
572 if (hinfo
->cfg
.mode
& XT_HASHLIMIT_HASH_DPT
)
573 dst
->dst_port
= ports
[1];
577 static u32
hashlimit_byte_cost(unsigned int len
, struct dsthash_ent
*dh
)
579 u64 tmp
= xt_hashlimit_len_to_chunks(len
);
580 tmp
= tmp
* dh
->rateinfo
.cost
;
582 if (unlikely(tmp
> CREDITS_PER_JIFFY_BYTES
* HZ
))
583 tmp
= CREDITS_PER_JIFFY_BYTES
* HZ
;
585 if (dh
->rateinfo
.credit
< tmp
&& dh
->rateinfo
.credit_cap
) {
586 dh
->rateinfo
.credit_cap
--;
587 dh
->rateinfo
.credit
= CREDITS_PER_JIFFY_BYTES
* HZ
;
593 hashlimit_mt(const struct sk_buff
*skb
, struct xt_action_param
*par
)
595 const struct xt_hashlimit_mtinfo1
*info
= par
->matchinfo
;
596 struct xt_hashlimit_htable
*hinfo
= info
->hinfo
;
597 unsigned long now
= jiffies
;
598 struct dsthash_ent
*dh
;
599 struct dsthash_dst dst
;
603 if (hashlimit_init_dst(hinfo
, &dst
, skb
, par
->thoff
) < 0)
607 dh
= dsthash_find(hinfo
, &dst
);
609 dh
= dsthash_alloc_init(hinfo
, &dst
, &race
);
611 rcu_read_unlock_bh();
614 /* Already got an entry, update expiration timeout */
615 dh
->expires
= now
+ msecs_to_jiffies(hinfo
->cfg
.expire
);
616 rateinfo_recalc(dh
, now
, hinfo
->cfg
.mode
);
618 dh
->expires
= jiffies
+ msecs_to_jiffies(hinfo
->cfg
.expire
);
619 rateinfo_init(dh
, hinfo
);
622 /* update expiration timeout */
623 dh
->expires
= now
+ msecs_to_jiffies(hinfo
->cfg
.expire
);
624 rateinfo_recalc(dh
, now
, hinfo
->cfg
.mode
);
627 if (info
->cfg
.mode
& XT_HASHLIMIT_BYTES
)
628 cost
= hashlimit_byte_cost(skb
->len
, dh
);
630 cost
= dh
->rateinfo
.cost
;
632 if (dh
->rateinfo
.credit
>= cost
) {
633 /* below the limit */
634 dh
->rateinfo
.credit
-= cost
;
635 spin_unlock(&dh
->lock
);
636 rcu_read_unlock_bh();
637 return !(info
->cfg
.mode
& XT_HASHLIMIT_INVERT
);
640 spin_unlock(&dh
->lock
);
641 rcu_read_unlock_bh();
642 /* default match is underlimit - so over the limit, we need to invert */
643 return info
->cfg
.mode
& XT_HASHLIMIT_INVERT
;
650 static int hashlimit_mt_check(const struct xt_mtchk_param
*par
)
652 struct net
*net
= par
->net
;
653 struct xt_hashlimit_mtinfo1
*info
= par
->matchinfo
;
656 if (info
->cfg
.gc_interval
== 0 || info
->cfg
.expire
== 0)
658 if (info
->name
[sizeof(info
->name
)-1] != '\0')
660 if (par
->family
== NFPROTO_IPV4
) {
661 if (info
->cfg
.srcmask
> 32 || info
->cfg
.dstmask
> 32)
664 if (info
->cfg
.srcmask
> 128 || info
->cfg
.dstmask
> 128)
668 if (info
->cfg
.mode
& ~XT_HASHLIMIT_ALL
) {
669 pr_info("Unknown mode mask %X, kernel too old?\n",
674 /* Check for overflow. */
675 if (info
->cfg
.mode
& XT_HASHLIMIT_BYTES
) {
676 if (user2credits_byte(info
->cfg
.avg
) == 0) {
677 pr_info("overflow, rate too high: %u\n", info
->cfg
.avg
);
680 } else if (info
->cfg
.burst
== 0 ||
681 user2credits(info
->cfg
.avg
* info
->cfg
.burst
) <
682 user2credits(info
->cfg
.avg
)) {
683 pr_info("overflow, try lower: %u/%u\n",
684 info
->cfg
.avg
, info
->cfg
.burst
);
688 mutex_lock(&hashlimit_mutex
);
689 info
->hinfo
= htable_find_get(net
, info
->name
, par
->family
);
690 if (info
->hinfo
== NULL
) {
691 ret
= htable_create(net
, info
, par
->family
);
693 mutex_unlock(&hashlimit_mutex
);
697 mutex_unlock(&hashlimit_mutex
);
701 static void hashlimit_mt_destroy(const struct xt_mtdtor_param
*par
)
703 const struct xt_hashlimit_mtinfo1
*info
= par
->matchinfo
;
705 htable_put(info
->hinfo
);
708 static struct xt_match hashlimit_mt_reg
[] __read_mostly
= {
712 .family
= NFPROTO_IPV4
,
713 .match
= hashlimit_mt
,
714 .matchsize
= sizeof(struct xt_hashlimit_mtinfo1
),
715 .checkentry
= hashlimit_mt_check
,
716 .destroy
= hashlimit_mt_destroy
,
719 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
723 .family
= NFPROTO_IPV6
,
724 .match
= hashlimit_mt
,
725 .matchsize
= sizeof(struct xt_hashlimit_mtinfo1
),
726 .checkentry
= hashlimit_mt_check
,
727 .destroy
= hashlimit_mt_destroy
,
734 static void *dl_seq_start(struct seq_file
*s
, loff_t
*pos
)
735 __acquires(htable
->lock
)
737 struct xt_hashlimit_htable
*htable
= s
->private;
738 unsigned int *bucket
;
740 spin_lock_bh(&htable
->lock
);
741 if (*pos
>= htable
->cfg
.size
)
744 bucket
= kmalloc(sizeof(unsigned int), GFP_ATOMIC
);
746 return ERR_PTR(-ENOMEM
);
752 static void *dl_seq_next(struct seq_file
*s
, void *v
, loff_t
*pos
)
754 struct xt_hashlimit_htable
*htable
= s
->private;
755 unsigned int *bucket
= (unsigned int *)v
;
758 if (*pos
>= htable
->cfg
.size
) {
765 static void dl_seq_stop(struct seq_file
*s
, void *v
)
766 __releases(htable
->lock
)
768 struct xt_hashlimit_htable
*htable
= s
->private;
769 unsigned int *bucket
= (unsigned int *)v
;
773 spin_unlock_bh(&htable
->lock
);
776 static int dl_seq_real_show(struct dsthash_ent
*ent
, u_int8_t family
,
780 const struct xt_hashlimit_htable
*ht
= s
->private;
782 spin_lock(&ent
->lock
);
783 /* recalculate to show accurate numbers */
784 rateinfo_recalc(ent
, jiffies
, ht
->cfg
.mode
);
788 res
= seq_printf(s
, "%ld %pI4:%u->%pI4:%u %u %u %u\n",
789 (long)(ent
->expires
- jiffies
)/HZ
,
791 ntohs(ent
->dst
.src_port
),
793 ntohs(ent
->dst
.dst_port
),
794 ent
->rateinfo
.credit
, ent
->rateinfo
.credit_cap
,
797 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
799 res
= seq_printf(s
, "%ld %pI6:%u->%pI6:%u %u %u %u\n",
800 (long)(ent
->expires
- jiffies
)/HZ
,
802 ntohs(ent
->dst
.src_port
),
804 ntohs(ent
->dst
.dst_port
),
805 ent
->rateinfo
.credit
, ent
->rateinfo
.credit_cap
,
813 spin_unlock(&ent
->lock
);
817 static int dl_seq_show(struct seq_file
*s
, void *v
)
819 struct xt_hashlimit_htable
*htable
= s
->private;
820 unsigned int *bucket
= (unsigned int *)v
;
821 struct dsthash_ent
*ent
;
823 if (!hlist_empty(&htable
->hash
[*bucket
])) {
824 hlist_for_each_entry(ent
, &htable
->hash
[*bucket
], node
)
825 if (dl_seq_real_show(ent
, htable
->family
, s
))
831 static const struct seq_operations dl_seq_ops
= {
832 .start
= dl_seq_start
,
838 static int dl_proc_open(struct inode
*inode
, struct file
*file
)
840 int ret
= seq_open(file
, &dl_seq_ops
);
843 struct seq_file
*sf
= file
->private_data
;
844 sf
->private = PDE_DATA(inode
);
849 static const struct file_operations dl_file_ops
= {
850 .owner
= THIS_MODULE
,
851 .open
= dl_proc_open
,
854 .release
= seq_release
857 static int __net_init
hashlimit_proc_net_init(struct net
*net
)
859 struct hashlimit_net
*hashlimit_net
= hashlimit_pernet(net
);
861 hashlimit_net
->ipt_hashlimit
= proc_mkdir("ipt_hashlimit", net
->proc_net
);
862 if (!hashlimit_net
->ipt_hashlimit
)
864 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
865 hashlimit_net
->ip6t_hashlimit
= proc_mkdir("ip6t_hashlimit", net
->proc_net
);
866 if (!hashlimit_net
->ip6t_hashlimit
) {
867 remove_proc_entry("ipt_hashlimit", net
->proc_net
);
874 static void __net_exit
hashlimit_proc_net_exit(struct net
*net
)
876 struct xt_hashlimit_htable
*hinfo
;
877 struct proc_dir_entry
*pde
;
878 struct hashlimit_net
*hashlimit_net
= hashlimit_pernet(net
);
880 /* recent_net_exit() is called before recent_mt_destroy(). Make sure
881 * that the parent xt_recent proc entry is is empty before trying to
884 mutex_lock(&hashlimit_mutex
);
885 pde
= hashlimit_net
->ipt_hashlimit
;
887 pde
= hashlimit_net
->ip6t_hashlimit
;
889 hlist_for_each_entry(hinfo
, &hashlimit_net
->htables
, node
)
890 remove_proc_entry(hinfo
->pde
->name
, pde
);
892 hashlimit_net
->ipt_hashlimit
= NULL
;
893 hashlimit_net
->ip6t_hashlimit
= NULL
;
894 mutex_unlock(&hashlimit_mutex
);
896 remove_proc_entry("ipt_hashlimit", net
->proc_net
);
897 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
898 remove_proc_entry("ip6t_hashlimit", net
->proc_net
);
902 static int __net_init
hashlimit_net_init(struct net
*net
)
904 struct hashlimit_net
*hashlimit_net
= hashlimit_pernet(net
);
906 INIT_HLIST_HEAD(&hashlimit_net
->htables
);
907 return hashlimit_proc_net_init(net
);
910 static void __net_exit
hashlimit_net_exit(struct net
*net
)
912 hashlimit_proc_net_exit(net
);
915 static struct pernet_operations hashlimit_net_ops
= {
916 .init
= hashlimit_net_init
,
917 .exit
= hashlimit_net_exit
,
918 .id
= &hashlimit_net_id
,
919 .size
= sizeof(struct hashlimit_net
),
922 static int __init
hashlimit_mt_init(void)
926 err
= register_pernet_subsys(&hashlimit_net_ops
);
929 err
= xt_register_matches(hashlimit_mt_reg
,
930 ARRAY_SIZE(hashlimit_mt_reg
));
935 hashlimit_cachep
= kmem_cache_create("xt_hashlimit",
936 sizeof(struct dsthash_ent
), 0, 0,
938 if (!hashlimit_cachep
) {
939 pr_warning("unable to create slab cache\n");
945 xt_unregister_matches(hashlimit_mt_reg
, ARRAY_SIZE(hashlimit_mt_reg
));
947 unregister_pernet_subsys(&hashlimit_net_ops
);
952 static void __exit
hashlimit_mt_exit(void)
954 xt_unregister_matches(hashlimit_mt_reg
, ARRAY_SIZE(hashlimit_mt_reg
));
955 unregister_pernet_subsys(&hashlimit_net_ops
);
958 kmem_cache_destroy(hashlimit_cachep
);
961 module_init(hashlimit_mt_init
);
962 module_exit(hashlimit_mt_exit
);