[NETFILTER]: recent match: replace by rewritten version

Replace the unmaintainable ipt_recent match by a rewritten version that
should be fully compatible.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/netfilter/ipt_recent.c

@@ -1,1007 +1,493 @@
-/* Kernel module to check if the source address has been seen recently. */
-/* Copyright 2002-2003, Stephen Frost, 2.5.x port by laforge@netfilter.org */
-/* Author: Stephen Frost <sfrost@snowman.net> */
-/* Project Page: http://snowman.net/projects/ipt_recent/ */
-/* This software is distributed under the terms of the GPL, Version 2 */
-/* This copyright does not cover user programs that use kernel services
- * by normal system calls. */
-
-#include <linux/module.h>
-#include <linux/skbuff.h>
+/*
+ * Copyright (c) 2006 Patrick McHardy <kaber@trash.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This is a replacement of the old ipt_recent module, which carried the
+ * following copyright notice:
+ *
+ * Author: Stephen Frost <sfrost@snowman.net>
+ * Copyright 2002-2003, Stephen Frost, 2.5.x port by laforge@netfilter.org
+ */
+#include <linux/init.h>
+#include <linux/moduleparam.h>
 #include <linux/proc_fs.h>
-#include <linux/spinlock.h>
-#include <linux/interrupt.h>
-#include <asm/uaccess.h>
+#include <linux/seq_file.h>
+#include <linux/string.h>
 #include <linux/ctype.h>
-#include <linux/ip.h>
-#include <linux/vmalloc.h>
-#include <linux/moduleparam.h>
+#include <linux/list.h>
+#include <linux/random.h>
+#include <linux/jhash.h>
+#include <linux/bitops.h>
+#include <linux/skbuff.h>
+#include <linux/inet.h>
 
 #include <linux/netfilter_ipv4/ip_tables.h>
 #include <linux/netfilter_ipv4/ipt_recent.h>
 
-#undef DEBUG
-#define HASH_LOG 9
+MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
+MODULE_DESCRIPTION("IP tables recently seen matching module");
+MODULE_LICENSE("GPL");
 
-/* Defaults, these can be overridden on the module command-line. */
 static unsigned int ip_list_tot = 100;
 static unsigned int ip_pkt_list_tot = 20;
 static unsigned int ip_list_hash_size = 0;
 static unsigned int ip_list_perms = 0644;
-#ifdef DEBUG
-static int debug = 1;
-#endif
-
-static char version[] =
-KERN_INFO RECENT_NAME " " RECENT_VER ": Stephen Frost <sfrost@snowman.net>.  http://snowman.net/projects/ipt_recent/\n";
-
-MODULE_AUTHOR("Stephen Frost <sfrost@snowman.net>");
-MODULE_DESCRIPTION("IP tables recently seen matching module " RECENT_VER);
-MODULE_LICENSE("GPL");
 module_param(ip_list_tot, uint, 0400);
 module_param(ip_pkt_list_tot, uint, 0400);
 module_param(ip_list_hash_size, uint, 0400);
 module_param(ip_list_perms, uint, 0400);
-#ifdef DEBUG
-module_param(debug, bool, 0600);
-MODULE_PARM_DESC(debug,"enable debugging output");
-#endif
-MODULE_PARM_DESC(ip_list_tot,"number of IPs to remember per list");
-MODULE_PARM_DESC(ip_pkt_list_tot,"number of packets per IP to remember");
-MODULE_PARM_DESC(ip_list_hash_size,"size of hash table used to look up IPs");
-MODULE_PARM_DESC(ip_list_perms,"permissions on /proc/net/ipt_recent/* files");
-
-/* Structure of our list of recently seen addresses. */
-struct recent_ip_list {
-	u_int32_t addr;
-	u_int8_t  ttl;
-	unsigned long last_seen;
-	unsigned long *last_pkts;
-	u_int32_t oldest_pkt;
-	u_int32_t hash_entry;
-	u_int32_t time_pos;
-};
-
-struct time_info_list {
-	u_int32_t position;
-	u_int32_t time;
+MODULE_PARM_DESC(ip_list_tot, "number of IPs to remember per list");
+MODULE_PARM_DESC(ip_pkt_list_tot, "number of packets per IP to remember (max. 255)");
+MODULE_PARM_DESC(ip_list_hash_size, "size of hash table used to look up IPs");
+MODULE_PARM_DESC(ip_list_perms, "permissions on /proc/net/ipt_recent/* files");
+
+
+struct recent_entry {
+	struct list_head	list;
+	struct list_head	lru_list;
+	u_int32_t		addr;
+	u_int8_t		ttl;
+	u_int8_t		index;
+	u_int16_t		nstamps;
+	unsigned long		stamps[0];
 };
 
-/* Structure of our linked list of tables of recent lists. */
-struct recent_ip_tables {
-	char name[IPT_RECENT_NAME_LEN];
-	int count;
-	int time_pos;
-	struct recent_ip_list *table;
-	struct recent_ip_tables *next;
-	spinlock_t list_lock;
-	int *hash_table;
-	struct time_info_list *time_info;
+struct recent_table {
+	struct list_head	list;
+	char			name[IPT_RECENT_NAME_LEN];
 #ifdef CONFIG_PROC_FS
-	struct proc_dir_entry *status_proc;
-#endif /* CONFIG_PROC_FS */
+	struct proc_dir_entry	*proc;
+#endif
+	unsigned int		refcnt;
+	unsigned int		entries;
+	struct list_head	lru_list;
+	struct list_head	iphash[0];
 };
 
-/* Our current list of addresses we have recently seen.
- * Only added to on a --set, and only updated on --set || --update 
- */
-static struct recent_ip_tables *r_tables = NULL;
-
-/* We protect r_list with this spinlock so two processors are not modifying
- * the list at the same time. 
- */
+static LIST_HEAD(tables);
 static DEFINE_SPINLOCK(recent_lock);
 
 #ifdef CONFIG_PROC_FS
-/* Our /proc/net/ipt_recent entry */
-static struct proc_dir_entry *proc_net_ipt_recent = NULL;
-#endif
-
-/* Function declaration for later. */
-static int
-match(const struct sk_buff *skb,
-      const struct net_device *in,
-      const struct net_device *out,
-      const struct xt_match *match,
-      const void *matchinfo,
-      int offset,
-      unsigned int protoff,
-      int *hotdrop);
-
-/* Function to hash a given address into the hash table of table_size size */
-static int hash_func(unsigned int addr, int table_size)
-{
-	int result = 0;
-	unsigned int value = addr;
-	do { result ^= value; } while((value >>= HASH_LOG));
-
-#ifdef DEBUG
-	if(debug) printk(KERN_INFO RECENT_NAME ": %d = hash_func(%u,%d)\n",
-			 result & (table_size - 1),
-			 addr,
-			 table_size);
+static struct proc_dir_entry	*proc_dir;
+static struct file_operations	recent_fops;
 #endif
 
-	return(result & (table_size - 1));
-}
+static u_int32_t hash_rnd;
+static int hash_rnd_initted;
 
-#ifdef CONFIG_PROC_FS
-/* This is the function which produces the output for our /proc output
- * interface which lists each IP address, the last seen time and the 
- * other recent times the address was seen.
- */
-
-static int ip_recent_get_info(char *buffer, char **start, off_t offset, int length, int *eof, void *data)
+static unsigned int recent_entry_hash(u_int32_t addr)
 {
-	int len = 0, count, last_len = 0, pkt_count;
-	off_t pos = 0;
-	off_t begin = 0;
-	struct recent_ip_tables *curr_table;
-
-	curr_table = (struct recent_ip_tables*) data;
-
-	spin_lock_bh(&curr_table->list_lock);
-	for(count = 0; count < ip_list_tot; count++) {
-		if(!curr_table->table[count].addr) continue;
-		last_len = len;
-		len += sprintf(buffer+len,"src=%u.%u.%u.%u ",NIPQUAD(curr_table->table[count].addr));
-		len += sprintf(buffer+len,"ttl: %u ",curr_table->table[count].ttl);
-		len += sprintf(buffer+len,"last_seen: %lu ",curr_table->table[count].last_seen);
-		len += sprintf(buffer+len,"oldest_pkt: %u ",curr_table->table[count].oldest_pkt);
-		len += sprintf(buffer+len,"last_pkts: %lu",curr_table->table[count].last_pkts[0]);
-		for(pkt_count = 1; pkt_count < ip_pkt_list_tot; pkt_count++) {
-			if(!curr_table->table[count].last_pkts[pkt_count]) break;
-			len += sprintf(buffer+len,", %lu",curr_table->table[count].last_pkts[pkt_count]);
-		}
-		len += sprintf(buffer+len,"\n");
-		pos = begin + len;
-		if(pos < offset) { len = 0; begin = pos; }
-		if(pos > offset + length) { len = last_len; break; }
+	if (!hash_rnd_initted) {
+		get_random_bytes(&hash_rnd, 4);
+		hash_rnd_initted = 1;
 	}
-
-	*start = buffer + (offset - begin);
-	len -= (offset - begin);
-	if(len > length) len = length;
-
-	spin_unlock_bh(&curr_table->list_lock);
-	return len;
+	return jhash_1word(addr, hash_rnd) & (ip_list_hash_size - 1);
 }
 
-/* ip_recent_ctrl provides an interface for users to modify the table
- * directly.  This allows adding entries, removing entries, and
- * flushing the entire table.
- * This is done by opening up the appropriate table for writing and
- * sending one of:
- * xx.xx.xx.xx   -- Add entry to table with current time
- * +xx.xx.xx.xx  -- Add entry to table with current time
- * -xx.xx.xx.xx  -- Remove entry from table
- * clear         -- Flush table, remove all entries
- */
-
-static int ip_recent_ctrl(struct file *file, const char __user *input, unsigned long size, void *data)
+static struct recent_entry *
+recent_entry_lookup(const struct recent_table *table, u_int32_t addr, u_int8_t ttl)
 {
-	static const u_int32_t max[4] = { 0xffffffff, 0xffffff, 0xffff, 0xff };
-	u_int32_t val;
-	int base, used = 0;
-	char c, *cp;
-	union iaddr {
-		uint8_t bytes[4];
-		uint32_t word;
-	} res;
-	uint8_t *pp = res.bytes;
-	int digit;
-
-	char buffer[20];
-	int len, check_set = 0, count;
-	u_int32_t addr = 0;
-	struct sk_buff *skb;
-	struct ipt_recent_info *info;
-	struct recent_ip_tables *curr_table;
-
-	curr_table = (struct recent_ip_tables*) data;
-
-	if(size > 20) len = 20; else len = size;
-
-	if(copy_from_user(buffer,input,len)) return -EFAULT;
-
-	if(len < 20) buffer[len] = '\0';
-
-#ifdef DEBUG
-	if(debug) printk(KERN_INFO RECENT_NAME ": ip_recent_ctrl len: %d, input: `%.20s'\n",len,buffer);
-#endif
+	struct recent_entry *e;
+	unsigned int h;
+
+	h = recent_entry_hash(addr);
+	list_for_each_entry(e, &table->iphash[h], list)
+		if (e->addr == addr && (ttl == e->ttl || !ttl || !e->ttl))
+			return e;
+	return NULL;
+}
 
-	cp = buffer;
-	while(isspace(*cp)) { cp++; used++; if(used >= len-5) return used; }
+static void recent_entry_remove(struct recent_table *t, struct recent_entry *e)
+{
+	list_del(&e->list);
+	list_del(&e->lru_list);
+	kfree(e);
+	t->entries--;
+}
 
-	/* Check if we are asked to flush the entire table */
-	if(!memcmp(cp,"clear",5)) {
-		used += 5;
-		spin_lock_bh(&curr_table->list_lock);
-		curr_table->time_pos = 0;
-		for(count = 0; count < ip_list_hash_size; count++) {
-			curr_table->hash_table[count] = -1;
-		}
-		for(count = 0; count < ip_list_tot; count++) {
-			curr_table->table[count].last_seen = 0;
-			curr_table->table[count].addr = 0;
-			curr_table->table[count].ttl = 0;
-			memset(curr_table->table[count].last_pkts,0,ip_pkt_list_tot*sizeof(unsigned long));
-			curr_table->table[count].oldest_pkt = 0;
-			curr_table->table[count].time_pos = 0;
-			curr_table->time_info[count].position = count;
-			curr_table->time_info[count].time = 0;
-		}
-		spin_unlock_bh(&curr_table->list_lock);
-		return used;
-	}
+static struct recent_entry *
+recent_entry_init(struct recent_table *t, u_int32_t addr, u_int8_t ttl)
+{
+	struct recent_entry *e;
 
-        check_set = IPT_RECENT_SET;
-	switch(*cp) {
-		case '+': check_set = IPT_RECENT_SET; cp++; used++; break;
-		case '-': check_set = IPT_RECENT_REMOVE; cp++; used++; break;
-		default: if(!isdigit(*cp)) return (used+1); break;
+	if (t->entries >= ip_list_tot) {
+		e = list_entry(t->lru_list.next, struct recent_entry, lru_list);
+		recent_entry_remove(t, e);
 	}
+	e = kmalloc(sizeof(*e) + sizeof(e->stamps[0]) * ip_pkt_list_tot,
+		    GFP_ATOMIC);
+	if (e == NULL)
+		return NULL;
+	e->addr      = addr;
+	e->ttl       = ttl;
+	e->stamps[0] = jiffies;
+	e->nstamps   = 1;
+	e->index     = 1;
+	list_add_tail(&e->list, &t->iphash[recent_entry_hash(addr)]);
+	list_add_tail(&e->lru_list, &t->lru_list);
+	t->entries++;
+	return e;
+}
 
-#ifdef DEBUG
-	if(debug) printk(KERN_INFO RECENT_NAME ": ip_recent_ctrl cp: `%c', check_set: %d\n",*cp,check_set);
-#endif
-	/* Get addr (effectively inet_aton()) */
-	/* Shamelessly stolen from libc, a function in the kernel for doing
-	 * this would, of course, be greatly preferred, but our options appear
-	 * to be rather limited, so we will just do it ourselves here.
-	 */
-	res.word = 0;
-
-	c = *cp;
-	for(;;) {
-		if(!isdigit(c)) return used;
-		val = 0; base = 10; digit = 0;
-		if(c == '0') {
-			c = *++cp;
-			if(c == 'x' || c == 'X') base = 16, c = *++cp;
-			else { base = 8; digit = 1; }
-		}
-		for(;;) {
-			if(isascii(c) && isdigit(c)) {
-				if(base == 8 && (c == '8' || c == '0')) return used;
-				val = (val * base) + (c - '0');
-				c = *++cp;
-				digit = 1;
-			} else if(base == 16 && isascii(c) && isxdigit(c)) {
-				val = (val << 4) | (c + 10 - (islower(c) ? 'a' : 'A'));
-				c = *++cp;
-				digit = 1;
-			} else break;
-		}
-		if(c == '.') {
-			if(pp > res.bytes + 2 || val > 0xff) return used;
-			*pp++ = val;
-			c = *++cp;
-		} else break;
-	}
-	used = cp - buffer;
-	if(c != '\0' && (!isascii(c) || !isspace(c))) return used;
-	if(c == '\n') used++;
-	if(!digit) return used;
+static void recent_entry_update(struct recent_table *t, struct recent_entry *e)
+{
+	e->stamps[e->index++] = jiffies;
+	if (e->index > e->nstamps)
+		e->nstamps = e->index;
+	e->index %= ip_pkt_list_tot;
+	list_move_tail(&e->lru_list, &t->lru_list);
+}
 
-	if(val > max[pp - res.bytes]) return used;
-	addr = res.word | htonl(val);
+static struct recent_table *recent_table_lookup(const char *name)
+{
+	struct recent_table *t;
 
-	if(!addr && check_set == IPT_RECENT_SET) return used;
+	list_for_each_entry(t, &tables, list)
+		if (!strcmp(t->name, name))
+			return t;
+	return NULL;
+}
 
-#ifdef DEBUG
-	if(debug) printk(KERN_INFO RECENT_NAME ": ip_recent_ctrl c: %c, addr: %u used: %d\n",c,addr,used);
-#endif
+static void recent_table_flush(struct recent_table *t)
+{
+	struct recent_entry *e, *next;
+	unsigned int i;
 
-	/* Set up and just call match */
-	info = kmalloc(sizeof(struct ipt_recent_info),GFP_KERNEL);
-	if(!info) { return -ENOMEM; }
-	info->seconds = 0;
-	info->hit_count = 0;
-	info->check_set = check_set;
-	info->invert = 0;
-	info->side = IPT_RECENT_SOURCE;
-	strncpy(info->name,curr_table->name,IPT_RECENT_NAME_LEN);
-	info->name[IPT_RECENT_NAME_LEN-1] = '\0';
-
-	skb = kmalloc(sizeof(struct sk_buff),GFP_KERNEL);
-	if (!skb) {
-		used = -ENOMEM;
-		goto out_free_info;
-	}
-	skb->nh.iph = kmalloc(sizeof(struct iphdr),GFP_KERNEL);
-	if (!skb->nh.iph) {
-		used = -ENOMEM;
-		goto out_free_skb;
+	for (i = 0; i < ip_list_hash_size; i++) {
+		list_for_each_entry_safe(e, next, &t->iphash[i], list)
+			recent_entry_remove(t, e);
 	}
-
-	skb->nh.iph->saddr = addr;
-	skb->nh.iph->daddr = 0;
-	/* Clear ttl since we have no way of knowing it */
-	skb->nh.iph->ttl = 0;
-	match(skb,NULL,NULL,NULL,info,0,0,NULL);
-
-	kfree(skb->nh.iph);
-out_free_skb:
-	kfree(skb);
-out_free_info:
-	kfree(info);
-
-#ifdef DEBUG
-	if(debug) printk(KERN_INFO RECENT_NAME ": Leaving ip_recent_ctrl addr: %u used: %d\n",addr,used);
-#endif
-	return used;
 }
 
-#endif /* CONFIG_PROC_FS */
-
-/* 'match' is our primary function, called by the kernel whenever a rule is
- * hit with our module as an option to it.
- * What this function does depends on what was specifically asked of it by
- * the user:
- * --set -- Add or update last seen time of the source address of the packet
- *   -- matchinfo->check_set == IPT_RECENT_SET
- * --rcheck -- Just check if the source address is in the list
- *   -- matchinfo->check_set == IPT_RECENT_CHECK
- * --update -- If the source address is in the list, update last_seen
- *   -- matchinfo->check_set == IPT_RECENT_UPDATE
- * --remove -- If the source address is in the list, remove it
- *   -- matchinfo->check_set == IPT_RECENT_REMOVE
- * --seconds -- Option to --rcheck/--update, only match if last_seen within seconds
- *   -- matchinfo->seconds
- * --hitcount -- Option to --rcheck/--update, only match if seen hitcount times
- *   -- matchinfo->hit_count
- * --seconds and --hitcount can be combined
- */
 static int
-match(const struct sk_buff *skb,
-      const struct net_device *in,
-      const struct net_device *out,
-      const struct xt_match *match,
-      const void *matchinfo,
-      int offset,
-      unsigned int protoff,
-      int *hotdrop)
+ipt_recent_match(const struct sk_buff *skb,
+		 const struct net_device *in, const struct net_device *out,
+		 const struct xt_match *match, const void *matchinfo,
+		 int offset, unsigned int protoff, int *hotdrop)
 {
-	int pkt_count, hits_found, ans;
-	unsigned long now;
 	const struct ipt_recent_info *info = matchinfo;
-	u_int32_t addr = 0, time_temp;
-	u_int8_t ttl = skb->nh.iph->ttl;
-	int *hash_table;
-	int orig_hash_result, hash_result, temp, location = 0, time_loc, end_collision_chain = -1;
-	struct time_info_list *time_info;
-	struct recent_ip_tables *curr_table;
-	struct recent_ip_tables *last_table;
-	struct recent_ip_list *r_list;
-
-#ifdef DEBUG
-	if(debug) printk(KERN_INFO RECENT_NAME ": match() called\n");
-#endif
-
-	/* Default is false ^ info->invert */
-	ans = info->invert;
+	struct recent_table *t;
+	struct recent_entry *e;
+	u_int32_t addr;
+	u_int8_t ttl;
+	int ret = info->invert;
 
-#ifdef DEBUG
-	if(debug) printk(KERN_INFO RECENT_NAME ": match(): name = '%s'\n",info->name);
-#endif
+	if (info->side == IPT_RECENT_DEST)
+		addr = skb->nh.iph->daddr;
+	else
+		addr = skb->nh.iph->saddr;
 
-	/* if out != NULL then routing has been done and TTL changed.
-	 * We change it back here internally for match what came in before routing. */
-	if(out) ttl++;
+	ttl = skb->nh.iph->ttl;
+	/* use TTL as seen before forwarding */
+	if (out && !skb->sk)
+		ttl++;
 
-	/* Find the right table */
 	spin_lock_bh(&recent_lock);
-	curr_table = r_tables;
-	while( (last_table = curr_table) && strncmp(info->name,curr_table->name,IPT_RECENT_NAME_LEN) && (curr_table = curr_table->next) );
-
-#ifdef DEBUG
-	if(debug) printk(KERN_INFO RECENT_NAME ": match(): table found('%s')\n",info->name);
-#endif
-
-	spin_unlock_bh(&recent_lock);
-
-	/* Table with this name not found, match impossible */
-	if(!curr_table) { return ans; }
-
-	/* Make sure no one is changing the list while we work with it */
-	spin_lock_bh(&curr_table->list_lock);
-
-	r_list = curr_table->table;
-	if(info->side == IPT_RECENT_DEST) addr = skb->nh.iph->daddr; else addr = skb->nh.iph->saddr;
-
-	if(!addr) { 
-#ifdef DEBUG
-		if(debug) printk(KERN_INFO RECENT_NAME ": match() address (%u) invalid, leaving.\n",addr);
-#endif
-		spin_unlock_bh(&curr_table->list_lock);
-		return ans;
+	t = recent_table_lookup(info->name);
+	e = recent_entry_lookup(t, addr,
+				info->check_set & IPT_RECENT_TTL ? ttl : 0);
+	if (e == NULL) {
+		if (!(info->check_set & IPT_RECENT_SET))
+			goto out;
+		e = recent_entry_init(t, addr, ttl);
+		if (e == NULL)
+			*hotdrop = 1;
+		ret ^= 1;
+		goto out;
 	}
 
-#ifdef DEBUG
-	if(debug) printk(KERN_INFO RECENT_NAME ": match(): checking table, addr: %u, ttl: %u, orig_ttl: %u\n",addr,ttl,skb->nh.iph->ttl);
-#endif
-
-	/* Get jiffies now in case they changed while we were waiting for a lock */
-	now = jiffies;
-	hash_table = curr_table->hash_table;
-	time_info = curr_table->time_info;
-
-	orig_hash_result = hash_result = hash_func(addr,ip_list_hash_size);
-	/* Hash entry at this result used */
-	/* Check for TTL match if requested.  If TTL is zero then a match would never
-	 * happen, so match regardless of existing TTL in that case.  Zero means the
-	 * entry was added via the /proc interface anyway, so we will just use the
-	 * first TTL we get for that IP address. */
-	if(info->check_set & IPT_RECENT_TTL) {
-		while(hash_table[hash_result] != -1 && !(r_list[hash_table[hash_result]].addr == addr &&
-			(!r_list[hash_table[hash_result]].ttl || r_list[hash_table[hash_result]].ttl == ttl))) {
-			/* Collision in hash table */
-			hash_result = (hash_result + 1) % ip_list_hash_size;
-		}
-	} else {
-		while(hash_table[hash_result] != -1 && r_list[hash_table[hash_result]].addr != addr) {
-			/* Collision in hash table */
-			hash_result = (hash_result + 1) % ip_list_hash_size;
-		}
-	}
-
-	if(hash_table[hash_result] == -1 && !(info->check_set & IPT_RECENT_SET)) {
-		/* IP not in list and not asked to SET */
-		spin_unlock_bh(&curr_table->list_lock);
-		return ans;
-	}
-
-	/* Check if we need to handle the collision, do not need to on REMOVE */
-	if(orig_hash_result != hash_result && !(info->check_set & IPT_RECENT_REMOVE)) {
-#ifdef DEBUG
-		if(debug) printk(KERN_INFO RECENT_NAME ": match(): Collision in hash table. (or: %d,hr: %d,oa: %u,ha: %u)\n",
-				 orig_hash_result,
-				 hash_result,
-				 r_list[hash_table[orig_hash_result]].addr,
-				 addr);
-#endif
-
-		/* We had a collision.
-		 * orig_hash_result is where we started, hash_result is where we ended up.
-		 * So, swap them because we are likely to see the same guy again sooner */
-#ifdef DEBUG
-		if(debug) {
-		  printk(KERN_INFO RECENT_NAME ": match(): Collision; hash_table[orig_hash_result] = %d\n",hash_table[orig_hash_result]);
-		  printk(KERN_INFO RECENT_NAME ": match(): Collision; r_list[hash_table[orig_hash_result]].hash_entry = %d\n",
-				r_list[hash_table[orig_hash_result]].hash_entry);
-		}
-#endif
-
-		r_list[hash_table[orig_hash_result]].hash_entry = hash_result;
-
-
-		temp = hash_table[orig_hash_result];
-#ifdef DEBUG
-		if(debug) printk(KERN_INFO RECENT_NAME ": match(): Collision; hash_table[hash_result] = %d\n",hash_table[hash_result]);
-#endif
-		hash_table[orig_hash_result] = hash_table[hash_result];
-		hash_table[hash_result] = temp;
-		temp = hash_result;
-		hash_result = orig_hash_result;
-		orig_hash_result = temp;
-		time_info[r_list[hash_table[orig_hash_result]].time_pos].position = hash_table[orig_hash_result];
-		if(hash_table[hash_result] != -1) {
-			r_list[hash_table[hash_result]].hash_entry = hash_result;
-			time_info[r_list[hash_table[hash_result]].time_pos].position = hash_table[hash_result];
-		}
-
-#ifdef DEBUG
-		if(debug) printk(KERN_INFO RECENT_NAME ": match(): Collision handled.\n");
-#endif
-	}
-
-	if(hash_table[hash_result] == -1) {
-#ifdef DEBUG
-		if(debug) printk(KERN_INFO RECENT_NAME ": match(): New table entry. (hr: %d,ha: %u)\n",
-				 hash_result, addr);
-#endif
-
-		/* New item found and IPT_RECENT_SET, so we need to add it */
-		location = time_info[curr_table->time_pos].position;
-		hash_table[r_list[location].hash_entry] = -1;
-		hash_table[hash_result] = location;
-		memset(r_list[location].last_pkts,0,ip_pkt_list_tot*sizeof(unsigned long));
-		r_list[location].time_pos = curr_table->time_pos;
-		r_list[location].addr = addr;
-		r_list[location].ttl = ttl;
-		r_list[location].last_seen = now;
-		r_list[location].oldest_pkt = 1;
-		r_list[location].last_pkts[0] = now;
-		r_list[location].hash_entry = hash_result;
-		time_info[curr_table->time_pos].time = r_list[location].last_seen;
-		curr_table->time_pos = (curr_table->time_pos + 1) % ip_list_tot;
-
-		ans = !info->invert;
-	} else {
-#ifdef DEBUG
-		if(debug) printk(KERN_INFO RECENT_NAME ": match(): Existing table entry. (hr: %d,ha: %u)\n",
-				 hash_result,
-				 addr);
-#endif
-
-		/* Existing item found */
-		location = hash_table[hash_result];
-		/* We have a match on address, now to make sure it meets all requirements for a
-		 * full match. */
-		if(info->check_set & IPT_RECENT_CHECK || info->check_set & IPT_RECENT_UPDATE) {
-			if(!info->seconds && !info->hit_count) ans = !info->invert; else ans = info->invert;
-			if(info->seconds && !info->hit_count) {
-				if(time_before_eq(now,r_list[location].last_seen+info->seconds*HZ)) ans = !info->invert; else ans = info->invert;
-			}
-			if(info->seconds && info->hit_count) {
-				for(pkt_count = 0, hits_found = 0; pkt_count < ip_pkt_list_tot; pkt_count++) {
-					if(r_list[location].last_pkts[pkt_count] == 0) break;
-					if(time_before_eq(now,r_list[location].last_pkts[pkt_count]+info->seconds*HZ)) hits_found++;
-				}
-				if(hits_found >= info->hit_count) ans = !info->invert; else ans = info->invert;
-			}
-			if(info->hit_count && !info->seconds) {
-				for(pkt_count = 0, hits_found = 0; pkt_count < ip_pkt_list_tot; pkt_count++) {
-					if(r_list[location].last_pkts[pkt_count] == 0) break;
-					hits_found++;
-				}
-				if(hits_found >= info->hit_count) ans = !info->invert; else ans = info->invert;
-			}
-		}
-#ifdef DEBUG
-		if(debug) {
-			if(ans)
-				printk(KERN_INFO RECENT_NAME ": match(): match addr: %u\n",addr);
-			else
-				printk(KERN_INFO RECENT_NAME ": match(): no match addr: %u\n",addr);
-		}
-#endif
-
-		/* If and only if we have been asked to SET, or to UPDATE (on match) do we add the
-		 * current timestamp to the last_seen. */
-		if((info->check_set & IPT_RECENT_SET && (ans = !info->invert)) || (info->check_set & IPT_RECENT_UPDATE && ans)) {
-#ifdef DEBUG
-			if(debug) printk(KERN_INFO RECENT_NAME ": match(): SET or UPDATE; updating time info.\n");
-#endif
-			/* Have to update our time info */
-			time_loc = r_list[location].time_pos;
-			time_info[time_loc].time = now;
-			time_info[time_loc].position = location;
-			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) {
-				time_temp = time_info[time_loc].time;
-				time_info[time_loc].time = time_info[(time_loc+1)%ip_list_tot].time;
-				time_info[(time_loc+1)%ip_list_tot].time = time_temp;
-				time_temp = time_info[time_loc].position;
-				time_info[time_loc].position = time_info[(time_loc+1)%ip_list_tot].position;
-				time_info[(time_loc+1)%ip_list_tot].position = time_temp;
-				r_list[time_info[time_loc].position].time_pos = time_loc;
-				r_list[time_info[(time_loc+1)%ip_list_tot].position].time_pos = (time_loc+1)%ip_list_tot;
-				time_loc = (time_loc+1) % ip_list_tot;
-			}
-			r_list[location].time_pos = time_loc;
-			r_list[location].ttl = ttl;
-			r_list[location].last_pkts[r_list[location].oldest_pkt] = now;
-			r_list[location].oldest_pkt = ++r_list[location].oldest_pkt % ip_pkt_list_tot;
-			r_list[location].last_seen = now;
-		}
-		/* If we have been asked to remove the entry from the list, just set it to 0 */
-		if(info->check_set & IPT_RECENT_REMOVE) {
-#ifdef DEBUG
-			if(debug) printk(KERN_INFO RECENT_NAME ": match(): REMOVE; clearing entry (or: %d, hr: %d).\n",orig_hash_result,hash_result);
-#endif
-			/* Check if this is part of a collision chain */
-			while(hash_table[(orig_hash_result+1) % ip_list_hash_size] != -1) {
-				orig_hash_result++;
-				if(hash_func(r_list[hash_table[orig_hash_result]].addr,ip_list_hash_size) == hash_result) {
-					/* Found collision chain, how deep does this rabbit hole go? */
-#ifdef DEBUG
-					if(debug) printk(KERN_INFO RECENT_NAME ": match(): REMOVE; found collision chain.\n");
-#endif
-					end_collision_chain = orig_hash_result;
-				}
-			}
-			if(end_collision_chain != -1) {
-#ifdef DEBUG
-				if(debug) printk(KERN_INFO RECENT_NAME ": match(): REMOVE; part of collision chain, moving to end.\n");
-#endif
-				/* Part of a collision chain, swap it with the end of the chain
-				 * before removing. */
-				r_list[hash_table[end_collision_chain]].hash_entry = hash_result;
-				temp = hash_table[end_collision_chain];
-				hash_table[end_collision_chain] = hash_table[hash_result];
-				hash_table[hash_result] = temp;
-				time_info[r_list[hash_table[hash_result]].time_pos].position = hash_table[hash_result];
-				hash_result = end_collision_chain;
-				r_list[hash_table[hash_result]].hash_entry = hash_result;
-				time_info[r_list[hash_table[hash_result]].time_pos].position = hash_table[hash_result];
-			}
-			location = hash_table[hash_result];
-			hash_table[r_list[location].hash_entry] = -1;
-			time_loc = r_list[location].time_pos;
-			time_info[time_loc].time = 0;
-			time_info[time_loc].position = location;
-			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) {
-				time_temp = time_info[time_loc].time;
-				time_info[time_loc].time = time_info[(time_loc+1)%ip_list_tot].time;
-				time_info[(time_loc+1)%ip_list_tot].time = time_temp;
-				time_temp = time_info[time_loc].position;
-				time_info[time_loc].position = time_info[(time_loc+1)%ip_list_tot].position;
-				time_info[(time_loc+1)%ip_list_tot].position = time_temp;
-				r_list[time_info[time_loc].position].time_pos = time_loc;
-				r_list[time_info[(time_loc+1)%ip_list_tot].position].time_pos = (time_loc+1)%ip_list_tot;
-				time_loc = (time_loc+1) % ip_list_tot;
+	if (info->check_set & IPT_RECENT_SET)
+		ret ^= 1;
+	else if (info->check_set & IPT_RECENT_REMOVE) {
+		recent_entry_remove(t, e);
+		ret ^= 1;
+	} else if (info->check_set & (IPT_RECENT_CHECK | IPT_RECENT_UPDATE)) {
+		unsigned long t = jiffies - info->seconds * HZ;
+		unsigned int i, hits = 0;
+
+		for (i = 0; i < e->nstamps; i++) {
+			if (info->seconds && time_after(t, e->stamps[i]))
+				continue;
+			if (++hits >= info->hit_count) {
+				ret ^= 1;
+				break;
 			}
-			r_list[location].time_pos = time_loc;
-			r_list[location].last_seen = 0;
-			r_list[location].addr = 0;
-			r_list[location].ttl = 0;
-			memset(r_list[location].last_pkts,0,ip_pkt_list_tot*sizeof(unsigned long));
-			r_list[location].oldest_pkt = 0;
-			ans = !info->invert;
 		}
-		spin_unlock_bh(&curr_table->list_lock);
-		return ans;
 	}
 
-	spin_unlock_bh(&curr_table->list_lock);
-#ifdef DEBUG
-	if(debug) printk(KERN_INFO RECENT_NAME ": match() left.\n");
-#endif
-	return ans;
+	if (info->check_set & IPT_RECENT_SET ||
+	    (info->check_set & IPT_RECENT_UPDATE && ret)) {
+		recent_entry_update(t, e);
+		e->ttl = ttl;
+	}
+out:
+	spin_unlock_bh(&recent_lock);
+	return ret;
 }
 
-/* This function is to verify that the rule given during the userspace iptables
- * command is correct.
- * If the command is valid then we check if the table name referred to by the
- * rule exists, if not it is created.
- */
 static int
-checkentry(const char *tablename,
-           const void *ip,
-	   const struct xt_match *match,
-           void *matchinfo,
-           unsigned int matchsize,
-           unsigned int hook_mask)
+ipt_recent_checkentry(const char *tablename, const void *ip,
+		      const struct xt_match *match, void *matchinfo,
+		      unsigned int matchsize, unsigned int hook_mask)
 {
-	int flag = 0, c;
-	unsigned long *hold;
 	const struct ipt_recent_info *info = matchinfo;
-	struct recent_ip_tables *curr_table, *find_table, *last_table;
-
-#ifdef DEBUG
-	if(debug) printk(KERN_INFO RECENT_NAME ": checkentry() entered.\n");
-#endif
-
-	/* seconds and hit_count only valid for CHECK/UPDATE */
-	if(info->check_set & IPT_RECENT_SET) { flag++; if(info->seconds || info->hit_count) return 0; }
-	if(info->check_set & IPT_RECENT_REMOVE) { flag++; if(info->seconds || info->hit_count) return 0; }
-	if(info->check_set & IPT_RECENT_CHECK) flag++;
-	if(info->check_set & IPT_RECENT_UPDATE) flag++;
-
-	/* One and only one of these should ever be set */
-	if(flag != 1) return 0;
+	struct recent_table *t;
+	unsigned i;
+	int ret = 0;
 
-	/* Name must be set to something */
-	if(!info->name || !info->name[0]) return 0;
+	if (hweight8(info->check_set &
+		     (IPT_RECENT_SET | IPT_RECENT_REMOVE |
+		      IPT_RECENT_CHECK | IPT_RECENT_UPDATE)) != 1)
+		return 0;
+	if ((info->check_set & (IPT_RECENT_SET | IPT_RECENT_REMOVE)) &&
+	    (info->seconds || info->hit_count))
+		return 0;
+	if (info->name[0] == '\0' ||
+	    strnlen(info->name, IPT_RECENT_NAME_LEN) == IPT_RECENT_NAME_LEN)
+		return 0;
 
-	/* Things look good, create a list for this if it does not exist */
-	/* Lock the linked list while we play with it */
 	spin_lock_bh(&recent_lock);
-
-	/* Look for an entry with this name already created */
-	/* Finds the end of the list and the entry before the end if current name does not exist */
-	find_table = r_tables;
-	while( (last_table = find_table) && strncmp(info->name,find_table->name,IPT_RECENT_NAME_LEN) && (find_table = find_table->next) );
-
-	/* If a table already exists just increment the count on that table and return */
-	if(find_table) { 
-#ifdef DEBUG
-		if(debug) printk(KERN_INFO RECENT_NAME ": checkentry: table found (%s), incrementing count.\n",info->name);
-#endif
-		find_table->count++;
-		spin_unlock_bh(&recent_lock);
-		return 1;
+	t = recent_table_lookup(info->name);
+	if (t != NULL) {
+		t->refcnt++;
+		ret = 1;
+		goto out;
 	}
 
-	spin_unlock_bh(&recent_lock);
-
-	/* Table with this name not found */
-	/* Allocate memory for new linked list item */
-
-#ifdef DEBUG
-	if(debug) {
-		printk(KERN_INFO RECENT_NAME ": checkentry: no table found (%s)\n",info->name);
-		printk(KERN_INFO RECENT_NAME ": checkentry: Allocationg %d for link-list entry.\n",sizeof(struct recent_ip_tables));
+	t = kzalloc(sizeof(*t) + sizeof(t->iphash[0]) * ip_list_hash_size,
+		    GFP_ATOMIC);
+	if (t == NULL)
+		goto out;
+	strcpy(t->name, info->name);
+	INIT_LIST_HEAD(&t->lru_list);
+	for (i = 0; i < ip_list_hash_size; i++)
+		INIT_LIST_HEAD(&t->iphash[i]);
+#ifdef CONFIG_PROC_FS
+	t->proc = create_proc_entry(t->name, ip_list_perms, proc_dir);
+	if (t->proc == NULL) {
+		kfree(t);
+		goto out;
 	}
+	t->proc->proc_fops = &recent_fops;
+	t->proc->data      = t;
 #endif
+	list_add_tail(&t->list, &tables);
+	ret = 1;
+out:
+	spin_unlock_bh(&recent_lock);
+	return ret;
+}
 
-	curr_table = vmalloc(sizeof(struct recent_ip_tables));
-	if(curr_table == NULL) return 0;
-
-	spin_lock_init(&curr_table->list_lock);
-	curr_table->next = NULL;
-	curr_table->count = 1;
-	curr_table->time_pos = 0;
-	strncpy(curr_table->name,info->name,IPT_RECENT_NAME_LEN);
-	curr_table->name[IPT_RECENT_NAME_LEN-1] = '\0';
-
-	/* Allocate memory for this table and the list of packets in each entry. */
-#ifdef DEBUG
-	if(debug) printk(KERN_INFO RECENT_NAME ": checkentry: Allocating %d for table (%s).\n",
-			sizeof(struct recent_ip_list)*ip_list_tot,
-			info->name);
-#endif
-
-	curr_table->table = vmalloc(sizeof(struct recent_ip_list)*ip_list_tot);
-	if(curr_table->table == NULL) { vfree(curr_table); return 0; }
-	memset(curr_table->table,0,sizeof(struct recent_ip_list)*ip_list_tot);
-#ifdef DEBUG
-	if(debug) printk(KERN_INFO RECENT_NAME ": checkentry: Allocating %d for pkt_list.\n",
-			sizeof(unsigned long)*ip_pkt_list_tot*ip_list_tot);
-#endif
-
-	hold = vmalloc(sizeof(unsigned long)*ip_pkt_list_tot*ip_list_tot);
-#ifdef DEBUG
-	if(debug) printk(KERN_INFO RECENT_NAME ": checkentry: After pkt_list allocation.\n");
-#endif
-	if(hold == NULL) { 
-		printk(KERN_INFO RECENT_NAME ": checkentry: unable to allocate for pkt_list.\n");
-		vfree(curr_table->table); 
-		vfree(curr_table);
-		return 0;
-	}
-	for(c = 0; c < ip_list_tot; c++) {
-		curr_table->table[c].last_pkts = hold + c*ip_pkt_list_tot;
-	}
+static void
+ipt_recent_destroy(const struct xt_match *match, void *matchinfo,
+		   unsigned int matchsize)
+{
+	const struct ipt_recent_info *info = matchinfo;
+	struct recent_table *t;
 
-	/* Allocate memory for the hash table */
-#ifdef DEBUG
-	if(debug) printk(KERN_INFO RECENT_NAME ": checkentry: Allocating %d for hash_table.\n",
-			sizeof(int)*ip_list_hash_size);
+	spin_lock_bh(&recent_lock);
+	t = recent_table_lookup(info->name);
+	if (--t->refcnt == 0) {
+		list_del(&t->list);
+		recent_table_flush(t);
+#ifdef CONFIG_PROC_FS
+		remove_proc_entry(t->name, proc_dir);
 #endif
-
-	curr_table->hash_table = vmalloc(sizeof(int)*ip_list_hash_size);
-	if(!curr_table->hash_table) {
-		printk(KERN_INFO RECENT_NAME ": checkentry: unable to allocate for hash_table.\n");
-		vfree(hold);
-		vfree(curr_table->table); 
-		vfree(curr_table);
-		return 0;
-	}
-
-	for(c = 0; c < ip_list_hash_size; c++) {
-		curr_table->hash_table[c] = -1;
+		kfree(t);
 	}
+	spin_unlock_bh(&recent_lock);
+}
 
-	/* Allocate memory for the time info */
-#ifdef DEBUG
-	if(debug) printk(KERN_INFO RECENT_NAME ": checkentry: Allocating %d for time_info.\n",
-			sizeof(struct time_info_list)*ip_list_tot);
-#endif
+#ifdef CONFIG_PROC_FS
+struct recent_iter_state {
+	struct recent_table	*table;
+	unsigned int		bucket;
+};
 
-	curr_table->time_info = vmalloc(sizeof(struct time_info_list)*ip_list_tot);
-	if(!curr_table->time_info) {
-		printk(KERN_INFO RECENT_NAME ": checkentry: unable to allocate for time_info.\n");
-		vfree(curr_table->hash_table);
-		vfree(hold);
-		vfree(curr_table->table); 
-		vfree(curr_table);
-		return 0;
-	}
-	for(c = 0; c < ip_list_tot; c++) {
-		curr_table->time_info[c].position = c;
-		curr_table->time_info[c].time = 0;
-	}
+static void *recent_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	struct recent_iter_state *st = seq->private;
+	struct recent_table *t = st->table;
+	struct recent_entry *e;
+	loff_t p = *pos;
 
-	/* Put the new table in place */
 	spin_lock_bh(&recent_lock);
-	find_table = r_tables;
-	while( (last_table = find_table) && strncmp(info->name,find_table->name,IPT_RECENT_NAME_LEN) && (find_table = find_table->next) );
-
-	/* If a table already exists just increment the count on that table and return */
-	if(find_table) { 
-		find_table->count++;	
-		spin_unlock_bh(&recent_lock);
-#ifdef DEBUG
-		if(debug) printk(KERN_INFO RECENT_NAME ": checkentry: table found (%s), created by other process.\n",info->name);
-#endif
-		vfree(curr_table->time_info);
-		vfree(curr_table->hash_table);
-		vfree(hold);
-		vfree(curr_table->table);
-		vfree(curr_table);
-		return 1;
-	}
-	if(!last_table) r_tables = curr_table; else last_table->next = curr_table;
 
-	spin_unlock_bh(&recent_lock);
-
-#ifdef CONFIG_PROC_FS
-	/* Create our proc 'status' entry. */
-	curr_table->status_proc = create_proc_entry(curr_table->name, ip_list_perms, proc_net_ipt_recent);
-	if (!curr_table->status_proc) {
-		vfree(hold);
-		printk(KERN_INFO RECENT_NAME ": checkentry: unable to allocate for /proc entry.\n");
-		/* Destroy the created table */
-		spin_lock_bh(&recent_lock);
-		last_table = NULL;
-		curr_table = r_tables;
-		if(!curr_table) {
-#ifdef DEBUG
-			if(debug) printk(KERN_INFO RECENT_NAME ": checkentry() create_proc failed, no tables.\n");
-#endif
-			spin_unlock_bh(&recent_lock);
-			return 0;
-		}
-		while( strncmp(info->name,curr_table->name,IPT_RECENT_NAME_LEN) && (last_table = curr_table) && (curr_table = curr_table->next) );
-		if(!curr_table) {
-#ifdef DEBUG
-			if(debug) printk(KERN_INFO RECENT_NAME ": checkentry() create_proc failed, table already destroyed.\n");
-#endif
-			spin_unlock_bh(&recent_lock);
-			return 0;
+	for (st->bucket = 0; st->bucket < ip_list_hash_size; st->bucket++) {
+		list_for_each_entry(e, &t->iphash[st->bucket], list) {
+			if (p-- == 0)
+				return e;
 		}
-		if(last_table) last_table->next = curr_table->next; else r_tables = curr_table->next;
-		spin_unlock_bh(&recent_lock);
-		vfree(curr_table->time_info);
-		vfree(curr_table->hash_table);
-		vfree(curr_table->table);
-		vfree(curr_table);
-		return 0;
 	}
-	
-	curr_table->status_proc->owner = THIS_MODULE;
-	curr_table->status_proc->data = curr_table;
-	wmb();
-	curr_table->status_proc->read_proc = ip_recent_get_info;
-	curr_table->status_proc->write_proc = ip_recent_ctrl;
-#endif /* CONFIG_PROC_FS */
-
-#ifdef DEBUG
-	if(debug) printk(KERN_INFO RECENT_NAME ": checkentry() left.\n");
-#endif
+	return NULL;
+}
 
-	return 1;
+static void *recent_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct recent_iter_state *st = seq->private;
+	struct recent_table *t = st->table;
+	struct recent_entry *e = v;
+	struct list_head *head = e->list.next;
+
+	while (head == &t->iphash[st->bucket]) {
+		if (++st->bucket >= ip_list_hash_size)
+			return NULL;
+		head = t->iphash[st->bucket].next;
+	}
+	(*pos)++;
+	return list_entry(head, struct recent_entry, list);
 }
 
-/* This function is called in the event that a rule matching this module is
- * removed.
- * When this happens we need to check if there are no other rules matching
- * the table given.  If that is the case then we remove the table and clean
- * up its memory.
- */
-static void
-destroy(const struct xt_match *match, void *matchinfo, unsigned int matchsize)
+static void recent_seq_stop(struct seq_file *s, void *v)
 {
-	const struct ipt_recent_info *info = matchinfo;
-	struct recent_ip_tables *curr_table, *last_table;
+	spin_unlock_bh(&recent_lock);
+}
 
-#ifdef DEBUG
-	if(debug) printk(KERN_INFO RECENT_NAME ": destroy() entered.\n");
-#endif
+static int recent_seq_show(struct seq_file *seq, void *v)
+{
+	struct recent_entry *e = v;
+	unsigned int i;
+
+	i = (e->index - 1) % ip_pkt_list_tot;
+	seq_printf(seq, "src=%u.%u.%u.%u ttl: %u last_seen: %lu oldest_pkt: %u",
+		   NIPQUAD(e->addr), e->ttl, e->stamps[i], e->index);
+	for (i = 0; i < e->nstamps; i++)
+		seq_printf(seq, "%s %lu", i ? "," : "", e->stamps[i]);
+	seq_printf(seq, "\n");
+	return 0;
+}
 
-	if(matchsize != IPT_ALIGN(sizeof(struct ipt_recent_info))) return;
+static struct seq_operations recent_seq_ops = {
+	.start		= recent_seq_start,
+	.next		= recent_seq_next,
+	.stop		= recent_seq_stop,
+	.show		= recent_seq_show,
+};
 
-	/* Lock the linked list while we play with it */
-	spin_lock_bh(&recent_lock);
+static int recent_seq_open(struct inode *inode, struct file *file)
+{
+	struct proc_dir_entry *pde = PDE(inode);
+	struct seq_file *seq;
+	struct recent_iter_state *st;
+	int ret;
+
+	st = kzalloc(sizeof(*st), GFP_KERNEL);
+	if (st == NULL)
+		return -ENOMEM;
+	ret = seq_open(file, &recent_seq_ops);
+	if (ret)
+		kfree(st);
+	st->table    = pde->data;
+	seq          = file->private_data;
+	seq->private = st;
+	return ret;
+}
 
-	/* Look for an entry with this name already created */
-	/* Finds the end of the list and the entry before the end if current name does not exist */
-	last_table = NULL;
-	curr_table = r_tables;
-	if(!curr_table) { 
-#ifdef DEBUG
-		if(debug) printk(KERN_INFO RECENT_NAME ": destroy() No tables found, leaving.\n");
-#endif
+static ssize_t recent_proc_write(struct file *file, const char __user *input,
+				 size_t size, loff_t *loff)
+{
+	struct proc_dir_entry *pde = PDE(file->f_dentry->d_inode);
+	struct recent_table *t = pde->data;
+	struct recent_entry *e;
+	char buf[sizeof("+255.255.255.255")], *c = buf;
+	u_int32_t addr;
+	int add;
+
+	if (size > sizeof(buf))
+		size = sizeof(buf);
+	if (copy_from_user(buf, input, size))
+		return -EFAULT;
+	while (isspace(*c))
+		c++;
+
+	if (size - (c - buf) < 5)
+		return c - buf;
+	if (!strncmp(c, "clear", 5)) {
+		c += 5;
+		spin_lock_bh(&recent_lock);
+		recent_table_flush(t);
 		spin_unlock_bh(&recent_lock);
-		return;
+		return c - buf;
 	}
-	while( strncmp(info->name,curr_table->name,IPT_RECENT_NAME_LEN) && (last_table = curr_table) && (curr_table = curr_table->next) );
 
-	/* If a table does not exist then do nothing and return */
-	if(!curr_table) { 
-#ifdef DEBUG
-		if(debug) printk(KERN_INFO RECENT_NAME ": destroy() table not found, leaving.\n");
-#endif
-		spin_unlock_bh(&recent_lock);
-		return;
+	switch (*c) {
+	case '-':
+		add = 0;
+		c++;
+		break;
+	case '+':
+		c++;
+	default:
+		add = 1;
+		break;
 	}
+	addr = in_aton(c);
 
-	curr_table->count--;
-
-	/* If count is still non-zero then there are still rules referenceing it so we do nothing */
-	if(curr_table->count) { 
-#ifdef DEBUG
-		if(debug) printk(KERN_INFO RECENT_NAME ": destroy() table found, non-zero count, leaving.\n");
-#endif
-		spin_unlock_bh(&recent_lock);
-		return;
+	spin_lock_bh(&recent_lock);
+	e = recent_entry_lookup(t, addr, 0);
+	if (e == NULL) {
+		if (add)
+			recent_entry_init(t, addr, 0);
+	} else {
+		if (add)
+			recent_entry_update(t, e);
+		else
+			recent_entry_remove(t, e);
 	}
-
-#ifdef DEBUG
-	if(debug) printk(KERN_INFO RECENT_NAME ": destroy() table found, zero count, removing.\n");
-#endif
-
-	/* Count must be zero so we remove this table from the list */
-	if(last_table) last_table->next = curr_table->next; else r_tables = curr_table->next;
-
 	spin_unlock_bh(&recent_lock);
+	return size;
+}
 
-	/* lock to make sure any late-runners still using this after we removed it from
-	 * the list finish up then remove everything */
-	spin_lock_bh(&curr_table->list_lock);
-	spin_unlock_bh(&curr_table->list_lock);
-
-#ifdef CONFIG_PROC_FS
-	if(curr_table->status_proc) remove_proc_entry(curr_table->name,proc_net_ipt_recent);
+static struct file_operations recent_fops = {
+	.open		= recent_seq_open,
+	.read		= seq_read,
+	.write		= recent_proc_write,
+	.release	= seq_release_private,
+	.owner		= THIS_MODULE,
+};
 #endif /* CONFIG_PROC_FS */
-	vfree(curr_table->table[0].last_pkts);
-	vfree(curr_table->table);
-	vfree(curr_table->hash_table);
-	vfree(curr_table->time_info);
-	vfree(curr_table);
-
-#ifdef DEBUG
-	if(debug) printk(KERN_INFO RECENT_NAME ": destroy() left.\n");
-#endif
 
-	return;
-}
-
-/* This is the structure we pass to ipt_register to register our
- * module with iptables.
- */
 static struct ipt_match recent_match = {
 	.name		= "recent",
-	.match		= match,
+	.match		= ipt_recent_match,
 	.matchsize	= sizeof(struct ipt_recent_info),
-	.checkentry	= checkentry,
-	.destroy	= destroy,
-	.me		= THIS_MODULE
+	.checkentry	= ipt_recent_checkentry,
+	.destroy	= ipt_recent_destroy,
+	.me		= THIS_MODULE,
 };
 
-/* Kernel module initialization. */
 static int __init ipt_recent_init(void)
 {
-	int err, count;
+	int err;
 
-	printk(version);
-#ifdef CONFIG_PROC_FS
-	proc_net_ipt_recent = proc_mkdir("ipt_recent",proc_net);
-	if(!proc_net_ipt_recent) return -ENOMEM;
-#endif
-
-	if(ip_list_hash_size && ip_list_hash_size <= ip_list_tot) {
-	  printk(KERN_WARNING RECENT_NAME ": ip_list_hash_size too small, resetting to default.\n");
-	  ip_list_hash_size = 0;
-	}
-
-	if(!ip_list_hash_size) {
-		ip_list_hash_size = ip_list_tot*3;
-		count = 2*2;
-		while(ip_list_hash_size > count) count = count*2;
-		ip_list_hash_size = count;
-	}
-
-#ifdef DEBUG
-	if(debug) printk(KERN_INFO RECENT_NAME ": ip_list_hash_size: %d\n",ip_list_hash_size);
-#endif
+	if (!ip_list_tot || !ip_pkt_list_tot || ip_pkt_list_tot > 255)
+		return -EINVAL;
+	ip_list_hash_size = 1 << fls(ip_list_tot);
 
 	err = ipt_register_match(&recent_match);
+#ifdef CONFIG_PROC_FS
 	if (err)
-		remove_proc_entry("ipt_recent", proc_net);
+		return err;
+	proc_dir = proc_mkdir("ipt_recent", proc_net);
+	if (proc_dir == NULL) {
+		ipt_unregister_match(&recent_match);
+		err = -ENOMEM;
+	}
+#endif
 	return err;
 }
 
-/* Kernel module destruction. */
-static void __exit ipt_recent_fini(void)
+static void __exit ipt_recent_exit(void)
 {
+	BUG_ON(!list_empty(&tables));
 	ipt_unregister_match(&recent_match);
-
-	remove_proc_entry("ipt_recent",proc_net);
+#ifdef CONFIG_PROC_FS
+	remove_proc_entry("ipt_recent", proc_net);
+#endif
 }
 
-/* Register our module with the kernel. */
 module_init(ipt_recent_init);
-module_exit(ipt_recent_fini);
+module_exit(ipt_recent_exit);