ipt_ACCOUNT: (tomj) fix for large networks
[ipt_ACCOUNT] / linux / net / ipv4 / netfilter / ipt_ACCOUNT.c
index e1a5262..61855b2 100644 (file)
@@ -1,6 +1,17 @@
-/*
- * This is a module which is used for counting packets.
- */
+/***************************************************************************
+ *   This is a module which is used for counting packets.                  *
+ *   See http://www.intra2net.com/opensource/ipt_account                   *
+ *   for further information                                               *
+ *                                                                         * 
+ *   Copyright (C) 2004 by Intra2net AG                                    *
+ *   opensource@intra2net.com                                              *
+ *                                                                         *
+ *   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;               *
+ *                                                                         *
+ ***************************************************************************/
+
 #include <linux/module.h>
 #include <linux/skbuff.h>
 #include <linux/ip.h>
 #include <net/udp.h>
 #include <net/tcp.h>
 #include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <asm/uaccess.h>
 
 struct in_device;
 #include <net/route.h>
 #include <linux/netfilter_ipv4/ipt_ACCOUNT.h>
 
-//#if 0
+#if 0
 #define DEBUGP printk
-//#else
-//#define DEBUGP(format, args...)
-//#endif
+#else
+#define DEBUGP(format, args...)
+#endif
+
+#if (PAGE_SIZE < 4096)
+#error "ipt_ACCOUNT needs at least a PAGE_SIZE of 4096"
+#endif
 
-struct ipt_account_table *ipt_account_tables = NULL;
-struct ipt_account_handle *ipt_account_handles = NULL;
-void *ipt_account_tmpbuf = NULL;
+struct ipt_acc_table *ipt_acc_tables = NULL;
+struct ipt_acc_handle *ipt_acc_handles = NULL;
+void *ipt_acc_tmpbuf = NULL;
 
-// Spinlock used for manipulating the current accounting tables/data
-static spinlock_t ipt_account_lock = SPIN_LOCK_UNLOCKED;
-// Spinlock used for manipulating userspace handles/snapshot data
-static spinlock_t ipt_account_userspace_lock = SPIN_LOCK_UNLOCKED;
+/* Spinlock used for manipulating the current accounting tables/data */
+static spinlock_t ipt_acc_lock = SPIN_LOCK_UNLOCKED;
+/* Spinlock used for manipulating userspace handles/snapshot data */
+static spinlock_t ipt_acc_userspace_lock = SPIN_LOCK_UNLOCKED;
 
 
 /* Recursive free of all data structures */
-void ipt_account_data_free(void *data, unsigned char depth)
+void ipt_acc_data_free(void *data, unsigned char depth)
 {
-    // Empty data set
+    /* Empty data set */
     if (!data)
         return;
-        
-    // Free for 8 bit network
-    if (depth == 0)
-    {
+
+    /* Free for 8 bit network */
+    if (depth == 0) {
         free_page((unsigned long)data);
-        data = NULL;
         return;
     }
-    
-    // Free for 16 bit network
-    if (depth == 1)
-    {
-        struct ipt_account_mask_16 *mask_16 = (struct ipt_account_mask_16 *)data;
-        unsigned int b;
-        for (b=0; b <= 255; b++)
-        {
-            if (mask_16->mask_24[b] != 0)
-            {
+
+    /* Free for 16 bit network */
+    if (depth == 1) {
+        struct ipt_acc_mask_16 *mask_16 = (struct ipt_acc_mask_16 *)data;
+        u_int32_t b;
+        for (b=0; b <= 255; b++) {
+            if (mask_16->mask_24[b] != 0) {
                 free_page((unsigned long)mask_16->mask_24[b]);
-                mask_16->mask_24[b] = NULL;
             }
         }
         free_page((unsigned long)data);
-        data = NULL;
         return;
-    } 
-   
-    // Free for 24 bit network
-    if (depth == 3)
-    {
-        unsigned int a, b;
-        for (a=0; a <= 255; a++)
-        {
-            if (((struct ipt_account_mask_8 *)data)->mask_16[a])
-            {
-                struct ipt_account_mask_16 *mask_16 = (struct ipt_account_mask_16*)((struct ipt_account_mask_8 *)data)->mask_16[a];
-                for (b=0; b <= 255; b++)
-                {
+    }
+
+    /* Free for 24 bit network */
+    if (depth == 2) {
+        u_int32_t a, b;
+        for (a=0; a <= 255; a++) {
+            if (((struct ipt_acc_mask_8 *)data)->mask_16[a]) {
+                struct ipt_acc_mask_16 *mask_16 = (struct ipt_acc_mask_16*)
+                                   ((struct ipt_acc_mask_8 *)data)->mask_16[a];
+                
+                for (b=0; b <= 255; b++) {
                     if (mask_16->mask_24[b]) {
                         free_page((unsigned long)mask_16->mask_24[b]);
-                        mask_16->mask_24[b] = NULL;
                     }
                 }
                 free_page((unsigned long)mask_16);
-                mask_16 = NULL;
             }
         }
         free_page((unsigned long)data);
-        data = NULL;
         return;
     }
-    
-    printk("ACCOUNT: ipt_account_data_free called with unknown depth: %d\n", depth);
+
+    printk("ACCOUNT: ipt_acc_data_free called with unknown depth: %d\n", 
+           depth);
     return;
 }
 
-/* Look for existing table / insert new one. Return internal ID or -1 on error */
-int ipt_account_table_insert(char *name, unsigned int ip, unsigned int netmask)
+/* Look for existing table / insert new one. 
+   Return internal ID or -1 on error */
+int ipt_acc_table_insert(char *name, u_int32_t ip, u_int32_t netmask)
 {
-    unsigned int i;
+    u_int32_t i;
 
-    DEBUGP("ACCOUNT: ipt_account_table_insert: %s, %u.%u.%u.%u/%u.%u.%u.%u\n", name, NIPQUAD(ip), NIPQUAD(netmask));
+    DEBUGP("ACCOUNT: ipt_acc_table_insert: %s, %u.%u.%u.%u/%u.%u.%u.%u\n",
+                                         name, NIPQUAD(ip), NIPQUAD(netmask));
 
-    // Look for existing table
-    for (i = 0; i < ACCOUNT_MAX_TABLES; i++)
-    {
-        if (strncmp(ipt_account_tables[i].name, name, ACCOUNT_TABLE_NAME_LEN) == 0)
-        {
-            DEBUGP("ACCOUNT: Found existing slot: %d - %u.%u.%u.%u/%u.%u.%u.%u\n", i,
-                   NIPQUAD(ipt_account_tables[i].ip), NIPQUAD(ipt_account_tables[i].netmask));
-            
-            if (ipt_account_tables[i].ip != ip || ipt_account_tables[i].netmask != netmask)
-            {
-                printk("ACCOUNT: Table %s found, but IP/netmask mismatch. IP/netmask found: %u.%u.%u.%u/%u.%u.%u.%u\n",
-                        name, NIPQUAD(ipt_account_tables[i].ip), NIPQUAD(ipt_account_tables[i].netmask));
+    /* Look for existing table */
+    for (i = 0; i < ACCOUNT_MAX_TABLES; i++) {
+        if (strncmp(ipt_acc_tables[i].name, name, 
+                    ACCOUNT_TABLE_NAME_LEN) == 0) {
+            DEBUGP("ACCOUNT: Found existing slot: %d - "
+                   "%u.%u.%u.%u/%u.%u.%u.%u\n", i, 
+                   NIPQUAD(ipt_acc_tables[i].ip), 
+                   NIPQUAD(ipt_acc_tables[i].netmask));
+
+            if (ipt_acc_tables[i].ip != ip 
+                || ipt_acc_tables[i].netmask != netmask) {
+                printk("ACCOUNT: Table %s found, but IP/netmask mismatch. "
+                       "IP/netmask found: %u.%u.%u.%u/%u.%u.%u.%u\n",
+                       name, NIPQUAD(ipt_acc_tables[i].ip), 
+                       NIPQUAD(ipt_acc_tables[i].netmask));
                 return -1;
             }
 
-            ipt_account_tables[i].refcount++;
-            DEBUGP("ACCOUNT: Refcount: %d\n", ipt_account_tables[i].refcount);
+            ipt_acc_tables[i].refcount++;
+            DEBUGP("ACCOUNT: Refcount: %d\n", ipt_acc_tables[i].refcount);
             return i;
         }
     }
 
-    // Insert new table
-    for (i = 0; i < ACCOUNT_MAX_TABLES; i++)
-    {
-        // Found free slot
-        if (ipt_account_tables[i].name[0] == 0)
-        {
-            DEBUGP("ACCOUNT: Found free slot: %d\n", i);
-        
-            strncpy (ipt_account_tables[i].name, name, ACCOUNT_TABLE_NAME_LEN-1);
-            
-            ipt_account_tables[i].ip = ip;
-            ipt_account_tables[i].netmask = netmask;
+    /* Insert new table */
+    for (i = 0; i < ACCOUNT_MAX_TABLES; i++) {
+        /* Found free slot */
+        if (ipt_acc_tables[i].name[0] == 0) {
+            u_int32_t j, calc_mask, netsize=0;
             
-            // Calculate netsize
-            unsigned int j, calc_mask, netsize=0;
+            DEBUGP("ACCOUNT: Found free slot: %d\n", i);
+            strncpy (ipt_acc_tables[i].name, name, ACCOUNT_TABLE_NAME_LEN-1);
+
+            ipt_acc_tables[i].ip = ip;
+            ipt_acc_tables[i].netmask = netmask;
+
+            /* Calculate netsize */
             calc_mask = htonl(netmask);
-            for (j = 31; j > 0; j--)
-            {
+            for (j = 31; j >= 0; j--) {
                 if (calc_mask&(1<<j))
                     netsize++;
                 else
                     break;
             }
-            
-            // Calculate depth from netsize
+
+            /* Calculate depth from netsize */
             if (netsize >= 24)
-                ipt_account_tables[i].depth = 0;
+                ipt_acc_tables[i].depth = 0;
             else if (netsize >= 16)
-                ipt_account_tables[i].depth = 1;
+                ipt_acc_tables[i].depth = 1;
             else if(netsize >= 8)
-                ipt_account_tables[i].depth = 2;
-            
-            printk("ACCOUNT: calculated netsize: %u -> ipt_account_table depth %u\n", netsize, ipt_account_tables[i].depth);
-                        
-            ipt_account_tables[i].refcount++;
-            if (!(ipt_account_tables[i].data = (void *)get_zeroed_page(GFP_KERNEL)))
-            {
+                ipt_acc_tables[i].depth = 2;
+
+            DEBUGP("ACCOUNT: calculated netsize: %u -> "
+                   "ipt_acc_table depth %u\n", netsize, 
+                   ipt_acc_tables[i].depth);
+
+            ipt_acc_tables[i].refcount++;
+            if ((ipt_acc_tables[i].data
+                = (void *)get_zeroed_page(GFP_ATOMIC)) == NULL) {
                 printk("ACCOUNT: out of memory for data of table: %s\n", name);
-                memset(&ipt_account_tables[i], 0, sizeof(struct ipt_account_table));
+                memset(&ipt_acc_tables[i], 0, 
+                       sizeof(struct ipt_acc_table));
                 return -1;
             }
-            
+
             return i;
         }
     }
-        
-    // No free slot found
-    printk("ACCOUNT: No free table slot found (max: %d). Please increase ACCOUNT_MAX_TABLES.\n", ACCOUNT_MAX_TABLES);
+
+    /* No free slot found */
+    printk("ACCOUNT: No free table slot found (max: %d). "
+           "Please increase ACCOUNT_MAX_TABLES.\n", ACCOUNT_MAX_TABLES);
     return -1;
 }
 
-static int ipt_account_checkentry(const char *tablename,
-    const struct ipt_entry *e,
-    void *targinfo,
-    unsigned int targinfosize,
-    unsigned int hook_mask)
+static int ipt_acc_checkentry(const char *tablename,
+                                  const struct ipt_entry *e,
+                                  void *targinfo,
+                                  unsigned int targinfosize,
+                                  unsigned int hook_mask)
 {
-    struct ipt_account_info *info = targinfo;
-    
-    if (targinfosize != IPT_ALIGN(sizeof(struct ipt_account_info))) {
+    struct ipt_acc_info *info = targinfo;
+    int table_nr;
+
+    if (targinfosize != IPT_ALIGN(sizeof(struct ipt_acc_info))) {
         DEBUGP("ACCOUNT: targinfosize %u != %u\n",
-                targinfosize, IPT_ALIGN(sizeof(struct ipt_account_info)));
+               targinfosize, IPT_ALIGN(sizeof(struct ipt_acc_info)));
         return 0;
     }
 
-    spin_lock_bh(&ipt_account_lock);
-    int table_nr = ipt_account_table_insert(info->table_name, info->net_ip, info->net_mask);
-    if (table_nr == -1)
-    {
+    spin_lock_bh(&ipt_acc_lock);
+    table_nr = ipt_acc_table_insert(info->table_name, info->net_ip,
+                                                      info->net_mask);
+    if (table_nr == -1) {
         printk("ACCOUNT: Table insert problem. Aborting\n");
-        spin_unlock_bh(&ipt_account_lock);
+        spin_unlock_bh(&ipt_acc_lock);
         return 0;
     }
-    // Table nr caching so we don't have to do an extra string compare for every packet
+    /* Table nr caching so we don't have to do an extra string compare 
+       for every packet */
     info->table_nr = table_nr;
-    
-    spin_unlock_bh(&ipt_account_lock);
+
+    spin_unlock_bh(&ipt_acc_lock);
 
     return 1;
 }
 
-void ipt_account_deleteentry(void *targinfo, unsigned int targinfosize)
+void ipt_acc_deleteentry(void *targinfo, unsigned int targinfosize)
 {
-    unsigned int i;
-    struct ipt_account_info *info = targinfo;
-    
-    if (targinfosize != IPT_ALIGN(sizeof(struct ipt_account_info))) {
+    u_int32_t i;
+    struct ipt_acc_info *info = targinfo;
+
+    if (targinfosize != IPT_ALIGN(sizeof(struct ipt_acc_info))) {
         DEBUGP("ACCOUNT: targinfosize %u != %u\n",
-                targinfosize, IPT_ALIGN(sizeof(struct ipt_account_info)));
+               targinfosize, IPT_ALIGN(sizeof(struct ipt_acc_info)));
     }
 
-    spin_lock_bh(&ipt_account_lock);
-    
-    DEBUGP("ACCOUNT: ipt_account_deleteentry called for table: %s (#%d)\n", info->table_name, info->table_nr);
-    
-    info->table_nr = -1;    // Set back to original state
-    
-    // Look for table
-    for (i = 0; i < ACCOUNT_MAX_TABLES; i++)
-    {
-        if (strncmp(ipt_account_tables[i].name, info->table_name, ACCOUNT_TABLE_NAME_LEN) == 0)
-        {
+    spin_lock_bh(&ipt_acc_lock);
+
+    DEBUGP("ACCOUNT: ipt_acc_deleteentry called for table: %s (#%d)\n", 
+           info->table_name, info->table_nr);
+
+    info->table_nr = -1;    /* Set back to original state */
+
+    /* Look for table */
+    for (i = 0; i < ACCOUNT_MAX_TABLES; i++) {
+        if (strncmp(ipt_acc_tables[i].name, info->table_name, 
+                    ACCOUNT_TABLE_NAME_LEN) == 0) {
             DEBUGP("ACCOUNT: Found table at slot: %d\n", i);
-            
-            ipt_account_tables[i].refcount--;
-            DEBUGP("ACCOUNT: Refcount left: %d\n", ipt_account_tables[i].refcount);
 
-            // Table not needed anymore?
-            if (ipt_account_tables[i].refcount == 0)
-            {
+            ipt_acc_tables[i].refcount--;
+            DEBUGP("ACCOUNT: Refcount left: %d\n", 
+                   ipt_acc_tables[i].refcount);
+
+            /* Table not needed anymore? */
+            if (ipt_acc_tables[i].refcount == 0) {
                 DEBUGP("ACCOUNT: Destroying table at slot: %d\n", i);
-                ipt_account_data_free(ipt_account_tables[i].data, ipt_account_tables[i].depth);
-                memset(&ipt_account_tables[i], 0, sizeof(struct ipt_account_table));
+                ipt_acc_data_free(ipt_acc_tables[i].data, 
+                                      ipt_acc_tables[i].depth);
+                memset(&ipt_acc_tables[i], 0, 
+                       sizeof(struct ipt_acc_table));
             }
-            
-            spin_unlock_bh(&ipt_account_lock);
+
+            spin_unlock_bh(&ipt_acc_lock);
             return;
         }
     }
 
-    // Table not found
+    /* Table not found */
     printk("ACCOUNT: Table %s not found for destroy\n", info->table_name);
-    spin_unlock_bh(&ipt_account_lock);
+    spin_unlock_bh(&ipt_acc_lock);
 }
 
-void ipt_account_depth0_insert(struct ipt_account_mask_24 *mask_24, unsigned int net_ip, unsigned int netmask,
-                               unsigned int src_ip, unsigned int dst_ip, unsigned int size, unsigned int *itemcount)
+void ipt_acc_depth0_insert(struct ipt_acc_mask_24 *mask_24,
+                               u_int32_t net_ip, u_int32_t netmask,
+                               u_int32_t src_ip, u_int32_t dst_ip,
+                               u_int32_t size, u_int32_t *itemcount)
 {
-    unsigned char is_src = 0, is_dst = 0;
-    
-    DEBUGP("ACCOUNT: ipt_account_depth0_insert: %u.%u.%u.%u/%u.%u.%u.%u for net %u.%u.%u.%u/%u.%u.%u.%u, size: %u\n",
-            NIPQUAD(src_ip), NIPQUAD(dst_ip), NIPQUAD(net_ip), NIPQUAD(netmask), size);
-        
-    // Check if src/dst is inside our network.
-    // Special: net_ip = 0.0.0.0/0 gets stored as src in slot 0
+    unsigned char is_src = 0, is_dst = 0, src_slot, dst_slot;
+    char is_src_new_ip = 0, is_dst_new_ip = 0; /* Check if this entry is new */
+
+    DEBUGP("ACCOUNT: ipt_acc_depth0_insert: %u.%u.%u.%u/%u.%u.%u.%u "
+           "for net %u.%u.%u.%u/%u.%u.%u.%u, size: %u\n", NIPQUAD(src_ip), 
+           NIPQUAD(dst_ip), NIPQUAD(net_ip), NIPQUAD(netmask), size);
+
+    /* Check if src/dst is inside our network. */
+    /* Special: net_ip = 0.0.0.0/0 gets stored as src in slot 0 */
     if (!netmask)
         src_ip = 0;
     if ((net_ip&netmask) == (src_ip&netmask))
         is_src = 1;
     if ((net_ip&netmask) == (dst_ip&netmask) && netmask)
         is_dst = 1;
-    
-    if (!is_src && !is_dst)
-    {
-        DEBUGP("ACCOUNT: Skipping packet %u.%u.%u.%u/%u.%u.%u.%u for net %u.%u.%u.%u/%u.%u.%u.%u\n",
-                NIPQUAD(src_ip), NIPQUAD(dst_ip), NIPQUAD(net_ip), NIPQUAD(netmask));
+
+    if (!is_src && !is_dst) {
+        DEBUGP("ACCOUNT: Skipping packet %u.%u.%u.%u/%u.%u.%u.%u "
+               "for net %u.%u.%u.%u/%u.%u.%u.%u\n", NIPQUAD(src_ip), 
+               NIPQUAD(dst_ip), NIPQUAD(net_ip), NIPQUAD(netmask));
         return;
     }
-        
-    // Check if this entry is new
-    char is_src_new_ip = 0, is_dst_new_ip = 0;
 
-    // Calculate array positions
-    unsigned char src_slot = (unsigned char)((src_ip&0xFF000000) >> 24);
-    unsigned char dst_slot = (unsigned char)((dst_ip&0xFF000000) >> 24);
-    
-    // Increase size counters
-    if (is_src)
-    {
-        // Calculate network slot
+    /* Calculate array positions */
+    src_slot = (unsigned char)((src_ip&0xFF000000) >> 24);
+    dst_slot = (unsigned char)((dst_ip&0xFF000000) >> 24);
+
+    /* Increase size counters */
+    if (is_src) {
+        /* Calculate network slot */
         DEBUGP("ACCOUNT: Calculated SRC 8 bit network slot: %d\n", src_slot);
-        if (!mask_24->ip[src_slot].src_packets && !mask_24->ip[src_slot].dst_packets)
+        if (!mask_24->ip[src_slot].src_packets 
+            && !mask_24->ip[src_slot].dst_packets)
             is_src_new_ip = 1;
-        
+
         mask_24->ip[src_slot].src_packets++;
         mask_24->ip[src_slot].src_bytes+=size;
     }
-    if (is_dst)
-    {
+    if (is_dst) {
         DEBUGP("ACCOUNT: Calculated DST 8 bit network slot: %d\n", dst_slot);
-        if (!mask_24->ip[dst_slot].src_packets && !mask_24->ip[dst_slot].dst_packets)
+        if (!mask_24->ip[dst_slot].src_packets 
+            && !mask_24->ip[dst_slot].dst_packets)
             is_dst_new_ip = 1;
-        
+
         mask_24->ip[dst_slot].dst_packets++;
         mask_24->ip[dst_slot].dst_bytes+=size;
     }
-    
-    // Increase itemcounter
+
+    /* Increase itemcounter */
     DEBUGP("ACCOUNT: Itemcounter before: %d\n", *itemcount);
-    if (src_slot == dst_slot)
-    {
+    if (src_slot == dst_slot) {
         if (is_src_new_ip || is_dst_new_ip) {
-            DEBUGP("ACCOUNT: src_slot == dst_slot: %d, %d\n", is_src_new_ip, is_dst_new_ip);
+            DEBUGP("ACCOUNT: src_slot == dst_slot: %d, %d\n", 
+                   is_src_new_ip, is_dst_new_ip);
             (*itemcount)++;
         }
     } else {
@@ -318,139 +337,144 @@ void ipt_account_depth0_insert(struct ipt_account_mask_24 *mask_24, unsigned int
     DEBUGP("ACCOUNT: Itemcounter after: %d\n", *itemcount);
 }
 
-void ipt_account_depth1_insert(struct ipt_account_mask_16 *mask_16, unsigned int net_ip, unsigned int netmask,
-                               unsigned int src_ip, unsigned int dst_ip, unsigned int size, unsigned int *itemcount)
+void ipt_acc_depth1_insert(struct ipt_acc_mask_16 *mask_16, 
+                               u_int32_t net_ip, u_int32_t netmask, 
+                               u_int32_t src_ip, u_int32_t dst_ip,
+                               u_int32_t size, u_int32_t *itemcount)
 {
-    // Do we need to process src IP?
-    if ((net_ip&netmask) == (src_ip&netmask))
-    {
+    /* Do we need to process src IP? */
+    if ((net_ip&netmask) == (src_ip&netmask)) {
         unsigned char slot = (unsigned char)((src_ip&0x00FF0000) >> 16);
         DEBUGP("ACCOUNT: Calculated SRC 16 bit network slot: %d\n", slot);
-        
-        // Do we need to create a new mask_24 bucket?
-        if (!mask_16->mask_24[slot] && !(mask_16->mask_24[slot] = (void *)get_zeroed_page(GFP_KERNEL)))
-        {
+
+        /* Do we need to create a new mask_24 bucket? */
+        if (!mask_16->mask_24[slot] && (mask_16->mask_24[slot] = 
+             (void *)get_zeroed_page(GFP_ATOMIC)) == NULL) {
             printk("ACCOUNT: Can't process packet because out of memory!\n");
             return;
         }
-        
-        ipt_account_depth0_insert((struct ipt_account_mask_24 *)mask_16->mask_24[slot], net_ip, netmask,
-                                    src_ip, 0, size, itemcount);
+
+        ipt_acc_depth0_insert((struct ipt_acc_mask_24 *)mask_16->mask_24[slot],
+                                  net_ip, netmask, src_ip, 0, size, itemcount);
     }
-    
-    // Do we need to process dst IP?
-    if ((net_ip&netmask) == (dst_ip&netmask))
-    {
+
+    /* Do we need to process dst IP? */
+    if ((net_ip&netmask) == (dst_ip&netmask)) {
         unsigned char slot = (unsigned char)((dst_ip&0x00FF0000) >> 16);
         DEBUGP("ACCOUNT: Calculated DST 16 bit network slot: %d\n", slot);
-        
-        // Do we need to create a new mask_24 bucket?
-        if (!mask_16->mask_24[slot] && !(mask_16->mask_24[slot] = (void *)get_zeroed_page(GFP_KERNEL)))
-        {
+
+        /* Do we need to create a new mask_24 bucket? */
+        if (!mask_16->mask_24[slot] && (mask_16->mask_24[slot] 
+            = (void *)get_zeroed_page(GFP_ATOMIC)) == NULL) {
             printk("ACCOUT: Can't process packet because out of memory!\n");
             return;
         }
-        
-        ipt_account_depth0_insert((struct ipt_account_mask_24 *)mask_16->mask_24[slot], net_ip, netmask,
-                                    0, dst_ip, size, itemcount);
+
+        ipt_acc_depth0_insert((struct ipt_acc_mask_24 *)mask_16->mask_24[slot],
+                                  net_ip, netmask, 0, dst_ip, size, itemcount);
     }
 }
 
-void ipt_account_depth2_insert(struct ipt_account_mask_8 *mask_8, unsigned int net_ip, unsigned int netmask,
-                               unsigned int src_ip, unsigned int dst_ip, unsigned int size, unsigned int *itemcount)
+void ipt_acc_depth2_insert(struct ipt_acc_mask_8 *mask_8, 
+                               u_int32_t net_ip, u_int32_t netmask,
+                               u_int32_t src_ip, u_int32_t dst_ip,
+                               u_int32_t size, u_int32_t *itemcount)
 {
-    // Do we need to process src IP?
-    if ((net_ip&netmask) == (src_ip&netmask))
-    {
+    /* Do we need to process src IP? */
+    if ((net_ip&netmask) == (src_ip&netmask)) {
         unsigned char slot = (unsigned char)((src_ip&0x0000FF00) >> 8);
         DEBUGP("ACCOUNT: Calculated SRC 24 bit network slot: %d\n", slot);
-                
-        // Do we need to create a new mask_24 bucket?
-        if (!mask_8->mask_16[slot] && !(mask_8->mask_16[slot] = (void *)get_zeroed_page(GFP_KERNEL)))
-        {
+
+        /* Do we need to create a new mask_24 bucket? */
+        if (!mask_8->mask_16[slot] && (mask_8->mask_16[slot] 
+            = (void *)get_zeroed_page(GFP_ATOMIC)) == NULL) {
             printk("ACCOUNT: Can't process packet because out of memory!\n");
             return;
         }
-        
-        ipt_account_depth1_insert((struct ipt_account_mask_16 *)mask_8->mask_16[slot], net_ip, netmask,
-                                    src_ip, 0, size, itemcount);
+
+        ipt_acc_depth1_insert((struct ipt_acc_mask_16 *)mask_8->mask_16[slot],
+                                  net_ip, netmask, src_ip, 0, size, itemcount);
     }
-    
-    // Do we need to process dst IP?
-    if ((net_ip&netmask) == (dst_ip&netmask))
-    {
+
+    /* Do we need to process dst IP? */
+    if ((net_ip&netmask) == (dst_ip&netmask)) {
         unsigned char slot = (unsigned char)((dst_ip&0x0000FF00) >> 8);
         DEBUGP("ACCOUNT: Calculated DST 24 bit network slot: %d\n", slot);
-        
-        // Do we need to create a new mask_24 bucket?
-        if (!mask_8->mask_16[slot] && !(mask_8->mask_16[slot] = (void *)get_zeroed_page(GFP_KERNEL)))
-        {
+
+        /* Do we need to create a new mask_24 bucket? */
+        if (!mask_8->mask_16[slot] && (mask_8->mask_16[slot] 
+            = (void *)get_zeroed_page(GFP_ATOMIC)) == NULL) {
             printk("ACCOUNT: Can't process packet because out of memory!\n");
             return;
         }
-        
-        ipt_account_depth1_insert((struct ipt_account_mask_16 *)mask_8->mask_16[slot], net_ip, netmask,
-                                    0, dst_ip, size, itemcount);
+
+        ipt_acc_depth1_insert((struct ipt_acc_mask_16 *)mask_8->mask_16[slot],
+                                  net_ip, netmask, 0, dst_ip, size, itemcount);
     }
 }
 
-static unsigned int ipt_account_target(struct sk_buff **pskb,
-    unsigned int hooknum,
-    const struct net_device *in,
-    const struct net_device *out,
-    const void *targinfo,
-    void *userinfo)
+static unsigned int ipt_acc_target(struct sk_buff **pskb,
+                                       unsigned int hooknum,
+                                       const struct net_device *in,
+                                       const struct net_device *out,
+                                       const void *targinfo,
+                                       void *userinfo)
 {
-    const struct ipt_account_info *info = (const struct ipt_account_info *)targinfo;
-    unsigned int src_ip = (*pskb)->nh.iph->saddr;
-    unsigned int dst_ip = (*pskb)->nh.iph->daddr;
-    unsigned int size = ntohs((*pskb)->nh.iph->tot_len);
-    
-    spin_lock_bh(&ipt_account_lock);
-    
-    if (ipt_account_tables[info->table_nr].name[0] == 0)
-    {
-        printk("ACCOUNT: ipt_account_target: Invalid table id %u. IPs %u.%u.%u.%u/%u.%u.%u.%u\n",
-               info->table_nr, NIPQUAD(src_ip), NIPQUAD(dst_ip));
-        spin_unlock_bh(&ipt_account_lock);
+    const struct ipt_acc_info *info = 
+        (const struct ipt_acc_info *)targinfo;
+    u_int32_t src_ip = (*pskb)->nh.iph->saddr;
+    u_int32_t dst_ip = (*pskb)->nh.iph->daddr;
+    u_int32_t size = ntohs((*pskb)->nh.iph->tot_len);
+
+    spin_lock_bh(&ipt_acc_lock);
+
+    if (ipt_acc_tables[info->table_nr].name[0] == 0) {
+        printk("ACCOUNT: ipt_acc_target: Invalid table id %u. "
+               "IPs %u.%u.%u.%u/%u.%u.%u.%u\n", info->table_nr, 
+               NIPQUAD(src_ip), NIPQUAD(dst_ip));
+        spin_unlock_bh(&ipt_acc_lock);
         return IPT_CONTINUE;
     }
-    
-    // 8 bit network or "any" network
-    if (ipt_account_tables[info->table_nr].depth == 0)
-    {
-        // Count packet and check if the IP is new
-        ipt_account_depth0_insert((struct ipt_account_mask_24 *)ipt_account_tables[info->table_nr].data,
-                                  ipt_account_tables[info->table_nr].ip, ipt_account_tables[info->table_nr].netmask,
-                                  src_ip, dst_ip, size, &ipt_account_tables[info->table_nr].itemcount);
-        spin_unlock_bh(&ipt_account_lock);
+
+    /* 8 bit network or "any" network */
+    if (ipt_acc_tables[info->table_nr].depth == 0) {
+        /* Count packet and check if the IP is new */
+        ipt_acc_depth0_insert(
+            (struct ipt_acc_mask_24 *)ipt_acc_tables[info->table_nr].data,
+            ipt_acc_tables[info->table_nr].ip, 
+            ipt_acc_tables[info->table_nr].netmask,
+            src_ip, dst_ip, size, &ipt_acc_tables[info->table_nr].itemcount);
+        spin_unlock_bh(&ipt_acc_lock);
         return IPT_CONTINUE;
-    }    
-    
-    // 16 bit network
-    if (ipt_account_tables[info->table_nr].depth == 1)
-    {
-        ipt_account_depth1_insert((struct ipt_account_mask_16 *)ipt_account_tables[info->table_nr].data,
-                                  ipt_account_tables[info->table_nr].ip, ipt_account_tables[info->table_nr].netmask,
-                                  src_ip, dst_ip, size, &ipt_account_tables[info->table_nr].itemcount);
-        spin_unlock_bh(&ipt_account_lock);
+    }
+
+    /* 16 bit network */
+    if (ipt_acc_tables[info->table_nr].depth == 1) {
+        ipt_acc_depth1_insert(
+            (struct ipt_acc_mask_16 *)ipt_acc_tables[info->table_nr].data,
+            ipt_acc_tables[info->table_nr].ip, 
+            ipt_acc_tables[info->table_nr].netmask,
+            src_ip, dst_ip, size, &ipt_acc_tables[info->table_nr].itemcount);
+        spin_unlock_bh(&ipt_acc_lock);
         return IPT_CONTINUE;
     }
-    
-    // 24 bit network
-    if (ipt_account_tables[info->table_nr].depth == 2)
-    {
-        ipt_account_depth2_insert((struct ipt_account_mask_8 *)ipt_account_tables[info->table_nr].data,
-                                  ipt_account_tables[info->table_nr].ip, ipt_account_tables[info->table_nr].netmask,
-                                  src_ip, dst_ip, size, &ipt_account_tables[info->table_nr].itemcount);
-        spin_unlock_bh(&ipt_account_lock);
+
+    /* 24 bit network */
+    if (ipt_acc_tables[info->table_nr].depth == 2) {
+        ipt_acc_depth2_insert(
+            (struct ipt_acc_mask_8 *)ipt_acc_tables[info->table_nr].data,
+            ipt_acc_tables[info->table_nr].ip, 
+            ipt_acc_tables[info->table_nr].netmask,
+            src_ip, dst_ip, size, &ipt_acc_tables[info->table_nr].itemcount);
+        spin_unlock_bh(&ipt_acc_lock);
         return IPT_CONTINUE;
     }
-    
-    printk("ACCOUNT: ipt_account_target: Unable to process packet. Table id %u. IPs %u.%u.%u.%u/%u.%u.%u.%u\n",
-            info->table_nr, NIPQUAD(src_ip), NIPQUAD(dst_ip));
-    
-    spin_unlock_bh(&ipt_account_lock);
+
+    printk("ACCOUNT: ipt_acc_target: Unable to process packet. "
+           "Table id %u. IPs %u.%u.%u.%u/%u.%u.%u.%u\n", 
+           info->table_nr, NIPQUAD(src_ip), NIPQUAD(dst_ip));
+
+    spin_unlock_bh(&ipt_acc_lock);
     return IPT_CONTINUE;
 }
 
@@ -471,529 +495,610 @@ static unsigned int ipt_account_target(struct sk_buff **pskb,
     but there could be two or more applications accessing the data
     at the same time.
 */
-int ipt_account_handle_find_slot(void)
+int ipt_acc_handle_find_slot(void)
 {
-    unsigned int i;
-    // Insert new table
-    for (i = 0; i < ACCOUNT_MAX_HANDLES; i++)
-    {
-        // Found free slot
-        if (ipt_account_handles[i].data == NULL)
-        {
-            // Don't "mark" data as used as we are protected by a spinlock by the calling function.
-            // handle_find_slot() is only a function to prevent code duplication.
+    u_int32_t i;
+    /* Insert new table */
+    for (i = 0; i < ACCOUNT_MAX_HANDLES; i++) {
+        /* Found free slot */
+        if (ipt_acc_handles[i].data == NULL) {
+            /* Don't "mark" data as used as we are protected by a spinlock 
+               by the calling function. handle_find_slot() is only a function
+               to prevent code duplication. */
             return i;
         }
     }
-        
-    // No free slot found
-    printk("ACCOUNT: No free handle slot found (max: %u). Please increase ACCOUNT_MAX_HANDLES.\n", ACCOUNT_MAX_HANDLES);
+
+    /* No free slot found */
+    printk("ACCOUNT: No free handle slot found (max: %u). "
+           "Please increase ACCOUNT_MAX_HANDLES.\n", ACCOUNT_MAX_HANDLES);
     return -1;
 }
 
-int ipt_account_handle_free(unsigned int handle)
+int ipt_acc_handle_free(u_int32_t handle)
 {
-    if (handle >= ACCOUNT_MAX_HANDLES)
-    {
-        printk("ACCOUNT: Invalid handle for ipt_account_handle_free() specified: %u\n", handle);
+    if (handle >= ACCOUNT_MAX_HANDLES) {
+        printk("ACCOUNT: Invalid handle for ipt_acc_handle_free() specified:"
+               " %u\n", handle);
         return -EINVAL;
     }
-    
-    ipt_account_data_free(ipt_account_handles[handle].data, ipt_account_handles[handle].depth);
-    memset (&ipt_account_handles[handle], 0, sizeof (struct ipt_account_handle));
+
+    ipt_acc_data_free(ipt_acc_handles[handle].data, 
+                          ipt_acc_handles[handle].depth);
+    memset (&ipt_acc_handles[handle], 0, sizeof (struct ipt_acc_handle));
     return 0;
 }
 
 /* Prepare data for read without flush. Use only for debugging!
    Real applications should use read&flush as it's way more efficent */
-int ipt_account_handle_prepare_read(char *tablename, unsigned int *count)
+int ipt_acc_handle_prepare_read(char *tablename, u_int32_t *count)
 {
     int handle, i, table_nr=-1;
-    
+    unsigned char depth;
+
     for (i = 0; i < ACCOUNT_MAX_TABLES; i++)
-        if (strncmp(ipt_account_tables[i].name, tablename, ACCOUNT_TABLE_NAME_LEN) == 0)
-        {
+        if (strncmp(ipt_acc_tables[i].name, tablename, 
+            ACCOUNT_TABLE_NAME_LEN) == 0) {
             table_nr = i;
             break;
         }
 
-    if (table_nr == -1)
-    {
-        printk("ACCOUNT: ipt_account_handle_prepare_read(): Table %s not found\n", tablename);
+    if (table_nr == -1) {
+        printk("ACCOUNT: ipt_acc_handle_prepare_read(): "
+               "Table %s not found\n", tablename);
         return -1;
     }
-            
-    // Can't find a free handle slot?
-    if ((handle = ipt_account_handle_find_slot()) == -1)
+
+    /* Can't find a free handle slot? */
+    if ((handle = ipt_acc_handle_find_slot()) == -1)
+        return -1;
+
+    /* Fill up handle structure */
+    ipt_acc_handles[handle].ip = ipt_acc_tables[table_nr].ip;
+    ipt_acc_handles[handle].depth = ipt_acc_tables[table_nr].depth;
+    ipt_acc_handles[handle].itemcount = ipt_acc_tables[table_nr].itemcount;
+
+    /* allocate "root" table */
+    if ((ipt_acc_handles[handle].data = 
+         (void*)get_zeroed_page(GFP_ATOMIC)) == NULL) {
+        printk("ACCOUNT: out of memory for root table "
+               "in ipt_acc_handle_prepare_read()\n");
+        memset (&ipt_acc_handles[handle], 0, 
+                sizeof(struct ipt_acc_handle));
         return -1;
-    
-    // Fill up handle structure
-    ipt_account_handles[handle].ip = ipt_account_tables[table_nr].ip;
-    ipt_account_handles[handle].depth = ipt_account_tables[table_nr].depth;
-    ipt_account_handles[handle].itemcount = ipt_account_tables[table_nr].itemcount;
-    
-    // allocate "root" table
-    if (!(ipt_account_handles[handle].data = (void*)get_zeroed_page(GFP_KERNEL)))
-    {
-        printk("ACCOUNT: out of memory for root table in ipt_account_handle_prepare_read()\n");
-        memset (&ipt_account_handles[handle], 0, sizeof(struct ipt_account_handle));
-        return -1;        
     }
-    
-    // Recursive copy of complete data structure
-    unsigned int depth = ipt_account_handles[handle].depth;
-    if (depth == 0)
-    {
-        memcpy(ipt_account_handles[handle].data, ipt_account_tables[table_nr].data, sizeof(struct ipt_account_mask_24));
+
+    /* Recursive copy of complete data structure */
+    depth = ipt_acc_handles[handle].depth;
+    if (depth == 0) {
+        memcpy(ipt_acc_handles[handle].data, 
+               ipt_acc_tables[table_nr].data, 
+               sizeof(struct ipt_acc_mask_24));
     } else if (depth == 1) {
-        struct ipt_account_mask_16 *src_16 = (struct ipt_account_mask_16 *)ipt_account_tables[table_nr].data;
-        struct ipt_account_mask_16 *network_16 = (struct ipt_account_mask_16 *)ipt_account_handles[handle].data;
-        unsigned int b;
-        
-        for (b = 0; b <= 255; b++)
-        {
-            if (src_16->mask_24[b])
-            {
-                if (!(network_16->mask_24[b] = (void*)get_zeroed_page(GFP_KERNEL)))
-                {
-                    printk("ACCOUNT: out of memory during copy of 16 bit network in ipt_account_handle_prepare_read()\n");
-                    ipt_account_data_free(ipt_account_handles[handle].data, depth);
-                    memset (&ipt_account_handles[handle], 0, sizeof(struct ipt_account_handle));
-                    return -1;                    
+        struct ipt_acc_mask_16 *src_16 = 
+            (struct ipt_acc_mask_16 *)ipt_acc_tables[table_nr].data;
+        struct ipt_acc_mask_16 *network_16 =
+            (struct ipt_acc_mask_16 *)ipt_acc_handles[handle].data;
+        u_int32_t b;
+
+        for (b = 0; b <= 255; b++) {
+            if (src_16->mask_24[b]) {
+                if ((network_16->mask_24[b] = 
+                     (void*)get_zeroed_page(GFP_ATOMIC)) == NULL) {
+                    printk("ACCOUNT: out of memory during copy of 16 bit "
+                           "network in ipt_acc_handle_prepare_read()\n");
+                    ipt_acc_data_free(ipt_acc_handles[handle].data, depth);
+                    memset (&ipt_acc_handles[handle], 0, 
+                            sizeof(struct ipt_acc_handle));
+                    return -1;
                 }
-                
-                memcpy(network_16->mask_24[b], src_16->mask_24[b], sizeof(struct ipt_account_mask_24));
+
+                memcpy(network_16->mask_24[b], src_16->mask_24[b], 
+                       sizeof(struct ipt_acc_mask_24));
             }
         }
     } else if(depth == 2) {
-        struct ipt_account_mask_8 *src_8 = (struct ipt_account_mask_8 *)ipt_account_tables[table_nr].data;
-        struct ipt_account_mask_8 *network_8 = (struct ipt_account_mask_8 *)ipt_account_handles[handle].data;
-        unsigned int a;
-        
-        for (a = 0; a <= 255; a++)
-        {
-            if (src_8->mask_16[a])
-            {
-                if (!(network_8->mask_16[a] = (void*)get_zeroed_page(GFP_KERNEL)))
-                {
-                    printk("ACCOUNT: out of memory during copy of 24 bit network in ipt_account_handle_prepare_read()\n");
-                    ipt_account_data_free(ipt_account_handles[handle].data, depth);
-                    memset (&ipt_account_handles[handle], 0, sizeof(struct ipt_account_handle));
-                    return -1;                    
+        struct ipt_acc_mask_8 *src_8 = 
+            (struct ipt_acc_mask_8 *)ipt_acc_tables[table_nr].data;
+        struct ipt_acc_mask_8 *network_8 = 
+            (struct ipt_acc_mask_8 *)ipt_acc_handles[handle].data;
+        u_int32_t a;
+
+        for (a = 0; a <= 255; a++) {
+            if (src_8->mask_16[a]) {
+                if ((network_8->mask_16[a] = 
+                     (void*)get_zeroed_page(GFP_ATOMIC)) == NULL) {
+                    printk("ACCOUNT: out of memory during copy of 24 bit network"
+                           " in ipt_acc_handle_prepare_read()\n");
+                    ipt_acc_data_free(ipt_acc_handles[handle].data, depth);
+                    memset (&ipt_acc_handles[handle], 0, 
+                            sizeof(struct ipt_acc_handle));
+                    return -1;
                 }
 
-                memcpy(network_8->mask_16[a], src_8->mask_16[a], sizeof(struct ipt_account_mask_16));
-                    
-                struct ipt_account_mask_16 *src_16 = src_8->mask_16[a];
-                struct ipt_account_mask_16 *network_16 = network_8->mask_16[a];
-                unsigned int b;
-                
-                for (b = 0; b <= 255; b++)
-                {
-                    if (src_16->mask_24[b])
-                    {
-                        if (!(network_16->mask_24[b] = (void*)get_zeroed_page(GFP_KERNEL)))
-                        {
-                            printk("ACCOUNT: out of memory during copy of 16 bit network in ipt_account_handle_prepare_read()\n");
-                            ipt_account_data_free(ipt_account_handles[handle].data, depth);
-                            memset (&ipt_account_handles[handle], 0, sizeof(struct ipt_account_handle));
-                            return -1;                    
+                memcpy(network_8->mask_16[a], src_8->mask_16[a], 
+                       sizeof(struct ipt_acc_mask_16));
+
+                struct ipt_acc_mask_16 *src_16 = src_8->mask_16[a];
+                struct ipt_acc_mask_16 *network_16 = network_8->mask_16[a];
+                u_int32_t b;
+
+                for (b = 0; b <= 255; b++) {
+                    if (src_16->mask_24[b]) {
+                        if ((network_16->mask_24[b] = 
+                             (void*)get_zeroed_page(GFP_ATOMIC)) == NULL) {
+                            printk("ACCOUNT: out of memory during copy of 16 bit"
+                                   " network in ipt_acc_handle_prepare_read()\n");
+                            ipt_acc_data_free(ipt_acc_handles[handle].data,
+                                                  depth);
+                            memset (&ipt_acc_handles[handle], 0, 
+                                    sizeof(struct ipt_acc_handle));
+                            return -1;
                         }
-                        
-                        memcpy(network_16->mask_24[b], src_16->mask_24[b], sizeof(struct ipt_account_mask_24));
+
+                        memcpy(network_16->mask_24[b], src_16->mask_24[b], 
+                               sizeof(struct ipt_acc_mask_24));
                     }
                 }
             }
         }
     }
 
-    *count = ipt_account_tables[table_nr].itemcount;
+    *count = ipt_acc_tables[table_nr].itemcount;
     return handle;
 }
 
 /* Prepare data for read and flush it */
-int ipt_account_handle_prepare_read_flush(char *tablename, unsigned int *count)
+int ipt_acc_handle_prepare_read_flush(char *tablename, u_int32_t *count)
 {
     int handle, i, table_nr=-1;
-    
+    void *new_data_page;
+
     for (i = 0; i < ACCOUNT_MAX_TABLES; i++)
-        if (strncmp(ipt_account_tables[i].name, tablename, ACCOUNT_TABLE_NAME_LEN) == 0)
-        {
+        if (strncmp(ipt_acc_tables[i].name, tablename, 
+                    ACCOUNT_TABLE_NAME_LEN) == 0) {
             table_nr = i;
             break;
         }
 
-    if (table_nr == -1)
-    {
-        printk("ACCOUNT: ipt_account_handle_prepare_read_flush(): Table %s not found\n", tablename);
+    if (table_nr == -1) {
+        printk("ACCOUNT: ipt_acc_handle_prepare_read_flush(): "
+               "Table %s not found\n", tablename);
         return -1;
     }
-            
-    // Can't find a free handle slot?
-    if ((handle = ipt_account_handle_find_slot()) == -1)
+
+    /* Can't find a free handle slot? */
+    if ((handle = ipt_acc_handle_find_slot()) == -1)
         return -1;
-    
-    // Fill up handle structure
-    ipt_account_handles[handle].ip = ipt_account_tables[table_nr].ip;
-    ipt_account_handles[handle].depth = ipt_account_tables[table_nr].depth;
-    ipt_account_handles[handle].itemcount = ipt_account_tables[table_nr].itemcount;
-    ipt_account_handles[handle].data = ipt_account_tables[table_nr].data;
-    *count = ipt_account_tables[table_nr].itemcount;
 
-    // "Flush" table data
-    ipt_account_tables[table_nr].data = (void*)get_zeroed_page(GFP_KERNEL);
-    ipt_account_tables[table_nr].itemcount = 0;
+    /* Try to allocate memory */
+    if (!(new_data_page = (void*)get_zeroed_page(GFP_ATOMIC))) {
+        printk("ACCOUNT: ipt_acc_handle_prepare_read_flush(): "
+               "Out of memory!\n");
+        return -1;
+    }
+
+    /* Fill up handle structure */
+    ipt_acc_handles[handle].ip = ipt_acc_tables[table_nr].ip;
+    ipt_acc_handles[handle].depth = ipt_acc_tables[table_nr].depth;
+    ipt_acc_handles[handle].itemcount = ipt_acc_tables[table_nr].itemcount;
+    ipt_acc_handles[handle].data = ipt_acc_tables[table_nr].data;
+    *count = ipt_acc_tables[table_nr].itemcount;
+
+    /* "Flush" table data */
+    ipt_acc_tables[table_nr].data = new_data_page;
+    ipt_acc_tables[table_nr].itemcount = 0;
 
     return handle;
 }
 
-/* Copy the actual that into a prepared buffer.
+/* Copy 8 bit network data into a prepared buffer.
    We only copy entries != 0 to increase performance.
-   The memory gets freed again in ipt_account_handle_free().
 */
-int ipt_account_handle_get_data(unsigned int handle, void *buffer)
+int ipt_acc_handle_copy_data(void *to_user, int *pos, 
+                                  struct ipt_acc_mask_24 *data,
+                                  u_int32_t net_ip, u_int32_t net_OR_mask)
 {
-    struct ipt_account_handle_ip handle_ip;    
-    unsigned int handle_ip_size = sizeof (struct ipt_account_handle_ip);
-    unsigned int i, tmpbuf_pos=0;
+    struct ipt_acc_handle_ip handle_ip;
+    u_int32_t handle_ip_size = sizeof (struct ipt_acc_handle_ip);
+    u_int32_t i;
+    
+    for (i = 0; i <= 255; i++) {
+        if (data->ip[i].src_packets || data->ip[i].dst_packets) {
+            handle_ip.ip = net_ip | net_OR_mask | (i<<24);
+            
+            handle_ip.src_packets = data->ip[i].src_packets;
+            handle_ip.src_bytes = data->ip[i].src_bytes;
+            handle_ip.dst_packets = data->ip[i].dst_packets;
+            handle_ip.dst_bytes = data->ip[i].dst_bytes;
 
-    if (handle >= ACCOUNT_MAX_HANDLES)
-    {
-        printk("ACCOUNT: invalid handle for ipt_account_handle_get_data() specified: %u\n", handle);
-        return -1;
+            /* Temporary buffer full? Flush to userspace */
+            if (*pos+handle_ip_size >= PAGE_SIZE) {
+                if (copy_to_user(to_user, ipt_acc_tmpbuf, *pos))
+                    return -EFAULT;
+                *pos = 0;
+            }
+            memcpy(ipt_acc_tmpbuf+*pos, &handle_ip, handle_ip_size);
+            *pos += handle_ip_size;
+        }
     }
     
-    if (ipt_account_handles[handle].data == NULL)
-    {
+    return 0;
+}
+   
+/* Copy the data from our internal structure 
+   We only copy entries != 0 to increase performance.
+   Overwrites ipt_acc_tmpbuf.
+*/
+int ipt_acc_handle_get_data(u_int32_t handle, void *to_user)
+{
+    u_int32_t tmpbuf_pos=0, net_ip;
+    unsigned char depth;
+
+    if (handle >= ACCOUNT_MAX_HANDLES) {
+        printk("ACCOUNT: invalid handle for ipt_acc_handle_get_data() "
+               "specified: %u\n", handle);
+        return -1;
+    }
+
+    if (ipt_acc_handles[handle].data == NULL) {
         printk("ACCOUNT: handle %u is BROKEN: Contains no data\n", handle);
         return -1;
     }
-    
-    unsigned int net_ip = ipt_account_handles[handle].ip;
-    unsigned int depth = ipt_account_handles[handle].depth;
-    
-    // 8 bit network
-    if (depth == 0)
-    {
-        struct ipt_account_mask_24 *network = (struct ipt_account_mask_24*)ipt_account_handles[handle].data;
-        for (i = 0; i <= 255; i++)
-        {
-            if (network->ip[i].src_packets || network->ip[i].dst_packets)
-            {
-                handle_ip.ip = net_ip | (i<<24);
-                handle_ip.src_packets = network->ip[i].src_packets;
-                handle_ip.src_bytes = network->ip[i].src_bytes;
-                handle_ip.dst_packets = network->ip[i].dst_packets;
-                handle_ip.dst_bytes = network->ip[i].dst_bytes;
-
-                // Temporary buffer full? Flush to userspace
-                if (tmpbuf_pos+handle_ip_size >= PAGE_SIZE)
-                {
-                    copy_to_user(buffer, ipt_account_tmpbuf, tmpbuf_pos);
-                    tmpbuf_pos = 0;
-                }
-                memcpy(ipt_account_tmpbuf+tmpbuf_pos, &handle_ip, handle_ip_size);
-                tmpbuf_pos += handle_ip_size;
-            }
-        }
 
-        // Flush remaining data to userspace
-        if (tmpbuf_pos)
-            copy_to_user(buffer, ipt_account_tmpbuf, tmpbuf_pos);
+    net_ip = ipt_acc_handles[handle].ip;
+    depth = ipt_acc_handles[handle].depth;
+
+    /* 8 bit network */
+    if (depth == 0) {
+        struct ipt_acc_mask_24 *network = 
+            (struct ipt_acc_mask_24*)ipt_acc_handles[handle].data;
+        if (ipt_acc_handle_copy_data(to_user, &tmpbuf_pos, network, net_ip, 0))
+            return -1;
         
+        /* Flush remaining data to userspace */
+        if (tmpbuf_pos)
+            if (copy_to_user(to_user, ipt_acc_tmpbuf, tmpbuf_pos))
+                return -1;
+
         return 0;
     }
-    
-    // 16 bit network
-    if (depth == 1)
-    {
-        struct ipt_account_mask_16 *network_16 = (struct ipt_account_mask_16*)ipt_account_handles[handle].data;
-        unsigned int b;
-        for (b = 0; b <= 255; b++)
-        {
-            if (network_16->mask_24[b])
-            {
-                struct ipt_account_mask_24 *network = (struct ipt_account_mask_24*)network_16->mask_24[b];
-                for (i = 0; i <= 255; i++)
-                {
-                    if (network->ip[i].src_packets || network->ip[i].dst_packets)
-                    {
-                        handle_ip.ip = net_ip | (b << 16) | (i<<24);
-                        handle_ip.src_packets = network->ip[i].src_packets;
-                        handle_ip.src_bytes = network->ip[i].src_bytes;
-                        handle_ip.dst_packets = network->ip[i].dst_packets;
-                        handle_ip.dst_bytes = network->ip[i].dst_bytes;
-        
-                        // Temporary buffer full? Flush to userspace
-                        if (tmpbuf_pos+handle_ip_size >= PAGE_SIZE)
-                        {
-                            copy_to_user(buffer, ipt_account_tmpbuf, tmpbuf_pos);
-                            tmpbuf_pos = 0;
-                        }
-                        memcpy(ipt_account_tmpbuf+tmpbuf_pos, &handle_ip, handle_ip_size);
-                        tmpbuf_pos += handle_ip_size;
-                    }
-                }
+
+    /* 16 bit network */
+    if (depth == 1) {
+        struct ipt_acc_mask_16 *network_16 = 
+            (struct ipt_acc_mask_16*)ipt_acc_handles[handle].data;
+        u_int32_t b;
+        for (b = 0; b <= 255; b++) {
+            if (network_16->mask_24[b]) {
+                struct ipt_acc_mask_24 *network = 
+                    (struct ipt_acc_mask_24*)network_16->mask_24[b];
+                if (ipt_acc_handle_copy_data(to_user, &tmpbuf_pos, network, 
+                                             net_ip, (b << 16)))
+                    return -1;
             }
         }
-        
-        // Flush remaining data to userspace
+
+        /* Flush remaining data to userspace */
         if (tmpbuf_pos)
-            copy_to_user(buffer, ipt_account_tmpbuf, tmpbuf_pos);
-        
+            if (copy_to_user(to_user, ipt_acc_tmpbuf, tmpbuf_pos))
+                return -1;
+
         return 0;
     }
-    
-    // 24 bit network
-    if (depth == 2)
-    {
-        struct ipt_account_mask_8 *network_8 = (struct ipt_account_mask_8*)ipt_account_handles[handle].data;
-        unsigned int a, b;
-        for (a = 0; a <= 255; a++)
-        {
-            if (network_8->mask_16[a])
-            {
-                struct ipt_account_mask_16 *network_16 = (struct ipt_account_mask_16*)network_8->mask_16[a];
-                for (b = 0; b <= 255; b++)
-                {
-                    if (network_16->mask_24[b])
-                    {
-                        struct ipt_account_mask_24 *network = (struct ipt_account_mask_24*)network_16->mask_24[b];
-                        for (i = 0; i <= 255; i++)
-                        {
-                            if (network->ip[i].src_packets || network->ip[i].dst_packets)
-                            {
-                                handle_ip.ip = net_ip | (a << 8) | (b << 16) | (i<<24);
-                                handle_ip.src_packets = network->ip[i].src_packets;
-                                handle_ip.src_bytes = network->ip[i].src_bytes;
-                                handle_ip.dst_packets = network->ip[i].dst_packets;
-                                handle_ip.dst_bytes = network->ip[i].dst_bytes;
-                
-                                // Temporary buffer full? Flush to userspace
-                                if (tmpbuf_pos+handle_ip_size >= PAGE_SIZE)
-                                {
-                                    copy_to_user(buffer, ipt_account_tmpbuf, tmpbuf_pos);
-                                    tmpbuf_pos = 0;
-                                }
-                                memcpy(ipt_account_tmpbuf+tmpbuf_pos, &handle_ip, handle_ip_size);
-                                tmpbuf_pos += handle_ip_size;
-                            }
-                        }
+
+    /* 24 bit network */
+    if (depth == 2) {
+        struct ipt_acc_mask_8 *network_8 = 
+            (struct ipt_acc_mask_8*)ipt_acc_handles[handle].data;
+        u_int32_t a, b;
+        for (a = 0; a <= 255; a++) {
+            if (network_8->mask_16[a]) {
+                struct ipt_acc_mask_16 *network_16 = 
+                    (struct ipt_acc_mask_16*)network_8->mask_16[a];
+                for (b = 0; b <= 255; b++) {
+                    if (network_16->mask_24[b]) {
+                        struct ipt_acc_mask_24 *network = 
+                            (struct ipt_acc_mask_24*)network_16->mask_24[b];
+                        if (ipt_acc_handle_copy_data(to_user, &tmpbuf_pos,
+                                        network, net_ip, (a << 8) | (b << 16)))
+                            return -1;
                     }
                 }
             }
         }
-        
-        // Flush remaining data to userspace
+
+        /* Flush remaining data to userspace */
         if (tmpbuf_pos)
-            copy_to_user(buffer, ipt_account_tmpbuf, tmpbuf_pos);
-        
+            if (copy_to_user(to_user, ipt_acc_tmpbuf, tmpbuf_pos))
+                return -1;
+
         return 0;
     }
     
     return -1;
 }
 
-static int ipt_account_set_ctl(struct sock *sk, int cmd, void *user, unsigned int len)
+static int ipt_acc_set_ctl(struct sock *sk, int cmd, 
+                               void *user, u_int32_t len)
 {
-    struct ipt_account_handle_sockopt handle;
+    struct ipt_acc_handle_sockopt handle;
     int ret = -EINVAL;
 
     if (!capable(CAP_NET_ADMIN))
-            return -EPERM;
-            
-    switch (cmd)
-    {
-        case IPT_SO_SET_ACCOUNT_HANDLE_FREE:
-            if (len != sizeof(struct ipt_account_handle_sockopt))
-            {
-                printk("ACCOUNT: ipt_account_set_ctl: wrong data size (%u != %u) for IPT_SO_SET_HANDLE_FREE\n", len, sizeof(struct ipt_account_handle_sockopt));
-                break;
-            }   
-            
-            if (copy_from_user (&handle, user, len))
-            {
-                printk("ACCOUNT: ipt_account_set_ctl: copy_from_user failed for IPT_SO_SET_HANDLE_FREE\n");
-                break;
-            }
-            
-            spin_lock_bh(&ipt_account_userspace_lock);
-            ret = ipt_account_handle_free(handle.handle_nr);
-            spin_unlock_bh(&ipt_account_userspace_lock);
+        return -EPERM;
+
+    switch (cmd) {
+    case IPT_SO_SET_ACCOUNT_HANDLE_FREE:
+        if (len != sizeof(struct ipt_acc_handle_sockopt)) {
+            printk("ACCOUNT: ipt_acc_set_ctl: wrong data size (%u != %u) "
+                   "for IPT_SO_SET_HANDLE_FREE\n", 
+                   len, sizeof(struct ipt_acc_handle_sockopt));
+            break;
+        }
+
+        if (copy_from_user (&handle, user, len)) {
+            printk("ACCOUNT: ipt_acc_set_ctl: copy_from_user failed for "
+                   "IPT_SO_SET_HANDLE_FREE\n");
             break;
-        default:
-            printk("ACCOUNT: ipt_account_set_ctl: unknown request %i\n", cmd);
+        }
+
+        spin_lock_bh(&ipt_acc_userspace_lock);
+        ret = ipt_acc_handle_free(handle.handle_nr);
+        spin_unlock_bh(&ipt_acc_userspace_lock);
+        break;
+    case IPT_SO_SET_ACCOUNT_HANDLE_FREE_ALL: {
+            u_int32_t i;
+            spin_lock_bh(&ipt_acc_userspace_lock);
+            for (i = 0; i < ACCOUNT_MAX_HANDLES; i++)
+                ipt_acc_handle_free(i);
+            spin_unlock_bh(&ipt_acc_userspace_lock);
+            ret = 0;
+            break;
+        }
+    default:
+        printk("ACCOUNT: ipt_acc_set_ctl: unknown request %i\n", cmd);
     }
 
     return ret;
 }
 
-static int ipt_account_get_ctl(struct sock *sk, int cmd, void *user, int *len)
+static int ipt_acc_get_ctl(struct sock *sk, int cmd, void *user, int *len)
 {
-    struct ipt_account_handle_sockopt handle;
+    struct ipt_acc_handle_sockopt handle;
     int ret = -EINVAL;
 
     if (!capable(CAP_NET_ADMIN))
-            return -EPERM;
-
-    switch (cmd)
-    {
-        case IPT_SO_GET_ACCOUNT_PREPARE_READ_FLUSH:
-        case IPT_SO_GET_ACCOUNT_PREPARE_READ:
-            if (*len < sizeof(struct ipt_account_handle_sockopt))
-            {
-                printk("ACCOUNT: ipt_account_get_ctl: wrong data size (%u != %u) for IPT_SO_GET_ACCOUNT_PREPARE_READ/READ_FLUSH\n",
-                       *len, sizeof(struct ipt_account_handle_sockopt));
-                break;
-            }   
-            
-            if (copy_from_user (&handle, user, sizeof(struct ipt_account_handle_sockopt)))
-            {
-                printk("ACCOUNT: ipt_account_get_ctl: copy_from_user failed for IPT_SO_GET_ACCOUNT_PREPARE_READ/READ_FLUSH\n");
-                break;
-            }
-            
-            spin_lock_bh(&ipt_account_lock);
-            spin_lock_bh(&ipt_account_userspace_lock);
-            if (cmd == IPT_SO_GET_ACCOUNT_PREPARE_READ_FLUSH)
-                handle.handle_nr = ipt_account_handle_prepare_read_flush(handle.name, &handle.itemcount);
-            else
-                handle.handle_nr = ipt_account_handle_prepare_read(handle.name, &handle.itemcount);
-            spin_unlock_bh(&ipt_account_userspace_lock);
-            spin_unlock_bh(&ipt_account_lock);
-                
-            if (handle.handle_nr == -1)
-            {
-                printk("ACCOUNT: ipt_account_get_ctl: ipt_account_handle_prepare_read failed\n");
+        return -EPERM;
+
+    switch (cmd) {
+    case IPT_SO_GET_ACCOUNT_PREPARE_READ_FLUSH:
+    case IPT_SO_GET_ACCOUNT_PREPARE_READ:
+        if (*len < sizeof(struct ipt_acc_handle_sockopt)) {
+            printk("ACCOUNT: ipt_acc_get_ctl: wrong data size (%u != %u) "
+                   "for IPT_SO_GET_ACCOUNT_PREPARE_READ/READ_FLUSH\n",
+                   *len, sizeof(struct ipt_acc_handle_sockopt));
+            break;
+        }
+
+        if (copy_from_user (&handle, user, 
+                            sizeof(struct ipt_acc_handle_sockopt))) {
+            return -EFAULT;
+            break;
+        }
+
+        spin_lock_bh(&ipt_acc_lock);
+        spin_lock_bh(&ipt_acc_userspace_lock);
+        if (cmd == IPT_SO_GET_ACCOUNT_PREPARE_READ_FLUSH)
+            handle.handle_nr = ipt_acc_handle_prepare_read_flush(
+                                   handle.name, &handle.itemcount);
+        else
+            handle.handle_nr = ipt_acc_handle_prepare_read(
+                                   handle.name, &handle.itemcount);
+        spin_unlock_bh(&ipt_acc_userspace_lock);
+        spin_unlock_bh(&ipt_acc_lock);
+
+        if (handle.handle_nr == -1) {
+            return -EINVAL;
+            break;
+        }
+
+        if (copy_to_user(user, &handle, 
+                         sizeof(struct ipt_acc_handle_sockopt))) {
+            return -EFAULT;
+            break;
+        }
+        ret = 0;
+        break;
+    case IPT_SO_GET_ACCOUNT_GET_DATA:
+        if (*len < sizeof(struct ipt_acc_handle_sockopt)) {
+            printk("ACCOUNT: ipt_acc_get_ctl: wrong data size (%u != %u)"
+                   " for IPT_SO_GET_ACCOUNT_PREPARE_READ/READ_FLUSH\n",
+                   *len, sizeof(struct ipt_acc_handle_sockopt));
+            break;
+        }
+
+        if (copy_from_user (&handle, user, 
+                            sizeof(struct ipt_acc_handle_sockopt))) {
+            return -EFAULT;
+            break;
+        }
+
+        if (handle.handle_nr >= ACCOUNT_MAX_HANDLES) {
+            return -EINVAL;
+            break;
+        }
+
+        if (*len < ipt_acc_handles[handle.handle_nr].itemcount
+                   * sizeof(struct ipt_acc_handle_ip)) {
+            printk("ACCOUNT: ipt_acc_get_ctl: not enough space (%u < %u)"
+                   " to store data from IPT_SO_GET_ACCOUNT_GET_DATA\n",
+                   *len, ipt_acc_handles[handle.handle_nr].itemcount
+                   * sizeof(struct ipt_acc_handle_ip));
+            ret = -ENOMEM;
+            break;
+        }
+
+        spin_lock_bh(&ipt_acc_userspace_lock);
+        ret = ipt_acc_handle_get_data(handle.handle_nr, user);
+        spin_unlock_bh(&ipt_acc_userspace_lock);
+        if (ret) {
+            printk("ACCOUNT: ipt_acc_get_ctl: ipt_acc_handle_get_data"
+                   " failed for handle %u\n", handle.handle_nr);
+            break;
+        }
+
+        ret = 0;
+        break;
+    case IPT_SO_GET_ACCOUNT_GET_HANDLE_USAGE: {
+            u_int32_t i;
+            if (*len < sizeof(struct ipt_acc_handle_sockopt)) {
+                printk("ACCOUNT: ipt_acc_get_ctl: wrong data size (%u != %u)"
+                       " for IPT_SO_GET_ACCOUNT_GET_HANDLE_USAGE\n",
+                       *len, sizeof(struct ipt_acc_handle_sockopt));
                 break;
             }
-            
-            if (copy_to_user(user, &handle, sizeof(struct ipt_account_handle_sockopt)))
-            {
-                printk("ACCOUNT: ipt_account_set_ctl: copy_to_user failed for IPT_SO_GET_ACCOUNT_PREPARE_READ/READ_FLUSH\n");
+
+            /* Find out how many handles are in use */
+            handle.itemcount = 0;
+            spin_lock_bh(&ipt_acc_userspace_lock);
+            for (i = 0; i < ACCOUNT_MAX_HANDLES; i++)
+                if (ipt_acc_handles[i].data)
+                    handle.itemcount++;
+            spin_unlock_bh(&ipt_acc_userspace_lock);
+
+            if (copy_to_user(user, &handle, 
+                             sizeof(struct ipt_acc_handle_sockopt))) {
+                return -EFAULT;
                 break;
             }
             ret = 0;
             break;
-        case IPT_SO_GET_ACCOUNT_GET_DATA:
-            if (*len < sizeof(struct ipt_account_handle_sockopt))
-            {
-                printk("ACCOUNT: ipt_account_get_ctl: wrong data size (%u != %u) for IPT_SO_GET_ACCOUNT_PREPARE_READ/READ_FLUSH\n",
-                       *len, sizeof(struct ipt_account_handle_sockopt));
-                break;
-            }   
+        }
+    case IPT_SO_GET_ACCOUNT_GET_TABLE_NAMES: {
+            u_int32_t size = 0, i;
+            char *tnames;
             
-            if (copy_from_user (&handle, user, sizeof(struct ipt_account_handle_sockopt)))
-            {
-                printk("ACCOUNT: ipt_account_get_ctl: copy_from_user failed for IPT_SO_GET_ACCOUNT_PREPARE_READ/READ_FLUSH\n");
-                break;
+            spin_lock_bh(&ipt_acc_lock);
+
+            /* Determine size of table names */
+            for (i = 0; i < ACCOUNT_MAX_TABLES; i++) {
+                if (ipt_acc_tables[i].name[0] != 0)
+                    size += strlen (ipt_acc_tables[i].name) + 1;
             }
-            
-            if (handle.handle_nr >= ACCOUNT_MAX_HANDLES)
-            {
-                printk("ACCOUNT: Invalid handle for IPT_SO_GET_ACCOUNT_GET_DATA: %u\n", handle.handle_nr);
+            size += 1;    /* Terminating NULL character */
+
+            if (*len < size) {
+                spin_unlock_bh(&ipt_acc_lock);
+                printk("ACCOUNT: ipt_acc_get_ctl: not enough space (%u < %u)"
+                       " to store table names\n", *len, size);
+                ret = -ENOMEM;
                 break;
             }
-            
-            if (*len < ipt_account_handles[handle.handle_nr].itemcount*sizeof(struct ipt_account_handle_ip))
-            {
-                printk("ACCOUNT: ipt_account_get_ctl: not enough space (%u < %u) to store data from IPT_SO_GET_ACCOUNT_GET_DATA\n",
-                       *len, ipt_account_handles[handle.handle_nr].itemcount*sizeof(struct ipt_account_handle_ip));
-                break;
-            }   
-            
-            spin_lock_bh(&ipt_account_userspace_lock);
-            ret = ipt_account_handle_get_data(handle.handle_nr, user);
-            spin_unlock_bh(&ipt_account_userspace_lock);
-            if (ret)
-            {
-                printk("ACCOUNT: ipt_account_get_ctl: ipt_account_handle_get_data failed for handle %u\n", handle.handle_nr);
-                break;
+            /* Copy table names to userspace */
+            tnames = user;
+            for (i = 0; i < ACCOUNT_MAX_TABLES; i++) {
+                if (ipt_acc_tables[i].name[0] != 0) {
+                    int len = strlen (ipt_acc_tables[i].name) + 1;
+                    /* copy string + terminating zero */
+                    if (copy_to_user(tnames, ipt_acc_tables[i].name, len)) {
+                        spin_unlock_bh(&ipt_acc_lock);
+                        return -EFAULT;
+                    }
+                    tnames += len;
+                }
             }
-            
+            /* Append terminating zero */
+            i = 0;
+            ret = copy_to_user(tnames, &i, 1);
+            spin_unlock_bh(&ipt_acc_lock);
+            if (ret)
+                return -EFAULT;
             ret = 0;
             break;
-        
-        default:
-            printk("ACCOUNT: ipt_account_get_ctl: unknown request %i\n", cmd);
+        }
+    default:
+        printk("ACCOUNT: ipt_acc_get_ctl: unknown request %i\n", cmd);
     }
 
     return ret;
 }
 
-static struct ipt_target ipt_account_reg
-= { { NULL, NULL }, "ACCOUNT", ipt_account_target, ipt_account_checkentry, ipt_account_deleteentry, 
-    THIS_MODULE };
+static struct ipt_target ipt_acc_reg = {
+    .name = "ACCOUNT",
+    .target = ipt_acc_target,
+    .checkentry = ipt_acc_checkentry,
+    .destroy = ipt_acc_deleteentry,
+    .me = THIS_MODULE
+};
+
+static struct nf_sockopt_ops ipt_acc_sockopts = {
+    .pf = PF_INET,
+    .set_optmin = IPT_SO_SET_ACCOUNT_HANDLE_FREE,
+    .set_optmax = IPT_SO_SET_ACCOUNT_MAX+1,
+    .set = ipt_acc_set_ctl,
+    .get_optmin = IPT_SO_GET_ACCOUNT_PREPARE_READ,
+    .get_optmax = IPT_SO_GET_ACCOUNT_MAX+1,
+    .get = ipt_acc_get_ctl
+};
 
-static struct nf_sockopt_ops ipt_account_sockopts
-= { { NULL, NULL }, PF_INET, IPT_SO_SET_ACCOUNT_HANDLE_FREE, IPT_SO_SET_ACCOUNT_MAX+1, ipt_account_set_ctl,
-    IPT_SO_GET_ACCOUNT_PREPARE_READ, IPT_SO_GET_ACCOUNT_MAX+1, ipt_account_get_ctl, 0, NULL  };
-    
 static int __init init(void)
 {
-    if (PAGE_SIZE < 4096)
-    {
-        printk("ACCOUNT: Sorry we need at least a PAGE_SIZE of 4096. Found: %lu\n", PAGE_SIZE);
-        return -EINVAL;
-    }
-
-    if (!(ipt_account_tables = kmalloc(ACCOUNT_MAX_TABLES*sizeof(struct ipt_account_table), GFP_KERNEL)))
-    {
+    if ((ipt_acc_tables = 
+         kmalloc(ACCOUNT_MAX_TABLES * 
+                 sizeof(struct ipt_acc_table), GFP_KERNEL)) == NULL) {
         printk("ACCOUNT: Out of memory allocating account_tables structure");
-        return -EINVAL;
+        goto error_cleanup;
     }
-    memset(ipt_account_tables, 0, ACCOUNT_MAX_TABLES*sizeof(struct ipt_account_table));
-                            
-    if (!(ipt_account_handles = kmalloc(ACCOUNT_MAX_HANDLES*sizeof(struct ipt_account_handle), GFP_KERNEL)))
-    {
+    memset(ipt_acc_tables, 0, 
+           ACCOUNT_MAX_TABLES * sizeof(struct ipt_acc_table));
+
+    if ((ipt_acc_handles = 
+         kmalloc(ACCOUNT_MAX_HANDLES * 
+                 sizeof(struct ipt_acc_handle), GFP_KERNEL)) == NULL) {
         printk("ACCOUNT: Out of memory allocating account_handles structure");
-        kfree (ipt_account_tables);
-        ipt_account_tables = NULL;
-        return -EINVAL;
+        goto error_cleanup;
     }
-    memset(ipt_account_handles, 0, ACCOUNT_MAX_HANDLES*sizeof(struct ipt_account_handle));
+    memset(ipt_acc_handles, 0, 
+           ACCOUNT_MAX_HANDLES * sizeof(struct ipt_acc_handle));
 
-    // Allocate one page as temporary storage
-    if ((ipt_account_tmpbuf = (void*)__get_free_page(GFP_KERNEL)) == NULL)
-    {
+    /* Allocate one page as temporary storage */
+    if ((ipt_acc_tmpbuf = (void*)__get_free_page(GFP_KERNEL)) == NULL) {
         printk("ACCOUNT: Out of memory for temporary buffer page\n");
-        kfree (ipt_account_tables);
-        kfree (ipt_account_handles);
-        ipt_account_tables = NULL;
-        ipt_account_handles = NULL;
-        return -EINVAL;
+        goto error_cleanup;
     }
-    
+
     /* Register setsockopt */
-    if (nf_register_sockopt(&ipt_account_sockopts) < 0)
-    {
+    if (nf_register_sockopt(&ipt_acc_sockopts) < 0) {
         printk("ACCOUNT: Can't register sockopts. Aborting\n");
-        
-        kfree (ipt_account_tables);
-        ipt_account_tables = NULL;
-        kfree(ipt_account_handles);
-        ipt_account_handles = NULL;
-        
-        return -EINVAL;
+        goto error_cleanup;
     }
-    
-    if (ipt_register_target(&ipt_account_reg))
-            return -EINVAL;
 
+    if (ipt_register_target(&ipt_acc_reg))
+        goto error_cleanup;
+        
     return 0;
+        
+error_cleanup:
+    if(ipt_acc_tables)
+        kfree(ipt_acc_tables);
+    if(ipt_acc_handles)
+        kfree(ipt_acc_handles);
+    if (ipt_acc_tmpbuf)
+        free_page((unsigned long)ipt_acc_tmpbuf);
+        
+    return -EINVAL;
 }
 
 static void __exit fini(void)
 {
-    ipt_unregister_target(&ipt_account_reg);
+    ipt_unregister_target(&ipt_acc_reg);
 
-    nf_unregister_sockopt(&ipt_account_sockopts);
-    
-    kfree(ipt_account_tables);
-    ipt_account_tables = NULL;
-        
-    kfree(ipt_account_handles);
-    ipt_account_handles = NULL;
+    nf_unregister_sockopt(&ipt_acc_sockopts);
+
+    kfree(ipt_acc_tables);
+    kfree(ipt_acc_handles);
+    free_page((unsigned long)ipt_acc_tmpbuf);
 }
 
 module_init(init);