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1324442bce4e4f00d8537bc7a5413a0f6a548dc9
xtables-addons/extensions/ACCOUNT/xt_ACCOUNT.c
Neal P. Murphy 1324442bce xt_ACCOUNT: make counters 64-bit wide 
The Smoothwall Express traffic stats collector (traffiClogger) does
not handle counter rollovers well and does not perform read&flush.
(Yes, the code is somewhat aged.) To change it to perform read&flush
is non-trivial. Then, it occurred to me that it might be easier to
change ipt_ACCOUNT in xtables-addons to use 64-bit counters,
considering it was designed around single kernel pages.

The following submission counts to at least 100 GB, produces no
obvious kernel gripes, and adjacent counters do not seem to interfere
with each other. Yes, it uses more memory, but RAM costs much less
than bugs that grown out of complex software.

The theory:

  - Use two kernel pages for the counters for each group of 256
    addresses.
  - Change counters to 64-bit.
  - Change to __get_free_pages/free_pages, using order=2
    (two consecutive pages), and zero both pages.
  - Change "%u" to "%llu" as needed.
  - Everything else pretty much stays the same.

I also changed tmpbuf to two pages (Justin Case's idea), but I
do not know if that's really necessary.
2015-06-05 13:51:55 +02:00

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/***************************************************************************
* This is a module which is used for counting packets. *
* See http://www.intra2net.com/opensource/ipt_account *
* for further information *
* *
* Copyright (C) 2004-2011 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; *
* *
***************************************************************************/
//#define DEBUG 1
#include <linux/module.h>
#include <linux/version.h>
#include <linux/skbuff.h>
#include <linux/ip.h>
#include <net/icmp.h>
#include <net/udp.h>
#include <net/tcp.h>
#include <linux/netfilter_ipv4/ip_tables.h>
#include <linux/semaphore.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/spinlock.h>
#include <asm/uaccess.h>
#include <net/route.h>
#include "xt_ACCOUNT.h"
#include "compat_xtables.h"
#if (PAGE_SIZE < 4096)
#error "ipt_ACCOUNT needs at least a PAGE_SIZE of 4096"
#endif
/**
* Internal table structure, generated by check_entry()
* @name: name of the table
* @ip: base IP address of the network
* @mask: netmask of the network
* @depth: size of network (0: 8-bit, 1: 16-bit, 2: 24-bit)
* @refcount: refcount of the table; if zero, destroy it
* @itemcount: number of IP addresses in this table
* @data; pointer to the actual data, depending on netmask
*/
struct ipt_acc_table {
char name[ACCOUNT_TABLE_NAME_LEN];
__be32 ip;
__be32 netmask;
uint8_t depth;
uint32_t refcount;
uint32_t itemcount;
void *data;
};
/**
* Internal handle structure
* @ip: base IP address of the network. Used for caculating the final
* address during get_data().
* @depth: size of the network; see above
* @itemcount: number of addresses in this table
*/
struct ipt_acc_handle {
uint32_t ip;
uint8_t depth;
uint32_t itemcount;
void *data;
};
/* Used for every IP entry
Size is 32 bytes so that 256 (class C network) * 16
fits in a double kernel (zero) page (two consecutive kernel pages)*/
struct ipt_acc_ip {
uint64_t src_packets;
uint64_t src_bytes;
uint64_t dst_packets;
uint64_t dst_bytes;
};
/*
* The IP addresses are organized as an array so that direct slot
* calculations are possible.
* Only 8-bit networks are preallocated, 16/24-bit networks
* allocate their slots when needed -> very efficent.
*/
struct ipt_acc_mask_24 {
struct ipt_acc_ip ip[256];
};
struct ipt_acc_mask_16 {
struct ipt_acc_mask_24 *mask_24[256];
};
struct ipt_acc_mask_8 {
struct ipt_acc_mask_16 *mask_16[256];
};
static struct ipt_acc_table *ipt_acc_tables;
static struct ipt_acc_handle *ipt_acc_handles;
static void *ipt_acc_tmpbuf;
/* Spinlock used for manipulating the current accounting tables/data */
static DEFINE_SPINLOCK(ipt_acc_lock);
/* Mutex (semaphore) used for manipulating userspace handles/snapshot data */
static struct semaphore ipt_acc_userspace_mutex;
/* Allocates a page pair and clears it */
static void *ipt_acc_zalloc_page(void)
{
// Don't use get_zeroed_page until it's fixed in the kernel.
// get_zeroed_page(GFP_ATOMIC)
void *mem = (void *)__get_free_pages(GFP_ATOMIC, 2);
if (mem) {
memset(mem, 0, 2 *PAGE_SIZE);
}
return mem;
}
/* Recursive free of all data structures */
static void ipt_acc_data_free(void *data, uint8_t depth)
{
/* Empty data set */
if (!data)
return;
/* Free for 8 bit network */
if (depth == 0) {
free_pages((unsigned long)data, 2);
return;
}
/* Free for 16 bit network */
if (depth == 1) {
struct ipt_acc_mask_16 *mask_16 = data;
unsigned int b;
for (b = 0; b <= 255; b++) {
if (mask_16->mask_24[b]) {
free_page((unsigned long)mask_16->mask_24[b]);
}
}
free_pages((unsigned long)data, 2);
return;
}
/* Free for 24 bit network */
if (depth == 2) {
unsigned int 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_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]);
}
}
free_page((unsigned long)mask_16);
}
}
free_pages((unsigned long)data, 2);
return;
}
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 */
static int ipt_acc_table_insert(const char *name, __be32 ip, __be32 netmask)
{
unsigned int i;
pr_debug("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_acc_tables[i].name, name,
ACCOUNT_TABLE_NAME_LEN) == 0) {
pr_debug("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_acc_tables[i].refcount++;
pr_debug("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_acc_tables[i].name[0] == 0) {
unsigned int netsize = 0;
uint32_t calc_mask;
int j; /* needs to be signed, otherwise we risk endless loop */
pr_debug("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--) {
if (calc_mask & (1 << j))
netsize++;
else
break;
}
/* Calculate depth from netsize */
if (netsize >= 24)
ipt_acc_tables[i].depth = 0;
else if (netsize >= 16)
ipt_acc_tables[i].depth = 1;
else if (netsize >= 8)
ipt_acc_tables[i].depth = 2;
pr_debug("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
= ipt_acc_zalloc_page()) == NULL) {
printk("ACCOUNT: out of memory for data of table: %s\n", name);
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);
return -1;
}
static int ipt_acc_checkentry(const struct xt_tgchk_param *par)
{
struct ipt_acc_info *info = par->targinfo;
int table_nr;
spin_lock_bh(&ipt_acc_lock);
table_nr = ipt_acc_table_insert(info->table_name, info->net_ip,
info->net_mask);
spin_unlock_bh(&ipt_acc_lock);
if (table_nr == -1) {
printk("ACCOUNT: Table insert problem. Aborting\n");
return -EINVAL;
}
/* Table nr caching so we don't have to do an extra string compare
for every packet */
info->table_nr = table_nr;
return 0;
}
static void ipt_acc_destroy(const struct xt_tgdtor_param *par)
{
unsigned int i;
struct ipt_acc_info *info = par->targinfo;
spin_lock_bh(&ipt_acc_lock);
pr_debug("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) {
pr_debug("ACCOUNT: Found table at slot: %d\n", i);
ipt_acc_tables[i].refcount--;
pr_debug("ACCOUNT: Refcount left: %d\n",
ipt_acc_tables[i].refcount);
/* Table not needed anymore? */
if (ipt_acc_tables[i].refcount == 0) {
pr_debug("ACCOUNT: Destroying table at slot: %d\n", i);
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_acc_lock);
return;
}
}
/* Table not found */
printk("ACCOUNT: Table %s not found for destroy\n", info->table_name);
spin_unlock_bh(&ipt_acc_lock);
}
static void ipt_acc_depth0_insert(struct ipt_acc_mask_24 *mask_24,
__be32 net_ip, __be32 netmask,
__be32 src_ip, __be32 dst_ip,
uint32_t size, uint32_t *itemcount)
{
uint8_t src_slot, dst_slot;
bool is_src = false, is_dst = false;
/* Check if this entry is new */
bool is_src_new_ip = false, is_dst_new_ip = false;
pr_debug("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 == 0)
src_ip = 0;
if ((net_ip & netmask) == (src_ip & netmask))
is_src = true;
if ((net_ip & netmask) == (dst_ip & netmask) && netmask != 0)
is_dst = true;
if (!is_src && !is_dst) {
pr_debug("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;
}
/* Calculate array positions */
src_slot = ntohl(src_ip) & 0xFF;
dst_slot = ntohl(dst_ip) & 0xFF;
/* Increase size counters */
if (is_src) {
/* Calculate network slot */
pr_debug("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)
is_src_new_ip = true;
mask_24->ip[src_slot].src_packets++;
mask_24->ip[src_slot].src_bytes += size;
}
if (is_dst) {
pr_debug("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)
is_dst_new_ip = true;
mask_24->ip[dst_slot].dst_packets++;
mask_24->ip[dst_slot].dst_bytes += size;
}
/* Increase itemcounter */
pr_debug("ACCOUNT: Itemcounter before: %d\n", *itemcount);
if (src_slot == dst_slot) {
if (is_src_new_ip || is_dst_new_ip) {
pr_debug("ACCOUNT: src_slot == dst_slot: %d, %d\n",
is_src_new_ip, is_dst_new_ip);
++*itemcount;
}
} else {
if (is_src_new_ip) {
pr_debug("ACCOUNT: New src_ip: %u.%u.%u.%u\n", NIPQUAD(src_ip));
++*itemcount;
}
if (is_dst_new_ip) {
pr_debug("ACCOUNT: New dst_ip: %u.%u.%u.%u\n", NIPQUAD(dst_ip));
++*itemcount;
}
}
pr_debug("ACCOUNT: Itemcounter after: %d\n", *itemcount);
}
static void ipt_acc_depth1_insert(struct ipt_acc_mask_16 *mask_16,
__be32 net_ip, __be32 netmask,
__be32 src_ip, __be32 dst_ip,
uint32_t size, uint32_t *itemcount)
{
/* Do we need to process src IP? */
if ((net_ip & netmask) == (src_ip & netmask)) {
uint8_t slot = (ntohl(src_ip) & 0xFF00) >> 8;
pr_debug("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] =
ipt_acc_zalloc_page()) == NULL) {
printk("ACCOUNT: Can't process packet because out of memory!\n");
return;
}
ipt_acc_depth0_insert(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)) {
uint8_t slot = (ntohl(dst_ip) & 0xFF00) >> 8;
pr_debug("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]
= ipt_acc_zalloc_page()) == NULL) {
printk("ACCOUT: Can't process packet because out of memory!\n");
return;
}
ipt_acc_depth0_insert(mask_16->mask_24[slot],
net_ip, netmask, 0, dst_ip, size, itemcount);
}
}
static void ipt_acc_depth2_insert(struct ipt_acc_mask_8 *mask_8,
__be32 net_ip, __be32 netmask,
__be32 src_ip, __be32 dst_ip,
uint32_t size, uint32_t *itemcount)
{
/* Do we need to process src IP? */
if ((net_ip & netmask) == (src_ip & netmask)) {
uint8_t slot = (ntohl(src_ip) & 0xFF0000) >> 16;
pr_debug("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]
= ipt_acc_zalloc_page()) == NULL) {
printk("ACCOUNT: Can't process packet because out of memory!\n");
return;
}
ipt_acc_depth1_insert(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)) {
uint8_t slot = (ntohl(dst_ip) & 0xFF0000) >> 16;
pr_debug("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]
= ipt_acc_zalloc_page()) == NULL) {
printk("ACCOUNT: Can't process packet because out of memory!\n");
return;
}
ipt_acc_depth1_insert(mask_8->mask_16[slot],
net_ip, netmask, 0, dst_ip, size, itemcount);
}
}
static unsigned int
ipt_acc_target(struct sk_buff *skb, const struct xt_action_param *par)
{
const struct ipt_acc_info *info =
par->targinfo;
__be32 src_ip = ip_hdr(skb)->saddr;
__be32 dst_ip = ip_hdr(skb)->daddr;
uint32_t size = ntohs(ip_hdr(skb)->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 XT_CONTINUE;
}
/* 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(
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 XT_CONTINUE;
}
/* 16 bit network */
if (ipt_acc_tables[info->table_nr].depth == 1) {
ipt_acc_depth1_insert(
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 XT_CONTINUE;
}
/* 24 bit network */
if (ipt_acc_tables[info->table_nr].depth == 2) {
ipt_acc_depth2_insert(
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 XT_CONTINUE;
}
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 XT_CONTINUE;
}
/*
Functions dealing with "handles":
Handles are snapshots of an accounting state.
read snapshots are only for debugging the code
and are very expensive concerning speed/memory
compared to read_and_flush.
The functions aren't protected by spinlocks themselves
as this is done in the ioctl part of the code.
*/
/*
Find a free handle slot. Normally only one should be used,
but there could be two or more applications accessing the data
at the same time.
*/
static 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_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);
return -1;
}
static int ipt_acc_handle_free(unsigned int handle)
{
if (handle >= ACCOUNT_MAX_HANDLES) {
printk("ACCOUNT: Invalid handle for ipt_acc_handle_free() specified:"
" %u\n", handle);
return -EINVAL;
}
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 */
static int ipt_acc_handle_prepare_read(char *tablename,
struct ipt_acc_handle *dest, uint32_t *count)
{
int table_nr = -1;
uint8_t depth;
for (table_nr = 0; table_nr < ACCOUNT_MAX_TABLES; table_nr++)
if (strncmp(ipt_acc_tables[table_nr].name, tablename,
ACCOUNT_TABLE_NAME_LEN) == 0)
break;
if (table_nr == ACCOUNT_MAX_TABLES) {
printk("ACCOUNT: ipt_acc_handle_prepare_read(): "
"Table %s not found\n", tablename);
return -1;
}
/* Fill up handle structure */
dest->ip = ipt_acc_tables[table_nr].ip;
dest->depth = ipt_acc_tables[table_nr].depth;
dest->itemcount = ipt_acc_tables[table_nr].itemcount;
/* allocate "root" table */
if ((dest->data = ipt_acc_zalloc_page()) == NULL) {
printk("ACCOUNT: out of memory for root table "
"in ipt_acc_handle_prepare_read()\n");
return -1;
}
/* Recursive copy of complete data structure */
depth = dest->depth;
if (depth == 0) {
memcpy(dest->data,
ipt_acc_tables[table_nr].data,
sizeof(struct ipt_acc_mask_24));
} else if (depth == 1) {
struct ipt_acc_mask_16 *src_16 =
ipt_acc_tables[table_nr].data;
struct ipt_acc_mask_16 *network_16 = dest->data;
unsigned int b;
for (b = 0; b <= 255; b++) {
if (src_16->mask_24[b]) {
if ((network_16->mask_24[b] =
ipt_acc_zalloc_page()) == NULL) {
printk("ACCOUNT: out of memory during copy of 16 bit "
"network in ipt_acc_handle_prepare_read()\n");
ipt_acc_data_free(dest->data, depth);
return -1;
}
memcpy(network_16->mask_24[b], src_16->mask_24[b],
sizeof(struct ipt_acc_mask_24));
}
}
} else if (depth == 2) {
struct ipt_acc_mask_8 *src_8 =
ipt_acc_tables[table_nr].data;
struct ipt_acc_mask_8 *network_8 = dest->data;
struct ipt_acc_mask_16 *src_16, *network_16;
unsigned int a, b;
for (a = 0; a <= 255; a++) {
if (src_8->mask_16[a]) {
if ((network_8->mask_16[a] =
ipt_acc_zalloc_page()) == NULL) {
printk("ACCOUNT: out of memory during copy of 24 bit network"
" in ipt_acc_handle_prepare_read()\n");
ipt_acc_data_free(dest->data, depth);
return -1;
}
memcpy(network_8->mask_16[a], src_8->mask_16[a],
sizeof(struct ipt_acc_mask_16));
src_16 = src_8->mask_16[a];
network_16 = network_8->mask_16[a];
for (b = 0; b <= 255; b++) {
if (src_16->mask_24[b]) {
if ((network_16->mask_24[b] =
ipt_acc_zalloc_page()) == NULL) {
printk("ACCOUNT: out of memory during copy of 16 bit"
" network in ipt_acc_handle_prepare_read()\n");
ipt_acc_data_free(dest->data, depth);
return -1;
}
memcpy(network_16->mask_24[b], src_16->mask_24[b],
sizeof(struct ipt_acc_mask_24));
}
}
}
}
}
*count = ipt_acc_tables[table_nr].itemcount;
return 0;
}
/* Prepare data for read and flush it */
static int ipt_acc_handle_prepare_read_flush(char *tablename,
struct ipt_acc_handle *dest, uint32_t *count)
{
int table_nr;
void *new_data_page;
for (table_nr = 0; table_nr < ACCOUNT_MAX_TABLES; table_nr++)
if (strncmp(ipt_acc_tables[table_nr].name, tablename,
ACCOUNT_TABLE_NAME_LEN) == 0)
break;
if (table_nr == ACCOUNT_MAX_TABLES) {
printk("ACCOUNT: ipt_acc_handle_prepare_read_flush(): "
"Table %s not found\n", tablename);
return -1;
}
/* Try to allocate memory */
if (!(new_data_page = ipt_acc_zalloc_page())) {
printk("ACCOUNT: ipt_acc_handle_prepare_read_flush(): "
"Out of memory!\n");
return -1;
}
/* Fill up handle structure */
dest->ip = ipt_acc_tables[table_nr].ip;
dest->depth = ipt_acc_tables[table_nr].depth;
dest->itemcount = ipt_acc_tables[table_nr].itemcount;
dest->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 0;
}
/* Copy 8 bit network data into a prepared buffer.
We only copy entries != 0 to increase performance.
*/
static int ipt_acc_handle_copy_data(void *to_user, unsigned long *to_user_pos,
unsigned long *tmpbuf_pos,
struct ipt_acc_mask_24 *data,
uint32_t net_ip, uint32_t net_OR_mask)
{
struct ipt_acc_handle_ip handle_ip;
size_t handle_ip_size = sizeof(struct ipt_acc_handle_ip);
unsigned int 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;
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;
/* Temporary buffer full? Flush to userspace */
if (*tmpbuf_pos + handle_ip_size >= PAGE_SIZE) {
if (copy_to_user(to_user + *to_user_pos, ipt_acc_tmpbuf,
*tmpbuf_pos))
return -EFAULT;
*to_user_pos = *to_user_pos + *tmpbuf_pos;
*tmpbuf_pos = 0;
}
memcpy(ipt_acc_tmpbuf + *tmpbuf_pos, &handle_ip, handle_ip_size);
*tmpbuf_pos += handle_ip_size;
}
}
return 0;
}
/* Copy the data from our internal structure
We only copy entries != 0 to increase performance.
Overwrites ipt_acc_tmpbuf.
*/
static int ipt_acc_handle_get_data(uint32_t handle, void *to_user)
{
unsigned long to_user_pos = 0, tmpbuf_pos = 0;
uint32_t net_ip;
uint8_t 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;
}
net_ip = ntohl(ipt_acc_handles[handle].ip);
depth = ipt_acc_handles[handle].depth;
/* 8 bit network */
if (depth == 0) {
struct ipt_acc_mask_24 *network =
ipt_acc_handles[handle].data;
if (ipt_acc_handle_copy_data(to_user, &to_user_pos, &tmpbuf_pos,
network, net_ip, 0))
return -1;
/* Flush remaining data to userspace */
if (tmpbuf_pos)
if (copy_to_user(to_user + to_user_pos, ipt_acc_tmpbuf, tmpbuf_pos))
return -1;
return 0;
}
/* 16 bit network */
if (depth == 1) {
struct ipt_acc_mask_16 *network_16 =
ipt_acc_handles[handle].data;
unsigned int b;
for (b = 0; b <= 255; b++) {
if (network_16->mask_24[b]) {
struct ipt_acc_mask_24 *network =
network_16->mask_24[b];
if (ipt_acc_handle_copy_data(to_user, &to_user_pos,
&tmpbuf_pos, network, net_ip, (b << 8)))
return -1;
}
}
/* Flush remaining data to userspace */
if (tmpbuf_pos)
if (copy_to_user(to_user + to_user_pos, ipt_acc_tmpbuf, tmpbuf_pos))
return -1;
return 0;
}
/* 24 bit network */
if (depth == 2) {
struct ipt_acc_mask_8 *network_8 =
ipt_acc_handles[handle].data;
unsigned int a, b;
for (a = 0; a <= 255; a++) {
if (network_8->mask_16[a]) {
struct ipt_acc_mask_16 *network_16 =
network_8->mask_16[a];
for (b = 0; b <= 255; b++) {
if (network_16->mask_24[b]) {
struct ipt_acc_mask_24 *network =
network_16->mask_24[b];
if (ipt_acc_handle_copy_data(to_user,
&to_user_pos, &tmpbuf_pos,
network, net_ip, (a << 16) | (b << 8)))
return -1;
}
}
}
}
/* Flush remaining data to userspace */
if (tmpbuf_pos)
if (copy_to_user(to_user + to_user_pos, ipt_acc_tmpbuf, tmpbuf_pos))
return -1;
return 0;
}
return -1;
}
static int ipt_acc_set_ctl(struct sock *sk, int cmd,
void *user, unsigned int len)
{
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_acc_handle_sockopt)) {
printk("ACCOUNT: ipt_acc_set_ctl: wrong data size (%u != %zu) "
"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;
}
down(&ipt_acc_userspace_mutex);
ret = ipt_acc_handle_free(handle.handle_nr);
up(&ipt_acc_userspace_mutex);
break;
case IPT_SO_SET_ACCOUNT_HANDLE_FREE_ALL: {
unsigned int i;
down(&ipt_acc_userspace_mutex);
for (i = 0; i < ACCOUNT_MAX_HANDLES; i++)
ipt_acc_handle_free(i);
up(&ipt_acc_userspace_mutex);
ret = 0;
break;
}
default:
printk("ACCOUNT: ipt_acc_set_ctl: unknown request %i\n", cmd);
}
return ret;
}
static int ipt_acc_get_ctl(struct sock *sk, int cmd, void *user, int *len)
{
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: {
struct ipt_acc_handle dest;
if (*len < sizeof(struct ipt_acc_handle_sockopt)) {
printk("ACCOUNT: ipt_acc_get_ctl: wrong data size (%u != %zu) "
"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);
if (cmd == IPT_SO_GET_ACCOUNT_PREPARE_READ_FLUSH)
ret = ipt_acc_handle_prepare_read_flush(
handle.name, &dest, &handle.itemcount);
else
ret = ipt_acc_handle_prepare_read(
handle.name, &dest, &handle.itemcount);
spin_unlock_bh(&ipt_acc_lock);
// Error occured during prepare_read?
if (ret == -1)
return -EINVAL;
/* Allocate a userspace handle */
down(&ipt_acc_userspace_mutex);
if ((handle.handle_nr = ipt_acc_handle_find_slot()) == -1) {
ipt_acc_data_free(dest.data, dest.depth);
up(&ipt_acc_userspace_mutex);
return -EINVAL;
}
memcpy(&ipt_acc_handles[handle.handle_nr], &dest,
sizeof(struct ipt_acc_handle));
up(&ipt_acc_userspace_mutex);
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 != %zu)"
" 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 < %zu)"
" 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;
}
down(&ipt_acc_userspace_mutex);
ret = ipt_acc_handle_get_data(handle.handle_nr, user);
up(&ipt_acc_userspace_mutex);
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: {
unsigned int i;
if (*len < sizeof(struct ipt_acc_handle_sockopt)) {
printk("ACCOUNT: ipt_acc_get_ctl: wrong data size (%u != %zu)"
" for IPT_SO_GET_ACCOUNT_GET_HANDLE_USAGE\n",
*len, sizeof(struct ipt_acc_handle_sockopt));
break;
}
/* Find out how many handles are in use */
handle.itemcount = 0;
down(&ipt_acc_userspace_mutex);
for (i = 0; i < ACCOUNT_MAX_HANDLES; i++)
if (ipt_acc_handles[i].data)
handle.itemcount++;
up(&ipt_acc_userspace_mutex);
if (copy_to_user(user, &handle,
sizeof(struct ipt_acc_handle_sockopt))) {
return -EFAULT;
break;
}
ret = 0;
break;
}
case IPT_SO_GET_ACCOUNT_GET_TABLE_NAMES: {
uint32_t size = 0, i, name_len;
char *tnames;
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;
}
size += 1; /* Terminating NULL character */
if (*len < size || size > PAGE_SIZE) {
spin_unlock_bh(&ipt_acc_lock);
printk("ACCOUNT: ipt_acc_get_ctl: not enough space (%u < %u < %lu)"
" to store table names\n", *len, size, PAGE_SIZE);
ret = -ENOMEM;
break;
}
/* Copy table names to userspace */
tnames = ipt_acc_tmpbuf;
for (i = 0; i < ACCOUNT_MAX_TABLES; i++) {
if (ipt_acc_tables[i].name[0] != 0) {
name_len = strlen(ipt_acc_tables[i].name) + 1;
memcpy(tnames, ipt_acc_tables[i].name, name_len);
tnames += name_len;
}
}
spin_unlock_bh(&ipt_acc_lock);
/* Terminating NULL character */
*tnames = 0;
/* Transfer to userspace */
if (copy_to_user(user, ipt_acc_tmpbuf, size))
return -EFAULT;
ret = 0;
break;
}
default:
printk("ACCOUNT: ipt_acc_get_ctl: unknown request %i\n", cmd);
}
return ret;
}
static struct xt_target xt_acc_reg __read_mostly = {
.name = "ACCOUNT",
.revision = 1,
.family = NFPROTO_IPV4,
.target = ipt_acc_target,
.targetsize = sizeof(struct ipt_acc_info),
.checkentry = ipt_acc_checkentry,
.destroy = ipt_acc_destroy,
.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 int __init account_tg_init(void)
{
sema_init(&ipt_acc_userspace_mutex, 1);
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");
goto error_cleanup;
}
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");
goto error_cleanup;
}
memset(ipt_acc_handles, 0,
ACCOUNT_MAX_HANDLES * sizeof(struct ipt_acc_handle));
/* Allocate one page as temporary storage */
if ((ipt_acc_tmpbuf = (void *)__get_free_pages(GFP_KERNEL, 2)) == NULL) {
printk("ACCOUNT: Out of memory for temporary buffer page\n");
goto error_cleanup;
}
/* Register setsockopt */
if (nf_register_sockopt(&ipt_acc_sockopts) < 0) {
printk("ACCOUNT: Can't register sockopts. Aborting\n");
goto error_cleanup;
}
if (xt_register_target(&xt_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_pages((unsigned long)ipt_acc_tmpbuf, 2);
return -EINVAL;
}
static void __exit account_tg_exit(void)
{
xt_unregister_target(&xt_acc_reg);
nf_unregister_sockopt(&ipt_acc_sockopts);
kfree(ipt_acc_tables);
kfree(ipt_acc_handles);
free_pages((unsigned long)ipt_acc_tmpbuf, 2);
}
module_init(account_tg_init);
module_exit(account_tg_exit);
MODULE_DESCRIPTION("Xtables: per-IP accounting for large prefixes");
MODULE_AUTHOR("Intra2net AG <opensource@intra2net.com>");
MODULE_ALIAS("ipt_ACCOUNT");
MODULE_LICENSE("GPL");
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