1 /* Kernel module to check if the source address has been seen recently. */
2 /* Copyright 2002-2003, Stephen Frost, 2.5.x port by laforge@netfilter.org */
3 /* Author: Stephen Frost <sfrost@snowman.net> */
4 /* Project Page: http://snowman.net/projects/ipt_recent/ */
5 /* This software is distributed under the terms of the GPL, Version 2 */
6 /* This copyright does not cover user programs that use kernel services
7 * by normal system calls. */
9 #include <linux/module.h>
10 #include <linux/skbuff.h>
11 #include <linux/proc_fs.h>
12 #include <linux/spinlock.h>
13 #include <linux/interrupt.h>
14 #include <asm/uaccess.h>
15 #include <linux/ctype.h>
17 #include <linux/vmalloc.h>
18 #include <linux/moduleparam.h>
20 #include <linux/netfilter_ipv4/ip_tables.h>
21 #include <linux/netfilter_ipv4/ipt_recent.h>
26 /* Defaults, these can be overridden on the module command-line. */
27 static unsigned int ip_list_tot = 100;
28 static unsigned int ip_pkt_list_tot = 20;
29 static unsigned int ip_list_hash_size = 0;
30 static unsigned int ip_list_perms = 0644;
35 static char version[] =
36 KERN_INFO RECENT_NAME " " RECENT_VER ": Stephen Frost <sfrost@snowman.net>. http://snowman.net/projects/ipt_recent/\n";
38 MODULE_AUTHOR("Stephen Frost <sfrost@snowman.net>");
39 MODULE_DESCRIPTION("IP tables recently seen matching module " RECENT_VER);
40 MODULE_LICENSE("GPL");
41 module_param(ip_list_tot, uint, 0400);
42 module_param(ip_pkt_list_tot, uint, 0400);
43 module_param(ip_list_hash_size, uint, 0400);
44 module_param(ip_list_perms, uint, 0400);
46 module_param(debug, bool, 0600);
47 MODULE_PARM_DESC(debug,"enable debugging output");
49 MODULE_PARM_DESC(ip_list_tot,"number of IPs to remember per list");
50 MODULE_PARM_DESC(ip_pkt_list_tot,"number of packets per IP to remember");
51 MODULE_PARM_DESC(ip_list_hash_size,"size of hash table used to look up IPs");
52 MODULE_PARM_DESC(ip_list_perms,"permissions on /proc/net/ipt_recent/* files");
54 /* Structure of our list of recently seen addresses. */
55 struct recent_ip_list {
58 unsigned long last_seen;
59 unsigned long *last_pkts;
65 struct time_info_list {
70 /* Structure of our linked list of tables of recent lists. */
71 struct recent_ip_tables {
72 char name[IPT_RECENT_NAME_LEN];
75 struct recent_ip_list *table;
76 struct recent_ip_tables *next;
79 struct time_info_list *time_info;
81 struct proc_dir_entry *status_proc;
82 #endif /* CONFIG_PROC_FS */
85 /* Our current list of addresses we have recently seen.
86 * Only added to on a --set, and only updated on --set || --update
88 static struct recent_ip_tables *r_tables = NULL;
90 /* We protect r_list with this spinlock so two processors are not modifying
91 * the list at the same time.
93 static DEFINE_SPINLOCK(recent_lock);
96 /* Our /proc/net/ipt_recent entry */
97 static struct proc_dir_entry *proc_net_ipt_recent = NULL;
100 /* Function declaration for later. */
102 match(const struct sk_buff *skb,
103 const struct net_device *in,
104 const struct net_device *out,
105 const struct xt_match *match,
106 const void *matchinfo,
108 unsigned int protoff,
111 /* Function to hash a given address into the hash table of table_size size */
112 static int hash_func(unsigned int addr, int table_size)
115 unsigned int value = addr;
116 do { result ^= value; } while((value >>= HASH_LOG));
119 if(debug) printk(KERN_INFO RECENT_NAME ": %d = hash_func(%u,%d)\n",
120 result & (table_size - 1),
125 return(result & (table_size - 1));
128 #ifdef CONFIG_PROC_FS
129 /* This is the function which produces the output for our /proc output
130 * interface which lists each IP address, the last seen time and the
131 * other recent times the address was seen.
134 static int ip_recent_get_info(char *buffer, char **start, off_t offset, int length, int *eof, void *data)
136 int len = 0, count, last_len = 0, pkt_count;
139 struct recent_ip_tables *curr_table;
141 curr_table = (struct recent_ip_tables*) data;
143 spin_lock_bh(&curr_table->list_lock);
144 for(count = 0; count < ip_list_tot; count++) {
145 if(!curr_table->table[count].addr) continue;
147 len += sprintf(buffer+len,"src=%u.%u.%u.%u ",NIPQUAD(curr_table->table[count].addr));
148 len += sprintf(buffer+len,"ttl: %u ",curr_table->table[count].ttl);
149 len += sprintf(buffer+len,"last_seen: %lu ",curr_table->table[count].last_seen);
150 len += sprintf(buffer+len,"oldest_pkt: %u ",curr_table->table[count].oldest_pkt);
151 len += sprintf(buffer+len,"last_pkts: %lu",curr_table->table[count].last_pkts[0]);
152 for(pkt_count = 1; pkt_count < ip_pkt_list_tot; pkt_count++) {
153 if(!curr_table->table[count].last_pkts[pkt_count]) break;
154 len += sprintf(buffer+len,", %lu",curr_table->table[count].last_pkts[pkt_count]);
156 len += sprintf(buffer+len,"\n");
158 if(pos < offset) { len = 0; begin = pos; }
159 if(pos > offset + length) { len = last_len; break; }
162 *start = buffer + (offset - begin);
163 len -= (offset - begin);
164 if(len > length) len = length;
166 spin_unlock_bh(&curr_table->list_lock);
170 /* ip_recent_ctrl provides an interface for users to modify the table
171 * directly. This allows adding entries, removing entries, and
172 * flushing the entire table.
173 * This is done by opening up the appropriate table for writing and
175 * xx.xx.xx.xx -- Add entry to table with current time
176 * +xx.xx.xx.xx -- Add entry to table with current time
177 * -xx.xx.xx.xx -- Remove entry from table
178 * clear -- Flush table, remove all entries
181 static int ip_recent_ctrl(struct file *file, const char __user *input, unsigned long size, void *data)
183 static const u_int32_t max[4] = { 0xffffffff, 0xffffff, 0xffff, 0xff };
191 uint8_t *pp = res.bytes;
195 int len, check_set = 0, count;
198 struct ipt_recent_info *info;
199 struct recent_ip_tables *curr_table;
201 curr_table = (struct recent_ip_tables*) data;
203 if(size > 20) len = 20; else len = size;
205 if(copy_from_user(buffer,input,len)) return -EFAULT;
207 if(len < 20) buffer[len] = '\0';
210 if(debug) printk(KERN_INFO RECENT_NAME ": ip_recent_ctrl len: %d, input: `%.20s'\n",len,buffer);
214 while(isspace(*cp)) { cp++; used++; if(used >= len-5) return used; }
216 /* Check if we are asked to flush the entire table */
217 if(!memcmp(cp,"clear",5)) {
219 spin_lock_bh(&curr_table->list_lock);
220 curr_table->time_pos = 0;
221 for(count = 0; count < ip_list_hash_size; count++) {
222 curr_table->hash_table[count] = -1;
224 for(count = 0; count < ip_list_tot; count++) {
225 curr_table->table[count].last_seen = 0;
226 curr_table->table[count].addr = 0;
227 curr_table->table[count].ttl = 0;
228 memset(curr_table->table[count].last_pkts,0,ip_pkt_list_tot*sizeof(unsigned long));
229 curr_table->table[count].oldest_pkt = 0;
230 curr_table->table[count].time_pos = 0;
231 curr_table->time_info[count].position = count;
232 curr_table->time_info[count].time = 0;
234 spin_unlock_bh(&curr_table->list_lock);
238 check_set = IPT_RECENT_SET;
240 case '+': check_set = IPT_RECENT_SET; cp++; used++; break;
241 case '-': check_set = IPT_RECENT_REMOVE; cp++; used++; break;
242 default: if(!isdigit(*cp)) return (used+1); break;
246 if(debug) printk(KERN_INFO RECENT_NAME ": ip_recent_ctrl cp: `%c', check_set: %d\n",*cp,check_set);
248 /* Get addr (effectively inet_aton()) */
249 /* Shamelessly stolen from libc, a function in the kernel for doing
250 * this would, of course, be greatly preferred, but our options appear
251 * to be rather limited, so we will just do it ourselves here.
257 if(!isdigit(c)) return used;
258 val = 0; base = 10; digit = 0;
261 if(c == 'x' || c == 'X') base = 16, c = *++cp;
262 else { base = 8; digit = 1; }
265 if(isascii(c) && isdigit(c)) {
266 if(base == 8 && (c == '8' || c == '0')) return used;
267 val = (val * base) + (c - '0');
270 } else if(base == 16 && isascii(c) && isxdigit(c)) {
271 val = (val << 4) | (c + 10 - (islower(c) ? 'a' : 'A'));
277 if(pp > res.bytes + 2 || val > 0xff) return used;
283 if(c != '\0' && (!isascii(c) || !isspace(c))) return used;
284 if(c == '\n') used++;
285 if(!digit) return used;
287 if(val > max[pp - res.bytes]) return used;
288 addr = res.word | htonl(val);
290 if(!addr && check_set == IPT_RECENT_SET) return used;
293 if(debug) printk(KERN_INFO RECENT_NAME ": ip_recent_ctrl c: %c, addr: %u used: %d\n",c,addr,used);
296 /* Set up and just call match */
297 info = kmalloc(sizeof(struct ipt_recent_info),GFP_KERNEL);
298 if(!info) { return -ENOMEM; }
301 info->check_set = check_set;
303 info->side = IPT_RECENT_SOURCE;
304 strncpy(info->name,curr_table->name,IPT_RECENT_NAME_LEN);
305 info->name[IPT_RECENT_NAME_LEN-1] = '\0';
307 skb = kmalloc(sizeof(struct sk_buff),GFP_KERNEL);
312 skb->nh.iph = kmalloc(sizeof(struct iphdr),GFP_KERNEL);
318 skb->nh.iph->saddr = addr;
319 skb->nh.iph->daddr = 0;
320 /* Clear ttl since we have no way of knowing it */
321 skb->nh.iph->ttl = 0;
322 match(skb,NULL,NULL,NULL,info,0,0,NULL);
331 if(debug) printk(KERN_INFO RECENT_NAME ": Leaving ip_recent_ctrl addr: %u used: %d\n",addr,used);
336 #endif /* CONFIG_PROC_FS */
338 /* 'match' is our primary function, called by the kernel whenever a rule is
339 * hit with our module as an option to it.
340 * What this function does depends on what was specifically asked of it by
342 * --set -- Add or update last seen time of the source address of the packet
343 * -- matchinfo->check_set == IPT_RECENT_SET
344 * --rcheck -- Just check if the source address is in the list
345 * -- matchinfo->check_set == IPT_RECENT_CHECK
346 * --update -- If the source address is in the list, update last_seen
347 * -- matchinfo->check_set == IPT_RECENT_UPDATE
348 * --remove -- If the source address is in the list, remove it
349 * -- matchinfo->check_set == IPT_RECENT_REMOVE
350 * --seconds -- Option to --rcheck/--update, only match if last_seen within seconds
351 * -- matchinfo->seconds
352 * --hitcount -- Option to --rcheck/--update, only match if seen hitcount times
353 * -- matchinfo->hit_count
354 * --seconds and --hitcount can be combined
357 match(const struct sk_buff *skb,
358 const struct net_device *in,
359 const struct net_device *out,
360 const struct xt_match *match,
361 const void *matchinfo,
363 unsigned int protoff,
366 int pkt_count, hits_found, ans;
368 const struct ipt_recent_info *info = matchinfo;
369 u_int32_t addr = 0, time_temp;
370 u_int8_t ttl = skb->nh.iph->ttl;
372 int orig_hash_result, hash_result, temp, location = 0, time_loc, end_collision_chain = -1;
373 struct time_info_list *time_info;
374 struct recent_ip_tables *curr_table;
375 struct recent_ip_tables *last_table;
376 struct recent_ip_list *r_list;
379 if(debug) printk(KERN_INFO RECENT_NAME ": match() called\n");
382 /* Default is false ^ info->invert */
386 if(debug) printk(KERN_INFO RECENT_NAME ": match(): name = '%s'\n",info->name);
389 /* if out != NULL then routing has been done and TTL changed.
390 * We change it back here internally for match what came in before routing. */
393 /* Find the right table */
394 spin_lock_bh(&recent_lock);
395 curr_table = r_tables;
396 while( (last_table = curr_table) && strncmp(info->name,curr_table->name,IPT_RECENT_NAME_LEN) && (curr_table = curr_table->next) );
399 if(debug) printk(KERN_INFO RECENT_NAME ": match(): table found('%s')\n",info->name);
402 spin_unlock_bh(&recent_lock);
404 /* Table with this name not found, match impossible */
405 if(!curr_table) { return ans; }
407 /* Make sure no one is changing the list while we work with it */
408 spin_lock_bh(&curr_table->list_lock);
410 r_list = curr_table->table;
411 if(info->side == IPT_RECENT_DEST) addr = skb->nh.iph->daddr; else addr = skb->nh.iph->saddr;
415 if(debug) printk(KERN_INFO RECENT_NAME ": match() address (%u) invalid, leaving.\n",addr);
417 spin_unlock_bh(&curr_table->list_lock);
422 if(debug) printk(KERN_INFO RECENT_NAME ": match(): checking table, addr: %u, ttl: %u, orig_ttl: %u\n",addr,ttl,skb->nh.iph->ttl);
425 /* Get jiffies now in case they changed while we were waiting for a lock */
427 hash_table = curr_table->hash_table;
428 time_info = curr_table->time_info;
430 orig_hash_result = hash_result = hash_func(addr,ip_list_hash_size);
431 /* Hash entry at this result used */
432 /* Check for TTL match if requested. If TTL is zero then a match would never
433 * happen, so match regardless of existing TTL in that case. Zero means the
434 * entry was added via the /proc interface anyway, so we will just use the
435 * first TTL we get for that IP address. */
436 if(info->check_set & IPT_RECENT_TTL) {
437 while(hash_table[hash_result] != -1 && !(r_list[hash_table[hash_result]].addr == addr &&
438 (!r_list[hash_table[hash_result]].ttl || r_list[hash_table[hash_result]].ttl == ttl))) {
439 /* Collision in hash table */
440 hash_result = (hash_result + 1) % ip_list_hash_size;
443 while(hash_table[hash_result] != -1 && r_list[hash_table[hash_result]].addr != addr) {
444 /* Collision in hash table */
445 hash_result = (hash_result + 1) % ip_list_hash_size;
449 if(hash_table[hash_result] == -1 && !(info->check_set & IPT_RECENT_SET)) {
450 /* IP not in list and not asked to SET */
451 spin_unlock_bh(&curr_table->list_lock);
455 /* Check if we need to handle the collision, do not need to on REMOVE */
456 if(orig_hash_result != hash_result && !(info->check_set & IPT_RECENT_REMOVE)) {
458 if(debug) printk(KERN_INFO RECENT_NAME ": match(): Collision in hash table. (or: %d,hr: %d,oa: %u,ha: %u)\n",
461 r_list[hash_table[orig_hash_result]].addr,
465 /* We had a collision.
466 * orig_hash_result is where we started, hash_result is where we ended up.
467 * So, swap them because we are likely to see the same guy again sooner */
470 printk(KERN_INFO RECENT_NAME ": match(): Collision; hash_table[orig_hash_result] = %d\n",hash_table[orig_hash_result]);
471 printk(KERN_INFO RECENT_NAME ": match(): Collision; r_list[hash_table[orig_hash_result]].hash_entry = %d\n",
472 r_list[hash_table[orig_hash_result]].hash_entry);
476 r_list[hash_table[orig_hash_result]].hash_entry = hash_result;
479 temp = hash_table[orig_hash_result];
481 if(debug) printk(KERN_INFO RECENT_NAME ": match(): Collision; hash_table[hash_result] = %d\n",hash_table[hash_result]);
483 hash_table[orig_hash_result] = hash_table[hash_result];
484 hash_table[hash_result] = temp;
486 hash_result = orig_hash_result;
487 orig_hash_result = temp;
488 time_info[r_list[hash_table[orig_hash_result]].time_pos].position = hash_table[orig_hash_result];
489 if(hash_table[hash_result] != -1) {
490 r_list[hash_table[hash_result]].hash_entry = hash_result;
491 time_info[r_list[hash_table[hash_result]].time_pos].position = hash_table[hash_result];
495 if(debug) printk(KERN_INFO RECENT_NAME ": match(): Collision handled.\n");
499 if(hash_table[hash_result] == -1) {
501 if(debug) printk(KERN_INFO RECENT_NAME ": match(): New table entry. (hr: %d,ha: %u)\n",
505 /* New item found and IPT_RECENT_SET, so we need to add it */
506 location = time_info[curr_table->time_pos].position;
507 hash_table[r_list[location].hash_entry] = -1;
508 hash_table[hash_result] = location;
509 memset(r_list[location].last_pkts,0,ip_pkt_list_tot*sizeof(unsigned long));
510 r_list[location].time_pos = curr_table->time_pos;
511 r_list[location].addr = addr;
512 r_list[location].ttl = ttl;
513 r_list[location].last_seen = now;
514 r_list[location].oldest_pkt = 1;
515 r_list[location].last_pkts[0] = now;
516 r_list[location].hash_entry = hash_result;
517 time_info[curr_table->time_pos].time = r_list[location].last_seen;
518 curr_table->time_pos = (curr_table->time_pos + 1) % ip_list_tot;
523 if(debug) printk(KERN_INFO RECENT_NAME ": match(): Existing table entry. (hr: %d,ha: %u)\n",
528 /* Existing item found */
529 location = hash_table[hash_result];
530 /* We have a match on address, now to make sure it meets all requirements for a
532 if(info->check_set & IPT_RECENT_CHECK || info->check_set & IPT_RECENT_UPDATE) {
533 if(!info->seconds && !info->hit_count) ans = !info->invert; else ans = info->invert;
534 if(info->seconds && !info->hit_count) {
535 if(time_before_eq(now,r_list[location].last_seen+info->seconds*HZ)) ans = !info->invert; else ans = info->invert;
537 if(info->seconds && info->hit_count) {
538 for(pkt_count = 0, hits_found = 0; pkt_count < ip_pkt_list_tot; pkt_count++) {
539 if(r_list[location].last_pkts[pkt_count] == 0) break;
540 if(time_before_eq(now,r_list[location].last_pkts[pkt_count]+info->seconds*HZ)) hits_found++;
542 if(hits_found >= info->hit_count) ans = !info->invert; else ans = info->invert;
544 if(info->hit_count && !info->seconds) {
545 for(pkt_count = 0, hits_found = 0; pkt_count < ip_pkt_list_tot; pkt_count++) {
546 if(r_list[location].last_pkts[pkt_count] == 0) break;
549 if(hits_found >= info->hit_count) ans = !info->invert; else ans = info->invert;
555 printk(KERN_INFO RECENT_NAME ": match(): match addr: %u\n",addr);
557 printk(KERN_INFO RECENT_NAME ": match(): no match addr: %u\n",addr);
561 /* If and only if we have been asked to SET, or to UPDATE (on match) do we add the
562 * current timestamp to the last_seen. */
563 if((info->check_set & IPT_RECENT_SET && (ans = !info->invert)) || (info->check_set & IPT_RECENT_UPDATE && ans)) {
565 if(debug) printk(KERN_INFO RECENT_NAME ": match(): SET or UPDATE; updating time info.\n");
567 /* Have to update our time info */
568 time_loc = r_list[location].time_pos;
569 time_info[time_loc].time = now;
570 time_info[time_loc].position = location;
571 while((time_info[(time_loc+1) % ip_list_tot].time < time_info[time_loc].time) && ((time_loc+1) % ip_list_tot) != curr_table->time_pos) {
572 time_temp = time_info[time_loc].time;
573 time_info[time_loc].time = time_info[(time_loc+1)%ip_list_tot].time;
574 time_info[(time_loc+1)%ip_list_tot].time = time_temp;
575 time_temp = time_info[time_loc].position;
576 time_info[time_loc].position = time_info[(time_loc+1)%ip_list_tot].position;
577 time_info[(time_loc+1)%ip_list_tot].position = time_temp;
578 r_list[time_info[time_loc].position].time_pos = time_loc;
579 r_list[time_info[(time_loc+1)%ip_list_tot].position].time_pos = (time_loc+1)%ip_list_tot;
580 time_loc = (time_loc+1) % ip_list_tot;
582 r_list[location].time_pos = time_loc;
583 r_list[location].ttl = ttl;
584 r_list[location].last_pkts[r_list[location].oldest_pkt] = now;
585 r_list[location].oldest_pkt = ++r_list[location].oldest_pkt % ip_pkt_list_tot;
586 r_list[location].last_seen = now;
588 /* If we have been asked to remove the entry from the list, just set it to 0 */
589 if(info->check_set & IPT_RECENT_REMOVE) {
591 if(debug) printk(KERN_INFO RECENT_NAME ": match(): REMOVE; clearing entry (or: %d, hr: %d).\n",orig_hash_result,hash_result);
593 /* Check if this is part of a collision chain */
594 while(hash_table[(orig_hash_result+1) % ip_list_hash_size] != -1) {
596 if(hash_func(r_list[hash_table[orig_hash_result]].addr,ip_list_hash_size) == hash_result) {
597 /* Found collision chain, how deep does this rabbit hole go? */
599 if(debug) printk(KERN_INFO RECENT_NAME ": match(): REMOVE; found collision chain.\n");
601 end_collision_chain = orig_hash_result;
604 if(end_collision_chain != -1) {
606 if(debug) printk(KERN_INFO RECENT_NAME ": match(): REMOVE; part of collision chain, moving to end.\n");
608 /* Part of a collision chain, swap it with the end of the chain
609 * before removing. */
610 r_list[hash_table[end_collision_chain]].hash_entry = hash_result;
611 temp = hash_table[end_collision_chain];
612 hash_table[end_collision_chain] = hash_table[hash_result];
613 hash_table[hash_result] = temp;
614 time_info[r_list[hash_table[hash_result]].time_pos].position = hash_table[hash_result];
615 hash_result = end_collision_chain;
616 r_list[hash_table[hash_result]].hash_entry = hash_result;
617 time_info[r_list[hash_table[hash_result]].time_pos].position = hash_table[hash_result];
619 location = hash_table[hash_result];
620 hash_table[r_list[location].hash_entry] = -1;
621 time_loc = r_list[location].time_pos;
622 time_info[time_loc].time = 0;
623 time_info[time_loc].position = location;
624 while((time_info[(time_loc+1) % ip_list_tot].time < time_info[time_loc].time) && ((time_loc+1) % ip_list_tot) != curr_table->time_pos) {
625 time_temp = time_info[time_loc].time;
626 time_info[time_loc].time = time_info[(time_loc+1)%ip_list_tot].time;
627 time_info[(time_loc+1)%ip_list_tot].time = time_temp;
628 time_temp = time_info[time_loc].position;
629 time_info[time_loc].position = time_info[(time_loc+1)%ip_list_tot].position;
630 time_info[(time_loc+1)%ip_list_tot].position = time_temp;
631 r_list[time_info[time_loc].position].time_pos = time_loc;
632 r_list[time_info[(time_loc+1)%ip_list_tot].position].time_pos = (time_loc+1)%ip_list_tot;
633 time_loc = (time_loc+1) % ip_list_tot;
635 r_list[location].time_pos = time_loc;
636 r_list[location].last_seen = 0;
637 r_list[location].addr = 0;
638 r_list[location].ttl = 0;
639 memset(r_list[location].last_pkts,0,ip_pkt_list_tot*sizeof(unsigned long));
640 r_list[location].oldest_pkt = 0;
643 spin_unlock_bh(&curr_table->list_lock);
647 spin_unlock_bh(&curr_table->list_lock);
649 if(debug) printk(KERN_INFO RECENT_NAME ": match() left.\n");
654 /* This function is to verify that the rule given during the userspace iptables
655 * command is correct.
656 * If the command is valid then we check if the table name referred to by the
657 * rule exists, if not it is created.
660 checkentry(const char *tablename,
662 const struct xt_match *match,
664 unsigned int matchsize,
665 unsigned int hook_mask)
669 const struct ipt_recent_info *info = matchinfo;
670 struct recent_ip_tables *curr_table, *find_table, *last_table;
673 if(debug) printk(KERN_INFO RECENT_NAME ": checkentry() entered.\n");
676 /* seconds and hit_count only valid for CHECK/UPDATE */
677 if(info->check_set & IPT_RECENT_SET) { flag++; if(info->seconds || info->hit_count) return 0; }
678 if(info->check_set & IPT_RECENT_REMOVE) { flag++; if(info->seconds || info->hit_count) return 0; }
679 if(info->check_set & IPT_RECENT_CHECK) flag++;
680 if(info->check_set & IPT_RECENT_UPDATE) flag++;
682 /* One and only one of these should ever be set */
683 if(flag != 1) return 0;
685 /* Name must be set to something */
686 if(!info->name || !info->name[0]) return 0;
688 /* Things look good, create a list for this if it does not exist */
689 /* Lock the linked list while we play with it */
690 spin_lock_bh(&recent_lock);
692 /* Look for an entry with this name already created */
693 /* Finds the end of the list and the entry before the end if current name does not exist */
694 find_table = r_tables;
695 while( (last_table = find_table) && strncmp(info->name,find_table->name,IPT_RECENT_NAME_LEN) && (find_table = find_table->next) );
697 /* If a table already exists just increment the count on that table and return */
700 if(debug) printk(KERN_INFO RECENT_NAME ": checkentry: table found (%s), incrementing count.\n",info->name);
703 spin_unlock_bh(&recent_lock);
707 spin_unlock_bh(&recent_lock);
709 /* Table with this name not found */
710 /* Allocate memory for new linked list item */
714 printk(KERN_INFO RECENT_NAME ": checkentry: no table found (%s)\n",info->name);
715 printk(KERN_INFO RECENT_NAME ": checkentry: Allocationg %d for link-list entry.\n",sizeof(struct recent_ip_tables));
719 curr_table = vmalloc(sizeof(struct recent_ip_tables));
720 if(curr_table == NULL) return 0;
722 spin_lock_init(&curr_table->list_lock);
723 curr_table->next = NULL;
724 curr_table->count = 1;
725 curr_table->time_pos = 0;
726 strncpy(curr_table->name,info->name,IPT_RECENT_NAME_LEN);
727 curr_table->name[IPT_RECENT_NAME_LEN-1] = '\0';
729 /* Allocate memory for this table and the list of packets in each entry. */
731 if(debug) printk(KERN_INFO RECENT_NAME ": checkentry: Allocating %d for table (%s).\n",
732 sizeof(struct recent_ip_list)*ip_list_tot,
736 curr_table->table = vmalloc(sizeof(struct recent_ip_list)*ip_list_tot);
737 if(curr_table->table == NULL) { vfree(curr_table); return 0; }
738 memset(curr_table->table,0,sizeof(struct recent_ip_list)*ip_list_tot);
740 if(debug) printk(KERN_INFO RECENT_NAME ": checkentry: Allocating %d for pkt_list.\n",
741 sizeof(unsigned long)*ip_pkt_list_tot*ip_list_tot);
744 hold = vmalloc(sizeof(unsigned long)*ip_pkt_list_tot*ip_list_tot);
746 if(debug) printk(KERN_INFO RECENT_NAME ": checkentry: After pkt_list allocation.\n");
749 printk(KERN_INFO RECENT_NAME ": checkentry: unable to allocate for pkt_list.\n");
750 vfree(curr_table->table);
754 for(c = 0; c < ip_list_tot; c++) {
755 curr_table->table[c].last_pkts = hold + c*ip_pkt_list_tot;
758 /* Allocate memory for the hash table */
760 if(debug) printk(KERN_INFO RECENT_NAME ": checkentry: Allocating %d for hash_table.\n",
761 sizeof(int)*ip_list_hash_size);
764 curr_table->hash_table = vmalloc(sizeof(int)*ip_list_hash_size);
765 if(!curr_table->hash_table) {
766 printk(KERN_INFO RECENT_NAME ": checkentry: unable to allocate for hash_table.\n");
768 vfree(curr_table->table);
773 for(c = 0; c < ip_list_hash_size; c++) {
774 curr_table->hash_table[c] = -1;
777 /* Allocate memory for the time info */
779 if(debug) printk(KERN_INFO RECENT_NAME ": checkentry: Allocating %d for time_info.\n",
780 sizeof(struct time_info_list)*ip_list_tot);
783 curr_table->time_info = vmalloc(sizeof(struct time_info_list)*ip_list_tot);
784 if(!curr_table->time_info) {
785 printk(KERN_INFO RECENT_NAME ": checkentry: unable to allocate for time_info.\n");
786 vfree(curr_table->hash_table);
788 vfree(curr_table->table);
792 for(c = 0; c < ip_list_tot; c++) {
793 curr_table->time_info[c].position = c;
794 curr_table->time_info[c].time = 0;
797 /* Put the new table in place */
798 spin_lock_bh(&recent_lock);
799 find_table = r_tables;
800 while( (last_table = find_table) && strncmp(info->name,find_table->name,IPT_RECENT_NAME_LEN) && (find_table = find_table->next) );
802 /* If a table already exists just increment the count on that table and return */
805 spin_unlock_bh(&recent_lock);
807 if(debug) printk(KERN_INFO RECENT_NAME ": checkentry: table found (%s), created by other process.\n",info->name);
809 vfree(curr_table->time_info);
810 vfree(curr_table->hash_table);
812 vfree(curr_table->table);
816 if(!last_table) r_tables = curr_table; else last_table->next = curr_table;
818 spin_unlock_bh(&recent_lock);
820 #ifdef CONFIG_PROC_FS
821 /* Create our proc 'status' entry. */
822 curr_table->status_proc = create_proc_entry(curr_table->name, ip_list_perms, proc_net_ipt_recent);
823 if (!curr_table->status_proc) {
824 printk(KERN_INFO RECENT_NAME ": checkentry: unable to allocate for /proc entry.\n");
825 /* Destroy the created table */
826 spin_lock_bh(&recent_lock);
828 curr_table = r_tables;
831 if(debug) printk(KERN_INFO RECENT_NAME ": checkentry() create_proc failed, no tables.\n");
833 spin_unlock_bh(&recent_lock);
836 while( strncmp(info->name,curr_table->name,IPT_RECENT_NAME_LEN) && (last_table = curr_table) && (curr_table = curr_table->next) );
839 if(debug) printk(KERN_INFO RECENT_NAME ": checkentry() create_proc failed, table already destroyed.\n");
841 spin_unlock_bh(&recent_lock);
844 if(last_table) last_table->next = curr_table->next; else r_tables = curr_table->next;
845 spin_unlock_bh(&recent_lock);
846 vfree(curr_table->time_info);
847 vfree(curr_table->hash_table);
849 vfree(curr_table->table);
854 curr_table->status_proc->owner = THIS_MODULE;
855 curr_table->status_proc->data = curr_table;
857 curr_table->status_proc->read_proc = ip_recent_get_info;
858 curr_table->status_proc->write_proc = ip_recent_ctrl;
859 #endif /* CONFIG_PROC_FS */
862 if(debug) printk(KERN_INFO RECENT_NAME ": checkentry() left.\n");
868 /* This function is called in the event that a rule matching this module is
870 * When this happens we need to check if there are no other rules matching
871 * the table given. If that is the case then we remove the table and clean
875 destroy(const struct xt_match *match, void *matchinfo, unsigned int matchsize)
877 const struct ipt_recent_info *info = matchinfo;
878 struct recent_ip_tables *curr_table, *last_table;
881 if(debug) printk(KERN_INFO RECENT_NAME ": destroy() entered.\n");
884 if(matchsize != IPT_ALIGN(sizeof(struct ipt_recent_info))) return;
886 /* Lock the linked list while we play with it */
887 spin_lock_bh(&recent_lock);
889 /* Look for an entry with this name already created */
890 /* Finds the end of the list and the entry before the end if current name does not exist */
892 curr_table = r_tables;
895 if(debug) printk(KERN_INFO RECENT_NAME ": destroy() No tables found, leaving.\n");
897 spin_unlock_bh(&recent_lock);
900 while( strncmp(info->name,curr_table->name,IPT_RECENT_NAME_LEN) && (last_table = curr_table) && (curr_table = curr_table->next) );
902 /* If a table does not exist then do nothing and return */
905 if(debug) printk(KERN_INFO RECENT_NAME ": destroy() table not found, leaving.\n");
907 spin_unlock_bh(&recent_lock);
913 /* If count is still non-zero then there are still rules referenceing it so we do nothing */
914 if(curr_table->count) {
916 if(debug) printk(KERN_INFO RECENT_NAME ": destroy() table found, non-zero count, leaving.\n");
918 spin_unlock_bh(&recent_lock);
923 if(debug) printk(KERN_INFO RECENT_NAME ": destroy() table found, zero count, removing.\n");
926 /* Count must be zero so we remove this table from the list */
927 if(last_table) last_table->next = curr_table->next; else r_tables = curr_table->next;
929 spin_unlock_bh(&recent_lock);
931 /* lock to make sure any late-runners still using this after we removed it from
932 * the list finish up then remove everything */
933 spin_lock_bh(&curr_table->list_lock);
934 spin_unlock_bh(&curr_table->list_lock);
936 #ifdef CONFIG_PROC_FS
937 if(curr_table->status_proc) remove_proc_entry(curr_table->name,proc_net_ipt_recent);
938 #endif /* CONFIG_PROC_FS */
939 vfree(curr_table->table[0].last_pkts);
940 vfree(curr_table->table);
941 vfree(curr_table->hash_table);
942 vfree(curr_table->time_info);
946 if(debug) printk(KERN_INFO RECENT_NAME ": destroy() left.\n");
952 /* This is the structure we pass to ipt_register to register our
953 * module with iptables.
955 static struct ipt_match recent_match = {
958 .matchsize = sizeof(struct ipt_recent_info),
959 .checkentry = checkentry,
964 /* Kernel module initialization. */
965 static int __init init(void)
970 #ifdef CONFIG_PROC_FS
971 proc_net_ipt_recent = proc_mkdir("ipt_recent",proc_net);
972 if(!proc_net_ipt_recent) return -ENOMEM;
975 if(ip_list_hash_size && ip_list_hash_size <= ip_list_tot) {
976 printk(KERN_WARNING RECENT_NAME ": ip_list_hash_size too small, resetting to default.\n");
977 ip_list_hash_size = 0;
980 if(!ip_list_hash_size) {
981 ip_list_hash_size = ip_list_tot*3;
983 while(ip_list_hash_size > count) count = count*2;
984 ip_list_hash_size = count;
988 if(debug) printk(KERN_INFO RECENT_NAME ": ip_list_hash_size: %d\n",ip_list_hash_size);
991 err = ipt_register_match(&recent_match);
993 remove_proc_entry("ipt_recent", proc_net);
997 /* Kernel module destruction. */
998 static void __exit fini(void)
1000 ipt_unregister_match(&recent_match);
1002 remove_proc_entry("ipt_recent",proc_net);
1005 /* Register our module with the kernel. */