2 * Copyright (c) 2006 Patrick McHardy <kaber@trash.net>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
8 * This is a replacement of the old ipt_recent module, which carried the
9 * following copyright notice:
11 * Author: Stephen Frost <sfrost@snowman.net>
12 * Copyright 2002-2003, Stephen Frost, 2.5.x port by laforge@netfilter.org
14 #include <linux/init.h>
15 #include <linux/moduleparam.h>
16 #include <linux/proc_fs.h>
17 #include <linux/seq_file.h>
18 #include <linux/string.h>
19 #include <linux/ctype.h>
20 #include <linux/list.h>
21 #include <linux/random.h>
22 #include <linux/jhash.h>
23 #include <linux/bitops.h>
24 #include <linux/skbuff.h>
25 #include <linux/inet.h>
27 #include <linux/netfilter_ipv4/ip_tables.h>
28 #include <linux/netfilter_ipv4/ipt_recent.h>
30 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
31 MODULE_DESCRIPTION("IP tables recently seen matching module");
32 MODULE_LICENSE("GPL");
34 static unsigned int ip_list_tot
= 100;
35 static unsigned int ip_pkt_list_tot
= 20;
36 static unsigned int ip_list_hash_size
= 0;
37 static unsigned int ip_list_perms
= 0644;
38 module_param(ip_list_tot
, uint
, 0400);
39 module_param(ip_pkt_list_tot
, uint
, 0400);
40 module_param(ip_list_hash_size
, uint
, 0400);
41 module_param(ip_list_perms
, uint
, 0400);
42 MODULE_PARM_DESC(ip_list_tot
, "number of IPs to remember per list");
43 MODULE_PARM_DESC(ip_pkt_list_tot
, "number of packets per IP to remember (max. 255)");
44 MODULE_PARM_DESC(ip_list_hash_size
, "size of hash table used to look up IPs");
45 MODULE_PARM_DESC(ip_list_perms
, "permissions on /proc/net/ipt_recent/* files");
49 struct list_head list
;
50 struct list_head lru_list
;
55 unsigned long stamps
[0];
59 struct list_head list
;
60 char name
[IPT_RECENT_NAME_LEN
];
62 struct proc_dir_entry
*proc
;
66 struct list_head lru_list
;
67 struct list_head iphash
[0];
70 static LIST_HEAD(tables
);
71 static DEFINE_SPINLOCK(recent_lock
);
72 static DEFINE_MUTEX(recent_mutex
);
75 static struct proc_dir_entry
*proc_dir
;
76 static struct file_operations recent_fops
;
79 static u_int32_t hash_rnd
;
80 static int hash_rnd_initted
;
82 static unsigned int recent_entry_hash(u_int32_t addr
)
84 if (!hash_rnd_initted
) {
85 get_random_bytes(&hash_rnd
, 4);
88 return jhash_1word(addr
, hash_rnd
) & (ip_list_hash_size
- 1);
91 static struct recent_entry
*
92 recent_entry_lookup(const struct recent_table
*table
, u_int32_t addr
, u_int8_t ttl
)
94 struct recent_entry
*e
;
97 h
= recent_entry_hash(addr
);
98 list_for_each_entry(e
, &table
->iphash
[h
], list
)
99 if (e
->addr
== addr
&& (ttl
== e
->ttl
|| !ttl
|| !e
->ttl
))
104 static void recent_entry_remove(struct recent_table
*t
, struct recent_entry
*e
)
107 list_del(&e
->lru_list
);
112 static struct recent_entry
*
113 recent_entry_init(struct recent_table
*t
, u_int32_t addr
, u_int8_t ttl
)
115 struct recent_entry
*e
;
117 if (t
->entries
>= ip_list_tot
) {
118 e
= list_entry(t
->lru_list
.next
, struct recent_entry
, lru_list
);
119 recent_entry_remove(t
, e
);
121 e
= kmalloc(sizeof(*e
) + sizeof(e
->stamps
[0]) * ip_pkt_list_tot
,
127 e
->stamps
[0] = jiffies
;
130 list_add_tail(&e
->list
, &t
->iphash
[recent_entry_hash(addr
)]);
131 list_add_tail(&e
->lru_list
, &t
->lru_list
);
136 static void recent_entry_update(struct recent_table
*t
, struct recent_entry
*e
)
138 e
->stamps
[e
->index
++] = jiffies
;
139 if (e
->index
> e
->nstamps
)
140 e
->nstamps
= e
->index
;
141 e
->index
%= ip_pkt_list_tot
;
142 list_move_tail(&e
->lru_list
, &t
->lru_list
);
145 static struct recent_table
*recent_table_lookup(const char *name
)
147 struct recent_table
*t
;
149 list_for_each_entry(t
, &tables
, list
)
150 if (!strcmp(t
->name
, name
))
155 static void recent_table_flush(struct recent_table
*t
)
157 struct recent_entry
*e
, *next
;
160 for (i
= 0; i
< ip_list_hash_size
; i
++) {
161 list_for_each_entry_safe(e
, next
, &t
->iphash
[i
], list
)
162 recent_entry_remove(t
, e
);
167 ipt_recent_match(const struct sk_buff
*skb
,
168 const struct net_device
*in
, const struct net_device
*out
,
169 const struct xt_match
*match
, const void *matchinfo
,
170 int offset
, unsigned int protoff
, int *hotdrop
)
172 const struct ipt_recent_info
*info
= matchinfo
;
173 struct recent_table
*t
;
174 struct recent_entry
*e
;
177 int ret
= info
->invert
;
179 if (info
->side
== IPT_RECENT_DEST
)
180 addr
= skb
->nh
.iph
->daddr
;
182 addr
= skb
->nh
.iph
->saddr
;
184 ttl
= skb
->nh
.iph
->ttl
;
185 /* use TTL as seen before forwarding */
189 spin_lock_bh(&recent_lock
);
190 t
= recent_table_lookup(info
->name
);
191 e
= recent_entry_lookup(t
, addr
,
192 info
->check_set
& IPT_RECENT_TTL
? ttl
: 0);
194 if (!(info
->check_set
& IPT_RECENT_SET
))
196 e
= recent_entry_init(t
, addr
, ttl
);
203 if (info
->check_set
& IPT_RECENT_SET
)
205 else if (info
->check_set
& IPT_RECENT_REMOVE
) {
206 recent_entry_remove(t
, e
);
208 } else if (info
->check_set
& (IPT_RECENT_CHECK
| IPT_RECENT_UPDATE
)) {
209 unsigned long t
= jiffies
- info
->seconds
* HZ
;
210 unsigned int i
, hits
= 0;
212 for (i
= 0; i
< e
->nstamps
; i
++) {
213 if (info
->seconds
&& time_after(t
, e
->stamps
[i
]))
215 if (++hits
>= info
->hit_count
) {
222 if (info
->check_set
& IPT_RECENT_SET
||
223 (info
->check_set
& IPT_RECENT_UPDATE
&& ret
)) {
224 recent_entry_update(t
, e
);
228 spin_unlock_bh(&recent_lock
);
233 ipt_recent_checkentry(const char *tablename
, const void *ip
,
234 const struct xt_match
*match
, void *matchinfo
,
235 unsigned int matchsize
, unsigned int hook_mask
)
237 const struct ipt_recent_info
*info
= matchinfo
;
238 struct recent_table
*t
;
242 if (hweight8(info
->check_set
&
243 (IPT_RECENT_SET
| IPT_RECENT_REMOVE
|
244 IPT_RECENT_CHECK
| IPT_RECENT_UPDATE
)) != 1)
246 if ((info
->check_set
& (IPT_RECENT_SET
| IPT_RECENT_REMOVE
)) &&
247 (info
->seconds
|| info
->hit_count
))
249 if (info
->name
[0] == '\0' ||
250 strnlen(info
->name
, IPT_RECENT_NAME_LEN
) == IPT_RECENT_NAME_LEN
)
253 mutex_lock(&recent_mutex
);
254 t
= recent_table_lookup(info
->name
);
261 t
= kzalloc(sizeof(*t
) + sizeof(t
->iphash
[0]) * ip_list_hash_size
,
266 strcpy(t
->name
, info
->name
);
267 INIT_LIST_HEAD(&t
->lru_list
);
268 for (i
= 0; i
< ip_list_hash_size
; i
++)
269 INIT_LIST_HEAD(&t
->iphash
[i
]);
270 #ifdef CONFIG_PROC_FS
271 t
->proc
= create_proc_entry(t
->name
, ip_list_perms
, proc_dir
);
272 if (t
->proc
== NULL
) {
276 t
->proc
->proc_fops
= &recent_fops
;
279 spin_lock_bh(&recent_lock
);
280 list_add_tail(&t
->list
, &tables
);
281 spin_unlock_bh(&recent_lock
);
284 mutex_unlock(&recent_mutex
);
289 ipt_recent_destroy(const struct xt_match
*match
, void *matchinfo
,
290 unsigned int matchsize
)
292 const struct ipt_recent_info
*info
= matchinfo
;
293 struct recent_table
*t
;
295 mutex_lock(&recent_mutex
);
296 t
= recent_table_lookup(info
->name
);
297 if (--t
->refcnt
== 0) {
298 spin_lock_bh(&recent_lock
);
300 spin_unlock_bh(&recent_lock
);
301 recent_table_flush(t
);
302 #ifdef CONFIG_PROC_FS
303 remove_proc_entry(t
->name
, proc_dir
);
307 mutex_unlock(&recent_mutex
);
310 #ifdef CONFIG_PROC_FS
311 struct recent_iter_state
{
312 struct recent_table
*table
;
316 static void *recent_seq_start(struct seq_file
*seq
, loff_t
*pos
)
318 struct recent_iter_state
*st
= seq
->private;
319 struct recent_table
*t
= st
->table
;
320 struct recent_entry
*e
;
323 spin_lock_bh(&recent_lock
);
325 for (st
->bucket
= 0; st
->bucket
< ip_list_hash_size
; st
->bucket
++) {
326 list_for_each_entry(e
, &t
->iphash
[st
->bucket
], list
) {
334 static void *recent_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
336 struct recent_iter_state
*st
= seq
->private;
337 struct recent_table
*t
= st
->table
;
338 struct recent_entry
*e
= v
;
339 struct list_head
*head
= e
->list
.next
;
341 while (head
== &t
->iphash
[st
->bucket
]) {
342 if (++st
->bucket
>= ip_list_hash_size
)
344 head
= t
->iphash
[st
->bucket
].next
;
347 return list_entry(head
, struct recent_entry
, list
);
350 static void recent_seq_stop(struct seq_file
*s
, void *v
)
352 spin_unlock_bh(&recent_lock
);
355 static int recent_seq_show(struct seq_file
*seq
, void *v
)
357 struct recent_entry
*e
= v
;
360 i
= (e
->index
- 1) % ip_pkt_list_tot
;
361 seq_printf(seq
, "src=%u.%u.%u.%u ttl: %u last_seen: %lu oldest_pkt: %u",
362 NIPQUAD(e
->addr
), e
->ttl
, e
->stamps
[i
], e
->index
);
363 for (i
= 0; i
< e
->nstamps
; i
++)
364 seq_printf(seq
, "%s %lu", i
? "," : "", e
->stamps
[i
]);
365 seq_printf(seq
, "\n");
369 static struct seq_operations recent_seq_ops
= {
370 .start
= recent_seq_start
,
371 .next
= recent_seq_next
,
372 .stop
= recent_seq_stop
,
373 .show
= recent_seq_show
,
376 static int recent_seq_open(struct inode
*inode
, struct file
*file
)
378 struct proc_dir_entry
*pde
= PDE(inode
);
379 struct seq_file
*seq
;
380 struct recent_iter_state
*st
;
383 st
= kzalloc(sizeof(*st
), GFP_KERNEL
);
386 ret
= seq_open(file
, &recent_seq_ops
);
389 st
->table
= pde
->data
;
390 seq
= file
->private_data
;
395 static ssize_t
recent_proc_write(struct file
*file
, const char __user
*input
,
396 size_t size
, loff_t
*loff
)
398 struct proc_dir_entry
*pde
= PDE(file
->f_dentry
->d_inode
);
399 struct recent_table
*t
= pde
->data
;
400 struct recent_entry
*e
;
401 char buf
[sizeof("+255.255.255.255")], *c
= buf
;
405 if (size
> sizeof(buf
))
407 if (copy_from_user(buf
, input
, size
))
412 if (size
- (c
- buf
) < 5)
414 if (!strncmp(c
, "clear", 5)) {
416 spin_lock_bh(&recent_lock
);
417 recent_table_flush(t
);
418 spin_unlock_bh(&recent_lock
);
435 spin_lock_bh(&recent_lock
);
436 e
= recent_entry_lookup(t
, addr
, 0);
439 recent_entry_init(t
, addr
, 0);
442 recent_entry_update(t
, e
);
444 recent_entry_remove(t
, e
);
446 spin_unlock_bh(&recent_lock
);
450 static struct file_operations recent_fops
= {
451 .open
= recent_seq_open
,
453 .write
= recent_proc_write
,
454 .release
= seq_release_private
,
455 .owner
= THIS_MODULE
,
457 #endif /* CONFIG_PROC_FS */
459 static struct ipt_match recent_match
= {
461 .match
= ipt_recent_match
,
462 .matchsize
= sizeof(struct ipt_recent_info
),
463 .checkentry
= ipt_recent_checkentry
,
464 .destroy
= ipt_recent_destroy
,
468 static int __init
ipt_recent_init(void)
472 if (!ip_list_tot
|| !ip_pkt_list_tot
|| ip_pkt_list_tot
> 255)
474 ip_list_hash_size
= 1 << fls(ip_list_tot
);
476 err
= ipt_register_match(&recent_match
);
477 #ifdef CONFIG_PROC_FS
480 proc_dir
= proc_mkdir("ipt_recent", proc_net
);
481 if (proc_dir
== NULL
) {
482 ipt_unregister_match(&recent_match
);
489 static void __exit
ipt_recent_exit(void)
491 BUG_ON(!list_empty(&tables
));
492 ipt_unregister_match(&recent_match
);
493 #ifdef CONFIG_PROC_FS
494 remove_proc_entry("ipt_recent", proc_net
);
498 module_init(ipt_recent_init
);
499 module_exit(ipt_recent_exit
);