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SubjectRe: [PATCH] fix mem-leak in netfilter
Stephen Frost wrote:
> * Patrick McHardy (kaber@trash.net) wrote:
>
>>I wasn't sure whether eviction was happening intentional in the old code
>>at all - still not able to locate the code where this happens, just
>>noticed that it does do eviction when I manually tried to trigger
>>a table overflow by adding entries through /proc. Anyway, it should
>>be easy to fix by keeping an additional lru list. I'll post
>>an updated patch soon.
>
>
> It was always done intentionally; as I mentioned, it was originally
> written with the expectation of the table always being full. That was
> also why I used one large malloc'd table and the hash chaining that I
> did- I always knew ahead of time exactly how much memory I'd be using as
> a running-set and never needed to do any allocation during operation.
> In hindsight I can see that the additional complexity from it was
> perhaps not worth the benefit that I saw from it.
>
> The eviction is handled through the 'time_info_list'. This is basically
> just an always-ordered (by time) array of positions into the main table.
> Line 504 (from stock 2.6.16) is where the list is used to add a new
> entry at the end of the list (replacing the oldest address). 'time_pos'
> points to the oldest entry. The 'position' is then used to clear out
> the entry associated with this address from the hash table and the main
> table. These are then replaced with the new address information and the
> time_pos is adjusted accordingly. This didn't help the complexity as it
> meant I was tracking through different systems the position of each
> address in the time_info_list, the main table, and the hash table.
> Using the lists might make this a bit easier to implement though.
>
> Then on line 566, if a new packet has come in for an existing address,
> we have to move that address up to the top of the time_info_list as it
> is now the 'most recent'. As someone else mentioned, this might have
> been better done using 'memmove' but I wasn't sure about its use or
> performance in the kernel. This is done again on line 617 when removing
> an address, which is expected to be a somewhat rare event (where an
> address is explicitly removed instead of just expiring). One issue I
> was concerned about was that I really didn't want the system to become
> unhappy if a huge number of different addresses suddenly came in (more
> than the list could support and/or more than would be sensible to try to
> allocate memory to track).
>
> I'm really not sure why I didn't break out this code into more
> functions. It certainly would have made things much clearer/simpler. I
> think I was (without any particular reason for it) concerned about
> adding too many functions or calling things from the match() function.
> As for why I didn't use existing kernel structures, well, I wasn't aware
> of them in part and when I was asking about things I was asking about
> more complicated things (such as a generic storage/hashing system) than
> really made sense. I'm not sure I would have used the lists anyway
> since I liked the general idea of just having the one 'main' table but
> it does seem to make things cleaner.


Indeed :) Thanks for your explanation and review Stephen.

This is the updated patch, it changes the eviction strategy
to LRU and fixes a bug related to TTL handling, the TTL stored
in the entry should only be overwritten if the IPT_RECENT_TTL
flag is set.

[NETFILTER]: Replace ipt_recent module

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

Signed-off-by: Patrick McHardy <kaber@trash.net>

---
commit e4f33e5c65efaf65d558365fd49ad5d83b13813d
tree fc8a4681aad273bb4f9a6c9c9484d331d7aac064
parent d8c3291c73b958243b33f8509d4507e76dafd055
author Patrick McHardy <kaber@trash.net> Mon, 15 May 2006 22:03:22 +0200
committer Patrick McHardy <kaber@trash.net> Mon, 15 May 2006 22:03:22 +0200

net/ipv4/netfilter/ipt_recent.c | 1274 ++++++++++++---------------------------
1 files changed, 380 insertions(+), 894 deletions(-)

diff --git a/net/ipv4/netfilter/ipt_recent.c b/net/ipv4/netfilter/ipt_recent.c
index 1438432..2e54062 100644
--- a/net/ipv4/netfilter/ipt_recent.c
+++ b/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");
+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;
+ unsigned int index;
+ unsigned int 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;
+static struct proc_dir_entry *proc_dir;
+static struct file_operations recent_fops;
#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);
-#endif
+static u_int32_t hash_rnd;
+static int hash_rnd_initted;

- return(result & (table_size - 1));
-}
-
-#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 u_int32_t 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;
-
- if(val > max[pp - res.bytes]) return used;
- addr = res.word | htonl(val);
+static void recent_entry_update(struct recent_entry *e)
+{
+ e->stamps[e->index++] = jiffies;
+ if (e->index > e->nstamps)
+ e->nstamps = e->index;
+ e->index %= ip_pkt_list_tot;
+}

- if(!addr && check_set == IPT_RECENT_SET) return used;
+static struct recent_table *recent_table_lookup(const char *name)
+{
+ struct recent_table *t;

-#ifdef DEBUG
- if(debug) printk(KERN_INFO RECENT_NAME ": ip_recent_ctrl c: %c, addr: %u used: %d\n",c,addr,used);
-#endif
+ list_for_each_entry(t, &tables, list)
+ if (!strcmp(t->name, name))
+ return t;
+ return NULL;
+}

- /* 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;
+static void recent_table_flush(struct recent_table *t)
+{
+ struct recent_entry *e, *next;
+ unsigned int i;
+
+ 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;
-
-#ifdef DEBUG
- if(debug) printk(KERN_INFO RECENT_NAME ": match(): name = '%s'\n",info->name);
-#endif
-
- /* 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++;
-
- /* 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;
- }
-
-#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;
+ struct recent_table *t;
+ struct recent_entry *e;
+ u_int32_t addr;
+ u_int8_t ttl;
+ int ret = info->invert;
+
+ if (info->side == IPT_RECENT_DEST)
+ addr = skb->nh.iph->daddr;
+ else
+ addr = skb->nh.iph->saddr;
+
+ ttl = 0;
+ if (info->check_set & IPT_RECENT_TTL) {
+ ttl = skb->nh.iph->ttl;
+ /* use TTL as seen before forwaring */
+ if (out && !skb->sk)
+ ttl++;
}

- /* 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
+ spin_lock_bh(&recent_lock);
+ t = recent_table_lookup(info->name);
+ e = recent_entry_lookup(t, addr, ttl);
+ 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;
}

- 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 (!info->hit_count || ++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(e);
+ if (info->check_set & IPT_RECENT_TTL)
+ 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
+ struct recent_table *t;
+ unsigned i;
+ int ret = 0;

- /* 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;
-
- /* 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) {
- 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(hold);
- 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 (!memcmp(c, "clear", 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(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)
+ 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)
{
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);
\
 
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  Last update: 2006-05-15 22:12    [W:0.162 / U:1.068 seconds]
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